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  • Converting Lighttpd config to NginX with php-fpm

    - by Le Dude
    Having so much issue with NginX configuration since I'm new with NginX. Been using Lighttpd for quite sometime. Here are the base info. New Machine - CentOS 6.3 64 Bit - NginX 1.2.4-1.e16.ngx - Php-FPM 5.3.18-1.e16.remi Old Machine - CentOS 6.2 64Bit - Lighttpd 1.4.25-3.e16 Original Lighttpd config file: ####################################################################### ## ## /etc/lighttpd/lighttpd.conf ## ## check /etc/lighttpd/conf.d/*.conf for the configuration of modules. ## ####################################################################### ####################################################################### ## ## Some Variable definition which will make chrooting easier. ## ## if you add a variable here. Add the corresponding variable in the ## chroot example aswell. ## var.log_root = "/var/log/lighttpd" var.server_root = "/var/www" var.state_dir = "/var/run" var.home_dir = "/var/lib/lighttpd" var.conf_dir = "/etc/lighttpd" ## ## run the server chrooted. ## ## This requires root permissions during startup. ## ## If you run Chrooted set the the variables to directories relative to ## the chroot dir. ## ## example chroot configuration: ## #var.log_root = "/logs" #var.server_root = "/" #var.state_dir = "/run" #var.home_dir = "/lib/lighttpd" #var.vhosts_dir = "/vhosts" #var.conf_dir = "/etc" # #server.chroot = "/srv/www" ## ## Some additional variables to make the configuration easier ## ## ## Base directory for all virtual hosts ## ## used in: ## conf.d/evhost.conf ## conf.d/simple_vhost.conf ## vhosts.d/vhosts.template ## var.vhosts_dir = server_root + "/vhosts" ## ## Cache for mod_compress ## ## used in: ## conf.d/compress.conf ## var.cache_dir = "/var/cache/lighttpd" ## ## Base directory for sockets. ## ## used in: ## conf.d/fastcgi.conf ## conf.d/scgi.conf ## var.socket_dir = home_dir + "/sockets" ## ####################################################################### ####################################################################### ## ## Load the modules. include "modules.conf" ## ####################################################################### ####################################################################### ## ## Basic Configuration ## --------------------- ## server.port = 80 ## ## Use IPv6? ## #server.use-ipv6 = "enable" ## ## bind to a specific IP ## #server.bind = "localhost" ## ## Run as a different username/groupname. ## This requires root permissions during startup. ## server.username = "lighttpd" server.groupname = "lighttpd" ## ## enable core files. ## #server.core-files = "disable" ## ## Document root ## server.document-root = server_root + "/lighttpd" ## ## The value for the "Server:" response field. ## ## It would be nice to keep it at "lighttpd". ## #server.tag = "lighttpd" ## ## store a pid file ## server.pid-file = state_dir + "/lighttpd.pid" ## ####################################################################### ####################################################################### ## ## Logging Options ## ------------------ ## ## all logging options can be overwritten per vhost. ## ## Path to the error log file ## server.errorlog = log_root + "/error.log" ## ## If you want to log to syslog you have to unset the ## server.errorlog setting and uncomment the next line. ## #server.errorlog-use-syslog = "enable" ## ## Access log config ## include "conf.d/access_log.conf" ## ## The debug options are moved into their own file. ## see conf.d/debug.conf for various options for request debugging. ## include "conf.d/debug.conf" ## ####################################################################### ####################################################################### ## ## Tuning/Performance ## -------------------- ## ## corresponding documentation: ## http://www.lighttpd.net/documentation/performance.html ## ## set the event-handler (read the performance section in the manual) ## ## possible options on linux are: ## ## select ## poll ## linux-sysepoll ## ## linux-sysepoll is recommended on kernel 2.6. ## server.event-handler = "linux-sysepoll" ## ## The basic network interface for all platforms at the syscalls read() ## and write(). Every modern OS provides its own syscall to help network ## servers transfer files as fast as possible ## ## linux-sendfile - is recommended for small files. ## writev - is recommended for sending many large files ## server.network-backend = "linux-sendfile" ## ## As lighttpd is a single-threaded server, its main resource limit is ## the number of file descriptors, which is set to 1024 by default (on ## most systems). ## ## If you are running a high-traffic site you might want to increase this ## limit by setting server.max-fds. ## ## Changing this setting requires root permissions on startup. see ## server.username/server.groupname. ## ## By default lighttpd would not change the operation system default. ## But setting it to 2048 is a better default for busy servers. ## ## With SELinux enabled, this is denied by default and needs to be allowed ## by running the following once : setsebool -P httpd_setrlimit on server.max-fds = 2048 ## ## Stat() call caching. ## ## lighttpd can utilize FAM/Gamin to cache stat call. ## ## possible values are: ## disable, simple or fam. ## server.stat-cache-engine = "simple" ## ## Fine tuning for the request handling ## ## max-connections == max-fds/2 (maybe /3) ## means the other file handles are used for fastcgi/files ## server.max-connections = 1024 ## ## How many seconds to keep a keep-alive connection open, ## until we consider it idle. ## ## Default: 5 ## #server.max-keep-alive-idle = 5 ## ## How many keep-alive requests until closing the connection. ## ## Default: 16 ## #server.max-keep-alive-requests = 18 ## ## Maximum size of a request in kilobytes. ## By default it is unlimited (0). ## ## Uploads to your server cant be larger than this value. ## #server.max-request-size = 0 ## ## Time to read from a socket before we consider it idle. ## ## Default: 60 ## #server.max-read-idle = 60 ## ## Time to write to a socket before we consider it idle. ## ## Default: 360 ## #server.max-write-idle = 360 ## ## Traffic Shaping ## ----------------- ## ## see /usr/share/doc/lighttpd/traffic-shaping.txt ## ## Values are in kilobyte per second. ## ## Keep in mind that a limit below 32kB/s might actually limit the ## traffic to 32kB/s. This is caused by the size of the TCP send ## buffer. ## ## per server: ## #server.kbytes-per-second = 128 ## ## per connection: ## #connection.kbytes-per-second = 32 ## ####################################################################### ####################################################################### ## ## Filename/File handling ## ------------------------ ## ## files to check for if .../ is requested ## index-file.names = ( "index.php", "index.rb", "index.html", ## "index.htm", "default.htm" ) ## index-file.names += ( "index.xhtml", "index.html", "index.htm", "default.htm", "index.php" ) ## ## deny access the file-extensions ## ## ~ is for backupfiles from vi, emacs, joe, ... ## .inc is often used for code includes which should in general not be part ## of the document-root url.access-deny = ( "~", ".inc" ) ## ## disable range requests for pdf files ## workaround for a bug in the Acrobat Reader plugin. ## $HTTP["url"] =~ "\.pdf$" { server.range-requests = "disable" } ## ## url handling modules (rewrite, redirect) ## #url.rewrite = ( "^/$" => "/server-status" ) #url.redirect = ( "^/wishlist/(.+)" => "http://www.example.com/$1" ) ## ## both rewrite/redirect support back reference to regex conditional using %n ## #$HTTP["host"] =~ "^www\.(.*)" { # url.redirect = ( "^/(.*)" => "http://%1/$1" ) #} ## ## which extensions should not be handle via static-file transfer ## ## .php, .pl, .fcgi are most often handled by mod_fastcgi or mod_cgi ## static-file.exclude-extensions = ( ".php", ".pl", ".fcgi", ".scgi" ) ## ## error-handler for status 404 ## #server.error-handler-404 = "/error-handler.html" #server.error-handler-404 = "/error-handler.php" ## ## Format: <errorfile-prefix><status-code>.html ## -> ..../status-404.html for 'File not found' ## #server.errorfile-prefix = "/srv/www/htdocs/errors/status-" ## ## mimetype mapping ## include "conf.d/mime.conf" ## ## directory listing configuration ## include "conf.d/dirlisting.conf" ## ## Should lighttpd follow symlinks? ## server.follow-symlink = "enable" ## ## force all filenames to be lowercase? ## #server.force-lowercase-filenames = "disable" ## ## defaults to /var/tmp as we assume it is a local harddisk ## server.upload-dirs = ( "/var/tmp" ) ## ####################################################################### ####################################################################### ## ## SSL Support ## ------------- ## ## To enable SSL for the whole server you have to provide a valid ## certificate and have to enable the SSL engine.:: ## ## ssl.engine = "enable" ## ssl.pemfile = "/path/to/server.pem" ## ## The HTTPS protocol does not allow you to use name-based virtual ## hosting with SSL. If you want to run multiple SSL servers with ## one lighttpd instance you must use IP-based virtual hosting: :: ## ## $SERVER["socket"] == "10.0.0.1:443" { ## ssl.engine = "enable" ## ssl.pemfile = "/etc/ssl/private/www.example.com.pem" ## server.name = "www.example.com" ## ## server.document-root = "/srv/www/vhosts/example.com/www/" ## } ## ## If you have a .crt and a .key file, cat them together into a ## single PEM file: ## $ cat /etc/ssl/private/lighttpd.key /etc/ssl/certs/lighttpd.crt \ ## > /etc/ssl/private/lighttpd.pem ## #ssl.pemfile = "/etc/ssl/private/lighttpd.pem" ## ## optionally pass the CA certificate here. ## ## #ssl.ca-file = "" ## ####################################################################### ####################################################################### ## ## custom includes like vhosts. ## #include "conf.d/config.conf" #include_shell "cat /etc/lighttpd/vhosts.d/*.conf" ## ####################################################################### ####################################################################### ### Custom Added by me #url.rewrite-once = (".*\.(js|ico|gif|jpg|png|css|jar|class)$" => "$0", "" => "/index.php") url.rewrite-once = ( ".*\?(.*)$" => "/index.php?$1", "^/js/.*$" => "$0", "^.*\.(js|ico|gif|jpg|png|css|swf |jar|class)$" => "$0", "" => "/index.php" ) # expire.url = ( "" => "access 1 days" ) include "myvhost-vhosts.conf" ####################################################################### Here is my Vhost file for lighttpd $HTTP["host"] =~ "192.168.8.35$" { server.document-root = "/var/www/lighttpd/qc41022012/public" server.errorlog = "/var/log/lighttpd/error.log" accesslog.filename = "/var/log/lighttpd/access.log" server.error-handler-404 = "/e404.php" } and here is my nginx.conf file user nginx; worker_processes 5; error_log /var/log/nginx/error.log warn; pid /var/run/nginx.pid; events { worker_connections 1024; } http { include /etc/nginx/mime.types; default_type application/octet-stream; log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"'; access_log /var/log/nginx/testsite/logs/access.log main; sendfile on; #tcp_nopush on; keepalive_timeout 65; #gzip on; # include /etc/nginx/conf.d/*.conf; ## I added this ## include /etc/nginx/sites-available/*; } Here is my NginX Vhost file server { server_name 192.168.8.91; access_log /var/log/nginx/myapps/logs/access.log; error_log /var/log/nginx/myapps/logs/error.log; root /var/www/html/myapps/public; location / { index index.html index.htm index.php; } location = /favicon.ico { return 204; access_log off; log_not_found off; } # location ~ \.php$ { # try_files $uri /index.php; # include /etc/nginx/fastcgi_params; # fastcgi_pass 127.0.0.1:9000; # fastcgi_index index.php; # fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; # fastcgi_param SCRIPT_NAME $fastcgi_script_name; location ~ \.php.*$ { rewrite ^(.*.php)/ $1 last; fastcgi_pass 127.0.0.1:9000; fastcgi_index index.php; include fastcgi_params; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; # fastcgi_intercept_errors on; # fastcgi_param SCRIPT_FILENAME $document_root/index.php; # fastcgi_param PATH_INFO $uri; # fastcgi_pass 127.0.0.1:9000; # include fastcgi_params; } } We have a custom apps that we created that works great with lighttpd. I went through some headache also when we were trying to figure out how to make it work with lighttpd. this is the line that helps make it work in lighttpd. url.rewrite-once = ( ".*\?(.*)$" => "/index.php?$1", "^/js/.*$" => "$0", "^.*\.(js|ico|gif|jpg|png|css|swf |jar|class)$" => "$0", "" => "/index.php" ) but I couldn't figure out how to make it works in NginX. The webserver run just fine when we use the phpinfo.php test file. However as soon as I point it to my apps, nothing comes up. Check the error.log file and there's no error. Very mind boggling. I spent over 1 week trying to figure it out with no luck.. Please help?

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  • Why is Java EE 6 better than Spring ?

    - by arungupta
    Java EE 6 was released over 2 years ago and now there are 14 compliant application servers. In all my talks around the world, a question that is frequently asked is Why should I use Java EE 6 instead of Spring ? There are already several blogs covering that topic: Java EE wins over Spring by Bill Burke Why will I use Java EE instead of Spring in new Enterprise Java projects in 2012 ? by Kai Waehner (more discussion on TSS) Spring to Java EE migration (Part 1 and 2, 3 and 4 coming as well) by David Heffelfinger Spring to Java EE - A Migration Experience by Lincoln Baxter Migrating Spring to Java EE 6 by Bert Ertman and Paul Bakker at NLJUG Moving from Spring to Java EE 6 - The Age of Frameworks is Over at TSS Java EE vs Spring Shootout by Rohit Kelapure and Reza Rehman at JavaOne 2011 Java EE 6 and the Ewoks by Murat Yener Definite excuse to avoid Spring forever - Bert Ertman and Arun Gupta I will try to share my perspective in this blog. First of all, I'd like to start with a note: Thank you Spring framework for filling the interim gap and providing functionality that is now included in the mainstream Java EE 6 application servers. The Java EE platform has evolved over the years learning from frameworks like Spring and provides all the functionality to build an enterprise application. Thank you very much Spring framework! While Spring was revolutionary in its time and is still very popular and quite main stream in the same way Struts was circa 2003, it really is last generation's framework - some people are even calling it legacy. However my theory is "code is king". So my approach is to build/take a simple Hello World CRUD application in Java EE 6 and Spring and compare the deployable artifacts. I started looking at the official tutorial Developing a Spring Framework MVC Application Step-by-Step but it is using the older version 2.5. I wasn't able to find any updated version in the current 3.1 release. Next, I downloaded Spring Tool Suite and thought that would provide some template samples to get started. A least a quick search did not show any handy tutorials - either video or text-based. So I searched and found a link to their SVN repository at src.springframework.org/svn/spring-samples/. I tried the "mvc-basic" sample and the generated WAR file was 4.43 MB. While it was named a "basic" sample it seemed to come with 19 different libraries bundled but it was what I could find: ./WEB-INF/lib/aopalliance-1.0.jar./WEB-INF/lib/hibernate-validator-4.1.0.Final.jar./WEB-INF/lib/jcl-over-slf4j-1.6.1.jar./WEB-INF/lib/joda-time-1.6.2.jar./WEB-INF/lib/joda-time-jsptags-1.0.2.jar./WEB-INF/lib/jstl-1.2.jar./WEB-INF/lib/log4j-1.2.16.jar./WEB-INF/lib/slf4j-api-1.6.1.jar./WEB-INF/lib/slf4j-log4j12-1.6.1.jar./WEB-INF/lib/spring-aop-3.0.5.RELEASE.jar./WEB-INF/lib/spring-asm-3.0.5.RELEASE.jar./WEB-INF/lib/spring-beans-3.0.5.RELEASE.jar./WEB-INF/lib/spring-context-3.0.5.RELEASE.jar./WEB-INF/lib/spring-context-support-3.0.5.RELEASE.jar./WEB-INF/lib/spring-core-3.0.5.RELEASE.jar./WEB-INF/lib/spring-expression-3.0.5.RELEASE.jar./WEB-INF/lib/spring-web-3.0.5.RELEASE.jar./WEB-INF/lib/spring-webmvc-3.0.5.RELEASE.jar./WEB-INF/lib/validation-api-1.0.0.GA.jar And it is not even using any database! The app deployed fine on GlassFish 3.1.2 but the "@Controller Example" link did not work as it was missing the context root. With a bit of tweaking I could deploy the application and assume that the account got created because no error was displayed in the browser or server log. Next I generated the WAR for "mvc-ajax" and the 5.1 MB WAR had 20 JARs (1 removed, 2 added): ./WEB-INF/lib/aopalliance-1.0.jar./WEB-INF/lib/hibernate-validator-4.1.0.Final.jar./WEB-INF/lib/jackson-core-asl-1.6.4.jar./WEB-INF/lib/jackson-mapper-asl-1.6.4.jar./WEB-INF/lib/jcl-over-slf4j-1.6.1.jar./WEB-INF/lib/joda-time-1.6.2.jar./WEB-INF/lib/jstl-1.2.jar./WEB-INF/lib/log4j-1.2.16.jar./WEB-INF/lib/slf4j-api-1.6.1.jar./WEB-INF/lib/slf4j-log4j12-1.6.1.jar./WEB-INF/lib/spring-aop-3.0.5.RELEASE.jar./WEB-INF/lib/spring-asm-3.0.5.RELEASE.jar./WEB-INF/lib/spring-beans-3.0.5.RELEASE.jar./WEB-INF/lib/spring-context-3.0.5.RELEASE.jar./WEB-INF/lib/spring-context-support-3.0.5.RELEASE.jar./WEB-INF/lib/spring-core-3.0.5.RELEASE.jar./WEB-INF/lib/spring-expression-3.0.5.RELEASE.jar./WEB-INF/lib/spring-web-3.0.5.RELEASE.jar./WEB-INF/lib/spring-webmvc-3.0.5.RELEASE.jar./WEB-INF/lib/validation-api-1.0.0.GA.jar 2 more JARs for just doing Ajax. Anyway, deploying this application gave the following error: Caused by: java.lang.NoSuchMethodError: org.codehaus.jackson.map.SerializationConfig.<init>(Lorg/codehaus/jackson/map/ClassIntrospector;Lorg/codehaus/jackson/map/AnnotationIntrospector;Lorg/codehaus/jackson/map/introspect/VisibilityChecker;Lorg/codehaus/jackson/map/jsontype/SubtypeResolver;)V    at org.springframework.samples.mvc.ajax.json.ConversionServiceAwareObjectMapper.<init>(ConversionServiceAwareObjectMapper.java:20)    at org.springframework.samples.mvc.ajax.json.JacksonConversionServiceConfigurer.postProcessAfterInitialization(JacksonConversionServiceConfigurer.java:40)    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:407) Seems like some incorrect repos in the "pom.xml". Next one is "mvc-showcase" and the 6.49 MB WAR now has 28 JARs as shown below: ./WEB-INF/lib/aopalliance-1.0.jar./WEB-INF/lib/aspectjrt-1.6.10.jar./WEB-INF/lib/commons-fileupload-1.2.2.jar./WEB-INF/lib/commons-io-2.0.1.jar./WEB-INF/lib/el-api-2.2.jar./WEB-INF/lib/hibernate-validator-4.1.0.Final.jar./WEB-INF/lib/jackson-core-asl-1.8.1.jar./WEB-INF/lib/jackson-mapper-asl-1.8.1.jar./WEB-INF/lib/javax.inject-1.jar./WEB-INF/lib/jcl-over-slf4j-1.6.1.jar./WEB-INF/lib/jdom-1.0.jar./WEB-INF/lib/joda-time-1.6.2.jar./WEB-INF/lib/jstl-api-1.2.jar./WEB-INF/lib/jstl-impl-1.2.jar./WEB-INF/lib/log4j-1.2.16.jar./WEB-INF/lib/rome-1.0.0.jar./WEB-INF/lib/slf4j-api-1.6.1.jar./WEB-INF/lib/slf4j-log4j12-1.6.1.jar./WEB-INF/lib/spring-aop-3.1.0.RELEASE.jar./WEB-INF/lib/spring-asm-3.1.0.RELEASE.jar./WEB-INF/lib/spring-beans-3.1.0.RELEASE.jar./WEB-INF/lib/spring-context-3.1.0.RELEASE.jar./WEB-INF/lib/spring-context-support-3.1.0.RELEASE.jar./WEB-INF/lib/spring-core-3.1.0.RELEASE.jar./WEB-INF/lib/spring-expression-3.1.0.RELEASE.jar./WEB-INF/lib/spring-web-3.1.0.RELEASE.jar./WEB-INF/lib/spring-webmvc-3.1.0.RELEASE.jar./WEB-INF/lib/validation-api-1.0.0.GA.jar The app at least deployed and showed results this time. But still no database! Next I tried building "jpetstore" and got the error: [ERROR] Failed to execute goal on project org.springframework.samples.jpetstore:Could not resolve dependencies for project org.springframework.samples:org.springframework.samples.jpetstore:war:1.0.0-SNAPSHOT: Failed to collect dependencies for [commons-fileupload:commons-fileupload:jar:1.2.1 (compile), org.apache.struts:com.springsource.org.apache.struts:jar:1.2.9 (compile), javax.xml.rpc:com.springsource.javax.xml.rpc:jar:1.1.0 (compile), org.apache.commons:com.springsource.org.apache.commons.dbcp:jar:1.2.2.osgi (compile), commons-io:commons-io:jar:1.3.2 (compile), hsqldb:hsqldb:jar:1.8.0.7 (compile), org.apache.tiles:tiles-core:jar:2.2.0 (compile), org.apache.tiles:tiles-jsp:jar:2.2.0 (compile), org.tuckey:urlrewritefilter:jar:3.1.0 (compile), org.springframework:spring-webmvc:jar:3.0.0.BUILD-SNAPSHOT (compile), org.springframework:spring-orm:jar:3.0.0.BUILD-SNAPSHOT (compile), org.springframework:spring-context-support:jar:3.0.0.BUILD-SNAPSHOT (compile), org.springframework.webflow:spring-js:jar:2.0.7.RELEASE (compile), org.apache.ibatis:com.springsource.com.ibatis:jar:2.3.4.726 (runtime), com.caucho:com.springsource.com.caucho:jar:3.2.1 (compile), org.apache.axis:com.springsource.org.apache.axis:jar:1.4.0 (compile), javax.wsdl:com.springsource.javax.wsdl:jar:1.6.1 (compile), javax.servlet:jstl:jar:1.2 (runtime), org.aspectj:aspectjweaver:jar:1.6.5 (compile), javax.servlet:servlet-api:jar:2.5 (provided), javax.servlet.jsp:jsp-api:jar:2.1 (provided), junit:junit:jar:4.6 (test)]: Failed to read artifact descriptor for org.springframework:spring-webmvc:jar:3.0.0.BUILD-SNAPSHOT: Could not transfer artifact org.springframework:spring-webmvc:pom:3.0.0.BUILD-SNAPSHOT from/to JBoss repository (http://repository.jboss.com/maven2): Access denied to: http://repository.jboss.com/maven2/org/springframework/spring-webmvc/3.0.0.BUILD-SNAPSHOT/spring-webmvc-3.0.0.BUILD-SNAPSHOT.pom It appears the sample is broken - maybe I was pulling from the wrong repository - would be great if someone were to point me at a good target to use here. With a 50% hit on samples in this repository, I started searching through numerous blogs, most of which have either outdated information (using XML-heavy Spring 2.5), some piece of configuration (which is a typical "feature" of Spring) is missing, or too much complexity in the sample. I finally found this blog that worked like a charm. This blog creates a trivial Spring MVC 3 application using Hibernate and MySQL. This application performs CRUD operations on a single table in a database using typical Spring technologies.  I downloaded the sample code from the blog, deployed it on GlassFish 3.1.2 and could CRUD the "person" entity. The source code for this application can be downloaded here. More details on the application statistics below. And then I built a similar CRUD application in Java EE 6 using NetBeans wizards in a couple of minutes. The source code for the application can be downloaded here and the WAR here. The Spring Source Tool Suite may also offer similar wizard-driven capabilities but this blog focus primarily on comparing the runtimes. The lack of STS tutorials was slightly disappointing as well. NetBeans however has tons of text-based and video tutorials and tons of material even by the community. One more bit on the download size of tools bundle ... NetBeans 7.1.1 "All" is 211 MB (which includes GlassFish and Tomcat) Spring Tool Suite  2.9.0 is 347 MB (~ 65% bigger) This blog is not about the tooling comparison so back to the Java EE 6 version of the application .... In order to run the Java EE version on GlassFish, copy the MySQL Connector/J to glassfish3/glassfish/domains/domain1/lib/ext directory and create a JDBC connection pool and JDBC resource as: ./bin/asadmin create-jdbc-connection-pool --datasourceclassname \\ com.mysql.jdbc.jdbc2.optional.MysqlDataSource --restype \\ javax.sql.DataSource --property \\ portNumber=3306:user=mysql:password=mysql:databaseName=mydatabase \\ myConnectionPool ./bin/asadmin create-jdbc-resource --connectionpoolid myConnectionPool jdbc/myDataSource I generated WARs for the two projects and the table below highlights some differences between them: Java EE 6 Spring WAR File Size 0.021030 MB 10.87 MB (~516x) Number of files 20 53 (> 2.5x) Bundled libraries 0 36 Total size of libraries 0 12.1 MB XML files 3 5 LoC in XML files 50 (11 + 15 + 24) 129 (27 + 46 + 16 + 11 + 19) (~ 2.5x) Total .properties files 1 Bundle.properties 2 spring.properties, log4j.properties Cold Deploy 5,339 ms 11,724 ms Second Deploy 481 ms 6,261 ms Third Deploy 528 ms 5,484 ms Fourth Deploy 484 ms 5,576 ms Runtime memory ~73 MB ~101 MB Some points worth highlighting from the table ... 516x WAR file, 10x deployment time - With 12.1 MB of libraries (for a very basic application) bundled in your application, the WAR file size and the deployment time will naturally go higher. The WAR file for Spring-based application is 516x bigger and the deployment time is double during the first deployment and ~ 10x during subsequent deployments. The Java EE 6 application is fully portable and will run on any Java EE 6 compliant application server. 36 libraries in the WAR - There are 14 Java EE 6 compliant application servers today. Each of those servers provide all the functionality like transactions, dependency injection, security, persistence, etc typically required of an enterprise or web application. There is no need to bundle 36 libraries worth 12.1 MB for a trivial CRUD application. These 14 compliant application servers provide all the functionality baked in. Now you can also deploy these libraries in the container but then you don't get the "portability" offered by Spring in that case. Does your typical Spring deployment actually do that ? 3x LoC in XML - The number of XML files is about 1.6x and the LoC is ~ 2.5x. So much XML seems circa 2003 when the Java language had no annotations. The XML files can be further reduced, e.g. faces-config.xml can be replaced without providing i18n, but I just want to compare stock applications. Memory usage - Both the applications were deployed on default GlassFish 3.1.2 installation and any additional memory consumed as part of deployment/access was attributed to the application. This is by no means scientific but at least provides an initial ballpark. This area definitely needs more investigation. Another table that compares typical Java EE 6 compliant application servers and the custom-stack created for a Spring application ... Java EE 6 Spring Web Container ? 53 MB (tcServer 2.6.3 Developer Edition) Security ? 12 MB (Spring Security 3.1.0) Persistence ? 6.3 MB (Hibernate 4.1.0, required) Dependency Injection ? 5.3 MB (Framework) Web Services ? 796 KB (Spring WS 2.0.4) Messaging ? 3.4 MB (RabbitMQ Server 2.7.1) 936 KB (Java client 936) OSGi ? 1.3 MB (Spring OSGi 1.2.1) GlassFish and WebLogic (starting at 33 MB) 83.3 MB There are differentiating factors on both the stacks. But most of the functionality like security, persistence, and dependency injection is baked in a Java EE 6 compliant application server but needs to be individually managed and patched for a Spring application. This very quickly leads to a "stack explosion". The Java EE 6 servers are tested extensively on a variety of platforms in different combinations whereas a Spring application developer is responsible for testing with different JDKs, Operating Systems, Versions, Patches, etc. Oracle has both the leading OSS lightweight server with GlassFish and the leading enterprise Java server with WebLogic Server, both Java EE 6 and both with lightweight deployment options. The Web Container offered as part of a Java EE 6 application server not only deploys your enterprise Java applications but also provide operational management, diagnostics, and mission-critical capabilities required by your applications. The Java EE 6 platform also introduced the Web Profile which is a subset of the specifications from the entire platform. It is targeted at developers of modern web applications offering a reasonably complete stack, composed of standard APIs, and is capable out-of-the-box of addressing the needs of a large class of Web applications. As your applications grow, the stack can grow to the full Java EE 6 platform. The GlassFish Server Web Profile starting at 33MB (smaller than just the non-standard tcServer) provides most of the functionality typically required by a web application. WebLogic provides battle-tested functionality for a high throughput, low latency, and enterprise grade web application. No individual managing or patching, all tested and commercially supported for you! Note that VMWare does have a server, tcServer, but it is non-standard and not even certified to the level of the standard Web Profile most customers expect these days. Customers who choose this risk proprietary lock-in since VMWare does not seem to want to formally certify with either Java EE 6 Enterprise Platform or with Java EE 6 Web Profile but of course it would be great if they were to join the community and help their customers reduce the risk of deploying on VMWare software. Some more points to help you decide choose between Java EE 6 and Spring ... Freedom to choose container - There are 14 Java EE 6 compliant application servers today, with a variety of open source and commercial offerings. A Java EE 6 application can be deployed on any of those containers. So if you deployed your application on GlassFish today and would like to scale up with your demands then you can deploy the same application to WebLogic. And because of the portability of a Java EE 6 application, you can even take it a different vendor altogether. Spring requires a runtime which could be any of these app servers as well. But why use Spring when all the required functionality is already baked into the application server itself ? Spring also has a different definition of portability where they claim to bundle all the libraries in the WAR file and move to any application server. But we saw earlier how bloated that archive could be. The equivalent features in Spring runtime offerings (mainly tcServer) are not all open source, not as mature, and often require manual assembly.  Vendor choice - The Java EE 6 platform is created using the Java Community Process where all the big players like Oracle, IBM, RedHat, and Apache are conritbuting to make the platform successful. Each application server provides the basic Java EE 6 platform compliance and has its own competitive offerings. This allows you to choose an application server for deploying your Java EE 6 applications. If you are not happy with the support or feature of one vendor then you can move your application to a different vendor because of the portability promise offered by the platform. Spring is a set of products from a single company, one price book, one support organization, one sustaining organization, one sales organization, etc. If any of those cause a customer headache, where do you go ? Java EE, backed by multiple vendors, is a safer bet for those that are risk averse. Production support - With Spring, typically you need to get support from two vendors - VMWare and the container provider. With Java EE 6, all of this is typically provided by one vendor. For example, Oracle offers commercial support from systems, operating systems, JDK, application server, and applications on top of them. VMWare certainly offers complete production support but do you really want to put all your eggs in one basket ? Do you really use tcServer ? ;-) Maintainability - With Spring, you are likely building your own distribution with multiple JAR files, integrating, patching, versioning, etc of all those components. Spring's claim is that multiple JAR files allow you to go à la carte and pick the latest versions of different components. But who is responsible for testing whether all these versions work together ? Yep, you got it, its YOU! If something does not work, who patches and maintains the JARs ? Of course, you! Commercial support for such a configuration ? On your own! The Java EE application servers manage all of this for you and provide a well-tested and commercially supported bundle. While it is always good to realize that there is something new and improved that updates and replaces older frameworks like Spring, the good news is not only does a Java EE 6 container offer what is described here, most also will let you deploy and run your Spring applications on them while you go through an upgrade to a more modern architecture. End result, you get the best of both worlds - keeping your legacy investment but moving to a more agile, lightweight world of Java EE 6. A message to the Spring lovers ... The complexity in J2EE 1.2, 1.3, and 1.4 led to the genesis of Spring but that was in 2004. This is 2012 and the name has changed to "Java EE 6" :-) There are tons of improvements in the Java EE platform to make it easy-to-use and powerful. Some examples: Adding @Stateless on a POJO makes it an EJB EJBs can be packaged in a WAR with no special packaging or deployment descriptors "web.xml" and "faces-config.xml" are optional in most of the common cases Typesafe dependency injection is now part of the Java EE platform Add @Path on a POJO allows you to publish it as a RESTful resource EJBs can be used as backing beans for Facelets-driven JSF pages providing full MVC Java EE 6 WARs are known to be kilobytes in size and deployed in milliseconds Tons of other simplifications in the platform and application servers So if you moved away from J2EE to Spring many years ago and have not looked at Java EE 6 (which has been out since Dec 2009) then you should definitely try it out. Just be at least aware of what other alternatives are available instead of restricting yourself to one stack. Here are some workshops and screencasts worth trying: screencast #37 shows how to build an end-to-end application using NetBeans screencast #36 builds the same application using Eclipse javaee-lab-feb2012.pdf is a 3-4 hours self-paced hands-on workshop that guides you to build a comprehensive Java EE 6 application using NetBeans Each city generally has a "spring cleanup" program every year. It allows you to clean up the mess from your house. For your software projects, you don't need to wait for an annual event, just get started and reduce the technical debt now! Move away from your legacy Spring-based applications to a lighter and more modern approach of building enterprise Java applications using Java EE 6. Watch this beautiful presentation that explains how to migrate from Spring -> Java EE 6: List of files in the Java EE 6 project: ./index.xhtml./META-INF./person./person/Create.xhtml./person/Edit.xhtml./person/List.xhtml./person/View.xhtml./resources./resources/css./resources/css/jsfcrud.css./template.xhtml./WEB-INF./WEB-INF/classes./WEB-INF/classes/Bundle.properties./WEB-INF/classes/META-INF./WEB-INF/classes/META-INF/persistence.xml./WEB-INF/classes/org./WEB-INF/classes/org/javaee./WEB-INF/classes/org/javaee/javaeemysql./WEB-INF/classes/org/javaee/javaeemysql/AbstractFacade.class./WEB-INF/classes/org/javaee/javaeemysql/Person.class./WEB-INF/classes/org/javaee/javaeemysql/Person_.class./WEB-INF/classes/org/javaee/javaeemysql/PersonController$1.class./WEB-INF/classes/org/javaee/javaeemysql/PersonController$PersonControllerConverter.class./WEB-INF/classes/org/javaee/javaeemysql/PersonController.class./WEB-INF/classes/org/javaee/javaeemysql/PersonFacade.class./WEB-INF/classes/org/javaee/javaeemysql/util./WEB-INF/classes/org/javaee/javaeemysql/util/JsfUtil.class./WEB-INF/classes/org/javaee/javaeemysql/util/PaginationHelper.class./WEB-INF/faces-config.xml./WEB-INF/web.xml List of files in the Spring 3.x project: ./META-INF ./META-INF/MANIFEST.MF./WEB-INF./WEB-INF/applicationContext.xml./WEB-INF/classes./WEB-INF/classes/log4j.properties./WEB-INF/classes/org./WEB-INF/classes/org/krams ./WEB-INF/classes/org/krams/tutorial ./WEB-INF/classes/org/krams/tutorial/controller ./WEB-INF/classes/org/krams/tutorial/controller/MainController.class ./WEB-INF/classes/org/krams/tutorial/domain ./WEB-INF/classes/org/krams/tutorial/domain/Person.class ./WEB-INF/classes/org/krams/tutorial/service ./WEB-INF/classes/org/krams/tutorial/service/PersonService.class ./WEB-INF/hibernate-context.xml ./WEB-INF/hibernate.cfg.xml ./WEB-INF/jsp ./WEB-INF/jsp/addedpage.jsp ./WEB-INF/jsp/addpage.jsp ./WEB-INF/jsp/deletedpage.jsp ./WEB-INF/jsp/editedpage.jsp ./WEB-INF/jsp/editpage.jsp ./WEB-INF/jsp/personspage.jsp ./WEB-INF/lib ./WEB-INF/lib/antlr-2.7.6.jar ./WEB-INF/lib/aopalliance-1.0.jar ./WEB-INF/lib/c3p0-0.9.1.2.jar ./WEB-INF/lib/cglib-nodep-2.2.jar ./WEB-INF/lib/commons-beanutils-1.8.3.jar ./WEB-INF/lib/commons-collections-3.2.1.jar ./WEB-INF/lib/commons-digester-2.1.jar ./WEB-INF/lib/commons-logging-1.1.1.jar ./WEB-INF/lib/dom4j-1.6.1.jar ./WEB-INF/lib/ejb3-persistence-1.0.2.GA.jar ./WEB-INF/lib/hibernate-annotations-3.4.0.GA.jar ./WEB-INF/lib/hibernate-commons-annotations-3.1.0.GA.jar ./WEB-INF/lib/hibernate-core-3.3.2.GA.jar ./WEB-INF/lib/javassist-3.7.ga.jar ./WEB-INF/lib/jstl-1.1.2.jar ./WEB-INF/lib/jta-1.1.jar ./WEB-INF/lib/junit-4.8.1.jar ./WEB-INF/lib/log4j-1.2.14.jar ./WEB-INF/lib/mysql-connector-java-5.1.14.jar ./WEB-INF/lib/persistence-api-1.0.jar ./WEB-INF/lib/slf4j-api-1.6.1.jar ./WEB-INF/lib/slf4j-log4j12-1.6.1.jar ./WEB-INF/lib/spring-aop-3.0.5.RELEASE.jar ./WEB-INF/lib/spring-asm-3.0.5.RELEASE.jar ./WEB-INF/lib/spring-beans-3.0.5.RELEASE.jar ./WEB-INF/lib/spring-context-3.0.5.RELEASE.jar ./WEB-INF/lib/spring-context-support-3.0.5.RELEASE.jar ./WEB-INF/lib/spring-core-3.0.5.RELEASE.jar ./WEB-INF/lib/spring-expression-3.0.5.RELEASE.jar ./WEB-INF/lib/spring-jdbc-3.0.5.RELEASE.jar ./WEB-INF/lib/spring-orm-3.0.5.RELEASE.jar ./WEB-INF/lib/spring-tx-3.0.5.RELEASE.jar ./WEB-INF/lib/spring-web-3.0.5.RELEASE.jar ./WEB-INF/lib/spring-webmvc-3.0.5.RELEASE.jar ./WEB-INF/lib/standard-1.1.2.jar ./WEB-INF/lib/xml-apis-1.0.b2.jar ./WEB-INF/spring-servlet.xml ./WEB-INF/spring.properties ./WEB-INF/web.xml So, are you excited about Java EE 6 ? Want to get started now ? Here are some resources: Java EE 6 SDK (including runtime, samples, tutorials etc) GlassFish Server Open Source Edition 3.1.2 (Community) Oracle GlassFish Server 3.1.2 (Commercial) Java EE 6 using WebLogic 12c and NetBeans (Video) Java EE 6 with NetBeans and GlassFish (Video) Java EE with Eclipse and GlassFish (Video)

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  • Scrum in 5 Minutes

    - by Stephen.Walther
    The goal of this blog entry is to explain the basic concepts of Scrum in less than five minutes. You learn how Scrum can help a team of developers to successfully complete a complex software project. Product Backlog and the Product Owner Imagine that you are part of a team which needs to create a new website – for example, an e-commerce website. You have an overwhelming amount of work to do. You need to build (or possibly buy) a shopping cart, install an SSL certificate, create a product catalog, create a Facebook page, and at least a hundred other things that you have not thought of yet. According to Scrum, the first thing you should do is create a list. Place the highest priority items at the top of the list and the lower priority items lower in the list. For example, creating the shopping cart and buying the domain name might be high priority items and creating a Facebook page might be a lower priority item. In Scrum, this list is called the Product Backlog. How do you prioritize the items in the Product Backlog? Different stakeholders in the project might have different priorities. Gary, your division VP, thinks that it is crucial that the e-commerce site has a mobile app. Sally, your direct manager, thinks taking advantage of new HTML5 features is much more important. Multiple people are pulling you in different directions. According to Scrum, it is important that you always designate one person, and only one person, as the Product Owner. The Product Owner is the person who decides what items should be added to the Product Backlog and the priority of the items in the Product Backlog. The Product Owner could be the customer who is paying the bills, the project manager who is responsible for delivering the project, or a customer representative. The critical point is that the Product Owner must always be a single person and that single person has absolute authority over the Product Backlog. Sprints and the Sprint Backlog So now the developer team has a prioritized list of items and they can start work. The team starts implementing the first item in the Backlog — the shopping cart — and the team is making good progress. Unfortunately, however, half-way through the work of implementing the shopping cart, the Product Owner changes his mind. The Product Owner decides that it is much more important to create the product catalog before the shopping cart. With some frustration, the team switches their developmental efforts to focus on implementing the product catalog. However, part way through completing this work, once again the Product Owner changes his mind about the highest priority item. Getting work done when priorities are constantly shifting is frustrating for the developer team and it results in lower productivity. At the same time, however, the Product Owner needs to have absolute authority over the priority of the items which need to get done. Scrum solves this conflict with the concept of Sprints. In Scrum, a developer team works in Sprints. At the beginning of a Sprint the developers and the Product Owner agree on the items from the backlog which they will complete during the Sprint. This subset of items from the Product Backlog becomes the Sprint Backlog. During the Sprint, the Product Owner is not allowed to change the items in the Sprint Backlog. In other words, the Product Owner cannot shift priorities on the developer team during the Sprint. Different teams use Sprints of different lengths such as one month Sprints, two-week Sprints, and one week Sprints. For high-stress, time critical projects, teams typically choose shorter sprints such as one week sprints. For more mature projects, longer one month sprints might be more appropriate. A team can pick whatever Sprint length makes sense for them just as long as the team is consistent. You should pick a Sprint length and stick with it. Daily Scrum During a Sprint, the developer team needs to have meetings to coordinate their work on completing the items in the Sprint Backlog. For example, the team needs to discuss who is working on what and whether any blocking issues have been discovered. Developers hate meetings (well, sane developers hate meetings). Meetings take developers away from their work of actually implementing stuff as opposed to talking about implementing stuff. However, a developer team which never has meetings and never coordinates their work also has problems. For example, Fred might get stuck on a programming problem for days and never reach out for help even though Tom (who sits in the cubicle next to him) has already solved the very same problem. Or, both Ted and Fred might have started working on the same item from the Sprint Backlog at the same time. In Scrum, these conflicting needs – limiting meetings but enabling team coordination – are resolved with the idea of the Daily Scrum. The Daily Scrum is a meeting for coordinating the work of the developer team which happens once a day. To keep the meeting short, each developer answers only the following three questions: 1. What have you done since yesterday? 2. What do you plan to do today? 3. Any impediments in your way? During the Daily Scrum, developers are not allowed to talk about issues with their cat, do demos of their latest work, or tell heroic stories of programming problems overcome. The meeting must be kept short — typically about 15 minutes. Issues which come up during the Daily Scrum should be discussed in separate meetings which do not involve the whole developer team. Stories and Tasks Items in the Product or Sprint Backlog – such as building a shopping cart or creating a Facebook page – are often referred to as User Stories or Stories. The Stories are created by the Product Owner and should represent some business need. Unlike the Product Owner, the developer team needs to think about how a Story should be implemented. At the beginning of a Sprint, the developer team takes the Stories from the Sprint Backlog and breaks the stories into tasks. For example, the developer team might take the Create a Shopping Cart story and break it into the following tasks: · Enable users to add and remote items from shopping cart · Persist the shopping cart to database between visits · Redirect user to checkout page when Checkout button is clicked During the Daily Scrum, members of the developer team volunteer to complete the tasks required to implement the next Story in the Sprint Backlog. When a developer talks about what he did yesterday or plans to do tomorrow then the developer should be referring to a task. Stories are owned by the Product Owner and a story is all about business value. In contrast, the tasks are owned by the developer team and a task is all about implementation details. A story might take several days or weeks to complete. A task is something which a developer can complete in less than a day. Some teams get lazy about breaking stories into tasks. Neglecting to break stories into tasks can lead to “Never Ending Stories” If you don’t break a story into tasks, then you can’t know how much of a story has actually been completed because you don’t have a clear idea about the implementation steps required to complete the story. Scrumboard During the Daily Scrum, the developer team uses a Scrumboard to coordinate their work. A Scrumboard contains a list of the stories for the current Sprint, the tasks associated with each Story, and the state of each task. The developer team uses the Scrumboard so everyone on the team can see, at a glance, what everyone is working on. As a developer works on a task, the task moves from state to state and the state of the task is updated on the Scrumboard. Common task states are ToDo, In Progress, and Done. Some teams include additional task states such as Needs Review or Needs Testing. Some teams use a physical Scrumboard. In that case, you use index cards to represent the stories and the tasks and you tack the index cards onto a physical board. Using a physical Scrumboard has several disadvantages. A physical Scrumboard does not work well with a distributed team – for example, it is hard to share the same physical Scrumboard between Boston and Seattle. Also, generating reports from a physical Scrumboard is more difficult than generating reports from an online Scrumboard. Estimating Stories and Tasks Stakeholders in a project, the people investing in a project, need to have an idea of how a project is progressing and when the project will be completed. For example, if you are investing in creating an e-commerce site, you need to know when the site can be launched. It is not enough to just say that “the project will be done when it is done” because the stakeholders almost certainly have a limited budget to devote to the project. The people investing in the project cannot determine the business value of the project unless they can have an estimate of how long it will take to complete the project. Developers hate to give estimates. The reason that developers hate to give estimates is that the estimates are almost always completely made up. For example, you really don’t know how long it takes to build a shopping cart until you finish building a shopping cart, and at that point, the estimate is no longer useful. The problem is that writing code is much more like Finding a Cure for Cancer than Building a Brick Wall. Building a brick wall is very straightforward. After you learn how to add one brick to a wall, you understand everything that is involved in adding a brick to a wall. There is no additional research required and no surprises. If, on the other hand, I assembled a team of scientists and asked them to find a cure for cancer, and estimate exactly how long it will take, they would have no idea. The problem is that there are too many unknowns. I don’t know how to cure cancer, I need to do a lot of research here, so I cannot even begin to estimate how long it will take. So developers hate to provide estimates, but the Product Owner and other product stakeholders, have a legitimate need for estimates. Scrum resolves this conflict by using the idea of Story Points. Different teams use different units to represent Story Points. For example, some teams use shirt sizes such as Small, Medium, Large, and X-Large. Some teams prefer to use Coffee Cup sizes such as Tall, Short, and Grande. Finally, some teams like to use numbers from the Fibonacci series. These alternative units are converted into a Story Point value. Regardless of the type of unit which you use to represent Story Points, the goal is the same. Instead of attempting to estimate a Story in hours (which is doomed to failure), you use a much less fine-grained measure of work. A developer team is much more likely to be able to estimate that a Story is Small or X-Large than the exact number of hours required to complete the story. So you can think of Story Points as a compromise between the needs of the Product Owner and the developer team. When a Sprint starts, the developer team devotes more time to thinking about the Stories in a Sprint and the developer team breaks the Stories into Tasks. In Scrum, you estimate the work required to complete a Story by using Story Points and you estimate the work required to complete a task by using hours. The difference between Stories and Tasks is that you don’t create a task until you are just about ready to start working on a task. A task is something that you should be able to create within a day, so you have a much better chance of providing an accurate estimate of the work required to complete a task than a story. Burndown Charts In Scrum, you use Burndown charts to represent the remaining work on a project. You use Release Burndown charts to represent the overall remaining work for a project and you use Sprint Burndown charts to represent the overall remaining work for a particular Sprint. You create a Release Burndown chart by calculating the remaining number of uncompleted Story Points for the entire Product Backlog every day. The vertical axis represents Story Points and the horizontal axis represents time. A Sprint Burndown chart is similar to a Release Burndown chart, but it focuses on the remaining work for a particular Sprint. There are two different types of Sprint Burndown charts. You can either represent the remaining work in a Sprint with Story Points or with task hours (the following image, taken from Wikipedia, uses hours). When each Product Backlog Story is completed, the Release Burndown chart slopes down. When each Story or task is completed, the Sprint Burndown chart slopes down. Burndown charts typically do not always slope down over time. As new work is added to the Product Backlog, the Release Burndown chart slopes up. If new tasks are discovered during a Sprint, the Sprint Burndown chart will also slope up. The purpose of a Burndown chart is to give you a way to track team progress over time. If, halfway through a Sprint, the Sprint Burndown chart is still climbing a hill then you know that you are in trouble. Team Velocity Stakeholders in a project always want more work done faster. For example, the Product Owner for the e-commerce site wants the website to launch before tomorrow. Developers tend to be overly optimistic. Rarely do developers acknowledge the physical limitations of reality. So Project stakeholders and the developer team often collude to delude themselves about how much work can be done and how quickly. Too many software projects begin in a state of optimism and end in frustration as deadlines zoom by. In Scrum, this problem is overcome by calculating a number called the Team Velocity. The Team Velocity is a measure of the average number of Story Points which a team has completed in previous Sprints. Knowing the Team Velocity is important during the Sprint Planning meeting when the Product Owner and the developer team work together to determine the number of stories which can be completed in the next Sprint. If you know the Team Velocity then you can avoid committing to do more work than the team has been able to accomplish in the past, and your team is much more likely to complete all of the work required for the next Sprint. Scrum Master There are three roles in Scrum: the Product Owner, the developer team, and the Scrum Master. I’v e already discussed the Product Owner. The Product Owner is the one and only person who maintains the Product Backlog and prioritizes the stories. I’ve also described the role of the developer team. The members of the developer team do the work of implementing the stories by breaking the stories into tasks. The final role, which I have not discussed, is the role of the Scrum Master. The Scrum Master is responsible for ensuring that the team is following the Scrum process. For example, the Scrum Master is responsible for making sure that there is a Daily Scrum meeting and that everyone answers the standard three questions. The Scrum Master is also responsible for removing (non-technical) impediments which the team might encounter. For example, if the team cannot start work until everyone installs the latest version of Microsoft Visual Studio then the Scrum Master has the responsibility of working with management to get the latest version of Visual Studio as quickly as possible. The Scrum Master can be a member of the developer team. Furthermore, different people can take on the role of the Scrum Master over time. The Scrum Master, however, cannot be the same person as the Product Owner. Using SonicAgile SonicAgile (SonicAgile.com) is an online tool which you can use to manage your projects using Scrum. You can use the SonicAgile Product Backlog to create a prioritized list of stories. You can estimate the size of the Stories using different Story Point units such as Shirt Sizes and Coffee Cup sizes. You can use SonicAgile during the Sprint Planning meeting to select the Stories that you want to complete during a particular Sprint. You can configure Sprints to be any length of time. SonicAgile calculates Team Velocity automatically and displays a warning when you add too many stories to a Sprint. In other words, it warns you when it thinks you are overcommitting in a Sprint. SonicAgile also includes a Scrumboard which displays the list of Stories selected for a Sprint and the tasks associated with each story. You can drag tasks from one task state to another. Finally, SonicAgile enables you to generate Release Burndown and Sprint Burndown charts. You can use these charts to view the progress of your team. To learn more about SonicAgile, visit SonicAgile.com. Summary In this post, I described many of the basic concepts of Scrum. You learned how a Product Owner uses a Product Backlog to create a prioritized list of tasks. I explained why work is completed in Sprints so the developer team can be more productive. I also explained how a developer team uses the daily scrum to coordinate their work. You learned how the developer team uses a Scrumboard to see, at a glance, who is working on what and the state of each task. I also discussed Burndown charts. You learned how you can use both Release and Sprint Burndown charts to track team progress in completing a project. Finally, I described the crucial role of the Scrum Master – the person who is responsible for ensuring that the rules of Scrum are being followed. My goal was not to describe all of the concepts of Scrum. This post was intended to be an introductory overview. For a comprehensive explanation of Scrum, I recommend reading Ken Schwaber’s book Agile Project Management with Scrum: http://www.amazon.com/Agile-Project-Management-Microsoft-Professional/dp/073561993X/ref=la_B001H6ODMC_1_1?ie=UTF8&qid=1345224000&sr=1-1

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  • SQL Server 2012 - AlwaysOn

    - by Claus Jandausch
    Ich war nicht nur irritiert, ich war sogar regelrecht schockiert - und für einen kurzen Moment sprachlos (was nur selten der Fall ist). Gerade eben hatte mich jemand gefragt "Wann Oracle denn etwas Vergleichbares wie AlwaysOn bieten würde - und ob überhaupt?" War ich hier im falschen Film gelandet? Ich konnte nicht anders, als meinen Unmut kundzutun und zu erklären, dass die Fragestellung normalerweise anders herum läuft. Zugegeben - es mag vielleicht strittige Punkte geben im Vergleich zwischen Oracle und SQL Server - bei denen nicht unbedingt immer Oracle die Nase vorn haben muss - aber das Thema Clustering für Hochverfügbarkeit (HA), Disaster Recovery (DR) und Skalierbarkeit gehört mit Sicherheit nicht dazu. Dieses Erlebnis hakte ich am Nachgang als Einzelfall ab, der so nie wieder vorkommen würde. Bis ich kurz darauf eines Besseren belehrt wurde und genau die selbe Frage erneut zu hören bekam. Diesmal sogar im Exadata-Umfeld und einem Oracle Stretch Cluster. Einmal ist keinmal, doch zweimal ist einmal zu viel... Getreu diesem alten Motto war mir klar, dass man das so nicht länger stehen lassen konnte. Ich habe keine Ahnung, wie die Microsoft Marketing Abteilung es geschafft hat, unter dem AlwaysOn Brading eine innovative Technologie vermuten zu lassen - aber sie hat ihren Job scheinbar gut gemacht. Doch abgesehen von einem guten Marketing, stellt sich natürlich die Frage, was wirklich dahinter steckt und wie sich das Ganze mit Oracle vergleichen lässt - und ob überhaupt? Damit wären wir wieder bei der ursprünglichen Frage angelangt.  So viel zum Hintergrund dieses Blogbeitrags - von meiner Antwort handelt der restliche Blog. "Windows was the God ..." Um den wahren Unterschied zwischen Oracle und Microsoft verstehen zu können, muss man zunächst das bedeutendste Microsoft Dogma kennen. Es lässt sich schlicht und einfach auf den Punkt bringen: "Alles muss auf Windows basieren." Die Überschrift dieses Absatzes ist kein von mir erfundener Ausspruch, sondern ein Zitat. Konkret stammt es aus einem längeren Artikel von Kurt Eichenwald in der Vanity Fair aus dem August 2012. Er lautet Microsoft's Lost Decade und sei jedem ans Herz gelegt, der die "Microsoft-Maschinerie" unter Steve Ballmer und einige ihrer Kuriositäten besser verstehen möchte. "YOU TALKING TO ME?" Microsoft C.E.O. Steve Ballmer bei seiner Keynote auf der 2012 International Consumer Electronics Show in Las Vegas am 9. Januar   Manche Dinge in diesem Artikel mögen überspitzt dargestellt erscheinen - sind sie aber nicht. Vieles davon kannte ich bereits aus eigener Erfahrung und kann es nur bestätigen. Anderes hat sich mir erst so richtig erschlossen. Insbesondere die folgenden Passagen führten zum Aha-Erlebnis: “Windows was the god—everything had to work with Windows,” said Stone... “Every little thing you want to write has to build off of Windows (or other existing roducts),” one software engineer said. “It can be very confusing, …” Ich habe immer schon darauf hingewiesen, dass in einem SQL Server Failover Cluster die Microsoft Datenbank eigentlich nichts Nenneswertes zum Geschehen beiträgt, sondern sich voll und ganz auf das Windows Betriebssystem verlässt. Deshalb muss man auch die Windows Server Enterprise Edition installieren, soll ein Failover Cluster für den SQL Server eingerichtet werden. Denn hier werden die Cluster Services geliefert - nicht mit dem SQL Server. Er ist nur lediglich ein weiteres Server Produkt, für das Windows in Ausfallszenarien genutzt werden kann - so wie Microsoft Exchange beispielsweise, oder Microsoft SharePoint, oder irgendein anderes Server Produkt das auf Windows gehostet wird. Auch Oracle kann damit genutzt werden. Das Stichwort lautet hier: Oracle Failsafe. Nur - warum sollte man das tun, wenn gleichzeitig eine überlegene Technologie wie die Oracle Real Application Clusters (RAC) zur Verfügung steht, die dann auch keine Windows Enterprise Edition voraussetzen, da Oracle die eigene Clusterware liefert. Welche darüber hinaus für kürzere Failover-Zeiten sorgt, da diese Cluster-Technologie Datenbank-integriert ist und sich nicht auf "Dritte" verlässt. Wenn man sich also schon keine technischen Vorteile mit einem SQL Server Failover Cluster erkauft, sondern zusätzlich noch versteckte Lizenzkosten durch die Lizenzierung der Windows Server Enterprise Edition einhandelt, warum hat Microsoft dann in den vergangenen Jahren seit SQL Server 2000 nicht ebenfalls an einer neuen und innovativen Lösung gearbeitet, die mit Oracle RAC mithalten kann? Entwickler hat Microsoft genügend? Am Geld kann es auch nicht liegen? Lesen Sie einfach noch einmal die beiden obenstehenden Zitate und sie werden den Grund verstehen. Anders lässt es sich ja auch gar nicht mehr erklären, dass AlwaysOn aus zwei unterschiedlichen Technologien besteht, die beide jedoch wiederum auf dem Windows Server Failover Clustering (WSFC) basieren. Denn daraus ergeben sich klare Nachteile - aber dazu später mehr. Um AlwaysOn zu verstehen, sollte man sich zunächst kurz in Erinnerung rufen, was Microsoft bisher an HA/DR (High Availability/Desaster Recovery) Lösungen für SQL Server zur Verfügung gestellt hat. Replikation Basiert auf logischer Replikation und Pubisher/Subscriber Architektur Transactional Replication Merge Replication Snapshot Replication Microsoft's Replikation ist vergleichbar mit Oracle GoldenGate. Oracle GoldenGate stellt jedoch die umfassendere Technologie dar und bietet High Performance. Log Shipping Microsoft's Log Shipping stellt eine einfache Technologie dar, die vergleichbar ist mit Oracle Managed Recovery in Oracle Version 7. Das Log Shipping besitzt folgende Merkmale: Transaction Log Backups werden von Primary nach Secondary/ies geschickt Einarbeitung (z.B. Restore) auf jedem Secondary individuell Optionale dritte Server Instanz (Monitor Server) für Überwachung und Alarm Log Restore Unterbrechung möglich für Read-Only Modus (Secondary) Keine Unterstützung von Automatic Failover Database Mirroring Microsoft's Database Mirroring wurde verfügbar mit SQL Server 2005, sah aus wie Oracle Data Guard in Oracle 9i, war funktional jedoch nicht so umfassend. Für ein HA/DR Paar besteht eine 1:1 Beziehung, um die produktive Datenbank (Principle DB) abzusichern. Auf der Standby Datenbank (Mirrored DB) werden alle Insert-, Update- und Delete-Operationen nachgezogen. Modi Synchron (High-Safety Modus) Asynchron (High-Performance Modus) Automatic Failover Unterstützt im High-Safety Modus (synchron) Witness Server vorausgesetzt     Zur Frage der Kontinuität Es stellt sich die Frage, wie es um diesen Technologien nun im Zusammenhang mit SQL Server 2012 bestellt ist. Unter Fanfaren seinerzeit eingeführt, war Database Mirroring das erklärte Mittel der Wahl. Ich bin kein Produkt Manager bei Microsoft und kann hierzu nur meine Meinung äußern, aber zieht man den SQL AlwaysOn Team Blog heran, so sieht es nicht gut aus für das Database Mirroring - zumindest nicht langfristig. "Does AlwaysOn Availability Group replace Database Mirroring going forward?” “The short answer is we recommend that you migrate from the mirroring configuration or even mirroring and log shipping configuration to using Availability Group. Database Mirroring will still be available in the Denali release but will be phased out over subsequent releases. Log Shipping will continue to be available in future releases.” Damit wären wir endlich beim eigentlichen Thema angelangt. Was ist eine sogenannte Availability Group und was genau hat es mit der vielversprechend klingenden Bezeichnung AlwaysOn auf sich?   SQL Server 2012 - AlwaysOn Zwei HA-Features verstekcne sich hinter dem “AlwaysOn”-Branding. Einmal das AlwaysOn Failover Clustering aka SQL Server Failover Cluster Instances (FCI) - zum Anderen die AlwaysOn Availability Groups. Failover Cluster Instances (FCI) Entspricht ungefähr dem Stretch Cluster Konzept von Oracle Setzt auf Windows Server Failover Clustering (WSFC) auf Bietet HA auf Instanz-Ebene AlwaysOn Availability Groups (Verfügbarkeitsgruppen) Ähnlich der Idee von Consistency Groups, wie in Storage-Level Replikations-Software von z.B. EMC SRDF Abhängigkeiten zu Windows Server Failover Clustering (WSFC) Bietet HA auf Datenbank-Ebene   Hinweis: Verwechseln Sie nicht eine SQL Server Datenbank mit einer Oracle Datenbank. Und auch nicht eine Oracle Instanz mit einer SQL Server Instanz. Die gleichen Begriffe haben hier eine andere Bedeutung - nicht selten ein Grund, weshalb Oracle- und Microsoft DBAs schnell aneinander vorbei reden. Denken Sie bei einer SQL Server Datenbank eher an ein Oracle Schema, das kommt der Sache näher. So etwas wie die SQL Server Northwind Datenbank ist vergleichbar mit dem Oracle Scott Schema. Wenn Sie die genauen Unterschiede kennen möchten, finden Sie eine detaillierte Beschreibung in meinem Buch "Oracle10g Release 2 für Windows und .NET", erhältich bei Lehmanns, Amazon, etc.   Windows Server Failover Clustering (WSFC) Wie man sieht, basieren beide AlwaysOn Technologien wiederum auf dem Windows Server Failover Clustering (WSFC), um einerseits Hochverfügbarkeit auf Ebene der Instanz zu gewährleisten und andererseits auf der Datenbank-Ebene. Deshalb nun eine kurze Beschreibung der WSFC. Die WSFC sind ein mit dem Windows Betriebssystem geliefertes Infrastruktur-Feature, um HA für Server Anwendungen, wie Microsoft Exchange, SharePoint, SQL Server, etc. zu bieten. So wie jeder andere Cluster, besteht ein WSFC Cluster aus einer Gruppe unabhängiger Server, die zusammenarbeiten, um die Verfügbarkeit einer Applikation oder eines Service zu erhöhen. Falls ein Cluster-Knoten oder -Service ausfällt, kann der auf diesem Knoten bisher gehostete Service automatisch oder manuell auf einen anderen im Cluster verfügbaren Knoten transferriert werden - was allgemein als Failover bekannt ist. Unter SQL Server 2012 verwenden sowohl die AlwaysOn Avalability Groups, als auch die AlwaysOn Failover Cluster Instances die WSFC als Plattformtechnologie, um Komponenten als WSFC Cluster-Ressourcen zu registrieren. Verwandte Ressourcen werden in eine Ressource Group zusammengefasst, die in Abhängigkeit zu anderen WSFC Cluster-Ressourcen gebracht werden kann. Der WSFC Cluster Service kann jetzt die Notwendigkeit zum Neustart der SQL Server Instanz erfassen oder einen automatischen Failover zu einem anderen Server-Knoten im WSFC Cluster auslösen.   Failover Cluster Instances (FCI) Eine SQL Server Failover Cluster Instanz (FCI) ist eine einzelne SQL Server Instanz, die in einem Failover Cluster betrieben wird, der aus mehreren Windows Server Failover Clustering (WSFC) Knoten besteht und so HA (High Availability) auf Ebene der Instanz bietet. Unter Verwendung von Multi-Subnet FCI kann auch Remote DR (Disaster Recovery) unterstützt werden. Eine weitere Option für Remote DR besteht darin, eine unter FCI gehostete Datenbank in einer Availability Group zu betreiben. Hierzu später mehr. FCI und WSFC Basis FCI, das für lokale Hochverfügbarkeit der Instanzen genutzt wird, ähnelt der veralteten Architektur eines kalten Cluster (Aktiv-Passiv). Unter SQL Server 2008 wurde diese Technologie SQL Server 2008 Failover Clustering genannt. Sie nutzte den Windows Server Failover Cluster. In SQL Server 2012 hat Microsoft diese Basistechnologie unter der Bezeichnung AlwaysOn zusammengefasst. Es handelt sich aber nach wie vor um die klassische Aktiv-Passiv-Konfiguration. Der Ablauf im Failover-Fall ist wie folgt: Solange kein Hardware-oder System-Fehler auftritt, werden alle Dirty Pages im Buffer Cache auf Platte geschrieben Alle entsprechenden SQL Server Services (Dienste) in der Ressource Gruppe werden auf dem aktiven Knoten gestoppt Die Ownership der Ressource Gruppe wird auf einen anderen Knoten der FCI transferriert Der neue Owner (Besitzer) der Ressource Gruppe startet seine SQL Server Services (Dienste) Die Connection-Anforderungen einer Client-Applikation werden automatisch auf den neuen aktiven Knoten mit dem selben Virtuellen Network Namen (VNN) umgeleitet Abhängig vom Zeitpunkt des letzten Checkpoints, kann die Anzahl der Dirty Pages im Buffer Cache, die noch auf Platte geschrieben werden müssen, zu unvorhersehbar langen Failover-Zeiten führen. Um diese Anzahl zu drosseln, besitzt der SQL Server 2012 eine neue Fähigkeit, die Indirect Checkpoints genannt wird. Indirect Checkpoints ähnelt dem Fast-Start MTTR Target Feature der Oracle Datenbank, das bereits mit Oracle9i verfügbar war.   SQL Server Multi-Subnet Clustering Ein SQL Server Multi-Subnet Failover Cluster entspricht vom Konzept her einem Oracle RAC Stretch Cluster. Doch dies ist nur auf den ersten Blick der Fall. Im Gegensatz zu RAC ist in einem lokalen SQL Server Failover Cluster jeweils nur ein Knoten aktiv für eine Datenbank. Für die Datenreplikation zwischen geografisch entfernten Sites verlässt sich Microsoft auf 3rd Party Lösungen für das Storage Mirroring.     Die Verbesserung dieses Szenario mit einer SQL Server 2012 Implementierung besteht schlicht darin, dass eine VLAN-Konfiguration (Virtual Local Area Network) nun nicht mehr benötigt wird, so wie dies bisher der Fall war. Das folgende Diagramm stellt dar, wie der Ablauf mit SQL Server 2012 gehandhabt wird. In Site A und Site B wird HA jeweils durch einen lokalen Aktiv-Passiv-Cluster sichergestellt.     Besondere Aufmerksamkeit muss hier der Konfiguration und dem Tuning geschenkt werden, da ansonsten völlig inakzeptable Failover-Zeiten resultieren. Dies liegt darin begründet, weil die Downtime auf Client-Seite nun nicht mehr nur von der reinen Failover-Zeit abhängt, sondern zusätzlich von der Dauer der DNS Replikation zwischen den DNS Servern. (Rufen Sie sich in Erinnerung, dass wir gerade von Multi-Subnet Clustering sprechen). Außerdem ist zu berücksichtigen, wie schnell die Clients die aktualisierten DNS Informationen abfragen. Spezielle Konfigurationen für Node Heartbeat, HostRecordTTL (Host Record Time-to-Live) und Intersite Replication Frequeny für Active Directory Sites und Services werden notwendig. Default TTL für Windows Server 2008 R2: 20 Minuten Empfohlene Einstellung: 1 Minute DNS Update Replication Frequency in Windows Umgebung: 180 Minuten Empfohlene Einstellung: 15 Minuten (minimaler Wert)   Betrachtet man diese Werte, muss man feststellen, dass selbst eine optimale Konfiguration die rigiden SLAs (Service Level Agreements) heutiger geschäftskritischer Anwendungen für HA und DR nicht erfüllen kann. Denn dies impliziert eine auf der Client-Seite erlebte Failover-Zeit von insgesamt 16 Minuten. Hierzu ein Auszug aus der SQL Server 2012 Online Dokumentation: Cons: If a cross-subnet failover occurs, the client recovery time could be 15 minutes or longer, depending on your HostRecordTTL setting and the setting of your cross-site DNS/AD replication schedule.    Wir sind hier an einem Punkt unserer Überlegungen angelangt, an dem sich erklärt, weshalb ich zuvor das "Windows was the God ..." Zitat verwendet habe. Die unbedingte Abhängigkeit zu Windows wird zunehmend zum Problem, da sie die Komplexität einer Microsoft-basierenden Lösung erhöht, anstelle sie zu reduzieren. Und Komplexität ist das Letzte, was sich CIOs heutzutage wünschen.  Zur Ehrenrettung des SQL Server 2012 und AlwaysOn muss man sagen, dass derart lange Failover-Zeiten kein unbedingtes "Muss" darstellen, sondern ein "Kann". Doch auch ein "Kann" kann im unpassenden Moment unvorhersehbare und kostspielige Folgen haben. Die Unabsehbarkeit ist wiederum Ursache vieler an der Implementierung beteiligten Komponenten und deren Abhängigkeiten, wie beispielsweise drei Cluster-Lösungen (zwei von Microsoft, eine 3rd Party Lösung). Wie man die Sache auch dreht und wendet, kommt man an diesem Fakt also nicht vorbei - ganz unabhängig von der Dauer einer Downtime oder Failover-Zeiten. Im Gegensatz zu AlwaysOn und der hier vorgestellten Version eines Stretch-Clusters, vermeidet eine entsprechende Oracle Implementierung eine derartige Komplexität, hervorgerufen duch multiple Abhängigkeiten. Den Unterschied machen Datenbank-integrierte Mechanismen, wie Fast Application Notification (FAN) und Fast Connection Failover (FCF). Für Oracle MAA Konfigurationen (Maximum Availability Architecture) sind Inter-Site Failover-Zeiten im Bereich von Sekunden keine Seltenheit. Wenn Sie dem Link zur Oracle MAA folgen, finden Sie außerdem eine Reihe an Customer Case Studies. Auch dies ist ein wichtiges Unterscheidungsmerkmal zu AlwaysOn, denn die Oracle Technologie hat sich bereits zigfach in höchst kritischen Umgebungen bewährt.   Availability Groups (Verfügbarkeitsgruppen) Die sogenannten Availability Groups (Verfügbarkeitsgruppen) sind - neben FCI - der weitere Baustein von AlwaysOn.   Hinweis: Bevor wir uns näher damit beschäftigen, sollten Sie sich noch einmal ins Gedächtnis rufen, dass eine SQL Server Datenbank nicht die gleiche Bedeutung besitzt, wie eine Oracle Datenbank, sondern eher einem Oracle Schema entspricht. So etwas wie die SQL Server Northwind Datenbank ist vergleichbar mit dem Oracle Scott Schema.   Eine Verfügbarkeitsgruppe setzt sich zusammen aus einem Set mehrerer Benutzer-Datenbanken, die im Falle eines Failover gemeinsam als Gruppe behandelt werden. Eine Verfügbarkeitsgruppe unterstützt ein Set an primären Datenbanken (primäres Replikat) und einem bis vier Sets von entsprechenden sekundären Datenbanken (sekundäre Replikate).       Es können jedoch nicht alle SQL Server Datenbanken einer AlwaysOn Verfügbarkeitsgruppe zugeordnet werden. Der SQL Server Spezialist Michael Otey zählt in seinem SQL Server Pro Artikel folgende Anforderungen auf: Verfügbarkeitsgruppen müssen mit Benutzer-Datenbanken erstellt werden. System-Datenbanken können nicht verwendet werden Die Datenbanken müssen sich im Read-Write Modus befinden. Read-Only Datenbanken werden nicht unterstützt Die Datenbanken in einer Verfügbarkeitsgruppe müssen Multiuser Datenbanken sein Sie dürfen nicht das AUTO_CLOSE Feature verwenden Sie müssen das Full Recovery Modell nutzen und es muss ein vollständiges Backup vorhanden sein Eine gegebene Datenbank kann sich nur in einer einzigen Verfügbarkeitsgruppe befinden und diese Datenbank düerfen nicht für Database Mirroring konfiguriert sein Microsoft empfiehl außerdem, dass der Verzeichnispfad einer Datenbank auf dem primären und sekundären Server identisch sein sollte Wie man sieht, eignen sich Verfügbarkeitsgruppen nicht, um HA und DR vollständig abzubilden. Die Unterscheidung zwischen der Instanzen-Ebene (FCI) und Datenbank-Ebene (Availability Groups) ist von hoher Bedeutung. Vor kurzem wurde mir gesagt, dass man mit den Verfügbarkeitsgruppen auf Shared Storage verzichten könne und dadurch Kosten spart. So weit so gut ... Man kann natürlich eine Installation rein mit Verfügbarkeitsgruppen und ohne FCI durchführen - aber man sollte sich dann darüber bewusst sein, was man dadurch alles nicht abgesichert hat - und dies wiederum für Desaster Recovery (DR) und SLAs (Service Level Agreements) bedeutet. Kurzum, um die Kombination aus beiden AlwaysOn Produkten und der damit verbundene Komplexität kommt man wohl in der Praxis nicht herum.    Availability Groups und WSFC AlwaysOn hängt von Windows Server Failover Clustering (WSFC) ab, um die aktuellen Rollen der Verfügbarkeitsreplikate einer Verfügbarkeitsgruppe zu überwachen und zu verwalten, und darüber zu entscheiden, wie ein Failover-Ereignis die Verfügbarkeitsreplikate betrifft. Das folgende Diagramm zeigt de Beziehung zwischen Verfügbarkeitsgruppen und WSFC:   Der Verfügbarkeitsmodus ist eine Eigenschaft jedes Verfügbarkeitsreplikats. Synychron und Asynchron können also gemischt werden: Availability Modus (Verfügbarkeitsmodus) Asynchroner Commit-Modus Primäres replikat schließt Transaktionen ohne Warten auf Sekundäres Synchroner Commit-Modus Primäres Replikat wartet auf Commit von sekundärem Replikat Failover Typen Automatic Manual Forced (mit möglichem Datenverlust) Synchroner Commit-Modus Geplanter, manueller Failover ohne Datenverlust Automatischer Failover ohne Datenverlust Asynchroner Commit-Modus Nur Forced, manueller Failover mit möglichem Datenverlust   Der SQL Server kennt keinen separaten Switchover Begriff wie in Oracle Data Guard. Für SQL Server werden alle Role Transitions als Failover bezeichnet. Tatsächlich unterstützt der SQL Server keinen Switchover für asynchrone Verbindungen. Es gibt nur die Form des Forced Failover mit möglichem Datenverlust. Eine ähnliche Fähigkeit wie der Switchover unter Oracle Data Guard ist so nicht gegeben.   SQL Sever FCI mit Availability Groups (Verfügbarkeitsgruppen) Neben den Verfügbarkeitsgruppen kann eine zweite Failover-Ebene eingerichtet werden, indem SQL Server FCI (auf Shared Storage) mit WSFC implementiert wird. Ein Verfügbarkeitesreplikat kann dann auf einer Standalone Instanz gehostet werden, oder einer FCI Instanz. Zum Verständnis: Die Verfügbarkeitsgruppen selbst benötigen kein Shared Storage. Diese Kombination kann verwendet werden für lokale HA auf Ebene der Instanz und DR auf Datenbank-Ebene durch Verfügbarkeitsgruppen. Das folgende Diagramm zeigt dieses Szenario:   Achtung! Hier handelt es sich nicht um ein Pendant zu Oracle RAC plus Data Guard, auch wenn das Bild diesen Eindruck vielleicht vermitteln mag - denn alle sekundären Knoten im FCI sind rein passiv. Es existiert außerdem eine weitere und ernsthafte Einschränkung: SQL Server Failover Cluster Instanzen (FCI) unterstützen nicht das automatische AlwaysOn Failover für Verfügbarkeitsgruppen. Jedes unter FCI gehostete Verfügbarkeitsreplikat kann nur für manuelles Failover konfiguriert werden.   Lesbare Sekundäre Replikate Ein oder mehrere Verfügbarkeitsreplikate in einer Verfügbarkeitsgruppe können für den lesenden Zugriff konfiguriert werden, wenn sie als sekundäres Replikat laufen. Dies ähnelt Oracle Active Data Guard, jedoch gibt es Einschränkungen. Alle Abfragen gegen die sekundäre Datenbank werden automatisch auf das Snapshot Isolation Level abgebildet. Es handelt sich dabei um eine Versionierung der Rows. Microsoft versuchte hiermit die Oracle MVRC (Multi Version Read Consistency) nachzustellen. Tatsächlich muss man die SQL Server Snapshot Isolation eher mit Oracle Flashback vergleichen. Bei der Implementierung des Snapshot Isolation Levels handelt sich um ein nachträglich aufgesetztes Feature und nicht um einen inhärenten Teil des Datenbank-Kernels, wie im Falle Oracle. (Ich werde hierzu in Kürze einen weiteren Blogbeitrag verfassen, wenn ich mich mit der neuen SQL Server 2012 Core Lizenzierung beschäftige.) Für die Praxis entstehen aus der Abbildung auf das Snapshot Isolation Level ernsthafte Restriktionen, derer man sich für den Betrieb in der Praxis bereits vorab bewusst sein sollte: Sollte auf der primären Datenbank eine aktive Transaktion zu dem Zeitpunkt existieren, wenn ein lesbares sekundäres Replikat in die Verfügbarkeitsgruppe aufgenommen wird, werden die Row-Versionen auf der korrespondierenden sekundären Datenbank nicht sofort vollständig verfügbar sein. Eine aktive Transaktion auf dem primären Replikat muss zuerst abgeschlossen (Commit oder Rollback) und dieser Transaktions-Record auf dem sekundären Replikat verarbeitet werden. Bis dahin ist das Isolation Level Mapping auf der sekundären Datenbank unvollständig und Abfragen sind temporär geblockt. Microsoft sagt dazu: "This is needed to guarantee that row versions are available on the secondary replica before executing the query under snapshot isolation as all isolation levels are implicitly mapped to snapshot isolation." (SQL Storage Engine Blog: AlwaysOn: I just enabled Readable Secondary but my query is blocked?)  Grundlegend bedeutet dies, dass ein aktives lesbares Replikat nicht in die Verfügbarkeitsgruppe aufgenommen werden kann, ohne das primäre Replikat vorübergehend stillzulegen. Da Leseoperationen auf das Snapshot Isolation Transaction Level abgebildet werden, kann die Bereinigung von Ghost Records auf dem primären Replikat durch Transaktionen auf einem oder mehreren sekundären Replikaten geblockt werden - z.B. durch eine lang laufende Abfrage auf dem sekundären Replikat. Diese Bereinigung wird auch blockiert, wenn die Verbindung zum sekundären Replikat abbricht oder der Datenaustausch unterbrochen wird. Auch die Log Truncation wird in diesem Zustant verhindert. Wenn dieser Zustand längere Zeit anhält, empfiehlt Microsoft das sekundäre Replikat aus der Verfügbarkeitsgruppe herauszunehmen - was ein ernsthaftes Downtime-Problem darstellt. Die Read-Only Workload auf den sekundären Replikaten kann eingehende DDL Änderungen blockieren. Obwohl die Leseoperationen aufgrund der Row-Versionierung keine Shared Locks halten, führen diese Operatioen zu Sch-S Locks (Schemastabilitätssperren). DDL-Änderungen durch Redo-Operationen können dadurch blockiert werden. Falls DDL aufgrund konkurrierender Lese-Workload blockiert wird und der Schwellenwert für 'Recovery Interval' (eine SQL Server Konfigurationsoption) überschritten wird, generiert der SQL Server das Ereignis sqlserver.lock_redo_blocked, welches Microsoft zum Kill der blockierenden Leser empfiehlt. Auf die Verfügbarkeit der Anwendung wird hierbei keinerlei Rücksicht genommen.   Keine dieser Einschränkungen existiert mit Oracle Active Data Guard.   Backups auf sekundären Replikaten  Über die sekundären Replikate können Backups (BACKUP DATABASE via Transact-SQL) nur als copy-only Backups einer vollständigen Datenbank, Dateien und Dateigruppen erstellt werden. Das Erstellen inkrementeller Backups ist nicht unterstützt, was ein ernsthafter Rückstand ist gegenüber der Backup-Unterstützung physikalischer Standbys unter Oracle Data Guard. Hinweis: Ein möglicher Workaround via Snapshots, bleibt ein Workaround. Eine weitere Einschränkung dieses Features gegenüber Oracle Data Guard besteht darin, dass das Backup eines sekundären Replikats nicht ausgeführt werden kann, wenn es nicht mit dem primären Replikat kommunizieren kann. Darüber hinaus muss das sekundäre Replikat synchronisiert sein oder sich in der Synchronisation befinden, um das Beackup auf dem sekundären Replikat erstellen zu können.   Vergleich von Microsoft AlwaysOn mit der Oracle MAA Ich komme wieder zurück auf die Eingangs erwähnte, mehrfach an mich gestellte Frage "Wann denn - und ob überhaupt - Oracle etwas Vergleichbares wie AlwaysOn bieten würde?" und meine damit verbundene (kurze) Irritation. Wenn Sie diesen Blogbeitrag bis hierher gelesen haben, dann kennen Sie jetzt meine darauf gegebene Antwort. Der eine oder andere Punkt traf dabei nicht immer auf Jeden zu, was auch nicht der tiefere Sinn und Zweck meiner Antwort war. Wenn beispielsweise kein Multi-Subnet mit im Spiel ist, sind alle diesbezüglichen Kritikpunkte zunächst obsolet. Was aber nicht bedeutet, dass sie nicht bereits morgen schon wieder zum Thema werden könnten (Sag niemals "Nie"). In manch anderes Fettnäpfchen tritt man wiederum nicht unbedingt in einer Testumgebung, sondern erst im laufenden Betrieb. Erst recht nicht dann, wenn man sich potenzieller Probleme nicht bewusst ist und keine dedizierten Tests startet. Und wer AlwaysOn erfolgreich positionieren möchte, wird auch gar kein Interesse daran haben, auf mögliche Schwachstellen und den besagten Teufel im Detail aufmerksam zu machen. Das ist keine Unterstellung - es ist nur menschlich. Außerdem ist es verständlich, dass man sich in erster Linie darauf konzentriert "was geht" und "was gut läuft", anstelle auf das "was zu Problemen führen kann" oder "nicht funktioniert". Wer will schon der Miesepeter sein? Für mich selbst gesprochen, kann ich nur sagen, dass ich lieber vorab von allen möglichen Einschränkungen wissen möchte, anstelle sie dann nach einer kurzen Zeit der heilen Welt schmerzhaft am eigenen Leib erfahren zu müssen. Ich bin davon überzeugt, dass es Ihnen nicht anders geht. Nachfolgend deshalb eine Zusammenfassung all jener Punkte, die ich im Vergleich zur Oracle MAA (Maximum Availability Architecture) als unbedingt Erwähnenswert betrachte, falls man eine Evaluierung von Microsoft AlwaysOn in Betracht zieht. 1. AlwaysOn ist eine komplexe Technologie Der SQL Server AlwaysOn Stack ist zusammengesetzt aus drei verschiedenen Technlogien: Windows Server Failover Clustering (WSFC) SQL Server Failover Cluster Instances (FCI) SQL Server Availability Groups (Verfügbarkeitsgruppen) Man kann eine derartige Lösung nicht als nahtlos bezeichnen, wofür auch die vielen von Microsoft dargestellten Einschränkungen sprechen. Während sich frühere SQL Server Versionen in Richtung eigener HA/DR Technologien entwickelten (wie Database Mirroring), empfiehlt Microsoft nun die Migration. Doch weshalb dieser Schwenk? Er führt nicht zu einem konsisten und robusten Angebot an HA/DR Technologie für geschäftskritische Umgebungen.  Liegt die Antwort in meiner These begründet, nach der "Windows was the God ..." noch immer gilt und man die Nachteile der allzu engen Kopplung mit Windows nicht sehen möchte? Entscheiden Sie selbst ... 2. Failover Cluster Instanzen - Kein RAC-Pendant Die SQL Server und Windows Server Clustering Technologie basiert noch immer auf dem veralteten Aktiv-Passiv Modell und führt zu einer Verschwendung von Systemressourcen. In einer Betrachtung von lediglich zwei Knoten erschließt sich auf Anhieb noch nicht der volle Mehrwert eines Aktiv-Aktiv Clusters (wie den Real Application Clusters), wie er von Oracle bereits vor zehn Jahren entwickelt wurde. Doch kennt man die Vorzüge der Skalierbarkeit durch einfaches Hinzufügen weiterer Cluster-Knoten, die dann alle gemeinsam als ein einziges logisches System zusammenarbeiten, versteht man was hinter dem Motto "Pay-as-you-Grow" steckt. In einem Aktiv-Aktiv Cluster geht es zwar auch um Hochverfügbarkeit - und ein Failover erfolgt zudem schneller, als in einem Aktiv-Passiv Modell - aber es geht eben nicht nur darum. An dieser Stelle sei darauf hingewiesen, dass die Oracle 11g Standard Edition bereits die Nutzung von Oracle RAC bis zu vier Sockets kostenfrei beinhaltet. Möchten Sie dazu Windows nutzen, benötigen Sie keine Windows Server Enterprise Edition, da Oracle 11g die eigene Clusterware liefert. Sie kommen in den Genuss von Hochverfügbarkeit und Skalierbarkeit und können dazu die günstigere Windows Server Standard Edition nutzen. 3. SQL Server Multi-Subnet Clustering - Abhängigkeit zu 3rd Party Storage Mirroring  Die SQL Server Multi-Subnet Clustering Architektur unterstützt den Aufbau eines Stretch Clusters, basiert dabei aber auf dem Aktiv-Passiv Modell. Das eigentlich Problematische ist jedoch, dass man sich zur Absicherung der Datenbank auf 3rd Party Storage Mirroring Technologie verlässt, ohne Integration zwischen dem Windows Server Failover Clustering (WSFC) und der darunterliegenden Mirroring Technologie. Wenn nun im Cluster ein Failover auf Instanzen-Ebene erfolgt, existiert keine Koordination mit einem möglichen Failover auf Ebene des Storage-Array. 4. Availability Groups (Verfügbarkeitsgruppen) - Vier, oder doch nur Zwei? Ein primäres Replikat erlaubt bis zu vier sekundäre Replikate innerhalb einer Verfügbarkeitsgruppe, jedoch nur zwei im Synchronen Commit Modus. Während dies zwar einen Vorteil gegenüber dem stringenten 1:1 Modell unter Database Mirroring darstellt, fällt der SQL Server 2012 damit immer noch weiter zurück hinter Oracle Data Guard mit bis zu 30 direkten Stanbdy Zielen - und vielen weiteren durch kaskadierende Ziele möglichen. Damit eignet sich Oracle Active Data Guard auch für die Bereitstellung einer Reader-Farm Skalierbarkeit für Internet-basierende Unternehmen. Mit AwaysOn Verfügbarkeitsgruppen ist dies nicht möglich. 5. Availability Groups (Verfügbarkeitsgruppen) - kein asynchrones Switchover  Die Technologie der Verfügbarkeitsgruppen wird auch als geeignetes Mittel für administrative Aufgaben positioniert - wie Upgrades oder Wartungsarbeiten. Man muss sich jedoch einem gravierendem Defizit bewusst sein: Im asynchronen Verfügbarkeitsmodus besteht die einzige Möglichkeit für Role Transition im Forced Failover mit Datenverlust! Um den Verlust von Daten durch geplante Wartungsarbeiten zu vermeiden, muss man den synchronen Verfügbarkeitsmodus konfigurieren, was jedoch ernstzunehmende Auswirkungen auf WAN Deployments nach sich zieht. Spinnt man diesen Gedanken zu Ende, kommt man zu dem Schluss, dass die Technologie der Verfügbarkeitsgruppen für geplante Wartungsarbeiten in einem derartigen Umfeld nicht effektiv genutzt werden kann. 6. Automatisches Failover - Nicht immer möglich Sowohl die SQL Server FCI, als auch Verfügbarkeitsgruppen unterstützen automatisches Failover. Möchte man diese jedoch kombinieren, wird das Ergebnis kein automatisches Failover sein. Denn ihr Zusammentreffen im Failover-Fall führt zu Race Conditions (Wettlaufsituationen), weshalb diese Konfiguration nicht länger das automatische Failover zu einem Replikat in einer Verfügbarkeitsgruppe erlaubt. Auch hier bestätigt sich wieder die tiefere Problematik von AlwaysOn, mit einer Zusammensetzung aus unterschiedlichen Technologien und der Abhängigkeit zu Windows. 7. Problematische RTO (Recovery Time Objective) Microsoft postioniert die SQL Server Multi-Subnet Clustering Architektur als brauchbare HA/DR Architektur. Bedenkt man jedoch die Problematik im Zusammenhang mit DNS Replikation und den möglichen langen Wartezeiten auf Client-Seite von bis zu 16 Minuten, sind strenge RTO Anforderungen (Recovery Time Objectives) nicht erfüllbar. Im Gegensatz zu Oracle besitzt der SQL Server keine Datenbank-integrierten Technologien, wie Oracle Fast Application Notification (FAN) oder Oracle Fast Connection Failover (FCF). 8. Problematische RPO (Recovery Point Objective) SQL Server ermöglicht Forced Failover (erzwungenes Failover), bietet jedoch keine Möglichkeit zur automatischen Übertragung der letzten Datenbits von einem alten zu einem neuen primären Replikat, wenn der Verfügbarkeitsmodus asynchron war. Oracle Data Guard hingegen bietet diese Unterstützung durch das Flush Redo Feature. Dies sichert "Zero Data Loss" und beste RPO auch in erzwungenen Failover-Situationen. 9. Lesbare Sekundäre Replikate mit Einschränkungen Aufgrund des Snapshot Isolation Transaction Level für lesbare sekundäre Replikate, besitzen diese Einschränkungen mit Auswirkung auf die primäre Datenbank. Die Bereinigung von Ghost Records auf der primären Datenbank, wird beeinflusst von lang laufenden Abfragen auf der lesabaren sekundären Datenbank. Die lesbare sekundäre Datenbank kann nicht in die Verfügbarkeitsgruppe aufgenommen werden, wenn es aktive Transaktionen auf der primären Datenbank gibt. Zusätzlich können DLL Änderungen auf der primären Datenbank durch Abfragen auf der sekundären blockiert werden. Und imkrementelle Backups werden hier nicht unterstützt.   Keine dieser Restriktionen existiert unter Oracle Data Guard.

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  • value types in the vm

    - by john.rose
    value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases.  Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both.  We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types.  These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im,         /*Complex y:*/ double y_re, double y_im) {     /*Complex z = x.minus(y):*/     double z_re = x_re - y_re, z_im = x_im - y_im;     /*return z.abs():*/     return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable {     // immutable component structure:     public final double re, im;     private Complex(double re, double im) {         this.re = re; this.im = im;     }     // interoperability methods:     public String toString() { return "Complex("+re+","+im+")"; }     public List<Double> asList() { return Arrays.asList(re, im); }     public boolean equals(Complex c) {         return re == c.re && im == c.im;     }     public boolean equals(@ValueSafe Object x) {         return x instanceof Complex && equals((Complex) x);     }     public int hashCode() {         return 31*Double.valueOf(re).hashCode()                 + Double.valueOf(im).hashCode();     }     // factory methods:     public static Complex valueOf(double re, double im) {         return new Complex(re, im);     }     public Complex changeRe(double re2) { return valueOf(re2, im); }     public Complex changeIm(double im2) { return valueOf(re, im2); }     public static Complex cast(@ValueSafe Object x) {         return x == null ? ZERO : (Complex) x;     }     // utility methods and constants:     public Complex plus(Complex c)  { return new Complex(re+c.re, im+c.im); }     public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); }     public double abs() { return Math.sqrt(re*re + im*im); }     public static final Complex PI = valueOf(Math.PI, 0.0);     public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts.  The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final.  (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations.  A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations.  No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type.  If a value-safe class is marked final, it is in fact a value type.  All other value-safe classes must be abstract.  The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex.  Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable {     // All methods listed here must get redefined.     // Definitions must be value-safe, which means     // they may depend on component values only.     List<? extends Object> asList();     int hashCode();     boolean equals(@ValueSafe Object c);     String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system.  It could appear as an element type or parameter bound, for facilities which are designed to work on value types only.  More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods.  (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.)  Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation.  In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation.  Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0);  //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe")   Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object();  // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi);  // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi);  // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi);  // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero);  // error: reference comparison on value type boolean z2 = (pi == null);  // error: reference comparison on value type boolean z3 = (pi == obj2);  // error: reference comparison on value type synchronized (pi) { }  // error: synch of value, unpredictable result synchronized (obj2) { }  // unpredictable result Complex qq = pi; qq = null;  // possible NPE; warning: “null-unsafe" qq = (Complex) obj;  // warning: “null-unsafe" qq = Complex.cast(obj);  // OK @SuppressWarnings("null-unsafe")   Complex empty = null;  // possible NPE qq = empty;  // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations.  Fields and variables of value types can be split into their unboxed components.  Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules?  Why not detect programs automagically and perform unboxing transparently?  The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced.  Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal.  In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur.  This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer.  Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules.  There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme.  Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions.  One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type.  That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances.  Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe.  Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around.  Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed.  This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods.  This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors.  The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type.  Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands.  When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not.  If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible.  Proxies must be managed carefully, and this can be expensive.  On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces.  (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.)  Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems.  They require the deepest transformations, relative to today’s JVM.  There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics.  It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form.  Such value-safe arrays would not be convertible to Object[] arrays.  Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex.  I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code.  On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly.  Likewise, there are rules for providing default access modifiers for interface members.  Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types.  Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType {  // implicitly final     public double re, im;  // implicitly public final     //implicit methods are defined elementwise from te fields:     //  toString, asList, equals(2), hashCode, valueOf, cast     //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner.  The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer.  A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point.  The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage?  Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number.  Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”).  What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple {      double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly.  The supertype is an abstract class which has suitable shared declarations.  The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it.  The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types.  (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language.  (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.)  At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists.  Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection.  That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types.  Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API.  The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components  that appear as parameters, return types, and array elements.  This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations.  A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile.  Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type.  It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack.  If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction?  Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot.  But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes.  I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value.  Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType {     protected final long header;     protected private final BigInteger digits;     public DecimalValue valueOf(int value, int scale) {         assert(scale >= 0);         return new DecimalValue(((long)value << 32) + scale, null);     }     public DecimalValue valueOf(long value, int scale) {         if (value == (int) value)             return valueOf((int)value, scale);         return new DecimalValue(-scale, new BigInteger(value));     } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case.  It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues.  (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.)  Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits.  For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types.  This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant.  An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes.  More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable,         Unsynchronizable, Interchangeable { … public class Complex implements ValueType {     // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe     … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types.  This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable.  It is likely that code which violates value-safety for wrapper types exists but is uncommon.  It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code.  The design presented above obscures that distinction.  As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations.  Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed.  For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi;  // convert to boxed myList.add(boxPi); complex z = myList.get(0);  // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM.  Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type.  Something like this which can also accommodate value type components seems worthwhile.  On the other hand, does it make sense for value types to contain short arrays?  And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure.  These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types.  In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids.  No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now.  Back to work!

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  • The Template Method Design Pattern using C# .Net

    - by nijhawan.saurabh
    First of all I'll just put this pattern in context and describe its intent as in the GOF book:   Template Method: Define the skeleton of an algorithm in an operation, deferring some steps to Subclasses. Template Method lets subclasses redefine certain steps of an algorithm without changing the Algorithm's Structure.    Usage: When you are certain about the High Level steps involved in an Algorithm/Work flow you can use the Template Pattern which allows the Base Class to define the Sequence of the Steps but permits the Sub classes to alter the implementation of any/all steps.   Example in the .Net framework: The most common example is the Asp.Net Page Life Cycle. The Page Life Cycle has a few methods which are called in a sequence but we have the liberty to modify the functionality of any of the methods by overriding them.   Sample implementation of Template Method Pattern:   Let's see the class diagram first:            Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0in; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-font-kerning:1.0pt; mso-ligatures:standard;}   And here goes the code:EmailBase.cs     1 using System;     2 using System.Collections.Generic;     3 using System.Linq;     4 using System.Text;     5 using System.Threading.Tasks;     6      7 namespace TemplateMethod     8 {     9     public abstract class EmailBase    10     {    11     12         public bool SendEmail()    13         {    14             if (CheckEmailAddress() == true) // Method1 in the sequence    15             {    16                 if (ValidateMessage() == true) // Method2 in the sequence    17                 {    18                     if (SendMail() == true) // Method3 in the sequence    19                     {    20                         return true;    21                     }    22                     else    23                     {    24                         return false;    25                     }    26     27                 }    28                 else    29                 {    30                     return false;    31                 }    32     33             }    34             else    35             {    36                 return false;    37     38             }    39     40     41         }    42     43         protected abstract bool CheckEmailAddress();    44         protected abstract bool ValidateMessage();    45         protected abstract bool SendMail();    46     47     48     }    49 }    50    EmailYahoo.cs      1 using System;     2 using System.Collections.Generic;     3 using System.Linq;     4 using System.Text;     5 using System.Threading.Tasks;     6      7 namespace TemplateMethod     8 {     9     public class EmailYahoo:EmailBase    10     {    11     12         protected override bool CheckEmailAddress()    13         {    14             Console.WriteLine("Checking Email Address : YahooEmail");    15             return true;    16         }    17         protected override bool ValidateMessage()    18         {    19             Console.WriteLine("Validating Email Message : YahooEmail");    20             return true;    21         }    22     23     24         protected override bool SendMail()    25         {    26             Console.WriteLine("Semding Email : YahooEmail");    27             return true;    28         }    29     30     31     }    32 }    33   EmailGoogle.cs      1 using System;     2 using System.Collections.Generic;     3 using System.Linq;     4 using System.Text;     5 using System.Threading.Tasks;     6      7 namespace TemplateMethod     8 {     9     public class EmailGoogle:EmailBase    10     {    11     12         protected override bool CheckEmailAddress()    13         {    14             Console.WriteLine("Checking Email Address : GoogleEmail");    15             return true;    16         }    17         protected override bool ValidateMessage()    18         {    19             Console.WriteLine("Validating Email Message : GoogleEmail");    20             return true;    21         }    22     23     24         protected override bool SendMail()    25         {    26             Console.WriteLine("Semding Email : GoogleEmail");    27             return true;    28         }    29     30     31     }    32 }    33   Program.cs      1 using System;     2 using System.Collections.Generic;     3 using System.Linq;     4 using System.Text;     5 using System.Threading.Tasks;     6      7 namespace TemplateMethod     8 {     9     class Program    10     {    11         static void Main(string[] args)    12         {    13             Console.WriteLine("Please choose an Email Account to send an Email:");    14             Console.WriteLine("Choose 1 for Google");    15             Console.WriteLine("Choose 2 for Yahoo");    16             string choice = Console.ReadLine();    17     18             if (choice == "1")    19             {    20                 EmailBase email = new EmailGoogle(); // Rather than newing it up here, you may use a factory to do so.    21                 email.SendEmail();    22     23             }    24             if (choice == "2")    25             {    26                 EmailBase email = new EmailYahoo(); // Rather than newing it up here, you may use a factory to do so.    27                 email.SendEmail();    28             }    29         }    30     }    31 }    32    Final Words: It's very obvious that why the Template Method Pattern is a popular pattern, everything at last revolves around Algorithms and if you are clear with the steps involved it makes real sense to delegate the duty of implementing the step's functionality to the sub classes. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0in; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-font-kerning:1.0pt; mso-ligatures:standard;}

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  • PC hangs and reboots from time to time

    - by Bevor
    Hello, I have a very strange problem: Since I have my new PC, I have always had problems with it. From time to time the computer freezes for some seconds and suddendly reboots by itself. I've had this problem since Ubuntu 9.10. The same with 10.04 and 10.10. That's why I don't think it's a software failure because the problem persist too long. It doesn't have anything to do with what I'm doing at this time. Sometimes I listen to music, sometimes I only use Firefox, sometimes I'm running 2 or 3 VMs, sometimes I watch DVD. So it's not isolatable. I could freeze once a day or once a week. I put the PC to the vendor twice(!). The first time they changed my power supply but the problem persisted. The second time they told me that they made some heavy performance tests 50 hours long but they didn't find anything. (How can that be that I have daily freezes with normal usage). The vendor didn't check the hard discs because they used their own disc with Windows. (So they never checked the Linux installation). Yesterday I made some intensive hard disc scans with "SMART" but no errors were found. I ran memtest for 3 times but no errors found. I already had this problem in my old flat, so I doubt that I has something to do with current fluctuation. I already tried another electrical socket and changed to connector strip but the problem persists. At the moment I removed 2 of the RAMs (2x 2GB). In all I have 6GB, 2x2GB and 2x1GB. Could this difference maybe be a problem? Here is a list of my components. I hope that anybody find something I didn't think about yet. And here a list of my components: 1x AMD Phenom II X4 965 Black Edition, 3,4Ghz, Quad Core, S-AM3, Boxed 2x DDR3-RAM 2048MB, PC3-1333 Mhz, CL9, Kingston ValueRAM 2x DDR3-RAM 1024MB, PC3-1333 Mhz, CL9, Kingston ValueRAM 2x SATA II Seagate Barracuda 7200.12, 1TB 32MB Cache = RAID 1 1x DVD ROM SATA LG DH16NSR, 16x/52x 1x DVD-+R/-+RW SATA LG GH-22NS50 1x Cardreader 18in1 1x PCI-E 2.0 GeForce GTS 250, Retail, 1024MB 1x Power Supply ATX 400 Watt, CHIEFTEC APS-400S, 80 Plus 1x Network card PCI Intel PRO/1000GT 10/100/1000 MBit 1x Mainboard Socket-AM3 ASUS M4A79XTD EVO, ATX lshw: description: Desktop Computer product: System Product Name vendor: System manufacturer version: System Version serial: System Serial Number width: 64 bits capabilities: smbios-2.5 dmi-2.5 vsyscall64 vsyscall32 configuration: boot=normal chassis=desktop uuid=80E4001E-8C00-002C-AA59-E0CB4EBAC29A *-core description: Motherboard product: M4A79XTD EVO vendor: ASUSTeK Computer INC. physical id: 0 version: Rev X.0X serial: MT709CK11101196 slot: To Be Filled By O.E.M. *-firmware description: BIOS vendor: American Megatrends Inc. physical id: 0 version: 0704 (11/25/2009) size: 64KiB capacity: 960KiB capabilities: isa pci pnp apm upgrade shadowing escd cdboot bootselect socketedrom edd int13floppy1200 int13floppy720 int13floppy2880 int5printscreen int9keyboard int14serial int17printer int10video acpi usb ls120boot zipboot biosbootspecification *-cpu description: CPU product: AMD Phenom(tm) II X4 965 Processor vendor: Advanced Micro Devices [AMD] physical id: 4 bus info: cpu@0 version: AMD Phenom(tm) II X4 965 Processor serial: To Be Filled By O.E.M. slot: AM3 size: 800MHz capacity: 3400MHz width: 64 bits clock: 200MHz capabilities: fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp x86-64 3dnowext 3dnow constant_tsc rep_good nonstop_tsc extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt npt lbrv svm_lock nrip_save cpufreq *-cache:0 description: L1 cache physical id: 5 slot: L1-Cache size: 512KiB capacity: 512KiB capabilities: pipeline-burst internal varies data *-cache:1 description: L2 cache physical id: 6 slot: L2-Cache size: 2MiB capacity: 2MiB capabilities: pipeline-burst internal varies unified *-cache:2 description: L3 cache physical id: 7 slot: L3-Cache size: 6MiB capacity: 6MiB capabilities: pipeline-burst internal varies unified *-memory description: System Memory physical id: 36 slot: System board or motherboard size: 2GiB *-bank:0 description: DIMM Synchronous 1333 MHz (0.8 ns) product: ModulePartNumber00 vendor: Manufacturer00 physical id: 0 serial: SerNum00 slot: DIMM0 size: 1GiB width: 64 bits clock: 1333MHz (0.8ns) *-bank:1 description: DIMM Synchronous 1333 MHz (0.8 ns) product: ModulePartNumber01 vendor: Manufacturer01 physical id: 1 serial: SerNum01 slot: DIMM1 size: 1GiB width: 64 bits clock: 1333MHz (0.8ns) *-bank:2 description: DIMM [empty] product: ModulePartNumber02 vendor: Manufacturer02 physical id: 2 serial: SerNum02 slot: DIMM2 *-bank:3 description: DIMM [empty] product: ModulePartNumber03 vendor: Manufacturer03 physical id: 3 serial: SerNum03 slot: DIMM3 *-pci:0 description: Host bridge product: RD780 Northbridge only dual slot PCI-e_GFX and HT1 K8 part vendor: ATI Technologies Inc physical id: 100 bus info: pci@0000:00:00.0 version: 00 width: 32 bits clock: 66MHz *-pci:0 description: PCI bridge product: RD790 PCI to PCI bridge (external gfx0 port A) vendor: ATI Technologies Inc physical id: 2 bus info: pci@0000:00:02.0 version: 00 width: 32 bits clock: 33MHz capabilities: pci pm pciexpress msi ht normal_decode bus_master cap_list configuration: driver=pcieport resources: irq:40 ioport:a000(size=4096) memory:f8000000-fbbfffff ioport:d0000000(size=268435456) *-display description: VGA compatible controller product: G92 [GeForce GTS 250] vendor: nVidia Corporation physical id: 0 bus info: pci@0000:01:00.0 version: a2 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress vga_controller bus_master cap_list rom configuration: driver=nvidia latency=0 resources: irq:18 memory:fa000000-faffffff memory:d0000000-dfffffff memory:f8000000-f9ffffff ioport:ac00(size=128) memory:fbbe0000-fbbfffff *-pci:1 description: PCI bridge product: RD790 PCI to PCI bridge (PCI express gpp port C) vendor: ATI Technologies Inc physical id: 6 bus info: pci@0000:00:06.0 version: 00 width: 32 bits clock: 33MHz capabilities: pci pm pciexpress msi ht normal_decode bus_master cap_list configuration: driver=pcieport resources: irq:41 ioport:b000(size=4096) memory:fbc00000-fbcfffff ioport:f6f00000(size=1048576) *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:02:00.0 logical name: eth0 version: 03 serial: e0:cb:4e:ba:c2:9a size: 10MB/s capacity: 1GB/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10MB/s resources: irq:45 ioport:b800(size=256) memory:f6fff000-f6ffffff memory:f6ff8000-f6ffbfff memory:fbcf0000-fbcfffff *-pci:2 description: PCI bridge product: RD790 PCI to PCI bridge (PCI express gpp port D) vendor: ATI Technologies Inc physical id: 7 bus info: pci@0000:00:07.0 version: 00 width: 32 bits clock: 33MHz capabilities: pci pm pciexpress msi ht normal_decode bus_master cap_list configuration: driver=pcieport resources: irq:42 ioport:c000(size=4096) memory:fbd00000-fbdfffff *-firewire description: FireWire (IEEE 1394) product: VT6315 Series Firewire Controller vendor: VIA Technologies, Inc. physical id: 0 bus info: pci@0000:03:00.0 version: 00 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress ohci bus_master cap_list configuration: driver=firewire_ohci latency=0 resources: irq:19 memory:fbdff800-fbdfffff ioport:c800(size=256) *-pci:3 description: PCI bridge product: RD790 PCI to PCI bridge (PCI express gpp port E) vendor: ATI Technologies Inc physical id: 9 bus info: pci@0000:00:09.0 version: 00 width: 32 bits clock: 33MHz capabilities: pci pm pciexpress msi ht normal_decode bus_master cap_list configuration: driver=pcieport resources: irq:43 ioport:d000(size=4096) memory:fbe00000-fbefffff *-ide description: IDE interface product: 88SE6121 SATA II Controller vendor: Marvell Technology Group Ltd. physical id: 0 bus info: pci@0000:04:00.0 version: b2 width: 32 bits clock: 33MHz capabilities: ide pm msi pciexpress bus_master cap_list configuration: driver=pata_marvell latency=0 resources: irq:17 ioport:dc00(size=8) ioport:d880(size=4) ioport:d800(size=8) ioport:d480(size=4) ioport:d400(size=16) memory:fbeffc00-fbefffff *-storage description: SATA controller product: SB700/SB800 SATA Controller [IDE mode] vendor: ATI Technologies Inc physical id: 11 bus info: pci@0000:00:11.0 logical name: scsi0 logical name: scsi2 version: 00 width: 32 bits clock: 66MHz capabilities: storage msi ahci_1.0 bus_master cap_list emulated configuration: driver=ahci latency=64 resources: irq:44 ioport:9000(size=8) ioport:8000(size=4) ioport:7000(size=8) ioport:6000(size=4) ioport:5000(size=16) memory:f7fffc00-f7ffffff *-disk:0 description: ATA Disk product: ST31000528AS vendor: Seagate physical id: 0 bus info: scsi@0:0.0.0 logical name: /dev/sda version: CC38 serial: 9VP3WD9Z size: 931GiB (1TB) capabilities: partitioned partitioned:dos configuration: ansiversion=5 signature=000ad206 *-volume:0 UNCLAIMED description: Linux filesystem partition vendor: Linux physical id: 1 bus info: scsi@0:0.0.0,1 version: 1.0 serial: 81839235-21ea-4853-90a4-814779f49000 size: 972MiB capacity: 972MiB capabilities: primary ext2 initialized configuration: filesystem=ext2 modified=2010-12-06 18:32:58 mounted=2010-11-01 07:05:10 state=unknown *-volume:1 UNCLAIMED description: Linux swap volume physical id: 2 bus info: scsi@0:0.0.0,2 version: 1 serial: 22b881d5-6f5c-484d-94e8-e231896fa91b size: 486MiB capacity: 486MiB capabilities: primary nofs swap initialized configuration: filesystem=swap pagesize=4096 *-volume:2 UNCLAIMED description: EXT3 volume vendor: Linux physical id: 3 bus info: scsi@0:0.0.0,3 version: 1.0 serial: ad5b0daf-11e8-4f8f-8598-4e89da9c0d84 size: 47GiB capacity: 47GiB capabilities: primary journaled extended_attributes large_files recover ext3 ext2 initialized configuration: created=2010-02-16 20:42:29 filesystem=ext3 modified=2010-11-29 17:02:34 mounted=2010-12-06 18:32:50 state=clean *-volume:3 UNCLAIMED description: Extended partition physical id: 4 bus info: scsi@0:0.0.0,4 size: 882GiB capacity: 882GiB capabilities: primary extended partitioned partitioned:extended *-logicalvolume UNCLAIMED description: Linux filesystem partition physical id: 5 capacity: 882GiB *-disk:1 description: ATA Disk product: ST31000528AS vendor: Seagate physical id: 1 bus info: scsi@2:0.0.0 logical name: /dev/sdb version: CC38 serial: 9VP3SCPF size: 931GiB (1TB) capabilities: partitioned partitioned:dos configuration: ansiversion=5 signature=000ad206 *-volume:0 UNCLAIMED description: Linux filesystem partition vendor: Linux physical id: 1 bus info: scsi@2:0.0.0,1 version: 1.0 serial: 81839235-21ea-4853-90a4-814779f49000 size: 972MiB capacity: 972MiB capabilities: primary ext2 initialized configuration: filesystem=ext2 modified=2010-12-06 18:32:58 mounted=2010-11-01 07:05:10 state=unknown *-volume:1 UNCLAIMED description: Linux swap volume physical id: 2 bus info: scsi@2:0.0.0,2 version: 1 serial: 22b881d5-6f5c-484d-94e8-e231896fa91b size: 486MiB capacity: 486MiB capabilities: primary nofs swap initialized configuration: filesystem=swap pagesize=4096 *-volume:2 UNCLAIMED description: EXT3 volume vendor: Linux physical id: 3 bus info: scsi@2:0.0.0,3 version: 1.0 serial: ad5b0daf-11e8-4f8f-8598-4e89da9c0d84 size: 47GiB capacity: 47GiB capabilities: primary journaled extended_attributes large_files recover ext3 ext2 initialized configuration: created=2010-02-16 20:42:29 filesystem=ext3 modified=2010-11-29 17:02:34 mounted=2010-12-06 18:32:50 state=clean *-volume:3 UNCLAIMED description: Extended partition physical id: 4 bus info: scsi@2:0.0.0,4 size: 882GiB capacity: 882GiB capabilities: primary extended partitioned partitioned:extended *-logicalvolume UNCLAIMED description: Linux filesystem partition physical id: 5 capacity: 882GiB *-usb:0 description: USB Controller product: SB700/SB800 USB OHCI0 Controller vendor: ATI Technologies Inc physical id: 12 bus info: pci@0000:00:12.0 version: 00 width: 32 bits clock: 66MHz capabilities: ohci bus_master configuration: driver=ohci_hcd latency=64 resources: irq:16 memory:f7ffd000-f7ffdfff *-usb:1 description: USB Controller product: SB700 USB OHCI1 Controller vendor: ATI Technologies Inc physical id: 12.1 bus info: pci@0000:00:12.1 version: 00 width: 32 bits clock: 66MHz capabilities: ohci bus_master configuration: driver=ohci_hcd latency=64 resources: irq:16 memory:f7ffe000-f7ffefff *-usb:2 description: USB Controller product: SB700/SB800 USB EHCI Controller vendor: ATI Technologies Inc physical id: 12.2 bus info: pci@0000:00:12.2 version: 00 width: 32 bits clock: 66MHz capabilities: pm debug ehci bus_master cap_list configuration: driver=ehci_hcd latency=64 resources: irq:17 memory:f7fff800-f7fff8ff *-usb:3 description: USB Controller product: SB700/SB800 USB OHCI0 Controller vendor: ATI Technologies Inc physical id: 13 bus info: pci@0000:00:13.0 version: 00 width: 32 bits clock: 66MHz capabilities: ohci bus_master configuration: driver=ohci_hcd latency=64 resources: irq:18 memory:f7ffb000-f7ffbfff *-usb:4 description: USB Controller product: SB700 USB OHCI1 Controller vendor: ATI Technologies Inc physical id: 13.1 bus info: pci@0000:00:13.1 version: 00 width: 32 bits clock: 66MHz capabilities: ohci bus_master configuration: driver=ohci_hcd latency=64 resources: irq:18 memory:f7ffc000-f7ffcfff *-usb:5 description: USB Controller product: SB700/SB800 USB EHCI Controller vendor: ATI Technologies Inc physical id: 13.2 bus info: pci@0000:00:13.2 version: 00 width: 32 bits clock: 66MHz capabilities: pm debug ehci bus_master cap_list configuration: driver=ehci_hcd latency=64 resources: irq:19 memory:f7fff400-f7fff4ff *-serial UNCLAIMED description: SMBus product: SBx00 SMBus Controller vendor: ATI Technologies Inc physical id: 14 bus info: pci@0000:00:14.0 version: 3c width: 32 bits clock: 66MHz capabilities: ht cap_list configuration: latency=0 *-ide description: IDE interface product: SB700/SB800 IDE Controller vendor: ATI Technologies Inc physical id: 14.1 bus info: pci@0000:00:14.1 logical name: scsi5 version: 00 width: 32 bits clock: 66MHz capabilities: ide msi bus_master cap_list emulated configuration: driver=pata_atiixp latency=64 resources: irq:16 ioport:1f0(size=8) ioport:3f6 ioport:170(size=8) ioport:376 ioport:ff00(size=16) *-cdrom:0 description: DVD reader product: DVDROM DH16NS30 vendor: HL-DT-ST physical id: 0.0.0 bus info: scsi@5:0.0.0 logical name: /dev/cdrom1 logical name: /dev/dvd1 logical name: /dev/scd0 logical name: /dev/sr0 version: 1.00 capabilities: removable audio dvd configuration: ansiversion=5 status=nodisc *-cdrom:1 description: DVD-RAM writer product: DVDRAM GH22NS50 vendor: HL-DT-ST physical id: 0.1.0 bus info: scsi@5:0.1.0 logical name: /dev/cdrom logical name: /dev/cdrw logical name: /dev/dvd logical name: /dev/dvdrw logical name: /dev/scd1 logical name: /dev/sr1 version: TN02 capabilities: removable audio cd-r cd-rw dvd dvd-r dvd-ram configuration: ansiversion=5 status=nodisc *-multimedia description: Audio device product: SBx00 Azalia (Intel HDA) vendor: ATI Technologies Inc physical id: 14.2 bus info: pci@0000:00:14.2 version: 00 width: 64 bits clock: 33MHz capabilities: pm bus_master cap_list configuration: driver=HDA Intel latency=64 resources: irq:16 memory:f7ff4000-f7ff7fff *-isa description: ISA bridge product: SB700/SB800 LPC host controller vendor: ATI Technologies Inc physical id: 14.3 bus info: pci@0000:00:14.3 version: 00 width: 32 bits clock: 66MHz capabilities: isa bus_master configuration: latency=0 *-pci:4 description: PCI bridge product: SBx00 PCI to PCI Bridge vendor: ATI Technologies Inc physical id: 14.4 bus info: pci@0000:00:14.4 version: 00 width: 32 bits clock: 66MHz capabilities: pci subtractive_decode bus_master resources: ioport:e000(size=4096) memory:fbf00000-fbffffff *-network description: Ethernet interface product: 82541PI Gigabit Ethernet Controller vendor: Intel Corporation physical id: 5 bus info: pci@0000:05:05.0 logical name: eth1 version: 05 serial: 00:1b:21:56:f3:60 size: 100MB/s capacity: 1GB/s width: 32 bits clock: 66MHz capabilities: pm pcix bus_master cap_list rom ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=e1000 driverversion=7.3.21-k6-NAPI duplex=full firmware=N/A ip=192.168.1.2 latency=64 link=yes mingnt=255 multicast=yes port=twisted pair speed=100MB/s resources: irq:20 memory:fbfe0000-fbffffff memory:fbfc0000-fbfdffff ioport:ec00(size=64) memory:fbfa0000-fbfbffff *-usb:6 description: USB Controller product: SB700/SB800 USB OHCI2 Controller vendor: ATI Technologies Inc physical id: 14.5 bus info: pci@0000:00:14.5 version: 00 width: 32 bits clock: 66MHz capabilities: ohci bus_master configuration: driver=ohci_hcd latency=64 resources: irq:18 memory:f7ffa000-f7ffafff *-pci:1 description: Host bridge product: Family 10h Processor HyperTransport Configuration vendor: Advanced Micro Devices [AMD] physical id: 101 bus info: pci@0000:00:18.0 version: 00 width: 32 bits clock: 33MHz *-pci:2 description: Host bridge product: Family 10h Processor Address Map vendor: Advanced Micro Devices [AMD] physical id: 102 bus info: pci@0000:00:18.1 version: 00 width: 32 bits clock: 33MHz *-pci:3 description: Host bridge product: Family 10h Processor DRAM Controller vendor: Advanced Micro Devices [AMD] physical id: 103 bus info: pci@0000:00:18.2 version: 00 width: 32 bits clock: 33MHz *-pci:4 description: Host bridge product: Family 10h Processor Miscellaneous Control vendor: Advanced Micro Devices [AMD] physical id: 104 bus info: pci@0000:00:18.3 version: 00 width: 32 bits clock: 33MHz configuration: driver=k10temp resources: irq:0 *-pci:5 description: Host bridge product: Family 10h Processor Link Control vendor: Advanced Micro Devices [AMD] physical id: 105 bus info: pci@0000:00:18.4 version: 00 width: 32 bits clock: 33MHz *-scsi physical id: 1 bus info: usb@2:3 logical name: scsi8 capabilities: emulated scsi-host configuration: driver=usb-storage *-disk:0 description: SCSI Disk physical id: 0.0.0 bus info: scsi@8:0.0.0 logical name: /dev/sdc *-disk:1 description: SCSI Disk physical id: 0.0.1 bus info: scsi@8:0.0.1 logical name: /dev/sdd *-disk:2 description: SCSI Disk physical id: 0.0.2 bus info: scsi@8:0.0.2 logical name: /dev/sde *-disk:3 description: SCSI Disk physical id: 0.0.3 bus info: scsi@8:0.0.3 logical name: /dev/sdf *-network DISABLED description: Ethernet interface physical id: 1 logical name: vboxnet0 serial: 0a:00:27:00:00:00 capabilities: ethernet physical configuration: broadcast=yes multicast=yes

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  • DirectX works for 64-bit but not 32-bit

    - by dtbarne
    I'm trying to play a game (Civilization 5) which was previously working but no longer. I believe I've narrowed it down to a DirectX issue because I get an error running dxdiag.exe in 32 bit mode. My goal (at least I believe) is to get Direct3D Acceleration "Enabled" in dxdiag (as it is in 64 bit dxdiag). A very similar issue is here: http://answers.microsoft.com/en-us/windows/forum/windows_7-gaming/direct3d-acceleration-is-not-available-in-windows/4c345e6e-dc68-e011-8dfc-68b599b31bf5?page=1 The proposed answer, which looks very promising, doesn't seem to work for me. Like other users in that thread, HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Direct3D\Drivers does not have a SoftwareOnly key to change. I even tried manually adding it as a string and dword, to no avail. I have a NVIDIA GeForce GT 525M, and before you ask, yes I've tried updating (also uninstalling, reinstalling) my drivers. I've also tried doing the same with DirectX (and Civilization 5 for that matter). Been debugging for some 4+ hours now after a full day of work and I've run out of ideas. I'm hoping somebody knows the solution here! :) Here's what I see when I open dxdiag: DxDiag has detected that there mgiht have been a problem accessing Direct3D the last time this program was used. Would you like to bypass Direct3D this time? No - Crash Yes - Works, but in Display tab: DirectDraw Acceleration: Disabled Direct3D Acceleration: Not Available AGP Texture Acceleration: Not Available If I click "Run 64-bit DxDiag", all three are "Enabled". I should also note that I've tried the following steps as Microsoft suggests, but I'm not able to do so as the "Change Settings" button is disabled. Some programs run very slowly—or not at all—unless Microsoft DirectDraw or Direct3D hardware acceleration is turned on. To determine this, click the Display tab, and then under DirectX Features, check to see whether DirectDraw, Direct3D, and AGP Texture Acceleration appear as Enabled. If not, try turning on hardware acceleration. Click to open Screen Resolution. Click Advanced settings. Click the Troubleshoot tab, and then click Change settings. If you're prompted for an administrator password or confirmation, type the password or provide confirmation. Move the Hardware Acceleration slider to Full. Full dxdiag dump: ------------------ System Information ------------------ Time of this report: 11/8/2012, 23:13:24 Machine name: DTBARNE Operating System: Windows 7 Professional 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.120830-0333) Language: English (Regional Setting: English) System Manufacturer: Dell Inc. System Model: Dell System XPS L502X BIOS: Default System BIOS Processor: Intel(R) Core(TM) i5-2450M CPU @ 2.50GHz (4 CPUs), ~2.5GHz Memory: 8192MB RAM Available OS Memory: 8086MB RAM Page File: 2466MB used, 13704MB available Windows Dir: C:\Windows DirectX Version: DirectX 11 DX Setup Parameters: Not found User DPI Setting: Using System DPI System DPI Setting: 96 DPI (100 percent) DWM DPI Scaling: Disabled DxDiag Version: 6.01.7601.17514 32bit Unicode DxDiag Previously: Crashed in Direct3D (stage 2). Re-running DxDiag with "dontskip" command line parameter or choosing not to bypass information gathering when prompted might result in DxDiag successfully obtaining this information ------------ DxDiag Notes ------------ Display Tab 1: No problems found. Sound Tab 1: No problems found. Sound Tab 2: No problems found. Input Tab: No problems found. -------------------- DirectX Debug Levels -------------------- Direct3D: 0/4 (retail) DirectDraw: 0/4 (retail) DirectInput: 0/5 (retail) DirectMusic: 0/5 (retail) DirectPlay: 0/9 (retail) DirectSound: 0/5 (retail) DirectShow: 0/6 (retail) --------------- Display Devices --------------- Card name: Intel(R) HD Graphics 3000 Manufacturer: Chip type: DAC type: Device Key: Enum\PCI\VEN_8086&DEV_0126&SUBSYS_04B61028&REV_09 Display Memory: Dedicated Memory: n/a Shared Memory: n/a Current Mode: 1920 x 1080 (32 bit) (60Hz) Monitor Name: Generic PnP Monitor Monitor Model: Monitor Id: Native Mode: Output Type: Driver Name: Driver File Version: () Driver Version: DDI Version: Driver Model: WDDM 1.1 Driver Attributes: Final Retail Driver Date/Size: , 0 bytes WHQL Logo'd: n/a WHQL Date Stamp: n/a Device Identifier: Vendor ID: Device ID: SubSys ID: Revision ID: Driver Strong Name: oem11.inf:IntelGfx.NTamd64.6.0:iSNBM0:8.15.10.2696:pci\ven_8086&dev_0126&subsys_04b61028 Rank Of Driver: 00E60001 Video Accel: Deinterlace Caps: n/a D3D9 Overlay: DXVA-HD: DDraw Status: Disabled D3D Status: Not Available AGP Status: Not Available ------------- Sound Devices ------------- Description: Speakers (High Definition Audio Device) Default Sound Playback: Yes Default Voice Playback: Yes Hardware ID: HDAUDIO\FUNC_01&VEN_10EC&DEV_0665&SUBSYS_102804B6&REV_1000 Manufacturer ID: 1 Product ID: 65535 Type: WDM Driver Name: HdAudio.sys Driver Version: 6.01.7601.17514 (English) Driver Attributes: Final Retail WHQL Logo'd: Yes Date and Size: 11/20/2010 22:23:47, 350208 bytes Other Files: Driver Provider: Microsoft HW Accel Level: Basic Cap Flags: 0xF1F Min/Max Sample Rate: 100, 200000 Static/Strm HW Mix Bufs: 1, 0 Static/Strm HW 3D Bufs: 0, 0 HW Memory: 0 Voice Management: No EAX(tm) 2.0 Listen/Src: No, No I3DL2(tm) Listen/Src: No, No Sensaura(tm) ZoomFX(tm): No Description: Digital Audio (S/PDIF) (High Definition Audio Device) Default Sound Playback: No Default Voice Playback: No Hardware ID: HDAUDIO\FUNC_01&VEN_10EC&DEV_0665&SUBSYS_102804B6&REV_1000 Manufacturer ID: 1 Product ID: 65535 Type: WDM Driver Name: HdAudio.sys Driver Version: 6.01.7601.17514 (English) Driver Attributes: Final Retail WHQL Logo'd: Yes Date and Size: 11/20/2010 22:23:47, 350208 bytes Other Files: Driver Provider: Microsoft HW Accel Level: Basic Cap Flags: 0xF1F Min/Max Sample Rate: 100, 200000 Static/Strm HW Mix Bufs: 1, 0 Static/Strm HW 3D Bufs: 0, 0 HW Memory: 0 Voice Management: No EAX(tm) 2.0 Listen/Src: No, No I3DL2(tm) Listen/Src: No, No Sensaura(tm) ZoomFX(tm): No --------------------- Sound Capture Devices --------------------- Description: Microphone (High Definition Audio Device) Default Sound Capture: Yes Default Voice Capture: Yes Driver Name: HdAudio.sys Driver Version: 6.01.7601.17514 (English) Driver Attributes: Final Retail Date and Size: 11/20/2010 22:23:47, 350208 bytes Cap Flags: 0x1 Format Flags: 0xFFFFF ------------------- DirectInput Devices ------------------- Device Name: Mouse Attached: 1 Controller ID: n/a Vendor/Product ID: n/a FF Driver: n/a Device Name: Keyboard Attached: 1 Controller ID: n/a Vendor/Product ID: n/a FF Driver: n/a Poll w/ Interrupt: No ----------- USB Devices ----------- + USB Root Hub | Vendor/Product ID: 0x8086, 0x1C26 | Matching Device ID: usb\root_hub20 | Service: usbhub | +-+ Generic USB Hub | | Vendor/Product ID: 0x8087, 0x0024 | | Location: Port_#0001.Hub_#0002 | | Matching Device ID: usb\class_09 | | Service: usbhub ---------------- Gameport Devices ---------------- ------------ PS/2 Devices ------------ + Standard PS/2 Keyboard | Matching Device ID: *pnp0303 | Service: i8042prt | + Terminal Server Keyboard Driver | Matching Device ID: root\rdp_kbd | Upper Filters: kbdclass | Service: TermDD | + Synaptics PS/2 Port TouchPad | Matching Device ID: *dll04b6 | Upper Filters: SynTP | Service: i8042prt | + Terminal Server Mouse Driver | Matching Device ID: root\rdp_mou | Upper Filters: mouclass | Service: TermDD ------------------------ Disk & DVD/CD-ROM Drives ------------------------ Drive: C: Free Space: 26.2 GB Total Space: 122.0 GB File System: NTFS Model: M4-CT128M4SSD2 ATA Device Drive: D: Model: Optiarc DVDRWBD BC-5540H ATA Device Driver: c:\windows\system32\drivers\cdrom.sys, 6.01.7601.17514 (English), , 0 bytes -------------- System Devices -------------- Name: High Definition Audio Controller Device ID: PCI\VEN_8086&DEV_1C20&SUBSYS_04B61028&REV_05\3&11583659&0&D8 Driver: n/a Name: PCI standard host CPU bridge Device ID: PCI\VEN_8086&DEV_0104&SUBSYS_04B61028&REV_09\3&11583659&0&00 Driver: n/a Name: PCI standard PCI-to-PCI bridge Device ID: PCI\VEN_8086&DEV_1C1A&SUBSYS_04B61028&REV_B5\3&11583659&0&E5 Driver: n/a Name: PCI standard PCI-to-PCI bridge Device ID: PCI\VEN_8086&DEV_0101&SUBSYS_20108086&REV_09\3&11583659&0&08 Driver: n/a Name: PCI standard PCI-to-PCI bridge Device ID: PCI\VEN_8086&DEV_1C18&SUBSYS_04B61028&REV_B5\3&11583659&0&E4 Driver: n/a Name: Intel(R) Centrino(R) Advanced-N 6230 Device ID: PCI\VEN_8086&DEV_0091&SUBSYS_52218086&REV_34\4&2634DE8D&0&00E1 Driver: n/a Name: PCI standard ISA bridge Device ID: PCI\VEN_8086&DEV_1C4B&SUBSYS_04B61028&REV_05\3&11583659&0&F8 Driver: n/a Name: PCI standard PCI-to-PCI bridge Device ID: PCI\VEN_8086&DEV_1C16&SUBSYS_04B61028&REV_B5\3&11583659&0&E3 Driver: n/a Name: Realtek PCIe GBE Family Controller Device ID: PCI\VEN_10EC&DEV_8168&SUBSYS_04B61028&REV_06\4&109EAB2F&0&00E5 Driver: n/a Name: Intel(R) Management Engine Interface Device ID: PCI\VEN_8086&DEV_1C3A&SUBSYS_04B61028&REV_04\3&11583659&0&B0 Driver: n/a Name: PCI standard PCI-to-PCI bridge Device ID: PCI\VEN_8086&DEV_1C12&SUBSYS_04B61028&REV_B5\3&11583659&0&E1 Driver: n/a Name: NVIDIA GeForce GT 525M Device ID: PCI\VEN_10DE&DEV_0DF5&SUBSYS_04B61028&REV_A1\4&4DCA75F&0&0008 Driver: n/a Name: Standard Enhanced PCI to USB Host Controller Device ID: PCI\VEN_8086&DEV_1C2D&SUBSYS_04B61028&REV_05\3&11583659&0&D0 Driver: n/a Name: PCI standard PCI-to-PCI bridge Device ID: PCI\VEN_8086&DEV_1C10&SUBSYS_04B61028&REV_B5\3&11583659&0&E0 Driver: n/a Name: Standard Enhanced PCI to USB Host Controller Device ID: PCI\VEN_8086&DEV_1C26&SUBSYS_04B61028&REV_05\3&11583659&0&E8 Driver: n/a Name: Standard AHCI 1.0 Serial ATA Controller Device ID: PCI\VEN_8086&DEV_1C03&SUBSYS_04B61028&REV_05\3&11583659&0&FA Driver: n/a Name: SM Bus Controller Device ID: PCI\VEN_8086&DEV_1C22&SUBSYS_04B61028&REV_05\3&11583659&0&FB Driver: n/a Name: Intel(R) HD Graphics 3000 Device ID: PCI\VEN_8086&DEV_0126&SUBSYS_04B61028&REV_09\3&11583659&0&10 Driver: n/a Name: Renesas Electronics USB 3.0 Host Controller Device ID: PCI\VEN_1033&DEV_0194&SUBSYS_04B61028&REV_04\4&3494AC3A&0&00E3 Driver: n/a ------------------ DirectShow Filters ------------------ DirectShow Filters: WMAudio Decoder DMO,0x00800800,1,1,WMADMOD.DLL,6.01.7601.17514 WMAPro over S/PDIF DMO,0x00600800,1,1,WMADMOD.DLL,6.01.7601.17514 WMSpeech Decoder DMO,0x00600800,1,1,WMSPDMOD.DLL,6.01.7601.17514 MP3 Decoder DMO,0x00600800,1,1,mp3dmod.dll,6.01.7600.16385 Mpeg4s Decoder DMO,0x00800001,1,1,mp4sdecd.dll,6.01.7600.16385 WMV Screen decoder DMO,0x00600800,1,1,wmvsdecd.dll,6.01.7601.17514 WMVideo Decoder DMO,0x00800001,1,1,wmvdecod.dll,6.01.7601.17514 Mpeg43 Decoder DMO,0x00800001,1,1,mp43decd.dll,6.01.7600.16385 Mpeg4 Decoder DMO,0x00800001,1,1,mpg4decd.dll,6.01.7600.16385 DV Muxer,0x00400000,0,0,qdv.dll,6.06.7601.17514 Color Space Converter,0x00400001,1,1,quartz.dll,6.06.7601.17713 WM ASF Reader,0x00400000,0,0,qasf.dll,12.00.7601.17514 Screen Capture filter,0x00200000,0,1,wmpsrcwp.dll,12.00.7601.17514 AVI Splitter,0x00600000,1,1,quartz.dll,6.06.7601.17713 VGA 16 Color Ditherer,0x00400000,1,1,quartz.dll,6.06.7601.17713 SBE2MediaTypeProfile,0x00200000,0,0,sbe.dll,6.06.7601.17528 Microsoft DTV-DVD Video Decoder,0x005fffff,2,4,msmpeg2vdec.dll,6.01.7140.0000 AC3 Parser Filter,0x00600000,1,1,mpg2splt.ax,6.06.7601.17528 StreamBufferSink,0x00200000,0,0,sbe.dll,6.06.7601.17528 MJPEG Decompressor,0x00600000,1,1,quartz.dll,6.06.7601.17713 MPEG-I Stream Splitter,0x00600000,1,2,quartz.dll,6.06.7601.17713 SAMI (CC) Parser,0x00400000,1,1,quartz.dll,6.06.7601.17713 VBI Codec,0x00600000,1,4,VBICodec.ax,6.06.7601.17514 MPEG-2 Splitter,0x005fffff,1,0,mpg2splt.ax,6.06.7601.17528 Closed Captions Analysis Filter,0x00200000,2,5,cca.dll,6.06.7601.17514 SBE2FileScan,0x00200000,0,0,sbe.dll,6.06.7601.17528 Microsoft MPEG-2 Video Encoder,0x00200000,1,1,msmpeg2enc.dll,6.01.7601.17514 Internal Script Command Renderer,0x00800001,1,0,quartz.dll,6.06.7601.17713 MPEG Audio Decoder,0x03680001,1,1,quartz.dll,6.06.7601.17713 DV Splitter,0x00600000,1,2,qdv.dll,6.06.7601.17514 Video Mixing Renderer 9,0x00200000,1,0,quartz.dll,6.06.7601.17713 Microsoft MPEG-2 Encoder,0x00200000,2,1,msmpeg2enc.dll,6.01.7601.17514 ACM Wrapper,0x00600000,1,1,quartz.dll,6.06.7601.17713 Video Renderer,0x00800001,1,0,quartz.dll,6.06.7601.17713 MPEG-2 Video Stream Analyzer,0x00200000,0,0,sbe.dll,6.06.7601.17528 Line 21 Decoder,0x00600000,1,1,qdvd.dll,6.06.7601.17835 Video Port Manager,0x00600000,2,1,quartz.dll,6.06.7601.17713 Video Renderer,0x00400000,1,0,quartz.dll,6.06.7601.17713 VPS Decoder,0x00200000,0,0,WSTPager.ax,6.06.7601.17514 WM ASF Writer,0x00400000,0,0,qasf.dll,12.00.7601.17514 VBI Surface Allocator,0x00600000,1,1,vbisurf.ax,6.01.7601.17514 File writer,0x00200000,1,0,qcap.dll,6.06.7601.17514 iTV Data Sink,0x00600000,1,0,itvdata.dll,6.06.7601.17514 iTV Data Capture filter,0x00600000,1,1,itvdata.dll,6.06.7601.17514 DVD Navigator,0x00200000,0,3,qdvd.dll,6.06.7601.17835 Overlay Mixer2,0x00200000,1,1,qdvd.dll,6.06.7601.17835 AVI Draw,0x00600064,9,1,quartz.dll,6.06.7601.17713 RDP DShow Redirection Filter,0xffffffff,1,0,DShowRdpFilter.dll, Microsoft MPEG-2 Audio Encoder,0x00200000,1,1,msmpeg2enc.dll,6.01.7601.17514 WST Pager,0x00200000,1,1,WSTPager.ax,6.06.7601.17514 MPEG-2 Demultiplexer,0x00600000,1,1,mpg2splt.ax,6.06.7601.17528 DV Video Decoder,0x00800000,1,1,qdv.dll,6.06.7601.17514 SampleGrabber,0x00200000,1,1,qedit.dll,6.06.7601.17514 Null Renderer,0x00200000,1,0,qedit.dll,6.06.7601.17514 MPEG-2 Sections and Tables,0x005fffff,1,0,Mpeg2Data.ax,6.06.7601.17514 Microsoft AC3 Encoder,0x00200000,1,1,msac3enc.dll,6.01.7601.17514 StreamBufferSource,0x00200000,0,0,sbe.dll,6.06.7601.17528 Smart Tee,0x00200000,1,2,qcap.dll,6.06.7601.17514 Overlay Mixer,0x00200000,0,0,qdvd.dll,6.06.7601.17835 AVI Decompressor,0x00600000,1,1,quartz.dll,6.06.7601.17713 AVI/WAV File Source,0x00400000,0,2,quartz.dll,6.06.7601.17713 Wave Parser,0x00400000,1,1,quartz.dll,6.06.7601.17713 MIDI Parser,0x00400000,1,1,quartz.dll,6.06.7601.17713 Multi-file Parser,0x00400000,1,1,quartz.dll,6.06.7601.17713 File stream renderer,0x00400000,1,1,quartz.dll,6.06.7601.17713 Microsoft DTV-DVD Audio Decoder,0x005fffff,1,1,msmpeg2adec.dll,6.01.7140.0000 StreamBufferSink2,0x00200000,0,0,sbe.dll,6.06.7601.17528 AVI Mux,0x00200000,1,0,qcap.dll,6.06.7601.17514 Line 21 Decoder 2,0x00600002,1,1,quartz.dll,6.06.7601.17713 File Source (Async.),0x00400000,0,1,quartz.dll,6.06.7601.17713 File Source (URL),0x00400000,0,1,quartz.dll,6.06.7601.17713 Infinite Pin Tee Filter,0x00200000,1,1,qcap.dll,6.06.7601.17514 Enhanced Video Renderer,0x00200000,1,0,evr.dll,6.01.7601.17514 BDA MPEG2 Transport Information Filter,0x00200000,2,0,psisrndr.ax,6.06.7601.17669 MPEG Video Decoder,0x40000001,1,1,quartz.dll,6.06.7601.17713 WDM Streaming Tee/Splitter Devices: Tee/Sink-to-Sink Converter,0x00200000,1,1,ksproxy.ax,6.01.7601.17514 Video Compressors: WMVideo8 Encoder DMO,0x00600800,1,1,wmvxencd.dll,6.01.7600.16385 WMVideo9 Encoder DMO,0x00600800,1,1,wmvencod.dll,6.01.7600.16385 MSScreen 9 encoder DMO,0x00600800,1,1,wmvsencd.dll,6.01.7600.16385 DV Video Encoder,0x00200000,0,0,qdv.dll,6.06.7601.17514 MJPEG Compressor,0x00200000,0,0,quartz.dll,6.06.7601.17713 Cinepak Codec by Radius,0x00200000,1,1,qcap.dll,6.06.7601.17514 Intel IYUV codec,0x00200000,1,1,qcap.dll,6.06.7601.17514 Intel IYUV codec,0x00200000,1,1,qcap.dll,6.06.7601.17514 Microsoft RLE,0x00200000,1,1,qcap.dll,6.06.7601.17514 Microsoft Video 1,0x00200000,1,1,qcap.dll,6.06.7601.17514 Audio Compressors: WM Speech Encoder DMO,0x00600800,1,1,WMSPDMOE.DLL,6.01.7600.16385 WMAudio Encoder DMO,0x00600800,1,1,WMADMOE.DLL,6.01.7600.16385 IMA ADPCM,0x00200000,1,1,quartz.dll,6.06.7601.17713 PCM,0x00200000,1,1,quartz.dll,6.06.7601.17713 Microsoft ADPCM,0x00200000,1,1,quartz.dll,6.06.7601.17713 GSM 6.10,0x00200000,1,1,quartz.dll,6.06.7601.17713 CCITT A-Law,0x00200000,1,1,quartz.dll,6.06.7601.17713 CCITT u-Law,0x00200000,1,1,quartz.dll,6.06.7601.17713 MPEG Layer-3,0x00200000,1,1,quartz.dll,6.06.7601.17713 Audio Capture Sources: Microphone (High Definition Aud,0x00200000,0,0,qcap.dll,6.06.7601.17514 PBDA CP Filters: PBDA DTFilter,0x00600000,1,1,CPFilters.dll,6.06.7601.17528 PBDA ETFilter,0x00200000,0,0,CPFilters.dll,6.06.7601.17528 PBDA PTFilter,0x00200000,0,0,CPFilters.dll,6.06.7601.17528 Midi Renderers: Default MidiOut Device,0x00800000,1,0,quartz.dll,6.06.7601.17713 Microsoft GS Wavetable Synth,0x00200000,1,0,quartz.dll,6.06.7601.17713 WDM Streaming Capture Devices: HD Audio Microphone 2,0x00200000,1,1,ksproxy.ax,6.01.7601.17514 Integrated Webcam,0x00200000,1,2,ksproxy.ax,6.01.7601.17514 WDM Streaming Rendering Devices: HD Audio Headphone/Speakers,0x00200000,1,1,ksproxy.ax,6.01.7601.17514 HD Audio SPDIF out,0x00200000,1,1,ksproxy.ax,6.01.7601.17514 BDA Network Providers: Microsoft ATSC Network Provider,0x00200000,0,1,MSDvbNP.ax,6.06.7601.17514 Microsoft DVBC Network Provider,0x00200000,0,1,MSDvbNP.ax,6.06.7601.17514 Microsoft DVBS Network Provider,0x00200000,0,1,MSDvbNP.ax,6.06.7601.17514 Microsoft DVBT Network Provider,0x00200000,0,1,MSDvbNP.ax,6.06.7601.17514 Microsoft Network Provider,0x00200000,0,1,MSNP.ax,6.06.7601.17514 Video Capture Sources: Integrated Webcam,0x00200000,1,2,ksproxy.ax,6.01.7601.17514 Multi-Instance Capable VBI Codecs: VBI Codec,0x00600000,1,4,VBICodec.ax,6.06.7601.17514 BDA Transport Information Renderers: BDA MPEG2 Transport Information Filter,0x00600000,2,0,psisrndr.ax,6.06.7601.17669 MPEG-2 Sections and Tables,0x00600000,1,0,Mpeg2Data.ax,6.06.7601.17514 BDA CP/CA Filters: Decrypt/Tag,0x00600000,1,1,EncDec.dll,6.06.7601.17708 Encrypt/Tag,0x00200000,0,0,EncDec.dll,6.06.7601.17708 PTFilter,0x00200000,0,0,EncDec.dll,6.06.7601.17708 XDS Codec,0x00200000,0,0,EncDec.dll,6.06.7601.17708 WDM Streaming Communication Transforms: Tee/Sink-to-Sink Converter,0x00200000,1,1,ksproxy.ax,6.01.7601.17514 Audio Renderers: Speakers (High Definition Audio,0x00200000,1,0,quartz.dll,6.06.7601.17713 Default DirectSound Device,0x00800000,1,0,quartz.dll,6.06.7601.17713 Default WaveOut Device,0x00200000,1,0,quartz.dll,6.06.7601.17713 Digital Audio (S/PDIF) (High De,0x00200000,1,0,quartz.dll,6.06.7601.17713 DirectSound: Digital Audio (S/PDIF) (High Definition Audio Device),0x00200000,1,0,quartz.dll,6.06.7601.17713 DirectSound: Speakers (High Definition Audio Device),0x00200000,1,0,quartz.dll,6.06.7601.17713 --------------- EVR Power Information --------------- Current Setting: {651288E5-A7ED-4076-A96B-6CC62D848FE1} (Balanced) Quality Flags: 2576 Enabled: Force throttling Allow half deinterlace Allow scaling Decode Power Usage: 100 Balanced Flags: 1424 Enabled: Force throttling Allow batching Force half deinterlace Force scaling Decode Power Usage: 50 PowerFlags: 1424 Enabled: Force throttling Allow batching Force half deinterlace Force scaling Decode Power Usage: 0

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  • Implementation of ZipCrypto / Zip 2.0 encryption in java

    - by gomesla
    I'm trying o implement the zipcrypto / zip 2.0 encryption algoritm to deal with encrypted zip files as discussed in http://www.pkware.com/documents/casestudies/APPNOTE.TXT I believe I've followed the specs but just can't seem to get it working. I'm fairly sure the issue has to do with my interpretation of the crc algorithm. The documentation states CRC-32: (4 bytes) The CRC-32 algorithm was generously contributed by David Schwaderer and can be found in his excellent book "C Programmers Guide to NetBIOS" published by Howard W. Sams & Co. Inc. The 'magic number' for the CRC is 0xdebb20e3. The proper CRC pre and post conditioning is used, meaning that the CRC register is pre-conditioned with all ones (a starting value of 0xffffffff) and the value is post-conditioned by taking the one's complement of the CRC residual. Here is the snippet that I'm using for the crc32 public class PKZIPCRC32 { private static final int CRC32_POLYNOMIAL = 0xdebb20e3; private int crc = 0xffffffff; private int CRCTable[]; public PKZIPCRC32() { buildCRCTable(); } private void buildCRCTable() { int i, j; CRCTable = new int[256]; for (i = 0; i <= 255; i++) { crc = i; for (j = 8; j > 0; j--) if ((crc & 1) == 1) crc = (crc >>> 1) ^ CRC32_POLYNOMIAL; else crc >>>= 1; CRCTable[i] = crc; } } private int crc32(byte buffer[], int start, int count, int lastcrc) { int temp1, temp2; int i = start; crc = lastcrc; while (count-- != 0) { temp1 = crc >>> 8; temp2 = CRCTable[(crc ^ buffer[i++]) & 0xFF]; crc = temp1 ^ temp2; } return crc; } public int crc32(int crc, byte buffer) { return crc32(new byte[] { buffer }, 0, 1, crc); } } Below is my complete code. Can anyone see what I'm doing wrong. package org.apache.commons.compress.archivers.zip; import java.io.IOException; import java.io.InputStream; public class ZipCryptoInputStream extends InputStream { public class PKZIPCRC32 { private static final int CRC32_POLYNOMIAL = 0xdebb20e3; private int crc = 0xffffffff; private int CRCTable[]; public PKZIPCRC32() { buildCRCTable(); } private void buildCRCTable() { int i, j; CRCTable = new int[256]; for (i = 0; i <= 255; i++) { crc = i; for (j = 8; j > 0; j--) if ((crc & 1) == 1) crc = (crc >>> 1) ^ CRC32_POLYNOMIAL; else crc >>>= 1; CRCTable[i] = crc; } } private int crc32(byte buffer[], int start, int count, int lastcrc) { int temp1, temp2; int i = start; crc = lastcrc; while (count-- != 0) { temp1 = crc >>> 8; temp2 = CRCTable[(crc ^ buffer[i++]) & 0xFF]; crc = temp1 ^ temp2; } return crc; } public int crc32(int crc, byte buffer) { return crc32(new byte[] { buffer }, 0, 1, crc); } } private static final long ENCRYPTION_KEY_1 = 0x12345678; private static final long ENCRYPTION_KEY_2 = 0x23456789; private static final long ENCRYPTION_KEY_3 = 0x34567890; private InputStream baseInputStream = null; private final PKZIPCRC32 checksumEngine = new PKZIPCRC32(); private long[] keys = null; public ZipCryptoInputStream(ZipArchiveEntry zipEntry, InputStream inputStream, String passwd) throws Exception { baseInputStream = inputStream; // Decryption // ---------- // PKZIP encrypts the compressed data stream. Encrypted files must // be decrypted before they can be extracted. // // Each encrypted file has an extra 12 bytes stored at the start of // the data area defining the encryption header for that file. The // encryption header is originally set to random values, and then // itself encrypted, using three, 32-bit keys. The key values are // initialized using the supplied encryption password. After each byte // is encrypted, the keys are then updated using pseudo-random number // generation techniques in combination with the same CRC-32 algorithm // used in PKZIP and described elsewhere in this document. // // The following is the basic steps required to decrypt a file: // // 1) Initialize the three 32-bit keys with the password. // 2) Read and decrypt the 12-byte encryption header, further // initializing the encryption keys. // 3) Read and decrypt the compressed data stream using the // encryption keys. // Step 1 - Initializing the encryption keys // ----------------------------------------- // // Key(0) <- 305419896 // Key(1) <- 591751049 // Key(2) <- 878082192 // // loop for i <- 0 to length(password)-1 // update_keys(password(i)) // end loop // // Where update_keys() is defined as: // // update_keys(char): // Key(0) <- crc32(key(0),char) // Key(1) <- Key(1) + (Key(0) & 000000ffH) // Key(1) <- Key(1) * 134775813 + 1 // Key(2) <- crc32(key(2),key(1) >> 24) // end update_keys // // Where crc32(old_crc,char) is a routine that given a CRC value and a // character, returns an updated CRC value after applying the CRC-32 // algorithm described elsewhere in this document. keys = new long[] { ENCRYPTION_KEY_1, ENCRYPTION_KEY_2, ENCRYPTION_KEY_3 }; for (int i = 0; i < passwd.length(); ++i) { update_keys((byte) passwd.charAt(i)); } // Step 2 - Decrypting the encryption header // ----------------------------------------- // // The purpose of this step is to further initialize the encryption // keys, based on random data, to render a plaintext attack on the // data ineffective. // // Read the 12-byte encryption header into Buffer, in locations // Buffer(0) thru Buffer(11). // // loop for i <- 0 to 11 // C <- buffer(i) ^ decrypt_byte() // update_keys(C) // buffer(i) <- C // end loop // // Where decrypt_byte() is defined as: // // unsigned char decrypt_byte() // local unsigned short temp // temp <- Key(2) | 2 // decrypt_byte <- (temp * (temp ^ 1)) >> 8 // end decrypt_byte // // After the header is decrypted, the last 1 or 2 bytes in Buffer // should be the high-order word/byte of the CRC for the file being // decrypted, stored in Intel low-byte/high-byte order. Versions of // PKZIP prior to 2.0 used a 2 byte CRC check; a 1 byte CRC check is // used on versions after 2.0. This can be used to test if the password // supplied is correct or not. byte[] encryptionHeader = new byte[12]; baseInputStream.read(encryptionHeader); for (int i = 0; i < encryptionHeader.length; i++) { encryptionHeader[i] ^= decrypt_byte(); update_keys(encryptionHeader[i]); } } protected byte decrypt_byte() { byte temp = (byte) (keys[2] | 2); return (byte) ((temp * (temp ^ 1)) >> 8); } @Override public int read() throws IOException { // // Step 3 - Decrypting the compressed data stream // ---------------------------------------------- // // The compressed data stream can be decrypted as follows: // // loop until done // read a character into C // Temp <- C ^ decrypt_byte() // update_keys(temp) // output Temp // end loop int read = baseInputStream.read(); read ^= decrypt_byte(); update_keys((byte) read); return read; } private final void update_keys(byte ch) { keys[0] = checksumEngine.crc32((int) keys[0], ch); keys[1] = keys[1] + (byte) keys[0]; keys[1] = keys[1] * 134775813 + 1; keys[2] = checksumEngine.crc32((int) keys[2], (byte) (keys[1] >> 24)); } }

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  • Error when Eclipse started and now my package explorer is empty!

    - by carpenteri
    Friends, Just a quick introduction, I'm currently learning Java, using a combination of the Head First Java book and Eclipse. Everything was going well until tonight! When I started up Eclipse tonight, I saw an error message which I didn't pay attention to (I know! I know!) and acknowledged after which the project explorer was empty where it used to contain my Head First project! After a quick "google" I found the workspace.metadata.log and the errors are shown below. The version of Eclipse I am using is: 20100218-1602 and the only plugin that I use is egit. Any help would be much appreciated. Thanks !SESSION 2010-06-08 19:24:33.841 ----------------------------------------------- eclipse.buildId=unknown java.version=1.5.0_22 java.vendor=Sun Microsystems Inc. BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=en_GB Framework arguments: -product org.eclipse.epp.package.java.product Command-line arguments: -os win32 -ws win32 -arch x86 -product org.eclipse.epp.package.java.product !ENTRY org.eclipse.ui.workbench 4 2 2010-06-08 19:24:36.475 !MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.ui.workbench". !STACK 1 org.eclipse.ui.WorkbenchException: Content is not allowed in prolog. at org.eclipse.ui.XMLMemento.createReadRoot(XMLMemento.java:121) at org.eclipse.ui.XMLMemento.createReadRoot(XMLMemento.java:64) at org.eclipse.ui.internal.Workbench$49.run(Workbench.java:1895) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.ui.internal.Workbench.restoreState(Workbench.java:1890) at org.eclipse.ui.internal.WorkbenchConfigurer.restoreState(WorkbenchConfigurer.java:183) at org.eclipse.ui.application.WorkbenchAdvisor$1.run(WorkbenchAdvisor.java:781) Caused by: org.xml.sax.SAXParseException: Content is not allowed in prolog. at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:264) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:292) at org.eclipse.ui.XMLMemento.createReadRoot(XMLMemento.java:94) ... 6 more !SUBENTRY 1 org.eclipse.ui 4 0 2010-06-08 19:24:36.475 !MESSAGE Content is not allowed in prolog. !STACK 0 org.xml.sax.SAXParseException: Content is not allowed in prolog. at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:264) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:292) at org.eclipse.ui.XMLMemento.createReadRoot(XMLMemento.java:94) at org.eclipse.ui.XMLMemento.createReadRoot(XMLMemento.java:64) at org.eclipse.ui.internal.Workbench$49.run(Workbench.java:1895) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.ui.internal.Workbench.restoreState(Workbench.java:1890) at org.eclipse.ui.internal.WorkbenchConfigurer.restoreState(WorkbenchConfigurer.java:183) at org.eclipse.ui.application.WorkbenchAdvisor$1.run(WorkbenchAdvisor.java:781) !SUBENTRY 1 org.eclipse.ui 4 0 2010-06-08 19:24:36.475 !MESSAGE Content is not allowed in prolog. !STACK 0 org.xml.sax.SAXParseException: Content is not allowed in prolog. at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:264) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:292) at org.eclipse.ui.XMLMemento.createReadRoot(XMLMemento.java:94) at org.eclipse.ui.XMLMemento.createReadRoot(XMLMemento.java:64) at org.eclipse.ui.internal.Workbench$49.run(Workbench.java:1895) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.ui.internal.Workbench.restoreState(Workbench.java:1890) at org.eclipse.ui.internal.WorkbenchConfigurer.restoreState(WorkbenchConfigurer.java:183) at org.eclipse.ui.application.WorkbenchAdvisor$1.run(WorkbenchAdvisor.java:781) !ENTRY org.eclipse.jdt.ui 4 10001 2010-06-08 19:24:41.442 !MESSAGE Internal Error !STACK 1 org.eclipse.jdt.internal.ui.JavaUIException: Problems reading information from XML 'OpenTypeHistory.xml' at org.eclipse.jdt.internal.corext.util.History.createException(History.java:70) at org.eclipse.jdt.internal.corext.util.History.load(History.java:257) at org.eclipse.jdt.internal.corext.util.History.load(History.java:166) at org.eclipse.jdt.internal.corext.util.OpenTypeHistory.<init>(OpenTypeHistory.java:199) at org.eclipse.jdt.internal.corext.util.OpenTypeHistory.getInstance(OpenTypeHistory.java:185) at org.eclipse.jdt.internal.ui.JavaPlugin.initializeAfterLoad(JavaPlugin.java:381) at org.eclipse.jdt.internal.ui.InitializeAfterLoadJob$RealJob.run(InitializeAfterLoadJob.java:36) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55) Caused by: org.xml.sax.SAXParseException: Content is not allowed in prolog. at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:264) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:292) at org.eclipse.jdt.internal.corext.util.History.load(History.java:255) ... 6 more !SUBENTRY 1 org.eclipse.jdt.ui 4 4 2010-06-08 19:24:41.442 !MESSAGE Problems reading information from XML 'OpenTypeHistory.xml' !STACK 0 org.xml.sax.SAXParseException: Content is not allowed in prolog. at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:264) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:292) at org.eclipse.jdt.internal.corext.util.History.load(History.java:255) at org.eclipse.jdt.internal.corext.util.History.load(History.java:166) at org.eclipse.jdt.internal.corext.util.OpenTypeHistory.<init>(OpenTypeHistory.java:199) at org.eclipse.jdt.internal.corext.util.OpenTypeHistory.getInstance(OpenTypeHistory.java:185) at org.eclipse.jdt.internal.ui.JavaPlugin.initializeAfterLoad(JavaPlugin.java:381) at org.eclipse.jdt.internal.ui.InitializeAfterLoadJob$RealJob.run(InitializeAfterLoadJob.java:36) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55) !ENTRY org.eclipse.jdt.ui 4 10001 2010-06-08 19:24:50.435 !MESSAGE Internal Error !STACK 1 org.eclipse.jdt.internal.ui.JavaUIException: Problems reading information from XML 'QualifiedTypeNameHistory.xml' at org.eclipse.jdt.internal.corext.util.History.createException(History.java:70) at org.eclipse.jdt.internal.corext.util.History.load(History.java:257) at org.eclipse.jdt.internal.corext.util.History.load(History.java:166) at org.eclipse.jdt.internal.corext.util.QualifiedTypeNameHistory.<init>(QualifiedTypeNameHistory.java:33) at org.eclipse.jdt.internal.corext.util.QualifiedTypeNameHistory.getDefault(QualifiedTypeNameHistory.java:26) at org.eclipse.jdt.internal.ui.JavaPlugin.stop(JavaPlugin.java:602) at org.eclipse.osgi.framework.internal.core.BundleContextImpl$2.run(BundleContextImpl.java:843) at java.security.AccessController.doPrivileged(Native Method) at org.eclipse.osgi.framework.internal.core.BundleContextImpl.stop(BundleContextImpl.java:836) at org.eclipse.osgi.framework.internal.core.BundleHost.stopWorker(BundleHost.java:474) at org.eclipse.osgi.framework.internal.core.AbstractBundle.suspend(AbstractBundle.java:546) at org.eclipse.osgi.framework.internal.core.Framework.suspendBundle(Framework.java:1098) at org.eclipse.osgi.framework.internal.core.StartLevelManager.decFWSL(StartLevelManager.java:593) at org.eclipse.osgi.framework.internal.core.StartLevelManager.doSetStartLevel(StartLevelManager.java:261) at org.eclipse.osgi.framework.internal.core.StartLevelManager.shutdown(StartLevelManager.java:216) at org.eclipse.osgi.framework.internal.core.InternalSystemBundle.suspend(InternalSystemBundle.java:266) at org.eclipse.osgi.framework.internal.core.Framework.shutdown(Framework.java:685) at org.eclipse.osgi.framework.internal.core.Framework.close(Framework.java:583) at org.eclipse.core.runtime.adaptor.EclipseStarter.shutdown(EclipseStarter.java:409) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:200) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:592) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:559) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:514) at org.eclipse.equinox.launcher.Main.run(Main.java:1311) Caused by: org.xml.sax.SAXParseException: Content is not allowed in prolog. at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:264) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:292) at org.eclipse.jdt.internal.corext.util.History.load(History.java:255) ... 25 more !SUBENTRY 1 org.eclipse.jdt.ui 4 4 2010-06-08 19:24:50.435 !MESSAGE Problems reading information from XML 'QualifiedTypeNameHistory.xml' !STACK 0 org.xml.sax.SAXParseException: Content is not allowed in prolog. at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:264) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:292) at org.eclipse.jdt.internal.corext.util.History.load(History.java:255) at org.eclipse.jdt.internal.corext.util.History.load(History.java:166) at org.eclipse.jdt.internal.corext.util.QualifiedTypeNameHistory.<init>(QualifiedTypeNameHistory.java:33) at org.eclipse.jdt.internal.corext.util.QualifiedTypeNameHistory.getDefault(QualifiedTypeNameHistory.java:26) at org.eclipse.jdt.internal.ui.JavaPlugin.stop(JavaPlugin.java:602) at org.eclipse.osgi.framework.internal.core.BundleContextImpl$2.run(BundleContextImpl.java:843) at java.security.AccessController.doPrivileged(Native Method) at org.eclipse.osgi.framework.internal.core.BundleContextImpl.stop(BundleContextImpl.java:836) at org.eclipse.osgi.framework.internal.core.BundleHost.stopWorker(BundleHost.java:474) at org.eclipse.osgi.framework.internal.core.AbstractBundle.suspend(AbstractBundle.java:546) at org.eclipse.osgi.framework.internal.core.Framework.suspendBundle(Framework.java:1098) at org.eclipse.osgi.framework.internal.core.StartLevelManager.decFWSL(StartLevelManager.java:593) at org.eclipse.osgi.framework.internal.core.StartLevelManager.doSetStartLevel(StartLevelManager.java:261) at org.eclipse.osgi.framework.internal.core.StartLevelManager.shutdown(StartLevelManager.java:216) at org.eclipse.osgi.framework.internal.core.InternalSystemBundle.suspend(InternalSystemBundle.java:266) at org.eclipse.osgi.framework.internal.core.Framework.shutdown(Framework.java:685) at org.eclipse.osgi.framework.internal.core.Framework.close(Framework.java:583) at org.eclipse.core.runtime.adaptor.EclipseStarter.shutdown(EclipseStarter.java:409) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:200) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:592) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:559) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:514) at org.eclipse.equinox.launcher.Main.run(Main.java:1311)

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  • Testing smart card minidriver

    - by user352792
    when testing smart card minidriver in windows 7, got the following errors: "cmck exec Reconnect" always show that Testing through CAPI calls Submitting CSP PIN for reader \.\DMWZ ESAFE 0\ CryptAcquireContext - CRYPT_NEWKEYSET CryptGenKey Reconnecting CryptAcquireContext - CRYPT_DELETEKEYSET CryptAcquireContext failed unexpectedly d:\5429t\testsrc\dstest\security\core\credentials\smartcard\cmck\cmck\fnreconnect.cpp Line: 264 WIN32 0x80090016 Keyset does not exist. in windows xp, it always passed. i have no idea! this is my log. in XP: /* P:608 T:3380 8-30-203 CardAcquireContext(): BEGIN /* P:608 T:3380 8-30-203 CardAcquireContext(): SUCCESS /* P:608 T:3380 8-30-203 CardAcquireContext(): BEGIN /* P:608 T:3380 8-30-203 CardAcquireContext(): SUCCESS /* P:608 T:3380 8-31-750 CardAcquireContext(): BEGIN /* P:608 T:3380 8-31-765 CardAcquireContext(): SUCCESS /* P:608 T:3380 8-31-765 CardDeleteContext(): BEGIN /* P:608 T:3380 8-31-765 CardDeleteContext(): SUCCESS /* P:608 T:3380 8-31-765 CardAcquireContext(): BEGIN /* P:608 T:3380 8-31-765 CardAcquireContext(): SUCCESS /* P:608 T:3380 8-31-765 CardDeleteContext(): BEGIN /* P:608 T:3380 8-31-781 CardDeleteContext(): SUCCESS /* P:608 T:3380 8-31-781 CardAcquireContext(): BEGIN /* P:608 T:3380 8-31-781 CardAcquireContext(): SUCCESS /* P:608 T:3380 8-31-781 CardGetChallenge(): BEGIN /* P:608 T:3380 CardGetChallenge(): Challenge = CE568537C1BC9318 / / P:608 T:3380 8-31-781 CardGetChallenge(): SUCCESS /* P:608 T:3380 8-31-796 CardAuthenticateChallenge(): BEGIN /* P:608 T:3380 CardAuthenticateChallenge(): Response = B99E85F50E1F5C29 / / P:608 T:3380 8-31-796 CardAuthenticateChallenge(): SUCCESS /* P:608 T:3380 8-31-812 CardDeauthenticate(): BEGIN /* P:608 T:3380 8-31-812 CardDeauthenticate(): SUCCESS /* P:608 T:3380 8-31-812 CardAuthenticatePin(): BEGIN /* P:608 T:3380 CardAuthenticatePin(): User PIN = 0000 / / P:608 T:3380 8-31-828 CardAuthenticatePin(): SUCCESS /* P:608 T:3380 8-31-828 CardDeauthenticate(): BEGIN /* P:608 T:3380 8-31-843 CardDeauthenticate(): SUCCESS /* P:608 T:3380 8-31-843 CardDeleteContext(): BEGIN /* P:608 T:3380 8-31-843 CardDeleteContext(): SUCCESS /* P:608 T:3380 8-31-859 CardAcquireContext(): BEGIN /* P:608 T:3380 8-31-859 CardAcquireContext(): SUCCESS /* P:608 T:3380 8-31-859 CardAuthenticatePin(): BEGIN /* P:608 T:3380 CardAuthenticatePin(): User PIN = 0000 / / P:608 T:3380 8-31-875 CardAuthenticatePin(): SUCCESS /* P:608 T:3380 8-31-875 CardQueryCapabilities(): BEGIN /* P:608 T:3380 8-31-875 CardQueryCapabilities(): SUCCESS /* P:608 T:3380 8-31-890 CardAuthenticatePin(): BEGIN /* P:608 T:3380 CardAuthenticatePin(): User PIN = 0000 / / P:608 T:3380 8-31-906 CardAuthenticatePin(): SUCCESS /* P:608 T:3380 8-31-906 CardDeauthenticate(): BEGIN /* P:608 T:3380 8-31-921 CardDeauthenticate(): SUCCESS /* P:608 T:3380 8-31-921 CardDeleteContext(): BEGIN /* P:608 T:3380 8-31-921 CardDeleteContext(): SUCCESS /* P:608 T:3380 8-32-0 CardAcquireContext(): BEGIN /* P:608 T:3380 8-32-0 CardAcquireContext(): SUCCESS /* P:608 T:3380 8-32-0 CardReadFile(): BEGIN /* P:608 T:3380 CardReadFile(): Dir Name = ROOT, File Name = cardid / / P:608 T:3380 CardReadFile(): cardid = 34646533393531342D643465662D3432 / / P:608 T:3380 8-32-46 CardReadFile(): SUCCESS /* P:608 T:3380 8-32-62 CardReadFile(): BEGIN /* P:608 T:3380 CardReadFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardReadFile(): cardcf = 000000000000 / / P:608 T:3380 8-32-109 CardReadFile(): SUCCESS /* P:608 T:3380 8-32-109 CardReadFile(): BEGIN /* P:608 T:3380 CardReadFile(): Dir Name = mscp, File Name = cmapfile / / P:608 T:3380 8-32-187 CardReadFile(): BEGIN /* P:608 T:3380 CardReadFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardReadFile(): cardcf = 000000000000 / / P:608 T:3380 8-32-234 CardReadFile(): SUCCESS /* P:608 T:3380 8-32-250 CardAuthenticatePin(): BEGIN /* P:608 T:3380 CardAuthenticatePin(): User PIN = 0000 / / P:608 T:3380 8-32-265 CardAuthenticatePin(): SUCCESS /* P:608 T:3380 8-32-265 CardDeauthenticate(): BEGIN /* P:608 T:3380 8-32-281 CardDeauthenticate(): SUCCESS /* P:608 T:3380 8-32-281 CardReadFile(): BEGIN /* P:608 T:3380 CardReadFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardReadFile(): cardcf = 000000000000 / / P:608 T:3380 8-32-328 CardReadFile(): SUCCESS /* P:608 T:3380 8-32-343 CardQueryFreeSpace(): BEGIN /* P:608 T:3380 8-32-359 CardQueryFreeSpace(): SUCCESS /* P:608 T:3380 8-32-375 CardReadFile(): BEGIN /* P:608 T:3380 CardReadFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardReadFile(): cardcf = 000000000000 / / P:608 T:3380 8-32-421 CardReadFile(): SUCCESS /* P:608 T:3380 8-32-421 CardAuthenticatePin(): BEGIN /* P:608 T:3380 CardAuthenticatePin(): User PIN = 0000 / / P:608 T:3380 8-32-453 CardAuthenticatePin(): SUCCESS /* P:608 T:3380 8-32-453 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardWriteFile(): cardcf = 000000000100 / / P:608 T:3380 8-32-531 CardWriteFile(): SUCCESS /* P:608 T:3380 8-32-531 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = mscp, File Name = cmapfile / / P:608 T:3380 CardWriteFile(): cmapfile = 660031006500300035003000300030002D0031003600380038002D0034006200380063002D0039006500300066002D003000310061006200300066006200340062003800660037000000000000000000010000000000 / / P:608 T:3380 8-32-921 CardWriteFile(): SUCCESS /* P:608 T:3380 8-32-921 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardWriteFile(): cardcf = 000000000200 / / P:608 T:3380 8-33-0 CardWriteFile(): SUCCESS /* P:608 T:3380 8-33-0 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = mscp, File Name = cmapfile / / P:608 T:3380 CardWriteFile(): cmapfile = 660031006500300035003000300030002D0031003600380038002D0034006200380063002D0039006500300066002D003000310061006200300066006200340062003800660037000000000000000000030000000000 / / P:608 T:3380 8-33-109 CardWriteFile(): SUCCESS /* P:608 T:3380 8-33-125 CardQueryCapabilities(): BEGIN /* P:608 T:3380 8-33-125 CardQueryCapabilities(): SUCCESS /* P:608 T:3380 8-33-125 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardWriteFile(): cardcf = 000001000200 / / P:608 T:3380 8-33-203 CardWriteFile(): SUCCESS /* P:608 T:3380 8-33-203 CardCreateContainer(): BEGIN /* P:608 T:3380 8-35-515 CardCreateContainer(): SUCCESS /* P:608 T:3380 8-35-531 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardWriteFile(): cardcf = 000001000300 / / P:608 T:3380 8-35-609 CardWriteFile(): SUCCESS /* P:608 T:3380 8-35-609 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = mscp, File Name = cmapfile / / P:608 T:3380 CardWriteFile(): cmapfile = 660031006500300035003000300030002D0031003600380038002D0034006200380063002D0039006500300066002D003000310061006200300066006200340062003800660037000000000000000000030000040000 / / P:608 T:3380 8-35-734 CardWriteFile(): SUCCESS /* P:608 T:3380 8-35-734 CardGetContainerInfo(): BEGIN /* P:608 T:3380 8-35-796 CardGetContainerInfo(): SUCCESS /* P:608 T:5764 8-37-296 CardDeauthenticate(): BEGIN /* P:608 T:5764 8-37-312 CardDeauthenticate(): SUCCESS /* P:608 T:3380 8-37-312 CardReadFile(): BEGIN /* P:608 T:3380 CardReadFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardReadFile(): cardcf = 000001000300 / / P:608 T:3380 8-37-375 CardReadFile(): SUCCESS /* P:608 T:3380 8-37-375 CardReadFile(): BEGIN /* P:608 T:3380 CardReadFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardReadFile(): cardcf = 000001000300 / / P:608 T:3380 8-37-437 CardReadFile(): SUCCESS /* P:608 T:3380 8-37-437 CardAuthenticatePin(): BEGIN /* P:608 T:3380 CardAuthenticatePin(): User PIN = 0000 / / P:608 T:3380 8-37-468 CardAuthenticatePin(): SUCCESS /* P:608 T:3380 8-37-484 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardWriteFile(): cardcf = 000001000400 / / P:608 T:3380 8-37-546 CardWriteFile(): SUCCESS /* P:608 T:3380 8-37-562 CardDeleteFile(): BEGIN /* P:608 T:3380 CardDeleteFile(): Dir Name = mscp, File Name = ksc00 / / P:608 T:3380 8-37-625 CardDeleteFile(): SCARD_E_FILE_NOT_FOUND (0x80100024) /* P:608 T:3380 CardDeleteFile(): FAILED /* P:608 T:3380 8-37-625 CardReadFile(): BEGIN /* P:608 T:3380 CardReadFile(): Dir Name = mscp, File Name = cmapfile / / P:608 T:3380 CardReadFile(): cmapfile = 660031006500300035003000300030002D0031003600380038002D0034006200380063002D0039006500300066002D003000310061006200300066006200340062003800660037000000000000000000030000040000 / / P:608 T:3380 8-37-718 CardReadFile(): SUCCESS /* P:608 T:3380 8-37-718 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardWriteFile(): cardcf = 000001000500 / / P:608 T:3380 8-37-796 CardWriteFile(): SUCCESS /* P:608 T:3380 8-37-796 CardDeleteFile(): BEGIN /* P:608 T:3380 CardDeleteFile(): Dir Name = mscp, File Name = kxc00 / / P:608 T:3380 8-37-875 CardDeleteFile(): SCARD_E_FILE_NOT_FOUND (0x80100024) /* P:608 T:3380 CardDeleteFile(): FAILED /* P:608 T:3380 8-37-875 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardWriteFile(): cardcf = 000002000500 / / P:608 T:3380 8-37-953 CardWriteFile(): SUCCESS /* P:608 T:3380 8-37-953 CardDeleteContainer(): BEGIN /* P:608 T:3380 8-38-578 CardDeleteContainer(): SUCCESS /* P:608 T:3380 8-38-593 CardReadFile(): BEGIN /* P:608 T:3380 CardReadFile(): Dir Name = mscp, File Name = cmapfile / / P:608 T:3380 CardReadFile(): cmapfile = 660031006500300035003000300030002D0031003600380038002D0034006200380063002D0039006500300066002D003000310061006200300066006200340062003800660037000000000000000000030000040000 / / P:608 T:3380 8-38-687 CardReadFile(): SUCCESS /* P:608 T:3380 8-38-687 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:608 T:3380 CardWriteFile(): cardcf = 000002000600 / / P:608 T:3380 8-38-781 CardWriteFile(): SUCCESS /* P:608 T:3380 8-38-781 CardWriteFile(): BEGIN /* P:608 T:3380 CardWriteFile(): Dir Name = mscp, File Name = cmapfile / / P:608 T:3380 CardWriteFile(): cmapfile = 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 / / P:608 T:3380 8-38-906 CardWriteFile(): SUCCESS /* P:608 T:5764 8-40-406 CardDeauthenticate(): BEGIN /* P:608 T:5764 8-40-421 CardDeauthenticate(): SUCCESS /* P:608 T:3380 8-40-671 CardDeleteContext(): BEGIN /* P:608 T:3380 8-40-687 CardDeleteContext(): SUCCESS in windows 7: /* P:3368 T:3800 17-39-515 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-39-515 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-39-515 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-39-515 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-39-531 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-39-531 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-39-531 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-39-531 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-41-187 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-41-187 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-41-187 CardDeleteContext(): BEGIN /* P:3368 T:3800 17-41-187 CardDeleteContext(): SUCCESS /* P:3368 T:3800 17-41-187 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-41-187 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-41-187 CardDeleteContext(): BEGIN /* P:3368 T:3800 17-41-203 CardDeleteContext(): SUCCESS /* P:3368 T:3800 17-41-203 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-41-203 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-41-203 CardDeleteContext(): BEGIN /* P:3368 T:3800 17-41-203 CardDeleteContext(): SUCCESS /* P:3368 T:3800 17-41-203 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-41-203 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-41-218 CardDeleteContext(): BEGIN /* P:3368 T:3800 17-41-218 CardDeleteContext(): SUCCESS /* P:3368 T:3800 17-41-218 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-41-218 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-41-218 CardGetChallenge(): BEGIN /* P:3368 T:3800 CardGetChallenge(): Challenge = BF830855CDCA4F0D / / P:3368 T:3800 17-41-234 CardGetChallenge(): SUCCESS /* P:3368 T:3800 17-41-234 CardAuthenticateChallenge(): BEGIN /* P:3368 T:3800 CardAuthenticateChallenge(): Response = A2DB6F882D402D94 / / P:3368 T:3800 17-41-234 CardAuthenticateChallenge(): SUCCESS /* P:3368 T:3800 17-41-234 CardDeauthenticate(): BEGIN /* P:3368 T:3800 17-41-250 CardDeauthenticate(): SUCCESS /* P:3368 T:3800 17-41-250 CardAuthenticatePin(): BEGIN /* P:3368 T:3800 CardAuthenticatePin(): User PIN = 0000 / / P:3368 T:3800 17-41-265 CardAuthenticatePin(): SUCCESS /* P:3368 T:3800 17-41-265 CardDeauthenticate(): BEGIN /* P:3368 T:3800 17-41-265 CardDeauthenticate(): SUCCESS /* P:3368 T:3800 17-41-265 CardDeleteContext(): BEGIN /* P:3368 T:3800 17-41-281 CardDeleteContext(): SUCCESS /* P:3368 T:3800 17-41-281 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-41-281 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-41-281 CardAuthenticatePin(): BEGIN /* P:3368 T:3800 CardAuthenticatePin(): User PIN = 0000 / / P:3368 T:3800 17-41-296 CardAuthenticatePin(): SUCCESS /* P:3368 T:3800 17-41-296 CardQueryCapabilities(): BEGIN /* P:3368 T:3800 17-41-296 CardQueryCapabilities(): SUCCESS /* P:3368 T:3800 17-41-296 CardAuthenticatePin(): BEGIN /* P:3368 T:3800 CardAuthenticatePin(): User PIN = 0000 / / P:3368 T:3800 17-41-312 CardAuthenticatePin(): SUCCESS /* P:3368 T:3800 17-41-312 CardDeauthenticate(): BEGIN /* P:3368 T:3800 17-41-328 CardDeauthenticate(): SUCCESS /* P:3368 T:3800 17-41-328 CardDeleteContext(): BEGIN /* P:3368 T:3800 17-41-328 CardDeleteContext(): SUCCESS /* P:3368 T:3800 17-41-359 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-41-359 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-41-359 CardReadFile(): BEGIN /* P:3368 T:3800 CardReadFile(): Dir Name = ROOT, File Name = cardid / / P:3368 T:3800 CardReadFile(): cardid = 34363438653733652D346430342D3463 / / P:3368 T:3800 17-41-406 CardReadFile(): SUCCESS /* P:3368 T:3800 17-41-406 CardReadFile(): BEGIN /* P:3368 T:3800 CardReadFile(): Dir Name = ROOT, File Name = cardcf / / P:3368 T:3800 CardReadFile(): cardcf = 000000000000 / / P:3368 T:3800 17-41-453 CardReadFile(): SUCCESS /* P:3368 T:3800 17-41-453 CardReadFile(): BEGIN /* P:3368 T:3800 CardReadFile(): Dir Name = mscp, File Name = cmapfile / / P:3368 T:3800 17-41-531 CardReadFile(): BEGIN /* P:3368 T:3800 CardReadFile(): Dir Name = ROOT, File Name = cardcf / / P:3368 T:3800 CardReadFile(): cardcf = 000000000000 / / P:3368 T:3800 17-41-593 CardReadFile(): SUCCESS /* P:3368 T:3800 17-41-593 CardAuthenticatePin(): BEGIN /* P:3368 T:3800 CardAuthenticatePin(): User PIN = 0000 / / P:3368 T:3800 17-41-609 CardAuthenticatePin(): SUCCESS /* P:3368 T:3800 17-41-609 CardDeauthenticate(): BEGIN /* P:3368 T:3800 17-41-609 CardDeauthenticate(): SUCCESS /* P:3368 T:3800 17-41-609 CardDeleteContext(): BEGIN /* P:3368 T:3800 17-41-625 CardDeleteContext(): SUCCESS /* P:3368 T:3800 17-41-625 CardAcquireContext(): BEGIN /* P:3368 T:3800 17-41-625 CardAcquireContext(): SUCCESS /* P:3368 T:3800 17-41-625 CardReadFile(): BEGIN /* P:3368 T:3800 CardReadFile(): Dir Name = ROOT, File Name = cardid / / P:3368 T:3800 CardReadFile(): cardid = 34363438653733652D346430342D3463 / / P:3368 T:3800 17-41-671 CardReadFile(): SUCCESS /* P:3368 T:3800 17-41-687 CardReadFile(): BEGIN /* P:3368 T:3800 CardReadFile(): Dir Name = ROOT, File Name = cardcf / / P:3368 T:3800 CardReadFile(): cardcf = 000000000000 / / P:3368 T:3800 17-41-734 CardReadFile(): SUCCESS /* P:3368 T:3800 17-41-734 CardQueryFreeSpace(): BEGIN /* P:3368 T:3800 17-41-750 CardQueryFreeSpace(): SUCCESS /* P:3368 T:3800 17-41-750 CardAuthenticatePin(): BEGIN /* P:3368 T:3800 CardAuthenticatePin(): User PIN = 0000 / / P:3368 T:3800 17-41-765 CardAuthenticatePin(): SUCCESS /* P:3368 T:3800 17-41-765 CardWriteFile(): BEGIN /* P:3368 T:3800 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:3368 T:3800 CardWriteFile(): cardcf = 000000000100 / / P:3368 T:3800 17-41-828 CardWriteFile(): SUCCESS /* P:3368 T:3800 17-41-828 CardWriteFile(): BEGIN /* P:3368 T:3800 CardWriteFile(): Dir Name = mscp, File Name = cmapfile / / P:3368 T:3800 CardWriteFile(): cmapfile = 370062003800640030006200390031002D0063003600650064002D0034003000650033002D0062006100610037002D006200620032003800640063003800610035003300330032000000000000000000010000000000 / / P:3368 T:3800 17-42-218 CardWriteFile(): SUCCESS /* P:3368 T:3800 17-42-234 CardWriteFile(): BEGIN /* P:3368 T:3800 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:3368 T:3800 CardWriteFile(): cardcf = 000000000200 / / P:3368 T:3800 17-42-296 CardWriteFile(): SUCCESS /* P:3368 T:3800 17-42-296 CardWriteFile(): BEGIN /* P:3368 T:3800 CardWriteFile(): Dir Name = mscp, File Name = cmapfile / / P:3368 T:3800 CardWriteFile(): cmapfile = 370062003800640030006200390031002D0063003600650064002D0034003000650033002D0062006100610037002D006200620032003800640063003800610035003300330032000000000000000000030000000000 / / P:3368 T:3800 17-42-390 CardWriteFile(): SUCCESS /* P:3368 T:3800 17-42-406 CardQueryCapabilities(): BEGIN /* P:3368 T:3800 17-42-406 CardQueryCapabilities(): SUCCESS /* P:3368 T:3800 17-42-406 CardWriteFile(): BEGIN /* P:3368 T:3800 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:3368 T:3800 CardWriteFile(): cardcf = 000001000200 / / P:3368 T:3800 17-42-468 CardWriteFile(): SUCCESS /* P:3368 T:3800 17-42-468 CardCreateContainer(): BEGIN /* P:3368 T:3800 17-48-421 CardCreateContainer(): SUCCESS /* P:3368 T:3800 17-48-437 CardWriteFile(): BEGIN /* P:3368 T:3800 CardWriteFile(): Dir Name = ROOT, File Name = cardcf / / P:3368 T:3800 CardWriteFile(): cardcf = 000001000300 / / P:3368 T:3800 17-48-484 CardWriteFile(): SUCCESS /* P:3368 T:3800 17-48-500 CardWriteFile(): BEGIN /* P:3368 T:3800 CardWriteFile(): Dir Name = mscp, File Name = cmapfile / / P:3368 T:3800 CardWriteFile(): cmapfile = 370062003800640030006200390031002D0063003600650064002D0034003000650033002D0062006100610037002D006200620032003800640063003800610035003300330032000000000000000000030000040000 / / P:3368 T:3800 17-48-593 CardWriteFile(): SUCCESS /* P:3368 T:3800 17-48-593 CardGetContainerInfo(): BEGIN /* P:3368 T:3800 17-48-640 CardGetContainerInfo(): SUCCESS /* P:3368 T:288 17-50-140 CardDeauthenticate(): BEGIN /* P:3368 T:288 17-50-140 CardDeauthenticate(): SUCCESS /* P:3368 T:3800 17-50-140 CardReadFile(): BEGIN /* P:3368 T:3800 CardReadFile(): Dir Name = ROOT, File Name = cardid / / P:3368 T:3800 CardReadFile(): cardid = 34363438653733652D346430342D3463 / / P:3368 T:3800 17-50-187 CardReadFile(): SUCCESS /* P:3368 T:3800 17-50-187 CardReadFile(): BEGIN /* P:3368 T:3800 CardReadFile(): Dir Name = ROOT, File Name = cardcf / / P:3368 T:3800 CardReadFile(): cardcf = 000001000300 / / P:3368 T:3800 17-50-234 CardReadFile(): SUCCESS /* P:3368 T:3800 17-50-234 CardReadFile(): BEGIN /* P:3368 T:3800 CardReadFile(): Dir Name = ROOT, File Name = cardid / / P:3368 T:3800 CardReadFile(): cardid = 34363438653733652D346430342D3463 / / P:3368 T:3800 17-50-296 CardReadFile(): SUCCESS /* P:3368 T:3800 17-50-296 CardReadFile(): BEGIN /* P:3368 T:3800 CardReadFile(): Dir Name = ROOT, File Name = cardid / / P:3368 T:3800 CardReadFile(): cardid = 34363438653733652D346430342D3463 / / P:3368 T:3800 17-50-343 CardReadFile(): SUCCESS Comparing the two logs, it seems that in win 7 cmck always read file, read file, read file... and fail, never get into CardDeleteContainer or CardWriteFile :( Please help me!!!! Many thanks!

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  • Why won't "!important" override ":first-line"?

    - by bazzlevi
    I am trying to do the tutorial in Chapter 6 of the 2nd edition of "CSS: The Missing Manual", and I've run into an issue I'm trying to understand. I have one style that looks like this: #main p:first-line { color: #999999; font-weight: bold; } Later I have another style that looks like this: #main p.byline { color: #00994D !important; font-size: 1.6em; margin: 5px 0 25px 50px; } I am confused because the second one won't override the color choice in the first one despite the fact that the second one has "!important" in it. I put both classes into an online specificity calculator, and the second one comes out being more specific, so I'm doubly confused. By the way, the inclusion of "!important" is the work-around suggested in the errata for the book. Odd that it still doesn't work! Here's the code for the entire page: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>CSS Typography</title> <style type="text/css"> html, body, h1, h2, h3, h4, h5, h6, p, ol, ul, li, pre, code, address, variable, form, fieldset, blockquote { padding: 0; margin: 0; font-size: 100%; font-weight: normal; } table { border-collapse: collapse; border-spacing: 0; } td, th, caption { font-weight: normal; text-align: left; } img, fieldset { border: 0; } ol { padding-left: 1.4em; list-style: decimal; } ul { padding-left: 1.4em; list-style:square; } q:before, q:after { content:''; } body { color: #002D4B; font-family: Arial, Helvetica, sans-serif; font-size: 62.5% } #main h1 { color: #F60; font-family: "Arial Black", Arial, Helvetica, sans-serif; font-size: 4em; } #main h2 { font: bold 3.5em "Hoefler Text", Garamond, Times, serif; border-bottom: 1px solid #002D4B; margin-top: 25px; } #main h3 { color: #F60; font-size: 1.9em; font-weight: bold; text-transform: uppercase; margin-top: 25px; margin-bottom: 10px; } #main p { font-size: 1.5em; line-height: 150%; margin-left: 150px; margin-right: 50px; margin-bottom: 10px; } #main p:first-line { color: #999999; font-weight: bold; } #main ul { margin: 50px 0 25px 50px; width: 150px; float: right; } #main li { color: #207EBF; font-size: 1.5em; margin-bottom: 7px; } #main p.byline { color: #00994D !important; font-size: 1.6em; margin: 5px 0 25px 50px; } #main .byline strong { color: #207EBF; text-transform: uppercase; margin-left: 5px; } </style> </head> <body> <div id="main"> <h1><strong>CSS</strong> The Missing Manual</h1> <h2>Exploring Typographic Possibilities</h2> <p class="byline">november 30 <strong>Rod Dibble</strong></p> <ul> <li>Lorem Ipsum</li> <li>Reprehenderit qui in ea</li> <li>Lorem Ipsum</li> <li>Reprehenderit qui in ea</li> <li>Lorem Ipsum</li> <li>Reprehenderit qui in ea</li> </ul> <h3>Esse quam nulla</h3> <p>Ut enim ad minima veniam, quis nostrum exercitationem ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur? Quis autem vel eum iure reprehenderit qui in ea voluptate velit esse quam nihil molestiae consequatur, vel illum qui dolorem eum fugiat quo voluptas nulla pariatur? Ut enim ad minima veniam, quis nostrum exercitationem ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur? Quis autem vel eum iure reprehenderit qui in ea voluptate velit esse quam nihil molestiae consequatur, vel illum qui dolorem eum fugiat quo voluptas nulla pariatur?</p> <h3>Quis autem vel eum</h3> <p>Ut enim ad minima veniam, quis nostrum exercitationem ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur? Quis autem vel eum iure reprehenderit qui in ea voluptate velit esse quam nihil molestiae consequatur, vel illum qui dolorem eum fugiat quo voluptas nulla pariatur? Ut enim ad minima veniam, quis nostrum exercitationem ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur? Quis autem vel eum iure reprehenderit qui in ea voluptate velit esse quam nihil molestiae consequatur, vel illum qui dolorem eum fugiat quo voluptas nulla pariatur?</p> </div> </body> </html> Here is the above code on JSBin: http://jsbin.com/unexe3

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  • JAVA image transfer problem

    - by user579098
    Hi, I have a school assignment, to send a jpg image,split it into groups of 100 bytes, corrupt it, use a CRC check to locate the errors and re-transmit until it eventually is built back into its original form. It's practically ready, however when I check out the new images, they appear with errors.. I would really appreciate if someone could look at my code below and maybe locate this logical mistake as I can't understand what the problem is because everything looks ok :S For the file with all the data needed including photos and error patterns one could download it from this link:http://rapidshare.com/#!download|932tl2|443122762|Data.zip|739 Thanks in advance, Stefan p.s dont forget to change the paths in the code for the image and error files package networks; import java.io.*; // for file reader import java.util.zip.CRC32; // CRC32 IEEE (Ethernet) public class Main { /** * Reads a whole file into an array of bytes. * @param file The file in question. * @return Array of bytes containing file data. * @throws IOException Message contains why it failed. */ public static byte[] readFileArray(File file) throws IOException { InputStream is = new FileInputStream(file); byte[] data=new byte[(int)file.length()]; is.read(data); is.close(); return data; } /** * Writes (or overwrites if exists) a file with data from an array of bytes. * @param file The file in question. * @param data Array of bytes containing the new file data. * @throws IOException Message contains why it failed. */ public static void writeFileArray(File file, byte[] data) throws IOException { OutputStream os = new FileOutputStream(file,false); os.write(data); os.close(); } /** * Converts a long value to an array of bytes. * @param data The target variable. * @return Byte array conversion of data. * @see http://www.daniweb.com/code/snippet216874.html */ public static byte[] toByta(long data) { return new byte[] { (byte)((data >> 56) & 0xff), (byte)((data >> 48) & 0xff), (byte)((data >> 40) & 0xff), (byte)((data >> 32) & 0xff), (byte)((data >> 24) & 0xff), (byte)((data >> 16) & 0xff), (byte)((data >> 8) & 0xff), (byte)((data >> 0) & 0xff), }; } /** * Converts a an array of bytes to long value. * @param data The target variable. * @return Long value conversion of data. * @see http://www.daniweb.com/code/snippet216874.html */ public static long toLong(byte[] data) { if (data == null || data.length != 8) return 0x0; return (long)( // (Below) convert to longs before shift because digits // are lost with ints beyond the 32-bit limit (long)(0xff & data[0]) << 56 | (long)(0xff & data[1]) << 48 | (long)(0xff & data[2]) << 40 | (long)(0xff & data[3]) << 32 | (long)(0xff & data[4]) << 24 | (long)(0xff & data[5]) << 16 | (long)(0xff & data[6]) << 8 | (long)(0xff & data[7]) << 0 ); } public static byte[] nextNoise(){ byte[] result=new byte[100]; // copy a frame's worth of data (or remaining data if it is less than frame length) int read=Math.min(err_data.length-err_pstn, 100); System.arraycopy(err_data, err_pstn, result, 0, read); // if read data is less than frame length, reset position and add remaining data if(read<100){ err_pstn=100-read; System.arraycopy(err_data, 0, result, read, err_pstn); }else // otherwise, increase position err_pstn+=100; // return noise segment return result; } /** * Given some original data, it is purposefully corrupted according to a * second data array (which is read from a file). In pseudocode: * corrupt = original xor corruptor * @param data The original data. * @return The new (corrupted) data. */ public static byte[] corruptData(byte[] data){ // get the next noise sequence byte[] noise = nextNoise(); // finally, xor data with noise and return result for(int i=0; i<100; i++)data[i]^=noise[i]; return data; } /** * Given an array of data, a packet is created. In pseudocode: * frame = corrupt(data) + crc(data) * @param data The original frame data. * @return The resulting frame data. */ public static byte[] buildFrame(byte[] data){ // pack = [data]+crc32([data]) byte[] hash = new byte[8]; // calculate crc32 of data and copy it to byte array CRC32 crc = new CRC32(); crc.update(data); hash=toByta(crc.getValue()); // create a byte array holding the final packet byte[] pack = new byte[data.length+hash.length]; // create the corrupted data byte[] crpt = new byte[data.length]; crpt = corruptData(data); // copy corrupted data into pack System.arraycopy(crpt, 0, pack, 0, crpt.length); // copy hash into pack System.arraycopy(hash, 0, pack, data.length, hash.length); // return pack return pack; } /** * Verifies frame contents. * @param frame The frame data (data+crc32). * @return True if frame is valid, false otherwise. */ public static boolean verifyFrame(byte[] frame){ // allocate hash and data variables byte[] hash=new byte[8]; byte[] data=new byte[frame.length-hash.length]; // read frame into hash and data variables System.arraycopy(frame, frame.length-hash.length, hash, 0, hash.length); System.arraycopy(frame, 0, data, 0, frame.length-hash.length); // get crc32 of data CRC32 crc = new CRC32(); crc.update(data); // compare crc32 of data with crc32 of frame return crc.getValue()==toLong(hash); } /** * Transfers a file through a channel in frames and reconstructs it into a new file. * @param jpg_file File name of target file to transfer. * @param err_file The channel noise file used to simulate corruption. * @param out_file The name of the newly-created file. * @throws IOException */ public static void transferFile(String jpg_file, String err_file, String out_file) throws IOException { // read file data into global variables jpg_data = readFileArray(new File(jpg_file)); err_data = readFileArray(new File(err_file)); err_pstn = 0; // variable that will hold the final (transfered) data byte[] out_data = new byte[jpg_data.length]; // holds the current frame data byte[] frame_orig = new byte[100]; byte[] frame_sent = new byte[100]; // send file in chunks (frames) of 100 bytes for(int i=0; i<Math.ceil(jpg_data.length/100); i++){ // copy jpg data into frame and init first-time switch System.arraycopy(jpg_data, i*100, frame_orig, 0, 100); boolean not_first=false; System.out.print("Packet #"+i+": "); // repeat getting same frame until frame crc matches with frame content do { if(not_first)System.out.print("F"); frame_sent=buildFrame(frame_orig); not_first=true; }while(!verifyFrame(frame_sent)); // usually, you'd constrain this by time to prevent infinite loops (in // case the channel is so wacked up it doesn't get a single packet right) // copy frame to image file System.out.println("S"); System.arraycopy(frame_sent, 0, out_data, i*100, 100); } System.out.println("\nDone."); writeFileArray(new File(out_file),out_data); } // global variables for file data and pointer public static byte[] jpg_data; public static byte[] err_data; public static int err_pstn=0; public static void main(String[] args) throws IOException { // list of jpg files String[] jpg_file={ "C:\\Users\\Stefan\\Desktop\\Data\\Images\\photo1.jpg", "C:\\Users\\Stefan\\Desktop\\Data\\Images\\photo2.jpg", "C:\\Users\\Stefan\\Desktop\\Data\\Images\\photo3.jpg", "C:\\Users\\Stefan\\Desktop\\Data\\Images\\photo4.jpg" }; // list of error patterns String[] err_file={ "C:\\Users\\Stefan\\Desktop\\Data\\Error Pattern\\Error Pattern 1.DAT", "C:\\Users\\Stefan\\Desktop\\Data\\Error Pattern\\Error Pattern 2.DAT", "C:\\Users\\Stefan\\Desktop\\Data\\Error Pattern\\Error Pattern 3.DAT", "C:\\Users\\Stefan\\Desktop\\Data\\Error Pattern\\Error Pattern 4.DAT" }; // loop through all jpg/channel combinations and run tests for(int x=0; x<jpg_file.length; x++){ for(int y=0; y<err_file.length; y++){ System.out.println("Transfering photo"+(x+1)+".jpg using Pattern "+(y+1)+"..."); transferFile(jpg_file[x],err_file[y],jpg_file[x].replace("photo","CH#"+y+"_photo")); } } } }

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  • How to call a new thread from button click

    - by Lynnooi
    Hi, I'm trying to call a thread on a button click (btn_more) but i cant get it right. The thread is to get some data and update the images. The problem i have is if i only update 4 or 5 images then it works fine. But if i load more than 5 images i will get a force close. At times when the internet is slow I will face the same problem too. Can please help me to solve this problem or provide me some guidance? Here is the error i got from LogCat: 04-19 18:51:44.907: ERROR/AndroidRuntime(1034): Uncaught handler: thread main exiting due to uncaught exception 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): java.lang.NullPointerException 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): at mobile9.android.gallery.GalleryWallpapers.setWallpaperThumb(GalleryWallpapers.java:383) 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): at mobile9.android.gallery.GalleryWallpapers.access$4(GalleryWallpapers.java:320) 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): at mobile9.android.gallery.GalleryWallpapers$1.handleMessage(GalleryWallpapers.java:266) 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): at android.os.Handler.dispatchMessage(Handler.java:99) 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): at android.os.Looper.loop(Looper.java:123) 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): at android.app.ActivityThread.main(ActivityThread.java:4310) 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): at java.lang.reflect.Method.invokeNative(Native Method) 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): at java.lang.reflect.Method.invoke(Method.java:521) 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860) 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 04-19 18:51:44.927: ERROR/AndroidRuntime(1034): at dalvik.system.NativeStart.main(Native Method) My Code: public class GalleryWallpapers extends Activity implements Runnable { public static String MODEL = android.os.Build.MODEL ; private static final String rootURL = "http://www.uploadhub.com/mobile9/gallery/c/"; private int wallpapers_count = 0; private int ringtones_count = 0; private int index = 0; private int folder_id; private int page; private int page_counter = 1; private String family; private String keyword; private String xmlURL = ""; private String thread_op = "xml"; private ImageButton btn_back; private ImageButton btn_home; private ImageButton btn_filter; private ImageButton btn_search; private TextView btn_more; private ProgressDialog pd; GalleryExampleHandler myExampleHandler = new GalleryExampleHandler(); Context context = GalleryWallpapers.this.getBaseContext(); Drawable image; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); MODEL = "HTC Legend"; // **needs to be remove after testing** try { MODEL = URLEncoder.encode(MODEL,"UTF-8"); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.gallerywallpapers); Bundle b = this.getIntent().getExtras(); family = b.getString("fm").trim(); folder_id = Integer.parseInt(b.getString("fi")); keyword = b.getString("kw").trim(); page = Integer.parseInt(b.getString("page").trim()); WindowManager w = getWindowManager(); Display d = w.getDefaultDisplay(); final int width = d.getWidth(); final int height = d.getHeight(); xmlURL = rootURL + "wallpapers/1/?output=rss&afm=wallpapers&mdl=" + MODEL + "&awd=" + width + "&aht=" + height; if (folder_id > 0) { xmlURL = xmlURL + "&fi=" + folder_id; } pd = ProgressDialog.show(GalleryWallpapers.this, "", "Loading...", true, false); Thread thread = new Thread(GalleryWallpapers.this); thread.start(); btn_more = (TextView) findViewById(R.id.btn_more); btn_more.setOnClickListener(new View.OnClickListener() { public void onClick(View view) { myExampleHandler.filenames.clear(); myExampleHandler.authors.clear(); myExampleHandler.duration.clear(); myExampleHandler.fileid.clear(); btn_more.setBackgroundResource(R.drawable.btn_more_click); page = page + 1; thread_op = "xml"; xmlURL = rootURL + "wallpapers/1/?output=rss&afm=wallpapers&mdl=" + MODEL + "&awd=" + width + "&aht=" + height; xmlURL = xmlURL + "&pg2=" + page; index = 0; pd = ProgressDialog.show(GalleryWallpapers.this, "", "Loading...", true, false); Thread thread = new Thread(GalleryWallpapers.this); thread.start(); } }); } public void run() { if(thread_op.equalsIgnoreCase("xml")){ readXML(); } else if(thread_op.equalsIgnoreCase("getImg")){ getWallpaperThumb(); } handler.sendEmptyMessage(0); } private Handler handler = new Handler() { @Override public void handleMessage(Message msg) { int count = 0; if (!myExampleHandler.filenames.isEmpty()){ count = myExampleHandler.filenames.size(); } count = 6; if(thread_op.equalsIgnoreCase("xml")){ pd.dismiss(); thread_op = "getImg"; btn_more.setBackgroundResource(R.drawable.btn_more); } else if(thread_op.equalsIgnoreCase("getImg")){ setWallpaperThumb(); index++; if (index < count){ Thread thread = new Thread(GalleryWallpapers.this); thread.start(); } } } }; private void readXML(){ if (xmlURL.length() != 0) { try { /* Create a URL we want to load some xml-data from. */ URL url = new URL(xmlURL); /* Get a SAXParser from the SAXPArserFactory. */ SAXParserFactory spf = SAXParserFactory.newInstance(); SAXParser sp = spf.newSAXParser(); /* Get the XMLReader of the SAXParser we created. */ XMLReader xr = sp.getXMLReader(); /* * Create a new ContentHandler and apply it to the * XML-Reader */ xr.setContentHandler(myExampleHandler); /* Parse the xml-data from our URL. */ xr.parse(new InputSource(url.openStream())); /* Parsing has finished. */ /* * Our ExampleHandler now provides the parsed data to * us. */ ParsedExampleDataSet parsedExampleDataSet = myExampleHandler .getParsedData(); } catch (Exception e) { //showDialog(DIALOG_SEND_LOG); } } } private void getWallpaperThumb(){ int i = this.index; if (!myExampleHandler.filenames.elementAt(i).toString().equalsIgnoreCase("")){ image = ImageOperations(context, myExampleHandler.thumbs.elementAt(i).toString(), "image.jpg"); } } private void setWallpaperThumb(){ int i = this.index; if (myExampleHandler.filenames.elementAt(i).toString() != null) { String file_info = myExampleHandler.filenames.elementAt(i).toString(); String author = "\nby " + myExampleHandler.authors.elementAt(i).toString(); final String folder = myExampleHandler.folder_id.elementAt(folder_id).toString(); final String fid = myExampleHandler.fileid.elementAt(i).toString(); ImageView imgView = new ImageView(context); TextView tv_filename = null; TextView tv_author = null; switch (i + 1) { case 1: imgView = (ImageView) findViewById(R.id.image1); tv_filename = (TextView) findViewById(R.id.filename1); tv_author = (TextView) findViewById(R.id.author1); break; case 2: imgView = (ImageView) findViewById(R.id.image2); tv_filename = (TextView) findViewById(R.id.filename2); tv_author = (TextView) findViewById(R.id.author2); break; case 3: imgView = (ImageView) findViewById(R.id.image3); tv_filename = (TextView) findViewById(R.id.filename3); tv_author = (TextView) findViewById(R.id.author3); break; case 4: . . . . . case 10: imgView = (ImageView) findViewById(R.id.image10); tv_filename = (TextView) findViewById(R.id.filename10); tv_author = (TextView) findViewById(R.id.author10); break; } if (image.getIntrinsicHeight() > 0) { imgView.setImageDrawable(image); } else { imgView.setImageResource(R.drawable.default_wallpaper); } tv_filename.setText(file_info); tv_author.setText(author); imgView.setOnClickListener(new View.OnClickListener() { public void onClick(View view) { // Perform action on click } }); } } private Drawable ImageOperations(Context ctx, String url, String saveFilename) { try { InputStream is = (InputStream) this.fetch(url); Drawable d = Drawable.createFromStream(is, "src"); return d; } catch (MalformedURLException e) { e.printStackTrace(); return null; } catch (IOException e) { e.printStackTrace(); return null; } } }

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  • Using getters/setters in Java

    - by Crystal
    I'm having some trouble with the idea of accessing variables from other classes. I had a post here: http://stackoverflow.com/questions/3011642/having-access-to-a-private-variable-from-other-classes-in-java where I got some useful information, and thought an example would be better show it, and ask a separate question as well. I have a form that I can input data to, and it has a List variable. I didn't make it static at first, but I thought if I needed to get the total size from another class, then I wouldn't create an instance of that class in order to use the function to getTotalContacts. I basically want to update my status bar with the total number of contacts that are in my list. One of the members said in the above post to use the original Foo member to get the contacts, but I'm not sure how that works in this case. Any thoughts would be appreciated. Thanks. import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.util.List; import java.util.ArrayList; public class AddressBook { public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { public void run() { AddressBookFrame frame = new AddressBookFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JMenuBar menuBar = new JMenuBar(); frame.setJMenuBar(menuBar); JMenu fileMenu = new JMenu("File"); JMenuItem openItem = new JMenuItem("Open"); JMenuItem saveItem = new JMenuItem("Save"); JMenuItem saveAsItem = new JMenuItem("Save As"); JMenuItem printItem = new JMenuItem("Print"); JMenuItem exitItem = new JMenuItem("Exit"); fileMenu.add(openItem); fileMenu.add(saveItem); fileMenu.add(saveAsItem); fileMenu.add(printItem); fileMenu.add(exitItem); menuBar.add(fileMenu); JMenu editMenu = new JMenu("Edit"); JMenuItem newItem = new JMenuItem("New"); JMenuItem editItem = new JMenuItem("Edit"); JMenuItem deleteItem = new JMenuItem("Delete"); JMenuItem findItem = new JMenuItem("Find"); JMenuItem firstItem = new JMenuItem("First"); JMenuItem previousItem = new JMenuItem("Previous"); JMenuItem nextItem = new JMenuItem("Next"); JMenuItem lastItem = new JMenuItem("Last"); editMenu.add(newItem); editMenu.add(editItem); editMenu.add(deleteItem); editMenu.add(findItem); editMenu.add(firstItem); editMenu.add(previousItem); editMenu.add(nextItem); editMenu.add(lastItem); menuBar.add(editMenu); JMenu helpMenu = new JMenu("Help"); JMenuItem documentationItem = new JMenuItem("Documentation"); JMenuItem aboutItem = new JMenuItem("About"); helpMenu.add(documentationItem); helpMenu.add(aboutItem); menuBar.add(helpMenu); frame.setVisible(true); } }); } } class AddressBookFrame extends JFrame { public AddressBookFrame() { setLayout(new BorderLayout()); setTitle("Address Book"); setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); AddressBookToolBar toolBar = new AddressBookToolBar(); add(toolBar, BorderLayout.NORTH); AddressBookStatusBar aStatusBar = new AddressBookStatusBar(); add(aStatusBar, BorderLayout.SOUTH); AddressBookForm form = new AddressBookForm(); add(form, BorderLayout.CENTER); } public static final int DEFAULT_WIDTH = 500; public static final int DEFAULT_HEIGHT = 500; } /* Create toolbar buttons and add buttons to toolbar */ class AddressBookToolBar extends JPanel { public AddressBookToolBar() { setLayout(new FlowLayout(FlowLayout.LEFT)); JToolBar bar = new JToolBar(); JButton newButton = new JButton("New"); JButton editButton = new JButton("Edit"); JButton deleteButton = new JButton("Delete"); JButton findButton = new JButton("Find"); JButton firstButton = new JButton("First"); JButton previousButton = new JButton("Previous"); JButton nextButton = new JButton("Next"); JButton lastButton = new JButton("Last"); bar.add(newButton); bar.add(editButton); bar.add(deleteButton); bar.add(findButton); bar.add(firstButton); bar.add(previousButton); bar.add(nextButton); bar.add(lastButton); add(bar); } } /* Creates the status bar string */ class AddressBookStatusBar extends JPanel { public AddressBookStatusBar() { setLayout(new FlowLayout(FlowLayout.LEFT)); this.statusBarString = new JLabel("Total: " + AddressBookForm.getTotalContacts()); add(this.statusBarString); } public void updateLabel() { contactsLabel.setText(AddressBookForm.getTotalContacts().toString()); } private JLabel statusBarString; private JLabel contactsLabel; } class AddressBookForm extends JPanel { public AddressBookForm() { // create form panel this.setLayout(new GridLayout(2, 1)); JPanel formPanel = new JPanel(); formPanel.setLayout(new GridLayout(4, 2)); firstName = new JTextField(20); lastName = new JTextField(20); telephone = new JTextField(20); email = new JTextField(20); JLabel firstNameLabel = new JLabel("First Name: ", JLabel.LEFT); formPanel.add(firstNameLabel); formPanel.add(firstName); JLabel lastNameLabel = new JLabel("Last Name: ", JLabel.LEFT); formPanel.add(lastNameLabel); formPanel.add(lastName); JLabel telephoneLabel = new JLabel("Telephone: ", JLabel.LEFT); formPanel.add(telephoneLabel); formPanel.add(telephone); JLabel emailLabel = new JLabel("Email: ", JLabel.LEFT); formPanel.add(emailLabel); formPanel.add(email); add(formPanel); // create button panel JPanel buttonPanel = new JPanel(); JButton insertButton = new JButton("Insert"); JButton displayButton = new JButton("Display"); ActionListener insertAction = new AddressBookListener(); ActionListener displayAction = new AddressBookListener(); insertButton.addActionListener(insertAction); displayButton.addActionListener(displayAction); buttonPanel.add(insertButton); buttonPanel.add(displayButton); add(buttonPanel); } public static int getTotalContacts() { return addressList.size(); } //void addContact(Person contact); private JTextField firstName; private JTextField lastName; private JTextField telephone; private JTextField email; private JLabel contacts; private static List<Person> addressList = new ArrayList<Person>(); private class AddressBookListener implements ActionListener { public void actionPerformed(ActionEvent e) { String buttonPressed = e.getActionCommand(); System.out.println(buttonPressed); if (buttonPressed == "Insert") { Person aPerson = new Person(firstName.getText(), lastName.getText(), telephone.getText(), email.getText()); addressList.add(aPerson); } else { for (Person p : addressList) { System.out.println(p); } } } } } My other question is why do I get the error, "int cannot be dereferenced contactsLabel.setText(AddressbookForm.getTotalContacts().toString()); Thanks!

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  • header confusion. Compiler not recognizing datatypes

    - by numerical25
    I am getting confused on why the compiler is not recognizing my classes. So I am just going to show you my code and let you guys decide. My error is this error C2653: 'RenderEngine' : is not a class or namespace name and it's pointing to this line std::vector<RenderEngine::rDefaultVertex> m_verts; Here is the code for rModel, in its entirety. It contains the varible. the class that holds it is further down. #ifndef _MODEL_H #define _MODEL_H #include "stdafx.h" #include <vector> #include <string> //#include "RenderEngine.h" #include "rTri.h" class rModel { public: typedef tri<WORD> sTri; std::vector<sTri> m_tris; std::vector<RenderEngine::rDefaultVertex> m_verts; std::wstring m_name; ID3D10Buffer *m_pVertexBuffer; ID3D10Buffer *m_pIndexBuffer; rModel( const TCHAR *filename ); rModel( const TCHAR *name, int nVerts, int nTris ); ~rModel(); float GenRadius(); void Scale( float amt ); void Draw(); //------------------------------------ Access functions. int NumVerts(){ return m_verts.size(); } int NumTris(){ return m_tris.size(); } const TCHAR *Name(){ return m_name.c_str(); } RenderEngine::cDefaultVertex *VertData(){ return &m_verts[0]; } sTri *TriData(){ return &m_tris[0]; } }; #endif at the very top of the code there is a header file #include "stdafx.h" that includes this // stdafx.h : include file for standard system include files, // or project specific include files that are used frequently, but // are changed infrequently // #include "targetver.h" #define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers // Windows Header Files: #include <windows.h> // C RunTime Header Files #include <stdlib.h> #include <malloc.h> #include <memory.h> #include <tchar.h> #include "resource.h" #include "d3d10.h" #include "d3dx10.h" #include "dinput.h" #include "RenderEngine.h" #include "rModel.h" // TODO: reference additional headers your program requires here as you can see, RenderEngine.h comes before rModel.h #include "RenderEngine.h" #include "rModel.h" According to my knowledge, it should recognize it. But on the other hand, I am not really that great with organizing headers. Here my my RenderEngine Declaration. #pragma once #include "stdafx.h" #define MAX_LOADSTRING 100 #define MAX_LIGHTS 10 class RenderEngine { public: class rDefaultVertex { public: D3DXVECTOR3 m_vPosition; D3DXVECTOR3 m_vNormal; D3DXCOLOR m_vColor; D3DXVECTOR2 m_TexCoords; }; class rLight { public: rLight() { } D3DXCOLOR m_vColor; D3DXVECTOR3 m_vDirection; }; static HINSTANCE m_hInst; HWND m_hWnd; int m_nCmdShow; TCHAR m_szTitle[MAX_LOADSTRING]; // The title bar text TCHAR m_szWindowClass[MAX_LOADSTRING]; // the main window class name void DrawTextString(int x, int y, D3DXCOLOR color, const TCHAR *strOutput); //static functions static LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam); static INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam); bool InitWindow(); bool InitDirectX(); bool InitInstance(); int Run(); void ShutDown(); void AddLight(D3DCOLOR color, D3DXVECTOR3 pos); RenderEngine() { m_screenRect.right = 800; m_screenRect.bottom = 600; m_iNumLights = 0; } protected: RECT m_screenRect; //direct3d Members ID3D10Device *m_pDevice; // The IDirect3DDevice10 // interface ID3D10Texture2D *m_pBackBuffer; // Pointer to the back buffer ID3D10RenderTargetView *m_pRenderTargetView; // Pointer to render target view IDXGISwapChain *m_pSwapChain; // Pointer to the swap chain RECT m_rcScreenRect; // The dimensions of the screen ID3D10Texture2D *m_pDepthStencilBuffer; ID3D10DepthStencilState *m_pDepthStencilState; ID3D10DepthStencilView *m_pDepthStencilView; //transformation matrixs system D3DXMATRIX m_mtxWorld; D3DXMATRIX m_mtxView; D3DXMATRIX m_mtxProj; //pointers to shaders matrix varibles ID3D10EffectMatrixVariable* m_pmtxWorldVar; ID3D10EffectMatrixVariable* m_pmtxViewVar; ID3D10EffectMatrixVariable* m_pmtxProjVar; //Application Lights rLight m_aLights[MAX_LIGHTS]; // Light array int m_iNumLights; // Number of active lights //light pointers from shader ID3D10EffectVectorVariable* m_pLightDirVar; ID3D10EffectVectorVariable* m_pLightColorVar; ID3D10EffectVectorVariable* m_pNumLightsVar; //Effect members ID3D10Effect *m_pDefaultEffect; ID3D10EffectTechnique *m_pDefaultTechnique; ID3D10InputLayout* m_pDefaultInputLayout; ID3DX10Font *m_pFont; // The font used for rendering text // Sprites used to hold font characters ID3DX10Sprite *m_pFontSprite; ATOM RegisterEngineClass(); void DoFrame(float); bool LoadEffects(); void UpdateMatrices(); void UpdateLights(); }; The classes are defined within the class class rDefaultVertex { public: D3DXVECTOR3 m_vPosition; D3DXVECTOR3 m_vNormal; D3DXCOLOR m_vColor; D3DXVECTOR2 m_TexCoords; }; class rLight { public: rLight() { } D3DXCOLOR m_vColor; D3DXVECTOR3 m_vDirection; }; Not sure if thats good practice, but I am just going by the book. In the end, I just need a good way to organize it so that rModel recognizes RenderEngine. and if possible, the other way around.

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  • I have made two template classes,could any one tell me if these things are useful?

    - by soul
    Recently i made two template classes,according to the book "Modern C++ design". I think these classes are useful but no one in my company agree with me,so could any one tell me if these things are useful? The first one is a parameter wrapper,it can package function paramters to a single dynamic object.It looks like TypeList in "Modern C++ design". You can use it like this: some place of your code: int i = 7; bool b = true; double d = 3.3; CParam *p1 = CreateParam(b,i); CParam *p2 = CreateParam(i,b,d); other place of your code: int i = 0; bool b = false; double d = 0.0; GetParam(p1,b,i); GetParam(p2,i,b,d); The second one is a generic callback wrapper,it has some special point compare to other wrappers: 1.This template class has a dynamic base class,which let you use a single type object represent all wrapper objects. 2.It can wrap the callback together with it's parameters,you can excute the callback sometimes later with the parameters. You can use it like this: somewhere of your code: void Test1(int i) { } void Test2(bool b,int i) { } CallbackFunc * p1 = CreateCallback(Test1,3); CallbackFunc * p2 = CreateCallback(Test2,false,99); otherwhere of your code: p1->Excute(); p2->Excute(); Here is a part of the codes: parameter wrapper: class NullType; struct CParam { virtual ~CParam(){} }; template<class T1,class T2> struct CParam2 : public CParam { CParam2(T1 &t1,T2 &t2):v1(t1),v2(t2){} CParam2(){} T1 v1; T2 v2; }; template<class T1> struct CParam2<T1,NullType> : public CParam { CParam2(T1 &t1):v1(t1){} CParam2(){} T1 v1; }; template<class T1> CParam * CreateParam(T1 t1) { return (new CParam2<T1,NullType>(t1)); } template<class T1,class T2> CParam * CreateParam(T1 t1,T2 t2) { return (new CParam2<T1,T2>(t1,t2)); } template<class T1,class T2,class T3> CParam * CreateParam(T1 t1,T2 t2,T3 t3) { CParam2<T2,T3> t(t2,t3); return new CParam2<T1,CParam2<T2,T3> >(t1,t); } template<class T1> void GetParam(CParam *p,T1 &t1) { PARAM1(T1)* p2 = dynamic_cast<CParam2<T1,NullType>*>(p); t1 = p2->v1; } callback wrapper: #define PARAM1(T1) CParam2<T1,NullType> #define PARAM2(T1,T2) CParam2<T1,T2> #define PARAM3(T1,T2,T3) CParam2<T1,CParam2<T2,T3> > class CallbackFunc { public: virtual ~CallbackFunc(){} virtual void Excute(void){} }; template<class T> class CallbackFunc2 : public CallbackFunc { public: CallbackFunc2():m_b(false){} CallbackFunc2(T &t):m_t(t),m_b(true){} T m_t; bool m_b; }; template<class M,class T> class StaticCallbackFunc : public CallbackFunc2<T> { public: StaticCallbackFunc(M m):m_m(m){} StaticCallbackFunc(M m,T t):CallbackFunc2<T>(t),m_m(m){} virtual void Excute(void){assert(CallbackFunc2<T>::m_b);CallMethod(CallbackFunc2<T>::m_t);} private: template<class T1> void CallMethod(PARAM1(T1) &t){m_m(t.v1);} template<class T1,class T2> void CallMethod(PARAM2(T1,T2) &t){m_m(t.v1,t.v2);} template<class T1,class T2,class T3> void CallMethod(PARAM3(T1,T2,T3) &t){m_m(t.v1,t.v2.v1,t.v2.v2);} private: M m_m; }; template<class M> class StaticCallbackFunc<M,void> : public CallbackFunc { public: StaticCallbackFunc(M method):m_m(method){} virtual void Excute(void){m_m();} private: M m_m; }; template<class C,class M,class T> class MemberCallbackFunc : public CallbackFunc2<T> { public: MemberCallbackFunc(C *pC,M m):m_pC(pC),m_m(m){} MemberCallbackFunc(C *pC,M m,T t):CallbackFunc2<T>(t),m_pC(pC),m_m(m){} virtual void Excute(void){assert(CallbackFunc2<T>::m_b);CallMethod(CallbackFunc2<T>::m_t);} template<class T1> void CallMethod(PARAM1(T1) &t){(m_pC->*m_m)(t.v1);} template<class T1,class T2> void CallMethod(PARAM2(T1,T2) &t){(m_pC->*m_m)(t.v1,t.v2);} template<class T1,class T2,class T3> void CallMethod(PARAM3(T1,T2,T3) &t){(m_pC->*m_m)(t.v1,t.v2.v1,t.v2.v2);} private: C *m_pC; M m_m; }; template<class T1> CallbackFunc *CreateCallback(CallbackFunc *p,T1 t1) { CParam2<T1,NullType> t(t1); return new StaticCallbackFunc<CallbackFunc *,CParam2<T1,NullType> >(p,t); } template<class C,class T1> CallbackFunc *CreateCallback(C *pC,void(C::*pF)(T1),T1 t1) { CParam2<T1,NullType>t(t1); return new MemberCallbackFunc<C,void(C::*)(T1),CParam2<T1,NullType> >(pC,pF,t); } template<class T1> CParam2<T1,NullType> CreateCallbackParam(T1 t1) { return CParam2<T1,NullType>(t1); } template<class T1> void ExcuteCallback(CallbackFunc *p,T1 t1) { CallbackFunc2<CParam2<T1,NullType> > *p2 = dynamic_cast<CallbackFunc2<CParam2<T1,NullType> > *>(p); p2->m_t.v1 = t1; p2->m_b = true; p->Excute(); }

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  • Am I just not understanding TDD unit testing (Asp.Net MVC project)?

    - by KallDrexx
    I am trying to figure out how to correctly and efficiently unit test my Asp.net MVC project. When I started on this project I bought the Pro ASP.Net MVC, and with that book I learned about TDD and unit testing. After seeing the examples, and the fact that I work as a software engineer in QA in my current company, I was amazed at how awesome TDD seemed to be. So I started working on my project and went gun-ho writing unit tests for my database layer, business layer, and controllers. Everything got a unit test prior to implementation. At first I thought it was awesome, but then things started to go downhill. Here are the issues I started encountering: I ended up writing application code in order to make it possible for unit tests to be performed. I don't mean this in a good way as in my code was broken and I had to fix it so the unit test pass. I mean that abstracting out the database to a mock database is impossible due to the use of linq for data retrieval (using the generic repository pattern). The reason is that with linq-sql or linq-entities you can do joins just by doing: var objs = select p from _container.Projects select p.Objects; However, if you mock the database layer out, in order to have that linq pass the unit test you must change the linq to be var objs = select p from _container.Projects join o in _container.Objects on o.ProjectId equals p.Id select o; Not only does this mean you are changing your application logic just so you can unit test it, but you are making your code less efficient for the sole purpose of testability, and getting rid of a lot of advantages using an ORM has in the first place. Furthermore, since a lot of the IDs for my models are database generated, I proved to have to write additional code to handle the non-database tests since IDs were never generated and I had to still handle those cases for the unit tests to pass, yet they would never occur in real scenarios. Thus I ended up throwing out my database unit testing. Writing unit tests for controllers was easy as long as I was returning views. However, the major part of my application (and the one that would benefit most from unit testing) is a complicated ajax web application. For various reasons I decided to change the app from returning views to returning JSON with the data I needed. After this occurred my unit tests became extremely painful to write, as I have not found any good way to write unit tests for non-trivial json. After pounding my head and wasting a ton of time trying to find a good way to unit test the JSON, I gave up and deleted all of my controller unit tests (all controller actions are focused on this part of the app so far). So finally I was left with testing the Service layer (BLL). Right now I am using EF4, however I had this issue with linq-sql as well. I chose to do the EF4 model-first approach because to me, it makes sense to do it that way (define my business objects and let the framework figure out how to translate it into the sql backend). This was fine at the beginning but now it is becoming cumbersome due to relationships. For example say I have Project, User, and Object entities. One Object must be associated to a project, and a project must be associated to a user. This is not only a database specific rule, these are my business rules as well. However, say I want to do a unit test that I am able to save an object (for a simple example). I now have to do the following code just to make sure the save worked: User usr = new User { Name = "Me" }; _userService.SaveUser(usr); Project prj = new Project { Name = "Test Project", Owner = usr }; _projectService.SaveProject(prj); Object obj = new Object { Name = "Test Object" }; _objectService.SaveObject(obj); // Perform verifications There are many issues with having to do all this just to perform one unit test. There are several issues with this. For starters, if I add a new dependency, such as all projects must belong to a category, I must go into EVERY single unit test that references a project, add code to save the category then add code to add the category to the project. This can be a HUGE effort down the road for a very simple business logic change, and yet almost none of the unit tests I will be modifying for this requirement are actually meant to test that feature/requirement. If I then add verifications to my SaveProject method, so that projects cannot be saved unless they have a name with at least 5 characters, I then have to go through every Object and Project unit test to make sure that the new requirement doesn't make any unrelated unit tests fail. If there is an issue in the UserService.SaveUser() method it will cause all project, and object unit tests to fail and it the cause won't be immediately noticeable without having to dig through the exceptions. Thus I have removed all service layer unit tests from my project. I could go on and on, but so far I have not seen any way for unit testing to actually help me and not get in my way. I can see specific cases where I can, and probably will, implement unit tests, such as making sure my data verification methods work correctly, but those cases are few and far between. Some of my issues can probably be mitigated but not without adding extra layers to my application, and thus making more points of failure just so I can unit test. Thus I have no unit tests left in my code. Luckily I heavily use source control so I can get them back if I need but I just don't see the point. Everywhere on the internet I see people talking about how great TDD unit tests are, and I'm not just talking about the fanatical people. The few people who dismiss TDD/Unit tests give bad arguments claiming they are more efficient debugging by hand through the IDE, or that their coding skills are amazing that they don't need it. I recognize that both of those arguments are utter bullocks, especially for a project that needs to be maintainable by multiple developers, but any valid rebuttals to TDD seem to be few and far between. So the point of this post is to ask, am I just not understanding how to use TDD and automatic unit tests?

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  • Logic error for Gauss elimination

    - by iwanttoprogram
    Logic error problem with the Gaussian Elimination code...This code was from my Numerical Methods text in 1990's. The code is typed in from the book- not producing correct output... Sample Run: SOLUTION OF SIMULTANEOUS LINEAR EQUATIONS USING GAUSSIAN ELIMINATION This program uses Gaussian Elimination to solve the system Ax = B, where A is the matrix of known coefficients, B is the vector of known constants and x is the column matrix of the unknowns. Number of equations: 3 Enter elements of matrix [A] A(1,1) = 0 A(1,2) = -6 A(1,3) = 9 A(2,1) = 7 A(2,2) = 0 A(2,3) = -5 A(3,1) = 5 A(3,2) = -8 A(3,3) = 6 Enter elements of [b] vector B(1) = -3 B(2) = 3 B(3) = -4 SOLUTION OF SIMULTANEOUS LINEAR EQUATIONS The solution is x(1) = 0.000000 x(2) = -1.#IND00 x(3) = -1.#IND00 Determinant = -1.#IND00 Press any key to continue . . . The code as copied from the text... //Modified Code from C Numerical Methods Text- June 2009 #include <stdio.h> #include <math.h> #define MAXSIZE 20 //function prototype int gauss (double a[][MAXSIZE], double b[], int n, double *det); int main(void) { double a[MAXSIZE][MAXSIZE], b[MAXSIZE], det; int i, j, n, retval; printf("\n \t SOLUTION OF SIMULTANEOUS LINEAR EQUATIONS"); printf("\n \t USING GAUSSIAN ELIMINATION \n"); printf("\n This program uses Gaussian Elimination to solve the"); printf("\n system Ax = B, where A is the matrix of known"); printf("\n coefficients, B is the vector of known constants"); printf("\n and x is the column matrix of the unknowns."); //get number of equations n = 0; while(n <= 0 || n > MAXSIZE) { printf("\n Number of equations: "); scanf ("%d", &n); } //read matrix A printf("\n Enter elements of matrix [A]\n"); for (i = 0; i < n; i++) for (j = 0; j < n; j++) { printf(" A(%d,%d) = ", i + 1, j + 1); scanf("%lf", &a[i][j]); } //read {B} vector printf("\n Enter elements of [b] vector\n"); for (i = 0; i < n; i++) { printf(" B(%d) = ", i + 1); scanf("%lf", &b[i]); } //call Gauss elimination function retval = gauss(a, b, n, &det); //print results if (retval == 0) { printf("\n\t SOLUTION OF SIMULTANEOUS LINEAR EQUATIONS\n"); printf("\n\t The solution is"); for (i = 0; i < n; i++) printf("\n \t x(%d) = %lf", i + 1, b[i]); printf("\n \t Determinant = %lf \n", det); } else printf("\n \t SINGULAR MATRIX \n"); return 0; } /* Solves the system of equations [A]{x} = {B} using */ /* the Gaussian elimination method with partial pivoting. */ /* Parameters: */ /* n - number of equations */ /* a[n][n] - coefficient matrix */ /* b[n] - right-hand side vector */ /* *det - determinant of [A] */ int gauss (double a[][MAXSIZE], double b[], int n, double *det) { double tol, temp, mult; int npivot, i, j, l, k, flag; //initialization *det = 1.0; tol = 1e-30; //initial tolerance value npivot = 0; //mult = 0; //forward elimination for (k = 0; k < n; k++) { //search for max coefficient in pivot row- a[k][k] pivot element for (i = k + 1; i < n; i++) { if (fabs(a[i][k]) > fabs(a[k][k])) { //interchange row with maxium element with pivot row npivot++; for (l = 0; l < n; l++) { temp = a[i][l]; a[i][l] = a[k][l]; a[k][l] = temp; } temp = b[i]; b[i] = b[k]; b[k] = temp; } } //test for singularity if (fabs(a[k][k]) < tol) { //matrix is singular- terminate flag = 1; return flag; } //compute determinant- the product of the pivot elements *det = *det * a[k][k]; //eliminate the coefficients of X(I) for (i = k; i < n; i++) { mult = a[i][k] / a[k][k]; b[i] = b[i] - b[k] * mult; //compute constants for (j = k; j < n; j++) //compute coefficients a[i][j] = a[i][j] - a[k][j] * mult; } } //adjust the sign of the determinant if(npivot % 2 == 1) *det = *det * (-1.0); //backsubstitution b[n] = b[n] / a[n][n]; for(i = n - 1; i > 1; i--) { for(j = n; j > i + 1; j--) b[i] = b[i] - a[i][j] * b[j]; b[i] = b[i] / a[i - 1][i]; } flag = 0; return flag; } The solution should be: 1.058824, 1.823529, 0.882353 with det as -102.000000 Any insight is appreciated...

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  • Run-Time Check Failure #2 - Stack around the variable 'indices' was corrupted.

    - by numerical25
    well I think I know what the problem is. I am just having a hard time debugging it. I am working with the directx api and I am trying to generate a plane along the x and z axis according to a book I have. The problem is when I am creating my indices. I think I am setting values out of the bounds of the indices array. I am just having a hard time figuring out what I did wrong. I am unfamiliar with the this method of generating a plane. so its a little difficult for me. below is my code. Take emphasis on the indices loop. #include "MyGame.h" //#include "CubeVector.h" /* This code sets a projection and shows a turning cube. What has been added is the project, rotation and a rasterizer to change the rasterization of the cube. The issue that was going on was something with the effect file which was causing the vertices not to be rendered correctly.*/ typedef struct { ID3D10Effect* pEffect; ID3D10EffectTechnique* pTechnique; //vertex information ID3D10Buffer* pVertexBuffer; ID3D10Buffer* pIndicesBuffer; ID3D10InputLayout* pVertexLayout; UINT numVertices; UINT numIndices; }ModelObject; ModelObject modelObject; // World Matrix D3DXMATRIX WorldMatrix; // View Matrix D3DXMATRIX ViewMatrix; // Projection Matrix D3DXMATRIX ProjectionMatrix; ID3D10EffectMatrixVariable* pProjectionMatrixVariable = NULL; //grid information #define NUM_COLS 16 #define NUM_ROWS 16 #define CELL_WIDTH 32 #define CELL_HEIGHT 32 #define NUM_VERTSX (NUM_COLS + 1) #define NUM_VERTSY (NUM_ROWS + 1) bool MyGame::InitDirect3D() { if(!DX3dApp::InitDirect3D()) { return false; } D3D10_RASTERIZER_DESC rastDesc; rastDesc.FillMode = D3D10_FILL_WIREFRAME; rastDesc.CullMode = D3D10_CULL_FRONT; rastDesc.FrontCounterClockwise = true; rastDesc.DepthBias = false; rastDesc.DepthBiasClamp = 0; rastDesc.SlopeScaledDepthBias = 0; rastDesc.DepthClipEnable = false; rastDesc.ScissorEnable = false; rastDesc.MultisampleEnable = false; rastDesc.AntialiasedLineEnable = false; ID3D10RasterizerState *g_pRasterizerState; mpD3DDevice->CreateRasterizerState(&rastDesc, &g_pRasterizerState); mpD3DDevice->RSSetState(g_pRasterizerState); // Set up the World Matrix D3DXMatrixIdentity(&WorldMatrix); D3DXMatrixLookAtLH(&ViewMatrix, new D3DXVECTOR3(0.0f, 10.0f, -20.0f), new D3DXVECTOR3(0.0f, 0.0f, 0.0f), new D3DXVECTOR3(0.0f, 1.0f, 0.0f)); // Set up the projection matrix D3DXMatrixPerspectiveFovLH(&ProjectionMatrix, (float)D3DX_PI * 0.5f, (float)mWidth/(float)mHeight, 0.1f, 100.0f); if(!CreateObject()) { return false; } return true; } //These are actions that take place after the clearing of the buffer and before the present void MyGame::GameDraw() { static float rotationAngle = 0.0f; // create the rotation matrix using the rotation angle D3DXMatrixRotationY(&WorldMatrix, rotationAngle); rotationAngle += (float)D3DX_PI * 0.0f; // Set the input layout mpD3DDevice->IASetInputLayout(modelObject.pVertexLayout); // Set vertex buffer UINT stride = sizeof(VertexPos); UINT offset = 0; mpD3DDevice->IASetVertexBuffers(0, 1, &modelObject.pVertexBuffer, &stride, &offset); mpD3DDevice->IASetIndexBuffer(modelObject.pIndicesBuffer, DXGI_FORMAT_R32_UINT, 0); // Set primitive topology mpD3DDevice->IASetPrimitiveTopology(D3D10_PRIMITIVE_TOPOLOGY_TRIANGLELIST); // Combine and send the final matrix to the shader D3DXMATRIX finalMatrix = (WorldMatrix * ViewMatrix * ProjectionMatrix); pProjectionMatrixVariable->SetMatrix((float*)&finalMatrix); // make sure modelObject is valid // Render a model object D3D10_TECHNIQUE_DESC techniqueDescription; modelObject.pTechnique->GetDesc(&techniqueDescription); // Loop through the technique passes for(UINT p=0; p < techniqueDescription.Passes; ++p) { modelObject.pTechnique->GetPassByIndex(p)->Apply(0); // draw the cube using all 36 vertices and 12 triangles mpD3DDevice->DrawIndexed(modelObject.numIndices,0,0); } } //Render actually incapsulates Gamedraw, so you can call data before you actually clear the buffer or after you //present data void MyGame::Render() { DX3dApp::Render(); } bool MyGame::CreateObject() { VertexPos vertices[NUM_VERTSX * NUM_VERTSY]; for(int z=0; z < NUM_VERTSY; ++z) { for(int x = 0; x < NUM_VERTSX; ++x) { vertices[x + z * NUM_VERTSX].pos.x = (float)x * CELL_WIDTH; vertices[x + z * NUM_VERTSX].pos.z = (float)z * CELL_HEIGHT; vertices[x + z * NUM_VERTSX].pos.y = 0.0f; vertices[x + z * NUM_VERTSX].color = D3DXVECTOR4(1.0, 0.0f, 0.0f, 0.0f); } } DWORD indices[NUM_VERTSX * NUM_VERTSY]; int curIndex = 0; for(int z=0; z < NUM_ROWS; ++z) { for(int x = 0; x < NUM_COLS; ++x) { int curVertex = x + (z * NUM_VERTSX); indices[curIndex] = curVertex; indices[curIndex + 1] = curVertex + NUM_VERTSX; indices[curIndex + 2] = curVertex + 1; indices[curIndex + 3] = curVertex + 1; indices[curIndex + 4] = curVertex + NUM_VERTSX; indices[curIndex + 5] = curVertex + NUM_VERTSX + 1; curIndex += 6; } } //Create Layout D3D10_INPUT_ELEMENT_DESC layout[] = { {"POSITION",0,DXGI_FORMAT_R32G32B32_FLOAT, 0 , 0, D3D10_INPUT_PER_VERTEX_DATA, 0}, {"COLOR",0,DXGI_FORMAT_R32G32B32A32_FLOAT, 0 , 12, D3D10_INPUT_PER_VERTEX_DATA, 0} }; UINT numElements = (sizeof(layout)/sizeof(layout[0])); modelObject.numVertices = sizeof(vertices)/sizeof(VertexPos); //Create buffer desc D3D10_BUFFER_DESC bufferDesc; bufferDesc.Usage = D3D10_USAGE_DEFAULT; bufferDesc.ByteWidth = sizeof(VertexPos) * modelObject.numVertices; bufferDesc.BindFlags = D3D10_BIND_VERTEX_BUFFER; bufferDesc.CPUAccessFlags = 0; bufferDesc.MiscFlags = 0; D3D10_SUBRESOURCE_DATA initData; initData.pSysMem = vertices; //Create the buffer HRESULT hr = mpD3DDevice->CreateBuffer(&bufferDesc, &initData, &modelObject.pVertexBuffer); if(FAILED(hr)) return false; modelObject.numIndices = sizeof(indices)/sizeof(DWORD); bufferDesc.ByteWidth = sizeof(DWORD) * modelObject.numIndices; bufferDesc.BindFlags = D3D10_BIND_INDEX_BUFFER; initData.pSysMem = indices; hr = mpD3DDevice->CreateBuffer(&bufferDesc, &initData, &modelObject.pIndicesBuffer); if(FAILED(hr)) return false; ///////////////////////////////////////////////////////////////////////////// //Set up fx files LPCWSTR effectFilename = L"effect.fx"; modelObject.pEffect = NULL; hr = D3DX10CreateEffectFromFile(effectFilename, NULL, NULL, "fx_4_0", D3D10_SHADER_ENABLE_STRICTNESS, 0, mpD3DDevice, NULL, NULL, &modelObject.pEffect, NULL, NULL); if(FAILED(hr)) return false; pProjectionMatrixVariable = modelObject.pEffect->GetVariableByName("Projection")->AsMatrix(); //Dont sweat the technique. Get it! LPCSTR effectTechniqueName = "Render"; modelObject.pTechnique = modelObject.pEffect->GetTechniqueByName(effectTechniqueName); if(modelObject.pTechnique == NULL) return false; //Create Vertex layout D3D10_PASS_DESC passDesc; modelObject.pTechnique->GetPassByIndex(0)->GetDesc(&passDesc); hr = mpD3DDevice->CreateInputLayout(layout, numElements, passDesc.pIAInputSignature, passDesc.IAInputSignatureSize, &modelObject.pVertexLayout); if(FAILED(hr)) return false; return true; }

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  • Passing ActionListeners in Java, pack()

    - by Crystal
    Two questions. First question is I'm trying to create a simple form that when you press a button, it adds a Person object to the ArrayList. However, since I am not used to GUIs, I tried creating one and am first just trying to get the user input from the JTextField, create an ActionListener object of the appropriate type, so once that works, then I can pass in all the JTextField inputs to create my Person object. Unfortunately, I am not getting any data when I type in something to the firstName JTextField and was wondering if someone could look at my code below. import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.util.List; import java.util.ArrayList; public class AddressBook { public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { public void run() { AddressBookFrame frame = new AddressBookFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JMenuBar menuBar = new JMenuBar(); frame.setJMenuBar(menuBar); JMenu fileMenu = new JMenu("File"); JMenuItem openItem = new JMenuItem("Open"); JMenuItem saveItem = new JMenuItem("Save"); JMenuItem saveAsItem = new JMenuItem("Save As"); JMenuItem printItem = new JMenuItem("Print"); JMenuItem exitItem = new JMenuItem("Exit"); fileMenu.add(openItem); fileMenu.add(saveItem); fileMenu.add(saveAsItem); fileMenu.add(printItem); fileMenu.add(exitItem); menuBar.add(fileMenu); JMenu editMenu = new JMenu("Edit"); JMenuItem newItem = new JMenuItem("New"); JMenuItem editItem = new JMenuItem("Edit"); JMenuItem deleteItem = new JMenuItem("Delete"); JMenuItem findItem = new JMenuItem("Find"); JMenuItem firstItem = new JMenuItem("First"); JMenuItem previousItem = new JMenuItem("Previous"); JMenuItem nextItem = new JMenuItem("Next"); JMenuItem lastItem = new JMenuItem("Last"); editMenu.add(newItem); editMenu.add(editItem); editMenu.add(deleteItem); editMenu.add(findItem); editMenu.add(firstItem); editMenu.add(previousItem); editMenu.add(nextItem); editMenu.add(lastItem); menuBar.add(editMenu); JMenu helpMenu = new JMenu("Help"); JMenuItem documentationItem = new JMenuItem("Documentation"); JMenuItem aboutItem = new JMenuItem("About"); helpMenu.add(documentationItem); helpMenu.add(aboutItem); menuBar.add(helpMenu); frame.setVisible(true); } }); } } class AddressBookFrame extends JFrame { public AddressBookFrame() { setLayout(new BorderLayout()); setTitle("Address Book"); setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); AddressBookToolBar toolBar = new AddressBookToolBar(); add(toolBar, BorderLayout.NORTH); AddressBookStatusBar aStatusBar = new AddressBookStatusBar("5"); add(aStatusBar, BorderLayout.SOUTH); AddressBookForm form = new AddressBookForm(); add(form, BorderLayout.CENTER); } public static final int DEFAULT_WIDTH = 500; public static final int DEFAULT_HEIGHT = 500; } /* Create toolbar buttons and add buttons to toolbar */ class AddressBookToolBar extends JPanel { public AddressBookToolBar() { setLayout(new FlowLayout(FlowLayout.LEFT)); JToolBar bar = new JToolBar(); JButton newButton = new JButton("New"); JButton editButton = new JButton("Edit"); JButton deleteButton = new JButton("Delete"); JButton findButton = new JButton("Find"); JButton firstButton = new JButton("First"); JButton previousButton = new JButton("Previous"); JButton nextButton = new JButton("Next"); JButton lastButton = new JButton("Last"); bar.add(newButton); bar.add(editButton); bar.add(deleteButton); bar.add(findButton); bar.add(firstButton); bar.add(previousButton); bar.add(nextButton); bar.add(lastButton); add(bar); } } /* Creates the status bar string */ class AddressBookStatusBar extends JPanel { public AddressBookStatusBar(String statusBarString) { setLayout(new FlowLayout(FlowLayout.LEFT)); this.statusBarString = new JLabel("Total number of people: " + statusBarString); add(this.statusBarString); } private JLabel statusBarString; private int totalContacts; } class AddressBookForm extends JPanel { public AddressBookForm() { this.setLayout(new GridLayout(2, 1)); JPanel formPanel = new JPanel(); formPanel.setLayout(new GridLayout(4, 2)); JTextField firstName = new JTextField(20); JTextField lastName = new JTextField(20); JTextField telephone = new JTextField(20); JTextField email = new JTextField(20); JLabel firstNameLabel = new JLabel("First Name: ", JLabel.LEFT); formPanel.add(firstNameLabel); formPanel.add(firstName); JLabel lastNameLabel = new JLabel("Last Name: ", JLabel.LEFT); formPanel.add(lastNameLabel); formPanel.add(lastName); JLabel telephoneLabel = new JLabel("Telephone: ", JLabel.LEFT); formPanel.add(telephoneLabel); formPanel.add(telephone); JLabel emailLabel = new JLabel("Email: ", JLabel.LEFT); formPanel.add(emailLabel); formPanel.add(email); add(formPanel); JPanel buttonPanel = new JPanel(); JButton insertButton = new JButton("Insert"); JButton displayButton = new JButton("Display"); // create button actions AddressBookManager insertAction = new AddressBookManager(firstName.getText()); insertButton.addActionListener(insertAction); buttonPanel.add(insertButton); buttonPanel.add(displayButton); add(buttonPanel); } private List<Person> addressList = new ArrayList<Person>(); private class AddressBookManager implements ActionListener { public AddressBookManager(String text) { // addressList.add( setName(text); System.out.println("Test" + text); } public void actionPerformed(ActionEvent e) { System.out.println("Hello" + name); } public void setName(String name) { this.name = name; } private String name; } } Second question is, how do I make my form not take up the whole center space. I don't like the stretch look and was hoping the JTextFields could be just one line long, not a big box. Same thing with the buttons. Any thoughts? Thanks.

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  • depth first search graph by using linked list

    - by programmerwannabe
    im using mac book and i cannot read the text file using this code. moreover, can you guys please add function(graph is connected?, and is this graph tree?) inputA.txt consist 1 2 1 6 1 5 2 3 2 6 3 4 3 6 4 5 4 6 5 6 #include <stdio.h> #include <memory.h> #include <stdlib.h> #define MAX 10 #define TRUE 1 #define FALSE 0 typedef struct Graph{ int vertex; struct Graph* link; } g_node; typedef struct graphType{ int x; int visited[MAX]; g_node* adjList_H[MAX]; } graphType; typedef struct stack{ int data; struct stack* link; } s_node; s_node* top; void push(int item){ s_node* n=(s_node*)malloc(sizeof(s_node)); n->data = item; n->link = top; top = n; } int pop(){ int item; s_node* n=top; if(top == NULL){ puts("\nstack is empty!\n"); return 0; } else { item = n-> data; top = n->link; free(n); return item; } } void createGraph(graphType* g){ int v; g->x = 1; for(v=1 ; v < MAX ; v++){ g -> visited[v] = FALSE; g -> adjList_H[v] = NULL; } } void insertVertex(graphType* g, int v){ if(((g->x)) > MAX){ puts("\n it has been overed the number of vertex\n"); return ; } g -> x++; } void insertEdge(graphType* g, int u, int v){ g_node* node; if(u >= g -> x || v >= g -> x){ puts("\n no vertex in the graph\n"); return ; } node = (g_node*)malloc(sizeof(g_node)); node -> vertex = v; node -> link = g -> adjList_H[u]; g-> adjList_H[u] = node; } void print_adjList(graphType* g){ int i; g_node *p; for(i=1 ; i<g -> x ; i++){ printf("\n\t\t vertex %d adjacency list ", i); p = g -> adjList_H[i]; while(p){ printf("-> %d", p-> vertex); p = p-> link; } } } void DFS_adjList(graphType* g, int v) { g_node* w; top = NULL; push(v); g->visited[v] = TRUE; printf(" %d", v); while(top != NULL){ w=g->adjList_H[v]; while(w){ if (!g->visited[w->vertex]){ push(w->vertex); g->visited[w->vertex] = TRUE; printf(" %d", w->vertex); v = w->vertex; w=g->adjList_H[v]; } else w= w->link; } v = pop(); } } int main (int argc, const char * argv[]) { FILE *fp; char mychar; char arr[][2]={0, }; int j, k; int i; graphType *G9; G9 = (graphType*)malloc(sizeof(graphType)); createGraph(G9); for(i=1; i<7 ; i++) insertVertex(G9, i); fp = fopen("inputD.txt", "r"); for(j = 0 ; j< 10 ; j++){ for(k = 0 ; k < 2 ; k++){ mychar = fgetc(fp); if(mychar = EOF){ j=10; break; } else if(mychar == ' ') continue; else if(mychar <= '9' || mychar >= '1'){ arr[j][k] = mychar; printf("%d%d", arr[i][k]); } } } insertEdge(G9, 1, 2); insertEdge(G9, 1, 6); insertEdge(G9, 1, 5); insertEdge(G9, 2, 3); insertEdge(G9, 2, 6); insertEdge(G9, 3, 4); insertEdge(G9, 3, 6); insertEdge(G9, 4, 5); insertEdge(G9, 4, 6); insertEdge(G9, 5, 6); insertEdge(G9, 6, 5); insertEdge(G9, 6, 4); insertEdge(G9, 5, 4); insertEdge(G9, 6, 3); insertEdge(G9, 4, 3); insertEdge(G9, 6, 2); insertEdge(G9, 3, 2); insertEdge(G9, 5, 1); insertEdge(G9, 6, 1); insertEdge(G9, 2, 1); printf("\n graph adjacency list "); print_adjList(G9); printf("\n \n//////////////////////////////////////////////\n\n depth fist search >> "); DFS_adjList(G9, 1); return 0; }

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  • Zen and the Art of File and Folder Organization

    - by Mark Virtue
    Is your desk a paragon of neatness, or does it look like a paper-bomb has gone off? If you’ve been putting off getting organized because the task is too huge or daunting, or you don’t know where to start, we’ve got 40 tips to get you on the path to zen mastery of your filing system. For all those readers who would like to get their files and folders organized, or, if they’re already organized, better organized—we have compiled a complete guide to getting organized and staying organized, a comprehensive article that will hopefully cover every possible tip you could want. Signs that Your Computer is Poorly Organized If your computer is a mess, you’re probably already aware of it.  But just in case you’re not, here are some tell-tale signs: Your Desktop has over 40 icons on it “My Documents” contains over 300 files and 60 folders, including MP3s and digital photos You use the Windows’ built-in search facility whenever you need to find a file You can’t find programs in the out-of-control list of programs in your Start Menu You save all your Word documents in one folder, all your spreadsheets in a second folder, etc Any given file that you’re looking for may be in any one of four different sets of folders But before we start, here are some quick notes: We’re going to assume you know what files and folders are, and how to create, save, rename, copy and delete them The organization principles described in this article apply equally to all computer systems.  However, the screenshots here will reflect how things look on Windows (usually Windows 7).  We will also mention some useful features of Windows that can help you get organized. Everyone has their own favorite methodology of organizing and filing, and it’s all too easy to get into “My Way is Better than Your Way” arguments.  The reality is that there is no perfect way of getting things organized.  When I wrote this article, I tried to keep a generalist and objective viewpoint.  I consider myself to be unusually well organized (to the point of obsession, truth be told), and I’ve had 25 years experience in collecting and organizing files on computers.  So I’ve got a lot to say on the subject.  But the tips I have described here are only one way of doing it.  Hopefully some of these tips will work for you too, but please don’t read this as any sort of “right” way to do it. At the end of the article we’ll be asking you, the reader, for your own organization tips. Why Bother Organizing At All? For some, the answer to this question is self-evident. And yet, in this era of powerful desktop search software (the search capabilities built into the Windows Vista and Windows 7 Start Menus, and third-party programs like Google Desktop Search), the question does need to be asked, and answered. I have a friend who puts every file he ever creates, receives or downloads into his My Documents folder and doesn’t bother filing them into subfolders at all.  He relies on the search functionality built into his Windows operating system to help him find whatever he’s looking for.  And he always finds it.  He’s a Search Samurai.  For him, filing is a waste of valuable time that could be spent enjoying life! It’s tempting to follow suit.  On the face of it, why would anyone bother to take the time to organize their hard disk when such excellent search software is available?  Well, if all you ever want to do with the files you own is to locate and open them individually (for listening, editing, etc), then there’s no reason to ever bother doing one scrap of organization.  But consider these common tasks that are not achievable with desktop search software: Find files manually.  Often it’s not convenient, speedy or even possible to utilize your desktop search software to find what you want.  It doesn’t work 100% of the time, or you may not even have it installed.  Sometimes its just plain faster to go straight to the file you want, if you know it’s in a particular sub-folder, rather than trawling through hundreds of search results. Find groups of similar files (e.g. all your “work” files, all the photos of your Europe holiday in 2008, all your music videos, all the MP3s from Dark Side of the Moon, all your letters you wrote to your wife, all your tax returns).  Clever naming of the files will only get you so far.  Sometimes it’s the date the file was created that’s important, other times it’s the file format, and other times it’s the purpose of the file.  How do you name a collection of files so that they’re easy to isolate based on any of the above criteria?  Short answer, you can’t. Move files to a new computer.  It’s time to upgrade your computer.  How do you quickly grab all the files that are important to you?  Or you decide to have two computers now – one for home and one for work.  How do you quickly isolate only the work-related files to move them to the work computer? Synchronize files to other computers.  If you have more than one computer, and you need to mirror some of your files onto the other computer (e.g. your music collection), then you need a way to quickly determine which files are to be synced and which are not.  Surely you don’t want to synchronize everything? Choose which files to back up.  If your backup regime calls for multiple backups, or requires speedy backups, then you’ll need to be able to specify which files are to be backed up, and which are not.  This is not possible if they’re all in the same folder. Finally, if you’re simply someone who takes pleasure in being organized, tidy and ordered (me! me!), then you don’t even need a reason.  Being disorganized is simply unthinkable. Tips on Getting Organized Here we present our 40 best tips on how to get organized.  Or, if you’re already organized, to get better organized. Tip #1.  Choose Your Organization System Carefully The reason that most people are not organized is that it takes time.  And the first thing that takes time is deciding upon a system of organization.  This is always a matter of personal preference, and is not something that a geek on a website can tell you.  You should always choose your own system, based on how your own brain is organized (which makes the assumption that your brain is, in fact, organized). We can’t instruct you, but we can make suggestions: You may want to start off with a system based on the users of the computer.  i.e. “My Files”, “My Wife’s Files”, My Son’s Files”, etc.  Inside “My Files”, you might then break it down into “Personal” and “Business”.  You may then realize that there are overlaps.  For example, everyone may want to share access to the music library, or the photos from the school play.  So you may create another folder called “Family”, for the “common” files. You may decide that the highest-level breakdown of your files is based on the “source” of each file.  In other words, who created the files.  You could have “Files created by ME (business or personal)”, “Files created by people I know (family, friends, etc)”, and finally “Files created by the rest of the world (MP3 music files, downloaded or ripped movies or TV shows, software installation files, gorgeous desktop wallpaper images you’ve collected, etc).”  This system happens to be the one I use myself.  See below:  Mark is for files created by meVC is for files created by my company (Virtual Creations)Others is for files created by my friends and familyData is the rest of the worldAlso, Settings is where I store the configuration files and other program data files for my installed software (more on this in tip #34, below). Each folder will present its own particular set of requirements for further sub-organization.  For example, you may decide to organize your music collection into sub-folders based on the artist’s name, while your digital photos might get organized based on the date they were taken.  It can be different for every sub-folder! Another strategy would be based on “currentness”.  Files you have yet to open and look at live in one folder.  Ones that have been looked at but not yet filed live in another place.  Current, active projects live in yet another place.  All other files (your “archive”, if you like) would live in a fourth folder. (And of course, within that last folder you’d need to create a further sub-system based on one of the previous bullet points). Put some thought into this – changing it when it proves incomplete can be a big hassle!  Before you go to the trouble of implementing any system you come up with, examine a wide cross-section of the files you own and see if they will all be able to find a nice logical place to sit within your system. Tip #2.  When You Decide on Your System, Stick to It! There’s nothing more pointless than going to all the trouble of creating a system and filing all your files, and then whenever you create, receive or download a new file, you simply dump it onto your Desktop.  You need to be disciplined – forever!  Every new file you get, spend those extra few seconds to file it where it belongs!  Otherwise, in just a month or two, you’ll be worse off than before – half your files will be organized and half will be disorganized – and you won’t know which is which! Tip #3.  Choose the Root Folder of Your Structure Carefully Every data file (document, photo, music file, etc) that you create, own or is important to you, no matter where it came from, should be found within one single folder, and that one single folder should be located at the root of your C: drive (as a sub-folder of C:\).  In other words, do not base your folder structure in standard folders like “My Documents”.  If you do, then you’re leaving it up to the operating system engineers to decide what folder structure is best for you.  And every operating system has a different system!  In Windows 7 your files are found in C:\Users\YourName, whilst on Windows XP it was C:\Documents and Settings\YourName\My Documents.  In UNIX systems it’s often /home/YourName. These standard default folders tend to fill up with junk files and folders that are not at all important to you.  “My Documents” is the worst offender.  Every second piece of software you install, it seems, likes to create its own folder in the “My Documents” folder.  These folders usually don’t fit within your organizational structure, so don’t use them!  In fact, don’t even use the “My Documents” folder at all.  Allow it to fill up with junk, and then simply ignore it.  It sounds heretical, but: Don’t ever visit your “My Documents” folder!  Remove your icons/links to “My Documents” and replace them with links to the folders you created and you care about! Create your own file system from scratch!  Probably the best place to put it would be on your D: drive – if you have one.  This way, all your files live on one drive, while all the operating system and software component files live on the C: drive – simply and elegantly separated.  The benefits of that are profound.  Not only are there obvious organizational benefits (see tip #10, below), but when it comes to migrate your data to a new computer, you can (sometimes) simply unplug your D: drive and plug it in as the D: drive of your new computer (this implies that the D: drive is actually a separate physical disk, and not a partition on the same disk as C:).  You also get a slight speed improvement (again, only if your C: and D: drives are on separate physical disks). Warning:  From tip #12, below, you will see that it’s actually a good idea to have exactly the same file system structure – including the drive it’s filed on – on all of the computers you own.  So if you decide to use the D: drive as the storage system for your own files, make sure you are able to use the D: drive on all the computers you own.  If you can’t ensure that, then you can still use a clever geeky trick to store your files on the D: drive, but still access them all via the C: drive (see tip #17, below). If you only have one hard disk (C:), then create a dedicated folder that will contain all your files – something like C:\Files.  The name of the folder is not important, but make it a single, brief word. There are several reasons for this: When creating a backup regime, it’s easy to decide what files should be backed up – they’re all in the one folder! If you ever decide to trade in your computer for a new one, you know exactly which files to migrate You will always know where to begin a search for any file If you synchronize files with other computers, it makes your synchronization routines very simple.   It also causes all your shortcuts to continue to work on the other machines (more about this in tip #24, below). Once you’ve decided where your files should go, then put all your files in there – Everything!  Completely disregard the standard, default folders that are created for you by the operating system (“My Music”, “My Pictures”, etc).  In fact, you can actually relocate many of those folders into your own structure (more about that below, in tip #6). The more completely you get all your data files (documents, photos, music, etc) and all your configuration settings into that one folder, then the easier it will be to perform all of the above tasks. Once this has been done, and all your files live in one folder, all the other folders in C:\ can be thought of as “operating system” folders, and therefore of little day-to-day interest for us. Here’s a screenshot of a nicely organized C: drive, where all user files are located within the \Files folder:   Tip #4.  Use Sub-Folders This would be our simplest and most obvious tip.  It almost goes without saying.  Any organizational system you decide upon (see tip #1) will require that you create sub-folders for your files.  Get used to creating folders on a regular basis. Tip #5.  Don’t be Shy About Depth Create as many levels of sub-folders as you need.  Don’t be scared to do so.  Every time you notice an opportunity to group a set of related files into a sub-folder, do so.  Examples might include:  All the MP3s from one music CD, all the photos from one holiday, or all the documents from one client. It’s perfectly okay to put files into a folder called C:\Files\Me\From Others\Services\WestCo Bank\Statements\2009.  That’s only seven levels deep.  Ten levels is not uncommon.  Of course, it’s possible to take this too far.  If you notice yourself creating a sub-folder to hold only one file, then you’ve probably become a little over-zealous.  On the other hand, if you simply create a structure with only two levels (for example C:\Files\Work) then you really haven’t achieved any level of organization at all (unless you own only six files!).  Your “Work” folder will have become a dumping ground, just like your Desktop was, with most likely hundreds of files in it. Tip #6.  Move the Standard User Folders into Your Own Folder Structure Most operating systems, including Windows, create a set of standard folders for each of its users.  These folders then become the default location for files such as documents, music files, digital photos and downloaded Internet files.  In Windows 7, the full list is shown below: Some of these folders you may never use nor care about (for example, the Favorites folder, if you’re not using Internet Explorer as your browser).  Those ones you can leave where they are.  But you may be using some of the other folders to store files that are important to you.  Even if you’re not using them, Windows will still often treat them as the default storage location for many types of files.  When you go to save a standard file type, it can become annoying to be automatically prompted to save it in a folder that’s not part of your own file structure. But there’s a simple solution:  Move the folders you care about into your own folder structure!  If you do, then the next time you go to save a file of the corresponding type, Windows will prompt you to save it in the new, moved location. Moving the folders is easy.  Simply drag-and-drop them to the new location.  Here’s a screenshot of the default My Music folder being moved to my custom personal folder (Mark): Tip #7.  Name Files and Folders Intelligently This is another one that almost goes without saying, but we’ll say it anyway:  Do not allow files to be created that have meaningless names like Document1.doc, or folders called New Folder (2).  Take that extra 20 seconds and come up with a meaningful name for the file/folder – one that accurately divulges its contents without repeating the entire contents in the name. Tip #8.  Watch Out for Long Filenames Another way to tell if you have not yet created enough depth to your folder hierarchy is that your files often require really long names.  If you need to call a file Johnson Sales Figures March 2009.xls (which might happen to live in the same folder as Abercrombie Budget Report 2008.xls), then you might want to create some sub-folders so that the first file could be simply called March.xls, and living in the Clients\Johnson\Sales Figures\2009 folder. A well-placed file needs only a brief filename! Tip #9.  Use Shortcuts!  Everywhere! This is probably the single most useful and important tip we can offer.  A shortcut allows a file to be in two places at once. Why would you want that?  Well, the file and folder structure of every popular operating system on the market today is hierarchical.  This means that all objects (files and folders) always live within exactly one parent folder.  It’s a bit like a tree.  A tree has branches (folders) and leaves (files).  Each leaf, and each branch, is supported by exactly one parent branch, all the way back to the root of the tree (which, incidentally, is exactly why C:\ is called the “root folder” of the C: drive). That hard disks are structured this way may seem obvious and even necessary, but it’s only one way of organizing data.  There are others:  Relational databases, for example, organize structured data entirely differently.  The main limitation of hierarchical filing structures is that a file can only ever be in one branch of the tree – in only one folder – at a time.  Why is this a problem?  Well, there are two main reasons why this limitation is a problem for computer users: The “correct” place for a file, according to our organizational rationale, is very often a very inconvenient place for that file to be located.  Just because it’s correctly filed doesn’t mean it’s easy to get to.  Your file may be “correctly” buried six levels deep in your sub-folder structure, but you may need regular and speedy access to this file every day.  You could always move it to a more convenient location, but that would mean that you would need to re-file back to its “correct” location it every time you’d finished working on it.  Most unsatisfactory. A file may simply “belong” in two or more different locations within your file structure.  For example, say you’re an accountant and you have just completed the 2009 tax return for John Smith.  It might make sense to you to call this file 2009 Tax Return.doc and file it under Clients\John Smith.  But it may also be important to you to have the 2009 tax returns from all your clients together in the one place.  So you might also want to call the file John Smith.doc and file it under Tax Returns\2009.  The problem is, in a purely hierarchical filing system, you can’t put it in both places.  Grrrrr! Fortunately, Windows (and most other operating systems) offers a way for you to do exactly that:  It’s called a “shortcut” (also known as an “alias” on Macs and a “symbolic link” on UNIX systems).  Shortcuts allow a file to exist in one place, and an icon that represents the file to be created and put anywhere else you please.  In fact, you can create a dozen such icons and scatter them all over your hard disk.  Double-clicking on one of these icons/shortcuts opens up the original file, just as if you had double-clicked on the original file itself. Consider the following two icons: The one on the left is the actual Word document, while the one on the right is a shortcut that represents the Word document.  Double-clicking on either icon will open the same file.  There are two main visual differences between the icons: The shortcut will have a small arrow in the lower-left-hand corner (on Windows, anyway) The shortcut is allowed to have a name that does not include the file extension (the “.docx” part, in this case) You can delete the shortcut at any time without losing any actual data.  The original is still intact.  All you lose is the ability to get to that data from wherever the shortcut was. So why are shortcuts so great?  Because they allow us to easily overcome the main limitation of hierarchical file systems, and put a file in two (or more) places at the same time.  You will always have files that don’t play nice with your organizational rationale, and can’t be filed in only one place.  They demand to exist in two places.  Shortcuts allow this!  Furthermore, they allow you to collect your most often-opened files and folders together in one spot for convenient access.  The cool part is that the original files stay where they are, safe forever in their perfectly organized location. So your collection of most often-opened files can – and should – become a collection of shortcuts! If you’re still not convinced of the utility of shortcuts, consider the following well-known areas of a typical Windows computer: The Start Menu (and all the programs that live within it) The Quick Launch bar (or the Superbar in Windows 7) The “Favorite folders” area in the top-left corner of the Windows Explorer window (in Windows Vista or Windows 7) Your Internet Explorer Favorites or Firefox Bookmarks Each item in each of these areas is a shortcut!  Each of those areas exist for one purpose only:  For convenience – to provide you with a collection of the files and folders you access most often. It should be easy to see by now that shortcuts are designed for one single purpose:  To make accessing your files more convenient.  Each time you double-click on a shortcut, you are saved the hassle of locating the file (or folder, or program, or drive, or control panel icon) that it represents. Shortcuts allow us to invent a golden rule of file and folder organization: “Only ever have one copy of a file – never have two copies of the same file.  Use a shortcut instead” (this rule doesn’t apply to copies created for backup purposes, of course!) There are also lesser rules, like “don’t move a file into your work area – create a shortcut there instead”, and “any time you find yourself frustrated with how long it takes to locate a file, create a shortcut to it and place that shortcut in a convenient location.” So how to we create these massively useful shortcuts?  There are two main ways: “Copy” the original file or folder (click on it and type Ctrl-C, or right-click on it and select Copy):  Then right-click in an empty area of the destination folder (the place where you want the shortcut to go) and select Paste shortcut: Right-drag (drag with the right mouse button) the file from the source folder to the destination folder.  When you let go of the mouse button at the destination folder, a menu pops up: Select Create shortcuts here. Note that when shortcuts are created, they are often named something like Shortcut to Budget Detail.doc (windows XP) or Budget Detail – Shortcut.doc (Windows 7).   If you don’t like those extra words, you can easily rename the shortcuts after they’re created, or you can configure Windows to never insert the extra words in the first place (see our article on how to do this). And of course, you can create shortcuts to folders too, not just to files! Bottom line: Whenever you have a file that you’d like to access from somewhere else (whether it’s convenience you’re after, or because the file simply belongs in two places), create a shortcut to the original file in the new location. Tip #10.  Separate Application Files from Data Files Any digital organization guru will drum this rule into you.  Application files are the components of the software you’ve installed (e.g. Microsoft Word, Adobe Photoshop or Internet Explorer).  Data files are the files that you’ve created for yourself using that software (e.g. Word Documents, digital photos, emails or playlists). Software gets installed, uninstalled and upgraded all the time.  Hopefully you always have the original installation media (or downloaded set-up file) kept somewhere safe, and can thus reinstall your software at any time.  This means that the software component files are of little importance.  Whereas the files you have created with that software is, by definition, important.  It’s a good rule to always separate unimportant files from important files. So when your software prompts you to save a file you’ve just created, take a moment and check out where it’s suggesting that you save the file.  If it’s suggesting that you save the file into the same folder as the software itself, then definitely don’t follow that suggestion.  File it in your own folder!  In fact, see if you can find the program’s configuration option that determines where files are saved by default (if it has one), and change it. Tip #11.  Organize Files Based on Purpose, Not on File Type If you have, for example a folder called Work\Clients\Johnson, and within that folder you have two sub-folders, Word Documents and Spreadsheets (in other words, you’re separating “.doc” files from “.xls” files), then chances are that you’re not optimally organized.  It makes little sense to organize your files based on the program that created them.  Instead, create your sub-folders based on the purpose of the file.  For example, it would make more sense to create sub-folders called Correspondence and Financials.  It may well be that all the files in a given sub-folder are of the same file-type, but this should be more of a coincidence and less of a design feature of your organization system. Tip #12.  Maintain the Same Folder Structure on All Your Computers In other words, whatever organizational system you create, apply it to every computer that you can.  There are several benefits to this: There’s less to remember.  No matter where you are, you always know where to look for your files If you copy or synchronize files from one computer to another, then setting up the synchronization job becomes very simple Shortcuts can be copied or moved from one computer to another with ease (assuming the original files are also copied/moved).  There’s no need to find the target of the shortcut all over again on the second computer Ditto for linked files (e.g Word documents that link to data in a separate Excel file), playlists, and any files that reference the exact file locations of other files. This applies even to the drive that your files are stored on.  If your files are stored on C: on one computer, make sure they’re stored on C: on all your computers.  Otherwise all your shortcuts, playlists and linked files will stop working! Tip #13.  Create an “Inbox” Folder Create yourself a folder where you store all files that you’re currently working on, or that you haven’t gotten around to filing yet.  You can think of this folder as your “to-do” list.  You can call it “Inbox” (making it the same metaphor as your email system), or “Work”, or “To-Do”, or “Scratch”, or whatever name makes sense to you.  It doesn’t matter what you call it – just make sure you have one! Once you have finished working on a file, you then move it from the “Inbox” to its correct location within your organizational structure. You may want to use your Desktop as this “Inbox” folder.  Rightly or wrongly, most people do.  It’s not a bad place to put such files, but be careful:  If you do decide that your Desktop represents your “to-do” list, then make sure that no other files find their way there.  In other words, make sure that your “Inbox”, wherever it is, Desktop or otherwise, is kept free of junk – stray files that don’t belong there. So where should you put this folder, which, almost by definition, lives outside the structure of the rest of your filing system?  Well, first and foremost, it has to be somewhere handy.  This will be one of your most-visited folders, so convenience is key.  Putting it on the Desktop is a great option – especially if you don’t have any other folders on your Desktop:  the folder then becomes supremely easy to find in Windows Explorer: You would then create shortcuts to this folder in convenient spots all over your computer (“Favorite Links”, “Quick Launch”, etc). Tip #14.  Ensure You have Only One “Inbox” Folder Once you’ve created your “Inbox” folder, don’t use any other folder location as your “to-do list”.  Throw every incoming or created file into the Inbox folder as you create/receive it.  This keeps the rest of your computer pristine and free of randomly created or downloaded junk.  The last thing you want to be doing is checking multiple folders to see all your current tasks and projects.  Gather them all together into one folder. Here are some tips to help ensure you only have one Inbox: Set the default “save” location of all your programs to this folder. Set the default “download” location for your browser to this folder. If this folder is not your desktop (recommended) then also see if you can make a point of not putting “to-do” files on your desktop.  This keeps your desktop uncluttered and Zen-like: (the Inbox folder is in the bottom-right corner) Tip #15.  Be Vigilant about Clearing Your “Inbox” Folder This is one of the keys to staying organized.  If you let your “Inbox” overflow (i.e. allow there to be more than, say, 30 files or folders in there), then you’re probably going to start feeling like you’re overwhelmed:  You’re not keeping up with your to-do list.  Once your Inbox gets beyond a certain point (around 30 files, studies have shown), then you’ll simply start to avoid it.  You may continue to put files in there, but you’ll be scared to look at it, fearing the “out of control” feeling that all overworked, chaotic or just plain disorganized people regularly feel. So, here’s what you can do: Visit your Inbox/to-do folder regularly (at least five times per day). Scan the folder regularly for files that you have completed working on and are ready for filing.  File them immediately. Make it a source of pride to keep the number of files in this folder as small as possible.  If you value peace of mind, then make the emptiness of this folder one of your highest (computer) priorities If you know that a particular file has been in the folder for more than, say, six weeks, then admit that you’re not actually going to get around to processing it, and move it to its final resting place. Tip #16.  File Everything Immediately, and Use Shortcuts for Your Active Projects As soon as you create, receive or download a new file, store it away in its “correct” folder immediately.  Then, whenever you need to work on it (possibly straight away), create a shortcut to it in your “Inbox” (“to-do”) folder or your desktop.  That way, all your files are always in their “correct” locations, yet you still have immediate, convenient access to your current, active files.  When you finish working on a file, simply delete the shortcut. Ideally, your “Inbox” folder – and your Desktop – should contain no actual files or folders.  They should simply contain shortcuts. Tip #17.  Use Directory Symbolic Links (or Junctions) to Maintain One Unified Folder Structure Using this tip, we can get around a potential hiccup that we can run into when creating our organizational structure – the issue of having more than one drive on our computer (C:, D:, etc).  We might have files we need to store on the D: drive for space reasons, and yet want to base our organized folder structure on the C: drive (or vice-versa). Your chosen organizational structure may dictate that all your files must be accessed from the C: drive (for example, the root folder of all your files may be something like C:\Files).  And yet you may still have a D: drive and wish to take advantage of the hundreds of spare Gigabytes that it offers.  Did you know that it’s actually possible to store your files on the D: drive and yet access them as if they were on the C: drive?  And no, we’re not talking about shortcuts here (although the concept is very similar). By using the shell command mklink, you can essentially take a folder that lives on one drive and create an alias for it on a different drive (you can do lots more than that with mklink – for a full rundown on this programs capabilities, see our dedicated article).  These aliases are called directory symbolic links (and used to be known as junctions).  You can think of them as “virtual” folders.  They function exactly like regular folders, except they’re physically located somewhere else. For example, you may decide that your entire D: drive contains your complete organizational file structure, but that you need to reference all those files as if they were on the C: drive, under C:\Files.  If that was the case you could create C:\Files as a directory symbolic link – a link to D:, as follows: mklink /d c:\files d:\ Or it may be that the only files you wish to store on the D: drive are your movie collection.  You could locate all your movie files in the root of your D: drive, and then link it to C:\Files\Media\Movies, as follows: mklink /d c:\files\media\movies d:\ (Needless to say, you must run these commands from a command prompt – click the Start button, type cmd and press Enter) Tip #18. Customize Your Folder Icons This is not strictly speaking an organizational tip, but having unique icons for each folder does allow you to more quickly visually identify which folder is which, and thus saves you time when you’re finding files.  An example is below (from my folder that contains all files downloaded from the Internet): To learn how to change your folder icons, please refer to our dedicated article on the subject. Tip #19.  Tidy Your Start Menu The Windows Start Menu is usually one of the messiest parts of any Windows computer.  Every program you install seems to adopt a completely different approach to placing icons in this menu.  Some simply put a single program icon.  Others create a folder based on the name of the software.  And others create a folder based on the name of the software manufacturer.  It’s chaos, and can make it hard to find the software you want to run. Thankfully we can avoid this chaos with useful operating system features like Quick Launch, the Superbar or pinned start menu items. Even so, it would make a lot of sense to get into the guts of the Start Menu itself and give it a good once-over.  All you really need to decide is how you’re going to organize your applications.  A structure based on the purpose of the application is an obvious candidate.  Below is an example of one such structure: In this structure, Utilities means software whose job it is to keep the computer itself running smoothly (configuration tools, backup software, Zip programs, etc).  Applications refers to any productivity software that doesn’t fit under the headings Multimedia, Graphics, Internet, etc. In case you’re not aware, every icon in your Start Menu is a shortcut and can be manipulated like any other shortcut (copied, moved, deleted, etc). With the Windows Start Menu (all version of Windows), Microsoft has decided that there be two parallel folder structures to store your Start Menu shortcuts.  One for you (the logged-in user of the computer) and one for all users of the computer.  Having two parallel structures can often be redundant:  If you are the only user of the computer, then having two parallel structures is totally redundant.  Even if you have several users that regularly log into the computer, most of your installed software will need to be made available to all users, and should thus be moved out of the “just you” version of the Start Menu and into the “all users” area. To take control of your Start Menu, so you can start organizing it, you’ll need to know how to access the actual folders and shortcut files that make up the Start Menu (both versions of it).  To find these folders and files, click the Start button and then right-click on the All Programs text (Windows XP users should right-click on the Start button itself): The Open option refers to the “just you” version of the Start Menu, while the Open All Users option refers to the “all users” version.  Click on the one you want to organize. A Windows Explorer window then opens with your chosen version of the Start Menu selected.  From there it’s easy.  Double-click on the Programs folder and you’ll see all your folders and shortcuts.  Now you can delete/rename/move until it’s just the way you want it. Note:  When you’re reorganizing your Start Menu, you may want to have two Explorer windows open at the same time – one showing the “just you” version and one showing the “all users” version.  You can drag-and-drop between the windows. Tip #20.  Keep Your Start Menu Tidy Once you have a perfectly organized Start Menu, try to be a little vigilant about keeping it that way.  Every time you install a new piece of software, the icons that get created will almost certainly violate your organizational structure. So to keep your Start Menu pristine and organized, make sure you do the following whenever you install a new piece of software: Check whether the software was installed into the “just you” area of the Start Menu, or the “all users” area, and then move it to the correct area. Remove all the unnecessary icons (like the “Read me” icon, the “Help” icon (you can always open the help from within the software itself when it’s running), the “Uninstall” icon, the link(s)to the manufacturer’s website, etc) Rename the main icon(s) of the software to something brief that makes sense to you.  For example, you might like to rename Microsoft Office Word 2010 to simply Word Move the icon(s) into the correct folder based on your Start Menu organizational structure And don’t forget:  when you uninstall a piece of software, the software’s uninstall routine is no longer going to be able to remove the software’s icon from the Start Menu (because you moved and/or renamed it), so you’ll need to remove that icon manually. Tip #21.  Tidy C:\ The root of your C: drive (C:\) is a common dumping ground for files and folders – both by the users of your computer and by the software that you install on your computer.  It can become a mess. There’s almost no software these days that requires itself to be installed in C:\.  99% of the time it can and should be installed into C:\Program Files.  And as for your own files, well, it’s clear that they can (and almost always should) be stored somewhere else. In an ideal world, your C:\ folder should look like this (on Windows 7): Note that there are some system files and folders in C:\ that are usually and deliberately “hidden” (such as the Windows virtual memory file pagefile.sys, the boot loader file bootmgr, and the System Volume Information folder).  Hiding these files and folders is a good idea, as they need to stay where they are and are almost never needed to be opened or even seen by you, the user.  Hiding them prevents you from accidentally messing with them, and enhances your sense of order and well-being when you look at your C: drive folder. Tip #22.  Tidy Your Desktop The Desktop is probably the most abused part of a Windows computer (from an organization point of view).  It usually serves as a dumping ground for all incoming files, as well as holding icons to oft-used applications, plus some regularly opened files and folders.  It often ends up becoming an uncontrolled mess.  See if you can avoid this.  Here’s why… Application icons (Word, Internet Explorer, etc) are often found on the Desktop, but it’s unlikely that this is the optimum place for them.  The “Quick Launch” bar (or the Superbar in Windows 7) is always visible and so represents a perfect location to put your icons.  You’ll only be able to see the icons on your Desktop when all your programs are minimized.  It might be time to get your application icons off your desktop… You may have decided that the Inbox/To-do folder on your computer (see tip #13, above) should be your Desktop.  If so, then enough said.  Simply be vigilant about clearing it and preventing it from being polluted by junk files (see tip #15, above).  On the other hand, if your Desktop is not acting as your “Inbox” folder, then there’s no reason for it to have any data files or folders on it at all, except perhaps a couple of shortcuts to often-opened files and folders (either ongoing or current projects).  Everything else should be moved to your “Inbox” folder. In an ideal world, it might look like this: Tip #23.  Move Permanent Items on Your Desktop Away from the Top-Left Corner When files/folders are dragged onto your desktop in a Windows Explorer window, or when shortcuts are created on your Desktop from Internet Explorer, those icons are always placed in the top-left corner – or as close as they can get.  If you have other files, folders or shortcuts that you keep on the Desktop permanently, then it’s a good idea to separate these permanent icons from the transient ones, so that you can quickly identify which ones the transients are.  An easy way to do this is to move all your permanent icons to the right-hand side of your Desktop.  That should keep them separated from incoming items. Tip #24.  Synchronize If you have more than one computer, you’ll almost certainly want to share files between them.  If the computers are permanently attached to the same local network, then there’s no need to store multiple copies of any one file or folder – shortcuts will suffice.  However, if the computers are not always on the same network, then you will at some point need to copy files between them.  For files that need to permanently live on both computers, the ideal way to do this is to synchronize the files, as opposed to simply copying them. We only have room here to write a brief summary of synchronization, not a full article.  In short, there are several different types of synchronization: Where the contents of one folder are accessible anywhere, such as with Dropbox Where the contents of any number of folders are accessible anywhere, such as with Windows Live Mesh Where any files or folders from anywhere on your computer are synchronized with exactly one other computer, such as with the Windows “Briefcase”, Microsoft SyncToy, or (much more powerful, yet still free) SyncBack from 2BrightSparks.  This only works when both computers are on the same local network, at least temporarily. A great advantage of synchronization solutions is that once you’ve got it configured the way you want it, then the sync process happens automatically, every time.  Click a button (or schedule it to happen automatically) and all your files are automagically put where they’re supposed to be. If you maintain the same file and folder structure on both computers, then you can also sync files depend upon the correct location of other files, like shortcuts, playlists and office documents that link to other office documents, and the synchronized files still work on the other computer! Tip #25.  Hide Files You Never Need to See If you have your files well organized, you will often be able to tell if a file is out of place just by glancing at the contents of a folder (for example, it should be pretty obvious if you look in a folder that contains all the MP3s from one music CD and see a Word document in there).  This is a good thing – it allows you to determine if there are files out of place with a quick glance.  Yet sometimes there are files in a folder that seem out of place but actually need to be there, such as the “folder art” JPEGs in music folders, and various files in the root of the C: drive.  If such files never need to be opened by you, then a good idea is to simply hide them.  Then, the next time you glance at the folder, you won’t have to remember whether that file was supposed to be there or not, because you won’t see it at all! To hide a file, simply right-click on it and choose Properties: Then simply tick the Hidden tick-box:   Tip #26.  Keep Every Setup File These days most software is downloaded from the Internet.  Whenever you download a piece of software, keep it.  You’ll never know when you need to reinstall the software. Further, keep with it an Internet shortcut that links back to the website where you originally downloaded it, in case you ever need to check for updates. See tip #33 below for a full description of the excellence of organizing your setup files. Tip #27.  Try to Minimize the Number of Folders that Contain Both Files and Sub-folders Some of the folders in your organizational structure will contain only files.  Others will contain only sub-folders.  And you will also have some folders that contain both files and sub-folders.  You will notice slight improvements in how long it takes you to locate a file if you try to avoid this third type of folder.  It’s not always possible, of course – you’ll always have some of these folders, but see if you can avoid it. One way of doing this is to take all the leftover files that didn’t end up getting stored in a sub-folder and create a special “Miscellaneous” or “Other” folder for them. Tip #28.  Starting a Filename with an Underscore Brings it to the Top of a List Further to the previous tip, if you name that “Miscellaneous” or “Other” folder in such a way that its name begins with an underscore “_”, then it will appear at the top of the list of files/folders. The screenshot below is an example of this.  Each folder in the list contains a set of digital photos.  The folder at the top of the list, _Misc, contains random photos that didn’t deserve their own dedicated folder: Tip #29.  Clean Up those CD-ROMs and (shudder!) Floppy Disks Have you got a pile of CD-ROMs stacked on a shelf of your office?  Old photos, or files you archived off onto CD-ROM (or even worse, floppy disks!) because you didn’t have enough disk space at the time?  In the meantime have you upgraded your computer and now have 500 Gigabytes of space you don’t know what to do with?  If so, isn’t it time you tidied up that stack of disks and filed them into your gorgeous new folder structure? So what are you waiting for?  Bite the bullet, copy them all back onto your computer, file them in their appropriate folders, and then back the whole lot up onto a shiny new 1000Gig external hard drive! Useful Folders to Create This next section suggests some useful folders that you might want to create within your folder structure.  I’ve personally found them to be indispensable. The first three are all about convenience – handy folders to create and then put somewhere that you can always access instantly.  For each one, it’s not so important where the actual folder is located, but it’s very important where you put the shortcut(s) to the folder.  You might want to locate the shortcuts: On your Desktop In your “Quick Launch” area (or pinned to your Windows 7 Superbar) In your Windows Explorer “Favorite Links” area Tip #30.  Create an “Inbox” (“To-Do”) Folder This has already been mentioned in depth (see tip #13), but we wanted to reiterate its importance here.  This folder contains all the recently created, received or downloaded files that you have not yet had a chance to file away properly, and it also may contain files that you have yet to process.  In effect, it becomes a sort of “to-do list”.  It doesn’t have to be called “Inbox” – you can call it whatever you want. Tip #31.  Create a Folder where Your Current Projects are Collected Rather than going hunting for them all the time, or dumping them all on your desktop, create a special folder where you put links (or work folders) for each of the projects you’re currently working on. You can locate this folder in your “Inbox” folder, on your desktop, or anywhere at all – just so long as there’s a way of getting to it quickly, such as putting a link to it in Windows Explorer’s “Favorite Links” area: Tip #32.  Create a Folder for Files and Folders that You Regularly Open You will always have a few files that you open regularly, whether it be a spreadsheet of your current accounts, or a favorite playlist.  These are not necessarily “current projects”, rather they’re simply files that you always find yourself opening.  Typically such files would be located on your desktop (or even better, shortcuts to those files).  Why not collect all such shortcuts together and put them in their own special folder? As with the “Current Projects” folder (above), you would want to locate that folder somewhere convenient.  Below is an example of a folder called “Quick links”, with about seven files (shortcuts) in it, that is accessible through the Windows Quick Launch bar: See tip #37 below for a full explanation of the power of the Quick Launch bar. Tip #33.  Create a “Set-ups” Folder A typical computer has dozens of applications installed on it.  For each piece of software, there are often many different pieces of information you need to keep track of, including: The original installation setup file(s).  This can be anything from a simple 100Kb setup.exe file you downloaded from a website, all the way up to a 4Gig ISO file that you copied from a DVD-ROM that you purchased. The home page of the software manufacturer (in case you need to look up something on their support pages, their forum or their online help) The page containing the download link for your actual file (in case you need to re-download it, or download an upgraded version) The serial number Your proof-of-purchase documentation Any other template files, plug-ins, themes, etc that also need to get installed For each piece of software, it’s a great idea to gather all of these files together and put them in a single folder.  The folder can be the name of the software (plus possibly a very brief description of what it’s for – in case you can’t remember what the software does based in its name).  Then you would gather all of these folders together into one place, and call it something like “Software” or “Setups”. If you have enough of these folders (I have several hundred, being a geek, collected over 20 years), then you may want to further categorize them.  My own categorization structure is based on “platform” (operating system): The last seven folders each represents one platform/operating system, while _Operating Systems contains set-up files for installing the operating systems themselves.  _Hardware contains ROMs for hardware I own, such as routers. Within the Windows folder (above), you can see the beginnings of the vast library of software I’ve compiled over the years: An example of a typical application folder looks like this: Tip #34.  Have a “Settings” Folder We all know that our documents are important.  So are our photos and music files.  We save all of these files into folders, and then locate them afterwards and double-click on them to open them.  But there are many files that are important to us that can’t be saved into folders, and then searched for and double-clicked later on.  These files certainly contain important information that we need, but are often created internally by an application, and saved wherever that application feels is appropriate. A good example of this is the “PST” file that Outlook creates for us and uses to store all our emails, contacts, appointments and so forth.  Another example would be the collection of Bookmarks that Firefox stores on your behalf. And yet another example would be the customized settings and configuration files of our all our software.  Granted, most Windows programs store their configuration in the Registry, but there are still many programs that use configuration files to store their settings. Imagine if you lost all of the above files!  And yet, when people are backing up their computers, they typically only back up the files they know about – those that are stored in the “My Documents” folder, etc.  If they had a hard disk failure or their computer was lost or stolen, their backup files would not include some of the most vital files they owned.  Also, when migrating to a new computer, it’s vital to ensure that these files make the journey. It can be a very useful idea to create yourself a folder to store all your “settings” – files that are important to you but which you never actually search for by name and double-click on to open them.  Otherwise, next time you go to set up a new computer just the way you want it, you’ll need to spend hours recreating the configuration of your previous computer! So how to we get our important files into this folder?  Well, we have a few options: Some programs (such as Outlook and its PST files) allow you to place these files wherever you want.  If you delve into the program’s options, you will find a setting somewhere that controls the location of the important settings files (or “personal storage” – PST – when it comes to Outlook) Some programs do not allow you to change such locations in any easy way, but if you get into the Registry, you can sometimes find a registry key that refers to the location of the file(s).  Simply move the file into your Settings folder and adjust the registry key to refer to the new location. Some programs stubbornly refuse to allow their settings files to be placed anywhere other then where they stipulate.  When faced with programs like these, you have three choices:  (1) You can ignore those files, (2) You can copy the files into your Settings folder (let’s face it – settings don’t change very often), or (3) you can use synchronization software, such as the Windows Briefcase, to make synchronized copies of all your files in your Settings folder.  All you then have to do is to remember to run your sync software periodically (perhaps just before you run your backup software!). There are some other things you may decide to locate inside this new “Settings” folder: Exports of registry keys (from the many applications that store their configurations in the Registry).  This is useful for backup purposes or for migrating to a new computer Notes you’ve made about all the specific customizations you have made to a particular piece of software (so that you’ll know how to do it all again on your next computer) Shortcuts to webpages that detail how to tweak certain aspects of your operating system or applications so they are just the way you like them (such as how to remove the words “Shortcut to” from the beginning of newly created shortcuts).  In other words, you’d want to create shortcuts to half the pages on the How-To Geek website! Here’s an example of a “Settings” folder: Windows Features that Help with Organization This section details some of the features of Microsoft Windows that are a boon to anyone hoping to stay optimally organized. Tip #35.  Use the “Favorite Links” Area to Access Oft-Used Folders Once you’ve created your great new filing system, work out which folders you access most regularly, or which serve as great starting points for locating the rest of the files in your folder structure, and then put links to those folders in your “Favorite Links” area of the left-hand side of the Windows Explorer window (simply called “Favorites” in Windows 7):   Some ideas for folders you might want to add there include: Your “Inbox” folder (or whatever you’ve called it) – most important! The base of your filing structure (e.g. C:\Files) A folder containing shortcuts to often-accessed folders on other computers around the network (shown above as Network Folders) A folder containing shortcuts to your current projects (unless that folder is in your “Inbox” folder) Getting folders into this area is very simple – just locate the folder you’re interested in and drag it there! Tip #36.  Customize the Places Bar in the File/Open and File/Save Boxes Consider the screenshot below: The highlighted icons (collectively known as the “Places Bar”) can be customized to refer to any folder location you want, allowing instant access to any part of your organizational structure. Note:  These File/Open and File/Save boxes have been superseded by new versions that use the Windows Vista/Windows 7 “Favorite Links”, but the older versions (shown above) are still used by a surprisingly large number of applications. The easiest way to customize these icons is to use the Group Policy Editor, but not everyone has access to this program.  If you do, open it up and navigate to: User Configuration > Administrative Templates > Windows Components > Windows Explorer > Common Open File Dialog If you don’t have access to the Group Policy Editor, then you’ll need to get into the Registry.  Navigate to: HKEY_CURRENT_USER \ Software \ Microsoft  \ Windows \ CurrentVersion \ Policies \ comdlg32 \ Placesbar It should then be easy to make the desired changes.  Log off and log on again to allow the changes to take effect. Tip #37.  Use the Quick Launch Bar as a Application and File Launcher That Quick Launch bar (to the right of the Start button) is a lot more useful than people give it credit for.  Most people simply have half a dozen icons in it, and use it to start just those programs.  But it can actually be used to instantly access just about anything in your filing system: For complete instructions on how to set this up, visit our dedicated article on this topic. Tip #38.  Put a Shortcut to Windows Explorer into Your Quick Launch Bar This is only necessary in Windows Vista and Windows XP.  The Microsoft boffins finally got wise and added it to the Windows 7 Superbar by default. Windows Explorer – the program used for managing your files and folders – is one of the most useful programs in Windows.  Anyone who considers themselves serious about being organized needs instant access to this program at any time.  A great place to create a shortcut to this program is in the Windows XP and Windows Vista “Quick Launch” bar: To get it there, locate it in your Start Menu (usually under “Accessories”) and then right-drag it down into your Quick Launch bar (and create a copy). Tip #39.  Customize the Starting Folder for Your Windows 7 Explorer Superbar Icon If you’re on Windows 7, your Superbar will include a Windows Explorer icon.  Clicking on the icon will launch Windows Explorer (of course), and will start you off in your “Libraries” folder.  Libraries may be fine as a starting point, but if you have created yourself an “Inbox” folder, then it would probably make more sense to start off in this folder every time you launch Windows Explorer. To change this default/starting folder location, then first right-click the Explorer icon in the Superbar, and then right-click Properties:Then, in Target field of the Windows Explorer Properties box that appears, type %windir%\explorer.exe followed by the path of the folder you wish to start in.  For example: %windir%\explorer.exe C:\Files If that folder happened to be on the Desktop (and called, say, “Inbox”), then you would use the following cleverness: %windir%\explorer.exe shell:desktop\Inbox Then click OK and test it out. Tip #40.  Ummmmm…. No, that’s it.  I can’t think of another one.  That’s all of the tips I can come up with.  I only created this one because 40 is such a nice round number… Case Study – An Organized PC To finish off the article, I have included a few screenshots of my (main) computer (running Vista).  The aim here is twofold: To give you a sense of what it looks like when the above, sometimes abstract, tips are applied to a real-life computer, and To offer some ideas about folders and structure that you may want to steal to use on your own PC. Let’s start with the C: drive itself.  Very minimal.  All my files are contained within C:\Files.  I’ll confine the rest of the case study to this folder: That folder contains the following: Mark: My personal files VC: My business (Virtual Creations, Australia) Others contains files created by friends and family Data contains files from the rest of the world (can be thought of as “public” files, usually downloaded from the Net) Settings is described above in tip #34 The Data folder contains the following sub-folders: Audio:  Radio plays, audio books, podcasts, etc Development:  Programmer and developer resources, sample source code, etc (see below) Humour:  Jokes, funnies (those emails that we all receive) Movies:  Downloaded and ripped movies (all legal, of course!), their scripts, DVD covers, etc. Music:  (see below) Setups:  Installation files for software (explained in full in tip #33) System:  (see below) TV:  Downloaded TV shows Writings:  Books, instruction manuals, etc (see below) The Music folder contains the following sub-folders: Album covers:  JPEG scans Guitar tabs:  Text files of guitar sheet music Lists:  e.g. “Top 1000 songs of all time” Lyrics:  Text files MIDI:  Electronic music files MP3 (representing 99% of the Music folder):  MP3s, either ripped from CDs or downloaded, sorted by artist/album name Music Video:  Video clips Sheet Music:  usually PDFs The Data\Writings folder contains the following sub-folders: (all pretty self-explanatory) The Data\Development folder contains the following sub-folders: Again, all pretty self-explanatory (if you’re a geek) The Data\System folder contains the following sub-folders: These are usually themes, plug-ins and other downloadable program-specific resources. The Mark folder contains the following sub-folders: From Others:  Usually letters that other people (friends, family, etc) have written to me For Others:  Letters and other things I have created for other people Green Book:  None of your business Playlists:  M3U files that I have compiled of my favorite songs (plus one M3U playlist file for every album I own) Writing:  Fiction, philosophy and other musings of mine Mark Docs:  Shortcut to C:\Users\Mark Settings:  Shortcut to C:\Files\Settings\Mark The Others folder contains the following sub-folders: The VC (Virtual Creations, my business – I develop websites) folder contains the following sub-folders: And again, all of those are pretty self-explanatory. Conclusion These tips have saved my sanity and helped keep me a productive geek, but what about you? What tips and tricks do you have to keep your files organized?  Please share them with us in the comments.  Come on, don’t be shy… Similar Articles Productive Geek Tips Fix For When Windows Explorer in Vista Stops Showing File NamesWhy Did Windows Vista’s Music Folder Icon Turn Yellow?Print or Create a Text File List of the Contents in a Directory the Easy WayCustomize the Windows 7 or Vista Send To MenuAdd Copy To / Move To on Windows 7 or Vista Right-Click Menu TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Acronis Online Backup DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows Track Daily Goals With 42Goals Video Toolbox is a Superb Online Video Editor Fun with 47 charts and graphs Tomorrow is Mother’s Day Check the Average Speed of YouTube Videos You’ve Watched OutlookStatView Scans and Displays General Usage Statistics

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  • Red Gate Coder interviews: Alex Davies

    - by Michael Williamson
    Alex Davies has been a software engineer at Red Gate since graduating from university, and is currently busy working on .NET Demon. We talked about tackling parallel programming with his actors framework, a scientific approach to debugging, and how JavaScript is going to affect the programming languages we use in years to come. So, if we start at the start, how did you get started in programming? When I was seven or eight, I was given a BBC Micro for Christmas. I had asked for a Game Boy, but my dad thought it would be better to give me a proper computer. For a year or so, I only played games on it, but then I found the user guide for writing programs in it. I gradually started doing more stuff on it and found it fun. I liked creating. As I went into senior school I continued to write stuff on there, trying to write games that weren’t very good. I got a real computer when I was fourteen and found ways to write BASIC on it. Visual Basic to start with, and then something more interesting than that. How did you learn to program? Was there someone helping you out? Absolutely not! I learnt out of a book, or by experimenting. I remember the first time I found a loop, I was like “Oh my God! I don’t have to write out the same line over and over and over again any more. It’s amazing!” When did you think this might be something that you actually wanted to do as a career? For a long time, I thought it wasn’t something that you would do as a career, because it was too much fun to be a career. I thought I’d do chemistry at university and some kind of career based on chemical engineering. And then I went to a careers fair at school when I was seventeen or eighteen, and it just didn’t interest me whatsoever. I thought “I could be a programmer, and there’s loads of money there, and I’m good at it, and it’s fun”, but also that I shouldn’t spoil my hobby. Now I don’t really program in my spare time any more, which is a bit of a shame, but I program all the rest of the time, so I can live with it. Do you think you learnt much about programming at university? Yes, definitely! I went into university knowing how to make computers do anything I wanted them to do. However, I didn’t have the language to talk about algorithms, so the algorithms course in my first year was massively important. Learning other language paradigms like functional programming was really good for breadth of understanding. Functional programming influences normal programming through design rather than actually using it all the time. I draw inspiration from it to write imperative programs which I think is actually becoming really fashionable now, but I’ve been doing it for ages. I did it first! There were also some courses on really odd programming languages, a bit of Prolog, a little bit of C. Having a little bit of each of those is something that I would have never done on my own, so it was important. And then there are knowledge-based courses which are about not programming itself but things that have been programmed like TCP. Those are really important for examples for how to approach things. Did you do any internships while you were at university? Yeah, I spent both of my summers at the same company. I thought I could code well before I went there. Looking back at the crap that I produced, it was only surpassed in its crappiness by all of the other code already in that company. I’m so much better at writing nice code now than I used to be back then. Was there just not a culture of looking after your code? There was, they just didn’t hire people for their abilities in that area. They hired people for raw IQ. The first indicator of it going wrong was that they didn’t have any computer scientists, which is a bit odd in a programming company. But even beyond that they didn’t have people who learnt architecture from anyone else. Most of them had started straight out of university, so never really had experience or mentors to learn from. There wasn’t the experience to draw from to teach each other. In the second half of my second internship, I was being given tasks like looking at new technologies and teaching people stuff. Interns shouldn’t be teaching people how to do their jobs! All interns are going to have little nuggets of things that you don’t know about, but they shouldn’t consistently be the ones who know the most. It’s not a good environment to learn. I was going to ask how you found working with people who were more experienced than you… When I reached Red Gate, I found some people who were more experienced programmers than me, and that was difficult. I’ve been coding since I was tiny. At university there were people who were cleverer than me, but there weren’t very many who were more experienced programmers than me. During my internship, I didn’t find anyone who I classed as being a noticeably more experienced programmer than me. So, it was a shock to the system to have valid criticisms rather than just formatting criticisms. However, Red Gate’s not so big on the actual code review, at least it wasn’t when I started. We did an entire product release and then somebody looked over all of the UI of that product which I’d written and say what they didn’t like. By that point, it was way too late and I’d disagree with them. Do you think the lack of code reviews was a bad thing? I think if there’s going to be any oversight of new people, then it should be continuous rather than chunky. For me I don’t mind too much, I could go out and get oversight if I wanted it, and in those situations I felt comfortable without it. If I was managing the new person, then maybe I’d be keener on oversight and then the right way to do it is continuously and in very, very small chunks. Have you had any significant projects you’ve worked on outside of a job? When I was a teenager I wrote all sorts of stuff. I used to write games, I derived how to do isomorphic projections myself once. I didn’t know what the word was so I couldn’t Google for it, so I worked it out myself. It was horrifically complicated. But it sort of tailed off when I started at university, and is now basically zero. If I do side-projects now, they tend to be work-related side projects like my actors framework, NAct, which I started in a down tools week. Could you explain a little more about NAct? It is a little C# framework for writing parallel code more easily. Parallel programming is difficult when you need to write to shared data. Sometimes parallel programming is easy because you don’t need to write to shared data. When you do need to access shared data, you could just have your threads pile in and do their work, but then you would screw up the data because the threads would trample on each other’s toes. You could lock, but locks are really dangerous if you’re using more than one of them. You get interactions like deadlocks, and that’s just nasty. Actors instead allows you to say this piece of data belongs to this thread of execution, and nobody else can read it. If you want to read it, then ask that thread of execution for a piece of it by sending a message, and it will send the data back by a message. And that avoids deadlocks as long as you follow some obvious rules about not making your actors sit around waiting for other actors to do something. There are lots of ways to write actors, NAct allows you to do it as if it was method calls on other objects, which means you get all the strong type-safety that C# programmers like. Do you think that this is suitable for the majority of parallel programming, or do you think it’s only suitable for specific cases? It’s suitable for most difficult parallel programming. If you’ve just got a hundred web requests which are all independent of each other, then I wouldn’t bother because it’s easier to just spin them up in separate threads and they can proceed independently of each other. But where you’ve got difficult parallel programming, where you’ve got multiple threads accessing multiple bits of data in multiple ways at different times, then actors is at least as good as all other ways, and is, I reckon, easier to think about. When you’re using actors, you presumably still have to write your code in a different way from you would otherwise using single-threaded code. You can’t use actors with any methods that have return types, because you’re not allowed to call into another actor and wait for it. If you want to get a piece of data out of another actor, then you’ve got to use tasks so that you can use “async” and “await” to await asynchronously for it. But other than that, you can still stick things in classes so it’s not too different really. Rather than having thousands of objects with mutable state, you can use component-orientated design, where there are only a few mutable classes which each have a small number of instances. Then there can be thousands of immutable objects. If you tend to do that anyway, then actors isn’t much of a jump. If I’ve already built my system without any parallelism, how hard is it to add actors to exploit all eight cores on my desktop? Usually pretty easy. If you can identify even one boundary where things look like messages and you have components where some objects live on one side and these other objects live on the other side, then you can have a granddaddy object on one side be an actor and it will parallelise as it goes across that boundary. Not too difficult. If we do get 1000-core desktop PCs, do you think actors will scale up? It’s hard. There are always in the order of twenty to fifty actors in my whole program because I tend to write each component as actors, and I tend to have one instance of each component. So this won’t scale to a thousand cores. What you can do is write data structures out of actors. I use dictionaries all over the place, and if you need a dictionary that is going to be accessed concurrently, then you could build one of those out of actors in no time. You can use queuing to marshal requests between different slices of the dictionary which are living on different threads. So it’s like a distributed hash table but all of the chunks of it are on the same machine. That means that each of these thousand processors has cached one small piece of the dictionary. I reckon it wouldn’t be too big a leap to start doing proper parallelism. Do you think it helps if actors get baked into the language, similarly to Erlang? Erlang is excellent in that it has thread-local garbage collection. C# doesn’t, so there’s a limit to how well C# actors can possibly scale because there’s a single garbage collected heap shared between all of them. When you do a global garbage collection, you’ve got to stop all of the actors, which is seriously expensive, whereas in Erlang garbage collections happen per-actor, so they’re insanely cheap. However, Erlang deviated from all the sensible language design that people have used recently and has just come up with crazy stuff. You can definitely retrofit thread-local garbage collection to .NET, and then it’s quite well-suited to support actors, even if it’s not baked into the language. Speaking of language design, do you have a favourite programming language? I’ll choose a language which I’ve never written before. I like the idea of Scala. It sounds like C#, only with some of the niggles gone. I enjoy writing static types. It means you don’t have to writing tests so much. When you say it doesn’t have some of the niggles? C# doesn’t allow the use of a property as a method group. It doesn’t have Scala case classes, or sum types, where you can do a switch statement and the compiler checks that you’ve checked all the cases, which is really useful in functional-style programming. Pattern-matching, in other words. That’s actually the major niggle. C# is pretty good, and I’m quite happy with C#. And what about going even further with the type system to remove the need for tests to something like Haskell? Or is that a step too far? I’m quite a pragmatist, I don’t think I could deal with trying to write big systems in languages with too few other users, especially when learning how to structure things. I just don’t know anyone who can teach me, and the Internet won’t teach me. That’s the main reason I wouldn’t use it. If I turned up at a company that writes big systems in Haskell, I would have no objection to that, but I wouldn’t instigate it. What about things in C#? For instance, there’s contracts in C#, so you can try to statically verify a bit more about your code. Do you think that’s useful, or just not worthwhile? I’ve not really tried it. My hunch is that it needs to be built into the language and be quite mathematical for it to work in real life, and that doesn’t seem to have ended up true for C# contracts. I don’t think anyone who’s tried them thinks they’re any good. I might be wrong. On a slightly different note, how do you like to debug code? I think I’m quite an odd debugger. I use guesswork extremely rarely, especially if something seems quite difficult to debug. I’ve been bitten spending hours and hours on guesswork and not being scientific about debugging in the past, so now I’m scientific to a fault. What I want is to see the bug happening in the debugger, to step through the bug happening. To watch the program going from a valid state to an invalid state. When there’s a bug and I can’t work out why it’s happening, I try to find some piece of evidence which places the bug in one section of the code. From that experiment, I binary chop on the possible causes of the bug. I suppose that means binary chopping on places in the code, or binary chopping on a stage through a processing cycle. Basically, I’m very stupid about how I debug. I won’t make any guesses, I won’t use any intuition, I will only identify the experiment that’s going to binary chop most effectively and repeat rather than trying to guess anything. I suppose it’s quite top-down. Is most of the time then spent in the debugger? Absolutely, if at all possible I will never debug using print statements or logs. I don’t really hold much stock in outputting logs. If there’s any bug which can be reproduced locally, I’d rather do it in the debugger than outputting logs. And with SmartAssembly error reporting, there’s not a lot that can’t be either observed in an error report and just fixed, or reproduced locally. And in those other situations, maybe I’ll use logs. But I hate using logs. You stare at the log, trying to guess what’s going on, and that’s exactly what I don’t like doing. You have to just look at it and see does this look right or wrong. We’ve covered how you get to grip with bugs. How do you get to grips with an entire codebase? I watch it in the debugger. I find little bugs and then try to fix them, and mostly do it by watching them in the debugger and gradually getting an understanding of how the code works using my process of binary chopping. I have to do a lot of reading and watching code to choose where my slicing-in-half experiment is going to be. The last time I did it was SmartAssembly. The old code was a complete mess, but at least it did things top to bottom. There wasn’t too much of some of the big abstractions where flow of control goes all over the place, into a base class and back again. Code’s really hard to understand when that happens. So I like to choose a little bug and try to fix it, and choose a bigger bug and try to fix it. Definitely learn by doing. I want to always have an aim so that I get a little achievement after every few hours of debugging. Once I’ve learnt the codebase I might be able to fix all the bugs in an hour, but I’d rather be using them as an aim while I’m learning the codebase. If I was a maintainer of a codebase, what should I do to make it as easy as possible for you to understand? Keep distinct concepts in different places. And name your stuff so that it’s obvious which concepts live there. You shouldn’t have some variable that gets set miles up the top of somewhere, and then is read miles down to choose some later behaviour. I’m talking from a very much SmartAssembly point of view because the old SmartAssembly codebase had tons and tons of these things, where it would read some property of the code and then deal with it later. Just thousands of variables in scope. Loads of things to think about. If you can keep concepts separate, then it aids me in my process of fixing bugs one at a time, because each bug is going to more or less be understandable in the one place where it is. And what about tests? Do you think they help at all? I’ve never had the opportunity to learn a codebase which has had tests, I don’t know what it’s like! What about when you’re actually developing? How useful do you find tests in finding bugs or regressions? Finding regressions, absolutely. Running bits of code that would be quite hard to run otherwise, definitely. It doesn’t happen very often that a test finds a bug in the first place. I don’t really buy nebulous promises like tests being a good way to think about the spec of the code. My thinking goes something like “This code works at the moment, great, ship it! Ah, there’s a way that this code doesn’t work. Okay, write a test, demonstrate that it doesn’t work, fix it, use the test to demonstrate that it’s now fixed, and keep the test for future regressions.” The most valuable tests are for bugs that have actually happened at some point, because bugs that have actually happened at some point, despite the fact that you think you’ve fixed them, are way more likely to appear again than new bugs are. Does that mean that when you write your code the first time, there are no tests? Often. The chance of there being a bug in a new feature is relatively unaffected by whether I’ve written a test for that new feature because I’m not good enough at writing tests to think of bugs that I would have written into the code. So not writing regression tests for all of your code hasn’t affected you too badly? There are different kinds of features. Some of them just always work, and are just not flaky, they just continue working whatever you throw at them. Maybe because the type-checker is particularly effective around them. Writing tests for those features which just tend to always work is a waste of time. And because it’s a waste of time I’ll tend to wait until a feature has demonstrated its flakiness by having bugs in it before I start trying to test it. You can get a feel for whether it’s going to be flaky code as you’re writing it. I try to write it to make it not flaky, but there are some things that are just inherently flaky. And very occasionally, I’ll think “this is going to be flaky” as I’m writing, and then maybe do a test, but not most of the time. How do you think your programming style has changed over time? I’ve got clearer about what the right way of doing things is. I used to flip-flop a lot between different ideas. Five years ago I came up with some really good ideas and some really terrible ideas. All of them seemed great when I thought of them, but they were quite diverse ideas, whereas now I have a smaller set of reliable ideas that are actually good for structuring code. So my code is probably more similar to itself than it used to be back in the day, when I was trying stuff out. I’ve got more disciplined about encapsulation, I think. There are operational things like I use actors more now than I used to, and that forces me to use immutability more than I used to. The first code that I wrote in Red Gate was the memory profiler UI, and that was an actor, I just didn’t know the name of it at the time. I don’t really use object-orientation. By object-orientation, I mean having n objects of the same type which are mutable. I want a constant number of objects that are mutable, and they should be different types. I stick stuff in dictionaries and then have one thing that owns the dictionary and puts stuff in and out of it. That’s definitely a pattern that I’ve seen recently. I think maybe I’m doing functional programming. Possibly. It’s plausible. If you had to summarise the essence of programming in a pithy sentence, how would you do it? Programming is the form of art that, without losing any of the beauty of architecture or fine art, allows you to produce things that people love and you make money from. So you think it’s an art rather than a science? It’s a little bit of engineering, a smidgeon of maths, but it’s not science. Like architecture, programming is on that boundary between art and engineering. If you want to do it really nicely, it’s mostly art. You can get away with doing architecture and programming entirely by having a good engineering mind, but you’re not going to produce anything nice. You’re not going to have joy doing it if you’re an engineering mind. Architects who are just engineering minds are not going to enjoy their job. I suppose engineering is the foundation on which you build the art. Exactly. How do you think programming is going to change over the next ten years? There will be an unfortunate shift towards dynamically-typed languages, because of JavaScript. JavaScript has an unfair advantage. JavaScript’s unfair advantage will cause more people to be exposed to dynamically-typed languages, which means other dynamically-typed languages crop up and the best features go into dynamically-typed languages. Then people conflate the good features with the fact that it’s dynamically-typed, and more investment goes into dynamically-typed languages. They end up better, so people use them. What about the idea of compiling other languages, possibly statically-typed, to JavaScript? It’s a reasonable idea. I would like to do it, but I don’t think enough people in the world are going to do it to make it pick up. The hordes of beginners are the lifeblood of a language community. They are what makes there be good tools and what makes there be vibrant community websites. And any particular thing which is the same as JavaScript only with extra stuff added to it, although it might be technically great, is not going to have the hordes of beginners. JavaScript is always to be quickest and easiest way for a beginner to start programming in the browser. And dynamically-typed languages are great for beginners. Compilers are pretty scary and beginners don’t write big code. And having your errors come up in the same place, whether they’re statically checkable errors or not, is quite nice for a beginner. If someone asked me to teach them some programming, I’d teach them JavaScript. If dynamically-typed languages are great for beginners, when do you think the benefits of static typing start to kick in? The value of having a statically typed program is in the tools that rely on the static types to produce a smooth IDE experience rather than actually telling me my compile errors. And only once you’re experienced enough a programmer that having a really smooth IDE experience makes a blind bit of difference, does static typing make a blind bit of difference. So it’s not really about size of codebase. If I go and write up a tiny program, I’m still going to get value out of writing it in C# using ReSharper because I’m experienced with C# and ReSharper enough to be able to write code five times faster if I have that help. Any other visions of the future? Nobody’s going to use actors. Because everyone’s going to be running on single-core VMs connected over network-ready protocols like JSON over HTTP. So, parallelism within one operating system is going to die. But until then, you should use actors. More Red Gater Coder interviews

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  • The Incremental Architect&rsquo;s Napkin - #5 - Design functions for extensibility and readability

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/08/24/the-incremental-architectrsquos-napkin---5---design-functions-for.aspx The functionality of programs is entered via Entry Points. So what we´re talking about when designing software is a bunch of functions handling the requests represented by and flowing in through those Entry Points. Designing software thus consists of at least three phases: Analyzing the requirements to find the Entry Points and their signatures Designing the functionality to be executed when those Entry Points get triggered Implementing the functionality according to the design aka coding I presume, you´re familiar with phase 1 in some way. And I guess you´re proficient in implementing functionality in some programming language. But in my experience developers in general are not experienced in going through an explicit phase 2. “Designing functionality? What´s that supposed to mean?” you might already have thought. Here´s my definition: To design functionality (or functional design for short) means thinking about… well, functions. You find a solution for what´s supposed to happen when an Entry Point gets triggered in terms of functions. A conceptual solution that is, because those functions only exist in your head (or on paper) during this phase. But you may have guess that, because it´s “design” not “coding”. And here is, what functional design is not: It´s not about logic. Logic is expressions (e.g. +, -, && etc.) and control statements (e.g. if, switch, for, while etc.). Also I consider calling external APIs as logic. It´s equally basic. It´s what code needs to do in order to deliver some functionality or quality. Logic is what´s doing that needs to be done by software. Transformations are either done through expressions or API-calls. And then there is alternative control flow depending on the result of some expression. Basically it´s just jumps in Assembler, sometimes to go forward (if, switch), sometimes to go backward (for, while, do). But calling your own function is not logic. It´s not necessary to produce any outcome. Functionality is not enhanced by adding functions (subroutine calls) to your code. Nor is quality increased by adding functions. No performance gain, no higher scalability etc. through functions. Functions are not relevant to functionality. Strange, isn´t it. What they are important for is security of investment. By introducing functions into our code we can become more productive (re-use) and can increase evolvability (higher unterstandability, easier to keep code consistent). That´s no small feat, however. Evolvable code can hardly be overestimated. That´s why to me functional design is so important. It´s at the core of software development. To sum this up: Functional design is on a level of abstraction above (!) logical design or algorithmic design. Functional design is only done until you get to a point where each function is so simple you are very confident you can easily code it. Functional design an logical design (which mostly is coding, but can also be done using pseudo code or flow charts) are complementary. Software needs both. If you start coding right away you end up in a tangled mess very quickly. Then you need back out through refactoring. Functional design on the other hand is bloodless without actual code. It´s just a theory with no experiments to prove it. But how to do functional design? An example of functional design Let´s assume a program to de-duplicate strings. The user enters a number of strings separated by commas, e.g. a, b, a, c, d, b, e, c, a. And the program is supposed to clear this list of all doubles, e.g. a, b, c, d, e. There is only one Entry Point to this program: the user triggers the de-duplication by starting the program with the string list on the command line C:\>deduplicate "a, b, a, c, d, b, e, c, a" a, b, c, d, e …or by clicking on a GUI button. This leads to the Entry Point function to get called. It´s the program´s main function in case of the batch version or a button click event handler in the GUI version. That´s the physical Entry Point so to speak. It´s inevitable. What then happens is a three step process: Transform the input data from the user into a request. Call the request handler. Transform the output of the request handler into a tangible result for the user. Or to phrase it a bit more generally: Accept input. Transform input into output. Present output. This does not mean any of these steps requires a lot of effort. Maybe it´s just one line of code to accomplish it. Nevertheless it´s a distinct step in doing the processing behind an Entry Point. Call it an aspect or a responsibility - and you will realize it most likely deserves a function of its own to satisfy the Single Responsibility Principle (SRP). Interestingly the above list of steps is already functional design. There is no logic, but nevertheless the solution is described - albeit on a higher level of abstraction than you might have done yourself. But it´s still on a meta-level. The application to the domain at hand is easy, though: Accept string list from command line De-duplicate Present de-duplicated strings on standard output And this concrete list of processing steps can easily be transformed into code:static void Main(string[] args) { var input = Accept_string_list(args); var output = Deduplicate(input); Present_deduplicated_string_list(output); } Instead of a big problem there are three much smaller problems now. If you think each of those is trivial to implement, then go for it. You can stop the functional design at this point. But maybe, just maybe, you´re not so sure how to go about with the de-duplication for example. Then just implement what´s easy right now, e.g.private static string Accept_string_list(string[] args) { return args[0]; } private static void Present_deduplicated_string_list( string[] output) { var line = string.Join(", ", output); Console.WriteLine(line); } Accept_string_list() contains logic in the form of an API-call. Present_deduplicated_string_list() contains logic in the form of an expression and an API-call. And then repeat the functional design for the remaining processing step. What´s left is the domain logic: de-duplicating a list of strings. How should that be done? Without any logic at our disposal during functional design you´re left with just functions. So which functions could make up the de-duplication? Here´s a suggestion: De-duplicate Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Processing step 2 obviously was the core of the solution. That´s where real creativity was needed. That´s the core of the domain. But now after this refinement the implementation of each step is easy again:private static string[] Parse_string_list(string input) { return input.Split(',') .Select(s => s.Trim()) .ToArray(); } private static Dictionary<string,object> Compile_unique_strings(string[] strings) { return strings.Aggregate( new Dictionary<string, object>(), (agg, s) => { agg[s] = null; return agg; }); } private static string[] Serialize_unique_strings( Dictionary<string,object> dict) { return dict.Keys.ToArray(); } With these three additional functions Main() now looks like this:static void Main(string[] args) { var input = Accept_string_list(args); var strings = Parse_string_list(input); var dict = Compile_unique_strings(strings); var output = Serialize_unique_strings(dict); Present_deduplicated_string_list(output); } I think that´s very understandable code: just read it from top to bottom and you know how the solution to the problem works. It´s a mirror image of the initial design: Accept string list from command line Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Present de-duplicated strings on standard output You can even re-generate the design by just looking at the code. Code and functional design thus are always in sync - if you follow some simple rules. But about that later. And as a bonus: all the functions making up the process are small - which means easy to understand, too. So much for an initial concrete example. Now it´s time for some theory. Because there is method to this madness ;-) The above has only scratched the surface. Introducing Flow Design Functional design starts with a given function, the Entry Point. Its goal is to describe the behavior of the program when the Entry Point is triggered using a process, not an algorithm. An algorithm consists of logic, a process on the other hand consists just of steps or stages. Each processing step transforms input into output or a side effect. Also it might access resources, e.g. a printer, a database, or just memory. Processing steps thus can rely on state of some sort. This is different from Functional Programming, where functions are supposed to not be stateful and not cause side effects.[1] In its simplest form a process can be written as a bullet point list of steps, e.g. Get data from user Output result to user Transform data Parse data Map result for output Such a compilation of steps - possibly on different levels of abstraction - often is the first artifact of functional design. It can be generated by a team in an initial design brainstorming. Next comes ordering the steps. What should happen first, what next etc.? Get data from user Parse data Transform data Map result for output Output result to user That´s great for a start into functional design. It´s better than starting to code right away on a given function using TDD. Please get me right: TDD is a valuable practice. But it can be unnecessarily hard if the scope of a functionn is too large. But how do you know beforehand without investing some thinking? And how to do this thinking in a systematic fashion? My recommendation: For any given function you´re supposed to implement first do a functional design. Then, once you´re confident you know the processing steps - which are pretty small - refine and code them using TDD. You´ll see that´s much, much easier - and leads to cleaner code right away. For more information on this approach I call “Informed TDD” read my book of the same title. Thinking before coding is smart. And writing down the solution as a bunch of functions possibly is the simplest thing you can do, I´d say. It´s more according to the KISS (Keep It Simple, Stupid) principle than returning constants or other trivial stuff TDD development often is started with. So far so good. A simple ordered list of processing steps will do to start with functional design. As shown in the above example such steps can easily be translated into functions. Moving from design to coding thus is simple. However, such a list does not scale. Processing is not always that simple to be captured in a list. And then the list is just text. Again. Like code. That means the design is lacking visuality. Textual representations need more parsing by your brain than visual representations. Plus they are limited in their “dimensionality”: text just has one dimension, it´s sequential. Alternatives and parallelism are hard to encode in text. In addition the functional design using numbered lists lacks data. It´s not visible what´s the input, output, and state of the processing steps. That´s why functional design should be done using a lightweight visual notation. No tool is necessary to draw such designs. Use pen and paper; a flipchart, a whiteboard, or even a napkin is sufficient. Visualizing processes The building block of the functional design notation is a functional unit. I mostly draw it like this: Something is done, it´s clear what goes in, it´s clear what comes out, and it´s clear what the processing step requires in terms of state or hardware. Whenever input flows into a functional unit it gets processed and output is produced and/or a side effect occurs. Flowing data is the driver of something happening. That´s why I call this approach to functional design Flow Design. It´s about data flow instead of control flow. Control flow like in algorithms is of no concern to functional design. Thinking about control flow simply is too low level. Once you start with control flow you easily get bogged down by tons of details. That´s what you want to avoid during design. Design is supposed to be quick, broad brush, abstract. It should give overview. But what about all the details? As Robert C. Martin rightly said: “Programming is abot detail”. Detail is a matter of code. Once you start coding the processing steps you designed you can worry about all the detail you want. Functional design does not eliminate all the nitty gritty. It just postpones tackling them. To me that´s also an example of the SRP. Function design has the responsibility to come up with a solution to a problem posed by a single function (Entry Point). And later coding has the responsibility to implement the solution down to the last detail (i.e. statement, API-call). TDD unfortunately mixes both responsibilities. It´s just coding - and thereby trying to find detailed implementations (green phase) plus getting the design right (refactoring). To me that´s one reason why TDD has failed to deliver on its promise for many developers. Using functional units as building blocks of functional design processes can be depicted very easily. Here´s the initial process for the example problem: For each processing step draw a functional unit and label it. Choose a verb or an “action phrase” as a label, not a noun. Functional design is about activities, not state or structure. Then make the output of an upstream step the input of a downstream step. Finally think about the data that should flow between the functional units. Write the data above the arrows connecting the functional units in the direction of the data flow. Enclose the data description in brackets. That way you can clearly see if all flows have already been specified. Empty brackets mean “no data is flowing”, but nevertheless a signal is sent. A name like “list” or “strings” in brackets describes the data content. Use lower case labels for that purpose. A name starting with an upper case letter like “String” or “Customer” on the other hand signifies a data type. If you like, you also can combine descriptions with data types by separating them with a colon, e.g. (list:string) or (strings:string[]). But these are just suggestions from my practice with Flow Design. You can do it differently, if you like. Just be sure to be consistent. Flows wired-up in this manner I call one-dimensional (1D). Each functional unit just has one input and/or one output. A functional unit without an output is possible. It´s like a black hole sucking up input without producing any output. Instead it produces side effects. A functional unit without an input, though, does make much sense. When should it start to work? What´s the trigger? That´s why in the above process even the first processing step has an input. If you like, view such 1D-flows as pipelines. Data is flowing through them from left to right. But as you can see, it´s not always the same data. It get´s transformed along its passage: (args) becomes a (list) which is turned into (strings). The Principle of Mutual Oblivion A very characteristic trait of flows put together from function units is: no functional units knows another one. They are all completely independent of each other. Functional units don´t know where their input is coming from (or even when it´s gonna arrive). They just specify a range of values they can process. And they promise a certain behavior upon input arriving. Also they don´t know where their output is going. They just produce it in their own time independent of other functional units. That means at least conceptually all functional units work in parallel. Functional units don´t know their “deployment context”. They now nothing about the overall flow they are place in. They are just consuming input from some upstream, and producing output for some downstream. That makes functional units very easy to test. At least as long as they don´t depend on state or resources. I call this the Principle of Mutual Oblivion (PoMO). Functional units are oblivious of others as well as an overall context/purpose. They are just parts of a whole focused on a single responsibility. How the whole is built, how a larger goal is achieved, is of no concern to the single functional units. By building software in such a manner, functional design interestingly follows nature. Nature´s building blocks for organisms also follow the PoMO. The cells forming your body do not know each other. Take a nerve cell “controlling” a muscle cell for example:[2] The nerve cell does not know anything about muscle cells, let alone the specific muscel cell it is “attached to”. Likewise the muscle cell does not know anything about nerve cells, let a lone a specific nerve cell “attached to” it. Saying “the nerve cell is controlling the muscle cell” thus only makes sense when viewing both from the outside. “Control” is a concept of the whole, not of its parts. Control is created by wiring-up parts in a certain way. Both cells are mutually oblivious. Both just follow a contract. One produces Acetylcholine (ACh) as output, the other consumes ACh as input. Where the ACh is going, where it´s coming from neither cell cares about. Million years of evolution have led to this kind of division of labor. And million years of evolution have produced organism designs (DNA) which lead to the production of these different cell types (and many others) and also to their co-location. The result: the overall behavior of an organism. How and why this happened in nature is a mystery. For our software, though, it´s clear: functional and quality requirements needs to be fulfilled. So we as developers have to become “intelligent designers” of “software cells” which we put together to form a “software organism” which responds in satisfying ways to triggers from it´s environment. My bet is: If nature gets complex organisms working by following the PoMO, who are we to not apply this recipe for success to our much simpler “machines”? So my rule is: Wherever there is functionality to be delivered, because there is a clear Entry Point into software, design the functionality like nature would do it. Build it from mutually oblivious functional units. That´s what Flow Design is about. In that way it´s even universal, I´d say. Its notation can also be applied to biology: Never mind labeling the functional units with nouns. That´s ok in Flow Design. You´ll do that occassionally for functional units on a higher level of abstraction or when their purpose is close to hardware. Getting a cockroach to roam your bedroom takes 1,000,000 nerve cells (neurons). Getting the de-duplication program to do its job just takes 5 “software cells” (functional units). Both, though, follow the same basic principle. Translating functional units into code Moving from functional design to code is no rocket science. In fact it´s straightforward. There are two simple rules: Translate an input port to a function. Translate an output port either to a return statement in that function or to a function pointer visible to that function. The simplest translation of a functional unit is a function. That´s what you saw in the above example. Functions are mutually oblivious. That why Functional Programming likes them so much. It makes them composable. Which is the reason, nature works according to the PoMO. Let´s be clear about one thing: There is no dependency injection in nature. For all of an organism´s complexity no DI container is used. Behavior is the result of smooth cooperation between mutually oblivious building blocks. Functions will often be the adequate translation for the functional units in your designs. But not always. Take for example the case, where a processing step should not always produce an output. Maybe the purpose is to filter input. Here the functional unit consumes words and produces words. But it does not pass along every word flowing in. Some words are swallowed. Think of a spell checker. It probably should not check acronyms for correctness. There are too many of them. Or words with no more than two letters. Such words are called “stop words”. In the above picture the optionality of the output is signified by the astrisk outside the brackets. It means: Any number of (word) data items can flow from the functional unit for each input data item. It might be none or one or even more. This I call a stream of data. Such behavior cannot be translated into a function where output is generated with return. Because a function always needs to return a value. So the output port is translated into a function pointer or continuation which gets passed to the subroutine when called:[3]void filter_stop_words( string word, Action<string> onNoStopWord) { if (...check if not a stop word...) onNoStopWord(word); } If you want to be nitpicky you might call such a function pointer parameter an injection. And technically you´re right. Conceptually, though, it´s not an injection. Because the subroutine is not functionally dependent on the continuation. Firstly continuations are procedures, i.e. subroutines without a return type. Remember: Flow Design is about unidirectional data flow. Secondly the name of the formal parameter is chosen in a way as to not assume anything about downstream processing steps. onNoStopWord describes a situation (or event) within the functional unit only. Translating output ports into function pointers helps keeping functional units mutually oblivious in cases where output is optional or produced asynchronically. Either pass the function pointer to the function upon call. Or make it global by putting it on the encompassing class. Then it´s called an event. In C# that´s even an explicit feature.class Filter { public void filter_stop_words( string word) { if (...check if not a stop word...) onNoStopWord(word); } public event Action<string> onNoStopWord; } When to use a continuation and when to use an event dependens on how a functional unit is used in flows and how it´s packed together with others into classes. You´ll see examples further down the Flow Design road. Another example of 1D functional design Let´s see Flow Design once more in action using the visual notation. How about the famous word wrap kata? Robert C. Martin has posted a much cited solution including an extensive reasoning behind his TDD approach. So maybe you want to compare it to Flow Design. The function signature given is:string WordWrap(string text, int maxLineLength) {...} That´s not an Entry Point since we don´t see an application with an environment and users. Nevertheless it´s a function which is supposed to provide a certain functionality. The text passed in has to be reformatted. The input is a single line of arbitrary length consisting of words separated by spaces. The output should consist of one or more lines of a maximum length specified. If a word is longer than a the maximum line length it can be split in multiple parts each fitting in a line. Flow Design Let´s start by brainstorming the process to accomplish the feat of reformatting the text. What´s needed? Words need to be assembled into lines Words need to be extracted from the input text The resulting lines need to be assembled into the output text Words too long to fit in a line need to be split Does sound about right? I guess so. And it shows a kind of priority. Long words are a special case. So maybe there is a hint for an incremental design here. First let´s tackle “average words” (words not longer than a line). Here´s the Flow Design for this increment: The the first three bullet points turned into functional units with explicit data added. As the signature requires a text is transformed into another text. See the input of the first functional unit and the output of the last functional unit. In between no text flows, but words and lines. That´s good to see because thereby the domain is clearly represented in the design. The requirements are talking about words and lines and here they are. But note the asterisk! It´s not outside the brackets but inside. That means it´s not a stream of words or lines, but lists or sequences. For each text a sequence of words is output. For each sequence of words a sequence of lines is produced. The asterisk is used to abstract from the concrete implementation. Like with streams. Whether the list of words gets implemented as an array or an IEnumerable is not important during design. It´s an implementation detail. Does any processing step require further refinement? I don´t think so. They all look pretty “atomic” to me. And if not… I can always backtrack and refine a process step using functional design later once I´ve gained more insight into a sub-problem. Implementation The implementation is straightforward as you can imagine. The processing steps can all be translated into functions. Each can be tested easily and separately. Each has a focused responsibility. And the process flow becomes just a sequence of function calls: Easy to understand. It clearly states how word wrapping works - on a high level of abstraction. And it´s easy to evolve as you´ll see. Flow Design - Increment 2 So far only texts consisting of “average words” are wrapped correctly. Words not fitting in a line will result in lines too long. Wrapping long words is a feature of the requested functionality. Whether it´s there or not makes a difference to the user. To quickly get feedback I decided to first implement a solution without this feature. But now it´s time to add it to deliver the full scope. Fortunately Flow Design automatically leads to code following the Open Closed Principle (OCP). It´s easy to extend it - instead of changing well tested code. How´s that possible? Flow Design allows for extension of functionality by inserting functional units into the flow. That way existing functional units need not be changed. The data flow arrow between functional units is a natural extension point. No need to resort to the Strategy Pattern. No need to think ahead where extions might need to be made in the future. I just “phase in” the remaining processing step: Since neither Extract words nor Reformat know of their environment neither needs to be touched due to the “detour”. The new processing step accepts the output of the existing upstream step and produces data compatible with the existing downstream step. Implementation - Increment 2 A trivial implementation checking the assumption if this works does not do anything to split long words. The input is just passed on: Note how clean WordWrap() stays. The solution is easy to understand. A developer looking at this code sometime in the future, when a new feature needs to be build in, quickly sees how long words are dealt with. Compare this to Robert C. Martin´s solution:[4] How does this solution handle long words? Long words are not even part of the domain language present in the code. At least I need considerable time to understand the approach. Admittedly the Flow Design solution with the full implementation of long word splitting is longer than Robert C. Martin´s. At least it seems. Because his solution does not cover all the “word wrap situations” the Flow Design solution handles. Some lines would need to be added to be on par, I guess. But even then… Is a difference in LOC that important as long as it´s in the same ball park? I value understandability and openness for extension higher than saving on the last line of code. Simplicity is not just less code, it´s also clarity in design. But don´t take my word for it. Try Flow Design on larger problems and compare for yourself. What´s the easier, more straightforward way to clean code? And keep in mind: You ain´t seen all yet ;-) There´s more to Flow Design than described in this chapter. In closing I hope I was able to give you a impression of functional design that makes you hungry for more. To me it´s an inevitable step in software development. Jumping from requirements to code does not scale. And it leads to dirty code all to quickly. Some thought should be invested first. Where there is a clear Entry Point visible, it´s functionality should be designed using data flows. Because with data flows abstraction is possible. For more background on why that´s necessary read my blog article here. For now let me point out to you - if you haven´t already noticed - that Flow Design is a general purpose declarative language. It´s “programming by intention” (Shalloway et al.). Just write down how you think the solution should work on a high level of abstraction. This breaks down a large problem in smaller problems. And by following the PoMO the solutions to those smaller problems are independent of each other. So they are easy to test. Or you could even think about getting them implemented in parallel by different team members. Flow Design not only increases evolvability, but also helps becoming more productive. All team members can participate in functional design. This goes beyon collective code ownership. We´re talking collective design/architecture ownership. Because with Flow Design there is a common visual language to talk about functional design - which is the foundation for all other design activities.   PS: If you like what you read, consider getting my ebook “The Incremental Architekt´s Napkin”. It´s where I compile all the articles in this series for easier reading. I like the strictness of Function Programming - but I also find it quite hard to live by. And it certainly is not what millions of programmers are used to. Also to me it seems, the real world is full of state and side effects. So why give them such a bad image? That´s why functional design takes a more pragmatic approach. State and side effects are ok for processing steps - but be sure to follow the SRP. Don´t put too much of it into a single processing step. ? Image taken from www.physioweb.org ? My code samples are written in C#. C# sports typed function pointers called delegates. Action is such a function pointer type matching functions with signature void someName(T t). Other languages provide similar ways to work with functions as first class citizens - even Java now in version 8. I trust you find a way to map this detail of my translation to your favorite programming language. I know it works for Java, C++, Ruby, JavaScript, Python, Go. And if you´re using a Functional Programming language it´s of course a no brainer. ? Taken from his blog post “The Craftsman 62, The Dark Path”. ?

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