Search Results

Search found 10071 results on 403 pages for 'operator module'.

Page 104/403 | < Previous Page | 100 101 102 103 104 105 106 107 108 109 110 111  | Next Page >

• Using visitor pattern with large object hierarchy

  - by T. Fabre

  Context I've been using with a hierarchy of objects (an expression tree) a "pseudo" visitor pattern (pseudo, as in it does not use double dispatch) : public interface MyInterface { void Accept(SomeClass operationClass); } public class MyImpl : MyInterface { public void Accept(SomeClass operationClass) { operationClass.DoSomething(); operationClass.DoSomethingElse(); // ... and so on ... } } This design was, however questionnable, pretty comfortable since the number of implementations of MyInterface is significant (~50 or more) and I didn't need to add extra operations. Each implementation is unique (it's a different expression or operator), and some are composites (ie, operator nodes that will contain other operator/leaf nodes). Traversal is currently performed by calling the Accept operation on the root node of the tree, which in turns calls Accept on each of its child nodes, which in turn... and so on... But the time has come where I need to add a new operation, such as pretty printing : public class MyImpl : MyInterface { // Property does not come from MyInterface public string SomeProperty { get; set; } public void Accept(SomeClass operationClass) { operationClass.DoSomething(); operationClass.DoSomethingElse(); // ... and so on ... } public void Accept(SomePrettyPrinter printer) { printer.PrettyPrint(this.SomeProperty); } } I basically see two options : Keep the same design, adding a new method for my operation to each derived class, at the expense of maintainibility (not an option, IMHO) Use the "true" Visitor pattern, at the expense of extensibility (not an option, as I expect to have more implementations coming along the way...), with about 50+ overloads of the Visit method, each one matching a specific implementation ? Question Would you recommand using the Visitor pattern ? Is there any other pattern that could help solve this issue ?

  Read the article

• Encapsulating code in F# (Part 2)

  - by MarkPearl

  In part one of this series I showed an example of encapsulation within a local definition. This is useful to know so that you are aware of the scope of value holders etc. but what I am more interested in is encapsulation with regards to generating useful F# code libraries in .Net, this is done by using Namespaces and Modules. Lets have a look at some C# code first… using System; namespace EncapsulationNS { public class EncapsulationCLS { public static void TestMethod() { Console.WriteLine("Hello"); } } } Pretty simple stuff… now the F# equivalent…. namespace EncapsulationNS module EncapsulationMDL = let TestFunction = System.Console.WriteLine("Hello") ()   Even easier… lets look at some specifics about F# namespaces… Namespaces are open. meaning you can have multiple source files and assemblies can contribute to the same namespace. So, Namespaces are a great way to group modules together, so the question needs to be asked, what role do modules play. For me, the F# module is in many ways similar to the vb6 days of modules. In vb6 modules were separate files and simply allowed us to group certain methods together. I find it easier to visualize F# modules this way than to compare them to the C# classes. However that being said one is not restricted to one module per file – there is flexibility to have multiple modules in one code file however with my limited F# experience I would still recommend using the file as the standard level of separating modules as it is very easy to then find your way around a solution. An important note about interop with F# and other .Net languages. I wrote a blog post a while back about a very basic F# to C# interop. If I were to reference an F# library in a C# project (for instance ‘TestFunction’), in C# it would show this method as a static method call, meaning I would not have to instantiate an instance of the module.

  Read the article

• Error: kernel headers not found. (But they are in place)

  - by Guandalino

  I'm trying to install the Guest Additions in VirtualBox 4.04. Host OS is Ubuntu desktop 11.04 64bit, guest OS is Ubuntu server 11.10 64bit. $ sudo ./VBoxLinuxAdditions.run After some output this line is printed: The headers for the current running kernel were not found. But the headers are installed, at least accordingly to dpkg: $ dpkg --get-selections | grep linux-headers linux-headers-3.0.0-12 install linux-headers-3.0.0-12-server install linux-headers-server install The running kernel is: $ uname -a Linux foobar 3.0.0-12-server #20-Ubuntu SMP Fri Oct 7 16:36:30 UTC 2011 x86_64 x86_64 X86_64 GNU/Linux How do I fix things so that Guest Additions installer is able to find kernel headers? Update: added full output. The headers for the current running kernel were not found. If the module compilation fails then this could be the reason. Building the main Guest Additions module ...done. Building the shared folder support module ...fail! (Look at /var/log/vboxadd-install.log to find out what went wrong) Installing the Window System drivers ...fails! (Could not find the X.Org or XFree86 Window System). I don't care for fail #2, because that's a server and I don't need X server. But I need shared folder support. Some further detail: $ tail /val/log/vboxadd-install.log .......... cc1: some warnings being treated as errors make[2]: *** [/tmp/vbox.0/vfsmod.o] Error 1 make[1]: *** [_module_/tmp/vbox.0] Error 2 make: *** [vboxsf] Error 2

  Read the article

• F# Application Entry Point

  - by MarkPearl

  Up to now I have been looking at F# for modular solutions, but have never considered writing an end to end application. Today I was wondering how one would even start to write an end to end application and realized that I didn’t even know where the entry point is for an F# application. After browsing MSDN a bit I got a basic example of a F# application with an entry point [<EntryPoint>] let main args = printfn "Arguments passed to function : %A" args // Return 0. This indicates success. 0 Pretty simple stuff… but what happens when you have a few modules in a program – so I created a F# project with two modules and a main module as illustrated in the image below… When I try to compile my program I get a build error… A function labeled with the 'EntryPointAttribute' attribute must be the last declaration in the last file in the compilation sequence, and can only be used when compiling to a .exe… What does this mean? After some more reading I discovered that the Program.fs needs to be the last file in the F# application – the order of the files in a F# solution are important. How do I move a source file up or down? I tried dragging the Program.fs file below ModuleB.fs but it wouldn’t allow me to. Then I thought to right click on a source file and got the following menu.   Wala… to move the source file to the bottom of the solution you can select the “Move Up” or “Move Down” option. Now that I got this right I decided to put some code in ModuleA & ModuleB and I have the start of a basic application structure. ModuleA Code namespace MyApp module ModuleA = let PrintModuleA = printf "hello a \n" ()   ModuleB Code namespace MyApp module ModuleB = let PrintModuleB = printf "hello b \n" ()   Program Code // Learn more about F# at http://fsharp.net #light namespace MyApp module Main = open System [<EntryPoint>] let main args = ModuleA.PrintModuleA let endofapp = Console.ReadKey() 0

  Read the article

• Structure of a .NET Assembly

  - by Om Talsania

  Assembly is the smallest unit of deployment in .NET Framework.When you compile your C# code, it will get converted into a managed module. A managed module is a standard EXE or DLL. This managed module will have the IL (Microsoft Intermediate Language) code and the metadata. Apart from this it will also have header information.The following table describes parts of a managed module.PartDescriptionPE HeaderPE32 Header for 32-bit PE32+ Header for 64-bit This is a standard Windows PE header which indicates the type of the file, i.e. whether it is an EXE or a DLL. It also contains the timestamp of the file creation date and time. It also contains some other fields which might be needed for an unmanaged PE (Portable Executable), but not important for a managed one. For managed PE, the next header i.e. CLR header is more importantCLR HeaderContains the version of the CLR required, some flags, token of the entry point method (Main), size and location of the metadata, resources, strong name, etc.MetadataThere can be many metadata tables. They can be categorized into 2 major categories.1. Tables that describe the types and members defined in your code2. Tables that describe the types and members referenced by your codeIL CodeMSIL representation of the C# code. At runtime, the CLR converts it into native instructions

  Read the article

• How to get Nvidia graphics working on Sony Z laptop?

  - by projectshave

  I have an older Sony VAIO Z 590 laptop with switchable graphics between Intel and Nvidia GeForce 9300M. It is NOT Optimus. I did a clean install of Ubuntu 12.04. Everything works, but it's using Unity 2D with the Intel drivers. I've tried loading the Nvidia drivers from "Additional Drivers", but it says "this driver is activated but not currently in use". When I run "nvidia-settings", an error window pops up to say "You do not appear to be using the NVIDIA X drivers." "lspci" shows both graphics cards. Let me know if I should add more info. How do I get the Nvidia graphics and Unity 3D working? More info: $ lshw -short -class display H/W path Device Class Description ============================================== /0/100/1/0 display G98 [GeForce 9300M GS] /0/100/2 display Mobile 4 Series Chipset Integrated Graphics C $ glxinfo name of display: :0 Xlib: extension "GLX" missing on display ":0". Xlib: extension "GLX" missing on display ":0". Xlib: extension "GLX" missing on display ":0". Xlib: extension "GLX" missing on display ":0". Xlib: extension "GLX" missing on display ":0". Error: couldn't find RGB GLX visual or fbconfig Xlib: extension "GLX" missing on display ":0". Xlib: extension "GLX" missing on display ":0". Xlib: extension "GLX" missing on display ":0". Xlib: extension "GLX" missing on display ":0". Xlib: extension "GLX" missing on display ":0". Xlib: extension "GLX" missing on display ":0". Xlib: extension "GLX" missing on display ":0". Excerpts from Xorg.0.log: [ 16.373] (II) LoadModule: "glx" [ 16.373] (II) Loading /usr/lib/x86_64-linux-gnu/xorg/extra-modules/libglx.so [ 16.386] (II) Module glx: vendor="NVIDIA Corporation" [ 16.386] compiled for 4.0.2, module version = 1.0.0 [ 16.386] Module class: X.Org Server Extension [ 16.386] (II) NVIDIA GLX Module 295.49 Tue May 1 00:09:10 PDT 2012 [ 16.608] (II) NVIDIA dlloader X Driver 295.49 Mon Apr 30 23:48:24 PDT 2012 [ 16.608] (II) NVIDIA Unified Driver for all Supported NVIDIA GPUs [ 17.693] (EE) Failed to initialize GLX extension (Compatible NVIDIA X driver not found)

  Read the article

• Lost access to the unity interface how to fix? (ubuntu 11.10)

  - by Tal Galili

  o.k, this is embarrassing: I have installed Compiz Config Settings Manager and tried to fix it so that the transition time between changing tabs (using alt+tab) will be short. by accident I un-pressed V from something else, and it asked me about a conflict - I pressed the "x" button to close the window and as a result I stopped seeing the unity interface. That is - I can not see any buttons of the left side. I went to the terminal (ctrl+alt+F1) and ran ccsm As a result I got the following error: $ ccsm /usr/lib/python2.7/site-packages/gtk-2.0/gtk/__init__.py:57: GtkWarning: could not open display warnings.warn(str(e), _gtk.Warning) Traceback (most recent call last): File "/usr/bin/ccsm", line 93, in <module> import ccm File "/usr/lib/python2.7/site-packages/ccm/__init__.py", line 1, in <module> from ccm.Conflicts import * File "/usr/lib/python2.7/site-packages/ccm/Conflicts.py", line 26, in <module> from ccm.Constants import * File "/usr/lib/python2.7/site-packages/ccm/Constants.py", line 29, in <module> CurrentScreenNum = gtk.gdk.display_get_default().get_default_screen().get_number() AttributeError: 'NoneType' object has no attribute 'get_default_screen' What should I do next? Thanks.

  Read the article

• Deploying Django on EC2 using Bitnami Djangostack: WSGI script cannot be loadded

  - by Arman

  I've been struggling to deploy Django application on Amazon EC2 using Bitnami Djangostack for the last couple of days. When I go to http://dewey.io I see the default bitnami page (/opt/bitnami/apache2/htdocs/index.html), however, when I open http://dewey.io/portnoy, I get 'Internal Server Error'. But it's known that if mod_wsgi is setup correctly, the DocumentRoot value from httpd.conf is ignored, thus, I should see my Django application when accessing http://dewey.io. Essentially, the main error is this - 'Target WSGI script cannot be loaded as Python module'. Two questions: 1) any ideas how to fix these mod_wsgi errors (the Apache logs are below)? 2) how to disable the default /opt/bitnami/apache2/htdocs/index.html page and show my homepage from django application when accessing http://dewey.io? Thank you in advance! The details On my EC2 instance I"m running 64-bit Ubuntu 12.04 with DjangoStack 1.4-1. My Django project is located here - /opt/bitnami/apps/django/django_projects/portnoy. root@dewey:/opt/bitnami/apps/django/django_projects/portnoy# ls manage.py README.md settings.py site_media users Procfile sandbox static test.py topics urls.py views.py __init__.pyc templates testviews.py Apache error logs (/opt/bitnami/apache2/logs/error_log): [Wed Jul 04 02:29:00 2012] [error] [client 140.180.6.212] File does not exist: /opt/bitnami/apache2/htdocs/favicon.ico [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] mod_wsgi (pid=3990): Target WSGI script '/opt/bitnami/apps/django/scripts/django.wsgi' cannot be loaded as Python module. [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] mod_wsgi (pid=3990): Exception occurred processing WSGI script '/opt/bitnami/apps/django/scripts/django.wsgi'. [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] Traceback (most recent call last): [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] File "/opt/bitnami/apps/django/scripts/django.wsgi", line 8, in <module> [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] import django.core.handlers.wsgi [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] File "/opt/bitnami/apps/django/lib/python2.7/site-packages/django/core/handlers/wsgi.py", line 8, in <module> [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] from django import http [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] File "/opt/bitnami/apps/django/lib/python2.7/site-packages/django/http/__init__.py", line 119, in <module> [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] from django.http.multipartparser import MultiPartParser [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] File "/opt/bitnami/apps/django/lib/python2.7/site-packages/django/http/multipartparser.py", line 13, in <module> [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] from django.utils.text import unescape_entities [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] File "/opt/bitnami/apps/django/lib/python2.7/site-packages/django/utils/text.py", line 4, in <module> [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] from gzip import GzipFile [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] File "/opt/bitnami/python/lib/python2.7/gzip.py", line 10, in <module> [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] import io [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] File "/opt/bitnami/python/lib/python2.7/io.py", line 60, in <module> [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] import _io [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] ImportError: /opt/bitnami/python/lib/python2.7/lib-dynload/_io.so: undefined symbol: PyUnicodeUCS2_AsEncodedString [Wed Jul 04 02:29:15 2012] [error] [client 140.180.6.212] File does not exist: /opt/bitnami/apache2/htdocs/favicon.ico [Wed Jul 04 02:44:00 2012] [error] [client 140.180.6.212] File does not exist: /opt/bitnami/apache2/htdocs/favicon.ico Let me quickly introduce the contents of the files to make the case more concrete. This is my /etc/apache2/sites-available/default file <VirtualHost *:80> ServerAdmin [email protected] ServerName dewey.io Alias /site_media/ /opt/bitnami/apps/django/django_projects/portnoy/site_media/ Alias /static/ /opt/bitnami/apps/django/lib/python2.7/site-packages/django/contrib/admin/static/ Alias /robots.txt /opt/bitnami/apps/django/django_projects/portnoy/site_media/robots.txt Alias /favicon.ico /opt/bitnami/apps/django/django_projects/portnoy/site_media/favicon.ico CustomLog "|/usr/sbin/rotatelogs /opt/bitnami/apps/django/django_projects/logs/access.log.%Y%m%d-%H%M%S 5M" combined ErrorLog "|/usr/sbin/rotatelogs /opt/bitnami/apps/django/django_projects/logs/error.log.%Y%m%d-%H%M%S 5M" LogLevel warn WSGIProcessGroup dewey.io WSGIScriptAlias / /opt/bitnami/apps/django/scripts/django.wsgi <Directory /opt/bitnami/apps/django/django_projects/portnoy/site_media> Order deny,allow Allow from all Options -Indexes FollowSymLinks </Directory> <Directory /opt/bitnami/apps/django/django_projects/portnoy/conf/apache> Order deny,allow Allow from all </Directory> </VirtualHost> This is my /opt/bitnami/apps/django/scripts/django.wsgi file import os, sys sys.path.append('/opt/bitnami/apps/django/lib/python2.7/site-packages/') sys.path.append('/opt/bitnami/apps/django/django_projects') sys.path.append('/opt/bitnami/apps/django/django_projects/portnoy') os.environ['DJANGO_SETTINGS_MODULE'] = 'portnoy.settings' import django.core.handlers.wsgi application = django.core.handlers.wsgi.WSGIHandler() Here is the relevant portion of /opt/bitnami/apache2/conf/httpd.conf file: ServerRoot "/opt/bitnami/apache2" Listen 80 ServerName dewey.io DocumentRoot "/opt/bitnami/apache2/htdocs" LoadModule wsgi_module modules/mod_wsgi.so WSGIPythonHome /opt/bitnami/python Include "/opt/bitnami/apache2/conf/ssi.conf" Include "/opt/bitnami/apps/django/conf/django.conf" Include "/opt/bitnami/apache2/conf/bitnami/httpd.conf"

  Read the article

• Hibernate exception

  - by Mark

  Hi all, im new to hibernate! i have followed the netbeans tutorial on creating a hibernate enabled application. after sucessfully creating a database in mysql workbench i reversed engineered the pojos etc and then tried to run a simple query(from Course) and got the following org.hibernate.MappingException: An association from the table coursemodule refers to an unmapped class: DAL.Module at org.hibernate.cfg.Configuration.secondPassCompileForeignKeys(Configuration.java:1252) at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1170) at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:324) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1286) at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:859) heres the generated class for Course package DAL; // Generated 02-May-2010 16:41:16 by Hibernate Tools 3.2.1.GA import java.util.HashSet; import java.util.Set; /** * Course generated by hbm2java */ public class Course implements java.io.Serializable { private int id; private String name; private Set<Module> modules = new HashSet<Module>(0); public Course() { } public Course(int id, String name) { this.id = id; this.name = name; } public Course(int id, String name, Set<Module> modules) { this.id = id; this.name = name; this.modules = modules; } public int getId() { return this.id; } public void setId(int id) { this.id = id; } public String getName() { return this.name; } public void setName(String name) { this.name = name; } public Set<Module> getModules() { return this.modules; } public void setModules(Set<Module> modules) { this.modules = modules; } } and its config file course.hbm.xml <?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <!-- Generated 02-May-2010 16:41:16 by Hibernate Tools 3.2.1.GA --> <hibernate-mapping> <class name="DAL.Course" table="course" catalog="walkthrough"> <id name="id" type="int"> <column name="id" /> <generator class="assigned" /> </id> <property name="name" type="string"> <column name="name" not-null="true" /> </property> <set name="modules" inverse="false" table="coursemodule"> <key> <column name="courseId" not-null="true" unique="true" /> </key> <many-to-many entity-name="DAL.Module"> <column name="moduleId" not-null="true" unique="true" /> </many-to-many> </set> </class> </hibernate-mapping> hibernate.reveng.xml <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-reverse-engineering PUBLIC "-//Hibernate/Hibernate Reverse Engineering DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-reverse-engineering-3.0.dtd"> <hibernate-reverse-engineering> <schema-selection match-catalog="Walkthrough"/> <table-filter match-name="walkthrough"/> <table-filter match-name="course"/> <table-filter match-name="module"/> <table-filter match-name="studentmodule"/> <table-filter match-name="attendee"/> <table-filter match-name="student"/> <table-filter match-name="coursemodule"/> <table-filter match-name="session"/> <table-filter match-name="test"/> </hibernate-reverse-engineering> hibernate.cfg.xml <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/Walkthrough</property> <property name="hibernate.connection.username">root</property> <property name="hibernate.connection.password">password</property> <property name="hibernate.show_sql">true</property> <property name="hibernate.current_session_context_class">thread</property> <mapping resource="DAL/Student.hbm.xml"/> <mapping resource="DAL/Walkthrough.hbm.xml"/> <mapping resource="DAL/Test.hbm.xml"/> <mapping resource="DAL/Module.hbm.xml"/> <mapping resource="DAL/Session.hbm.xml"/> <mapping resource="DAL/Course.hbm.xml"/> </session-factory> </hibernate-configuration> any ideas on why im getting this exception? ps. test is just a table with an id in it and is not related to anything. running "from Test" works

  Read the article

• Error when running a GWTTestCase using maven gwt plugin

  - by adancu

  Hi, I've created a test which extends GWTTestCase but I'm getting this error: mvn integration-test gwt:test Running com.myproject.test.ui. GwtTestMyFirstTestCase Translatable source found in... [WARN] No source path entries; expect subsequent failures [ERROR] Unable to find type 'java.lang.Object' [ERROR] Hint: Check that your module inherits 'com.google.gwt.core.Core' either directly or indirectly (most often by inheriting module 'com.google.gwt.user.User') Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 2.1 sec <<< FAILURE! GwtTestMyFirstTestCase.java is in /src/test/java, while the GWT module is located in src/main/java. I assume this shouldn't be a problem. I've done everything required according to http://mojo.codehaus.org/gwt-maven-plugin/user-guide/testing.html and of course that my gwt module already has com.google.gwt.core.Core indirectly imported. http://maven.apache.org/maven-v4_0_0.xsd" 4.0.0 com.myproject main jar 0.0.1-SNAPSHOT Main Module <properties> <gwt.module>com.myproject.MainModule</gwt.module> </properties> <parent> <groupId>com.myproject</groupId> <artifactId>app</artifactId> <version>0.1.0-SNAPSHOT</version> </parent> <dependencies> <dependency> <groupId>com.myproject</groupId> <artifactId>app-commons</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> <dependency> <groupId>com.google.gwt</groupId> <artifactId>gwt-dev</artifactId> <version>${gwt.version}</version> <scope>provided</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-dependency-plugin</artifactId> <configuration> <outputFile>../app/src/main/webapp/WEB-INF/main.tree</outputFile> </configuration> </plugin> <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>gwt-maven-plugin</artifactId> <executions> <execution> <goals> <goal>test</goal> </goals> </execution> </executions> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-jar-plugin</artifactId> <configuration> <classesDirectory> ${project.build.directory}/${project.build.finalName}/${gwt.module} </classesDirectory> </configuration> </plugin> </plugins> </build> Here is the test case, located in /src/test/java/com/myproject/test/ui public class GwtTestMyFirstTestCase extends GWTTestCase { @Override public String getModuleName() { return "com.myproject.MainModule"; } public void testSomething() { } } Here is the gwt module I'm trying to test, located in src/main/java/com/myproject/MainModule.gwt.xml: <inherits name='com.myproject.Commons' /> <source path="site" /> <source path="com.myproject.test.ui" /> <set-property name="gwt.suppressNonStaticFinalFieldWarnings" value="true" /> <entry-point class='com.myproject.site.SiteModuleEntry' /> Can anyone give me a hint or two about what I'm doing wrong? Thanks in advance.

  Read the article

• Using ASP.NET MVC, Linq To SQL, and StructureMap causing DataContext to cache data

  - by Dragn1821

  I'll start by telling my project setup: ASP.NET MVC 1.0 StructureMap 2.6.1 VB I've created a bootstrapper class shown here: Imports StructureMap Imports DCS.Data Imports DCS.Services Public Class BootStrapper Public Shared Sub ConfigureStructureMap() ObjectFactory.Initialize(AddressOf StructureMapRegistry) End Sub Private Shared Sub StructureMapRegistry(ByVal x As IInitializationExpression) x.AddRegistry(New MainRegistry()) x.AddRegistry(New DataRegistry()) x.AddRegistry(New ServiceRegistry()) x.Scan(AddressOf StructureMapScanner) End Sub Private Shared Sub StructureMapScanner(ByVal scanner As StructureMap.Graph.IAssemblyScanner) scanner.Assembly("DCS") scanner.Assembly("DCS.Data") scanner.Assembly("DCS.Services") scanner.WithDefaultConventions() End Sub End Class I've created a controller factory shown here: Imports System.Web.Mvc Imports StructureMap Public Class StructureMapControllerFactory Inherits DefaultControllerFactory Protected Overrides Function GetControllerInstance(ByVal controllerType As System.Type) As System.Web.Mvc.IController Return ObjectFactory.GetInstance(controllerType) End Function End Class I've modified the Global.asax.vb as shown here: ... Sub Application_Start() RegisterRoutes(RouteTable.Routes) 'StructureMap BootStrapper.ConfigureStructureMap() ControllerBuilder.Current.SetControllerFactory(New StructureMapControllerFactory()) End Sub ... I've added a Structure Map registry file to each of my three projects: DCS, DCS.Data, and DCS.Services. Here is the DCS.Data registry: Imports StructureMap.Configuration.DSL Public Class DataRegistry Inherits Registry Public Sub New() 'Data Connections. [For](Of DCSDataContext)() _ .HybridHttpOrThreadLocalScoped _ .Use(New DCSDataContext()) 'Repositories. [For](Of IShiftRepository)() _ .Use(Of ShiftRepository)() [For](Of IMachineRepository)() _ .Use(Of MachineRepository)() [For](Of IShiftSummaryRepository)() _ .Use(Of ShiftSummaryRepository)() [For](Of IOperatorRepository)() _ .Use(Of OperatorRepository)() [For](Of IShiftSummaryJobRepository)() _ .Use(Of ShiftSummaryJobRepository)() End Sub End Class Everything works great as far as loading the dependecies, but I'm having problems with the DCSDataContext class that was genereated by Linq2SQL Classes. I have a form that posts to a details page (/Summary/Details), which loads in some data from SQL. I then have a button that opens a dialog box in JQuery, which populates the dialog from a request to (/Operator/Modify). On the dialog box, the form has a combo box and an OK button that lets the user change the operator's name. Upon clicking OK, the form is posted to (/Operator/Modify) and sent through the service and repository layers of my program and updates the record in the database. Then, the RedirectToAction is called to send the user back to the details page (/Summary/Details) where there is a call to pull the data from SQL again, updating the details view. Everything works great, except the details view does not show the new operator that was selected. I can step through the code and see the DCSDataContext class being accessed to update the operator (which does actually change the database record), but when the DCSDataContext is accessed to reload the details objects, it pulls in the old value. I'm guessing that StructureMap is causing not only the DCSDataContext class but also the data to be cached? I have also tried adding the following to the Global.asax, but it just ends up crashing the program telling me the DCSDataContext has been disposed... Private Sub MvcApplication_EndRequest(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.EndRequest StructureMap.ObjectFactory.ReleaseAndDisposeAllHttpScopedObjects() End Sub Can someone please help?

  Read the article

• Problem with combination boost::exception and boost::variant

  - by Rick

  Hello all, I have strange problem with two-level variant struct when boost::exception is included. I have following code snippet: #include <boost/variant.hpp> #include <boost/exception/all.hpp> typedef boost::variant< int > StoredValue; typedef boost::variant< StoredValue > ExpressionItem; inline std::ostream& operator << ( std::ostream & os, const StoredValue& stvalue ) { return os;} inline std::ostream& operator << ( std::ostream & os, const ExpressionItem& stvalue ) { return os; } When I try to compile it, I have following error: boost/exception/detail/is_output_streamable.hpp(45): error C2593: 'operator <<' is ambiguous test.cpp(11): could be 'std::ostream &operator <<(std::ostream &,const ExpressionItem &)' [found using argument-dependent lookup] test.cpp(8): or 'std::ostream &operator <<(std::ostream &,const StoredValue &)' [found using argument-dependent lookup] 1> while trying to match the argument list '(std::basic_ostream<_Elem,_Traits>, const boost::error_info<Tag,T>)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> and 1> [ 1> Tag=boost::tag_original_exception_type, 1> T=const type_info * 1> ] Code snippet is simplified as much as possible, in the real code are structures much more complicated and each variant has five sub-types. When i remove #include and try following test snippet, program is compiled correctly: void TestVariant() { ExpressionItem test; std::stringstream str; str << test; } Could someone please advise me how to define operators << in order to function even when using boost::Exception ? Thanks and regards Rick

  Read the article

• Are there known problems with >= and <= and the eval function in JS?

  - by Augier

  I am currently writing a JS rules engine which at one point needs to evaluate boolean expressions using the eval() function. Firstly I construct an equation as such: var equation = "relation.relatedTrigger.previousValue" + " " + relation.operator + " " + "relation.value"; relation.relatedTrigger.previousValue is the value I want to compare. relation.operator is the operator (either "==", "!=", <=, "<", "", ="). relation.value is the value I want to compare with. I then simply pass this string to the eval function and it returns true or false as such: return eval(equation); This works absolutely fine (with words and numbers) or all of the operators except for = and <=. E.g. When evaluating the equation: relation.relatedTrigger.previousValue <= 100 It returns true when previousValue = 0,1,10,100 & all negative numbers but false for everything in between. I would greatly appreciate the help of anyone to either answer my question or to help me find an alternative solution. Regards, Augier. P.S. I don't need a speech on the insecurities of the eval() function. Any value given to relation.relatedTrigger.previousValue is predefined. edit: Here is the full function: function evaluateRelation(relation) { console.log("Evaluating relation") var currentValue; //if multiple values if(relation.value.indexOf(";") != -1) { var values = relation.value.split(";"); for (x in values) { var equation = "relation.relatedTrigger.previousValue" + " " + relation.operator + " " + "values[x]"; currentValue = eval(equation); if (currentValue) return true; } return false; } //if single value else { //Evaluate the relation and get boolean var equation = "relation.relatedTrigger.previousValue" + " " + relation.operator + " " + "relation.value"; console.log("relation.relatedTrigger.previousValue " + relation.relatedTrigger.previousValue); console.log(equation); return eval(equation); } } Answer: Provided by KennyTM below. A string comparison doesn't work. Converting to a numerical was needed.

  Read the article

• Is it ok to dynamic cast "this" as a return value?

  - by Panayiotis Karabassis

  This is more of a design question. I have a template class, and I want to add extra methods to it depending on the template type. To practice the DRY principle, I have come up with this pattern (definitions intentionally omitted): template <class T> class BaseVector: public boost::array<T, 3> { protected: BaseVector<T>(const T x, const T y, const T z); public: bool operator == (const Vector<T> &other) const; Vector<T> operator + (const Vector<T> &other) const; Vector<T> operator - (const Vector<T> &other) const; Vector<T> &operator += (const Vector<T> &other) { (*this)[0] += other[0]; (*this)[1] += other[1]; (*this)[2] += other[2]; return *dynamic_cast<Vector<T> * const>(this); } } template <class T> class Vector : public BaseVector<T> { public: Vector<T>(const T x, const T y, const T z) : BaseVector<T>(x, y, z) { } }; template <> class Vector<double> : public BaseVector<double> { public: Vector<double>(const double x, const double y, const double z); Vector<double>(const Vector<int> &other); double norm() const; }; I intend BaseVector to be nothing more than an implementation detail. This works, but I am concerned about operator+=. My question is: is the dynamic cast of the this pointer a code smell? Is there a better way to achieve what I am trying to do (avoid code duplication, and unnecessary casts in the user code)? Or am I safe since, the BaseVector constructor is private?

  Read the article

• How to pass operators as parameters

  - by Rodion Ingles

  I have to load an array of doubles from a file, multiply each element by a value in a table (different values for different elements), do some work on it, invert the multiplication (that is, divide) and then save the data back to file. Currently I implement the multiplication and division process in two separate methods. Now there is some extra work behind the scenes but apart from the specific statements where the multiplication/division occurs, the rest of the code is identical. As you can imagine, with this approach you have to be very careful making any changes. The surrounding code is not trivial, so its either a case of manually editing each method or copying changes from one method to the other and remembering to change the * and / operators. After too many close calls I am fed up of this and would like to make a common function which implements the common logic and two wrapper functions which pass which operator to use as a parameter. My initial approach was to use function pointers: MultiplyData(double data) { TransformData(data, &(operator *)); } DivideData(double data) { TransformData(data, &(operator /)); } TransformData(double data, double (*func)(double op1, double op2)) { /* Do stuff here... */ } However, I can't pass the operators as pointers (is this because it is an operator on a native type?), so I tried to use function objects. Initially I thought that multiplies and divides functors in <functional> would be ideal: MultiplyData(double data) { std::multiplies<double> multFunct; TransformData(data, &multFunct); } DivideData(double data) { std::divides<double> divFunct; TransformData(data, &divFunct); } TransformData(double data, std::binary_function<double, double, double> *funct) { /* Do stuff here... */ } As you can see I was trying to use a base class pointer to pass the functor polymorphically. The problem is that std::binary_function does not declare an operator() member for the child classes to implement. Is there something I am missing, or is the solution to implement my own functor heirarchy (which really seems more trouble than it is worth)?

  Read the article

• Understanding C++ dynamic allocation

  - by kiokko89

  Consider the following code: class CString { private: char* buff; size_t len; public: CString(const char* p):len(0), buff(nullptr) { cout << "Constructor called!"<<endl; if (p!=nullptr) { len= strlen(p); if (len>0) { buff= new char[len+1]; strcpy_s(buff, len+1, p); } } } CString (const CString& s) { cout << "Copy constructor called!"<<endl; len= s.len; buff= new char[len+1]; strcpy_s(buff, len+1, s.buff); } CString& operator = (const CString& rhs) { cout << "Assignment operator called!"<<endl; if (this != &rhs) { len= rhs.len; delete[] buff; buff= new char[len+1]; strcpy_s(buff, len+1, rhs.buff); } return *this; } CString operator + (const CString& rhs) const { cout << "Addition operator called!"<<endl; size_t lenght= len+rhs.len+1; char* tmp = new char[lenght]; strcpy_s(tmp, lenght, buff); strcat_s(tmp, lenght, rhs.buff); return CString(tmp); } ~CString() { cout << "Destructor called!"<<endl; delete[] buff; } }; int main() { CString s1("Hello"); CString s2("World"); CString s3 = s1+s2; } My problem is that I don't know how to delete the memory allocated in the addition operator function(char* tmp = new char[length]). I couldn't do this in the constructor(I tried delete[] p) because it is also called from the main function with arrays of chars as parameters which are not allocated on the heap...How can I get around this? (Sorry for my bad English...)

  Read the article

• Implementing default constructors

  - by James

  Implement the default constructor, the constructors with one and two int parameters. The one-parameter constructor should initialize the first member of the pair, the second member of the pair is to be 0. Overload binary operator + to add the pairs as follows: (a, b) + (c, d) = (a + c, b + d); Overload the - analogously. Overload the * on pairs ant int as follows: (a, b) * c = (a * c, b * c). Write a program to test all the member functions and overloaded operators in your class definition. You will also need to write accessor (get) functions for each member. The definition of the class Pairs: class Pairs { public: Pairs(); Pairs(int first, int second); Pairs(int first); // other members and friends friend istream& operator>> (istream&, Pair&); friend ostream& operator<< (ostream&, const Pair&); private: int f; int s; }; Self-Test Exercise #17: istream& operator (istream& ins, Pair& second) { char ch; ins ch; // discard init '(' ins second.f; ins ch; // discard comma ',' ins second.s; ins ch; // discard final '(' return ins; } ostream& operator<< (ostream& outs, const Pair& second) { outs << '('; outs << second.f; outs << ", " ;// I followed the Author's suggestion here. outs << second.s; outs << ")"; return outs; }

  Read the article

• Copy constructor bug

  - by user168715

  I'm writing a simple nD-vector class, but am encountering a strange bug. I've stripped out the class to the bare minimum that still reproduces the bug: #include <iostream> using namespace std; template<unsigned int size> class nvector { public: nvector() {data_ = new double[size];} ~nvector() {delete[] data_;} template<unsigned int size2> nvector(const nvector<size2> &other) { data_ = new double[size]; int i=0; for(; i<size && i < size2; i++) data_[i] = other[i]; for(; i<size; i++) data_[i] = 0; } double &operator[](int i) {return data_[i];} const double&operator[](int i) const {return data_[i];} private: const nvector<size> &operator=(const nvector<size> &other); //Intentionally unimplemented for now double *data_; }; int main() { nvector<2> vector2d; vector2d[0] = 1; vector2d[1] = 2; nvector<3> vector3d(vector2d); for(int i=0; i<3; i++) cout << vector3d[i] << " "; cout << endl; //Prints 1 2 0 nvector<3> other3d(vector3d); for(int i=0; i<3; i++) cout << other3d[i] << " "; cout << endl; //Prints 1 2 0 } //Segfault??? On the surface this seems to work fine, and both tests print out the correct values. However, at the end of main the program crashes with a segfault, which I've traced to nvector's destructor. At first I thought the (incorrect) default assignment operator was somehow being called, which is why I added the (currently) unimplemented explicit assignment operator to rule this possibility out. So my copy constructor must be buggy, but I'm having one of those days where I'm staring at extremely simple code and just can't see it. Do you guys have any ideas?

  Read the article

• Can't insert a number into a C++ custom streambuf/ostream

  - by 0xbe5077ed

  I have written a custom std::basic_streambuf and std::basic_ostream because I want an output stream that I can get a JNI string from in a manner similar to how you can call std::ostringstream::str(). These classes are quite simple. namespace myns { class jni_utf16_streambuf : public std::basic_streambuf<char16_t> { JNIEnv * d_env; std::vector<char16_t> d_buf; virtual int_type overflow(int_type); public: jni_utf16_streambuf(JNIEnv *); jstring jstr() const; }; typedef std::basic_ostream<char16_t, std::char_traits<char16_t>> utf16_ostream; class jni_utf16_ostream : public utf16_ostream { jni_utf16_streambuf d_buf; public: jni_utf16_ostream(JNIEnv *); jstring jstr() const; }; // ... } // namespace myns In addition, I have made four overloads of operator<<, all in the same namespace: namespace myns { // ... utf16_ostream& operator<<(utf16_ostream&, jstring) throw(std::bad_cast); utf16_ostream& operator<<(utf16_ostream&, const char *); utf16_ostream& operator<<(utf16_ostream&, const jni_utf16_string_region&); jni_utf16_ostream& operator<<(jni_utf16_ostream&, jstring); // ... } // namespace myns The implementation of jni_utf16_streambuf::overflow(int_type) is trivial. It just doubles the buffer width, puts the requested character, and sets the base, put, and end pointers correctly. It is tested and I am quite sure it works. The jni_utf16_ostream works fine inserting unicode characters. For example, this works fine and results in the stream containing "hello, world": myns::jni_utf16_ostream o(env); o << u"hello, wor" << u'l' << u'd'; My problem is as soon as I try to insert an integer value, the stream's bad bit gets set, for example: myns::jni_utf16_ostream o(env); if (o.badbit()) throw "bad bit before"; // does not throw int32_t x(5); o << x; if (o.badbit()) throw "bad bit after"; // throws :( I don't understand why this is happening! Is there some other method on std::basic_streambuf I need to be implementing????

  Read the article

• Big Data Matters with ODI12c

  - by Madhu Nair

  contributed by Mike Eisterer On October 17th, 2013, Oracle announced the release of Oracle Data Integrator 12c (ODI12c).  This release signifies improvements to Oracle’s Data Integration portfolio of solutions, particularly Big Data integration. Why Big Data = Big Business Organizations are gaining greater insights and actionability through increased storage, processing and analytical benefits offered by Big Data solutions.  New technologies and frameworks like HDFS, NoSQL, Hive and MapReduce support these benefits now. As further data is collected, analytical requirements increase and the complexity of managing transformations and aggregations of data compounds and organizations are in need for scalable Data Integration solutions. ODI12c provides enterprise solutions for the movement, translation and transformation of information and data heterogeneously and in Big Data Environments through: The ability for existing ODI and SQL developers to leverage new Big Data technologies. A metadata focused approach for cataloging, defining and reusing Big Data technologies, mappings and process executions. Integration between many heterogeneous environments and technologies such as HDFS and Hive. Generation of Hive Query Language. Working with Big Data using Knowledge Modules  ODI12c provides developers with the ability to define sources and targets and visually develop mappings to effect the movement and transformation of data.  As the mappings are created, ODI12c leverages a rich library of prebuilt integrations, known as Knowledge Modules (KMs).  These KMs are contextual to the technologies and platforms to be integrated.  Steps and actions needed to manage the data integration are pre-built and configured within the KMs.  The Oracle Data Integrator Application Adapter for Hadoop provides a series of KMs, specifically designed to integrate with Big Data Technologies.  The Big Data KMs include: Check Knowledge Module Reverse Engineer Knowledge Module Hive Transform Knowledge Module Hive Control Append Knowledge Module File to Hive (LOAD DATA) Knowledge Module File-Hive to Oracle (OLH-OSCH) Knowledge Module  Nothing to beat an Example: To demonstrate the use of the KMs which are part of the ODI Application Adapter for Hadoop, a mapping may be defined to move data between files and Hive targets.  The mapping is defined by dragging the source and target into the mapping, performing the attribute (column) mapping (see Figure 1) and then selecting the KM which will govern the process.  In this mapping example, movie data is being moved from an HDFS source into a Hive table.  Some of the attributes, such as “CUSTID to custid”, have been mapped over. Figure 1  Defining the Mapping Before the proper KM can be assigned to define the technology for the mapping, it needs to be added to the ODI project.  The Big Data KMs have been made available to the project through the KM import process.   Generally, this is done prior to defining the mapping. Figure 2  Importing the Big Data Knowledge Modules Following the import, the KMs are available in the Designer Navigator. v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false EN-US ZH-TW X-NONE MicrosoftInternetExplorer4 /* 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-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Figure 3  The Project View in Designer, Showing Installed IKMs Once the KM is imported, it may be assigned to the mapping target.  This is done by selecting the Physical View of the mapping and examining the Properties of the Target.  In this case MOVIAPP_LOG_STAGE is the target of our mapping. Figure 4  Physical View of the Mapping and Assigning the Big Data Knowledge Module to the Target Alternative KMs may have been selected as well, providing flexibility and abstracting the logical mapping from the physical implementation.  Our mapping may be applied to other technologies as well. The mapping is now complete and is ready to run.  We will see more in a future blog about running a mapping to load Hive. To complete the quick ODI for Big Data Overview, let us take a closer look at what the IKM File to Hive is doing for us.  ODI provides differentiated capabilities by defining the process and steps which normally would have to be manually developed, tested and implemented into the KM.  As shown in figure 5, the KM is preparing the Hive session, managing the Hive tables, performing the initial load from HDFS and then performing the insert into Hive.  HDFS and Hive options are selected graphically, as shown in the properties in Figure 4. Figure 5  Process and Steps Managed by the KM What’s Next Big Data being the shape shifting business challenge it is is fast evolving into the deciding factor between market leaders and others. Now that an introduction to ODI and Big Data has been provided, look for additional blogs coming soon using the Knowledge Modules which make up the Oracle Data Integrator Application Adapter for Hadoop: Importing Big Data Metadata into ODI, Testing Data Stores and Loading Hive Targets Generating Transformations using Hive Query language Loading Oracle from Hadoop Sources For more information now, please visit the Oracle Data Integrator Application Adapter for Hadoop web site, http://www.oracle.com/us/products/middleware/data-integration/hadoop/overview/index.html Do not forget to tune in to the ODI12c Executive Launch webcast on the 12th to hear more about ODI12c and GG12c. Normal 0 false false false EN-US ZH-TW X-NONE MicrosoftInternetExplorer4 /* 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-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";}

  Read the article

• MapRedux - PowerShell and Big Data

  - by Dittenhafer Solutions

  MapRedux – #PowerShell and #Big Data Have you been hearing about “big data”, “map reduce” and other large scale computing terms over the past couple of years and been curious to dig into more detail? Have you read some of the Apache Hadoop online documentation and unfortunately concluded that it wasn't feasible to setup a “test” hadoop environment on your machine? More recently, I have read about some of Microsoft’s work to enable Hadoop on the Azure cloud. Being a "Microsoft"-leaning technologist, I am more inclinded to be successful with experimentation when on the Windows platform. Of course, it is not that I am "religious" about one set of technologies other another, but rather more experienced. Anyway, within the past couple of weeks I have been thinking about PowerShell a bit more as the 2012 PowerShell Scripting Games approach and it occured to me that PowerShell's support for Windows Remote Management (WinRM), and some other inherent features of PowerShell might lend themselves particularly well to a simple implementation of the MapReduce framework. I fired up my PowerShell ISE and started writing just to see where it would take me. Quite simply, the ScriptBlock feature combined with the ability of Invoke-Command to create remote jobs on networked servers provides much of the plumbing of a distributed computing environment. There are some limiting factors of course. Microsoft provided some default settings which prevent PowerShell from taking over a network without administrative approval first. But even with just one adjustment, a given Windows-based machine can become a node in a MapReduce-style distributed computing environment. Ok, so enough introduction. Let's talk about the code. First, any machine that will participate as a remote "node" will need WinRM enabled for remote access, as shown below. This is not exactly practical for hundreds of intended nodes, but for one (or five) machines in a test environment it does just fine. C:> winrm quickconfig WinRM is not set up to receive requests on this machine. The following changes must be made: Set the WinRM service type to auto start. Start the WinRM service. Make these changes [y/n]? y Alternatively, you could take the approach described in the Remotely enable PSRemoting post from the TechNet forum and use PowerShell to create remote scheduled tasks that will call Enable-PSRemoting on each intended node. Invoke-MapRedux Moving on, now that you have one or more remote "nodes" enabled, you can consider the actual Map and Reduce algorithms. Consider the following snippet: $MyMrResults = Invoke-MapRedux -MapReduceItem $Mr -ComputerName $MyNodes -DataSet $dataset -Verbose Invoke-MapRedux takes an instance of a MapReduceItem which references the Map and Reduce scriptblocks, an array of computer names which are the remote nodes, and the initial data set to be processed. As simple as that, you can start working with concepts of big data and the MapReduce paradigm. Now, how did we get there? I have published the initial version of my PsMapRedux PowerShell Module on GitHub. The PsMapRedux module provides the Invoke-MapRedux function described above. Feel free to browse the underlying code and even contribute to the project! In a later post, I plan to show some of the inner workings of the module, but for now let's move on to how the Map and Reduce functions are defined. Map Both the Map and Reduce functions need to follow a prescribed prototype. The prototype for a Map function in the MapRedux module is as follows. A simple scriptblock that takes one PsObject parameter and returns a hashtable. It is important to note that the PsObject $dataset parameter is a MapRedux custom object that has a "Data" property which offers an array of data to be processed by the Map function. $aMap = { Param ( [PsObject] $dataset ) # Indicate the job is running on the remote node. Write-Host ($env:computername + "::Map"); # The hashtable to return $list = @{}; # ... Perform the mapping work and prepare the $list hashtable result with your custom PSObject... # ... The $dataset has a single 'Data' property which contains an array of data rows # which is a subset of the originally submitted data set. # Return the hashtable (Key, PSObject) Write-Output $list; } Reduce Likewise, with the Reduce function a simple prototype must be followed which takes a $key and a result $dataset from the MapRedux's partitioning function (which joins the Map results by key). Again, the $dataset is a MapRedux custom object that has a "Data" property as described in the Map section. $aReduce = { Param ( [object] $key, [PSObject] $dataset ) Write-Host ($env:computername + "::Reduce - Count: " + $dataset.Data.Count) # The hashtable to return $redux = @{}; # Return Write-Output $redux; } All Together Now When everything is put together in a short example script, you implement your Map and Reduce functions, query for some starting data, build the MapReduxItem via New-MapReduxItem and call Invoke-MapRedux to get the process started: # Import the MapRedux and SQL Server providers Import-Module "MapRedux" Import-Module “sqlps” -DisableNameChecking # Query the database for a dataset Set-Location SQLSERVER:\sql\dbserver1\default\databases\myDb $query = "SELECT MyKey, Date, Value1 FROM BigData ORDER BY MyKey"; Write-Host "Query: $query" $dataset = Invoke-SqlCmd -query $query # Build the Map function $MyMap = { Param ( [PsObject] $dataset ) Write-Host ($env:computername + "::Map"); $list = @{}; foreach($row in $dataset.Data) { # Write-Host ("Key: " + $row.MyKey.ToString()); if($list.ContainsKey($row.MyKey) -eq $true) { $s = $list.Item($row.MyKey); $s.Sum += $row.Value1; $s.Count++; } else { $s = New-Object PSObject; $s | Add-Member -Type NoteProperty -Name MyKey -Value $row.MyKey; $s | Add-Member -type NoteProperty -Name Sum -Value $row.Value1; $list.Add($row.MyKey, $s); } } Write-Output $list; } $MyReduce = { Param ( [object] $key, [PSObject] $dataset ) Write-Host ($env:computername + "::Reduce - Count: " + $dataset.Data.Count) $redux = @{}; $count = 0; foreach($s in $dataset.Data) { $sum += $s.Sum; $count += 1; } # Reduce $redux.Add($s.MyKey, $sum / $count); # Return Write-Output $redux; } # Create the item data $Mr = New-MapReduxItem "My Test MapReduce Job" $MyMap $MyReduce # Array of processing nodes... $MyNodes = ("node1", "node2", "node3", "node4", "localhost") # Run the Map Reduce routine... $MyMrResults = Invoke-MapRedux -MapReduceItem $Mr -ComputerName $MyNodes -DataSet $dataset -Verbose # Show the results Set-Location C:\ $MyMrResults | Out-GridView Conclusion I hope you have seen through this article that PowerShell has a significant infrastructure available for distributed computing. While it does take some code to expose a MapReduce-style framework, much of the work is already done and PowerShell could prove to be the the easiest platform to develop and run big data jobs in your corporate data center, potentially in the Azure cloud, or certainly as an academic excerise at home or school. Follow me on Twitter to stay up to date on the continuing progress of my Powershell MapRedux module, and thanks for reading! Daniel

  Read the article

• SQL SERVER – Merge Operations – Insert, Update, Delete in Single Execution

  - by pinaldave

  This blog post is written in response to T-SQL Tuesday hosted by Jorge Segarra (aka SQLChicken). I have been very active using these Merge operations in my development. However, I have found out from my consultancy work and friends that these amazing operations are not utilized by them most of the time. Here is my attempt to bring the necessity of using the Merge Operation to surface one more time. MERGE is a new feature that provides an efficient way to do multiple DML operations. In earlier versions of SQL Server, we had to write separate statements to INSERT, UPDATE, or DELETE data based on certain conditions; however, at present, by using the MERGE statement, we can include the logic of such data changes in one statement that even checks when the data is matched and then just update it, and similarly, when the data is unmatched, it is inserted. One of the most important advantages of MERGE statement is that the entire data are read and processed only once. In earlier versions, three different statements had to be written to process three different activities (INSERT, UPDATE or DELETE); however, by using MERGE statement, all the update activities can be done in one pass of database table. I have written about these Merge Operations earlier in my blog post over here SQL SERVER – 2008 – Introduction to Merge Statement – One Statement for INSERT, UPDATE, DELETE. I was asked by one of the readers that how do we know that this operator was doing everything in single pass and was not calling this Merge Operator multiple times. Let us run the same example which I have used earlier; I am listing the same here again for convenience. --Let’s create Student Details and StudentTotalMarks and inserted some records. USE tempdb GO CREATE TABLE StudentDetails ( StudentID INTEGER PRIMARY KEY, StudentName VARCHAR(15) ) GO INSERT INTO StudentDetails VALUES(1,'SMITH') INSERT INTO StudentDetails VALUES(2,'ALLEN') INSERT INTO StudentDetails VALUES(3,'JONES') INSERT INTO StudentDetails VALUES(4,'MARTIN') INSERT INTO StudentDetails VALUES(5,'JAMES') GO CREATE TABLE StudentTotalMarks ( StudentID INTEGER REFERENCES StudentDetails, StudentMarks INTEGER ) GO INSERT INTO StudentTotalMarks VALUES(1,230) INSERT INTO StudentTotalMarks VALUES(2,255) INSERT INTO StudentTotalMarks VALUES(3,200) GO -- Select from Table SELECT * FROM StudentDetails GO SELECT * FROM StudentTotalMarks GO -- Merge Statement MERGE StudentTotalMarks AS stm USING (SELECT StudentID,StudentName FROM StudentDetails) AS sd ON stm.StudentID = sd.StudentID WHEN MATCHED AND stm.StudentMarks > 250 THEN DELETE WHEN MATCHED THEN UPDATE SET stm.StudentMarks = stm.StudentMarks + 25 WHEN NOT MATCHED THEN INSERT(StudentID,StudentMarks) VALUES(sd.StudentID,25); GO -- Select from Table SELECT * FROM StudentDetails GO SELECT * FROM StudentTotalMarks GO -- Clean up DROP TABLE StudentDetails GO DROP TABLE StudentTotalMarks GO The Merge Join performs very well and the following result is obtained. Let us check the execution plan for the merge operator. You can click on following image to enlarge it. Let us evaluate the execution plan for the Table Merge Operator only. We can clearly see that the Number of Executions property suggests value 1. Which is quite clear that in a single PASS, the Merge Operation completes the operations of Insert, Update and Delete. I strongly suggest you all to use this operation, if possible, in your development. I have seen this operation implemented in many data warehousing applications. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Joins, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Merge

  Read the article

• concurrency::extent<N> from amp.h

  - by Daniel Moth

  Overview We saw in a previous post how index<N> represents a point in N-dimensional space and in this post we'll see how to define the N-dimensional space itself. With C++ AMP, an N-dimensional space can be specified with the template class extent<N> where you define the size of each dimension. From a look and feel perspective, you'd expect the programmatic interface of a point type and size type to be similar (even though the concepts are different). Indeed, exactly like index<N>, extent<N> is essentially a coordinate vector of N integers ordered from most- to least- significant, BUT each integer represents the size for that dimension (and hence cannot be negative). So, if you read the description of index, you won't be surprised with the below description of extent<N> There is the rank field returning the value of N you passed as the template parameter. You can construct one extent from another (via the copy constructor or the assignment operator), you can construct it by passing an integer array, or via convenience constructor overloads for 1- 2- and 3- dimension extents. Note that the parameterless constructor creates an extent of the specified rank with all bounds initialized to 0. You can access the components of the extent through the subscript operator (passing it an integer). You can perform some arithmetic operations between extent objects through operator overloading, i.e. ==, !=, +=, -=, +, -. There are operator overloads so that you can perform operations between an extent and an integer: -- (pre- and post- decrement), ++ (pre- and post- increment), %=, *=, /=, +=, –= and, finally, there are additional overloads for plus and minus (+,-) between extent<N> and index<N> objects, returning a new extent object as the result. In addition to the usual suspects, extent offers a contains function that tests if an index is within the bounds of the extent (assuming an origin of zero). It also has a size function that returns the total linear size of this extent<N> in units of elements. Example code extent<2> e(3, 4); _ASSERT(e.rank == 2); _ASSERT(e.size() == 3 * 4); e += 3; e[1] += 6; e = e + index<2>(3,-4); _ASSERT(e == extent<2>(9, 9)); _ASSERT( e.contains(index<2>(8, 8))); _ASSERT(!e.contains(index<2>(8, 9))); grid<N> Our upcoming pre-release bits also have a similar type to extent, grid<N>. The way you create a grid is by passing it an extent, e.g. extent<3> e(4,2,6); grid<3> g(e); I am not going to dive deeper into grid, suffice for now to think of grid<N> simply as an alias for the extent<N> object, that you create when you encounter a function that expects a grid object instead of an extent object. Usage The extent class on its own simply defines the size of the N-dimensional space. We'll see in future posts that when you create containers (arrays) and wrappers (array_views) for your data, it is an extent<N> object that you'll need to use to create those (and use an index<N> object to index into them). We'll also see that it is a grid<N> object that you pass to the new parallel_for_each function that I'll cover in the next post. Comments about this post by Daniel Moth welcome at the original blog.

  Read the article

• How can I get a Belkin N600 DB (F9L1101v1) to work on Ubuntu 12,04 64-Bit

  - by rheide

  I could use some assistance to trying to get a Belkin N600 DB Wireless Dual-Band USB Adapter to work on a Dell Inspiron 1525 with 64-Bit Ubuntu 12.04. The device won't work out of the box. Tried to go the NDISWrapper route, but using the GUI, received the following message: Module could not be loaded. Error was: FATAL: Module ndiswrapper not found. Is the ndiswrapper module installed? Despite the fact that it showed up listed in the GUI, the device still did not function properly. How should I proceed from here?

  Read the article

• how to solve error processing /usr/lib/python2.7/dist-packages/pygst.pth:?

  - by ChitKo

  Error processing line 1 of /usr/lib/python2.7/dist-packages/pygst.pth: Traceback (most recent call last): File "/usr/lib/python2.7/site.py", line 161, in addpackage if not dircase in known_paths and os.path.exists(dir): File "/usr/lib/python2.7/genericpath.py", line 18, in exists os.stat(path) TypeError: must be encoded string without NULL bytes, not str Remainder of file ignored Error processing line 1 of /usr/lib/python2.7/dist-packages/pygtk.pth: Traceback (most recent call last): File "/usr/lib/python2.7/site.py", line 161, in addpackage if not dircase in known_paths and os.path.exists(dir): File "/usr/lib/python2.7/genericpath.py", line 18, in exists os.stat(path) TypeError: must be encoded string without NULL bytes, not str Remainder of file ignored Traceback (most recent call last): File "/usr/share/apport/apport-gtk", line 16, in <module> from gi.repository import GObject File "/usr/lib/python2.7/dist-packages/gi/importer.py", line 76, in load_module dynamic_module._load() File "/usr/lib/python2.7/dist-packages/gi/module.py", line 222, in _load version) File "/usr/lib/python2.7/dist-packages/gi/module.py", line 90, in __init__ repository.require(namespace, version) gi.RepositoryError: Failed to load typelib file '/usr/lib/girepository-1.0/GLib-2.0.typelib' for namespace 'GLib': Invalid magic header

  Read the article

< Previous Page | 100 101 102 103 104 105 106 107 108 109 110 111  | Next Page >