Search Results

Search found 50 results on 2 pages for 'statics'.

Page 2/2 | < Previous Page | 1 2 

  • "static" as a semantic clue about statelessness?

    - by leoger
    this might be a little philosophical but I hope someone can help me find a good way to think about this. I've recently undertaken a refactoring of a medium sized project in Java to go back and add unit tests. When I realized what a pain it was to mock singletons and statics, I finally "got" what I've been reading about them all this time. (I'm one of those people that needs to learn from experience. Oh well.) So, now that I'm using Spring to create the objects and wire them around, I'm getting rid of static keywords left and right. (If I could potentially want to mock it, it's not really static in the same sense that Math.abs() is, right?) The thing is, I had gotten into the habit of using static to denote that a method didn't rely on any object state. For example: //Before import com.thirdparty.ThirdPartyLibrary.Thingy; public class ThirdPartyLibraryWrapper { public static Thingy newThingy(InputType input) { new Thingy.Builder().withInput(input).alwaysFrobnicate().build(); } } //called as... ThirdPartyLibraryWrapper.newThingy(input); //After public class ThirdPartyFactory { public Thingy newThingy(InputType input) { new Thingy.Builder().withInput(input).alwaysFrobnicate().build(); } } //called as... thirdPartyFactoryInstance.newThingy(input); So, here's where it gets touchy-feely. I liked the old way because the capital letter told me that, just like Math.sin(x), ThirdPartyLibraryWrapper.newThingy(x) did the same thing the same way every time. There's no object state to change how the object does what I'm asking it to do. Here are some possible answers I'm considering. Nobody else feels this way so there's something wrong with me. Maybe I just haven't really internalized the OO way of doing things! Maybe I'm writing in Java but thinking in FORTRAN or somesuch. (Which would be impressive since I've never written FORTRAN.) Maybe I'm using staticness as a sort of proxy for immutability for the purposes of reasoning about code. That being said, what clues should I have in my code for someone coming along to maintain it to know what's stateful and what's not? Perhaps this should just come for free if I choose good object metaphors? e.g. thingyWrapper doesn't sound like it has state indepdent of the wrapped Thingy which may itself be mutable. Similarly, a thingyFactory sounds like it should be immutable but could have different strategies that are chosen among at creation. I hope I've been clear and thanks in advance for your advice!

    Read the article

  • Apache2, making my site publicly available

    - by Shackler
    Hello, I want to make my apache 2 development server public to the internet, it is a Django based website. Here is my apache2 config: <VirtualHost *:80> Alias /media /home/user/myproject/statics Alias /admin_media /home/myuser/django/Django-1.1.1/django/contrib/admin/media WSGIScriptAlias / /home/myuser/myproject/myproject_wsgi.py WSGIDaemonProcess myproject user=myuser group=myuser threads=25 WSGIProcessGroup myproject </VirtualHost> When I do netstat -lntup I get: Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN - tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN - tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN - tcp6 0 0 :::80 :::* LISTEN - tcp6 0 0 :::22 :::* LISTEN - tcp6 0 0 ::1:631 :::* LISTEN - udp 0 0 0.0.0.0:5353 0.0.0.0:* - udp 0 0 0.0.0.0:38582 0.0.0.0:* I connect with ADSL thus I am behind a router. For this I have made my computer DMZ enabled to my machine. What can be the problem? When I try to login with my ip, I get my routers config page, when a friend tries to connect to me from internet, he gets "not authorized".

    Read the article

  • Apache 2.2, worker mpm, mod_fcgid and PHP: Can't apply process slot

    - by mopoke
    We're having an issue on an apache server where every 15 to 20 minutes it stops serving PHP requests entirely. On occasions it will return a 503 error, other times it will recover enough to serve the page but only after a delay of a minute or more. Static content is still served during that time. In the log file, there's errors reported along the lines of: [Wed Sep 28 10:45:39 2011] [warn] mod_fcgid: can't apply process slot for /xxx/ajaxfolder/ajax_features.php [Wed Sep 28 10:45:41 2011] [warn] mod_fcgid: can't apply process slot for /xxx/statics/poll/index.php [Wed Sep 28 10:45:45 2011] [warn] mod_fcgid: can't apply process slot for /xxx/index.php [Wed Sep 28 10:45:45 2011] [warn] mod_fcgid: can't apply process slot for /xxx/index.php There is RAM free and, indeed, it seems that more php processes get spawned. /server-status shows lots of threads in the "W" state as well as some FastCGI processes in "Exiting(communication error)" state. I rebuilt mod_fcgid from source as the packaged version was quite old. It's using current stable version (2.3.6) of mod_fcgid. FCGI config: FcgidBusyScanInterval 30 FcgidBusyTimeout 60 FcgidIdleScanInterval 30 FcgidIdleTimeout 45 FcgidIOTimeout 60 FcgidConnectTimeout 20 FcgidMaxProcesses 100 FcgidMaxRequestsPerProcess 500 FcgidOutputBufferSize 1048576 System info: Linux xxx.com 2.6.28-11-server #42-Ubuntu SMP Fri Apr 17 02:45:36 UTC 2009 x86_64 GNU/Linux DISTRIB_ID=Ubuntu DISTRIB_RELEASE=9.04 DISTRIB_CODENAME=jaunty DISTRIB_DESCRIPTION="Ubuntu 9.04" Apache info: Server version: Apache/2.2.11 (Ubuntu) Server built: Aug 16 2010 17:45:55 Server's Module Magic Number: 20051115:21 Server loaded: APR 1.2.12, APR-Util 1.2.12 Compiled using: APR 1.2.12, APR-Util 1.2.12 Architecture: 64-bit Server MPM: Worker threaded: yes (fixed thread count) forked: yes (variable process count) Server compiled with.... -D APACHE_MPM_DIR="server/mpm/worker" -D APR_HAS_SENDFILE -D APR_HAS_MMAP -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled) -D APR_USE_SYSVSEM_SERIALIZE -D APR_USE_PTHREAD_SERIALIZE -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT -D APR_HAS_OTHER_CHILD -D AP_HAVE_RELIABLE_PIPED_LOGS -D DYNAMIC_MODULE_LIMIT=128 -D HTTPD_ROOT="" -D SUEXEC_BIN="/usr/lib/apache2/suexec" -D DEFAULT_PIDLOG="/var/run/apache2.pid" -D DEFAULT_SCOREBOARD="logs/apache_runtime_status" -D DEFAULT_ERRORLOG="logs/error_log" -D AP_TYPES_CONFIG_FILE="/etc/apache2/mime.types" -D SERVER_CONFIG_FILE="/etc/apache2/apache2.conf" Apache modules loaded: alias.load auth_basic.load authn_file.load authz_default.load authz_groupfile.load authz_host.load authz_user.load autoindex.load cgi.load deflate.load dir.load env.load expires.load fcgid.load headers.load include.load mime.load negotiation.load rewrite.load setenvif.load ssl.load status.load suexec.load PHP info: PHP 5.2.6-3ubuntu4.6 with Suhosin-Patch 0.9.6.2 (cli) (built: Sep 16 2010 19:51:25) Copyright (c) 1997-2008 The PHP Group Zend Engine v2.2.0, Copyright (c) 1998-2008 Zend Technologies

    Read the article

  • Best tool for monitoring backups, etc. and trending statstics from that data

    - by Randy Syring
    I have done some research on nagios, opennms, and zenoss but am not confident that I have found what I am looking for. The main driving force for me right now is being able to monitor backups. This includes mysql, mssql, and eventually some file system backups. We have a tool that wraps the backup process for these different systems and collects statistics. So, items like: number of databases backed up size of db backup file size of db backup file compressed time to make backup time to zip file I want to be able to A) have notifications if the jobs are not run according to schedule B) be able to set thresholds on the statistics which would trigger notifications C) I want to be able to trend and graph the statistics I am planning on sending this information to the monitoring application through an HTTP POST. Or, the monitoring application could pull it from a log file as well. However, we will have other processes with other "arbitrary" (from the monitoring system's perspective) statics that will want to monitor and trend, so flexibility is very important. The tool or tools should also be able to do general monitoring and trending of network interfaces, server load, etc. Once we get the backup monitoring in place, we will want to include those items as well. Thanks.

    Read the article

  • Synchronize Active Directory to Database

    - by Tommy Jakobsen
    We are in a situation where we would like to offer our customers to be able to manage their users themselves. It is around 300 customers with up to a total of 10.000 users. Besides creating, updating and removing users, they will very often read information about users for statics and other useful informations available. All this functionality, should be available from an Intranet web page (.NET Framework 4) that the users will access through Citrix or similar. Now the problem is that we would really like the users not to query AD directly for each request, but rather make them hit a database that is synchronized with AD. It would be sufficient to run this synchronization a few time each day (maybe every 5. hour). When they create a user, it should not be available right away, but reviewed and then created within two days (the next step would be to remove this manual review, but that's out of scope for this question). What do you think about this synchronization of AD? Does anyone have any experience with it and is it something that is done in other organizations, where you will have lots of requests which is better handled by a database than AD (I presume)? Are there any techniques out there for writing such a script that synchronizes AD with database tables? My primary concern is the groups/members relations which can be rather complicated. Or are there software that synchronizes AD with a database? Any comments will be much appreciated. Thank you.

    Read the article

  • Accessing Static Methods on a Generic class in c#

    - by mrlane
    Hello, I have the following situation in code, which I suspect may be a bit dodgey: I have a class: abstract class DataAccessBase<T> : IDataAccess where T : AnotherAbstractClass This class DataAccessBase also has a static factory method which creates instances of derived classes of itself using an enum value in a which statement to decide which derived type to create: static IDataAccess CreateInstance(TypeToCreateEnum) Now, the types derived from DataAccessBase<T> are themselves NOT generic, they specify a type for T: class PoLcZoneData : DataAccessBase<PoLcZone> // PoLcZone is derived from AnotherAbstractClass So far I am not sure if this is pushing the limits of good use of generics, but what I am really concerned about is how to access the static CreateInstance() method in the first place: The way I am doing this at the moment is to simply pass any type T where T : AnotherAbstractClass. In particular I am passing AnotherAbstractClass itself. This allows compilation just fine, but it does seem to me that passing any type to a generic class just to get at the statics is a bit dodgey. I have actually simplified the situation somewhat as DataAccessBase<T> is the lower level in the inheritance chain, but the static factory methods exists in a middle tier with classes such as PoLcZoneData being the most derived on the only level that is not generic. What are peoples thoughts on this arrangement?

    Read the article

  • static block instance block java Order

    - by Rollerball
    Having read this question In what order are the different parts of a class initialized when a class is loaded in the JVM? and the related JLS. I would like to know in more detail why for example having class Animal (superclass) and class Dog (subclass) as following: class Animal { static{ System.out.println("This is Animal's static block speaking"): } { System.out.println("This is Animal's instance block speaking"); } class Dog{ static{ System.out.println("This is Dog's static block speaking"); } { System.out.println("This is Dog's instance block speaking"); } public static void main (String [] args) { Dog dog = new Dog(); } } Ok before instantiating a class its direct superclass needs to be initialized (therefore all the statics variables and block need to be executed). So basically the question is: Why after initializing the static variables and static blocks of the super class, control goes down to the subclass for static variables initialization rather then finishing off the initialization of also the instance member? The control goes like: superclass (Animal): static variables and static blocks subclass (Dog): static variables and static blocks superclass (Animal): instance variables and instance blocks sublcass (Dog):instance variables and instance blocks What is the reason why it is in this way rather than : superclass -> static members superclass -> instance members subclass -> static members sublcass-> instance members

    Read the article

  • DLL Exports: not all my functions are exported

    - by carmellose
    I'm trying to create a Windows DLL which exports a number of functions, howver all my functions are exported but one !! I can't figure it out. The macro I use is this simple one : __declspec(dllexport) void myfunction(); It works for all my functions except one. I've looked inside Dependency Walker and here they all are, except one. How can that be ? What would be the cause for that ? I'm stuck. Edit: to be more precise, here is the function in the .h : namespace my { namespace great { namespace namespaaace { __declspec(dllexport) void prob_dump(const char *filename, const double p[], int nx, const double Q[], const double xlow[], const char ixlow[], const double xupp[], const char ixupp[], const double A[], int my, const double bA[], const double C[], int mz, const double clow[], const char iclow[], const double cupp[], const char icupp[] ); }}} And in the .cpp file it goes like this: namespace my { namespace great { namespace namespaaace { namespace { void dump_mtx(std::ostream& ostr, const double *mtx, int rows, int cols, const char *ind = 0) { /* some random code there, nothing special, no statics whatsoever */ } } // end anonymous namespace here // dump the problem specification into a file void prob_dump( const char *filename, const double p[], int nx, const double Q[], const double xlow[], const char ixlow[], const double xupp[], const char ixupp[], const double A[], int my, const double bA[], const double C[], int mz, const double clow[], const char iclow[], const double cupp[], const char icupp[] ) { std::ofstream fout; fout.open(filename, std::ios::trunc); /* implementation there */ dump_mtx(fout, Q, nx, nx); } }}} Thanks

    Read the article

  • Random number generation in MVC applications

    - by SlimShaggy
    What is the correct way of generating random numbers in an ASP.NET MVC application if I need exactly one number per request? According to MSDN, in order to get randomness of sufficient quality, it is necessary to generate multiple numbers using a single System.Random object, created once. Since a new instance of a controller class is created for each request in MVC, I cannot use a private field initialized in the controller's constructor for the Random object. So in what part of the MVC app should I create and store the Random object? Currently I store it in a static field of the controller class and lazily initialize it in the action method that uses it: public class HomeController : Controller { ... private static Random random; ... public ActionResult Download() { ... if (random == null) random = new Random(); ... } } Since the "random" field can be accessed by multiple instances of the controller class, is it possible for its value to become corrupted if two instances attempt to initialize it simultaneously? And one more question: I know that the lifetime of statics is the lifetime of the application, but in case of an MVC app what is it? Is it from IIS startup till IIS shutdown?

    Read the article

  • static initialization confusion

    - by Happy Mittal
    I am getting very confused in some concepts in c++. For ex: I have following two files //file1.cpp class test { static int s; public: test(){s++;} }; static test t; int test::s=5; //file2.cpp #include<iostream> using namespace std; class test { static int s; public: test(){s++;} static int get() { return s; } }; static test t; int main() { cout<<test::get()<<endl; } Now My question is : 1. How two files link successfully even if they have different class definitions? 2. Are the static member s of two classes related because I get output as 7. Please explain this concept of statics.

    Read the article

  • Best loose way to get objects with common base class

    - by Michael Teper
    I struggled to come up with a good title for this question, so suggestions are welcome. Let's say we have an abstract base class ActionBase that looks something like this: public abstract class ActionBase { public abstract string Name { get; } public abstract string Description { get; } // rest of declaration follows } And we have a bunch of different actions defined, like a MoveFileAction, WriteToRegistryAction, etc. These actions get attached to Worker objects: public class Worker { private IList<ActionBase> _actions = new List<ActionBase>(); public IList<ActionBase> Actions { get { return _actions; } } // worker stuff ... } So far, pretty straight-forward. Now, I'd like to have a UI for setting up Workers, assigning Actions, setting properties, and so on. In this UI, I want to present a list of all available actions, along with their properties, and for that I'd want to first gather up all the names and descriptions of available actions (plus the type) into a collection of the following type of item: public class ActionDescriptor { public string Name { get; } public string Description { get; } poblic Type Type { get; } } Certainly, I can use reflection to do this, but is there a better way? Having Name and Description be instance properties of ActionBase (as opposed to statics on derived classes) smells a bit, but there isn't an abstract static in C#. Thank you!

    Read the article

  • Nullable values in C++

    - by DanDan
    I'm creating a database access layer in native C++, and I'm looking at ways to support NULL values. Here is what I have so far: class CNullValue { public: static CNullValue Null() { static CNullValue nv; return nv; } }; template<class T> class CNullableT { public: CNullableT(CNullValue &v) : m_Value(T()), m_IsNull(true) { } CNullableT(T value) : m_Value(value), m_IsNull(false) { } bool IsNull() { return m_IsNull; } T GetValue() { return m_Value; } private: T m_Value; bool m_IsNull; }; This is how I'll have to define functions: void StoredProc(int i, CNullableT<int> j) { ...connect to database ...if j.IsNull pass null to database etc } And I call it like this: sp.StoredProc(1, 2); or sp.StoredProc(3, CNullValue::Null()); I was just wondering if there was a better way than this. In particular I don't like the singleton-like object of CNullValue with the statics. I'd prefer to just do sp.StoredProc(3, CNullValue); or something similar. How do others solve this problem?

    Read the article

  • Help Prevent Carpal Tunnel Problems with Workrave

    - by Matthew Guay
    Whether for work or leisure, many of us spend entirely too much time on the computer everyday.  This puts us at risk of having or aggravating Carpal Tunnel problems, but thanks to Workrave you can help to divert these problems. Workrave helps Carpal Tunnel problems by reminding you to get away from your computer periodically.  Breaking up your computer time with movement can help alleviate many computer and office related health problems.  Workrave helps by reminding you to take short pauses after several minutes of computer use, and longer breaks after continued use.  You can also use it to keep from using the computer for too much You time in a day.  Since you can change the settings to suit you, this can be a great way to make sure you’re getting the breaks you need. Install Workrave on Windows If you’re using Workrave on Windows, download (link below) and install it with the default settings. One installation setting you may wish to change is the startup.  By default Workrave will run automatically when you start your computer; if you don’t want this, you can simply uncheck the box and proceed with the installation. Once setup is finished, you can run Workrave directly from the installer. Or you can open it from your start menu by entering “workrave” in the search box. Install Workrave in Ubuntu If you wish to use it in Ubuntu, you can install it directly from the Ubuntu Software Center.  Click the Applications menu, and select Ubuntu Software Center. Enter “workrave” into the search box in the top right corner of the Software Center, and it will automatically find it.  Click the arrow to proceed to Workrave’s page. This will give you information about Workrave; simply click Install to install Workrave on your system. Enter your password when prompted. Workrave will automatically download and install.   When finished, you can find Workrave in your Applications menu under Universal Access. Using Workrave Workrave by default shows a small counter on your desktop, showing the length of time until your next Micro break (30 second break), Rest break (10 minute break), and max amount of computer usage for the day. When it’s time for a micro break, Workrave will popup a reminder on your desktop. If you continue working, it will disappear at the end of the timer.  If you stop, it will start a micro-break which will freeze most on-screen activities until the timer is over.  You can click Skip or Postpone if you do not want to take a break right then. After an hour of work, Workrave will give you a 10 minute rest break.  During this it will show you some exercises that can help eliminate eyestrain, muscle tension, and other problems from prolonged computer usage.  You can click through the exercises, or can skip or postpone the break if you wish.   Preferences You can change your Workrave preferences by right-clicking on its icon in your system tray and selecting Preferences. Here you can customize the time between your breaks, and the length of your breaks.  You can also change your daily computer usage limit, and can even turn off the postpone and skip buttons on notifications if you want to make sure you follow Workrave and take your rests! From the context menu, you can also choose Statistics.  This gives you an overview of how many breaks, prompts, and more were shown on a given day.  It also shows a total Overdue time, which is the total length of the breaks you skipped or postponed.  You can view your Workrave history as well by simply selecting a date on the calendar.   Additionally, the Activity tab in the Statics pane shows more info about your computer usage, including total mouse movement, mouse button clicks, and keystrokes. Conclusion Whether you’re suffering with Carpal Tunnel or trying to prevent it, Workrave is a great solution to help remind you to get away from your computer periodically and rest.  Of course, since you can simply postpone or skip the prompts, you’ve still got to make an effort to help your own health.  But it does give you a great way to remind yourself to get away from the computer, and especially for geeks, this may be something that we really need! Download Workrave Similar Articles Productive Geek Tips Switch to the Dvorak Keyboard Layout in XPAccess Your MySQL Server Remotely Over SSHHow to Secure Gaim Instant Messenger traffic at Work with SecureCRT and SSHConnect to VMware Server Console Over SSHDisclaimers 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 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional StockFox puts a Lightweight Stock Ticker in your Statusbar Explore Google Public Data Visually The Ultimate Excel Cheatsheet Convert the Quick Launch Bar into a Super Application Launcher Automate Tasks in Linux with Crontab Discover New Bundled Feeds in Google Reader

    Read the article

  • Subterranean IL: The ThreadLocal type

    - by Simon Cooper
    I came across ThreadLocal<T> while I was researching ConcurrentBag. To look at it, it doesn't really make much sense. What's all those extra Cn classes doing in there? Why is there a GenericHolder<T,U,V,W> class? What's going on? However, digging deeper, it's a rather ingenious solution to a tricky problem. Thread statics Declaring that a variable is thread static, that is, values assigned and read from the field is specific to the thread doing the reading, is quite easy in .NET: [ThreadStatic] private static string s_ThreadStaticField; ThreadStaticAttribute is not a pseudo-custom attribute; it is compiled as a normal attribute, but the CLR has in-built magic, activated by that attribute, to redirect accesses to the field based on the executing thread's identity. TheadStaticAttribute provides a simple solution when you want to use a single field as thread-static. What if you want to create an arbitary number of thread static variables at runtime? Thread-static fields can only be declared, and are fixed, at compile time. Prior to .NET 4, you only had one solution - thread local data slots. This is a lesser-known function of Thread that has existed since .NET 1.1: LocalDataStoreSlot threadSlot = Thread.AllocateNamedDataSlot("slot1"); string value = "foo"; Thread.SetData(threadSlot, value); string gettedValue = (string)Thread.GetData(threadSlot); Each instance of LocalStoreDataSlot mediates access to a single slot, and each slot acts like a separate thread-static field. As you can see, using thread data slots is quite cumbersome. You need to keep track of LocalDataStoreSlot objects, it's not obvious how instances of LocalDataStoreSlot correspond to individual thread-static variables, and it's not type safe. It's also relatively slow and complicated; the internal implementation consists of a whole series of classes hanging off a single thread-static field in Thread itself, using various arrays, lists, and locks for synchronization. ThreadLocal<T> is far simpler and easier to use. ThreadLocal ThreadLocal provides an abstraction around thread-static fields that allows it to be used just like any other class; it can be used as a replacement for a thread-static field, it can be used in a List<ThreadLocal<T>>, you can create as many as you need at runtime. So what does it do? It can't just have an instance-specific thread-static field, because thread-static fields have to be declared as static, and so shared between all instances of the declaring type. There's something else going on here. The values stored in instances of ThreadLocal<T> are stored in instantiations of the GenericHolder<T,U,V,W> class, which contains a single ThreadStatic field (s_value) to store the actual value. This class is then instantiated with various combinations of the Cn types for generic arguments. In .NET, each separate instantiation of a generic type has its own static state. For example, GenericHolder<int,C0,C1,C2> has a completely separate s_value field to GenericHolder<int,C1,C14,C1>. This feature is (ab)used by ThreadLocal to emulate instance thread-static fields. Every time an instance of ThreadLocal is constructed, it is assigned a unique number from the static s_currentTypeId field using Interlocked.Increment, in the FindNextTypeIndex method. The hexadecimal representation of that number then defines the specific Cn types that instantiates the GenericHolder class. That instantiation is therefore 'owned' by that instance of ThreadLocal. This gives each instance of ThreadLocal its own ThreadStatic field through a specific unique instantiation of the GenericHolder class. Although GenericHolder has four type variables, the first one is always instantiated to the type stored in the ThreadLocal<T>. This gives three free type variables, each of which can be instantiated to one of 16 types (C0 to C15). This puts an upper limit of 4096 (163) on the number of ThreadLocal<T> instances that can be created for each value of T. That is, there can be a maximum of 4096 instances of ThreadLocal<string>, and separately a maximum of 4096 instances of ThreadLocal<object>, etc. However, there is an upper limit of 16384 enforced on the total number of ThreadLocal instances in the AppDomain. This is to stop too much memory being used by thousands of instantiations of GenericHolder<T,U,V,W>, as once a type is loaded into an AppDomain it cannot be unloaded, and will continue to sit there taking up memory until the AppDomain is unloaded. The total number of ThreadLocal instances created is tracked by the ThreadLocalGlobalCounter class. So what happens when either limit is reached? Firstly, to try and stop this limit being reached, it recycles GenericHolder type indexes of ThreadLocal instances that get disposed using the s_availableIndices concurrent stack. This allows GenericHolder instantiations of disposed ThreadLocal instances to be re-used. But if there aren't any available instantiations, then ThreadLocal falls back on a standard thread local slot using TLSHolder. This makes it very important to dispose of your ThreadLocal instances if you'll be using lots of them, so the type instantiations can be recycled. The previous way of creating arbitary thread-static variables, thread data slots, was slow, clunky, and hard to use. In comparison, ThreadLocal can be used just like any other type, and each instance appears from the outside to be a non-static thread-static variable. It does this by using the CLR type system to assign each instance of ThreadLocal its own instantiated type containing a thread-static field, and so delegating a lot of the bookkeeping that thread data slots had to do to the CLR type system itself! That's a very clever use of the CLR type system.

    Read the article

  • WMemoryProfiler is Released

    - by Alois Kraus
    What is it? WMemoryProfiler is a managed profiling Api to aid integration testing. This free library can get managed heap statistics and memory usage for your own process (remember testing) and other processes as well. The best thing is that it does work from .NET 2.0 up to .NET 4.5 in x86 and x64. To make it more interesting it can attach to any running .NET process. The reason why I do mention this is that commercial profilers do support this functionality only for their professional editions. An normally only since .NET 4.0 since the profiling API only since then does support attaching to a running process. This thing does differ in many aspects from “normal” profilers because while profiling yourself you can get all objects from all managed heaps back as an object array. If you ever wanted to change the state of an object which does only exist a method local in another thread you can get your hands on it now … Enough theory. Show me some code /// <summary> /// Show feature to not only get statisics out of a process but also the newly allocated /// instances since the last call to MarkCurrentObjects. /// GetNewObjects does return the newly allocated objects as object array /// </summary> static void InstanceTracking() { using (var dumper = new MemoryDumper()) // if you have problems use to see the debugger windows true,true)) { dumper.MarkCurrentObjects(); Allocate(); ILookup<Type, object> newObjects = dumper.GetNewObjects() .ToLookup( x => x.GetType() ); Console.WriteLine("New Strings:"); foreach (var newStr in newObjects[typeof(string)] ) { Console.WriteLine("Str: {0}", newStr); } } } … New Strings: Str: qqd Str: String data: Str: String data: 0 Str: String data: 1 … This is really hot stuff. Not only you can get heap statistics but you can directly examine the new objects and make queries upon them. When I do find more time I can reconstruct the object root graph from it from my own process. It this cool or what? You can also peek into the Finalization Queue to check if you did accidentally forget to dispose a whole bunch of objects … /// <summary> /// .NET 4.0 or above only. Get all finalizable objects which are ready for finalization and have no other object roots anymore. /// </summary> static void NotYetFinalizedObjects() { using (var dumper = new MemoryDumper()) { object[] finalizable = dumper.GetObjectsReadyForFinalization(); Console.WriteLine("Currently {0} objects of types {1} are ready for finalization. Consider disposing them before.", finalizable.Length, String.Join(",", finalizable.ToLookup( x=> x.GetType() ) .Select( x=> x.Key.Name)) ); } } How does it work? The W of WMemoryProfiler is a good hint. It does employ Windbg and SOS dll to do the heavy lifting and concentrates on an easy to use Api which does hide completely Windbg. If you do not want to see Windbg you will never see it. In my experience the most complex thing is actually to download Windbg from the Windows 8 Stanalone SDK. This is described in the Readme and the exception you are greeted with if it is missing in much greater detail. So I will not go into this here.   What Next? Depending on the feedback I do get I can imagine some features which might be useful as well Calculate first order GC Roots from the actual object graph Identify global statics in Types in object graph Support read out of finalization queue of .NET 2.0 as well. Support Memory Dump analysis (again a feature only supported by commercial profilers in their professional editions if it is supported at all) Deserialize objects from a memory dump into a live process back (this would need some more investigation but it is doable) The last item needs some explanation. Why on earth would you want to do that? The basic idea is to store in your live process some logging/tracing data which can become quite big but since it is never written to it is very fast to generate. When your process crashes with a memory dump you could transfer this data structure back into a live viewer which can then nicely display your program state at the point it did crash. This is an advanced trouble shooting technique I have not seen anywhere yet but it could be quite useful. You can have here a look at the current feature list of WMemoryProfiler with some examples.   How To Get Started? First I would download the released source package (it is tiny). And compile the complete project. Then you can compile the Example project (it has this name) and uncomment in the main method the scenario you want to check out. If you are greeted with an exception it is time to install the Windows 8 Standalone SDK which is described in great detail in the exception text. Thats it for the first round. I have seen something more limited in the Java world some years ago (now I cannot find the link anymore) but anyway. Now we have something much better.

    Read the article

  • IF Statement has strange behavior

    - by BSchlinker
    I've developed a 'custom' cout, so that I can display text to console and also print it to a log file. This cout class is passed a different integer on initialization, with the integer representing the verbosity level of the message. If the current verbosity level is greater then or equal to the verbosity level of the message, the message should print. The problem is, I have messages printing even when the current verbosity level is too low. I went ahead and debugged it, expecting to find the problem. Instead, I found multiple scenarios where my if statements are not working as expected. The statement if(ilralevel_passed <= ilralevel_set) will sometimes proceed even if ilralevel_set is LESS then ilralevel_passed. You can see this behavior in the following picture (my apologizes for using Twitpic) http://twitpic.com/1xtx4g/full. Notice how ilralevel_set is equal to zero, and ilralevel_passed is equal to one. Yet, the if statement has returned true and is now moving forward to pass the line to cout. I've never seen this type of behavior before and I'm not exactly sure how to proceed debugging it. I'm not able to isolate the behavior either -- it only occurs in certain parts of my program. Any suggestions are appreciated as always. // Here is an example use of the function: // ilra_status << setfill('0') << setw(2) << dispatchtime.tm_sec << endl; // ilra_warning << "Dispatch time (seconds): " << mktime(&dispatchtime) << endl; // Here is the 'custom' cout function: #ifndef ILRA_H_ #define ILRA_H_ // System libraries #include <iostream> #include <ostream> #include <sstream> #include <iomanip> // Definitions #define ilra_talk ilra(__FUNCTION__,0) #define ilra_update ilra(__FUNCTION__,0) #define ilra_error ilra(__FUNCTION__,1) #define ilra_warning ilra(__FUNCTION__,2) #define ilra_status ilra(__FUNCTION__,3) // Statics static int ilralevel_set = 0; static int ilralevel_passed; // Classes class ilra { public: // constructor / destructor ilra(const std::string &funcName, int toset) { ilralevel_passed = toset; } ~ilra(){}; // enable / disable irla functions static void ilra_verbose_level(int toset){ ilralevel_set = toset; } // output template <class T> ilra &operator<<(const T &v) { if(ilralevel_passed <= ilralevel_set) std::cout << v; return *this; } ilra &operator<<(std::ostream&(*f)(std::ostream&)) { if(ilralevel_passed <= ilralevel_set) std::cout << *f; return *this; } }; // end of the class #endif /* ILRA_H_ */

    Read the article

  • Performance Tuning a High-Load Apache Server

    - by futureal
    I am looking to understand some server performance problems I am seeing with a (for us) heavily loaded web server. The environment is as follows: Debian Lenny (all stable packages + patched to security updates) Apache 2.2.9 PHP 5.2.6 Amazon EC2 large instance The behavior we're seeing is that the web typically feels responsive, but with a slight delay to begin handling a request -- sometimes a fraction of a second, sometimes 2-3 seconds in our peak usage times. The actual load on the server is being reported as very high -- often 10.xx or 20.xx as reported by top. Further, running other things on the server during these times (even vi) is very slow, so the load is definitely up there. Oddly enough Apache remains very responsive, other than that initial delay. We have Apache configured as follows, using prefork: StartServers 5 MinSpareServers 5 MaxSpareServers 10 MaxClients 150 MaxRequestsPerChild 0 And KeepAlive as: KeepAlive On MaxKeepAliveRequests 100 KeepAliveTimeout 5 Looking at the server-status page, even at these times of heavy load we are rarely hitting the client cap, usually serving between 80-100 requests and many of those in the keepalive state. That tells me to rule out the initial request slowness as "waiting for a handler" but I may be wrong. Amazon's CloudWatch monitoring tells me that even when our OS is reporting a load of 15, our instance CPU utilization is between 75-80%. Example output from top: top - 15:47:06 up 31 days, 1:38, 8 users, load average: 11.46, 7.10, 6.56 Tasks: 221 total, 28 running, 193 sleeping, 0 stopped, 0 zombie Cpu(s): 66.9%us, 22.1%sy, 0.0%ni, 2.6%id, 3.1%wa, 0.0%hi, 0.7%si, 4.5%st Mem: 7871900k total, 7850624k used, 21276k free, 68728k buffers Swap: 0k total, 0k used, 0k free, 3750664k cached The majority of the processes look like: 24720 www-data 15 0 202m 26m 4412 S 9 0.3 0:02.97 apache2 24530 www-data 15 0 212m 35m 4544 S 7 0.5 0:03.05 apache2 24846 www-data 15 0 209m 33m 4420 S 7 0.4 0:01.03 apache2 24083 www-data 15 0 211m 35m 4484 S 7 0.5 0:07.14 apache2 24615 www-data 15 0 212m 35m 4404 S 7 0.5 0:02.89 apache2 Example output from vmstat at the same time as the above: procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 8 0 0 215084 68908 3774864 0 0 154 228 5 7 32 12 42 9 6 21 0 198948 68936 3775740 0 0 676 2363 4022 1047 56 16 9 15 23 0 0 169460 68936 3776356 0 0 432 1372 3762 835 76 21 0 0 23 1 0 140412 68936 3776648 0 0 280 0 3157 827 70 25 0 0 20 1 0 115892 68936 3776792 0 0 188 8 2802 532 68 24 0 0 6 1 0 133368 68936 3777780 0 0 752 71 3501 878 67 29 0 1 0 1 0 146656 68944 3778064 0 0 308 2052 3312 850 38 17 19 24 2 0 0 202104 68952 3778140 0 0 28 90 2617 700 44 13 33 5 9 0 0 188960 68956 3778200 0 0 8 0 2226 475 59 17 6 2 3 0 0 166364 68956 3778252 0 0 0 21 2288 386 65 19 1 0 And finally, output from Apache's server-status: Server uptime: 31 days 2 hours 18 minutes 31 seconds Total accesses: 60102946 - Total Traffic: 974.5 GB CPU Usage: u209.62 s75.19 cu0 cs0 - .0106% CPU load 22.4 requests/sec - 380.3 kB/second - 17.0 kB/request 107 requests currently being processed, 6 idle workers C.KKKW..KWWKKWKW.KKKCKK..KKK.KKKK.KK._WK.K.K.KKKKK.K.R.KK..C.C.K K.C.K..WK_K..KKW_CK.WK..W.KKKWKCKCKW.W_KKKKK.KKWKKKW._KKK.CKK... KK_KWKKKWKCKCWKK.KKKCK.......................................... ................................................................ From my limited experience I draw the following conclusions/questions: We may be allowing far too many KeepAlive requests I do see some time spent waiting for IO in the vmstat although not consistently and not a lot (I think?) so I am not sure this is a big concern or not, I am less experienced with vmstat Also in vmstat, I see in some iterations a number of processes waiting to be served, which is what I am attributing the initial page load delay on our web server to, possibly erroneously We serve a mixture of static content (75% or higher) and script content, and the script content is often fairly processor intensive, so finding the right balance between the two is important; long term we want to move statics elsewhere to optimize both servers but our software is not ready for that today I am happy to provide additional information if anybody has any ideas, the other note is that this is a high-availability production installation so I am wary of making tweak after tweak, and is why I haven't played with things like the KeepAlive value myself yet.

    Read the article

  • Augmenting your Social Efforts via Data as a Service (DaaS)

    - by Mike Stiles
    The following is the 3rd in a series of posts on the value of leveraging social data across your enterprise by Oracle VP Product Development Don Springer and Oracle Cloud Data and Insight Service Sr. Director Product Management Niraj Deo. In this post, we will discuss the approach and value of integrating additional “public” data via a cloud-based Data-as-as-Service platform (or DaaS) to augment your Socially Enabled Big Data Analytics and CX Management. Let’s assume you have a functional Social-CRM platform in place. You are now successfully and continuously listening and learning from your customers and key constituents in Social Media, you are identifying relevant posts and following up with direct engagement where warranted (both 1:1, 1:community, 1:all), and you are starting to integrate signals for communication into your appropriate Customer Experience (CX) Management systems as well as insights for analysis in your business intelligence application. What is the next step? Augmenting Social Data with other Public Data for More Advanced Analytics When we say advanced analytics, we are talking about understanding causality and correlation from a wide variety, volume and velocity of data to Key Performance Indicators (KPI) to achieve and optimize business value. And in some cases, to predict future performance to make appropriate course corrections and change the outcome to your advantage while you can. The data to acquire, process and analyze this is very nuanced: It can vary across structured, semi-structured, and unstructured data It can span across content, profile, and communities of profiles data It is increasingly public, curated and user generated The key is not just getting the data, but making it value-added data and using it to help discover the insights to connect to and improve your KPIs. As we spend time working with our larger customers on advanced analytics, we have seen a need arise for more business applications to have the ability to ingest and use “quality” curated, social, transactional reference data and corresponding insights. The challenge for the enterprise has been getting this data inline into an easily accessible system and providing the contextual integration of the underlying data enriched with insights to be exported into the enterprise’s business applications. The following diagram shows the requirements for this next generation data and insights service or (DaaS): Some quick points on these requirements: Public Data, which in this context is about Common Business Entities, such as - Customers, Suppliers, Partners, Competitors (all are organizations) Contacts, Consumers, Employees (all are people) Products, Brands This data can be broadly categorized incrementally as - Base Utility data (address, industry classification) Public Master Reference data (trade style, hierarchy) Social/Web data (News, Feeds, Graph) Transactional Data generated by enterprise process, workflows etc. This Data has traits of high-volume, variety, velocity etc., and the technology needed to efficiently integrate this data for your needs includes - Change management of Public Reference Data across all categories Applied Big Data to extract statics as well as real-time insights Knowledge Diagnostics and Data Mining As you consider how to deploy this solution, many of our customers will be using an online “cloud” service that provides quality data and insights uniformly to all their necessary applications. In addition, they are requesting a service that is: Agile and Easy to Use: Applications integrated with the service can obtain data on-demand, quickly and simply Cost-effective: Pre-integrated into applications so customers don’t have to Has High Data Quality: Single point access to reference data for data quality and linkages to transactional, curated and social data Supports Data Governance: Becomes more manageable and cost-effective since control of data privacy and compliance can be enforced in a centralized place Data-as-a-Service (DaaS) Just as the cloud has transformed and now offers a better path for how an enterprise manages its IT from their infrastructure, platform, and software (IaaS, PaaS, and SaaS), the next step is data (DaaS). Over the last 3 years, we have seen the market begin to offer a cloud-based data service and gain initial traction. On one side of the DaaS continuum, we see an “appliance” type of service that provides a single, reliable source of accurate business data plus social information about accounts, leads, contacts, etc. On the other side of the continuum we see more of an online market “exchange” approach where ISVs and Data Publishers can publish and sell premium datasets within the exchange, with the exchange providing a rich set of web interfaces to improve the ease of data integration. Why the difference? It depends on the provider’s philosophy on how fast the rate of commoditization of certain data types will occur. How do you decide the best approach? Our perspective, as shown in the diagram below, is that the enterprise should develop an elastic schema to support multi-domain applicability. This allows the enterprise to take the most flexible approach to harness the speed and breadth of public data to achieve value. The key tenet of the proposed approach is that an enterprise carefully federates common utility, master reference data end points, mobility considerations and content processing, so that they are pervasively available. One way you may already be familiar with this approach is in how you do Address Verification treatments for accounts, contacts etc. If you design and revise this service in such a way that it is also easily available to social analytic needs, you could extend this to launch geo-location based social use cases (marketing, sales etc.). Our fundamental belief is that value-added data achieved through enrichment with specialized algorithms, as well as applying business “know-how” to weight-factor KPIs based on innovative combinations across an ever-increasing variety, volume and velocity of data, will be where real value is achieved. Essentially, Data-as-a-Service becomes a single entry point for the ever-increasing richness and volume of public data, with enrichment and combined capabilities to extract and integrate the right data from the right sources with the right factoring at the right time for faster decision-making and action within your core business applications. As more data becomes available (and in many cases commoditized), this value-added data processing approach will provide you with ongoing competitive advantage. Let’s look at a quick example of creating a master reference relationship that could be used as an input for a variety of your already existing business applications. In phase 1, a simple master relationship is achieved between a company (e.g. General Motors) and a variety of car brands’ social insights. The reference data allows for easy sort, export and integration into a set of CRM use cases for analytics, sales and marketing CRM. In phase 2, as you create more data relationships (e.g. competitors, contacts, other brands) to have broader and deeper references (social profiles, social meta-data) for more use cases across CRM, HCM, SRM, etc. This is just the tip of the iceberg, as the amount of master reference relationships is constrained only by your imagination and the availability of quality curated data you have to work with. DaaS is just now emerging onto the marketplace as the next step in cloud transformation. For some of you, this may be the first you have heard about it. Let us know if you have questions, or perspectives. In the meantime, we will continue to share insights as we can.Photo: Erik Araujo, stock.xchng

    Read the article

  • Cisco ASA5505 8.2 Multiple Outside IP to Multiple Inside IP

    - by GriffJ
    Trying to setup ASA5505. Semi working but having issues with accessing services from the outside. ASA5505 Basic License, Version 8.2. (plus upgrade to unlimited inside hosts). Alert: I'm a Cisco Noob. 321.321.39.X is a place holder for privacy. I came up with this config and tested it tonight. ASA Version 8.2(1) ! hostname <removed> domain-name <removed> enable password <removed> encrypted passwd <removed> encrypted names ! interface Vlan1 nameif inside security-level 100 ip address 172.21.36.1 255.255.252.0 ! interface Vlan2 nameif outside security-level 0 ip address 321.321.39.10 255.255.255.248 ! interface Ethernet0/0 switchport access vlan 2 ! interface Ethernet0/1 ! interface Ethernet0/2 ! interface Ethernet0/3 ! interface Ethernet0/4 ! interface Ethernet0/5 ! interface Ethernet0/6 ! interface Ethernet0/7 ! ftp mode passive dns server-group DefaultDNS domain-name <removed> access-list outside_inbound extended permit tcp any host 321.321.39.10 eq pptp access-list outside_inbound extended permit tcp any host 321.321.39.11 eq https access-list outside_inbound extended permit tcp any host 321.321.39.11 eq 993 access-list outside_inbound extended permit tcp any host 321.321.39.11 eq smtp access-list outside_inbound extended permit tcp any host 321.321.39.11 eq 1001 access-list outside_inbound extended permit tcp any host 321.321.39.11 eq 465 access-list outside_inbound extended permit tcp any host 321.321.39.11 eq domain access-list outside_inbound extended permit udp any eq domain host 321.321.39.11 eq domain access-list outside_inbound extended permit tcp any host 321.321.39.12 eq www access-list outside_inbound extended permit tcp any host 321.321.39.12 eq https access-list outside_inbound extended permit tcp any host 321.321.39.13 eq www access-list outside_inbound extended permit tcp any host 321.321.39.13 eq https access-list outside_inbound extended permit icmp any any echo-reply access-list outside_inbound extended permit icmp any any source-quench access-list outside_inbound extended permit icmp any any unreachable access-list outside_inbound extended permit icmp any any time-exceeded access-list outside_inbound extended permit icmp any any traceroute access-list outside_inbound extended permit icmp any any echo pager lines 24 logging asdm informational mtu inside 1500 mtu outside 1500 icmp unreachable rate-limit 1 burst-size 1 no asdm history enable arp timeout 14400 global (outside) 2 321.321.39.11-321.321.39.14 netmask 255.255.255.248 global (outside) 1 interface nat (inside) 1 0.0.0.0 0.0.0.0 static (inside,outside) tcp interface pptp 172.21.37.20 pptp netmask 255.255.255.255 static (inside,outside) 321.321.39.11 172.21.37.14 netmask 255.255.255.255 static (inside,outside) 321.321.39.12 172.21.37.24 netmask 255.255.255.255 static (inside,outside) 321.321.39.13 172.21.37.17 netmask 255.255.255.255 access-group outside_inbound in interface outside route outside 0.0.0.0 0.0.0.0 321.321.39.9 1 route inside 192.168.15.0 255.255.255.0 172.21.36.52 1 timeout xlate 3:00:00 timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02 timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00 timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00 timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute timeout tcp-proxy-reassembly 0:01:00 dynamic-access-policy-record DfltAccessPolicy http server enable http 172.21.36.0 255.255.252.0 inside no snmp-server location no snmp-server contact snmp-server enable traps snmp authentication linkup linkdown coldstart crypto ipsec security-association lifetime seconds 28800 crypto ipsec security-association lifetime kilobytes 4608000 telnet 172.21.36.0 255.255.252.0 inside telnet timeout 60 ssh timeout 5 console timeout 0 threat-detection basic-threat threat-detection statistics access-list no threat-detection statistics tcp-intercept webvpn ! class-map inspection_default match default-inspection-traffic ! ! policy-map type inspect dns preset_dns_map parameters message-length maximum 512 policy-map global_policy class inspection_default inspect dns preset_dns_map inspect ftp inspect h323 h225 inspect h323 ras inspect rsh inspect rtsp inspect sqlnet inspect skinny inspect sunrpc inspect xdmcp inspect sip inspect netbios inspect tftp inspect pptp inspect ipsec-pass-thru inspect http ! service-policy global_policy global prompt hostname context The servers that had static forwards did not have any outside network access. couldn't ping google.com for instance. mail server couldn't Domain POP the Barracuda spam filter from our ISP etc. So after doing some reading I removed the statics for 172.21.37.11, 12 and 13, and replaced those three with what's below.. static (inside,outside) tcp 321.321.39.11 https 172.21.37.14 https netmask 255.255.255.255 static (inside,outside) tcp 321.321.39.11 993 172.21.37.14 993 netmask 255.255.255.255 static (inside,outside) tcp 321.321.39.11 smtp 172.21.37.14 smtp netmask 255.255.255.255 static (inside,outside) tcp 321.321.39.11 1001 172.21.37.14 1001 netmask 255.255.255.255 static (inside,outside) tcp 321.321.39.11 465 172.21.37.14 465 netmask 255.255.255.255 static (inside,outside) tcp 321.321.39.11 domain 172.21.37.14 domain netmask 255.255.255.255 static (inside,outside) tcp 321.321.39.12 www 172.21.37.24 www netmask 255.255.255.255 static (inside,outside) tcp 321.321.39.12 https 172.21.37.24 https netmask 255.255.255.255 static (inside,outside) tcp 321.321.39.13 www 172.21.37.17 www netmask 255.255.255.255 static (inside,outside) tcp 321.321.39.13 https 172.21.37.17 https netmask 255.255.255.255 Now the servers (for instance 172.21.37.14) could ping the outside world again. Mail started flowing (Domain POP was successful) etc. etc. But I forgot to check if webmail worked from the outside admittedly. But the webservers at 172.21.37.17 and 172.21.37.24 still didn't respond from the outside world. Although I was able to PPTP VPN in on 321.321.39.10 (interface) which is the outside interface IP address. and it is static mapped to 172.21.37.20. So I'm thinking there must be something wrong with NAT somewhere? no response from 321.321.39.11 to 321.321.39.14.. Could anyone look over the config and please let me know what I've done wrong? Is there something I've missed? well obviously but.. please help! Thank you.

    Read the article

  • Rails 2 and Ngnix: https pages can't load css or js (but will load graphics)

    - by Max Williams
    ADMISSION: i've posted this same question on stackoverflow, before realising it's probabaly better suited to superuser, but it kind of depends on the answer: If it turns out to be a problem in my nginx config, it's definitely superuser. If it turns out to be a problem in my Rails config (or code) then it's arguably stackoverflow. I'm adding some https pages to my rails site. In order to test it locally, i'm running my site under one mongrel_rails instance (on 3000) and nginx. I've managed to get my nginx config to the point where i can actually go to the https pages, and they load. Except, the javascript and css files all fail to load: looking in the Network tab in chrome web tools, i can see that it is trying to load them via an https url. Eg, one of the non-working file urls is https://cmw-local.co.uk/stylesheets/cmw-logged-out.css?1383759216 I have these set up (or at least think i do) in my nginx config to redirect to the http versions of the static files. This seems to be working for graphics, but not for css and js files. If i click on this in the Network tab, it takes me to the above url, which redirects to the http version. So, the redirect seems to be working in some sense, but not when they're loaded by an https page. Like i say, i thought i had this covered in the second try_files directive in my config below, but maybe not. Can anyone see what i'm doing wrong? thanks, Max Here's my nginx config - sorry it's a bit lengthy! I think the error is likely to be in the first (ssl) server block: server { listen 443 ssl; keepalive_timeout 70; ssl_certificate /home/max/work/charanga/elearn_container/elearn/config/nginx/certs/max-local-server.crt; ssl_certificate_key /home/max/work/charanga/elearn_container/elearn/config/nginx/certs/max-local-server.key; ssl_session_cache shared:SSL:10m; ssl_session_timeout 10m; ssl_protocols SSLv3 TLSv1; ssl_ciphers RC4:HIGH:!aNULL:!MD5; ssl_prefer_server_ciphers on; server_name elearning.dev cmw-dev.co.uk cmw-dev.com cmw-nginx.co.uk cmw-local.co.uk; root /home/max/work/charanga/elearn_container/elearn; # ensure that we serve css, js, other statics when requested # as SSL, but if the files don't exist (i.e. any non /basket controller) # then redirect to the non-https version location / { try_files $uri @non-ssl-redirect; } # securely serve everything under /basket (/basket/checkout etc) # we need general too, because of the email/username checking location ~ ^/(basket|general|cmw/account/check_username_availability) { # make sure cached copies are revalidated once they're stale add_header Cache-Control "public, must-revalidate, proxy-revalidate"; # this serves Rails static files that exist without running # other rewrite tests try_files $uri @rails-ssl; expires 1h; } location @non-ssl-redirect { return 301 http://$host$request_uri; } location @rails-ssl { proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header Host $http_host; proxy_redirect off; proxy_read_timeout 180; proxy_next_upstream off; proxy_pass http://127.0.0.1:3000; expires 0d; } } #upstream elrs { # server 127.0.0.1:3000; #} server { listen 80; server_name elearning.dev cmw-dev.co.uk cmw-dev.com cmw-nginx.co.uk cmw-local.co.uk; root /home/max/work/charanga/elearn_container/elearn; access_log /home/max/work/charanga/elearn_container/elearn/log/access.log; error_log /home/max/work/charanga/elearn_container/elearn/log/error.log debug; client_max_body_size 50M; index index.html index.htm; # gzip html, css & javascript, but don't gzip javascript for pre-SP2 MSIE6 (i.e. those *without* SV1 in their user-agent string) gzip on; gzip_http_version 1.1; gzip_vary on; gzip_comp_level 6; gzip_proxied any; gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript; #text/html # make sure gzip does not lose large gzipped js or css files # see http://blog.leetsoft.com/2007/7/25/nginx-gzip-ssl gzip_buffers 16 8k; # Disable gzip for certain browsers. #gzip_disable "MSIE [1-6].(?!.*SV1)"; gzip_disable "MSIE [1-6]"; # blank gif like it's 1995 location = /images/blank.gif { empty_gif; } # don't serve files beginning with dots location ~ /\. { access_log off; log_not_found off; deny all; } # we don't care if these are missing location = /robots.txt { log_not_found off; } location = /favicon.ico { log_not_found off; } location ~ affiliate.xml { log_not_found off; } location ~ copyright.xml { log_not_found off; } # convert urls with multiple slashes to a single / if ($request ~ /+ ) { rewrite ^(/)+(.*) /$2 break; } # X-Accel-Redirect # Don't tie up mongrels with serving the lesson zips or exes, let Nginx do it instead location /zips { internal; root /var/www/apps/e_learning_resource/shared/assets; } location /tmp { internal; root /; } location /mnt{ root /; } # resource library thumbnails should be served as usual location ~ ^/resource_library/.*/*thumbnail.jpg$ { if (!-f $request_filename) { rewrite ^(.*)$ /images/no-thumb.png break; } expires 1m; } # don't make Rails generate the dynamic routes to the dcr and swf, we'll do it here location ~ "lesson viewer.dcr" { rewrite ^(.*)$ "/assets/players/lesson viewer.dcr" break; } # we need this rule so we don't serve the older lessonviewer when the rule below is matched location = /assets/players/virgin_lesson_viewer/_cha5513/lessonViewer.swf { rewrite ^(.*)$ /assets/players/virgin_lesson_viewer/_cha5513/lessonViewer.swf break; } location ~ v6lessonViewer.swf { rewrite ^(.*)$ /assets/players/v6lessonViewer.swf break; } location ~ lessonViewer.swf { rewrite ^(.*)$ /assets/players/lessonViewer.swf break; } location ~ lgn111.dat { empty_gif; } # try to get autocomplete school names from memcache first, then # fallback to rails when we can't location /schools/autocomplete { set $memcached_key $uri?q=$arg_q; memcached_pass 127.0.0.1:11211; default_type text/html; error_page 404 =200 @rails; # 404 not really! Hand off to rails } location / { # make sure cached copies are revalidated once they're stale add_header Cache-Control "public, must-revalidate, proxy-revalidate"; # this serves Rails static files that exist without running other rewrite tests try_files $uri @rails; expires 1h; } location @rails { proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header Host $http_host; proxy_redirect off; proxy_read_timeout 180; proxy_next_upstream off; proxy_pass http://127.0.0.1:3000; expires 0d; } }

    Read the article

  • Using BPEL Performance Statistics to Diagnose Performance Bottlenecks

    - by fip
    Tuning performance of Oracle SOA 11G applications could be challenging. Because SOA is a platform for you to build composite applications that connect many applications and "services", when the overall performance is slow, the bottlenecks could be anywhere in the system: the applications/services that SOA connects to, the infrastructure database, or the SOA server itself.How to quickly identify the bottleneck becomes crucial in tuning the overall performance. Fortunately, the BPEL engine in Oracle SOA 11G (and 10G, for that matter) collects BPEL Engine Performance Statistics, which show the latencies of low level BPEL engine activities. The BPEL engine performance statistics can make it a bit easier for you to identify the performance bottleneck. Although the BPEL engine performance statistics are always available, the access to and interpretation of them are somewhat obscure in the early and current (PS5) 11G versions. This blog attempts to offer instructions that help you to enable, retrieve and interpret the performance statistics, before the future versions provides a more pleasant user experience. Overview of BPEL Engine Performance Statistics  SOA BPEL has a feature of collecting some performance statistics and store them in memory. One MBean attribute, StatLastN, configures the size of the memory buffer to store the statistics. This memory buffer is a "moving window", in a way that old statistics will be flushed out by the new if the amount of data exceeds the buffer size. Since the buffer size is limited by StatLastN, impacts of statistics collection on performance is minimal. By default StatLastN=-1, which means no collection of performance data. Once the statistics are collected in the memory buffer, they can be retrieved via another MBean oracle.as.soainfra.bpel:Location=[Server Name],name=BPELEngine,type=BPELEngine.> My friend in Oracle SOA development wrote this simple 'bpelstat' web app that looks up and retrieves the performance data from the MBean and displays it in a human readable form. It does not have beautiful UI but it is fairly useful. Although in Oracle SOA 11.1.1.5 onwards the same statistics can be viewed via a more elegant UI under "request break down" at EM -> SOA Infrastructure -> Service Engines -> BPEL -> Statistics, some unsophisticated minds like mine may still prefer the simplicity of the 'bpelstat' JSP. One thing that simple JSP does do well is that you can save the page and send it to someone to further analyze Follows are the instructions of how to install and invoke the BPEL statistic JSP. My friend in SOA Development will soon blog about interpreting the statistics. Stay tuned. Step1: Enable BPEL Engine Statistics for Each SOA Servers via Enterprise Manager First st you need to set the StatLastN to some number as a way to enable the collection of BPEL Engine Performance Statistics EM Console -> soa-infra(Server Name) -> SOA Infrastructure -> SOA Administration -> BPEL Properties Click on "More BPEL Configuration Properties" Click on attribute "StatLastN", set its value to some integer number. Typically you want to set it 1000 or more. Step 2: Download and Deploy bpelstat.war File to Admin Server, Note: the WAR file contains a JSP that does NOT have any security restriction. You do NOT want to keep in your production server for a long time as it is a security hazard. Deactivate the war once you are done. Download the bpelstat.war to your local PC At WebLogic Console, Go to Deployments -> Install Click on the "upload your file(s)" Click the "Browse" button to upload the deployment to Admin Server Accept the uploaded file as the path, click next Check the default option "Install this deployment as an application" Check "AdminServer" as the target server Finish the rest of the deployment with default settings Console -> Deployments Check the box next to "bpelstat" application Click on the "Start" button. It will change the state of the app from "prepared" to "active" Step 3: Invoke the BPEL Statistic Tool The BPELStat tool merely call the MBean of BPEL server and collects and display the in-memory performance statics. You usually want to do that after some peak loads. Go to http://<admin-server-host>:<admin-server-port>/bpelstat Enter the correct admin hostname, port, username and password Enter the SOA Server Name from which you want to collect the performance statistics. For example, SOA_MS1, etc. Click Submit Keep doing the same for all SOA servers. Step 3: Interpret the BPEL Engine Statistics You will see a few categories of BPEL Statistics from the JSP Page. First it starts with the overall latency of BPEL processes, grouped by synchronous and asynchronous processes. Then it provides the further break down of the measurements through the life time of a BPEL request, which is called the "request break down". 1. Overall latency of BPEL processes The top of the page shows that the elapse time of executing the synchronous process TestSyncBPELProcess from the composite TestComposite averages at about 1543.21ms, while the elapse time of executing the asynchronous process TestAsyncBPELProcess from the composite TestComposite2 averages at about 1765.43ms. The maximum and minimum latency were also shown. Synchronous process statistics <statistics>     <stats key="default/TestComposite!2.0.2-ScopedJMSOSB*soa_bfba2527-a9ba-41a7-95c5-87e49c32f4ff/TestSyncBPELProcess" min="1234" max="4567" average="1543.21" count="1000">     </stats> </statistics> Asynchronous process statistics <statistics>     <stats key="default/TestComposite2!2.0.2-ScopedJMSOSB*soa_bfba2527-a9ba-41a7-95c5-87e49c32f4ff/TestAsyncBPELProcess" min="2234" max="3234" average="1765.43" count="1000">     </stats> </statistics> 2. Request break down Under the overall latency categorized by synchronous and asynchronous processes is the "Request breakdown". Organized by statistic keys, the Request breakdown gives finer grain performance statistics through the life time of the BPEL requests.It uses indention to show the hierarchy of the statistics. Request breakdown <statistics>     <stats key="eng-composite-request" min="0" max="0" average="0.0" count="0">         <stats key="eng-single-request" min="22" max="606" average="258.43" count="277">             <stats key="populate-context" min="0" max="0" average="0.0" count="248"> Please note that in SOA 11.1.1.6, the statistics under Request breakdown is aggregated together cross all the BPEL processes based on statistic keys. It does not differentiate between BPEL processes. If two BPEL processes happen to have the statistic that share same statistic key, the statistics from two BPEL processes will be aggregated together. Keep this in mind when we go through more details below. 2.1 BPEL process activity latencies A very useful measurement in the Request Breakdown is the performance statistics of the BPEL activities you put in your BPEL processes: Assign, Invoke, Receive, etc. The names of the measurement in the JSP page directly come from the names to assign to each BPEL activity. These measurements are under the statistic key "actual-perform" Example 1:  Follows is the measurement for BPEL activity "AssignInvokeCreditProvider_Input", which looks like the Assign activity in a BPEL process that assign an input variable before passing it to the invocation:                                <stats key="AssignInvokeCreditProvider_Input" min="1" max="8" average="1.9" count="153">                                     <stats key="sensor-send-activity-data" min="0" max="1" average="0.0" count="306">                                     </stats>                                     <stats key="sensor-send-variable-data" min="0" max="0" average="0.0" count="153">                                     </stats>                                     <stats key="monitor-send-activity-data" min="0" max="0" average="0.0" count="306">                                     </stats>                                 </stats> Note: because as previously mentioned that the statistics cross all BPEL processes are aggregated together based on statistic keys, if two BPEL processes happen to name their Invoke activity the same name, they will show up at one measurement (i.e. statistic key). Example 2: Follows is the measurement of BPEL activity called "InvokeCreditProvider". You can not only see that by average it takes 3.31ms to finish this call (pretty fast) but also you can see from the further break down that most of this 3.31 ms was spent on the "invoke-service".                                  <stats key="InvokeCreditProvider" min="1" max="13" average="3.31" count="153">                                     <stats key="initiate-correlation-set-again" min="0" max="0" average="0.0" count="153">                                     </stats>                                     <stats key="invoke-service" min="1" max="13" average="3.08" count="153">                                         <stats key="prep-call" min="0" max="1" average="0.04" count="153">                                         </stats>                                     </stats>                                     <stats key="initiate-correlation-set" min="0" max="0" average="0.0" count="153">                                     </stats>                                     <stats key="sensor-send-activity-data" min="0" max="0" average="0.0" count="306">                                     </stats>                                     <stats key="sensor-send-variable-data" min="0" max="0" average="0.0" count="153">                                     </stats>                                     <stats key="monitor-send-activity-data" min="0" max="0" average="0.0" count="306">                                     </stats>                                     <stats key="update-audit-trail" min="0" max="2" average="0.03" count="153">                                     </stats>                                 </stats> 2.2 BPEL engine activity latency Another type of measurements under Request breakdown are the latencies of underlying system level engine activities. These activities are not directly tied to a particular BPEL process or process activity, but they are critical factors in the overall engine performance. These activities include the latency of saving asynchronous requests to database, and latency of process dehydration. My friend Malkit Bhasin is working on providing more information on interpreting the statistics on engine activities on his blog (https://blogs.oracle.com/malkit/). I will update this blog once the information becomes available. Update on 2012-10-02: My friend Malkit Bhasin has published the detail interpretation of the BPEL service engine statistics at his blog http://malkit.blogspot.com/2012/09/oracle-bpel-engine-soa-suite.html.

    Read the article

  • Dynamically loading Assemblies to reduce Runtime Depencies

    - by Rick Strahl
    I've been working on a request to the West Wind Application Configuration library to add JSON support. The config library is a very easy to use code-first approach to configuration: You create a class that holds the configuration data that inherits from a base configuration class, and then assign a persistence provider at runtime that determines where and how the configuration data is store. Currently the library supports .NET Configuration stores (web.config/app.config), XML files, SQL records and string storage.About once a week somebody asks me about JSON support and I've deflected this question for the longest time because frankly I think that JSON as a configuration store doesn't really buy a heck of a lot over XML. Both formats require the user to perform some fixup of the plain configuration data - in XML into XML tags, with JSON using JSON delimiters for properties and property formatting rules. Sure JSON is a little less verbose and maybe a little easier to read if you have hierarchical data, but overall the differences are pretty minor in my opinion. And yet - the requests keep rolling in.Hard Link Issues in a Component LibraryAnother reason I've been hesitant is that I really didn't want to pull in a dependency on an external JSON library - in this case JSON.NET - into the core library. If you're not using JSON.NET elsewhere I don't want a user to have to require a hard dependency on JSON.NET unless they want to use the JSON feature. JSON.NET is also sensitive to versions and doesn't play nice with multiple versions when hard linked. For example, when you have a reference to V4.4 in your project but the host application has a reference to version 4.5 you can run into assembly load problems. NuGet's Update-Package can solve some of this *if* you can recompile, but that's not ideal for a component that's supposed to be just plug and play. This is no criticism of JSON.NET - this really applies to any dependency that might change.  So hard linking the DLL can be problematic for a number reasons, but the primary reason is to not force loading of JSON.NET unless you actually need it when you use the JSON configuration features of the library.Enter Dynamic LoadingSo rather than adding an assembly reference to the project, I decided that it would be better to dynamically load the DLL at runtime and then use dynamic typing to access various classes. This allows me to run without a hard assembly reference and allows more flexibility with version number differences now and in the future.But there are also a couple of downsides:No assembly reference means only dynamic access - no compiler type checking or IntellisenseRequirement for the host application to have reference to JSON.NET or else get runtime errorsThe former is minor, but the latter can be problematic. Runtime errors are always painful, but in this case I'm willing to live with this. If you want to use JSON configuration settings JSON.NET needs to be loaded in the project. If this is a Web project, it'll likely be there already.So there are a few things that are needed to make this work:Dynamically create an instance and optionally attempt to load an Assembly (if not loaded)Load types into dynamic variablesUse Reflection for a few tasks like statics/enumsThe dynamic keyword in C# makes the formerly most difficult Reflection part - method calls and property assignments - fairly painless. But as cool as dynamic is it doesn't handle all aspects of Reflection. Specifically it doesn't deal with object activation, truly dynamic (string based) member activation or accessing of non instance members, so there's still a little bit of work left to do with Reflection.Dynamic Object InstantiationThe first step in getting the process rolling is to instantiate the type you need to work with. This might be a two step process - loading the instance from a string value, since we don't have a hard type reference and potentially having to load the assembly. Although the host project might have a reference to JSON.NET, that instance might have not been loaded yet since it hasn't been accessed yet. In ASP.NET this won't be a problem, since ASP.NET preloads all referenced assemblies on AppDomain startup, but in other executable project, assemblies are just in time loaded only when they are accessed.Instantiating a type is a two step process: Finding the type reference and then activating it. Here's the generic code out of my ReflectionUtils library I use for this:/// <summary> /// Creates an instance of a type based on a string. Assumes that the type's /// </summary> /// <param name="typeName">Common name of the type</param> /// <param name="args">Any constructor parameters</param> /// <returns></returns> public static object CreateInstanceFromString(string typeName, params object[] args) { object instance = null; Type type = null; try { type = GetTypeFromName(typeName); if (type == null) return null; instance = Activator.CreateInstance(type, args); } catch { return null; } return instance; } /// <summary> /// Helper routine that looks up a type name and tries to retrieve the /// full type reference in the actively executing assemblies. /// </summary> /// <param name="typeName"></param> /// <returns></returns> public static Type GetTypeFromName(string typeName) { Type type = null; // Let default name binding find it type = Type.GetType(typeName, false); if (type != null) return type; // look through assembly list var assemblies = AppDomain.CurrentDomain.GetAssemblies(); // try to find manually foreach (Assembly asm in assemblies) { type = asm.GetType(typeName, false); if (type != null) break; } return type; } To use this for loading JSON.NET I have a small factory function that instantiates JSON.NET and sets a bunch of configuration settings on the generated object. The startup code also looks for failure and tries loading up the assembly when it fails since that's the main reason the load would fail. Finally it also caches the loaded instance for reuse (according to James the JSON.NET instance is thread safe and quite a bit faster when cached). Here's what the factory function looks like in JsonSerializationUtils:/// <summary> /// Dynamically creates an instance of JSON.NET /// </summary> /// <param name="throwExceptions">If true throws exceptions otherwise returns null</param> /// <returns>Dynamic JsonSerializer instance</returns> public static dynamic CreateJsonNet(bool throwExceptions = true) { if (JsonNet != null) return JsonNet; lock (SyncLock) { if (JsonNet != null) return JsonNet; // Try to create instance dynamic json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); if (json == null) { try { var ass = AppDomain.CurrentDomain.Load("Newtonsoft.Json"); json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); } catch (Exception ex) { if (throwExceptions) throw; return null; } } if (json == null) return null; json.ReferenceLoopHandling = (dynamic) ReflectionUtils.GetStaticProperty("Newtonsoft.Json.ReferenceLoopHandling", "Ignore"); // Enums as strings in JSON dynamic enumConverter = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.Converters.StringEnumConverter"); json.Converters.Add(enumConverter); JsonNet = json; } return JsonNet; }This code's purpose is to return a fully configured JsonSerializer instance. As you can see the code tries to create an instance and when it fails tries to load the assembly, and then re-tries loading.Once the instance is loaded some configuration occurs on it. Specifically I set the ReferenceLoopHandling option to not blow up immediately when circular references are encountered. There are a host of other small config setting that might be useful to set, but the default seem to be good enough in recent versions. Note that I'm setting ReferenceLoopHandling which requires an Enum value to be set. There's no real easy way (short of using the cardinal numeric value) to set a property or pass parameters from static values or enums. This means I still need to use Reflection to make this work. I'm using the same ReflectionUtils class I previously used to handle this for me. The function looks up the type and then uses Type.InvokeMember() to read the static property.Another feature I need is have Enum values serialized as strings rather than numeric values which is the default. To do this I can use the StringEnumConverter to convert enums to strings by adding it to the Converters collection.As you can see there's still a bit of Reflection to be done even in C# 4+ with dynamic, but with a few helpers this process is relatively painless.Doing the actual JSON ConversionFinally I need to actually do my JSON conversions. For the Utility class I need serialization that works for both strings and files so I created four methods that handle these tasks two each for serialization and deserialization for string and file.Here's what the File Serialization looks like:/// <summary> /// Serializes an object instance to a JSON file. /// </summary> /// <param name="value">the value to serialize</param> /// <param name="fileName">Full path to the file to write out with JSON.</param> /// <param name="throwExceptions">Determines whether exceptions are thrown or false is returned</param> /// <param name="formatJsonOutput">if true pretty-formats the JSON with line breaks</param> /// <returns>true or false</returns> public static bool SerializeToFile(object value, string fileName, bool throwExceptions = false, bool formatJsonOutput = false) { dynamic writer = null; FileStream fs = null; try { Type type = value.GetType(); var json = CreateJsonNet(throwExceptions); if (json == null) return false; fs = new FileStream(fileName, FileMode.Create); var sw = new StreamWriter(fs, Encoding.UTF8); writer = Activator.CreateInstance(JsonTextWriterType, sw); if (formatJsonOutput) writer.Formatting = (dynamic)Enum.Parse(FormattingType, "Indented"); writer.QuoteChar = '"'; json.Serialize(writer, value); } catch (Exception ex) { Debug.WriteLine("JsonSerializer Serialize error: " + ex.Message); if (throwExceptions) throw; return false; } finally { if (writer != null) writer.Close(); if (fs != null) fs.Close(); } return true; }You can see more of the dynamic invocation in this code. First I grab the dynamic JsonSerializer instance using the CreateJsonNet() method shown earlier which returns a dynamic. I then create a JsonTextWriter and configure a couple of enum settings on it, and then call Serialize() on the serializer instance with the JsonTextWriter that writes the output to disk. Although this code is dynamic it's still fairly short and readable.For full circle operation here's the DeserializeFromFile() version:/// <summary> /// Deserializes an object from file and returns a reference. /// </summary> /// <param name="fileName">name of the file to serialize to</param> /// <param name="objectType">The Type of the object. Use typeof(yourobject class)</param> /// <param name="binarySerialization">determines whether we use Xml or Binary serialization</param> /// <param name="throwExceptions">determines whether failure will throw rather than return null on failure</param> /// <returns>Instance of the deserialized object or null. Must be cast to your object type</returns> public static object DeserializeFromFile(string fileName, Type objectType, bool throwExceptions = false) { dynamic json = CreateJsonNet(throwExceptions); if (json == null) return null; object result = null; dynamic reader = null; FileStream fs = null; try { fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); var sr = new StreamReader(fs, Encoding.UTF8); reader = Activator.CreateInstance(JsonTextReaderType, sr); result = json.Deserialize(reader, objectType); reader.Close(); } catch (Exception ex) { Debug.WriteLine("JsonNetSerialization Deserialization Error: " + ex.Message); if (throwExceptions) throw; return null; } finally { if (reader != null) reader.Close(); if (fs != null) fs.Close(); } return result; }This code is a little more compact since there are no prettifying options to set. Here JsonTextReader is created dynamically and it receives the output from the Deserialize() operation on the serializer.You can take a look at the full JsonSerializationUtils.cs file on GitHub to see the rest of the operations, but the string operations are very similar - the code is fairly repetitive.These generic serialization utilities isolate the dynamic serialization logic that has to deal with the dynamic nature of JSON.NET, and any code that uses these functions is none the wiser that JSON.NET is dynamically loaded.Using the JsonSerializationUtils WrapperThe final consumer of the SerializationUtils wrapper is an actual ConfigurationProvider, that is responsible for handling reading and writing JSON values to and from files. The provider is simple a small wrapper around the SerializationUtils component and there's very little code to make this work now:The whole provider looks like this:/// <summary> /// Reads and Writes configuration settings in .NET config files and /// sections. Allows reading and writing to default or external files /// and specification of the configuration section that settings are /// applied to. /// </summary> public class JsonFileConfigurationProvider<TAppConfiguration> : ConfigurationProviderBase<TAppConfiguration> where TAppConfiguration: AppConfiguration, new() { /// <summary> /// Optional - the Configuration file where configuration settings are /// stored in. If not specified uses the default Configuration Manager /// and its default store. /// </summary> public string JsonConfigurationFile { get { return _JsonConfigurationFile; } set { _JsonConfigurationFile = value; } } private string _JsonConfigurationFile = string.Empty; public override bool Read(AppConfiguration config) { var newConfig = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfiguration)) as TAppConfiguration; if (newConfig == null) { if(Write(config)) return true; return false; } DecryptFields(newConfig); DataUtils.CopyObjectData(newConfig, config, "Provider,ErrorMessage"); return true; } /// <summary> /// Return /// </summary> /// <typeparam name="TAppConfig"></typeparam> /// <returns></returns> public override TAppConfig Read<TAppConfig>() { var result = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfig)) as TAppConfig; if (result != null) DecryptFields(result); return result; } /// <summary> /// Write configuration to XmlConfigurationFile location /// </summary> /// <param name="config"></param> /// <returns></returns> public override bool Write(AppConfiguration config) { EncryptFields(config); bool result = JsonSerializationUtils.SerializeToFile(config, JsonConfigurationFile,false,true); // Have to decrypt again to make sure the properties are readable afterwards DecryptFields(config); return result; } }This incidentally demonstrates how easy it is to create a new provider for the West Wind Application Configuration component. Simply implementing 3 methods will do in most cases.Note this code doesn't have any dynamic dependencies - all that's abstracted away in the JsonSerializationUtils(). From here on, serializing JSON is just a matter of calling the static methods on the SerializationUtils class.Already, there are several other places in some other tools where I use JSON serialization this is coming in very handy. With a couple of lines of code I was able to add JSON.NET support to an older AJAX library that I use replacing quite a bit of code that was previously in use. And for any other manual JSON operations (in a couple of apps I use JSON Serialization for 'blob' like document storage) this is also going to be handy.Performance?Some of you might be thinking that using dynamic and Reflection can't be good for performance. And you'd be right… In performing some informal testing it looks like the performance of the native code is nearly twice as fast as the dynamic code. Most of the slowness is attributable to type lookups. To test I created a native class that uses an actual reference to JSON.NET and performance was consistently around 85-90% faster with the referenced code. That being said though - I serialized 10,000 objects in 80ms vs. 45ms so this isn't hardly slouchy. For the configuration component speed is not that important because both read and write operations typically happen once on first access and then every once in a while. But for other operations - say a serializer trying to handle AJAX requests on a Web Server one would be well served to create a hard dependency.Dynamic Loading - Worth it?On occasion dynamic loading makes sense. But there's a price to be paid in added code complexity and a performance hit. But for some operations that are not pivotal to a component or application and only used under certain circumstances dynamic loading can be beneficial to avoid having to ship extra files and loading down distributions. These days when you create new projects in Visual Studio with 30 assemblies before you even add your own code, trying to keep file counts under control seems a good idea. It's not the kind of thing you do on a regular basis, but when needed it can be a useful tool. Hopefully some of you find this information useful…© Rick Strahl, West Wind Technologies, 2005-2013Posted in .NET  C#   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

    Read the article

  • Dynamically loading Assemblies to reduce Runtime Dependencies

    - by Rick Strahl
    I've been working on a request to the West Wind Application Configuration library to add JSON support. The config library is a very easy to use code-first approach to configuration: You create a class that holds the configuration data that inherits from a base configuration class, and then assign a persistence provider at runtime that determines where and how the configuration data is store. Currently the library supports .NET Configuration stores (web.config/app.config), XML files, SQL records and string storage.About once a week somebody asks me about JSON support and I've deflected this question for the longest time because frankly I think that JSON as a configuration store doesn't really buy a heck of a lot over XML. Both formats require the user to perform some fixup of the plain configuration data - in XML into XML tags, with JSON using JSON delimiters for properties and property formatting rules. Sure JSON is a little less verbose and maybe a little easier to read if you have hierarchical data, but overall the differences are pretty minor in my opinion. And yet - the requests keep rolling in.Hard Link Issues in a Component LibraryAnother reason I've been hesitant is that I really didn't want to pull in a dependency on an external JSON library - in this case JSON.NET - into the core library. If you're not using JSON.NET elsewhere I don't want a user to have to require a hard dependency on JSON.NET unless they want to use the JSON feature. JSON.NET is also sensitive to versions and doesn't play nice with multiple versions when hard linked. For example, when you have a reference to V4.4 in your project but the host application has a reference to version 4.5 you can run into assembly load problems. NuGet's Update-Package can solve some of this *if* you can recompile, but that's not ideal for a component that's supposed to be just plug and play. This is no criticism of JSON.NET - this really applies to any dependency that might change.  So hard linking the DLL can be problematic for a number reasons, but the primary reason is to not force loading of JSON.NET unless you actually need it when you use the JSON configuration features of the library.Enter Dynamic LoadingSo rather than adding an assembly reference to the project, I decided that it would be better to dynamically load the DLL at runtime and then use dynamic typing to access various classes. This allows me to run without a hard assembly reference and allows more flexibility with version number differences now and in the future.But there are also a couple of downsides:No assembly reference means only dynamic access - no compiler type checking or IntellisenseRequirement for the host application to have reference to JSON.NET or else get runtime errorsThe former is minor, but the latter can be problematic. Runtime errors are always painful, but in this case I'm willing to live with this. If you want to use JSON configuration settings JSON.NET needs to be loaded in the project. If this is a Web project, it'll likely be there already.So there are a few things that are needed to make this work:Dynamically create an instance and optionally attempt to load an Assembly (if not loaded)Load types into dynamic variablesUse Reflection for a few tasks like statics/enumsThe dynamic keyword in C# makes the formerly most difficult Reflection part - method calls and property assignments - fairly painless. But as cool as dynamic is it doesn't handle all aspects of Reflection. Specifically it doesn't deal with object activation, truly dynamic (string based) member activation or accessing of non instance members, so there's still a little bit of work left to do with Reflection.Dynamic Object InstantiationThe first step in getting the process rolling is to instantiate the type you need to work with. This might be a two step process - loading the instance from a string value, since we don't have a hard type reference and potentially having to load the assembly. Although the host project might have a reference to JSON.NET, that instance might have not been loaded yet since it hasn't been accessed yet. In ASP.NET this won't be a problem, since ASP.NET preloads all referenced assemblies on AppDomain startup, but in other executable project, assemblies are just in time loaded only when they are accessed.Instantiating a type is a two step process: Finding the type reference and then activating it. Here's the generic code out of my ReflectionUtils library I use for this:/// <summary> /// Creates an instance of a type based on a string. Assumes that the type's /// </summary> /// <param name="typeName">Common name of the type</param> /// <param name="args">Any constructor parameters</param> /// <returns></returns> public static object CreateInstanceFromString(string typeName, params object[] args) { object instance = null; Type type = null; try { type = GetTypeFromName(typeName); if (type == null) return null; instance = Activator.CreateInstance(type, args); } catch { return null; } return instance; } /// <summary> /// Helper routine that looks up a type name and tries to retrieve the /// full type reference in the actively executing assemblies. /// </summary> /// <param name="typeName"></param> /// <returns></returns> public static Type GetTypeFromName(string typeName) { Type type = null; // Let default name binding find it type = Type.GetType(typeName, false); if (type != null) return type; // look through assembly list var assemblies = AppDomain.CurrentDomain.GetAssemblies(); // try to find manually foreach (Assembly asm in assemblies) { type = asm.GetType(typeName, false); if (type != null) break; } return type; } To use this for loading JSON.NET I have a small factory function that instantiates JSON.NET and sets a bunch of configuration settings on the generated object. The startup code also looks for failure and tries loading up the assembly when it fails since that's the main reason the load would fail. Finally it also caches the loaded instance for reuse (according to James the JSON.NET instance is thread safe and quite a bit faster when cached). Here's what the factory function looks like in JsonSerializationUtils:/// <summary> /// Dynamically creates an instance of JSON.NET /// </summary> /// <param name="throwExceptions">If true throws exceptions otherwise returns null</param> /// <returns>Dynamic JsonSerializer instance</returns> public static dynamic CreateJsonNet(bool throwExceptions = true) { if (JsonNet != null) return JsonNet; lock (SyncLock) { if (JsonNet != null) return JsonNet; // Try to create instance dynamic json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); if (json == null) { try { var ass = AppDomain.CurrentDomain.Load("Newtonsoft.Json"); json = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.JsonSerializer"); } catch (Exception ex) { if (throwExceptions) throw; return null; } } if (json == null) return null; json.ReferenceLoopHandling = (dynamic) ReflectionUtils.GetStaticProperty("Newtonsoft.Json.ReferenceLoopHandling", "Ignore"); // Enums as strings in JSON dynamic enumConverter = ReflectionUtils.CreateInstanceFromString("Newtonsoft.Json.Converters.StringEnumConverter"); json.Converters.Add(enumConverter); JsonNet = json; } return JsonNet; }This code's purpose is to return a fully configured JsonSerializer instance. As you can see the code tries to create an instance and when it fails tries to load the assembly, and then re-tries loading.Once the instance is loaded some configuration occurs on it. Specifically I set the ReferenceLoopHandling option to not blow up immediately when circular references are encountered. There are a host of other small config setting that might be useful to set, but the default seem to be good enough in recent versions. Note that I'm setting ReferenceLoopHandling which requires an Enum value to be set. There's no real easy way (short of using the cardinal numeric value) to set a property or pass parameters from static values or enums. This means I still need to use Reflection to make this work. I'm using the same ReflectionUtils class I previously used to handle this for me. The function looks up the type and then uses Type.InvokeMember() to read the static property.Another feature I need is have Enum values serialized as strings rather than numeric values which is the default. To do this I can use the StringEnumConverter to convert enums to strings by adding it to the Converters collection.As you can see there's still a bit of Reflection to be done even in C# 4+ with dynamic, but with a few helpers this process is relatively painless.Doing the actual JSON ConversionFinally I need to actually do my JSON conversions. For the Utility class I need serialization that works for both strings and files so I created four methods that handle these tasks two each for serialization and deserialization for string and file.Here's what the File Serialization looks like:/// <summary> /// Serializes an object instance to a JSON file. /// </summary> /// <param name="value">the value to serialize</param> /// <param name="fileName">Full path to the file to write out with JSON.</param> /// <param name="throwExceptions">Determines whether exceptions are thrown or false is returned</param> /// <param name="formatJsonOutput">if true pretty-formats the JSON with line breaks</param> /// <returns>true or false</returns> public static bool SerializeToFile(object value, string fileName, bool throwExceptions = false, bool formatJsonOutput = false) { dynamic writer = null; FileStream fs = null; try { Type type = value.GetType(); var json = CreateJsonNet(throwExceptions); if (json == null) return false; fs = new FileStream(fileName, FileMode.Create); var sw = new StreamWriter(fs, Encoding.UTF8); writer = Activator.CreateInstance(JsonTextWriterType, sw); if (formatJsonOutput) writer.Formatting = (dynamic)Enum.Parse(FormattingType, "Indented"); writer.QuoteChar = '"'; json.Serialize(writer, value); } catch (Exception ex) { Debug.WriteLine("JsonSerializer Serialize error: " + ex.Message); if (throwExceptions) throw; return false; } finally { if (writer != null) writer.Close(); if (fs != null) fs.Close(); } return true; }You can see more of the dynamic invocation in this code. First I grab the dynamic JsonSerializer instance using the CreateJsonNet() method shown earlier which returns a dynamic. I then create a JsonTextWriter and configure a couple of enum settings on it, and then call Serialize() on the serializer instance with the JsonTextWriter that writes the output to disk. Although this code is dynamic it's still fairly short and readable.For full circle operation here's the DeserializeFromFile() version:/// <summary> /// Deserializes an object from file and returns a reference. /// </summary> /// <param name="fileName">name of the file to serialize to</param> /// <param name="objectType">The Type of the object. Use typeof(yourobject class)</param> /// <param name="binarySerialization">determines whether we use Xml or Binary serialization</param> /// <param name="throwExceptions">determines whether failure will throw rather than return null on failure</param> /// <returns>Instance of the deserialized object or null. Must be cast to your object type</returns> public static object DeserializeFromFile(string fileName, Type objectType, bool throwExceptions = false) { dynamic json = CreateJsonNet(throwExceptions); if (json == null) return null; object result = null; dynamic reader = null; FileStream fs = null; try { fs = new FileStream(fileName, FileMode.Open, FileAccess.Read); var sr = new StreamReader(fs, Encoding.UTF8); reader = Activator.CreateInstance(JsonTextReaderType, sr); result = json.Deserialize(reader, objectType); reader.Close(); } catch (Exception ex) { Debug.WriteLine("JsonNetSerialization Deserialization Error: " + ex.Message); if (throwExceptions) throw; return null; } finally { if (reader != null) reader.Close(); if (fs != null) fs.Close(); } return result; }This code is a little more compact since there are no prettifying options to set. Here JsonTextReader is created dynamically and it receives the output from the Deserialize() operation on the serializer.You can take a look at the full JsonSerializationUtils.cs file on GitHub to see the rest of the operations, but the string operations are very similar - the code is fairly repetitive.These generic serialization utilities isolate the dynamic serialization logic that has to deal with the dynamic nature of JSON.NET, and any code that uses these functions is none the wiser that JSON.NET is dynamically loaded.Using the JsonSerializationUtils WrapperThe final consumer of the SerializationUtils wrapper is an actual ConfigurationProvider, that is responsible for handling reading and writing JSON values to and from files. The provider is simple a small wrapper around the SerializationUtils component and there's very little code to make this work now:The whole provider looks like this:/// <summary> /// Reads and Writes configuration settings in .NET config files and /// sections. Allows reading and writing to default or external files /// and specification of the configuration section that settings are /// applied to. /// </summary> public class JsonFileConfigurationProvider<TAppConfiguration> : ConfigurationProviderBase<TAppConfiguration> where TAppConfiguration: AppConfiguration, new() { /// <summary> /// Optional - the Configuration file where configuration settings are /// stored in. If not specified uses the default Configuration Manager /// and its default store. /// </summary> public string JsonConfigurationFile { get { return _JsonConfigurationFile; } set { _JsonConfigurationFile = value; } } private string _JsonConfigurationFile = string.Empty; public override bool Read(AppConfiguration config) { var newConfig = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfiguration)) as TAppConfiguration; if (newConfig == null) { if(Write(config)) return true; return false; } DecryptFields(newConfig); DataUtils.CopyObjectData(newConfig, config, "Provider,ErrorMessage"); return true; } /// <summary> /// Return /// </summary> /// <typeparam name="TAppConfig"></typeparam> /// <returns></returns> public override TAppConfig Read<TAppConfig>() { var result = JsonSerializationUtils.DeserializeFromFile(JsonConfigurationFile, typeof(TAppConfig)) as TAppConfig; if (result != null) DecryptFields(result); return result; } /// <summary> /// Write configuration to XmlConfigurationFile location /// </summary> /// <param name="config"></param> /// <returns></returns> public override bool Write(AppConfiguration config) { EncryptFields(config); bool result = JsonSerializationUtils.SerializeToFile(config, JsonConfigurationFile,false,true); // Have to decrypt again to make sure the properties are readable afterwards DecryptFields(config); return result; } }This incidentally demonstrates how easy it is to create a new provider for the West Wind Application Configuration component. Simply implementing 3 methods will do in most cases.Note this code doesn't have any dynamic dependencies - all that's abstracted away in the JsonSerializationUtils(). From here on, serializing JSON is just a matter of calling the static methods on the SerializationUtils class.Already, there are several other places in some other tools where I use JSON serialization this is coming in very handy. With a couple of lines of code I was able to add JSON.NET support to an older AJAX library that I use replacing quite a bit of code that was previously in use. And for any other manual JSON operations (in a couple of apps I use JSON Serialization for 'blob' like document storage) this is also going to be handy.Performance?Some of you might be thinking that using dynamic and Reflection can't be good for performance. And you'd be right… In performing some informal testing it looks like the performance of the native code is nearly twice as fast as the dynamic code. Most of the slowness is attributable to type lookups. To test I created a native class that uses an actual reference to JSON.NET and performance was consistently around 85-90% faster with the referenced code. This will change though depending on the size of objects serialized - the larger the object the more processing time is spent inside the actual dynamically activated components and the less difference there will be. Dynamic code is always slower, but how much it really affects your application primarily depends on how frequently the dynamic code is called in relation to the non-dynamic code executing. In most situations where dynamic code is used 'to get the process rolling' as I do here the overhead is small enough to not matter.All that being said though - I serialized 10,000 objects in 80ms vs. 45ms so this is hardly slouchy performance. For the configuration component speed is not that important because both read and write operations typically happen once on first access and then every once in a while. But for other operations - say a serializer trying to handle AJAX requests on a Web Server one would be well served to create a hard dependency.Dynamic Loading - Worth it?Dynamic loading is not something you need to worry about but on occasion dynamic loading makes sense. But there's a price to be paid in added code  and a performance hit which depends on how frequently the dynamic code is accessed. But for some operations that are not pivotal to a component or application and are only used under certain circumstances dynamic loading can be beneficial to avoid having to ship extra files adding dependencies and loading down distributions. These days when you create new projects in Visual Studio with 30 assemblies before you even add your own code, trying to keep file counts under control seems like a good idea. It's not the kind of thing you do on a regular basis, but when needed it can be a useful option in your toolset… © Rick Strahl, West Wind Technologies, 2005-2013Posted in .NET  C#   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

    Read the article

  • Customized listfield with image displaying from a url

    - by arunabha
    I am displaying a customized list field with text on the right side and image on the left side.The image comes from a URL dynamically.Initially i am placing a blank image on the left of the list field,then call URLBitmapField class's setURL method,which actually does the processing and places the processed image on top of the blank image.The image gets displayed on the list field,but to see that processed image i need to press any key or click on the list field items.I want the processed image to be displayed automatically in the list field after the processing.Can anyone tell me where i am getting wrong? import java.util.Vector; import net.rim.device.api.system.Bitmap; import net.rim.device.api.system.Display; import net.rim.device.api.ui.ContextMenu; import net.rim.device.api.ui.DrawStyle; import net.rim.device.api.ui.Field; import net.rim.device.api.ui.Font; import net.rim.device.api.ui.Graphics; import net.rim.device.api.ui.Manager; import net.rim.device.api.ui.MenuItem; import net.rim.device.api.ui.UiApplication; import net.rim.device.api.ui.component.BitmapField; import net.rim.device.api.ui.component.Dialog; import net.rim.device.api.ui.component.LabelField; import net.rim.device.api.ui.component.ListField; import net.rim.device.api.ui.component.ListFieldCallback; import net.rim.device.api.ui.component.NullField; import net.rim.device.api.ui.container.FullScreen; import net.rim.device.api.ui.container.MainScreen; import net.rim.device.api.ui.container.VerticalFieldManager; import net.rim.device.api.util.Arrays; import net.rim.device.api.ui.component.ListField; public class TaskListField extends UiApplication { // statics // ------------------------------------------------------------------ public static void main(String[] args) { TaskListField theApp = new TaskListField(); theApp.enterEventDispatcher(); } public TaskListField() { pushScreen(new TaskList()); } } class TaskList extends MainScreen implements ListFieldCallback { private Vector rows; private Bitmap p1; private Bitmap p2; private Bitmap p3; String Task; ListField listnew = new ListField(); private VerticalFieldManager metadataVFM; TableRowManager row; public TaskList() { super(); URLBitmapField artistImgField; listnew.setRowHeight(80); listnew.setCallback(this); rows = new Vector(); for (int x = 0; x <3; x++) { row = new TableRowManager(); artistImgField = new URLBitmapField(Bitmap .getBitmapResource("res/images/bg.jpg")); row.add(artistImgField); String photoURL = "someimagefrmurl.jpg"; Log.info(photoURL); // strip white spaces in the url, which is causing the // images to not display properly for (int i = 0; i < photoURL.length(); i++) { if (photoURL.charAt(i) == ' ') { photoURL = photoURL.substring(0, i) + "%20" + photoURL.substring(i + 1, photoURL.length()); } } Log.info("Processed URL: " + photoURL); artistImgField.setURL(photoURL); LabelField task = new LabelField("Display"); row.add(task); LabelField task1 = new LabelField( "Now Playing" + String.valueOf(x)); Font myFont = Font.getDefault().derive(Font.PLAIN, 12); task1.setFont(myFont); row.add(task1); rows.addElement(row); } listnew.setSize(rows.size()); this.add(listnew); //listnew.invalidate(); } // ListFieldCallback Implementation public void drawListRow(ListField listField, Graphics g, int index, int y, int width) { TableRowManager rowManager = (TableRowManager) rows.elementAt(index); rowManager.drawRow(g, 0, y, width, listnew.getRowHeight()); } protected void drawFocus(Graphics graphics, boolean on) { } private class TableRowManager extends Manager { public TableRowManager() { super(0); } // Causes the fields within this row manager to be layed out then // painted. public void drawRow(Graphics g, int x, int y, int width, int height) { // Arrange the cell fields within this row manager. layout(width, height); // Place this row manager within its enclosing list. setPosition(x, y); // Apply a translating/clipping transformation to the graphics // context so that this row paints in the right area. g.pushRegion(getExtent()); // Paint this manager's controlled fields. subpaint(g); g.setColor(0x00CACACA); g.drawLine(0, 0, getPreferredWidth(), 0); // Restore the graphics context. g.popContext(); } // Arrages this manager's controlled fields from left to right within // the enclosing table's columns. protected void sublayout(int width, int height) { // set the size and position of each field. int fontHeight = Font.getDefault().getHeight(); int preferredWidth = getPreferredWidth(); // start with the Bitmap Field of the priority icon Field field = getField(0); layoutChild(field, 146,80); setPositionChild(field, 0, 0); // set the task name label field field = getField(1); layoutChild(field, preferredWidth - 16, fontHeight + 1); setPositionChild(field, 149, 3); // set the list name label field field = getField(2); layoutChild(field, 150, fontHeight + 1); setPositionChild(field, 149, fontHeight + 6); setExtent(360, 480); } // The preferred width of a row is defined by the list renderer. public int getPreferredWidth() { return listnew.getWidth(); } // The preferred height of a row is the "row height" as defined in the // enclosing list. public int getPreferredHeight() { return listnew.getRowHeight(); } } public Object get(ListField listField, int index) { // TODO Auto-generated method stub return null; } public int getPreferredWidth(ListField listField) { return 0; } public int indexOfList(ListField listField, String prefix, int start) { // TODO Auto-generated method stub return 0; } }

    Read the article

  • Set postion in customized list field in blackberry

    - by arunabha
    I want three list field items to be displayed, from bottom to top. I am able to display three list field items, but they display from top to bottom. I have tried setting the position, but it isn't working. import java.util.Vector; import net.rim.device.api.system.Bitmap; import net.rim.device.api.system.Display; import net.rim.device.api.ui.ContextMenu; import net.rim.device.api.ui.DrawStyle; import net.rim.device.api.ui.Field; import net.rim.device.api.ui.Font; import net.rim.device.api.ui.Graphics; import net.rim.device.api.ui.Manager; import net.rim.device.api.ui.MenuItem; import net.rim.device.api.ui.UiApplication; import net.rim.device.api.ui.component.BitmapField; import net.rim.device.api.ui.component.Dialog; import net.rim.device.api.ui.component.LabelField; import net.rim.device.api.ui.component.ListField; import net.rim.device.api.ui.component.ListFieldCallback; import net.rim.device.api.ui.component.NullField; import net.rim.device.api.ui.container.FullScreen; import net.rim.device.api.ui.container.MainScreen; import net.rim.device.api.util.Arrays; import net.rim.device.api.ui.component.ListField; /** * @author Jason Emerick */ public class TaskListField extends UiApplication { //statics ------------------------------------------------------------------ public static void main(String[] args) { TaskListField theApp = new TaskListField(); theApp.enterEventDispatcher(); } public TaskListField() { pushScreen(new TaskList()); } } /*class List extends FullScreen { TaskList tl; List(){ super(); TaskList tl=new TaskList(); } }*/ class TaskList extends MainScreen implements ListFieldCallback { private Vector rows; private Bitmap p1; private Bitmap p2; private Bitmap p3; String Task; ListField listnew=new ListField(); public TaskList() { super(); listnew.setRowHeight(50); //setEmptyString("Hooray, no tasks here!", DrawStyle.HCENTER); listnew.setCallback(this); p1 = Bitmap.getBitmapResource("1.png"); p2 = Bitmap.getBitmapResource("2.png"); p3 = Bitmap.getBitmapResource("3.png"); rows = new Vector(); for (int x = 0; x < 3; x++) { TableRowManager row = new TableRowManager(); if (x== 0) { Task="On Air Now"; } if (x== 1) { Task="Music Channel"; } if (x==2) { Task="News Channel"; } // SET THE PRIORITY BITMAP FIELD // if high priority, display p1 bitmap if (x % 2 == 0) { row.add(new BitmapField(p1)); } // if priority is 2, set p2 bitmap else if (x % 3 == 0) { row.add(new BitmapField(p2)); } // if priority is 3, set p3 bitmap else { row.add(new BitmapField(p3)); } // SET THE TASK NAME LABELFIELD // if overdue, bold/underline LabelField task = new LabelField(Task, DrawStyle.ELLIPSIS); // if due today, bold if (x % 2 == 0) { task.setFont(Font.getDefault().derive( Font.BOLD)); } else { task.setFont(Font.getDefault().derive(Font.BOLD)); } row.add(task); LabelField task1 = new LabelField("Now Playing" + String.valueOf(x), DrawStyle.ELLIPSIS); // if due today, bold /* if (x % 2 == 0) { task.setFont(Font.getDefault().derive( Font.BOLD)); } else { task.setFont(Font.getDefault().derive(Font.BOLD)); }*/ Font myFont = Font.getDefault().derive(Font.PLAIN, 12); task1.setFont(myFont); row.add(task1); // SET THE DUE DATE/TIME row.add(new LabelField("", DrawStyle.ELLIPSIS | LabelField.USE_ALL_WIDTH | DrawStyle.RIGHT) { protected void paint(Graphics graphics) { graphics.setColor(0x00878787); super.paint(graphics); } }); rows.addElement(row); } listnew.setSize(rows.size()); this.add(listnew); } // ListFieldCallback Implementation public void drawListRow(ListField listField, Graphics g, int index, int y, int width) { //TaskList list =(TaskListField) listnew; TableRowManager rowManager = (TableRowManager)rows .elementAt(index); rowManager.drawRow(g, 0, y, width, listnew.getRowHeight()); } private class TableRowManager extends Manager { public TableRowManager() { super(0); } // Causes the fields within this row manager to be layed out then // painted. public void drawRow(Graphics g, int x, int y, int width, int height) { // Arrange the cell fields within this row manager. layout(0, 1); // Place this row manager within its enclosing list. setPosition(x,y); // Apply a translating/clipping transformation to the graphics // context so that this row paints in the right area. g.pushRegion(getExtent()); // Paint this manager's controlled fields. subpaint(g); g.setColor(0x00CACACA); g.drawLine(0, 0, getPreferredWidth(), 0); // Restore the graphics context. g.popContext(); } // Arrages this manager's controlled fields from left to right within // the enclosing table's columns. protected void sublayout(int width, int height) { // set the size and position of each field. int fontHeight = Font.getDefault().getHeight(); int preferredWidth = getPreferredWidth(); // start with the Bitmap Field of the priority icon /* Field field = getField(0); layoutChild(field, 0, 0); setPositionChild(field, 150, 300);*/ // set the task name label field /* field = getField(1); layoutChild(field, preferredWidth - 16, fontHeight + 1); setPositionChild(field, 34, 3); // set the list name label field field = getField(2); layoutChild(field, 150, fontHeight + 1); setPositionChild(field, 34, fontHeight + 6);*/ // set the due time name label field /* field = getField(3); layoutChild(field, 150, fontHeight + 1); setPositionChild(field,4,340);*/ /* layoutChild(listnew, preferredWidth, fontHeight); setPositionChild(listnew, 3, 396);*/ setExtent(360, 480); } // The preferred width of a row is defined by the list renderer. public int getPreferredWidth() { return getWidth(); } // The preferred height of a row is the "row height" as defined in the // enclosing list. public int getPreferredHeight() { return listnew.getRowHeight(); } } public Object get(ListField listField, int index) { // TODO Auto-generated method stub return null; } public int getPreferredWidth(ListField listField) { // TODO Auto-generated method stub return 0; } public int indexOfList(ListField listField, String prefix, int start) { // TODO Auto-generated method stub return 0; } }

    Read the article

< Previous Page | 1 2