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• Windows forms application blocks after station lock

  - by Silviu

  We're having a serious issue at work. We've discovered that after the station where the client was running is locked/unlocked the client is blocked. No repaint. So the UI thread is blocked with something. Looking at the callstack of the UI thread (thread 0) using windbg we see that a UserPreferenceChanged event gets raised. It is marshalled through a WindowsFormsSynchronizationContext using it's controlToSend field to the UI. It gets blocked by a call to the marshalling control. The method called is MarshaledInvoke it builds a ThreadMethodEntry entry = new ThreadMethodEntry(caller, method, args, synchronous, executionContext); This entry is supposed to do the magic. The call is a synchronous call and because of that (still in the MarshaledInvoke of the Control class) the wait call is reached: if (!entry.IsCompleted) { this.WaitForWaitHandle(entry.AsyncWaitHandle); } The last thing that i can see on the stack is the WaitOne called on the previously mentioned AsyncWaitHandle. This is very annoying because having just the callstack of the runtime and not one of our methods being invoked we cannot really point to a bug in our code. I might be wrong, but I'm guessing that the marshaling control is not "marshaling" to the ui thread. But another one...i don't really know which one because the other threads are being used by us and are blocked...maybe this is the issue. But none of the other threads are running a message loop. This is very annoying. We had some issues in the past with marshaling controls to the right ui thread. That is because the first form that is constructed is a splash form. Which is not the main form. We used to use the main form to marshal call to the ui thread. But from time to time some calls would go to a non ui thread and some grids would broke with a big red X on them. I fixed this by creating a specific class: public class WindowsFormsSynchronizer { private static readonly WindowsFormsSynchronizationContext = new WindowsFormsSynchronizationContext(); //Methods are following that would build the same interface of the synchronization context. } This class gets build as one of the first objects in the first form being constructed. We've noticed some other strange thing. Looking at the heap there are 7 WindowsFormsSynchronizationContext objects. 6 of these have the same instance of controlToSend, and the other one has some different instance of controlToSend. This last one is the one that should marshal the calls to the UI. I don't have any other idea...maybe some of you guys had this same issue?

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• Asynchronous subprocess on Windows

  - by Stigma

  First of all, the overall problem I am solving is a bit more complicated than I am showing here, so please do not tell me 'use threads with blocking' as it would not solve my actual situation without a fair, FAIR bit of rewriting and refactoring. I have several applications which are not mine to modify, which take data from stdin and poop it out on stdout after doing their magic. My task is to chain several of these programs. Problem is, sometimes they choke, and as such I need to track their progress which is outputted on STDERR. pA = subprocess.Popen(CommandA, shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE) # ... some more processes make up the chain, but that is irrelevant to the problem pB = subprocess.Popen(CommandB, shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=pA.stdout ) Now, reading directly through pA.stdout.readline() and pB.stdout.readline(), or the plain read() functions, is a blocking matter. Since different applications output in different paces and different formats, blocking is not an option. (And as I wrote above, threading is not an option unless at a last, last resort.) pA.communicate() is deadlock safe, but since I need the information live, that is not an option either. Thus google brought me to this asynchronous subprocess snippet on ActiveState. All good at first, until I implement it. Comparing the cmd.exe output of pA.exe | pB.exe, ignoring the fact both output to the same window making for a mess, I see very instantaneous updates. However, I implement the same thing using the above snippet and the read_some() function declared there, and it takes over 10 seconds to notify updates of a single pipe. But when it does, it has updates leading all the way upto 40% progress, for example. Thus I do some more research, and see numerous subjects concerning PeekNamedPipe, anonymous handles, and returning 0 bytes available even though there is information available in the pipe. As the subject has proven quite a bit beyond my expertise to fix or code around, I come to Stack Overflow to look for guidance. :) My platform is W7 64-bit with Python 2.6, the applications are 32-bit in case it matters, and compatibility with Unix is not a concern. I can even deal with a full ctypes or pywin32 solution that subverts subprocess entirely if it is the only solution, as long as I can read from every stderr pipe asynchronously with immediate performance and no deadlocks. :)

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• imagick showing script url instead of image

  - by Raz

  Hi, currently i'm trying to use imagick to generate some images without saving them on the server and then outputting to the browser, my method of choice was image magic with the imagick extension for php. I read the documentation, and i'm sure the package is installed on my machine (windows xp, with xampp). the class is installed imagick module enabled imagick module version 2.0.0-alpha imagick classes Imagick, ImagickDraw, ImagickPixel, ImagickPixelIterator ImageMagick version ImageMagick 6.3.3 04/21/07 Q16 http://www.imagemagick.org ImageMagick release date 04/21/07 ImageMagick Number of supported formats: 164 ImageMagick Supported formats A, ART, AVI, AVS, B, BIE, BMP, BMP2, BMP3, C, CACHE, CAPTION, CIN, CIP, CLIP, CLIPBOARD, CMYK, CMYKA, CUR, CUT, DCM, DCX, DFONT, DPS, DPX, EMF, EPDF, EPI, EPS, EPS2, EPS3, EPSF, EPSI, EPT, EPT2, EPT3, FAX, FITS, FRACTAL, FTS, G, G3, GIF, GIF87, GRADIENT, GRAY, HISTOGRAM, HTM, HTML, ICB, ICO, ICON, INFO, JBG, JBIG, JNG, JP2, JPC, JPEG, JPG, JPX, K, LABEL, M, M2V, MAP, MAT, MATTE, MIFF, MNG, MONO, MPC, MPEG, MPG, MSL, MSVG, MTV, MVG, NULL, O, OTB, OTF, PAL, PALM, PAM, PATTERN, PBM, PCD, PCDS, PCL, PCT, PCX, PDB, PDF, PFA, PFB, PGM, PGX, PICON, PICT, PIX, PJPEG, PLASMA, PNG, PNG24, PNG32, PNG8, PNM, PPM, PREVIEW, PS, PS2, PS3, PSD, PTIF, PWP, R, RAS, RGB, RGBA, RGBO, RLA, RLE, SCR, SCT, SFW, SGI, SHTML, STEGANO, SUN, SVG, SVGZ, TEXT, TGA, THUMBNAIL, TIFF, TILE, TIM, TTC, TTF, TXT, UIL, UYVY, VDA, VICAR, VID, VIFF, VST, WBMP, WMF, WMFWIN32, WMZ, WPG, X, XBM, XC, XCF, XPM, XV, XWD, Y, YCbCr, YCbCrA, YUV this is from the phpinfo so i know i have it installed, the thing is when i try to generate an image and save it, it works flawlessly, but when i try to output the image directly, i get the script url as an image $draw = new ImagickDraw(); $draw->setFont('AnkeCalligraph.TTF'); $draw->setFontSize(52); $draw->annotation(110, 110, "Hello World!"); $draw->annotation(50, 220, "Hello World!"); $canvas = new Imagick('./pictures/test_live.PNG'); $canvas->drawImage($draw); $canvas->setImageFormat('png'); header("Content-Type: image/png"); echo $canvas; this is the code used. if i use writeimage, then the file on the server is created with no problems. does anyone have any ideas what i'm doing wrong ?

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• Rail test case fixtures not loading

  - by Deano

  Rails appears to not be loading any fixtures for unit or functional tests. I have a simple 'products.yml' that parses and appears correct: ruby: title: Programming Ruby 1.9 description: Ruby is the fastest growing and most exciting dynamic language out there. If you need to get working programs delivered fast, you should add Ruby to your toolbox. price: 49.50 image_url: ruby.png My controller functional test begins with: require 'test_helper' class ProductsControllerTest < ActionController::TestCase fixtures :products setup do @product = products(:one) @update = { :title => 'Lorem Ipsum' , :description => 'Wibbles are fun!' , :image_url => 'lorem.jpg' , :price => 19.95 } end According to the book, Rails should "magically" load the fixtures (as my test_helper.rb has fixtures :all in it. I also added the explicit fixtures load (seen above). Yes Rails complains: user @ host ~/Dropbox/Rails/depot > rake test:functionals (in /Somewhere/Users/user/Dropbox/Rails/depot) /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -Ilib:test "/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake/rake_test_loader.rb" "test/functional/products_controller_test.rb" Loaded suite /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake/rake_test_loader Started EEEEEEE Finished in 0.062506 seconds. 1) Error: test_should_create_product(ProductsControllerTest): NoMethodError: undefined method `products' for ProductsControllerTest:Class /test/functional/products_controller_test.rb:7 2) Error: test_should_destroy_product(ProductsControllerTest): NoMethodError: undefined method `products' for ProductsControllerTest:Class /test/functional/products_controller_test.rb:7 ... I did come across the other Rails test fixture question http://stackoverflow.com/questions/1547634/rails-unit-testing-doesnt-load-fixtures, but that leads to a plugin issue (something to do with the order of loading fixtures). BTW, I am developing on Mac OS X 10.6 with Rail 2.3.5 and Ruby 1.8.7, no additional plugins (beyond the base install). Any pointers on how to debug, why the magic of Rails appears to be failing here? Is it a version problem? Can I trace code into the libraries and find the answer? There are so many "mixin" modules I can't find where the fixtures method really lives.

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• Keeping files or database records? Java and Python

  - by danpalmer

  My website will use a Neural Network to predict thing based on user data. The user can select the data to be used in training the network and then use their trained network to predict things. I am using a framework to create, train and query the networks. This uses Java. The framework has persistence for saving a network to an XML file. What is the best way to store these files? I can see several potential ideas, but I need help on choosing which is best: Save each network to a separate XML file with a name that is stored in the database. Load this each time. Save all the networks to the same XML file with each network having a different name that is stored in the database. Somehow pass what would normally be written to an XML file to the Django site for writing to the database. This would need to be returned to the Java code when a prediction needs to be made. I am able to do 1 or 2, but I think their performance will be quite limited and I am on shared hosting at the moment, so I don't know how pleased they would be with thousands of files. Also, after adding a few thousand records to one XML file, I was noticing a massive performance hit on saving to it. If I were able to implement version 3 somehow I think it would be best. No issues with separate processes accessing the database and I think performance would be better. Not to mention having no files lying around. However, the stuff in the neural network framework I am using (Encog) for saving to a file needs access to a Java file object, not a string that could be saved to a database. Unless there is some Java magic I can do here (I know very little Java), the only way I can see of doing this would be with a temporary files but I don't know if this is the correct way to do it. I would appreciate any ideas on the best way to implement any of the above 3 ideas or any alternatives. Thanks!

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• Silverlight ControlTemplate and F#

  - by akaphenom

  Has anybody had any success incorporating a Silverlight ControlTemplate into an F# Silverlight application. I am trying to add transitions to the Navgiation.Frame element and following along on with a C# example: http://www.davidpoll.com/2009/07/19/silverlight-3-navigation-adding-transitions-to-the-frame-control The downloaded source uses the MSBUILD:Compile option on the template XAML and the file is included as a "Page"... ILDASM doesn't show any object created for the XAML; In my project I incldued it as a "Resource" (same as I have done for my pages) and referenced it in app.xaml: <Application xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="Module1.MyApp"> <Application.Resources> <ResourceDictionary> <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="/FSSilverlightApp;component/TransitioningFrame.xaml"/> </ResourceDictionary.MergedDictionaries> </ResourceDictionary> </Application.Resources> </Application> the TransitioningFrame.xaml is as follows: <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation" xmlns:toolkit="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Layout.Toolkit"> <ControlTemplate x:Key="TransitioningFrame" TargetType="navigation:Frame"> <Border Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"> <toolkit:TransitioningContentControl Content="{TemplateBinding Content}" Cursor="{TemplateBinding Cursor}" Margin="{TemplateBinding Padding}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" Transition="DefaultTransition" /> </Border> </ControlTemplate> </ResourceDictionary> My page objects all load their respective xaml with the follwoing code: type Page1() as this = inherit UriUserControl("/FSSilverlightApp;component/Page1.xaml") do Application.LoadComponent(this, base.uri) and somewhere in app startup: let p1 = new Page1() I donot have a comparable piece for the ControlTemplate - though I was hoping the application object and App.xaml would pull it in magically (as an aside, the reliance on this magic has made setting up a 100% f# silverlight application rather tricky - as nearly all the published articles I find are based around wizards and short cuts - very little on the acual plumbing - ugh). Any advice or thougts on the subject are appreciated.

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• PerlIO in Windows PowerShell and CMD.exe

  - by Evan Carroll

  Apparently, a Perl script I have results in two different output files depending on if I run it under Windows PowerShell, or cmd.exe. The script can be found at the bottom of this question. The file handle is opened with IO::File, I believe that PerlIO is doing some screwy stuff. It seems as if under cmd.exe the encoding chosen is much more compact encoding (4.09 KB), as compared to PowerShell which generates a file nearly twice the size (8.19 KB). This script takes a shell script and generates a Windows batch file. It seems like the one generated under cmd.exe is just regular ASCII (1 byte character), while the other one appears to be UTF-16 (first two bytes FF FE) Can someone verify and explain why PerlIO works differently under Windows Powershell than cmd.exe? Also, how do I explicitly get an ASCII-magic PerlIO filehandle using IO::File? Currently, only the file generated with cmd.exe is executable. The UTF-16 .bat (I think that's the encoding) is not executable by either PowerShell or cmd.exe. BTW, we're using Perl 5.12.1 for MSWin32 #!/usr/bin/env perl use strict; use warnings; use File::Spec; use IO::File; use IO::Dir; use feature ':5.10'; my $bash_ftp_script = File::Spec->catfile( 'bin', 'dm-ftp-push' ); my $fh = IO::File->new( $bash_ftp_script, 'r' ) or die $!; my @lines = grep $_ !~ /^#.*/, <$fh>; my $file = join '', @lines; $file =~ s/ \\\n/ /gm; $file =~ tr/'\t/"/d; $file =~ s/ +/ /g; $file =~ s/\b"|"\b/"/g; my @singleLnFile = grep /ncftp|echo/, split $/, $file; s/\$PWD\///g for @singleLnFile; my $dh = IO::Dir->new( '.' ); my @files = grep /\.pl$/, $dh->read; say 'echo off'; say "perl $_" for @files; say for @singleLnFile; 1;

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• How can I inject Javascript (including Prototype.js) in other sites without cluttering the global na

  - by Daniel Magliola

  I'm currently on a project that is a big site that uses the Prototype library, and there is already a humongous amount of Javascript code. We're now working on a piece of code that will get "injected" into other people's sites (picture people adding a <script> tag in their sites) which will then run our code and add a bunch of DOM elements and functionality to their site. This will have new pieces of code, and will also reuse a lot of the code that we use on our main site. The problem I have is that it's of course not cool to just add a <script> that will include Prototype in people's pages. If we do that in a page that's already using ANY framework, we're guaranteed to screw everything up. jQuery gives us the option to "rename" the $ object, so it could handle this situation decently, except obviously for the fact that we're not using jQuery, so we'd have to migrate everything. Right now i'm contemplating a number of ugly choices, and I'm not sure what's best... Rewrite everything to use jQuery, with a renamed $ object everywhere. Creating a "new" Prototype library with only the subset we'd be using in "injected" code, and renaming $ to something else. Then again I'd have to adapt the parts of my code that would be shared somehow. Not using a library at all in injected code, to keep it as clean as possible, and rewriting the shared code to use no library at all. This would obviously degenerate into us creating our own frankenstein of a library, which is probably the worst case scenario ever. I'm wondering what you guys think I could do, and also whether there's some magic option that would solve all my problems... For example, do you think I could use something like Caja / Cajita to sandbox my own code and isolate it from the rest of the site, and have Prototype inside of there? Or am I completely missing the point with that? I also read once about a technique for bookmarklets, were you add your code like this: (function() { /* your code */ })(); And then your code is all inside your anonymous function and you haven't touched the global namespace at all. Do you think I could make one file containing: (function() { /* Full Code of the Prototype file here */ /* All my code that will run in the "other" site */ InitializeStuff_CreateDOMElements_AttachEventHandlers(); })(); Would that work? Would it accomplish the objective of not cluttering the global namespace, and not killing the functionality on a site that uses jQuery, for example? Or is Prototype too complex somehow to isolate it like that? (NOTE: I think I know that that would create closures everywhere and that's slower, but I don't care too much about performance, my code is not doing anything that complex)

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• Webdriver: Tests crash with internet explorer7 with error Modal dialog present

  - by user1207450

  Following tests is automated by using java and selenium-server-standalone-2.20.0.jar. The test crashes with the error: Page title is: cheese! - Google Search Starting browserTest 2922 [main] INFO org.apache.http.impl.client.DefaultHttpClient - I/O exception (org.apache.http.NoHttpResponseException) caught when processing request: The target server failed to respond 2922 [main] INFO org.apache.http.impl.client.DefaultHttpClient - Retrying request Exception in thread "main" org.openqa.selenium.UnhandledAlertException: Modal dialog present (WARNING: The server did not provide any stacktrace information) Command duration or timeout: 1.20 seconds Build info: version: '2.20.0', revision: '16008', time: '2012-02-27 19:03:04' System info: os.name: 'Windows XP', os.arch: 'x86', os.version: '5.1', java.version: '1.6.0_24' Driver info: driver.version: InternetExplorerDriver at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:170) at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:129) at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:438) at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:139) at org.openqa.selenium.ie.InternetExplorerDriver.setup(InternetExplorerDriver.java:91) at org.openqa.selenium.ie.InternetExplorerDriver.<init>(InternetExplorerDriver.java:48) at com.pwc.test.java.InternetExplorer7.browserTest(InternetExplorer7.java:34) at com.pwc.test.java.InternetExplorer7.main(InternetExplorer7.java:27) Test Class: package com.pwc.test.java; import org.openqa.selenium.By; import org.openqa.selenium.WebDriver; import org.openqa.selenium.WebDriverBackedSelenium; import org.openqa.selenium.WebElement; import org.openqa.selenium.htmlunit.HtmlUnitDriver; import org.openqa.selenium.ie.InternetExplorerDriver; import com.thoughtworks.selenium.Selenium; public class InternetExplorer7 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub WebDriver webDriver = new HtmlUnitDriver(); webDriver.get("http://www.google.com"); WebElement webElement = webDriver.findElement(By.name("q")); webElement.sendKeys("cheese!"); webElement.submit(); System.out.println("Page title is: "+webDriver.getTitle()); browserTest(); } public static void browserTest() { System.out.println("Starting browserTest"); String baseURL = "http://www.mail.yahoo.com"; WebDriver driver = new InternetExplorerDriver(); driver.get(baseURL); Selenium selenium = new WebDriverBackedSelenium(driver, baseURL); selenium.windowMaximize(); WebElement username = driver.findElement(By.id("username")); WebElement password = driver.findElement(By.id("passwd")); WebElement signInButton = driver.findElement(By.id(".save")); username.sendKeys("myusername"); password.sendKeys("magic"); signInButton.click(); driver.close(); } } I don't see any modal dialog when I launched the IE7/8 browser manually. What could be causing this?

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• How can I make Swig correctly wrap a char* buffer that is modified in C as a Java Something-or-other

  - by Ukko

  I am trying to wrap some legacy code for use in Java and I was quite happy to see that Swig was able to handle the header file and it generate a great wrapper that almost works. Now I am looking for the deep magic that will make it really work. In C I have a function that looks like this DLL_IMPORT int DustyVoodoo(char *buff, int len, char *curse); This integer returned by this function is an error code in case it fails. The arguments are buff is a character buffer len is the length of the data in the buffer curse the another character buffer that contains the result of calling DustyVoodoo So, you can see where this is going, the result is actually coming back via the third argument. Also len is confusing since it may be the length of both buffers, they are always allocated as being the same size in calling code but given what DustyVoodoo does I don't think that they need be the same. To be safe both buffers should be the same size in practice, say 512 chars. The C code generated for the binding is as follows: SWIGEXPORT jint JNICALL Java_pemapiJNI_DustyVoodoo(JNIEnv *jenv, jclass jcls, jstring jarg1, jint jarg2, jstring jarg3) { jint jresult = 0 ; char *arg1 = (char *) 0 ; int arg2 ; char *arg3 = (char *) 0 ; int result; (void)jenv; (void)jcls; arg1 = 0; if (jarg1) { arg1 = (char *)(*jenv)->GetStringUTFChars(jenv, jarg1, 0); if (!arg1) return 0; } arg2 = (int)jarg2; arg3 = 0; if (jarg3) { arg3 = (char *)(*jenv)->GetStringUTFChars(jenv, jarg3, 0); if (!arg3) return 0; } result = (int)PemnEncrypt(arg1,arg2,arg3); jresult = (jint)result; if (arg1) (*jenv)->ReleaseStringUTFChars(jenv, jarg1, (const char *)arg1); if (arg3) (*jenv)->ReleaseStringUTFChars(jenv, jarg3, (const char *)arg3); return jresult; } It is correct for what it does; however, it misses the fact that cursed is not just an input, it is altered by the function and should be returned as an output. It also does not know that the java Strings are really buffers and should be backed by a suitably sized array. I think that Swig can do the right thing here, I just can't figure out from the documentation how to tell Swig what it needs to know. Any typemap masers in the house?

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• Translate Java class with static attributes and Annotation to Scala equivalent

  - by ifischer

  I'm currently trying to "translate" the following Java class to an equivalent Scala class. It's part of a JavaEE6-application and i need it to use the JPA2 MetaModel. import javax.persistence.metamodel.SingularAttribute; import javax.persistence.metamodel.StaticMetamodel; @StaticMetamodel(Person.class) public class Person_ { public static volatile SingularAttribute<Person, String> name; } A dissassembling of the compiled class file reveals the following information for the compiled file: > javap Person_.class : public class model.Person_ extends java.lang.Object{ public static volatile javax.persistence.metamodel.SingularAttribute name; public model.Person_(); } So now i need an equivalent Scala file that has the same structure, as JPA depends on it, cause it resolves the attributes by reflection to make them accessible at runtime. So the main problem i think is that the attribute is static, but the Annotation has to be on an (Java)Object (i guess) My first naive attempt to create a Scala equivalent is the following: @StaticMetamodel(classOf[Person]) class Person_ object Person_ { @volatile var name:SingularAttribute[Person, String] = _; } But the resulting classfile is far away from the Java one, so it doesn't work. When trying to access the attributes at runtime, e.g. "Person_.firstname", it resolves to null, i think JPA can't do the right reflection magic on the compiled classfile (the Java variant resolves to an instance of org.hibernate.ejb.metamodel.SingularAttributeImpl at runtime). > javap Person_.class : public class model.Person_ extends java.lang.Object implements scala.ScalaObject{ public static final void name_$eq(javax.persistence.metamodel.SingularAttribute); public static final javax.persistence.metamodel.SingularAttribute name(); public model.Person_(); } > javap Person_$.class : public final class model.Person__$ extends java.lang.Object implements scala.ScalaObject public static final model.Person__$ MODULE$; public static {}; public javax.persistence.metamodel.SingularAttribute name(); public void name_$eq(javax.persistence.metamodel.SingularAttribute); } So now what i'd like to know is if it's possible at all to create a Scala equivalent of the Java class? It seems to me that it's absolutely not, but maybe there is a workaround or something (except just using Java, but i want my app to be in Scala where possible) Any ideas, anyone? Thanks in advance!

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• Delphi LoadLibrary Failing to find DLL other directory - any good options?

  - by Chris Thornton

  Two Delphi programs need to load foo.dll, which contains some code that injects a client-auth certificate into a SOAP request. foo.dll resides in c:\fooapp\foo.dll and is normally loaded by c:\fooapp\foo.exe. That works fine. The other program needs the same functionality, but it resides in c:\program files\unwantedstepchild\sadapp.exe. Both aps load the DLL with this code: FOOLib := LoadLibrary('foo.dll'); ... If FOOLib <> 0 then begin FOOProc := GetProcAddress(FOOLib , 'xInjectCert'); FOOProc(myHttpRequest, Data, CertName); end; It works great for foo.exe, as the dll is right there. sadapp.exe fails to load the library, so FOOLib is 0, and the rest never gets called. The sadapp.exe program therefore silently fails to inject the cert, and when we test against production, it the cert is missing, do the connection fails. Obviously, we should have fully-qualified the path to the DLL. Without going into a lot of details, there were aspects of the testing that masked this problem until recently, and now it's basically too late to fix in code, as that would require a full regression test, and there isn't time for that. Since we've painted ourselves into a corner, I need to know if there are any options that I've overlooked. While we can't change the code (for this release), we CAN tweak the installer. I've found that placing c:\fooapp into the path works. As does adding a second copy of foo.dll directly into c:\program files\unwantedstepchild. c:\fooapp\foo.exe will always be running while sadapp.exe is running, so I was hoping that Windows would find it that way, but apparently not. Is there a way to tell Windows that I really want that same DLL? Maybe a manifest or something? This is the sort of "magic bullet" that I'm looking for. I know I can: Modify the windows path, probably in the installer. That's ugly. Add a second copy of the DLL, directly into the unwantedstepchild folder. Also ugly Delay the project while we code and test a proper fix. Unacceptable. Other? Thanks for any guidance, especially with "Other". I understand that this issue is not necessarily specific to Delphi. Thanks!

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• Giving event control back to xaml/callee to access check/uncheck

  - by dovholuk

  Hi All, I've scoured the Internet but my search-foo must not work if it's out there cause I just can't find the proper search terms to get me the answer I am looking for. So I turn to the experts here as a last resort to point me in the right direction. What I'm trying to do is create a composite control of a text box and a list box but I want to allow the control consumer to decide what to do when say the checkbox is checked/unchecked and I just can't figure it out... Maybe i'm going about it all wrong. What I've done thus far is to: create a custom control that extends ListBox expose a custom DP named "Text" (for the Text box but it's not the important part) craft the generic.xaml so that the list items have a default ItemTemplate/DataTemplate inside the DataTemplate I'm trying to set the "Checked" or "Unchecked" events expose 'wrapper' events as DPs in the custom control that would get 'set' via the template when instatiated As soon as I try something like the following (inside generic.xaml): <DataTemplate> <...> <CheckBox Checked="{TemplateBinding MyCheckedDP}"/> <...> </DataTemplate> I get runtime exceptions, the designer - vs2010 - pukes out a LONG list of errors that are all very similar and nothing I do can make it work. I went so far as to try using the VisualTreeHelper but no magic combination I could find would work nor would it allow me to traverse the tree because when the OnApplyTemplate method fires the listbox items don't exist yet and aren't in the tree. So hopefully this all makes sense but if not please let me know and I'll edit the post for clarifications. Thanks to all for any pointers or thoughts... Like I said maybe I'm heading about it in the wrong way from the start... EDIT (Request for xaml) generic.xaml datatemplate: <DataTemplate > <StackPanel Orientation="Horizontal" > <local:FilterCheckbox x:Name="chk"> <TextBlock Text="{Binding Path=Display}" /> </local:FilterCheckbox> </StackPanel> </DataTemplate> usercontrol.xaml (invocation of custom control) <local:MyControl FancyName="This is the fancy name" ItemChecked="DoThisWhenACheckboxIsChecked" <-- this is where the consumer "ties" to the checkbox events ItemsSource="{Binding Source={StaticResource someDataSource}}" />

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• bmp image header doubts

  - by vikramtheone

  Hi Guys, I'm doing a project where I have to make use of the pixel information of a bmp image. So, I'm gathering the image information by reading the header information of the input .bmp image. I'm quite successful with everything but one thing bothers me, can any one here clarify it? The header information of my .bmp image is as follows (My test image is very tiny and gray scale)- BMP File header File size 1210 Offset information 1078 BMP Information header Image Header Size 40 Image Size 132 Image width 9 Image height 11 Image bits_p_p 8 So, from the .bmp header I see that the image size is 132 (bytes) but when I multiply the width and height it is only 99, how is such a thing possible? I'm confident with 132 bytes because when I subtract the Offset value with the File Size value, I get 132(1210 - 1078 = 132) and also when I manually count the number of bytes (In a HEX editor) from the point 1078 or 436h (End of the offset field), there are exactly 132 bytes of pixel information. So, why is there a disparity between the size filed and the (width x height)? My future implementations are dependent on the image width and height information and not on Image size information. So, I have to understand thoroughly whats going on here. My understanding of the header should be clearly wrong... I guess!!! Help!!! Regards Vikram My bmp structures are a as follows - typedef struct bmpfile_magic { short magic; }BMP_MAGIC_NUMBER; typedef struct bmpfile_header { uint32_t filesz; uint16_t creator1; uint16_t creator2; uint32_t bmp_offset; }BMP_FILE_HEADER; typedef struct { uint32_t header_sz; uint32_t width; uint32_t height; uint16_t nplanes; uint16_t bitspp; uint32_t compress_type; uint32_t bmp_bytesz; uint32_t hres; uint32_t vres; uint32_t ncolors; uint32_t nimpcolors; } BMP_INFO_HEADER;

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• Hotfixing Code running inside Web Container with Groovy

  - by raoulsson

  I have a webapp running that has a bug. I know how to fix it in the sources. However I cannot redeploy the app as I would have to take it offline to do so. (At least not right now). I now want to fix the code "at runtime". Surgery on the living object, so to speak. The app is implemented in Java and is build on top of Seam. I have added a Groovy Console to the app previous to the last release. (A way to run arbitrary code at runtime) The normal way of adding behaviour to a class with Groovy would be similar to this: String.metaClass.foo= { x -> x * x } println "anything".foo(3) This code added the method foo to java.lang.String and prints 9. I can do the same thing with classes running inside my webapp container. New instances will thereafter show the same behaviour: com.my.package.SomeService.metaClass.foo= { x -> x * x } def someService = new com.my.package.SomeService() println someService.foo(3) Works as excpected. All good so far. My problem is now that the container, the web framework, Seam in this case, has already instantiated and cached the classes that I would like to manipulate (that is change their behaviour to reflect my bug fix). Ideally this code would work: com.my.package.SomeService.metaClass.foo= { x -> x * x } def x = org.jboss.seam.Component.getInstance(com.my.package.SomeService) println x.foo(3) However the instantiation of SomeService has already happened and there is no effect. Thus I need a way to make my changes "sticky". Has the groovy magic gone after my script has been run? Well, after logging out and in again, I can run this piece of code and get the expected result: def someService = new com.my.package.SomeService() println someService.foo(3) So the foo method is still around and it looks like my change has been permanent... So I guess the question that remains is how to force Seam to re-instantiate all its components and/or how to permanently make the change on all living instances...?

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• What am I not getting about this abstract class implementation?

  - by Schnapple

  PREFACE: I'm relatively inexperienced in C++ so this very well could be a Day 1 n00b question. I'm working on something whose long term goal is to be portable across multiple operating systems. I have the following files: Utilities.h #include <string> class Utilities { public: Utilities() { }; virtual ~Utilities() { }; virtual std::string ParseString(std::string const& RawString) = 0; }; UtilitiesWin.h (for the Windows class/implementation) #include <string> #include "Utilities.h" class UtilitiesWin : public Utilities { public: UtilitiesWin() { }; virtual ~UtilitiesWin() { }; virtual std::string ParseString(std::string const& RawString); }; UtilitiesWin.cpp #include <string> #include "UtilitiesWin.h" std::string UtilitiesWin::ParseString(std::string const& RawString) { // Magic happens here! // I'll put in a line of code to make it seem valid return ""; } So then elsewhere in my code I have this #include <string> #include "Utilities.h" void SomeProgram::SomeMethod() { Utilities *u = new Utilities(); StringData = u->ParseString(StringData); // StringData defined elsewhere } The compiler (Visual Studio 2008) is dying on the instance declaration c:\somepath\somecode.cpp(3) : error C2259: 'Utilities' : cannot instantiate abstract class due to following members: 'std::string Utilities::ParseString(const std::string &)' : is abstract c:\somepath\utilities.h(9) : see declaration of 'Utilities::ParseString' So in this case what I'm wanting to do is use the abstract class (Utilities) like an interface and have it know to go to the implemented version (UtilitiesWin). Obviously I'm doing something wrong but I'm not sure what. It occurs to me as I'm writing this that there's probably a crucial connection between the UtilitiesWin implementation of the Utilities abstract class that I've missed, but I'm not sure where. I mean, the following works #include <string> #include "UtilitiesWin.h" void SomeProgram::SomeMethod() { Utilities *u = new UtilitiesWin(); StringData = u->ParseString(StringData); // StringData defined elsewhere } but it means I'd have to conditionally go through the different versions later (i.e., UtilitiesMac(), UtilitiesLinux(), etc.) What have I missed here?

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• mounting ext4 fs with block size of 65536

  - by seaquest

  I am doing some benchmarking on EXT4 performance on Compact Flash media. I have created an ext4 fs with block size of 65536. however I can not mount it on ubuntu-10.10-netbook-i386. (it is already mounting ext4 fs with 4096 bytes of block sizes) According to my readings on ext4 it should allow such big block sized fs. I want to hear your comments. root@ubuntu:~# mkfs.ext4 -b 65536 /dev/sda3 Warning: blocksize 65536 not usable on most systems. mke2fs 1.41.12 (17-May-2010) mkfs.ext4: 65536-byte blocks too big for system (max 4096) Proceed anyway? (y,n) y Warning: 65536-byte blocks too big for system (max 4096), forced to continue Filesystem label= OS type: Linux Block size=65536 (log=6) Fragment size=65536 (log=6) Stride=0 blocks, Stripe width=0 blocks 19968 inodes, 19830 blocks 991 blocks (5.00%) reserved for the super user First data block=0 1 block group 65528 blocks per group, 65528 fragments per group 19968 inodes per group Writing inode tables: done Creating journal (1024 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 37 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. root@ubuntu:~# tune2fs -l /dev/sda3 tune2fs 1.41.12 (17-May-2010) Filesystem volume name: <none> Last mounted on: <not available> Filesystem UUID: 4cf3f507-e7b4-463c-be11-5b408097099b Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Filesystem features: has_journal ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize Filesystem flags: signed_directory_hash Default mount options: (none) Filesystem state: clean Errors behavior: Continue Filesystem OS type: Linux Inode count: 19968 Block count: 19830 Reserved block count: 991 Free blocks: 18720 Free inodes: 19957 First block: 0 Block size: 65536 Fragment size: 65536 Blocks per group: 65528 Fragments per group: 65528 Inodes per group: 19968 Inode blocks per group: 78 Flex block group size: 16 Filesystem created: Sat Feb 5 14:39:55 2011 Last mount time: n/a Last write time: Sat Feb 5 14:40:02 2011 Mount count: 0 Maximum mount count: 37 Last checked: Sat Feb 5 14:39:55 2011 Check interval: 15552000 (6 months) Next check after: Thu Aug 4 14:39:55 2011 Lifetime writes: 70 MB Reserved blocks uid: 0 (user root) Reserved blocks gid: 0 (group root) First inode: 11 Inode size: 256 Required extra isize: 28 Desired extra isize: 28 Journal inode: 8 Default directory hash: half_md4 Directory Hash Seed: afb5b570-9d47-4786-bad2-4aacb3b73516 Journal backup: inode blocks root@ubuntu:~# mount -t ext4 /dev/sda3 /mnt/ mount: wrong fs type, bad option, bad superblock on /dev/sda3, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so

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• Normalizing Item Names & Synonyms

  - by RabidFire

  Consider an e-commerce application with multiple stores. Each store owner can edit the item catalog of his store. My current database schema is as follows: item_names: id | name | description | picture | common(BOOL) items: id | item_name_id | picture | price | description | picture item_synonyms: id | item_name_id | name | error(BOOL) Notes: error indicates a wrong spelling (eg. "Ericson"). description and picture of the item_names table are "globals" that can optionally be overridden by "local" description and picture fields of the items table (in case the store owner wants to supply a different picture for an item). common helps separate unique item names ("Jimmy Joe's Cheese Pizza" from "Cheese Pizza") I think the bright side of this schema is: Optimized searching & Handling Synonyms: I can query the item_names & item_synonyms tables using name LIKE %QUERY% and obtain the list of item_name_ids that need to be joined with the items table. (Examples of synonyms: "Sony Ericsson", "Sony Ericson", "X10", "X 10") Autocompletion: Again, a simple query to the item_names table. I can avoid the usage of DISTINCT and it minimizes number of variations ("Sony Ericsson Xperia™ X10", "Sony Ericsson - Xperia X10", "Xperia X10, Sony Ericsson") The down side would be: Overhead: When inserting an item, I query item_names to see if this name already exists. If not, I create a new entry. When deleting an item, I count the number of entries with the same name. If this is the only item with that name, I delete the entry from the item_names table (just to keep things clean; accounts for possible erroneous submissions). And updating is the combination of both. Weird Item Names: Store owners sometimes use sentences like "Harry Potter 1, 2 Books + CDs + Magic Hat". There's something off about having so much overhead to accommodate cases like this. This would perhaps be the prime reason I'm tempted to go for a schema like this: items: id | name | picture | price | description | picture (... with item_names and item_synonyms as utility tables that I could query) Is there a better schema you would suggested? Should item names be normalized for autocomplete? Is this probably what Facebook does for "School", "City" entries? Is the first schema or the second better/optimal for search? Thanks in advance! References: (1) Is normalizing a person's name going too far?, (2) Avoiding DISTINCT

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• Chrome extension: sendMessage doesn't work

  - by user3334776

  I've already read the documentation from Google on 'message passing' a few times and have probably looked at over 10 other questions with the same problem and already tried quiet a few variations of most of their "solutions" and of what I have below... This is black magic, right? Either way, here it goes. Manifest File: { "manifest_version" : 2, "name" : "Message Test", "version" : "1.0", "browser_action": { "default_popup": "popup.html" }, "background": { "scripts": ["background.js"] }, "content_scripts": [ { "matches" : ["<all_urls>"], "js": ["message-test.js"] } ] } I'm aware extensions aren't suppose to use inline JS, but I'm leaving this in so the original question can be left as it was since I still can't get the message to send from the background page, When I switch from the popup to the background, I removed the appropriate lines from the manifest.json popup.html file: <html> <head> <script> chrome.tabs.query({active: true, currentWindow: true}, function(tabs) { chrome.tabs.sendMessage(tabs[0].id, {greeting: "hello", theMessage: "Why isn\'t this working?"}, function(response) { console.log(response.farewell); }); }); </script> </head> <body> </body> </html> OR background.js file: chrome.tabs.query({active: true, currentWindow: true}, function(tabs) { chrome.tabs.sendMessage(tabs[0].id, {greeting: "hello", theMessage: "Why isn\'t this working?"}, function(response) { console.log(response.farewell); }); }); message-test.js file: var Mymessage; chrome.runtime.onMessage.addListener(function(message, sender, sendResponse) { if (message.greeting == "hello"){ Mymessage = message.theMessage; alert(Mymessage); } else{ sendResponse({}); } }); No alert(Mymessage) goes off. I'm also trying to execute this after pressing a button from a popup and having a window at a specified url, but that's a later issue. The other files can be found here except with the background.js content wrapped in an addEventListener("click"....: http://pastebin.com/KhqxLx5y AND http://pastebin.com/JaGcp6tj

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• CRM2011 - "The given key was not present in the dictionary"

  - by DJZorrow

  I am what you call a "n00b" in CRM plugin development. I am trying to write a plugin for Microsoft's Dynamics CRM 2011 that will create a new activity entity when you create a new contact. I want this activity entity to be associated with the contact entity. This is my current code: using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.Xrm.Sdk; namespace ITPH_CRM_Deactivate_Account_SSP_Disable { public class SSPDisable_Plugin: IPlugin { public void Execute(IServiceProvider serviceProvider) { // Obtain the execution context from the service provider. IPluginExecutionContext context = (IPluginExecutionContext) serviceProvider.GetService(typeof(IPluginExecutionContext)); IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory)); IOrganizationService service = serviceFactory.CreateOrganizationService(context.UserId); if (context.InputParameters.Contains("Target") && context.InputParameters["target"] is Entity) { Entity entity = context.InputParameters["Target"] as Entity; if (entity.LogicalName != "account") { return; } Entity followup = new Entity(); followup.LogicalName = "activitypointer"; followup.Attributes = new AttributeCollection(); followup.Attributes.Add("subject", "Created via Plugin."); followup.Attributes.Add("description", "This is generated by the magic of C# ..."); followup.Attributes.Add("scheduledstart", DateTime.Now.AddDays(3)); followup.Attributes.Add("actualend", DateTime.Now.AddDays(5)); if (context.OutputParameters.Contains("id")) { Guid regardingobjectid = new Guid(context.OutputParameters["id"].ToString()); string regardingobjectidType = "account"; followup["regardingobjectid"] = new EntityReference(regardingobjectidType, regardingobjectid); } service.Create(followup); } } } But when i try to run this code: I get an error when i try to create a new contact in the CRM environment. The error is: "The given key was not present in the dictionary" (Link *1). The error pops up right as i try to save the new contact. Link *1: http://puu.sh/4SXrW.png (Translated bold text: "Error on business process") Thanks for any help or suggestions :)

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• C#: My callback function gets called twice for every Sent Request

  - by Madi D.

  I've Got a program that uploads/downloads files into an online server,Has a callback to report progress and log it into a textfile, The program is built with the following structure: public void Upload(string source, string destination) { //Object containing Source and destination to pass to the threaded function KeyValuePair<string, string> file = new KeyValuePair<string, string>(source, destination); //Threading to make sure no blocking happens after calling upload Function Thread t = new Thread(new ParameterizedThreadStart(amazonHandler.TUpload)); t.Start(file); } private void TUpload(object fileInfo) { KeyValuePair<string, string> file = (KeyValuePair<string, string>)fileInfo; /* Some Magic goes here,Checking The file and Authorizing Upload */ var ftiObject = new FtiObject () { FileNameOnHDD = file.Key, DestinationPath = file.Value, //Has more data used for calculations. }; //Threading to make sure progress gets callback gets called. Thread t = new Thread(new ParameterizedThreadStart(amazonHandler.UploadOP)); t.Start(ftiObject); //Signal used to stop progress untill uploadCompleted is called. uploadChunkDoneSignal.WaitOne(); /* Some Extra Code */ } private void UploadOP(object ftiSentObject) { FtiObject ftiObject = (FtiObject)ftiSentObject; /* Some useless code to create the uri and prepare the ftiObject. */ // webClient.UploadFileAsync will open a thread that // will upload the file and report // progress/complete using registered callback functions. webClient.UploadFileAsync(uri, "PUT", ftiObject.FileNameOnHDD, ftiObject); } I got a callback that is registered to the Webclient's UploadProgressChanged event , however it is getting called twice per sent request. void UploadProgressCallback(object sender, UploadProgressChangedEventArgs e) { FtiObject ftiObject = (FtiObject )e.UserState; Logger.log(ftiObject.FileNameOnHDD, (double)e.BytesSent ,e.TotalBytesToSend); } Log Output: Filename: C:\Text1.txt Uploaded:1024 TotalFileSize: 665241 Filename: C:\Text1.txt Uploaded:1024 TotalFileSize: 665241 Filename: C:\Text1.txt Uploaded:2048 TotalFileSize: 665241 Filename: C:\Text1.txt Uploaded:2048 TotalFileSize: 665241 Filename: C:\Text1.txt Uploaded:3072 TotalFileSize: 665241 Filename: C:\Text1.txt Uploaded:3072 TotalFileSize: 665241 Etc... I am watching the Network Traffic using a watcher, and only 1 request is being sent. Some how i cant Figure out why the callback is being called twice, my doubt was that the callback is getting fired by each thread opened(the main Upload , and TUpload), however i dont know how to test if thats the cause. Note: The reason behind the many /**/ Comments is to indicate that the functions do more than just opening threads, and threading is being used to make sure no blocking occurs (there a couple of "Signal.WaitOne()" around the code for synchronization)

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• UDP Tracker not responding

  - by kelton52

  Alright, so I'm trying to connect to UDP trackers using c#, but I never get a response. I also don't get any errors. Here's my code. namespace UDPTester { class MainClass { public static bool messageReceived = false; public static Random Random = new Random(); public static void LOG(string format, params object[] args) { Console.WriteLine (format,args); } public static void Main (string[] args) { LOG ("Creating Packet..."); byte[] packet; using(var stream = new MemoryStream()) { var bc = new MiscUtil.Conversion.BigEndianBitConverter(); using(var br = new MiscUtil.IO.EndianBinaryWriter(bc,stream)) { LOG ("Magic Num: {0}",(Int64)0x41727101980); br.Write (0x41727101980); br.Write((Int32)0); br.Write ((Int32)Random.Next()); packet = stream.ToArray(); LOG ("Packet Size: {0}",packet.Length); } } LOG ("Connecting to tracker..."); var client = new System.Net.Sockets.UdpClient("tracker.openbittorrent.com",80); UdpState s = new UdpState(); s.e = client.Client.RemoteEndPoint; s.u = client; StartReceiving(s); LOG ("Sending Packet..."); client.Send(packet,packet.Length); while(!messageReceived) { Thread.Sleep(1000); } LOG ("Ended"); } public static void StartReceiving(UdpState state) { state.u.BeginReceive(ReceiveCallback,state); } public static void ReceiveCallback(IAsyncResult ar) { UdpClient u = (UdpClient)((UdpState)(ar.AsyncState)).u; IPEndPoint e = (IPEndPoint)((UdpState)(ar.AsyncState)).e; Byte[] receiveBytes = u.EndReceive(ar, ref e); string receiveString = Encoding.ASCII.GetString(receiveBytes); LOG("Received: {0}", receiveString); messageReceived = true; StartReceiving((UdpState)ar.AsyncState); } } public class UdpState { public UdpClient u; public EndPoint e; } } I was using a normal BinaryWriter, but that didn't work, and I read somewhere that it wants it's data in BigEndian. This doesn't work for any of the UDP trackers I've found, any ideas why I'm not getting a response? Did they maybe change the protocol and not tell anyone? HTTP trackers all work fine. Trackers I've tried udp://tracker.publicbt.com:80 udp://tracker.ccc.de:80 udp://tracker.istole.it:80 Also, I'm not interested in using MonoTorrent(and when I was using it, the UDP didn't work anyways). Protocol Sources http://xbtt.sourceforge.net/udp_tracker_protocol.html http://www.rasterbar.com/products/libtorrent/udp_tracker_protocol.html

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• Which network protocol to use for lightweight notification of remote apps?

  - by Chris Thornton

  I have this situation.... Client-initiated SOAP 1.1 communication between one server and let's say, tens of thousands of clients. Clients are external, coming in through our firewall, authenticated by certificate, https, etc.. They can be anywhere, and usually have their own firewalls, NAT routers, etc... They're truely external, not just remote corporate offices. They could be in a corporate/campus network, DSL/Cable, even Dialup. Client uses Delphi (2005 + SOAP fixes from 2007), and the server is C#, but from an architecture/design standpoint, that shouldn't matter. Currently, clients push new data to the server and pull new data from the server on 15-minute polling loop. The server currently does not push data - the client hits the "messagecount" method, to see if there is new data to pull. If 0, it sleeps for another 15 min and checks again. We're trying to get that down to 7 seconds. If this were an internal app, with one or just a few dozen clients, we'd write a cilent "listener" soap service, and would push data to it. But since they're external, sit behind their own firewalls, and sometimes private networks behind NAT routers, this is not practical. So we're left with polling on a much quicker loop. 10K clients, each checking their messagecount every 10 seconds, is going to be 1000/sec messages that will mostly just waste bandwidth, server, firewall, and authenticator resources. So I'm trying to design something better than what would amount to a self-inflicted DoS attack. I don't think it's practical to have the server send soap messages to the client (push) as this would require too much configuration at the client end. But I think there are alternatives that I don't know about. Such as: 1) Is there a way for the client to make a request for GetMessageCount() via Soap 1.1, and get the response, and then perhaps, "stay on the line" for perhaps 5-10 minutes to get additional responses in case new data arrives? i.e the server says "0", then a minute later in response to some SQL trigger (the server is C# on Sql Server, btw), knows that this client is still "on the line" and sends the updated message count of "5"? 2) Is there some other protocol that we could use to "ping" the client, using information gathered from their last GetMessageCount() request? 3) I don't even know. I guess I'm looking for some magic protocol where the client can send a GetMessageCount() request, which would include info for "oh by the way, in case the answer changes in the next hour, ping me at this address...". Also, I'm assuming that any of these "keep the line open" schemes would seriously impact the server sizing, as it would need to keep many thousands of connections open, simultaneously. That would likely impact the firewalls too, I think. Is there anything out there like that? Or am I pretty much stuck with polling? TIA, Chris

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• Asp.net Mvc - Kigg: Maintain User object in HttpContext.Items between requests.

  - by Pickels

  Hallo, first I want to say that I hope this doesn't look like I am lazy but I have some trouble understanding a piece of code from the following project. http://kigg.codeplex.com/ I was going through the source code and I noticed something that would be usefull for my own little project I am making. In their BaseController they have the following code: private static readonly Type CurrentUserKey = typeof(IUser); public IUser CurrentUser { get { if (!string.IsNullOrEmpty(CurrentUserName)) { IUser user = HttpContext.Items[CurrentUserKey] as IUser; if (user == null) { user = AccountRepository.FindByClaim(CurrentUserName); if (user != null) { HttpContext.Items[CurrentUserKey] = user; } } return user; } return null; } } This isn't an exact copy of the code I adjusted it a little to my needs. This part of the code I still understand. They store their IUser in HttpContext.Items. I guess they do it so that they don't have to call the database eachtime they need the User object. The part that I don't understand is how they maintain this object in between requests. If I understand correctly the HttpContext.Items is a per request cache storage. So after some more digging I found the following code. internal static IDictionary<UnityPerWebRequestLifetimeManager, object> GetInstances(HttpContextBase httpContext) { IDictionary<UnityPerWebRequestLifetimeManager, object> instances; if (httpContext.Items.Contains(Key)) { instances = (IDictionary<UnityPerWebRequestLifetimeManager, object>) httpContext.Items[Key]; } else { lock (httpContext.Items) { if (httpContext.Items.Contains(Key)) { instances = (IDictionary<UnityPerWebRequestLifetimeManager, object>) httpContext.Items[Key]; } else { instances = new Dictionary<UnityPerWebRequestLifetimeManager, object>(); httpContext.Items.Add(Key, instances); } } } return instances; } This is the part where some magic happens that I don't understand. I think they use Unity to do some dependency injection on each request? In my project I am using Ninject and I am wondering how I can get the same result. I guess InRequestScope in Ninject is the same as UnityPerWebRequestLifetimeManager? I am also wondering which class/method they are binding to which interface? Since the HttpContext.Items get destroyed each request how do they prevent losing their user object? Anyway it's kinda a long question so I am gradefull for any push in the right direction. Kind regards, Pickels

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• Java NoSuchElementException using scanner.nextInt()

  - by othnin

  I am trying to read in a pgm file (512x512 array) and when I read in a larger file I get the error: java.util.NoSuchElementException on reading element (3,97). I have created a much smaller file to read (23x23) and it reads fine. Is there a size limit? I have checked the file and confirmed that there is an int for the value: This appears to be the line it crashes at: fileArray[row][col] = scan.nextInt(); Here is the file: import java.util.Scanner; import java.io.*; public class FileReader { public static void main(String[] args) throws IOException { String fileName = "lena.pgma"; int width, height, maxValue; FileInputStream fileInputStream = null; fileInputStream = new FileInputStream(fileName); Scanner scan = new Scanner(fileInputStream); // Discard the magic number scan.nextLine(); // Discard the comment line scan.nextLine(); // Read pic width, height and max value width = scan.nextInt(); System.out.println("Width: " + width); height = scan.nextInt(); System.out.println("Heigth: " + height); maxValue = scan.nextInt(); fileInputStream.close(); // Now parse the file as binary data FileInputStream fin = new FileInputStream(fileName); DataInputStream dis = new DataInputStream(fin); // look for 4 lines (i.e.: the header) and discard them int numnewlines = 4; while (numnewlines > 0) { char c; do { c = (char)(dis.readUnsignedByte()); } while (c != '\n'); numnewlines--; } // read the image data int[][] fileArray = new int[height][width]; for (int row = 0; row < height; row++) { for (int col = 0; col < width; col++) { fileArray[row][col] = scan.nextInt(); System.out.print("(" + row + " ," + col +"): " + fileArray[row][col]+ " "); } System.out.println(); } dis.close(); } } any advise would be appreciated.

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