Search Results

Search found 6053 results on 243 pages for 'solutionsfactory usage'.

Page 225/243 | < Previous Page | 221 222 223 224 225 226 227 228 229 230 231 232  | Next Page >

  • MSVC Compiler options with mojo-native in Maven

    - by graham.reeds
    I'm trying to set up a test environment with Maven to build VC++ and I am way behind on this. I have 3 source files that I builds a dll (once I get this fixed it should be a simple matter to add the unit-tests): hook.cpp hook.h hook.def This is compiled, on the command line, with the following: C:\Develop\hook\src\main\msvc>cl -o hook.dll Hook.cpp /D HOOK_DLLEXPORT /link /DLL /DEF:"Hook.def" Which produces the expected obj, dll, lib and exp files. So now to get this working in Maven2 with the Mojo-native plugin. With no options Maven w/Mojo gives me this (truncated) output: [INFO] [native:initialize {execution: default-initialize}] [INFO] [native:unzipinc {execution: default-unzipinc}] [INFO] [native:javah {execution: default-javah}] [INFO] [native:compile {execution: default-compile}] [INFO] cmd.exe /X /C "cl -IC:\Develop\hook\src\main\msvc /FoC:\Develop\hook\targ et\objs\Hook.obj -c C:\Develop\hook\src\main\msvc\Hook.cpp" Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 15.00.30729.01 for 80x86 Copyright (C) Microsoft Corporation. All rights reserved. Hook.cpp [INFO] [native:link {execution: default-link}] [INFO] cmd.exe /X /C "link.exe /out:C:\Develop\hook\target\hook.dll target\objs\ Hook.obj" Microsoft (R) Incremental Linker Version 9.00.30729.01 Copyright (C) Microsoft Corporation. All rights reserved. LINK : fatal error LNK1561: entry point must be defined [INFO] ------------------------------------------------------------------------ [ERROR] BUILD ERROR [INFO] ------------------------------------------------------------------------ [INFO] Error executing command line. Exit code:1561 mojo-native gives options for manipulating the compiler/linker options but gives no example of usage. No matter what I tweak in these settings I get the error of: [ERROR] BUILD ERROR [INFO] ------------------------------------------------------------------------ [INFO] Failed to configure plugin parameters for: org.codehaus.mojo:native-maven -plugin:1.0-alpha-4 (found static expression: '-o hook.dll Hook.cpp /D HOOK_DLLEXPORT /link /DLL /DEF:"Hook.def"' which may act as a default value). Cause: Cannot assign configuration entry 'compilerStartOptions' to 'interface ja va.util.List' from '-o hook.dll Hook.cpp /D HOOK_DLLEXPORT /link /DLL /DEF:"Hook .def"', which is of type class java.lang.String The relevant part of my pom.xml looks like this: <configuration> <sources> <source> <directory>src/main/msvc</directory> <includes> <include>**/*.cpp</include> </includes> </source> </sources> <compilerProvider>msvc</compilerProvider> <compilerExecutable>cl</compilerExecutable> <!-- cl -o hook.dll Hook.cpp /D HOOK_DLLEXPORT /link /DLL /DEF:"Hook.def" --> <compilerStartOptions>-o hook.dll Hook.cpp /D HOOK_DLLEXPORT /link /DLL /DEF:"Hook.def"</compilerStartOptions> <!-- <compilerMiddleOptions></compilerMiddleOptions> <compilerEndOptions></compilerEndOptions> <linkerStartOptions></linkerStartOptions> <linkerMiddleOptions></linkerMiddleOptions> <linkerEndOptions></linkerEndOptions> --> </configuration> How do I manipulate the compiler to produce a DLL like the command line version does? Or should I give up and just use exec?

    Read the article

  • protobuf-net: Issues deserializing DataMember fields in lieu of read-only property

    - by Paul Smith
    I'm having issues deserializing certain properties of ORM-generated entities using protobuf-net. I suspect something in the way the ORM manages serialization attributes on read-only properties (uses public backing fields with DataMember attributes & [de]serializes) those instead of the corresponding read-only property, which has an IgnoreDataMember attribute). Guid properties might have issues of their own, but the field vs. property thing is my working theory now. Here's a simplified example of the code. Say I have a class, Account with an AccountID read-only guid, and an AccountName read-write string. I serialize & immediately deserialize a clone. In this scenario I get one of two results (depending on the entity, haven't isolated the specific commonality yet). The deserialized clone either: ...has a different AccountID from the original, or ...throws an Incorrect wire-type deserializing Guid exception while deserializing. Here's example usage... Account acct = new Account() { AccountName = "Bob's Checking" }; Debug.WriteLine(acct.AccountID.ToString()); using (MemoryStream ms = new MemoryStream()) { ProtoBuf.Serializer.Serialize<Account>(ms, acct); Debug.WriteLine(Encoding.UTF8.GetString(ms.GetBuffer())); ms.Position = 0; Account clone = ProtoBuf.Serializer.Deserialize<Account>(ms); Debug.WriteLine(clone.AccountID.ToString()); } And here's an example ORM'd class (simplified; hopefully haven't removed the cause of the issue in the process). Uses a shell game to deserialize read-only properties by exposing the backing field ("can't write" essentially becomes "shouldn't write," but we can scan code for instances of assigning to these fields, so the hack works for our purposes): [DataContract()] [Serializable()] public partial class Account { public Account() { _accountID = Guid.NewGuid(); } [XmlAttribute("AccountID")] [DataMember(Name = "AccountID", Order = 0)] public Guid _accountID; /// <summary> /// A read-only property; XML, JSON and DataContract serializers all seem /// to correctly recognize the public backing field when deserializing: /// </summary> [IgnoreDataMember] [XmlIgnore] public Guid AccountID { get { return this._accountID; } } [IgnoreDataMember] protected string _accountName; [DataMember(Name = "AccountName", Order = 1)] [XmlAttribute] public string AccountName { get { return this._accountName; } set { this._accountName = value; } } } XML, JSON and DataContract serializers all seem to serialize / deserialize matching object graphs here, so this attribute arrangement apparently causes those serializers to correctly assign to the public backing field when deserializing. I've tried protobuf-net with lists vs. single instances, different prefix styles, etc., but always either get the 'incorrect wire type ... Guid' exception, or the Guid property (field) not deserializing correctly. So the specific questions are, is there a quick workaround for this, and/or is there an explanation for both of outcomes 1 & 2 above, and/or can protobuf-net somehow be corralled into behaving like WCF in cases like this (i.e. follow the same DataMember/IgnoreDataMember semantics)? We hope not to have to create a protobuf dependency directly in the entity layer; if that's the case, we'll probably create proxy DTO entities with all public properties having protobuf attributes. (This is a subjective issue I have with all declarative serialization models; it's a ubiquitous pattern, but IMO, "normal" should be to have objects and serialization contracts decoupled.) Thanks!

    Read the article

  • protobuf-net: incorrect wire-type exception deserializing Guid properties

    - by Paul Smith
    I'm having issues deserializing certain Guid properties of ORM-generated entities using protobuf-net. Here's a simplified example of the code (reproduces most elements of the scenario, but doesn't reproduce the behavior; I can't expose our internal entities, so I'm looking for clues to account for the exception). Say I have a class, Account with an AccountID read-only guid, and an AccountName read-write string. I serialize & immediately deserialize a clone. Deserializing throws an Incorrect wire-type deserializing Guid exception while deserializing. Here's example usage... Account acct = new Account() { AccountName = "Bob's Checking" }; Debug.WriteLine(acct.AccountID.ToString()); using (MemoryStream ms = new MemoryStream()) { ProtoBuf.Serializer.Serialize<Account>(ms, acct); Debug.WriteLine(Encoding.UTF8.GetString(ms.GetBuffer())); ms.Position = 0; Account clone = ProtoBuf.Serializer.Deserialize<Account>(ms); Debug.WriteLine(clone.AccountID.ToString()); } And here's an example ORM'd class (simplified, but demonstrates the relevant semantics I can think of). Uses a shell game to deserialize read-only properties by exposing the backing field ("can't write" essentially becomes "shouldn't write," but we can scan code for instances of assigning to these fields, so the hack works for our purposes). Again, this does not reproduce the exception behavior; I'm looking for clues as to what could: [DataContract()] [Serializable()] public partial class Account { public Account() { _accountID = Guid.NewGuid(); } [XmlAttribute("AccountID")] [DataMember(Name = "AccountID", Order = 1)] public Guid _accountID; /// <summary> /// A read-only property; XML, JSON and DataContract serializers all seem /// to correctly recognize the public backing field when deserializing: /// </summary> [IgnoreDataMember] [XmlIgnore] public Guid AccountID { get { return this._accountID; } } [IgnoreDataMember] protected string _accountName; [DataMember(Name = "AccountName", Order = 2)] [XmlAttribute] public string AccountName { get { return this._accountName; } set { this._accountName = value; } } } XML, JSON and DataContract serializers all seem to serialize / deserialize these object graphs just fine, so the attribute arrangement basically works. I've tried protobuf-net with lists vs. single instances, different prefix styles, etc., but still always get the 'incorrect wire-type ... Guid' exception when deserializing. So the specific questions is, is there any known explanation / workaround for this? I'm at a loss trying to trace what circumstances (in the real code but not the example) could be causing it. We hope not to have to create a protobuf dependency directly in the entity layer; if that's the case, we'll probably create proxy DTO entities with all public properties having protobuf attributes. (This is a subjective issue I have with all declarative serialization models; it's a ubiquitous pattern & I understand why it arose, but IMO, if we can put a man on the moon, then "normal" should be to have objects and serialization contracts decoupled. ;-) ) Thanks!

    Read the article

  • Small performance test on a web service

    - by vtortola
    Hi, I'm trying to develop a small application that test how many requests per second can my service support but I think I'm doing something wrong. The service is in an early development stage, but I'd like to have this test handy in order to check in time to time I'm not doing something that decrease the performance. The problem is that I cannot get the web server or the database server go to the 100% of CPU. I'm using three different computers, in one is the web server (WinSrv Standard 2008 x64 IIS7), in other the database (Win 2K - SQL Server 2005) and the last is my computer (Win7 x64 ultimate), where I'll run the test. The computers are connected through a 100 ethernet switch. The request POST is 9 bytes and the response will be 842 bytes. The test launches several threads, and each thread has a "while" loop, in each loop it creates a WebRequest object, performs a call, increment a common counter and waits between 1 and 5 millisencods, then it do it again: static Int32 counter = 0; static void Main(string[] args) { ServicePointManager.DefaultConnectionLimit = 250; Console.WriteLine("Ready. Press any key..."); Console.ReadKey(); Console.WriteLine("Running..."); String localhost = "localhost"; String linuxmono = "192.168.1.74"; String server= "192.168.1.5:8080"; DateTime start = DateTime.Now; Random r = new Random(DateTime.Now.Millisecond); for (int i = 0; i < 50; i++) { new Thread(new ParameterizedThreadStart(Test)).Start(server); Thread.Sleep(r.Next(1, 3)); } Thread.Sleep(2000); while (true) { Console.WriteLine("Request per second :" + counter/DateTime.Now.Subtract(start).TotalSeconds ); Thread.Sleep(3000); } } public static void Test(Object ip) { Guid guid = Guid.NewGuid(); Random r = new Random(DateTime.Now.Millisecond); while (true) { String test = "<lalala/>"; WebRequest req = WebRequest.Create("http://" + (String)ip + "/WebApp/"+guid.ToString()+"/Data/Tables=whatever"); req.Method = "POST"; req.ContentType = "application/xml"; req.Credentials = new NetworkCredential("aaa", "aaa","domain"); Byte[] array = Encoding.UTF8.GetBytes(test); req.ContentLength = array.Length; using (Stream reqStream = req.GetRequestStream()) { reqStream.Write(array, 0, array.Length); reqStream.Close(); } using (Stream responseStream = req.GetResponse().GetResponseStream()) { String response = new StreamReader(responseStream).ReadToEnd(); if (response.Length != 842) Console.Write(" EEEE "); } Interlocked.Increment(ref counter); Thread.Sleep(r.Next(1,5)); } } If I run the test neither of the computers do an excesive CPU usage. Let's say I get a X requests per second, if I run the console application two times at the same moment, I get X/2 request per second in each one... but still the web server is on 30% of CPU, the database server on 25%... I've tried to remove the thread.sleep in the loop, but it doesn't make a big difference. I'd like to put the machines to the maximun, to check how may requests per second they can provide. I guessed that I could do it in this way... but apparently I'm missing something here... What is the problem? Kind regards.

    Read the article

  • email-spec destroys my rake cucumber:all

    - by Leonardo Dario Perna
    This works fine: $ rake cucumber:all Then $ script/plugin install git://github.com/bmabey/email-spec.git remote: Counting objects: 162, done. remote: Compressing objects: 100% (130/130), done. remote: Total 162 (delta 18), reused 79 (delta 13) Receiving objects: 100% (162/162), 127.65 KiB | 15 KiB/s, done. Resolving deltas: 100% (18/18), done. From git://github.com/bmabey/email-spec * branch HEAD - FETCH_HEAD And $ script/generate email_spec exists features/step_definitions create features/step_definitions/email_steps.rb And I add 'require 'email_spec/cucumber' in /feature/support/env.rb so it looks somethinng like: require File.expand_path(File.dirname(__FILE__) + '/../../config/environment') require 'cucumber/rails/world' require 'cucumber/formatter/unicode' # Comment out this line if you don't want Cucumber Unicode support require 'email_spec/cucumber' and now: rake cucumber:all gives me this error: $ rake cucumber:all --trace (in /Users/leonardodarioperna/Projects/frestyl/frestyl) ** Invoke cucumber:all (first_time) ** Invoke cucumber:ok (first_time) ** Invoke db:test:prepare (first_time) ** Invoke db:abort_if_pending_migrations (first_time) ** Invoke environment (first_time) ** Execute environment ** Execute db:abort_if_pending_migrations ** Execute db:test:prepare ** Invoke db:test:load (first_time) ** Invoke db:test:purge (first_time) ** Invoke environment ** Execute db:test:purge ** Execute db:test:load ** Invoke db:schema:load (first_time) ** Invoke environment ** Execute db:schema:load ** Execute cucumber:ok /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -I "/Library/Ruby/Gems/1.8/gems/cucumber-0.4.4/lib:lib" "/Library/Ruby/Gems/1.8/gems/cucumber-0.4.4/bin/cucumber" --profile default cucumber.yml was not found. Please refer to cucumber's documentation on defining profiles in cucumber.yml. You must define a 'default' profile to use the cucumber command without any arguments. Type 'cucumber --help' for usage. rake aborted! Command failed with status (1): [/System/Library/Frameworks/Ruby.framework/...] /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:995:in `sh' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1010:in `call' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1010:in `sh' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1094:in `sh' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1029:in `ruby' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1094:in `ruby' /Library/Ruby/Gems/1.8/gems/cucumber-0.4.4/lib/cucumber/rake/task.rb:68:in `run' /Library/Ruby/Gems/1.8/gems/cucumber-0.4.4/lib/cucumber/rake/task.rb:138:in `define_task' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `call' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `execute' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `each' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `execute' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:597:in `invoke_with_call_chain' /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_chain' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:607:in `invoke_prerequisites' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:604:in `each' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:604:in `invoke_prerequisites' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:596:in `invoke_with_call_chain' /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_chain' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:583:in `invoke' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2051:in `invoke_task' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `each' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2001:in `run' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/lib/rake.rb:1998:in `run' /Library/Ruby/Gems/1.8/gems/rake-0.8.7/bin/rake:31 /usr/bin/rake:19:in `load' /usr/bin/rake:19 WHY? but the command: $ cucumber still works Any idea?

    Read the article

  • PHP/GD - Cropping and Resizing Images

    - by Alix Axel
    I've coded a function that crops an image to a given aspect ratio and finally then resizes it and outputs it as JPG: <?php function Image($image, $crop = null, $size = null) { $image = ImageCreateFromString(file_get_contents($image)); if (is_resource($image) === true) { $x = 0; $y = 0; $width = imagesx($image); $height = imagesy($image); /* CROP (Aspect Ratio) Section */ if (is_null($crop) === true) { $crop = array($width, $height); } else { $crop = array_filter(explode(':', $crop)); if (empty($crop) === true) { $crop = array($width, $height); } else { if ((empty($crop[0]) === true) || (is_numeric($crop[0]) === false)) { $crop[0] = $crop[1]; } else if ((empty($crop[1]) === true) || (is_numeric($crop[1]) === false)) { $crop[1] = $crop[0]; } } $ratio = array ( 0 => $width / $height, 1 => $crop[0] / $crop[1], ); if ($ratio[0] > $ratio[1]) { $width = $height * $ratio[1]; $x = (imagesx($image) - $width) / 2; } else if ($ratio[0] < $ratio[1]) { $height = $width / $ratio[1]; $y = (imagesy($image) - $height) / 2; } /* How can I skip (join) this operation with the one in the Resize Section? */ $result = ImageCreateTrueColor($width, $height); if (is_resource($result) === true) { ImageSaveAlpha($result, true); ImageAlphaBlending($result, false); ImageFill($result, 0, 0, ImageColorAllocateAlpha($result, 255, 255, 255, 127)); ImageCopyResampled($result, $image, 0, 0, $x, $y, $width, $height, $width, $height); $image = $result; } } /* Resize Section */ if (is_null($size) === true) { $size = array(imagesx($image), imagesy($image)); } else { $size = array_filter(explode('x', $size)); if (empty($size) === true) { $size = array(imagesx($image), imagesy($image)); } else { if ((empty($size[0]) === true) || (is_numeric($size[0]) === false)) { $size[0] = round($size[1] * imagesx($image) / imagesy($image)); } else if ((empty($size[1]) === true) || (is_numeric($size[1]) === false)) { $size[1] = round($size[0] * imagesy($image) / imagesx($image)); } } } $result = ImageCreateTrueColor($size[0], $size[1]); if (is_resource($result) === true) { ImageSaveAlpha($result, true); ImageAlphaBlending($result, true); ImageFill($result, 0, 0, ImageColorAllocate($result, 255, 255, 255)); ImageCopyResampled($result, $image, 0, 0, 0, 0, $size[0], $size[1], imagesx($image), imagesy($image)); header('Content-Type: image/jpeg'); ImageInterlace($result, true); ImageJPEG($result, null, 90); } } return false; } ?> The function works as expected but I'm creating a non-required GD image resource, how can I fix it? I've tried joining both calls but I must be doing some miscalculations. <?php /* Usage Examples */ Image('http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png', '1:1', '600x'); Image('http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png', '2:1', '600x'); Image('http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png', '2:', '250x300'); ?> Any help is greatly appreciated, thanks.

    Read the article

  • boost::asio::async_write problem

    - by user368831
    Hi, I'm trying to figure out how asynchronous reads and writes work in boost asio by manipulating the echo example. Currently, I have a server that should, when sent a sentence, respond with only the first word. However, the boost::asio::async_write never seems to complete even though the write handler is being called. Can someone please explain what's going on? Here's the code: #include <cstdlib> #include <iostream> #include <boost/bind.hpp> #include <boost/asio.hpp> using boost::asio::ip::tcp; class session { public: session(boost::asio::io_service& io_service) : socket_(io_service) { } tcp::socket& socket() { return socket_; } void start() { std::cout<<"starting"<<std::endl; boost::asio::async_read_until(socket_, buffer, ' ', boost::bind(&session::handle_read, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } void handle_read(const boost::system::error_code& error, size_t bytes_transferred) { // std::ostringstream ss; // ss<<&buffer; char* c = new char[bytes_transferred]; //std::string s; buffer.sgetn(c,bytes_transferred); std::cout<<"data: "<< c<<" bytes: "<<bytes_transferred<<std::endl; if (!error) { boost::asio::async_write(socket_, boost::asio::buffer(c,bytes_transferred), boost::bind(&session::handle_write, this, boost::asio::placeholders::error)); } else { delete this; } } void handle_write(const boost::system::error_code& error) { std::cout<<"handling write"<<std::endl; if (!error) { } else { delete this; } } private: tcp::socket socket_; boost::asio::streambuf buffer; }; class server { public: server(boost::asio::io_service& io_service, short port) : io_service_(io_service), acceptor_(io_service, tcp::endpoint(tcp::v4(), port)) { session* new_session = new session(io_service_); acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error)); } void handle_accept(session* new_session, const boost::system::error_code& error) { if (!error) { new_session->start(); new_session = new session(io_service_); acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error)); } else { delete new_session; } } private: boost::asio::io_service& io_service_; tcp::acceptor acceptor_; }; int main(int argc, char* argv[]) { try { if (argc != 2) { std::cerr << "Usage: async_tcp_echo_server <port>\n"; return 1; } boost::asio::io_service io_service; using namespace std; // For atoi. server s(io_service, atoi(argv[1])); io_service.run(); } catch (std::exception& e) { std::cerr << "Exception: " << e.what() << "\n"; } return 0; } Thanks!

    Read the article

  • Filtering in a HierarchicalDataTemplate via MarkupExtension?

    - by Dan Bryant
    I'm trying to create a MarkupExtension to allow filtering of items in an ItemsSource of a HierarchicalDataTemplate. In particular, I'd like to be able to supply a method name that will be executed on the DataContext in order to perform the filtering. The usage syntax I'm after looks like this: <HierarchicalDataTemplate DataType="{x:Type src:DeviceBindingViewModel}" ItemsSource="{Utilities:FilterCollection {Binding Definition.Entries}, MethodName=FilterEntries}"> <StackPanel Orientation="Horizontal"> <Image Source="{StaticResource BindingImage}" Width="24" Height="24" Margin="3"/> <TextBlock Text="{Binding DisplayName}" FontSize="12" VerticalAlignment="Center"/> </StackPanel> </HierarchicalDataTemplate> My code for the custom MarkupExtension looks like this: public sealed class FilterCollectionExtension : MarkupExtension { private readonly MultiBinding _binding; private Predicate<Object> _filterMethod; public string MethodName { get; set; } public FilterCollectionExtension(Binding binding) { _binding = new MultiBinding(); _binding.Bindings.Add(binding); //We package a reference to the DataContext with the binding so that the Converter has access to it var selfBinding = new Binding {RelativeSource = RelativeSource.Self}; _binding.Bindings.Add(selfBinding); _binding.Converter = new InternalConverter(this); } public FilterCollectionExtension(Binding binding, string methodName) : this(binding) { MethodName = methodName; } public override object ProvideValue(IServiceProvider serviceProvider) { return _binding; } private bool FilterInternal(Object dataContext, Object value) { //Filtering is only applicable if a DataContext is defined if (dataContext != null) { if (_filterMethod == null) { var type = dataContext.GetType(); var method = type.GetMethod(MethodName, new[] { typeof(Object) }); if (method == null || method.ReturnType != typeof(bool)) throw new InvalidOperationException("Could not locate a filter predicate named " + MethodName + " on the DataContext"); _filterMethod = (Predicate<Object>)Delegate.CreateDelegate(typeof(Predicate<Object>), dataContext, method); } else { if (_filterMethod.Target != dataContext) { _filterMethod = (Predicate<Object>) Delegate.CreateDelegate(typeof (Predicate<Object>), dataContext, _filterMethod.Method); } } if (_filterMethod != null) return _filterMethod(value); } //If no filtering resolved, just allow all elements return true; } private class InternalConverter : IMultiValueConverter { private readonly FilterCollectionExtension _owner; public InternalConverter(FilterCollectionExtension owner) { _owner = owner; } public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture) { var enumerable = values[0]; var targetElement = (FrameworkElement)values[1]; var view = CollectionViewSource.GetDefaultView(enumerable); view.Filter = item => _owner.FilterInternal(targetElement.DataContext, item); return view; } public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture) { throw new NotSupportedException("Cannot convert back"); } } } I can see that the extension is instantiated and I can see it return the MultiBinding that is used by the Template. I also see the call to the InternalConverter.Convert method, which sees the expected parameters (I see the collection provided by the nested {Binding}) and is successfully able to retrieve the ICollectionView for the incoming collection. The only problem is that FilterInternal never gets called. The template is ultimately being used by a TreeView, if that's relevant. I haven't been able to figure out why the FilterInternal method is not being called and I was hoping somebody might be able to offer some insight.

    Read the article

  • Need help diagnosing network performance issues

    - by tokes
    I am currently working in a developing country as a system analyst for a government department. My area of expertise is software projects, but I've come across a few issues with the network setup in my office. (Unfortunately, being a developing country, there's not a lot of professional help available for this sort of thing.) Most recently, I am trying to diagnose a problem with slowness on the network. Our office is connected to the internet via an ADSL wireless modem/router (called Router). The modem is connected via ethernet to a switch (called Switch). The modem also acts as a wireless access point (called Wireless1), though because it is in a room at the end of the floor, it's range is limited. There are ethernet ports installed around the office. The cables of these all lead back to the same switch. In closer vicinity to the bulk of the client computers, there is another wireless router that acts as an access point for those clients (called Wireless2). That router is connected via ethernet to a wall port, and therefore to Switch. There is also a Windows server which acts as a DNS server (called DNSBox) which is located in the same room and is connected directly to Switch. ---Internet----------| Router/Wireless1 192.168.10.1 ---------------| |----|=========| DNSBox | |-------------------- 192.168.10.4 --------------------| Switch |---Other clients---- | |-------------------- |----|=========| Wireless2 ------------------| 192.168.10.198 One final thing to mention about the network setup. All clients are configured with manual IP addresses. Their router/gateway is set to the IP address of Router, and their DNS server is set to the IP address of DNSBox (with a secondary IP set to an external IP - that of our ISP's DNS server). Here are the symptoms we are experiencing: Clients connected to Wireless2 AP experience slow and unstable connections to the internet. (Slow here is defined as speeds of ~1KB/s, though ping response times seem to be as normal.) Clients connected via ethernet to Switch also experience the same slowness. Clients connected to Wireless1 AP (i.e. connecting via wireless directly to the ADSL modem) experience normal connections to the internet. Clients connected via ethernet to Router (i.e. connecting via ethernet directly to the ADSL modem) also experience normal connections to the internet. I also tried to gauge the connection performance between two machines on the network via ethernet: A file transfer between two clients who were both directly connected to Switch was the fastest; A file transfer between one client directly connected to Switch, and one client directly connected to Router (which is directly connected to Switch) performed much slower; A file transfer between two clients directly connected to Router also performed slowly. Things I have attempted to diagnose the problem: Restarted Switch -- no change. We tried unplugging ethernet jacks from Switch 4 at a time and testing the internet connection. The thought here was that perhaps a client on the network has contracted a virus, and is possibly spamming the network with traffic? (Not very technical, I know.) Unfortunately we couldn't get any significant increases in performance using this method. There were a couple of times when it seemed to be better, but then the connection speed quickly dropped back to slow/dead pace. I didn't want to unplug all jacks from Switch because I was concerned that users might be affected or that I would re-plug in the jacks incorrectly (should I even be worried about that? a port is a port on a switch, right?) I tried swapping the ethernet cable used to connect Router to Switch -- no change in performance. I tried swapping the port used on Switch for Router -- no change in performance. Anyone got any ideas on what this could be? Should I be mentioning specific brand names/models of the hardware used? Virii outbreaks are common in this country/office -- what could I be doing to figure out if a virus is at fault? If it is a virus, it doesn't seem to be generating a lot of traffic to/from the internet, because a) I can still get a good speed if I am directly connected to Router / Wireless1 and b) our ISP data usage has not risen suspiciously. Thanks for your help! Update #1 Here are the specs of some of the hardware: Switch is an Edimax ES3132RL 32-Port 10/100 Rackmount Switch Router is a D-Link DSL-G604T Update #2 I just tried unplugging everything except a laptop and Router from Switch. Speeds are still slow. I guess that means that Router / Switch are not being flooded? It seems more and more likely that the cause is something to do with the interaction between Router and Switch. However, I still can't find any useful resources on setting the LAN speed for either (and I'm not well-versed in these advanced networking configurations).

    Read the article

  • If record exists in database, UPDATE a single column

    - by Doug
    I have a bulk uploading object in place that is being used to bulk upload roughly 25-40 image files at a time. Each image is about 100-150 kb in size. During the upload, I've created a for each loop that takes the file name of the image (minus the file extension) to write it into a column named "sku". Also, for each file being uploaded, the date is recorded to a column named DateUpdated, as well as some image path data. Here is my c# code: protected void graphicMultiFileButton_Click(object sender, EventArgs e) { //graphicMultiFile is the ID of the bulk uploading object ( provided by Dean Brettle: http://www.brettle.com/neatupload ) if (graphicMultiFile.Files.Length > 0) { foreach (UploadedFile file in graphicMultiFile.Files) { //strip ".jpg" from file name (will be assigned as SKU) string sku = file.FileName.Substring(0, file.FileName.Length - 4); //assign the directory where the images will be stored on the server string directoryPath = Server.MapPath("~/images/graphicsLib/" + file.FileName); //ensure that if image existes on server that it will get overwritten next time it's uploaded: file.MoveTo(directoryPath, MoveToOptions.Overwrite); //current sql that inserts a record to the db SqlCommand comm; SqlConnection conn; string connectionString = ConfigurationManager.ConnectionStrings["DataConnect"].ConnectionString; conn = new SqlConnection(connectionString); comm = new SqlCommand("INSERT INTO GraphicsLibrary (sku, imagePath, DateUpdated) VALUES (@sku, @imagePath, @DateUpdated)", conn); comm.Parameters.Add("@sku", System.Data.SqlDbType.VarChar, 50); comm.Parameters["@sku"].Value = sku; comm.Parameters.Add("@imagePath", System.Data.SqlDbType.VarChar, 300); comm.Parameters["@imagePath"].Value = "images/graphicsLib/" + file.FileName; comm.Parameters.Add("@DateUpdated", System.Data.SqlDbType.DateTime); comm.Parameters["@DateUpdated"].Value = DateTime.Now; conn.Open(); comm.ExecuteNonQuery(); conn.Close(); } } } After images are uploaded, managers will go back and re-upload images that have previously been uploaded. This is because these product images are always being revised and improved. For each new/improved image, the file name and extension will remain the same - so that when image 321-54321.jpg was first uploaded to the server, the new/improved version of that image will still have the image file name as 321-54321.jpg. I can't say for sure if the file sizes will remain in the 100-150KB range. I'll assume that the image file size will grow eventually. When images get uploaded (again), there of course will be an existing record in the database for that image. What is the best way to: Check the database for the existing record (stored procedure or SqlDataReader or create a DataSet ...?) Then if record exists, simply UPDATE that record so that the DateUpdated column gets today's date. If no record exists, do the INSERT of the record as normal. Things to consider: If the record exists, we'll let the actual image be uploaded. It will simply overwrite the existing image so that the new version gets displayed on the web. We're using SQL Server 2000 on hosted environment (DiscountAsp). I'm programming in C#. The uploading process will be used by about 2 managers a few times a month (each) - which to me is not a allot of usage. Although I'm a jr. developer, I'm guessing that a stored procedure would be the way to go. Just seems more efficient - to do this record check away from the for each loop... but not sure. I'd need extra help writing a sproc, since I don't have too much experience with them. Thank everyone...

    Read the article

  • Linker error when compiling boost.asio example

    - by Alon
    Hi, I'm trying to learn a little bit C++ and Boost.Asio. I'm trying to compile the following code example: #include <iostream> #include <boost/array.hpp> #include <boost/asio.hpp> using boost::asio::ip::tcp; int main(int argc, char* argv[]) { try { if (argc != 2) { std::cerr << "Usage: client <host>" << std::endl; return 1; } boost::asio::io_service io_service; tcp::resolver resolver(io_service); tcp::resolver::query query(argv[1], "daytime"); tcp::resolver::iterator endpoint_iterator = resolver.resolve(query); tcp::resolver::iterator end; tcp::socket socket(io_service); boost::system::error_code error = boost::asio::error::host_not_found; while (error && endpoint_iterator != end) { socket.close(); socket.connect(*endpoint_iterator++, error); } if (error) throw boost::system::system_error(error); for (;;) { boost::array<char, 128> buf; boost::system::error_code error; size_t len = socket.read_some(boost::asio::buffer(buf), error); if (error == boost::asio::error::eof) break; // Connection closed cleanly by peer. else if (error) throw boost::system::system_error(error); // Some other error. std::cout.write(buf.data(), len); } } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; } With the following command line: g++ -I /usr/local/boost_1_42_0 a.cpp and it throws an unclear error: /tmp/ccCv9ZJA.o: In function `__static_initialization_and_destruction_0(int, int)': a.cpp:(.text+0x654): undefined reference to `boost::system::get_system_category()' a.cpp:(.text+0x65e): undefined reference to `boost::system::get_generic_category()' a.cpp:(.text+0x668): undefined reference to `boost::system::get_generic_category()' a.cpp:(.text+0x672): undefined reference to `boost::system::get_generic_category()' a.cpp:(.text+0x67c): undefined reference to `boost::system::get_system_category()' /tmp/ccCv9ZJA.o: In function `boost::system::error_code::error_code()': a.cpp:(.text._ZN5boost6system10error_codeC2Ev[_ZN5boost6system10error_codeC5Ev]+0x10): undefined reference to `boost::system::get_system_category()' /tmp/ccCv9ZJA.o: In function `boost::asio::error::get_system_category()': a.cpp:(.text._ZN5boost4asio5error19get_system_categoryEv[boost::asio::error::get_system_category()]+0x7): undefined reference to `boost::system::get_system_category()' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_thread::~posix_thread()': a.cpp:(.text._ZN5boost4asio6detail12posix_threadD2Ev[_ZN5boost4asio6detail12posix_threadD5Ev]+0x1d): undefined reference to `pthread_detach' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_thread::join()': a.cpp:(.text._ZN5boost4asio6detail12posix_thread4joinEv[boost::asio::detail::posix_thread::join()]+0x25): undefined reference to `pthread_join' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_tss_ptr<boost::asio::detail::call_stack<boost::asio::detail::task_io_service<boost::asio::detail::epoll_reactor<false> > >::context>::~posix_tss_ptr()': a.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEED2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEED5Ev]+0xf): undefined reference to `pthread_key_delete' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_tss_ptr<boost::asio::detail::call_stack<boost::asio::detail::task_io_service<boost::asio::detail::epoll_reactor<false> > >::context>::posix_tss_ptr()': a.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEEC2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEEC5Ev]+0x22): undefined reference to `pthread_key_create' collect2: ld returned 1 exit status How can I fix it? Thank you.

    Read the article

  • How to install PyQt on Mac OS X 10.6.

    - by Jebagnanadas
    Hello all, I'm quite new to Mac OS X. when i tried to install PyQt on Mac Os X after installing python 3.1, Qt 4.6.2 and SIP 4.10.1 i encounter the following error when i execute $python3 configure.py command. Determining the layout of your Qt installation... This is the GPL version of PyQt 4.7 (licensed under the GNU General Public License) for Python 3.1 on darwin. Type '2' to view the GPL v2 license. Type '3' to view the GPL v3 license. Type 'yes' to accept the terms of the license. Type 'no' to decline the terms of the license. Do you accept the terms of the license? yes Checking to see if the QtGui module should be built... Checking to see if the QtHelp module should be built... Checking to see if the QtMultimedia module should be built... Checking to see if the QtNetwork module should be built... Checking to see if the QtOpenGL module should be built... Checking to see if the QtScript module should be built... Checking to see if the QtScriptTools module should be built... Checking to see if the QtSql module should be built... Checking to see if the QtSvg module should be built... Checking to see if the QtTest module should be built... Checking to see if the QtWebKit module should be built... Checking to see if the QtXml module should be built... Checking to see if the QtXmlPatterns module should be built... Checking to see if the phonon module should be built... Checking to see if the QtAssistant module should be built... Checking to see if the QtDesigner module should be built... Qt v4.6.2 free edition is being used. Qt is built as a framework. SIP 4.10.1 is being used. The Qt header files are in /usr/include. The shared Qt libraries are in /Library/Frameworks. The Qt binaries are in /Developer/Tools/Qt. The Qt mkspecs directory is in /usr/local/Qt4.6. These PyQt modules will be built: QtCore. The PyQt Python package will be installed in /Library/Frameworks/Python.framework/Versions/3.1/lib/python3.1/site-packages. PyQt is being built with generated docstrings. PyQt is being built with 'protected' redefined as 'public'. The Designer plugin will be installed in /Developer/Applications/Qt/plugins/designer. The PyQt .sip files will be installed in /Library/Frameworks/Python.framework/Versions/3.1/share/sip/PyQt4. pyuic4, pyrcc4 and pylupdate4 will be installed in /Library/Frameworks/Python.framework/Versions/3.1/bin. Generating the C++ source for the QtCore module... sip: Usage: sip [-h] [-V] [-a file] [-b file] [-c dir] [-d file] [-e] [-g] [-I dir] [-j #] [-k] [-m file] [-o] [-p module] [-r] [-s suffix] [-t tag] [-w] [-x feature] [-z file] [file] Error: Unable to create the C++ code. Anybody here installed PyQt on Mac OS X 10.6.2 successfully.. Any help would be much appreciated.. Thanks in advance..

    Read the article

  • Linux IPTables / routing issue

    - by Jon
    Hi all, EDIT 1/3/10 22:00 GMT - rewrote some of it after further investigation It has been a while since I looked at IPtables and I seem to be worse than before as I can not seem to get my webserver online. Below is my firewall rules on the gateway server that is running the dhcp server accessing the net. The webserver is inside my network on a static IP (192.168.0.98, default port). When I use Nmap or GRC.com I see that port 80 is open on the gateway server but when I browse to it, (via public URL. http://www.houseofhawkins.com) it always fails with a connection error, (nmap cannot connect and figure out what the web server is either). I can nmap the webserver and browse to it just fine via same IP inside my network. I believe it is my IPTable rules that are not letting it through. Internally I can route all my requests. Each machine can browse to the website and traffic works just fine. I can MSTSC / ssh to all the webservers internally and they inturn can connect to the web. IPTABLE: *EDIT - Added new firewall rules 2/3/10 * #!/bin/sh iptables="/sbin/iptables" modprobe="/sbin/modprobe" depmod="/sbin/depmod" EXTIF="eth2" INTIF="eth1" load () { $depmod -a $modprobe ip_tables $modprobe ip_conntrack $modprobe ip_conntrack_ftp $modprobe ip_conntrack_irc $modprobe iptable_nat $modprobe ip_nat_ftp echo "enable forwarding.." echo "1" > /proc/sys/net/ipv4/ip_forward echo "enable dynamic addr" echo "1" > /proc/sys/net/ipv4/ip_dynaddr # start firewall # default policies $iptables -P INPUT DROP $iptables -F INPUT $iptables -P OUTPUT DROP $iptables -F OUTPUT $iptables -P FORWARD DROP $iptables -F FORWARD $iptables -t nat -F #echo " Opening loopback interface for socket based services." $iptables -A INPUT -i lo -j ACCEPT $iptables -A OUTPUT -o lo -j ACCEPT #echo " Allow all connections OUT and only existing and related ones IN" $iptables -A INPUT -i $INTIF -j ACCEPT $iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT $iptables -A OUTPUT -o $EXTIF -j ACCEPT $iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT $iptables -A FORWARD -i $EXTIF -o $INTIF -m state --state ESTABLISHED,RELATED -j ACCEPT $iptables -A FORWARD -i $INTIF -o $EXTIF -j ACCEPT $iptables -A FORWARD -j LOG --log-level 7 --log-prefix "Dropped by firewall: " $iptables -A INPUT -j LOG --log-level 7 --log-prefix "Dropped by firewall: " $iptables -A OUTPUT -j LOG --log-level 7 --log-prefix "Dropped by firewall: " #echo " Enabling SNAT (MASQUERADE) functionality on $EXTIF" $iptables -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE $iptables -A INPUT -i $INTIF -j ACCEPT $iptables -A OUTPUT -o $INTIF -j ACCEPT #echo " Allowing packets with ICMP data (i.e. ping)." $iptables -A INPUT -p icmp -j ACCEPT $iptables -A OUTPUT -p icmp -j ACCEPT $iptables -A INPUT -p udp -i $INTIF --dport 67 -m state --state NEW -j ACCEPT #echo " Port 137 is for NetBIOS." $iptables -A INPUT -i $INTIF -p udp --dport 137 -j ACCEPT $iptables -A OUTPUT -o $INTIF -p udp --dport 137 -j ACCEPT #echo " Opening port 53 for DNS queries." $iptables -A INPUT -p udp -i $EXTIF --sport 53 -j ACCEPT #echo " opening Apache webserver" $iptables -A PREROUTING -t nat -i $EXTIF -p tcp --dport 80 -j DNAT --to 192.168.0.96:80 $iptables -A FORWARD -p tcp -m state --state NEW -d 192.168.0.96 --dport 80 -j ACCEPT } flush () { echo "flushing rules..." $iptables -P FORWARD ACCEPT $iptables -F INPUT $iptables -P INPUT ACCEPT echo "rules flushed" } case "$1" in start|restart) flush load ;; stop) flush ;; *) echo "usage: start|stop|restart." ;; esac exit 0 route info: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 5e0412a6.bb.sky * 255.255.255.255 UH 0 0 0 eth2 192.168.0.0 * 255.255.255.0 U 0 0 0 eth1 default 5e0412a6.bb.sky 0.0.0.0 UG 100 0 0 eth2 ifconfig: eth1 Link encap:Ethernet HWaddr 00:22:b0:cf:4a:1c inet addr:192.168.0.1 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::222:b0ff:fecf:4a1c/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:79023 errors:0 dropped:0 overruns:0 frame:0 TX packets:57786 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:11580918 (11.5 MB) TX bytes:22872030 (22.8 MB) Interrupt:17 Base address:0x2b00 eth2 Link encap:Ethernet HWaddr 00:0c:f1:7c:45:5b inet addr:94.4.18.166 Bcast:94.4.18.166 Mask:255.255.255.255 inet6 addr: fe80::20c:f1ff:fe7c:455b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:57038 errors:0 dropped:0 overruns:0 frame:0 TX packets:34532 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:21631721 (21.6 MB) TX bytes:7685444 (7.6 MB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:16 errors:0 dropped:0 overruns:0 frame:0 TX packets:16 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:1517 (1.5 KB) TX bytes:1517 (1.5 KB) EDIT OK so as requested I will try and expand on my infrastructure: I previously had it setup with a Sky broadband modem router that did the DHCP and I used its web interface to port forward the web across to the web server. The network looked something like this: I have now replaced the sky modem with a dlink modem which gives the IP to the gateway server that now does the DHCP. It looks like: The internet connection is a standard broadband connection with a dynamic IP, (use zoneedit.com to keep it updated). I have tried it on each of the webservers(one Ubuntu Apache server and one WS2008 IIS7). I think there must also be an issue with my IPTable rules as it can route to my win7 box which has the default IIS7 page and that would not display when I forwarded all port 80 to it. I would be really grateful for any and all help with this. Thanks Jon

    Read the article

  • Understanding Node.js and concept of non-blocking I/O

    - by Saif Bechan
    Recently I became interested in using Node.js to tackle some of the parts of my web-application. I love the part that its full JavaScript and its very light weight so no use anymore to call an JavaScript-PHP call but a lighter JavaScript-JavaScript call. I however do not understand all the concepts explained. Basic concepts Now in the presentation for Node.js Ryan Dahl talks about non-blocking IO and why this is the way we need to create our programs. I can understand the theoretical concept. You just don't wait for a response, you go ahead and do other things. You make a callback for the response, and when the response arrives millions of clock-cycles later, you can fire that. If you have not already I recommend to watch this presentation. It is very easy to follow and pretty detailed. There are some nice concepts explained on how to write your code in a good manner. There are also some examples given and I am going to work with the basic example given. Examples The way we do thing now: puts("Enter your name: "); var name = gets(); puts("Name: " + name); Now the problem with this is that the code is halted at line 1. It blocks your code. The way we need to do things according to node puts("Enter your name: "); gets(function (name) { puts("Name: " + name); }); Now with this your program does not halt, because the input is a function within the output. So the programs continues to work without halting. Questions Now the basic question I have is how does this work in real-life situations. I am talking here for the use in web-applications. The application I am writing does I/O, bit is still does it in am blocking matter. I think that most of the time, if not all, you need to block, because you have to wait on what the response is you have to work with. When you need to get some information from the database, most of the time this data needs to be verified before you can further with the code. Example 1 If you take a login for example. You have to wait for the database to response to return, because you can not do anything else. I can't see a way around this without blocking. Example 2 Going back to the basic example. The use just request something from a database which does not need any verification. You still have to block because you don't have anything to do more. I can not come up with a single example where you want to do other things while you wait for the response to return. Possible answers I have read that this frees up recourses. When you program like this it takes less CPU or memory usage. So this non-blocking IO is ONLY meant to free up recourses and does not have any other practical use. Not that this is not a huge plus, freeing up recourses is always good. Yet I fail to see this as a good solution. because in both of the above examples, the program has to wait for the response of the user. Whether this is inside a function, or just inline, in my opinion there is a program that wait for input. Resources I looked at I have looked at some recourses before I posted this question. They talk a lot about the theoretical concept, which is quite clear. Yet i fail to see some real-life examples where this is makes a huge difference. Stackoverflow: What is in simple words blocking IO and non-blocking IO? Blocking IO vs non-blocking IO; looking for good articles tidy code for asynchronous IO Other recources: Wikipedia: Asynchronous I/O Introduction to non-blocking I/O The C10K problem

    Read the article

  • All downloads being interrupted

    - by Jake
    System: Windows 7 Professional 64bit. 8GB RAM, Intel i5-2400 CPU, +300GB free on the hard drive. AVG Internet Security 2012 (enabled & disabled, with firewall enabled and disabled - no effect for either). This computer is less than a year old. Network: This problem is occurring on a single computer on a network with multiple computers. The router is a Motorola Netopia 3347-02 (DSL Modem/Wireless Router combined). The computer is plugged in directly to the modem, other computers are using the wireless successfully. The router has been reset. The only thing odd about the connection between the router and computer is that it is configured to allow RDP through, so it is assigned a static IP by the router and port forwarding is enabled for port 3389. Also, though I doubt it matters, a second wireless router is active behind this router providing a second network that some computers in the area use without issues. Details: All downloads initiated on this specific computer eventually fail, this includes streaming from youtube, specialized downloads (itunes), downloads from websites, FTP downloads, etc. Failure occurs with all browsers, but in chrome this is the process it takes: 1) Download begins normally, 2) At some point between (observed) 7MBs and 229MBs the download stops progressing (at this point, if watching chrome's task manager, you can see the network activity for the downloading tab drop to 0kps), 3) for some time the download sits there still attempting to complete, but will eventually display "123,049,871/0 B, Interrupted" (where the number is whatever it actually got to). The file I am using to test this is a very large .zip file located on a server I control, but the problem seems to occur on any site. The amount downloaded is completely random, and seems to be more time-based than anything (if I start a download immediately after the last one fails, it tends to get further than the last one). Small files can get through for this reason, though they can fail as well. In a test where I simultaneously downloaded the same file via HTTP (chrome) and FTP (windows explorer), both downloads failed at the same instant, though explorer displayed "Connection timed out" several minutes before chrome finally showed the download as interrupted. Other things I have tried based on advice given to people with similar/identical problems: Setting my MTU to 1492 (as described here: http://blog.thecompwiz.com/2011/08/networking-issues.html) Disabling write caching to the hard drive storing the download on an external device successfully transmitted +1GB file from one computer on the same network to this computer disabling indexing in the folder the download was being stored in disabling all security software checked to make sure all drivers were up to date read about 50 accounts with nearly exact descriptions of what I'm experiencing, none of which had a solution given Running Processes: Image Name PID Session Name Session# Mem Usage ========================= ======== ================ =========== ============ System Idle Process 0 Services 0 24 K System 4 Services 0 104,836 K smss.exe 332 Services 0 1,276 K csrss.exe 764 Services 0 5,060 K wininit.exe 820 Services 0 4,748 K csrss.exe 844 Console 1 23,764 K services.exe 876 Services 0 11,856 K lsass.exe 892 Services 0 14,420 K lsm.exe 900 Services 0 7,820 K winlogon.exe 944 Console 1 7,716 K svchost.exe 428 Services 0 12,744 K svchost.exe 796 Services 0 12,240 K svchost.exe 1036 Services 0 22,372 K svchost.exe 1084 Services 0 174,132 K svchost.exe 1112 Services 0 56,144 K svchost.exe 1288 Services 0 18,640 K svchost.exe 1404 Services 0 29,616 K spoolsv.exe 1576 Services 0 25,924 K svchost.exe 1616 Services 0 12,788 K AppleMobileDeviceService. 1728 Services 0 9,796 K avgwdsvc.exe 1820 Services 0 8,268 K mDNSResponder.exe 1844 Services 0 5,832 K w3dbsmgr.exe 1108 Services 0 43,760 K QBCFMonitorService.exe 1336 Services 0 16,408 K svchost.exe 2404 Services 0 28,240 K taskhost.exe 3020 Console 1 12,372 K dwm.exe 2280 Console 1 5,968 K explorer.exe 2964 Console 1 152,476 K WUDFHost.exe 3316 Services 0 6,740 K svchost.exe 3408 Services 0 5,556 K RAVCpl64.exe 3684 Console 1 13,864 K igfxtray.exe 3700 Console 1 7,804 K hkcmd.exe 3772 Console 1 7,868 K igfxpers.exe 3788 Console 1 10,940 K sidebar.exe 3836 Console 1 84,400 K chrome.exe 3964 Console 1 19,640 K pptd40nt.exe 4068 Console 1 5,156 K acrotray.exe 3908 Console 1 14,676 K avgtray.exe 3872 Console 1 9,508 K jusched.exe 4076 Console 1 4,412 K iTunesHelper.exe 1532 Console 1 87,308 K SearchIndexer.exe 3492 Services 0 36,948 K iPodService.exe 4136 Services 0 7,944 K BrccMCtl.exe 4276 Console 1 18,132 K splwow64.exe 4380 Console 1 32,600 K qbupdate.exe 4836 Console 1 24,236 K svchost.exe 4288 Services 0 20,700 K wmpnetwk.exe 3112 Services 0 9,516 K FNPLicensingService.exe 5248 Services 0 5,852 K QBW32.EXE 5508 Console 1 127,068 K QBDBMgrN.exe 5600 Services 0 42,252 K EXCEL.EXE 2512 Console 1 99,100 K LMS.exe 3188 Services 0 5,616 K UNS.exe 1600 Services 0 7,308 K axlbridge.exe 5260 Console 1 5,132 K chrome.exe 5888 Console 1 200,336 K chrome.exe 3536 Console 1 26,076 K chrome.exe 1952 Console 1 20,168 K chrome.exe 4596 Console 1 24,696 K chrome.exe 4292 Console 1 48,096 K chrome.exe 2796 Console 1 23,520 K Acrobat.exe 1240 Console 1 87,252 K 123w.exe 4892 Console 1 22,728 K calc.exe 1700 Console 1 12,636 K chrome.exe 1328 Console 1 28,888 K chrome.exe 3696 Console 1 47,012 K rundll32.exe 6320 Console 1 7,104 K chrome.exe 4928 Console 1 44,248 K AVGIDSAgent.exe 260 Services 0 12,940 K avgfws.exe 6052 Services 0 26,912 K avgnsa.exe 5064 Services 0 2,496 K avgrsa.exe 3088 Services 0 2,200 K avgcsrva.exe 2596 Services 0 380 K avgcsrva.exe 6948 Services 0 408 K StikyNot.exe 452 Console 1 14,772 K chrome.exe 4580 Console 1 28,200 K chrome.exe 4016 Console 1 57,756 K svchost.exe 7140 Services 0 4,500 K chrome.exe 6264 Console 1 56,824 K chrome.exe 7008 Console 1 56,896 K chrome.exe 2224 Console 1 38,032 K taskhost.exe 612 Console 1 7,228 K chrome.exe 6000 Console 1 10,928 K chrome.exe 2568 Console 1 43,052 K chrome.exe 272 Console 1 75,988 K chrome.exe 7328 Console 1 53,240 K PaprPort.exe 7976 Console 1 137,152 K pplinks.exe 7500 Console 1 14,052 K ppscanmg.exe 5744 Console 1 18,996 K taskeng.exe 7388 Console 1 6,308 K SearchProtocolHost.exe 8024 Services 0 8,804 K SearchFilterHost.exe 7232 Services 0 7,848 K chrome.exe 8016 Console 1 37,440 K cmd.exe 7692 Console 1 3,096 K conhost.exe 7516 Console 1 5,872 K tasklist.exe 8160 Console 1 5,772 K WmiPrvSE.exe 7684 Services 0 6,400 K Any help with this would be greatly appreciated, I've been beating my head against a wall over this all day. This computer serves dual purpose as the main company document server and the Owner's work computer, it's fairly important it be fully functional and I cannot figure this out.

    Read the article

  • ASP.NET WebControl ITemplate child controls are null

    - by tster
    Here is what I want: I want a control to put on a page, which other developers can place form elements inside of to display the entities that my control is searching. I have the Searching logic all working. The control builds custom search fields and performs searches based on declarative C# classes implementing my SearchSpec interface. Here is what I've been trying: I've tried using ITemplate on a WebControl which implements INamingContainer I've tried implementing a CompositeControl The closest I can get to working is below. OK I have a custom WebControl [ AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal), AspNetHostingPermission(SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal), DefaultProperty("SearchSpecName"), ParseChildren(true), ToolboxData("<{0}:SearchPage runat=\"server\"> </{0}:SearchPage>") ] public class SearchPage : WebControl, INamingContainer { [Browsable(false), PersistenceMode(PersistenceMode.InnerProperty), DefaultValue(typeof(ITemplate), ""), Description("Form template"), TemplateInstance(TemplateInstance.Single), TemplateContainer(typeof(FormContainer))] public ITemplate FormTemplate { get; set; } public class FormContainer : Control, INamingContainer{ } public Control MyTemplateContainer { get; private set; } [Bindable(true), Category("Behavior"), DefaultValue(""), Description("The class name of the SearchSpec to use."), Localizable(false)] public virtual string SearchSpecName { get; set; } [Bindable(true), Category("Behavior"), DefaultValue(true), Description("True if this is query mode."), Localizable(false)] public virtual bool QueryMode { get; set; } private SearchSpec _spec; private SearchSpec Spec { get { if (_spec == null) { Type type = Assembly.GetExecutingAssembly().GetTypes().Where(t => t.Name == SearchSpecName).First(); _spec = (SearchSpec)Assembly.GetExecutingAssembly().CreateInstance(type.Namespace + "." + type.Name); } return _spec; } } protected override void CreateChildControls() { if (FormTemplate != null) { MyTemplateContainer = new FormTemplateContainer(this); FormTemplate.InstantiateIn(MyTemplateContainer); Controls.Add(MyTemplateContainer); } else { Controls.Add(new LiteralControl("blah")); } } protected override void RenderContents(HtmlTextWriter writer) { // <snip> } protected override HtmlTextWriterTag TagKey { get { return HtmlTextWriterTag.Div; } } } public class FormTemplateContainer : Control, INamingContainer { private SearchPage parent; public FormTemplateContainer(SearchPage parent) { this.parent = parent; } } then the usage: <tster:SearchPage ID="sp1" runat="server" SearchSpecName="TestSearchSpec" QueryMode="False"> <FormTemplate> <br /> Test Name: <asp:TextBox ID="testNameBox" runat="server" Width="432px"></asp:TextBox> <br /> Owner: <asp:TextBox ID="ownerBox" runat="server" Width="427px"></asp:TextBox> <br /> Description: <asp:TextBox ID="descriptionBox" runat="server" Height="123px" Width="432px" TextMode="MultiLine" Wrap="true"></asp:TextBox> </FormTemplate> </tster:SearchPage> The problem is that in the CodeBehind, the page has members descriptionBox, ownerBox and testNameBox. However, they are all null. Furthermore, FindControl("ownerBox") returns null as does this.sp1.FindControl("ownerBox"). I have to do this.sp1.MyTemplateContainer.FindControl("ownerBox") to get the control. How can I make it so that the C# Code Behind will have the controls generated and not null in my Page_Load event so that developers can just do this: testNameBox.Text = "foo"; ownerBox.Text = "bar"; descriptionBox.Text = "baz";

    Read the article

  • Nginx + php-fpm "504 Gateway Time-out" error with almost zero load (on a test-server)

    - by rahul286
    After debugging for 6-hours - I am giving this up :| We have a nginx+php-fpm+mysql in LAN with almost 100 wordpress (created and used by different designers/developers all working on test wordpres setup) We are using nginx without any issues from long. Today, all of a sudden - nginx started returning "504 Gateway Time-out" out of the blue... I checked nginx error log for a virtual host... 2010/09/06 21:24:24 [error] 12909#0: *349 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 21:25:11 [error] 12909#0: *349 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 21:25:11 [error] 12909#0: *443 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /info.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 21:25:12 [error] 12909#0: *443 connect() failed (111: Connection refused) while connecting to upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:08:32 [error] 12909#0: *1025 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:09:33 [error] 12909#0: *1025 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:09:40 [error] 12909#0: *1064 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /info.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:09:40 [error] 12909#0: *1064 connect() failed (111: Connection refused) while connecting to upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:24:44 [error] 12909#0: *1313 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" 2010/09/06 22:24:53 [error] 12909#0: *1313 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 192.168.0.1, server: rahul286.rtcamp.info, request: "GET /favicon.ico HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "rahul286.rtcamp.info" As I run php-fpm on port 9000 via TCP mode, I ran "netstat | grep 9000" and noticed something unusual... (Pasting partial output here for ease of read) tcp 9 0 localhost:9000 localhost:36094 CLOSE_WAIT 14269/php5-fpm tcp 0 0 localhost:46664 localhost:9000 FIN_WAIT2 - tcp 1257 0 localhost:9000 localhost:36135 CLOSE_WAIT - tcp 1257 0 localhost:9000 localhost:36125 CLOSE_WAIT - tcp 9 0 localhost:9000 localhost:36102 CLOSE_WAIT 14268/php5-fpm tcp 0 0 localhost:46662 localhost:9000 FIN_WAIT2 - tcp 745 0 localhost:9000 localhost:46644 CLOSE_WAIT - tcp 0 0 localhost:46658 localhost:9000 FIN_WAIT2 - tcp 1265 0 localhost:9000 localhost:46607 CLOSE_WAIT - tcp 0 0 localhost:46672 localhost:9000 ESTABLISHED 12909/nginx: worker tcp 1257 0 localhost:9000 localhost:36119 CLOSE_WAIT - tcp 1265 0 localhost:9000 localhost:46613 CLOSE_WAIT - tcp 0 0 localhost:46646 localhost:9000 FIN_WAIT2 - tcp 1257 0 localhost:9000 localhost:36137 CLOSE_WAIT - tcp 0 0 localhost:46670 localhost:9000 ESTABLISHED 12909/nginx: worker tcp 1265 0 localhost:9000 localhost:46619 CLOSE_WAIT - tcp 1336 0 localhost:9000 localhost:46668 ESTABLISHED - tcp 0 0 localhost:46648 localhost:9000 FIN_WAIT2 - tcp 1336 0 localhost:9000 localhost:46670 ESTABLISHED - tcp 9 0 localhost:9000 localhost:36108 CLOSE_WAIT 14274/php5-fpm tcp 1336 0 localhost:9000 localhost:46684 ESTABLISHED - tcp 0 0 localhost:46674 localhost:9000 ESTABLISHED 12909/nginx: worker tcp 1336 0 localhost:9000 localhost:46666 ESTABLISHED - tcp 1257 0 localhost:9000 localhost:46648 CLOSE_WAIT - tcp 1336 0 localhost:9000 localhost:46678 ESTABLISHED - tcp 0 0 localhost:46668 localhost:9000 ESTABLISHED 12909/nginx: wo There are plenty of "CLOSE_WAIT" & "FIN_WAIT2" pairs as highlighted below (in above output): tcp 1337 0 localhost:9000 localhost:46680 CLOSE_WAIT - tcp 0 0 localhost:46680 localhost:9000 FIN_WAIT2 - Please note port 46680 in above. I enabled mysql slow queries error log, but it didn't work. As of now restarting php5-fpm every minute via a cronjob (see command below) keeping everything running "smoothly" but I hate patchwork and want to solve this... 1 * * * * service php5-fpm restart > /dev/null I searched extensively on Google - got no help. As mentioned, this a test-server in LAN, CPU load is never crossed 0.10 and memory usage is also below 25% (System has 2GB RAM and ubuntu-server installed) So if you find its time-confusing to help me out, please atleast drop a hint. Thanks in advance for help. -Rahul (note - this is reposting of - http://forum.nginx.org/read.php?11,127694) Update: I found answer, which is posted below.

    Read the article

  • Load-balancing between a Procurve switch and a server

    - by vlad
    Hello I've been searching around the web for this problem i've been having. It's similar in a way to this question: How exactly & specifically does layer 3 LACP destination address hashing work? My setup is as follows: I have a central switch, a Procurve 2510G-24, image version Y.11.16. It's the center of a star topology, there are four switches connected to it via a single gigabit link. Those switches service the users. On the central switch, I have a server with two gigabit interfaces that I want to bond together in order to achieve higher throughput, and two other servers that have single gigabit connections to the switch. The topology looks as follows: sw1 sw2 sw3 sw4 | | | | --------------------- | sw0 | --------------------- || | | srv1 srv2 srv3 The servers were running FreeBSD 8.1. On srv1 I set up a lagg interface using the lacp protocol, and on the switch I set up a trunk for the two ports using lacp as well. The switch showed that the server was a lacp partner, I could ping the server from another computer, and the server could ping other computers. If I unplugged one of the cables, the connection would keep working, so everything looked fine. Until I tested throughput. There was only one link used between srv1 and sw0. All testing was conducted with iperf, and load distribution was checked with systat -ifstat. I was looking to test the load balancing for both receive and send operations, as I want this server to be a file server. There were therefore two scenarios: iperf -s on srv1 and iperf -c on the other servers iperf -s on the other servers and iperf -c on srv1 connected to all the other servers. Every time only one link was used. If one cable was unplugged, the connections would keep going. However, once the cable was plugged back in, the load was not distributed. Each and every server is able to fill the gigabit link. In one-to-one test scenarios, iperf was reporting around 940Mbps. The CPU usage was around 20%, which means that the servers could withstand a doubling of the throughput. srv1 is a dell poweredge sc1425 with onboard intel 82541GI nics (em driver on freebsd). After troubleshooting a previous problem with vlan tagging on top of a lagg interface, it turned out that the em could not support this. So I figured that maybe something else is wrong with the em drivers and / or lagg stack, so I started up backtrack 4r2 on this same server. So srv1 now uses linux kernel 2.6.35.8. I set up a bonding interface bond0. The kernel module was loaded with option mode=4 in order to get lacp. The switch was happy with the link, I could ping to and from the server. I could even put vlans on top of the bonding interface. However, only half the problem was solved: if I used srv1 as a client to the other servers, iperf was reporting around 940Mbps for each connection, and bwm-ng showed, of course, a nice distribution of the load between the two nics; if I run the iperf server on srv1 and tried to connect with the other servers, there was no load balancing. I thought that maybe I was out of luck and the hashes for the two mac addresses of the clients were the same, so I brought in two new servers and tested with the four of them at the same time, and still nothing changed. I tried disabling and reenabling one of the links, and all that happened was the traffic switched from one link to the other and back to the first again. I also tried setting the trunk to "plain trunk mode" on the switch, and experimented with other bonding modes (roundrobin, xor, alb, tlb) but I never saw any traffic distribution. One interesting thing, though: one of the four switches is a Cisco 2950, image version 12.1(22)EA7. It has 48 10/100 ports and 2 gigabit uplinks. I have a server (call it srv4) with a 4 channel trunk connected to it (4x100), FreeBSD 8.0 release. The switch is connected to sw0 via gigabit. If I set up an iperf server on one of the servers connected to sw0 and a client on srv4, ALL 4 links are used, and iperf reports around 330Mbps. systat -ifstat shows all four interfaces are used. The cisco port-channel uses src-mac to balance the load. The HP should use both the source and destination according to the manual, so it should work as well. Could this mean there is some bug in the HP firmware? Am I doing something wrong?

    Read the article

  • Modern Java alternatives

    - by Ralph
    I'm not sure if stackoverflow is the best forum for this discussion. I have been a Java developer for 14 years and have written an enterprise-level (~500,000 line) Swing application that uses most of the standard library APIs. Recently, I have become disappointed with the progress that the language has made to "modernize" itself, and am looking for an alternative for ongoing development. I have considered moving to the .NET platform, but I have issues with using something the only runs well in Windows (I know about Mono, but that is still far behind Microsoft). I also plan on buying a new Macbook Pro as soon as Apple releases their new rumored Arrandale-based machines and want to develop in an environment that will feel "at home" in Unix/Linux. I have considered using Python or Ruby, but the standard Java library is arguably the largest of any modern language. In JVM-based languages, I looked at Groovy, but am disappointed with its performance. Rumor has it that with the soon-to-be released JDK7, with its InvokeDynamic instruction, this will improve, but I don't know how much. Groovy is also not truly a functional language, although it provides closures and some of the "functional" features on collections. It does not embrace immutability. I have narrowed my search down to two JVM-based alternatives: Scala and Clojure. Each has its strengths and weaknesses. I am looking for the stackoverflow readerships' opinions. I am not an expert at either of these languages; I have read 2 1/2 books on Scala and am currently reading Stu Halloway's book on Clojure. Scala is strongly statically typed. I know the dynamic language folks claim that static typing is a crutch for not doing unit testing, but it does provide a mechanism for compile-time location of a whole class of errors. Scala is more concise than Java, but not as much as Clojure. Scala's inter-operation with Java seems to be better than Clojure's, in that most Java operations are easier to do in Scala than in Clojure. For example, I can find no way in Clojure to create a non-static initialization block in a class derived from a Java superclass. For example, I like the Apache commons CLI library for command line argument parsing. In Java and Scala, I can create a new Options object and add Option items to it in an initialization block as follows (Java code): final Options options = new Options() { { addOption(new Option("?", "help", false, "Show this usage information"); // other options } }; I can't figure out how to the same thing in Clojure (except by using (doit...)), although that may reflect my lack of knowledge of the language. Clojure's collections are optimized for immutability. They rarely require copy-on-write semantics. I don't know if Scala's immutable collections are implemented using similar algorithms, but Rich Hickey (Clojure's inventor) goes out of his way to explain how that language's data structures are efficient. Clojure was designed from the beginning for concurrency (as was Scala) and with modern multi-core processors, concurrency takes on more importance, but I occasionally need to write simple non-concurrent utilities, and Scala code probably runs a little faster for these applications since it discourages, but does not prohibit, "simple" mutability. One could argue that one-off utilities do not have to be super-fast, but sometimes they do tasks that take hours or days to complete. I know that there is no right answer to this "question", but I thought I would open it up for discussion. If anyone has a suggestion for another JVM-based language that can be used for enterprise level development, please list it. Also, it is not my intent to start a flame war. Thanks, Ralph

    Read the article

  • Simple Convention Automapper for two-way Mapping (Entities to/from ViewModels)

    - by Omu
    UPDATE: this stuff has evolved into a nice project, see it at http://valueinjecter.codeplex.com check this out, I just wrote a simple automapper, it takes the value from the property with the same name and type of one object and puts it into another, and you can add exceptions (ifs, switch) for each type you may need so tell me what do you think about it ? I did it so I could do something like this: Product –> ProductDTO ProductDTO –> Product that's how it begun: I use the "object" type in my Inputs/Dto/ViewModels for DropDowns because I send to the html a IEnumerable<SelectListItem> and I receive a string array of selected keys back public void Map(object a, object b) { var pp = a.GetType().GetProperties(); foreach (var pa in pp) { var value = pa.GetValue(a, null); // property with the same name in b var pb = b.GetType().GetProperty(pa.Name); if (pb == null) { //no such property in b continue; } if (pa.PropertyType == pb.PropertyType) { pb.SetValue(b, value, null); } } } UPDATE: the real usage: the Build methods (Input = Dto): public static TI BuildInput<TI, T>(this T entity) where TI: class, new() { var input = new TI(); input = Map(entity, input) as TI; return input; } public static T BuildEntity<T, TI, TR>(this TI input) where T : class, new() where TR : IBaseAdvanceService<T> { var id = (long)input.GetType().GetProperty("Id").GetValue(input, null); var entity = LocatorConfigurator.Resolve<TR>().Get(id) ?? new T(); entity = Map(input, entity) as T; return entity; } public static TI RebuildInput<T, TI, TR>(this TI input) where T: class, new() where TR : IBaseAdvanceService<T> where TI : class, new() { return input.BuildEntity<T, TI, TR>().BuildInput<TI, T>(); } in the controller: public ActionResult Create() { return View(new Organisation().BuildInput<OrganisationInput, Organisation>()); } [AcceptVerbs(HttpVerbs.Post)] public ActionResult Create(OrganisationInput o) { if (!ModelState.IsValid) { return View(o.RebuildInput<Organisation,OrganisationInput, IOrganisationService>()); } organisationService.SaveOrUpdate(o.BuildEntity<Organisation, OrganisationInput, IOrganisationService>()); return RedirectToAction("Index"); } The real Map method public static object Map(object a, object b) { var lookups = GetLookups(); var propertyInfos = a.GetType().GetProperties(); foreach (var pa in propertyInfos) { var value = pa.GetValue(a, null); // property with the same name in b var pb = b.GetType().GetProperty(pa.Name); if (pb == null) { continue; } if (pa.PropertyType == pb.PropertyType) { pb.SetValue(b, value, null); } else if (lookups.Contains(pa.Name) && pa.PropertyType == typeof(LookupItem)) { pb.SetValue(b, (pa.GetValue(a, null) as LookupItem).GetSelectList(pa.Name), null); } else if (lookups.Contains(pa.Name) && pa.PropertyType == typeof(object)) { pb.SetValue(b, pa.GetValue(a, null).ReadSelectItemValue(), null); } else if (pa.PropertyType == typeof(long) && pb.PropertyType == typeof(Organisation)) { pb.SetValue(b, pa.GetValue<long>(a).ReadOrganisationId(), null); } else if (pa.PropertyType == typeof(Organisation) && pb.PropertyType == typeof(long)) { pb.SetValue(b, pa.GetValue<Organisation>(a).Id, null); } } return b; }

    Read the article

  • Is this question too hard for a seasoned C++ architect?

    - by Monomer
    Background Information We're looking to hire a seasoned C++ architect (10+years dev, of which at least 6years must be C++ ) for a high frequency trading platform. Job advert says STL, Boost proficiency is a must with preferences to modern uses of C++. The company I work for is a Fortune 500 IB (aka finance industry), it requires passes in all the standard SHL tests (numeric, vocab, spatial etc) before interviews can commence. Everyone on the team was given the task of coming up with one question to ask the candidates during a written/typed test, please note this is the second test provided to the candidates, the first being Advanced IKM C++ test, done in the offices supervised and without internet access. People passing that do the second test. After roughly 70 candidates, my question has been determined to be statistically the worst performing - aka least number of people attempted it, furthermore even less people were able to give meaningful answers. Please note, the second test is not timed, the candidate can literally take as long as they like (we've had one person take roughly 10.5hrs) My question to SO is this, after SHL and IKM adv c++ tests, backed up with at least 6+ years C++ development experience, is it still ok not to be able to even comment about let alone come up with some loose strategy for solving the following question. The Question There is a class C with methods foo, boo, boo_and_foo and foo_and_boo. Each method takes i,j,k and l clock cycles respectively, where i < j, k < i+j and l < i+j. class C { public: int foo() {...} int boo() {...} int boo_and_foo() {...} int foo_and_boo() {...} }; In code one might write: C c; . . int i = c.foo() + c.boo(); But it would be better to have: int i = c.foo_and_boo(); What changes or techniques could one make to the definition of C, that would allow similar syntax of the original usage, but instead have the compiler generate the latter. Note that foo and boo are not commutative. Possible Solution We were basically looking for an expression templates based approach, and were willing to give marks to anyone who had even hinted or used the phrase or related terminology. We got only two people that used the wording, but weren't able to properly describe how they accomplish the task in detail. We use such techniques all over the place, due to the use of various mathematical operators for matrix and vector based calculations, for example to decide when to use IPP or hand woven implementations at compile time for a particular architecture and many other things. The particular area of software development requires microsecond response times. I believe could/should be able to teach a junior such techniques, but given the assumed caliber of candidates I expected a little more. Is this really a difficult question? Should it be removed? Or are we just not seeing the right candidates?

    Read the article

  • Manipulating matrix operations (transpose, negation, addition, and mutiplication) using functions in

    - by user292489
    I was trying to manipulate matrices in my input file using functions. My input file is: A 3 3 1 2 3 4 5 6 7 8 9 B 3 3 1 0 0 0 1 0 0 0 1 C 2 3 3 5 8 -1 -2 -3 D 3 5 0 0 0 1 0 1 0 1 0 1 0 1 0 0 1 E 1 1 10 F 3 10 1 0 2 0 3 0 4 0 5 0 0 2 3 -1 -3 -4 -3 8 3 7 0 0 0 4 6 5 8 2 -1 10 I am having trouble in implementing the functions that I declared. I assumed my program will perform those operations: transpose, negate, add, and multiply matices according to the users choice: /* once this program is compiled and executed, it will perform the basic matrix * operations: negation, transpose, addition, and multiplication. */ #include <stdio.h> #include <stdlib.h> #define MAX 10 int readmatrix(FILE *input, char martixname[6],int , mat[10][10], int i, int j); void printmatrix(char matrixname[6], int mat[10][10], int i, int j); void Negate(char matrixname[6], int mat[10][10], int i, int j); void add(char matrixname[6], int mat[10][10],int i, int k); void multiply(char matrixname[], int mat[][10], char A[], int i, int k); void transpose (char matrixname[], int mat[][10], char A[], int); void printT(int mat[][10], int); int selctoption(); char selectmatrix(); int main(int argc, char *argv[]) { char matrixtype[6]; int mat[][10]; FILE *filein; int size; int optionop; int matrixop; int option; if (argc != 2) { printf("Usage: executable input.\n"); exit(0); } filein = fopen(argv[1], "r"); if (!filein) { printf("ERROR: input file not found.\n"); exit (0); } size = readmatrix (filein, matrixtype); printmatrix(matrix[][10], size); option = selectoption(); matrixtype = selectmatrix(); //printf("You have: %5.2f ", deposit); optionop = readmatrix(option, matrix[][10], size); if (choiceop == 6) { printf("Thanks for using the matrix operation program.\n"); exit(0); } printf("Please select from the following matrix operations:\n") printf("\t1. Print matrix\n"); printf("\t2. Negate matrix\n"); printf("\t3. Transpose matrix\n"); printf("\t4. Add matrices\n"); printf("\t5. Multiply matrices\n"); printf("\t6. Quit\n"); fclose(filein); return 0; } do { printf("Please select option(1-%d):", optionop); scanf("%d", &matrixop); } while(matrixop <= 0 || matrixop > optionop); void readmatrix (FILE *in, int mat[][10], char A[], int i, int j) { int i=0,j = 0; while (fscanf(in, "%d", &mat[i][j]) != EOF) return 0; } // I would appreciate anyone's feedback.

    Read the article

  • Converting AES encryption token code in C# to php

    - by joey
    Hello, I have the following .Net code which takes two inputs. 1) A 128 bit base 64 encoded key and 2) the userid. It outputs the AES encrypted token. I need the php equivalent of the same code, but dont know which corresponding php classes are to be used for RNGCryptoServiceProvider,RijndaelManaged,ICryptoTransform,MemoryStream and CryptoStream. Im stuck so any help regarding this would be really appreciated. using System; using System.Text; using System.IO; using System.Security.Cryptography; class AESToken { [STAThread] static int Main(string[] args) { if (args.Length != 2) { Console.WriteLine("Usage: AESToken key userId\n"); Console.WriteLine("key Specifies 128-bit AES key base64 encoded supplied by MediaNet to the partner"); Console.WriteLine("userId specifies the unique id"); return -1; } string key = args[0]; string userId = args[1]; StringBuilder sb = new StringBuilder(); // This example code uses the magic string “CAMB2B”. The implementer // must use the appropriate magic string for the web services API. sb.Append("CAMB2B"); sb.Append(args[1]); // userId sb.Append('|'); // pipe char sb.Append(System.DateTime.UtcNow.ToString("yyyy-MM-dd HH:mm:ssUTC")); //timestamp Byte[] payload = Encoding.ASCII.GetBytes(sb.ToString()); byte[] salt = new Byte[16]; // 16 bytes of random salt RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider(); rng.GetBytes(salt); // the plaintext is 16 bytes of salt followed by the payload. byte[] plaintext = new byte[salt.Length + payload.Length]; salt.CopyTo(plaintext, 0); payload.CopyTo(plaintext, salt.Length); // the AES cryptor: 128-bit key, 128-bit block size, CBC mode RijndaelManaged cryptor = new RijndaelManaged(); cryptor.KeySize = 128; cryptor.BlockSize = 128; cryptor.Mode = CipherMode.CBC; cryptor.GenerateIV(); cryptor.Key = Convert.FromBase64String(args[0]); // the key byte[] iv = cryptor.IV; // the IV. // do the encryption ICryptoTransform encryptor = cryptor.CreateEncryptor(cryptor.Key, iv); MemoryStream ms = new MemoryStream(); CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write); cs.Write(plaintext, 0, plaintext.Length); cs.FlushFinalBlock(); byte[] ciphertext = ms.ToArray(); ms.Close(); cs.Close(); // build the token byte[] tokenBytes = new byte[iv.Length + ciphertext.Length]; iv.CopyTo(tokenBytes, 0); ciphertext.CopyTo(tokenBytes, iv.Length); string token = Convert.ToBase64String(tokenBytes); Console.WriteLine(token); return 0; } } Please help. Thank You.

    Read the article

  • multiple-inheritance substitution

    - by Luigi
    I want to write a module (framework specific), that would wrap and extend Facebook PHP-sdk (https://github.com/facebook/php-sdk/). My problem is - how to organize classes, in a nice way. So getting into details - Facebook PHP-sdk consists of two classes: BaseFacebook - abstract class with all the stuff sdk does Facebook - extends BaseFacebook, and implements parent abstract persistance-related methods with default session usage Now I have some functionality to add: Facebook class substitution, integrated with framework session class shorthand methods, that run api calls, I use mostly (through BaseFacebook::api()), authorization methods, so i don't have to rewrite this logic every time, configuration, sucked up from framework classes, insted of passed as params caching, integrated with framework cache module I know something has gone very wrong, because I have too much inheritance that doesn't look very normal.Wrapping everything in one "complex extension" class also seems too much. I think I should have few working togheter classes - but i get into problems like: if cache class doesn't really extend and override BaseFacebook::api() method - shorthand and authentication classes won't be able to use the caching. Maybe some kind of a pattern would be right in here? How would you organize these classes and their dependencies? EDIT 04.07.2012 Bits of code, related to the topic: This is how the base class of Facebook PHP-sdk: abstract class BaseFacebook { // ... some methods public function api(/* polymorphic */) { // ... method, that makes api calls } public function getUser() { // ... tries to get user id from session } // ... other methods abstract protected function setPersistentData($key, $value); abstract protected function getPersistentData($key, $default = false); // ... few more abstract methods } Normaly Facebook class extends it, and impelements those abstract methods. I replaced it with my substitude - Facebook_Session class: class Facebook_Session extends BaseFacebook { protected function setPersistentData($key, $value) { // ... method body } protected function getPersistentData($key, $default = false) { // ... method body } // ... implementation of other abstract functions from BaseFacebook } Ok, then I extend this more with shorthand methods and configuration variables: class Facebook_Custom extends Facebook_Session { public funtion __construct() { // ... call parent's constructor with parameters from framework config } public function api_batch() { // ... a wrapper for parent's api() method return $this->api('/?batch=' . json_encode($calls), 'POST'); } public function redirect_to_auth_dialog() { // method body } // ... more methods like this, for common queries / authorization } I'm not sure, if this isn't too much for a single class ( authorization / shorthand methods / configuration). Then there comes another extending layer - cache: class Facebook_Cache extends Facebook_Custom { public function api() { $cache_file_identifier = $this->getUser(); if(/* cache_file_identifier is not null and found a valid file with cached query result */) { // return the result } else { try { // call Facebook_Custom::api, cache and return the result } catch(FacebookApiException $e) { // if Access Token is expired force refreshing it parent::redirect_to_auth_dialog(); } } } // .. some other stuff related to caching } Now this pretty much works. New instance of Facebook_Cache gives me all the functionality. Shorthand methods from Facebook_Custom use caching, because Facebook_Cache overwrited api() method. But here is what is bothering me: I think it's too much inheritance. It's all very tight coupled - like look how i had to specify 'Facebook_Custom::api' instead of 'parent:api', to avoid api() method loop on Facebook_Cache class extending. Overall mess and ugliness. So again, this works but I'm just asking about patterns / ways of doing this in a cleaner and smarter way.

    Read the article

  • HP-UX: libstd_v2 in stack trace of JNI code compiled with g++

    - by Miguel Rentes
    Hello, uname -mr: B.11.23 ia64 g++ --version: g++ (GCC) 4.4.0 java -version: Java(TM) SE Runtime Environment (build 1.6.0.06-jinteg_20_jan_2010_05_50-b00) Java HotSpot(TM) Server VM (build 14.3-b01-jre1.6.0.06-rc1, mixed mode) I'm trying to run a Java application that uses JNI. It is crashing inside the JNI code with the following (abbreviated) stack trace: (0) 0xc0000000249353e0 VMError::report_and_die{_ZN7VMError14report_and_dieEv} + 0x440 at /CLO/Components/JAVA_HOTSPOT/Src/src/share/vm/utilities/vmError.cpp:738 [/opt/java6/jre/lib/IA64W/server/libjvm.so] (1) 0xc000000024559240 os::Hpux::JVM_handle_hpux_signal{_ZN2os4Hpux22JVM_handle_hpux_signalEiP9 __siginfoPvi} + 0x760 at /CLO/Components/JAVA_HOTSPOT/Src/src/os_cpu/hp-ux_ia64/vm/os_hp-ux_ia64.cpp:1051 [/opt/java6/jre/lib/IA64W/server/libjvm.so] (2) 0xc0000000245331c0 os::Hpux::signalHandler{_ZN2os4Hpux13signalHandlerEiP9__siginfoPv} + 0x80 at /CLO/Components/JAVA_HOTSPOT/Src/src/os/hp-ux/vm/os_hp-ux.cpp:4295 [/opt/java6/jre/lib/IA64W/server/libjvm.so] (3) 0xe00000010e002620 ---- Signal 11 (SIGSEGV) delivered ---- (4) 0xc0000000000d2d20 __pthread_mutex_lock + 0x400 at /ux/core/libs/threadslibs/src/common/pthreads/mutex.c:3895 [/usr/lib/hpux64/libpthread.so.1] (5) 0xc000000000342e90 __thread_mutex_lock + 0xb0 at ../../../../../core/libs/libc/shared_em_64/../core/threads/wrappers1.c:273 [/usr/lib/hpux64/libc.so.1] (6) 0xc00000000177dff0 _HPMutexWrapper::lock{_ZN15_HPMutexWrapper4lockEPv} + 0x90 [/usr/lib/hpux64/libstd_v2.so.1] (7) 0xc0000000017e9960 std::basic_string,std::allocator{_ZNSsC1ERKSs} + 0x80 [/usr/lib/hpux64/libstd_v2.so.1] (8) 0xc000000008fd9fe0 JniString::str{_ZNK9JniString3strEv} + 0x50 at eg_handler_jni.cxx:50 [/soft/bus-7_0/lib/libbus_registry_jni.so.7.0.0] (9) 0xc000000008fd7060 pt_efacec_se_aut_frk_cmp_registry_REGHandler::getKey{_ZN44pt_efacec_se_aut_frk_cmp_registry_REGHandler6getKeyEP8_jstringi} + 0xa0 [/soft/bus-7_0/lib/libbus_registry_jni.so.7.0.0] (10) 0xc000000008fd17f0 Java_pt_efacec_se_aut_frk_cmp_registry_REGHandler_getKey__Ljava_lang_String_2I + 0xa0 [/soft/bus-7_0/lib/libbus_registry_jni.so.7.0.0] (11) 0x9fffffffdf400ed0 Internal error (-3) while unwinding stack [/CLO/Components/JAVA_HOTSPOT/Src/src/os_cpu/hp-ux_ia64/vm/thread_hp-ux_ia64.cpp:142] This JNI code and dependencies are being compiled using g++, are multithreaded and 64 bit (-pthread -mlp64 -shared -fPIC). The LD_LIBRARY_PATH environment variable is set the dependencies location, and running ldd on the JNI shared libraries finds them all: ldd libbus_registry_jni.so: libefa-d.so.7 = /soft/bus-7_0/lib/libefa-d.so.7 libbus_registry-d.so.7 = /soft/bus-7_0/lib/libbus_registry-d.so.7 libboost_thread-gcc44-mt-d-1_41.so = /usr/local/lib/libboost_thread-gcc44-mt-d-1_41.so libboost_system-gcc44-mt-d-1_41.so = /usr/local/lib/libboost_system-gcc44-mt-d-1_41.so libboost_regex-gcc44-mt-d-1_41.so = /usr/local/lib/libboost_regex-gcc44-mt-d-1_41.so librt.so.1 = /usr/lib/hpux64/librt.so.1 libstdc++.so.6 = /opt/hp-gcc-4.4.0/lib/gcc/ia64-hp-hpux11.23/4.4.0/../../../hpux64/libstdc++.so.6 libm.so.1 = /usr/lib/hpux64/libm.so.1 libgcc_s.so.0 = /opt/hp-gcc-4.4.0/lib/gcc/ia64-hp-hpux11.23/4.4.0/../../../hpux64/libgcc_s.so.0 libunwind.so.1 = /usr/lib/hpux64/libunwind.so.1 librt.so.1 = /usr/lib/hpux64/librt.so.1 libm.so.1 = /usr/lib/hpux64/libm.so.1 libunwind.so.1 = /usr/lib/hpux64/libunwind.so.1 libdl.so.1 = /usr/lib/hpux64/libdl.so.1 libunwind.so.1 = /usr/lib/hpux64/libunwind.so.1 libc.so.1 = /usr/lib/hpux64/libc.so.1 libuca.so.1 = /usr/lib/hpux64/libuca.so.1 Looking at the stack trace, it seams odd that, although ldd list g++'s libstdc++ is being used, the std:string copy c'tor being reported as used is the one in libstd_v2, the implementation provided by aCC. The crash happens in the following code, when method str() returns: class JniString { std::string m_utf8; public: JniString(JNIEnv* env, jstring instance) { const char* utf8Chars = env-GetStringUTFChars(instance, 0); if (utf8Chars == 0) { env-ExceptionClear(); // RPF throw std::runtime_error("GetStringUTFChars returned 0"); } m_utf8.assign(utf8Chars); env-ReleaseStringUTFChars(instance, utf8Chars); } std::string str() const { return m_utf8; } }; Simultaneous usage of the two C++ implementations could likely be a reason for the crash, but that should not be happening. Any ideas?

    Read the article

< Previous Page | 221 222 223 224 225 226 227 228 229 230 231 232  | Next Page >