Search Results

Search found 20211 results on 809 pages for 'language implementation'.

Page 572/809 | < Previous Page | 568 569 570 571 572 573 574 575 576 577 578 579  | Next Page >

• How to efficiently deal with a large amount of HTML5 canvas pixel data over websockets

  - by user730569

  Using imageData = context.getImageData(0, 0, width, height); JSON.stringify(imageData.data); I grab the pixel data, convert it to a string, and then send it over the wire via websockets. However, this string can be pretty large, depending on the size of the canvas object. I tried using the compression technique found here: JavaScript implementation of Gzip but socket.io throws the error Websocket message contains invalid character(s). Is there an effective way to compress this data so that it can be sent over websockets?

  Read the article

• A general question about compilation and interpretation.

  - by wucnuc

  Hi stackoverflow, I apologize in advance for the possible stupidity of this question. However, the following has been the source of some confusion for me and I know the people here will be able to handily clear up the confusion for me. Basically, I would like to finally understand the relationship between any and all of the following terms. Some of the terms I do actually understand pretty well, but some of them are similar in my mind and I would like to once and for all to see their relationships/distinctions laid out all at once. They are: compiler interpreter bytecode machine code assembler assembly language binary object code executable Ideally, an answer would use examples from Java and C++ and other well-known programming languages that a young-ish student like me would be familiar with. Also, if you want to throw in any other useful terms that would be fine too :)

  Read the article

• What strategies are efficient to handle concurrent reads on heterogeneous multi-core architectures?

  - by fabrizioM

  I am tackling the challenge of using both the capabilities of a 8 core machine and a high-end GPU (Tesla 10). I have one big input file, one thread for each core, and one for the the GPU handling. The Gpu thread, to be efficient, needs a big number of lines from the input, while the Cpu thread needs only one line to proceed (storing multiple lines in a temp buffer was slower). The file doesn't need to be read sequentially. I am using boost. My strategy is to have a mutex on the input stream and each thread locks - unlocks it. This is not optimal because the gpu thread should have a higher precedence when locking the mutex, being the fastest and the most demanding one. I can come up with different solutions but before rush into implementation I would like to have some guidelines. What approach do you use / recommend ?

  Read the article

• Facebook API - Get comments

  - by Simon R

  Our business has a Facebook Fan Page. The fan page doesn't seem to generate any emails to us when updates are made to the page, whether someone adds a new status or someone comments on one of the statuses etc. Currently, we are running a very crude script to grab the content of the page and then use regular expressions to get the information we require. Obviously this is not fool proof and I'm looking into alternatives to this method. I've been looking at the facebook API and wonder if the rest server might be an option. I cannot, however, seem to find out how to return information of fan page statuses and their comments. Is anyone able to direct me how to use the API to retrieve this information. I am an admin of the fan page. The programming language I'm using is PHP. Many thanks.

  Read the article

• What should I know about Python to identify comments in different source files?

  - by Can't Tell

  I have a need to identify comments in different kinds of source files in a given directory. ( For example java,XML, JavaScript, bash). I have decided to do this using Python (as an attempt to learn Python). The questions I have are 1) What should I know about python to get this done? ( I have an idea that Regular Expressions will be useful but are there alternatives/other modules that will be useful? Libraries that I can use to get this done?) 2) Is Python a good choice for such a task? Will some other language make this easier to accomplish?

  Read the article

• form submit not working in firefox but works fine in IE

  - by jestges

  Hi, I want to submit my parent page when I click on submit button of the child page. In my child page I've written my code as string scriptString = "<script language=JavaScript> window.opener.document.forms(0).submit(); </script>"; // ASP.NET 2.0 if (!Page.ClientScript.IsClientScriptBlockRegistered(scriptString)) { Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "script", scriptString); } it is working fine in IE but not working in Firefox. What could be the alternate method for this? Thank in advance

  Read the article

• Instance where embedded C++ compilers don't support multiple inheritance?

  - by Nathan

  I read a bit about a previous attempt to make a C++ standard for embedded platforms where they specifically said multiple inheritance was bad and thus not supported. From what I understand, this was never implemented as a mainstream thing and most embedded C++ compilers support most standard C++ constructs. Are there cases where a compiler on a current embedded platform (i.e. something not more than a few years old) absolutely does not support multiple inheritance? I don't really want to do multiple inheritance in a sense where I have a child with two full implementations of a class. What I am most interested in is inheriting from a single implementation of a class and then also inheriting one or more pure virtual classes as interfaces only. This is roughly equivalent to Java/.Net where I can extend only one class but implement as many interfaces as I need. In C++ this is all done through multiple inheritance rather than being able to specifically define an interface and declare a class implements it.

  Read the article

• How to override the attr_protected?

  - by KandadaBoggu

  I have STI implementation as follows: class Automobile < ActiveRecord::Base end class Car < Automobile end class Truck < Automobile end class User < ActiveRecord::Base has_many :automobiles accepts_nested_attributes_for :automobiles end I am creating a list of automobiles for a user. For each automobile, the UI sets the type field and the properties associated with the automobile.While form submission, the type field is ignored as it is a protected attribute. How do I work around this issue? Is there a declarative way to unprotect a protected attribute?

  Read the article

• Auto pointer for unsigned char array?

  - by Gianluca

  I'd need a class like std::auto_ptr for an array of unsigned char*, allocated with new[]. But auto_ptr only calls delete and not delete[], so i can't use it. I also need to have a function which creates and returns the array. I came out with my own implementation within a class ArrayDeleter, which i use like in this example: #include <Utils/ArrayDeleter.hxx> typedef Utils::ArrayDeleter<unsigned char> Bytes; void f() { // Create array with new unsigned char* xBytes = new unsigned char[10]; // pass array to constructor of ArrayDeleter and // wrap it into auto_ptr return std::auto_ptr<Bytes>(new Bytes(xBytes)); } ... // usage of return value { auto_ptr<Bytes> xBytes(f()); }// unsigned char* is destroyed with delete[] in destructor of ArrayDeleter Is there a more elegant way to solve this? (Even using another "popular" library)

  Read the article

• Aspect Oriented Programming vs List<IAction> To execute methods based on conditions

  - by David Robbins

  I'm new to AOP so bear with me. Consider the following scenario: A state machine is used in a workflow engine, and after the state of the application is changed, a series of commands are executed. Depending on the state, different types of commands should be executed. As I see it, one implementation is to create List<IAction> and have each individual action determine whether it should execute. Would a Aspect Oriented process work as well? That is, could you create an aspect that notifies a class when a property changes, and execute the appropriate processes from that class? Would this help centralize the state specific rules?

  Read the article

• Can I use WCF NET.TCP Protocol from Silverlight 4 for a public website ?

  - by pixel3cs

  Does anyone know if the new NET.TCP feature of Silverlight 4 can be used for public websites ? From what I know, in the Silverlight 4 Beta they announced that WCF NET.TCP can only be used for intranet applications. The reason I am asking this is because I want to recode my Silverlight multiplayer chess game (build with SL 3 Sockets support) based on the new SL 4 WCF TCP communication protocol. My Socket implementation is build from scratch and have big issues with thread safe and few unsolvable bugs from my side. I am sure that SL 4 team did a great job and they simplified all hard part for me, letting us, developers, concentrate more on the game code instead on underlying communication layers.

  Read the article

• Simple Serialization Faster Than JSON? (in Ruby)

  - by Sinan Taifour

  I have an application written in ruby (that runs in the JRuby VM). When profiling it, I realized that it spends a lot (actually almost all of) its time converting some hashes into JSON. These hashes have keys of symbols, values of other similar hashes, arrays, strings, and numbers. Is there a serialization method that is suitable for such an input, and would typically run faster than JSON? It would preferable if it is has a Java or JRuby-compatible gem, too. I am currently using the jruby-json gem, which is the fastest JSON implementation in JRuby (as I am told), so the move will most likely be to a different serialization method rather than just a different library. Any help is appreciated! Thanks.

  Read the article

• SVN merge adding parameters. WTF? Or how to do big merges?

  - by HeavyWave

  I am doing an SVN merge for a branch, and in one of the files I see this: GetQueryReferenceData(int sessionId, Int32 sessionId) Which means that the merge tool just added another parameter without asking any questions. Imagine if it was a call to Substring(0) and in another branch it would be Substring(0,2). That is completely different behavior, how does it even get to decide which one to choose? Good thing it came up during compile time. The problem is that it will not be marked as a conflict and will be merged automatically. That is very dangerous behavior and if you don't have the luxury of having a unit test for every line of code - you are screwed. What am I doing wrong and how to do big merges without the merging tool putting in dangerous changes silently? Is there a merge tool that is not language agnostic? I am using Tortoise SVN.

  Read the article

• Python: How To copy function parameters into object's fields effortlessly ?

  - by bandana

  Many times I have member functions that copy parameters into object's fields. For Example: class NouveauRiches(object): def __init__(self, car, mansion, jet, bling): self.car = car self.mansion = mansion self.jet = jet self.bling = bling Is there a python language construct that would make the above code less tedious? One could use *args: def __init__(self, *args): self.car, self.mansion, self.jet, self.bling = args +: less tedious -: function signature not revealing enough. need to dive into function code to know how to use function -: does not raise a TypeError on call with wrong # of parameters (but does raise a ValueError) Any other ideas? (Whatever your suggestion, make sure the code calling the function does stays simple)

  Read the article

• ValidateRequest = False but in action it's still True and ignored that?

  - by Sadegh

  hi guy's, i want disable RequestValidation on particular view in ASP.NET MVC 2.0 RTM. so i added some necessary to view Page directive section as below: <%@ Page ValidateRequest="false" Language="C#" MasterPageFile="Path" Inherits="System.Web.Mvc.ViewPage<Path>" %> but RequestValidation isn't Disabled! i also added RequestValidation Attribute to related action in controller as below: [System.Web.Mvc.ValidateInput(false)] public System.Web.Mvc.ActionResult Create(Model instance) { //Do here something } :') but RequestValidation isn't Disabled too! in last try i set RequestValidation to false in Web.config file as below: <pages validateRequest="false" /> RequestValidation still isn't turned off! Why? thank's in advance ;)

  Read the article

• Simplest LINQ in C# troubleshooting.

  - by Jay

  I'm trying to learn a bit of LINQ but I'm having compile issues right off the bat. Is there any specific reason why this won't work? using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace HelloLINQ { class HelloLINQ { public static void Main() { Example1(); } public static void Example1() { var numbers = new int[] { 1, 5, 3, 7, 3, 8, 9, 3, 6, 6, 2 }; var under5 = from n in numbers select n; foreach (var n in under5) { Console.WriteLine(n); } } } } The error is: Could not find an implementation of the query pattern for source type 'int[]'. 'Select' not found. Are you missing a reference to 'System.Core.dll' or a using directive for 'System.Linq'?

  Read the article

• How to synchronize static method in java.

  - by Summer_More_More_Tea

  Hi there: I come up with this question when implementing singleton pattern in Java. Even though the example listed blow is not my real code, yet very similar to the original one. public class ConnectionFactory{ private static ConnectionFactory instance; public static synchronized ConnectionFactory getInstance(){ if( instance == null ){ instance = new ConnectionFactory(); } return instance; } private ConnectionFactory(){ // private constructor implementation } } Because I'm not quite sure about the behavior of a static synchronized method, I get some suggestion from google -- do not have (or as less as possible) multiple static synchronized methods in the same class. I guess when implementing static synchronized method, a lock belongs to Class object is used so that multiple static synchronized methods may degrade performance of the system. Am I right? or JVM use other mechanism to implement static synchronized method? What's the best practice if I have to implement multiple static synchronized methods in a class? Thank you all! Kind regards!

  Read the article

• C5 Generics Collection IntervalHeap<T> -- getting an IPriorityQueueHandle from a T for Replace or De

  - by Jared Updike

  I'm using the Generics Collection library C5 (server down :-( ) and I have an IntervalHeap(T) and I need to Delete or Replace a T that is not the Max or Min. How do I get an IPriorityQueueHandle from my T? The C5 library source code shows that IPriorityQueueHandle(T) has no methods or properties to implement and the compiler thinks my implementation of IPriorityQueueHandle(T) for my T is acceptable. I try to use a T like this: q.Replace(t, t); and the C5 library throws an InvalidCastException because it cannot convert my T to a (Handle).

  Read the article

• Graphiz: how to set 'default' arrow style?

  - by sdaau

  Hi all, Consider this dot language code: digraph graphname { subgraph clusterA { node [shape=plaintext,style=filled]; 1 -> 2 [arrowhead=normal,arrowtail=dot]; 2 -> 3 -> X2 -> 5; 6; 7; label = "A"; color=blue } } In the above example, only the 1 -> 2 connection will have the arrowhead=normal,arrowtail=dot style applied; all the other arrows will be of the "default" style. My question is - how do I set the arrow style (for the entire subgraph - or for the entire graph), without having to copy paste "[arrowhead=normal,arrowtail=dot];" next to each edge connection? Thanks in advance, Cheers!

  Read the article

• Asking for input without stopping the script in python.

  - by ImTooStupidForThis

  I am (trying) to make a simple IRC client in python (as kind of a project while I learn the language). I have a loop that I use to receive and parse what the IRC server sends me, but if I use raw_input to input stuff, it stops the loop dead in its tracks until I input something (obviously). How can I input something without the loop stopping? Thanks in advance. (I don´t think I need to post the code, I just want to input something without the while 1 loop stopping.)

  Read the article

• Ranged integers in .NET (or C#)

  - by Mal Ross

  Am I being blind, or does the .NET framework not provide any kind of ranged integer class? That is, a type that would prevent you setting a value outside some given bounds that are not the full range of the basic data type. For example, an integer type that would restrict its values to between 1 and 100. Showing my age here, but back in '93, I remember using that sort of thing in Modula-2 (eeek!), but I've not seen explicit framework / language support for it since. Am I just missing something, or is it a case of "it's so simple to make your own that the framework doesn't bother"? Cheers.

  Read the article

• Why I can't called my doSomething method?

  - by Tattat

  This is my DrawSomethingCmd: #import "Command.h"; @interface DrawSomethingCmd : Command { } -(void)doSomething; -(void)execute; @end and the DrawSomethingCmd.m's doSomething method is like that: -(void)doSomething{ NSLog(@"did"); } The Command.h: #import <Foundation/Foundation.h> @interface Command : NSObject { } -(void)execute; And the Command.m: #import "Command.h" @implementation Command -(id)init{ return self; } -(void)execute{ } @end And I have the method like this: DrawSomethingCmd *tempCmd = [[DrawSomethingCmd alloc] init]; [tempCmd doSomething]; But my Console did't show any things on that, what's going on?

  Read the article

• gVim and multiple programming languages

  - by Abhi

  My day job involves coding with Perl. At home I play around with Python and Erlang. For Perl I want to indent my code with two spaces. Whereas for Python the standard is 4. Also I have some key bindings to open function declarations which I would like to use with all programming languages. How can this be achieved in gVim? As in, is there a way to maintain a configuration file for each programming language or something of that sort?

  Read the article

• How to parse a string to an integer without library functions?

  - by dack

  Hi, I was recently asked this question in an interview: "How could you parse a string of the form '12345' into its integer representation 12345 without using any library functions, and regardless of language?" I thought of two answers, but the interviewer said there was a third. Here are my two solutions: Solution 1: Keep a dictionary which maps '1' = 1, '2' = 2, etc. Then parse the string one character at a time, look up the character in your dictionary, and multiply by place value. Sum the results. Solution 2: Parse the string one character at a time and subtract '0' from each character. This will give you '1' - '0' = 0x1, '2' - '0' = 0x2, etc. Again, multiply by place value and sum the results. Can anyone think of what a third solution might be? Thanks.

  Read the article

• Double Inner Join generates unexpected error

  - by Itamar Marom

  In my database I have three tables: Users: UserID (Auto Numbering), UserName, UserPassword and a few other unimportant fields. PrivateMessages: MessageID (Auto Numbering), SenderID and a few other fields defining the message content. MessageStatus: MessageID, ReceiverID, MessageWasRead (Boolean) What I need is a query to which I input a user's id and I get all the private messages he has received. In addition, I also need to receive each message's sender UserName. For this I wrote the following query: SELECT Users.*, PrivateMessages.*, MessageStatus.* FROM PrivateMessages INNER JOIN Users ON PrivateMessages.SenderID = Users.UserID INNER JOIN MessageStatus ON PrivateMessages.MessageID = MessageStatus.MessageID WHERE MessageStatus.ReceiverID=[@userid]; But for some reason when I try saving it in my Access database, I get the following error (translated to English by me, since my office is in a different language): Syntax error (missing operator) at expression: "PrivateMessages.SenderID = Users.UserID INNER JOIN MessageStatus ON PrivateMessages.MessageID = MessageStatus.MessageI". Any ideas what could cause this? Thanks.

  Read the article

< Previous Page | 568 569 570 571 572 573 574 575 576 577 578 579  | Next Page >