Search Results

Search found 19055 results on 763 pages for 'high performance'.

Page 554/763 | < Previous Page | 550 551 552 553 554 555 556 557 558 559 560 561  | Next Page >

  • What stack would you use for a new web Java project if you started today?

    - by Joelio
    If you were to start a brand new java project today with the following requirements: high scale (20k + users) you want to use something that is fairly mature (not changing dramatically) & wont be dead technology in 3 years you want something very productive (no server restarts in dev, save the code and its automatically compiled and deployed), productivity and time to market are key. some amount of ajax on front end no scripting language, jruby, groovy, php etc , has to be java has to support i8n What stack would you use & Why? (when I say stack, I mean, everything soup to nuts, so app server, mvc framework, bean framework, ORM framework, javascript framework etc...)

    Read the article

  • How to modularize a b2b webservice transformation application

    - by hstoerr
    How would you modularize a large application that has some incoming (SOAP) webservices, some outgoing webservices, transformations between them and internal formats, internal logging services, accesses external archiving webservices, delays stuff and works on this asynchronously and so forth? One way is to split the functionality into a collection of WAR, deploy all of them on one application server and have them communicate with internal webservices. This has some overhead, especially if the messages are large, and you might run into performance problems due to thread count restrictions and so forth. Another way would be to put everything into a giant WAR, such that you can communicate directly. Not exactly modularization. What would you do?

    Read the article

  • PHP application variable... maybe?

    - by James
    I went to a PHP job interview, I was asked to implement a piece of code to detect visitors are bots to crawl thru the website and steal content. So I implemented a few lines of code to detect if the site is being refreshed/visited too quickly/often by using a session variable to store last visit timestamp. I got told that session varaibles can be manupilated by cookies etc, so I am wondering if there is a application variable that I can use to store the timestamp information against visitor IPs eg $_SERVER[REMOTE_ADDR]? I know that I can write the data to a file but it's not very good for a high traffic website. Regards James

    Read the article

  • The speed of .NET in numerical computing

    - by Yin Zhu
    In my experience, .net is 2 to 3 times slower than native code. (I implemented L-BFGS for multivariate optimization). I have traced the ads on stackoverflow to http://www.centerspace.net/products/ the speed is really amazing, the speed is close to native code. How can they do that? They said that: Q. Is NMath "pure" .NET? A. The answer depends somewhat on your definition of "pure .NET". NMath is written in C#, plus a small Managed C++ layer. For better performance of basic linear algebra operations, however, NMath does rely on the native Intel Math Kernel Library (included with NMath). But there are no COM components, no DLLs--just .NET assemblies. Also, all memory allocated in the Managed C++ layer and used by native code is allocated from the managed heap. Can someone explain more to me? Thanks!

    Read the article

  • improving conversions to binary and back in C#

    - by Saad Imran.
    I'm trying to write a general purpose socket server for a game I'm working on. I know I could very well use already built servers like SmartFox and Photon, but I wan't to go through the pain of creating one myself for learning purposes. I've come up with a BSON inspired protocol to convert the the basic data types, their arrays, and a special GSObject to binary and arrange them in a way so that it can be put back together into object form on the client end. At the core, the conversion methods utilize the .Net BitConverter class to convert the basic data types to binary. Anyways, the problem is performance, if I loop 50,000 times and convert my GSObject to binary each time it takes about 5500ms (the resulting byte[] is just 192 bytes per conversion). I think think this would be way too slow for an MMO that sends 5-10 position updates per second with a 1000 concurrent users. Yes, I know it's unlikely that a game will have a 1000 users on at the same time, but like I said earlier this is supposed to be a learning process for me, I want to go out of my way and build something that scales well and can handle at least a few thousand users. So yea, if anyone's aware of other conversion techniques or sees where I'm loosing performance I would appreciate the help. GSBitConverter.cs This is the main conversion class, it adds extension methods to main datatypes to convert to the binary format. It uses the BitConverter class to convert the base types. I've shown only the code to convert integer and integer arrays, but the rest of the method are pretty much replicas of those two, they just overload the type. public static class GSBitConverter { public static byte[] ToGSBinary(this short value) { return BitConverter.GetBytes(value); } public static byte[] ToGSBinary(this IEnumerable<short> value) { List<byte> bytes = new List<byte>(); short length = (short)value.Count(); bytes.AddRange(length.ToGSBinary()); for (int i = 0; i < length; i++) bytes.AddRange(value.ElementAt(i).ToGSBinary()); return bytes.ToArray(); } public static byte[] ToGSBinary(this bool value); public static byte[] ToGSBinary(this IEnumerable<bool> value); public static byte[] ToGSBinary(this IEnumerable<byte> value); public static byte[] ToGSBinary(this int value); public static byte[] ToGSBinary(this IEnumerable<int> value); public static byte[] ToGSBinary(this long value); public static byte[] ToGSBinary(this IEnumerable<long> value); public static byte[] ToGSBinary(this float value); public static byte[] ToGSBinary(this IEnumerable<float> value); public static byte[] ToGSBinary(this double value); public static byte[] ToGSBinary(this IEnumerable<double> value); public static byte[] ToGSBinary(this string value); public static byte[] ToGSBinary(this IEnumerable<string> value); public static string GetHexDump(this IEnumerable<byte> value); } Program.cs Here's the the object that I'm converting to binary in a loop. class Program { static void Main(string[] args) { GSObject obj = new GSObject(); obj.AttachShort("smallInt", 15); obj.AttachInt("medInt", 120700); obj.AttachLong("bigInt", 10900800700); obj.AttachDouble("doubleVal", Math.PI); obj.AttachStringArray("muppetNames", new string[] { "Kermit", "Fozzy", "Piggy", "Animal", "Gonzo" }); GSObject apple = new GSObject(); apple.AttachString("name", "Apple"); apple.AttachString("color", "red"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)1.5); GSObject lemon = new GSObject(); apple.AttachString("name", "Lemon"); apple.AttachString("color", "yellow"); apple.AttachBool("inStock", false); apple.AttachFloat("price", (float)0.8); GSObject apricoat = new GSObject(); apple.AttachString("name", "Apricoat"); apple.AttachString("color", "orange"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)1.9); GSObject kiwi = new GSObject(); apple.AttachString("name", "Kiwi"); apple.AttachString("color", "green"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)2.3); GSArray fruits = new GSArray(); fruits.AddGSObject(apple); fruits.AddGSObject(lemon); fruits.AddGSObject(apricoat); fruits.AddGSObject(kiwi); obj.AttachGSArray("fruits", fruits); Stopwatch w1 = Stopwatch.StartNew(); for (int i = 0; i < 50000; i++) { byte[] b = obj.ToGSBinary(); } w1.Stop(); Console.WriteLine(BitConverter.IsLittleEndian ? "Little Endian" : "Big Endian"); Console.WriteLine(w1.ElapsedMilliseconds + "ms"); } Here's the code for some of my other classes that are used in the code above. Most of it is repetitive. GSObject GSArray GSWrappedObject

    Read the article

  • Subsonic SQLite Multiple Files

    - by Marcus Vinicius de LIma
    Hi, I have an application that must be accessed for many users. To optimize the performance I intend to store each user profile information at a independant database file. I need everytime a user login the application, to setup a new provider linked with his own database. All databases have the same structure. So while querying user the commom generated DAL classes must switch for the database file relative the the user. Is there a way for configure SubSonic for doing that switch at runtime? Thanks.

    Read the article

  • Choosing between ExtJS and YUI based on application parameters.

    - by Kabeer
    Hello. I need help in taking call to choose between Ext JS and YUI libraries. Here are the key factors I have derived from my application requirements & development process: Complex, windows forms like controls Widgets, Layouts, Utilities Inter widget communication Easy to extend Easy to learn Intuitive & concise coding Strong exception handling Active support / community To update with upcoming technologies (HTML5, etc.) Skins & Themes to be easy to change Skins & Themes to support variety (a text box for different context to appear differently) Support & Utilities for standard protocols (XmlHttp, JSON) Good performance (responsive) Cost is not crucial, but I don't mind saving :)

    Read the article

  • Storyboard editor layout confusion

    - by drew
    I am having layout problems with the storyboard editor with a fairly simple screen. I have a UIViewController to which I have added a 320x440 UIScrollView at 0,0 followed by a 320x20 UIProgressBar at 0,440. It looks fine in Storyboard editor. I'm not entirely sure how the 20 pixel status bar at the top of the screen is accommodated given the CGRect frame coordinates that Storyboard calculates. On loading ( in -(void)viewDidLoad ), the UIScrollView frame seems to be set to 320x460 pixels at 0,0 but the UIProgressBar is still 320x20 at 0,440. When I add subviews to the UIScrollView, (UIImageViews in particular), they get stretched and get clipped on the screen because although the UIScrollView thinks it is 460 pixels high, it only has 440 pixels of screen to display in. Can anyone point me to a solution? Thanks

    Read the article

  • Minimum Acceptable Code Coverage Numbers in the real world.

    - by Pita.O
    Hi, I am in the middle of putting together some guidelines around code coverage and I want to specify a number that really makes sense. It's easy to repeat the 100% mantra that I see all over the internet without considering the cost benefit analysis and when diminishing returns actually sets in. I solicit comments from persons who have actually reported code coverage on real-life, medium/large-sized projects. What percentages were you seeing? How much is too much? I really want some balance (in figures) that will help developers produce hight quality code. Is 65% coverage too low to expect? Is 80% too high?

    Read the article

  • Remove first 'n' elements from list without itterating

    - by Eldhose M Babu
    I need an efficient way of removing items from list. If some condition happens, I need to remove first 'n' elements from a list. Can some one suggest the best way to do this? Please keep in mind: performance is a factor for me, so I need a faster way than itterating. Thanks. I'm thinking of a way through which the 'n'th item can be made as the starting of the list so that the 0-n items will get garbage collected. Is it possible?

    Read the article

  • select only new row in oracle

    - by Hlex
    Hi, I have table with "varchar2" as primary key. Transaction is about 1 000 000 per day. my app wake up every 5 minute to generate text file by query only new record. It will remember last point and do only new record. 1)Do you have idea how query with good performance? I able to add new column if need. 2)what do you think this process should do by? plsql? java?

    Read the article

  • VC7.1 C1204 internal compiler error

    - by Nathan Ernst
    I'm working on modifying Firaxis' Civilization 4 core game DLL. The host application is built using VC7, hence the constraint (source not provided for the host EXE). I've been working on rewriting a large chunk of the code (focusing on low-hanging performance issues & memory leaks). I recently ran into an internal compiler error when trying to mod the code to use an array class instead of dynamically allocated 2-d arrays, I was going to use matrices from the boost lib (Civ4 is already using boost, so why not?). Basically, the issue comes down to: if I include "boost/numeric/ublas/matrix.hpp", I run into an internal compiler error C1204. MSDN has this to say: MSDN C1204 KB has this to say: KB 883655 So, I'm curious, is it possible to solve this error without a KB/SP being applied and dramatically reducing the complexity of the code? Additionally, as VC7 is no longer "supported", does anyone have a valid (supported) link for a VC7 service pack?

    Read the article

  • Displaying large file in JTextArea.

    - by Sathish Gopal
    Hi All, I'm currently working in Swing UI Assignment. This work involves showing large file content in JTextArea. The file size can be as large as 2 GB. My initial idea is to lazily load content from the file, say 1 MB of content will be shown to the user. As the user scrolls i will retrieve the next 1 MB of content to be shown. All these operation will be happening in background thread (Swing Worker). I looked at the JTextArea API, the method insert takes String and int(position of the insert) as the parameter. This will suffice, but i'm worried about performance, because the content (1 MB at a time) retrieved will have to be converted to String object. Is there any other work around or any other alternative/better solution for this.

    Read the article

  • Dynamically create sprite images for Cocos2d-iPhone

    - by AlexChilcott
    Hey guys, I'm working on a platformer, and looking for a way to create a sprite for an arbitrarily sized platform. For example, I may know I have a platform that should appear 200 pixels wide by 32 pixels high, and, say, I have a texture of bricks that I can tile to fill that area. I may also want to draw a black border around the platform. Is this possible at all? Anyone have any ideas for how I might go about doing this? I could always try generating the image on the fly and building a sprite with that image, but I sincerely doubt (hope) that this isn't the most efficient way of doing something like this. Cheers, Alex

    Read the article

  • Compilier optimization of repeated accessor calls C#

    - by apocalypse9
    I've found recently that for some types of financial calculations that the following pattern is much easier to follow and test especially in situations where we may need to get numbers from various stages of the computation. public class nonsensical_calculator { ... double _rate; int _term; int _days; double monthlyRate { get { return _rate / 12; }} public double days { get { return (1 - i); }} double ar { get { return (1+ days) /(monthlyRate * days) double bleh { get { return Math.Pow(ar - days, _term) public double raar { get { return bleh * ar/2 * ar / days; }} .... } Obviously this often results in multiple calls to the same accessor within a given formula. I was curious as to whether or not the compiler is smart enough to optimize away these repeated calls with no intervening change in state, or whether this style is causing a decent performance hit. Further reading suggestions are always appreciated

    Read the article

  • How reliable is HTTP compression using gzip?

    - by Liam
    YSlow has suggested that I use HTTP compression to improve the performance of my site. However, as noted by Yahoo that are some problems. There are known issues with browsers and proxies that may cause a mismatch in what the browser expects and what it receives with regard to compressed content. Fortunately, these edge cases are dwindling as the use of older browsers drops off. The Apache modules help out by adding appropriate Vary response headers automatically. I understand that the most common problem occurs with IE6 behind a proxy. But how common are these problems today? To quantify it, roughly what percentage of web users experience bugs with HTTP compression?

    Read the article

  • Is adding indexes to a SQL Server ever a bad idea?

    - by Aerik
    We have a mid-size SQL Server based application that has no indexes defined. Not even on the the identity columns. I suggested to our moderately expensive application consultant that perhaps we might get better performance (particularly as our database grows) by creating some indexes on appropriate fields, and he said: "Indexes will significantly impact other areas of the application and customers should not create them under any circumstances." Anybody ever heard of anything like this? Are there ever circumstances where one should not create any indexes? I can see nothing special about this app - it's got int identity columns, then lots of string columns, bunch of relational tables but nothing special or weird that I can see. Thanks!

    Read the article

  • Which can handle a huge surge of queries: SQL Server 2008 Fulltext or Lucene

    - by Luke101
    I am creating a widget that will be installed on several websites and blogs. The widget will analyse the remote webpage title and content, then it will return relevent articles/links on my website. The amount of traffic we expect will be very huge roughly 500K queries a day and up from there. I need the queries to be returned very quickly, so I need the candidate to be high performance, similar to google adsense. The remote title can be from 5 to 50 words and the description we will use no more then 3000 words. Which of these two do you think can handle the load.

    Read the article

  • Fast multi-window rendering with C#

    - by seb
    I've been searching and testing different kind of rendering libraries for C# days for many weeks now. So far I haven't found a single library that works well on multi-windowed rendering setups. The requirement is to be able to run the program on 12+ monitor setups (financial charting) without latencies on a fast computer. Each window needs to update multiple times every second. While doing this CPU needs to do lots of intensive and time critical tasks so some of the burden has to be shifted to GPUs. That's where hardware rendering steps in, in another words DirectX or OpenGL. I have tried GDI+ with windows forms and figured it's way too slow for my needs. I have tried OpenGL via OpenTK (on windows forms control) which seemed decently quick (I still have some tests to run on it) but painfully difficult to get working properly (hard to find/program good text rendering libraries). Recently I tried DirectX9, DirectX10 and Direct2D with Windows forms via SharpDX. I tried a separate device for each window and a single device/multiple swap chains approaches. All of these resulted in very poor performance on multiple windows. For example if I set target FPS to 20 and open 4 full screen windows on different monitors the whole operating system starts lagging very badly. Rendering is simply clearing the screen to black, no primitives rendered. CPU usage on this test was about 0% and GPU usage about 10%, I don't understand what is the bottleneck here? My development computer is very fast, i7 2700k, AMD HD7900, 16GB ram so the tests should definitely run on this one. In comparison I did some DirectX9 tests on C++/Win32 API one device/multiple swap chains and I could open 100 windows spread all over the 4-monitor workspace (with 3d teapot rotating on them) and still had perfectly responsible operating system (fps was dropping of course on the rendering windows quite badly to around 5 which is what I would expect running 100 simultaneous renderings). Does anyone know any good ways to do multi-windowed rendering on C# or am I forced to re-write my program in C++ to get that performance (major pain)? I guess I'm giving OpenGL another shot before I go the C++ route... I'll report any findings here. Test methods for reference: For C# DirectX one-device multiple swapchain test I used the method from this excellent answer: Display Different images per monitor directX 10 Direct3D10 version: I created the d3d10device and DXGIFactory like this: D3DDev = new SharpDX.Direct3D10.Device(SharpDX.Direct3D10.DriverType.Hardware, SharpDX.Direct3D10.DeviceCreationFlags.None); DXGIFac = new SharpDX.DXGI.Factory(); Then initialized the rendering windows like this: var scd = new SwapChainDescription(); scd.BufferCount = 1; scd.ModeDescription = new ModeDescription(control.Width, control.Height, new Rational(60, 1), Format.R8G8B8A8_UNorm); scd.IsWindowed = true; scd.OutputHandle = control.Handle; scd.SampleDescription = new SampleDescription(1, 0); scd.SwapEffect = SwapEffect.Discard; scd.Usage = Usage.RenderTargetOutput; SC = new SwapChain(Parent.DXGIFac, Parent.D3DDev, scd); var backBuffer = Texture2D.FromSwapChain<Texture2D>(SC, 0); _rt = new RenderTargetView(Parent.D3DDev, backBuffer); Drawing command executed on each rendering iteration is simply: Parent.D3DDev.ClearRenderTargetView(_rt, new Color4(0, 0, 0, 0)); SC.Present(0, SharpDX.DXGI.PresentFlags.None); DirectX9 version is very similar: Device initialization: PresentParameters par = new PresentParameters(); par.PresentationInterval = PresentInterval.Immediate; par.Windowed = true; par.SwapEffect = SharpDX.Direct3D9.SwapEffect.Discard; par.PresentationInterval = PresentInterval.Immediate; par.AutoDepthStencilFormat = SharpDX.Direct3D9.Format.D16; par.EnableAutoDepthStencil = true; par.BackBufferFormat = SharpDX.Direct3D9.Format.X8R8G8B8; // firsthandle is the handle of first rendering window D3DDev = new SharpDX.Direct3D9.Device(new Direct3D(), 0, DeviceType.Hardware, firsthandle, CreateFlags.SoftwareVertexProcessing, par); Rendering window initialization: if (parent.D3DDev.SwapChainCount == 0) { SC = parent.D3DDev.GetSwapChain(0); } else { PresentParameters pp = new PresentParameters(); pp.Windowed = true; pp.SwapEffect = SharpDX.Direct3D9.SwapEffect.Discard; pp.BackBufferFormat = SharpDX.Direct3D9.Format.X8R8G8B8; pp.EnableAutoDepthStencil = true; pp.AutoDepthStencilFormat = SharpDX.Direct3D9.Format.D16; pp.PresentationInterval = PresentInterval.Immediate; SC = new SharpDX.Direct3D9.SwapChain(parent.D3DDev, pp); } Code for drawing loop: SharpDX.Direct3D9.Surface bb = SC.GetBackBuffer(0); Parent.D3DDev.SetRenderTarget(0, bb); Parent.D3DDev.Clear(ClearFlags.Target, Color.Black, 1f, 0); SC.Present(Present.None, new SharpDX.Rectangle(), new SharpDX.Rectangle(), HWND); bb.Dispose(); C++ DirectX9/Win32 API test with multiple swapchains and one device code is here: http://pastebin.com/tjnRvATJ It's a modified version from Kevin Harris's nice example code.

    Read the article

  • Programming tests: are they relevant?

    - by BlackVoid
    Do online programming tests have any value (except for providing an evidence to potential employers) in terms of evaluating your knowledge, or a they too broad or too narrow in general? For examples, brainbench.com and similar websites. From my experience I have never found myself scoring particularly high, although I have many years of commercial experience and is doing great at work. These tests mostly refer to things I have never worked with (WebForms or ADO .Net, who works with ADO .Net directly anyway?), yet these tests claim to be C# tests. If you were hiring a programmer, would you consider online tests as an evidence of real skill?

    Read the article

  • Is there a Java equivalent to libevent?

    - by JoelPM
    I've written a high-throughput server that handles each request in its own thread. For requests coming in it is occasionally necessary to do RPCs to one or more back-ends. These back-end RPCs are handled by a separate queue and thread-pool, which provides some bounding on the number of threads created and the maximum number of connections to the back-end (it does some caching to reuse clients and save the overhead of constantly creating connections). Having done all this, though, I'm beginning to think an event-based architecture would be more efficient. In searching around I haven't found any equivalents to libevent for Java, but maybe I'm not looking in the right place? Mina-statemachine from Apache was the closest thing I found, but it looks more verbose than I need and there's no real release available. Any suggestions?

    Read the article

  • Do you know a good and efficient FFT?

    - by yan bellavance
    Hi, I am trying to find a very fast and efficient Fourier transform (FFT). Does anyone know of any good ones. I need to run it on the iPhone so it must not be intensive. Instead, maybe you know of one that is wavelet like, i need frequency resolution but only a narrow band (vocal audio range up to 10khz max...even 10Khz might be too high). Im thinking also of truncating this FFT to keep the frequency resolution while eliminating the unwanted frequency band. This is for an iphone ...I have taken a look at the FFT in Aurio touch but it seems this is an int FFT but my app uses floats.....would it give a big performance increase to try and adapt program to an int FFT or not(which i really dont feel like doing...plus aurio touch uses a radix 2 FFT which is not that great).

    Read the article

  • Validation of user input or ?????????

    - by zaf
    We're letting users search a database from a single text input and I'm having difficulties in filtering some user supplied strings. For example, if the user submits: ????????? lcd SONY (Note the ?'s) I need to cancel the search. I include the base64 encoded version of the above string wrapped up so that its easy run: print(base64_decode("1MfLxc/RwdPHIGxjZCBTT05Z")); I've ignored such inputs before but now (am not sure why) just realised the mysql database query is taking nearly forever to execute so this is now on high priority. Another example to highlight that we are using utf-8 and mb_detect_encoding is not helping much: print(base64_decode("zqDOm8+Fzr3PhM63z4HOuc6/IM+Bzr/Phc+HzyU=")); ????t???? ?????% So: how can I detect/filter these inputs? how is this input being generated?

    Read the article

  • Displaying thumbnails of images (present at different locations in the sdcard) in a listview

    - by frieza
    Hi all, I have several images present in different folders in my sdcard. I would like to display a list of thumbnails. So what I have done is while rendering any row in the list I read the file in an input stream, get the byte array, decode it to obtain a bitmap and set it in an imageview. So far so good. But when I scroll the list, the list scrolls in jerks. I believe this is because decoding a bitmap from byte array takes some time. What I would like to know is that, is there any optimization which I can do to improve the performance, or better still is there any better method to achieve what I want ?

    Read the article

  • Init modules in apache2

    - by user306963
    Hello, I used to write apache modules in apache 1.3, but these days I am willing to pass to apache2. The module that I am writing at the moment has is own binary data, not a database, for performance purposes. I need to load this data in shared memory, so every child can access it without making his own copy, and it would be practical to load/create the binary data at startup, as I was used to do with apache 1.3. Problem is that I don't find an init event in apache2, in 1.3 in the module struct, immediatly after STANDARD_MODULE_STUFF you find a place for a /** module initializer */, in which you can put a function that will be executed early. Body of the function I used to write is something like: if ( getppid == 1 ) { // Load global data here // this is the parent process void* data = loadGlobalData( someFilePath ); setGlobalData( config, data ); } else { // this is the init of a child process // do nothing } I am looking for a place in apache2 in where I can put a similar function. Can you help? Thanks Benvenuto

    Read the article

< Previous Page | 550 551 552 553 554 555 556 557 558 559 560 561  | Next Page >