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  • What's slowing for loops/assignment vs. C?

    - by Lee
    I have a collection of PHP scripts that are extremely CPU intensive, juggling millions of calculations across hundreds of simultaneous users. I'm trying to find a way to speed up the internals of PHP variable assignment, and looping sequences vs C. Although PHP is obviously loosely typed, is there any way/extension to specifically assign type (assign, not cast, which seems even more expensive) in a C-style fashion? Here's what I mean. This is some dummy code in C: #include <stdio.h> int main() { unsigned long add=0; for(unsigned long x=0;x<100000000;x++) { add = x*59328409238; } printf("x is %ld\n",add); } Pretty self-explanatory -- it loops 100 million times, multiples each iteration by an arbitrary number of some 59 billion, assigns it to a variable and prints it out. On my Macbook, compiling it and running it produced: lees-macbook-pro:Desktop lee$ time ./test2 x is 5932840864471590762 real 0m0.266s user 0m0.253s sys 0m0.002s Pretty darn fast! A similar script in PHP 5.3 CLI... <?php for($i=0;$i<100000000;$i++){ $a=$i*59328409238; } echo $a."\n"; ?> ... produced: lees-macbook-pro:Desktop lee$ time /Applications/XAMPP/xamppfiles/bin/php test3.php 5.93284086447E+18 real 0m22.837s user 0m22.110s sys 0m0.078s Over 22 seconds vs 0.2! I realize PHP is doing a heck of a lot more behind the scenes than this simple C program - but is there any way to make the PHP internals to behave more 'natively' on primitive types and loops?

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  • Switching from ListView to VirtualStringTree

    - by Jeff
    Hey S.O! I am trying to build my projects with a VirtualStringTree rather than a Listview, because of the vast speed difference. The thing is, even after looking thru the demo's, I just can't figure out exactly how I would use it as a ListView. Like, adding, deleting, and basically just working with ListView items is so easy, but when I look at the VT, it gets almost too complicated. All I am looking for, is a VT that looks like a ListView, with subitems etc. Here are some routines using the ListView, that I would like to use with VT (This is just a pseudo example: procedure Add; begin with ListView.Items.Add do Begin Caption := EditCaption.Text; SubItems.Add(EditSubItem.Text): End; end; Procedure ReadItem(I : Integer); begin ShowMessage(ListView.Items[I].Caption); ShowMessage(ListView.Items[I].SubItems[0]); end; Of course, also the Delete function, but since thats like 1 line, I didnt bother :P Could anyone maybe translate the above examples into using a ListView style VT? Thanks!

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  • SQL MIN in Sub query causes huge delay

    - by Spencer
    I have a SQL query that I'm trying to debug. It works fine for small sets of data, but in large sets of data, this particular part of it causes it to take 45-50 seconds instead of being sub second in speed. This subquery is one of the select items in a larger query. I'm basically trying to figure out when the earliest work date is that fits in the same category as the current row we are looking at (from table dr) ISNULL(CONVERT(varchar(25),(SELECT MIN(drsd.DateWorked) FROM [TableName] drsd WHERE drsd.UserID = dr.UserID AND drsd.Val1 = dr.Val1 OR (((drsd.Val2 = dr.Val2 AND LEN(dr.Val2) > 0) AND (drsd.Val3 = dr.Val3 AND LEN(dr.Val3) > 0) AND (drsd.Val4 = dr.Val4 AND LEN(dr.Val4) > 0)) OR (drsd.Val5 = dr.Val5 AND LEN(dr.Val5) > 0) OR ((drsd.Val6 = dr.Val6 AND LEN(dr.Val6) > 0) AND (drsd.Val7 = dr.Val7 AND LEN(dr.Val2) > 0))))), '') AS WorkStartDate, This winds up executing a key lookup some 18 million times on a table that has 346,000 records. I've tried creating an index on it, but haven't had any success. Also, selecting a max value in this same query is sub second in time, as it doesn't have to execute very many times at all. Any suggestions of a different approach to try? Thanks!

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  • maven and lift using scala 2.8 : lift-mapper missing?

    - by Bjorn J
    Newbie question since I'm not up to speed using maven at all. I'm trying to use scala + lift using scala 2.8, environment is a win7 box if that matters. I create a basic project using: mvn archetype:generate -U -DarchetypeGroupId=net.liftweb -DarchetypeArtifactId=lift-archetype-basic -DarchetypeVersion=2.0-scala280-SNAPSHOT -DarchetypeRepository=http://scala-tools.org/repo-snapshots -DremoteRepositories=http://scala-tools.org/repo-snapshots -DgroupId=com.liftworkshop -DartifactId=todo -Dversion=1.0-SNAPSHOT So far so good, but then, I try to cd into my new project and do: mvn jetty:run I after quite a few downloads end up with a error like below: [ERROR] BUILD ERROR [INFO] ------------------------------------------------------------------------ [INFO] Failed to resolve artifact. Missing: ---------- 1) net.liftweb:lift-mapper:jar:2.0-scala280-SNAPSHOT Try downloading the file manually from the project website. Then, install it using the command: mvn install:install-file -DgroupId=net.liftweb -DartifactId=lift-mapper -D version=2.0-scala280-SNAPSHOT -Dpackaging=jar -Dfile=/path/to/file Alternatively, if you host your own repository you can deploy the file there: mvn deploy:deploy-file -DgroupId=net.liftweb -DartifactId=lift-mapper -Dve rsion=2.0-scala280-SNAPSHOT -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -Dr epositoryId=[id] Path to dependency: 1) com.liftworkshop:todo:war:1.0-SNAPSHOT 2) net.liftweb:lift-mapper:jar:2.0-scala280-SNAPSHOT ---------- 1 required artifact is missing. for artifact: com.liftworkshop:todo:war:1.0-SNAPSHOT from the specified remote repositories: scala-tools.snapshots (http://scala-tools.org/repo-snapshots), scala-tools.releases (http://scala-tools.org/repo-releases), central (http://repo1.maven.org/maven2) Any ideas?

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  • Is it possible to store ObjectContext on the client when using WCF and Entity Framework?

    - by Sergey
    Hello, I have a WCF service which performs CRUD operation on my data model: Add, Get, Update and Delete. And I'm using Entity Framework for my data model. On the other side there is a client application which calls methods of the WCF service. For example I have a Customer class: [DataContract] public class Customer { public Guid CustomerId {get; set;} public string CustomerName {get; set;} } and WCF service defines this method: public void AddCustomer(Customer c) { MyEntities _entities = new MyEntities(); _entities.AddToCustomers(c); _entities.SaveChanges(); } and the client application passes objects to the WCF service: var customer = new Customer(){CustomerId = Guid.NewGuid, CustomerName="SomeName"}; MyService svc = new MyService(); svc.Add(customer); // or svc.Update(customer) for example But when I need to pass a great amount of objects to the WCF it could be a perfomance issue because of I need to create ObjectContext each time when I'm doing Add(), Update(), Get() or Delete(). What I'm thinking on is to keep ObjectContext on the client and pass ObjectContext to the wcf methods as additional parameter. Is it possible to create and keep ObjectContext on the client and don't recreate it for each operation? If it is not, how could speed up the passing of huge amount of data to the wcf service? Sergey

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  • Fastest way to remove non-numeric characters from a VARCHAR in SQL Server

    - by Dan Herbert
    I'm writing an import utility that is using phone numbers as a unique key within the import. I need to check that the phone number does not already exist in my DB. The problem is that phone numbers in the DB could have things like dashes and parenthesis and possibly other things. I wrote a function to remove these things, the problem is that it is slow and with thousands of records in my DB and thousands of records to import at once, this process can be unacceptably slow. I've already made the phone number column an index. I tried using the script from this post: http://stackoverflow.com/questions/52315/t-sql-trim-nbsp-and-other-non-alphanumeric-characters But that didn't speed it up any. Is there a faster way to remove non-numeric characters? Something that can perform well when 10,000 to 100,000 records have to be compared. Whatever is done needs to perform fast. Update Given what people responded with, I think I'm going to have to clean the fields before I run the import utility. To answer the question of what I'm writing the import utility in, it is a C# app. I'm comparing BIGINT to BIGINT now, with no need to alter DB data and I'm still taking a performance hit with a very small set of data (about 2000 records). Could comparing BIGINT to BIGINT be slowing things down? I've optimized the code side of my app as much as I can (removed regexes, removed unneccessary DB calls). Although I can't isolate SQL as the source of the problem anymore, I still feel like it is.

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  • Can get coordinates from iPhone simulator, but can't get coordinates from iPhone device

    - by iPhoneARguy
    Hi everyone, I've run into something of a mysterious bug (to me). I have some code to pick out the user's current location on the iPhone SDK. It works fine on the iPhone simulator, but when I try to run it on the actual device, I get a weird error. Here is the code (I am using ASIFormDataRequest to create a POST request): ASIFormDataRequest * request = [ASIFormDataRequest requestWithURL:url]; [request setPostValue:@"testauthor" forKey:@"author"]; [request setPostValue:[[NSNumber numberWithDouble:datum.location.coordinate.latitude] stringValue] forKey:@"latitude"]; NSLog(@"%f", datum.location.coordinate.latitude); NSLog(@"%f", datum.location.coordinate.longitude); [request setPostValue:[[NSNumber numberWithDouble:datum.location.coordinate.longitude] stringValue] forKey:@"longitude"]; [request setPostValue:datum.comment forKey:@"comment"]; On the simulator, NSLog does log both the latitude and longitude, but on the iPhone, it does not. Even stranger, when I go through with the debugger on the device, I try "po datum.location", I get <+###, -###> +/- 223.10m (speed 0.00 mps / course -1.00) @ 2010-05-02 22:18:37 -0400 (### replaced by my location) but when I do "(gdb) po datum.location.coordinate" I get: There is no member named coordinate. Do you guys have any idea why this might happen? Thanks in advance for your help!

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  • Tips on creating user interfaces and optimizing the user experience

    - by Saif Bechan
    I am currently working on a project where a lot of user interaction is going to take place. There is also a commercial side as people can buy certain items and services. In my opinion a good blend of user interface, speed and security is essential for these types of websites. It is fairly easy to use ajax and JavaScript nowadays to do almost everything, as there are a lot of libraries available such as jQuery and others. But this can have some performance and incompatibility issues. This can lead to users just going to the next website. The overall look of the website is important too. Where to place certain buttons, where to place certain types of articles such as faq and support. Where and how to display error messages so that the user sees them but are not bothering him. And an overall color scheme is important too. The basic question is: How to create an interface that triggers a user to buy/use your services I know psychology also plays a huge role in how users interact with your website. The color scheme for example is important. When the colors are irritating on a website you just want to click away. I have not found any articles that explain those concept. Does anyone have any tips and/or recourses where i can get some articles that guide you in making the correct choices for your website.

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  • How can I encrypt CoreData contents on an iPhone

    - by James A. Rosen
    I have some information I'd like to store statically encrypted on an iPhone application. I'm new to iPhone development, some I'm not terribly familiar with CoreData and how it integrates with the views. I have the data as JSON, though I can easily put it into a SQLITE3 database or any other backing data format. I'll take whatever is easiest (a) to encrypt and (b) to integrate with the iPhone view layer. The user will need to enter the password to decrypt the data each time the app is launched. The purpose of the encryption is to keep the data from being accessible if the user loses the phone. For speed reasons, I would prefer to encrypt and decrypt the entire file at once rather than encrypting each individual field in each row of the database. Note: this isn't the same idea as Question 929744, in which the purpose is to keep the user from messing with or seeing the data. The data should be perfectly transparent when in use. Also note: I'm willing to use SQLCipher to store the data, but would prefer to use things that already exist on the iPhone/CoreData framework rather than go through the lengthy build/integration process involved.

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  • .NET assembly cache / ngen / jit image warm-up and cool-down behavior

    - by Mike Jiang
    Hi, I have an Input Method (IME) program built with C#.NET 2.0 DLL through C++/CLI. Since an IME is always attaching to another application, the C#.NET DLL seems not able to avoid image address rebasing. Although I have applied ngen to create a native image of that C#.NET 2.0 DLL and installed it into Global Assembly Cache, it didn't improved much, approximately 12 sec. down to 9 sec. on a slow PIII level PC. Therefore I uses a small application, which loads all the components referenced by the C#.NET DLL at the boot up time, to "warm up" the native image of that DLL. It works fine to speed up the loading time to 0.5 sec. However, it only worked for a while. About 30 min. later, it seems to "cool down" again. Is there any way to control the behavior of GAC or native image to be always "hot"? Is this exactly a image address rebasing problem? Thank you for your precious time. Sincerely, Mike

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  • Error when creating a new entity foo, editing a previously existing foo, then saving. Generic 4004 e

    - by Tarks
    The steps are as simple as that so I imagine there's something else going on here, the problem is I just get back 4004, no exception anywhere etc, making it annoying to debug, I get this from the ie error window Microsoft JScript runtime error: Unhandled Error in Silverlight Application Code: 4004 Category: ManagedRuntimeError Message: System.Windows.Ria.DomainOperationException: Submit operation failed. An error occurred while updating the entries. See the inner exception for details. at System.Windows.Ria.OperationBase.Complete(Exception error) at System.Windows.Ria.SubmitOperation.Complete(Exception error) at System.Windows.Ria.DomainContext.CompleteSubmitChanges(IAsyncResult asyncResult) at System.Windows.Ria.DomainContext.<c_DisplayClassd.b_5(Object ) public void TurnPage(bool forward) { TurnPageForward = forward; // If the pages are already turning then don't try and skip days, just run the animation function so it inreases the speed if (!workBook.IsTransitioning && !IsWaitingForData) { IsWaitingForData = true; workBook.SnapshotPages(); NoteCtx.SubmitChanges().Completed += (s, a) => { workBook.ClearPageContents(); CurrentDate = CurrentDate.AddDays(forward ? 1 : -1); PullNotes(CurrentDate); }; } else { workBook.BeginTurnPages(TurnPageForward); } } public void PullNotes(DateTime? noteTime) { NoteCtx.NoteItems.Clear(); var loadOp = NoteCtx.Load(NoteCtx.GetNoteItemsForDayQuery(CurrentDate)); loadOp.Completed += new EventHandler(NotesReady); }

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  • what can be causes of http server crash?

    - by mithunmo
    Hello , I am using WAMP server on Windows XP. - Apache 2.2.11 - MySQL 5.1.36 (INNODB engine) - PHP 5.3.0 I observe that my WAMP server crashes in the following scenarios 1) IF I use a Low end PC ( low processor speed and low RAM) 2) After making some changes to httpd.conf file .For eg changing the Allow from IP address . But here it crashes only once and then it starts to work fine. 3) Random crashes CRASH LOG szAppName : httpd.exe szAppVer : 2.2.11.0 szModName : php5ts.dll szModVer : 5.3.0.0 offset : 0000c309 C:\DOCUME~1\blrcom\LOCALS~1\Temp\WERc677.dir00\httpd.exe.mdmp C:\DOCUME~1\blrcom\LOCALS~1\Temp\WERc677.dir00\appcompat.txt My questions 1) Does high CPU utilization/LOW RAM can also cause the HTTP server to crash ? 2) excessive file reading as in every 10 seconds ? 3) unlimited script execution time . I have set the maximum execution time in php script to 0 as my script has to execute for sometimes 2-3 days. Is there any way to avoid this ? 4) Access to Database ? Should we use lock before reading and writing Can these be the reasons for random wamp server crashes ? OR is is some other programming error ? Please guide me . Regards, Mithun

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  • Looking for ideas for a simple pattern matching algorithm to run on a microcontroller

    - by pic_audio
    I'm working on a project to recognize simple audio patterns. I have two data sets, each made up of between 4 and 32 note/duration pairs. One set is predefined, the other is from an incoming data stream. The length of the two strongly correlated data sets is often different, but roughly the same "shape". My goal is to come up with some sort of ranking as to how well the two data sets correlate/match. I have converted the incoming frequencies to pitch and shifted the incoming data stream's pitch so that it's average pitch matches that of the predefined data set. I also stretch/compress the incoming data set's durations to match the overall duration of the predefined set. Here are two graphical examples of data that should be ranked as strongly correlated: http://s2.postimage.org/FVeG0-ee3c23ecc094a55b15e538c3a0d83dd5.gif (Sorry, as a new user I couldn't directly post images) I'm doing this on a 8-bit microcontroller so resources are minimal. Speed is less an issue, a second or two of processing isn't a deal breaker. It wouldn't surprise me if there is an obvious solution, I've just been staring at the problem too long. Any ideas? Thanks in advance...

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  • How to Watch Youtube Videos on PSP with iMoviesoft FLV Converter

    - by user312417
    Do you have worried about it? You can not watch Youtube videos anytime, anywhere.It is so boring on the way to work and home.How you want to be able to enjoy the wonderful Youtube Video on PSP that you can watch them on the way to home, home on bus. This artice will tell you about how to convert Youtube VIdeos to PSP Player, take "Alice.in.Wonderland" as an example, We can use iMoviesoft FLV Converter to convert it to PSP video file. iMoviesoft FLV Converter is a powerful FLV Converter which can convert FLV and YouTube Videos to almost any video formats, with excellent conversion speed and quality, such as converting FLV to MP4, FLV to AVI, FLV to WMV, FLV to MPEG etc. Furthermore, it can also easily convert video files to some popular audio formats, such as WMA, MP3, M4A, AAC, etc. You can convert FLV and YouTube videos to PSP, iPod, iPhone, Zune video player and other portable video players. After easy and wonderful conversion, you can fully enjoy videos on your PSP, iPod, iPhone and some other portable video players. Besides, you can also use it to join videos. Merge several videos into one output PSP video and enjoy them conveniently. You can also trim your favarite clips or remove the video black edges by [iMoviesoft FLV Converter. Hope to help every Video Enthusiasts.

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  • Do I really need an ORM?

    - by alchemical
    We're about to begin development on a mid-size ASP.Net MVC 2 web site. For a typical page, we grab data and throw it up on the web page, i.e. there is not much pre-processing of the data before it is sent to the UI. We're now making the decision whether or not to use an ORM and if yes, which one. We had been looking at EF2 AKA EF4 (ASP.Net Entity Framework in VS 2010) as one possibility. However, I'm thinking a simple solution in this case may be just to use datatables. The reason being that we don't plan to move the data around or process it a lot once we fetch it, so I'm not sure there is that much value in having strongly-typed objects as DTOs. Also, this way we avoid mapping altogether, thereby I think simplifying the code and allowing for faster development. I should mention budget is an issue on this project, as well as speed of execution. We are striving for simplicity anywhere we can, both to keep the budget smaller, the schedule shorter, and performance fast. We haven't fully decided this yet, but are currently leaning towards no ORM. Will we be OK with the no ORM approach or is an ORM worth it?

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  • Optimizing Levenshtein Distance Algorithm

    - by Matt
    I have a stored procedure that uses Levenshtein Distance to determine the result closest to what the user typed. The only thing really affecting the speed is the function that calculates the Levenshtein Distance for all the records before selecting the record with the lowest distance (I've verified this by putting a 0 in place of the call to the Levenshtein function). The table has 1.5 million records, so even the slightest adjustment may shave off a few seconds. Right now the entire thing runs over 10 minutes. Here's the method I'm using: ALTER function dbo.Levenshtein ( @Source nvarchar(200), @Target nvarchar(200) ) RETURNS int AS BEGIN DECLARE @Source_len int, @Target_len int, @i int, @j int, @Source_char nchar, @Dist int, @Dist_temp int, @Distv0 varbinary(8000), @Distv1 varbinary(8000) SELECT @Source_len = LEN(@Source), @Target_len = LEN(@Target), @Distv1 = 0x0000, @j = 1, @i = 1, @Dist = 0 WHILE @j <= @Target_len BEGIN SELECT @Distv1 = @Distv1 + CAST(@j AS binary(2)), @j = @j + 1 END WHILE @i <= @Source_len BEGIN SELECT @Source_char = SUBSTRING(@Source, @i, 1), @Dist = @i, @Distv0 = CAST(@i AS binary(2)), @j = 1 WHILE @j <= @Target_len BEGIN SET @Dist = @Dist + 1 SET @Dist_temp = CAST(SUBSTRING(@Distv1, @j+@j-1, 2) AS int) + CASE WHEN @Source_char = SUBSTRING(@Target, @j, 1) THEN 0 ELSE 1 END IF @Dist > @Dist_temp BEGIN SET @Dist = @Dist_temp END SET @Dist_temp = CAST(SUBSTRING(@Distv1, @j+@j+1, 2) AS int)+1 IF @Dist > @Dist_temp SET @Dist = @Dist_temp BEGIN SELECT @Distv0 = @Distv0 + CAST(@Dist AS binary(2)), @j = @j + 1 END END SELECT @Distv1 = @Distv0, @i = @i + 1 END RETURN @Dist END Anyone have any ideas? Any input is appreciated. Thanks, Matt

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  • How to use javascript-xpath

    - by Nirmal Patel
    I am using Selenium RC with IE 6 and XPath locators are terribly slow. So I am trying to see if javascript-xpath actually speeds up things. But could not find enough/clear documentation on how to use native x- path libraries. I am doing the following: protected void startSelenium (String testServer, String appName, String testInBrowser){ selenium = new DefaultSelenium("localhost", 4444, "*" +testInBrowser, testServer+ "/"+ appName + "/"); echo("selenium instance created:"+selenium.getClass()); selenium.start(); echo("selenium instance started..." + testServer + "/" + appName +"/"); selenium.runScript("lib/javascript-xpath-latest-cmp.js"); selenium.useXpathLibrary("javascript-xpath"); selenium.allowNativeXpath("true"); } This results in speed improvement of XPath locator but the improvements are not consistent. On some runs the time taken for a locator is halved; while sometimes its randomly high. Am I missing any configuration step here? Would be great if someone who has had success with this could share their views and approach. Thanks, Nirmal

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  • Playing online video on iphone web, the iphone seems to cache the reference movie

    - by Mad Oxyn
    We are working on an online mobile video app, and are trying to play a reference movie on an iphone from the iphone browser. The problem is, the movie plays the first time, but when we try to play a different movie the second time, it doesnt. Quicktime gives a general error message sayin "Cannot Play Movie". More precisely this is what we are trying to do: Connect with an iPhone to a webserver that serves a reference movie (generated with quicktime pro). The ref movie automatically gets downloaded to the iphone by quicktime. Quicktime then chooses one of the 3 references in the reference movie, based on the connection speed, and tries to download the designated movie via a relative path. A servlet gets called and forwards the relative path to the right movie. This all works the first time. However the second time when we want download different movies, we get the quicktime error. Test case: Open reference movie 1 Movie plays in Quicktime Open reference movie 2 ERROR: Quicktime gives an error - Cannot Play Movie Shut down Iphone Turn Iphone on again Open reference movie 2 Iphone plays movie Open movie ERROR: Quicktime gives an error - Cannot Play Movie Did anyone encounter similar issues with quicktime and the use of reference movies and is there something we can do to work around that?

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  • CKEditor plugin to close editor

    - by David Lawson
    The problem with destroying the editor from within a plugin, is that certain code tries to use the editor after the destructive plugin code, when in fact the editor is no longer there, causing errors and instability. I have come up with the following code for a plugin which closes the editor using both async:true and setTimeout: var cancelAddCmd = { modes : { wysiwyg:1, source:1 }, async: true, exec : function( editor ) { if(confirm('Are you sure you want to cancel editing and discard all content?')) setTimeout(function() { editor.destroy(); }, 100); } }; The problem I see is that it uses a dodgy setTimout call that would likely have mixed results depending on the computer's speed of execution - 100ms might not have passed by the time it would be OK to destroy the editor. Is there a proper way to destroy the editor from within a plugin? Even with async: true; and no setTimeout errors are created. Maybe a possible solution would be to stop any existing/any more code related to the editor from running afterwards, if possible? I have tried using events, like on('afterCommandExec', function(){ editor.destroy(); }) and some other events, but that hasn't helped much... doesn't seem like there is an event for when the editor has jumped out of its stack call for handling the button. And there is no way to stop execution by disposing of the CKEditor instance more properly?

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  • Large number of simultaneous long-running operations in Qt

    - by Hostile Fork
    I have some long-running operations that number in the hundreds. At the moment they are each on their own thread. My main goal in using threads is not to speed these operations up. The more important thing in this case is that they appear to run simultaneously. I'm aware of cooperative multitasking and fibers. However, I'm trying to avoid anything that would require touching the code in the operations, e.g. peppering them with things like yieldToScheduler(). I also don't want to prescribe that these routines be stylized to be coded to emit queues of bite-sized task items...I want to treat them as black boxes. For the moment I can live with these downsides: Maximum # of threads tend to be O(1000) Cost per thread is O(1MB) To address the bad cache performance due to context-switches, I did have the idea of a timer which would juggle the priorities such that only idealThreadCount() threads were ever at Normal priority, with all the rest set to Idle. This would let me widen the timeslices, which would mean fewer context switches and still be okay for my purposes. Question #1: Is that a good idea at all? One certain downside is it won't work on Linux (docs say no QThread::setPriority() there). Question #2: Any other ideas or approaches? Is QtConcurrent thinking about this scenario? (Some related reading: how-many-threads-does-it-take-to-make-them-a-bad-choice, many-threads-or-as-few-threads-as-possible, maximum-number-of-threads-per-process-in-linux)

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  • PostgreSQL: Full Text Search - How to search partial words ?

    - by Anthoni Gardner
    Hello, Following a question posted here about how I can increase the speed on one of my SQL Search methods, I was advised to update my table to make use of Full Text Search. This is what I have now done, using Gist indexes to make searching faster. On some of the "plain" queries I have noticed a marked increase which I am very happy about. However, I am having difficulty in searching for partial words. For example I have several records that contain the word Squire (454) and I have several records that contain Squirrel (173). Now if I search for Squire it only returns the 454 records but I also want it to return the Squirrel records as well. My query looks like this SELECT title FROM movies WHERE vectors @@ to_tsoquery('squire'); I thought I could do to_tsquery('squire%') but that does not work. How do I get it to search for partial matches ? Also, in my database I have records that are movies and others that are just TV Shows. These are differentiated by the "" over the name, so like "Munsters" is a TV Show, whereas The Munsters is the film of the show. What I want to be able to do is search for just the TV Show AND just the movies. Any idea on how I can achieve this ? Regards Anthoni

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  • Netbeans Profile JUnit 4 problem

    - by Krishna K
    I have a unit test that takes 200 sec to run. I am trying to use NetBeans profiler to speed it up. But the profiler doesn't run the unit test. It just creates an object of the test and exits. Doesn't run the actual test methods or @Before / @After methods. This is a maven project with surefire and junit 4. And partial output is below. Profiler Agent: Waiting for connection on port 5140, timeout 10 seconds (Protocol version: 9) Profiler Agent: Established local connection with the tool ------------------------------------------------------- T E S T S ------------------------------------------------------- Running com.cris.puzzle.solvers.SudokuSolverTest Tests run: 0, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.031 sec Results : Tests run: 0, Failures: 0, Errors: 0, Skipped: 0 Profiler Agent: Connection with agent closed Profiler Agent: Connection with agent closed Profiler Agent: Initializing... Profiler Agent: Options: >C:/Program Files/NetBeans 6.8/profiler3/lib,5140,10< Profiler Agent: Initialized succesfully ------------------------------------------------------------------------ BUILD SUCCESSFUL ------------------------------------------------------------------------ Total time: 14 seconds Does anyone know how to make it work? Thank you.

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  • Java and tomcat vs ASP.NET and IIS

    - by Mark Cooper
    Until recently I'd considered myself to be a pretty good web programmer (coming up for 10yrs commercial experience on a variety of e-commerce, static and enterprise applications). I'm self taught and have always used the Microsoft product stack (ASP, ASP.NET)... My applications are always functional, relatively bug free, but have never been lightening quick. As a frequent web user I always found this to be the norm... how fast are the websites from the big tech players (eBay, Facebook, Microsoft, IBM, Dell, Telerik etc etc) - in truth none are particularly fast. I always attributed this to "the way things are with web apps"... ...then I cam across a product called Jira from atlasian and this has stopped me in my tracks... This application is fast, and I mean blindingly fast.. too fast to time the switches between pages, fully live content, lots of images and data and cross references etc etc... I run this on an intranet, with a large application DB, and this is running on a very normal server (single processor, SATA HDD, 8GB RAM). Am I missing something?? Are my programming techniques that bad?? I am wondering if this speed gain is down to it being written in Java and running on Tomcat. Does anyone have any benchmarks to compare JSP / ASP or Tomcat / IIS??? Thanks, Mark NOTE: this isn't a blatant plug for Jira. I don't work for them or have any affiliation to them... but I would like to be able to write applications like them :)

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  • Which key:value store to use with Python?

    - by Kurt
    So I'm looking at various key:value (where value is either strictly a single value or possibly an object) stores for use with Python, and have found a few promising ones. I have no specific requirement as of yet because I am in the evaluation phase. I'm looking for what's good, what's bad, what are the corner cases these things handle well or don't, etc. I'm sure some of you have already tried them out so I'd love to hear your findings/problems/etc. on the various key:value stores with Python. I'm looking primarily at: memcached - http://www.danga.com/memcached/ python clients: http://pypi.python.org/pypi/python-memcached/1.40 http://www.tummy.com/Community/software/python-memcached/ CouchDB - http://couchdb.apache.org/ python clients: http://code.google.com/p/couchdb-python/ Tokyo Tyrant - http://1978th.net/tokyotyrant/ python clients: http://code.google.com/p/pytyrant/ Lightcloud - http://opensource.plurk.com/LightCloud/ Based on Tokyo Tyrant, written in Python Redis - http://code.google.com/p/redis/ python clients: http://pypi.python.org/pypi/txredis/0.1.1 MemcacheDB - http://memcachedb.org/ So I started benchmarking (simply inserting keys and reading them) using a simple count to generate numeric keys and a value of "A short string of text": memcached: CentOS 5.3/python-2.4.3-24.el5_3.6, libevent 1.4.12-stable, memcached 1.4.2 with default settings, 1 gig memory, 14,000 inserts per second, 16,000 seconds to read. No real optimization, nice. memcachedb claims on the order of 17,000 to 23,000 inserts per second, 44,000 to 64,000 reads per second. I'm also wondering how the others stack up speed wise.

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  • Java (Tomcat): how to configure a cookieless subdomain to serve static content

    - by Webinator
    One of the tip given by both Google and Yahoo! to speed up webpages loading is to configure a cookieless subdomain to server static content. How do you configure a "cookieless subdomain" using Tomcat in standalone mode (this question is not about how to use Apache to serve static content in a cookieless-way, but about how to do it in Tomcat-standalone mode)? Note that I don't care about filters supporting If-Modified-Since nor care about filters supporting gzipping: the static content I'm serving is forever cacheable (or its name will change) and it is already compressed data (so gzip would only slow down the transfer). Do I need two different Tomcat webapps? (one "cookiefull" and one "cookieless") Do I need two different servlets? (as of now I've got only one dispatcher/controller servlet). Why would a "regular" link to, say, a static image be called in a cookiefull way when it would be on the same domain as the main webapp and then be called in a "cookie-less" way when it is on a subdomain? I don't understand exactly what is going on: is it the browser that decides to append or not cookies to the query? If so, why would it not append the cookies to a static query on a "cookieless" subdomain. Any example as to what is going on behind the scene is most welcome :)

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