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  • How to reliably run a batch job every 5 seconds?

    - by Benjamin
    I'm building an application where the sending of all notifications (email, SMS, fax) will be asynchronous. The application will write the notifications to the database, and a batch job will read these notifications and send them with the appropriate transport. I was first reading at ways to run cron faster than the minute, and realized this was a bad idea. The batch scripts are written in PHP, and I guess that writing a proper daemon would be quite an overhead (though I'm open to any suggestion, as PHP car run indefinitely as well). What I have in mind is a solution that would: Run the PHP script every 5 seconds Check that the previous run has finished, or abort (never 2 concurrent batches running) Kill the script if live for more than x minutes (a security in case it hangs) Start with the system (if a reboot occurs) Any idea how to do this?

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  • How to get around batch file processing limit

    - by Patrick Cuff
    I have a Windows batch file that processes all the files in a given directory. I have 206,783 files I need to process: for %%f in (*.xml) do call :PROCESS %%f goto :STOP :PROCESS :: do something with the file program.exe %1 > %1.new set /a COUNTER=%COUNTER%+1 goto :EOF :STOP @echo %COUNTER% files processed When I run the batch file, the following output is written: 65535 files processed As part of the processing, an output file is created for each file procesed, with a .new extension. When I do a dir *.new it reports 65,535 files exist. So, it appears my command environment has a hard limit on the number of files it can recognize, and that limit is 64K - 1. Is there a way to extend the command environment to manage more than 64K - 1 files? If not, would a VBScript or JavaScript be able to process all 206,783 files? I'm running on Windows 2003 server, Enterprise Edition, 32-bit. UPDATE It looks like the root cause of my issue was with the built-in Windows "extract" command for ZIP files. The files I have to process were copied from another system via a ZIP file. My server doesn't have a ZIP utility installed, just the native Windows commands. I right-clicked on the ZIP file, and did an "Extract all...", which apparently just extracted the first 65,535 files. I downloaded and installed 7-zip onto my server, unzipped all the files, and my batch script worked as intended.

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  • Unable to load huge XML document (incorrectly suppose it's due to the XSLT processing)

    - by krisvandenbergh
    I'm trying to match certain elements using XSLT. My input document is very large and the source XML fails to load after processing the following code (consider especially the first line). <xsl:template match="XMI/XMI.content/Model_Management.Model/Foundation.Core.Namespace.ownedElement/Model_Management.Package/Foundation.Core.Namespace.ownedElement"> <rdf:RDF> <rdf:Description rdf:about=""> <xsl:for-each select="Foundation.Core.Class"> <xsl:for-each select="Foundation.Core.ModelElement.name"> <owl:Class rdf:ID="@Foundation.Core.ModelElement.name" /> </xsl:for-each> </xsl:for-each> </rdf:Description> </rdf:RDF> </xsl:template> Apparently the XSLT fails to load after "Model_Management.Model". The PHP code is as follows: if ($xml->loadXML($source_xml) == false) { die('Failed to load source XML: ' . $http_file); } It then fails to perform loadXML and immediately dies. I think there are two options now. 1) I should set a maximum executing time. Frankly, I don't know how that I do this for the built-in PHP 5 XSLT processor. 2) Think about another way to match. What would be the best way to deal with this? The input document can be found at http://krisvandenbergh.be/uml_pricing.xml Any help would be appreciated! Thanks.

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  • Apache module, is it possible to have asynchronous processing

    - by prashant2361
    Hi, I have a requirement where I need to send continous updates to my clients. Client is browser in this case. We have some data which updates every sec, so once client connects to our server, we maintain a persistent connection and keep pushing data to the client. I am looking for suggestions of this implementation at the server end. Basically what I need is this: 1. client connects to server. I maintain the socket and metadata about the socket. metadata contains what updates need to be send to this client 2. server process now waits for new client connections 3. One other process will have the list of all the sockets opened and will go through each of them and send the updates if required. Can we do something like this in apache module: 1. apache process gets the new connection. It maintains the state for the connection. It keeps the state in some global memory and returns back to root process to signify that it is done so that it can accept the new connection 2. the apache process though has returned the status to root process but it is also executing parallely where it going through its global store and sending updates to the client, if any. So can a apache process do these things: 1. Have more than one connection associated with it 2. Asynchronously waiting for new connection and at the same time processing the previous connections? Regards Prashant

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  • Is it possible to have asynchronous processing

    - by prashant2361
    Hi, I have a requirement where I need to send continuous updates to my clients. Client is browser in this case. We have some data which updates every sec, so once client connects to our server, we maintain a persistent connection and keep pushing data to the client. I am looking for suggestions of this implementation at the server end. Basically what I need is this: 1. client connects to server. I maintain the socket and metadata about the socket. metadata contains what updates need to be send to this client 2. server process now waits for new client connections 3. One other process will have the list of all the sockets opened and will go through each of them and send the updates if required. Can we do something like this in Apache module: 1. Apache process gets the new connection. It maintains the state for the connection. It keeps the state in some global memory and returns back to root process to signify that it is done so that it can accept the new connection 2. the Apache process though has returned the status to root process but it is also executing in parallel where it going through its global store and sending updates to the client, if any. So can a Apache process do these things: 1. Have more than one connection associated with it 2. Asynchronously waiting for new connection and at the same time processing the previous connections? Regards Prashant

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  • Objective C code to handle large amount of data processing in iPhone

    - by user167662
    I had the following code that takes in 14 mb or more of image data encoded in base4 string and converts them to jpeg before writing to a file in iphone. It crashes my program giving the following error : Program received signal: “0”. warning: check_safe_call: could not restore current frame I tweak my program and it can process a few more images before the error appear again. My coding is as follows: // parameters is an array where the fourth element contains a list of images in base64 >encoded string NSMutableArray *imageStrList = (NSMutableArray*) [parameters objectAtIndex:5]; while (imageStrList.count != 0) { NSString *imgString = [imageStrList objectAtIndex:0]; // Create a file name using my own Utility class NSString *fileName = [Utility generateFileNName]; NSData *restoredImg = [NSData decodeWebSafeBase64ForString:imgString]; UIImage *img = [UIImage imageWithData: restoredImg]; NSData *imgJPEG = UIImageJPEGRepresentation(img, 0.4f); [imgJPEG writeToFile:fileName atomically:YES]; [imageStrList removeObjectAtIndex:0]; } I tried playing around with UIImageJPEGRepresentation and found out that the lower the value, the more image it can processed but this should not be the way. I am wondering if there is anyway to free up memory of the imageStrList immediately after processing each image so that it can be used by the next one in the line.

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  • Program structure in long running data processing python script

    - by fmark
    For my current job I am writing some long-running (think hours to days) scripts that do CPU intensive data-processing. The program flow is very simple - it proceeds into the main loop, completes the main loop, saves output and terminates: The basic structure of my programs tends to be like so: <import statements> <constant declarations> <misc function declarations> def main(): for blah in blahs(): <lots of local variables> <lots of tightly coupled computation> for something in somethings(): <lots more local variables> <lots more computation> <etc., etc.> <save results> if __name__ == "__main__": main() This gets unmanageable quickly, so I want to refactor it into something more manageable. I want to make this more maintainable, without sacrificing execution speed. Each chuck of code relies on a large number of variables however, so refactoring parts of the computation out to functions would make parameters list grow out of hand very quickly. Should I put this sort of code into a python class, and change the local variables into class variables? It doesn't make a great deal of sense tp me conceptually to turn the program into a class, as the class would never be reused, and only one instance would ever be created per instance. What is the best practice structure for this kind of program? I am using python but the question is relatively language-agnostic, assuming a modern object-oriented language features.

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  • Processing more than one button click at Android Widget

    - by dive
    Hi, all. I saw this topic and implement IntentService as describes, but what if I want more that one button? How can I distinguish button from each other? I'm trying to setFlags, but cannot read it at onHandleIntent() method: public static class UpdateService extends IntentService { ... @Override public void onHandleIntent(Intent intent) { ComponentName me = new ComponentName(this, ExampleProvider.class); AppWidgetManager manager = AppWidgetManager.getInstance(this); manager.updateAppWidget(me, buildUpdate(this)); } private RemoteViews buildUpdate(Context context) { RemoteViews updateViews = new RemoteViews(context.getPackageName(), R.layout.main_layout); Intent i = new Intent(this, ExampleProvider.class); PendingIntent pi = PendingIntent.getBroadcast(context, 0, i, 0); updateViews.setOnClickPendingIntent(R.id.button_refresh, pi); i = new Intent(this, ExampleProvider.class); pi = PendingIntent.getBroadcast(context, 0, i, 0); updateViews.setOnClickPendingIntent(R.id.button_about, pi); return updateViews; } } At this little piece of code I have two PendingIntent linked with setOnClickPendingIntent, can I distinguish this intent for different actions and processing? Thanks for help

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  • Processing velocity-vectors during collision as neatly as possible

    - by DevEight
    Hello. I'm trying to create a good way to handle all possible collisions between two objects. Typically one will be moving and hitting the other, and should then "bounce" away. What I've done so far (I'm creating a typical game where you have a board and bounce a ball at bricks) is to check if the rectangles intersect and if they do, invert the Y-velocity. This is a really ugly and temporary solution that won't work in the long haul and since this is kind of processing is very common in games I'd really like to find a great way of doing this for future projects aswell. Any links or helpful info is appreciated. Below is what my collision-handling function looks like right now. protected void collision() { #region Boundaries if (bal.position.X + bal.velocity.X >= viewportRect.Width || bal.position.X + bal.velocity.X <= 0) { bal.velocity.X *= -1; } if (bal.position.Y + bal.velocity.Y <= 0) { bal.velocity.Y *= -1; } #endregion bal.rect = new Rectangle((int)bal.position.X+(int)bal.velocity.X-bal.sprite.Width/2, (int)bal.position.Y-bal.sprite.Height/2+(int)bal.velocity.Y, bal.sprite.Width, bal.sprite.Height); player.rect = new Rectangle((int)player.position.X-player.sprite.Width/2, (int)player.position.Y-player.sprite.Height/2, player.sprite.Width, player.sprite.Height); if (bal.rect.Intersects(player.rect)) { bal.position.Y = player.position.Y - player.sprite.Height / 2 - bal.sprite.Height / 2; if (player.position.X != player.prevPos.X) { bal.velocity.X -= (player.prevPos.X - player.position.X) / 2; } bal.velocity.Y *= -1; } foreach (Brick b in brickArray.list) { b.rect.X = Convert.ToInt32(b.position.X-b.sprite.Width/2); b.rect.Y = Convert.ToInt32(b.position.Y-b.sprite.Height/2); if (bal.rect.Intersects(b.rect)) { b.recieveHit(); bal.velocity.Y *= -1; } } brickArray.removeDead(); }

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  • Java, Massive message processing with queue manager (trading)

    - by Ronny
    Hello, I would like to design a simple application (without j2ee and jms) that can process massive amount of messages (like in trading systems) I have created a service that can receive messages and place them in a queue to so that the system won't stuck when overloaded. Then I created a service (QueueService) that wraps the queue and has a pop method that pops out a message from the queue and if there is no messages returns null, this method is marked as "synchronized" for the next step. I have created a class that knows how process the message (MessageHandler) and another class that can "listen" for messages in a new thread (MessageListener). The thread has a "while(true)" and all the time tries to pop a message. If a message was returned, the thread calls the MessageHandler class and when it's done, he will ask for another message. Now, I have configured the application to open 10 MessageListener to allow multi message processing. I have now 10 threads that all time are in a loop. Is that a good design?? Can anyone reference me to some books or sites how to handle such scenario?? Thanks, Ronny

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  • Processing forms that generate many rows in DB

    - by Zack
    I'm wondering what the best approach to take here is. I've got a form that people use to register for a class and a lot of times the manager of a company will register multiple people for the class at the same time. Presently, they'd have to go through the registration process multiple times and resubmit the form once for every person they want to register. What I want to do is give the user a form that has a single <input/> for one person to register with, along with all the other fields they'll need to fill out (Email, phone number, etc); if they want to add more people, they'll be able to press a button and a new <input/> will be generated. This part I know how to do, but I'm including it to best describe what I'm aiming to do. The part I don't know how to approach is processing that data the form submits, I need some way of making a new row in the Registrant table for every <input/> that's added and include the same contact information (phone, email, etc) as the first row with that row. For the record, I'm using the Django framework for my back-end code. What's the best approach here? Should it just POST the form x times for x people, or is there a less "brute force" way of handling this?

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  • Spring-security not processing pre/post annotations

    - by wuntee
    Trying to get pre/post annotations working with a web application, but for some reason nothing is happening with spring-security. Can anyone see what im missing? web.xml contextConfigLocation /WEB-INF/rvaContext-business.xml /WEB-INF/rvaContext-security.xml <context-param> <param-name>log4jConfigLocation</param-name> <param-value>/WEB-INF/log4j.properties</param-value> </context-param> <!-- Spring security filter --> <filter> <filter-name>springSecurityFilterChain</filter-name> <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class> </filter> <filter-mapping> <filter-name>springSecurityFilterChain</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- - Publishes events for session creation and destruction through the application - context. Optional unless concurrent session control is being used. --> <listener> <listener-class>org.springframework.security.web.session.HttpSessionEventPublisher</listener-class> </listener> <listener> <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class> </listener> <servlet> <servlet-name>rva</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>rva</servlet-name> <url-pattern>/rva/*</url-pattern> </servlet-mapping> rvaContext-secuity.xml: <?xml version="1.0" encoding="UTF-8"?> <beans:beans xmlns="http://www.springframework.org/schema/security" xmlns:beans="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.0.xsd"> <global-method-security pre-post-annotations="enabled"/> <http use-expressions="true"> <form-login /> <logout /> <remember-me /> <!-- Uncomment to limit the number of sessions a user can have --> <session-management invalid-session-url="/timeout.jsp"> <concurrency-control max-sessions="1" error-if-maximum-exceeded="true" /> </session-management> <form-login login-page="rva/login" /> </http> ... LoginController class: @Controller @RequestMapping("/login") public class LoginController { @RequestMapping(method = RequestMethod.GET) public String login(ModelMap map){ map.addAttribute("title", "Login: AD Credentials"); return("login"); } @RequestMapping("/secure") @PreAuthorize("hasRole('ROLE_USER')") public String secure(ModelMap map){ return("secure"); } } In the logs, there is nothing even related to spring-security: logs: INFO: Initializing Spring FrameworkServlet 'rva' INFO [org.springframework.web.servlet.DispatcherServlet] - FrameworkServlet 'rva': initialization started INFO [org.springframework.web.context.support.XmlWebApplicationContext] - Refreshing WebApplicationContext for namespace 'rva-servlet': startup date [Fri Mar 26 10:28:51 MDT 2010]; parent: Root WebApplicationContext INFO [org.springframework.beans.factory.xml.XmlBeanDefinitionReader] - Loading XML bean definitions from ServletContext resource [/WEB-INF/rva-servlet.xml] INFO [org.springframework.beans.factory.support.DefaultListableBeanFactory] - Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@a2fc31: defining beans [loginController,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,freemarkerConfig,viewResolver]; parent: org.springframework.beans.factory.support.DefaultListableBeanFactory@cc74e7 INFO [org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer] - ClassTemplateLoader for Spring macros added to FreeMarker configuration INFO [org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping] - Mapped URL path [/login/secure] onto handler [com.cable.comcast.neto.nse.rva.controller.LoginController@79b32a] INFO [org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping] - Mapped URL path [/login/secure.*] onto handler [com.cable.comcast.neto.nse.rva.controller.LoginController@79b32a] INFO [org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping] - Mapped URL path [/login/secure/] onto handler [com.cable.comcast.neto.nse.rva.controller.LoginController@79b32a] INFO [org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping] - Mapped URL path [/login] onto handler [com.cable.comcast.neto.nse.rva.controller.LoginController@79b32a] INFO [org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping] - Mapped URL path [/login.*] onto handler [com.cable.comcast.neto.nse.rva.controller.LoginController@79b32a] INFO [org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping] - Mapped URL path [/login/] onto handler [com.cable.comcast.neto.nse.rva.controller.LoginController@79b32a] INFO [org.springframework.web.servlet.DispatcherServlet] - FrameworkServlet 'rva': initialization completed in 417 ms Mar 26, 2010 10:28:52 AM org.apache.coyote.http11.Http11Protocol start INFO: Starting Coyote HTTP/1.1 on http-8080 Mar 26, 2010 10:28:52 AM org.apache.jk.common.ChannelSocket init INFO: JK: ajp13 listening on /0.0.0.0:8009 Mar 26, 2010 10:28:52 AM org.apache.jk.server.JkMain start INFO: Jk running ID=0 time=0/31 config=null Mar 26, 2010 10:28:52 AM org.apache.catalina.startup.Catalina start INFO: Server startup in 1873 ms WARN [org.springframework.web.servlet.PageNotFound] - No mapping found for HTTP request with URI [/rva-web/] in DispatcherServlet with name 'rva'

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  • Error processing Spree sample images - file not recognized by identify command in paperclip geometry.rb:29

    - by purpletonic
    I'm getting an error when I run the Spree sample data. It occurs when Spree tries to load in the product data, specifically the product images. Here's the error I'm getting: * Execute db:load_file loading ruby <GEM DIR>/sample/lib/tasks/../../db/sample/spree/products.rb -- Processing image: ror_tote.jpeg rake aborted! /var/folders/91/63kgbtds2czgp0skw3f8190r0000gn/T/ror_tote.jpeg20121007-21549-2rktq1 is not recognized by the 'identify' command. <GEM DIR>/paperclip-2.7.1/lib/paperclip/geometry.rb:31:in `from_file' <GEM DIR>/spree/core/app/models/spree/image.rb:35:in `find_dimensions' I've made sure ImageMagick is installed correctly, as previously I was having problems with it. Here's the output I'm getting when running the identify command directly. $ identify Version: ImageMagick 6.7.7-6 2012-10-06 Q16 http://www.imagemagick.org Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC Features: OpenCL ... other usage info omitted ... I also used pry with the pry-debugger and put a breakpoint in geometry.rb inside of Paperclip. Here's what that section of geometry.rb looks like: # Uses ImageMagick to determing the dimensions of a file, passed in as either a # File or path. # NOTE: (race cond) Do not reassign the 'file' variable inside this method as it is likely to be # a Tempfile object, which would be eligible for file deletion when no longer referenced. def self.from_file file file_path = file.respond_to?(:path) ? file.path : file raise(Errors::NotIdentifiedByImageMagickError.new("Cannot find the geometry of a file with a blank name")) if file_path.blank? geometry = begin silence_stream(STDERR) do binding.pry Paperclip.run("identify", "-format %wx%h :file", :file => "#{file_path}[0]") end rescue Cocaine::ExitStatusError "" rescue Cocaine::CommandNotFoundError => e raise Errors::CommandNotFoundError.new("Could not run the `identify` command. Please install ImageMagick.") end parse(geometry) || raise(Errors::NotIdentifiedByImageMagickError.new("#{file_path} is not recognized by the 'identify' command.")) end At the point of my binding.pry statement, the file_path variable is set to the following: file_path => "/var/folders/91/63kgbtds2czgp0skw3f8190r0000gn/T/ror_tote.jpeg20121007-22732-1ctl1g1" I've also double checked that this exists, by opening my finder in this directory, and opened it with preview app; and also that the program can run identify by running %x{identify} in pry, and I receive the same version Version: ImageMagick 6.7.7-6 2012-10-06 Q16 as before. Removing the additional digits (is this a timestamp?) after the file extension and running the Paperclip.run command manually in Pry gives me a different error: Cocaine::ExitStatusError: Command 'identify -format %wx%h :file' returned 1. Expected 0 I've also tried manually updating the Paperclip gem in Spree to 3.0.2 and still get the same error. So, I'm not really sure what else to try. Is there still something incorrect with my ImageMagick setup?

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  • What is the "opposite" of request serialization called?

    - by Adam Lindberg
    For example, if a request is made to a resource and another identical request is made before the first has returned a result, the server returns the result of the first request for the second request as well. This to avoid unnecessary processing on the resource. This is not the same thing as caching/memoization since it only concerns identical requests ongoing in parallel. Is there a term for the reuse of results for currently ongoing requests to a resource for the purpose of minimizing processing?

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  • how to wait multiple function processing to finish

    - by user351412
    I have a problem about multiple function processing , listed as below code, the main function is btnEvalClick, I have try to use alter native 1and 2 to wait the function not move to next record before theprocessed function finish, but it does not work //private function btnEvalClick(event:Event):void { // var i:int; // for(i= 0; i < (dataArr1.length); i++) { // dispatchEvent( new FlexEvent('test') ); // callfunc1('cydatGMX'); //call function 1 // callfun2('cydatGMO'); //call function 1 // editSave(); //save record (HTTP) //## Alternative 1 //if (String(event) == 'SAVEOK') { // RecMov('next'); //move record if save = OK //} //## Alternative 2 //while (waitfc == '') // if waitfc not 'OK' continue looping //{ // z = z + 1; //} // RecMov('next'); //Move to next record to process //} //private function callfunc1(tasal:String):void { // var mySO :SharedObject; // var myDP: Array; // var i:int; // var prm:Array; // try // { // mySO = SharedObject.getLocal(tasal,'/'); // prm = mySO.data.txt.split('?'); // for(i=0; i < (prm.length - 1); i++) { // myDP = prm[i].toString().split('^'); // if ( myDP[0].toString() == String(dataArr1[dg].MatrixCDCol)){ // myDPX = myDP; // break; // } // } // } // catch (err:Error) { // Alert.show('Limit object creation fail (' + tasal + '), please retry ); // } //} //private function editSave():void //{ // var parameters:* = // { // 'CertID': CertIDCol.text, 'AssetID': AssetIDCol.text, 'CertDate': cdt, //'Ccatat': CcatatCol.text, 'CertBy': CertByCol.text, 'StatusID': StatusIDCol.text, //'UpdDate': lele, 'UpdUsr': ApplicationState.instance.luNm }; // doRequest('Update', parameters, saveItemHandler); //} //private function doRequest(method_name:String, parameters:Object, callback:Function):void // { // add the method to the parameters list // parameters['method'] = (method_name + 'ASC'); // gateway.request = parameters; // var call:AsyncToken = gateway.send(); // call.request_params = gateway.request; // call.handler = callback; // } //private function saveItemHandler(e:Object):void // { // if (e.isError) // { // Alert.show('Error: ' + e.data.error); // } // else // { // Alert.show('Record Saved..'); // waitfc = 'OK'; // dispatchEvent( new FlexEvent('SAVEOK') ); // } // }

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  • Parallel programming patterns for C#?

    - by VoidDweller
    With Intel's launch of a Hexa-Core processor for the desktop, it looks like we can no longer wait for Microsoft to make many-core programming "easy". I just order a copy of Joe Duffy's book Concurrent Programming on Windows. This looks like a great place to start, though, I am hoping some of you who have been targeting multi/many core systems would point me to some good resources that have or would have helped on your projects?

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  • How to learn about Threads, Especially in Java.

    - by Javed Ahamed
    I have always been kind of confused by threads, and my class right now makes heavy use of them. We are using java.util.concurrent but I don't even really get the basics. UpDownLatch, Futures, Executors; these words just fly over my head. Can you guys suggest any resources to help learn what I need from the ground up? Thanks a lot in advance!

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  • Fastest way to move records from a oracle DB into MS sql server after processing

    - by user347748
    Hi.. Ok this is the scenario...I have a table in Oracle that acts like a queue... A VB.net program reads the queue and calls a stored proc in MS SQL Server that processes and then inserts the message into another SQL server table and then deletes the record from the oracle table. We use a datareader to read the records from Oracle and then call the stored proc for each of the records. The program seems to be a little slow. The stored procedure itself isnt slow. The SP by itself when called in a loop can process about 2000 records in 20 seconds. BUt when called from the .Net program, the execution time is about 5 records per second. I have seen that most of the time consumed is in calling the stored procedure and waiting for it to return. Is there a better way of doing this? Here is a snippet of the actual code Function StartDataXfer() As Boolean Dim status As Boolean = False Try SqlConn.Open() OraConn.Open() c.ErrorLog(Now.ToString & "--Going to Get the messages from oracle", 1) If GetMsgsFromOracle() Then c.ErrorLog(Now.ToString & "--Got messages from oracle", 1) If ProcessMessages() Then c.ErrorLog(Now.ToString & "--Finished Processing all messages in the queue", 0) status = True Else c.ErrorLog(Now.ToString & "--Failed to Process all messages in the queue", 0) status = False End If Else status = True End If StartDataXfer = status Catch ex As Exception Finally SqlConn.Close() OraConn.Close() End Try End Function Private Function GetMsgsFromOracle() As Boolean Try OraDataAdapter = New OleDb.OleDbDataAdapter OraDataTable = New System.Data.DataTable OraSelCmd = New OleDb.OleDbCommand GetMsgsFromOracle = False With OraSelCmd .CommandType = CommandType.Text .Connection = OraConn .CommandText = GetMsgSql End With OraDataAdapter.SelectCommand = OraSelCmd OraDataAdapter.Fill(OraDataTable) If OraDataTable.Rows.Count > 0 Then GetMsgsFromOracle = True End If Catch ex As Exception GetMsgsFromOracle = False End Try End Function Private Function ProcessMessages() As Boolean Try ProcessMessages = False PrepareSQLInsert() PrepOraDel() i = 0 Dim Method As Integer Dim OraDataRow As DataRow c.ErrorLog(Now.ToString & "--Going to call message sending procedure", 2) For Each OraDataRow In OraDataTable.Rows With OraDataRow Method = GetMethod(.Item(0)) SQLInsCmd.Parameters("RelLifeTime").Value = c.RelLifetime SQLInsCmd.Parameters("Param1").Value = Nothing SQLInsCmd.Parameters("ID").Value = GenerateTransactionID() ' Nothing SQLInsCmd.Parameters("UID").Value = Nothing SQLInsCmd.Parameters("Param").Value = Nothing SQLInsCmd.Parameters("Credit").Value = 0 SQLInsCmd.ExecuteNonQuery() 'check the return value If SQLInsCmd.Parameters("ReturnValue").Value = 1 And SQLInsCmd.Parameters("OutPutParam").Value = 0 Then 'success 'delete the input record from the source table once it is logged c.ErrorLog(Now.ToString & "--Moved record successfully", 2) OraDataAdapter.DeleteCommand.Parameters("P(0)").Value = OraDataRow.Item(6) OraDataAdapter.DeleteCommand.ExecuteNonQuery() c.ErrorLog(Now.ToString & "--Deleted record successfully", 2) OraDataAdapter.Update(OraDataTable) c.ErrorLog(Now.ToString & "--Committed record successfully", 2) i = i + 1 Else 'failure c.ErrorLog(Now.ToString & "--Failed to exec: " & c.DestIns & "Status: " & SQLInsCmd.Parameters("OutPutParam").Value & " and TrackId: " & SQLInsCmd.Parameters("TrackID").Value.ToString, 0) End If If File.Exists("stop.txt") Then c.ErrorLog(Now.ToString & "--Stop File Found", 1) 'ProcessMessages = True 'Exit Function Exit For End If End With Next OraDataAdapter.Update(OraDataTable) c.ErrorLog(Now.ToString & "--Updated Oracle Table", 1) c.ErrorLog(Now.ToString & "--Moved " & i & " records from Oracle to SQL Table", 1) ProcessMessages = True Catch ex As Exception ProcessMessages = False c.ErrorLog(Now.ToString & "--MoveMsgsToSQL: " & ex.Message, 0) Finally OraDataTable.Clear() OraDataTable.Dispose() OraDataAdapter.Dispose() OraDelCmd.Dispose() OraDelCmd = Nothing OraSelCmd = Nothing OraDataTable = Nothing OraDataAdapter = Nothing End Try End Function Public Function GenerateTransactionID() As Int64 Dim SeqNo As Int64 Dim qry As String Dim SqlTransCmd As New OleDb.OleDbCommand qry = " select seqno from StoreSeqNo" SqlTransCmd.CommandType = CommandType.Text SqlTransCmd.Connection = SqlConn SqlTransCmd.CommandText = qry SeqNo = SqlTransCmd.ExecuteScalar If SeqNo > 2147483647 Then qry = "update StoreSeqNo set seqno=1" SqlTransCmd.CommandText = qry SqlTransCmd.ExecuteNonQuery() GenerateTransactionID = 1 Else qry = "update StoreSeqNo set seqno=" & SeqNo + 1 SqlTransCmd.CommandText = qry SqlTransCmd.ExecuteNonQuery() GenerateTransactionID = SeqNo End If End Function Private Function PrepareSQLInsert() As Boolean 'function to prepare the insert statement for the insert into the SQL stmt using 'the sql procedure SMSProcessAndDispatch Try Dim dr As DataRow SQLInsCmd = New OleDb.OleDbCommand With SQLInsCmd .CommandType = CommandType.StoredProcedure .Connection = SqlConn .CommandText = SQLInsProc .Parameters.Add("ReturnValue", OleDb.OleDbType.Integer) .Parameters("ReturnValue").Direction = ParameterDirection.ReturnValue .Parameters.Add("OutPutParam", OleDb.OleDbType.Integer) .Parameters("OutPutParam").Direction = ParameterDirection.Output .Parameters.Add("TrackID", OleDb.OleDbType.VarChar, 70) .Parameters.Add("RelLifeTime", OleDb.OleDbType.TinyInt) .Parameters("RelLifeTime").Direction = ParameterDirection.Input .Parameters.Add("Param1", OleDb.OleDbType.VarChar, 160) .Parameters("Param1").Direction = ParameterDirection.Input .Parameters.Add("TransID", OleDb.OleDbType.VarChar, 70) .Parameters("TransID").Direction = ParameterDirection.Input .Parameters.Add("UID", OleDb.OleDbType.VarChar, 20) .Parameters("UID").Direction = ParameterDirection.Input .Parameters.Add("Param", OleDb.OleDbType.VarChar, 160) .Parameters("Param").Direction = ParameterDirection.Input .Parameters.Add("CheckCredit", OleDb.OleDbType.Integer) .Parameters("CheckCredit").Direction = ParameterDirection.Input .Prepare() End With Catch ex As Exception c.ErrorLog(Now.ToString & "--PrepareSQLInsert: " & ex.Message) End Try End Function Private Function PrepOraDel() As Boolean OraDelCmd = New OleDb.OleDbCommand Try PrepOraDel = False With OraDelCmd .CommandType = CommandType.Text .Connection = OraConn .CommandText = DelSrcSQL .Parameters.Add("P(0)", OleDb.OleDbType.VarChar, 160) 'RowID .Parameters("P(0)").Direction = ParameterDirection.Input .Prepare() End With OraDataAdapter.DeleteCommand = OraDelCmd PrepOraDel = True Catch ex As Exception PrepOraDel = False End Try End Function WHat i would like to know is, if there is anyway to speed up this program? Any ideas/suggestions would be highly appreciated... Regardss, Chetan

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  • Convert color photos of documents to good black-and-white images?

    - by Norman Ramsey
    Since I don't have a copier or scanner, I'm using an 8 megapixel camera to copy documents. This works pretty well except they need a lot of processing afterward. I'd like to get from a photo to a bitmap, but using djpeg -grayscale -pnm photo.jpg | pgmtopbm -threshold -value XXX does not work so well, for two reasons: It's hard to guess what XXX should be, and XXX is different for different photos. Illumination varies, and sometimes a single threshold isn't what's right for the image. How can I do better? The ideal solution will be fully automatic command-line program that I can run on Linux. (I have already written a program to remove dark pixels from the edges of images.)

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  • WPF Infinite loop in references found while processing the Template

    - by Ryan
    I am pretty new to WPF and am getting this error after my mouse is over my custom listbox item. Error: Infinite loop in references found while processing the Template for an element named '' of type 'System.Windows.Controls.TextBox'. <Window.Resources> <ControlTemplate x:Key="MouseOverFocusTemplate" > <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FF6FB8FD" FontSize="24" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="#FF013B73" Offset="0.501"/> <GradientStop Color="#FF091F34"/> <GradientStop Color="#FF014A8F" Offset="0.5"/> <GradientStop Color="#FF003363" Offset="1"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </ControlTemplate> <Style x:Key="MouseOverFocusStyle" TargetType="{x:Type TextBox}"> <Setter Property="Template" Value="{StaticResource MouseOverFocusTemplate}"/> </Style> <ControlTemplate x:Key="LostFocusTemplate" > <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FF6FB8FD" FontSize="24" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <ScaleTransform CenterX="0.5" CenterY="0.5"/> <SkewTransform CenterX="0.5" CenterY="0.5"/> <RotateTransform CenterX="0.5" CenterY="0.5"/> <TranslateTransform/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <GradientStop Color="#FF091F34" Offset="1"/> <GradientStop Color="#FF002F5C" Offset="0.4"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </ControlTemplate> <Style x:Key="LostFocusStyle" TargetType="{x:Type TextBox}"> <Setter Property="Template" Value="{StaticResource LostFocusTemplate}"/> </Style> <ControlTemplate x:Key="GotFocusTemplate" > <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FFE38E27" FontSize="24" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="Black" Offset="0.501"/> <GradientStop Color="#FF091F34"/> <GradientStop Color="#FF002F5C" Offset="0.5"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </ControlTemplate> <Style x:Key="GotFocusStyle" TargetType="{x:Type TextBox}"> <Setter Property="Template" Value="{StaticResource GotFocusTemplate}"/> </Style> <Style TargetType="ListBoxItem"> <EventSetter Event="GotFocus" Handler="ListItem_GotFocus"></EventSetter> <EventSetter Event="LostFocus" Handler="ListItem_LostFocus"></EventSetter> <EventSetter Event="Mouse.MouseMove" Handler="ListItem_MouseOver"></EventSetter> </Style> <DataTemplate DataType="{x:Type TextBlock}"> </DataTemplate> <DataTemplate x:Key="CustomListData" DataType="{x:Type ListBoxItem}"> <Border BorderBrush="Black" BorderThickness="1" Margin="-2,0,0,-1"> <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <Grid.RenderTransform> <TransformGroup> <ScaleTransform ScaleX="1" ScaleY="1"/> <SkewTransform AngleX="0" AngleY="0"/> <RotateTransform Angle="0"/> <TranslateTransform X="0" Y="0"/> </TransformGroup> </Grid.RenderTransform> <!--<ScrollViewer x:Name="PART_ContentHost" />--> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FF6FB8FD" FontSize="24" FocusVisualStyle="{StaticResource GotFocusStyle}" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <ScaleTransform CenterX="0.5" CenterY="0.5"/> <SkewTransform CenterX="0.5" CenterY="0.5"/> <RotateTransform CenterX="0.5" CenterY="0.5"/> <TranslateTransform/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <GradientStop Color="#FF091F34" Offset="1"/> <GradientStop Color="#FF002F5C" Offset="0.4"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </Border> </DataTemplate> <Style TargetType="{x:Type ListBox}"> <Setter Property="ItemTemplate" Value="{StaticResource CustomListData }" /> <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled" /> </Style> </Window.Resources> <Window.DataContext> <ObjectDataProvider ObjectType="{x:Type local:ImageLoader}" MethodName="LoadImages" /> </Window.DataContext> <ListBox ItemsSource="{Binding}" Width="320" Background="#FF021422" BorderBrush="#FF1C4B79"> <ListBox.Resources> <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}">Transparent</SolidColorBrush> </ListBox.Resources> </ListBox> The code behind for the mouse over event is as follows private void ListItem_MouseOver(object sender, RoutedEventArgs e) { e.Handled = true; FrameworkElement element = e.OriginalSource as FrameworkElement; if (element != null) { while (VisualTreeHelper.GetParent(element) != null) { element = VisualTreeHelper.GetParent(element) as FrameworkElement; TextBox item = element as TextBox; if (item != null) { item.Style = (Style)item.FindResource("MouseOverFocusStyle"); return; } } } } What am I missing? Is there an easier way to do this ? Thanks in advance Ryan

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  • Is FreeBSD more suitable than CentOS for firing 40k concurrent connections (for Jmeter)?

    - by blacklotus
    Hi, I am trying to run Jmeter to simulate 40k concurrent users and stress test a particular system. Putting aside the possibility that Jmeter may not be able to push such a high number (although I have read that it is at least possible to handle 10k concurrent threads on a very powerful machine), is FreeBSD a more suitable OS as compare to CentOS to be used for my Jmeter machine for handling 40k (or as high as possible) of concurrent outbound connections? Reason for asking this is that, I have found articles on FreeBSD for tuning and optimizing for maximum outbound connections, but seem to have little luck with CentOS. It makes me wonder if for some specific reasons, people don't use CentOS for such high number of outbound connections. Personally however, I am more familiar with CentOS and would like to stick with it if possible. Any input is greatly appreciated!

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  • Does LINQ require significantly more processing cycles and memory than lower-level data iteration techniques?

    - by Matthew Patrick Cashatt
    Background I am recently in the process of enduring grueling tech interviews for positions that use the .NET stack, some of which include silly questions like this one, and some questions that are more valid. I recently came across an issue that may be valid but I want to check with the community here to be sure. When asked by an interviewer how I would count the frequency of words in a text document and rank the results, I answered that I would Use a stream object put the text file in memory as a string. Split the string into an array on spaces while ignoring punctuation. Use LINQ against the array to .GroupBy() and .Count(), then OrderBy() said count. I got this answer wrong for two reasons: Streaming an entire text file into memory could be disasterous. What if it was an entire encyclopedia? Instead I should stream one block at a time and begin building a hash table. LINQ is too expensive and requires too many processing cycles. I should have built a hash table instead and, for each iteration, only added a word to the hash table if it didn't otherwise exist and then increment it's count. The first reason seems, well, reasonable. But the second gives me more pause. I thought that one of the selling points of LINQ is that it simply abstracts away lower-level operations like hash tables but that, under the veil, it is still the same implementation. Question Aside from a few additional processing cycles to call any abstracted methods, does LINQ require significantly more processing cycles to accomplish a given data iteration task than a lower-level task (such as building a hash table) would?

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  • Branchless memory manager?

    - by Richard Fabian
    Anyone thought about how to write a memory manager (in C++) that is completely branch free? I've written a pool, a stack, a queue, and a linked list (allocating from the pool), but I am wondering how plausible it is to write a branch free general memory manager. This is all to help make a really reusable framework for doing solid concurrent, in-order CPU, and cache friendly development. Edit: by branchless I mean without doing direct or indirect function calls, and without using ifs. I've been thinking that I can probably implement something that first changes the requested size to zero for false calls, but haven't really got much more than that. I feel that it's not impossible, but the other aspect of this exercise is then profiling it on said "unfriendly" processors to see if it's worth trying as hard as this to avoid branching.

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  • Can in-memory SQLite databases be used concurrently?

    - by Kent Boogaart
    In order to prevent a SQLite in-memory database from being cleaned up, one must use the same connection to access the database. However, using the same connection causes SQLite to synchronize access to the database. Thus, if I have many threads performing reads against an in-memory database, it is slower on a multi-core machine than the exact same code running against a file-backed database. Is there any way to get the best of both worlds? That is, an in-memory database that permits multiple, concurrent calls to the database?

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