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  • curl_multi_exec stops if one url is 404, how can I change that?

    - by Rob
    Currently, my cURL multi exec stops if one url it connects to doesn't work, so a few questions: 1: Why does it stop? That doesn't make sense to me. 2: How can I make it continue? EDIT: Here is my code: $SQL = mysql_query("SELECT url FROM shells") ; $mh = curl_multi_init(); $handles = array(); while($resultSet = mysql_fetch_array($SQL)){ //load the urls and send GET data $ch = curl_init($resultSet['url'] . $fullcurl); //Only load it for two seconds (Long enough to send the data) curl_setopt($ch, CURLOPT_TIMEOUT, 5); curl_multi_add_handle($mh, $ch); $handles[] = $ch; } // Create a status variable so we know when exec is done. $running = null; //execute the handles do { // Call exec. This call is non-blocking, meaning it works in the background. curl_multi_exec($mh,$running); // Sleep while it's executing. You could do other work here, if you have any. sleep(2); // Keep going until it's done. } while ($running > 0); // For loop to remove (close) the regular handles. foreach($handles as $ch) { // Remove the current array handle. curl_multi_remove_handle($mh, $ch); } // Close the multi handle curl_multi_close($mh);

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  • LinqToSQL: Not possible to update PrimaryKey?

    - by Zuhaib
    I have a simple table (lets call it Table1) that has a NVARCHAR field as the PK. Table1 has no association with any other tables. When I update Table1's PK column using LinqToSQL it fails. If I update other column it succeeds. I could delete this row and insert new one in Table1, but I don't want to. There is a transaction table which has Table1's PK column as a column. When the PK of Table1 is changed I want no effect in the transaction table. But when the row from Table1 is deleted, I want the transaction rows to be deleted. The cascading is done via Trigger. As there is not association between these two tables, if I update the PK column of Table1 using normal SQL, it works and there is no effect on the transaction table as expected. When I delete the row the trigger deletes the rows from transaction table. For this reason I can't delete and then add new row in Table1. So what can be done to successfully update the PrimaryKey of the Table1?

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  • Can this auto-stretcing scenario be realized undex XHTML/CSS?

    - by Vilx-
    I want two horizontal areas in my webpage. The first one is the menu. It's on the top. Unfortunately I don't know its size, and it might change in response to user actions. Below the menu is the main area which should stretch at least as far as the bottom of the window (if there is little content) or beyond (if there is a lot of content. To illustrate with ASCII art: +----------------------------------------------------+ | This area resizes vertically depending on contents | +----------------------------------------------------+ | This area stretches to the bottom of the window, | | but can be even larger if necessary. Note: this | | should be a separate area because it will contain | | children with height:100% as well. | | | +----------------------------------------------------+ Can this be done? Can it be done with Javascript? Added: To put things in perspective and avoid confusion, think of it this way: the top menu is generated by myself, but the bottom area is an IFrame which I want to fill the rest of the page. This is what it eventually comes down to anyway in my case.

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  • How to Store and Retrieve Images Using MsSQL (Server Management Studio)

    - by Joe Majewski
    I am having difficulties when trying to insert files into an MsSQL database. I'll try to break this down as best as I can: What data type should I be using to store image files (jpeg/png/gif/etc)? Right now my table is using the image data type, but I am curious if varbinary would be a better option. How would I go about inserting the image into the database? Does Microsoft SQL Server Management Studio have any built in functions that allow insertions of files into tables? If so, how is that done? Also, how could this be done through the use of an HTML form with PHP handling the input data and placing it into the table? How would I fetch the image from the table and display it on the page? I understand how to SELECT the cell's contents, but how would I go about translating that into a picture. Would I have to have a header(Content type: image/jpeg)? I have no problem doing any of these things with MySQL, but the MsSQL environment is still new to me, and I am working on a project for my job that requires the use of stored procedures to grab various data. Any and all help is appreciated. Thank you very much for your responses!

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  • VB.NET: Dialog exits when enter pressed?

    - by Camilo Martin
    Hi all; My problem seems to be quite simple, but it's not working the intuitive way. I'm designing a Windows Forms Application, and there is a dialog that should NOT exit when the enter key is pressed, instead it has to validate data first, in case enter was pressed after changing the text of a ComboBox. I've tried by telling it what to do on KeyPress event of the ComboBox if e is the Enter key: Private Sub ComboBoxSizeChoose_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles ComboBoxSizeChoose.KeyPress If e.KeyChar = Convert.ToChar(Keys.Enter) Then Try TamanhoDaNovaFonte = Single.Parse(ComboBoxSizeChoose.Text) Catch ex As Exception Dim Dialogo2 As New Dialog2 Dialog2.ShowDialog() ComboBoxSizeChoose.Text = TamanhoDaNovaFonte End Try End If End Sub But no success so far. When the Enter key is pressed, even with the ComboBox on focus, the whole dialog is closed, returning to the previous form. The validation is NOT done at all, and it has to be done before exiting. In fact, I don't even want to exit on the form's enter KeyPress, the only purpose of the enter key on the whole dialog is to validate the ComboBox (but only when in focus, for the sake of an intuitive UI). I've also tried appending the validation to the KeyPress event of the whole dialog's form, if the key is Enter. NO SUCCESS! It's like my code wasn't there at all. What should I do? (Visual Studio 2008, VB.NET)

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  • real time stock quotes, StreamReader performance optimization

    - by sean717
    I am working on a program that extracts real time quote for 900+ stocks from a website. I use HttpWebRequest to send HTTP request to the site and store the response to a stream and open a stream using the following code: HttpWebResponse response = (HttpWebResponse)request.GetResponse(); Stream stream = response.GetResponseStream (); StreamReader reader = new StreamReader( stream ) the size of the received HTML is large (5000+ lines), so it takes a long time to parse it and extract the price. For 900 files, It takes about 6 mins for parsing and extracting. Which my boss isn't happy with, he told me he'd want the whole process to be done in TWO mins. I've identified the part of the program that takes most of time to finish is parsing and extracting. I've tried to optimize the code to make it faster, the following is what I have now after some optimization: // skip lines at the top for(int i=0;i<1500;++i) reader.ReadLine(); // read the line that contains the price string theLine = reader.ReadLine(); // ... extract the price from the line now it takes about 4 mins to process all the files, there is still a significant gap to what my boss's expecting. So I am wondering, is there other way that I can further speed up the parsing and extracting and have everything done within 2 mins?

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  • How to install Zend Framework on Windows

    - by sombe
    "installing Zend Framework is so easy!!!!" yeah right... Ok I'm working with a beginner's book and the ONE thing that is not excessively detailed is the most important part: Installing the darn thing. After browsing the quickstart guide for hours, all it said was: "download Zend [...] add the include directory (bla bla) and YOU'RE DONE!" right, i'm done using Zend. Ok, not really, not yet anyway. I beg of you people, I wanna go to bed, please tell me how (in simple 6th grade detail) to install the framework. I've got the unzipped folder in my htdocs directory, and I placed zf.bat+zf.php in the htdocs root. What's next? thank you so much. EDIT: Thanks guys for all the answers. Unfortunately I haven't been able to work with this or find a good enough resource to explain it to me in plain english. It seems that this framework adheres more so to programmers than to beginners. I've since yesterday read a little on CakePHP and found that it was incredibly easy to install and tune. As oppose to Zend Framework, where I had to dig in my "environment variables", configure "httpd.conf" and almost tie the knot between my computer driver cables to just get it running, CakePHP has already allowed me to put together a nice newbie application. In conclusion, I very much appreciate all of your help. I hope someone else venturing on ZF will be more successful with it. Thanks!

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  • Convert Google Analytics cookies to Local/Session Storage

    - by David Murdoch
    Google Analytics sets 4 cookies that will be sent with all requests to that domain (and ofset its subdomains). From what I can tell no server actually uses them directly; they're only sent with __utm.gif as a query param. Now, obviously Google Analytics reads, writes and acts on their values and they will need to be available to the GA tracking script. So, what I am wondering is if it is possible to: rewrite the __utm* cookies to local storage after ga.js has written them delete them after ga.js has run rewrite the cookies FROM local storage back to cookie form right before ga.js reads them start over Or, monkey patch ga.js to use local storage before it begins the cookie read/write part. Obviously if we are going so far out of the way to remove the __utm* cookies we'll want to also use the Async variant of Analytics. I'm guessing the down vote was because I didn't ask a question. DOH! My questions are: Can it be done as described above? If so, why hasn't it been done? I have a default HTML/CSS/JS boilerplate template that passes YSlow, PageSpeed, and Chrome's Audit with near perfect scores. I'm really looking for a way to squeeze those remaining cookie bytes from Google Analytics in browsers that support local storage.

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  • how to return a list using SwingWorker

    - by Ender
    I have an assignment where i have to create an Image Gallery which uses a SwingWorker to load the images froma a file, once the image is load you can flip threw the image and have a slideshow play. I am having trouble getting the list of loaded images using SwingWorker. This is what happens in the background it just publishes the results to a TextArea // In a thread @Override public List<Image> doInBackground() { List<Image> images = new ArrayList<Image>(); for (File filename : filenames) { try { //File file = new File(filename); System.out.println("Attempting to add: " + filename.getAbsolutePath()); images.add(ImageIO.read(filename)); publish("Loaded " + filename); System.out.println("Added file" + filename.getAbsolutePath()); } catch (IOException ioe) { publish("Error loading " + filename); } } return images; } } when it is done I just insert the images in a List<Image> and that is all it does. // In the EDT @Override protected void done() { try { for (Image image : get()) { list.add(image); } } catch (Exception e) { } } Also I created an method that returns the list called getImages() what I need to get is the list from getImages() but doesn't seam to work when I call execute() for example MySwingWorkerClass swingworker = new MySwingWorkerClass(log,list,filenames); swingworker.execute(); imageList = swingworker.getImage() Once it reaches the imageList it doesn't return anything the only way I was able to get the list was when i used the run() instead of the execute() is there another way to get the list or is the run() method the only way?. or perhaps i am not understanding the Swing Worker Class.

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  • How to best launch C++ application from web page

    - by JB
    I guess there are two parts to this question, one technical and one best practice for security and doing things "right". I'm working on a little game using C++ / directx but I would like to be able to launch it from a web page by someone clicking on a link on that page. Ideally I would like the first time they clicked for it to launch an installer downloads and installs the game on their machine, and then the next time to launch an application which updates the game from a web site if it's old and then launches it. I have no problems with the expected security popups and questions the first time it runs. I want people to be certain what they are installing and understand what they are doing. But it would be nice if once it is installed they could run it with the minimum of fuss. My question then is what technologies I could use to do this? I'm thinking that it would need a browser plugin and an activex control so that first time you'd install that, and subsequently the control/plugin would be able to launch the game. I'm not sure that under newer browser secuity models that a plugin would have the permissions to be able to run an installer though or silently invoke applications on the client machine even if they are already installed. Is there a more sensible way to achive what I want to achieve? And I'm worried about the security aspects too. I want this to be convenient for users but I of course want to do it "right". I know this can be done as I've seen several mmorpg type games that launch in this way from the browser now but it's not entirely clear to me how they've done it.

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  • What shall be the code in xaml which makes a particular image to act as a button?

    - by Abhi
    Dear all I am new to Silverlight. And i have to make a demo application where in designing is done by using Microsoft Expression Blend 2 and developing should be done using Visual Studio(c++). Now i am first trying to become familiar with xaml files. So i was trying to make a simple demo where in i have to create a button and that button should be replace with an png image. In order to do so i tried with the mentioned below example. But i was not able to see anything in the screen. <UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="SilverlightApplication1.Page" Width="640" Height="480"> <Grid x:Name="LayoutRoot" Background="White"> <Button x:Name="LogoutButton" > <Button.Template> <ControlTemplate> <Image Source="SilverlightApplication1\bounce_photo.png" /> </ControlTemplate> </Button.Template> </Button> </Grid> Please let me know where i am wrong and what shall i do to obtain the result. With regards Abhineet Agarwal

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  • Not able to connect to TFS Server from TFS Proxy

    - by GV India
    In our office we have setup TFS for project development. The TFS Server is WIN 2003 server SP2 with VSTFS 2008 and is running fine. Now we need to setup a TFS Proxy server on client site for client to access. Before going for the client setup, I wanted to build and test proxy in our office on a dummy server (will call it Proxy server hereon) by keeping it on a different domain. OS configuration of the Proxy server is the same as TFS server. I have installed and configured TFS proxy on Proxy server to connect to TFS Server. Also we have built trust between the two different domains to enable communication. Now problem is that I am not able to at all connect to TFS server. I am trying to connect from Internet Explorer of proxy server using proxy service account. It gives me error: The page cannot be displayed. HTTP 500 - Internal server error. The page I was browsing was http://tfs:8080/VersionControl/v1.0/ProxyStatistics.asmx. I think I have done all the required steps correctly to configure proxy as described in MSDN and also TFS installation guide. Here Proxy service account is a member of ‘Team Foundation Valid Users’ group. I am able to connect to TFS Server (specifying port) using Telnet from command prompt on proxy server as suggested by few sites. The TFS server web sites have been configured to use Integration Windows Authentication. Event Logs on both the servers are also not giving any error. Overall I’m not able to get it done. Any ideas on what might be the problem???

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  • Java object graph -> xml when direction of object association needs to be reversed.

    - by Sigmoidal
    An application I have been working on has objects with a relationship similar to below. In the real application both objects are JPA entities. class Underlying{} class Thing { private Underlying underlying; public Underlying getUnderlying() { return underlying; } public void setUnderlying(final Underlying underlying) { this.underlying = underlying; } } There is a requirement in the application to create xml of the form: <template> <underlying> <thing/> <thing/> <thing/> </underlying> </template> So we have a situation where the object graph expresses the relationship between Thing and Underlying in the opposite direction to how it's expressed in the xml. I expect to use JAXB to create the xml but ideally I don't want to have to create a new object hierarchy to reflect the associations in the xml. Is there any way to create xml of the form required from the entities in their current form (through the use of xml annotations or something)? I don't have any experience using JAXB but from the limited research I've done it doesn't seem like it's possible to reverse the direction of association in any straightforward way. Any help/advice would be greatly appreciated. One other option that has been suggested is to use XLST to transform the xml into the correct format. I have done no research on this topic as yet but I'll add to the question when I have some more info. Thanks, Matt.

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  • Multiple Inheritence with same Base Classes in Python

    - by Jordan Reiter
    I'm trying to wrap my head around multiple inheritance in python. Suppose I have the following base class: class Structure(object): def build(self, *args): print "I am building a structure!" self.components = args And let's say I have two classes that inherit from it: class House(Structure): def build(self, *args): print "I am building a house!" super(House, self).build(*args) class School(Structure): def build(self, type="Elementary", *args): print "I am building a school!" super(School, self).build(*args) Finally, a create a class that uses multiple inheritance: class SchoolHouse(School, House): def build(self, *args): print "I am building a schoolhouse!" super(School, self).build(*args) Then, I create a SchoolHouse object and run build on it: >>> sh = SchoolHouse() >>> sh.build("roof", "walls") I am building a schoolhouse! I am building a house! I am building a structure! So I'm wondering -- what happened to the School class? Is there any way to get Python to run both somehow? I'm wondering specifically because there are a fair number of Django packages out there that provide custom Managers for models. But there doesn't appear to be a way to combine them without writing one or the other of the Managers as inheriting from the other one. It'd be nice to just import both and use both somehow, but looks like it can't be done? Also I guess it'd just help to be pointed to a good primer on multiple inheritance in Python. I have done some work with Mixins before and really enjoy using them. I guess I just wonder if there is any elegant way to combine functionality from two different classes when they inherit from the same base class.

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  • Android: onListItemClick not opening up the .xml file

    - by Capsud
    Hi, public void onListItemClick(ListView l, View v, int position, long id) { if(position == 0){ setContentView(R.layout.cuisine); } } I have an array of Strings and i'm using the above method to try and open up a new xml file called 'cuisine' when it is clicked. but it keeps failing! Have I done this right, or what am I doing wrong? Thanks. Ok from looking at similar problems on the web, people have said to get the onListItemClick() to start a new activity and using that new activity to then open up the new view? So what i've done is this... protected void onListItemClick(ListView l, View v, int position, long id) { Intent dundrumIntent = new Intent(v.getContext(), DundrumSelector.class); dundrumIntent.putExtra("position", position); startActivityForResult(dundrumIntent, 0); } and then import android.app.Activity; import android.os.Bundle; public class DundrumSelector extends Activity { @Override public void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); int position = getIntent().getExtras().getInt("position"); if(position == 0){ setContentView(R.layout.cuisine); } } } Yet i'm still getting the same problem. The program crashes when I click on an item in the listView. And yes i've added the activity to the manifest. Does anyone have a resolution to this as alot of people seem to be having the same problem. Thanks alot.

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  • Any merit to a lazy-ish juxt function?

    - by NielsK
    In answering a question about a function that maps over multiple functions with the same arguments (A: juxt), I came up with a function that basically took the same form as juxt, but used map: (defn could-be-lazy-juxt [& funs] (fn [& args] (map #(apply %1 %2) funs (repeat args)))) => ((juxt inc dec str) 1) [2 0 "1"] => ((could-be-lazy-juxt inc dec str) 1) (2 0 "1") => ((juxt * / -) 6 2) [12 3 4] => ((could-be-lazy-juxt * / -) 6 2) (12 3 4) As posted in the original question, I have little clue about the laziness or performance of it, but timing in the REPL does suggest something lazy-ish is going on. => (time (apply (juxt + -) (range 1 100))) "Elapsed time: 0.097198 msecs" [4950 -4948] => (time (apply (could-be-lazy-juxt + -) (range 1 100))) "Elapsed time: 0.074558 msecs" (4950 -4948) => (time (apply (juxt + -) (range 10000000))) "Elapsed time: 1019.317913 msecs" [49999995000000 -49999995000000] => (time (apply (could-be-lazy-juxt + -) (range 10000000))) "Elapsed time: 0.070332 msecs" (49999995000000 -49999995000000) I'm sure this function is not really that quick (the print of the outcome 'feels' about as long in both). Doing a 'take x' on the function only limits the amount of functions evaluated, which probably is limited in it's applicability, and limiting the other parameters by 'take' should be just as lazy in normal juxt. Is this juxt really lazy ? Would a lazy juxt bring anything useful to the table, for instance as a compositing step between other lazy functions ? What are the performance (mem / cpu / object count / compilation) implications ? Is that why the Clojure juxt implementation is done with a reduce and returns a vector ? Edit: Somehow things can always be done simpler in Clojure. (defn could-be-lazy-juxt [& funs] (fn [& args] (map #(apply % args) funs)))

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  • Qt application crashing immediately without debugging info. How do I track down the problem?

    - by jjacksonRIAB
    I run an Qt app I've built: ./App Segmentation fault I run it with strace: strace ./App execve("./App", ["./App"], [/* 27 vars */]) = 0 --- SIGSEGV (Segmentation fault) @ 0 (0) --- +++ killed by SIGSEGV +++ Process 868 detached Again, no useful info. I run it with gdb: (gdb) run Starting program: /root/test/App Reading symbols from shared object read from target memory...(no debugging symbols found)...done. Loaded system supplied DSO at 0xffffe000 Program received signal SIGSEGV, Segmentation fault. 0x00000001 in ?? () Again, nothing. I run it with valgrind: ==948== Process terminating with default action of signal 11 (SIGSEGV) ==948== Bad permissions for mapped region at address 0x0 ==948== at 0x1: (within /root/test/App) Even if I put in debugging symbols, it doesn't give any more useful info. ldd shows all libraries being linked properly. Is there any other way I can find out what's wrong? I can't even do standard printf, cout, etc debugging. The executable doesn't even seem to start running at all. I rebuilt with symbols, and tried the suggestion below (gdb) break main Breakpoint 1 at 0x45470 (gdb) run Starting program: /root/test/App Breakpoint 1 at 0x80045470 Reading symbols from shared object read from target memory...done. Loaded system supplied DSO at 0xffffe000 Program received signal SIGSEGV, Segmentation fault. 0x00000001 in ?? () I checked for static initializers and I don't seem to have any. Yep, I tried printf, cout, etc. It doesn't even make it into the main routine, so I'm looking for problems with static initializers in link libraries, adding them in one-by-one. I'm not getting any stack traces either.

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  • Aligning music notes using String matching algorithms or Dynamic Programming

    - by Dolphin
    Hi I need to compare 2 sets of musical pieces (i.e. a playing-taken in MIDI format-note details extracted and saved in a database table, against sheet music-taken into XML format). When evaluating playing against sheet music (i.e.note details-pitch, duration, rhythm), note alignment needs to be done - to identify missed/extra/incorrect/swapped notes that from the reference (sheet music) notes. I have like 1800-2500 notes in one piece approx (can even be more-with polyphonic, right now I'm doing for monophonic). So will I have to have all these into an array? Will it be memory overloading or stack overflow? There are string matching algorithms like KMP, Boyce-Moore. But note alignment can also be done through Dynamic Programming. How can I use Dynamic Programming to approach this? What are the available algorithms? Is it about approximate string matching? Which approach is much productive? String matching algos like Boyce-Moore, or dynamic programming? How can I assess which is more effective? Greatly appreciate any insight or suggestions Thanks in advance

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  • How to make an AJAX call immediately on document loading

    - by Ankur
    I want to execute an ajax call as soon as a document is loaded. What I am doing is loading a string that contains data that I will use for an autocomplete feature. This is what I have done, but it is not calling the servlet. I have removed the calls to the various JS scripts to make it clearer. I have done several similar AJAX calls in my code but usually triggered by a click event, I am not sure what the syntax for doing it as soon as the document loads, but I thought this would be it (but it's not): <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <script type="text/javascript"> $(document).ready(function(){ $.ajax({ type: "GET", url: "AutoComplete", dataType: 'json', data: queryString, success: function(data) { var dataArray = data; alert(dataArray); } }); $("#example").autocomplete(dataArray); }); </script> <title></title> </head> <body> API Reference: <form><input id="example"> (try "C" or "E")</form> </body> </html>

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  • Should i write my own forum? If my site has banning/PM/etc?

    - by acidzombie24
    I built a site from scratch (already done). It has banning, PM, comments, etc. The PMs and comments are done using markdown (like SO system). Should i write my own forum code or should i find one already made? What are reasons for or against writing my own? There are pros and cons for writing my own or using another software. But some cons keeping me from using another forum software is Multiple Logins: One for the site, one for separate forums. Need to Customization code: I'll need to change the toolbar in the forum software so i can access pages on the regular site. Look consistency: It may look drastically different from my site even after applying lots of css changes. Banning and User consistency. Users may be ban on site or on forums but not the other. users may select a different or multiple usernames on the forum instead of being forced to use the same username on both site and forum. What are reasons for or against writing my own and using forum software?

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  • Unable to create a breakpoint in Eclipse and Tomcat

    - by Traroth
    Since yesterday, I get a strange error message when I start my Tomcat (6.0.35) under Eclipse Juno (build 20120614-1722): Among the things I tried in order to get rid of the error: Check in Preferences - Java - Compiler if all "Classfile Generation" checkboxes where checked. I did that for both general preferences and project preference Uncheck them, build, check them build again (found on another question) Add org.eclipse.jdt.core.compiler.debug.lineNumber=generate to my .settings/org.eclipse.jdt.core.prefs file Use a new CVS checkout (same symptoms) And now, I don't know what to do anymore. The problem is really stopping me from get anything done. I can't work anymore. Crazy is: the problem doesn't happen on every class, only on some of them. Neither does it happen on my other Eclipse projects. And it didn't happen before yesterday, even if I can't remeber having done anything weird. Actually, I have never seen a problem like this in almost 10 years I'm using Eclipse... If you have any idea, I would be really grateful... Edit: I also tried to ignore the message and go on with my tests: If I create another breakpoint upstream from my problematic class, when I enter this problematic class, it tries to open a $Proxy132 class, which means it actually opens an empty page, with a source not found message

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  • Fastest inline-assembly spinlock

    - by sigvardsen
    I'm writing a multithreaded application in c++, where performance is critical. I need to use a lot of locking while copying small structures between threads, for this I have chosen to use spinlocks. I have done some research and speed testing on this and I found that most implementations are roughly equally fast: Microsofts CRITICAL_SECTION, with SpinCount set to 1000, scores about 140 time units Implementing this algorithm with Microsofts InterlockedCompareExchange scores about 95 time units Ive also tried to use some inline assembly with __asm {} using something like this code and it scores about 70 time units, but I am not sure that a proper memory barrier has been created. Edit: The times given here are the time it takes for 2 threads to lock and unlock the spinlock 1,000,000 times. I know this isn't a lot of difference but as a spinlock is a heavily used object, one would think that programmers would have agreed on the fastest possible way to make a spinlock. Googling it leads to many different approaches however. I would think this aforementioned method would be the fastest if implemented using inline assembly and using the instruction CMPXCHG8B instead of comparing 32bit registers. Furthermore memory barriers must be taken into account, this could be done by LOCK CMPXHG8B (I think?), which guarantees "exclusive rights" to the shared memory between cores. At last [some suggests] that for busy waits should be accompanied by NOP:REP that would enable Hyper-threading processors to switch to another thread, but I am not sure whether this is true or not? From my performance-test of different spinlocks, it is seen that there is not much difference, but for purely academic purpose I would like to know which one is fastest. However as I have extremely limited experience in the assembly-language and with memory barriers, I would be happy if someone could write the assembly code for the last example I provided with LOCK CMPXCHG8B and proper memory barriers in the following template: __asm { spin_lock: ;locking code. spin_unlock: ;unlocking code. }

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  • Cross-domain data access in JavaScript

    - by vit
    We have an ASP.Net application hosted on our network and exposed to a specific client. This client wants to be able to import data from their own server into our application. The data is retrieved with an HTTP request and is CSV formatted. The problem is that they do not want to expose their server to our network and are requesting the import to be done on the client side (all clients are from the same network as their server). So, what needs to be done is: They request an import page from our server The client script on the page issues a request to their server to get CSV formatted data The data is sent back to our application This is not a challenge when both servers are on the same domain: a simple hidden iframe or something similar will do the trick, but here what I'm getting is a cross-domain "access denied" error. They also refuse to change the data format to return JSON or XML formatted data. What I tried and learned so far is: Hidden iframe -- "access denied" XMLHttpRequest -- behaviour depends on the browser security settings: may work, may work while nagging a user with security warnings, or may not work at all Dynamic script tags -- would have worked if they could have returned data in JSON format IE client data binding -- the same "access denied" error Is there anything else I can try before giving up and saying that it will not be possible without exposing their server to our application, changing their data format or changing their browser security settings? (DNS trick is not an option, by the way).

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  • redirecting the root domain - SEO and other issues, need some guidance!

    - by Jim Sp
    I'm not familiar with some of these forwarding methods and I need help. My issue is this: I have a site hosted on discountasp.net. My domain was registered through 1&1 and I redirected the DNS to what discountasp.net wanted. So when a user types www.mydomain.com, he/she sees the ASP.NET site hosted on discountasp.net, which is all fine My main page is Index.aspx, I really suck at html page design and I don't have time or the talent to fiddle with it (or money to get it done by a pro). The rest of the pages are fine. I want to use a good theme from tumblr or bloggr - one of the blog sites and create a page that I want to use as the first page - directly on blogger or tumblr - say yyy.blogspot.com (I have many reasons, so for now please don't bash my decision - let's just say that's what I want). That means when a user types www.mydomain.com, it should redirect it to the blogger or tumblr page. Everything else stays the sme - the links on the blogger page will say www.mydomain.com/xxxx and show up what's on the hosted website. I have setup the IIS rewrite rules etc. etc. so that all works just fine The bottom line is I want to show an external site's web page as my root page. I suppose I'm struggling to even explain what I want! I can of course do a response.redirect on the Index.aspx page - which is the simplest way to manage this, but the big question is will this hurt SEO in some way? If not, that would be what I do and leave the rest of the infrastructure intact (I have already done this to test and it works fine) Thank you very much j

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  • Alternative to using c:out to prevent XSS

    - by lynxforest
    I'm working on preventing cross site scripting (XSS) in a Java, Spring based, Web application. I have already implemented a servlet filter similar to this example http://greatwebguy.com/programming/java/simple-cross-site-scripting-xss-servlet-filter/ which sanitizes all the input into the application. As an extra security measure I would like to also sanitize all output of the application in all JSPs. I have done some research to see how this could be done and found two complementary options. One of them is the use of Spring's defaultHtmlEscape attribute. This was very easy to implement (a few lines in web.xml), and it works great when your output is going through one of spring's tags (ie: message, or form tags). The other option I have found is to not directly use EL expressions such as ${...} and instead use <c:out value="${...}" /> That second approach works perfectly, however due to the size of the application I am working on (200+ JSP files). It is a very cumbersome task to have to replace all inappropriate uses of EL expressions with the c:out tag. Also it would become a cumbersome task in the future to make sure all developers stick to this convention of using the c:out tag (not to mention, how much more unreadable the code would be). Is there alternative way to escape the output of EL expressions that would require fewer code modifications? Thank you in advance.

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