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  • Change the content type of a pop up window.

    - by Oscar Reyes
    This question brought a new one: I have a html page and I need it to change the content type when the user press "save" button so the browser prompt to save the file to disk I've been doing this in the server side to offer "excel" versions of the page ( which is basically a html table ) <c:if test="${page.asExcelAction}"> <% response.setContentType("application/vnd.ms-excel"); %> What I'm trying to do now is to do the same, but in the client side with javacript but I can't manage to do it so. This is what I've got so far: <html> <head> <script> function saveAs(){ var sMarkup = document.getElementById('content').innerHTML; //var oNewDoc = document.open('application/vnd.ms-excel'); var oNewDoc = document.open('text/html'); oNewDoc.write( sMarkup ); oNewDoc.close(); } </script> </head> <body> <div id='content'> <table> <tr> <td>Stack</td> <td>Overflow</td> </tr> </table> </div> <input type="button" value="Save as" onClick="saveAs()"/> </body> </html>

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  • Java runs out of memory, even though I give it plenty!

    - by spitzanator
    Hey, folks. So, I'm running a java server (specifically Winstone: http://winstone.sourceforge.net/ ) Like this: java -server -Xmx12288M -jar /usr/share/java/winstone-0.9.10.jar --useSavedSessions=false --webappsDir=/var/servlets --commonLibFolder=/usr/share/java This has worked fine in the past, but now it needs to load a bunch more stuff into memory than it has before. The odd part is that, according to 'top', it has 15.0g of VIRT(ual memory) and it's RES(ident set) is 8.4g. Once it hits 8.4g, the CPU hangs at 100% (even though it's loading from disk), and eventually, I get Java's OutOfMemoryError. Presumably, the CPU hanging at 100% is Java doing garbage collection. So, my question is, what gives? I gave it 12 gigs of memory! And it's only using 8.2 gigs before it throws in the towel. What am I doing wrong? Oh, and I'm using java version "1.6.0_07" Java(TM) SE Runtime Environment (build 1.6.0_07-b06) Java HotSpot(TM) 64-Bit Server VM (build 10.0-b23, mixed mode) on Linux. Thanks, Matt

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  • Atomic int writes on file

    - by Waneck
    Hello! I'm writing an application that will have to be able to handle many concurrent accesses to it, either by threads as by processes. So no mutex'es or locks should be applied to this. To make the use of locks go down to a minimum, I'm designing for the file to be "append-only", so all data is first appended to disk, and then the address pointing to the info it has updated, is changed to refer to the new one. So I will need to implement a small lock system only to change this one int so it refers to the new address. How is the best way to do it? I was thinking about maybe putting a flag before the address, that when it's set, the readers will use a spin lock until it's released. But I'm afraid that it isn't at all atomic, is it? e.g. a reader reads the flag, and it is unset on the same time, a writer writes the flag and changes the value of the int the reader may read an inconsistent value! I'm looking for locking techniques but all I find is either for thread locking techniques, or to lock an entire file, not fields. Is it not possible to do this? How do append-only databases handle this? Thanks! Cauê

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  • % style macros not supported in some C++/CLI project property pages under VS2010?

    - by Dave Foster
    We're currently evaluating VS2010 and have upgraded our VS2008 C++/CLI project to the new .vcxproj format. I've noticed that a certain property we had set in the project settings did not get translated properly. Under Configuration Properties - Managed Resources - Resource Logical Name, we used to have (in VS2008) the setting: $(IntDir)\$(RootNamespace).$(InputName).resources which indicated that all .resx files were to compile into OurLib.SomeForm.resources inside of the assembly. (the Debug portion is dropped when assembled) According to MSDN, the $(InputName) macro no longer exists and should be replaced with %(Filename). However, when translating the above line to swap those macros, it does not seem to ever expand. The second .resx file it tries to compile, I get a "LINK : fatal error LNK1316: duplicate managed resource name 'Debug\OurLib.%(Filename).resources". This indicates to me that the % style macros are not being expanded here, at least in this specific property. If we don't set anything in that property, the default behavior seems to be to add the subdirectory as a prefix, such as: OurLib.Forms.SomeForm.resources where Forms is the subdir of our project that the .resx file lives. This only occurs when the .resx file is in an immediate subdirectory of the project being built. If a .resx file exists somewhere else on disk (aka ..\OtherLib\Forms\SomeForm2.resx) this prefix is NOT added. This is causing an issue with loading form resources, as it does not account for this possible prefix, even though we are using the standard Forms Designer method of getting at resources: System::ComponentModel::ComponentResourceManager^ resources = (gcnew System::ComponentModel::ComponentResourceManager(SomeForm::typeid)); and do not specify the .resources file by name. The issue I've just described may not be the same as the original question, but if I were to fix the Resource Logical Name issue I think this would all go away. Does anyone have any information about these % macros and where they are allowed to be used?

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  • Displaying tree path of record in SQL Server 2005

    - by jskiles1
    An example of my tree table is: ([id] is an identity) [id], [parent_id], [path] 1, NULL, 1 2, 1, 1-2 3, 1, 1-3 4, 3, 1-3-4 My goal is to query quickly for multiple rows of this table and view the full path of the node from its root, through its superiors, down to itself. The ultimate question is, should I generate this path on inserts and maintain it in its own column or generate this path on query to save disk space? I guess it depends if this table is write heavy or read heavy. I've been contemplating several approaches to using the "path" characteristic of this parent/child relationship and I just can't seem to settle on one. This "path" is simply for display purposes and serves absolutely no purpose other than that. Here is what I have done to implement this "path." AFTER INSERT TRIGGER - requires passing a NULL path to the insert and updating the path for the record at the inserted rows identity INSTEAD OF INSERT TRIGGER - does not require insert to have NULL path passed, but does require the trigger to insert with a NULL path and updating the path for the record at SCOPE_IDENTITY() STORED PROCEDURE - requiring all inserts into this table to be done through the stored procedure implementing the trigger logic VIEW - requires building the path in the view 1 and 2 seem annoying if massive amounts of data are entered at once. 3 seems annoying because all inserts must go through the procedure in order to have a valid path populated. 1, 2, and 3 require maintaining a path column on the table. 4 removes all the limitations of the above but require the view to perform the path logic and requires use of the view if a path is to be displayed. I have successfully implemented all of the above approaches and I'm mainly looking for some advice. Am I way off the mark here or are any of the above acceptable? Each has it's advantages and disadvantages.

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  • Is there a way to easily convert a series of tarballs of a source tree into a git repository?

    - by Hotei
    I'm new to git and I have a moderately large number of weekly tarballs from a long running project. Each tarball has on average a few hundred files in it. I'm looking for a git strategy that will allow me to add the expanded contents of each tarball to a new git repository, starting from version 1.001 and going through version 1.650. As of this stage of the project 99.5% of tarball(n) is just a copy of version(n-1) - in other words, a perfect candidate for git. The desired end result is to have only the master branch remaining at the end of the process. I think I know git well enough to do this "by hand". As I understand it there is no possibility of a merge conflict since there will be no opportunity to change the master before the next version is added and committed. A shell script is my first guess, but I'm not sure how well bash will like it when git checkout branch_n gets processed while bash is executing in branch_n-1. For the purposes of this project the host environment is Ubuntu 10.4, resources available are 8 Gig RAM, 500 Gig Disk space free and 4 CPU processor at 3.ghz . I don't need someone else to solve the problem but I could use a nudge in the right direction as to how a git expert would approach it. Any advice from someone who's "been there done that" would be appreciated. Hotei PS: I have looked at site's suggested "related questions" and found nothing relevant.

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  • How can I see which shared folders my program has access to?

    - by Kasper Hansen
    My program needs to read and write to folders on other machines that might be in another domain. So I used the System.Runtime.InteropServices to add shared folders. This worked fine when it was hard coded in the main menu of my windows service. But since then something went wrong and I don't know if it is a coding error or configuration error. What is the scope of a shared folder? If a thread in my program adds a shared folder, can the entire local machine see it? Is there a way to view what shared folders has been added? Or is there a way to see when a folder is added? [DllImport("NetApi32.dll", SetLastError = true, CharSet = CharSet.Unicode)] internal static extern System.UInt32 NetUseAdd(string UncServerName, int Level, ref USE_INFO_2 Buf, out uint ParmError); [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)] internal struct USE_INFO_2 { internal LPWSTR ui2_local; internal LPWSTR ui2_remote; internal LPWSTR ui2_password; internal DWORD ui2_status; internal DWORD ui2_asg_type; internal DWORD ui2_refcount; internal DWORD ui2_usecount; internal LPWSTR ui2_username; internal LPWSTR ui2_domainname; } private void AddSharedFolder(string name, string domain, string username, string password) { if (name == null || domain == null || username == null || password == null) return; USE_INFO_2 useInfo = new USE_INFO_2(); useInfo.ui2_remote = name; useInfo.ui2_password = password; useInfo.ui2_asg_type = 0; //disk drive useInfo.ui2_usecount = 1; useInfo.ui2_username = username; useInfo.ui2_domainname = domain; uint paramErrorIndex; uint returnCode = NetUseAdd(String.Empty, 2, ref useInfo, out paramErrorIndex); if (returnCode != 0) { throw new Win32Exception((int)returnCode); } }

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  • How to correctly waitFor() a saveScreenShot() end of execution.

    - by Alain
    Here is my full first working test: var expect = require('chai').expect; var assert = require('assert'); var webdriverjs = require('webdriverjs'); var client = {}; var webdriverOptions = { desiredCapabilities: { browserName: 'phantomjs' }, logLevel: 'verbose' }; describe('Test mysite', function(){ before(function() { client = webdriverjs.remote( webdriverOptions ); client.init(); }); var selector = "#mybodybody"; it('should see the correct title', function(done) { client.url('http://localhost/mysite/') .getTitle( function(err, title){ expect(err).to.be.null; assert.strictEqual(title, 'My title page' ); }) .waitFor( selector, 2000, function(){ client.saveScreenshot( "./ExtractScreen.png" ); }) .waitFor( selector, 7000, function(){ }) .call(done); }); after(function(done) { client.end(done); }); }); Ok, it does not do much, but after working many hours to get the environement correctly setup, it passed. Now, the only way I got it working is by playing with the waitFor() method and adjust the delays. It works, but I still do not understand how to surely wait for a png file to be saved on disk. As I will deal with tests orders, I will eventually get hung up from the test script before securely save the file. Now, How can I improve this screen save sequence and avoid loosing my screenshot ? Thanks.

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  • Python: Catching / blocking SIGINT during system call

    - by danben
    I've written a web crawler that I'd like to be able to stop via the keyboard. I don't want the program to die when I interrupt it; it needs to flush its data to disk first. I also don't want to catch KeyboardInterruptedException, because the persistent data could be in an inconsistent state. My current solution is to define a signal handler that catches SIGINT and sets a flag; each iteration of the main loop checks this flag before processing the next url. However, I've found that if the system happens to be executing socket.recv() when I send the interrupt, I get this: ^C Interrupted; stopping... // indicates my interrupt handler ran Traceback (most recent call last): File "crawler_test.py", line 154, in <module> main() ... File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/socket.py", line 397, in readline data = recv(1) socket.error: [Errno 4] Interrupted system call and the process exits completely. Why does this happen? Is there a way I can prevent the interrupt from affecting the system call?

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  • ASP.NET error on Bitmap.Save "Exception (0x80004005): A generic error occurred in GDI+."

    - by Batu
    Hi, I have a function which first reads an image from disk, resizes it and then saves to another directory. when i use the Bitmap.Save(directory + theimagename) it returns the error as i stated in the question title. i checked the directory is right, and the given image name doesn't exist in that dir. what is weird, is that the same code works great on the local machine. but when i upload it to my shared server. it just doesn't work. the code is below. bmpOut = new Bitmap(Size, Size); Graphics g = Graphics.FromImage(bmpOut); g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; g.FillRectangle(Brushes.White, 0, 0, Size, Size); int topBottomPadding = 0; int leftRightPadding = 0; if (Size > lnNewWidth + 1) leftRightPadding = Convert.ToInt32((Size - lnNewWidth) / 2); else if (Size > lnNewHeight + 1) topBottomPadding = Convert.ToInt32((Size - lnNewHeight) / 2); g.DrawImage(loBMP, leftRightPadding, topBottomPadding, lnNewWidth, lnNewHeight); Bitmap bmp = new Bitmap(bmpOut); if (bmp != null) bmp.Save(ResizedOutput); bmp.Dispose(); bmpOut.Dispose(); g.Dispose(); loBMP.Dispose(); stack trace: [ExternalException (0x80004005): A generic error occurred in GDI+.] System.Drawing.Image.Save(String filename, ImageCodecInfo encoder, EncoderParameters encoderParams) +377630 System.Drawing.Image.Save(String filename, ImageFormat format) +69 System.Drawing.Image.Save(String filename) +25 Utilities.ResizeImage(String fileName, String mode) in c:\inetpub\vhosts\batuhanakcay.com\httpdocs\App_Code\Utilities.cs:181 Link.ToProductImage(String fileName) in c:\inetpub\vhosts\batuhanakcay.com\httpdocs\App_Code\Link.cs:79 Product.PopulateControls(ProductDetails pd) in c:\inetpub\vhosts\batuhanakcay.com\httpdocs\Product.aspx.cs:37 Product.Page_Load(Object sender, EventArgs e) in c:\inetpub\vhosts\batuhanakcay.com\httpdocs\Product.aspx.cs:20

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  • .net IHTTPHandler Streaming SQL Binary Data

    - by Yisman
    Hello everybody I am trying to implement an ihttphandeler for streaming files. files may be tiny thumbnails or gigantic movies the binaries r stored in sql server i looked at a lot of code online but something does not make sense isnt streaming supposed to read the data piece by piece and move it over the line? most of the code seems to first read the whole field from mssql to memory and then use streaming for the output writing wouldnt it b more eficient to actually stream from disk directly to http byte by byte (or buffered chunks?) heres my code so far but cant figure out the correct combination of the sqlreader mode and the stream object and the writing system Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest context.Response.BufferOutput = False Dim FileField=safeparam(context.Request.QueryString("FileField")) Dim FileTable=safeparam(context.Request.QueryString("FileTable")) Dim KeyField=safeparam(context.Request.QueryString("KeyField")) Dim FileKey=safeparam(context.Request.QueryString("FileKey")) Using connection As New SqlConnection(ConfigurationManager.ConnectionStrings("Main").ConnectionString) Using command As New SqlCommand("SELECT " & FileField & "Bytes," & FileField & "Type FROM " & FileTable & " WHERE " & KeyField & "=" & FileKey, connection) command.CommandType = Data.CommandType.Text enbd using end using end sub please be aware that this sql command also returns the file extension (pdf,jpg,doc...) in the second field of the query thank you all very much

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  • Minimal deployment of couchdb on windows

    - by MartinStettner
    Hi, I'd like to use couchdb for a client-only application on Windows (the document-oriented structure and the synchronization features would be perfect for me). There is a Windows installer package here, but the installer itself has about 45 MB, when installed it takes more than 100 MB on my HD. This is far to much for my (relatively small) application. I noticed that there are a lot of "src" directories in the couchdb/lib subdirs. I've been experimenting with removing some of them and it didn't seem to break the system. Now I'm wondering what would be the "minimal" set of files (preferably binary-only) that would be needed in order to run a local couchdb server. Are there already any efforts to create such a deployment-friendly installer? Or could anyone give some (even very general) hints how to create it? How much disk space would be minimally required for such an installation? Needless to say that I'm not at all familiar with neither the couchdb internals nor the Erlang system :). But perhaps I could figure out if I got some direction (or I could stop trying if someone told me that this would be impossible or didn't make sense at all ...) Thanks anyway!

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  • Output reformatted text within a file included in a JSP

    - by javanix
    I have a few HTML files that I'd like to include via tags in my webapp. Within some of the files, I have pseudo-dynamic code - specially formatted bits of text that, at runtime, I'd like to be resolved to their respective bits of data in a MySQL table. For instance, the HTML file might include a line that says: Welcome, [username]. I want this resolved to (via a logged-in user's data): Welcome, [email protected]. This would be simple to do in a JSP file, but requirements dictate that the files will be created by people who know basic HTML, but not JSP. Simple text-tags like this should be easy enough for me to explain to them, however. I have the code set up to do resolutions like that for strings, but can anyone think of a way to do it across files? I don't actually need to modify the file on disk - just load the content, modify it, and output it w/in the containing JSP file. I've been playing around with trying to load the files into strings via the apache readFileToString, but I can't figure out how to load files from a specific folder within the webapp's content directory without hardcoding it in and having to worry about it breaking if I deploy to a different system in the future.

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  • Read from one large file and write to many (tens, hundreds, or thousands) files in Java?

    - by Rudiger
    I have a large-ish file (4-5 GB compressed) of small messages that I wish to parse into approximately 6,000 files by message type. Messages are small; anywhere from 5 to 50 bytes depending on the type. Each message starts with a fixed-size type field (a 6-byte key). If I read a message of type '000001', I want to write append its payload to 000001.dat, etc. The input file contains a mixture of messages; I want N homogeneous output files, where each output file contains only the messages of a given type. What's an efficient a fast way of writing these messages to so many individual files? I'd like to use as much memory and processing power to get it done as fast as possible. I can write compressed or uncompressed files to the disk. I'm thinking of using a hashmap with a message type key and an outputstream value, but I'm sure there's a better way to do it. Thanks!

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  • How can we serialize a class that is not a custom class of our own?

    - by Doug
    I need to look at the properties of an object and I cannot instantiate this object in the proper state on my dev machine. I need my client to run some code on her machine, serialize the object in question to disk and then I can analyze the file. Here is the class I want to serialize. System.Security.AccessControl.RegistrySecurity Here is my code: Private Sub SerializeRegSecurity(ByVal regKey As RegistryKey) Try Dim regSecurity As System.Security.AccessControl.RegistrySecurity = regKey.GetAccessControl() Dim oXS As XmlSerializer = New XmlSerializer(GetType(System.Security.AccessControl.RegistrySecurity)) Dim oStmW As StreamWriter Dim regDebugFilePath As String = Path.Combine(My.Computer.FileSystem.SpecialDirectories.Desktop, "RegDebugFile.xml") 'Serialize object to XML and write it to XML file oStmW = New StreamWriter(regDebugFilePath) oXS.Serialize(oStmW, regSecurity) oStmW.Close() Catch ex As Exception Console.WriteLine(ex.ToString) End Try End Sub And here's what I end up with in my XML file: <?xml version="1.0" encoding="utf-8"?> Any ideas on how to accomplish what I am trying to do? How can we serialize a class that is not a custom class of our own? Thanks for ANY help. Even an alternate method.

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  • Clustered index - multi-part vs single-part index and effects of inserts/deletes

    - by Anssssss
    This question is about what happens with the reorganizing of data in a clustered index when an insert is done. I assume that it should be more expensive to do inserts on a table which has a clustered index than one that does not because reorganizing the data in a clustered index involves changing the physical layout of the data on the disk. I'm not sure how to phrase my question except through an example I came across at work. Assume there is a table (Junk) and there are two queries that are done on the table, the first query searches by Name and the second query searches by Name and Something. As I'm working on the database I discovered that the table has been created with two indexes, one to support each query, like so: --drop table Junk1 CREATE TABLE Junk1 ( Name char(5), Something char(5), WhoCares int ) CREATE CLUSTERED INDEX IX_Name ON Junk1 ( Name ) CREATE NONCLUSTERED INDEX IX_Name_Something ON Junk1 ( Name, Something ) Now when I looked at the two indexes, it seems that IX_Name is redundant since IX_Name_Something can be used by any query that desires to search by Name. So I would eliminate IX_Name and make IX_Name_Something the clustered index instead: --drop table Junk2 CREATE TABLE Junk2 ( Name char(5), Something char(5), WhoCares int ) CREATE CLUSTERED INDEX IX_Name_Something ON Junk2 ( Name, Something ) Someone suggested that the first indexing scheme should be kept since it would result in more efficient inserts/deletes (assume that there is no need to worry about updates for Name and Something). Would that make sense? I think the second indexing method would be better since it means one less index needs to be maintained. I would appreciate any insight into this specific example or directing me to more info on maintenance of clustered indexes.

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  • Failure remediation strategy for File I/O

    - by Brett
    I'm doing buffered IO into a file, both read and write. I'm using fopen(), fseeko(), standard ANSI C file I/O functions. In all cases, I'm writing to a standard local file on a disk. How often do these file I/O operations fail, and what should the strategy be for failures? I'm not exactly looking for stats, but I'm looking for a general purpose statement on how far I should go to handle error conditions. For instance, I think everyone recognizes that malloc() could and probably will fail someday on some user's machine and the developer should check for a NULL being returned, but there is no great remediation strategy since it probably means the system is out of memory. At least, this seems to be the approach taken with malloc() on desktop systems, embedded systems are different. Likewise, is it worth reattempting a file I/O operation, or should I just consider a failure to be basically unrecoverable, etc. I would appreciate some code samples demonstrating proper usage, or a library guide reference that indicates how this is to be handled. Any other data is, of course, welcome.

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  • Is it OK to use WPF assemblies in a web app?

    - by Chris
    I have an ASP.NET MVC 2 app targeting .NET 4 that needs to be able to resize images on the fly and write them to the response. I have code that does this and it works. I am using System.Drawing.dll. However, I want to enhance my code so that not only am I resizing the image, but I am dropping it from 24bpp down to 4bit grayscale. I could not, for the life of me, find code on how to do this with System.Drawing.dll. But I did find a bunch of WPF stuff. This is my working/sample code (runs in LinqPad). // Load the original 24 bit image var bitmapImage = new BitmapImage(); bitmapImage.BeginInit(); bitmapImage.UriSource = new Uri(@"C:\Temp\Resized\18_appa2_015.png", UriKind.Absolute); //bitmapImage.DecodePixelWidth = 600; bitmapImage.EndInit(); // Create the destination image var formatConvertedBitmap = new FormatConvertedBitmap(); formatConvertedBitmap.BeginInit(); formatConvertedBitmap.Source = bitmapImage; formatConvertedBitmap.DestinationFormat = PixelFormats.Gray4; formatConvertedBitmap.EndInit(); // Encode and dump the image to disk var encoder = new PngBitmapEncoder(); encoder.Frames.Add(BitmapFrame.Create(formatConvertedBitmap)); using (var fileStream = File.Create(@"C:\Temp\Resized\18_appa2_015_s2.png")) { encoder.Save(fileStream); } It uses System.Xaml.dll, WindowsBase.dll, PresentationCore.dll, and PresentationFramework.dll. The namespaces used are: System.Windows.Controls, System.Windows.Media, and System.Windows.Media.Imaging. Is there any problem using these namespaces in my web application? It doesn't seem right. If anyone knows how to drop the bit depth without all this WPF stuff (which I barely understand, BTW) I would be thrilled to see that too.

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  • Java Random Slowdowns on Mac OS cont'd

    - by javajustice
    I asked this question a few weeks ago, but I'm still having the problem and I have some new hints. The original question is here: http://stackoverflow.com/questions/1651887/java-random-slowdowns-on-mac-os Basically, I have a java application that splits a job into independent pieces and runs them in separate threads. The threads have no synchronization or shared memory items. The only resources they do share are data files on the hard disk, with each thread having an open file channel. Most of the time it runs very fast, but occasionally it will run very slow for no apparent reason. If I attach a CPU profiler to it, then it will start running quickly again. If I take a CPU snapshot, it says its spending most of its time in "self time" in a function that doesn't do anything except check a few (unshared unsynchronized) booleans. I don't know how this could be accurate because 1, it makes no sense, and 2, attaching the profiler seems to knock the threads out of whatever mode they're in and fix the problem. Also, regardless of whether it runs fast or slow, it always finishes and gives the same output, and it never dips in total cpu usage (in this case ~1500%), implying that the threads aren't getting blocked. I have tried different garbage collectors, different sizings the parts of the memory space, writing data output to non-raid drives, and putting all data output in threads separate the main worker threads. Does anyone have any idea what kind of problem this could be? Could it be the operating system (OS X 10.6.2) ? I have not been able to duplicate it on a windows machine, but I don't have one with a similar hardware configuration.

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  • Catching / blocking SIGINT during system call

    - by danben
    I've written a web crawler that I'd like to be able to stop via the keyboard. I don't want the program to die when I interrupt it; it needs to flush its data to disk first. I also don't want to catch KeyboardInterruptedException, because the persistent data could be in an inconsistent state. My current solution is to define a signal handler that catches SIGINT and sets a flag; each iteration of the main loop checks this flag before processing the next url. However, I've found that if the system happens to be executing socket.recv() when I send the interrupt, I get this: ^C Interrupted; stopping... // indicates my interrupt handler ran Traceback (most recent call last): File "crawler_test.py", line 154, in <module> main() ... File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/socket.py", line 397, in readline data = recv(1) socket.error: [Errno 4] Interrupted system call and the process exits completely. Why does this happen? Is there a way I can prevent the interrupt from affecting the system call?

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  • EC2 persistence of machine

    - by Seagull
    I want to 'persist' my Amazon EC2 images. My scenario: I have a range of Windows and Linux machines Some machines are EBS backed, whereas others are S3 backed. I need to be able to persist a machine (put it to sleep), preferably keeping all settings active I had them when the machine was running. I need to be able to quickly wake up a machine from sleep [Ideally with an SLA of less than 2 min to turn-on, if such an SLA is available with Amazon]. Here's the stuff that confuses me: AWS allows me to put EBS backed machines to sleep, but not S3 backed. I believe I can put S3 machines into some sort of persistence mode. But this involves shutting down the machine, writing it to S3 storage and then recovering from there (not a real sleep mode, but at least I don't continue to get billed for CPU). S3 backing seems to take a long time to either writing a machine to disk, or to recover (turn on a machine). I can't tell immediately which machines are EBS backed and which are S3 backed? It seems like I can instantiate either type, but it's not immediately clear how Amazon decided whether a given machine should be EBS or S3 backed. Advice?

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  • Serializing QGraphicsScene contents

    - by Rob
    I am using the Qt QGraphicsScene class, adding pre-defined items such as QGraphicsRectItem, QGraphicsLineItem, etc. and I want to serialize the scene contents to disk. However, the base QGraphicsItem class (that the other items I use derive from) doesn't support serialization so I need to roll my own code. The problem is that all access to these objects is via a base QGraphicsItem pointer, so the serialization code I have is horrible: QGraphicsScene* scene = new QGraphicsScene; scene->addRect(QRectF(0, 0, 100, 100)); scene->addLine(QLineF(0, 0, 100, 100)); ... QList<QGraphicsItem*> list = scene->items(); foreach (QGraphicsItem* item, items) { if (item->type() == QGraphicsRectItem::Type) { QGraphicsRectItem* rect = qgraphicsitem_cast<QGraphicsRectItem*>(item); // Access QGraphicsRectItem members here } else if (item->type() == QGraphicsLineItem::Type) { QGraphicsLineItem* line = qgraphicsitem_cast<QGraphicsLineItem*>(item); // Access QGraphicsLineItem members here } ... } This is not good code IMHO. So, instead I could create an ABC class like this: class Item { public: virtual void serialize(QDataStream& strm, int version) = 0; }; class Rect : public QGraphicsRectItem, public Item { public: void serialize(QDataStream& strm, int version) { // Serialize this object } ... }; I can then add Rect objects using QGraphicsScene::addItem(new Rect(,,,)); But this doesn't really help me as the following will crash: QList<QGraphicsItem*> list = scene->items(); foreach (QGraphicsItem* item, items) { Item* myitem = reinterpret_class<Item*>(item); myitem->serialize(...) // FAIL } Any way I can make this work?

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  • NullPointerException in NetBeans 6.5 IDE itself

    - by titaniumdecoy
    When I use NetBeans for almost any task (in particular, attempting to open a project), a red minus sign in the bottom right corner of the IDE starts blinking and I get the following NullPointerException error when I click it. Unfortunately I cannot reinstall NetBeans since I am using a shared computer lab account. java.lang.NullPointerException at org.openide.util.Exceptions.attachMessage(Unknown Source) at org.netbeans.modules.project.ant.Util$ErrHandler.annotate(Unknown Source) at org.netbeans.modules.project.ant.Util$ErrHandler.fatalError(Unknown Source) at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:177) at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:388) at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1414) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:925) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:648) at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:140) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:807) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:737) at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:107) at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:225) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:283) at org.openide.xml.XMLUtil.parse(Unknown Source) at org.netbeans.modules.project.ant.AntBasedProjectFactorySingleton.loadProjectXml(Unknown Source) at org.netbeans.modules.project.ant.AntBasedProjectFactorySingleton.loadProject(Unknown Source) at org.netbeans.api.project.ProjectManager.createProject(Unknown Source) at org.netbeans.api.project.ProjectManager.access$300(Unknown Source) at org.netbeans.api.project.ProjectManager$2.run(Unknown Source) at org.netbeans.api.project.ProjectManager$2.run(Unknown Source) at org.openide.util.Mutex.readAccess(Unknown Source) at org.netbeans.api.project.ProjectManager.findProject(Unknown Source) at org.netbeans.modules.project.ui.OpenProjectList.fileToProject(Unknown Source) at org.netbeans.modules.project.ui.ProjectChooserAccessory$ProjectFileView.run(Unknown Source) at org.openide.util.RequestProcessor$Task.run(Unknown Source) [catch] at org.openide.util.RequestProcessor$Processor.run(Unknown Source) I have recently had problems with going over my disk space quota on this computer lab account. I cleaned up my files and I now have about 10MB free. I'm not sure whether or not this is related to the problem with NetBeans.

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  • Returning Database Blobs in TurboGears 2.x / FCGI / Lighttpd extremely slow

    - by Tom
    Hey everyone, I am running a TG2 App on lighttpd via flup/fastcgi. We are reading images (~30kb each) from BlobFields in a MySQL database and return those images with a custom mime type via a controller method. Caching these images on the hard disk makes no sense because they change with every request, the only reason we cache these in the DB is that creating these images is quite expensive and the data used to create the images is also present in plain text on the website. Now to the problem itself: When returning such an image, things get extremely slow. The code runs totally fine on paster itself with no visible delay, but as soon as its running via fcgi/lighttpd the described phenomenon happens. I profiled the method of my controller that returns my blob, and the entire method runs in a few miliseconds, but when "return" executes, the entire app hangs for roughly 10 seconds. We could not reproduce the same error with PHP on FCGI. This only seems to happen with Turbogears or Pylons. Here for your consideration the concerned piece of source code: @expose(content_type=CUSTOM_CONTENT_TYPE) def return_img(self, img_id): """ Return a DB persisted image when requested """ img = model.Images.by_id(img_id) #get image from DB response.headers['content-type'] = 'image/png' return img.data # this causes the app to hang for 10 seconds

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  • Technical choices in unmarshaling hash-consed data

    - by Pascal Cuoq
    There seems to be quite a bit of folklore knowledge floating about in restricted circles about the pitfalls of hash-consing combined with marshaling-unmarshaling of data. I am looking for citable references to these tidbits. For instance, someone once pointed me to library aterm and mentioned that the authors had clearly thought about this and that the representation on disk was bottom-up (children of a node come before the node itself in the data stream). This is indeed the right way to do things when you need to re-share each node (with a possible identical node already in memory). This re-sharing pass needs to be done bottom-up, so the unmarshaling itself might as well be, too, so that it's possible to do everything in a single pass. I am in the process of describing difficulties encountered in our own context, and the solutions we found. I would appreciate any citable reference to the kind of aforementioned folklore knowledge. Some people obviously have encountered the problems before (the aterm library is only one example). But I didn't find anything in writing. Even the little piece of information I have about aterm is hear-say. I am not worried it's not reliable (you can't make this up), but "personal communication" and "look how it's done in the source code" are considered poor form in citations. I have enough references on hash-consing alone. I am only interested in references where it interferes with other aspects of programming, such as marshaling or distribution.

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