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  • Convert asp.net webforms logic to asp.net MVC

    - by gmcalab
    I had this code in an old asp.net webforms app to take a MemoryStream and pass it as the Response showing a PDF as the response. I am now working with an asp.net MVC application and looking to do this this same thing, but how should I go about showing the MemoryStream as PDF using MVC? Here's my asp.net webforms code: private void ShowPDF(MemoryStream ms) { try { //get byte array of pdf in memory byte[] fileArray = ms.ToArray(); //send file to the user Page.Response.Cache.SetCacheability(HttpCacheability.NoCache); Page.Response.Buffer = true; Response.Clear(); Response.ClearContent(); Response.ClearHeaders(); Response.Charset = string.Empty; Response.ContentType = "application/pdf"; Response.AddHeader("content-length", fileArray.Length.ToString()); Response.AddHeader("Content-Disposition", "attachment;filename=TID.pdf;"); Response.BinaryWrite(fileArray); Response.Flush(); Response.Close(); } catch { // and boom goes the dynamite... } }

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  • Interface for reading variable length files with header and footer.

    - by John S
    I could use some hints or tips for a decent interface for reading file of special characteristics. The files in question has a header (~120 bytes), a body (1 byte - 3gb) and a footer (4 bytes). The header contains information about the body and the footer is only a simple CRC32-value of the body. I use Java so my idea was to extend the "InputStream" class and add a constructor such as "public MyInStream( InputStream in)" where I immediately read the header and the direct the overridden read()'s the body. Problem is, I can't give the user of the class the CRC32-value until the whole body has been read. Because the file can be 3gb large, putting it all in memory is a be an idea. Reading it all in to a temporary file is going to be a performance hit if there are many small files. I don't know how large the file is because the InputStream doesn't have to be a file, it could be a socket. Looking at it again, maybe extending InputStream is a bad idea. Thank you for reading the confused thoughts of a tired programmer. :)

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  • ERROR_MORE_DATA ---- Reading from Registry

    - by user314749
    I am trying to create an offline registry in memory using the offreg.dll provided in the windows ddk 7 package. You can find out more information on the offreg.dll here: MSDN Currently, while attempting to read a value from an open registry hive / key I receive the following error: 234 or ERROR_MORE_DATA Here is the .h code that contains ORGetValue: DWORD ORAPI ORGetValue ( __in ORHKEY Handle, __in_opt PCWSTR lpSubKey, __in_opt PCWSTR lpValue, __out_opt PDWORD pdwType, __out_bcount_opt(*pcbData) PVOID pvData, __inout_opt PDWORD pcbData ); Here is the code that I am using to pull the data [DllImport("offreg.dll", CharSet = CharSet.Auto, EntryPoint = "ORGetValue", SetLastError = true, CallingConvention = CallingConvention.StdCall)] public static extern uint ORGetValue(IntPtr Handle, string lpSubKey, string lpValue, out uint pdwType, out string pvData, out uint pcbData); IntPtr myHive; IntPtr myKey; string myValue; uint pdwtype; uint pcbdata; uint ret3 = ORGetValue(myKey, "", "DefaultUserName", out pdwtype, out myValue, out pcbdata); The goal is to be able to read myValue as a string. I am not sure if I need to use marshaling... or a second call with an adjusted buffer.. Or really how to adjust the buffer in C#. Any help or pointers would be greatly appreciated. Thank you.

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  • Java application design question

    - by ring bearer
    I have a hobby project, which is basically to maintain 'todo' tasks in the way I like. One task can be described as: public class TodoItem { private String subject; private Date dueBy; private Date startBy; private Priority priority; private String category; private Status status; private String notes; } As you can imagine I would have 1000s of todo items at a given time. What is the best strategy to store a todo item? (currently on an XML file) such that all the items are loaded quickly up on app start up(the application shows kind of a dashboard of all the items at start up)? What is the best way to design its back-end so that it can be ported to Android/or a J2ME based phone? Currently this is done using Java Swing. What should I concentrate on so that it works efficiently on a device where memory is limited? The application throws open a form to enter new todo task. For now, I would like to save the newly added task to my-todos.xml once the user presses "save" button. What are the common ways to append such a change to an existing XML file?(note that I don't want to read the whole file again and then persist)

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  • NSDictionary, NSArray, NSSet and efficiency

    - by ryyst
    Hi, I've got a text file, with about 200,000 lines. Each line represents an object with multiple properties. I only search through one of the properties (the unique ID) of the objects. If the unique ID I'm looking for is the same as the current object's unique ID, I'm gonna read the rest of the object's values. Right now, each time I search for an object, I just read the whole text file line by line, create an object for each line and see if it's the object I'm looking for - which is basically the most inefficient way to do the search. I would like to read all those objects into memory, so I can later search through them more efficiently. The question is, what's the most efficient way to perform such a search? Is a 200,000-entries NSArray a good way to do this (I doubt it)? How about an NSSet? With an NSSet, is it possible to only search for one property of the objects? Thanks for any help! -- Ry

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  • Why execution of a portion of code loaded from external file is not halted by the OS?

    - by menjaraz
    I've harnessed a project released on internet a long time ago. Here comes the details, all irrelevant things being stripped off for sake of concision and clarity. A binary file whose content is descibed below HEX DUMP: 55 89 E5 83 EC 08 C7 45 FC 00 00 00 00 8B 45 FC 3B 45 10 72 02 EB 19 8B 45 FC 8B 55 0C 01 C2 8B 45 FC 03 45 08 8A 00 88 02 8D 45 FC FF 00 EB DD C6 45 FA 00 83 7D 10 01 76 6C 80 7D FA 00 74 02 EB 64 C6 45 FA 01 C7 45 FC 00 00 00 00 8B 45 10 48 39 45 FC 72 02 EB E2 8B 45 FC 8B 4D 0C 01 C1 8B 45 FC 03 45 0C 8D 50 01 8A 01 3A 02 73 30 8B 45 FC 03 45 0C 8A 00 88 45 FB 8B 45 FC 8B 55 0C 01 C2 8B 45 FC 03 45 0C 40 8A 00 88 02 8B 45 FC 03 45 0C 8D 50 01 8A 45 FB 88 02 C6 45 FA 00 8D 45 FC FF 00 EB A7 C9 C2 0C 00 90 90 90 90 90 90 is loaded into memory and executed using the following method snippet var MySrcArray, MyDestArray: array [1 .. 15] of Byte; // ... MyBuffer: Pointer; TheProc: procedure; SortIt: procedure(ASrc, ADest: Pointer; ASize: LongWord); stdcall; begin // Initialization of MySrcArray with random Bytes and display here ... // Instructions of loading of the binary file into MyBuffer using merely **GetMem** here ... @SortIt := MyBuffer; try SortIt(@MySrcArray, @MyDestArray, 15); // Display of MyDestArray (The outcome of the processing !) except // Invalid code error handling end; // Cleaning code here ... end; works like a charm on my box. My Question: How comes it works without using VirtualAlloc and/or VirtualProtect?

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  • What is the best database structure for this scenario?

    - by Ricketts
    I have a database that is holding real estate MLS (Multiple Listing Service) data. Currently, I have a single table that holds all the listing attributes (price, address, sqft, etc.). There are several different property types (residential, commercial, rental, income, land, etc.) and each property type share a majority of the attributes, but there are a few that are unique to that property type. My question is the shared attributes are in excess of 250 fields and this seems like too many fields to have in a single table. My thought is I could break them out into an EAV (Entity-Attribute-Value) format, but I've read many bad things about that and it would make running queries a real pain as any of the 250 fields could be searched on. If I were to go that route, I'd literally have to pull all the data out of the EAV table, grouped by listing id, merge it on the application side, then run my query against the in memory object collection. This also does not seem very efficient. I am looking for some ideas or recommendations on which way to proceed. Perhaps the 250+ field table is the only way to proceed. Just as a note, I'm using SQL Server 2012, .NET 4.5 w/ Entity Framework 5, C# and data is passed to asp.net web application via WCF service. Thanks in advance.

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  • Use a non-coalescing parser in Axis2

    - by Nathan
    Does anyone know how I can get Axis2 to use a non-coalescing XMLStreamReader when it parses a SOAP message? I am writing code that reads a large base64 binary text element. Coalescing is the default behaviour, and this causes the default XMLStreamReader to load the entire text into memory rather than returning multiple CHARACTERS events. The upshot of this is that I run out of heap space when running the following code: reader = element.getTextAsStream( true ); The OutOfMemory error occurs in com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next: java.lang.OutOfMemoryError: Java heap space at com.sun.org.apache.xerces.internal.util.XMLStringBuffer.append(XMLStringBuffer.java:208) at com.sun.org.apache.xerces.internal.util.XMLStringBuffer.append(XMLStringBuffer.java:226) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanContent(XMLDocumentFragmentScannerImpl.java:1552) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2864) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:607) at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:116) at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(XMLStreamReaderImpl.java:558) at org.apache.axiom.util.stax.wrapper.XMLStreamReaderWrapper.next(XMLStreamReaderWrapper.java:225) at org.apache.axiom.util.stax.dialect.DisallowDoctypeDeclStreamReaderWrapper.next(DisallowDoctypeDeclStreamReaderWrapper.java:34) at org.apache.axiom.util.stax.wrapper.XMLStreamReaderWrapper.next(XMLStreamReaderWrapper.java:225) at org.apache.axiom.util.stax.dialect.SJSXPStreamReaderWrapper.next(SJSXPStreamReaderWrapper.java:138) at org.apache.axiom.om.impl.builder.StAXOMBuilder.parserNext(StAXOMBuilder.java:668) at org.apache.axiom.om.impl.builder.StAXOMBuilder.next(StAXOMBuilder.java:214) at org.apache.axiom.om.impl.llom.SwitchingWrapper.updateNextNode(SwitchingWrapper.java:1098) at org.apache.axiom.om.impl.llom.SwitchingWrapper.<init>(SwitchingWrapper.java:198) at org.apache.axiom.om.impl.llom.OMStAXWrapper.<init>(OMStAXWrapper.java:73) at org.apache.axiom.om.impl.llom.OMContainerHelper.getXMLStreamReader(OMContainerHelper.java:67) at org.apache.axiom.om.impl.llom.OMContainerHelper.getXMLStreamReader(OMContainerHelper.java:40) at org.apache.axiom.om.impl.llom.OMElementImpl.getXMLStreamReader(OMElementImpl.java:790) at org.apache.axiom.om.impl.llom.OMElementImplUtil.getTextAsStream(OMElementImplUtil.java:114) at org.apache.axiom.om.impl.llom.OMElementImpl.getTextAsStream(OMElementImpl.java:826) at org.example.UploadFileParser.invokeBusinessLogic(UploadFileParser.java:160)

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  • Float compile-time calculation not happening?

    - by Klaim
    A little test program: #include <iostream> const float TEST_FLOAT = 1/60; const float TEST_A = 1; const float TEST_B = 60; const float TEST_C = TEST_A / TEST_B; int main() { std::cout << TEST_FLOAT << std::endl; std::cout << TEST_C << std::endl; std::cin.ignore(); return 0; } Result : 0 0.0166667 Tested on Visual Studio 2008 & 2010. I worked on other compilers that, if I remember well, made the first result like the second result. Now my memory could be wrong, but shouldn't TEST_FLOAT have the same value than TEST_C? If not, why? Is TEST_C value resolved at compile time or at runtime? I always assumed the former but now that I see those results I have some doubts...

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  • Transitioning from FlexBuilder 3 to FlashBuilder 4 ... there and back again.

    - by Robusto
    It's growing pains time again. Some of our stuff requires FlashBuilder 4 and some still requires FlexBuilder 3. Both are installed OK, and no projects use both IDEs. The trouble is, when I go back to work on a FlexBuilder 3 project it takes freakin' forever to build and I get weird errors like these: This doesn't seem to cause any identifiable problems except to throw up a modal dialog at various points in the build process, forcing user interaction. But I do notice that memory fills up fast in FB3 and generally FB3 starts behaving strangely and ultimately quits once it gets up over 700MB. This is only a temporary bridge situation until we get all projects into FB4, but "temporary" could mean weeks if not months. Does anyone have any advice for how to get through this bridge period? Is there anything I can do to make these two IDEs work and play well together? Failing that, does anyone know what "java.lang.String" is the "reason" for the problem? Does Eclipse have a resource bundle somewhere that is getting corrupted when i go back and forth between the two?

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  • How can I SETF an element in a tree by an accessor?

    - by Willi Ballenthin
    We've been using Lisp in my AI course. The assignments I've received have involved searching and generating tree-like structures. For each assignment, I've ended up writing something like: (defun initial-state () (list 0 ; score nil ; children 0 ; value 0)) ; something else and building my functions around these "states", which are really just nested lists with some loosely defined structure. To make the structure more rigid, I've tried to write accessors, such as: (defun state-score ( state ) (nth 2 state)) This works for reading the value (which should be all I need to do in a nicely functional world. However, as time crunches, and I start to madly hack, sometimes I want a mutable structure). I don't seem to be able to SETF the returned ...thing (place? value? pointer?). I get an error with something like: (setf (state-score *state*) 10) Sometimes I seem to have a little more luck writing the accessor/mutator as a macro: (defmacro state-score ( state ) `(nth 2 ,state)) However I don't know why this should be a macro, so I certainly shouldn't write it as a macro (except that sometimes it works. Programming by coincidence is bad). What is an appropriate strategy to build up such structures? More importantly, where can I learn about whats going on here (what operations affect the memory in what way)?

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  • How to handle error with content-disposition

    - by František Žiacik
    Hi, how should I handle an exception that occurs after sending a Content-Disposition header for an attachment? I'm trying to generate a report at server and send it as a file, but if an exception occurs during the report generation, the error message itself is sent to browser which still takes it as a content of a file and shows a Save As dialog. User cannot know there was an error generating report, saves the file which is in wrong format now. Is there a way to cancel the response with this header and redirect to an error page? Or what else can I do to inform user about the error? Probably I could generate the report first and only if there was no error send the headers, but I want the report render directly to the Response output stream so that it does not need to stay in memory. Here is my code: this.Response.ContentType = "application/octet-stream"; this.Response.AddHeader("Content-Disposition", @"attachment; filename=""" + item.Name + @""""); this.Response.Flush(); GenerateReportTo(this.Response.OutputStream); // Exception occurs Thanks for any suggestions

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  • Can I load a UIImage from a URL?

    - by progrmr
    I have a URL for an image (got it from UIImagePickerController) but I no longer have the image in memory (the URL was saved from a previous run of the app). Can I reload the UIImage from the URL again? I see that UIImage has a imageWithContentsOfFile: but I have a URL. Can I use NSData's dataWithContentsOfURL: to read the URL? EDIT based on @Daniel's answer I tried the following code but it doesn't work... NSLog(@"%s %@", __PRETTY_FUNCTION__, photoURL); if (photoURL) { NSURL* aURL = [NSURL URLWithString:photoURL]; NSData* data = [[NSData alloc] initWithContentsOfURL:aURL]; self.photoImage = [UIImage imageWithData:data]; [data release]; } When I ran it the console shows: -[PhotoBox willMoveToWindow:] file://localhost/Users/gary/Library/Application%20Support/iPhone%20Simulator/3.2/Media/DCIM/100APPLE/IMG_0004.JPG *** -[NSURL length]: unrecognized selector sent to instance 0x536fbe0 *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSURL length]: unrecognized selector sent to instance 0x536fbe0' Looking at the call stack, I'm calling URLWithString, which calls URLWithString:relativeToURL:, then initWithString:relativeToURL:, then _CFStringIsLegalURLString, then CFStringGetLength, then forwarding_prep_0, then forwarding, then -[NSObject doesNotRecognizeSelector]. Any ideas why my NSString (photoURL's address is 0x536fbe0) doesn't respond to length? Why does it say it doesn't respond to -[NSURL length]? Doesn't it know that param is an NSString, not a NSURL?

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  • Elegant way of parsing Data files for Simulation

    - by sc_ray
    I am working on this project where I need to read in a lot of data from .dat files and use the data to perform simulations. The data in my .dat file looks as follows: DeviceID InteractingDeviceID InteractionStartTime InteractionEndTime 1 2 1101 1105 1,2 1101 and 1105 are tab delimited and it means Device 1 interacted with Device 2 at 1101 ms and ended the interaction at 1105ms. I have a trace data sets that compile thousands of such interactions and my job is to analyze these interactions. The first step is to parse the file. The language of choice is C++. The approach I was thinking of taking was to read the file, for every line that's read create a Device Object. This Device object will contain the property DeviceId and an array/vector of structs, that will contain a list of all the devices the given DeviceId interacted with over the course of the simulation.The struct will contain the Interacting Device Id, Interaction Start Time and Interaction End Time. I have a two fold question here: Is my approach correct? If I am on the right track, how do I rapidly parse these tab delimited data files and create Device objects without excessive memory overhead using C++? A push in the right direction will be much appreciated. Thanks

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  • Strategy for animating a lot of "LED's" - thread?, UIView animations? NSOperation? (iPhone)

    - by RickiG
    Hi I have to do some different views containing 72 LED lights. I built an LED Class so I can loop through the LED's and set them to different colors (Green, Red, Orange, Blue None etc.). The LED then loads the appropriate .png. This works fine, I loop over the LED's and set them. Now I know that at some time they will need to not just turn on/off change color, but will have to turn on with a small delay. Like an equalizer. I have a 5-10 views containing the 72 LED's and I would like to achieve the above with the minimum amount of memory/CPU strain. for(LED *l in self.ledArray) { [l display:Green]; } I simply loop as shown above and inside the LED is a switch case that does the correct logic. If this were actual LED's and a microController I would use sleep(100) or similar in the loop, but I would really like to avoid stuff like that for obvious reasons. I was thinking that doing a performOnThread withDelay would really be consuming, so would UIView animation changing the alpha and NSOperation would also be a lot of lifting for a small feature. Is there a both efficient and clever way to go around this? Thanks for any inspiration given:)

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  • Problem in accessing Windows shared folder on Ubuntu using terminal

    - by vikramtheone
    Hi Guys, Description I have 2 systems with me, one running on Windows(Host) and one on Ubuntu, both on a LAN. On the Windows(Host) I develop software intended for the Linux system and because the Linux system has little external memory, my idea to overcome this is by making the project folder on the Host side a Shared Folder with full access and access it on Ubuntu over the network. To achieve this, I have installed Samba on Ubuntu, when I go to Places -> Network I can see the shared project folder and I simply mount it. A link appears on the desktop. Next, using Nautilus I open the link and I can access the contents of the shared folder. Problem Even though I mount the shared project folder, I don't see it appearing in the /media or the /mnt folder, as a result of this I don't know what path to use to access this folder, from the terminal. For example: When, I mounted my USB stick, as expected, a link for the device appears on the Desktop and I also see a folder in the media folder. So, similarly, a mounted shared folder should have appeared on the /mnt folder, too. Can anyone suggest what I should do now? There are many posts around, but no solid solution for this problem. Help!!! :) Vikram

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  • Is there a way to get number of connections in Signalr hub group?

    - by pajo
    Here is my problem, I want to track if user is online or offline and notify other clients about it. I'm using hubs and implemented both IConnected and IDisconnect interfaces. My idea was to send notification to all clients when hub detects connect or disconnect. By default when user refreshes page he will get new connection id and eventually previous connection will call disconnect notifying other clients user is offline even though he's actually online. I tired to use my own ConnectionIdFactory returning username for connection id but with multiple tabs opened at some point it will detect user connectionid disconnected and after that client side hub will try to unsuccessfully connect to the hub in endless loop wasting memory and cpu making browser almost unusable. I needed to fix it fast so I removed my factory and now I add every new connection to the group using username, so I can easily notify single user on all connections, but then I have problem of detecting if user is online or offline as I don't know how many active connection user is having. So I'm wondering is there a way to get number of connections in one group? Or if anybody has some better idea how to track when user goes offline? I'm using Signalr 0.4

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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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  • Django caching seems to be causing problems

    - by Issy
    Hey guys, i have just implemented the Django Cache Local Memory back end in some my code, however it seems to be causing a problem. I get the following error when trying to view the site (With Debug On): Traceback (most recent call last): File "/usr/lib/python2.6/dist-packages/django/core/servers/basehttp.py", line 279, in run self.result = application(self.environ, self.start_response) File "/usr/lib/python2.6/dist-packages/django/core/servers/basehttp.py", line 651, in __call__ return self.application(environ, start_response) File "/usr/lib/python2.6/dist-packages/django/core/handlers/wsgi.py", line 245, in __call__ response = middleware_method(request, response) File "/usr/lib/python2.6/dist-packages/django/middleware/cache.py", line 91, in process_response patch_response_headers(response, timeout) File "/usr/lib/python2.6/dist-packages/django/utils/cache.py", line 112, in patch_response_headers response['Expires'] = http_date(time.time() + cache_timeout) TypeError: unsupported operand type(s) for +: 'float' and 'str' I have checked my code, for caching everything seems to be ok. For example, i have the following in my middleware. MIDDLEWARE_CLASSES = ( 'django.contrib.sessions.middleware.SessionMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware', 'django.middleware.cache.UpdateCacheMiddleware', 'django.middleware.common.CommonMiddleware', 'django.middleware.cache.FetchFromCacheMiddleware', 'django.contrib.flatpages.middleware.FlatpageFallbackMiddleware', ) My settings for Cache: CACHE_BACKEND = 'locmem://' CACHE_MIDDLEWARE_SECONDS = '3600' CACHE_MIDDLEWARE_KEY_PREFIX = 'za' CACHE_MIDDLEWARE_ANONYMOUS_ONLY = True And some of my code (template tag): def get_featured_images(): """ provides featured images """ cache_key = 'featured_images' images = cache.get(cache_key) if images is None: images = FeaturedImage.objects.all().filter(enabled=True)[:5] cache.set(cache_key, images) return {'images': images} Any idea what could be the problem, from the error message below it looks like there's an issue in django's cache.py?

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  • Wait on multiple condition variables on Linux without unnecessary sleeps?

    - by Joseph Garvin
    I'm writing a latency sensitive app that in effect wants to wait on multiple condition variables at once. I've read before of several ways to get this functionality on Linux (apparently this is builtin on Windows), but none of them seem suitable for my app. The methods I know of are: Have one thread wait on each of the condition variables you want to wait on, which when woken will signal a single condition variable which you wait on instead. Cycling through multiple condition variables with a timed wait. Writing dummy bytes to files or pipes instead, and polling on those. #1 & #2 are unsuitable because they cause unnecessary sleeping. With #1, you have to wait for the dummy thread to wake up, then signal the real thread, then for the real thread to wake up, instead of the real thread just waking up to begin with -- the extra scheduler quantum spent on this actually matters for my app, and I'd prefer not to have to use a full fledged RTOS. #2 is even worse, you potentially spend N * timeout time asleep, or your timeout will be 0 in which case you never sleep (endlessly burning CPU and starving other threads is also bad). For #3, pipes are problematic because if the thread being 'signaled' is busy or even crashes (I'm in fact dealing with separate process rather than threads -- the mutexes and conditions would be stored in shared memory), then the writing thread will be stuck because the pipe's buffer will be full, as will any other clients. Files are problematic because you'd be growing it endlessly the longer the app ran. Is there a better way to do this? Curious for answers appropriate for Solaris as well.

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  • document.onclick settimeout function javascript help

    - by Jamex
    Hi, I have a document.onclick function that I would like to have a delay. I can't seem to get the syntax right. my original code is <script type="text/javascript"> document.onclick=check; function check(e){do something} I tried the below, but that code is incorrect, the function did not execute and nothing happened. <script type="text/javascript"> document.onclick=setTimeout("check", 1000); function check(e){do something} I tried the next set, the function got executed, but no delay. <script type="text/javascript"> setTimeout(document.onclick=check, 1000); function check(e){do something} what is the correct syntax for this code. TIA Edit: The solutions were all good, my problem was that I use the function check to obtain the id of the element being clicked on. But after the delay, there is no "memory" of what was being clicked on, so the rest of the function does not get executed. Jimr wrote the short code to preserve clicked event. The code that is working is // Delay execution of event handler function "f" by "time" ms. document.onclick = makeDelayedHandler(check, 250); function makeDelayedHandler( f, time) { return function( e ) {setTimeout(function() {f( e );}, time ); }; } function check(e){ var click = (e && e.target) || (event && event.srcElement); . . . Thank you all.

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  • MYSQL not running on Ubuntu OS - Error 2002.

    - by mgj
    Hi, I am a novice to mysql DB. I am trying to run the MYSQL Server on Ubuntu 10.04. Through Synaptic Package Manager I am have installed the mysql version: mysql-client-5.1 I wonder that how was the database password set for the mysql-client software that I installed through the above way.It would be nice if you could enlighten me on this. When I tried running this database, I encountered the error given below: mohnish@mohnish-laptop:/var/lib$ mysql ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2) mohnish@mohnish-laptop:/var/lib$ I referred to a similar question posted by another user. I didn't find a solution through the proposed answers. For instance when I tried the solutions posted for the similar question I got the following: mohnish@mohnish-laptop:/var/lib$ service start mysqld start: unrecognized service mohnish@mohnish-laptop:/var/lib$ ps -u mysql ERROR: User name does not exist. ********* simple selection ********* ********* selection by list ********* -A all processes -C by command name -N negate selection -G by real group ID (supports names) -a all w/ tty except session leaders -U by real user ID (supports names) -d all except session leaders -g by session OR by effective group name -e all processes -p by process ID T all processes on this terminal -s processes in the sessions given a all w/ tty, including other users -t by tty g OBSOLETE -- DO NOT USE -u by effective user ID (supports names) r only running processes U processes for specified users x processes w/o controlling ttys t by tty *********** output format ********** *********** long options *********** -o,o user-defined -f full --Group --User --pid --cols --ppid -j,j job control s signal --group --user --sid --rows --info -O,O preloaded -o v virtual memory --cumulative --format --deselect -l,l long u user-oriented --sort --tty --forest --version -F extra full X registers --heading --no-heading --context ********* misc options ********* -V,V show version L list format codes f ASCII art forest -m,m,-L,-T,H threads S children in sum -y change -l format -M,Z security data c true command name -c scheduling class -w,w wide output n numeric WCHAN,UID -H process hierarchy mohnish@mohnish-laptop:/var/lib$ which mysql /usr/bin/mysql mohnish@mohnish-laptop:/var/lib$ mysql ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2) I even tried referring to http://forums.mysql.com/read.php?11,27769,84713#msg-84713 but couldn't find anything useful. Please let me know how I could tackle this error. Thank you very much..

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  • how to implement a really efficient bitvector sorting in python

    - by xiao
    Hello guys! Actually this is an interesting topic from programming pearls, sorting 10 digits telephone numbers in a limited memory with an efficient algorithm. You can find the whole story here What I am interested in is just how fast the implementation could be in python. I have done a naive implementation with the module bitvector. The code is as following: from BitVector import BitVector import timeit import random import time import sys def sort(input_li): return sorted(input_li) def vec_sort(input_li): bv = BitVector( size = len(input_li) ) for i in input_li: bv[i] = 1 res_li = [] for i in range(len(bv)): if bv[i]: res_li.append(i) return res_li if __name__ == "__main__": test_data = range(int(sys.argv[1])) print 'test_data size is:', sys.argv[1] random.shuffle(test_data) start = time.time() sort(test_data) elapsed = (time.time() - start) print "sort function takes " + str(elapsed) start = time.time() vec_sort(test_data) elapsed = (time.time() - start) print "sort function takes " + str(elapsed) start = time.time() vec_sort(test_data) elapsed = (time.time() - start) print "vec_sort function takes " + str(elapsed) I have tested from array size 100 to 10,000,000 in my macbook(2GHz Intel Core 2 Duo 2GB SDRAM), the result is as following: test_data size is: 1000 sort function takes 0.000274896621704 vec_sort function takes 0.00383687019348 test_data size is: 10000 sort function takes 0.00380706787109 vec_sort function takes 0.0371489524841 test_data size is: 100000 sort function takes 0.0520560741425 vec_sort function takes 0.374383926392 test_data size is: 1000000 sort function takes 0.867373943329 vec_sort function takes 3.80475401878 test_data size is: 10000000 sort function takes 12.9204008579 vec_sort function takes 38.8053860664 What disappoints me is that even when the test_data size is 100,000,000, the sort function is still faster than vec_sort. Is there any way to accelerate the vec_sort function?

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  • Divide and conquer of large objects for GC performance

    - by Aperion
    At my work we're discussing different approaches to cleaning up a large amount of managed ~50-100MB memory.There are two approaches on the table (read: two senior devs can't agree) and not having the experience the rest of the team is unsure of what approach is more desirable, performance or maintainability. The data being collected is many small items, ~30000 which in turn contains other items, all objects are managed. There is a lot of references between these objects including event handlers but not to outside objects. We'll call this large group of objects and references as a single entity called a blob. Approach #1: Make sure all references to objects in the blob are severed and let the GC handle the blob and all the connections. Approach #2: Implement IDisposable on these objects then call dispose on these objects and set references to Nothing and remove handlers. The theory behind the second approach is since the large longer lived objects take longer to cleanup in the GC. So, by cutting the large objects into smaller bite size morsels the garbage collector will processes them faster, thus a performance gain. So I think the basic question is this: Does breaking apart large groups of interconnected objects optimize data for garbage collection or is better to keep them together and rely on the garbage collection algorithms to processes the data for you? I feel this is a case of pre-optimization, but I do not know enough of the GC to know what does help or hinder it.

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  • Please critique this method

    - by Jakob
    Hi I've been looking around the net for some tab button close functionality, but all those solutions had some complicated eventhandler, and i wanted to try and keep it simple, but I might have broken good code ethics doing so, so please review this method and tell me what is wrong. public void AddCloseItem(string header, object content){ //Create tabitem with header and content StackPanel headerPanel = new StackPanel() { Orientation = Orientation.Horizontal, Height = 14}; headerPanel.Children.Add(new TextBlock() { Text = header }); Button closeBtn = new Button() { Content = new Image() { Source = new BitmapImage(new Uri("images/cross.png", UriKind.Relative)) }, Margin = new Thickness() { Left = 10 } }; headerPanel.Children.Add(closeBtn); TabItem newTabItem = new TabItem() { Header = headerPanel, Content = content }; //Add close button functionality closeBtn.Tag = newTabItem; closeBtn.Click += new RoutedEventHandler(closeBtn_Click); //Add item to list this.Add(newTabItem); } void closeBtn_Click(object sender, RoutedEventArgs e) { this.Remove((TabItem)((Button)sender).Tag); } So what I'm doing is storing the tabitem in the btn.Tag property, and then when the button is clicked i just remove the tabitem from my observablecollection, and the UI is updated appropriately. Am I using too much memory saving the tabitem to the Tag property?

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