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• edmx - The operation could not be completed - When adding Inheritance

  - by vdh_ant

  Hey guys I have an edmx model which I have draged 2 tables onto - One called 'File' and the other 'ApplicaitonFile'. These two tables have a 1 to 1 relationship in the database. If I stop here everything works fine. But in my model, I want 'ApplicaitonFile' to inherit from 'File'. So I delete the 1 to 1 relationship then configure 'ApplicaitonFile' from 'File' and then remove the FileId from 'ApplicaitonFile' which was the primary key. (Note I am following the instructions from here). If I leave the model open at this point everything is fine, but as soon as I close it, if I try and reopen it again I get the following error "The operation could not be completed". I have been searching for a solution and found this - http://stackoverflow.com/questions/944050/entity-model-does-not-load but as far as I can tell I don't have a duplicate InheritanceConnectors (although I don't know exactly what I'm looking for but I can't see anything out of the ordinary - like 2 connectors with the same name) and the relationship I originally have is a 1 to 1 not a 1 to 0..1 Any ideas??? this is driving me crazy...

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• Fastest XML parser for small, simple documents in Java

  - by Varkhan

  I have to objectify very simple and small XML documents (less than 1k, and it's almost SGML: no namespaces, plain UTF-8, you name it...), read from a stream, in Java. I am using JAXP to process the data from my stream into a Document object. I have tried Xerces, it's way too big and slow... I am using Dom4j, but I am still spending way too much time in org.dom4j.io.SAXReader. Does anybody out there have any suggestion on a faster, more efficient implementation, keeping in mind I have very tough CPU and memory constraints? [Edit 1] Keep in mind that my documents are very small, so the overhead of staring the parser can be important. For instance I am spending as much time in org.xml.sax.helpers.XMLReaderFactory.createXMLReader as in org.dom4j.io.SAXReader.read [Edit 2] The result has to be in Dom format, as I pass the document to decision tools that do arbitrary processing on it, like switching code based on the value of arbitrary XPaths, but also extracting lists of values packed as children of a predefined node. [Edit 3] In any case I eventually need to load/parse the complete document, since all the information it contains is going to be used at some point. (This question is related to, but different from, http://stackoverflow.com/questions/373833/best-xml-parser-for-java )

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• Writing an audio player in C#

  - by Malki

  Hi, I have a pretty cool idea for a very special media player. I like to think about this project as a mini-startup, since I don't yet know if my idea is practical. Anyways, before implementing my idea, I first need to be able to implement a simple audio player. My preferred language for this project is C#, simply because it's so easy to use, but any other object oriented language would be fine too I guess. I started out with no knowledge whatsoever about audio. My main goals right now are: Being able to play audio files - as many formats as possible (sort of a VLC type player, but only audio for now). Being able to analyze audio files - as in, reading frequency, amplitude, volume, and other information about the audio. I think maybe a good idea here is to be able to analyze one file format (PCM?), and then temporarily converting any file I want to analyze to that format. This is in order to later implement a mechanism that compares songs and identifies similar songs to recommend to the user (this feature isn't part of my idea, but I figured since it exists in many players nowadays, I need to have it too if I want be able to compete with them). BTW - I currently don't have any knowledge about audio/wavelengths/frequencies and such, so I'd appreciate it if someone could point me in the right direction about this analyzation feature. Maybe in the future I'd expand to playing video files as well, but for now I'm concentrating on audio. After searching the Internet for a while, I've come across LAME. Problem is, it's not C#, and I'm not sure how to use it. I know there is something called "Interoperability", that is supposed to let me work with native DLL files through C#. Any information about that would be helpful as well. Any help would be much appreciated. Thanks, Malki :)

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• php error reporting - having trouble matching local & web server settings

  - by Andrew Heath

  I'm trying to add a custom error handler to my site, but in doing so have discovered that my webhost's PHP error reporting settings and those of my localhost (default XAMPP) vary considerably. While I thought I was programming to E_STRICT like a good little boy, adding the error handler to my webhost revealed craploads of Runtime Notices. Example: Runtime notice strtotime() [function.strtotime]: It is not safe to rely on the system's timezone settings. Please use the date.timezone setting, the TZ environment variable or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Chicago' for 'CST/-6.0/no DST' instead In /home/... Clearly this isn't a red-alert, showstopping error. But what bothers me is that it doesn't show up on my localhost. I'd certainly like to improve my code by addressing these sorts of issues if I could see them! I've looked through both php.ini files, and my webhost's setting is error_reporting = E_ALL & ~E_NOTICE whereas mine was error_reporting = E_STRICT, which I had thought was better. However, changing mine to match and rebooting the server doesn't seem to have accomplished anything. Could someone please point me in the right direction?

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• Mysql and PHP - Reading multiple insert queries from a file and executing at runtime

  - by SpikETidE

  Hi everyone... I am trying out a back-up and restore system. Basically, what i try to do is, when creating the back up i make a file which looks like DELETE FROM bank_account; INSERT INTO bank_account VALUES('1', 'IB6872', 'Indian Bank', 'Indian Bank', '2', '1', '0', '0000-00-00 00:00:00', '1', '2010-04-13 17:09:05');INSERT INTO bank_account VALUES('2', 'IB7391', 'Indian Bank', 'Indian Bank', '3', '1', '0', '0000-00-00 00:00:00', '1', '2010-04-13 17:09:32'); and so on and so forth. When i restore the db i just read the query from the file, save it to a string and then execute it over the DB using mysql_query(); The problem is, when i run the query through mysql_query(), the execution stops after the delete query with the error 'Error in syntax near '; INSERT INTO bank_account VALUES('1', 'IB6872', 'Indian Bank', 'Indian Bank', '2',' at line 1. But when i run the queries directly over the Db, using phpmyadmin it executes without any errors. As far as i can see, i can't notice any syntax error in the query. Can anyone point out where there might be a glitch...? Thanks and regards....

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• Question about the evolution of interaction paradigm between web server program and content provider program?

  - by smwikipedia

  Hi experts, In my opinion, web server is responsible to deliver content to client. If it is static content like pictures and static html document, web server just deliver them as bitstream directly. If it is some dynamic content that is generated during processing client's request, the web server will not generate the conetnt itself but call some external proram to genearte the content. AFAIK, this kind of dynamice content generation technologies include the following: CGI ISAPI ... And from here, I noticed that: ...In IIS 7, modules replace ISAPI filters... Is there any others? Could anyone help me complete the above list and elabrate on or show some links to their evolution? I think it would be very helpful to understand application such as IIS, TomCat, and Apache. I once wrote a small CGI program, and though it serves as a content generator, it is still nothing but a normal standalone program. I call it normal because the CGI program has a main() entry point. But with the recenetly technology like ASP.NET, I am not writing complete program, but only some class library. Why does such radical change happens? Many thanks.

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• what is meant by normalization in huge pointers

  - by wrapperm

  Hi, I have a lot of confusion on understanding the difference between a "far" pointer and "huge" pointer, searched for it all over in google for a solution, couldnot find one. Can any one explain me the difference between the two. Also, what is the exact normalization concept related to huge pointers. Please donot give me the following or any similar answers: "The only difference between a far pointer and a huge pointer is that a huge pointer is normalized by the compiler. A normalized pointer is one that has as much of the address as possible in the segment, meaning that the offset is never larger than 15. A huge pointer is normalized only when pointer arithmetic is performed on it. It is not normalized when an assignment is made. You can cause it to be normalized without changing the value by incrementing and then decrementing it. The offset must be less than 16 because the segment can represent any value greater than or equal to 16 (e.g. Absolute address 0x17 in a normalized form would be 0001:0001. While a far pointer could address the absolute address 0x17 with 0000:0017, this is not a valid huge (normalized) pointer because the offset is greater than 0000F.). Huge pointers can also be incremented and decremented using arithmetic operators, but since they are normalized they will not wrap like far pointers." Here the normalization concept is not very well explained, or may be I'm unable to understand it very well. Can anyone try explaining this concept from a beginners point of view. Thanks, Rahamath

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• JMeter CSV Data Set is corrupting Japanese strings stored as proper UTF-8, I get Question Marks instead

  - by Mark Bennett

  I read in search terms from a simple text file to send to a search engine. It works fine in English, but gives me ???? for any Japanese text. Text with mixed English and Japanese does show the English text, so I know it's reading it. What I'm seeing: Input text: Snow Leopard ??????????????? Turns into: Snow Leopard ??????????????? This is in my POST field of an HTTP. If I set JMeter to encode the data, it just puts in the percent sequence for question marks. Interesting note: In the example above there are 15 Japanese characters, and then 15 question marks, so at some point it's being seen as full characters and not just bytes. About the Data: The CSV file is very simple in structure. There's only one field / one column, which I name TERM, and later use as ${TERM} I don't really need full CSV because it's only one string per line. There's no commas or quotes. When I run the Unix "file" command on the file, it says UTF-8 text. I've also verified it in command line and graphical mode on two machines. JMeter CSV Dataset Config: Filename: japanese-searches.csv File encoding: UTF-8 (also tried without) Variable names: TERM Delimiter: , Allow Quoted Data: False (I also tried True, different, but still wrong) Recycle at EOF: True Stop at EOF: False Staring mode: All threads A few things I've tried: Tried Allow quoted Data. It changed to other strange characters. -Dfile.encoding=UTF-8 Tried encoding the POST, but it just turned into a bunch of %nn for question marks And I'm not sure how "debug" just after the each line of the CSV is read in. I think it's corrupted right away, but I'm not sure. If it's only mangled when I reference it, then instead of ${TERM} perhaps there's some other "to bytes" function call. I'll start checking into that. I haven't done anything with the JMeter functions yet.

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• Open source libraries to design directed graphs

  - by Benjamin

  Hi all, I'm going to need to write a software that takes a list of persons and connects them together in a directed-graph-like manner. The GUI aspect of the whole project is very important. The graph must allow a lot of interaction. Such as selecting several people and hiding the others, moving them around. Additionally, the software will need to be able to provide other kind of GUI-features such as several tabs, text boxes etc. The application must be quite performant. As in, it must be able to handle hundreds if not thousands of widgets. Hence, I would like to know which open source libraries (at this point the programming language they are written in does not matter - I just want an overview of everything good that is out there) would allow me to develop such piece of software? What would you recommend? Thanks for that. Edit: Could you please also link to tutorials explaining how I could program a GUI that can interact with the generated graph? For example mouse events.

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• ASP.NET MVC 2.0 + Implementation of a IRouteHandler goes not fire

  - by Peter

  Can anybody please help me with this as I have no idea why public IHttpHandler GetHttpHandler(RequestContext requestContext) is not executing. In my Global.asax.cs I have public class MvcApplication : System.Web.HttpApplication { public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); routes.MapRoute( "Default", // Route name "{controller}/{action}/{id}", // URL with parameters new { controller = "Home", action = "Index", id = "" } // Parameter defaults ); routes.Add("ImageRoutes", new Route("Images/{filename}", new CustomRouteHandler())); } protected void Application_Start() { RegisterRoutes(RouteTable.Routes); } } //CustomRouteHandler implementation is below public class CustomRouteHandler : IRouteHandler { public IHttpHandler GetHttpHandler(RequestContext requestContext) { // IF I SET A BREAK POINT HERE IT DOES NOT HIT FOR SOME REASON. string filename = requestContext.RouteData.Values["filename"] as string; if (string.IsNullOrEmpty(filename)) { // return a 404 HttpHandler here } else { requestContext.HttpContext.Response.Clear(); requestContext.HttpContext.Response.ContentType = GetContentType(requestContext.HttpContext.Request.Url.ToString()); // find physical path to image here. string filepath = requestContext.HttpContext.Server.MapPath("~/logo.jpg"); requestContext.HttpContext.Response.WriteFile(filepath); requestContext.HttpContext.Response.End(); } return null; } } Can any body tell me what I'm missing here. Simply public IHttpHandler GetHttpHandler(RequestContext requestContext) does not fire. I havn't change anything in the web.config either. What I'm missing here? Please help.

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• How do I make VC++'s debugger break on exceptions?

  - by Mason Wheeler

  I'm trying to debug a problem in a DLL written in C that keeps causing access violations. I'm using Visual C++ 2008, but the code is straight C. I'm used to Delphi, where if an exception occurs while running under the debugger, the program will immediately break to the debugger and it will give you a chance to examine the program state. In Visual C++, though, all I get is a message in the Output tab: First-chance exception at blah blah blah: Access violation reading location 0x04410000. No breaks, nothing. It just goes and unwinds the stack until it's back in my Delphi EXE, which recognizes something's wrong and alerts me there, but by that point I've lost several layers of call stack and I don't know what's going on. I've tried other debugging techniques, but whatever it's doing is taking place deep within a nested loop inside a C macro that's getting called more than 500 times, and that's just a bit beyond my skill (or my patience) to trace through. I figure there has to be some way to get the "first-chance" exception to actually give me a "chance" to handle it. There's probably some "break immediately on first-chance exceptions" configuration setting I don't know about, but it doesn't seem to be all that discoverable. Does anyone know where it is and how to enable it?

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• Saving a remote image with cURL?

  - by thebluefox

  Morning all, Theres a few questions around this but none that really answer my question, as far as I ca understand. Basically I have a GD script that deals with resizing and caching images on our server, but I need to do the same with images stored on a remote server. So, I'm wanting to save the image locally, then resize and display it as normal. I've got this far... $file_name_array = explode('/', $filename); $file_name_array_r = array_reverse($file_name_array); $save_to = 'system/cache/remote/'.$file_name_array_r[1].'-'.$file_name_array_r[0]; $ch = curl_init($filename); $fp = fopen($save_to, "wb"); // set URL and other appropriate options $options = array(CURLOPT_FILE => $fp, CURLOPT_HEADER => 0, CURLOPT_FOLLOWLOCATION => 1, CURLOPT_TIMEOUT => 60); // 1 minute timeout (should be enough) curl_setopt_array($ch, $options); curl_exec($ch); curl_close($ch); fclose($fp); This creates the image file, but does not copy it accross? Am I missing the point? Cheers guys.

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• How do you verify that 2 copies of a VB 6 executable came from the same code base?

  - by Tim Visher

  I have a program under version control that has gone through multiple releases. A situation came up today where someone had somehow managed to point to an old copy of the program and thus was encountering bugs that have since been fixed. I'd like to go back and just delete all the old copies of the program (keeping them around is a company policy that dates from before version control was common and should no longer be necessary) but I need a way of verifying that I can generate the exact same executable that is better than saying "The old one came out of this commit so this one should be the same." My initial thought was to simply MD5 hash the executable, store the hash file in source control, and be done with it but I've come up against a problem which I can't even parse. It seems that every time the executable is generated (method: Open Project. File Make X.exe) it hashes differently. I've noticed that Visual Basic messes with files every time the project is opened in seemingly random ways but I didn't think that would make it into the executable, nor do I have any evidence that that is indeed what's happening. To try to guard against that I tried generating the executable multiple times within the same IDE session and checking the hashes but they continued to be different every time. So that's: Generate Executable Generate MD5 Checksum: md5sum X.exe > X.md5 Verify MD5 for current executable: md5sum -c X.md5 Generate New Executable Verify MD5 for new executable: md5sum -c X.md5 Fail verification because computed checksum doesn't match. I'm not understanding something about either MD5 or the way VB 6 is generating the executable but I'm also not married to the idea of using MD5. If there is a better way to verify that two executables are indeed the same then I'm all ears. Thanks in advance for your help!

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• mysql image disable print download

  - by Vish

  Hi, We use a Flex AIR client and a WAMP server. Tiff images are stored in MySQL. Currently, I can download the image from AIR client and it prompts for a download dialog. Things are fine till this point. We got a new requirement. Requirement is that only some users can print the image which gets downloaded. For other users, they should not be able to print the tiff image. Wondering how to accomplish this. One idea, not sure if its efficient, is to convert the image requested to pdf at the server side, disable print option there(hope there are API's available) and send back the pdf. Please let me know btter ideas. Also, is there a way to prevent file download dialog from popping up everytime the file is requested for download? Can we just get the file stream to the client and manipulate it to open with a particular viewer or write it to pdf... Please help.

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• Meta tag depending of selected language and title

  - by lena

  Hi, I'm aware about Google ignore most of the time, meta tag and use content. (This is not the point here) I'm working on an existing web site, not created by me. I need a quick solution, I guess with variables. The website construction: (no known template system) index.html which is presentation page with language selection index.php which embeding menu, content, footer several content pages that are embedded by index.php What I need to do only for those 2 pages welcome_en.html and welcome_fr.html (these pages are embedded so no header possible on these page) to have different page title (browser title) and different META tag. Any solution is welcome Thanks extra information Language detection on index.php: <?php $lang = $_GET['lang']; $page = $_GET['page']; if ($_GET['page'] == "" || !$_GET['page']) { $page = "welcome"; } if ($_GET['lang'] == "" || !$_GET['lang']) { $lang = "_fr"; } ? <td><img src="images/ban02<?php echo "$lang" ?>.jpg" width="531" height="60" <?php if ($_GET['lang'] == "_fr" || $_GET['lang'] == "" || !$_GET['lang']) { echo "alt='text'";} else if ($_GET['lang'] == "_en") {echo "alt='text'"; } ?>></td> for the embeded menu, footer ect like this one <?php include "menu.php"; ?> for the embedded content <?php //echo "$page$lang.html"; $lang = preg_replace('/[^a-z0-9_ ]/i', '', $_GET['lang']); $page = preg_replace('/[^a-z0-9_ ]/i', '', $_GET['page']); include $page . $lang . ".html"; ?>

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• Choosing a W3C valid DOCTYPE and charset combination?

  - by George Carter

  I have a homepage with the following: <DOCTYPE html> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> My choice of the DOCTYPE "html" is based on a recommendation for html pages using jQuery. My choice of charset=utf=8 is based on a recommendation to make my pages readable on most browsers. But these choices may be wrong. When I run this page thru the W3C HTML validator, I get messages you see below. Any way I can eliminate the 2 errors? ! Using experimental feature: HTML5 Conformance Checker. The validator checked your document with an experimental feature: HTML5 Conformance Checker. This feature has been made available for your convenience, but be aware that it may be unreliable, or not perfectly up to date with the latest development of some cutting-edge technologies. If you find any issue with this feature, please report them. Thank you. Validation Output: 2 Errors 1. Error Line 18, Column 70: Changing character encoding utf-8 and reparsing. …ntent-Type" content="text/html; charset=utf-8"> 2. Error Line 18, Column 70: Changing encoding at this point would need non-streamable behavior. …ntent-Type" content="text/html; charset=utf-8">

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• What is an elegant way to set up a leiningen project that requires different dependencies based on the build platform?

  - by Savanni D'Gerinel

  In order to do some multi-platform GUI development, I have just switched from GTK + Clojure (because it looks like the Java bindings for GTK never got ported to Windows) to SWT + Clojure. So far, so good in that I have gotten an uberjar built for Linux. The catch, though, is that I want to build an uberjar for Windows and I am trying to figure out a clean way to manage the project.clj file. At first, I thought I would set the classpath to point to the SWT libraries and then build the uberjar. This would require that I set a classpath to the SWT libraries before running the jar, but I would likely need a launcher script, anyway. However, leiningen seems to ignore the classpath in this instance because it always reports that Currently, project.clj looks like this for me: (defproject alyra.mana-punk/character "1.0.0-SNAPSHOT" :description "FIXME: write" :dependencies [[org.clojure/clojure "1.2.0"] [org.clojure/clojure-contrib "1.2.0"] [org.eclipse/swt-gtk-linux-x86 "3.5.2"]] :main alyra.mana-punk.character.core) The relevant line is the org.eclipse/swt-gtk-linux-x86 line. If I want to make an uberjar for Windows, I have to depend on org.eclipse/swt-win32-win32-x86, and another one for x86-64, and so on and so forth. My current solution is to simply create a separate branch for each build environment with a different project.clj. This seems kinda like using a semi to deliver a single gallon of milk, but I am using bazaar for version control, so branching and repeated integrations are easy. Maybe the better way is to have a project.linux.clj, project.win32.clj, etc, but I do not see any way to tell leiningen which project descriptor to use. What are other (preferably more elegant) ways to set up such an environment?

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• How do I run NUnit in debug mode from Visual Studio?

  - by Jon Cage

  I've recently been building a test framework for a bit of C# I've been working on. I have NUnit set up and a new project within my workspace to test the component. All works well if I load up my unit tests from Nunit (v2.4), but I've got to the point where it would be really useful to run in debug mode and set some break points. I've tried the suggestions from several guides which all suggest changing the 'Debug' properties of the test project: Start external program: C:\Program Files\NUnit 2.4.8\bin\nunit-console.exe Command line arguments: /assembly: <full-path-to-solution>\TestDSP\bin\Debug\TestDSP.dll I'm using the console version there, but have tried the calling the GUI as well. Both give me the same error when I try and start debugging: Cannot start test project 'TestDSP' because the project does not contain any tests. Is this because I normally load \DSP.nunit into the Nunit GUI and that's where the tests are held? I'm beginning to think the problem may be that VS wants to run it's own test framework and that's why it's failing to find the NUnit tests? [Edit] To those asking about test fixtures, one of my .cs files in the TestDSP project looks roughly like this: namespace Some.TestNamespace { // Testing framework includes using NUnit.Framework; [TestFixture] public class FirFilterTest { /// <summary> /// Tests that a FirFilter can be created /// </summary> [Test] public void Test01_ConstructorTest() { ...some tests... } } } ...I'm pretty new to C# and the Nunit test framework so it's entirely possible I've missed some crucial bit of information ;-) [FINAL SOLUTION] The big problem was the project I'd used. If you pick: Other Languages->Visual C#->Test->Test Project ...when you're choosing the project type, Visual Studio will try and use it's own testing framework as far as I can tell. You should pick a normal c# class library project instead and then the instructions in my selected answer will work.

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• updating dataset using join and bindingsource?

  - by netadictos

  Hi, I have created a dataset and in the designer I have created the relations and foreign keys that exist in the database. Basically, I have a product that has a relationship to a table of prices. The keyfield they share is IdProduct in the Prices table. In the Fill/Get of the product I return the Price field. I also have a DataGrid that uses a BindingSource which uses this table. Everything displays correctly and when I double click on a row within the datagrid I then open up a tabbed form that contains a detailed view of the record selected. The user at this point is able to make changes to the record and they are properly propogated back to the BindingSource. The problem is that the TableAdapter does not contain the appopriate update, therefore I am not able to call the TableAdapter.Update method with the dataset as I would had I created a tableadapter not using a join. How am I best to handle this situation. At the same time I cannot get any modified row: dTiendasDs.ProductosDataTable modified = (dTiendasDs.ProductosDataTable) dTiendasDs.Productos.GetChanges(DataRowState.Modified); modified is always null Thanks,

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• NoSQL for filesystem storage organization and replication?

  - by wheaties

  We've been discussing design of a data warehouse strategy within our group for meeting testing, reproducibility, and data syncing requirements. One of the suggested ideas is to adapt a NoSQL approach using an existing tool rather than try to re-implement a whole lot of the same on a file system. I don't know if a NoSQL approach is even the best approach to what we're trying to accomplish but perhaps if I describe what we need/want you all can help. Most of our files are large, 50+ Gig in size, held in a proprietary, third-party format. We need to be able to access each file by a name/date/source/time/artifact combination. Essentially a key-value pair style look-up. When we query for a file, we don't want to have to load all of it into memory. They're really too large and would swamp our server. We want to be able to somehow get a reference to the file and then use a proprietary, third-party API to ingest portions of it. We want to easily add, remove, and export files from storage. We'd like to set up automatic file replication between two servers (we can write a script for this.) That is, sync the contents of one server with another. We don't need a distributed system where it only appears as if we have one server. We'd like complete replication. We also have other smaller files that have a tree type relationship with the Big files. One file's content will point to the next and so on, and so on. It's not a "spoked wheel," it's a full blown tree. We'd prefer a Python, C or C++ API to work with a system like this but most of us are experienced with a variety of languages. We don't mind as long as it works, gets the job done, and saves us time. What you think? Is there something out there like this?

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• Javascript CS-PRNG - 64-bit random

  - by Jack

  Hi, I need to generate a cryptographically secure 64-bit unsigned random integer in Javascript. The first problem is that Javascript only allows 64-bit signed integers, so 9223372036854775808 is the biggest supported integer without going into floating point use I think? To fix this I can use a big number library, no problem. My Method: var randNum = SHA256( randBigInt(128, 0) ) % 2^64; Where SHA256() is a secure hash function and randBigInt() is defined below as a non-crypto PRNG, im giving it a 128bit seed so brute force shouldn't be a problem. randBigInt(n,s) //return an n-bit random BigInt (n>=1). If s=1, then the most significant of those n bits is set to 1. Is this a secure method to generate a cryptographically secure 64-bit random int? And importantly does taking the 2^64 mod guarantee 100% I have a 64-bit number? An abstract example, say this number is prime (it isn't i know), I will use it in the Galois Field [2^p], where p must be 64bits so that every possible 1-63bit number is a field element. In this query, my random int must be larger than any 63-bit number. And Im not sure im correct in taking the 2^64 mod of a 256bit hash output. Thanks (hope that makes sense)

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• Perl - Using hashes in classes

  - by brydgesk

  I have a class with several variables, one of which is a hash (_runs): sub new { my ($class, $name) = @_; my $self = { _name => $name, ... _runs => (), _times => [], ... }; bless ($self, $class); return $self; } Now, all I'm trying to do is create an accessor/mutator, as well as another subroutine that pushes new data into the hash. But I'm having a hell of a time getting all the referencing/dereferencing/$self calls working together. I've about burned my eyes out with "Can't use string ("blah") as a HASH ref etc etc" errors. For the accessor, what is 'best practice' for returning hashes? Which one of these options should I be using (if any)?: return $self->{_runs}; return %{ $self->{_runs} }; return \$self->{_runs}; Further, when I'm using the hash within other subroutines in the class, what syntax do I use to copy it? my @runs = $self->{_runs}; my @runs = %{ $self->{_runs} }; my @runs = $%{ $self->{_runs} }; my @runs = $$self->{_runs}; Same goes for iterating over the keys: foreach my $dt (keys $self->{_runs}) foreach my $dt (keys %{ $self->{_runs} }) And how about actually adding the data? $self->{_runs}{$dt} = $duration; %{ $self->{_runs} }{$dt} = $duration; $$self->{_runs}{$dt} = $duration; You get the point. I've been reading articles about using classes, and articles about referencing and dereferencing, but I can't seem to get my brain to combine the knowledge and use both at the same time. I got my _times array working finally, but mimicking my array syntax over to hashes didn't work.

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• c++ use of winmain()

  - by Jack

  Hi, I just started learning programming for windows in c++. I had this crazy image, that win32 programming is based on calling windows functions and sending parameters to and from them. Like, when you want to create window, you call some win32 function that handles windows GUI and say "Hi, please, create me new window, 100 x 100 px, with two buttons", and that GUI function says "Hi, no problem, when something happends, like user clicks one button, I will change this variable xy located in this location". So, I thought that it will be very similiar to console programming. But the very first instruction surprised me. I always thought that every program executes main() function first. So, when I launch app, windows stores some parameters on top of stack and run that application. So I assumed that initializing main() is just a c++ way to tell the compiler where the first instruction should be. But in win32 programming, there is function called winmain() which starts first. So I am little confused. I thought it´s rule that compiler must have main() to start with, that main just defines where ti start, like some start point identifier. So, please, why is there winmain() function instead of main()? When I thought that C++ programming is as logical as assembler, it confuses me once again.

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• c++ use of winmain()

  - by Jack

  Hi, I just started learning programming for windows in c++. I had this crazy image, that win32 programming is based on calling windows functions and sending parameters to and from them. Like, when you want to create window, you call some win32 function that handles windows GUI and say "Hi, please, create me new window, 100 x 100 px, with two buttons", and that GUI function says "Hi, no problem, when something happends, like user clicks one button, I will change this variable xy located in this location". So, I thought that it will be very similiar to console programming. But the very first instruction surprised me. I always thought that every program executes main() function first. So, when I launch app, windows stores some parameters on top of stack and run that application. So I assumed that initializing main() is just a c++ way to tell the compiler where the first instruction should be. But in win32 programming, there is function called winmain() which starts first. So I am little confused. I thought it´s rule that compiler must have main() to start with, that main just defines where ti start, like some start point identifier. So, please, why is there winmain() function instead of main()? When I thought that C++ programming is as logical as assembler, it confuses me once again.

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• NSTimer Reset Not Working

  - by user355900

  hi, i have a nstimer and it works perfectly counting down from 2:00 but when i hit the reset button it does not work it just stops the timer and when i press start again it will carry on with the timer as if it had never been stopped. Here is my code `@implementation TimerAppDelegate @synthesize window; (void)applicationDidFinishLaunching:(UIApplication *)application { timerLabel.text = @"2:00"; seconds = 120; // Override point for customization after application launch [window makeKeyAndVisible]; } (void)viewDidLoad { [timer invalidate]; } (void)countDownOneSecond { seconds--; int currentTime = [timerLabel.text intValue]; int newTime = currentTime - 1; int displaySeconds = !(seconds % 60) ? 0 : seconds < 60 ? seconds : seconds - 60; int displayMinutes = floor(seconds / 60); NSString *time = [NSString stringWithFormat:@"%d:%@%d", displayMinutes, [[NSString stringWithFormat:@"%d", displaySeconds] length] == 1 ? @"0" : @"", displaySeconds ]; timerLabel.text = time; if(seconds == 0) { [timer invalidate]; } } (void)startOrStopTimer { if(timerIsRunning){ [timer invalidate]; [startOrStopButton setTitle:@"Start" forState:UIControlStateNormal]; } else { timer = [[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(countDownOneSecond) userInfo:nil repeats:YES] retain]; [startOrStopButton setTitle:@"Stop" forState:UIControlStateNormal]; } timerIsRunning = !timerIsRunning; } (void)resetTimer { [timer invalidate]; [startOrStopButton setTitle:@"Start" forState:UIControlStateNormal]; [timer invalidate]; timerLabel.text = @"2:00"; } (void)dealloc { [window release]; [super dealloc]; } @end` thanks

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