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• Even lighter than SQLite

  - by Richard Fabian

  I've been looking for a C++ SQL library implementation that is simple to hook in like SQLite, but faster and smaller. My projects are in games development and there's definitely a cutoff point between needing to pass the ACID test and wanting some extreme performance. I'm willing to move away from SQL string style queries, allowing it to be code driven, but I haven't found anything out there that provides SQL like flexibility while also preferring performance over the ACID test. I don't want to go reinventing the wheel, and the idea of implementing an SQL library on my own is quite daunting, even if it's only going to be simple subset of all the calls you could make. I need the basic commands (SELECT, MODIFY, DELETE, INSERT, with JOIN, and WHERE), not data operations (like sorting, min, max, count) and don't need the database to be atomic, or even enforce consistency (I can use a real SQL service while I'm testing and debugging).

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• delete,copy,rename files and directories in WINAPI ..?

  - by Kristian

  hi I made a code that search in a givin path for a certain file name or folder and print the value BUT now how can i modify it to instead of printing its name perform on of the operations ( delete,copy,rename ) I searched on google and found nothin. #include "stdafx.h" #include <windows.h> int _tmain(int argc, _TCHAR* argv[]) { TCHAR *fn; fn=L"d:\\*"; HANDLE f; WIN32_FIND_DATA data; f=FindFirstFile(fn,&data); if(f==INVALID_HANDLE_VALUE){ printf("not found\n"); return 0; } else{ _tprintf(L"found this file: %s\n",data.cFileName); } while(FindNextFile(f,&data)){ { _tprintf(L"found this file: %s\n",data.cFileName); } } } FindClose(f); return 0; }

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• Hibernate Unit tests - Reset schema

  - by Marco

  Hi, I'm testing the CRUD operations of my DAOs in JUnit tests. When i execute the single test, Hibernate always resets the schema and populates the DB in a known state. But when i execute multiple tests in a row, Hibernate resets the schema once, and then the data is accumulated during the execution of the tests. This is an unexpected behavior, so I'd like to add in the @Before method of the tests a function that explicitly resets the schema to avoid the pesistence of side data created by previous tests during the execution chain. Any tips? Thanks

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• How to enable 'wget' to download the whole content of HTML with Javascript

  - by neversaint

  I have a site which I want to download using Unix wget. If you look at the source code and content of the file it contain section called SUMMARY. However after issuing a wget command like this: wget -O downdloadedtext.txt http://www.ncbi.nlm.nih.gov/IEB/Research/Acembly/av.cgi?db=mouse&c=gene&a=fiche&l=2610008E11Rik The content of the downdloadedtext.txt is incomplete and different with the source code of that site. For example it doesn't contain SUMMARY section. Is there a correct way to obtain the full content correctly? The reason I ask this because I want to automate the download from different values in that HTML.

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• The ** idiom in C++ for object construction

  - by bobobobo

  In a lot of C++ API'S (COM-based ones spring to mind) that make something for you, the pointer to the object that is constructed is usually required as a ** pointer (and the function will construct and init it for you) You usually see signatures like: HRESULT createAnObject( int howbig, Object **objectYouWantMeToInitialize ) ; -- but you seldom see the new object being passed as a return value. Besides people wanting to see error codes, what is the reason for this? Is it better to use the ** pattern rather than a returned pointer for simpler operations such as: wchar_t* getUnicode( const char* src ) ; Or would this better be written as: void getUnicode( const char* src, wchar_t** dst ) ; The most important thing I can think of is to remember to free it, and the ** way, for some reason, tends to remind me that I have to deallocate it as well.

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• .htaccess wildcard problem

  - by niggles

  I've come across a problem with an .htaccess rule I can't sort out. It works on my MAMP stack and it works on 3 other servers, but it won't work on a particular server and keeps giving me a "500 error with an additional 302 error". It's the wildcard that's throwing it and from Google research it says it may be because of an infinite loop, but it works on other servers just fine. The site in question is being developed in a sub-directory, but then again, so have the other sites: RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^$ public/ [L] RewriteRule (.*) public/$1 [L] /public has it's own .htaccess file that is: RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ index.php?url=$1 [PT,L] Any suggestions as mod_rewrite's not my specialty and I can't seem to fix this.2

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• SQlite/Firebird: Does any of them support multiple concurrent write access ?

  - by Quandary

  Question: I currently store ASP.net application data in XML files. Now the problem is I have asynchronous operations, which means I ran into the problem of simultanous write access on a XML file... Now, I'm considering moving to an embedded database to solve the issue. I'm currently considering SQlite and embeddable Firebird. I'm not sure however if SQlite or Firebird can handle multiple concurrent write access. And I certainly don't want the same problem again. Anybody knows ? SQlite certainly is better known, but which one is better - SQlite or Firebird ? I tend to say Firebird, but I don't really know. No MS-Access or MS-SQL-express recommodations please, I'm a sane person.

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• how to protect an imported win32 dll into a .net application from memory issues

  - by Eric

  I have a c# application that needs to use a legacy win32 dll. The dll is almost its own app, it has dialogs, operations with hardware, etc. When this dll is imported and used, there are a couple of problems that occur: Dragging a dialog (not a windows system dialog, but one created by the dll) across the managed code app causes the UI to not repaint. Further it generates a system out of memory exception from various ui controls. The performance is incredibly slow. There seems to be no way to unload the dll so the memory never gets cleaned up. When we close our managed app, we get another memory exception. At the moment we import each method call as such: [DllImport("dllname.dll", EntryPoint = "MethodName", SetLastError = true, CharSet = CharSet.Auto, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]

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• C++ Translation Phase Confusion

  - by blakecl

  Can someone explain why the following doesn't work? int main() // Tried on several recent C++ '03 compilers. { #define FOO L const wchar_t* const foo = FOO"bar"; // Will error out with something like: "identifier 'L' is undefined." #undef FOO } I thought that preprocessing was done in an earlier translation phase than string literal operations and general token translation. Wouldn't the compiler be more or less seeing this: int main() { const wchar_t* const foo = L"bar"; } It would be great if someone could cite an explanation from the standard.

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• Strange behaviour of Android debugger in Eclipse when using Camera for preview.

  - by Buzzy

  Hi, I have an Android application that uses a SurfaceView subclass and Camera object to preview images before capture. Once I capture an image, I stop the preview and release the camera. Execution stops at any breakpoint after this. However, apart from the "Suspend" and "Terminate" icons, the rest are disabled. This is strange because the "Debug Current Instruction Pointer" is clearly at the said breakpoint and execution is already suspended. I can't perform any debugging operations and have no option but to terminate the session. Sometimes (very rarely), the session terminates by itself. I can confirm that this odd behavior takes place only after I preview the camera capture. I am fairly new to Android development. Is there some obvious mistake I am making? Any help would be highly appreciated.

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• JavaScript pack("d") - binary strings

  - by Tim Whitlock

  I'm trying to replicate the Perl and PHP style pack and unpack functions in JavaScript. Unsigned integers were easy enough, so my pack('n') and pack('N') are ok. But my lack of a computer science background is a hurdle now and I don't know where to start with pack('d') for packing JavaScript's standard floating point. Is there a JavaScript library for this out there? If not, is there a good resource where I can learn how to do this? I am fine with bitwise and binary level operations in JS, I just don't know where to start with the logic. Thanks.

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• Which relational databases exist with a public API for a high level language?

  - by Jens Schauder

  We typically interface with a RDBMS through SQL. I.e. we create a sql string and send it to the server through JDBC or ODBC or something similar. Are there any RDBMS that allow direct interfacing with the database engine through some API in Java, C#, C or similar? I would expect an API that allows constructs like this (in some arbitrary pseudo code): Iterator iter = engine.getIndex("myIndex").getReferencesForValue("23"); for (Reference ref: iter){ Row row = engine.getTable("mytable").getRow(ref); } I guess something like this is hidden somewhere in (and available from) open source databases, but I am looking for something that is officially supported as a public API, so one finds at least a note in the release notes, when it changes. In order to make this a question that actually has a 'best' answer: I prefer languages in the order given above and I will prefer mature APIs over prototypes and research work, although these are welcome as well.

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• Connect Android application to remote data

  - by tadywankenobi

  Sheesh talk about limited information! I'm trying to get my Android application to connect to an online database to access information. There's quite a bit of info including geotags and these are going to be mapped on my app. The developer site has the very informative piece of information: You can use the network (when it's available) to store and retrieve data on your own web-based services. To do network operations, use classes in the following packages: java.net.* android.net.* Like I said in my previous question, I'm still very much an android newbie, and trying to remember my java oop from college is slow. Does anyone have an example of how this might work, or how I could implement it? I wouldn't mind even connecting to a local xml file, if I could find a good example of how to do that!? Am I just looking in all the wrong places?! Help. Please! T

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• Apache and Rewrite Module

  - by Yvon Blais

  I created a file .htaccess in the /var/www directory., The rights are root root --wxrwxrwxr The content of the file is : Options +FollowSymlinks RewriteEngine on RewriteLogLevel 3 RewriteLog "/var/log/apache2/rewrite.log" RewriteRule ^(.*?)$ testphp.php When I call the page phpinfo.php, I've got: Loaded Modules ... mod_rewrite ... Therefore, the modules is loaded Afer each modification,I restared the server manually with sudo /etc/init.d/apache2 restart The error.log gives Apache/2.2.14 (Ubuntu) PHP/5.3.2-1ubuntu4.2 with Suhosin-Patch configured -- resuming normal operations When I call a page anyone.htm or anyone.php, the rewrite.log does contain nothing and the real page is called. If I understand, the page anyone.php should be replaced by testphp.php Did I make siomething wrong ? Thanks

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• Is there a Windows utility that will let me do multiple programmatic find/replaces on text that I cu

  - by billmaya

  I've inherited some C# code that contains about a thousand lines of source that I need to modify, transforming it from this: newDataRow["to_dir"] = comboBox108.Text; To this: assetAttributes.Add("to_dir", comboBox108.Text); The lines occur in various places throughout the application in groups of 40 or 50. Modifying each line by hand in Visual Studio 2008 can be done but it's labor intensive and prone to errors. Is there a Windows utility out there that will let me cut and paste groups of code into it and then run some sort of reg-ex expression to transform the individual lines one-by-one? I'd also be willing to use some sort of VS 2008 add-in that performed the same set of reg-ex operations against a selection of code. Thanks in advance.

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• Faking a Single Address Space

  - by dsimcha

  I have a large scientific computing task that parallelizes very well with SMP, but at too fine grained a level to be easily parallelized via explicit message passing. I'd like to parallelize it across address spaces and physical machines. Is it feasible to create a scheduler that would parallelize already multithreaded code across multiple physical computers under the following conditions: The code is already multithreaded and can scale pretty well on SMP configurations. The fact that not all of the threads are running in the same address space or on the same physical machine must be transparent to the program, even if this comes at a significant performance penalty in some use cases. You may assume that all of the physical machines involved are running operating systems and CPU architectures that are binary compatible. Things like locks and atomic operations may be slow (having network latency to deal with and all) but must "just work".

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• Representing a very large array of bits in little memory

  - by user614624

  Hello, I would like to represent a structure containing 250 M states(1 bit each) somehow into as less memory as possible (100 k maximum). The operations on it are set/get. I cold not say that it's dense or sparse, it may vary. The language I want to use is C. I looked at other threads here to find something suitable also. A probabilistic structure like Bloom filter for example would not fit because of the possible false answers. Any suggestions please?

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• PHP: Simulate multiple MySQL connections to same database

  - by Varun

  An insert query is constantly getting logged in my MySQL slow query log. I want to see how much time the INSERT query is taking with 100 simultaneous insert operations(to the same table). So I need to simulate the follwoing. 500 different simultaneous connections from PHP to the same database on a mysql server, all of which are inserting a row(simultaneously) to the same table. DO I need to use any load testing tool? Or Can I simply write a PHP script to do this? Any thoughts?

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• Simple integer encryption

  - by tloflin

  Is there a simple algorithm to encrypt integers? That is, a function E(i,k) that accepts an n-bit integer and a key (of any type) and produces another, unrelated n-bit integer that, when fed into a second function D(i,k) (along with the key) produces the original integer? Obviously there are some simple reversible operations you can perform, but they all seem to produce clearly related outputs (e.g. consecutive inputs lead to consecutive outputs). Also, of course, there are cryptographically strong standard algorithms, but they don't produce small enough outputs (e.g. 32-bit). I know any 32-bit cryptography can be brute-forced, but I'm not looking for something cryptographically strong, just something that looks random. Theoretically speaking it should be possible; after all, I could just create a dictionary by randomly pairing every integer. But I was hoping for something a little less memory-intensive.

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• Using generics in dotnet for functions with any number of arguments?

  - by Zarigani

  I would like to have a function that can "wrap" any other function call. In this particular case, it would allow me to write some more generic transaction handling around some specific operations. I can write this for any particular number of arguments, e.g. for one argument: Public Shared Sub WrapFunc(Of T)(ByVal f As Action(Of T), ByVal arg As T) ' Test some stuff, start transaction f(arg) ' Test some stuff, end transaction End Sub ... but I was hoping to have this handle any number of arguments without having to have duplicate code for 0 args, 1 arg, 2 args, etc. Is there a way of doing this?

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• How to optimize indexing of large number of DB records using Zend_Lucene and Zend_Paginator

  - by jdichev

  So I have this cron script that is deployed and ran using Cron on a host and indexes all the records in a database table - the index is later used both for the front end of the site and the backed operations as well. After the operation, the index is about 3-4 MB. The problem is it takes a lot of resources (CPU: 30+ and a good chunk of memory) and slows the machine down. My question is about how to optimize the operation described below: First there is a select query built using the Zend Framework API, this query is then passed to a Paginator factory that returns a paginator which I am using to balance the current number of items being indexed and not iterate over too much items. The script is iterating over the current items in the paginator object using a foreach loop until reaching the end and then it starts from the beginning after getting items for the next page. I am suspecting this overhead is caused by the Zend_Lucene but no idea how this could be improved.

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• Do I need to syncronize thread access to an int

  - by Martin Harris

  I've just written a method that is called by multiple threads simultaneously and I need to keep track of when all the threads have completed, the code uses this pattern: private void RunReport() { _reportsRunning++; try { //code to run the report } finally { _reportsRunning--; } } This is the only place within the code that _reportsRunning's value is changed, and the method takes about a second to run. Occasionally when I have more than six or so threads running reports together the final result for _reportsRunning can get down to -1, if I wrap the calls to _runningReports++ and _runningReports-- in a lock then the behaviour appears to be correct and consistant. So, to the question: When I was learning multithreading in C++ I was taught that you didn't need to synchronize calls to increment and decrement operations because they were always one assembly instruction and therefore it was impossible for the thread to be switched out mid-call. Was I taught correctly, and if so how come that doesn't hold true for C#?

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• Identify a non-computer network device?

  - by Avilan

  I'm current working on a program that scans my network and discoveres computers and devices on the network. I use various operations to find data on the devices I discover, but want to distinguish the network devices from computers. And I'm wondering if anyone knows how I could do this? I looked a bit at SNMP, and tried connecting to my network printer, router and modem. But I seem to only be able to connect to the printer, neither the router or modem responds. Is there another way to identify what kind of a device an IP address belongs to?

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• A window that behaves both modally and non-modally

  - by Chris

  I want to create a WPF window that behaves as a modal dialogue box while at the same time facilitating selected operations on certain other windows of the same application. An example of this behaviour can be seen in Adobe Photoshop, which offers several dialogues that allow the user to use an eyedropper tool to make selections from an image while disabling virtually all other application features. I'm guessing that the way forward is to create a non-modal, always-on-top dialogue and programmatically disable those application features that are not applicable to the dialogue. Is there an easy way to achieve this in WPF? Or perhaps there's a design pattern I could adopt.

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• Prevent auto scrolling when clicking tab anchor

  - by JohnCrossy

  On my page I have some tabs that I've added some javascript so when they're clicked the page loads the tab's anchor URL instead of simply changing the view with AJAX, but I now want to stop the browser from auto scrolling to the anchor location. Having done some research, I'm pretty sure I just need to add a couple of lines so that when clicked it returns false or prevents default but, being a noob, I've no idea where to put them!?! I know it's cheeky, but if any answers could include the full script (ie. the below) with the solution, that way I'll understand better and hopefully learn some valuable lessons also :) Here's the code I'm using: jQuery( function() { jQuery('.ui-tabs').bind( 'tabsselect', function( e, ui ) { window.location.hash = ui.tab.hash }); });

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