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  • Program is not displaying output correctly

    - by Dave Lee
    My program is suppose to display information from a text file. The text file is here http://pastebin.com/qB6nX2x4 I cant find the problem in my program. I think it has to deal with the looping but im not sure. My program runs correctly but only displays the first line of text. Any help would be appreciated. #include <iostream> #include <string> #include <cstdlib> #include <fstream> using namespace std; int buildArrays(int A[],int B[],int C[]) { int i=0,num; ifstream inFile; inFile.open("candycrush.txt"); if(inFile.fail()) { cout<<"The candycrush.txt input file did not open"<<endl; exit(-1); } while(inFile) { inFile>>num; A[i]=num; inFile>>num; B[i]=num; inFile>>num; C[i]=num; i++; } inFile.close(); return i; } void printArrays( string reportTitle, int levelsArray[], int scoresArray[], int starsArray[], int numberOfLevels ) { cout<<endl; cout<<reportTitle<<endl; cout<<"Levels\tScores\tStars"<<endl; cout<<"---------------------"<<endl; for(int i=0;i<numberOfLevels;i++) { cout<<levelsArray[i]<<"\t"<<scoresArray[i]<<"\t"; for(int j=0;j<starsArray[j];j++) { cout<<"*"; } cout<<endl; } } void sortArrays( int levelsArray[], int scoresArray[], int starsArray[], int numberOfLevels ) { for(int i=0;i<numberOfLevels;i++) { for(int j=0;j<numberOfLevels;j++) { if(levelsArray[i]<levelsArray[j]) { int temp1=levelsArray[i]; int temp2=scoresArray[i]; int temp3=starsArray[i]; levelsArray[i]=levelsArray[j]; scoresArray[i]=scoresArray[j]; starsArray[i]=starsArray[j]; levelsArray[j]=temp1; scoresArray[j]=temp2; starsArray[j]=temp3; } } } } int main() { const int MAX=400; int levelsArray[MAX]; int scoresArray[MAX]; int starsArray[MAX]; int numberOfLevels=buildArrays(levelsArray,scoresArray,starsArray); printArrays( "Candy Crush UNSORTED Report", levelsArray, scoresArray, starsArray, numberOfLevels ); sortArrays( levelsArray, scoresArray, starsArray, numberOfLevels); printArrays( "Candy Crush SORTED Report", levelsArray, scoresArray, starsArray, numberOfLevels ); system("pause"); }

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  • ANSI C as core of a C# project? Is this possible?

    - by Nektarios
    I'm writing a NON-GUI app which I want to be cross platform between OS X and Windows. I'm looking at the following architecture, but I don't know if it will work on the windows side: (Platform specific entry point) - ANSI C main loop = ANSI C model code doing data processing / logic = (Platform specific helpers) So the core stuff I'm planning to write in regular ANSI C, because A) it should be platform independent, B) I'm extremely comfortable with C, C) It can do the job and do it well (Platform specific entry point) can be written in whatever necessary to get the job done, this is a small amount of code, doesn't matter to me. (Platform specific helpers) is the sticky thing. This is stuff like parsing XML, accessing databases, graphics toolkit stuff, whatever. Things that aren't easy in C. Things that modern languages/frameworks will give for free. On OS X this code will be written in Objective-C interfacing with Cocoa. On Windows I'm thinking my best bet is to use C# So on Windows my architecture (simplified) looks like (C# or C?) - ANSI C - C# Is this possible? Some thoughts/suggestions so far.. 1) Compile my C core as a .dll -- this is fine, but seems there's no way to call my C# helpers unless I can somehow get function pointers and pass them to my core, but that seems unlikely 2) Compile a C .exe and a C# .exe and have them talk via shared memory or some kind of IPC. I'm not entirely opposed to this but it obviously introduces a lot of complexity so it doesn't seem ideal 3) Instead of C# use C++, it gets me some nice data management stuff and nice helper code. And I can mix it pretty easily. And the work I do could probably easily port to Linux. But I really don't like C++, and I don't want this to turn in to a 3rd-party-library-fest. Not that it's a huge deal, but it's 2010.. anything for basic data management should be built in. And targetting Linux is really not a priority. Note that no "total" alternatives are OK as suggested in other similar questions on SO I've seen; java, RealBasic, mono.. this is an extremely performance intensive application doing soft realtime for game/simulation purposes, I need C & friends here to do it right (maybe you don't, but I do)

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  • Is it possible to use CSS to align these divs/spans in a table-like manner?

    - by Justin L.
    I have <div class='line'> <div class='chord_line'> <span class='chord_block'></span> <span class='chord_block'>E</span> <span class='chord_block'>B</span> <span class='chord_block'>C#m</span> <span class='chord_block'>A</span> </div> <div class='lyric_line'> <span class='lyric_block'></span> <span class='lyric_block'>Just a</span> <span class='lyric_block'>small-town girl</span> <span class='lyric_block'>living in a</span> <span class='lyric_block'>lonely world</span> </div> </div> (Excuse me for not being too familiar with proper css conventions for when to use div/spans) I want to be able to display them so that each chord_block span and lyric_block span is aligned vertically, as if they were left-aligned and on the same row of a table. For example: E B C#m A Just a small-town girl living in a lonely world (There will often be cases where an empty chord block is matched up to non-empty lyric block, and vice-versa.) I'm completely new to using CSS to align things, and have had no real understanding/experience of CSS aside from changing background colors and link styles. Is this possible in CSS? If not, how could the div/class nesting structure be revised to make this possible? I could change the spans to divs if necessary. Some things I cannot use: I can't change the structure to group things by a chord_and_lyric_block div (and have their width stretch to the length of the lyric, and stack them horizontally), because I couldn't really copy/select the lyrical lines continuously in their entirety, which is extremely critical. I'm trying to avoid a table-like solution, because this data is not tabular at all. The chord line and the lyric line are meant to be read as one continuous line, not a set of cells. Also, apart from the design philosophy reasons, I think it might have the same problems as the previous thing bullet point. If this is possible, what div/span attributes should I be using? Can you provide sample css? If this is not possible, can it be done with javascript?

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  • What is the best practice when coding math class/functions ?

    - by Isaac Clarke
    Introductory note : I voluntarily chose a wide subject. You know that quote about learning a cat to fish, that's it. I don't need an answer to my question, I need an explanation and advice. I know you guys are good at this ;) Hi guys, I'm currently implementing some algorithms into an existing program. Long story short, I created a new class, "Adder". An Adder is a member of another class representing the physical object actually doing the calculus , which calls adder.calc() with its parameters (merely a list of objects to do the maths on). To do these maths, I need some parameters, which do not exist outside of the class (but can be set, see below). They're neither config parameters nor members of other classes. These parameters are D1 and D2, distances, and three arrays of fixed size : alpha, beta, delta. I know some of you are more comfortable reading code than reading text so here you go : class Adder { public: Adder(); virtual Adder::~Adder(); void set( float d1, float d2 ); void set( float d1, float d2, int alpha[N_MAX], int beta[N_MAX], int delta[N_MAX] ); // Snipped prototypes float calc( List& ... ); // ... inline float get_d1() { return d1_ ;}; inline float get_d2() { return d2_ ;}; private: float d1_; float d2_; int alpha_[N_MAX]; // A #define N_MAX is done elsewhere int beta_[N_MAX]; int delta_[N_MAX]; }; Since this object is used as a member of another class, it is declared in a *.h : private: Adder adder_; By doing that, I couldn't initialize the arrays (alpha/beta/delta) directly in the constructor ( int T[3] = { 1, 2, 3 }; ), without having to iterate throughout the three arrays. I thought of putting them in static const, but I don't think that's the proper way of solving such problems. My second guess was to use the constructor to initialize the arrays Adder::Adder() { int alpha[N_MAX] = { 0, -60, -120, 180, 120, 60 }; int beta[N_MAX] = { 0, 0, 0, 0, 0, 0 }; int delta[N_MAX] = { 0, 0, 180, 180, 180, 0 }; set( 2.5, 0, alpha, beta, delta ); } void Adder::set( float d1, float d2 ) { if (d1 > 0) d1_ = d1; if (d2 > 0) d2_ = d2; } void Adder::set( float d1, float d2, int alpha[N_MAX], int beta[N_MAX], int delta[N_MAX] ) { set( d1, d2 ); for (int i = 0; i < N_MAX; ++i) { alpha_[i] = alpha[i]; beta_[i] = beta[i]; delta_[i] = delta[i]; } } My question is : Would it be better to use another function - init() - which would initialize arrays ? Or is there a better way of doing that ? My bonus question is : Did you see some mistakes or bad practice along the way ?

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  • Is there a library available which easily can record and replay results of API calls?

    - by Billy ONeal
    I'm working on writing various things that call relatively complicated Win32 API functions. Here's an example: //Encapsulates calling NtQuerySystemInformation buffer management. WindowsApi::AutoArray NtDll::NtQuerySystemInformation( SystemInformationClass toGet ) const { AutoArray result; ULONG allocationSize = 1024; ULONG previousSize; NTSTATUS errorCheck; do { previousSize = allocationSize; result.Allocate(allocationSize); errorCheck = WinQuerySystemInformation(toGet, result.GetAs<void>(), allocationSize, &allocationSize); if (allocationSize <= previousSize) allocationSize = previousSize * 2; } while (errorCheck == 0xC0000004L); if (errorCheck != 0) { THROW_MANUAL_WINDOWS_ERROR(WinRtlNtStatusToDosError(errorCheck)); } return result; } //Client of the above. ProcessSnapshot::ProcessSnapshot() { using Dll::NtDll; NtDll ntdll; AutoArray systemInfoBuffer = ntdll.NtQuerySystemInformation( NtDll::SystemProcessInformation); BYTE * currentPtr = systemInfoBuffer.GetAs<BYTE>(); //Loop through the results, creating Process objects. SYSTEM_PROCESSES * asSysInfo; do { // Loop book keeping asSysInfo = reinterpret_cast<SYSTEM_PROCESSES *>(currentPtr); currentPtr += asSysInfo->NextEntryDelta; //Create the process for the current iteration and fill it with data. std::auto_ptr<ProcImpl> currentProc(ProcFactory( static_cast<unsigned __int32>(asSysInfo->ProcessId), this)); NormalProcess* nptr = dynamic_cast<NormalProcess*>(currentProc.get()); if (nptr) { nptr->SetProcessName(asSysInfo->ProcessName); } // Populate process threads for(ULONG idx = 0; idx < asSysInfo->ThreadCount; ++idx) { SYSTEM_THREADS& sysThread = asSysInfo->Threads[idx]; Thread thread( currentProc.get(), static_cast<unsigned __int32>(sysThread.ClientId.UniqueThread), sysThread.StartAddress); currentProc->AddThread(thread); } processes.push_back(currentProc); } while(asSysInfo->NextEntryDelta != 0); } My problem is in mocking out the NtDll::NtQuerySystemInformation method -- namely, that the data structure returned is complicated (Well, here it's actually relatively simple but it can be complicated), and writing a test which builds the data structure like the API call does can take 5-6 times as long as writing the code that uses the API. What I'd like to do is take a call to the API, and record it somehow, so that I can return that recorded value to the code under test without actually calling the API. The returned structures cannot simply be memcpy'd, because they often contain inner pointers (pointers to other locations in the same buffer). The library in question would need to check for these kinds of things, and be able to restore pointer values to a similar buffer upon replay. (i.e. check each pointer sized value if it could be interpreted as a pointer within the buffer, change that to an offset, and remember to change it back to a pointer on replay -- a false positive rate here is acceptable) Is there anything out there that does anything like this?

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  • Specializing a template on a lambda in C++0x

    - by Tony A.
    I've written a traits class that lets me extract information about the arguments and type of a function or function object in C++0x (tested with gcc 4.5.0). The general case handles function objects: template <typename F> struct function_traits { template <typename R, typename... A> struct _internal { }; template <typename R, typename... A> struct _internal<R (F::*)(A...)> { // ... }; typedef typename _internal<decltype(&F::operator())>::<<nested types go here>>; }; Then I have a specialization for plain functions at global scope: template <typename R, typename... A> struct function_traits<R (*)(A...)> { // ... }; This works fine, I can pass a function into the template or a function object and it works properly: template <typename F> void foo(F f) { typename function_traits<F>::whatever ...; } int f(int x) { ... } foo(f); What if, instead of passing a function or function object into foo, I want to pass a lambda expression? foo([](int x) { ... }); The problem here is that neither specialization of function_traits<> applies. The C++0x draft says that the type of the expression is a "unique, unnamed, non-union class type". Demangling the result of calling typeid(...).name() on the expression gives me what appears to be gcc's internal naming convention for the lambda, main::{lambda(int)#1}, not something that syntactically represents a C++ typename. In short, is there anything I can put into the template here: template <typename R, typename... A> struct function_traits<????> { ... } that will allow this traits class to accept a lambda expression?

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  • Filling in gaps for outlines

    - by user146780
    I'm using an algorithm to generate quads. These become outlines. The algorithm is: void OGLENGINEFUNCTIONS::GenerateLinePoly(const std::vector<std::vector<GLdouble>> &input, std::vector<GLfloat> &output, int width) { output.clear(); if(input.size() < 2) { return; } int temp; float dirlen; float perplen; POINTFLOAT start; POINTFLOAT end; POINTFLOAT dir; POINTFLOAT ndir; POINTFLOAT perp; POINTFLOAT nperp; POINTFLOAT perpoffset; POINTFLOAT diroffset; POINTFLOAT p0, p1, p2, p3; for(unsigned int i = 0; i < input.size() - 1; ++i) { start.x = static_cast<float>(input[i][0]); start.y = static_cast<float>(input[i][1]); end.x = static_cast<float>(input[i + 1][0]); end.y = static_cast<float>(input[i + 1][1]); dir.x = end.x - start.x; dir.y = end.y - start.y; dirlen = sqrt((dir.x * dir.x) + (dir.y * dir.y)); ndir.x = static_cast<float>(dir.x * 1.0 / dirlen); ndir.y = static_cast<float>(dir.y * 1.0 / dirlen); perp.x = dir.y; perp.y = -dir.x; perplen = sqrt((perp.x * perp.x) + (perp.y * perp.y)); nperp.x = static_cast<float>(perp.x * 1.0 / perplen); nperp.y = static_cast<float>(perp.y * 1.0 / perplen); perpoffset.x = static_cast<float>(nperp.x * width * 0.5); perpoffset.y = static_cast<float>(nperp.y * width * 0.5); diroffset.x = static_cast<float>(ndir.x * 0 * 0.5); diroffset.y = static_cast<float>(ndir.y * 0 * 0.5); // p0 = start + perpoffset - diroffset //p1 = start - perpoffset - diroffset //p2 = end + perpoffset + diroffset // p3 = end - perpoffset + diroffset p0.x = start.x + perpoffset.x - diroffset.x; p0.y = start.y + perpoffset.y - diroffset.y; p1.x = start.x - perpoffset.x - diroffset.x; p1.y = start.y - perpoffset.y - diroffset.y; p2.x = end.x + perpoffset.x + diroffset.x; p2.y = end.y + perpoffset.y + diroffset.y; p3.x = end.x - perpoffset.x + diroffset.x; p3.y = end.y - perpoffset.y + diroffset.y; output.push_back(p2.x); output.push_back(p2.y); output.push_back(p0.x); output.push_back(p0.y); output.push_back(p1.x); output.push_back(p1.y); output.push_back(p3.x); output.push_back(p3.y); } } The problem is that there are then gaps as seen here: http://img816.imageshack.us/img816/2882/eeekkk.png There must be a way to fix this. I see a pattern but I just cant figure it out. There must be a way to fill the missing inbetweens. Thanks

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  • jQuery: Giving each matched element an unique ID

    - by AnGafraidh
    I am writing an 'inline translator' application to be used with a cloud computing platform to extend non-supported languages. The majority of this uses jQuery to find the text value, replace it with the translation, then append the element with a span tag that has an unique ID, to be used elsewhere within the application. The problem arises however, when there are more than one element, say , that have the exact same value to be translated (matched elements). What happens in the function in question is that it puts all matched elements in the same span, taking the second, third, fourth, etc. out of their parent tags. My code is pretty much like this example: <script src='jquery-1.4.2.js'></script> <script> jQuery.noConflict(); var uniqueID='asdfjkl'; jQuery(window).ready(function() { var myQ1 = jQuery("input[id~=test1]"); myClone=myQ1.clone(); myClone.val('Replaced this button'); myQ1.replaceWith('<span id='+uniqueID+'></span>'); jQuery('#'+uniqueID).append(myClone); }); </script> <table> <tr><td> <input id='test1' type='button' value="I'm a button!"></input> &nbsp; <input id='test2' type='button' value="And so am I"></input> </tr></td> <tr><td> <input id='test1' type='button' value="I'm a button!"></input> </tr></td> </table> As a workaround, I've experimented with using a loop to create a class for each span, rising in increment until jQuery("input[id~=test1]").length, but I can't seem to get anything I do to work. Is there any way to give each matched element an unique ID? My fluency in jQuery is being put to the test! Thanks for any help in advance. Aaron

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  • Cocoa WebView won't render all images on OSX 10.8

    - by user2906962
    I'm currently developing an application for OS X, backwards compatible with OS X 10.6. At some point I create a WebView in which I load html content that I create dynamically. The html content is formed only of image links <img src= and text, there is no javascript or anything of that kind. All the images (there are only 5 png images) are stored locally and their size is 4 KB. The problem I have is that some images (those that are not on the visible side of the "scroll"), the very first time I run the application,the images are not shown unless I drag the window to another screen or load again the view controller that contains the WebView. In those cases the images appear on the "scroll" even if they are offsite. I've tried creating the WebView both with IB and programatically, I've used WebPreferences like Autosaves, AllowsAnimatedImages … I've tried using NSURLCache to load each image so that the WebView will get access to them easier ... same result. Taking into account that my code is quite extensive I'm gonna post only the bits that I think are relevant: NSString *finalHtml ... //contains the complete html CGRect screenRect = [self.fixedView bounds]; CGRect webFrame = CGRectMake(0.0f, 0.0f, screenRect.size.width, screenRect.size.height); self.miwebView=[[WebView alloc] initWithFrame:webFrame]; [self.miwebView setEditable:NO]; [self.miwebView setUIDelegate:self]; ... NSURLCache *URLCache = [[NSURLCache alloc] initWithMemoryCapacity:4 * 1024 * 1024 diskCapacity:20 * 1024 * 1024 diskPath:nil]; [NSURLCache setSharedURLCache:URLCache]; NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"line" ofType:@"png"]; NSURL *resourceUrl = [NSURL URLWithString:imagePath]; NSURLRequest *request = [NSURLRequest requestWithURL:resourceUrl cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10.0f]; [URLCache cachedResponseForRequest:request]; ... [self.miwebView setResourceLoadDelegate:self]; WebPreferences *webPref = [[WebPreferences alloc]init]; [webPref setAutosaves:YES]; [webPref setAllowsAnimatedImages:YES]; [webPref setAllowsAnimatedImageLooping:YES]; [self.miwebView setPreferences:webPref]; NSString *pathResult = [[NSBundle mainBundle] bundlePath]; NSURL *baseURLRes = [NSURL fileURLWithPath:pathResult]; [[self.miwebView mainFrame] loadHTMLString:finalHtml baseURL:baseURLRes]; [self.fixedView addSubview:self.miwebView]; I should also mention that if an image is caught somewhere in between the visible and non visible side of the "scroll" only the visible bit of the image is going to be rendered even if the page gets scrolled up ... so I think all this is some rendering issue ... I appreciate your help, thank you!

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  • Adjust parameters of serial port reading

    - by clinisbut
    Hello. I'm facing a particular issue that regards serial communication under win32. I'm communicating with a device can only accept frames when it is not already communicating. So I must find a valid frame and then inmediatelly send my request. I developed a class named Serial that handles basic operations on serial port (open, close, read, write) and then a Thread calls inside a loop read and write functions. Thread loop //Device is an object of class Serial while( device->isOpen() && !terminate ) { unsigned int readed = 0; unsigned long error = ERROR_SUCCESS; unsigned char* data = device->read( &readed, &error ); if( error==ERROR_SUCCESS ) { //If data received, deliver to upper level if( readed>0 ) { QByteArray output( (const char*)data, (signed int)readed ); emit dataArrived( output, readed ); } } else { //unrelated stuff } //Here I manage the writting issue //Only when nothing is received, and Upper layer wants to send a frame //(Upper layer only will mark as something to send when it detects a valid frame) if( readed==0 ) { out_lock.lock(); //If something to send... if( something_to_send > 0 ) { if( device->write( output_buffer, output_size, &error ) ) { //things... } } } } The Thread basically keeps reading, and when nothing is received, sees if somebody has signaled to send a frame (this means that a valid frame is just received). When this happens, it writes the frame through serial port. Here comes my problem. Inside the Serial::read() function: I use the overlapped way of reading: ::ClearCommError( handle, &dwErrors, &stat); if( stat.cbInQue ) { //If there's something to read, read it, please note the bytes to read parameter, here 1. bool ok = ::ReadFile( handle, buffer_in, 1, &bytes_read, &ov_reader ); if( !ok ) { DWORD _error = ::GetLastError(); if( _error == ERROR_IO_PENDING ) { DWORD result = ::WaitForMultipleObjects( 2, waiters, FALSE,INFINITE ); switch( result ) { //Eventshutdown case WAIT_OBJECT_0: /*code omitted*/break; case WAIT_OBJECT_0+1: ok = ::GetOverlappedResult( handle, &ov_reader, &bytes_read, true ); //check ok value omitted break; } } } } if( bytes_read>0 ) { *size = bytes_read; } Here starts my problem. When device sends me small frames (around 30 bytes) everything works fine, but when larger frames are sent, the code is not able to find any free time between frames causing the thread to never be able send any frame because readed is never 0. If I increase the number of bytes to read inside the read() function, lose the ability to detect when the device "listens": bool ok = ::ReadFile(handle, buffer_in, 50, &bytes_read, &ov_reader ); This happens because my app can receive the end of a frame together with the start of the next one. This behaviour is very common. In the other hand, if I change the INFINITE argument by a valid timeout in the WaitForMultipleObjects function, I lose data. So my question basically is... what I'm doing wrong? Why when reading 1 byte each time I don't find any free time to send my own frames? Thank you

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  • How would you structure your entity model for storing arbitrary key/value data with different data t

    - by Nathan Ridley
    I keep coming across scenarios where it will be useful to store a set of arbitrary data in a table using a per-row key/value model, rather than a rigid column/field model. The problem is, I want to store the values with their correct data type rather than converting everything to a string. This means I have to choose either a single table with multiple nullable columns, one for each data type, or a set of value tables, one for each data type. I'm also unsure as to whether I should use full third normal form and separate the keys into a separate table, referencing them via a foreign key from the value table(s), or if it would be better to keep things simple and store the string keys in the value table(s) and accept the duplication of strings. Old/bad: This solution makes adding additional values a pain in a fluid environment because the table needs to be modified regularly. MyTable ============================ ID Key1 Key2 Key3 int int string date ---------------------------- 1 Value1 Value2 Value3 2 Value4 Value5 Value6 Single Table Solution This solution allows simplicity via a single table. The querying code still needs to check for nulls to determine which data type the field is storing. A check constraint is probably also required to ensure only one of the value fields contains non-nulll data. DataValues ============================================================= ID RecordID Key IntValue StringValue DateValue int int string int string date ------------------------------------------------------------- 1 1 Key1 Value1 NULL NULL 2 1 Key2 NULL Value2 NULL 3 1 Key3 NULL NULL Value3 4 2 Key1 Value4 NULL NULL 5 2 Key2 NULL Value5 NULL 6 2 Key3 NULL NULL Value6 Multiple-Table Solution This solution allows for more concise purposing of each table, though the code needs to know the data type in advance as it needs to query a different table for each data type. Indexing is probably simpler and more efficient because there are less columns that need indexing. IntegerValues =============================== ID RecordID Key Value int int string int ------------------------------- 1 1 Key1 Value1 2 2 Key1 Value4 StringValues =============================== ID RecordID Key Value int int string string ------------------------------- 1 1 Key2 Value2 2 2 Key2 Value5 DateValues =============================== ID RecordID Key Value int int string date ------------------------------- 1 1 Key3 Value3 2 2 Key3 Value6 How do you approach this problem? Which solution is better? Also, should the key column be separated into a separate table and referenced via a foreign key or be should it be kept in the value table and bulk updated if for some reason the key name changes?

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  • jQuery - Show field based on value of a type-hidden on refresh.

    - by Sebhael
    Hello, I'm trying to create something in jQuery and having a bit of problems with it. I'm not too adept on the framework, so I'm sure this is all wrong. Anyways, the ultimate goal is a full form that contains 3 radio buttons - depending on the value of the button, a LI is shown. I have all of that done, but my problem is coming with validation. If something fails then the page is reloaded and the div that was selected doesn't show without clicking another radio first, then back to the original. This process is basically the same as someone came up with here. Here's what I got so far. HTML <li> <label> License (radio) </label> <label for="commercial" class="checkBox"> Commercial </label> <input type="radio" name="license" value="commercial" id="commercial" class="checkBox" <?php echo set_radio('license', 'commercial'); ?> /> <label for="abandonware" class="checkBox"> Abandonware </label> <input type="radio" name="license" value="abandonware" id="abandonware" class="checkBox" <?php echo set_radio('license', 'abandonware'); ?> /> <label for="freeware" class="checkBox"> Freeware </label> <input type="radio" name="license" value="freeware" id="freeware" class="checkBox" <?php echo set_radio('license', 'freeware'); ?> /> </li> This is followed by three LI's that contain id="commercial, abandonware, and freeware" and class="licenseli" My jQuery is, as said, something from here. $('li.licenseli').hide(); $('input[name=license]:radio').change(function(){ var Type = $(this).val(); // Get value of radio $('li.licenseli').slideUp(); // Hide non-selected $('li#'+Type).slideDown(); // Show Selected }); So what I need help with is I have a hidden input that retrieves the value of the radio box from validation - I want to take this value (or the radio's if possible?) and have the original selected option's LI already visible.

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  • Constructors taking references in C++

    - by sasquatch
    I'm trying to create constructor taking reference to an object. After creating object using reference I need to prints field values of both objects. Then I must delete first object, and once again show values of fields of both objects. My class Person looks like this : class Person { char* name; int age; public: Person(){ int size=0; cout << "Give length of char*" << endl; cin >> size; name = new char[size]; age = 0; } ~Person(){ cout << "Destroying resources" << endl; delete[] name; delete age; } void init(char* n, int a) { name = n; age = a; } }; Here's my implementation (with the use of function show() ). My professor said that if this task is written correctly it will return an error. #include <iostream> using namespace std; class Person { char* name; int age; public: Person(){ int size=0; cout << "Give length of char*" << endl; cin >> size; name = new char[size]; age = 0; } Person(const Person& p){ name = p.name; age = p.age; } ~Person(){ cout << "Destroying resources" << endl; delete[] name; delete age; } void init(char* n, int a) { name = n; age = a; } void show(char* n, int a){ cout << "Name: " << name << "," << "age: " << age << "," << endl; } }; int main(void) { Person *p = new Person; p->init("Mary", 25); p->show(); Person &p = pRef; pRef->name = "Tom"; pRef->age = 18; Person *p2 = new Person(pRef); p->show(); p2->show(); system("PAUSE"); return 0; }

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  • How can I keep my MVC Views, models, and model binders as clean as possible?

    - by MBonig
    I'm rather new to MVC and as I'm getting into the whole framework more and more I'm finding the modelbinders are becoming tough to maintain. Let me explain... I am writing a basic CRUD-over-database app. My domain models are going to be very rich. In an attempt to keep my controllers as thin as possible I've set it up so that on Create/Edit commands the parameter for the action is a richly populated instance of my domain model. To do this I've implemented a custom model binder. As a result, though, this custom model binder is very specific to the view and the model. I've decided to just override the DefaultModelBinder that ships with MVC 2. In the case where the field being bound to my model is just a textbox (or something as simple), I just delegate to the base method. However, when I'm working with a dropdown or something more complex (the UI dictates that date and time are separate data entry fields but for the model it is one Property), I have to perform some checks and some manual data munging. The end result of this is that I have some pretty tight ties between the View and Binder. I'm architecturally fine with this but from a code maintenance standpoint, it's a nightmare. For example, my model I'm binding here is of type Log (this is the object I will get as a parameter on my Action). The "ServiceStateTime" is a property on Log. The form values of "log.ServiceStartDate" and "log.ServiceStartTime" are totally arbitrary and come from two textboxes on the form (Html.TextBox("log.ServiceStartTime",...)) protected override object GetPropertyValue(ControllerContext controllerContext, ModelBindingContext bindingContext, PropertyDescriptor propertyDescriptor, IModelBinder propertyBinder) { if (propertyDescriptor.Name == "ServiceStartTime") { string date = bindingContext.ValueProvider.GetValue("log.ServiceStartDate").ConvertTo(typeof (string)) as string; string time = bindingContext.ValueProvider.GetValue("log.ServiceStartTime").ConvertTo(typeof (string)) as string; DateTime dateTime = DateTime.Parse(date + " " + time); return dateTime; } if (propertyDescriptor.Name == "ServiceEndTime") { string date = bindingContext.ValueProvider.GetValue("log.ServiceEndDate").ConvertTo(typeof(string)) as string; string time = bindingContext.ValueProvider.GetValue("log.ServiceEndTime").ConvertTo(typeof(string)) as string; DateTime dateTime = DateTime.Parse(date + " " + time); return dateTime; } The Log.ServiceEndTime is a similar field. This doesn't feel very DRY to me. First, if I refactor the ServiceStartTime or ServiceEndTime into different field names, the text strings may get missed (although my refactoring tool of choice, R#, is pretty good at this sort of thing, it wouldn't cause a build-time failure and would only get caught by manual testing). Second, if I decided to arbitrarily change the descriptors "log.ServiceStartDate" and "log.ServiceStartTime", I would run into the same problem. To me, runtime silent errors are the worst kind of error out there. So, I see a couple of options to help here and would love to get some input from people who have come across some of these issues: Refactor any text strings in common between the view and model binders out into const strings attached to the ViewModel object I pass from controller to the aspx/ascx view. This pollutes the ViewModel object, though. Provide unit tests around all of the interactions. I'm a big proponent of unit tests and haven't started fleshing this option out but I've got a gut feeling that it won't save me from foot-shootings. If it matters, the Log and other entities in the system are persisted to the database using Fluent NHibernate. I really want to keep my controllers as thin as possible. So, any suggestions here are greatly welcomed! Thanks

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  • SQL not yielding expected results

    - by AnonJr
    I have three tables related to this particular query: Lawson_Employees: LawsonID (pk), LastName, FirstName, AccCode (numeric) Lawson_DeptInfo: AccCode (pk), AccCode2 (don't ask, HR set up), DisplayName tblExpirationDates: EmpID (pk), ACLS (date), EP (date), CPR (date), CPR_Imported (date), PALS (date), Note The goal is to get the data I need to report on all those who have already expired in one or more certification, or are going to expire in the next 90 days. Some important notes: This is being run as part of a vbScript, so the 90-day date is being calculated when the script is run. I'm using 2010-08-31 as a placeholder since its the result at the time this question is being posted. All cards expire at the end of the month. (which is why the above date is for the end of August and not 90 days on the dot) A valid EP card supersedes ACLS certification, but only the latter is required of some employees. (wasn't going to worry about it until I got this question answered, but if I can get the help I'll take it) The CPR column contains the expiration date for the last class they took with us. (NULL if they didn't take any classes with us) The CPR_Imported column contains the expiration date for the last class they took somewhere else. (NULL if they didn't take it elsewhere, and bravo for following policy) The distinction between CPR classes is important for other reports. For purposes of this report, all we really care about is which one is the most current - or at least is currently current. If I have to, I'll ignore ACLS and PALS for the time being as it is non-compliance with CPR training that is the big issue at the moment. (not that the others won't be, but they weren't mentioned in the last meeting...) Here's the query I have so far, which is giving me good data: SELECT iEmp.LawsonID, iEmp.LastName, iEmp.FirstName, dept.AccCode2, dept.DisplayName, Exp.ACLS, Exp.EP, Exp.CPR, Exp.CPR_Imported, Exp.PALS, Exp.Note FROM (Lawson_Employees AS iEmp LEFT JOIN Lawson_DeptInfo AS dept ON dept.AccCode = iEmp.AccCode) LEFT JOIN tblExpirationDates AS Exp ON iEmp.LawsonID = Exp.EmpID WHERE iEmp.CurrentEmp = 1 AND ((Exp.ACLS <= #2010-08-31# AND Exp.ACLS IS NOT NULL) OR (Exp.CPR <= #2010-08-31# AND Exp.CPR_Imported <= #2010-08-31#) OR (Exp.PALS <= #2010-08-31# AND Exp.PALS IS NOT NULL)) ORDER BY dept.AccCode2, iEmp.LastName, iEmp.FirstName; After perusing the result set, I think I'm missing some expiration dates that should be in the result set. Am I missing something? This is the sucky part of being the only developer in the department... no one to ask for a little help.

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  • Can I have a workspace that is both a git workspace and a svn workspace?

    - by Troy
    I have checked out now a local working copy of a codebase that lives in an svn repo. It's a big Java project that I use Eclipse to develop in. Eclipse of course builds everything on the fly, in it's own way with all the binaries ending up in [project root]/bin. That's perfectly fine with me, for development, but when the build runs on the build server, it looks quite a lot different (maven build, binaries end up in a different directory structure, etc). Sometimes I need to recreate the build server environment on my local development system to debug the build or what have you, so I usually end up downloading an entirely new working copy into a new workspace and running the build from there (prevents cluttering my development workspace with all the build artifacts and dirtying up the working copy). Of course sometimes I'm interested in running the full build on code that I don't want to check in yet, so I will manually copy over the "development" workspace onto the "build" workspace. Besides taking a lot of extra time copying a lot of files that I don't actually need (just overlaying the new over the old), this also screws up my svn metadata, meaning that I can't check in changes from that "build workspace" working copy, and I often end up having to re-download the code to get it back into a known state. So I'm thinking I make my svn working copy a local git repo, then "check out" the in-development code from the svn working copy/git master, into the local build workspace. Then I can build, revert my changes, have all the advantages of a version controlled working copy in the build workspace. Then if I need to make changes to the build, push those back into the git master (which is also a svn working copy), then check them into the main svn repo. |-------------| |main svn repo| <------- |---------------------| |-------------| |svn working copy | <------- |--------------------| | (svn dev workspace/ | | non-svn-versioned | | git master) | | build workspace | |---------------------| | (git working copy) | |--------------------| Just switching everything to git would obviously be better, but, big company, too many people using svn, too costly to change everything, etc. We're stuck with svn as the main repo for now. BTW, I know there is a maven plugin for Eclipse and everything, I'm mainly interested to know if there is a way to maintain a workspace that is both a git working copy and an svn working copy. Actually any distributed version control system would probably work (hg possibly?). Advice? How does everybody else handle this situation of having a to manage both a "development" build process and a "production" build process?

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  • Custom WM profile - issues with codec

    - by dominolog
    Hello I create my custom WM encoder profile. The reason I need a custom, non standard WM profile is that I need that the video resolution must be the same as input video stream. I created below profile but after I encode my video and audio with it, the WMP while loading says that the WMV1 codec is not found and prompts me for downloading WM encoder codecs. After installing them, the problem still exists. <profile version="589824" storageformat="1" name="mReplay Hi-End profile; WM Format 9; Audio &amp; Video" description="Streams: 1 audio 1 video"> <streamconfig majortype="{73647561-0000-0010-8000-00AA00389B71}" streamnumber="1" streamname="Audio Stream" inputname="Audio409" bitrate="320008" bufferwindow="-1" reliabletransport="0" decodercomplexity="" rfc1766langid="en-us" > <wmmediatype subtype="{00000161-0000-0010-8000-00AA00389B71}" bfixedsizesamples="1" btemporalcompression="0" lsamplesize="14861"> <waveformatex wFormatTag="353" nChannels="2" nSamplesPerSec="44100" nAvgBytesPerSec="40001" nBlockAlign="14861" wBitsPerSample="16" codecdata="008800000F0035E80000"/> </wmmediatype> </streamconfig> <streamconfig majortype="{73646976-0000-0010-8000-00AA00389B71}" streamnumber="2" streamname="Video Stream" inputname="Video409" bitrate="100000" bufferwindow="-1" reliabletransport="0" decodercomplexity="AU" rfc1766langid="en-us" vbrenabled="1" vbrquality="95" bitratemax="0" bufferwindowmax="0"> <videomediaprops maxkeyframespacing="80000000" quality="100"/> <wmmediatype subtype="{31564D57-0000-0010-8000-00AA00389B71}" bfixedsizesamples="0" btemporalcompression="1" lsamplesize="0"> <videoinfoheader dwbitrate="100000" dwbiterrorrate="0" avgtimeperframe="400000"> <rcsource left="0" top="0" right="0" bottom="0"/> <rctarget left="0" top="0" right="0" bottom="0"/> <bitmapinfoheader biwidth="0" biheight="0" biplanes="1" bibitcount="24" bicompression="WMV1" bisizeimage="0" bixpelspermeter="0" biypelspermeter="0" biclrused="0" biclrimportant="0"/> </videoinfoheader> </wmmediatype> </streamconfig> <streamprioritization> <stream number="1" mandatory="0"/> <stream number="2" mandatory="0"/> </streamprioritization> </profile>

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  • Exit code 3 (not my return value, looking for source)

    - by Kathoz
    Greetings, my program exits with the code 3. No error messages, no exceptions, and the exit is not initiated by my code. The problem occurs when I am trying to read extremely long integer values from a text file (the text file is present and correctly opened, with successful prior reading). I am using very large amounts of memory (in fact, I think that this might be the cause, as I am nearly sure I go over the 2GB per process memory limit). I am also using the GMP (or, rather, MPIR) library to multiply bignums. I am fairly sure that this is not a file I/O problem as I got the same error code on a previous program version that was fully in-memory. System: MS Visual Studio 2008 MS Windows Vista Home Premium x86 MPIR 2.1.0 rc2 4GB RAM Where might this error code originate from? EDIT: this is the procedure that exits with the code void condenseBinSplitFile(const char *sourceFilename, int partCount){ //condense results file into final P and Q std::string tempFilename; std::string inputFilename(sourceFilename); std::string outputFilename(BIN_SPLIT_FILENAME_DATA2); mpz_class *P = new mpz_class(0); mpz_class *Q = new mpz_class(0); mpz_class *PP = new mpz_class(0); mpz_class *QQ = new mpz_class(0); FILE *sourceFile; FILE *resultFile; fpos_t oldPos; int swapCount = 0; while (partCount > 1){ std::cout << partCount << std::endl; sourceFile = fopen(inputFilename.c_str(), "r"); resultFile = fopen(outputFilename.c_str(), "w"); for (int i=0; i<partCount/2; i++){ //Multiplication order: //Get Q, skip P //Get QQ, mul Q and QQ, print Q, delete Q //Jump back to P, get P //Mul P and QQ, delete QQ //Skip QQ, get PP //Mul P and PP, delete P and PP //Get Q, skip P mpz_inp_str(Q->get_mpz_t(), sourceFile, CALC_BASE); fgetpos(sourceFile, &oldPos); skipLine(sourceFile); skipLine(sourceFile); //Get QQ, mul Q and QQ, print Q, delete Q mpz_inp_str(QQ->get_mpz_t(), sourceFile, CALC_BASE); (*Q) *= (*QQ); mpz_out_str(resultFile, CALC_BASE, Q->get_mpz_t()); fputc('\n', resultFile); (*Q) = 0; //Jump back to P, get P fsetpos(sourceFile, &oldPos); mpz_inp_str(P->get_mpz_t(), sourceFile, CALC_BASE); //Mul P and QQ, delete QQ (*P) *= (*QQ); (*QQ) = 0; //Skip QQ, get PP skipLine(sourceFile); skipLine(sourceFile); mpz_inp_str(PP->get_mpz_t(), sourceFile, CALC_BASE); //Mul P and PP, delete PP, print P, delete P (*P) += (*PP); (*PP) = 0; mpz_out_str(resultFile, CALC_BASE, P->get_mpz_t()); fputc('\n', resultFile); (*P) = 0; } partCount /= 2; fclose(sourceFile); fclose(resultFile); //swap filenames tempFilename = inputFilename; inputFilename = outputFilename; outputFilename = tempFilename; swapCount++; } delete P; delete Q; delete PP; delete QQ; remove(BIN_SPLIT_FILENAME_RESULTS); if (swapCount%2 == 0) rename(sourceFilename, BIN_SPLIT_FILENAME_RESULTS); else rename(BIN_SPLIT_FILENAME_DATA2, BIN_SPLIT_FILENAME_RESULTS); }

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  • how to mount partitions from USB drives in Windows using Delphi?

    - by user569556
    Hi. I'm a Delphi programmer. I want to mount all partitions from USB drives in Windows (XP). The OS is doing this automatically but there are situations when such a program is useful. I know how to find if a drive is on USB or not. My code so far is: type STORAGE_QUERY_TYPE = (PropertyStandardQuery = 0, PropertyExistsQuery, PropertyMaskQuery, PropertyQueryMaxDefined); TStorageQueryType = STORAGE_QUERY_TYPE; STORAGE_PROPERTY_ID = (StorageDeviceProperty = 0, StorageAdapterProperty); TStoragePropertyID = STORAGE_PROPERTY_ID; STORAGE_PROPERTY_QUERY = packed record PropertyId: STORAGE_PROPERTY_ID; QueryType: STORAGE_QUERY_TYPE; AdditionalParameters: array[0..9] of AnsiChar; end; TStoragePropertyQuery = STORAGE_PROPERTY_QUERY; STORAGE_BUS_TYPE = (BusTypeUnknown = 0, BusTypeScsi, BusTypeAtapi, BusTypeAta, BusType1394, BusTypeSsa, BusTypeFibre, BusTypeUsb, BusTypeRAID, BusTypeiScsi, BusTypeSas, BusTypeSata, BusTypeMaxReserved = $7F); TStorageBusType = STORAGE_BUS_TYPE; STORAGE_DEVICE_DESCRIPTOR = packed record Version: DWORD; Size: DWORD; DeviceType: Byte; DeviceTypeModifier: Byte; RemovableMedia: Boolean; CommandQueueing: Boolean; VendorIdOffset: DWORD; ProductIdOffset: DWORD; ProductRevisionOffset: DWORD; SerialNumberOffset: DWORD; BusType: STORAGE_BUS_TYPE; RawPropertiesLength: DWORD; RawDeviceProperties: array[0..0] of AnsiChar; end; TStorageDeviceDescriptor = STORAGE_DEVICE_DESCRIPTOR; const IOCTL_STORAGE_QUERY_PROPERTY = $002D1400; var i: Integer; H: THandle; USBDrives: array of Byte; Query: TStoragePropertyQuery; dwBytesReturned: DWORD; Buffer: array[0..1023] of Byte; sdd: TStorageDeviceDescriptor absolute Buffer; begin SetLength(UsbDrives, 0); SetErrorMode(SEM_FAILCRITICALERRORS); for i := 0 to 99 do begin H := CreateFile(PChar('\\.\PhysicalDrive' + IntToStr(i)), 0, FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_EXISTING, 0, 0); if H <> INVALID_HANDLE_VALUE then begin try dwBytesReturned := 0; FillChar(Query, SizeOf(Query), 0); FillChar(Buffer, SizeOf(Buffer), 0); sdd.Size := SizeOf(Buffer); Query.PropertyId := StorageDeviceProperty; Query.QueryType := PropertyStandardQuery; if DeviceIoControl(H, IOCTL_STORAGE_QUERY_PROPERTY, @Query, SizeOf(Query), @Buffer, SizeOf(Buffer), dwBytesReturned, nil) then if sdd.BusType = BusTypeUsb then begin SetLength(USBDrives, Length(USBDrives) + 1); UsbDrives[High(USBDrives)] := Byte(i); end; finally CloseHandle(H); end; end; end; for i := 0 to High(USBDrives) do begin // end; end. But I don't know how to access partitions on each drive and mounts them. Can you please help me? I searched before I asked and I couldn't find a working code. But if I did not properly then I'm sorry and please show me that topic. Best regards, John

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  • Dynamic loaded libraries and shared global symbols

    - by phlipsy
    Since I observed some strange behavior of global variables in my dynamically loaded libraries, I wrote the following test. At first we need a statically linked library: The header test.hpp #ifndef __BASE_HPP #define __BASE_HPP #include <iostream> class test { private: int value; public: test(int value) : value(value) { std::cout << "test::test(int) : value = " << value << std::endl; } ~test() { std::cout << "test::~test() : value = " << value << std::endl; } int get_value() const { return value; } void set_value(int new_value) { value = new_value; } }; extern test global_test; #endif // __BASE_HPP and the source test.cpp #include "base.hpp" test global_test = test(1); Then I wrote a dynamically loaded library: library.cpp #include "base.hpp" extern "C" { test* get_global_test() { return &global_test; } } and a client program loading this library: client.cpp #include <iostream> #include <dlfcn.h> #include "base.hpp" typedef test* get_global_test_t(); int main() { global_test.set_value(2); // global_test from libbase.a std::cout << "client: " << global_test.get_value() << std::endl; void* handle = dlopen("./liblibrary.so", RTLD_LAZY); if (handle == NULL) { std::cout << dlerror() << std::endl; return 1; } get_global_test_t* get_global_test = NULL; void* func = dlsym(handle, "get_global_test"); if (func == NULL) { std::cout << dlerror() << std::endl; return 1; } else get_global_test = reinterpret_cast<get_global_test_t*>(func); test* t = get_global_test(); // global_test from liblibrary.so std::cout << "liblibrary.so: " << t->get_value() << std::endl; std::cout << "client: " << global_test.get_value() << std::endl; dlclose(handle); return 0; } Now I compile the statically loaded library with g++ -Wall -g -c base.cpp ar rcs libbase.a base.o the dynamically loaded library g++ -Wall -g -fPIC -shared library.cpp libbase.a -o liblibrary.so and the client g++ -Wall -g -ldl client.cpp libbase.a -o client Now I observe: The client and the dynamically loaded library possess a different version of the variable global_test. But in my project I'm using cmake. The build script looks like this: CMAKE_MINIMUM_REQUIRED(VERSION 2.6) PROJECT(globaltest) ADD_LIBRARY(base STATIC base.cpp) ADD_LIBRARY(library MODULE library.cpp) TARGET_LINK_LIBRARIES(library base) ADD_EXECUTABLE(client client.cpp) TARGET_LINK_LIBRARIES(client base dl) analyzing the created makefiles I found that cmake builds the client with g++ -Wall -g -ldl -rdynamic client.cpp libbase.a -o client This ends up in a slightly different but fatal behavior: The global_test of the client and the dynamically loaded library are the same but will be destroyed two times at the end of the program. Am I using cmake in a wrong way? Is it possible that the client and the dynamically loaded library use the same global_test but without this double destruction problem?

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  • Multi-threaded random_r is slower than single threaded version.

    - by Nixuz
    The following program is essentially the same the one described here. When I run and compile the program using two threads (NTHREADS == 2), I get the following run times: real 0m14.120s user 0m25.570s sys 0m0.050s When it is run with just one thread (NTHREADS == 1), I get run times significantly better even though it is only using one core. real 0m4.705s user 0m4.660s sys 0m0.010s My system is dual core, and I know random_r is thread safe and I am pretty sure it is non-blocking. When the same program is run without random_r and a calculation of cosines and sines is used as a replacement, the dual-threaded version runs in about 1/2 the time as expected. #include <pthread.h> #include <stdlib.h> #include <stdio.h> #define NTHREADS 2 #define PRNG_BUFSZ 8 #define ITERATIONS 1000000000 void* thread_run(void* arg) { int r1, i, totalIterations = ITERATIONS / NTHREADS; for (i = 0; i < totalIterations; i++){ random_r((struct random_data*)arg, &r1); } printf("%i\n", r1); } int main(int argc, char** argv) { struct random_data* rand_states = (struct random_data*)calloc(NTHREADS, sizeof(struct random_data)); char* rand_statebufs = (char*)calloc(NTHREADS, PRNG_BUFSZ); pthread_t* thread_ids; int t = 0; thread_ids = (pthread_t*)calloc(NTHREADS, sizeof(pthread_t)); /* create threads */ for (t = 0; t < NTHREADS; t++) { initstate_r(random(), &rand_statebufs[t], PRNG_BUFSZ, &rand_states[t]); pthread_create(&thread_ids[t], NULL, &thread_run, &rand_states[t]); } for (t = 0; t < NTHREADS; t++) { pthread_join(thread_ids[t], NULL); } free(thread_ids); free(rand_states); free(rand_statebufs); } I am confused why when generating random numbers the two threaded version performs much worse than the single threaded version, considering random_r is meant to be used in multi-threaded applications.

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  • Twisted + SQLAlchemy and the best way to do it.

    - by Khorkrak
    So I'm writing yet another Twisted based daemon. It'll have an xmlrpc interface as usual so I can easily communicate with it and have other processes interchange data with it as needed. This daemon needs to access a database. We've been using SQL Alchemy in place of hard coding SQL strings for our latest projects - those mostly done for web apps in Pylons. We'd like to do the same for this app and re-use library code that makes use of SQL Alchemy. So what to do? Well of course since that library was written for use in a Pylons app it's all the straight-forward blocking style code that everyone is accustomed to and all of the non-blocking is magically handled by Pylons via threading, thread locals, scoped sessions and so on. So now for Twisted I guess I'm a bit stuck. I could: Just write the sql I need directly if it's minimal and use the dbapi pool in twisted to do runInteractions etc when I need to hit the db. Use the objects and inherently blocking methods in our library and block now and then in my Twisted daemon. Bah. Use sAsync which was last updated in 2008 and kind of reuse the models we have defined already but not really and it does address code that needs to work in Pylons either. Does that even work with the latest version SQL Alchemy? Who knows. That project looked great though - why was it apparently abandoned? Spawn a separate subprocess and have it deal with the library code and all it's blocking, the results being returned back to my daemon when ready as objects marshalled via YAML over xmlrpc. Use deferToThread and then expunge the objects returned having made sure to do eager loads so that I have all my stuff that I might need. Seems kind of ugha to me. I'm also stuck using Python 2.5.4 atm so no 2.6 yet and I don't think I can just do an import from future to get access to the cool new multiprocessing module stuff in there. That's OK though I guess as we've got dealing with interprocess communication down pretty well. So I'm leaning towards option 4 mostly as that would avoid the mortal sin of logic duplication with option 1 while also staying the heck away from threads. Any better ideas?

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  • Binding on a port with netpipes/netcat

    - by mindas
    I am trying to write a simple bash script that is listening on a port and responding with a trivial HTTP response. My specific issue is that I am not sure if the port is available and in case of bind failure I fall back to next port until bind succeeds. So far to me the easiest way to achieve this was something like: for (( i=$PORT_BASE; i < $(($PORT_BASE+$PORT_RANGE)); i++ )) do if [ $DEBUG -eq 1 ] ; then echo trying to bind on $i fi /usr/bin/faucet $i --out --daemon echo test 2>/dev/null if [ $? -eq 0 ] ; then #success? port=$i if [ $DEBUG -eq 1 ] ; then echo "bound on port $port" fi break fi done Here I am using faucet from netpipes Ubuntu package. The problem with this is that if I simply print "test" to the output, curl complains about non-standard HTTP response (error code 18). That's fair enough as I don't print HTTP-compatible response. If I replace echo test with echo -ne "HTTP/1.0 200 OK\r\n\r\ntest", curl still complains: user@server:$ faucet 10020 --out --daemon echo -ne "HTTP/1.0 200 OK\r\n\r\ntest" ... user@client:$ curl ip.of.the.server:10020 curl: (56) Failure when receiving data from the peer I think the problem lies in how faucet is printing the response and handling the connection. For example if I do the server side in netcat, curl works fine: user@server:$ echo -ne "HTTP/1.0 200 OK\r\n\r\ntest\r\n" | nc -l 10020 ... user@client:$ curl ip.of.the.server:10020 test user@client:$ I would be more than happy to replace faucet with netcat in my main script, but the problem is that I want to spawn independent server process to be able to run client from the same base shell. faucet has a very handy --daemon parameter as it forks to background and I can use $? (exit status code) to check if bind succeeded. If I was to use netcat for a similar purpose, I would have to fork it using & and $? would not work. Does anybody know why faucet isn't responding correctly in this particular case and/or can suggest a solution to this problem. I am not married neither to faucet nor netcat but would like the solution to be implemented using bash or it's utilities (as opposed to write something in yet another scripting language, such as Perl or Python).

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  • Synchronous communication using NSOperationQueue

    - by chip_munks
    I am new to Objective C programming. I have created two threads called add and display using the NSInvocationOperation and added it on to the NSOperationQueue. I make the display thread to run first and then run the add thread. The display thread after printing the "Welcome to display" has to wait for the results to print from the add method. So i have set the waitUntilFinished method. Both the Operations are on the same queue. If i use waitUntilFinished for operations on the same queue there may be a situation for deadlock to happen(from apples developer documentation). Is it so? To wait for particular time interval there is a method called waitUntilDate: But if i need to like this wait(min(100,dmax)); let dmax = 20; How to do i wait for these conditions? It would be much helpful if anyone can explain with an example. EDITED: threadss.h ------------ #import <Foundation/Foundation.h> @interface threadss : NSObject { BOOL m_bRunThread; int a,b,c; NSOperationQueue* queue; NSInvocationOperation* operation; NSInvocationOperation* operation1; NSConditionLock* theConditionLock; } -(void)Thread; -(void)add; -(void)display; @end threadss.m ------------ #import "threadss.h" @implementation threadss -(id)init { if (self = [super init]) { queue = [[NSOperationQueue alloc]init]; operation = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(display) object:nil]; operation1 = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(add) object:nil]; theConditionLock = [[NSConditionLock alloc]init]; } return self; } -(void)Thread { m_bRunThread = YES; //[operation addDependency:operation1]; if (m_bRunThread) { [queue addOperation:operation]; } //[operation addDependency:operation1]; [queue addOperation:operation1]; //[self performSelectorOnMainThread:@selector(display) withObject:nil waitUntilDone:YES]; //NSLog(@"I'm going to do the asynchronous communication btwn the threads!!"); //[self add]; //[operation addDependency:self]; sleep(1); [queue release]; [operation release]; //[operation1 release]; } -(void)add { NSLog(@"Going to add a and b!!"); a=1; b=2; c = a + b; NSLog(@"Finished adding!!"); } -(void)display { NSLog(@"Into the display method"); [operation1 waitUntilFinished]; NSLog(@"The Result is:%d",c); } @end main.m ------- #import <Foundation/Foundation.h> #import "threadss.h" int main (int argc, const char * argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; threadss* thread = [[threadss alloc]init]; [thread Thread]; [pool drain]; return 0; } This is what i have tried with a sample program. output 2011-06-03 19:40:47.898 threads_NSOperationQueue[3812:1503] Going to add a and b!! 2011-06-03 19:40:47.898 threads_NSOperationQueue[3812:1303] Into the display method 2011-06-03 19:40:47.902 threads_NSOperationQueue[3812:1503] Finished adding!! 2011-06-03 19:40:47.904 threads_NSOperationQueue[3812:1303] The Result is:3 Is the way of invoking the thread is correct. 1.Will there be any deadlock condition? 2.How to do wait(min(100,dmax)) where dmax = 50.

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  • Having trouble understanding some code (Ruby on Rails)

    - by user284194
    I posted a question awhile ago asking how I could limit the rate at which a form could be submitted from a rails application. I was helped by a very patient user and their solution works great. The code was for my comments controller, and now I find myself wanting to add this functionality to another controller, my Messages controller. I immediately tried reusing the working code from the comments controller but I couldn't get it to work. Instead of asking for the working code, could someone please help me understand my working comment controller code? class CommentsController < ApplicationController #... before_filter :post_check def record_post_time cookies[:last_post_at] = Time.now.to_i end def last_post_time Time.at((cookies[:last_post_at].to_i rescue 0)) end MIN_POST_TIME = 2.minutes def post_check return true if (Time.now - last_post_time) > MIN_POST_TIME flash[:warning] = "You are trying to reply too fast." @message = Message.find(params[:message_id]) redirect_to(@message) return false end #... def create @message = Message.find(params[:message_id]) @comment = @message.comments.build(params[:comment]) if @comment.save record_post_time flash[:notice] = "Replied to \"#{@message.title}\"" redirect_to(@message) else render :action => "new" end end def update @message = Message.find(params[:message_id]) @comment = Comment.find(params[:id]) if @comment.update_attributes(params[:comment]) record_post_time redirect_to post_comment_url(@message, @comment) else render :action => "edit" end end #... end My Messages controller is pretty much a standard rails generated controller with a few before filters and associated private methods for DRYing up the code and a redirect for non existent pages. I'll explain how much of the code I understand. When a comment is created, a cookie is created with a last_post_time value. If they try to post another comment, the cookie is checked if the last one was made in the last two minutes. If it was a flash warning is displayed and no comment is recorded. What I don't really understand is how the post_check method works and how I can adapt it for my simpler posts controller. I thought I could reuse all the code in the message controller with the exception of the line: @message = Message.find(params[:message_id]) # (don't need the redirect code) in the post_check method. But it trips up on the "record_post_time" in the create action/method. I really want to understand this. Can someone explain why this doesn't work? I greatly appreciate you reading my lengthy question.

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