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  • How perform USort() on an Array of Objects class definition as a method?

    - by user558724
    class Contact{ public $name; public $bgcolor; public $lgcolor; public $email; public $element; public function __construct($name, $bgcolor, $lgcolor, $email, $element) { $this->name = $name; $this->bgcolor = $bgcolor; $this->lgcolor = $lgcolor; $this->email = $email; $this->element = $element; } public static function sortByName(Contact $p1, Contact $p2) { return strcmp($p1->name, $p2->name); } } class ContactList implements Iterator, ArrayAccess { protected $_label; protected $_contacts = array(); public function __construct($label) { $this->_label = $label; } public function getLabel() { return $this->_label; } public function addContact(Contact $contact) { $this->_contacts[] = $contact; } public function current() { return current($this->_contacts); } public function key() { return key($this->_contacts); } public function next() { return next($this->_contacts); } public function rewind() { return reset($this->_contacts); } public function valid() { return current($this->_contacts); } public function offsetGet($offset) { return $this->_contacts[$offset]; } public function offsetSet($offset, $data) { if (!$data instanceof Contact) throw new InvalidArgumentException('Only Contact objects allowed in a ContactList'); if ($offset == '') { $this->_contacts[] = $data; } else { $this->_contacts[$offset] = $data; } } public function offsetUnset($offset) { unset($this->_contacts[$offset]); } public function offsetExists($offset) { return isset($this->_contacts[$offset]); } public function sort($attribute = 'name') { $sortFct = 'sortBy' . ucfirst(strtolower($attribute)); if (!in_array($sortFct, get_class_methods('Contact'))) { throw new Exception('contact->sort(): Can\'t sort by ' . $attribute); } usort($this->contact, 'ContactList::' . $sortFct); } } public function Sort($property, $asc=true) { // this is where sorting logic takes place $_pd = $this->_contact->getProperty($property); if ($_pd == null) { user_error('Property '.$property.' does not exist in class '.$this->_contact->getName(), E_WARNING); return; } // set sortDescriptor ContactList::$sortProperty = $_pd; // and apply sorting usort($this->_array, array('ContactList', ($asc?'USortAsc':'USortDesc'))); } function getItems(){ return $this->_array; } class SortableItem extends ContactList { static public $sortProperty; static function USortAsc($a, $b) { /*@var $_pd ReflectionProperty*/ /* $_pd = self::$sortProperty; if ($_pd !== null) { if ($_pd->getValue($a) === $_pd->getValue($b)) return 0; else return (($_pd->getValue($a) < $_pd->getValue($b))?-1:1); } return 0; } static function USortDesc($a, $b) { return -(self::USortAsc($a,$b)); } } This approach keeps giving me PHP Warnings: usort() [function.usort]: of all kinds which I can provide later as needed to comment out those methods and definitions in order to test and fix some minor bugs of our program. **$billy parameters are already defined. $all -> addContact($billy); // --> ended up adding each contact manually above $all->Sort('name',true); $items = $all->getItems(); foreach($items as $contact) { echo $contact->__toString(); } $all->sort(); The reason for using usort is to re-arrange the order alphabetically by name but somehow is either stating that the function comparison needs to be an array or another errors which obviously I have seemed to pass. Any help would be greatly appreciated, thanks in advance.

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  • NSMutableArray memory leak when reloading objects

    - by Davin
    I am using Three20/TTThumbsviewcontroller to load photos. I am struggling since quite a some time now to fix memory leak in setting photosource. I am beginner in Object C & iOS memory management. Please have a look at following code and suggest any obvious mistakes or any errors in declaring and releasing variables. -- PhotoViewController.h @interface PhotoViewController : TTThumbsViewController <UIPopoverControllerDelegate,CategoryPickerDelegate,FilterPickerDelegate,UISearchBarDelegate>{ ...... NSMutableArray *_photoList; ...... @property(nonatomic,retain) NSMutableArray *photoList; -- PhotoViewController.m @implementation PhotoViewController .... @synthesize photoList; ..... - (void)LoadPhotoSource:(NSString *)query:(NSString *)title:(NSString* )stoneName{ NSLog(@"log- in loadPhotosource method"); if (photoList == nil) photoList = [[NSMutableArray alloc] init ]; [photoList removeAllObjects]; @try { sqlite3 *db; NSFileManager *fileMgr = [NSFileManager defaultManager]; NSString* documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; NSString *dbPath = [documentsPath stringByAppendingPathComponent: @"DB.s3db"]; BOOL success = [fileMgr fileExistsAtPath:dbPath]; if(!success) { NSLog(@"Cannot locate database file '%@'.", dbPath); } if(!(sqlite3_open([dbPath UTF8String], &db) == SQLITE_OK)) { NSLog(@"An error has occured."); } NSString *_sql = query;//[NSString stringWithFormat:@"SELECT * FROM Products where CategoryId = %i",[categoryId integerValue]]; const char *sql = [_sql UTF8String]; sqlite3_stmt *sqlStatement; if(sqlite3_prepare(db, sql, -1, &sqlStatement, NULL) != SQLITE_OK) { NSLog(@"Problem with prepare statement"); } if ([stoneName length] != 0) { NSString *wildcardSearch = [NSString stringWithFormat:@"%@%%",[stoneName stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]]; sqlite3_bind_text(sqlStatement, 1, [wildcardSearch UTF8String], -1, SQLITE_STATIC); } while (sqlite3_step(sqlStatement)==SQLITE_ROW) { NSString* urlSmallImage = @"Mahallati_NoImage.png"; NSString* urlThumbImage = @"Mahallati_NoImage.png"; NSString *designNo = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,2)]; designNo = [designNo stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; NSString *desc = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,7)]; desc = [desc stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; NSString *caption = designNo;//[designNo stringByAppendingString:desc]; caption = [caption stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; NSString *smallFilePath = [documentsPath stringByAppendingPathComponent: [NSString stringWithFormat:@"Small%@.JPG",designNo] ]; smallFilePath = [smallFilePath stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; if ([fileMgr fileExistsAtPath:smallFilePath]){ urlSmallImage = [NSString stringWithFormat:@"Small%@.JPG",designNo]; } NSString *thumbFilePath = [documentsPath stringByAppendingPathComponent: [NSString stringWithFormat:@"Thumb%@.JPG",designNo] ]; thumbFilePath = [thumbFilePath stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; if ([fileMgr fileExistsAtPath:thumbFilePath]){ urlThumbImage = [NSString stringWithFormat:@"Thumb%@.JPG",designNo]; } NSNumber *photoProductId = [NSNumber numberWithInt:(int)sqlite3_column_int(sqlStatement, 0)]; NSNumber *photoPrice = [NSNumber numberWithInt:(int)sqlite3_column_int(sqlStatement, 6)]; char *productNo1 = sqlite3_column_text(sqlStatement, 3); NSString* productNo; if (productNo1 == NULL) productNo = nil; else productNo = [NSString stringWithUTF8String:productNo1]; Photo *jphoto = [[[Photo alloc] initWithCaption:caption urlLarge:[NSString stringWithFormat:@"documents://%@",urlSmallImage] urlSmall:[NSString stringWithFormat:@"documents://%@",urlSmallImage] urlThumb:[NSString stringWithFormat:@"documents://%@",urlThumbImage] size:CGSizeMake(123, 123) productId:photoProductId price:photoPrice description:desc designNo:designNo productNo:productNo ] autorelease]; [photoList addObject:jphoto]; [jphoto release]; } } @catch (NSException *exception) { NSLog(@"An exception occured: %@", [exception reason]); } self.photoSource = [[[MockPhotoSource alloc] initWithType:MockPhotoSourceNormal title:[NSString stringWithFormat: @"%@",title] photos: photoList photos2:nil] autorelease]; } Memory leaks happen when calling above LoadPhotosource method again with different query... I feel its something wrong in declaring NSMutableArray (photoList), but can't figure out how to fix memory leak. Any suggestion is really appreciated.

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  • Testing approach for multi-threaded software

    - by Shane MacLaughlin
    I have a piece of mature geospatial software that has recently had areas rewritten to take better advantage of the multiple processors available in modern PCs. Specifically, display, GUI, spatial searching, and main processing have all been hived off to seperate threads. The software has a pretty sizeable GUI automation suite for functional regression, and another smaller one for performance regression. While all automated tests are passing, I'm not convinced that they provide nearly enough coverage in terms of finding bugs relating race conditions, deadlocks, and other nasties associated with multi-threading. What techniques would you use to see if such bugs exist? What techniques would you advocate for rooting them out, assuming there are some in there to root out? What I'm doing so far is running the GUI functional automation on the app running under a debugger, such that I can break out of deadlocks and catch crashes, and plan to make a bounds checker build and repeat the tests against that version. I've also carried out a static analysis of the source via PC-Lint with the hope of locating potential dead locks, but not had any worthwhile results. The application is C++, MFC, mulitple document/view, with a number of threads per doc. The locking mechanism I'm using is based on an object that includes a pointer to a CMutex, which is locked in the ctor and freed in the dtor. I use local variables of this object to lock various bits of code as required, and my mutex has a time out that fires my a warning if the timeout is reached. I avoid locking where possible, using resource copies where possible instead. What other tests would you carry out?

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  • Can someone tell me why I'm seg faulting in this simple C program?

    - by user299648
    I keep on getting seg faulted, and for the life of me I dont why. The file I'm scanning is just 18 strings in 18 lines. I thinks the problem is the way I'm mallocing the double pointer called picks, but I dont know exactly why. I'm am only trying to scanf strings that are less than 15 chars long, so I don't see the problem. Can someone please help. #include <stdio.h> #include <stdlib.h> #include <string.h> #define MAX_LENGTH 100 int main( int argc,char *argv[] ) { char* string = malloc( sizeof(char) ); char** picks = malloc(15*sizeof(char)); FILE* pick_file = fopen( argv[l], "r" ); int num_picks; for( num_picks=0 ; fgets( string, MAX_LENGTH, pick_file ) != NULL ; num_picks++ ) { printf("pick a/an %s ", string ); scanf( "%s", picks+num_picks ); } int x; for(x=0; x<num_picks;x++) printf("s\n", picks+x); }

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  • List local printers

    - by vladimir
    hi all, i am using this routine to list the local printers installed on on a machine... var p: pointer; hpi: _PRINTER_INFO_2A; hGlobal: cardinal; dwNeeded, dwReturned: DWORD; bFlag: boolean; i: dword; begin p := nil; EnumPrinters(PRINTER_ENUM_LOCAL, nil, 2, p, 0, dwNeeded, dwReturned); if (dwNeeded = 0) then exit; GetMem(p,dwNeeded); if (p = nil) then exit; bFlag := EnumPrinters(PRINTER_ENUM_LOCAL, nil, 2, p, dwneeded, dwNeeded, dwReturned); if (not bFlag) then exit; CbLblPrinterPath.Properties.Items.Clear; for i := 0 to dwReturned - 1 do begin CbLblPrinterPath.Properties.Items.Add(TPrinterInfos(p^)[i].pPrinterName); end; FreeMem(p); TPrinterInfos(p^)[i].pPrinterName returns a 'P' for printer name. i have a PdfCreator installed as a printer. TPrinterInfos is an array of _PRINTER_INFO_2A. how can i fix this?

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  • How is external memory, internal memory, and cache organized?

    - by goldenmean
    Consider a system as follows:= A hardware board having say ARM Cortex-A8 and Neon Vector coprocessor, and Embedded Linux OS running on Cortex-A8. On this environment, if there is some application - say, a video decoder is executing - then: How is it decided that which buffers would be in external memory, which ones would be allocated in internal SRAM, etc. When one says calloc/malloc on such system/code, the pointer returned is from which memory: internal or external? Can a user make buffers to be allocated to the memories of his choice (internal/external)? In ARM architectures, there is another memory called as Tightly coupled memory (TCM). What is that and how can user enable and use it? Can I declare buffers in this memory? Do I need to see the memory map (if any) of the hardware board to understand about all these different physical memories present in a typical hardware board? How much of a role does the OS play in distinguishing these different memories? Sorry for multiple questions, but i think they all are interlinked.

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  • TCP client in C and server in Java

    - by faldren
    I would like to communicate with 2 applications : a client in C which send a message to the server in TCP and the server in Java which receive it and send an acknowledgement. Here is the client (the code is a thread) : static void *tcp_client(void *p_data) { if (p_data != NULL) { char const *message = p_data; int sockfd, n; struct sockaddr_in serv_addr; struct hostent *server; char buffer[256]; sockfd = socket(AF_INET, SOCK_STREAM, 0); if (sockfd < 0) { error("ERROR opening socket"); } server = gethostbyname(ALARM_PC_IP); if (server == NULL) { fprintf(stderr,"ERROR, no such host\n"); exit(0); } bzero((char *) &serv_addr, sizeof(serv_addr)); serv_addr.sin_family = AF_INET; bcopy((char *)server->h_addr, (char *)&serv_addr.sin_addr.s_addr, server->h_length); serv_addr.sin_port = htons(TCP_PORT); if (connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0) { error("ERROR connecting"); } n = write(sockfd,message,strlen(message)); if (n < 0) { error("ERROR writing to socket"); } bzero(buffer,256); n = read(sockfd,buffer,255); if (n < 0) { error("ERROR reading from socket"); } printf("Message from the server : %s\n",buffer); close(sockfd); } return 0; } And the java server : try { int port = 9015; ServerSocket server=new ServerSocket(port); System.out.println("Server binded at "+((server.getInetAddress()).getLocalHost()).getHostAddress()+":"+port); System.out.println("Run the Client"); while (true) { Socket socket=server.accept(); BufferedReader in= new BufferedReader(new InputStreamReader(socket.getInputStream())); System.out.println(in.readLine()); PrintStream out=new PrintStream(socket.getOutputStream()); out.print("Welcome by server\n"); out.flush(); out.close(); in.close(); System.out.println("finished"); } } catch(Exception err) { System.err.println("* err"+err); } With n = read(sockfd,buffer,255); the client is waiting a response and for the server, the message is never ended so it doesn't send a response with PrintStream. If I remove these lines : bzero(buffer,256); n = read(sockfd,buffer,255); if (n < 0) { error("ERROR reading from socket"); } printf("Message from the server : %s\n",buffer); The server knows that the message is finished but the client can't receive the response. How solve that ? Thank you

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  • Endianness and C API's: Specifically OpenSSL.

    - by Hassan Syed
    I have an algorithm that uses the following OpenSSL calls: HMAC_update() / HMAC_final() // ripe160 EVP_CipherUpdate() / EVP_CipherFinal() // cbc_blowfish These algorithm take a unsigned char * into the "plain text". My input data is comes from a C++ std::string::c_str() which originate from a protocol buffer object as a encoded UTF-8 string. UTF-8 strings are meant to be endian neutrial. However I'm a bit paranoid about how OpenSSL may perform operations on the data. My understanding is that encryption algorithms work on 8-bit blocks of data, and if a unsigned char * is used for pointer arithmetic when the operations are performed the algorithms should be endian neutral and I do not need to worry about anything. My uncertainty is compounded by the fact that I am working on a little-endian machine and have never done any real cross-architecture programming. My beliefs/reasoning are/is based on the following two properties std::string (not wstring) internally uses a 8-bit ptr and a the resulting c_str() ptr will itterate the same way regardless of the CPU architecture. Encryption algorithms are either by design, or by implementation, endian neutral. I know the best way to get a definitive answer is to use QEMU and do some cross-platform unit tests (which I plan to do). My question is a request for comments on my reasoning, and perhaps will assist other programmers when faced with similar problems.

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  • How safe and reliable are C++ String Literals?

    - by DoctorT
    So, I'm wanting to get a better grasp on how string literals in C++ work. I'm mostly concerned with situations where you're assigning the address of a string literal to a pointer, and passing it around. For example: char* advice = "Don't stick your hands in the toaster."; Now lets say I just pass this string around by copying pointers for the duration of the program. Sure, it's probably not a good idea, but I'm curious what would actually be going on behind the scenes. For another example, let's say we make a function that returns a string literal: char* foo() { // function does does stuff return "Yikes!"; // somebody's feeble attempt at an error message } Now lets say this function is called very often, and the string literal is only used about half the time it's called: // situation #1: it's just randomly called without heed to the return value foo(); // situation #2: the returned string is kept and used for who knows how long char* retVal = foo(); In the first situation, what's actually happening? Is the string just created but not used, and never deallocated? In the second situation, is the string going to be maintained as long as the user finds need for it? What happens when it isn't needed anymore... will that memory be freed up then (assuming nothing points to that space anymore)? Don't get me wrong, I'm not planning on using string literals like this. I'm planning on using a container to keep my strings in check (probably std::string). I'm mostly just wanting to know if these situations could cause problems either for memory management or corrupted data.

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  • HTC Incredible displaying blank ImageView

    - by Todd
    HI, I have an app that displays an an image in an ImageView using the setImageDrawable(Drawable) method. However, with the release of the Droid Incredible the images are coming up as a blank screen. I am using Drawable.createFromPath(Environment.getExternalStorageDirectory() + "\imagefile") to access the image from the SD card. I don't get any sort of error, just a black screen. I will get a null pointer exception if after trying to load the image I try to access a property of the Drawable. This makes me believe that the Drawable wasn't loaded, but I don't know why or how to make it work. This code as been working on all other Android devices, so I'm not sure what is different with the Incredible. Unfortunately I don't have access to an Incredible to test on, so I've got to rely on others to test and send me the log files. Any help you can offer would be greatly appreciated. If anyone knows how to replicate this issue on the emulator, that would be helpful too. I've configured an emulator with firmware 7 and the correct screen resolution, but I was unable to replicate the issue. Thanks.

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  • Obj-C: Passing pointers to initialized classes in other classes

    - by FnGreg7
    Hey all. I initialized a class in my singleton called DataModel. Now, from my UIViewController, when I click a button, I have a method that is trying to access that class so that I may add an object to one of its dictionaries. My get/set method passes back the pointer to the class from my singleton, but when I am back in my UIViewController, the class passed back doesn't respond to methods. It's like it's just not there. I think it has something to do with the difference in passing pointers around classes or something. I even tried using the copy method to throw a copy back, but no luck. UIViewController: ApplicationSingleton *applicationSingleton = [[ApplicationSingleton alloc] init]; DataModel *dataModel = [applicationSingleton getDataModel]; [dataModel retrieveDataCategory:dataCategory]; Singleton: ApplicationSingleton *m_instance; DataModel *m_dataModel; - (id) init { NSLog(@"ApplicationSingleton.m initialized."); self = [super init]; if(self != nil) { if(m_instance != nil) { return m_instance; } NSLog(@"Initializing the application singleton."); m_instance = self; m_dataModel = [[DataModel alloc] init]; } NSLog(@"ApplicationSingleton init method returning."); return m_instance; } -(DataModel *)getDataModel { DataModel *dataModel_COPY = [m_dataModel copy]; return dataModel_COPY; } For the getDataModel method, I also tried this: -(DataModel *)getDataModel { return m_dataModel; } In my DataModel retrieveDataCategory method, I couldn't get anything to work. I even just tried putting a NSLog in there but it never would come onto the console. Any ideas?

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  • c++ File input/output

    - by Myx
    Hi: I am trying to read from a file using fgets and sscanf. In my file, I have characters on each line of the while which I wish to put into a vector. So far, I have the following: FILE *fp; fp = fopen(filename, "r"); if(!fp) { fprintf(stderr, "Unable to open file %s\n", filename); return 0; } // Read file int line_count = 0; char buffer[1024]; while(fgets(buffer, 1023, fp)) { // Increment line counter line_count++; char *bufferp = buffer; ... while(*bufferp != '\n') { char *tmp; if(sscanf(bufferp, "%c", tmp) != 1) { fprintf(stderr, "Syntax error reading axiom on " "line %d in file %s\n", line_count, filename); return 0; } axiom.push_back(tmp); printf("put %s in axiom vector\n", axiom[axiom.size()-1]); // increment buffer pointer bufferp++; } } my axiom vector is defined as vector<char *> axiom;. When I run my program, I get a seg fault. It happens when I do the sscanf. Any suggestions on what I'm doing wrong?

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  • Question about Virtual Inheritance hierarchy

    - by Summer_More_More_Tea
    Hi there: I encounter this problem when tackling with virtual inheritance. I remember that in a non-virtual inheritance hierarchy, object of sub-class hold an object of its direct super-class. What about virtual inheritance? In this situation, does object of sub-class hold an object of its super-class directly or just hold a pointer pointing to an object of its super-class? By the way, why the output of the following code is: sizeof(A): 8 sizeof(B): 20 sizeof(C): 20 sizeof(C): 36 Code: #include <iostream> using namespace std; class A{ char k[ 3 ]; public: virtual void a(){}; }; class B : public virtual A{ char j[ 3 ]; public: virtual void b(){}; }; class C : public virtual B{ char i[ 3 ]; public: virtual void c(){}; }; class D : public B, public C{ char h[ 3 ]; public: virtual void d(){}; }; int main( int argc, char *argv[] ){ cout << "sizeof(A): " << sizeof( A ) << endl; cout << "sizeof(B): " << sizeof( B ) << endl; cout << "sizeof(C): " << sizeof( C ) << endl; cout << "sizeof(D): " << sizeof( D ) << endl; return 0; } Thanks in advance. Kind regards.

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  • How to mimic polymorphism in classes with template methods (c++)?

    - by davide
    in the problem i am facing i need something which works more or less like a polymorphic class, but which would allow for virtual template methods. the point is, i would like to create an array of subproblems, each one being solved by a different technique implemented in a different class, but holding the same interface, then pass a set of parameters (which are functions/functors - this is where templates jump up) to all the subproblems and get back a solution. if the parameters would be, e.g., ints, this would be something like: struct subproblem { ... virtual void solve (double& solution, double parameter)=0; } struct subproblem0: public subproblem { ... virtual void solve (double& solution, double parameter){...}; } struct subproblem1: public subproblem { ... virtual void solve (double* solution, double parameter){...}; } int main{ subproblem problem[2]; subproblem[0] = new subproblem0(); subproblem[1] = new subproblem1(); double argument0(0), argument1(1), sol0[2], sol1[2]; for(unsigned int i(0);i<2;++i) { problem[i]->solve( &(sol0[i]) , argument0); problem[i]->solve( &(sol1[i]) , argument1); } return 0; } but the problem is, i need the arguments to be something like Arg<T1,T2> argument0(f1,f2) and thus the solve method to be something of the likes of template<T1,T2> solve (double* solution, Arg<T1,T2> parameter) which cant obviously be declared virtual ( so cant be called from a pointer to the base class)... now i'm pretty stuck and don't know how to procede...

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  • Modelling in Agile Development

    - by bertzzie
    I'm writing a bachelor dissertation report where I'm developing a system with Agile methodology. Given that the development is an one man show, of course the "Agile" I did was not really agile at all (from my understanding at least). So I want some perspective from SO crowds, who is of course a professional, real world, developer with tons of experience. I think real world experience is better than the theory and experiments that I did. My question is: Do we model during development time when using Agile? UML? DFD? Or a Functional Specification is enough1? If modelling is not really necessary, what do we use to communicate to the user, as the user almost always won't understand UML or DFD? For my system, I use UI & UX Design with heavy prototyping, but then I don't have time to draw UML any more. Which one is better? 1 http://www.joelonsoftware.com/articles/fog0000000036.html I hope the question's not "subjective and argumentative" as I know this question exist because of my lack of understanding in the agile development. If it is, could someone just give me a pointer or reference about that? Possible duplicate: Do you use UML in Agile development practices?

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  • Warning: cast increases required alignment

    - by dash-tom-bang
    I'm recently working on this platform for which a legacy codebase issues a large number of "cast increases required alignment to N" warnings, where N is the size of the target of the cast. struct Message { int32_t id; int32_t type; int8_t data[16]; }; int32_t GetMessageInt(const Message& m) { return *reinterpret_cast<int32_t*>(&data[0]); } Hopefully it's obvious that a "real" implementation would be a bit more complex, but the basic point is that I've got data coming from somewhere, I know that it's aligned (because I need the id and type to be aligned), and yet I get the message that the cast is increasing the alignment, in the example case, to 4. Now I know that I can suppress the warning with an argument to the compiler, and I know that I can cast the bit inside the parentheses to void* first, but I don't really want to go through every bit of code that needs this sort of manipulation (there's a lot because we load a lot of data off of disk, and that data comes in as char buffers so that we can easily pointer-advance), but can anyone give me any other thoughts on this problem? I mean, to me it seems like such an important and common option that you wouldn't want to warn, and if there is actually the possibility of doing it wrong then suppressing the warning isn't going to help. Finally, can't the compiler know as I do how the object in question is actually aligned in the structure, so it should be able to not worry about the alignment on that particular object unless it got bumped a byte or two?

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  • making an array controller the target of a button

    - by ian
    I am working through a chapter of COCOA PROGRAMMING FOR MAC OS X (3RD EDITION) on NSArrayController and it tells me to: Control-Drag to make the array controller become the target of the Add New Employee button. Set the action to add: However when I drag over the array controller it does not highlight so I get no target options. How do I do this correctly in the new XCode full size image document.h: // // Document.h // RaiseMan // // Created by user on 11/12/11. // Copyright (c) 2011 __MyCompanyName__. All rights reserved. // #import <Cocoa/Cocoa.h> @interface Document : NSDocument { NSMutableArray *employees; } @end document.m: // // Document.m // RaiseMan // // Created by user on 11/12/11. // Copyright (c) 2011 __MyCompanyName__. All rights reserved. // #import "Document.h" @implementation Document - (id)init { self = [super init]; if (self) { employees = [[NSMutableArray alloc] init]; } return self; } - (void)dealloc { [self setEmployees:nil]; [super dealloc]; } -(void)setEmployees:(NSMutableArray *)a { //this is an unusual setter method we are goign to ad a lot of smarts in the next chapter if (a == employees) return; [a retain]; [employees release]; employees = a; } - (NSString *)windowNibName { // Override returning the nib file name of the document // If you need to use a subclass of NSWindowController or if your document supports multiple NSWindowControllers, you should remove this method and override -makeWindowControllers instead. return @"Document"; } - (void)windowControllerDidLoadNib:(NSWindowController *)aController { [super windowControllerDidLoadNib:aController]; // Add any code here that needs to be executed once the windowController has loaded the document's window. } - (NSData *)dataOfType:(NSString *)typeName error:(NSError **)outError { /* Insert code here to write your document to data of the specified type. If outError != NULL, ensure that you create and set an appropriate error when returning nil. You can also choose to override -fileWrapperOfType:error:, -writeToURL:ofType:error:, or -writeToURL:ofType:forSaveOperation:originalContentsURL:error: instead. */ NSException *exception = [NSException exceptionWithName:@"UnimplementedMethod" reason:[NSString stringWithFormat:@"%@ is unimplemented", NSStringFromSelector(_cmd)] userInfo:nil]; @throw exception; return nil; } - (BOOL)readFromData:(NSData *)data ofType:(NSString *)typeName error:(NSError **)outError { /* Insert code here to read your document from the given data of the specified type. If outError != NULL, ensure that you create and set an appropriate error when returning NO. You can also choose to override -readFromFileWrapper:ofType:error: or -readFromURL:ofType:error: instead. If you override either of these, you should also override -isEntireFileLoaded to return NO if the contents are lazily loaded. */ NSException *exception = [NSException exceptionWithName:@"UnimplementedMethod" reason:[NSString stringWithFormat:@"%@ is unimplemented", NSStringFromSelector(_cmd)] userInfo:nil]; @throw exception; return YES; } + (BOOL)autosavesInPlace { return YES; } - (void)setEmployees:(NSMutableArray *)a; @end person.h: // // Person.h // RaiseMan // // Created by user on 11/12/11. // Copyright (c) 2011 __MyCompanyName__. All rights reserved. // #import <Foundation/Foundation.h> @interface Person : NSObject { NSString *personName; float expectedRaise; } @property (readwrite, copy) NSString *personName; @property (readwrite) float expectedRaise; @end person.m: // // Person.m // RaiseMan // // Created by user on 11/12/11. // Copyright (c) 2011 __MyCompanyName__. All rights reserved. // #import "Person.h" @implementation Person - (id) init { self = [super init]; expectedRaise = 5.0; personName = @"New Person"; return self; } - (void)dealloc { [personName release]; [super dealloc]; } @synthesize personName; @synthesize expectedRaise; @end

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  • How to get data from struts2 action with jQuery?

    - by Rafa Romero
    I have an Struts2 Web with GoogleMaps. I want to load a list of markers which are saved in a SQL DDBB. To do this, I tried with jQuery and Ajax. Here you are the code: loadMarkers.java public class loadMarkers extends ActionSupport implements ServletRequestAware,ServletResponseAware{ //Variables de sesion/cookie FunctionClass ses; protected HttpServletResponse servletResponse; protected HttpServletRequest servletRequest; private String userID=""; //Variables del marker private List<marker> markersList = new ArrayList<marker>(); public String execute() throws Exception{ FunctionClass friends = new FunctionClass(); //Leemos de la cookie for(Cookie c : servletRequest.getCookies()) { if (c.getName().equals("userID")) userID = (c.getValue()); } System.out.println("en el loadMarkers"); connectionBBDD con = new connectionBBDD(); markersList = con.loadMarkers(userID); return SUCCESS; } I want to use the markerList array in Javascript, to create the markers. This is the struts.xml file: <package name="jsonActions" namespace="/test" extends="json-default"> <action name="LoadMarkers" class="web.localizadroid.maps.loadMarkers"> <interceptor-ref name="basicStack"/> <result type="json"> <param name="root">markersList</param> </result> </action> </package> And here you are the Javascript (jQuery) code: function loadMarkersJ(){ alert("dentro"); $.ajax({ type : "post", url : "LoadMarkers", dataType: "json", success : function(data) { alert(data); var image = new google.maps.MarkerImage ('http://i53.tinypic.com/ettquh.png'); var jSon_Object = eval("(" + data + ")"); //For para analizar los datos (Json) obtenidos de la BBDD for (x = 0; x < jSon_Object.length; x++) { var markersArray = []; var myLatlng = new google.maps.LatLng(jSon_Object[x].lat, jSon_Object[x].lon); markerLoaded = new google.maps.Marker( { position : myLatlng, map : map, icon: image, title: "NOMBRE: " + jSon_Object[x].tarjetName + "\n" + "ANOTACIONES: " + jSon_Object[x].anotaciones + "\n" + "TIME: " + jSon_Object[x].time }); markersArray.push(markerLoaded); if (markersArray) { for (i in markersArray) { alert("entro en forColocaMarkers"); if (markersArray[i].getAnimation() != null) { markersArray[i].setAnimation(null); } else { markersArray[i].setAnimation(google.maps.Animation.BOUNCE); } markersArray[i].setMap(map); } } } } }); } From success : function(data) { to the end, is JavaScript code to create de markers, and this it's OK. The problem is whith ajax, because I don't get to obtain markerList Array by jSon data return...I think that the problem is in the url attribute from $.ajax...I tried loadMarkers.action and loadMarkers, but nothing happens. When I execute the web, only prints the alert alert("dentro"), the alert alert(data) never has been printed. I have forgotten to add the code where I call the Javascript function (loadMarkersJ). Here you are: <p><s:a action="LoadMarkers.action" namespace="/test" onclick="loadMarkersJ(this)">Cargar Marcadores S</s:a></p> Somebody can help me please?

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  • Rails destroy confirm with Jquery AJAX

    - by Mike
    I have got this working for the most part. My rails link is: <%= link_to(image_tag('/images/bin.png', :alt => 'Remove'), @business, :class => 'delete', :confirm => 'Are you sure?', :id => 'trash') %> :class = "delete" is calling an ajax function so that it is deleted and the page isn't refreshed that works great. But because the page doesn't refresh, it is still there. So my id trash is calling this jquery function: $('[id^=trash]').click(function(){ var row = $(this).closest("tr").get(0); $(row).hide(); return false; }); Which is hiding the row of whatever trash icon i clicked on. This also works great. I thought I had it all worked out and then I hit this problem. When you click on my trash can I have this confirm box pop up to ask you if you are sure. Regardless of whether you choose cancel or accept, the jquery fires and it hides the row. It isn't deleted, only hidden till you refresh the page. I tried changing it so that the prompt is done through jquery, but then rails was deleteing the row regardless of what i choose in my prompt because the .destroy function was being called when the prompt was being called. My question really is how can i get the value to cancel or accept from the rails confirm pop up so that in my jquery I can have an if statement that hides if they click accept and does nothing if they click cancel. EDIT: Answering Question below. That did not work. I tried changing my link to: <%= link_to(image_tag('/images/bin.png', :alt => 'Remove'), @business, :class => "delete", :onclick => "trash") %> and putting this in my jquery function trash(){ if(confirm("Are you sure?")){ var row = $(this).closest("tr").get(0); $(row).hide(); return false; } else { //they clicked no. } } But the function was never called. It just deletes it with no prompt and doesn't hide it. But that gave me an idea. I took the delete function that ajax was calling $('a.delete').click (function(){ $.post(this.href, {_method:'delete'}, null, "script"); $(row).hide(); }); And modified it implementing your code: remove :confirm = 'Are you sure?' $('a.delete').click (function(){ if(confirm("Are you sure?")){ var row = $(this).closest("tr").get(0); $.post(this.href, {_method:'delete'}, null, "script"); $(row).hide(); return false; } else { //they clicked no. return false; } }); Which does the trick.

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  • How to reduce virtual memory by optimising my PHP code?

    - by iCeR
    My current code (see below) uses 147MB of virtual memory! My provider has allocated 100MB by default and the process is killed once run, causing an internal error. The code is utilising curl multi and must be able to loop with more than 150 iterations whilst still minimizing the virtual memory. The code below is only set at 150 iterations and still causes the internal server error. At 90 iterations the issue does not occur. How can I adjust my code to lower the resource use / virtual memory? Thanks! <?php function udate($format, $utimestamp = null) { if ($utimestamp === null) $utimestamp = microtime(true); $timestamp = floor($utimestamp); $milliseconds = round(($utimestamp - $timestamp) * 1000); return date(preg_replace('`(?<!\\\\)u`', $milliseconds, $format), $timestamp); } $url = 'https://www.testdomain.com/'; $curl_arr = array(); $master = curl_multi_init(); for($i=0; $i<150; $i++) { $curl_arr[$i] = curl_init(); curl_setopt($curl_arr[$i], CURLOPT_URL, $url); curl_setopt($curl_arr[$i], CURLOPT_RETURNTRANSFER, 1); curl_setopt($curl_arr[$i], CURLOPT_SSL_VERIFYHOST, FALSE); curl_setopt($curl_arr[$i], CURLOPT_SSL_VERIFYPEER, FALSE); curl_multi_add_handle($master, $curl_arr[$i]); } do { curl_multi_exec($master,$running); } while($running > 0); for($i=0; $i<150; $i++) { $results = curl_multi_getcontent ($curl_arr[$i]); $results = explode("<br>", $results); echo $results[0]; echo "<br>"; echo $results[1]; echo "<br>"; echo udate('H:i:s:u'); echo "<br><br>"; usleep(100000); } ?> Processor Information Total processors: 8 Processor #1 Vendor GenuineIntel Name Intel(R) Xeon(R) CPU E5405 @ 2.00GHz Speed 1995.120 MHz Cache 6144 KB Processor #2 Vendor GenuineIntel Name Intel(R) Xeon(R) CPU E5405 @ 2.00GHz Speed 1995.120 MHz Cache 6144 KB Processor #3 Vendor GenuineIntel Name Intel(R) Xeon(R) CPU E5405 @ 2.00GHz Speed 1995.120 MHz Cache 6144 KB Processor #4 Vendor GenuineIntel Name Intel(R) Xeon(R) CPU E5405 @ 2.00GHz Speed 1995.120 MHz Cache 6144 KB Processor #5 Vendor GenuineIntel Name Intel(R) Xeon(R) CPU E5405 @ 2.00GHz Speed 1995.120 MHz Cache 6144 KB Processor #6 Vendor GenuineIntel Name Intel(R) Xeon(R) CPU E5405 @ 2.00GHz Speed 1995.120 MHz Cache 6144 KB Processor #7 Vendor GenuineIntel Name Intel(R) Xeon(R) CPU E5405 @ 2.00GHz Speed 1995.120 MHz Cache 6144 KB Processor #8 Vendor GenuineIntel Name Intel(R) Xeon(R) CPU E5405 @ 2.00GHz Speed 1995.120 MHz Cache 6144 KB Memory Information Memory for crash kernel (0x0 to 0x0) notwithin permissible range Memory: 8302344k/9175040k available (2176k kernel code, 80272k reserved, 901k data, 228k init, 7466304k highmem) System Information Linux server3.server.com 2.6.18-194.17.1.el5PAE #1 SMP Wed Sep 29 13:31:51 EDT 2010 i686 i686 i386 GNU/Linux Physical Disks SCSI device sda: 1952448512 512-byte hdwr sectors (999654 MB) sda: Write Protect is off sda: Mode Sense: 03 00 00 08 SCSI device sda: drive cache: write back SCSI device sda: 1952448512 512-byte hdwr sectors (999654 MB) sda: Write Protect is off sda: Mode Sense: 03 00 00 08 SCSI device sda: drive cache: write back sd 0:1:0:0: Attached scsi disk sda sd 4:0:0:0: Attached scsi removable disk sdb sd 0:1:0:0: Attached scsi generic sg4 type 0 sd 4:0:0:0: Attached scsi generic sg7 type 0 Current Memory Usage total used free shared buffers cached Mem: 8306672 7847384 459288 0 487912 6444548 -/+ buffers/cache: 914924 7391748 Swap: 4095992 496 4095496 Total: 12402664 7847880 4554784 Current Disk Usage Filesystem Size Used Avail Use% Mounted on /dev/mapper/VolGroup00-LogVol00 898G 307G 546G 36% / /dev/sda1 99M 19M 76M 20% /boot none 4.0G 0 4.0G 0% /dev/shm /var/tmpMnt 4.0G 1.8G 2.0G 48% /tmp

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  • How to partition bits in a bit array with less than linear time

    - by SiLent SoNG
    This is an interview question I faced recently. Given an array of 1 and 0, find a way to partition the bits in place so that 0's are grouped together, and 1's are grouped together. It does not matter whether 1's are ahead of 0's or 0's are ahead of 1's. An example input is 101010101, and output is either 111110000 or 000011111. Solve the problem in less than linear time. Make the problem simpler. The input is an integer array, with each element either 1 or 0. Output is the same integer array with integers partitioned well. To me, this is an easy question if it can be solved in O(N). My approach is to use two pointers, starting from both ends of the array. Increases and decreases each pointer; if it does not point to the correct integer, swap the two. int * start = array; int * end = array + length - 1; while (start < end) { // Assume 0 always at the end if (*end == 0) { --end; continue; } // Assume 1 always at the beginning if (*start == 1) { ++start; continue; } swap(*start, *end); } However, the interview insists there is a sub-linear solution. This makes me thinking hard but still not get an answer. Can anyone help on this interview question?

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  • Implementing a c/c++ style union as a column in MySQL

    - by user81338
    Friends, I have a strange need and cannot think my way through the problem. The great and mighty Google is of little help due to keyword recycling (as you'll see). Can you help? What I want to do is store data of multiple types in a single column in MySQL. This is the database equivalent to a C union (and if you search for MySQL and Union, you obviously get a whole bunch of stuff on the UNION keyword in SQL). [Contrived and simplified case follows] So, let us say that we have people - who have names - and STORMTROOPERS - who have TK numbers. You cannot have BOTH a NAME and a TK number. You're either BOB SMITH -or- TK409. In C I could express this as a union, like so: union { char * name; int tkNo; } EmperialPersonnelRecord; This makes it so that I am either storing a pointer to a char array or an ID in the type EmperialPersonnelRecord, but not both. I am looking for a MySQL equivalent on a column. My column would store either an int, double, or varchar(255) (or whatever combination). But would only take up the space of the largest element. Is this possible? (of course anything is possible given enough time, money and will - I mean is it possible if I am poor, lazy and on a deadline... aka "out of the box")

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  • gtk draw "expose-event" and redraw

    - by warem
    I want to use expose-event to draw something then update or redraw. That's to say, there are a drawing area and a button in window. When clicking button, the drawing area will be redrawn accordingly. My problems are Following code worked but it only had a drawing area no button. If I add the button(cancel the comment for button), nothing is drawn. What's the reason? In the following code, if I changed gtk_container_add (GTK_CONTAINER (box), canvas); to gtk_box_pack_start(GTK_BOX(box), canvas, FALSE, FALSE, 0);, nothing is drawn. Usually we use gtk_box_pack_start to add something into box. Why doesn't it work this time? The function build_ACC_axis refreshed drawing area and prepared for new draw. I google it but I didn't know if it worked. Could you please comment on it? If the source file is test.c, then compilation is gcc -o test test.c `pkg-config --cflags --libs gtk+-2.0` The code is below: #include <gtk/gtk.h> #include <glib.h> static void draw (GdkDrawable *d, GdkGC *gc) { /* Draw with GDK */ gdk_draw_line (d, gc, 0, 0, 50, 50); gdk_draw_line (d, gc, 50, 50, 50, 150); gdk_draw_line (d, gc, 50, 150, 0, 200); gdk_draw_line (d, gc, 200, 0, 150, 50); gdk_draw_line (d, gc, 150, 50, 150, 150); gdk_draw_line (d, gc, 150, 150, 200, 200); gdk_draw_line (d, gc, 50, 50, 150, 50); gdk_draw_line (d, gc, 50, 150, 150, 150); } static gboolean expose_cb (GtkWidget *canvas, GdkEventExpose *event, gpointer user_data) { GdkGC *gc; gc = gdk_gc_new (canvas->window); draw (canvas->window, gc); g_object_unref (gc); return FALSE; } void build_ACC_axis (GtkWidget *button, GtkWidget *widget) { GdkRegion *region; GtkWidget *canvas = g_object_get_data(G_OBJECT(widget), "plat_GA_canvas"); region = gdk_drawable_get_visible_region(canvas->window); gdk_window_invalidate_region(canvas->window, region, TRUE); gtk_widget_queue_draw(canvas); /* gdk_window_process_updates(canvas->window, TRUE); */ gdk_region_destroy (region); } int main (int argc, char **argv) { GtkWidget *window; GtkWidget *canvas, *box, *button; gtk_init (&argc, &argv); window = gtk_window_new (GTK_WINDOW_TOPLEVEL); g_signal_connect (G_OBJECT (window), "destroy", G_CALLBACK (gtk_main_quit), NULL); box = gtk_vbox_new(FALSE, 0); gtk_container_add (GTK_CONTAINER (window), box); canvas = gtk_drawing_area_new (); g_object_set_data(G_OBJECT(window), "plat_GA_canvas", canvas); /* gtk_box_pack_start(GTK_BOX(box), canvas, FALSE, FALSE, 0); */ gtk_container_add (GTK_CONTAINER (box), canvas); g_signal_connect (G_OBJECT (canvas), "expose-event", G_CALLBACK (expose_cb), NULL); /* button = gtk_button_new_with_label ("ok"); gtk_box_pack_start(GTK_BOX(box), button, FALSE, FALSE, 0); |+ gtk_container_add (GTK_CONTAINER (box), button); +| gtk_signal_connect(GTK_OBJECT(button), "clicked", GTK_SIGNAL_FUNC(build_ACC_axis), window); */ gtk_widget_show_all (window); gtk_main (); }

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  • openDatabase Hello World - 2

    - by cf_PhillipSenn
    This is a continuation from a previous stackoverflow question. I've renamed some variables so that I can tell what are keywords and what are names that I can control. Q: Why is the deleteRow function not working? <html> <head> <title>html5 openDatabase Hello World</title> <script src="http://www.google.com/jsapi"></script> <script type="text/javascript"> google.load("jquery", "1"); google.setOnLoadCallback(OnLoadCallback); function OnLoadCallback() { var dbo; dbo = openDatabase('HelloWorld'); dbo.transaction( function(T1) { T1.executeSql( 'CREATE TABLE IF NOT EXISTS myTable ' + ' (myTableID INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, ' + ' Field1 TEXT NOT NULL );' ); } ); dbo.transaction(function(T2) { T2.executeSql('SELECT * FROM myTable',[], function (T6, result) { for (var i=0; i < result.rows.length; i++) { var row = result.rows.item(i); $('#savedData').append('<li id="'+row.myTableID+'">' + row.Field1 + '</li>'); } }, errorHandler); }); $('form').submit(function() { var xxx = $('#xxx').val(); dbo.transaction( function(T3) { T3.executeSql( 'INSERT INTO myTable (Field1) VALUES (?);', [xxx], function(){ $('#savedData').append('<li id="ThisisWhereIneedHELP">' + xxx + '</li>'); $('#xxx').val(''); }, errorHandler ); } ); return false; }); $('#savedData > li').live('click', function (){ deleteRow(this.id); $(this).remove(); }); } function deleteRow(myTableID) { alert('trying to delete'); dbo.transaction(function(T4) { T4.executeSql('DELETE FROM myTable WHERE myTableID = ?', [myTableID], function(){ alert('Deleted!'); }, errorHandler); }); } function errorHandler(T5, error) { alert('Oops. Error was '+error.message+' (Code '+error.code+')'); // T5.executeSql('INSERT INTO errors (code, message) VALUES (?, ?);', // [error.code, error.message]); return false; } </script> </head> <body> <form method="post"> <input name="xxx" id="xxx" /> <p> <input type="submit" name="OK" /> </p> <ul id="savedData"> </ul> </form> </body> </html>

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  • Multi-reader IPC solution?

    - by gct
    I'm working on a framework in C++ (just for fun for now), that lets the user write plugins that use a standard API to stream data between each other. There's going to be three basic transport mechanisms for the data: files, sockets, and some kind of IPC piping system. The system is set up so that for the non-file transport, each stream can have multiple readers. IE once a server socket it setup, multiple computers can connect and stream the data. I'm a little stuck at the multi-reader IPC system though. All my plugins run in threads so they live in the same address space, so some kind of shared memory system would work fine, I was thinking I'd write my own circular buffer with a write pointer and read pointers chassing it around the buffer, but I have my doubts that I can achieve the same performance as something like linux pipes. I'm curious what people would suggest for a multi-reader solution to something like this? Is the overhead for pipes or domain sockets low enough that I could just open a connection to each reader and issue separate writes to each reader? This is intended to be significant volumes of data (tens of mega-samples/sec), so performance is a must.

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