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  • Reworking my singly linked list

    - by Stradigos
    Hello everyone, thanks for taking the time to stop by my question. Below you will find my working SLL, but I want to make more use of C# and, instead of having two classes, SLL and Node, I want to use Node's constructors to do all the work (To where if you pass a string through the node, the constructor will chop it up into char nodes). The problem is, after an a few hours of tinkering, I'm not really getting anywhere... using System; using System.Collections.Generic; using System.Text; using System.IO; namespace PalindromeTester { class Program { static void Main(string[] args) { SLL mySLL = new SLL(); mySLL.add('a'); mySLL.add('b'); mySLL.add('c'); mySLL.add('d'); mySLL.add('e'); mySLL.add('f'); Console.Out.WriteLine("Node count = " + mySLL.count); mySLL.reverse(); mySLL.traverse(); Console.Out.WriteLine("\n The header is: " + mySLL.gethead); Console.In.ReadLine(); } class Node { private char letter; private Node next; public Node() { next = null; } public Node(char c) { this.data = c; } public Node(string s) { } public char data { get { return letter; } set { letter = value; } } public Node nextNode { get { return next; } set { next = value; } } } class SLL { private Node head; private int totalNode; public SLL() { head = null; totalNode = 0; } public void add(char s) { if (head == null) { head = new Node(); head.data = s; } else { Node temp; temp = new Node(); temp.data = s; temp.nextNode = head; head = temp; } totalNode++; } public int count { get { return totalNode; } } public char gethead { get { return head.data; } } public void traverse() { Node temp = head; while(temp != null) { Console.Write(temp.data + " "); temp = temp.nextNode; } } public void reverse() { Node q = null; Node p = this.head; while(p!=null) { Node r=p; p=p.nextNode; r.nextNode=q; q=r; } this.head = q; } } } } Here's what I have so far in trying to work it into Node's constructors: using System; using System.Collections.Generic; using System.Text; using System.IO; namespace PalindromeTester { class Program { static void Main(string[] args) { //Node myList = new Node(); //TextReader tr = new StreamReader("data.txt"); //string line; //while ((line = tr.ReadLine()) != null) //{ // Console.WriteLine(line); //} //tr.Close(); Node myNode = new Node("hello"); Console.Out.WriteLine(myNode.count); myNode.reverse(); myNode.traverse(); // Console.Out.WriteLine(myNode.gethead); Console.In.ReadLine(); } class Node { private char letter; private Node next; private Node head; private int totalNode; public Node() { head = null; totalNode = 0; } public Node(char c) { if (head == null) { head = new Node(); head.data = c; } else { Node temp; temp = new Node(); temp.data = c; temp.nextNode = head; head = temp; } totalNode++; } public Node(string s) { foreach (char x in s) { new Node(x); } } public char data { get { return letter; } set { letter = value; } } public Node nextNode { get { return next; } set { next = value; } } public void reverse() { Node q = null; Node p = this.head; while (p != null) { Node r = p; p = p.nextNode; r.nextNode = q; q = r; } this.head = q; } public void traverse() { Node temp = head; while (temp != null) { Console.Write(temp.data + " "); temp = temp.nextNode; } } public int count { get { return totalNode; } } } } } Ideally, the only constructors and methods I would be left with are Node(), Node(char c), Node(string s), Node reserve() and I'll be reworking traverse into a ToString overload. Any suggestions?

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  • C# Reading and Writing a Char[] to and from a Byte[] - Updated with Solution

    - by Simon G
    Hi, I have a byte array of around 10,000 bytes which is basically a blob from delphi that contains char, string, double and arrays of various types. This need to be read in and updated via C#. I've created a very basic reader that gets the byte array from the db and converts the bytes to the relevant object type when accessing the property which works fine. My problem is when I try to write to a specific char[] item, it doesn't seem to update the byte array. I've created the following extensions for reading and writing: public static class CharExtension { public static byte ToByte( this char c ) { return Convert.ToByte( c ); } public static byte ToByte( this char c, int position, byte[] blob ) { byte b = c.ToByte(); blob[position] = b; return b; } } public static class CharArrayExtension { public static byte[] ToByteArray( this char[] c ) { byte[] b = new byte[c.Length]; for ( int i = 1; i < c.Length; i++ ) { b[i] = c[i].ToByte(); } return b; } public static byte[] ToByteArray( this char[] c, int positon, int length, byte[] blob ) { byte[] b = c.ToByteArray(); Array.Copy( b, 0, blob, positon, length ); return b; } } public static class ByteExtension { public static char ToChar( this byte[] b, int position ) { return Convert.ToChar( b[position] ); } } public static class ByteArrayExtension { public static char[] ToCharArray( this byte[] b, int position, int length ) { char[] c = new char[length]; for ( int i = 0; i < length; i++ ) { c[i] = b.ToChar( position ); position += 1; } return c; } } to read and write chars and char arrays my code looks like: Byte[] _Blob; // set from a db field public char ubin { get { return _tariffBlob.ToChar( 14 ); } set { value.ToByte( 14, _Blob ); } } public char[] usercaplas { get { return _tariffBlob.ToCharArray( 2035, 10 ); } set { value.ToByteArray( 2035, 10, _Blob ); } } So to write to the objects I can do: ubin = 'C'; // this will update the byte[] usercaplas = new char[10] { 'A', 'B', etc. }; // this will update the byte[] usercaplas[3] = 'C'; // this does not update the byte[] I know the reason is that the setter property is not being called but I want to know is there a way around this using code similar to what I already have? I know a possible solution is to use a private variable called _usercaplas that I set and update as needed however as the byte array is nearly 10,000 bytes in length the class is already long and I would like a simpler approach as to reduce the overall code length and complexity. Thank Solution Here's my solution should anyone want it. If you have a better way of doing then let me know please. First I created a new class for the array: public class CharArrayList : ArrayList { char[] arr; private byte[] blob; private int length = 0; private int position = 0; public CharArrayList( byte[] blob, int position, int length ) { this.blob = blob; this.length = length; this.position = position; PopulateInternalArray(); SetArray(); } private void PopulateInternalArray() { arr = blob.ToCharArray( position, length ); } private void SetArray() { foreach ( char c in arr ) { this.Add( c ); } } private void UpdateInternalArray() { this.Clear(); SetArray(); } public char this[int i] { get { return arr[i]; } set { arr[i] = value; UpdateInternalArray(); } } } Then I created a couple of extension methods to help with converting to a byte[] public static byte[] ToByteArray( this CharArrayList c ) { byte[] b = new byte[c.Count]; for ( int i = 0; i < c.Count; i++ ) { b[i] = Convert.ToChar( c[i] ).ToByte(); } return b; } public static byte[] ToByteArray( this CharArrayList c, byte[] blob, int position, int length ) { byte[] b = c.ToByteArray(); Array.Copy( b, 0, blob, position, length ); return b; } So to read and write to the object: private CharArrayList _usercaplass; public CharArrayList usercaplas { get { if ( _usercaplass == null ) _usercaplass = new CharArrayList( _tariffBlob, 2035, 100 ); return _usercaplass; } set { _usercaplass = value; _usercaplass.ToByteArray( _tariffBlob, 2035, 100 ); } } As mentioned before its not an ideal solutions as I have to have private variables and extra code in the setter but I couldnt see a way around it.

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  • iphone - UIViewController header view errors

    - by Fiona
    Hi there, So to give a little background: I've an app that has a UITableViewController- (ContactDetailViewController) In this view at the top, I require a few labels and buttons, followed by a group style tableview. So I've created a nib file containing these elements. (ContactHeaderView.xib) Then in the viewDidLoad of ContactDetailViewController I've loaded this nib as the headerView. See implementation file below: #import "ContactDetailViewController.h" #import "DisplayInfoViewController.h" #import "ActionViewController.h" @implementation ContactDetailViewController @synthesize name; @synthesize date; @synthesize nextAction; @synthesize nameLabel; @synthesize usernameLabel; @synthesize nextActionTextField; @synthesize dateLabel; @synthesize contactInfoButton; @synthesize backgroundInfoButton; @synthesize actionDoneButton; - (void)viewDidLoad { [super viewDidLoad]; } - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Release any cached data, images, etc that aren't in use. } - (void)viewDidUnload { // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } #pragma mark Table view methods - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 1; } // Customize the number of rows in the table view. - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 3; } - (UIView *) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section { if (section == 0){ UIViewController *chv = [[[UIViewController alloc] initWithNibName:@"ContactHeaderView" bundle:nil] autorelease]; // self.nameLabel.text = self.name; return chv.view; }else{ return nil; } } - (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section{ return 300.0; } // Customize the appearance of table view cells. - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } // Set up the cell... return cell; } - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { // Navigation logic may go here. Create and push another view controller. // AnotherViewController *anotherViewController = [[AnotherViewController alloc] initWithNibName:@"AnotherView" bundle:nil]; // [self.navigationController pushViewController:anotherViewController]; // [anotherViewController release]; } /* // Override to support conditional editing of the table view. - (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath { // Return NO if you do not want the specified item to be editable. return YES; } */ - (void)dealloc { [name release]; [date release]; [nextAction release]; [nameLabel release]; [usernameLabel release]; [nextActionTextField release]; [dateLabel release]; [contactInfoButton release]; [backgroundInfoButton release]; [actionDoneButton release]; [super dealloc]; } -(IBAction)displayContactInfo:(id)sender{ DisplayInfoViewController *divc = [[DisplayInfoViewController alloc] init]; divc.textView = self.nextAction; divc.title = @"Contact Info"; [self.navigationController pushViewController:divc animated:YES]; [divc release]; } -(IBAction)displayBackgroundInfo:(id)sender{ DisplayInfoViewController *divc = [[DisplayInfoViewController alloc] init]; divc.textView = self.nextAction; divc.title = @"Background Info"; [self.navigationController pushViewController:divc animated:YES]; [divc release]; } -(IBAction)actionDone:(id)sender{ ActionViewController *avc = [[ActionViewController alloc] init]; avc.title = @"Action"; avc.nextAction = self.nextAction; [self.navigationController pushViewController:avc animated:YES]; [avc release]; } @end Here's the Header File: #import <UIKit/UIKit.h> @interface ContactDetailViewController : UITableViewController { NSString *name; NSString *date; NSString *nextAction; IBOutlet UILabel *nameLabel; IBOutlet UILabel *usernameLabel; IBOutlet UITextField *nextActionTextField; IBOutlet UILabel *dateLabel; IBOutlet UIButton *contactInfoButton; IBOutlet UIButton *backgroundInfoButton; IBOutlet UIButton *actionDoneButton; } @property (nonatomic, retain) NSString *name; @property (nonatomic, retain) NSString *date; @property (nonatomic, retain) NSString *nextAction; @property (nonatomic, retain) IBOutlet UILabel *nameLabel; @property (nonatomic, retain) IBOutlet UILabel *usernameLabel; @property (nonatomic, retain) IBOutlet UITextField *nextActionTextField; @property (nonatomic, retain) IBOutlet UILabel *dateLabel; @property (nonatomic, retain) IBOutlet UIButton *contactInfoButton; @property (nonatomic, retain) IBOutlet UIButton *backgroundInfoButton; @property (nonatomic, retain) IBOutlet UIButton *actionDoneButton; -(IBAction)displayContactInfo: (id)sender; -(IBAction)displayBackgroundInfo: (id)sender; -(IBAction)actionDone: (id)sender; @end However when I run it, I get the following error message: * Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key nameLabel.' In IB I've hooked up the labels/buttons/textbox to the File's Owner (set the File's Owner Class to: ContactDetailViewController) Anyone any idea what I'm doing wrong? Regards, Fiona

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  • Making swap faster, easier to use and exception-safe

    - by FredOverflow
    I could not sleep last night and started thinking about std::swap. Here is the familiar C++98 version: template <typename T> void swap(T& a, T& b) { T c(a); a = b; b = c; } If a user-defined class Foo uses external ressources, this is inefficient. The common idiom is to provide a method void Foo::swap(Foo& other) and a specialization of std::swap<Foo>. Note that this does not work with class templates since you cannot partially specialize a function template, and overloading names in the std namespace is illegal. The solution is to write a template function in one's own namespace and rely on argument dependent lookup to find it. This depends critically on the client to follow the "using std::swap idiom" instead of calling std::swap directly. Very brittle. In C++0x, if Foo has a user-defined move constructor and a move assignment operator, providing a custom swap method and a std::swap<Foo> specialization has little to no performance benefit, because the C++0x version of std::swap uses efficient moves instead of copies: #include <utility> template <typename T> void swap(T& a, T& b) { T c(std::move(a)); a = std::move(b); b = std::move(c); } Not having to fiddle with swap anymore already takes a lot of burden away from the programmer. Current compilers do not generate move constructors and move assignment operators automatically yet, but as far as I know, this will change. The only problem left then is exception-safety, because in general, move operations are allowed to throw, and this opens up a whole can of worms. The question "What exactly is the state of a moved-from object?" complicates things further. Then I was thinking, what exactly are the semantics of std::swap in C++0x if everything goes fine? What is the state of the objects before and after the swap? Typically, swapping via move operations does not touch external resources, only the "flat" object representations themselves. So why not simply write a swap template that does exactly that: swap the object representations? #include <cstring> template <typename T> void swap(T& a, T& b) { unsigned char c[sizeof(T)]; memcpy( c, &a, sizeof(T)); memcpy(&a, &b, sizeof(T)); memcpy(&b, c, sizeof(T)); } This is as efficient as it gets: it simply blasts through raw memory. It does not require any intervention from the user: no special swap methods or move operations have to be defined. This means that it even works in C++98 (which does not have rvalue references, mind you). But even more importantly, we can now forget about the exception-safety issues, because memcpy never throws. I can see two potential problems with this approach: First, not all objects are meant to be swapped. If a class designer hides the copy constructor or the copy assignment operator, trying to swap objects of the class should fail at compile-time. We can simply introduce some dead code that checks whether copying and assignment are legal on the type: template <typename T> void swap(T& a, T& b) { if (false) // dead code, never executed { T c(a); // copy-constructible? a = b; // assignable? } unsigned char c[sizeof(T)]; std::memcpy( c, &a, sizeof(T)); std::memcpy(&a, &b, sizeof(T)); std::memcpy(&b, c, sizeof(T)); } Any decent compiler can trivially get rid of the dead code. (There are probably better ways to check the "swap conformance", but that is not the point. What matters is that it's possible). Second, some types might perform "unusual" actions in the copy constructor and copy assignment operator. For example, they might notify observers of their change. I deem this a minor issue, because such kinds of objects probably should not have provided copy operations in the first place. Please let me know what you think of this approach to swapping. Would it work in practice? Would you use it? Can you identify library types where this would break? Do you see additional problems? Discuss!

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  • Zend_Form validation problem

    - by GrumpyCanuck
    I am having problems getting validation to work for a form built using Zend_Form. The idea is this: I have two dropdown. One is a list of players. The other is a list of free agents who play the same position as the player. I am using an onChange javascript callback to run some Ajax code that replaces the free agent list dropdown with a new one at the position of the player they've selected from the player dropdown. Now, perhaps this is the wrong way, but I built the form by creating an instance of Zend_Form and then creating all these setX methods that add elements to the form. My reasoning was that I wanted to display certain elements in specific places on the page, not just output $this-form on my template. The problem appears to be when I get the form post back, the validator seems to not know about the validation rule I set up for the free agent drop down. Here's some relevant code to look at. I'm a relative ZF n00b so feel free to tell me I am not doing things the ZF way if it leaps out at you. The action in the controller: public function indexAction() { if ($this->getRequest()->isPost()) { $form = new Baseball_Form_Transactions(); if ($form->isValid($this->_request->getPost())) { $data = $this->_request->getPost(); $leagueInfo = Doctrine::getTable('League')->findOneByShortName($data['shortLeagueName'])->toArray(); // Create the request top drop an existing player $transactionInfo = array( 'league_id' => $leagueInfo['id'], 'team_id' => $data['teamId'], 'player_id' => $data['players'], 'type' => 'drop', 'target_team_id' => 0, 'transaction_date' => date('Y-m-d H:m:s') ); $transaction = new Transaction(); $transaction->fromArray($transactionInfo); $transaction->save(); // Now we do the request to add a player $transactionInfo['team_id'] = 0; $transactionInfo['player_id'] = $data['freeAgents']; $transactionInfo['target_team_id'] = $data['teamId']; $transactionInfo['type'] = 'add'; $transaction = new Transaction(); $transaction->fromArray($transactionInfo); $transaction->save(); $this->_flashMessenger->addMessage('Added transaction'); } } $options = array( 'teamId' => $this->teamId, 'position' => 'C', 'leagueShortName' => $this->league ); $this->transactionForm->setMyPlayers($options); $this->transactionForm->setFreeAgents($options); $this->transactionForm->setTeamId($options); $this->transactionForm->setShortLeagueName($options); $this->view->transactionForm = $this->transactionForm; $this->view->messages = $this->_flashMessenger->getMessages(); $transaction = new Transaction(); $this->view->transactions = $transaction->byTeam($options); } Next we have the form itself public function setMyPlayers($options) { $data = Doctrine::getTable('Team')->find($options['teamId']); $players = array(); foreach ($data->Players->toArray() as $player) { $players[$player['id']] = "{$player['position']} - {$player['first_name']} {$player['last_name']}"; } $playersSelect = new Zend_Form_Element_Select( 'players', array( 'required' => true, 'label' => 'Players', 'multiOptions' => $players, ) ); $this->addElement($playersSelect); } public function setFreeAgents($options) { $q = Doctrine_Query::create() ->select('CONCAT(p.first_name, " ", p.last_name) as full_name, p.id, p.position') ->from('Player p') ->leftJoin('p.Teams t') ->leftJoin('t.League l ON l.short_name = ?', $options['leagueShortName']) ->where('t.id IS NULL') ->andWhere('p.position = ?', $options['position']) ->orderBy('p.last_name'); $q->setHydrationMode(Doctrine_Core::HYDRATE_ARRAY); $data = $q->execute(); $freeAgents = array(); foreach ($data as $player) { $freeAgents[$player['id']] = $player['full_name']; } $freeAgentsSelect = new Zend_Form_Element_Select( 'freeAgents', array( 'label' => 'Free Agents', 'multiOptions' => $freeAgents, 'size' => 15 ) ); $freeAgentsSelect->setRequired(true); $this->addElement($freeAgentsSelect); } public function setShortLeagueName($options) { $shortLeagueNameHidden = new Zend_Form_Element_Hidden( 'shortLeagueName', array('value' => $options['leagueShortName']) ); $this->addElement($shortLeagueNameHidden); } public function setTeamId($options) { $teamIdHidden = new Zend_Form_Element_Hidden( 'teamId', array('value' => $options['teamId']) ); $this->addElement($teamIdHidden); } There is no init or __construct() method in the form. My problem seems simple enough: reject the form contents as invalid if they have not selected someone from the free agent list. Right now, it sails through as valid. I've spent some considerable time searching online for an answer, and haven't been able to find it. Thanks in advance for any help.

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  • Pointers to Derived Class Objects Losing vfptr

    - by duckworthd
    To begin, I am trying to write a run-of-the-mill, simple Ray Tracer. In my Ray Tracer, I have multiple types of geometries in the world, all derived from a base class called "SceneObject". I've included the header for it here. /** Interface for all objects that will appear in a scene */ class SceneObject { public: mat4 M, M_inv; Color c; SceneObject(); ~SceneObject(); /** The transformation matrix to be applied to all points of this object. Identity leaves the object in world frame. */ void setMatrix(mat4 M); void setMatrix(MatrixStack mStack); void getMatrix(mat4& M); /** The color of the object */ void setColor(Color c); void getColor(Color& c); /** Alter one portion of the color, leaving the rest as they were. */ void setDiffuse(vec3 rgb); void setSpecular(vec3 rgb); void setEmission(vec3 rgb); void setAmbient(vec3 rgb); void setShininess(double s); /** Fills 'inter' with information regarding an intersection between this object and 'ray'. Ray should be in world frame. */ virtual void intersect(Intersection& inter, Ray ray) = 0; /** Returns a copy of this SceneObject */ virtual SceneObject* clone() = 0; /** Print information regarding this SceneObject for debugging */ virtual void print() = 0; }; As you can see, I've included a couple virtual functions to be implemented elsewhere. In this case, I have only two derived class -- Sphere and Triangle, both of which implement the missing member functions. Finally, I have a Parser class, which is full of static methods that do the actual "Ray Tracing" part. Here's a couple snippets for relevant portions void Parser::trace(Camera cam, Scene scene, string outputFile, int maxDepth) { int width = cam.getNumXPixels(); int height = cam.getNumYPixels(); vector<vector<vec3>> colors; colors.clear(); for (int i = 0; i< width; i++) { vector<vec3> ys; for (int j = 0; j<height; j++) { Intersection intrsct; Ray ray; cam.getRay(ray, i, j); vec3 color; printf("Obtaining color for Ray[%d,%d]\n", i,j); getColor(color, scene, ray, maxDepth); ys.push_back(color); } colors.push_back(ys); } printImage(colors, width, height, outputFile); } void Parser::getColor(vec3& color, Scene scene, Ray ray, int numBounces) { Intersection inter; scene.intersect(inter,ray); if(inter.isIntersecting()){ Color c; inter.getColor(c); c.getAmbient(color); } else { color = vec3(0,0,0); } } Right now, I've forgone the true Ray Tracing part and instead simply return the color of the first object hit, if any. As you have no doubt noticed, the only way the computer knows that a ray has intersected an object is through Scene.intersect(), which I also include. void Scene::intersect(Intersection& i, Ray r) { Intersection result; result.setDistance(numeric_limits<double>::infinity()); result.setIsIntersecting(false); double oldDist; result.getDistance(oldDist); /* Cycle through all objects, making result the closest one */ for(int ind=0; ind<objects.size(); ind++){ SceneObject* thisObj = objects[ind]; Intersection betterIntersect; thisObj->intersect(betterIntersect, r); double newDist; betterIntersect.getDistance(newDist); if (newDist < oldDist){ result = betterIntersect; oldDist = newDist; } } i = result; } Alright, now for the problem. I begin by creating a scene and filling it with objects outside of the Parser::trace() method. Now for some odd reason, I cast Ray for i=j=0 and everything works wonderfully. However, by the time the second ray is cast all of the objects stored in my Scene no longer recognize their vfptr's! I stepped through the code with a debugger and found that the information to all the vfptr's are lost somewhere between the end of getColor() and the continuation of the loop. However, if I change the arguments of getColor() to use a Scene& instead of a Scene, then no loss occurs. What crazy voodoo is this?

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  • Error using CreateFileMapping - C

    - by Jamie Keeling
    Hello, I am using the tutorial on this MSDN link to implement a way of transferring data from one process to another. Although I was advised in an earlier question to use the Pipe methods, due to certain constraints I have no choice but to use the CreateFileMapping method. Now, i've succesfully managed to make two seperate window form projects within the same solution and by editing some properties both of the forms load at the same time. Furthermore I have managed to implement the code given in the MSDN sample into the first (Producer) and second (Consumer) program without any compilation errors. The problem I am having now is when I run the first program and try to create the handle to the mapped file, I am given an error saying it was unsuccesful and I do not understand why this is happening. I have added both the Producer and Consumer code files to demonstrate what I am trying to do. Producer: #include <windows.h> #include <stdio.h> #include <conio.h> //File header definitions #define IDM_FILE_ROLLDICE 1 #define IDM_FILE_QUIT 2 #define BUF_SIZE 256 TCHAR szName[]=TEXT("Global\\MyFileMappingObject"); TCHAR szMsg[]=TEXT("Message from first process!"); void AddMenus(HWND); LRESULT CALLBACK WindowFunc(HWND, UINT, WPARAM, LPARAM); ////Standard windows stuff - omitted to save space. ////////////////////// // WINDOWS FUNCTION // ////////////////////// LRESULT CALLBACK WindowFunc(HWND hMainWindow, UINT message, WPARAM wParam, LPARAM lParam) { WCHAR buffer[256]; LPCTSTR pBuf; struct DiceData storage; HANDLE hMapFile; switch(message) { case WM_CREATE: { // Create Menus AddMenus(hMainWindow); } break; case WM_COMMAND: // Intercept menu choices switch(LOWORD(wParam)) { case IDM_FILE_ROLLDICE: { //Roll dice and store results in variable //storage = RollDice(); ////Copy results to buffer //swprintf(buffer,255,L"Dice 1: %d, Dice 2: %d",storage.dice1,storage.dice2); ////Show via message box //MessageBox(hMainWindow,buffer,L"Dice Result",MB_OK); hMapFile = CreateFileMapping( (HANDLE)0xFFFFFFFF, // use paging file NULL, // default security PAGE_READWRITE, // read/write access 0, // maximum object size (high-order DWORD) BUF_SIZE, // maximum object size (low-order DWORD) szName); // name of mapping object if (hMapFile == NULL) { MessageBox(hMainWindow,L"Could not create file mapping object",L"Error",NULL); return 1; } pBuf = (LPTSTR) MapViewOfFile(hMapFile, // handle to map object FILE_MAP_ALL_ACCESS, // read/write permission 0, 0, BUF_SIZE); if (pBuf == NULL) { MessageBox(hMainWindow,L"Could not map view of file",L"Error",NULL); CloseHandle(hMapFile); return 1; } CopyMemory((PVOID)pBuf, szMsg, (_tcslen(szMsg) * sizeof(TCHAR))); _getch(); UnmapViewOfFile(pBuf); CloseHandle(hMapFile); } break; case IDM_FILE_QUIT: SendMessage(hMainWindow, WM_CLOSE, 0, 0); break; } break; case WM_DESTROY: PostQuitMessage(0); break; } return DefWindowProc(hMainWindow, message, wParam, lParam); } // //Setup menus // Consumer: #include <windows.h> #include <stdio.h> #include <conio.h> //File header definitions #define IDM_FILE_QUIT 1 #define IDM_FILE_POLL 2 #define BUF_SIZE 256 TCHAR szName[]=TEXT("Global\\MyFileMappingObject"); //Prototypes void AddMenus(HWND); LRESULT CALLBACK WindowFunc(HWND, UINT, WPARAM, LPARAM); //More standard windows creation, again omitted. ////////////////////// // WINDOWS FUNCTION // ////////////////////// LRESULT CALLBACK WindowFunc(HWND hMainWindow, UINT message, WPARAM wParam, LPARAM lParam) { HANDLE hMapFile; LPCTSTR pBuf; switch(message) { case WM_CREATE: { // Create Menus AddMenus(hMainWindow); break; } case WM_COMMAND: { // Intercept menu choices switch(LOWORD(wParam)) { case IDM_FILE_POLL: { hMapFile = OpenFileMapping( FILE_MAP_ALL_ACCESS, // read/write access FALSE, // do not inherit the name szName); // name of mapping object if (hMapFile == NULL) { MessageBox(hMainWindow,L"Could not open file mapping object",L"Error",NULL); return 1; } pBuf = (LPTSTR) MapViewOfFile(hMapFile, // handle to map object FILE_MAP_ALL_ACCESS, // read/write permission 0, 0, BUF_SIZE); if (pBuf == NULL) { MessageBox(hMainWindow,L"Could not map view of file",L"Error",NULL); CloseHandle(hMapFile); return 1; } MessageBox(NULL, pBuf, TEXT("Process2"), MB_OK); UnmapViewOfFile(pBuf); CloseHandle(hMapFile); break; } case IDM_FILE_QUIT: SendMessage(hMainWindow, WM_CLOSE, 0, 0); break; } break; } case WM_DESTROY: { PostQuitMessage(0); break; } } return DefWindowProc(hMainWindow, message, wParam, lParam); } // //Setup menus // It's by no means tidy and final but it's just a start, thanks for any help.

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  • Transaction issue in java with hibernate - latest entries not pulled from database

    - by Gearóid
    Hi, I'm having what seems to be a transactional issue in my application. I'm using Java 1.6 and Hibernate 3.2.5. My application runs a monthly process where it creates billing entries for a every user in the database based on their monthly activity. These billing entries are then used to create Monthly Bill object. The process is: Get users who have activity in the past month Create the relevant billing entries for each user Get the set of billing entries that we've just created Create a Monthly Bill based on these entries Everything works fine until Step 3 above. The Billing Entries are correctly created (I can see them in the database if I add a breakpoint after the Billing Entry creation method), but they are not pulled out of the database. As a result, an incorrect Monthly Bill is generated. If I run the code again (without clearing out the database), new Billing Entries are created and Step 3 pulls out the entries created in the first run (but not the second run). This, to me, is very confusing. My code looks like the following: for (User user : usersWithActivities) { createBillingEntriesForUser(user.getId()); userBillingEntries = getLastMonthsBillingEntriesForUser(user.getId()); createXMLBillForUser(user.getId(), userBillingEntries); } The methods called look like the following: @Transactional public void createBillingEntriesForUser(Long id) { UserManager userManager = ManagerFactory.getUserManager(); User user = userManager.getUser(id); List<AccountEvent> events = getLastMonthsAccountEventsForUser(id); BillingEntry entry = new BillingEntry(); if (null != events) { for (AccountEvent event : events) { if (event.getEventType().equals(EventType.ENABLE)) { Calendar cal = Calendar.getInstance(); Date eventDate = event.getTimestamp(); cal.setTime(eventDate); double startDate = cal.get(Calendar.DATE); double numOfDaysInMonth = cal.getActualMaximum(Calendar.DAY_OF_MONTH); double numberOfDaysInUse = numOfDaysInMonth - startDate; double fractionToCharge = numberOfDaysInUse/numOfDaysInMonth; BigDecimal amount = BigDecimal.valueOf(fractionToCharge * Prices.MONTHLY_COST); amount.scale(); entry.setAmount(amount); entry.setUser(user); entry.setTimestamp(eventDate); userManager.saveOrUpdate(entry); } } } } @Transactional public Collection<BillingEntry> getLastMonthsBillingEntriesForUser(Long id) { if (log.isDebugEnabled()) log.debug("Getting all the billing entries for last month for user with ID " + id); //String queryString = "select billingEntry from BillingEntry as billingEntry where billingEntry>=:firstOfLastMonth and billingEntry.timestamp<:firstOfCurrentMonth and billingEntry.user=:user"; String queryString = "select be from BillingEntry as be join be.user as user where user.id=:id and be.timestamp>=:firstOfLastMonth and be.timestamp<:firstOfCurrentMonth"; //This parameter will be the start of the last month ie. start of billing cycle SearchParameter firstOfLastMonth = new SearchParameter(); firstOfLastMonth.setTemporalType(TemporalType.DATE); //this parameter holds the start of the CURRENT month - ie. end of billing cycle SearchParameter firstOfCurrentMonth = new SearchParameter(); firstOfCurrentMonth.setTemporalType(TemporalType.DATE); Query query = super.entityManager.createQuery(queryString); query.setParameter("firstOfCurrentMonth", getFirstOfCurrentMonth()); query.setParameter("firstOfLastMonth", getFirstOfLastMonth()); query.setParameter("id", id); List<BillingEntry> entries = query.getResultList(); return entries; } public MonthlyBill createXMLBillForUser(Long id, Collection<BillingEntry> billingEntries) { BillingHistoryManager manager = ManagerFactory.getBillingHistoryManager(); UserManager userManager = ManagerFactory.getUserManager(); MonthlyBill mb = new MonthlyBill(); User user = userManager.getUser(id); mb.setUser(user); mb.setTimestamp(new Date()); Set<BillingEntry> entries = new HashSet<BillingEntry>(); entries.addAll(billingEntries); String xml = createXmlForMonthlyBill(user, entries); mb.setXmlBill(xml); mb.setBillingEntries(entries); MonthlyBill bill = (MonthlyBill) manager.saveOrUpdate(mb); return bill; } Help with this issue would be greatly appreciated as its been wracking my brain for weeks now! Thanks in advance, Gearoid.

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  • Nhibernate multilevel hierarchy save error?

    - by nisbus
    Hi, I have a database with a 6 level hierarchy and a domain model on top of that. something like this: Category -SubCategory -Container -DataDescription | Meta data -Data The mapping I'm using follows the following pattern: <class name="Category, Sample" table="Categories"> <id name="Id" column="Id" type="System.Int32" unsaved-value="0"> <generator class="native"/> </id> <property name="Name" access="property" type="String" column="Name"/> <property name="Metadata" access="property" type="String" column="Metadata"/> <bag name="SubCategories" cascade="save-update" lazy="true" inverse="true"> <key column="Id" foreign-key="category_subCategory_fk"/> <one-to-many class="SubCategory, Sample" /> </bag> </class> <class name="SubCategory, Sample" table="SubCategories"> <id name="Id" column="Id" type="System.Int32" unsaved-value="0"> <generator class="native"/> </id> <many-to-one name="Category" class="Category, Sample" foreign-key="subCat_category_fk"/> <property name="Name" access="property" type="String"/> <property name="Metadata" access="property" type="String"/> <bag name="Containers" inverse="true" cascade="save-update" lazy="true"> <key column="Id" foreign-key="subCat_container_fk" /> <one-to-many class="Container, Sample" /> </bag> </class> <class name="Container, Sample" table="Containers"> <id name="Id" column="Id" type="System.Int32" unsaved-value="0"> <generator class="assigned"/> </id> <many-to-one name="SubCategory" class="SubCategory,Sample" foreign-key="container_subCat_fk"/> <property name="Name" access="property" type="String" column="Name"/> <bag name="DataDescription" cascade="all" lazy="true" inverse="true"> <key column="Id" foreign-key="container_ DataDescription_fk"/> <one-to-many class="DataDescription, Sample" /> </bag> <bag name="MetaData" cascade="all" lazy="true" inverse="true"> <key column="Id" foreign-key="container_metadata_cat_fk"/> <one-to-many class="MetaData, Sample" /> </bag> </class> For some reason when I try to save the category (with the subcategory, container etc. attached) I get a foreign key violation from the database. The code is something like this (Pseudo). var category = new Category(); var subCategory = new SubCategory(); var container = new Container(); var dataDescription = new DataDescription(); var metaData = new MetaData(); category.AddSubCategory(subCategory); subCategory.AddContainer(container); container.AddDataDescription(dataDescription); container.AddMetaData(metaData); Session.Save(category); Here is the log from this test : DEBUG NHibernate.SQL - INSERT INTO Categories (Name, Metadata) VALUES (@p0, @p1); select SCOPE_IDENTITY(); @p0 = 'Unit test', @p1 = 'unit test' DEBUG NHibernate.SQL - INSERT INTO SubCategories (Category, Name, Metadata) VALUES (@p0, @p1, @p2); select SCOPE_IDENTITY(); @p0 = '1', @p1 = 'Unit test', @p2 = 'unit test' DEBUG NHibernate.SQL - INSERT INTO Containers (SubCategory, Name, Frequency, Scale, Measurement, Currency, Metadata, Id) VALUES (@p0, @p1, @p2, @p3, @p4, @p5, @p6, @p7); @p0 = '1', @p1 = 'Unit test', @p2 = '15', @p3 = '1', @p4 = '1', @p5 = '1', @p6 = 'unit test', @p7 = '0' ERROR NHibernate.Util.ADOExceptionReporter - The INSERT statement conflicted with the FOREIGN KEY constraint "subCat_container_fk". The conflict occurred in database "Sample", table "dbo.SubCategories", column 'Id'. The methods for adding items to objects is always as follows: public void AddSubCategory(ISubCategory subCategory) { subCategory.Category = this; SubCategories.Add(subCategory); } What am I missing?? Thanks, nisbus

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  • 405: Method Not Allowed WCF

    - by luiscarlosch
    I can perfectly call a WCF web method from localhost. I published to this server: http://luiscarlosch.com/WebFormClean.aspx (only firefox or chrome) with the Visual Studio publishing tool and it works fine. The problem is when a try to access it from another computer. I get the 405: Method Not Allowed. But It doest make sense because It works fine when i access it remotely from the publisher computer as I said. Any idea? [ServiceContract(Namespace = "")] [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] public class ContactProxy { [WebGet()] [OperationContract] public Contact getByID(int IDContact) { Contact contact = new Contact(IDContact); return contact; } [OperationContract] public EntityData insertEntityData(int IDEntityDataFieldType, int IDContact, String value) { //Contact contact = new Contact(); // contact.insertEntityData(IDEntityDataFieldType, IDContact, value); EntityData entityData = new EntityData(); entityData.save(IDEntityDataFieldType, IDContact, value); return entityData; } } Neither method seems to work. I just noticed some user were able to access http://luiscarlosch.com/WebFormClean.aspx because they change the values. So. some clients can read the methods but some cant. This should be happening. Web Config <?xml version="1.0"?> <configuration> <configSections> </configSections> <connectionStrings> <add name="ApplicationServices" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\aspnetdb.mdf;User Instance=true" providerName="System.Data.SqlClient" /> </connectionStrings> <system.web> <compilation debug="true" targetFramework="4.0" /> <customErrors mode="Off"/> <authentication mode="Forms"> <forms loginUrl="~/Account/Login.aspx" timeout="2880" /> </authentication> <membership> <providers> <clear/> <add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="ApplicationServices" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/" /> </providers> </membership> <profile> <providers> <clear/> <add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="ApplicationServices" applicationName="/"/> </providers> </profile> <roleManager enabled="false"> <providers> <clear/> <add name="AspNetSqlRoleProvider" type="System.Web.Security.SqlRoleProvider" connectionStringName="ApplicationServices" applicationName="/" /> <add name="AspNetWindowsTokenRoleProvider" type="System.Web.Security.WindowsTokenRoleProvider" applicationName="/" /> </providers> </roleManager> </system.web> <system.webServer> <modules runAllManagedModulesForAllRequests="true"/> </system.webServer> <system.serviceModel> <behaviors> <serviceBehaviors> <behavior name="MyServiceTypeBehaviors" > <serviceMetadata httpGetEnabled="true" /> </behavior> </serviceBehaviors> <endpointBehaviors> <behavior name="WebApplicationTest.WCFProxy.EmployeeProxyAspNetAjaxBehavior"> <enableWebScript /> </behavior> <behavior name="WebApplicationTest.WCFProxy.EntityDataFieldCollectionProxyAspNetAjaxBehavior"> <enableWebScript /> </behavior> <behavior name="WebApplicationTest.WCFProxy.Service1AspNetAjaxBehavior"> <enableWebScript /> </behavior> <behavior name="WebApplicationTest.WCFProxy.ContactProxyAspNetAjaxBehavior"> <enableWebScript /> </behavior> </endpointBehaviors> </behaviors> <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" /> <services> <service name="WebApplicationTest.WCFProxy.EmployeeProxy" behaviorConfiguration="MyServiceTypeBehaviors" > <endpoint address="" behaviorConfiguration="WebApplicationTest.WCFProxy.EmployeeProxyAspNetAjaxBehavior" binding="webHttpBinding" contract="WebApplicationTest.WCFProxy.EmployeeProxy" /> <endpoint contract="IMetadataExchange" binding="mexHttpBinding" address="mex" /> </service> <service name="WebApplicationTest.WCFProxy.EntityDataFieldCollectionProxy" behaviorConfiguration="MyServiceTypeBehaviors" > <endpoint address="" behaviorConfiguration="WebApplicationTest.WCFProxy.EntityDataFieldCollectionProxyAspNetAjaxBehavior" binding="webHttpBinding" contract="WebApplicationTest.WCFProxy.EntityDataFieldCollectionProxy" /> <endpoint contract="IMetadataExchange" binding="mexHttpBinding" address="mex" /> </service> <service name="WebApplicationTest.WCFProxy.Service1"> <endpoint address="" behaviorConfiguration="WebApplicationTest.WCFProxy.Service1AspNetAjaxBehavior" binding="webHttpBinding" contract="WebApplicationTest.WCFProxy.Service1" /> </service> <service name="WebApplicationTest.WCFProxy.ContactProxy" behaviorConfiguration="MyServiceTypeBehaviors" ><!--new--> <endpoint address="" behaviorConfiguration="WebApplicationTest.WCFProxy.ContactProxyAspNetAjaxBehavior" binding="webHttpBinding" contract="WebApplicationTest.WCFProxy.ContactProxy" /> <endpoint contract="IMetadataExchange" binding="mexHttpBinding" address="mex" /> </service> </services> <bindings /> <client /> </system.serviceModel> </configuration>

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  • When i close window cookies are destroying in flex

    - by praveen
    Hi, I am using external interface to store cookies in client side of application. Like I have created a cookie in html and i am using those methods in flex using External Interface. I am saving a username in cookie when I re use cookie is displaying, I have deployed in server and i ran like http://localhost/[Path]/index.html.in this html I am embedded swf file and I have saved cookie in html JavaScript, now if I open this url cookie is saving if I open a new window what ever the cookies are a raised and it is loading from start. for cookies saving i am using this code in flex:`package Name{ import flash.external.ExternalInterface; /** * The Cookie class provides a simple way to create or access * cookies in the embedding HTML document of the application. * */ public class Cookies { /** * Flag if the class was properly initialized. */ private static var _initialized:Boolean = false; /** * Name of the cookie. */ private var _name:String; /** * Contents of the cookie. */ private var _value:String; /** * Flag indicating if a cookie was just created. It is <code>true</code> * when the cookie did not exist before and <code>false</code> otherwise. */ private var _isNew:Boolean; /** * Name of the external javascript function used for getting * cookie information. */ private static const GET_COOKIE:String = "cookieGetCookie"; /** * Name of the external javascript function used for setting * cookie information. */ private static const SET_COOKIE:String = "cookieSetCookie"; /** * Javascript code to define the GET_COOKIE function. */ private static var FUNCTION_GET_COOKIE:String = "function () { " + "if (document." + GET_COOKIE + " == null) {" + GET_COOKIE + " = function (name) { " + "if (document.cookie) {" + "cookies = document.cookie.split('; ');" + "for (i = 0; i < cookies.length; i++) {" + "param = cookies[i].split('=', 2);" + "if (decodeURIComponent(param[0]) == name) {" + "value = decodeURIComponent(param[1]);" + "return value;" + "}" + "}" + "}" + "return null;" + "};" + "}" + "}"; /** * Javascript code to define the SET_COOKIE function. */ private static var FUNCTION_SET_COOKIE:String = "function () { " + "if (document." + SET_COOKIE + " == null) {" + SET_COOKIE + " = function (name, value) { " + "document.cookie = name + '=' + value;" + "};" + "}" + "}"; /** * Initializes the class by injecting javascript code into * the embedding document. If the class was already initialized * before, this method does nothing. */ private static function initialize():void { if (Cookies._initialized) { return; } if (!ExternalInterface.available) { throw new Error("ExternalInterface is not available in this container. Internet Explorer ActiveX, Firefox, Mozilla 1.7.5 and greater, or other browsers that support NPRuntime are required."); } // Add functions to DOM if they aren't already there ExternalInterface.call(FUNCTION_GET_COOKIE); ExternalInterface.call(FUNCTION_SET_COOKIE); Cookies._initialized = true; } /** * Creates a new Cookie object. If a cookie with the specified * name already exists, the existing value is used. Otherwise * a new cookie is created as soon as a value is assigned to it. * * @param name The name of the cookie */ public function Cookies(name:String) { Cookies.initialize(); this._name = name; this._value = ExternalInterface.call(GET_COOKIE, name) as String; this._isNew = this._value == null; } /** * The name of the cookie. */ public function get name():String { return this._name; } /** * The value of the cookie. If it is a new cookie, it is not * made persistent until a value is assigned to it. */ public function get value():String { return this._value; } /** * @private */ public function set value(value:String):void { this._value = value; ExternalInterface.call(SET_COOKIE, this._name, this._value); } /** * The <code>isNew</code> property indicates if the cookie * already exists or not. */ public function get isNew():Boolean { return this._isNew; } } } I am using cookie like thisvar anotherCookie:Cookies = new Cookies("username"); anotherCookie.value=[Textinput].text;`.is there any code i need to use save cookie in new window also? Please help me Thanks in Advance.

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  • For Loop help In a Hash Cracker Homework.

    - by aaron burns
    On the homework I am working on we are making a hash cracker. I am implementing it so as to have my cracker. java call worker.java. Worker.java implements Runnable. Worker is to take the start and end of a list of char, the hash it is to crack, and the max length of the password that made the hash. I know I want to do a loop in run() BUT I cannot think of how I would do it so it would go to the given max pasword length. I have posted the code I have so far. Any directions or areas I should look into.... I thought there was a way to do this with a certain way to write the loop but I don't know or can't find the correct syntax. Oh.. also. In main I divide up so x amount of threads can be chosen and I know that as of write now it only works for an even number of the 40 possible char given. package HashCracker; import java.util.*; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class Cracker { // Array of chars used to produce strings public static final char[] CHARS = "abcdefghijklmnopqrstuvwxyz0123456789.,-!".toCharArray(); public static final int numOfChar=40; /* Given a byte[] array, produces a hex String, such as "234a6f". with 2 chars for each byte in the array. (provided code) */ public static String hexToString(byte[] bytes) { StringBuffer buff = new StringBuffer(); for (int i=0; i<bytes.length; i++) { int val = bytes[i]; val = val & 0xff; // remove higher bits, sign if (val<16) buff.append('0'); // leading 0 buff.append(Integer.toString(val, 16)); } return buff.toString(); } /* Given a string of hex byte values such as "24a26f", creates a byte[] array of those values, one byte value -128..127 for each 2 chars. (provided code) */ public static byte[] hexToArray(String hex) { byte[] result = new byte[hex.length()/2]; for (int i=0; i<hex.length(); i+=2) { result[i/2] = (byte) Integer.parseInt(hex.substring(i, i+2), 16); } return result; } public static void main(String args[]) throws NoSuchAlgorithmException { if(args.length==1)//Hash Maker { //create a byte array , meassage digestand put password into it //and get out a hash value printed to the screen using provided methods. byte[] myByteArray=args[0].getBytes(); MessageDigest hasher=MessageDigest.getInstance("SHA-1"); hasher.update(myByteArray); byte[] digestedByte=hasher.digest(); String hashValue=Cracker.hexToString(digestedByte); System.out.println(hashValue); } else//Hash Cracker { ArrayList<Thread> myRunnables=new ArrayList<Thread>(); int numOfThreads = Integer.parseInt(args[2]); int charPerThread=Cracker.numOfChar/numOfThreads; int start=0; int end=charPerThread-1; for(int i=0; i<numOfThreads; i++) { //creates, stores and starts threads. Runnable tempWorker=new Worker(start, end, args[1], Integer.parseInt(args[1])); Thread temp=new Thread(tempWorker); myRunnables.add(temp); temp.start(); start=end+1; end=end+charPerThread; } } } import java.util.*; public class Worker implements Runnable{ private int charStart; private int charEnd; private String Hash2Crack; private int maxLength; public Worker(int start, int end, String hashValue, int maxPWlength) { charStart=start; charEnd=end; Hash2Crack=hashValue; maxLength=maxPWlength; } public void run() { byte[] myHash2Crack_=Cracker.hexToArray(Hash2Crack); for(int i=charStart; i<charEnd+1; i++) { Cracker.numOfChar[i]////// this is where I am stuck. } } }

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  • Lua metatable Objects cannot be purge from memory?

    - by Prometheus3k
    Hi there, I'm using a proprietary platform that reported memory usage in realtime on screen. I decided to use a Class.lua I found on http://lua-users.org/wiki/SimpleLuaClasses However, I noticed memory issues when purging object created by this using a simple Account class. Specifically, I would start with say 146k of memory used, create 1000 objects of a class that just holds an integer instance variable and store each object into a table. The memory used is now 300k I would then exit, iterating through the table and setting each element in the table to nil. But would never get back the 146k, usually after this I am left using 210k or something similar. If I run the load sequence again during the same session, it does not exceed 300k so it is not a memory leak. I have tried creating 1000 integers in a table and setting these to nil, which does give me back 146k. In addition I've tried a simpler class file (Account2.lua) that doesn't rely on a class.lua. This still incurs memory fragmentation but not as much as the one that uses Class.lua Can anybody explain what is going on here? How can I purge these objects and get back the memory? here is the code --------Class.lua------ -- class.lua -- Compatible with Lua 5.1 (not 5.0). --http://lua-users.org/wiki/SimpleLuaClasses function class(base,ctor) local c = {} -- a new class instance if not ctor and type(base) == 'function' then ctor = base base = nil elseif type(base) == 'table' then -- our new class is a shallow copy of the base class! for i,v in pairs(base) do c[i] = v end c._base = base end -- the class will be the metatable for all its objects, -- and they will look up their methods in it. c.__index = c -- expose a ctor which can be called by () local mt = {} mt.__call = function(class_tbl,...) local obj = {} setmetatable(obj,c) if ctor then ctor(obj,...) else -- make sure that any stuff from the base class is initialized! if base and base.init then base.init(obj,...) end end return obj end c.init = ctor c.instanceOf = function(self,klass) local m = getmetatable(self) while m do if m == klass then return true end m = m._base end return false end setmetatable(c,mt) return c end --------Account.lua------ --Import Class template require 'class' local classname = "Account" --Declare class Constructor Account = class(function(acc,balance) --Instance variables declared here. if(balance ~= nil)then acc.balance = balance else --default value acc.balance = 2097 end acc.classname = classname end) --------Account2.lua------ local account2 = {} account2.classname = "unnamed" account2.balance = 2097 -----------Constructor 1 do local metatable = { __index = account2; } function Account2() return setmetatable({}, metatable); end end --------Main.lua------ require 'Account' require 'Account2' MAX_OBJ = 5000; test_value = 1000; Obj_Table = {}; MODE_ACC0 = 0 --integers MODE_ACC1 = 1 --Account MODE_ACC2 = 2 --Account2 TEST_MODE = MODE_ACC0; Lua_mem = ""; print("##1) collectgarbage('count'): " .. collectgarbage('count')); function Load() for i=1, MAX_OBJ do if(TEST_MODE == MODE_ACC0 )then table.insert(Obj_Table, test_value); elseif(TEST_MODE == MODE_ACC1 )then table.insert(Obj_Table, Account(test_value)); --Account.lua elseif(TEST_MODE == MODE_ACC2 )then table.insert(Obj_Table, Account2()); --Account2.lua Obj_Table[i].balance = test_value; end end print("##2) collectgarbage('count'): " .. collectgarbage('count')); end function Purge() --metatable purge if(TEST_MODE ~= MODE_ACC0)then --purge stage 0: print("set each elements metatable to nil") for i=1, MAX_OBJ do setmetatable(Obj_Table[i], nil); end end --purge stage 1: print("set table element to nil") for i=1, MAX_OBJ do Obj_Table[i] = nil; end --purge stage 2: print("start table.remove..."); for i=1, MAX_OBJ do table.remove(Obj_Table, i); end print("...end table.remove"); --purge stage 3: print("create new object_table {}"); Obj_Table= {}; --purge stage 4: print("collectgarbage('collect')"); collectgarbage('collect'); print("##3) collectgarbage('count'): " .. collectgarbage('count')); end --Loop callback function OnUpdate() collectgarbage('collect'); Lua_mem = collectgarbage('count'); end ------------------- --NOTE: --On start of game runs Load(), another runs Purge() --Update I've updated the code with suggestions from comments below, and will post my findings later today.

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  • Need some suggestions on my softwares architecture. [Code review]

    - by Sergio Tapia
    I'm making an open source C# library for other developers to use. My key concern is ease of use. This means using intuitive names, intuitive method usage and such. This is the first time I've done something with other people in mind, so I'm really concerned about the quality of the architecture. Plus, I wouldn't mind learning a thing or two. :) I have three classes: Downloader, Parser and Movie I was thinking that it would be best to only expose the Movie class of my library and have Downloader and Parser remain hidden from invocation. Ultimately, I see my library being used like this. using FreeIMDB; public void Test() { var MyMovie = Movie.FindMovie("The Matrix"); //Now MyMovie would have all it's fields set and ready for the big show. } Can you review how I'm planning this, and point out any wrong judgement calls I've made and where I could improve. Remember, my main concern is ease of use. Movie.cs using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Drawing; namespace FreeIMDB { public class Movie { public Image Poster { get; set; } public string Title { get; set; } public DateTime ReleaseDate { get; set; } public string Rating { get; set; } public string Director { get; set; } public List<string> Writers { get; set; } public List<string> Genres { get; set; } public string Tagline { get; set; } public string Plot { get; set; } public List<string> Cast { get; set; } public string Runtime { get; set; } public string Country { get; set; } public string Language { get; set; } public Movie FindMovie(string Title) { Movie film = new Movie(); Parser parser = Parser.FromMovieTitle(Title); film.Poster = parser.Poster(); film.Title = parser.Title(); film.ReleaseDate = parser.ReleaseDate(); //And so an so forth. } public Movie FindKnownMovie(string ID) { Movie film = new Movie(); Parser parser = Parser.FromMovieID(ID); film.Poster = parser.Poster(); film.Title = parser.Title(); film.ReleaseDate = parser.ReleaseDate(); //And so an so forth. } } } Parser.cs using System; using System.Collections.Generic; using System.Linq; using System.Text; using HtmlAgilityPack; namespace FreeIMDB { /// <summary> /// Provides a simple, and intuitive way for searching for movies and actors on IMDB. /// </summary> class Parser { private Downloader downloader = new Downloader(); private HtmlDocument Page; #region "Page Loader Events" private Parser() { } public static Parser FromMovieTitle(string MovieTitle) { var newParser = new Parser(); newParser.Page = newParser.downloader.FindMovie(MovieTitle); return newParser; } public static Parser FromActorName(string ActorName) { var newParser = new Parser(); newParser.Page = newParser.downloader.FindActor(ActorName); return newParser; } public static Parser FromMovieID(string MovieID) { var newParser = new Parser(); newParser.Page = newParser.downloader.FindKnownMovie(MovieID); return newParser; } public static Parser FromActorID(string ActorID) { var newParser = new Parser(); newParser.Page = newParser.downloader.FindKnownActor(ActorID); return newParser; } #endregion #region "Page Parsing Methods" public string Poster() { //Logic to scrape the Poster URL from the Page element of this. return null; } public string Title() { return null; } public DateTime ReleaseDate() { return null; } #endregion } } ----------------------------------------------- Do you guys think I'm heading towards a good path, or am I setting myself up for a world of hurt later on? My original thought was to separate the downloading, the parsing and the actual populating to easily have an extensible library. Imagine if one day the website changed its HTML, I would then only have to modifiy the parsing class without touching the Downloader.cs or Movie.cs class. Thanks for reading and for helping!

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  • Unable to Calculate Position within Owner-Draw Text

    - by Jonathan Wood
    I'm trying to use Visual Studio 2012 to create a Windows Forms application that can place the caret at the current position within a owner-drawn string. However, I've been unable to find a way to accurately calculate that position. I've done this successfully before in C++. I've now tried numerous methods in C#. Originally, I tried using .NET classes to determine the correct position, but then I tried accessing the Windows API directly. In some cases, I came close, but after some time I still cannot place the caret accurately. I've created a small test program and posted key parts below. I've also posted the entire project here. The exact font used is not important to me; however, my application assumes a mono-spaced font. Any help is appreciated. Form1.cs This is my main form. public partial class Form1 : Form { private string TestString; private int AveCharWidth; private int Position; public Form1() { InitializeComponent(); TestString = "123456789012345678901234567890123456789012345678901234567890"; AveCharWidth = GetFontWidth(); Position = 0; } private void Form1_Load(object sender, EventArgs e) { Font = new Font(FontFamily.GenericMonospace, 12, FontStyle.Regular, GraphicsUnit.Pixel); } protected override void OnGotFocus(EventArgs e) { Windows.CreateCaret(Handle, (IntPtr)0, 2, (int)Font.Height); Windows.ShowCaret(Handle); UpdateCaretPosition(); base.OnGotFocus(e); } protected void UpdateCaretPosition() { Windows.SetCaretPos(Padding.Left + (Position * AveCharWidth), Padding.Top); } protected override void OnLostFocus(EventArgs e) { Windows.HideCaret(Handle); Windows.DestroyCaret(); base.OnLostFocus(e); } protected override void OnPaint(PaintEventArgs e) { e.Graphics.DrawString(TestString, Font, SystemBrushes.WindowText, new PointF(Padding.Left, Padding.Top)); } protected override bool IsInputKey(Keys keyData) { switch (keyData) { case Keys.Right: case Keys.Left: return true; } return base.IsInputKey(keyData); } protected override void OnKeyDown(KeyEventArgs e) { switch (e.KeyCode) { case Keys.Left: Position = Math.Max(Position - 1, 0); UpdateCaretPosition(); break; case Keys.Right: Position = Math.Min(Position + 1, TestString.Length); UpdateCaretPosition(); break; } base.OnKeyDown(e); } protected int GetFontWidth() { int AverageCharWidth = 0; using (var graphics = this.CreateGraphics()) { try { Windows.TEXTMETRIC tm; var hdc = graphics.GetHdc(); IntPtr hFont = this.Font.ToHfont(); IntPtr hOldFont = Windows.SelectObject(hdc, hFont); var a = Windows.GetTextMetrics(hdc, out tm); var b = Windows.SelectObject(hdc, hOldFont); var c = Windows.DeleteObject(hFont); AverageCharWidth = tm.tmAveCharWidth; } catch { } finally { graphics.ReleaseHdc(); } } return AverageCharWidth; } } Windows.cs Here are my Windows API declarations. public static class Windows { [Serializable, StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)] public struct TEXTMETRIC { public int tmHeight; public int tmAscent; public int tmDescent; public int tmInternalLeading; public int tmExternalLeading; public int tmAveCharWidth; public int tmMaxCharWidth; public int tmWeight; public int tmOverhang; public int tmDigitizedAspectX; public int tmDigitizedAspectY; public short tmFirstChar; public short tmLastChar; public short tmDefaultChar; public short tmBreakChar; public byte tmItalic; public byte tmUnderlined; public byte tmStruckOut; public byte tmPitchAndFamily; public byte tmCharSet; } [DllImport("user32.dll")] public static extern bool CreateCaret(IntPtr hWnd, IntPtr hBitmap, int nWidth, int nHeight); [DllImport("User32.dll")] public static extern bool SetCaretPos(int x, int y); [DllImport("User32.dll")] public static extern bool DestroyCaret(); [DllImport("User32.dll")] public static extern bool ShowCaret(IntPtr hWnd); [DllImport("User32.dll")] public static extern bool HideCaret(IntPtr hWnd); [DllImport("gdi32.dll", CharSet = CharSet.Auto)] public static extern bool GetTextMetrics(IntPtr hdc, out TEXTMETRIC lptm); [DllImport("gdi32.dll")] public static extern IntPtr SelectObject(IntPtr hdc, IntPtr hgdiobj); [DllImport("GDI32.dll")] public static extern bool DeleteObject(IntPtr hObject); }

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  • Core Data: Fetch all entities in a to-many-relationship of a particular object?

    - by Björn Marschollek
    Hi there, in my iPhone application I am using simple Core Data Model with two entities (Item and Property): Item name properties Property name value item Item has one attribute (name) and one one-to-many-relationship (properties). Its inverse relationship is item. Property has two attributes the according inverse relationship. Now I want to show my data in table views on two levels. The first one lists all items; when one row is selected, a new UITableViewController is pushed onto my UINavigationController's stack. The new UITableView is supposed to show all properties (i.e. their names) of the selected item. To achieve this, I use a NSFetchedResultsController stored in an instance variable. On the first level, everything works fine when setting up the NSFetchedResultsController like this: -(NSFetchedResultsController *) fetchedResultsController { if (fetchedResultsController) return fetchedResultsController; // goal: tell the FRC to fetch all item objects. NSFetchRequest *fetch = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Item" inManagedObjectContext:self.moContext]; [fetch setEntity:entity]; NSSortDescriptor *sort = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES]; [fetch setSortDescriptors:[NSArray arrayWithObject:sort]]; [fetch setFetchBatchSize:10]; NSFetchedResultsController *frController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetch managedObjectContext:self.moContext sectionNameKeyPath:nil cacheName:@"cache"]; self.fetchedResultsController = frController; fetchedResultsController.delegate = self; [sort release]; [frController release]; [fetch release]; return fetchedResultsController; } However, on the second-level UITableView, I seem to do something wrong. I implemented the fetchedresultsController in a similar way: -(NSFetchedResultsController *) fetchedResultsController { if (fetchedResultsController) return fetchedResultsController; // goal: tell the FRC to fetch all property objects that belong to the previously selected item NSFetchRequest *fetch = [[NSFetchRequest alloc] init]; // fetch all Property entities. NSEntityDescription *entity = [NSEntityDescription entityForName:@"Property" inManagedObjectContext:self.moContext]; [fetch setEntity:entity]; // limit to those entities that belong to the particular item NSPredicate *predicate = [NSPredicate predicateWithFormat:[NSString stringWithFormat:@"item.name like '%@'",self.item.name]]; [fetch setPredicate:predicate]; // sort it. Boring. NSSortDescriptor *sort = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES]; [fetch setSortDescriptors:[NSArray arrayWithObject:sort]]; NSError *error = nil; NSLog(@"%d entities found.",[self.moContext countForFetchRequest:fetch error:&error]); // logs "3 entities found."; I added those properties before. See below for my saving "problem". if (error) NSLog("%@",error); // no error, thus nothing logged. [fetch setFetchBatchSize:20]; NSFetchedResultsController *frController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetch managedObjectContext:self.moContext sectionNameKeyPath:nil cacheName:@"cache"]; self.fetchedResultsController = frController; fetchedResultsController.delegate = self; [sort release]; [frController release]; [fetch release]; return fetchedResultsController; } Now it's getting weird. The above NSLog statement returns me the correct number of properties for the selected item. However, the UITableViewDelegate method tells me that there are no properties: -(NSInteger) tableView:(UITableView *)table numberOfRowsInSection:(NSInteger)section { id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section]; NSLog(@"Found %d properties for item \"%@\". Should have found %d.",[sectionInfo numberOfObjects], self.item.name, [self.item.properties count]); // logs "Found 0 properties for item "item". Should have found 3." return [sectionInfo numberOfObjects]; } The same implementation works fine on the first level. It's getting even weirder. I implemented some kind of UI to add properties. I create a new Property instance via Property *p = [NSEntityDescription insertNewObjectForEntityForName:@"Property" inManagedObjectContext:self.moContext];, set up the relationships and call [self.moContext save:&error]. This seems to work, as error is still nil and the object gets saved (I can see the number of properties when logging the Item instance, see above). However, the delegate methods are not fired. This seems to me due to the possibly messed up fetchRequest(Controller). Any ideas? Did I mess up the second fetch request? Is this the right way to fetch all entities in a to-many-relationship for a particular instance at all?

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  • Core Plot: only works ok with three plots

    - by Luis
    I am adding a scatter plot to my app (iGear) so when the user selects one, two or three chainrings combined with a cogset on a bike, lines will show the gears meters. The problem is that Core Plot only shows the plots when three chainrings are selected. I need your help, this is my first try at Core Plot and I'm lost. My code is the following: iGearMainViewController.m - (IBAction)showScatterIpad:(id)sender { cogsetToPass = [NSMutableArray new]; arrayForChainringOne = [NSMutableArray new]; arrayForChainringTwo = [NSMutableArray new]; arrayForChainringThree = [NSMutableArray new]; //behavior according to number of chainrings switch (self.segmentedControl.selectedSegmentIndex) { case 0: // one chainring selected for (int i = 1; i<= [cassette.numCogs intValue]; i++) { if (i <10) { corona = [NSString stringWithFormat:@"cog0%d",i]; }else { corona = [NSString stringWithFormat:@"cog%d",i]; } float one = (wheelSize*[_oneChainring.text floatValue]/[[cassette valueForKey:corona]floatValue])/1000; float teeth = [[cassette valueForKey:corona] floatValue]; [cogsetToPass addObject:[NSNumber numberWithFloat:teeth]]; [arrayForChainringOne addObject:[NSNumber numberWithFloat:one]]; } break; case 1: // two chainrings selected for (int i = 1; i<= [cassette.numCogs intValue]; i++) { if (i <10) { corona = [NSString stringWithFormat:@"cog0%d",i]; }else { corona = [NSString stringWithFormat:@"cog%d",i]; } float one = (wheelSize*[_oneChainring.text floatValue]/[[cassette valueForKey:corona]floatValue])/1000; //NSLog(@" gearsForOneChainring = %@",[NSNumber numberWithFloat:one]); float two = (wheelSize*[_twoChainring.text floatValue]/[[cassette valueForKey:corona]floatValue])/1000; [cogsetToPass addObject:[NSNumber numberWithFloat:[[cassette valueForKey:corona]floatValue]]]; [arrayForChainringOne addObject:[NSNumber numberWithFloat:one]]; [arrayForChainringTwo addObject:[NSNumber numberWithFloat:two]]; } break; case 2: // three chainrings selected for (int i = 1; i<= [cassette.numCogs intValue]; i++) { if (i <10) { corona = [NSString stringWithFormat:@"cog0%d",i]; }else { corona = [NSString stringWithFormat:@"cog%d",i]; } float one = (wheelSize*[_oneChainring.text floatValue]/[[cassette valueForKey:corona]floatValue])/1000; float two = (wheelSize*[_twoChainring.text floatValue]/[[cassette valueForKey:corona]floatValue])/1000; float three = (wheelSize*[_threeChainring.text floatValue]/[[cassette valueForKey:corona]floatValue])/1000; [cogsetToPass addObject:[cassette valueForKey:corona]]; [arrayForChainringOne addObject:[NSNumber numberWithFloat:one]]; [arrayForChainringTwo addObject:[NSNumber numberWithFloat:two]]; [arrayForChainringThree addObject:[NSNumber numberWithFloat:three]]; } default: break; } ScatterIpadViewController *sivc = [[ScatterIpadViewController alloc]initWithNibName: @"ScatterIpadViewController" bundle:nil]; [sivc setModalTransitionStyle:UIModalTransitionStyleFlipHorizontal]; sivc.records = [cassetteNumCogs integerValue]; sivc.cogsetSelected = self.cogsetToPass; sivc.chainringOne = self.arrayForChainringOne; sivc.chainringThree = self.arrayForChainringThree; sivc.chainringTwo = self.arrayForChainringTwo; [self presentViewController:sivc animated:YES completion:nil]; } And the child view with the code to draw the plots: ScatterIpadViewController.m #pragma mark - CPTPlotDataSource methods - (NSUInteger)numberOfRecordsForPlot: (CPTPlot *)plot { return records; } - (NSNumber *)numberForPlot: (CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index{ switch (fieldEnum) { case CPTScatterPlotFieldX: return [NSNumber numberWithInt:index]; break; case CPTScatterPlotFieldY:{ if ([plot.identifier isEqual:@"one"]==YES) { //NSLog(@"chainringOne objectAtIndex:index = %@", [chainringOne objectAtIndex:index]); return [chainringOne objectAtIndex:index]; }else if ([plot.identifier isEqual:@"two"] == YES ){ //NSLog(@"chainringTwo objectAtIndex:index = %@", [chainringTwo objectAtIndex:index]); return [chainringTwo objectAtIndex:index]; }else if ([plot.identifier isEqual:@"three"] == YES){ //NSLog(@"chainringThree objectAtIndex:index = %@", [chainringThree objectAtIndex:index]); return [chainringThree objectAtIndex:index]; } default: break; } } return nil; } The error returned is an exception on trying to access an empty array. 2012-11-15 11:02:42.962 iGearScatter[3283:11603] Terminating app due to uncaught exception 'NSRangeException', reason: ' -[__NSArrayM objectAtIndex:]: index 0 beyond bounds for empty array' First throw call stack: (0x1989012 0x1696e7e 0x192b0b4 0x166cd 0x183f4 0x1bd39 0x179c0 0x194fb 0x199e1 0x43250 0x14b66 0x13ef0 0x13e89 0x3b5753 0x3b5b2f 0x3b5d54 0x3c35c9 0x5c0814 0x392594 0x39221c 0x394563 0x3103b6 0x310554 0x1e87d8 0x27b3014 0x27a37d5 0x192faf5 0x192ef44 0x192ee1b 0x29ea7e3 0x29ea668 0x2d265c 0x22dd 0x2205 0x1)* libc++abi.dylib: terminate called throwing an exception Thank you!

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  • PHP: How to automate building a 100 <UL>/<LI> menuitems, while keeping the Menu Structure File Flat / Simply Managable?

    - by Sam
    Above: current "stupid" menu. (entire ul/li menu for javascript menu system) + (some li lines as page-specific submenu) Hi folks! With passion for automation and elegancy, but limited knowledge/knowhow, im stuck with "my hands in my hair" as we Dutch say, for my current menu system works perfectly, but is a pain in the a*s to update! So, i would appreciate it greatly, if you can suggest how to automate this in php: how to let the php generate the html menu code basing on a flat menu input file with TABS indented. OLD SITUATION <ul> <!-- about 100 of these <li>....</li> lines --> <li><a href="carrot.php"><p class="mnu" style="background-position:0 -820px"><? echo __("carrot juice") ?></p></a></li> <!-- lots of data, with only little bit thats really the menu itself--> </ul a javascript file reads a ul/li structure as input to build menu of format in that ul/li, the items with a hyperlink and sprite-bg position represent webpages, (inside LI) while items without hyperlink and sprite-bg are just headers of that menusection, (inside H6) to highlight the current page in the menu, the javascript menumaker uses an id number. this number corresponds to the consequtive li that is a webpage, skips h6 headers correctly. these h6 headers are only there for when importing sections of the same menu as submenu. non-li headers are not shown in menu, nore counted by the javascript menu for their ID. to know which page should be shown, i have to count from ID 0, the li items till finding the current webpage in the li structure and then manually put it in each webpage! BUT: changing an item in li order, means stupidly re-counting their entire li again! each webpage has an icon (= sprite bg-position numer), which is also used in the webpage. INTENDED RESULT I dream of, once setting what the current webpage is (e.g carrot.php) the menu system automatically "finds" and "counts" the li's and returns the id nr (for proper highlight of main menu); generates the entire menu html, and depending on which headings are set for submenu, (e.g. meals, drinks) generates those submenu (entire section below each given header); ginally adds h5 highlight inside the li of that submenu item. For the menu, i wish an easily readable, simple plain txt menu that is indented with tabs, (each tab is one depth for example) and further tabs follow for url and sprite position of icon. MY DREAM MENU-MANAGEMENT FILE |>TAB SEPARATED/INDENTED FLATMENU FILE |MUST BE CALCULATED BY PHP: |>MENUTEXT============URL=============SPRITE=====|ID===TAG================== |>about "#" -520 |00 li |> INFORMATION |—— h6 |> physical state "physical.php" -920 |01 li |> mental health "mental.php" -10 |02 li |> |>apetite "#" -1290 |03 li |> meals "#" -600 |04 li |> COLD MEAL |—— h6 |> egg salade "salad.php" -1040 |05 li |> salmon fish "salmon.php" -540 |06 li |> HOT MEAL |—— h6 |> spare ribs "spareribs.php" -120 |07 li |> di macaroni "macaroni.php" -870 |08 li |> |> drinks "#" -230 |09 li |> JUCY DRINK |—— h6 |> carrot juice "carrot.php" -820 |10 li |> mango hive "mango.php" -270 |11 li DESIRED CHRONOLOGY php outputs the entire ul/li html so the javascript can show the menu: webpage items go inside li tags, and header items go inside h6 tags, e.g. <h6>JUCY DRINK</h6> Each website page has a url filename [eg: salad.php]. Based on this given fact, the php menu generator detects the pagename, gives the IDnr of the position of that page according to the li-item nr and sets variable for javascript to highlight current menu item. the menu items below the specified headers are loaded as submenu in which the current page.php is wrapped inside h5 to highlight current page in submenu: e.g. (<li><h5><a href="carrot.php"><p>..etc..</p></h5></li> Question Which methods / steps / (chronological)ways are there for doing this? I am no good in php programming, but am learning it so please dont write any code without a line of comment why I should use that method etc. Where do I start? If I am unclear in my question, please ask. Thanks. Much appreciated!! Concrete Task List from the provided Comments/Answers, sofar: (RobertB) First, get some PHP code working that can read through a tab-delimited file and put the data into an appropriate data structure. NOW WORKING AT THIS

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  • std::vector optimisation required

    - by marcp
    I've written a routine that uses std::vector<double> rather heavily. It runs rather slowly and AQTime seems to imply that I am constructing mountains of vectors but I'm not sure why I would be. For some context, my sample run iterates 10 times. Each iteration copies 3 c arrays of ~400 points into vectors and creates 3 new same sized vectors for output. Each output point might be the result of summing up to 20 points from 2 of the input vectors, which works out to a worst case of 10*400*3*2*20 = 480,000 dereferences. Incredibly the profiler indicates that some of the std:: methods are being called 46 MILLION times. I suspect I'm doing something wrong! Some code: vector<double>gdbChannel::GetVector() { if (fHaveDoubleData & (fLength > 0)) { double * pD = getDoublePointer(); vector<double>v(pD, pD + fLength); return v; } else { throw(Exception("attempt to retrieve vector on empty line")); ; } } void gdbChannel::SaveVector(GX_HANDLE _hLine, const vector<double> & V) { if (hLine != _hLine) { GetLine(_hLine, V.size(), true); } GX_DOUBLE * pData = getDoublePointer(); memcpy(pData, &V[0], V.size()*sizeof(V[0])); ReplaceData(); } ///This routine gets called 10 times bool SpecRatio::DoWork(GX_HANDLE_PTR pLine) { if (!(hKin.GetLine(*pLine, true) && hUin.GetLine(*pLine, true) && hTHin.GetLine(*pLine, true))) { return true; } vector<double>vK = hKin.GetVector(); vector<double>vU = hUin.GetVector(); vector<double>vTh = hTHin.GetVector(); if ((vK.size() == 0) || (vU.size() == 0) || (vTh.size() == 0)) { return true; } ///TODO: confirm all vectors the same lenghth len = vK.size(); vUK.clear(); // these 3 vectors are declared as private class members vUTh.clear(); vThK.clear(); vUK.reserve(len); vUTh.reserve(len); vThK.reserve(len); // TODO: ensure everything is same fidincr, fidstart and length for (int i = 0; i < len; i++) { if (vK.at(i) < MinK) { vUK.push_back(rDUMMY); vUTh.push_back(rDUMMY); vThK.push_back(rDUMMY); } else { vUK.push_back(RatioPoint(vU, vK, i, UMin, KMin)); vUTh.push_back(RatioPoint(vU, vTh, i, UMin, ThMin)); vThK.push_back(RatioPoint(vTh, vK, i, ThMin, KMin)); } } hUKout.setFidParams(hKin); hUKout.SaveVector(*pLine, vUK); hUTHout.setFidParams(hKin); hUTHout.SaveVector(*pLine, vUTh); hTHKout.setFidParams(hKin); hTHKout.SaveVector(*pLine, vThK); return TestError(); } double SpecRatio::VValue(vector<double>V, int Index) { double result; if ((Index < 0) || (Index >= len)) { result = 0; } else { try { result = V.at(Index); if (OasisUtils::isDummy(result)) { result = 0; } } catch (out_of_range) { result = 0; } } return result; } double SpecRatio::RatioPoint(vector<double>Num, vector<double>Denom, int Index, double NumMin, double DenomMin) { double num = VValue(Num, Index); double denom = VValue(Denom, Index); int s = 0; // Search equalled 10 in this case while (((num < NumMin) || (denom < DenomMin)) && (s < Search)) { num += VValue(Num, Index - s) + VValue(Num, Index + s); denom += VValue(Denom, Index - s) + VValue(Denom, Index + s); s++; } if ((num < NumMin) || (denom < DenomMin)) { return rDUMMY; } else { return num / denom; } } The top AQTime offenders are: std::_Uninit_copy , double *, std::allocator 3.65 secs and 115731 Hits std::_Construct 1.69 secs and 46450637 Hits std::_Vector_const_iterator ::operator !=1.66 secs and 46566395 Hits and so on... std::allocator<double>::construct, operator new, std::_Vector_const_iterator<double, std::allocator<double> >::operator ++, std::_Vector_const_iterator<double, std::allocator<double> >::operator * std::_Vector_const_iterator<double, std::allocator<double> >::operator == each get called over 46 million times. I'm obviously doing something wrong to cause all these objects to be created. Can anyone see my error(s)?

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  • how to cout a vector of structs (that's a class member, using extraction operator)

    - by Julz
    hi, i'm trying to simply cout the elements of a vector using an overloaded extraction operator. the vector contians Point, which is just a struct containing two doubles. the vector is a private member of a class called Polygon, so heres my Point.h #ifndef POINT_H #define POINT_H #include <iostream> #include <string> #include <sstream> struct Point { double x; double y; //constructor Point() { x = 0.0; y = 0.0; } friend std::istream& operator >>(std::istream& stream, Point &p) { stream >> std::ws; stream >> p.x; stream >> p.y; return stream; } friend std::ostream& operator << (std::ostream& stream, Point &p) { stream << p.x << p.y; return stream; } }; #endif my Polygon.h #ifndef POLYGON_H #define POLYGON_H #include "Segment.h" #include <vector> class Polygon { //insertion operator needs work friend std::istream & operator >> (std::istream &inStream, Polygon &vertStr); // extraction operator friend std::ostream & operator << (std::ostream &outStream, const Polygon &vertStr); public: //Constructor Polygon(const std::vector<Point> &theVerts); //Default Constructor Polygon(); //Copy Constructor Polygon(const Polygon &polyCopy); //Accessor/Modifier methods inline std::vector<Point> getVector() const {return vertices;} //Return number of Vector elements inline int sizeOfVect() const {return vertices.size();} //add Point elements to vector inline void setVertices(const Point &theVerts){vertices.push_back (theVerts);} private: std::vector<Point> vertices; }; and Polygon.cc using namespace std; #include "Polygon.h" // Constructor Polygon::Polygon(const vector<Point> &theVerts) { vertices = theVerts; } //Default Constructor Polygon::Polygon(){} istream & operator >> (istream &inStream, Polygon::Polygon &vertStr) { inStream >> ws; inStream >> vertStr; return inStream; } // extraction operator ostream & operator << (ostream &outStream, const Polygon::Polygon &vertStr) { outStream << vertStr.vertices << endl; return outStream; } i figure my Point insertion/extraction is right, i can insert and cout using it and i figure i should be able to just...... cout << myPoly[i] << endl; in my driver? (in a loop) or even... cout << myPoly[0] << endl; without a loop? i've tried all sorts of myPoly.at[i]; myPoly.vertices[i]; etc etc also tried all veriations in my extraction function outStream << vertStr.vertices[i] << endl; within loops, etc etc. when i just create a... vector<Point> myVect; in my driver i can just... cout << myVect.at(i) << endl; no problems. tried to find an answer for days, really lost and not through lack of trying!!! thanks in advance for any help. please excuse my lack of comments and formatting also there's bits and pieces missing but i really just need an answer to this problem thanks again

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  • How to make a form using ajax, onchange event, reload to SAME page

    - by user1348220
    I've been studying this for a while and I'm not sure if I'm going about this the right way because every form I setup according to examples, it doesn't do what I need. I need to setup a form that will: set session when you select from dropdown menu not reload/refresh page (i've read that using AJAX solves this) submit and stay on SAME page (confused because most AJAX examples send it to different process.php page which is supposedly "invisible" but it doesn't "stay" on the same page, it redirects. Basically, client selects quantity of 1 to 10. If they select "2"... it does NOT reload the page.. but it DOES set a session[quantity]=2. Should be simple... but do I POST to same page as form? or POST to different page and it somehow redirects? Also, one test I did it kept pasting my "echo session[quantity]" down the page like 7, 2, 3, 5, etc. etc. each time instead of replacing it. I would paste code but it's all over the place and I'm hoping for direction on which methods to use. Feel I need to start all over again. Edit: trying to add code below but can't seem to paste it properly. <? ob_start();?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <?php session_start(); ?> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Submit Form with out refreshing page Tutorial</title> <!-- JavaScript --> <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.0/jquery.min.js"></script> <script type="text/javascript" > $(function() { $(".submit").click(function() { var gender = $("#gender").val(); var dataString = '&gender=' + gender; if(gender=='') { $('.success').fadeOut(200).hide(); $('.error').fadeOut(200).show(); } else { $.ajax({ type: "POST", url: "join.php", data: dataString, success: function(){ $('.success').fadeIn(200).show(); $('.error').fadeOut(200).hide(); } }); } return false; }); }); </script> <style type="text/css"> body{ } .error{ color:#d12f19; font-size:12px; } .success{ color:#006600; font-size:12px; } </style> </head> <body id="public"> <div style="height:30px"></div> <div id="container"> <div style="height:30px"></div> <form method="post" name="form"> <select id="gender" name="gender"> <option value="">Gender</option> <option value="male">Male</option> <option value="female">Female</option> </select> <div> <input type="submit" value="Submit" class="submit"/> <span class="error" style="display:none"> Please Enter Valid Data</span> <span class="success" style="display:none"> Your gender is <?php echo $_SESSION['gender'];?></span> </div> </form> <div style="height:20px"></div> </div><!--container--> </body> </html> <? ob_flush(); ?> and here is my page where the POST goes called join.php (called that in example so I went with it for now) <?php session_start(); if($_POST) { $gender = $_POST['gender']; $_SESSION['gender'] = $gender; } else { } ?>

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  • .NET SerialPort.Read skipps bytes

    - by Lukas Rieger
    Solution Reading the data byte wise via "port.ReadByte" is too slow, the problem is inside the SerialPort class. i changed it to reading bigger chunks via "port.Read" and there are now no buffer overruns. although i found the solution myself, writing it down helped me and maybe someone else has the same problem and finds this via google... (how can i mark it as answered?) EDIT 2 by setting port.ReadBufferSize = 2000000; i can delay the problem for ~30 seconds. so it seems, .Net really is too slow... since my application is not that critical, i just set the buffer to 20MB, but i am still interested in the cause. EDIT i just tested something i had not thought of before (shame on me): port.ErrorReceived += (object self, SerialErrorReceivedEventArgs se_arg) => { Console.Write("| Error: {0} | ", System.Enum.GetName(se_arg.EventType.GetType(), se_arg.EventType)); }; and it seems that i have an overrun. Is the .Net implementation too slow for 500k or is there an error on my side? Original Question i built a very primitive oszilloscope (avr, which sends adc data over uart to an ftdi chip). On the pc side i have a WPF Programm that displays this data. The Protokoll is: two sync bytes (0xaffe) - 14 data bytes - two sync bytes - 14 data bytes - ... i use 16bit values, so inside the 14 data bytes are 7 channels (lsb first). I verified the uC Firmware with hTerm, and it does send and receive everything correct. But, if i try to read the data with C#, sometimes some bytes are lost. The oszilloscop programm is a mess, but i created a small sample application, which has the same symptoms. I added two extension methods to a) read one byte from the COM Port and ignore -1 (EOF) and b) wait for the sync pattern. The sample programm first syncs onto the data stream by waiting for (0xaffe) and then compares the received bytes with the expected values. the loop runs a few times until an assert failed message pops up. I could not find anything about lost bytes via google, any help would be appreciated. Code using System; using System.Collections.Generic; using System.Diagnostics; using System.IO.Ports; using System.Linq; using System.Text; using System.Threading.Tasks; namespace SerialTest { public static class SerialPortExtensions { public static byte ReadByteSerial(this SerialPort port) { int i = 0; do { i = port.ReadByte(); } while (i < 0 || i > 0xff); return (byte)i; } public static void WaitForPattern_Ushort(this SerialPort port, ushort pattern) { byte hi = 0; byte lo = 0; do { lo = hi; hi = port.ReadByteSerial(); } while (!(hi == (pattern >> 8) && lo == (pattern & 0x00ff))); } } class Program { static void Main(string[] args) { //500000 8n1 SerialPort port = new SerialPort("COM3", 500000, Parity.None, 8, StopBits.One); port.Open(); port.DiscardInBuffer(); port.DiscardOutBuffer(); //Sync port.WaitForPattern_Ushort(0xaffe); byte hi = 0; byte lo = 0; int val; int n = 0; // Start Loop, the stream is already synced while (true) { //Read 7 16-bit values (=14 Bytes) for (int i = 0; i < 7; i++) { lo = port.ReadByteSerial(); hi = port.ReadByteSerial(); val = ((hi << 8) | lo); Debug.Assert(val != 0xaffe); } //Read two sync bytes lo = port.ReadByteSerial(); hi = port.ReadByteSerial(); val = ((hi << 8) | lo); Debug.Assert(val == 0xaffe); n++; } } } }

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  • HTML + javascript mouse over, mouseout, onclick not working in firefox.

    - by lucky
    Hello Everyone, My question is to get onMouseover,onMouseout,onMousedown,onClick on a table row. For which i am calling javascript userdefined functions. onMouseover --- Background color should change. onMouseout --- Reset to original color onClick --- First column checkbox/radio button should be set and background color should change onMousedown --- background color should change. My code in html is:- <tr onMouseOver="hover(this)" onMouseOut="hover_out(this)" onMouseDown="get_first_state(this)" onClick="checkit(this)" > and the methods in javascripts are:- var first_state = false; var oldcol = '#ffffff'; var oldcol_cellarray = new Array(); function hover(element) { if (! element) element = this; while (element.tagName != 'TR') { element = element.parentNode; } if (element.style.fontWeight != 'bold') { for (var i = 0; i<element.cells.length; i++) { if (element.cells[i].className != "no_hover") { oldcol_cellarray[i] = element.cells[i].style.backgroundColor; element.cells[i].style.backgroundColor='#e6f6f6'; } } } } // ----------------------------------------------------------------------------------------------- function hover_out(element) { if (! element) element = this; while (element.tagName != 'TR') { element = element.parentNode; } if (element.style.fontWeight != 'bold') { for (var i = 0; i<element.cells.length; i++) { if (element.cells[i].className != "no_hover") { if (typeof oldcol_cellarray != undefined) { element.cells[i].style.backgroundColor=oldcol_cellarray[i]; } else { element.cells[i].style.backgroundColor='#ffffff'; } //var oldcol_cellarray = new Array(); } } } } // ----------------------------------------------------------------------------------------------- function get_first_state(element) { while (element.tagName != 'TR') { element = element.parentNode; } first_state = element.cells[0].firstChild.checked; } // ----------------------------------------------------------------------------------------------- function checkit (element) { while (element.tagName != 'TR') { element = element.parentNode; } if (element.cells[0].firstChild.type == 'radio') { var typ = 0; } else if (element.cells[0].firstChild.type == 'checkbox') { typ = 1; } if (element.cells[0].firstChild.checked == true && typ == 1) { if (element.cells[0].firstChild.checked == first_state) { element.cells[0].firstChild.checked = false; } set_rowstyle(element, element.cells[0].firstChild.checked); } else { if (typ == 0 || element.cells[0].firstChild.checked == first_state) { element.cells[0].firstChild.checked = true; } set_rowstyle(element, element.cells[0].firstChild.checked); } if (typ == 0) { var table = element.parentNode; if (table.tagName != "TABLE") { table = table.parentNode; } if (table.tagName == "TABLE") { table=table.tBodies[0].rows; //var table = document.getElementById("js_tb").tBodies[0].rows; for (var i = 1; i< table.length; i++) { if (table[i].cells[0].firstChild.checked == true && table[i] != element) { table[i].cells[0].firstChild.checked = false; } if (table[i].cells[0].firstChild.checked == false) { set_rowstyle(table[i], false); } } } } } function set_rowstyle(r, on) { if (on == true) { for (var i =0; i < r.cells.length; i++) { r.style.fontWeight = 'bold'; r.cells[i].style.backgroundColor = '#f2f2c2'; } } else { for ( i =0; i < r.cells.length; i++) { r.style.fontWeight = 'normal'; r.cells[i].style.backgroundColor = '#ffffff'; } } } It is working as expected in IE. But coming to firefox i am surprised on seeing the output after so much of coding. In Firefox:-- onMouseOver is working as expected. color change of that particular row. onClick -- Setting the background color permenantly..eventhough i do onmouseover on different rows. the clicked previous row color is not reset to white. -- not as expected onclick on 2 rows..the background of both the rows is set..Only the latest row color should be set. other rows that are selected before should be set back..not as expected i.e if i click on all the rows..background color of everything is changed... Eventhough i click on the row. First column i.e radio button or checkbox is not set.. Please help me to solve this issue in firefox. Do let me know where my code needs to be changed... Thanks in advance!!

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  • Patching this Code to apply dynamic (iPhone) background position

    - by Brian
    I posted a question previously that got off topic, I'm reposting with better code that I have VERIFIED is compatible with iPhone (it works with mine anyway!) I just want to apply background-position coordinates to the body element and call the script conditionally for iPhone, iPod, & iPad. Here's my conditional call for those devices: var deviceAgent = navigator.userAgent.toLowerCase(); var agentID = deviceAgent.match(/(iphone|ipod|ipad)/); if (agentID) { // do something } else { //do this } Now, I've found this excellent script that sets the "top: x" dynamically on the basis of scroll position. Everyone has told me (and ALL of the tutorials and Google search results as well) that it's impossible to set scroll position dynamically for iPhone because of the viewport issue. HOWEVER, they are wrong because if you scroll to the bottom of the page and view this javascript demo on iPhone, you can scroll and the <div style="background-position: fixed; top: x (variable)"></div> div DOES stay centered on iPhone. I really hope this question helps alot of people, I thought it was impossible, but it's NOT... I just need help stitching it together! The original code (you can test it on iPhone yourself) is here: http://stevenbenner.com/2010/04/calculate-page-size-and-view-port-position-in-javascript/ So I just need help getting the following code to apply the dynamic "background-position: 0 x" to the BODY tag where x is centered and relative to the viewport position. Also, needs to be nested inside the above code that is conditional for iPhone and similar devices. // Page Size and View Port Dimension Tools // http://stevenbenner.com/2010/04/calculate-page-size-and-view-port-position-in-javascript/ if (!sb_windowTools) { var sb_windowTools = new Object(); }; sb_windowTools = { scrollBarPadding: 17, // padding to assume for scroll bars // EXAMPLE METHODS // center an element in the viewport centerElementOnScreen: function(element) { var pageDimensions = this.updateDimensions(); element.style.top = ((this.pageDimensions.verticalOffset() + this.pageDimensions.windowHeight() / 2) - (this.scrollBarPadding + element.offsetHeight / 2)) + 'px'; element.style.left = ((this.pageDimensions.windowWidth() / 2) - (this.scrollBarPadding + element.offsetWidth / 2)) + 'px'; element.style.position = 'absolute'; }, // INFORMATION GETTERS // load the page size, view port position and vertical scroll offset updateDimensions: function() { this.updatePageSize(); this.updateWindowSize(); this.updateScrollOffset(); }, // load page size information updatePageSize: function() { // document dimensions var viewportWidth, viewportHeight; if (window.innerHeight && window.scrollMaxY) { viewportWidth = document.body.scrollWidth; viewportHeight = window.innerHeight + window.scrollMaxY; } else if (document.body.scrollHeight > document.body.offsetHeight) { // all but explorer mac viewportWidth = document.body.scrollWidth; viewportHeight = document.body.scrollHeight; } else { // explorer mac...would also work in explorer 6 strict, mozilla and safari viewportWidth = document.body.offsetWidth; viewportHeight = document.body.offsetHeight; }; this.pageSize = { viewportWidth: viewportWidth, viewportHeight: viewportHeight }; }, // load window size information updateWindowSize: function() { // view port dimensions var windowWidth, windowHeight; if (self.innerHeight) { // all except explorer windowWidth = self.innerWidth; windowHeight = self.innerHeight; } else if (document.documentElement && document.documentElement.clientHeight) { // explorer 6 strict mode windowWidth = document.documentElement.clientWidth; windowHeight = document.documentElement.clientHeight; } else if (document.body) { // other explorers windowWidth = document.body.clientWidth; windowHeight = document.body.clientHeight; }; this.windowSize = { windowWidth: windowWidth, windowHeight: windowHeight }; }, // load scroll offset information updateScrollOffset: function() { // viewport vertical scroll offset var horizontalOffset, verticalOffset; if (self.pageYOffset) { horizontalOffset = self.pageXOffset; verticalOffset = self.pageYOffset; } else if (document.documentElement && document.documentElement.scrollTop) { // Explorer 6 Strict horizontalOffset = document.documentElement.scrollLeft; verticalOffset = document.documentElement.scrollTop; } else if (document.body) { // all other Explorers horizontalOffset = document.body.scrollLeft; verticalOffset = document.body.scrollTop; }; this.scrollOffset = { horizontalOffset: horizontalOffset, verticalOffset: verticalOffset }; }, // INFORMATION CONTAINERS // raw data containers pageSize: {}, windowSize: {}, scrollOffset: {}, // combined dimensions object with bounding logic pageDimensions: { pageWidth: function() { return sb_windowTools.pageSize.viewportWidth > sb_windowTools.windowSize.windowWidth ? sb_windowTools.pageSize.viewportWidth : sb_windowTools.windowSize.windowWidth; }, pageHeight: function() { return sb_windowTools.pageSize.viewportHeight > sb_windowTools.windowSize.windowHeight ? sb_windowTools.pageSize.viewportHeight : sb_windowTools.windowSize.windowHeight; }, windowWidth: function() { return sb_windowTools.windowSize.windowWidth; }, windowHeight: function() { return sb_windowTools.windowSize.windowHeight; }, horizontalOffset: function() { return sb_windowTools.scrollOffset.horizontalOffset; }, verticalOffset: function() { return sb_windowTools.scrollOffset.verticalOffset; } } };

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  • Is multithreading the right way to go for my case?

    - by Julien Lebosquain
    Hello, I'm currently designing a multi-client / server application. I'm using plain good old sockets because WCF or similar technology is not what I need. Let me explain: it isn't the classical case of a client simply calling a service; all clients can 'interact' with each other by sending a packet to the server, which will then do some action, and possible re-dispatch an answer message to one or more clients. Although doable with WCF, the application will get pretty complex with hundreds of different messages. For each connected client, I'm of course using asynchronous methods to send and receive bytes. I've got the messages fully working, everything's fine. Except that for each line of code I'm writing, my head just burns because of multithreading issues. Since there could be around 200 clients connected at the same time, I chose to go the fully multithreaded way: each received message on a socket is immediately processed on the thread pool thread it was received, not on a single consumer thread. Since each client can interact with other clients, and indirectly with shared objects on the server, I must protect almost every object that is mutable. I first went with a ReaderWriterLockSlim for each resource that must be protected, but quickly noticed that there are more writes overall than reads in the server application, and switched to the well-known Monitor to simplify the code. So far, so good. Each resource is protected, I have helper classes that I must use to get a lock and its protected resource, so I can't use an object without getting a lock. Moreover, each client has its own lock that is entered as soon as a packet is received from its socket. It's done to prevent other clients from making changes to the state of this client while it has some messages being processed, which is something that will happen frequently. Now, I don't just need to protect resources from concurrent accesses. I must keep every client in sync with the server for some collections I have. One tricky part that I'm currently struggling with is the following: I have a collection of clients. Each client has its own unique ID. When a client connects, it must receive the IDs of every connected client, and each one of them must be notified of the newcomer's ID. When a client disconnects, every other client must know it so that its ID is no longer valid for them. Every client must always have, at a given time, the same clients collection as the server so that I can assume that everybody knows everybody. This way if I'm sending a message to client #1 telling "Client #2 has done something", I know that it will always be correctly interpreted: Client 1 will never wonder "but who is Client 2 anyway?". My first attempt for handling the connection of a new client (let's call it X) was this pseudo-code (remember that newClient is already locked here): lock (clients) { foreach (var client in clients) { lock (client) { client.Send("newClient with id X has connected"); } } clients.Add(newClient); newClient.Send("the list of other clients"); } Now imagine that in the same time, another client has sent a packet that translates into a message that must be broadcasted to every connected client, the pseudo-code will be something like this (remember that the current client - let's call it Y - is already locked here): lock (clients) { foreach (var client in clients) { lock (client) { client.Send("something"); } } } An obvious deadlock occurs here: on one thread X is locked, the clients lock has been entered, started looping through the clients, and at one moment must get Y's lock... which is already acquired on the second thread, itself waiting for the clients collection lock to be released! This is not the only case like this in the server application. There are other collections which must be kept in sync with the clients, some properties on a client can be changed by another one, etc. I tried other types of locks, lock-free mechanisms and a bunch of other things. Either there were obvious deadlocks when I'm using too much locks for safety, or obvious race conditions otherwise. When I finally find a good middle point between the two, it usually comes with very subtle race conditions / dead locks and other multi-threading issues... my head hurts very quickly since for any single line of code I'm writing I have to review almost the whole application to ensure everything will behave correctly with any number of threads. So here's my final question: how would you resolve this specific case, the general case, and more importantly: aren't I going the wrong way here? I have little problems with the .NET framework, C#, simple concurrency or algorithms in general. Still, I'm lost here. I know I could use only one thread processing the incoming requests and everything will be fine. However, that won't scale well at all with more clients... But I'm thinking more and more to go this simple way. What do you think? Thanks in advance to you, StackOverflow people which have taken the time to read this huge question. I really had to explain the whole context if I want to get some help.

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