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• C++ 2d Array Class Function Call Help

  - by johnny-conrad

  I hope this question takes a simple fix, and I am just missing something very small. I am in my second semester of C++ in college, and we are just getting into OOP. This is my first OOP program, and it is causing me a little problem. Here are the errors I am getting: Member function must be called or its address taken in function displayGrid(int,Cell ( *)[20]) Member function must be called or its address taken in function Turn(int,int,Cell ( *)[20]) Member function must be called or its address taken in function Turn(int,int,Cell ( *)[20]) Warning: Parameter 'grid' is never used in function displayGrid(int,Cell ( *)[20]) Here is all of my code. I am aware It is much more code than necessary, sorry if it makes it more difficult. I was worried that I might accidentally delete something. const int MAX=20; //Struct Cell holds player and their symbol. class Cell { private: int Player; char Symbol; public: Cell(void); void setPlayer(int); void setSymbol(char); int getPlayer(void); char getSymbol(void); }; Cell::Cell(void) { Symbol ='-'; } void Cell::setPlayer(int player_num) { Player = player_num; } void Cell::setSymbol(char rps) { Symbol = rps; } int Cell::getPlayer(void) { return Player; } char Cell::getSymbol(void) { return Symbol; } void Turn(int, int, Cell[MAX][MAX]); void displayGrid(int, Cell[MAX][MAX]); void main(void) { int size; cout << "How big would you like the grid to be: "; cin >> size; //Checks to see valid grid size while(size>MAX || size<3) { cout << "Grid size must between 20 and 3." << endl; cout << "Please re-enter the grid size: "; cin >> size; } int cnt=1; int full; Cell grid[MAX][MAX]; //I use full to detect when the game is over by squaring size. full = size*size; cout << "Starting a new game." << endl; //Exits loop when cnt reaches full. while(cnt<full+1) { displayGrid(size, grid); //calls function to display grid if(cnt%2==0) //if cnt is even then it's 2nd players turn cout << "Player 2's turn." << endl; else cout << "Player 1's turn" << endl; Turn(size, cnt, grid); //calls Turn do each players turn cnt++; } cout << endl; cout << "Board is full... Game Over" << endl; } void displayGrid(int size, Cell grid[MAX][MAX]) { cout << endl; cout << " "; for(int x=1; x<size+1; x++) // prints first row cout << setw(3) << x; // of numbers. cout << endl; //Nested-For prints the grid. for(int i=1; i<size+1; i++) { cout << setw(2) << i; for(int c=1; c<size+1; c++) { cout << setw(3) << grid[i][c].getSymbol; } cout << endl; } cout << endl; } void Turn(int size, int cnt, Cell grid[MAX][MAX]) { char temp; char choice; int row=0; int column=0; cout << "Enter the Row: "; cin >> row; cout << "Enter the Column: "; cin >> column; //puts what is in the current cell in "temp" temp = grid[row][column].getSymbol; //Checks to see if temp is occupied or not while(temp!='-') { cout << "Cell space is Occupied..." << endl; cout << "Enter the Row: "; cin >> row; cout << "Enter the Column: "; cin >> column; temp = grid[row][column].getSymbol; //exits loop when finally correct } if(cnt%2==0) //if cnt is even then its player 2's turn { cout << "Enter your Symbol R, P, or S (Capitals): "; cin >> choice; grid[row][column].setPlayer(1); in >> choice; } //officially sets choice to grid cell grid[row][column].setSymbol(choice); } else //if cnt is odd then its player 1's turn { cout << "Enter your Symbol r, p, or s (Lower-Case): "; cin >> choice; grid[row][column].setPlayer(2); //checks for valid input by user1 while(choice!= 'r' && choice!='p' && choice!='s') { cout << "Invalid Symbol... Please Re-Enter: "; cin >> choice; } //officially sets choice to grid cell. grid[row][column].setSymbol(choice); } cout << endl; } Thanks alot for your help!

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• iOS bluetooth low energy not detecting peripherals

  - by user3712524

  My app won't detect peripherals. Im using light blue to simulate a bluetooth low energy peripheral and my app just won't sense it. I even installed light blue on two devices to make sure it was generating a peripheral signal properly and it is. Any suggestions? My labels are updating and the NSLog is showing that the scanning is starting. Thanks in advance. #import <UIKit/UIKit.h> #import <CoreBluetooth/CoreBluetooth.h> @interface ViewController : UIViewController @property (weak, nonatomic) IBOutlet UITextField *navDestination; @end #import "ViewController.h" @implementation ViewController - (IBAction)connect:(id)sender { } - (IBAction)navDestination:(id)sender { NSString *destinationText = self.navDestination.text; } - (void)viewDidLoad { } - (void)viewWillDisappear:(BOOL)animated { [super viewWillDisappear:animated]; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } @end #import <UIKit/UIKit.h> #import "ViewController.h" @interface BlueToothViewController : UIViewController @property (strong, nonatomic) CBCentralManager *centralManager; @property (strong, nonatomic) CBPeripheral *discoveredPerepheral; @property (strong, nonatomic) NSMutableData *data; @property (strong, nonatomic) IBOutlet UITextView *textview; @property (weak, nonatomic) IBOutlet UILabel *charLabel; @property (weak, nonatomic) IBOutlet UILabel *isConnected; @property (weak, nonatomic) IBOutlet UILabel *myPeripherals; @property (weak, nonatomic) IBOutlet UILabel *aLabel; - (void)centralManagerDidUpdateState:(CBCentralManager *)central; - (void)centralManger:(CBCentralManager *)central didDiscoverPeripheral: (CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI; -(void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error; -(void)cleanup; -(void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral; -(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error; -(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error; -(void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error; -(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error; -(void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error; @end @interface BlueToothViewController () @end @implementation BlueToothViewController - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; if (self) { // Custom initialization } return self; } - (void)viewDidLoad { _centralManager = [[CBCentralManager alloc]initWithDelegate:self queue:nil options:nil]; _data = [[NSMutableData alloc]init]; } - (void)viewWillDisappear:(BOOL)animated { [super viewWillDisappear:animated]; [_centralManager stopScan]; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } - (void)centralManagerDidUpdateState:(CBCentralManager *)central { //you should test all scenarios if (central.state == CBCentralManagerStateUnknown) { self.aLabel.text = @"I dont do anything because my state is unknown."; return; } if (central.state == CBCentralManagerStatePoweredOn) { //scan for devices [_centralManager scanForPeripheralsWithServices:nil options:@{ CBCentralManagerScanOptionAllowDuplicatesKey : @YES }]; NSLog(@"Scanning Started"); } if (central.state == CBCentralManagerStateResetting) { self.aLabel.text = @"I dont do anything because my state is resetting."; return; } if (central.state == CBCentralManagerStateUnsupported) { self.aLabel.text = @"I dont do anything because my state is unsupported."; return; } if (central.state == CBCentralManagerStateUnauthorized) { self.aLabel.text = @"I dont do anything because my state is unauthorized."; return; } if (central.state == CBCentralManagerStatePoweredOff) { self.aLabel.text = @"I dont do anything because my state is powered off."; return; } } - (void)centralManger:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI { NSLog(@"Discovered %@ at %@", peripheral.name, RSSI); self.myPeripherals.text = [NSString stringWithFormat:@"%@%@",peripheral.name, RSSI]; if (_discoveredPerepheral != peripheral) { //save a copy of the peripheral _discoveredPerepheral = peripheral; //and connect NSLog(@"Connecting to peripheral %@", peripheral); [_centralManager connectPeripheral:peripheral options:nil]; self.aLabel.text = [NSString stringWithFormat:@"%@", peripheral]; } } -(void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error { NSLog(@"Failed to connect"); [self cleanup]; } -(void)cleanup { //see if we are subscribed to a characteristic on the peripheral if (_discoveredPerepheral.services != nil) { for (CBService *service in _discoveredPerepheral.services) { if (service.characteristics != nil) { for (CBCharacteristic *characteristic in service.characteristics) { if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:@"508EFF8E-F541-57EF-BD82-B0B4EC504CA9"]]) { if (characteristic.isNotifying) { [_discoveredPerepheral setNotifyValue:NO forCharacteristic:characteristic]; return; } } } } } } [_centralManager cancelPeripheralConnection:_discoveredPerepheral]; } -(void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral { NSLog(@"Connected"); [_centralManager stopScan]; NSLog(@"Scanning stopped"); self.isConnected.text = [NSString stringWithFormat:@"Connected"]; [_data setLength:0]; peripheral.delegate = self; [peripheral discoverServices:nil]; } -(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error { if (error) { [self cleanup]; return; } for (CBService *service in peripheral.services) { [peripheral discoverCharacteristics:nil forService:service]; } //discover other characteristics } -(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error { if (error) { [self cleanup]; return; } for (CBCharacteristic *characteristic in service.characteristics) { [peripheral setNotifyValue:YES forCharacteristic:characteristic]; } } -(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error { if (error) { NSLog(@"Error"); return; } NSString *stringFromData = [[NSString alloc]initWithData:characteristic.value encoding:NSUTF8StringEncoding]; self.charLabel.text = [NSString stringWithFormat:@"%@", stringFromData]; //Have we got everything we need? if ([stringFromData isEqualToString:@"EOM"]) { [_textview setText:[[NSString alloc]initWithData:self.data encoding:NSUTF8StringEncoding]]; [peripheral setNotifyValue:NO forCharacteristic:characteristic]; [_centralManager cancelPeripheralConnection:peripheral]; } } -(void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error { if ([characteristic.UUID isEqual:nil]) { return; } if (characteristic.isNotifying) { NSLog(@"Notification began on %@", characteristic); } else { [_centralManager cancelPeripheralConnection:peripheral]; } } -(void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error { _discoveredPerepheral = nil; self.isConnected.text = [NSString stringWithFormat:@"Connecting..."]; [_centralManager scanForPeripheralsWithServices:nil options:@{ CBCentralManagerScanOptionAllowDuplicatesKey : @YES}]; } @end

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• Collision problems with drag-n-drop puzzle game.

  - by Amplify91

  I am working on an Android game similar to the Rush Hour/Traffic Jam/Blocked puzzle games. The board is a square containing rectangular pieces. Long pieces may only move horizontally, and tall pieces may only move vertically. The object is to free the red piece and move it out of the board. This game is only my second ever programming project in any language, so any tips or best practices would be appreciated along with your answer. I have a class for the game pieces called Pieces that describes how they are sized and drawn to the screen, gives them drag-and-drop functionality, and detects and handles collisions. I then have an activity class called GameView which creates my layout and creates Pieces objects to add to a RelativeLayout called Board. I have considered making Board its own class, but haven't needed to yet. Here's what my work in progress looks like: My Question: Most of this works perfectly fine except for my collision handling. It seems to be detecting collisions well but instead of pushing the pieces outside of each other when there is a collision, it frantically snaps back and forth between (what seems to be) where the piece is being dragged to and where it should be. It looks something like this: Another oddity: when the dragged piece collides with a piece to its left, the collision handling seems to work perfectly. Only piece above, below, and to the right cause problems. Here's the collision code: @Override public boolean onTouchEvent(MotionEvent event){ float eventX = event.getX(); float eventY = event.getY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: //check if touch is on piece if (eventX > x && eventX < (x+width) && eventY > y && eventY < (y+height)){ initialX=x; initialY=y; break; }else{ return false; } case MotionEvent.ACTION_MOVE: //determine if piece should move horizontally or vertically if(width>height){ for (Pieces piece : aPieces) { //if object equals itself in array, skip to next object if(piece==this){ continue; } //if next to another piece, //do not allow to move any further towards said piece if(eventX<x&&(x==piece.right+1)){ return false; }else if(eventX>x&&(x==piece.x-width-1)){ return false; } //move normally if no collision //if collision, do not allow to move through other piece if(collides(this,piece)==false){ x = (eventX-(width/2)); }else if(collidesLeft(this,piece)){ x = piece.right+1; break; }else if(collidesRight(this,piece)){ x = piece.x-width-1; break; } } break; }else if(height>width){ for (Pieces piece : aPieces) { if(piece==this){ continue; }else if(collides(this,piece)==false){ y = (eventY-(height/2)); }else if(collidesUp(this,piece)){ y = piece.bottom+1; break; }else if(collidesDown(this,piece)){ y = piece.y-height-1; break; } } } invalidate(); break; case MotionEvent.ACTION_UP: // end move if(this.moves()){ GameView.counter++; } initialX=x; initialY=y; break; } // parse puzzle invalidate(); return true; } This takes place during onDraw: width = sizedBitmap.getWidth(); height = sizedBitmap.getHeight(); right = x+width; bottom = y+height; My collision-test methods look like this with different math for each: private boolean collidesDown(Pieces piece1, Pieces piece2){ float x1 = piece1.x; float y1 = piece1.y; float r1 = piece1.right; float b1 = piece1.bottom; float x2 = piece2.x; float y2 = piece2.y; float r2 = piece2.right; float b2 = piece2.bottom; if((y1<y2)&&(y1<b2)&&(b1>=y2)&&(b1<b2)&&((x1>=x2&&x1<=r2)||(r1>=x2&&x1<=r2))){ return true; }else{ return false; } } private boolean collides(Pieces piece1, Pieces piece2){ if(collidesLeft(piece1,piece2)){ return true; }else if(collidesRight(piece1,piece2)){ return true; }else if(collidesUp(piece1,piece2)){ return true; }else if(collidesDown(piece1,piece2)){ return true; }else{ return false; } } As a second question, should my x,y,right,bottom,width,height variables be ints instead of floats like they are now? Also, any suggestions on how to implement things better would be greatly appreciated, even if not relevant to the question! Thanks in advance for the help and for sitting through such a long question! Update: I have gotten it working almost perfectly with the following code (this doesn't include the code for vertical pieces): @Override public boolean onTouchEvent(MotionEvent event){ float eventX = event.getX(); float eventY = event.getY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: //check if touch is on piece if (eventX > x && eventX < (x+width) && eventY > y && eventY < (y+height)){ initialX=x; initialY=y; break; }else{ return false; } case MotionEvent.ACTION_MOVE: //determine if piece should move horizontally or vertically if(width>height){ for (Pieces piece : aPieces) { //if object equals itself in array, skip to next object if(piece==this){ continue; } //check if there the possibility for a horizontal collision if(this.isAllignedHorizontallyWith(piece)){ //check for and handle collisions while moving left if(this.isRightOf(piece)){ if(eventX>piece.right+(width/2)){ x = (int)(eventX-(width/2)); //move normally }else{ x = piece.right+1; } } //check for and handle collisions while moving right if(this.isLeftOf(piece)){ if(eventX<piece.x-(width/2)){ x = (int)(eventX-(width/2)); }else{ x = piece.x-width-1; } } break; }else{ x = (int)(eventX-(width/2)); } The only problem with this code is that it only detects collisions between the moving piece and one other (with preference to one on the left). If there is a piece to collide with on the left and another on the right, it will only detect collisions with the one on the left. I think this is because once it finds a possible collision, it handles it without finishing looping through the array holding all the pieces. How do I get it to check for multiple possible collisions at the same time?

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• Changing the action of a form with javascript/jquery

  - by Micah

  I'm having an issue that is driving me crazy. I'm trying to modify the openid-selector to support facebook. I'm using RPXNow as my provider so it requires the form to be submitted to a different url than the standard. For example. RpxNow requires me to setup my form like this: <form action="https://wikipediamaze.rpxnow.com/openid/start?token_url=..."> This works for every provider except for facebook and myspace. Those require the form to be posted to a different url like this: <form action="https://wikipediamaze.rpxnow.com/facebook/start?token_url=..."> and <form action="https://wikipediamaze.rpxnow.com/myspace/start?token_url=..."> The open id selector has a bunch of buttons on the form each representing the openid providers. What I'm trying to do is detect when the facebook or myspace button is clicked and changed the action on the form before submitting. However it's not working. Here is my code. I've tried several variations all with the same "not supported" exception $("#openid_form").attr("action", form_url) document.forms[0].action = form_url Any suggestions? Update Here are more details on the code. I've ommitted some for brevity. The only thing i've done is added the facebook section to the "providers_large" object (which successfully adds the logo to the website), and instead of supply a url identifying the user, I'm creating a property called "form_url" which is what I want to set the action of my form to. If you look at the section title "Provider image click" you'll see where I'm checking for the presence of the property "form_url" and using jquery to change the action and submit the form. However when I step through the javascript in debug mode it tells me it's an ivalid operation. var providers_large = { google: { name: 'Google', url: 'https://www.google.com/accounts/o8/id' }, facebook: { name: 'Facebook', form_url: 'http://wikipediamaze.rpxnow.com/facebook/start?token_url=http://www.wikipediamaze.com/Accounts/Logon' }, }; var providers_small = { myopenid: { name: 'MyOpenID', label: 'Enter your MyOpenID username.', url: 'http://{username}.myopenid.com/' }, livejournal: { name: 'LiveJournal', label: 'Enter your Livejournal username.', url: 'http://{username}.livejournal.com/' }, flickr: { name: 'Flickr', label: 'Enter your Flickr username.', url: 'http://flickr.com/{username}/' }, technorati: { name: 'Technorati', label: 'Enter your Technorati username.', url: 'http://technorati.com/people/technorati/{username}/' }, wordpress: { name: 'Wordpress', label: 'Enter your Wordpress.com username.', url: 'http://{username}.wordpress.com/' }, blogger: { name: 'Blogger', label: 'Your Blogger account', url: 'http://{username}.blogspot.com/' }, verisign: { name: 'Verisign', label: 'Your Verisign username', url: 'http://{username}.pip.verisignlabs.com/' }, vidoop: { name: 'Vidoop', label: 'Your Vidoop username', url: 'http://{username}.myvidoop.com/' }, verisign: { name: 'Verisign', label: 'Your Verisign username', url: 'http://{username}.pip.verisignlabs.com/' }, claimid: { name: 'ClaimID', label: 'Your ClaimID username', url: 'http://claimid.com/{username}' } }; var providers = $.extend({}, providers_large, providers_small); var openid = { cookie_expires: 6*30, // 6 months. cookie_name: 'openid_provider', cookie_path: '/', img_path: 'images/', input_id: null, provider_url: null, init: function(input_id) { var openid_btns = $('#openid_btns'); this.input_id = input_id; $('#openid_choice').show(); $('#openid_input_area').empty(); // add box for each provider for (id in providers_large) { openid_btns.append(this.getBoxHTML(providers_large[id], 'large', '.gif')); } if (providers_small) { openid_btns.append('<br/>'); for (id in providers_small) { openid_btns.append(this.getBoxHTML(providers_small[id], 'small', '.ico')); } } $('#openid_form').submit(this.submit); var box_id = this.readCookie(); if (box_id) { this.signin(box_id, true); } }, getBoxHTML: function(provider, box_size, image_ext) { var box_id = provider["name"].toLowerCase(); return '<a title="'+provider["name"]+'" href="javascript: openid.signin(\''+ box_id +'\');"' + ' style="background: #FFF url(' + this.img_path + box_id + image_ext+') no-repeat center center" ' + 'class="' + box_id + ' openid_' + box_size + '_btn"></a>'; }, /* Provider image click */ signin: function(box_id, onload) { var provider = providers[box_id]; if (! provider) { return; } this.highlight(box_id); this.setCookie(box_id); // prompt user for input? if (provider['label']) { this.useInputBox(provider); this.provider_url = provider['url']; } else if(provider['form_url']) { $('#openid_form').attr("action", provider['form_url']); $('#openid_form').submit(); } else { this.setOpenIdUrl(provider['url']); if (! onload) { $('#openid_form').submit(); } } }, /* Sign-in button click */ submit: function() { var url = openid.provider_url; if (url) { url = url.replace('{username}', $('#openid_username').val()); openid.setOpenIdUrl(url); } return true; }, setOpenIdUrl: function (url) { var hidden = $('#'+this.input_id); if (hidden.length > 0) { hidden.value = url; } else { $('#openid_form').append('<input type="hidden" id="' + this.input_id + '" name="' + this.input_id + '" value="'+url+'"/>'); } }, highlight: function (box_id) { // remove previous highlight. var highlight = $('#openid_highlight'); if (highlight) { highlight.replaceWith($('#openid_highlight a')[0]); } // add new highlight. $('.'+box_id).wrap('<div id="openid_highlight"></div>'); }, setCookie: function (value) { var date = new Date(); date.setTime(date.getTime()+(this.cookie_expires*24*60*60*1000)); var expires = "; expires="+date.toGMTString(); document.cookie = this.cookie_name+"="+value+expires+"; path=" + this.cookie_path; }, readCookie: function () { var nameEQ = this.cookie_name + "="; var ca = document.cookie.split(';'); for(var i=0;i < ca.length;i++) { var c = ca[i]; while (c.charAt(0)==' ') c = c.substring(1,c.length); if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length); } return null; }, useInputBox: function (provider) { var input_area = $('#openid_input_area'); var html = ''; var id = 'openid_username'; var value = ''; var label = provider['label']; var style = ''; if (label) { html = '<p>' + label + '</p>'; } if (provider['name'] == 'OpenID') { id = this.input_id; value = 'http://'; style = 'background:#FFF url('+this.img_path+'openid-inputicon.gif) no-repeat scroll 0 50%; padding-left:18px;'; } html += '<input id="'+id+'" type="text" style="'+style+'" name="'+id+'" value="'+value+'" />' + '<input id="openid_submit" type="submit" value="Sign-In"/>'; input_area.empty(); input_area.append(html); $('#'+id).focus(); } };

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• Problems with with A* algorithm

  - by V_Programmer

  I'm trying to implement the A* algorithm in Java. I followed this tutorial,in particular, this pseudocode: http://theory.stanford.edu/~amitp/GameProgramming/ImplementationNotes.html The problem is my code doesn't work. It goes into an infinite loop. I really don't know why this happens... I suspect that the problem are in F = G + H function implemented in Graph constructors. I suspect I am not calculate the neighbor F correclty. Here's my code: List<Graph> open; List<Graph> close; private void createRouteAStar(Unit u) { open = new ArrayList<Graph>(); close = new ArrayList<Graph>(); u.ai_route_endX = 11; u.ai_route_endY = 5; List<Graph> neigh; int index; int i; boolean finish = false; Graph current; int cost; Graph start = new Graph(u.xMap, u.yMap, 0, ManhattanDistance(u.xMap, u.yMap, u.ai_route_endX, u.ai_route_endY)); open.add(start); current = start; while(!finish) { index = findLowerF(); current = new Graph(open, index); System.out.println(current.x); System.out.println(current.y); if (current.x == u.ai_route_endX && current.y == u.ai_route_endY) { finish = true; } else { close.add(current); neigh = current.getNeighbors(); for (i = 0; i < neigh.size(); i++) { cost = current.g + ManhattanDistance(current.x, current.y, neigh.get(i).x, neigh.get(i).y); if (open.contains(neigh.get(i)) && cost < neigh.get(i).g) { open.remove(open.indexOf(neigh)); } else if (close.contains(neigh.get(i)) && cost < neigh.get(i).g) { close.remove(close.indexOf(neigh)); } else if (!open.contains(neigh.get(i)) && !close.contains(neigh.get(i))) { neigh.get(i).g = cost; neigh.get(i).f = cost + ManhattanDistance(neigh.get(i).x, neigh.get(i).y, u.ai_route_endX, u.ai_route_endY); neigh.get(i).setParent(current); open.add(neigh.get(i)); } } } } System.out.println("step"); for (i=0; i < close.size(); i++) { if (close.get(i).parent != null) { System.out.println(i); System.out.println(close.get(i).parent.x); System.out.println(close.get(i).parent.y); } } } private int findLowerF() { int i; int min = 10000; int minIndex = -1; for (i=0; i < open.size(); i++) { if (open.get(i).f < min) { min = open.get(i).f; minIndex = i; System.out.println("min"); System.out.println(min); } } return minIndex; } private int ManhattanDistance(int ax, int ay, int bx, int by) { return Math.abs(ax-bx) + Math.abs(ay-by); } And, as I've said. I suspect that the Graph class has the main problem. However I've not been able to detect and fix it. public class Graph { int x, y; int f,g,h; Graph parent; public Graph(int x, int y, int g, int h) { this.x = x; this.y = y; this.g = g; this.h = h; this.f = g + h; } public Graph(List<Graph> list, int index) { this.x = list.get(index).x; this.y = list.get(index).y; this.g = list.get(index).g; this.h = list.get(index).h; this.f = list.get(index).f; this.parent = list.get(index).parent; } public Graph(Graph gp) { this.x = gp.x; this.y = gp.y; this.g = gp.g; this.h = gp.h; this.f = gp.f; } public Graph(Graph gp, Graph parent) { this.x = gp.x; this.y = gp.y; this.g = gp.g; this.h = gp.h; this.f = g + h; this.parent = parent; } public List<Graph> getNeighbors() { List<Graph> aux = new ArrayList<Graph>(); aux.add(new Graph(x+1, y, g,h)); aux.add(new Graph(x-1, y, g,h)); aux.add(new Graph(x, y+1, g,h)); aux.add(new Graph(x, y-1, g,h)); return aux; } public void setParent(Graph g) { parent = g; } } Little Edit: Using the System.out and the Debugger I discovered that the program ALWAYS is check the same "current" graph, (15,8) which is the (u.xMap, u.yMap) position. Looks like it keeps forever in the first step.

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• PHP Pear Installation on CentOS

  - by Prabhakar

  [root@ip ~]# yum install php-pear* Reducing CentOS-5 Testing to included packages only Finished Setting up Install Process Package 1:php-pear-1.8.1-2.el5.centos.noarch already installed and latest versio n Package php-pear-XML-Util is obsoleted by php-pear, trying to install 1:php-pear -1.8.1-2.el5.centos.noarch instead Package 1:php-pear-1.8.1-2.el5.centos.noarch already installed and latest versio n Package php-pear-DB is obsoleted by php-pear-db, trying to install php-pear-db-1 .7.13-2.el5.rf.noarch instead Resolving Dependencies --> Running transaction check ---> Package php-pear-Auth-RADIUS.noarch 0:1.0.6-1.el5 set to be updated --> Processing Dependency: php-pecl(radius) >= 1.2.5 for package: php-pear-Auth- RADIUS --> Processing Dependency: php-mcrypt for package: php-pear-Auth-RADIUS ---> Package php-pear-Auth-SASL.noarch 0:1.0.4-1.el5 set to be updated ---> Package php-pear-Benchmark.noarch 0:1.2.7-1.el5 set to be updated ---> Package php-pear-CAS.noarch 0:1.1.3-1.el5 set to be updated --> Processing Dependency: php-domxml-php4-php5 for package: php-pear-CAS ---> Package php-pear-Cache-Lite.noarch 0:1.7.5-1.el5 set to be updated ---> Package php-pear-CodeGen.noarch 0:1.0.7-3.el5 set to be updated ---> Package php-pear-CodeGen-PECL.noarch 0:1.1.3-3.el5 set to be updated ---> Package php-pear-Console-CommandLine.noarch 0:1.1.3-3.el5 set to be updated ---> Package php-pear-Console-Getargs.noarch 0:1.3.5-1.el5 set to be updated ---> Package php-pear-Console-ProgressBar.noarch 0:0.5.2-0.2.beta.el5 set to be updated ---> Package php-pear-Console-Table.noarch 0:1.1.1-1.el5 set to be updated ---> Package php-pear-Crypt-Blowfish.noarch 0:1.0.1-1.el5 set to be updated ---> Package php-pear-Crypt-CHAP.noarch 0:1.0.2-1.el5 set to be updated ---> Package php-pear-DB-DataObject.noarch 0:1.8.12-1.el5 set to be updated ---> Package php-pear-DB-DataObject-FormBuilder.noarch 0:1.0.0-1.el5 set to be u pdated ---> Package php-pear-DB-QueryTool.noarch 0:1.1.2-1.el5 set to be updated ---> Package php-pear-Date.noarch 0:1.4.7-2.el5.centos set to be updated ---> Package php-pear-Date-Holidays.noarch 0:0.21.4-1.el5 set to be updated ---> Package php-pear-Date-Holidays-USA.noarch 0:0.1.1-1.el5 set to be updated ---> Package php-pear-Event-Dispatcher.noarch 0:1.1.0-1.el5 set to be updated ---> Package php-pear-File.noarch 0:1.2.2-1.el5.centos set to be updated ---> Package php-pear-File-Find.noarch 0:1.3.0-1.el5 set to be updated ---> Package php-pear-File-Passwd.noarch 0:1.1.7-1.el5 set to be updated ---> Package php-pear-File-SMBPasswd.noarch 0:1.0.3-1.el5 set to be updated ---> Package php-pear-HTML-Common.noarch 0:1.2.5-1.el5 set to be updated ---> Package php-pear-HTML-QuickForm.noarch 0:3.2.12-1.el5 set to be updated ---> Package php-pear-HTML-QuickForm-ElementGrid.noarch 0:0.1.1-1.el5 set to be updated ---> Package php-pear-HTML-QuickForm-advmultiselect.noarch 0:1.4.1-1.el5 set to be updated ---> Package php-pear-HTML-Table.noarch 0:1.7.5-1.el5 set to be updated ---> Package php-pear-HTML-Template-IT.noarch 0:1.3.0-2.el5 set to be updated ---> Package php-pear-HTML_Template_PHPLIB.noarch 0:1.4.0-2.el5 set to be update d ---> Package php-pear-HTTP.noarch 0:1.4.0-7.el5 set to be updated ---> Package php-pear-HTTP-Client.noarch 0:1.1.1-1.el5 set to be updated ---> Package php-pear-HTTP-Request.noarch 0:1.4.4-1.el5 set to be updated ---> Package php-pear-HTTP-Upload.noarch 0:0.9.1-2.el5 set to be updated ---> Package php-pear-Image-Canvas.noarch 0:0.3.1-1.el5 set to be updated ---> Package php-pear-Image-Color.noarch 0:1.0.3-1.el5 set to be updated ---> Package php-pear-Image-Graph.noarch 0:0.8.0-1.el5 set to be updated ---> Package php-pear-Image-GraphViz.noarch 0:1.2.1-4.el5 set to be updated --> Processing Dependency: graphviz for package: php-pear-Image-GraphViz ---> Package php-pear-Log.noarch 0:1.12.7-1.el5 set to be updated ---> Package php-pear-MDB2.noarch 0:2.4.1-2.el5.centos set to be updated ---> Package php-pear-MDB2-Driver-mysql.noarch 0:1.4.1-3.el5.centos set to be up dated ---> Package php-pear-MDB2-Driver-pgsql.noarch 0:1.4.1-1.el5 set to be updated ---> Package php-pear-MDB2-Schema.noarch 0:0.8.0-2.el5 set to be updated ---> Package php-pear-Mail.noarch 0:1.1.14-5.el5.1 set to be updated ---> Package php-pear-Mail-Mime.noarch 0:1.4.0-1.el5.centos set to be updated ---> Package php-pear-Math-Stats.noarch 0:0.9.0-0.1.beta3.el5 set to be updated ---> Package php-pear-Net-Curl.noarch 0:1.2.5-1.el5 set to be updated ---> Package php-pear-Net-DIME.noarch 0:1.0.1-1.el5 set to be updated ---> Package php-pear-Net-FTP.noarch 0:1.3.4-1.el5 set to be updated ---> Package php-pear-Net-POP3.noarch 0:1.3.7-1.el5 set to be updated ---> Package php-pear-Net-Ping.noarch 0:2.4.5-1.el5 set to be updated ---> Package php-pear-Net-SMTP.noarch 0:1.4.4-1.el5 set to be updated ---> Package php-pear-Net-Sieve.noarch 0:1.3.2-1.el5 set to be updated ---> Package php-pear-Net-Socket.noarch 0:1.0.10-1.el5 set to be updated ---> Package php-pear-Net-Traceroute.noarch 0:0.21.3-1.el5 set to be updated ---> Package php-pear-Net-URL.noarch 0:1.0.15-1.el5.centos set to be updated ---> Package php-pear-Net-URL-Mapper.noarch 0:0.9.0-2.el5.1 set to be updated ---> Package php-pear-Net-URL2.noarch 0:0.3.0-1.el5 set to be updated ---> Package php-pear-Net-UserAgent-Detect.noarch 0:2.5.2-1.el5 set to be update d ---> Package php-pear-Numbers-Roman.noarch 0:1.0.2-2.el5 set to be updated ---> Package php-pear-Numbers-Words.noarch 0:0.16.1-1.el5 set to be updated ---> Package php-pear-OLE.noarch 0:1.0.0-0.4.rc1.el5 set to be updated ---> Package php-pear-PHP-CodeSniffer.noarch 0:1.2.2-1.el5 set to be updated ---> Package php-pear-PHP-Compat.noarch 0:1.5.0-1.el5 set to be updated ---> Package php-pear-PHP-CompatInfo.noarch 0:1.4.3-1.el5 set to be updated ---> Package php-pear-PHPUnit.noarch 0:3.3.5-2.el5 set to be updated --> Processing Dependency: php-pecl(Xdebug) >= 2.0.0 for package: php-pear-PHPUn it --> Processing Dependency: php-channel(pear.phpunit.de) for package: php-pear-PH PUnit ---> Package php-pear-Pager.noarch 0:2.4.8-1.el5 set to be updated ---> Package php-pear-Payment-Process.noarch 0:0.6.6-1.el5 set to be updated ---> Package php-pear-Phlickr.noarch 0:0.2.7-2.el5 set to be updated ---> Package php-pear-PhpDocumentor.noarch 0:1.4.3-1.el5 set to be updated --> Processing Dependency: php-Smarty >= 2.6.0 for package: php-pear-PhpDocument or ---> Package php-pear-PhpDocumentor-docs.noarch 0:1.4.3-1.el5 set to be updated ---> Package php-pear-SOAP.noarch 0:0.11.0-2.el5 set to be updated ---> Package php-pear-Spreadsheet-Excel-Writer.noarch 0:0.9.2-2.el5 set to be up dated ---> Package php-pear-Structures-DataGrid.noarch 0:0.8.3-1.el5 set to be updated ---> Package php-pear-Structures-DataGrid-DataSource-Array.noarch 0:0.1.3-1.el5 set to be updated ---> Package php-pear-Structures-DataGrid-DataSource-DataObject.noarch 0:0.1.2-1 .el5 set to be updated ---> Package php-pear-Structures-DataGrid-DataSource-MDB2.noarch 0:0.1.10-1.el5 set to be updated ---> Package php-pear-Structures-DataGrid-DataSource-RSS.noarch 0:0.1.1-1.el5 se t to be updated ---> Package php-pear-Structures-DataGrid-Renderer-Pager.noarch 0:0.1.2-1.el5 se t to be updated ---> Package php-pear-Text-Diff.noarch 0:1.1.0-1.el5 set to be updated ---> Package php-pear-Validate.noarch 0:0.8.3-1.el5 set to be updated ---> Package php-pear-Validate-Finance-CreditCard.noarch 0:0.5.2-1.el5 set to be updated ---> Package php-pear-Var-Dump.noarch 0:1.0.3-2.el5 set to be updated ---> Package php-pear-XML-Beautifier.noarch 0:1.1-3.el5 set to be updated ---> Package php-pear-XML-Parser.noarch 0:1.2.8-1.el5 set to be updated ---> Package php-pear-XML-RSS.noarch 0:1.0.0-1.el5 set to be updated ---> Package php-pear-XML-Serializer.noarch 0:0.20.0-1.el5 set to be updated ---> Package php-pear-date.noarch 0:1.4.6-1.el5.rf set to be updated ---> Package php-pear-db.noarch 0:1.7.13-2.el5.rf set to be updated ---> Package php-pear-excel.noarch 0:0.9.0-1.el5.rf set to be updated ---> Package php-pear-file.noarch 0:1.2.2-1.el5.rf set to be updated ---> Package php-pear-log.noarch 0:1.9.3-1.el5.rf set to be updated ---> Package php-pear-mail_mime.noarch 0:1.3.1-1.el5.rf set to be updated ---> Package php-pear-ole.noarch 0:0.5-2.el5.rf set to be updated --> Running transaction check ---> Package graphviz.i386 0:2.22.0-4.el5.rf set to be updated ---> Package php-Smarty.noarch 0:2.6.26-1.el5 set to be updated ---> Package php-channel-phpunit.noarch 0:1.0-2.el5 set to be updated ---> Package php-domxml-php4-php5.noarch 0:1.21.2-1.el5 set to be updated ---> Package php-mcrypt.i386 0:5.2.9-2.el5.centos.3 set to be updated --> Processing Dependency: php-api = 20041225 for package: php-mcrypt ---> Package php-pecl-radius.i386 0:1.2.5-4.el5 set to be updated --> Processing Dependency: php-api = 20041225 for package: php-pecl-radius ---> Package php-pecl-xdebug.i386 0:2.0.5-1.el5.1 set to be updated --> Processing Dependency: php-api = 20041225 for package: php-pecl-xdebug --> Finished Dependency Resolution php-pecl-xdebug-2.0.5-1.el5.1.i386 from epel has depsolving problems --> Missing Dependency: php-api = 20041225 is needed by package php-pecl-xdebu g-2.0.5-1.el5.1.i386 (epel) php-pecl-radius-1.2.5-4.el5.i386 from epel has depsolving problems --> Missing Dependency: php-api = 20041225 is needed by package php-pecl-radiu s-1.2.5-4.el5.i386 (epel) php-mcrypt-5.2.9-2.el5.centos.3.i386 from c5-testing has depsolving problems --> Missing Dependency: php-api = 20041225 is needed by package php-mcrypt-5.2 .9-2.el5.centos.3.i386 (c5-testing) Error: Missing Dependency: php-api = 20041225 is needed by package php-pecl-radi us-1.2.5-4.el5.i386 (epel) Error: Missing Dependency: php-api = 20041225 is needed by package php-mcrypt-5. 2.9-2.el5.centos.3.i386 (c5-testing) Error: Missing Dependency: php-api = 20041225 is needed by package php-pecl-xdeb ug-2.0.5-1.el5.1.i386 (epel) You could try using --skip-broken to work around the problem You could try running: package-cleanup --problems package-cleanup --dupes rpm -Va --nofiles --nodigest The program package-cleanup is found in the yum-utils package.

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• Capturing and Transforming ASP.NET Output with Response.Filter

  - by Rick Strahl

  During one of my Handlers and Modules session at DevConnections this week one of the attendees asked a question that I didn’t have an immediate answer for. Basically he wanted to capture response output completely and then apply some filtering to the output – effectively injecting some additional content into the page AFTER the page had completely rendered. Specifically the output should be captured from anywhere – not just a page and have this code injected into the page. Some time ago I posted some code that allows you to capture ASP.NET Page output by overriding the Render() method, capturing the HtmlTextWriter() and reading its content, modifying the rendered data as text then writing it back out. I’ve actually used this approach on a few occasions and it works fine for ASP.NET pages. But this obviously won’t work outside of the Page class environment and it’s not really generic – you have to create a custom page class in order to handle the output capture. [updated 11/16/2009 – updated ResponseFilterStream implementation and a few additional notes based on comments] Enter Response.Filter However, ASP.NET includes a Response.Filter which can be used – well to filter output. Basically Response.Filter is a stream through which the OutputStream is piped back to the Web Server (indirectly). As content is written into the Response object, the filter stream receives the appropriate Stream commands like Write, Flush and Close as well as read operations although for a Response.Filter that’s uncommon to be hit. The Response.Filter can be programmatically replaced at runtime which allows you to effectively intercept all output generation that runs through ASP.NET. A common Example: Dynamic GZip Encoding A rather common use of Response.Filter hooking up code based, dynamic  GZip compression for requests which is dead simple by applying a GZipStream (or DeflateStream) to Response.Filter. The following generic routines can be used very easily to detect GZip capability of the client and compress response output with a single line of code and a couple of library helper routines: WebUtils.GZipEncodePage(); which is handled with a few lines of reusable code and a couple of static helper methods: /// <summary> ///Sets up the current page or handler to use GZip through a Response.Filter ///IMPORTANT:  ///You have to call this method before any output is generated! /// </summary> public static void GZipEncodePage() {     HttpResponse Response = HttpContext.Current.Response;     if(IsGZipSupported())     {         stringAcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"];         if(AcceptEncoding.Contains("deflate"))         {             Response.Filter = newSystem.IO.Compression.DeflateStream(Response.Filter,                                        System.IO.Compression.CompressionMode.Compress);             Response.AppendHeader("Content-Encoding", "deflate");         }         else        {             Response.Filter = newSystem.IO.Compression.GZipStream(Response.Filter,                                       System.IO.Compression.CompressionMode.Compress);             Response.AppendHeader("Content-Encoding", "gzip");                            }     }     // Allow proxy servers to cache encoded and unencoded versions separately    Response.AppendHeader("Vary", "Content-Encoding"); } /// <summary> /// Determines if GZip is supported /// </summary> /// <returns></returns> public static bool IsGZipSupported() { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (!string.IsNullOrEmpty(AcceptEncoding) && (AcceptEncoding.Contains("gzip") || AcceptEncoding.Contains("deflate"))) return true; return false; } GZipStream and DeflateStream are streams that are assigned to Response.Filter and by doing so apply the appropriate compression on the active Response. Response.Filter content is chunked So to implement a Response.Filter effectively requires only that you implement a custom stream and handle the Write() method to capture Response output as it’s written. At first blush this seems very simple – you capture the output in Write, transform it and write out the transformed content in one pass. And that indeed works for small amounts of content. But you see, the problem is that output is written in small buffer chunks (a little less than 16k it appears) rather than just a single Write() statement into the stream, which makes perfect sense for ASP.NET to stream data back to IIS in smaller chunks to minimize memory usage en route. Unfortunately this also makes it a more difficult to implement any filtering routines since you don’t directly get access to all of the response content which is problematic especially if those filtering routines require you to look at the ENTIRE response in order to transform or capture the output as is needed for the solution the gentleman in my session asked for. So in order to address this a slightly different approach is required that basically captures all the Write() buffers passed into a cached stream and then making the stream available only when it’s complete and ready to be flushed. As I was thinking about the implementation I also started thinking about the few instances when I’ve used Response.Filter implementations. Each time I had to create a new Stream subclass and create my custom functionality but in the end each implementation did the same thing – capturing output and transforming it. I thought there should be an easier way to do this by creating a re-usable Stream class that can handle stream transformations that are common to Response.Filter implementations. Creating a semi-generic Response Filter Stream Class What I ended up with is a ResponseFilterStream class that provides a handful of Events that allow you to capture and/or transform Response content. The class implements a subclass of Stream and then overrides Write() and Flush() to handle capturing and transformation operations. By exposing events it’s easy to hook up capture or transformation operations via single focused methods. ResponseFilterStream exposes the following events: CaptureStream, CaptureString Captures the output only and provides either a MemoryStream or String with the final page output. Capture is hooked to the Flush() operation of the stream. TransformStream, TransformString Allows you to transform the complete response output with events that receive a MemoryStream or String respectively and can you modify the output then return it back as a return value. The transformed output is then written back out in a single chunk to the response output stream. These events capture all output internally first then write the entire buffer into the response. TransformWrite, TransformWriteString Allows you to transform the Response data as it is written in its original chunk size in the Stream’s Write() method. Unlike TransformStream/TransformString which operate on the complete output, these events only see the current chunk of data written. This is more efficient as there’s no caching involved, but can cause problems due to searched content splitting over multiple chunks. Using this implementation, creating a custom Response.Filter transformation becomes as simple as the following code. To hook up the Response.Filter using the MemoryStream version event: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformStream += filter_TransformStream; Response.Filter = filter; and the event handler to do the transformation: MemoryStream filter_TransformStream(MemoryStream ms) { Encoding encoding = HttpContext.Current.Response.ContentEncoding; string output = encoding.GetString(ms.ToArray()); output = FixPaths(output); ms = new MemoryStream(output.Length); byte[] buffer = encoding.GetBytes(output); ms.Write(buffer,0,buffer.Length); return ms; } private string FixPaths(string output) { string path = HttpContext.Current.Request.ApplicationPath; // override root path wonkiness if (path == "/") path = ""; output = output.Replace("\"~/", "\"" + path + "/").Replace("'~/", "'" + path + "/"); return output; } The idea of the event handler is that you can do whatever you want to the stream and return back a stream – either the same one that’s been modified or a brand new one – which is then sent back to as the final response. The above code can be simplified even more by using the string version events which handle the stream to string conversions for you: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; and the event handler to do the transformation calling the same FixPaths method shown above: string filter_TransformString(string output) { return FixPaths(output); } The events for capturing output and capturing and transforming chunks work in a very similar way. By using events to handle the transformations ResponseFilterStream becomes a reusable component and we don’t have to create a new stream class or subclass an existing Stream based classed. By the way, the example used here is kind of a cool trick which transforms “~/” expressions inside of the final generated HTML output – even in plain HTML controls not HTML controls – and transforms them into the appropriate application relative path in the same way that ResolveUrl would do. So you can write plain old HTML like this: <a href=”~/default.aspx”>Home</a>  and have it turned into: <a href=”/myVirtual/default.aspx”>Home</a>  without having to use an ASP.NET control like Hyperlink or Image or having to constantly use: <img src=”<%= ResolveUrl(“~/images/home.gif”) %>” /> in MVC applications (which frankly is one of the most annoying things about MVC especially given the path hell that extension-less and endpoint-less URLs impose). I can’t take credit for this idea. While discussing the Response.Filter issues on Twitter a hint from Dylan Beattie who pointed me at one of his examples which does something similar. I thought the idea was cool enough to use an example for future demos of Response.Filter functionality in ASP.NET next I time I do the Modules and Handlers talk (which was great fun BTW). How practical this is is debatable however since there’s definitely some overhead to using a Response.Filter in general and especially on one that caches the output and the re-writes it later. Make sure to test for performance anytime you use Response.Filter hookup and make sure it' doesn’t end up killing perf on you. You’ve been warned :-}. How does ResponseFilterStream work? The big win of this implementation IMHO is that it’s a reusable  component – so for implementation there’s no new class, no subclassing – you simply attach to an event to implement an event handler method with a straight forward signature to retrieve the stream or string you’re interested in. The implementation is based on a subclass of Stream as is required in order to handle the Response.Filter requirements. What’s different than other implementations I’ve seen in various places is that it supports capturing output as a whole to allow retrieving the full response output for capture or modification. The exception are the TransformWrite and TransformWrite events which operate only active chunk of data written by the Response. For captured output, the Write() method captures output into an internal MemoryStream that is cached until writing is complete. So Write() is called when ASP.NET writes to the Response stream, but the filter doesn’t pass on the Write immediately to the filter’s internal stream. The data is cached and only when the Flush() method is called to finalize the Stream’s output do we actually send the cached stream off for transformation (if the events are hooked up) and THEN finally write out the returned content in one big chunk. Here’s the implementation of ResponseFilterStream: /// <summary> /// A semi-generic Stream implementation for Response.Filter with /// an event interface for handling Content transformations via /// Stream or String. /// <remarks> /// Use with care for large output as this implementation copies /// the output into a memory stream and so increases memory usage. /// </remarks> /// </summary> public class ResponseFilterStream : Stream { /// <summary> /// The original stream /// </summary> Stream _stream; /// <summary> /// Current position in the original stream /// </summary> long _position; /// <summary> /// Stream that original content is read into /// and then passed to TransformStream function /// </summary> MemoryStream _cacheStream = new MemoryStream(5000); /// <summary> /// Internal pointer that that keeps track of the size /// of the cacheStream /// </summary> int _cachePointer = 0; /// <summary> /// /// </summary> /// <param name="responseStream"></param> public ResponseFilterStream(Stream responseStream) { _stream = responseStream; } /// <summary> /// Determines whether the stream is captured /// </summary> private bool IsCaptured { get { if (CaptureStream != null || CaptureString != null || TransformStream != null || TransformString != null) return true; return false; } } /// <summary> /// Determines whether the Write method is outputting data immediately /// or delaying output until Flush() is fired. /// </summary> private bool IsOutputDelayed { get { if (TransformStream != null || TransformString != null) return true; return false; } } /// <summary> /// Event that captures Response output and makes it available /// as a MemoryStream instance. Output is captured but won't /// affect Response output. /// </summary> public event Action<MemoryStream> CaptureStream; /// <summary> /// Event that captures Response output and makes it available /// as a string. Output is captured but won't affect Response output. /// </summary> public event Action<string> CaptureString; /// <summary> /// Event that allows you transform the stream as each chunk of /// the output is written in the Write() operation of the stream. /// This means that that it's possible/likely that the input /// buffer will not contain the full response output but only /// one of potentially many chunks. /// /// This event is called as part of the filter stream's Write() /// operation. /// </summary> public event Func<byte[], byte[]> TransformWrite; /// <summary> /// Event that allows you to transform the response stream as /// each chunk of bytep[] output is written during the stream's write /// operation. This means it's possibly/likely that the string /// passed to the handler only contains a portion of the full /// output. Typical buffer chunks are around 16k a piece. /// /// This event is called as part of the stream's Write operation. /// </summary> public event Func<string, string> TransformWriteString; /// <summary> /// This event allows capturing and transformation of the entire /// output stream by caching all write operations and delaying final /// response output until Flush() is called on the stream. /// </summary> public event Func<MemoryStream, MemoryStream> TransformStream; /// <summary> /// Event that can be hooked up to handle Response.Filter /// Transformation. Passed a string that you can modify and /// return back as a return value. The modified content /// will become the final output. /// </summary> public event Func<string, string> TransformString; protected virtual void OnCaptureStream(MemoryStream ms) { if (CaptureStream != null) CaptureStream(ms); } private void OnCaptureStringInternal(MemoryStream ms) { if (CaptureString != null) { string content = HttpContext.Current.Response.ContentEncoding.GetString(ms.ToArray()); OnCaptureString(content); } } protected virtual void OnCaptureString(string output) { if (CaptureString != null) CaptureString(output); } protected virtual byte[] OnTransformWrite(byte[] buffer) { if (TransformWrite != null) return TransformWrite(buffer); return buffer; } private byte[] OnTransformWriteStringInternal(byte[] buffer) { Encoding encoding = HttpContext.Current.Response.ContentEncoding; string output = OnTransformWriteString(encoding.GetString(buffer)); return encoding.GetBytes(output); } private string OnTransformWriteString(string value) { if (TransformWriteString != null) return TransformWriteString(value); return value; } protected virtual MemoryStream OnTransformCompleteStream(MemoryStream ms) { if (TransformStream != null) return TransformStream(ms); return ms; } /// <summary> /// Allows transforming of strings /// /// Note this handler is internal and not meant to be overridden /// as the TransformString Event has to be hooked up in order /// for this handler to even fire to avoid the overhead of string /// conversion on every pass through. /// </summary> /// <param name="responseText"></param> /// <returns></returns> private string OnTransformCompleteString(string responseText) { if (TransformString != null) TransformString(responseText); return responseText; } /// <summary> /// Wrapper method form OnTransformString that handles /// stream to string and vice versa conversions /// </summary> /// <param name="ms"></param> /// <returns></returns> internal MemoryStream OnTransformCompleteStringInternal(MemoryStream ms) { if (TransformString == null) return ms; //string content = ms.GetAsString(); string content = HttpContext.Current.Response.ContentEncoding.GetString(ms.ToArray()); content = TransformString(content); byte[] buffer = HttpContext.Current.Response.ContentEncoding.GetBytes(content); ms = new MemoryStream(); ms.Write(buffer, 0, buffer.Length); //ms.WriteString(content); return ms; } /// <summary> /// /// </summary> public override bool CanRead { get { return true; } } public override bool CanSeek { get { return true; } } /// <summary> /// /// </summary> public override bool CanWrite { get { return true; } } /// <summary> /// /// </summary> public override long Length { get { return 0; } } /// <summary> /// /// </summary> public override long Position { get { return _position; } set { _position = value; } } /// <summary> /// /// </summary> /// <param name="offset"></param> /// <param name="direction"></param> /// <returns></returns> public override long Seek(long offset, System.IO.SeekOrigin direction) { return _stream.Seek(offset, direction); } /// <summary> /// /// </summary> /// <param name="length"></param> public override void SetLength(long length) { _stream.SetLength(length); } /// <summary> /// /// </summary> public override void Close() { _stream.Close(); } /// <summary> /// Override flush by writing out the cached stream data /// </summary> public override void Flush() { if (IsCaptured && _cacheStream.Length > 0) { // Check for transform implementations _cacheStream = OnTransformCompleteStream(_cacheStream); _cacheStream = OnTransformCompleteStringInternal(_cacheStream); OnCaptureStream(_cacheStream); OnCaptureStringInternal(_cacheStream); // write the stream back out if output was delayed if (IsOutputDelayed) _stream.Write(_cacheStream.ToArray(), 0, (int)_cacheStream.Length); // Clear the cache once we've written it out _cacheStream.SetLength(0); } // default flush behavior _stream.Flush(); } /// <summary> /// /// </summary> /// <param name="buffer"></param> /// <param name="offset"></param> /// <param name="count"></param> /// <returns></returns> public override int Read(byte[] buffer, int offset, int count) { return _stream.Read(buffer, offset, count); } /// <summary> /// Overriden to capture output written by ASP.NET and captured /// into a cached stream that is written out later when Flush() /// is called. /// </summary> /// <param name="buffer"></param> /// <param name="offset"></param> /// <param name="count"></param> public override void Write(byte[] buffer, int offset, int count) { if ( IsCaptured ) { // copy to holding buffer only - we'll write out later _cacheStream.Write(buffer, 0, count); _cachePointer += count; } // just transform this buffer if (TransformWrite != null) buffer = OnTransformWrite(buffer); if (TransformWriteString != null) buffer = OnTransformWriteStringInternal(buffer); if (!IsOutputDelayed) _stream.Write(buffer, offset, buffer.Length); } } The key features are the events and corresponding OnXXX methods that handle the event hookups, and the Write() and Flush() methods of the stream implementation. All the rest of the members tend to be plain jane passthrough stream implementation code without much consequence. I do love the way Action<t> and Func<T> make it so easy to create the event signatures for the various events – sweet. A few Things to consider Performance Response.Filter is not great for performance in general as it adds another layer of indirection to the ASP.NET output pipeline, and this implementation in particular adds a memory hit as it basically duplicates the response output into the cached memory stream which is necessary since you may have to look at the entire response. If you have large pages in particular this can cause potentially serious memory pressure in your server application. So be careful of wholesale adoption of this (or other) Response.Filters. Make sure to do some performance testing to ensure it’s not killing your app’s performance. Response.Filter works everywhere A few questions came up in comments and discussion as to capturing ALL output hitting the site and – yes you can definitely do that by assigning a Response.Filter inside of a module. If you do this however you’ll want to be very careful and decide which content you actually want to capture especially in IIS 7 which passes ALL content – including static images/CSS etc. through the ASP.NET pipeline. So it is important to filter only on what you’re looking for – like the page extension or maybe more effectively the Response.ContentType. Response.Filter Chaining Originally I thought that filter chaining doesn’t work at all due to a bug in the stream implementation code. But it’s quite possible to assign multiple filters to the Response.Filter property. So the following actually works to both compress the output and apply the transformed content: WebUtils.GZipEncodePage(); ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; However the following does not work resulting in invalid content encoding errors: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; WebUtils.GZipEncodePage(); In other words multiple Response filters can work together but it depends entirely on the implementation whether they can be chained or in which order they can be chained. In this case running the GZip/Deflate stream filters apparently relies on the original content length of the output and chokes when the content is modified. But if attaching the compression first it works fine as unintuitive as that may seem. Resources Download example code Capture Output from ASP.NET Pages © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  

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• Node.js Adventure - When Node Flying in Wind

  - by Shaun

  In the first post of this series I mentioned some popular modules in the community, such as underscore, async, etc.. I also listed a module named “Wind (zh-CN)”, which is created by one of my friend, Jeff Zhao (zh-CN). Now I would like to use a separated post to introduce this module since I feel it brings a new async programming style in not only Node.js but JavaScript world. If you know or heard about the new feature in C# 5.0 called “async and await”, or you learnt F#, you will find the “Wind” brings the similar async programming experience in JavaScript. By using “Wind”, we can write async code that looks like the sync code. The callbacks, async stats and exceptions will be handled by “Wind” automatically and transparently.   What’s the Problem: Dense “Callback” Phobia Let’s firstly back to my second post in this series. As I mentioned in that post, when we wanted to read some records from SQL Server we need to open the database connection, and then execute the query. In Node.js all IO operation are designed as async callback pattern which means when the operation was done, it will invoke a function which was taken from the last parameter. For example the database connection opening code would be like this. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: } 8: }); And then if we need to query the database the code would be like this. It nested in the previous function. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: conn.queryRaw(command, function(error, results) { 8: if(error) { 9: // failed to execute this command 10: } 11: else { 12: // records retrieved successfully 13: } 14: }; 15: } 16: }); Assuming if we need to copy some data from this database to another then we need to open another connection and execute the command within the function under the query function. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: conn.queryRaw(command, function(error, results) { 8: if(error) { 9: // failed to execute this command 10: } 11: else { 12: // records retrieved successfully 13: target.open(targetConnectionString, function(error, t_conn) { 14: if(error) { 15: // connect failed 16: } 17: else { 18: t_conn.queryRaw(copy_command, function(error, results) { 19: if(error) { 20: // copy failed 21: } 22: else { 23: // and then, what do you want to do now... 24: } 25: }; 26: } 27: }; 28: } 29: }; 30: } 31: }); This is just an example. In the real project the logic would be more complicated. This means our application might be messed up and the business process will be fragged by many callback functions. I would like call this “Dense Callback Phobia”. This might be a challenge how to make code straightforward and easy to read, something like below. 1: try 2: { 3: // open source connection 4: var s_conn = sqlConnect(s_connectionString); 5: // retrieve data 6: var results = sqlExecuteCommand(s_conn, s_command); 7: 8: // open target connection 9: var t_conn = sqlConnect(t_connectionString); 10: // prepare the copy command 11: var t_command = getCopyCommand(results); 12: // execute the copy command 13: sqlExecuteCommand(s_conn, t_command); 14: } 15: catch (ex) 16: { 17: // error handling 18: }   What’s the Problem: Sync-styled Async Programming Similar as the previous problem, the callback-styled async programming model makes the upcoming operation as a part of the current operation, and mixed with the error handling code. So it’s very hard to understand what on earth this code will do. And since Node.js utilizes non-blocking IO mode, we cannot invoke those operations one by one, as they will be executed concurrently. For example, in this post when I tried to copy the records from Windows Azure SQL Database (a.k.a. WASD) to Windows Azure Table Storage, if I just insert the data into table storage one by one and then print the “Finished” message, I will see the message shown before the data had been copied. This is because all operations were executed at the same time. In order to make the copy operation and print operation executed synchronously I introduced a module named “async” and the code was changed as below. 1: async.forEach(results.rows, 2: function (row, callback) { 3: var resource = { 4: "PartitionKey": row[1], 5: "RowKey": row[0], 6: "Value": row[2] 7: }; 8: client.insertEntity(tableName, resource, function (error) { 9: if (error) { 10: callback(error); 11: } 12: else { 13: console.log("entity inserted."); 14: callback(null); 15: } 16: }); 17: }, 18: function (error) { 19: if (error) { 20: error["target"] = "insertEntity"; 21: res.send(500, error); 22: } 23: else { 24: console.log("all done."); 25: res.send(200, "Done!"); 26: } 27: }); It ensured that the “Finished” message will be printed when all table entities had been inserted. But it cannot promise that the records will be inserted in sequence. It might be another challenge to make the code looks like in sync-style? 1: try 2: { 3: forEach(row in rows) { 4: var entity = { /* ... */ }; 5: tableClient.insert(tableName, entity); 6: } 7:  8: console.log("Finished"); 9: } 10: catch (ex) { 11: console.log(ex); 12: }   How “Wind” Helps “Wind” is a JavaScript library which provides the control flow with plain JavaScript for asynchronous programming (and more) without additional pre-compiling steps. It’s available in NPM so that we can install it through “npm install wind”. Now let’s create a very simple Node.js application as the example. This application will take some website URLs from the command arguments and tried to retrieve the body length and print them in console. Then at the end print “Finish”. I’m going to use “request” module to make the HTTP call simple so I also need to install by the command “npm install request”. The code would be like this. 1: var request = require("request"); 2:  3: // get the urls from arguments, the first two arguments are `node.exe` and `fetch.js` 4: var args = process.argv.splice(2); 5:  6: // main function 7: var main = function() { 8: for(var i = 0; i < args.length; i++) { 9: // get the url 10: var url = args[i]; 11: // send the http request and try to get the response and body 12: request(url, function(error, response, body) { 13: if(!error && response.statusCode == 200) { 14: // log the url and the body length 15: console.log( 16: "%s: %d.", 17: response.request.uri.href, 18: body.length); 19: } 20: else { 21: // log error 22: console.log(error); 23: } 24: }); 25: } 26: 27: // finished 28: console.log("Finished"); 29: }; 30:  31: // execute the main function 32: main(); Let’s execute this application. (I made them in multi-lines for better reading.) 1: node fetch.js 2: "http://www.igt.com/us-en.aspx" 3: "http://www.igt.com/us-en/games.aspx" 4: "http://www.igt.com/us-en/cabinets.aspx" 5: "http://www.igt.com/us-en/systems.aspx" 6: "http://www.igt.com/us-en/interactive.aspx" 7: "http://www.igt.com/us-en/social-gaming.aspx" 8: "http://www.igt.com/support.aspx" Below is the output. As you can see the finish message was printed at the beginning, and the pages’ length retrieved in a different order than we specified. This is because in this code the request command, console logging command are executed asynchronously and concurrently. Now let’s introduce “Wind” to make them executed in order, which means it will request the websites one by one, and print the message at the end.   First of all we need to import the “Wind” package and make sure the there’s only one global variant named “Wind”, and ensure it’s “Wind” instead of “wind”. 1: var Wind = require("wind");   Next, we need to tell “Wind” which code will be executed asynchronously so that “Wind” can control the execution process. In this case the “request” operation executed asynchronously so we will create a “Task” by using a build-in helps function in “Wind” named Wind.Async.Task.create. 1: var requestBodyLengthAsync = function(url) { 2: return Wind.Async.Task.create(function(t) { 3: request(url, function(error, response, body) { 4: if(error || response.statusCode != 200) { 5: t.complete("failure", error); 6: } 7: else { 8: var data = 9: { 10: uri: response.request.uri.href, 11: length: body.length 12: }; 13: t.complete("success", data); 14: } 15: }); 16: }); 17: }; The code above created a “Task” from the original request calling code. In “Wind” a “Task” means an operation will be finished in some time in the future. A “Task” can be started by invoke its start() method, but no one knows when it actually will be finished. The Wind.Async.Task.create helped us to create a task. The only parameter is a function where we can put the actual operation in, and then notify the task object it’s finished successfully or failed by using the complete() method. In the code above I invoked the request method. If it retrieved the response successfully I set the status of this task as “success” with the URL and body length. If it failed I set this task as “failure” and pass the error out.   Next, we will change the main() function. In “Wind” if we want a function can be controlled by Wind we need to mark it as “async”. This should be done by using the code below. 1: var main = eval(Wind.compile("async", function() { 2: })); When the application is running, Wind will detect “eval(Wind.compile(“async”, function” and generate an anonymous code from the body of this original function. Then the application will run the anonymous code instead of the original one. In our example the main function will be like this. 1: var main = eval(Wind.compile("async", function() { 2: for(var i = 0; i < args.length; i++) { 3: try 4: { 5: var result = $await(requestBodyLengthAsync(args[i])); 6: console.log( 7: "%s: %d.", 8: result.uri, 9: result.length); 10: } 11: catch (ex) { 12: console.log(ex); 13: } 14: } 15: 16: console.log("Finished"); 17: })); As you can see, when I tried to request the URL I use a new command named “$await”. It tells Wind, the operation next to $await will be executed asynchronously, and the main thread should be paused until it finished (or failed). So in this case, my application will be pause when the first response was received, and then print its body length, then try the next one. At the end, print the finish message.   Finally, execute the main function. The full code would be like this. 1: var request = require("request"); 2: var Wind = require("wind"); 3:  4: var args = process.argv.splice(2); 5:  6: var requestBodyLengthAsync = function(url) { 7: return Wind.Async.Task.create(function(t) { 8: request(url, function(error, response, body) { 9: if(error || response.statusCode != 200) { 10: t.complete("failure", error); 11: } 12: else { 13: var data = 14: { 15: uri: response.request.uri.href, 16: length: body.length 17: }; 18: t.complete("success", data); 19: } 20: }); 21: }); 22: }; 23:  24: var main = eval(Wind.compile("async", function() { 25: for(var i = 0; i < args.length; i++) { 26: try 27: { 28: var result = $await(requestBodyLengthAsync(args[i])); 29: console.log( 30: "%s: %d.", 31: result.uri, 32: result.length); 33: } 34: catch (ex) { 35: console.log(ex); 36: } 37: } 38: 39: console.log("Finished"); 40: })); 41:  42: main().start();   Run our new application. At the beginning we will see the compiled and generated code by Wind. Then we can see the pages were requested one by one, and at the end the finish message was printed. Below is the code Wind generated for us. As you can see the original code, the output code were shown. 1: // Original: 2: function () { 3: for(var i = 0; i < args.length; i++) { 4: try 5: { 6: var result = $await(requestBodyLengthAsync(args[i])); 7: console.log( 8: "%s: %d.", 9: result.uri, 10: result.length); 11: } 12: catch (ex) { 13: console.log(ex); 14: } 15: } 16: 17: console.log("Finished"); 18: } 19:  20: // Compiled: 21: /* async << function () { */ (function () { 22: var _builder_$0 = Wind.builders["async"]; 23: return _builder_$0.Start(this, 24: _builder_$0.Combine( 25: _builder_$0.Delay(function () { 26: /* var i = 0; */ var i = 0; 27: /* for ( */ return _builder_$0.For(function () { 28: /* ; i < args.length */ return i < args.length; 29: }, function () { 30: /* ; i ++) { */ i ++; 31: }, 32: /* try { */ _builder_$0.Try( 33: _builder_$0.Delay(function () { 34: /* var result = $await(requestBodyLengthAsync(args[i])); */ return _builder_$0.Bind(requestBodyLengthAsync(args[i]), function (result) { 35: /* console.log("%s: %d.", result.uri, result.length); */ console.log("%s: %d.", result.uri, result.length); 36: return _builder_$0.Normal(); 37: }); 38: }), 39: /* } catch (ex) { */ function (ex) { 40: /* console.log(ex); */ console.log(ex); 41: return _builder_$0.Normal(); 42: /* } */ }, 43: null 44: ) 45: /* } */ ); 46: }), 47: _builder_$0.Delay(function () { 48: /* console.log("Finished"); */ console.log("Finished"); 49: return _builder_$0.Normal(); 50: }) 51: ) 52: ); 53: /* } */ })   How Wind Works Someone may raise a big concern when you find I utilized “eval” in my code. Someone may assume that Wind utilizes “eval” to execute some code dynamically while “eval” is very low performance. But I would say, Wind does NOT use “eval” to run the code. It only use “eval” as a flag to know which code should be compiled at runtime. When the code was firstly been executed, Wind will check and find “eval(Wind.compile(“async”, function”. So that it knows this function should be compiled. Then it utilized parse-js to analyze the inner JavaScript and generated the anonymous code in memory. Then it rewrite the original code so that when the application was running it will use the anonymous one instead of the original one. Since the code generation was done at the beginning of the application was started, in the future no matter how long our application runs and how many times the async function was invoked, it will use the generated code, no need to generate again. So there’s no significant performance hurt when using Wind.   Wind in My Previous Demo Let’s adopt Wind into one of my previous demonstration and to see how it helps us to make our code simple, straightforward and easy to read and understand. In this post when I implemented the functionality that copied the records from my WASD to table storage, the logic would be like this. 1, Open database connection. 2, Execute a query to select all records from the table. 3, Recreate the table in Windows Azure table storage. 4, Create entities from each of the records retrieved previously, and then insert them into table storage. 5, Finally, show message as the HTTP response. But as the image below, since there are so many callbacks and async operations, it’s very hard to understand my logic from the code. Now let’s use Wind to rewrite our code. First of all, of course, we need the Wind package. Then we need to include the package files into project and mark them as “Copy always”. Add the Wind package into the source code. Pay attention to the variant name, you must use “Wind” instead of “wind”. 1: var express = require("express"); 2: var async = require("async"); 3: var sql = require("node-sqlserver"); 4: var azure = require("azure"); 5: var Wind = require("wind"); Now we need to create some async functions by using Wind. All async functions should be wrapped so that it can be controlled by Wind which are open database, retrieve records, recreate table (delete and create) and insert entity in table. Below are these new functions. All of them are created by using Wind.Async.Task.create. 1: sql.openAsync = function (connectionString) { 2: return Wind.Async.Task.create(function (t) { 3: sql.open(connectionString, function (error, conn) { 4: if (error) { 5: t.complete("failure", error); 6: } 7: else { 8: t.complete("success", conn); 9: } 10: }); 11: }); 12: }; 13:  14: sql.queryAsync = function (conn, query) { 15: return Wind.Async.Task.create(function (t) { 16: conn.queryRaw(query, function (error, results) { 17: if (error) { 18: t.complete("failure", error); 19: } 20: else { 21: t.complete("success", results); 22: } 23: }); 24: }); 25: }; 26:  27: azure.recreateTableAsync = function (tableName) { 28: return Wind.Async.Task.create(function (t) { 29: client.deleteTable(tableName, function (error, successful, response) { 30: console.log("delete table finished"); 31: client.createTableIfNotExists(tableName, function (error, successful, response) { 32: console.log("create table finished"); 33: if (error) { 34: t.complete("failure", error); 35: } 36: else { 37: t.complete("success", null); 38: } 39: }); 40: }); 41: }); 42: }; 43:  44: azure.insertEntityAsync = function (tableName, entity) { 45: return Wind.Async.Task.create(function (t) { 46: client.insertEntity(tableName, entity, function (error, entity, response) { 47: if (error) { 48: t.complete("failure", error); 49: } 50: else { 51: t.complete("success", null); 52: } 53: }); 54: }); 55: }; Then in order to use these functions we will create a new function which contains all steps for data copying. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: } 4: catch (ex) { 5: console.log(ex); 6: res.send(500, "Internal error."); 7: } 8: })); Let’s execute steps one by one with the “$await” keyword introduced by Wind so that it will be invoked in sequence. First is to open the database connection. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: } 7: catch (ex) { 8: console.log(ex); 9: res.send(500, "Internal error."); 10: } 11: })); Then retrieve all records from the database connection. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: } 10: catch (ex) { 11: console.log(ex); 12: res.send(500, "Internal error."); 13: } 14: })); After recreated the table, we need to create the entities and insert them into table storage. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage one by one 14: for (var i = 0; i < results.rows.length; i++) { 15: var entity = { 16: "PartitionKey": results.rows[i][1], 17: "RowKey": results.rows[i][0], 18: "Value": results.rows[i][2] 19: }; 20: $await(azure.insertEntityAsync(tableName, entity)); 21: console.log("entity inserted"); 22: } 23: } 24: } 25: catch (ex) { 26: console.log(ex); 27: res.send(500, "Internal error."); 28: } 29: })); Finally, send response back to the browser. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage one by one 14: for (var i = 0; i < results.rows.length; i++) { 15: var entity = { 16: "PartitionKey": results.rows[i][1], 17: "RowKey": results.rows[i][0], 18: "Value": results.rows[i][2] 19: }; 20: $await(azure.insertEntityAsync(tableName, entity)); 21: console.log("entity inserted"); 22: } 23: // send response 24: console.log("all done"); 25: res.send(200, "All done!"); 26: } 27: } 28: catch (ex) { 29: console.log(ex); 30: res.send(500, "Internal error."); 31: } 32: })); If we compared with the previous code we will find now it became more readable and much easy to understand. It’s very easy to know what this function does even though without any comments. When user go to URL “/was/copyRecords” we will execute the function above. The code would be like this. 1: app.get("/was/copyRecords", function (req, res) { 2: copyRecords(req, res).start(); 3: }); And below is the logs printed in local compute emulator console. As we can see the functions executed one by one and then finally the response back to me browser.   Scaffold Functions in Wind Wind provides not only the async flow control and compile functions, but many scaffold methods as well. We can build our async code more easily by using them. I’m going to introduce some basic scaffold functions here. In the code above I created some functions which wrapped from the original async function such as open database, create table, etc.. All of them are very similar, created a task by using Wind.Async.Task.create, return error or result object through Task.complete function. In fact, Wind provides some functions for us to create task object from the original async functions. If the original async function only has a callback parameter, we can use Wind.Async.Binding.fromCallback method to get the task object directly. For example the code below returned the task object which wrapped the file exist check function. 1: var Wind = require("wind"); 2: var fs = require("fs"); 3:  4: fs.existsAsync = Wind.Async.Binding.fromCallback(fs.exists); In Node.js a very popular async function pattern is that, the first parameter in the callback function represent the error object, and the other parameters is the return values. In this case we can use another build-in function in Wind named Wind.Async.Binding.fromStandard. For example, the open database function can be created from the code below. 1: sql.openAsync = Wind.Async.Binding.fromStandard(sql.open); 2:  3: /* 4: sql.openAsync = function (connectionString) { 5: return Wind.Async.Task.create(function (t) { 6: sql.open(connectionString, function (error, conn) { 7: if (error) { 8: t.complete("failure", error); 9: } 10: else { 11: t.complete("success", conn); 12: } 13: }); 14: }); 15: }; 16: */ When I was testing the scaffold functions under Wind.Async.Binding I found for some functions, such as the Azure SDK insert entity function, cannot be processed correctly. So I personally suggest writing the wrapped method manually.   Another scaffold method in Wind is the parallel tasks coordination. In this example, the steps of open database, retrieve records and recreated table should be invoked one by one, but it can be executed in parallel when copying data from database to table storage. In Wind there’s a scaffold function named Task.whenAll which can be used here. Task.whenAll accepts a list of tasks and creates a new task. It will be returned only when all tasks had been completed, or any errors occurred. For example in the code below I used the Task.whenAll to make all copy operation executed at the same time. 1: var copyRecordsInParallel = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage in parallal 14: var tasks = new Array(results.rows.length); 15: for (var i = 0; i < results.rows.length; i++) { 16: var entity = { 17: "PartitionKey": results.rows[i][1], 18: "RowKey": results.rows[i][0], 19: "Value": results.rows[i][2] 20: }; 21: tasks[i] = azure.insertEntityAsync(tableName, entity); 22: } 23: $await(Wind.Async.Task.whenAll(tasks)); 24: // send response 25: console.log("all done"); 26: res.send(200, "All done!"); 27: } 28: } 29: catch (ex) { 30: console.log(ex); 31: res.send(500, "Internal error."); 32: } 33: })); 34:  35: app.get("/was/copyRecordsInParallel", function (req, res) { 36: copyRecordsInParallel(req, res).start(); 37: });   Besides the task creation and coordination, Wind supports the cancellation solution so that we can send the cancellation signal to the tasks. It also includes exception solution which means any exceptions will be reported to the caller function.   Summary In this post I introduced a Node.js module named Wind, which created by my friend Jeff Zhao. As you can see, different from other async library and framework, adopted the idea from F# and C#, Wind utilizes runtime code generation technology to make it more easily to write async, callback-based functions in a sync-style way. By using Wind there will be almost no callback, and the code will be very easy to understand. Currently Wind is still under developed and improved. There might be some problems but the author, Jeff, should be very happy and enthusiastic to learn your problems, feedback, suggestion and comments. You can contact Jeff by - Email: [email protected] - Group: https://groups.google.com/d/forum/windjs - GitHub: https://github.com/JeffreyZhao/wind/issues   Source code can be download here.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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• value types in the vm

  - by john.rose

  value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases.  Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both.  We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types.  These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im,         /*Complex y:*/ double y_re, double y_im) {     /*Complex z = x.minus(y):*/     double z_re = x_re - y_re, z_im = x_im - y_im;     /*return z.abs():*/     return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable {     // immutable component structure:     public final double re, im;     private Complex(double re, double im) {         this.re = re; this.im = im;     }     // interoperability methods:     public String toString() { return "Complex("+re+","+im+")"; }     public List<Double> asList() { return Arrays.asList(re, im); }     public boolean equals(Complex c) {         return re == c.re && im == c.im;     }     public boolean equals(@ValueSafe Object x) {         return x instanceof Complex && equals((Complex) x);     }     public int hashCode() {         return 31*Double.valueOf(re).hashCode()                 + Double.valueOf(im).hashCode();     }     // factory methods:     public static Complex valueOf(double re, double im) {         return new Complex(re, im);     }     public Complex changeRe(double re2) { return valueOf(re2, im); }     public Complex changeIm(double im2) { return valueOf(re, im2); }     public static Complex cast(@ValueSafe Object x) {         return x == null ? ZERO : (Complex) x;     }     // utility methods and constants:     public Complex plus(Complex c)  { return new Complex(re+c.re, im+c.im); }     public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); }     public double abs() { return Math.sqrt(re*re + im*im); }     public static final Complex PI = valueOf(Math.PI, 0.0);     public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts.  The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final.  (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations.  A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations.  No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type.  If a value-safe class is marked final, it is in fact a value type.  All other value-safe classes must be abstract.  The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex.  Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable {     // All methods listed here must get redefined.     // Definitions must be value-safe, which means     // they may depend on component values only.     List<? extends Object> asList();     int hashCode();     boolean equals(@ValueSafe Object c);     String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system.  It could appear as an element type or parameter bound, for facilities which are designed to work on value types only.  More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods.  (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.)  Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation.  In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation.  Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0);  //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe")   Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object();  // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi);  // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi);  // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi);  // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero);  // error: reference comparison on value type boolean z2 = (pi == null);  // error: reference comparison on value type boolean z3 = (pi == obj2);  // error: reference comparison on value type synchronized (pi) { }  // error: synch of value, unpredictable result synchronized (obj2) { }  // unpredictable result Complex qq = pi; qq = null;  // possible NPE; warning: “null-unsafe" qq = (Complex) obj;  // warning: “null-unsafe" qq = Complex.cast(obj);  // OK @SuppressWarnings("null-unsafe")   Complex empty = null;  // possible NPE qq = empty;  // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations.  Fields and variables of value types can be split into their unboxed components.  Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules?  Why not detect programs automagically and perform unboxing transparently?  The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced.  Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal.  In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur.  This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer.  Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules.  There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme.  Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions.  One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type.  That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances.  Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe.  Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around.  Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed.  This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods.  This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors.  The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type.  Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands.  When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not.  If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible.  Proxies must be managed carefully, and this can be expensive.  On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces.  (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.)  Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems.  They require the deepest transformations, relative to today’s JVM.  There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics.  It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form.  Such value-safe arrays would not be convertible to Object[] arrays.  Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex.  I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code.  On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly.  Likewise, there are rules for providing default access modifiers for interface members.  Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types.  Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType {  // implicitly final     public double re, im;  // implicitly public final     //implicit methods are defined elementwise from te fields:     //  toString, asList, equals(2), hashCode, valueOf, cast     //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner.  The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer.  A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point.  The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage?  Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number.  Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”).  What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple {      double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly.  The supertype is an abstract class which has suitable shared declarations.  The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it.  The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types.  (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language.  (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.)  At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists.  Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection.  That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types.  Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API.  The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components  that appear as parameters, return types, and array elements.  This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations.  A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile.  Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type.  It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack.  If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction?  Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot.  But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes.  I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value.  Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType {     protected final long header;     protected private final BigInteger digits;     public DecimalValue valueOf(int value, int scale) {         assert(scale >= 0);         return new DecimalValue(((long)value << 32) + scale, null);     }     public DecimalValue valueOf(long value, int scale) {         if (value == (int) value)             return valueOf((int)value, scale);         return new DecimalValue(-scale, new BigInteger(value));     } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case.  It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues.  (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.)  Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits.  For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types.  This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant.  An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes.  More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable,         Unsynchronizable, Interchangeable { … public class Complex implements ValueType {     // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe     … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types.  This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable.  It is likely that code which violates value-safety for wrapper types exists but is uncommon.  It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code.  The design presented above obscures that distinction.  As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations.  Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed.  For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi;  // convert to boxed myList.add(boxPi); complex z = myList.get(0);  // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM.  Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type.  Something like this which can also accommodate value type components seems worthwhile.  On the other hand, does it make sense for value types to contain short arrays?  And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure.  These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types.  In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids.  No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now.  Back to work!

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• Parsing concatenated, non-delimited XML messages from TCP-stream using C#

  - by thaller

  I am trying to parse XML messages which are send to my C# application over TCP. Unfortunately, the protocol can not be changed and the XML messages are not delimited and no length prefix is used. Moreover the character encoding is not fixed but each message starts with an XML declaration <?xml>. The question is, how can i read one XML message at a time, using C#. Up to now, I tried to read the data from the TCP stream into a byte array and use it through a MemoryStream. The problem is, the buffer might contain more than one XML messages or the first message may be incomplete. In these cases, I get an exception when trying to parse it with XmlReader.Read or XmlDocument.Load, but unfortunately the XmlException does not really allow me to distinguish the problem (except parsing the localized error string). I tried using XmlReader.Read and count the number of Element and EndElement nodes. That way I know when I am finished reading the first, entire XML message. However, there are several problems. If the buffer does not yet contain the entire message, how can I distinguish the XmlException from an actually invalid, non-well-formed message? In other words, if an exception is thrown before reading the first root EndElement, how can I decide whether to abort the connection with error, or to collect more bytes from the TCP stream? If no exception occurs, the XmlReader is positioned at the start of the root EndElement. Casting the XmlReader to IXmlLineInfo gives me the current LineNumber and LinePosition, however it is not straight forward to get the byte position where the EndElement really ends. In order to do that, I would have to convert the byte array into a string (with the encoding specified in the XML declaration), seek to LineNumber,LinePosition and convert that back to the byte offset. I try to do that with StreamReader.ReadLine, but the stream reader gives no public access to the current byte position. All this seams very inelegant and non robust. I wonder if you have ideas for a better solution. Thank you. EDIT: I looked around and think that the situation is as follows (I might be wrong, corrections are welcome): I found no method so that the XmlReader can continue parsing a second XML message (at least not, if the second message has an XmlDeclaration). XmlTextReader.ResetState could do something similar, but for that I would have to assume the same encoding for all messages. Therefor I could not connect the XmlReader directly to the TcpStream. After closing the XmlReader, the buffer is not positioned at the readers last position. So it is not possible to close the reader and use a new one to continue with the next message. I guess the reason for this is, that the reader could not successfully seek on every possible input stream. When XmlReader throws an exception it can not be determined whether it happened because of an premature EOF or because of a non-wellformed XML. XmlReader.EOF is not set in case of an exception. As workaround I derived my own MemoryBuffer, which returns the very last byte as a single byte. This way I know that the XmlReader was really interested in the last byte and the following exception is likely due to a truncated message (this is kinda sloppy, in that it might not detect every non-wellformed message. However, after appending more bytes to the buffer, sooner or later the error will be detected. I could cast my XmlReader to the IXmlLineInfo interface, which gives access to the LineNumber and the LinePosition of the current node. So after reading the first message I remember these positions and use it to truncate the buffer. Here comes the really sloppy part, because I have to use the character encoding to get the byte position. I am sure you could find test cases for the code below where it breaks (e.g. internal elements with mixed encoding). But up to now it worked for all my tests. The parser class follows here -- may it be useful (I know, its very far from perfect...) class XmlParser { private byte[] buffer = new byte[0]; public int Length { get { return buffer.Length; } } // Append new binary data to the internal data buffer... public XmlParser Append(byte[] buffer2) { if (buffer2 != null && buffer2.Length > 0) { // I know, its not an efficient way to do this. // The EofMemoryStream should handle a List<byte[]> ... byte[] new_buffer = new byte[buffer.Length + buffer2.Length]; buffer.CopyTo(new_buffer, 0); buffer2.CopyTo(new_buffer, buffer.Length); buffer = new_buffer; } return this; } // MemoryStream which returns the last byte of the buffer individually, // so that we know that the buffering XmlReader really locked at the last // byte of the stream. // Moreover there is an EOF marker. private class EofMemoryStream: Stream { public bool EOF { get; private set; } private MemoryStream mem_; public override bool CanSeek { get { return false; } } public override bool CanWrite { get { return false; } } public override bool CanRead { get { return true; } } public override long Length { get { return mem_.Length; } } public override long Position { get { return mem_.Position; } set { throw new NotSupportedException(); } } public override void Flush() { mem_.Flush(); } public override long Seek(long offset, SeekOrigin origin) { throw new NotSupportedException(); } public override void SetLength(long value) { throw new NotSupportedException(); } public override void Write(byte[] buffer, int offset, int count) { throw new NotSupportedException(); } public override int Read(byte[] buffer, int offset, int count) { count = Math.Min(count, Math.Max(1, (int)(Length - Position - 1))); int nread = mem_.Read(buffer, offset, count); if (nread == 0) { EOF = true; } return nread; } public EofMemoryStream(byte[] buffer) { mem_ = new MemoryStream(buffer, false); EOF = false; } protected override void Dispose(bool disposing) { mem_.Dispose(); } } // Parses the first xml message from the stream. // If the first message is not yet complete, it returns null. // If the buffer contains non-wellformed xml, it ~should~ throw an exception. // After reading an xml message, it pops the data from the byte array. public Message deserialize() { if (buffer.Length == 0) { return null; } Message message = null; Encoding encoding = Message.default_encoding; //string xml = encoding.GetString(buffer); using (EofMemoryStream sbuffer = new EofMemoryStream (buffer)) { XmlDocument xmlDocument = null; XmlReaderSettings settings = new XmlReaderSettings(); int LineNumber = -1; int LinePosition = -1; bool truncate_buffer = false; using (XmlReader xmlReader = XmlReader.Create(sbuffer, settings)) { try { // Read to the first node (skipping over some element-types. // Don't use MoveToContent here, because it would skip the // XmlDeclaration too... while (xmlReader.Read() && (xmlReader.NodeType==XmlNodeType.Whitespace || xmlReader.NodeType==XmlNodeType.Comment)) { }; // Check for XML declaration. // If the message has an XmlDeclaration, extract the encoding. switch (xmlReader.NodeType) { case XmlNodeType.XmlDeclaration: while (xmlReader.MoveToNextAttribute()) { if (xmlReader.Name == "encoding") { encoding = Encoding.GetEncoding(xmlReader.Value); } } xmlReader.MoveToContent(); xmlReader.Read(); break; } // Move to the first element. xmlReader.MoveToContent(); // Read the entire document. xmlDocument = new XmlDocument(); xmlDocument.Load(xmlReader.ReadSubtree()); } catch (XmlException e) { // The parsing of the xml failed. If the XmlReader did // not yet look at the last byte, it is assumed that the // XML is invalid and the exception is re-thrown. if (sbuffer.EOF) { return null; } throw e; } { // Try to serialize an internal data structure using XmlSerializer. Type type = null; try { type = Type.GetType("my.namespace." + xmlDocument.DocumentElement.Name); } catch (Exception e) { // No specialized data container for this class found... } if (type == null) { message = new Message(); } else { // TODO: reuse the serializer... System.Xml.Serialization.XmlSerializer ser = new System.Xml.Serialization.XmlSerializer(type); message = (Message)ser.Deserialize(new XmlNodeReader(xmlDocument)); } message.doc = xmlDocument; } // At this point, the first XML message was sucessfully parsed. // Remember the lineposition of the current end element. IXmlLineInfo xmlLineInfo = xmlReader as IXmlLineInfo; if (xmlLineInfo != null && xmlLineInfo.HasLineInfo()) { LineNumber = xmlLineInfo.LineNumber; LinePosition = xmlLineInfo.LinePosition; } // Try to read the rest of the buffer. // If an exception is thrown, another xml message appears. // This way the xml parser could tell us that the message is finished here. // This would be prefered as truncating the buffer using the line info is sloppy. try { while (xmlReader.Read()) { } } catch { // There comes a second message. Needs workaround for trunkating. truncate_buffer = true; } } if (truncate_buffer) { if (LineNumber < 0) { throw new Exception("LineNumber not given. Cannot truncate xml buffer"); } // Convert the buffer to a string using the encoding found before // (or the default encoding). string s = encoding.GetString(buffer); // Seek to the line. int char_index = 0; while (--LineNumber > 0) { // Recognize \r , \n , \r\n as newlines... char_index = s.IndexOfAny(new char[] {'\r', '\n'}, char_index); // char_index should not be -1 because LineNumber>0, otherwise an RangeException is // thrown, which is appropriate. char_index++; if (s[char_index-1]=='\r' && s.Length>char_index && s[char_index]=='\n') { char_index++; } } char_index += LinePosition - 1; var rgx = new System.Text.RegularExpressions.Regex(xmlDocument.DocumentElement.Name + "[ \r\n\t]*\\>"); System.Text.RegularExpressions.Match match = rgx.Match(s, char_index); if (!match.Success || match.Index != char_index) { throw new Exception("could not find EndElement to truncate the xml buffer."); } char_index += match.Value.Length; // Convert the character offset back to the byte offset (for the given encoding). int line1_boffset = encoding.GetByteCount(s.Substring(0, char_index)); // remove the bytes from the buffer. buffer = buffer.Skip(line1_boffset).ToArray(); } else { buffer = new byte[0]; } } return message; } }

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• C code won't compile

  - by cc

  Please help me to understand why the following code will not compile: #include <stdio.h> //#include <iostream> //using namespace std; int main(void){ int i,k,x,y,run,e,r,s,m,count=0; char numbers[19][19]; for(i=0;i<19;i++){ for (k=0;k<19;k++){ numbers[i][k]='.'; } } void drawB(){ printf(" 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 \n"); printf ("0 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[0][0],numbers[0][1],numbers[0][2],numbers[0][3],numbers[0][4], numbers[0][5],numbers[0][6],numbers[0][7],numbers[0][8],numbers[0][9], numbers[0][10],numbers[1][11],numbers[1][12],numbers[1][13],numbers[0][14] ,numbers[0][15],numbers[0][16],numbers[0][17],numbers[0][18]); printf ("1 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[1][0],numbers[1][1],numbers[1][2],numbers[1][3],numbers[1][4], numbers[1][5],numbers[1][6],numbers[1][7],numbers[1][8],numbers[1][9], numbers[1][10],numbers[1][11],numbers[1][12],numbers[1][13],numbers[1][14] ,numbers[1][15],numbers[1][16],numbers[1][17],numbers[1][18]); printf ("2 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" numbers[2][0],numbers[2][1],numbers[2][2],numbers[2][3],numbers[2][4], numbers[2][5],numbers[2][6],numbers[2][7],numbers[2][8],numbers[2][9], numbers[2][10],numbers[2][11],numbers[2][12],numbers[2][13],numbers[2][14] ,numbers[2][15],numbers[2][16],numbers[2][17],numbers[2][18]); printf ("3 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[3][0],numbers[3][1],numbers[3][2],numbers[3][3],numbers[3][4], numbers[3][5],numbers[3][6],numbers[3][7],numbers[3][8],numbers[3][9], numbers[3][10],numbers[3][11],numbers[3][12],numbers[3][13],numbers[3][14] ,numbers[3][15],numbers[3][16],numbers[3][17],numbers[3][18]); printf ("4 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[4][0],numbers[4][1],numbers[4][2],numbers[4][3],numbers[4][4], numbers[4][5],numbers[4][6],numbers[4][7],numbers[4][8],numbers[4][9], numbers[4][10],numbers[4][11],numbers[4][12],numbers[4][13],numbers[4][14] ,numbers[4][15],numbers[4][16],numbers[4][17],numbers[4][18]); printf ("5 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[5][0],numbers[5][1],numbers[5][2],numbers[5][3],numbers[5][4], numbers[5][5],numbers[5][6],numbers[5][7],numbers[5][8],numbers[5][9], numbers[5][10],numbers[5][11],numbers[5][12],numbers[5][13],numbers[5][14] ,numbers[5][15],numbers[5][16],numbers[5][17],numbers[5][18]); printf ("6 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[6][0],numbers[6][1],numbers[6][2],numbers[6][3],numbers[6][4], numbers[6][5],numbers[6][6],numbers[6][7],numbers[6][8],numbers[6][9], numbers[6][10],numbers[6][11],numbers[6][12],numbers[6][13],numbers[6][14] ,numbers[6][15],numbers[6][16],numbers[6][17],numbers[6][18]); printf ("7 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[7][0],numbers[7][1],numbers[7][2],numbers[7][3],numbers[7][4], numbers[7][5],numbers[7][6],numbers[7][7],numbers[7][8],numbers[7][9], numbers[7][10],numbers[7][11],numbers[7][12],numbers[7][13],numbers[7][14] ,numbers[7][15],numbers[7][16],numbers[7][17],numbers[7][18]); printf ("8 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[8][0],numbers[8][1],numbers[8][2],numbers[8][3],numbers[8][4], numbers[8][5],numbers[8][6],numbers[8][7],numbers[8][8],numbers[8][9], numbers[8][10],numbers[8][11],numbers[8][12],numbers[8][13],numbers[8][14] ,numbers[8][15],numbers[8][16],numbers[8][17],numbers[8][18]); printf ("9 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[9][0],numbers[9][1],numbers[9][2],numbers[9][3],numbers[9][4], numbers[9][5],numbers[9][6],numbers[9][7],numbers[9][8],numbers[9][9], numbers[9][10],numbers[9][11],numbers[9][12],numbers[9][13],numbers[9][14] ,numbers[9][15],numbers[9][16],numbers[9][17],numbers[9][18]); printf ("0 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[10][0],numbers[10][1],numbers[10][2],numbers[10][3],numbers[10][4], numbers[10][5],numbers[10][6],numbers[10][7],numbers[10][8],numbers[10][9], numbers[10][10],numbers[10][11],numbers[10][12],numbers[10][13],numbers[10][14] ,numbers[10][15],numbers[10][16],numbers[10][17],numbers[10][18]); printf ("1 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[11][0],numbers[11][1],numbers[11][2],numbers[11][3],numbers[11][4], numbers[11][5],numbers[11][6],numbers[11][7],numbers[11][8],numbers[11][9], numbers[11][10],numbers[11][11],numbers[11][12],numbers[11][13],numbers[11][14] ,numbers[11][15],numbers[11][16],numbers[11][17],numbers[11][18]); printf ("2 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[12][0],numbers[12][1],numbers[12][2],numbers[12][3],numbers[12][4], numbers[12][5],numbers[12][6],numbers[12][7],numbers[12][8],numbers[12][9], numbers[12][10],numbers[12][11],numbers[12][12],numbers[12][13],numbers[12][14] ,numbers[12][15],numbers[12][16],numbers[12][17],numbers[12][18]); printf ("3 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[13][0],numbers[13][1],numbers[13][2],numbers[13][3],numbers[13][4], numbers[13][5],numbers[13][6],numbers[13][7],numbers[13][8],numbers[13][9], numbers[13][10],numbers[13][11],numbers[13][12],numbers[13][13],numbers[13][14] ,numbers[13][15],numbers[13][16],numbers[13][17],numbers[13][18]); printf ("4 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[14][0],numbers[14][1],numbers[14][2],numbers[14][3],numbers[14][4], numbers[14][5],numbers[14][6],numbers[14][7],numbers[14][8],numbers[14][9], numbers[14][10],numbers[14][11],numbers[14][12],numbers[14][13],numbers[14][14] ,numbers[14][15],numbers[14][16],numbers[14][17],numbers[14][18]); printf ("5 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[15][0],numbers[15][1],numbers[15][2],numbers[15][3],numbers[15][4], numbers[15][5],numbers[15][6],numbers[15][7],numbers[15][8],numbers[15][9], numbers[15][10],numbers[15][11],numbers[15][12],numbers[15][13],numbers[15][14] ,numbers[15][15],numbers[15][16],numbers[15][17],numbers[15][18]); printf ("6 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[16][0],numbers[16][1],numbers[16][2],numbers[16][3],numbers[16][4], numbers[16][5],numbers[16][6],numbers[16][7],numbers[16][8],numbers[16][9], numbers[16][10],numbers[16][11],numbers[16][12],numbers[16][13],numbers[16][14] ,numbers[16][15],numbers[16][16],numbers[16][17],numbers[16][18]); printf ("7 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[17][0],numbers[17][1],numbers[17][2],numbers[17][3],numbers[17][4], numbers[17][5],numbers[17][6],numbers[17][7],numbers[17][8],numbers[17][9], numbers[17][10],numbers[17][11],numbers[17][12],numbers[17][13],numbers[17][14] ,numbers[17][15],numbers[17][16],numbers[17][17],numbers[17][18]); printf ("8 %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \n\n" ,numbers[18][0],numbers[18][1],numbers[18][2],numbers[18][3],numbers[18][4], numbers[18][5],numbers[18][6],numbers[18][7],numbers[18][8],numbers[18][9], numbers[18][10],numbers[18][11],numbers[18][12],numbers[18][13],numbers[18][14] ,numbers[18][15],numbers[18][16],numbers[18][17],numbers[18][18]); } void checkSurrounded (int x,int y){ //numbers [x-1,y-1 ] , numbers [x-1,y ] , numbers [x-1,y+1 ] //numbers [x,y-1 ] , numbers [x,y ] , numbers [x,y+1 ] //numbers [x+1,y-1, ] , numbers [x+1,y ] , numbers [x+1,y+1 ] if(numbers[x][y]=='A'){ if((numbers[x-1][y-1]=='B') && (numbers[x-1][y]=='B') && (numbers[x-1][y+1]=='B') && (numbers[x][y-1]=='B') && (numbers[x][y+1]=='B') && (numbers[x+1][y-1]=='B') && (numbers[x+1][y]=='B')){ numbers[x][y]='B';} } if(numbers[x][y]=='B'){ if((numbers[x-1][y-1]=='A') && (numbers[x-1][y]=='A') && (numbers[x-1][y+1]=='A') && (numbers[x][y-1]=='A') && (numbers[x][y+1]=='A') && (numbers[x+1][y-1]=='A') && (numbers[x+1][y]=='A')){ numbers[x][y]='A'; } } } /** void checkArea(){ //detect enemy stone //store in array //find adjacent enemy stones // store the enemy stones in the array //keep on doing this until there are no more enemy stones that are adjacent for (s=0;s<19;s++) { for (m=0;m<19;m++) { if (numbers[s][m]=='A'){ count++; } } } }//end fn void checkAdjacent(int x, int y){ if (numbers [x][y]=='A'){ if((numbers[x][y-1]=='B' && numbers [x-1][y]=='B' && numbers[x][y+1]=='B' && numbers[x+1][y]=='B')){ } } } void getUserInput(){ int run=1; while(run){ printf("Enter x coordinate\n"); scanf("%d",&x); printf("Enter y coordinate\n"); scanf("%d",&y); if((x>18 || y>18 || x<0 || y<0) && !( numbers[x][y]=='.' )){ printf("invalid imput\n"); } else{ numbers[x][y]='B'; run=0; drawB(); } } } */ void getCupInput(){ //go through borad //starting from [0][0] //stop at first player stone //save as target x and target y //surround target x and target y //if already surrounded //start looking in borad again from last position //at end of board reset to [0][0] for(s=0;s<19;s++) { for(m=0;m<19;m++) { if (numbers[s][m]==0){ count++; } } } x=x-2; y=y+2; numbers[x][y]='A'; drawB(); } while(1){ //getUserInput(); getCupInput(); } system("pause"); return 0; }

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• Memory leak / GLib issue.

  - by Andrei Ciobanu

  1: /* 2: * File: xyn-playlist.c 3: * Author: Andrei Ciobanu 4: * 5: * Created on June 4, 2010, 12:47 PM 6: */ 7:   8: #include <dirent.h> 9: #include <glib.h> 10: #include <stdio.h> 11: #include <stdlib.h> 12: #include <sys/stat.h> 13: #include <unistd.h> 14:   15: /** 16: * Returns a list all the file(paths) from a directory. 17: * Returns 'NULL' if a certain error occurs. 18: * @param dir_path. 19: * @param A list of gchars* indicating what file patterns to detect. 20: */ 21: GSList *xyn_pl_get_files(const gchar *dir_path, GSList *file_patterns) { 22: /* Returning list containing file paths */ 23: GSList *fpaths = NULL; 24: /* Used to scan directories for subdirs. Acts like a 25: * stack, to avoid recursion. */ 26: GSList *dirs = NULL; 27: /* Current dir */ 28: DIR *cdir = NULL; 29: /* Current dir entries */ 30: struct dirent *cent = NULL; 31: /* File stats */ 32: struct stat cent_stat; 33: /* dir_path duplicate, on the heap */ 34: gchar *dir_pdup; 35:   36: if (dir_path == NULL) { 37: return NULL; 38: } 39:   40: dir_pdup = g_strdup((const gchar*) dir_path); 41: dirs = g_slist_append(dirs, (gpointer) dir_pdup); 42: while (dirs != NULL) { 43: cdir = opendir((const gchar*) dirs->data); 44: if (cdir == NULL) { 45: g_slist_free(dirs); 46: g_slist_free(fpaths); 47: return NULL; 48: } 49: chdir((const gchar*) dirs->data); 50: while ((cent = readdir(cdir)) != NULL) { 51: lstat(cent->d_name, &cent_stat); 52: if (S_ISDIR(cent_stat.st_mode)) { 53: if (g_strcmp0(cent->d_name, ".") == 0 || 54: g_strcmp0(cent->d_name, "..") == 0) { 55: /* Skip "." and ".." dirs */ 56: continue; 57: } 58: dirs = g_slist_append(dirs, 59: g_strconcat((gchar*) dirs->data, "/", cent->d_name, NULL)); 60: } else { 61: fpaths = g_slist_append(fpaths, 62: g_strconcat((gchar*) dirs->data, "/", cent->d_name, NULL)); 63: } 64: } 65: g_free(dirs->data); 66: dirs = g_slist_delete_link(dirs, dirs); 67: closedir(cdir); 68: } 69: return fpaths; 70: } 71:   72: int main(int argc, char** argv) { 73: GSList *l = NULL; 74: l = xyn_pl_get_files("/home/andrei/Music", NULL); 75: g_slist_foreach(l,(GFunc)printf,NULL); 76: printf("%d\n",g_slist_length(l)); 77: g_slist_free(l); 78: return (0); 79: } 80:   81:   82: -----------------------------------------------------------------------------------------------==15429== 83: ==15429== HEAP SUMMARY: 84: ==15429== in use at exit: 751,451 bytes in 7,263 blocks 85: ==15429== total heap usage: 8,611 allocs, 1,348 frees, 22,898,217 bytes allocated 86: ==15429== 87: ==15429== 120 bytes in 1 blocks are possibly lost in loss record 1 of 11 88: ==15429== at 0x4024106: memalign (vg_replace_malloc.c:581) 89: ==15429== by 0x4024163: posix_memalign (vg_replace_malloc.c:709) 90: ==15429== by 0x40969C1: ??? (in /lib/libglib-2.0.so.0.2400.1) 91: ==15429== by 0x40971F6: g_slice_alloc (in /lib/libglib-2.0.so.0.2400.1) 92: ==15429== by 0x40988A5: g_slist_append (in /lib/libglib-2.0.so.0.2400.1) 93: ==15429== by 0x80488F0: xyn_pl_get_files (xyn-playlist.c:41) 94: ==15429== by 0x8048848: main (main.c:18) 95: ==15429== 96: ==15429== 129 bytes in 1 blocks are possibly lost in loss record 2 of 11 97: ==15429== at 0x4024F20: malloc (vg_replace_malloc.c:236) 98: ==15429== by 0x4081243: g_malloc (in /lib/libglib-2.0.so.0.2400.1) 99: ==15429== by 0x409B85B: g_strconcat (in /lib/libglib-2.0.so.0.2400.1) 100: ==15429== by 0x80489FE: xyn_pl_get_files (xyn-playlist.c:62) 101: ==15429== by 0x8048848: main (main.c:18) 102: ==15429== 103: ==15429== 360 bytes in 3 blocks are possibly lost in loss record 3 of 11 104: ==15429== at 0x4024106: memalign (vg_replace_malloc.c:581) 105: ==15429== by 0x4024163: posix_memalign (vg_replace_malloc.c:709) 106: ==15429== by 0x40969C1: ??? (in /lib/libglib-2.0.so.0.2400.1) 107: ==15429== by 0x4097222: g_slice_alloc (in /lib/libglib-2.0.so.0.2400.1) 108: ==15429== by 0x40988A5: g_slist_append (in /lib/libglib-2.0.so.0.2400.1) 109: ==15429== by 0x80488F0: xyn_pl_get_files (xyn-playlist.c:41) 110: ==15429== by 0x8048848: main (main.c:18) 111: ==15429== 112: ==15429== 508 bytes in 1 blocks are still reachable in loss record 4 of 11 113: ==15429== at 0x402425F: calloc (vg_replace_malloc.c:467) 114: ==15429== by 0x408113B: g_malloc0 (in /lib/libglib-2.0.so.0.2400.1) 115: ==15429== by 0x409624D: ??? (in /lib/libglib-2.0.so.0.2400.1) 116: ==15429== by 0x409710C: g_slice_alloc (in /lib/libglib-2.0.so.0.2400.1) 117: ==15429== by 0x40988A5: g_slist_append (in /lib/libglib-2.0.so.0.2400.1) 118: ==15429== by 0x80488F0: xyn_pl_get_files (xyn-playlist.c:41) 119: ==15429== by 0x8048848: main (main.c:18) 120: ==15429== 121: ==15429== 508 bytes in 1 blocks are still reachable in loss record 5 of 11 122: ==15429== at 0x402425F: calloc (vg_replace_malloc.c:467) 123: ==15429== by 0x408113B: g_malloc0 (in /lib/libglib-2.0.so.0.2400.1) 124: ==15429== by 0x409626F: ??? (in /lib/libglib-2.0.so.0.2400.1) 125: ==15429== by 0x409710C: g_slice_alloc (in /lib/libglib-2.0.so.0.2400.1) 126: ==15429== by 0x40988A5: g_slist_append (in /lib/libglib-2.0.so.0.2400.1) 127: ==15429== by 0x80488F0: xyn_pl_get_files (xyn-playlist.c:41) 128: ==15429== by 0x8048848: main (main.c:18) 129: ==15429== 130: ==15429== 508 bytes in 1 blocks are still reachable in loss record 6 of 11 131: ==15429== at 0x402425F: calloc (vg_replace_malloc.c:467) 132: ==15429== by 0x408113B: g_malloc0 (in /lib/libglib-2.0.so.0.2400.1) 133: ==15429== by 0x4096291: ??? (in /lib/libglib-2.0.so.0.2400.1) 134: ==15429== by 0x409710C: g_slice_alloc (in /lib/libglib-2.0.so.0.2400.1) 135: ==15429== by 0x40988A5: g_slist_append (in /lib/libglib-2.0.so.0.2400.1) 136: ==15429== by 0x80488F0: xyn_pl_get_files (xyn-playlist.c:41) 137: ==15429== by 0x8048848: main (main.c:18) 138: ==15429== 139: ==15429== 1,200 bytes in 10 blocks are possibly lost in loss record 7 of 11 140: ==15429== at 0x4024106: memalign (vg_replace_malloc.c:581) 141: ==15429== by 0x4024163: posix_memalign (vg_replace_malloc.c:709) 142: ==15429== by 0x40969C1: ??? (in /lib/libglib-2.0.so.0.2400.1) 143: ==15429== by 0x40971F6: g_slice_alloc (in /lib/libglib-2.0.so.0.2400.1) 144: ==15429== by 0x40988A5: g_slist_append (in /lib/libglib-2.0.so.0.2400.1) 145: ==15429== by 0x8048A0D: xyn_pl_get_files (xyn-playlist.c:61) 146: ==15429== by 0x8048848: main (main.c:18) 147: ==15429== 148: ==15429== 2,040 bytes in 1 blocks are still reachable in loss record 8 of 11 149: ==15429== at 0x402425F: calloc (vg_replace_malloc.c:467) 150: ==15429== by 0x408113B: g_malloc0 (in /lib/libglib-2.0.so.0.2400.1) 151: ==15429== by 0x40970AB: g_slice_alloc (in /lib/libglib-2.0.so.0.2400.1) 152: ==15429== by 0x40988A5: g_slist_append (in /lib/libglib-2.0.so.0.2400.1) 153: ==15429== by 0x80488F0: xyn_pl_get_files (xyn-playlist.c:41) 154: ==15429== by 0x8048848: main (main.c:18) 155: ==15429== 156: ==15429== 4,320 bytes in 36 blocks are possibly lost in loss record 9 of 11 157: ==15429== at 0x4024106: memalign (vg_replace_malloc.c:581) 158: ==15429== by 0x4024163: posix_memalign (vg_replace_malloc.c:709) 159: ==15429== by 0x40969C1: ??? (in /lib/libglib-2.0.so.0.2400.1) 160: ==15429== by 0x4097222: g_slice_alloc (in /lib/libglib-2.0.so.0.2400.1) 161: ==15429== by 0x40988A5: g_slist_append (in /lib/libglib-2.0.so.0.2400.1) 162: ==15429== by 0x80489D2: xyn_pl_get_files (xyn-playlist.c:58) 163: ==15429== by 0x8048848: main (main.c:18) 164: ==15429== 165: ==15429== 56,640 bytes in 472 blocks are possibly lost in loss record 10 of 11 166: ==15429== at 0x4024106: memalign (vg_replace_malloc.c:581) 167: ==15429== by 0x4024163: posix_memalign (vg_replace_malloc.c:709) 168: ==15429== by 0x40969C1: ??? (in /lib/libglib-2.0.so.0.2400.1) 169: ==15429== by 0x4097222: g_slice_alloc (in /lib/libglib-2.0.so.0.2400.1) 170: ==15429== by 0x40988A5: g_slist_append (in /lib/libglib-2.0.so.0.2400.1) 171: ==15429== by 0x8048A0D: xyn_pl_get_files (xyn-playlist.c:61) 172: ==15429== by 0x8048848: main (main.c:18) 173: ==15429== 174: ==15429== 685,118 bytes in 6,736 blocks are definitely lost in loss record 11 of 11 175: ==15429== at 0x4024F20: malloc (vg_replace_malloc.c:236) 176: ==15429== by 0x4081243: g_malloc (in /lib/libglib-2.0.so.0.2400.1) 177: ==15429== by 0x409B85B: g_strconcat (in /lib/libglib-2.0.so.0.2400.1) 178: ==15429== by 0x80489FE: xyn_pl_get_files (xyn-playlist.c:62) 179: ==15429== by 0x8048848: main (main.c:18) 180: ==15429== 181: ==15429== LEAK SUMMARY: 182: ==15429== definitely lost: 685,118 bytes in 6,736 blocks 183: ==15429== indirectly lost: 0 bytes in 0 blocks 184: ==15429== possibly lost: 62,769 bytes in 523 blocks 185: ==15429== still reachable: 3,564 bytes in 4 blocks 186: ==15429== suppressed: 0 bytes in 0 blocks 187: ==15429== 188: ==15429== For counts of detected and suppressed errors, rerun with: -v 189: ==15429== ERROR SUMMARY: 7 errors from 7 contexts (suppressed: 17 from 8) 190: ---------------------------------------------------------------------------------------------- I am using the above code in order to create a list with all the filepaths in a certain directory. (In my case fts.h or ftw.h are not an option). I am using GLib as the data structures library. Still I have my doubts in regarding the way GLib is allocating, de-allocating memory ? When invoking g_slist_free(list) i also free the data contained by the elements ? Why all those memory leaks appear ? Is valgrind a suitable tool for profilinf memory issues when using a complex library like GLib ? LATER EDIT: If I g_slist_foreach(l,(GFunc)g_free,NULL);, the valgrind report is different, (All the memory leaks from 'definitely lost' will move to 'indirectly lost'). Still I don't see the point ? Aren't GLib collections implement a way to be freed ?

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• Getting problem in collision detection in Java Game

  - by chetans

  Hi I am developing Spaceship Game in which i am getting problem in collision detection of moving images Game has a spaceship and number of asteroids(obstacles) i want to detect the collision between them How can i do this?`package Game; import java.applet.Applet; import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Image; import java.awt.MediaTracker; import java.awt.event.KeyEvent; import java.awt.event.KeyListener; import java.net.MalformedURLException; import java.net.URL; public class ThreadInApplet extends Applet implements KeyListener { private static final long serialVersionUID = 1L; Image[] asteroidImage; Image spaceshipImage; int[] XPosObst,YPosObst; int numberOfObstacles=0,XPosOfSpaceship,YPosOfSpaceship; int spaceButtnCntr=0,noOfObstaclesLevel=20; boolean gameStart=false,collideUp=false,collideDown=false,collideLeft=false,collideRight=false; private Image offScreenImage; private Dimension offScreenSize,d; private Graphics offScreenGraphics; int speedObstacles=1; String spaceshipImagePath="images/spaceship.png",obstacleImagepath="images/asteroid.png"; String buttonToStart="Press Space to start"; public void init() { try { asteroidImage=new Image[noOfObstaclesLevel]; XPosObst=new int[noOfObstaclesLevel]; YPosObst=new int[noOfObstaclesLevel]; XPosOfSpaceship=getWidth()/2-35; YPosOfSpaceship=getHeight()-100; spaceshipImage=getImage(new URL(getCodeBase(),spaceshipImagePath)); for(int i=0;i<noOfObstaclesLevel;i++) { asteroidImage[i]=getImage(new URL(getCodeBase(),obstacleImagepath)); XPosObst[i]=(int) (Math.random()*700); YPosObst[i]=0; } MediaTracker tracker = new MediaTracker (this); for(int i=0;i<noOfObstaclesLevel;i++) { tracker.addImage (asteroidImage[i], 0); } } catch (MalformedURLException e) { e.printStackTrace(); } setBackground(Color.black); addKeyListener(this); } public void paint(Graphics g) { g.setColor(Color.white); if(gameStart==false) { g.drawString(buttonToStart, (getWidth()/2)-60, getHeight()/2); } g.drawString("HEADfitted Solutions Pvt.Ltd.", (getWidth()/2)-80, getHeight()-20); for(int n=0;n<numberOfObstacles;n++) { if(n>0) g.drawImage(asteroidImage[n],XPosObst[n],YPosObst[n],this); } g.drawImage(spaceshipImage,XPosOfSpaceship,YPosOfSpaceship,this); } @SuppressWarnings("deprecation") public void update(Graphics g) { d = size(); if((offScreenImage == null) || (d.width != offScreenSize.width) || (d.height != offScreenSize.height)) { offScreenImage = createImage(d.width, d.height); offScreenSize = d; offScreenGraphics = offScreenImage.getGraphics(); } offScreenGraphics.clearRect(0, 0, d.width, d.height); paint(offScreenGraphics); g.drawImage(offScreenImage, 0, 0, null); } public void keyReleased(KeyEvent arg0){} public void keyTyped(KeyEvent arg0) {} Thread mainThread=new Thread() { synchronized public void run () { try { //System.out.println("in main thread"); if (gameStart==true) { moveObstacles.start(); if(collide()==false) { createObsThread.start(); } } } catch (Exception e) { e.printStackTrace(); } } }; Thread createObsThread=new Thread() { synchronized public void run () { if (spaceButtnCntr==1) { if (collide()==false) { for(int g=0;g<noOfObstaclesLevel;g++) { try { sleep(1000); } catch (InterruptedException e) { e.printStackTrace(); } numberOfObstacles++; } } } } }; Thread moveObstacles=new Thread() // Moving Obstacle images downwards after every 10 ms { synchronized public void run () { while(YPosObst[19]!=600) { if (collide()==false) { //createObsThread.start(); for(int l=0;l } repaint(); try { sleep(10); } catch (InterruptedException e) { e.printStackTrace(); } } } } }; public void keyPressed(KeyEvent e) { if(e.getKeyCode()==32) { gameStart=true; spaceButtnCntr++; if (spaceButtnCntr==1) { mainThread.start(); } } if(gameStart==true) { if(e.getKeyCode()==37 && collideLeft==false)//Spaceship movement left { new Thread () { synchronized public void run () { XPosOfSpaceship-=10; repaint(); } }.start(); } if(e.getKeyCode()==38 && collideUp==false)//Spaceship movement up { new Thread () { synchronized public void run () { YPosOfSpaceship-=10; repaint(); } }.start(); } if(e.getKeyCode()==39 && collideRight==false)//Spaceship movement right { new Thread () { synchronized public void run () { XPosOfSpaceship+=10; repaint(); } }.start(); } if(e.getKeyCode()==40 && collideDown==false)//Spaceship movement down { new Thread () { synchronized public void run () { YPosOfSpaceship+=10; repaint(); } }.start(); } } } /*public boolean collide() { int x0, y0, w0, h0, x2, y2, w2, h2; x0=XPosOfSpaceship; y0=YPosOfSpaceship; h0=spaceshipImage.getHeight(null); w0=spaceshipImage.getWidth(null); for(int i=0;i<20;i++) { x2=XPosObst[i]; y2=YPosObst[i]; h2=asteroidImage[i].getHeight(null); w2=asteroidImage[i].getWidth(null); if ((x0 > (x2 + w2)) || ((x0 + w0) < x2)) return false; System.out.println(x2+" "+y2+" "+h2+" "+w2); if ((y0 > (y2 + h2)) || ((y0 + h0) < y2)) return false; } return true; }*/ public boolean collide() { int x1,y1,x2,y2,x3,y3,x4,y4; //coordinates of obstacles int a1,b1,a2,b2,a3,b3,a4,b4; //coordinates of spaceship a1 =XPosOfSpaceship; b1=YPosOfSpaceship; a2=a1+spaceshipImage.getWidth(this); b2=b1; a3=a1; b3=b1+spaceshipImage.getHeight(this); a4=a2; b4=b3; for(int a=0;a if(x1>=a1 && x1<=a2 && x1<=b3 && x1>=b1) return (true); if(x2>=a1 && x2<=a2 && x2<=b3 && x2>=b1) return(true); //********checking asteroid touch spaceship from up direction******** if(y3==b1 && x4>=a1 && x4<=a2) { collideUp = true; return(true); } if(y3==b1 && x3>=a1 && x3<=a2) { collideUp = true; return(true); } //********checking asteroid touch spaceship from left direction****** if(x2==a1 && y4>=b1 && y4<=b3) { collideLeft=true; return(true); } if(x2==a1 && y2>=b1 && y2<=b3) { collideLeft=true; return(true); } //********checking asteroid touch spaceship from right direction***** if(x1==a2 && y3>=b2 && y3<=b4) { collideRight=true; return(true); } if(x1==a2 && y1>=b2 && y1<=b4) { collideRight=true; return(true); } //********checking asteroid touch spaceship from down direction***** if(y1==b3 && x2>=a3 && x2<=a4) { collideDown=true; return(true); } if(y1==b3 && x1>=a3 && x1<=a4) { collideDown=true; return(true); } else { collideUp=false; collideDown=false; collideLeft=false; collideRight=false; } } return(false); } } `

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• no more hitcollision at 1 life

  - by user1449547

  So I finally got my implementation of lives fixed, and it works. Now however when I collide with a ghost when I am at 1 life, nothing happens. I can fall to my death enough times for a game over. from what i can tell the problem is that hit collision is not longer working, because it does not detect a hit, I do not fall. the question is why? update if i kill myself fast enough it works, but if i play for like 30 seconds, it stops the hit collision detection on my ghosts. platforms and springs still work. public class World { public interface WorldListener { public void jump(); public void highJump(); public void hit(); public void coin(); public void dying(); } public static final float WORLD_WIDTH = 10; public static final float WORLD_HEIGHT = 15 * 20; public static final int WORLD_STATE_RUNNING = 0; public static final int WORLD_STATE_NEXT_LEVEL = 1; public static final int WORLD_STATE_GAME_OVER = 2; public static final Vector2 gravity = new Vector2(0, -12); public Hero hero; public final List<Platform> platforms; public final List<Spring> springs; public final List<Ghost> ghosts; public final List<Coin> coins; public Castle castle; public final WorldListener listener; public final Random rand; public float heightSoFar; public int score; public int state; public int lives=3; public World(WorldListener listener) { this.hero = new Hero(5, 1); this.platforms = new ArrayList<Platform>(); this.springs = new ArrayList<Spring>(); this.ghosts = new ArrayList<Ghost>(); this.coins = new ArrayList<Coin>(); this.listener = listener; rand = new Random(); generateLevel(); this.heightSoFar = 0; this.score = 0; this.state = WORLD_STATE_RUNNING; } private void generateLevel() { float y = Platform.PLATFORM_HEIGHT / 2; float maxJumpHeight = Hero.hero_JUMP_VELOCITY * Hero.hero_JUMP_VELOCITY / (2 * -gravity.y); while (y < WORLD_HEIGHT - WORLD_WIDTH / 2) { int type = rand.nextFloat() > 0.8f ? Platform.PLATFORM_TYPE_MOVING : Platform.PLATFORM_TYPE_STATIC; float x = rand.nextFloat() * (WORLD_WIDTH - Platform.PLATFORM_WIDTH) + Platform.PLATFORM_WIDTH / 2; Platform platform = new Platform(type, x, y); platforms.add(platform); if (rand.nextFloat() > 0.9f && type != Platform.PLATFORM_TYPE_MOVING) { Spring spring = new Spring(platform.position.x, platform.position.y + Platform.PLATFORM_HEIGHT / 2 + Spring.SPRING_HEIGHT / 2); springs.add(spring); } if (rand.nextFloat() > 0.7f) { Ghost ghost = new Ghost(platform.position.x + rand.nextFloat(), platform.position.y + Ghost.GHOST_HEIGHT + rand.nextFloat() * 3); ghosts.add(ghost); } if (rand.nextFloat() > 0.6f) { Coin coin = new Coin(platform.position.x + rand.nextFloat(), platform.position.y + Coin.COIN_HEIGHT + rand.nextFloat() * 3); coins.add(coin); } y += (maxJumpHeight - 0.5f); y -= rand.nextFloat() * (maxJumpHeight / 3); } castle = new Castle(WORLD_WIDTH / 2, y); } public void update(float deltaTime, float accelX) { updatehero(deltaTime, accelX); updatePlatforms(deltaTime); updateGhosts(deltaTime); updateCoins(deltaTime); if (hero.state != Hero.hero_STATE_HIT) checkCollisions(); checkGameOver(); checkFall(); } private void updatehero(float deltaTime, float accelX) { if (hero.state != Hero.hero_STATE_HIT && hero.position.y <= 0.5f) hero.hitPlatform(); if (hero.state != Hero.hero_STATE_HIT) hero.velocity.x = -accelX / 10 * Hero.hero_MOVE_VELOCITY; hero.update(deltaTime); heightSoFar = Math.max(hero.position.y, heightSoFar); } private void updatePlatforms(float deltaTime) { int len = platforms.size(); for (int i = 0; i < len; i++) { Platform platform = platforms.get(i); platform.update(deltaTime); if (platform.state == Platform.PLATFORM_STATE_PULVERIZING && platform.stateTime > Platform.PLATFORM_PULVERIZE_TIME) { platforms.remove(platform); len = platforms.size(); } } } private void updateGhosts(float deltaTime) { int len = ghosts.size(); for (int i = 0; i < len; i++) { Ghost ghost = ghosts.get(i); ghost.update(deltaTime); if (ghost.state == Ghost.GHOST_STATE_DYING && ghost.stateTime > Ghost.GHOST_DYING_TIME) { ghosts.remove(ghost); len = ghosts.size(); } } } private void updateCoins(float deltaTime) { int len = coins.size(); for (int i = 0; i < len; i++) { Coin coin = coins.get(i); coin.update(deltaTime); } } private void checkCollisions() { checkPlatformCollisions(); checkGhostCollisions(); checkItemCollisions(); checkCastleCollisions(); } private void checkPlatformCollisions() { if (hero.velocity.y > 0) return; int len = platforms.size(); for (int i = 0; i < len; i++) { Platform platform = platforms.get(i); if (hero.position.y > platform.position.y) { if (OverlapTester .overlapRectangles(hero.bounds, platform.bounds)) { hero.hitPlatform(); listener.jump(); if (rand.nextFloat() > 0.5f) { platform.pulverize(); } break; } } } } private void checkGhostCollisions() { int len = ghosts.size(); for (int i = 0; i < len; i++) { Ghost ghost = ghosts.get(i); if (hero.position.y < ghost.position.y) { if (OverlapTester.overlapRectangles(ghost.bounds, hero.bounds)){ hero.hitGhost(); listener.hit(); } break; } else { if(hero.position.y > ghost.position.y) { if (OverlapTester.overlapRectangles(hero.bounds, ghost.bounds)){ hero.hitGhostJump(); listener.jump(); ghost.dying(); score += Ghost.GHOST_SCORE; } break; } } } } private void checkItemCollisions() { int len = coins.size(); for (int i = 0; i < len; i++) { Coin coin = coins.get(i); if (OverlapTester.overlapRectangles(hero.bounds, coin.bounds)) { coins.remove(coin); len = coins.size(); listener.coin(); score += Coin.COIN_SCORE; } } if (hero.velocity.y > 0) return; len = springs.size(); for (int i = 0; i < len; i++) { Spring spring = springs.get(i); if (hero.position.y > spring.position.y) { if (OverlapTester.overlapRectangles(hero.bounds, spring.bounds)) { hero.hitSpring(); listener.highJump(); } } } } private void checkCastleCollisions() { if (OverlapTester.overlapRectangles(castle.bounds, hero.bounds)) { state = WORLD_STATE_NEXT_LEVEL; } } private void checkFall() { if (heightSoFar - 7.5f > hero.position.y) { --lives; hero.hitSpring(); listener.highJump(); } } private void checkGameOver() { if (lives<=0) { state = WORLD_STATE_GAME_OVER; } } }

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• Joining Windows 7 Professional to a Windows Server 2003 R2 x64 domain fails.

  - by Vinko Vrsalovic

  I have a windows 7 professional (spanish) laptop trying to join a Windows Server 2003 (english) domain. It detect correctly the SRV record, finding the proper domain controller, but then the join fails with the error message (snippet, because the error is in spanish) An Active Directory Domain Controller for This Domain Could Not be Contacted The DNS is correctly set, and client can ping by name and IP the server, the server can ping the client by IP. I've tested with the FW down to no avail. A host of other XP Pro clients are connected to the domain. I've restarted Net Logon and checked that Windows Time is up. Also the times are in sync between the server and the client. I'll put below diagnostics output. I'm wondering if there's anything special to be done on either the server or the client to have a Win 7 Pro join a 2k3 R2 domain. The following diagnostic information follows: netdiag /q for the DC dcdiag on the DC ipconfig /all on the Win 7 client netdiag /q on the DC: .................................. Computer Name: HI-X2 DNS Host Name: hi-x2.hi.local System info : Microsoft Windows Server 2003 R2 (Build 3790) Processor : EM64T Family 6 Model 23 Stepping 10, GenuineIntel List of installed hotfixes : KB923561 KB924667-v2 KB925398_WMP64 KB925902 KB926122 KB927891 KB929123 KB930178 KB932168 KB936357 KB938127 KB941569 KB942830 KB942831 KB943055 KB943460 KB944338-v2 KB944653 KB945553 KB946026 KB948496 KB950760 KB950762 KB950974 KB951066 KB951748 KB952004 KB952069 KB952954 KB954155 KB954550-v7 KB955069 KB955759 KB956572 KB956802 KB956803 KB956844 KB958469 KB958644 KB958869 KB959426 KB960225 KB960803 KB960859 KB961063 KB961118 KB961501 KB967715 KB967723 KB968389 KB968816 KB969059 KB969947 KB970238 KB970430 KB970483 KB971032 KB971468 KB971657 KB971737 KB971961 KB971961-IE8 KB972270 KB973037 KB973354 KB973507 KB973540 KB973687 KB973815 KB973825 KB973869 KB973904 KB973917-v2 KB974112 KB974318 KB974392 KB974571 KB975025 KB975467 KB975560 KB975713 KB976662-IE8 KB977290 KB977816 KB977914 KB978037 KB978262 KB978338 KB978542 KB978601 KB978706 KB979306 KB979309 KB979683 KB980182 KB980182-IE8 KB980232 KB980302-IE8 KB981332-IE8 KB981350 Q147222 Per interface results: Adapter : Local Area Connection Host Name. . . . . . . . . : hi-x2.hi.local IP Address . . . . . . . . : 10.0.1.199 Subnet Mask. . . . . . . . : 255.0.0.0 Default Gateway. . . . . . : 10.0.1.1 Dns Servers. . . . . . . . : 10.0.1.199 WINS service test. . . . . : Skipped Global results: [WARNING] You don't have a single interface with the 'WorkStation Service', 'Messenger Service', 'WINS' names defined. DNS test . . . . . . . . . . . . . : Passed PASS - All the DNS entries for DC are registered on DNS server '10.0.1.199'. IP Security test . . . . . . . . . : Skipped The command completed successfully dcdiag on the DC: Domain Controller Diagnosis Performing initial setup: Done gathering initial info. Doing initial required tests Testing server: Default-First-Site-Name\HI-X2 Starting test: Connectivity ......................... HI-X2 passed test Connectivity Doing primary tests Testing server: Default-First-Site-Name\HI-X2 Starting test: Replications ......................... HI-X2 passed test Replications Starting test: NCSecDesc ......................... HI-X2 passed test NCSecDesc Starting test: NetLogons ......................... HI-X2 passed test NetLogons Starting test: Advertising ......................... HI-X2 passed test Advertising Starting test: KnowsOfRoleHolders ......................... HI-X2 passed test KnowsOfRoleHolders Starting test: RidManager ......................... HI-X2 passed test RidManager Starting test: MachineAccount ......................... HI-X2 passed test MachineAccount Starting test: Services ......................... HI-X2 passed test Services Starting test: ObjectsReplicated ......................... HI-X2 passed test ObjectsReplicated Starting test: frssysvol ......................... HI-X2 passed test frssysvol Starting test: frsevent ......................... HI-X2 passed test frsevent Starting test: kccevent ......................... HI-X2 passed test kccevent Starting test: systemlog ......................... HI-X2 passed test systemlog Starting test: VerifyReferences ......................... HI-X2 passed test VerifyReferences Running partition tests on : ForestDnsZones Starting test: CrossRefValidation ......................... ForestDnsZones passed test CrossRefValidation Starting test: CheckSDRefDom ......................... ForestDnsZones passed test CheckSDRefDom Running partition tests on : DomainDnsZones Starting test: CrossRefValidation ......................... DomainDnsZones passed test CrossRefValidation Starting test: CheckSDRefDom ......................... DomainDnsZones passed test CheckSDRefDom Running partition tests on : Schema Starting test: CrossRefValidation ......................... Schema passed test CrossRefValidation Starting test: CheckSDRefDom ......................... Schema passed test CheckSDRefDom Running partition tests on : Configuration Starting test: CrossRefValidation ......................... Configuration passed test CrossRefValidation Starting test: CheckSDRefDom ......................... Configuration passed test CheckSDRefDom Running partition tests on : hi Starting test: CrossRefValidation ......................... hi passed test CrossRefValidation Starting test: CheckSDRefDom ......................... hi passed test CheckSDRefDom Running enterprise tests on : hi.local Starting test: Intersite ......................... hi.local passed test Intersite Starting test: FsmoCheck ......................... hi.local passed test FsmoCheck ipconfig /all on the Windows 7 client: Configuraci¢n IP de Windows Nombre de host. . . . . . . . . : hi-p6 Sufijo DNS principal . . . . . : Tipo de nodo. . . . . . . . . . : h¡brido Enrutamiento IP habilitado. . . : no Proxy WINS habilitado . . . . . : no Adaptador de LAN inal mbrica Conexi¢n de red inal mbrica: Sufijo DNS espec¡fico para la conexi¢n. . : Descripci¢n . . . . . . . . . . . . . . . : Intel(R) WiFi Link 5100 AGN Direcci¢n f¡sica. . . . . . . . . . . . . : 00-22-FB-63-47-A0 DHCP habilitado . . . . . . . . . . . . . : no Configuraci¢n autom tica habilitada . . . : s¡ Direcci¢n IPv4. . . . . . . . . . . . . . : 10.0.1.42(Preferido) M scara de subred . . . . . . . . . . . . : 255.255.255.0 Puerta de enlace predeterminada . . . . . : 10.0.1.1 Servidores DNS. . . . . . . . . . . . . . : 10.0.1.199 NetBIOS sobre TCP/IP. . . . . . . . . . . : habilitado Adaptador de Ethernet Conexi¢n de  rea local: Estado de los medios. . . . . . . . . . . : medios desconectados Sufijo DNS espec¡fico para la conexi¢n. . : Descripci¢n . . . . . . . . . . . . . . . : Realtek PCIe GBE Family Controller Direcci¢n f¡sica. . . . . . . . . . . . . : 00-1E-33-1F-35-B1 DHCP habilitado . . . . . . . . . . . . . : s¡ Configuraci¢n autom tica habilitada . . . : s¡ Adaptador de t£nel isatap.{8926581E-09AC-4123-906B-DA6386AD2D60}: Estado de los medios. . . . . . . . . . . : medios desconectados Sufijo DNS espec¡fico para la conexi¢n. . : Descripci¢n . . . . . . . . . . . . . . . : Adaptador ISATAP de Microsoft Direcci¢n f¡sica. . . . . . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP habilitado . . . . . . . . . . . . . : no Configuraci¢n autom tica habilitada . . . : s¡ Adaptador de t£nel Teredo Tunneling Pseudo-Interface: Sufijo DNS espec¡fico para la conexi¢n. . : Descripci¢n . . . . . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface Direcci¢n f¡sica. . . . . . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP habilitado . . . . . . . . . . . . . : no Configuraci¢n autom tica habilitada . . . : s¡ Direcci¢n IPv6 . . . . . . . . . . : 2001:0:5ef5:73ba:1cec:3883:f5ff:fed5(Preferido) V¡nculo: direcci¢n IPv6 local. . . : fe80::1cec:3883:f5ff:fed5%13(Preferido) Puerta de enlace predeterminada . . . . . : :: NetBIOS sobre TCP/IP. . . . . . . . . . . : deshabilitado

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• Is there a Telecommunications Reference Architecture?

  - by raul.goycoolea

  @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Abstract   Reference architecture provides needed architectural information that can be provided in advance to an enterprise to enable consistent architectural best practices. Enterprise Reference Architecture helps business owners to actualize their strategies, vision, objectives, and principles. It evaluates the IT systems, based on Reference Architecture goals, principles, and standards. It helps to reduce IT costs by increasing functionality, availability, scalability, etc. Telecom Reference Architecture provides customers with the flexibility to view bundled service bills online with the provision of multiple services. It provides real-time, flexible billing and charging systems, to handle complex promotions, discounts, and settlements with multiple parties. This paper attempts to describe the Reference Architecture for the Telecom Enterprises. It lays the foundation for a Telecom Reference Architecture by articulating the requirements, drivers, and pitfalls for telecom service providers. It describes generic reference architecture for telecom enterprises and moves on to explain how to achieve Enterprise Reference Architecture by using SOA.   Introduction   A Reference Architecture provides a methodology, set of practices, template, and standards based on a set of successful solutions implemented earlier. These solutions have been generalized and structured for the depiction of both a logical and a physical architecture, based on the harvesting of a set of patterns that describe observations in a number of successful implementations. It helps as a reference for the various architectures that an enterprise can implement to solve various problems. It can be used as the starting point or the point of comparisons for various departments/business entities of a company, or for the various companies for an enterprise. It provides multiple views for multiple stakeholders.   Major artifacts of the Enterprise Reference Architecture are methodologies, standards, metadata, documents, design patterns, etc.   Purpose of Reference Architecture   In most cases, architects spend a lot of time researching, investigating, defining, and re-arguing architectural decisions. It is like reinventing the wheel as their peers in other organizations or even the same organization have already spent a lot of time and effort defining their own architectural practices. This prevents an organization from learning from its own experiences and applying that knowledge for increased effectiveness.   Reference architecture provides missing architectural information that can be provided in advance to project team members to enable consistent architectural best practices.   Enterprise Reference Architecture helps an enterprise to achieve the following at the abstract level:   ·       Reference architecture is more of a communication channel to an enterprise ·       Helps the business owners to accommodate to their strategies, vision, objectives, and principles. ·       Evaluates the IT systems based on Reference Architecture Principles ·       Reduces IT spending through increasing functionality, availability, scalability, etc ·       A Real-time Integration Model helps to reduce the latency of the data updates Is used to define a single source of Information ·       Provides a clear view on how to manage information and security ·       Defines the policy around the data ownership, product boundaries, etc. ·       Helps with cost optimization across project and solution portfolios by eliminating unused or duplicate investments and assets ·       Has a shorter implementation time and cost   Once the reference architecture is in place, the set of architectural principles, standards, reference models, and best practices ensure that the aligned investments have the greatest possible likelihood of success in both the near term and the long term (TCO).     Common pitfalls for Telecom Service Providers   Telecom Reference Architecture serves as the first step towards maturity for a telecom service provider. During the course of our assignments/experiences with telecom players, we have come across the following observations – Some of these indicate a lack of maturity of the telecom service provider:   ·       In markets that are growing and not so mature, it has been observed that telcos have a significant amount of in-house or home-grown applications. In some of these markets, the growth has been so rapid that IT has been unable to cope with business demands. Telcos have shown a tendency to come up with workarounds in their IT applications so as to meet business needs. ·       Even for core functions like provisioning or mediation, some telcos have tried to manage with home-grown applications. ·       Most of the applications do not have the required scalability or maintainability to sustain growth in volumes or functionality. ·       Applications face interoperability issues with other applications in the operator's landscape. Integrating a new application or network element requires considerable effort on the part of the other applications. ·       Application boundaries are not clear, and functionality that is not in the initial scope of that application gets pushed onto it. This results in the development of the multiple, small applications without proper boundaries. ·       Usage of Legacy OSS/BSS systems, poor Integration across Multiple COTS Products and Internal Systems. Most of the Integrations are developed on ad-hoc basis and Point-to-Point Integration. ·       Redundancy of the business functions in different applications • Fragmented data across the different applications and no integrated view of the strategic data • Lot of performance Issues due to the usage of the complex integration across OSS and BSS systems   However, this is where the maturity of the telecom industry as a whole can be of help. The collaborative efforts of telcos to overcome some of these problems have resulted in bodies like the TM Forum. They have come up with frameworks for business processes, data, applications, and technology for telecom service providers. These could be a good starting point for telcos to clean up their enterprise landscape.   Industry Trends in Telecom Reference Architecture   Telecom reference architectures are evolving rapidly because telcos are facing business and IT challenges.   “The reality is that there probably is no killer application, no silver bullet that the telcos can latch onto to carry them into a 21st Century.... Instead, there are probably hundreds – perhaps thousands – of niche applications.... And the only way to find which of these works for you is to try out lots of them, ramp up the ones that work, and discontinue the ones that fail.” – Martin Creaner President & CTO TM Forum.   The following trends have been observed in telecom reference architecture:   ·       Transformation of business structures to align with customer requirements ·       Adoption of more Internet-like technical architectures. The Web 2.0 concept is increasingly being used. ·       Virtualization of the traditional operations support system (OSS) ·       Adoption of SOA to support development of IP-based services ·       Adoption of frameworks like Service Delivery Platforms (SDPs) and IP Multimedia Subsystem ·       (IMS) to enable seamless deployment of various services over fixed and mobile networks ·       Replacement of in-house, customized, and stove-piped OSS/BSS with standards-based COTS products ·       Compliance with industry standards and frameworks like eTOM, SID, and TAM to enable seamless integration with other standards-based products   Drivers of Reference Architecture   The drivers of the Reference Architecture are Reference Architecture Goals, Principles, and Enterprise Vision and Telecom Transformation. The details are depicted below diagram. @font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }div.Section1 { page: Section1; } Figure 1. Drivers for Reference Architecture @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Today’s telecom reference architectures should seamlessly integrate traditional legacy-based applications and transition to next-generation network technologies (e.g., IP multimedia subsystems). This has resulted in new requirements for flexible, real-time billing and OSS/BSS systems and implications on the service provider’s organizational requirements and structure.   Telecom reference architectures are today expected to:   ·       Integrate voice, messaging, email and other VAS over fixed and mobile networks, back end systems ·       Be able to provision multiple services and service bundles • Deliver converged voice, video and data services ·       Leverage the existing Network Infrastructure ·       Provide real-time, flexible billing and charging systems to handle complex promotions, discounts, and settlements with multiple parties. ·       Support charging of advanced data services such as VoIP, On-Demand, Services (e.g.  Video), IMS/SIP Services, Mobile Money, Content Services and IPTV. ·       Help in faster deployment of new services • Serve as an effective platform for collaboration between network IT and business organizations ·       Harness the potential of converging technology, networks, devices and content to develop multimedia services and solutions of ever-increasing sophistication on a single Internet Protocol (IP) ·       Ensure better service delivery and zero revenue leakage through real-time balance and credit management ·       Lower operating costs to drive profitability   Enterprise Reference Architecture   The Enterprise Reference Architecture (RA) fills the gap between the concepts and vocabulary defined by the reference model and the implementation. Reference architecture provides detailed architectural information in a common format such that solutions can be repeatedly designed and deployed in a consistent, high-quality, supportable fashion. This paper attempts to describe the Reference Architecture for the Telecom Application Usage and how to achieve the Enterprise Level Reference Architecture using SOA.   • Telecom Reference Architecture • Enterprise SOA based Reference Architecture   Telecom Reference Architecture   Tele Management Forum’s New Generation Operations Systems and Software (NGOSS) is an architectural framework for organizing, integrating, and implementing telecom systems. NGOSS is a component-based framework consisting of the following elements:   ·       The enhanced Telecom Operations Map (eTOM) is a business process framework. ·       The Shared Information Data (SID) model provides a comprehensive information framework that may be specialized for the needs of a particular organization. ·       The Telecom Application Map (TAM) is an application framework to depict the functional footprint of applications, relative to the horizontal processes within eTOM. ·       The Technology Neutral Architecture (TNA) is an integrated framework. TNA is an architecture that is sustainable through technology changes.   NGOSS Architecture Standards are:   ·       Centralized data ·       Loosely coupled distributed systems ·       Application components/re-use  ·       A technology-neutral system framework with technology specific implementations ·       Interoperability to service provider data/processes ·       Allows more re-use of business components across multiple business scenarios ·       Workflow automation   The traditional operator systems architecture consists of four layers,   ·       Business Support System (BSS) layer, with focus toward customers and business partners. Manages order, subscriber, pricing, rating, and billing information. ·       Operations Support System (OSS) layer, built around product, service, and resource inventories. ·       Networks layer – consists of Network elements and 3rd Party Systems. ·       Integration Layer – to maximize application communication and overall solution flexibility.   Reference architecture for telecom enterprises is depicted below. @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Figure 2. Telecom Reference Architecture   The major building blocks of any Telecom Service Provider architecture are as follows:   1. Customer Relationship Management   CRM encompasses the end-to-end lifecycle of the customer: customer initiation/acquisition, sales, ordering, and service activation, customer care and support, proactive campaigns, cross sell/up sell, and retention/loyalty.   CRM also includes the collection of customer information and its application to personalize, customize, and integrate delivery of service to a customer, as well as to identify opportunities for increasing the value of the customer to the enterprise.   The key functionalities related to Customer Relationship Management are   ·       Manage the end-to-end lifecycle of a customer request for products. ·       Create and manage customer profiles. ·       Manage all interactions with customers – inquiries, requests, and responses. ·       Provide updates to Billing and other south bound systems on customer/account related updates such as customer/ account creation, deletion, modification, request bills, final bill, duplicate bills, credit limits through Middleware. ·       Work with Order Management System, Product, and Service Management components within CRM. ·       Manage customer preferences – Involve all the touch points and channels to the customer, including contact center, retail stores, dealers, self service, and field service, as well as via any media (phone, face to face, web, mobile device, chat, email, SMS, mail, the customer's bill, etc.). ·       Support single interface for customer contact details, preferences, account details, offers, customer premise equipment, bill details, bill cycle details, and customer interactions.   CRM applications interact with customers through customer touch points like portals, point-of-sale terminals, interactive voice response systems, etc. The requests by customers are sent via fulfillment/provisioning to billing system for ordering processing.   2. Billing and Revenue Management   Billing and Revenue Management handles the collection of appropriate usage records and production of timely and accurate bills – for providing pre-bill usage information and billing to customers; for processing their payments; and for performing payment collections. In addition, it handles customer inquiries about bills, provides billing inquiry status, and is responsible for resolving billing problems to the customer's satisfaction in a timely manner. This process grouping also supports prepayment for services.   The key functionalities provided by these applications are   ·       To ensure that enterprise revenue is billed and invoices delivered appropriately to customers. ·       To manage customers’ billing accounts, process their payments, perform payment collections, and monitor the status of the account balance. ·       To ensure the timely and effective fulfillment of all customer bill inquiries and complaints. ·       Collect the usage records from mediation and ensure appropriate rating and discounting of all usage and pricing. ·       Support revenue sharing; split charging where usage is guided to an account different from the service consumer. ·       Support prepaid and post-paid rating. ·       Send notification on approach / exceeding the usage thresholds as enforced by the subscribed offer, and / or as setup by the customer. ·       Support prepaid, post paid, and hybrid (where some services are prepaid and the rest of the services post paid) customers and conversion from post paid to prepaid, and vice versa. ·       Support different billing function requirements like charge prorating, promotion, discount, adjustment, waiver, write-off, account receivable, GL Interface, late payment fee, credit control, dunning, account or service suspension, re-activation, expiry, termination, contract violation penalty, etc. ·       Initiate direct debit to collect payment against an invoice outstanding. ·       Send notification to Middleware on different events; for example, payment receipt, pre-suspension, threshold exceed, etc.   Billing systems typically get usage data from mediation systems for rating and billing. They get provisioning requests from order management systems and inquiries from CRM systems. Convergent and real-time billing systems can directly get usage details from network elements.   3. Mediation   Mediation systems transform/translate the Raw or Native Usage Data Records into a general format that is acceptable to billing for their rating purposes.   The following lists the high-level roles and responsibilities executed by the Mediation system in the end-to-end solution.   ·       Collect Usage Data Records from different data sources – like network elements, routers, servers – via different protocol and interfaces. ·       Process Usage Data Records – Mediation will process Usage Data Records as per the source format. ·       Validate Usage Data Records from each source. ·       Segregates Usage Data Records coming from each source to multiple, based on the segregation requirement of end Application. ·       Aggregates Usage Data Records based on the aggregation rule if any from different sources. ·       Consolidates multiple Usage Data Records from each source. ·       Delivers formatted Usage Data Records to different end application like Billing, Interconnect, Fraud Management, etc. ·       Generates audit trail for incoming Usage Data Records and keeps track of all the Usage Data Records at various stages of mediation process. ·       Checks duplicate Usage Data Records across files for a given time window.   4. Fulfillment   This area is responsible for providing customers with their requested products in a timely and correct manner. It translates the customer's business or personal need into a solution that can be delivered using the specific products in the enterprise's portfolio. This process informs the customers of the status of their purchase order, and ensures completion on time, as well as ensuring a delighted customer. These processes are responsible for accepting and issuing orders. They deal with pre-order feasibility determination, credit authorization, order issuance, order status and tracking, customer update on customer order activities, and customer notification on order completion. Order management and provisioning applications fall into this category.   The key functionalities provided by these applications are   ·       Issuing new customer orders, modifying open customer orders, or canceling open customer orders; ·       Verifying whether specific non-standard offerings sought by customers are feasible and supportable; ·       Checking the credit worthiness of customers as part of the customer order process; ·       Testing the completed offering to ensure it is working correctly; ·       Updating of the Customer Inventory Database to reflect that the specific product offering has been allocated, modified, or cancelled; ·       Assigning and tracking customer provisioning activities; ·       Managing customer provisioning jeopardy conditions; and ·       Reporting progress on customer orders and other processes to customer.   These applications typically get orders from CRM systems. They interact with network elements and billing systems for fulfillment of orders.   5. Enterprise Management   This process area includes those processes that manage enterprise-wide activities and needs, or have application within the enterprise as a whole. They encompass all business management processes that   ·       Are necessary to support the whole of the enterprise, including processes for financial management, legal management, regulatory management, process, cost, and quality management, etc.;   ·       Are responsible for setting corporate policies, strategies, and directions, and for providing guidelines and targets for the whole of the business, including strategy development and planning for areas, such as Enterprise Architecture, that are integral to the direction and development of the business;   ·       Occur throughout the enterprise, including processes for project management, performance assessments, cost assessments, etc.     (i) Enterprise Risk Management:   Enterprise Risk Management focuses on assuring that risks and threats to the enterprise value and/or reputation are identified, and appropriate controls are in place to minimize or eliminate the identified risks. The identified risks may be physical or logical/virtual. Successful risk management ensures that the enterprise can support its mission critical operations, processes, applications, and communications in the face of serious incidents such as security threats/violations and fraud attempts. Two key areas covered in Risk Management by telecom operators are:   ·       Revenue Assurance: Revenue assurance system will be responsible for identifying revenue loss scenarios across components/systems, and will help in rectifying the problems. The following lists the high-level roles and responsibilities executed by the Revenue Assurance system in the end-to-end solution. o   Identify all usage information dropped when networks are being upgraded. o   Interconnect bill verification. o   Identify where services are routinely provisioned but never billed. o   Identify poor sales policies that are intensifying collections problems. o   Find leakage where usage is sent to error bucket and never billed for. o   Find leakage where field service, CRM, and network build-out are not optimized.   ·       Fraud Management: Involves collecting data from different systems to identify abnormalities in traffic patterns, usage patterns, and subscription patterns to report suspicious activity that might suggest fraudulent usage of resources, resulting in revenue losses to the operator.   The key roles and responsibilities of the system component are as follows:   o   Fraud management system will capture and monitor high usage (over a certain threshold) in terms of duration, value, and number of calls for each subscriber. The threshold for each subscriber is decided by the system and fixed automatically. o   Fraud management will be able to detect the unauthorized access to services for certain subscribers. These subscribers may have been provided unauthorized services by employees. The component will raise the alert to the operator the very first time of such illegal calls or calls which are not billed. o   The solution will be to have an alarm management system that will deliver alarms to the operator/provider whenever it detects a fraud, thus minimizing fraud by catching it the first time it occurs. o   The Fraud Management system will be capable of interfacing with switches, mediation systems, and billing systems   (ii) Knowledge Management   This process focuses on knowledge management, technology research within the enterprise, and the evaluation of potential technology acquisitions.   Key responsibilities of knowledge base management are to   ·       Maintain knowledge base – Creation and updating of knowledge base on ongoing basis. ·       Search knowledge base – Search of knowledge base on keywords or category browse ·       Maintain metadata – Management of metadata on knowledge base to ensure effective management and search. ·       Run report generator. ·       Provide content – Add content to the knowledge base, e.g., user guides, operational manual, etc.   (iii) Document Management   It focuses on maintaining a repository of all electronic documents or images of paper documents relevant to the enterprise using a system.   (iv) Data Management   It manages data as a valuable resource for any enterprise. For telecom enterprises, the typical areas covered are Master Data Management, Data Warehousing, and Business Intelligence. It is also responsible for data governance, security, quality, and database management.   Key responsibilities of Data Management are   ·       Using ETL, extract the data from CRM, Billing, web content, ERP, campaign management, financial, network operations, asset management info, customer contact data, customer measures, benchmarks, process data, e.g., process inputs, outputs, and measures, into Enterprise Data Warehouse. ·       Management of data traceability with source, data related business rules/decisions, data quality, data cleansing data reconciliation, competitors data – storage for all the enterprise data (customer profiles, products, offers, revenues, etc.) ·       Get online update through night time replication or physical backup process at regular frequency. ·       Provide the data access to business intelligence and other systems for their analysis, report generation, and use.   (v) Business Intelligence   It uses the Enterprise Data to provide the various analysis and reports that contain prospects and analytics for customer retention, acquisition of new customers due to the offers, and SLAs. It will generate right and optimized plans – bolt-ons for the customers.   The following lists the high-level roles and responsibilities executed by the Business Intelligence system at the Enterprise Level:   ·       It will do Pattern analysis and reports problem. ·       It will do Data Analysis – Statistical analysis, data profiling, affinity analysis of data, customer segment wise usage patterns on offers, products, service and revenue generation against services and customer segments. ·       It will do Performance (business, system, and forecast) analysis, churn propensity, response time, and SLAs analysis. ·       It will support for online and offline analysis, and report drill down capability. ·       It will collect, store, and report various SLA data. ·       It will provide the necessary intelligence for marketing and working on campaigns, etc., with cost benefit analysis and predictions.   It will advise on customer promotions with additional services based on loyalty and credit history of customer   ·       It will Interface with Enterprise Data Management system for data to run reports and analysis tasks. It will interface with the campaign schedules, based on historical success evidence.   (vi) Stakeholder and External Relations Management   It manages the enterprise's relationship with stakeholders and outside entities. Stakeholders include shareholders, employee organizations, etc. Outside entities include regulators, local community, and unions. Some of the processes within this grouping are Shareholder Relations, External Affairs, Labor Relations, and Public Relations.   (vii) Enterprise Resource Planning   It is used to manage internal and external resources, including tangible assets, financial resources, materials, and human resources. Its purpose is to facilitate the flow of information between all business functions inside the boundaries of the enterprise and manage the connections to outside stakeholders. ERP systems consolidate all business operations into a uniform and enterprise wide system environment.   The key roles and responsibilities for Enterprise System are given below:   ·        It will handle responsibilities such as core accounting, financial, and management reporting. ·       It will interface with CRM for capturing customer account and details. ·       It will interface with billing to capture the billing revenue and other financial data. ·       It will be responsible for executing the dunning process. Billing will send the required feed to ERP for execution of dunning. ·       It will interface with the CRM and Billing through batch interfaces. Enterprise management systems are like horizontals in the enterprise and typically interact with all major telecom systems. E.g., an ERP system interacts with CRM, Fulfillment, and Billing systems for different kinds of data exchanges.   6. External Interfaces/Touch Points   The typical external parties are customers, suppliers/partners, employees, shareholders, and other stakeholders. External interactions from/to a Service Provider to other parties can be achieved by a variety of mechanisms, including:   ·       Exchange of emails or faxes ·       Call Centers ·       Web Portals ·       Business-to-Business (B2B) automated transactions   These applications provide an Internet technology driven interface to external parties to undertake a variety of business functions directly for themselves. These can provide fully or partially automated service to external parties through various touch points.   Typical characteristics of these touch points are   ·       Pre-integrated self-service system, including stand-alone web framework or integration front end with a portal engine ·       Self services layer exposing atomic web services/APIs for reuse by multiple systems across the architectural environment ·       Portlets driven connectivity exposing data and services interoperability through a portal engine or web application   These touch points mostly interact with the CRM systems for requests, inquiries, and responses.   7. Middleware   The component will be primarily responsible for integrating the different systems components under a common platform. It should provide a Standards-Based Platform for building Service Oriented Architecture and Composite Applications. The following lists the high-level roles and responsibilities executed by the Middleware component in the end-to-end solution.   ·       As an integration framework, covering to and fro interfaces ·       Provide a web service framework with service registry. ·       Support SOA framework with SOA service registry. ·       Each of the interfaces from / to Middleware to other components would handle data transformation, translation, and mapping of data points. ·       Receive data from the caller / activate and/or forward the data to the recipient system in XML format. ·       Use standard XML for data exchange. ·       Provide the response back to the service/call initiator. ·       Provide a tracking until the response completion. ·       Keep a store transitional data against each call/transaction. ·       Interface through Middleware to get any information that is possible and allowed from the existing systems to enterprise systems; e.g., customer profile and customer history, etc. ·       Provide the data in a common unified format to the SOA calls across systems, and follow the Enterprise Architecture directive. ·       Provide an audit trail for all transactions being handled by the component.   8. Network Elements   The term Network Element means a facility or equipment used in the provision of a telecommunications service. Such terms also includes features, functions, and capabilities that are provided by means of such facility or equipment, including subscriber numbers, databases, signaling systems, and information sufficient for billing and collection or used in the transmission, routing, or other provision of a telecommunications service.   Typical network elements in a GSM network are Home Location Register (HLR), Intelligent Network (IN), Mobile Switching Center (MSC), SMS Center (SMSC), and network elements for other value added services like Push-to-talk (PTT), Ring Back Tone (RBT), etc.   Network elements are invoked when subscribers use their telecom devices for any kind of usage. These elements generate usage data and pass it on to downstream systems like mediation and billing system for rating and billing. They also integrate with provisioning systems for order/service fulfillment.   9. 3rd Party Applications   3rd Party systems are applications like content providers, payment gateways, point of sale terminals, and databases/applications maintained by the Government.   Depending on applicability and the type of functionality provided by 3rd party applications, the integration with different telecom systems like CRM, provisioning, and billing will be done.   10. Service Delivery Platform   A service delivery platform (SDP) provides the architecture for the rapid deployment, provisioning, execution, management, and billing of value added telecom services. SDPs are based on the concept of SOA and layered architecture. They support the delivery of voice, data services, and content in network and device-independent fashion. They allow application developers to aggregate network capabilities, services, and sources of content. SDPs typically contain layers for web services exposure, service application development, and network abstraction.   SOA Reference Architecture   SOA concept is based on the principle of developing reusable business service and building applications by composing those services, instead of building monolithic applications in silos. It’s about bridging the gap between business and IT through a set of business-aligned IT services, using a set of design principles, patterns, and techniques.   In an SOA, resources are made available to participants in a value net, enterprise, line of business (typically spanning multiple applications within an enterprise or across multiple enterprises). It consists of a set of business-aligned IT services that collectively fulfill an organization’s business processes and goals. We can choreograph these services into composite applications and invoke them through standard protocols. SOA, apart from agility and reusability, enables:   ·       The business to specify processes as orchestrations of reusable services ·       Technology agnostic business design, with technology hidden behind service interface ·       A contractual-like interaction between business and IT, based on service SLAs ·       Accountability and governance, better aligned to business services ·       Applications interconnections untangling by allowing access only through service interfaces, reducing the daunting side effects of change ·       Reduced pressure to replace legacy and extended lifetime for legacy applications, through encapsulation in services   ·       A Cloud Computing paradigm, using web services technologies, that makes possible service outsourcing on an on-demand, utility-like, pay-per-usage basis   The following section represents the Reference Architecture of logical view for the Telecom Solution. The new custom built application needs to align with this logical architecture in the long run to achieve EA benefits.   Packaged implementation applications, such as ERP billing applications, need to expose their functions as service providers (as other applications consume) and interact with other applications as service consumers.   COT applications need to expose services through wrappers such as adapters to utilize existing resources and at the same time achieve Enterprise Architecture goal and objectives.   The following are the various layers for Enterprise level deployment of SOA. This diagram captures the abstract view of Enterprise SOA layers and important components of each layer. Layered architecture means decomposition of services such that most interactions occur between adjacent layers. However, there is no strict rule that top layers should not directly communicate with bottom layers.   The diagram below represents the important logical pieces that would result from overall SOA transformation. @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Figure 3. Enterprise SOA Reference Architecture 1.          Operational System Layer: This layer consists of all packaged applications like CRM, ERP, custom built applications, COTS based applications like Billing, Revenue Management, Fulfilment, and the Enterprise databases that are essential and contribute directly or indirectly to the Enterprise OSS/BSS Transformation.   ERP holds the data of Asset Lifecycle Management, Supply Chain, and Advanced Procurement and Human Capital Management, etc.   CRM holds the data related to Order, Sales, and Marketing, Customer Care, Partner Relationship Management, Loyalty, etc.   Content Management handles Enterprise Search and Query. Billing application consists of the following components:   ·       Collections Management, Customer Billing Management, Invoices, Real-Time Rating, Discounting, and Applying of Charges ·       Enterprise databases will hold both the application and service data, whether structured or unstructured.   MDM - Master data majorly consists of Customer, Order, Product, and Service Data.     2.          Enterprise Component Layer:   This layer consists of the Application Services and Common Services that are responsible for realizing the functionality and maintaining the QoS of the exposed services. This layer uses container-based technologies such as application servers to implement the components, workload management, high availability, and load balancing.   Application Services: This Service Layer enables application, technology, and database abstraction so that the complex accessing logic is hidden from the other service layers. This is a basic service layer, which exposes application functionalities and data as reusable services. The three types of the Application access services are:   ·       Application Access Service: This Service Layer exposes application level functionalities as a reusable service between BSS to BSS and BSS to OSS integration. This layer is enabled using disparate technology such as Web Service, Integration Servers, and Adaptors, etc.   ·       Data Access Service: This Service Layer exposes application data services as a reusable reference data service. This is done via direct interaction with application data. and provides the federated query.   ·       Network Access Service: This Service Layer exposes provisioning layer as a reusable service from OSS to OSS integration. This integration service emphasizes the need for high performance, stateless process flows, and distributed design.   Common Services encompasses management of structured, semi-structured, and unstructured data such as information services, portal services, interaction services, infrastructure services, and security services, etc.   3.          Integration Layer:   This consists of service infrastructure components like service bus, service gateway for partner integration, service registry, service repository, and BPEL processor. Service bus will carry the service invocation payloads/messages between consumers and providers. The other important functions expected from it are itinerary based routing, distributed caching of routing information, transformations, and all qualities of service for messaging-like reliability, scalability, and availability, etc. Service registry will hold all contracts (wsdl) of services, and it helps developers to locate or discover service during design time or runtime.   • BPEL processor would be useful in orchestrating the services to compose a complex business scenario or process. • Workflow and business rules management are also required to support manual triggering of certain activities within business process. based on the rules setup and also the state machine information. Application, data, and service mediation layer typically forms the overall composite application development framework or SOA Framework.   4.          Business Process Layer: These are typically the intermediate services layer and represent Shared Business Process Services. At Enterprise Level, these services are from Customer Management, Order Management, Billing, Finance, and Asset Management application domains.   5.          Access Layer: This layer consists of portals for Enterprise and provides a single view of Enterprise information management and dashboard services.   6.          Channel Layer: This consists of various devices; applications that form part of extended enterprise; browsers through which users access the applications.   7.          Client Layer: This designates the different types of users accessing the enterprise applications. The type of user typically would be an important factor in determining the level of access to applications.   8.          Vertical pieces like management, monitoring, security, and development cut across all horizontal layers Management and monitoring involves all aspects of SOA-like services, SLAs, and other QoS lifecycle processes for both applications and services surrounding SOA governance.     9.          EA Governance, Reference Architecture, Roadmap, Principles, and Best Practices:   EA Governance is important in terms of providing the overall direction to SOA implementation within the enterprise. This involves board-level involvement, in addition to business and IT executives. At a high level, this involves managing the SOA projects implementation, managing SOA infrastructure, and controlling the entire effort through all fine-tuned IT processes in accordance with COBIT (Control Objectives for Information Technology).   Devising tools and techniques to promote reuse culture, and the SOA way of doing things needs competency centers to be established in addition to training the workforce to take up new roles that are suited to SOA journey.   Conclusions   Reference Architectures can serve as the basis for disparate architecture efforts throughout the organization, even if they use different tools and technologies. Reference architectures provide best practices and approaches in the independent way a vendor deals with technology and standards. Reference Architectures model the abstract architectural elements for an enterprise independent of the technologies, protocols, and products that are used to implement an SOA. Telecom enterprises today are facing significant business and technology challenges due to growing competition, a multitude of services, and convergence. Adopting architectural best practices could go a long way in meeting these challenges. The use of SOA-based architecture for communication to each of the external systems like Billing, CRM, etc., in OSS/BSS system has made the architecture very loosely coupled, with greater flexibility. Any change in the external systems would be absorbed at the Integration Layer without affecting the rest of the ecosystem. The use of a Business Process Management (BPM) tool makes the management and maintenance of the business processes easy, with better performance in terms of lead time, quality, and cost. Since the Architecture is based on standards, it will lower the cost of deploying and managing OSS/BSS applications over their lifecycles.

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  - by user365559

  hi. i have javscript file for history management.IT is not supported by chrome when i am trying to navigate to back page with backbutton in the browser.I can see the url change but it doesnt go to preceeding page. BrowserHistoryUtils = { addEvent: function(elm, evType, fn, useCapture) { useCapture = useCapture || false; if (elm.addEventListener) { elm.addEventListener(evType, fn, useCapture); return true; } else if (elm.attachEvent) { var r = elm.attachEvent('on' + evType, fn); return r; } else { elm['on' + evType] = fn; } } } BrowserHistory = (function() { // type of browser var browser = { ie: false, firefox: false, safari: false, opera: false, version: -1 }; // if setDefaultURL has been called, our first clue // that the SWF is ready and listening //var swfReady = false; // the URL we'll send to the SWF once it is ready //var pendingURL = ''; // Default app state URL to use when no fragment ID present var defaultHash = ''; // Last-known app state URL var currentHref = document.location.href; // Initial URL (used only by IE) var initialHref = document.location.href; // Initial URL (used only by IE) var initialHash = document.location.hash; // History frame source URL prefix (used only by IE) var historyFrameSourcePrefix = 'history/historyFrame.html?'; // History maintenance (used only by Safari) var currentHistoryLength = -1; var historyHash = []; var initialState = createState(initialHref, initialHref + '#' + initialHash, initialHash); var backStack = []; var forwardStack = []; var currentObjectId = null; //UserAgent detection var useragent = navigator.userAgent.toLowerCase(); if (useragent.indexOf("opera") != -1) { browser.opera = true; } else if (useragent.indexOf("msie") != -1) { browser.ie = true; browser.version = parseFloat(useragent.substring(useragent.indexOf('msie') + 4)); } else if (useragent.indexOf("safari") != -1) { browser.safari = true; browser.version = parseFloat(useragent.substring(useragent.indexOf('safari') + 7)); } else if (useragent.indexOf("gecko") != -1) { browser.firefox = true; } if (browser.ie == true && browser.version == 7) { window["_ie_firstload"] = false; } // Accessor functions for obtaining specific elements of the page. function getHistoryFrame() { return document.getElementById('ie_historyFrame'); } function getAnchorElement() { return document.getElementById('firefox_anchorDiv'); } function getFormElement() { return document.getElementById('safari_formDiv'); } function getRememberElement() { return document.getElementById("safari_remember_field"); } // Get the Flash player object for performing ExternalInterface callbacks. // Updated for changes to SWFObject2. function getPlayer(id) { if (id && document.getElementById(id)) { var r = document.getElementById(id); if (typeof r.SetVariable != "undefined") { return r; } else { var o = r.getElementsByTagName("object"); var e = r.getElementsByTagName("embed"); if (o.length > 0 && typeof o[0].SetVariable != "undefined") { return o[0]; } else if (e.length > 0 && typeof e[0].SetVariable != "undefined") { return e[0]; } } } else { var o = document.getElementsByTagName("object"); var e = document.getElementsByTagName("embed"); if (e.length > 0 && typeof e[0].SetVariable != "undefined") { return e[0]; } else if (o.length > 0 && typeof o[0].SetVariable != "undefined") { return o[0]; } else if (o.length > 1 && typeof o[1].SetVariable != "undefined") { return o[1]; } } return undefined; } function getPlayers() { var players = []; if (players.length == 0) { var tmp = document.getElementsByTagName('object'); players = tmp; } if (players.length == 0 || players[0].object == null) { var tmp = document.getElementsByTagName('embed'); players = tmp; } return players; } function getIframeHash() { var doc = getHistoryFrame().contentWindow.document; var hash = String(doc.location.search); if (hash.length == 1 && hash.charAt(0) == "?") { hash = ""; } else if (hash.length >= 2 && hash.charAt(0) == "?") { hash = hash.substring(1); } return hash; } /* Get the current location hash excluding the '#' symbol. */ function getHash() { // It would be nice if we could use document.location.hash here, // but it's faulty sometimes. var idx = document.location.href.indexOf('#'); return (idx >= 0) ? document.location.href.substr(idx+1) : ''; } /* Get the current location hash excluding the '#' symbol. */ function setHash(hash) { // It would be nice if we could use document.location.hash here, // but it's faulty sometimes. if (hash == '') hash = '#' document.location.hash = hash; } function createState(baseUrl, newUrl, flexAppUrl) { return { 'baseUrl': baseUrl, 'newUrl': newUrl, 'flexAppUrl': flexAppUrl, 'title': null }; } /* Add a history entry to the browser. * baseUrl: the portion of the location prior to the '#' * newUrl: the entire new URL, including '#' and following fragment * flexAppUrl: the portion of the location following the '#' only */ function addHistoryEntry(baseUrl, newUrl, flexAppUrl) { //delete all the history entries forwardStack = []; if (browser.ie) { //Check to see if we are being asked to do a navigate for the first //history entry, and if so ignore, because it's coming from the creation //of the history iframe if (flexAppUrl == defaultHash && document.location.href == initialHref && window['_ie_firstload']) { currentHref = initialHref; return; } if ((!flexAppUrl || flexAppUrl == defaultHash) && window['_ie_firstload']) { newUrl = baseUrl + '#' + defaultHash; flexAppUrl = defaultHash; } else { // for IE, tell the history frame to go somewhere without a '#' // in order to get this entry into the browser history. getHistoryFrame().src = historyFrameSourcePrefix + flexAppUrl; } setHash(flexAppUrl); } else { //ADR if (backStack.length == 0 && initialState.flexAppUrl == flexAppUrl) { initialState = createState(baseUrl, newUrl, flexAppUrl); } else if(backStack.length > 0 && backStack[backStack.length - 1].flexAppUrl == flexAppUrl) { backStack[backStack.length - 1] = createState(baseUrl, newUrl, flexAppUrl); } if (browser.safari) { // for Safari, submit a form whose action points to the desired URL if (browser.version <= 419.3) { var file = window.location.pathname.toString(); file = file.substring(file.lastIndexOf("/")+1); getFormElement().innerHTML = '<form name="historyForm" action="'+file+'#' + flexAppUrl + '" method="GET"></form>'; //get the current elements and add them to the form var qs = window.location.search.substring(1); var qs_arr = qs.split("&"); for (var i = 0; i < qs_arr.length; i++) { var tmp = qs_arr[i].split("="); var elem = document.createElement("input"); elem.type = "hidden"; elem.name = tmp[0]; elem.value = tmp[1]; document.forms.historyForm.appendChild(elem); } document.forms.historyForm.submit(); } else { top.location.hash = flexAppUrl; } // We also have to maintain the history by hand for Safari historyHash[history.length] = flexAppUrl; _storeStates(); } else { // Otherwise, write an anchor into the page and tell the browser to go there addAnchor(flexAppUrl); setHash(flexAppUrl); } } backStack.push(createState(baseUrl, newUrl, flexAppUrl)); } function _storeStates() { if (browser.safari) { getRememberElement().value = historyHash.join(","); } } function handleBackButton() { //The "current" page is always at the top of the history stack. var current = backStack.pop(); if (!current) { return; } var last = backStack[backStack.length - 1]; if (!last && backStack.length == 0){ last = initialState; } forwardStack.push(current); } function handleForwardButton() { //summary: private method. Do not call this directly. var last = forwardStack.pop(); if (!last) { return; } backStack.push(last); } function handleArbitraryUrl() { //delete all the history entries forwardStack = []; } /* Called periodically to poll to see if we need to detect navigation that has occurred */ function checkForUrlChange() { if (browser.ie) { if (currentHref != document.location.href && currentHref + '#' != document.location.href) { //This occurs when the user has navigated to a specific URL //within the app, and didn't use browser back/forward //IE seems to have a bug where it stops updating the URL it //shows the end-user at this point, but programatically it //appears to be correct. Do a full app reload to get around //this issue. if (browser.version < 7) { currentHref = document.location.href; document.location.reload(); } else { if (getHash() != getIframeHash()) { // this.iframe.src = this.blankURL + hash; var sourceToSet = historyFrameSourcePrefix + getHash(); getHistoryFrame().src = sourceToSet; } } } } if (browser.safari) { // For Safari, we have to check to see if history.length changed. if (currentHistoryLength >= 0 && history.length != currentHistoryLength) { //alert("did change: " + history.length + ", " + historyHash.length + "|" + historyHash[history.length] + "|>" + historyHash.join("|")); // If it did change, then we have to look the old state up // in our hand-maintained array since document.location.hash // won't have changed, then call back into BrowserManager. currentHistoryLength = history.length; var flexAppUrl = historyHash[currentHistoryLength]; if (flexAppUrl == '') { //flexAppUrl = defaultHash; } //ADR: to fix multiple if (typeof BrowserHistory_multiple != "undefined" && BrowserHistory_multiple == true) { var pl = getPlayers(); for (var i = 0; i < pl.length; i++) { pl[i].browserURLChange(flexAppUrl); } } else { getPlayer().browserURLChange(flexAppUrl); } _storeStates(); } } if (browser.firefox) { if (currentHref != document.location.href) { var bsl = backStack.length; var urlActions = { back: false, forward: false, set: false } if ((window.location.hash == initialHash || window.location.href == initialHref) && (bsl == 1)) { urlActions.back = true; // FIXME: could this ever be a forward button? // we can't clear it because we still need to check for forwards. Ugg. // clearInterval(this.locationTimer); handleBackButton(); } // first check to see if we could have gone forward. We always halt on // a no-hash item. if (forwardStack.length > 0) { if (forwardStack[forwardStack.length-1].flexAppUrl == getHash()) { urlActions.forward = true; handleForwardButton(); } } // ok, that didn't work, try someplace back in the history stack if ((bsl >= 2) && (backStack[bsl - 2])) { if (backStack[bsl - 2].flexAppUrl == getHash()) { urlActions.back = true; handleBackButton(); } } if (!urlActions.back && !urlActions.forward) { var foundInStacks = { back: -1, forward: -1 } for (var i = 0; i < backStack.length; i++) { if (backStack[i].flexAppUrl == getHash() && i != (bsl - 2)) { arbitraryUrl = true; foundInStacks.back = i; } } for (var i = 0; i < forwardStack.length; i++) { if (forwardStack[i].flexAppUrl == getHash() && i != (bsl - 2)) { arbitraryUrl = true; foundInStacks.forward = i; } } handleArbitraryUrl(); } // Firefox changed; do a callback into BrowserManager to tell it. currentHref = document.location.href; var flexAppUrl = getHash(); if (flexAppUrl == '') { //flexAppUrl = defaultHash; } //ADR: to fix multiple if (typeof BrowserHistory_multiple != "undefined" && BrowserHistory_multiple == true) { var pl = getPlayers(); for (var i = 0; i < pl.length; i++) { pl[i].browserURLChange(flexAppUrl); } } else { getPlayer().browserURLChange(flexAppUrl); } } } //setTimeout(checkForUrlChange, 50); } /* Write an anchor into the page to legitimize it as a URL for Firefox et al. */ function addAnchor(flexAppUrl) { if (document.getElementsByName(flexAppUrl).length == 0) { getAnchorElement().innerHTML += "<a name='" + flexAppUrl + "'>" + flexAppUrl + "</a>"; } } var _initialize = function () { if (browser.ie) { var scripts = document.getElementsByTagName('script'); for (var i = 0, s; s = scripts[i]; i++) { if (s.src.indexOf("history.js") > -1) { var iframe_location = (new String(s.src)).replace("history.js", "historyFrame.html"); } } historyFrameSourcePrefix = iframe_location + "?"; var src = historyFrameSourcePrefix; var iframe = document.createElement("iframe"); iframe.id = 'ie_historyFrame'; iframe.name = 'ie_historyFrame'; //iframe.src = historyFrameSourcePrefix; try { document.body.appendChild(iframe); } catch(e) { setTimeout(function() { document.body.appendChild(iframe); }, 0); } } if (browser.safari) { var rememberDiv = document.createElement("div"); rememberDiv.id = 'safari_rememberDiv'; document.body.appendChild(rememberDiv); rememberDiv.innerHTML = '<input type="text" id="safari_remember_field" style="width: 500px;">'; var formDiv = document.createElement("div"); formDiv.id = 'safari_formDiv'; document.body.appendChild(formDiv); var reloader_content = document.createElement('div'); reloader_content.id = 'safarireloader'; var scripts = document.getElementsByTagName('script'); for (var i = 0, s; s = scripts[i]; i++) { if (s.src.indexOf("history.js") > -1) { html = (new String(s.src)).replace(".js", ".html"); } } reloader_content.innerHTML = '<iframe id="safarireloader-iframe" src="about:blank" frameborder="no" scrolling="no"></iframe>'; document.body.appendChild(reloader_content); reloader_content.style.position = 'absolute'; reloader_content.style.left = reloader_content.style.top = '-9999px'; iframe = reloader_content.getElementsByTagName('iframe')[0]; if (document.getElementById("safari_remember_field").value != "" ) { historyHash = document.getElementById("safari_remember_field").value.split(","); } } if (browser.firefox) { var anchorDiv = document.createElement("div"); anchorDiv.id = 'firefox_anchorDiv'; document.body.appendChild(anchorDiv); } //setTimeout(checkForUrlChange, 50); } return { historyHash: historyHash, backStack: function() { return backStack; }, forwardStack: function() { return forwardStack }, getPlayer: getPlayer, initialize: function(src) { _initialize(src); }, setURL: function(url) { document.location.href = url; }, getURL: function() { return document.location.href; }, getTitle: function() { return document.title; }, setTitle: function(title) { try { backStack[backStack.length - 1].title = title; } catch(e) { } //if on safari, set the title to be the empty string. if (browser.safari) { if (title == "") { try { var tmp = window.location.href.toString(); title = tmp.substring((tmp.lastIndexOf("/")+1), tmp.lastIndexOf("#")); } catch(e) { title = ""; } } } document.title = title; }, setDefaultURL: function(def) { defaultHash = def; def = getHash(); //trailing ? is important else an extra frame gets added to the history //when navigating back to the first page. Alternatively could check //in history frame navigation to compare # and ?. if (browser.ie) { window['_ie_firstload'] = true; var sourceToSet = historyFrameSourcePrefix + def; var func = function() { getHistoryFrame().src = sourceToSet; window.location.replace("#" + def); setInterval(checkForUrlChange, 50); } try { func(); } catch(e) { window.setTimeout(function() { func(); }, 0); } } if (browser.safari) { currentHistoryLength = history.length; if (historyHash.length == 0) { historyHash[currentHistoryLength] = def; var newloc = "#" + def; window.location.replace(newloc); } else { //alert(historyHash[historyHash.length-1]); } //setHash(def); setInterval(checkForUrlChange, 50); } if (browser.firefox || browser.opera) { var reg = new RegExp("#" + def + "$"); if (window.location.toString().match(reg)) { } else { var newloc ="#" + def; window.location.replace(newloc); } setInterval(checkForUrlChange, 50); //setHash(def); } }, /* Set the current browser URL; called from inside BrowserManager to propagate * the application state out to the container. */ setBrowserURL: function(flexAppUrl, objectId) { if (browser.ie && typeof objectId != "undefined") { currentObjectId = objectId; } //fromIframe = fromIframe || false; //fromFlex = fromFlex || false; //alert("setBrowserURL: " + flexAppUrl); //flexAppUrl = (flexAppUrl == "") ? defaultHash : flexAppUrl ; var pos = document.location.href.indexOf('#'); var baseUrl = pos != -1 ? document.location.href.substr(0, pos) : document.location.href; var newUrl = baseUrl + '#' + flexAppUrl; if (document.location.href != newUrl && document.location.href + '#' != newUrl) { currentHref = newUrl; addHistoryEntry(baseUrl, newUrl, flexAppUrl); currentHistoryLength = history.length; } return false; }, browserURLChange: function(flexAppUrl) { var objectId = null; if (browser.ie && currentObjectId != null) { objectId = currentObjectId; } pendingURL = ''; if (typeof BrowserHistory_multiple != "undefined" && BrowserHistory_multiple == true) { var pl = getPlayers(); for (var i = 0; i < pl.length; i++) { try { pl[i].browserURLChange(flexAppUrl); } catch(e) { } } } else { try { getPlayer(objectId).browserURLChange(flexAppUrl); } catch(e) { } } currentObjectId = null; } } })(); // Initialization // Automated unit testing and other diagnostics function setURL(url) { document.location.href = url; } function backButton() { history.back(); } function forwardButton() { history.forward(); } function goForwardOrBackInHistory(step) { history.go(step); } //BrowserHistoryUtils.addEvent(window, "load", function() { BrowserHistory.initialize(); }); (function(i) { var u =navigator.userAgent;var e=/*@cc_on!@*/false; var st = setTimeout; if(/webkit/i.test(u)){ st(function(){ var dr=document.readyState; if(dr=="loaded"||dr=="complete"){i()} else{st(arguments.callee,10);}},10); } else if((/mozilla/i.test(u)&&!/(compati)/.test(u)) || (/opera/i.test(u))){ document.addEventListener("DOMContentLoaded",i,false); } else if(e){ (function(){ var t=document.createElement('doc:rdy'); try{t.doScroll('left'); i();t=null; }catch(e){st(arguments.callee,0);}})(); } else{ window.onload=i; } })( function() {BrowserHistory.initialize();} );

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• Thread not behaving correctly

  - by ivor

  Hello, I wonder if anyone can help me to understand where I could be going wrong with this code; Basically I'm working on a turorial and calling the class below from another class - and it is getting the following error; Exception in thread "Thread-1" java.lang.NullPointerException at org.newdawn.spaceinvaders.TCPChat.run(TCPChat.java:322) at java.lang.Thread.run(Unknown Source) I realise the error is beibg flagged in another class- but I have tested the other class with a small class which sets up a separate thread - and it works fine, but as soon as I try and implement a new thread in this class - it causes all sorts of problems. Am I setting up the thread correctly in this class? Basically I can set up a thread in this class, with a test loop and it's fine, but when I bring in the functionality of the rest of the game it sometimes hangs, or does not display at all. Any suggestions on where I could be going wrong would be greatly appreciated. Thanks for looking. package org.newdawn.spaceinvaders; import java.awt.BorderLayout; import java.awt.Canvas; import java.awt.Color; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.Graphics2D; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyAdapter; import java.awt.event.KeyEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.awt.image.BufferStrategy; import java.util.ArrayList; import java.util.Scanner; import java.awt.*;//maybe not needed import javax.swing.*;//maybenot needed import java.util.Random; //import java.io.*; /** * The main hook of our game. This class with both act as a manager * for the display and central mediator for the game logic. * * Display management will consist of a loop that cycles round all * entities in the game asking them to move and then drawing them * in the appropriate place. With the help of an inner class it * will also allow the player to control the main ship. * * As a mediator it will be informed when entities within our game * detect events (e.g. alient killed, played died) and will take * appropriate game actions. * * @author Kevin Glass */ public class Game extends Canvas implements Runnable{ /** The stragey that allows us to use accelerate page flipping */ private BufferStrategy strategy; /** True if the game is currently "running", i.e. the game loop is looping */ private boolean gameRunning = true; /** The list of all the entities that exist in our game */ private ArrayList entities = new ArrayList(); /** The list of entities that need to be removed from the game this loop */ private ArrayList removeList = new ArrayList(); /** The entity representing the player */ private Entity ship; /** The speed at which the player's ship should move (pixels/sec) */ private double moveSpeed = 300; /** The time at which last fired a shot */ private long lastFire = 0; /** The interval between our players shot (ms) */ private long firingInterval = 500; /** The number of aliens left on the screen */ private int alienCount; /** The number of levels progressed */ private double levelCount; /** high score for the user */ private int highScore; /** high score for the user */ private String player = "bob"; //private GetUserInput getPlayer; /** The list of entities that need to be removed from the game this loop */ /** The message to display which waiting for a key press */ private String message = ""; /** True if we're holding up game play until a key has been pressed */ private boolean waitingForKeyPress = true; /** True if the left cursor key is currently pressed */ private boolean leftPressed = false; /** True if the right cursor key is currently pressed */ private boolean rightPressed = false; /** True if we are firing */ private boolean firePressed = false; /** True if game logic needs to be applied this loop, normally as a result of a game event */ private boolean logicRequiredThisLoop = false; //private Thread cThread = new Thread(this); //public Thread t = new Thread(this); //private Thread g = new Thread(this); void setHighscore(int setHS) { highScore = setHS; } public int getHighscore() { return highScore; } public void setPlayer(String setPlayer) { player = setPlayer; } public String getPlayer() { return player; } public void run() { //setup(); System.out.println("hello im running bob"); /*int count = 1; do { System.out.println("Count is: " + count); count++; try{Thread.sleep(1);} catch(InterruptedException e){} } while (count <= 2000000);*/ //Game g =new Game(); //Game g = this; // Start the main game loop, note: this method will not // return until the game has finished running. Hence we are // using the actual main thread to run the game. //setup(); //this.gameLoop(); //try{thread.sleep(1);} //catch{InterruptedException e} } /** * Construct our game and set it running. */ public Game () { //Thread t = new Thread(this);//set up new thread for invaders game //t.run();//run the run method of the game //Game g =new Game(); //setup(); //Thread t = new Thread(this); //thread.start(); //SwingUtilities.invokeLater(this); Thread er = new Thread(this); er.start(); } public void setup(){ //initialise highscore setHighscore(0); // create a frame to contain our game JFrame container = new JFrame("Space Invaders 101"); // get hold the content of the frame and set up the resolution of the game JPanel panel = (JPanel) container.getContentPane(); panel.setPreferredSize(new Dimension(800,600)); //panel.setLayout(null); // setup our canvas size and put it into the content of the frame setBounds(0,0,800,600); panel.add(this); // Tell AWT not to bother repainting our canvas since we're // going to do that our self in accelerated mode setIgnoreRepaint(true); // finally make the window visible container.pack(); container.setResizable(false); container.setVisible(true); // add a listener to respond to the user closing the window. If they // do we'd like to exit the game container.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { //cThread.interrupt(); System.exit(0); } }); // add a key input system (defined below) to our canvas // so we can respond to key pressed addKeyListener(new KeyInputHandler()); // request the focus so key events come to us requestFocus(); // create the buffering strategy which will allow AWT // to manage our accelerated graphics createBufferStrategy(2); strategy = getBufferStrategy(); // initialise the entities in our game so there's something // to see at startup initEntities(); } /** * Start a fresh game, this should clear out any old data and * create a new set. */ private void startGame() { // clear out any existing entities and intialise a new set entities.clear(); initEntities(); //initialise highscore setHighscore(0); // blank out any keyboard settings we might currently have leftPressed = false; rightPressed = false; firePressed = false; } /** * Initialise the starting state of the entities (ship and aliens). Each * entitiy will be added to the overall list of entities in the game. */ //private void initEntities() { public void initEntities() { Random randomAlien = new Random(); // create the player ship and place it roughly in the center of the screen //ship = new ShipEntity(this,"sprites/ship.gif",370,550);//orignal ship = new ShipEntity(this,"sprites/ship.gif",700,300);//changed postioning to right hand side entities.add(ship); // create a block of aliens (5 rows, by 12 aliens, spaced evenly) alienCount = 0; levelCount = 1.02; for (int row=0;row<7;row++) {//altered number of rows for (int x=0;x<5;x++) { int r = randomAlien.nextInt(100);//loop added to produce random aliens if (r < 50){ //Entity alien = new AlienEntity(this,"sprites/alien.gif",/*100+*/(x*50),(50)+row*30); Entity alien = new AlienEntity(this,"sprites/alien.gif",100+(x*90),(12)+row*85); entities.add(alien); alienCount++; } } } } //private void initEntities() { public void initAlienEntities() { Random randomAlien = new Random(); // create the player ship and place it roughly in the center of the screen //ship = new ShipEntity(this,"sprites/ship.gif",370,550);//orignal //ship = new ShipEntity(this,"sprites/ship.gif",700,300);//changed postioning to right hand side //entities.add(ship); // create a block of aliens (5 rows, by 12 aliens, spaced evenly) alienCount = 0; levelCount = levelCount + 0.10;//this increases the speed on every level for (int row=0;row<7;row++) {//altered number of rows for (int x=0;x<5;x++) { int r = randomAlien.nextInt(100);//loop added to produce random aliens if (r < 50){//randome check to show alien //Entity alien = new AlienEntity(this,"sprites/alien.gif",/*100+*/(x*50),(50)+row*30); Entity alien = new AlienEntity(this,"sprites/alien.gif",-250+(x*90),(12)+row*85); entities.add(alien); alienCount++; } } } advanceAlienSpeed(levelCount); } /** * Notification from a game entity that the logic of the game * should be run at the next opportunity (normally as a result of some * game event) */ public void updateLogic() { logicRequiredThisLoop = true; } /** * Remove an entity from the game. The entity removed will * no longer move or be drawn. * * @param entity The entity that should be removed */ public void removeEntity(Entity entity) { removeList.add(entity); } /** * Notification that the player has died. */ public void notifyDeath() { message = "Oh no! They got you, try again?"; waitingForKeyPress = true; } /** * Notification that the player has won since all the aliens * are dead. */ public void notifyWin() { message = "Well done! You Win!"; waitingForKeyPress = true; } /** * Notification that an alien has been killed */ public void notifyAlienKilled() { // reduce the alient count, if there are none left, the player has won! alienCount--; if (alienCount == 0) { //notifyWin();win not relevant here... this.initAlienEntities();//call fresh batch of aliens } // if there are still some aliens left then they all need to get faster, so // speed up all the existing aliens advanceAlienSpeed(1.30); } public void advanceAlienSpeed(double speed) { // if there are still some aliens left then they all need to get faster, so // speed up all the existing aliens for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); if (entity instanceof AlienEntity) { // speed up by 2% entity.setHorizontalMovement(entity.getHorizontalMovement() * speed); //entity.setVerticalMovement(entity.getVerticalMovement() * 1.02); } } } /** * Attempt to fire a shot from the player. Its called "try" * since we must first check that the player can fire at this * point, i.e. has he/she waited long enough between shots */ public void tryToFire() { // check that we have waiting long enough to fire if (System.currentTimeMillis() - lastFire < firingInterval) { return; } // if we waited long enough, create the shot entity, and record the time. lastFire = System.currentTimeMillis(); ShotEntity shot = new ShotEntity(this,"sprites/shot.gif",ship.getX()+10,ship.getY()-30); entities.add(shot); } /** * The main game loop. This loop is running during all game * play as is responsible for the following activities: * <p> * - Working out the speed of the game loop to update moves * - Moving the game entities * - Drawing the screen contents (entities, text) * - Updating game events * - Checking Input * <p> */ public void gameLoop() { long lastLoopTime = System.currentTimeMillis(); // keep looping round til the game ends while (gameRunning) { // work out how long its been since the last update, this // will be used to calculate how far the entities should // move this loop long delta = System.currentTimeMillis() - lastLoopTime; lastLoopTime = System.currentTimeMillis(); // Get hold of a graphics context for the accelerated // surface and blank it out Graphics2D g = (Graphics2D) strategy.getDrawGraphics(); g.setColor(Color.black); g.fillRect(0,0,800,600); // cycle round asking each entity to move itself if (!waitingForKeyPress) { for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.move(delta); } } // cycle round drawing all the entities we have in the game for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.draw(g); } // brute force collisions, compare every entity against // every other entity. If any of them collide notify // both entities that the collision has occured for (int p=0;p<entities.size();p++) { for (int s=p+1;s<entities.size();s++) { Entity me = (Entity) entities.get(p); Entity him = (Entity) entities.get(s); if (me.collidesWith(him)) { me.collidedWith(him); him.collidedWith(me); } } } // remove any entity that has been marked for clear up entities.removeAll(removeList); removeList.clear(); // if a game event has indicated that game logic should // be resolved, cycle round every entity requesting that // their personal logic should be considered. if (logicRequiredThisLoop) { //g.drawString("Press any key",(800-g.getFontMetrics().stringWidth("Press any key"))/2,300); for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.doLogic(); } logicRequiredThisLoop = false; } // if we're waiting for an "any key" press then draw the // current message //show highscore at top of screen //show name at top of screen g.setColor(Color.white); g.drawString("Player : "+getPlayer()+" : Score : "+getHighscore(),20,20); if (waitingForKeyPress) { g.setColor(Color.white); g.drawString(message,(800-g.getFontMetrics().stringWidth(message))/2,250); g.drawString("Press any key",(800-g.getFontMetrics().stringWidth("Press any key"))/2,300); } // finally, we've completed drawing so clear up the graphics // and flip the buffer over g.dispose(); strategy.show(); // resolve the movement of the ship. First assume the ship // isn't moving. If either cursor key is pressed then // update the movement appropraitely ship.setVerticalMovement(0);//set to vertical movement if ((leftPressed) && (!rightPressed)) { ship.setVerticalMovement(-moveSpeed);//**took out setHorizaontalMOvement } else if ((rightPressed) && (!leftPressed)) { ship.setVerticalMovement(moveSpeed);//**took out setHorizaontalMOvement } // if we're pressing fire, attempt to fire if (firePressed) { tryToFire(); } // finally pause for a bit. Note: this should run us at about // 100 fps but on windows this might vary each loop due to // a bad implementation of timer try { Thread.sleep(10); } catch (Exception e) {} } } /** * A class to handle keyboard input from the user. The class * handles both dynamic input during game play, i.e. left/right * and shoot, and more static type input (i.e. press any key to * continue) * * This has been implemented as an inner class more through * habbit then anything else. Its perfectly normal to implement * this as seperate class if slight less convienient. * * @author Kevin Glass */ private class KeyInputHandler extends KeyAdapter { /** The number of key presses we've had while waiting for an "any key" press */ private int pressCount = 1; /** * Notification from AWT that a key has been pressed. Note that * a key being pressed is equal to being pushed down but *NOT* * released. Thats where keyTyped() comes in. * * @param e The details of the key that was pressed */ public void keyPressed(KeyEvent e) { // if we're waiting for an "any key" typed then we don't // want to do anything with just a "press" if (waitingForKeyPress) { return; } // if (e.getKeyCode() == KeyEvent.VK_LEFT) { ////leftPressed = true; ///} //// if (e.getKeyCode() == KeyEvent.VK_RIGHT) { //rightPressed = true; if (e.getKeyCode() == KeyEvent.VK_UP) { leftPressed = true; } if (e.getKeyCode() == KeyEvent.VK_DOWN) { rightPressed = true; } if (e.getKeyCode() == KeyEvent.VK_SPACE) { firePressed = true; } } /** * Notification from AWT that a key has been released. * * @param e The details of the key that was released */ public void keyReleased(KeyEvent e) { // if we're waiting for an "any key" typed then we don't // want to do anything with just a "released" if (waitingForKeyPress) { return; } if (e.getKeyCode() == KeyEvent.VK_UP) {//changed from VK_LEFT leftPressed = false; } if (e.getKeyCode() == KeyEvent.VK_DOWN) {//changed from VK_RIGHT rightPressed = false; } if (e.getKeyCode() == KeyEvent.VK_SPACE) { firePressed = false; } } /** * Notification from AWT that a key has been typed. Note that * typing a key means to both press and then release it. * * @param e The details of the key that was typed. */ public void keyTyped(KeyEvent e) { // if we're waiting for a "any key" type then // check if we've recieved any recently. We may // have had a keyType() event from the user releasing // the shoot or move keys, hence the use of the "pressCount" // counter. if (waitingForKeyPress) { if (pressCount == 1) { // since we've now recieved our key typed // event we can mark it as such and start // our new game waitingForKeyPress = false; startGame(); pressCount = 0; } else { pressCount++; } } // if we hit escape, then quit the game if (e.getKeyChar() == 27) { //cThread.interrupt(); System.exit(0); } } } /** * The entry point into the game. We'll simply create an * instance of class which will start the display and game * loop. * * @param argv The arguments that are passed into our game */ //public static void main(String argv[]) { //Game g =new Game(); // Start the main game loop, note: this method will not // return until the game has finished running. Hence we are // using the actual main thread to run the game. //g.gameLoop(); //} }

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• Why my application ask for a codec to pla the MVI(.MOV) video files while i can play them on WMP and QuickTime?

  - by Daniel Lip

  I have an application i did some time ago when im loading the video file its ok when trying to play/use the file im getting the messageBox message say that its need a codec to use gspot or search the internet. Wehn im playing this files on my hard disk with Windows Media Play or either QuickTime there is no problems. The Video files for example name are: MVI_2483 in the file name properties i see its type: Quick Time Movie (.MOV) In my application im using DirectShowLib-2005.dll this is the class im using in my case to extract the video file im using it in my application to extract only lightnings from the video file name. In Form1 i have a button click event that just starting the action: private void button8_Click(object sender, EventArgs e) { viewToolStripMenuItem.Enabled = false; fileToolStripMenuItem.Enabled = false; button2.Enabled = false; label14.Visible = false; label15.Visible = false; label21.Visible = false; label22.Visible = false; label24.Visible = false; label25.Visible = false; ExtractAutomatic = true; DirectoryInfo info = new DirectoryInfo(_videoFile); string dirName = info.Name; automaticModeDirectory = dirName + "_Automatic"; subDirectoryName = _outputDir + "\\" + automaticModeDirectory; if (secondPass == true) { Start(true); } Start(false); } This is the function start in Form1: private void Start(bool secondpass) { setpicture(-1); if (Directory.Exists(_outputDir) && secondpass == false) { } else { Directory.CreateDirectory(_outputDir); } if (ExtractAutomatic == true) { string subDirectory_Automatic_Name = _outputDir + "\\" + automaticModeDirectory; Directory.CreateDirectory(subDirectory_Automatic_Name); f = new WmvAdapter(_videoFile, Path.Combine(subDirectory_Automatic_Name)); } else { string subDirectory_Manual_Name; if (Directory.Exists(subDirectoryName)) { subDirectory_Manual_Name = subDirectoryName; f = new WmvAdapter(_videoFile, Path.Combine(subDirectory_Manual_Name)); } else { subDirectory_Manual_Name = _outputDir + "\\" + averagesListTextFileDirectory + "_Manual"; Directory.CreateDirectory(subDirectory_Manual_Name); f = new WmvAdapter(_videoFile, Path.Combine(subDirectory_Manual_Name)); } } button1.Enabled = false; f.Secondpass = secondpass; f.FramesToSave = _fts; f.FrameCountAvailable += new WmvAdapter.FrameCountEventHandler(f_FrameCountAvailable); f.StatusChanged += new WmvAdapter.EventHandler(f_StatusChanged); f.ProgressChanged += new WmvAdapter.ProgressEventHandler(f_ProgressChanged); this.Text = "Processing Please Wait..."; label5.ForeColor = Color.Green; label5.Text = "Processing Please Wait"; button8.Enabled = false; button5.Enabled = false; label5.Visible = true; pictureBox1.Image = Lightnings_Extractor.Properties.Resources.Weather_Michmoret; Hrs = 0; //number of hours Min = 0; //number of Minutes Sec = 0; //number of Sec timeElapsed = 0; label10.Text = "00:00:00"; label11.Visible = false; label12.Visible = false; label9.Visible = false; label8.Visible = false; this.button1.Enabled = false; myTrackPanelss1.trackBar1.Enabled = false; this.checkBox2.Enabled = false; this.checkBox1.Enabled = false; numericUpDown1.Enabled = false; timer1.Start(); label2.Text = ""; label1.Visible = true; label2.Visible = true; label3.Visible = true; label4.Visible = true; f.Start(); } And this is the class wich is not my oqn class i just just defined it in some places wich making the problem: using System; using System.Diagnostics; using System.Drawing; using System.Drawing.Imaging; using System.IO; using System.Runtime.InteropServices; using DirectShowLib; using System.Collections.Generic; using Extracting_Frames; using System.Windows.Forms; namespace Polkan.DataSource { internal class WmvAdapter : ISampleGrabberCB, IDisposable { #region Fields_Properties_and_Events bool dis = false; int count = 0; const string fileName = @"d:\histogramValues.dat"; private IFilterGraph2 _filterGraph; private IMediaControl _mediaCtrl; private IMediaEvent _mediaEvent; private int _width; private int _height; private readonly string _outFolder; private int _frameId; //better use a custom EventHandler that passes the results of the action to the subscriber. public delegate void EventHandler(object sender, EventArgs e); public event EventHandler StatusChanged; public delegate void FrameCountEventHandler(object sender, FrameCountEventArgs e); public event FrameCountEventHandler FrameCountAvailable; public delegate void ProgressEventHandler(object sender, ProgressEventArgs e); public event ProgressEventHandler ProgressChanged; private IMediaSeeking _mSeek; private long _duration = 0; private long _avgFrameTime = 0; //just save the averages to a List (not to fs) public List<double> AveragesList { get; set; } public List<long> histogramValuesList; public bool Secondpass { get; set; } public List<int> FramesToSave { get; set; } #endregion #region Constructors and Destructors public WmvAdapter(string file, string outFolder) { _outFolder = outFolder; try { SetupGraph(file); } catch { Dispose(); MessageBox.Show("A codec is required to load this video file. Please use http://www.headbands.com/gspot/ or search the web for the correct codec"); } } ~WmvAdapter() { CloseInterfaces(); } #endregion public void Dispose() { CloseInterfaces(); } public void Start() { EstimateFrameCount(); int hr = _mediaCtrl.Run(); WaitUntilDone(); DsError.ThrowExceptionForHR(hr); } public void WaitUntilDone() { int hr; const int eAbort = unchecked((int)0x80004004); do { System.Windows.Forms.Application.DoEvents(); EventCode evCode; if (dis == true) { return; } hr = _mediaEvent.WaitForCompletion(100, out evCode); }while (hr == eAbort); DsError.ThrowExceptionForHR(hr); OnStatusChanged(); } //Edit: added events protected virtual void OnStatusChanged() { if (StatusChanged != null) StatusChanged(this, new EventArgs()); } protected virtual void OnFrameCountAvailable(long frameCount) { if (FrameCountAvailable != null) FrameCountAvailable(this, new FrameCountEventArgs() { FrameCount = frameCount }); } protected virtual void OnProgressChanged(int frameID) { if (ProgressChanged != null) ProgressChanged(this, new ProgressEventArgs() { FrameID = frameID }); } /// <summary> build the capture graph for grabber. </summary> private void SetupGraph(string file) { ISampleGrabber sampGrabber = null; IBaseFilter capFilter = null; IBaseFilter nullrenderer = null; _filterGraph = (IFilterGraph2)new FilterGraph(); _mediaCtrl = (IMediaControl)_filterGraph; _mediaEvent = (IMediaEvent)_filterGraph; _mSeek = (IMediaSeeking)_filterGraph; var mediaFilt = (IMediaFilter)_filterGraph; try { // Add the video source int hr = _filterGraph.AddSourceFilter(file, "Ds.NET FileFilter", out capFilter); DsError.ThrowExceptionForHR(hr); // Get the SampleGrabber interface sampGrabber = new SampleGrabber() as ISampleGrabber; var baseGrabFlt = sampGrabber as IBaseFilter; ConfigureSampleGrabber(sampGrabber); // Add the frame grabber to the graph hr = _filterGraph.AddFilter(baseGrabFlt, "Ds.NET Grabber"); DsError.ThrowExceptionForHR(hr); // --------------------------------- // Connect the file filter to the sample grabber // Hopefully this will be the video pin, we could check by reading it's mediatype IPin iPinOut = DsFindPin.ByDirection(capFilter, PinDirection.Output, 0); // Get the input pin from the sample grabber IPin iPinIn = DsFindPin.ByDirection(baseGrabFlt, PinDirection.Input, 0); hr = _filterGraph.Connect(iPinOut, iPinIn); DsError.ThrowExceptionForHR(hr); // Add the null renderer to the graph nullrenderer = new NullRenderer() as IBaseFilter; hr = _filterGraph.AddFilter(nullrenderer, "Null renderer"); DsError.ThrowExceptionForHR(hr); // --------------------------------- // Connect the sample grabber to the null renderer iPinOut = DsFindPin.ByDirection(baseGrabFlt, PinDirection.Output, 0); iPinIn = DsFindPin.ByDirection(nullrenderer, PinDirection.Input, 0); hr = _filterGraph.Connect(iPinOut, iPinIn); DsError.ThrowExceptionForHR(hr); // Turn off the clock. This causes the frames to be sent // thru the graph as fast as possible hr = mediaFilt.SetSyncSource(null); DsError.ThrowExceptionForHR(hr); // Read and cache the image sizes SaveSizeInfo(sampGrabber); //Edit: get the duration hr = _mSeek.GetDuration(out _duration); DsError.ThrowExceptionForHR(hr); } finally { if (capFilter != null) { Marshal.ReleaseComObject(capFilter); } if (sampGrabber != null) { Marshal.ReleaseComObject(sampGrabber); } if (nullrenderer != null) { Marshal.ReleaseComObject(nullrenderer); } GC.Collect(); } } private void EstimateFrameCount() { try { //1sec / averageFrameTime double fr = 10000000.0 / _avgFrameTime; double frameCount = fr * (_duration / 10000000.0); OnFrameCountAvailable((long)frameCount); } catch { } } public double framesCounts() { double fr = 10000000.0 / _avgFrameTime; double frameCount = fr * (_duration / 10000000.0); return frameCount; } private void SaveSizeInfo(ISampleGrabber sampGrabber) { // Get the media type from the SampleGrabber var media = new AMMediaType(); int hr = sampGrabber.GetConnectedMediaType(media); DsError.ThrowExceptionForHR(hr); if ((media.formatType != FormatType.VideoInfo) || (media.formatPtr == IntPtr.Zero)) { throw new NotSupportedException("Unknown Grabber Media Format"); } // Grab the size info var videoInfoHeader = (VideoInfoHeader)Marshal.PtrToStructure(media.formatPtr, typeof(VideoInfoHeader)); _width = videoInfoHeader.BmiHeader.Width; _height = videoInfoHeader.BmiHeader.Height; //Edit: get framerate _avgFrameTime = videoInfoHeader.AvgTimePerFrame; DsUtils.FreeAMMediaType(media); GC.Collect(); } private void ConfigureSampleGrabber(ISampleGrabber sampGrabber) { var media = new AMMediaType { majorType = MediaType.Video, subType = MediaSubType.RGB24, formatType = FormatType.VideoInfo }; int hr = sampGrabber.SetMediaType(media); DsError.ThrowExceptionForHR(hr); DsUtils.FreeAMMediaType(media); GC.Collect(); hr = sampGrabber.SetCallback(this, 1); DsError.ThrowExceptionForHR(hr); } private void CloseInterfaces() { try { if (_mediaCtrl != null) { _mediaCtrl.Stop(); _mediaCtrl = null; dis = true; } } catch (Exception ex) { Debug.WriteLine(ex); } if (_filterGraph != null) { Marshal.ReleaseComObject(_filterGraph); _filterGraph = null; } GC.Collect(); } int ISampleGrabberCB.SampleCB(double sampleTime, IMediaSample pSample) { Marshal.ReleaseComObject(pSample); return 0; } int ISampleGrabberCB.BufferCB(double sampleTime, IntPtr pBuffer, int bufferLen) { if (Form1.ExtractAutomatic == true) { using (var bitmap = new Bitmap(_width, _height, _width * 3, PixelFormat.Format24bppRgb, pBuffer)) { if (!this.Secondpass) { long[] HistogramValues = Form1.GetHistogram(bitmap); long t = Form1.GetTopLumAmount(HistogramValues, 1000); Form1.averagesTest.Add(t); } else { //this is the changed part if (_frameId > 0) { if (Form1.averagesTest[_frameId] / 1000.0 - Form1.averagesTest[_frameId - 1] / 1000.0 > 150.0) { count = 6; } if (count > 0) { bitmap.RotateFlip(RotateFlipType.Rotate180FlipX); bitmap.Save(Path.Combine(_outFolder, _frameId.ToString("D6") + ".bmp")); count --; } } } _frameId++; //let only report each 100 frames for performance if (_frameId % 100 == 0) OnProgressChanged(_frameId); } } else { using (var bitmap = new Bitmap(_width, _height, _width * 3, PixelFormat.Format24bppRgb, pBuffer)) { if (!this.Secondpass) { //get avg double average = GetAveragePixelValue(bitmap); if (AveragesList == null) AveragesList = new List<double>(); //save avg AveragesList.Add(average); //***************************\\ // for (int i = 0; i < (int)framesCounts(); i++) // { // get histogram values long[] HistogramValues = Form1.GetHistogram(bitmap); if (histogramValuesList == null) histogramValuesList = new List<long>(256); histogramValuesList.AddRange(HistogramValues); //***************************\\ //} } else { if (FramesToSave != null && FramesToSave.Contains(_frameId)) { bitmap.RotateFlip(RotateFlipType.Rotate180FlipX); bitmap.Save(Path.Combine(_outFolder, _frameId.ToString("D6") + ".bmp")); // get histogram values long[] HistogramValues = Form1.GetHistogram(bitmap); if (histogramValuesList == null) histogramValuesList = new List<long>(256); histogramValuesList.AddRange(HistogramValues); using (BinaryWriter binWriter = new BinaryWriter(File.Open(fileName, FileMode.Create))) { for (int i = 0; i < histogramValuesList.Count; i++) { binWriter.Write(histogramValuesList[(int)i]); } binWriter.Close(); } } } _frameId++; //let only report each 100 frames for performance if (_frameId % 100 == 0) OnProgressChanged(_frameId); } } return 0; } /* int ISampleGrabberCB.SampleCB(double sampleTime, IMediaSample pSample) { Marshal.ReleaseComObject(pSample); return 0; } int ISampleGrabberCB.BufferCB(double sampleTime, IntPtr pBuffer, int bufferLen) { using (var bitmap = new Bitmap(_width, _height, _width * 3, PixelFormat.Format24bppRgb, pBuffer)) { if (!this.Secondpass) { //get avg double average = GetAveragePixelValue(bitmap); if (AveragesList == null) AveragesList = new List<double>(); //save avg AveragesList.Add(average); //***************************\\ // for (int i = 0; i < (int)framesCounts(); i++) // { // get histogram values long[] HistogramValues = Form1.GetHistogram(bitmap); if (histogramValuesList == null) histogramValuesList = new List<long>(256); histogramValuesList.AddRange(HistogramValues); long t = Form1.GetTopLumAmount(HistogramValues, 1000); //***************************\\ Form1.averagesTest.Add(t); // to add this list to a text file or binary file and read the averages from the file when its is Secondpass !!!!! //} } else { if (FramesToSave != null && FramesToSave.Contains(_frameId)) { bitmap.RotateFlip(RotateFlipType.Rotate180FlipX); bitmap.Save(Path.Combine(_outFolder, _frameId.ToString("D6") + ".bmp")); // get histogram values long[] HistogramValues = Form1.GetHistogram(bitmap); if (histogramValuesList == null) histogramValuesList = new List<long>(256); histogramValuesList.AddRange(HistogramValues); using (BinaryWriter binWriter = new BinaryWriter(File.Open(fileName, FileMode.Create))) { for (int i = 0; i < histogramValuesList.Count; i++) { binWriter.Write(histogramValuesList[(int)i]); } binWriter.Close(); } } for (int x = 1; x < Form1.averagesTest.Count; x++) { double fff = Form1.averagesTest[x] / 1000.0 - Form1.averagesTest[x - 1] / 1000.0; if (Form1.averagesTest[x] / 1000.0 - Form1.averagesTest[x - 1] / 1000.0 > 180.0) { bitmap.RotateFlip(RotateFlipType.Rotate180FlipX); bitmap.Save(Path.Combine(_outFolder, _frameId.ToString("D6") + ".bmp")); _frameId++; } } } _frameId++; //let only report each 100 frames for performance if (_frameId % 100 == 0) OnProgressChanged(_frameId); } return 0; }*/ private unsafe double GetAveragePixelValue(Bitmap bmp) { BitmapData bmData = null; try { bmData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb); int stride = bmData.Stride; IntPtr scan0 = bmData.Scan0; int w = bmData.Width; int h = bmData.Height; double sum = 0; long pixels = bmp.Width * bmp.Height; byte* p = (byte*)scan0.ToPointer(); for (int y = 0; y < h; y++) { p = (byte*)scan0.ToPointer(); p += y * stride; for (int x = 0; x < w; x++) { double i = ((double)p[0] + p[1] + p[2]) / 3.0; sum += i; p += 3; } //no offset incrementation needed when getting //the pointer at the start of each row } bmp.UnlockBits(bmData); double result = sum / (double)pixels; return result; } catch { try { bmp.UnlockBits(bmData); } catch { } } return -1; } } public class FrameCountEventArgs { public long FrameCount { get; set; } } public class ProgressEventArgs { public int FrameID { get; set; } } } I remember i had this codec problem/s before and i installed the codec/'s that were needed but in this case both quick time and windows media player can play the video files so why the application cant detect and find the codec/'s on my computer ? Gspot say that the codec is AVC1 but again wmp and quicktime play the video files no problems. The video files are from my digital camera !

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