Source/GDBpConnection.m

   1 /*
   2  * MacGDBp
   3  * Copyright (c) 2007 - 2010, Blue Static <http://www.bluestatic.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under the terms of the GNU
   6  * General Public License as published by the Free Software Foundation; either version 2 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
  10  * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with this program; if not,
  14  * write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  15  */
  16
  17 #import <sys/socket.h>
  18 #import <netinet/in.h>
  19
  20 #import "GDBpConnection.h"
  21
  22 #import "AppDelegate.h"
  23
  24 // GDBpConnection (Private) ////////////////////////////////////////////////////
  25
  26 @interface GDBpConnection ()
  27 @property (readwrite, copy) NSString* status;
  28 @property (assign) CFSocketRef socket;
  29 @property (assign) CFReadStreamRef readStream;
  30 @property NSUInteger lastReadTransaction;
  31 @property (retain) NSMutableString* currentPacket;
  32 @property (assign) CFWriteStreamRef writeStream;
  33 @property NSUInteger lastWrittenTransaction;
  34 @property (retain) NSMutableArray* queuedWrites;
  35
  36 - (void)connect;
  37 - (void)close;
  38 - (void)socketDidAccept;
  39 - (void)socketDisconnected;
  40 - (void)readStreamHasData;
  41 - (void)send:(NSString*)command;
  42 - (void)performSend:(NSString*)command;
  43 - (void)errorEncountered:(NSString*)error;
  44
  45 - (void)handleResponse:(NSXMLDocument*)response;
  46 - (void)initReceived:(NSXMLDocument*)response;
  47 - (void)updateStatus:(NSXMLDocument*)response;
  48 - (void)debuggerStep:(NSXMLDocument*)response;
  49 - (void)rebuildStack:(NSXMLDocument*)response;
  50 - (void)getStackFrame:(NSXMLDocument*)response;
  51 - (void)setSource:(NSXMLDocument*)response;
  52 - (void)contextsReceived:(NSXMLDocument*)response;
  53 - (void)variablesReceived:(NSXMLDocument*)response;
  54
  55 - (NSNumber*)sendCommandWithCallback:(SEL)callback format:(NSString*)format, ...;
  56
  57 - (void)sendQueuedWrites;
  58
  59 - (NSString*)escapedURIPath:(NSString*)path;
  60 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response;
  61 @end
  62
  63 // CFNetwork Callbacks /////////////////////////////////////////////////////////
  64
  65 void ReadStreamCallback(CFReadStreamRef stream, CFStreamEventType eventType, void* connectionRaw)
  66 {
  67         GDBpConnection* connection = (GDBpConnection*)connectionRaw;
  68         switch (eventType)
  69         {
  70                 case kCFStreamEventHasBytesAvailable:
  71                         NSLog(@"About to read.");
  72                         [connection readStreamHasData];
  73                         break;
  74
  75                 case kCFStreamEventErrorOccurred:
  76                 {
  77                         CFErrorRef error = CFReadStreamCopyError(stream);
  78                         CFReadStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  79                         CFReadStreamClose(stream);
  80                         CFRelease(stream);
  81                         [connection errorEncountered:[[(NSError*)error autorelease] description]];
  82                         break;
  83                 }
  84
  85                 case kCFStreamEventEndEncountered:
  86                         CFReadStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  87                         CFReadStreamClose(stream);
  88                         CFRelease(stream);
  89                         [connection socketDisconnected];
  90                         break;
  91         };
  92 }
  93
  94 void WriteStreamCallback(CFWriteStreamRef stream, CFStreamEventType eventType, void* connectionRaw)
  95 {
  96         GDBpConnection* connection = (GDBpConnection*)connectionRaw;
  97         switch (eventType)
  98         {
  99                 case kCFStreamEventCanAcceptBytes:
 100                         [connection sendQueuedWrites];
 101                         break;
 102
 103                 case kCFStreamEventErrorOccurred:
 104                 {
 105                         CFErrorRef error = CFWriteStreamCopyError(stream);
 106                         CFWriteStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 107                         CFWriteStreamClose(stream);
 108                         CFRelease(stream);
 109                         [connection errorEncountered:[[(NSError*)error autorelease] description]];
 110                         break;
 111                 }
 112
 113                 case kCFStreamEventEndEncountered:
 114                         CFWriteStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 115                         CFWriteStreamClose(stream);
 116                         CFRelease(stream);
 117                         [connection socketDisconnected];
 118                         break;
 119         }
 120 }
 121
 122 void SocketAcceptCallback(CFSocketRef socket,
 123                                                   CFSocketCallBackType callbackType,
 124                                                   CFDataRef address,
 125                                                   const void* data,
 126                                                   void* connectionRaw)
 127 {
 128         assert(callbackType == kCFSocketAcceptCallBack);
 129         NSLog(@"SocketAcceptCallback()");
 130
 131         GDBpConnection* connection = (GDBpConnection*)connectionRaw;
 132
 133         CFReadStreamRef readStream;
 134         CFWriteStreamRef writeStream;
 135
 136         // Create the streams on the socket.
 137         CFStreamCreatePairWithSocket(kCFAllocatorDefault,
 138                                                                  *(CFSocketNativeHandle*)data,  // Socket handle.
 139                                                                  &readStream,  // Read stream in-pointer.
 140                                                                  &writeStream);  // Write stream in-pointer.
 141
 142         // Create struct to register callbacks for the stream.
 143         CFStreamClientContext context;
 144         context.version = 0;
 145         context.info = connection;
 146         context.retain = NULL;
 147         context.release = NULL;
 148         context.copyDescription = NULL;
 149
 150         // Set the client of the read stream.
 151         CFOptionFlags readFlags =
 152                 kCFStreamEventOpenCompleted |
 153                 kCFStreamEventHasBytesAvailable |
 154                 kCFStreamEventErrorOccurred |
 155                 kCFStreamEventEndEncountered;
 156         if (CFReadStreamSetClient(readStream, readFlags, ReadStreamCallback, &context))
 157                 // Schedule in run loop to do asynchronous communication with the engine.
 158                 CFReadStreamScheduleWithRunLoop(readStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 159         else
 160                 return;
 161
 162         // Open the stream now that it's scheduled on the run loop.
 163         if (!CFReadStreamOpen(readStream))
 164         {
 165                 CFStreamError error = CFReadStreamGetError(readStream);
 166                 NSLog(@"error! %@", error);
 167                 return;
 168         }
 169
 170         // Set the client of the write stream.
 171         CFOptionFlags writeFlags =
 172                 kCFStreamEventOpenCompleted |
 173                 kCFStreamEventCanAcceptBytes |
 174                 kCFStreamEventErrorOccurred |
 175                 kCFStreamEventEndEncountered;
 176         if (CFWriteStreamSetClient(writeStream, writeFlags, WriteStreamCallback, &context))
 177                 // Schedule it in the run loop to receive error information.
 178                 CFWriteStreamScheduleWithRunLoop(writeStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 179         else
 180                 return;
 181
 182         // Open the write stream.
 183         if (!CFWriteStreamOpen(writeStream))
 184         {
 185                 CFStreamError error = CFWriteStreamGetError(writeStream);
 186                 NSLog(@"error! %@", error);
 187                 return;
 188         }
 189
 190         connection.readStream = readStream;
 191         connection.writeStream = writeStream;
 192         [connection socketDidAccept];
 193 }
 194
 195 // GDBpConnection //////////////////////////////////////////////////////////////
 196
 197 @implementation GDBpConnection
 198 @synthesize socket = socket_;
 199 @synthesize readStream = readStream_;
 200 @synthesize lastReadTransaction = lastReadTransaction_;
 201 @synthesize currentPacket = currentPacket_;
 202 @synthesize writeStream = writeStream_;
 203 @synthesize lastWrittenTransaction = lastWrittenTransaction_;
 204 @synthesize queuedWrites = queuedWrites_;
 205 @synthesize status;
 206 @synthesize delegate;
 207
 208 /**
 209  * Creates a new DebuggerConnection and initializes the socket from the given connection
 210  * paramters.
 211  */
 212 - (id)initWithPort:(NSUInteger)aPort
 213 {
 214         if (self = [super init])
 215         {
 216                 port = aPort;
 217                 connected = NO;
 218
 219                 [[BreakpointManager sharedManager] setConnection:self];
 220
 221                 [self connect];
 222         }
 223         return self;
 224 }
 225
 226 /**
 227  * Deallocates the object
 228  */
 229 - (void)dealloc
 230 {
 231         [self close];
 232         self.currentPacket = nil;
 233
 234         [super dealloc];
 235 }
 236
 237 /**
 238  * Gets the port number
 239  */
 240 - (NSUInteger)port
 241 {
 242         return port;
 243 }
 244
 245 /**
 246  * Returns the name of the remote host
 247  */
 248 - (NSString*)remoteHost
 249 {
 250         if (!connected)
 251         {
 252                 return @"(DISCONNECTED)";
 253         }
 254         // TODO: Either impl or remove.
 255         return @"";
 256 }
 257
 258 /**
 259  * Returns whether or not we have an active connection
 260  */
 261 - (BOOL)isConnected
 262 {
 263         return connected;
 264 }
 265
 266 /**
 267  * Called by SocketWrapper after the connection is successful. This immediately calls
 268  * -[SocketWrapper receive] to clear the way for communication, though the information
 269  * could be useful server information that we don't use right now.
 270  */
 271 - (void)socketDidAccept
 272 {
 273         connected = YES;
 274         transactionID = 1;
 275         stackFrames_ = [[NSMutableDictionary alloc] init];
 276         self.queuedWrites = [NSMutableArray array];
 277         writeQueueLock_ = [NSRecursiveLock new];
 278         callTable_ = [NSMutableDictionary new];
 279         callbackContext_ = [NSMutableDictionary new];
 280 }
 281
 282 /**
 283  * Receives errors from the SocketWrapper and updates the display
 284  */
 285 - (void)errorEncountered:(NSString*)error
 286 {
 287         [delegate errorEncountered:error];
 288 }
 289
 290 /**
 291  * Reestablishes communication with the remote debugger so that a new connection doesn't have to be
 292  * created every time you want to debug a page
 293  */
 294 - (void)reconnect
 295 {
 296         [self close];
 297         self.status = @"Connecting";
 298         [self connect];
 299 }
 300
 301 /**
 302  * Creates an entirely new stack and returns it as an array of StackFrame objects.
 303  */
 304 - (NSArray*)getCurrentStack
 305 {
 306         NSMutableArray* stack = [NSMutableArray array];
 307         NSLog(@"NOTIMPLEMENTED(): %s", _cmd);
 308         return stack;
 309 }
 310
 311 /**
 312  * Tells the debugger to continue running the script. Returns the current stack frame.
 313  */
 314 - (void)run
 315 {
 316         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"run"];
 317 }
 318
 319 /**
 320  * Tells the debugger to step into the current command.
 321  */
 322 - (void)stepIn
 323 {
 324         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_into"];
 325 }
 326
 327 /**
 328  * Tells the debugger to step out of the current context
 329  */
 330 - (void)stepOut
 331 {
 332         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_out"];
 333 }
 334
 335 /**
 336  * Tells the debugger to step over the current function
 337  */
 338 - (void)stepOver
 339 {
 340         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_over"];
 341 }
 342
 343 /**
 344  * Tells the debugger engine to get a specifc property. This also takes in the NSXMLElement
 345  * that requested it so that the child can be attached.
 346  */
 347 - (NSArray*)getProperty:(NSString*)property
 348 {
 349         [socket send:[self createCommand:[NSString stringWithFormat:@"property_get -n \"%@\"", property]]];
 350
 351         NSXMLDocument* doc = [self processData:[socket receive]];
 352
 353         /*
 354          <response>
 355                 <property> <!-- this is the one we requested -->
 356                         <property ... /> <!-- these are what we want -->
 357                 </property>
 358          </repsonse>
 359          */
 360
 361         // we now have to detach all the children so we can insert them into another document
 362         NSXMLElement* parent = (NSXMLElement*)[[doc rootElement] childAtIndex:0];
 363         NSArray* children = [parent children];
 364         [parent setChildren:nil];
 365         return children;
 366 }
 367
 368 #pragma mark Breakpoints
 369
 370 /**
 371  * Send an add breakpoint command
 372  */
 373 - (void)addBreakpoint:(Breakpoint*)bp
 374 {
 375         if (!connected)
 376                 return;
 377
 378         NSString* file = [self escapedURIPath:[bp transformedPath]];
 379         NSNumber* transaction = [self sendCommandWithCallback:@selector(breakpointReceived:)
 380                                                                                                    format:@"breakpoint_set -t line -f %@ -n %i", file, [bp line]];
 381         [callbackContext_ setObject:bp forKey:transaction];
 382 }
 383
 384 /**
 385  * Callback for setting a breakpoint.
 386  */
 387 - (void)breakpointReceived:(NSXMLDocument*)response
 388 {
 389         NSNumber* transaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 390         Breakpoint* bp = [callbackContext_ objectForKey:transaction];
 391         if (!bp)
 392                 return;
 393
 394         [callbackContext_ removeObjectForKey:callbackContext_];
 395         [bp setDebuggerId:[[[[response rootElement] attributeForName:@"id"] stringValue] intValue]];
 396 }
 397
 398 /**
 399  * Removes a breakpoint
 400  */
 401 - (void)removeBreakpoint:(Breakpoint*)bp
 402 {
 403         if (!connected)
 404         {
 405                 return;
 406         }
 407
 408         [self sendCommandWithCallback:nil format:@"breakpoint_remove -d %i", [bp debuggerId]];
 409 }
 410
 411 #pragma mark Socket and Stream Callbacks
 412
 413 /**
 414  * Creates, connects to, and schedules a CFSocket.
 415  */
 416 - (void)connect
 417 {
 418         // Pass ourselves to the callback so we don't have to use ugly globals.
 419         CFSocketContext context;
 420         context.version = 0;
 421         context.info = self;
 422         context.retain = NULL;
 423         context.release = NULL;
 424         context.copyDescription = NULL;
 425
 426         // Create the address structure.
 427         struct sockaddr_in address;
 428         memset(&address, 0, sizeof(address));
 429         address.sin_len = sizeof(address);
 430         address.sin_family = AF_INET;
 431         address.sin_port = htons(port);
 432         address.sin_addr.s_addr = htonl(INADDR_ANY);
 433
 434         // Create the socket signature.
 435         CFSocketSignature signature;
 436         signature.protocolFamily = PF_INET;
 437         signature.socketType = SOCK_STREAM;
 438         signature.protocol = IPPROTO_TCP;
 439         signature.address = (CFDataRef)[NSData dataWithBytes:&address length:sizeof(address)];
 440
 441         socket_ = CFSocketCreateWithSocketSignature(kCFAllocatorDefault,
 442                                                                                                 &signature,  // Socket signature.
 443                                                                                                 kCFSocketAcceptCallBack,  // Callback types.
 444                                                                                                 SocketAcceptCallback,  // Callout function pointer.
 445                                                                                                 &context);  // Context to pass to callout.
 446         if (!socket_)
 447         {
 448                 [self errorEncountered:@"Could not open socket."];
 449                 return;
 450         }
 451
 452         // Allow old, yet-to-be recycled sockets to be reused.
 453         BOOL yes = YES;
 454         setsockopt(CFSocketGetNative(socket_), SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(BOOL));
 455
 456         // Schedule the socket on the run loop.
 457         CFRunLoopSourceRef source = CFSocketCreateRunLoopSource(kCFAllocatorDefault, socket_, 0);
 458         CFRunLoopAddSource(CFRunLoopGetCurrent(), source, kCFRunLoopCommonModes);
 459         CFRelease(source);
 460
 461         self.status = @"Connecting";
 462 }
 463
 464 /**
 465  * Closes a socket and releases the ref.
 466  */
 467 - (void)close
 468 {
 469         // The socket goes down, so do the streams, which clean themselves up.
 470         CFSocketInvalidate(socket_);
 471         CFRelease(socket_);
 472         [stackFrames_ release];
 473         self.queuedWrites = nil;
 474         [writeQueueLock_ release];
 475         [callTable_ release];
 476         [callbackContext_ release];
 477 }
 478
 479 /**
 480  * Notification that the socket disconnected.
 481  */
 482 - (void)socketDisconnected
 483 {
 484         [self close];
 485         [delegate debuggerDisconnected];
 486 }
 487
 488 /**
 489  * Callback from the CFReadStream that there is data waiting to be read.
 490  */
 491 - (void)readStreamHasData
 492 {
 493         UInt8 buffer[1024];
 494         CFIndex bytesRead = CFReadStreamRead(readStream_, buffer, 1024);
 495         const char* charBuffer = (const char*)buffer;
 496
 497         // We haven't finished reading a packet, so just read more data in.
 498         if (currentPacketIndex_ < packetSize_)
 499         {
 500                 currentPacketIndex_ += bytesRead;
 501                 CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 502                                                                                                                    buffer,
 503                                                                                                                    bytesRead,
 504                                                                                                                    kCFStringEncodingUTF8,
 505                                                                                                                    true);
 506                 [self.currentPacket appendString:(NSString*)bufferString];
 507                 CFRelease(bufferString);
 508         }
 509         // Time to read a new packet.
 510         else
 511         {
 512                 // Read the message header: the size.
 513                 packetSize_ = atoi(charBuffer);
 514                 currentPacketIndex_ = bytesRead - strlen(charBuffer);
 515                 CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 516                                                                                                                    buffer + strlen(charBuffer) + 1,
 517                                                                                                                    bytesRead - strlen(charBuffer) - 1,
 518                                                                                                                    kCFStringEncodingUTF8,
 519                                                                                                                    true);
 520                 self.currentPacket = [NSMutableString stringWithString:(NSString*)bufferString];
 521                 CFRelease(bufferString);
 522         }
 523
 524         // We have finished reading the packet.
 525         if (currentPacketIndex_ >= packetSize_)
 526         {
 527                 packetSize_ = 0;
 528                 currentPacketIndex_ = 0;
 529
 530                 // Test if we can convert it into an NSXMLDocument.
 531                 NSError* error = nil;
 532                 NSXMLDocument* xmlTest = [[NSXMLDocument alloc] initWithXMLString:currentPacket_ options:NSXMLDocumentTidyXML error:&error];
 533                 if (error)
 534                 {
 535                         NSLog(@"Could not parse XML? --- %@", error);
 536                         NSLog(@"Error UserInfo: %@", [error userInfo]);
 537                         NSLog(@"This is the XML Document: %@", currentPacket_);
 538                         return;
 539                 }
 540                 [self handleResponse:[xmlTest autorelease]];
 541         }
 542 }
 543
 544 /**
 545  * Writes a command into the write stream. If the stream is ready for writing,
 546  * we do so immediately. If not, the command is queued and will be written
 547  * when the stream is ready.
 548  */
 549 - (void)send:(NSString*)command
 550 {
 551         if (lastReadTransaction_ >= lastWrittenTransaction_ && CFWriteStreamCanAcceptBytes(writeStream_))
 552                 [self performSend:command];
 553         else
 554                 [queuedWrites_ addObject:command];
 555 }
 556
 557 /**
 558  * This performs a blocking send. This should ONLY be called when we know we
 559  * have write access to the stream. We will busy wait in case we don't do a full
 560  * send.
 561  */
 562 - (void)performSend:(NSString*)command
 563 {
 564         BOOL done = NO;
 565
 566         char* string = (char*)[command UTF8String];
 567         int stringLength = strlen(string);
 568
 569         // Log the command if TransportDebug is enabled.
 570         if ([[[[NSProcessInfo processInfo] environment] objectForKey:@"TransportDebug"] boolValue])
 571                 NSLog(@"--> %@", command);
 572
 573         // Busy wait while writing. BAADD. Should background this operation.
 574         while (!done)
 575         {
 576                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 577                 {
 578                         // Include the NULL byte in the string when we write.
 579                         int bytesWritten = CFWriteStreamWrite(writeStream_, (UInt8*)string, stringLength + 1);
 580                         if (bytesWritten < 0)
 581                         {
 582                                 NSLog(@"write error");
 583                         }
 584                         // Incomplete write.
 585                         else if (bytesWritten < strlen(string))
 586                         {
 587                                 // Adjust the buffer and wait for another chance to write.
 588                                 stringLength -= bytesWritten;
 589                                 memmove(string, string + bytesWritten, stringLength);
 590                         }
 591                         else
 592                         {
 593                                 done = YES;
 594
 595                                 // We need to scan the string to find the transactionID.
 596                                 NSRange occurrence = [command rangeOfString:@"-i "];
 597                                 if (occurrence.location == NSNotFound)
 598                                 {
 599                                         NSLog(@"sent %@ without a transaction ID", command);
 600                                         continue;
 601                                 }
 602                                 NSString* transaction = [command substringFromIndex:occurrence.location + occurrence.length];
 603                                 lastWrittenTransaction_ = [transaction intValue];
 604                                 NSLog(@"command = %@", command);
 605                                 NSLog(@"read=%d, write=%d", lastReadTransaction_, lastWrittenTransaction_);
 606                         }
 607                 }
 608         }
 609 }
 610
 611 #pragma mark Response Handlers
 612
 613 - (void)handleResponse:(NSXMLDocument*)response
 614 {
 615         // Check and see if there's an error.
 616         NSArray* error = [[response rootElement] elementsForName:@"error"];
 617         if ([error count] > 0)
 618         {
 619                 NSLog(@"Xdebug error: %@", error);
 620                 [delegate errorEncountered:[[[[error objectAtIndex:0] children] objectAtIndex:0] stringValue]];
 621         }
 622
 623         // If TransportDebug is enabled, log the response.
 624         if ([[[[NSProcessInfo processInfo] environment] objectForKey:@"TransportDebug"] boolValue])
 625                 NSLog(@"<-- %@", response);
 626
 627         // Get the name of the command from the engine's response.
 628         NSInteger transaction = [self transactionIDFromResponse:response];
 629         if (transaction < lastReadTransaction_)
 630                 NSLog(@"out of date transaction %@", response);
 631
 632         if (transaction != lastWrittenTransaction_)
 633                 NSLog(@"txn doesn't match last written %@", response);
 634
 635         lastReadTransaction_ = transaction;
 636         NSLog(@"read=%d, write=%d", lastReadTransaction_, lastWrittenTransaction_);
 637
 638         if ([[[response rootElement] name] isEqualToString:@"init"])
 639         {
 640                 [self initReceived:response];
 641                 return;
 642         }
 643
 644         NSString* callbackStr = [callTable_ objectForKey:[NSNumber numberWithInt:lastReadTransaction_]];
 645         if (callbackStr)
 646         {
 647                 SEL callback = NSSelectorFromString(callbackStr);
 648                 [self performSelector:callback withObject:response];
 649         }
 650
 651         [self sendQueuedWrites];
 652 }
 653
 654 /**
 655  * Initial packet received. We've started a brand-new connection to the engine.
 656  */
 657 - (void)initReceived:(NSXMLDocument*)response
 658 {
 659         // Register any breakpoints that exist offline.
 660         for (Breakpoint* bp in [[BreakpointManager sharedManager] breakpoints])
 661                 [self addBreakpoint:bp];
 662
 663         // Load the debugger to make it look active.
 664         [delegate debuggerConnected];
 665
 666         // TODO: update the status.
 667 }
 668
 669 /**
 670  * Receiver for status updates. This just freshens up the UI.
 671  */
 672 - (void)updateStatus:(NSXMLDocument*)response
 673 {
 674         self.status = [[[[response rootElement] attributeForName:@"status"] stringValue] capitalizedString];
 675         if (status == nil || [status isEqualToString:@"Stopped"] || [status isEqualToString:@"Stopping"])
 676         {
 677                 connected = NO;
 678                 [self close];
 679                 [delegate debuggerDisconnected];
 680
 681                 self.status = @"Stopped";
 682         }
 683 }
 684
 685 /**
 686  * Step in/out/over and run all take this path. We first get the status of the
 687  * debugger and then request fresh stack information.
 688  */
 689 - (void)debuggerStep:(NSXMLDocument*)response
 690 {
 691         [self sendCommandWithCallback:@selector(updateStatus:) format:@"status"];
 692         NSString* command = [[[response rootElement] attributeForName:@"command"] stringValue];
 693
 694         // If this is the run command, tell the delegate that a bunch of updates
 695         // are coming. Also remove all existing stack routes and request a new stack.
 696         // TODO: figure out if we can not clobber the stack every time.
 697         if (YES || [command isEqualToString:@"run"])
 698         {
 699                 if ([delegate respondsToSelector:@selector(clobberStack)])
 700                         [delegate clobberStack];
 701                 [stackFrames_ removeAllObjects];
 702                 stackFirstTransactionID_ = [[self sendCommandWithCallback:@selector(rebuildStack:) format:@"stack_depth"] intValue];
 703         }
 704 }
 705
 706 /**
 707  * We ask for the stack_depth and now we clobber the stack and start rebuilding
 708  * it.
 709  */
 710 - (void)rebuildStack:(NSXMLDocument*)response
 711 {
 712         NSInteger depth = [[[[response rootElement] attributeForName:@"depth"] stringValue] intValue];
 713
 714         if (stackFirstTransactionID_ == [self transactionIDFromResponse:response])
 715                 stackDepth_ = depth;
 716
 717         // We now need to alloc a bunch of stack frames and get the basic information
 718         // for them.
 719         for (NSInteger i = 0; i < depth; i++)
 720         {
 721                 // Use the transaction ID to create a routing path.
 722                 NSNumber* routingID = [self sendCommandWithCallback:@selector(getStackFrame:) format:@"stack_get -d %d", i];
 723                 [stackFrames_ setObject:[StackFrame alloc] forKey:routingID];
 724         }
 725 }
 726
 727 /**
 728  * The initial rebuild of the stack frame. We now have enough to initialize
 729  * a StackFrame object.
 730  */
 731 - (void)getStackFrame:(NSXMLDocument*)response
 732 {
 733         // Get the routing information.
 734         NSInteger routingID = [self transactionIDFromResponse:response];
 735         if (routingID < stackFirstTransactionID_)
 736                 return;
 737         NSNumber* routingNumber = [NSNumber numberWithInt:routingID];
 738
 739         // Make sure we initialized this frame in our last |-rebuildStack:|.
 740         StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 741         if (!frame)
 742                 return;
 743
 744         NSXMLElement* xmlframe = [[[response rootElement] children] objectAtIndex:0];
 745
 746         // Initialize the stack frame.
 747         [frame initWithIndex:[[[xmlframe attributeForName:@"level"] stringValue] intValue]
 748                         withFilename:[[xmlframe attributeForName:@"filename"] stringValue]
 749                           withSource:nil
 750                                   atLine:[[[xmlframe attributeForName:@"lineno"] stringValue] intValue]
 751                           inFunction:[[xmlframe attributeForName:@"where"] stringValue]
 752                    withVariables:nil];
 753
 754         // Get the source code of the file. Escape % in URL chars.
 755         NSString* escapedFilename = [frame.filename stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 756         NSNumber* transaction = [self sendCommandWithCallback:@selector(setSource:) format:@"source -f %@", escapedFilename];
 757         [callbackContext_ setObject:routingNumber forKey:transaction];
 758
 759         // Get the names of all the contexts.
 760         transaction = [self sendCommandWithCallback:@selector(contextsReceived:) format:@"context_names -d %d", frame.index];
 761         [callbackContext_ setObject:routingNumber forKey:transaction];
 762
 763         if ([delegate respondsToSelector:@selector(newStackFrame:)])
 764                 [delegate newStackFrame:frame];
 765 }
 766
 767 /**
 768  * Callback for setting the source of a file while rebuilding a specific stack
 769  * frame.
 770  */
 771 - (void)setSource:(NSXMLDocument*)response
 772 {
 773         NSNumber* transaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 774         if ([transaction intValue] < stackFirstTransactionID_)
 775                 return;
 776         NSNumber* routingNumber = [callbackContext_ objectForKey:transaction];
 777         if (!routingNumber)
 778                 return;
 779
 780         [callbackContext_ removeObjectForKey:transaction];
 781         StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 782         if (!frame)
 783                 return;
 784
 785         frame.source = [[response rootElement] value];
 786
 787         if ([delegate respondsToSelector:@selector(sourceUpdated:)])
 788                 [delegate sourceUpdated:frame];
 789 }
 790
 791 /**
 792  * Enumerates all the contexts of a given stack frame. We then in turn get the
 793  * contents of each one of these contexts.
 794  */
 795 - (void)contextsReceived:(NSXMLDocument*)response
 796 {
 797         // Get the stack frame's routing ID and use it again.
 798         NSNumber* receivedTransaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 799         if ([receivedTransaction intValue] < stackFirstTransactionID_)
 800                 return;
 801         NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 802         if (!routingID)
 803                 return;
 804
 805         // Get the stack frame by the |routingID|.
 806         StackFrame* frame = [stackFrames_ objectForKey:routingID];
 807
 808         NSXMLElement* contextNames = [response rootElement];
 809         for (NSXMLElement* context in [contextNames children])
 810         {
 811                 NSInteger cid = [[[context attributeForName:@"id"] stringValue] intValue];
 812
 813                 // Fetch each context's variables.
 814                 NSNumber* transaction = [self sendCommandWithCallback:@selector(variablesReceived:)
 815                                                                                                            format:@"context_get -d %d -c %d", frame.index, cid];
 816                 [callbackContext_ setObject:routingID forKey:transaction];
 817         }
 818 }
 819
 820 /**
 821  * Receives the variables from the context and attaches them to the stack frame.
 822  */
 823 - (void)variablesReceived:(NSXMLDocument*)response
 824 {
 825         // Get the stack frame's routing ID and use it again.
 826         NSInteger transaction = [self transactionIDFromResponse:response];
 827         if (transaction < stackFirstTransactionID_)
 828                 return;
 829         NSNumber* receivedTransaction = [NSNumber numberWithInt:transaction];
 830         NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 831         if (!routingID)
 832                 return;
 833
 834         // Get the stack frame by the |routingID|.
 835         StackFrame* frame = [stackFrames_ objectForKey:routingID];
 836
 837         NSMutableArray* variables = [NSMutableArray array];
 838
 839         // Merge the frame's existing variables.
 840         if (frame.variables)
 841                 [variables addObjectsFromArray:frame.variables];
 842
 843         // Add these new variables.
 844         NSArray* addVariables = [[response rootElement] children];
 845         if (addVariables)
 846                 [variables addObjectsFromArray:addVariables];
 847
 848         frame.variables = variables;
 849 }
 850
 851 #pragma mark Private
 852
 853 /**
 854  * This will send a command to the debugger engine. It will append the
 855  * transaction ID automatically. It accepts a NSString command along with a
 856  * a variable number of arguments to substitute into the command, a la
 857  * +[NSString stringWithFormat:]. Returns the transaction ID as a NSNumber.
 858  */
 859 - (NSNumber*)sendCommandWithCallback:(SEL)callback format:(NSString*)format, ...
 860 {
 861         // Collect varargs and format command.
 862         va_list args;
 863         va_start(args, format);
 864         NSString* command = [[NSString alloc] initWithFormat:format arguments:args];
 865         va_end(args);
 866
 867         NSNumber* callbackKey = [NSNumber numberWithInt:transactionID++];
 868         if (callback)
 869                 [callTable_ setObject:NSStringFromSelector(callback) forKey:callbackKey];
 870
 871         [self send:[NSString stringWithFormat:@"%@ -i %@", [command autorelease], callbackKey]];
 872
 873         return callbackKey;
 874 }
 875
 876 /**
 877  * Checks if there are unsent commands in the |queuedWrites_| queue and sends
 878  * them if it's OK to do so. This will not block.
 879  */
 880 - (void)sendQueuedWrites
 881 {
 882         [writeQueueLock_ lock];
 883         if (lastReadTransaction_ >= lastWrittenTransaction_ && [queuedWrites_ count] > 0)
 884         {
 885                 NSString* command = [queuedWrites_ objectAtIndex:0];
 886                 NSLog(@"Sending queued write: %@", command);
 887
 888                 // We don't want to block because this is called from the main thread.
 889                 // |-performSend:| busy waits when the stream is not ready. Bail out
 890                 // before we do that becuase busy waiting is BAD.
 891                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 892                 {
 893                         [self performSend:command];
 894                         [queuedWrites_ removeObjectAtIndex:0];
 895                 }
 896         }
 897         [writeQueueLock_ unlock];
 898 }
 899
 900 /**
 901  * Given a file path, this returns a file:// URI and escapes any spaces for the
 902  * debugger engine.
 903  */
 904 - (NSString*)escapedURIPath:(NSString*)path
 905 {
 906         // Custon GDBp paths are fine.
 907         if ([[path substringToIndex:4] isEqualToString:@"gdbp"])
 908                 return path;
 909
 910         // Create a temporary URL that will escape all the nasty characters.
 911         NSURL* url = [NSURL fileURLWithPath:path];
 912         NSString* urlString = [url absoluteString];
 913
 914         // Remove the host because this is a file:// URL;
 915         urlString = [urlString stringByReplacingOccurrencesOfString:[url host] withString:@""];
 916
 917         // Escape % for use in printf-style NSString formatters.
 918         urlString = [urlString stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 919         return urlString;
 920 }
 921
 922 /**
 923  * Returns the transaction_id from an NSXMLDocument.
 924  */
 925 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response
 926 {
 927         return [[[[response rootElement] attributeForName:@"transaction_id"] stringValue] intValue];
 928 }
 929
 930 @end