Source/DebuggerConnection.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 "DebuggerConnection.h"
  21
  22 #import "AppDelegate.h"
  23
  24 // GDBpConnection (Private) ////////////////////////////////////////////////////
  25
  26 @interface DebuggerConnection ()
  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 - (void)propertiesReceived:(NSXMLDocument*)response;
  55
  56 - (NSNumber*)sendCommandWithCallback:(SEL)callback format:(NSString*)format, ...;
  57
  58 - (void)sendQueuedWrites;
  59
  60 - (NSString*)escapedURIPath:(NSString*)path;
  61 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response;
  62 @end
  63
  64 // CFNetwork Callbacks /////////////////////////////////////////////////////////
  65
  66 void ReadStreamCallback(CFReadStreamRef stream, CFStreamEventType eventType, void* connectionRaw)
  67 {
  68         DebuggerConnection* connection = (DebuggerConnection*)connectionRaw;
  69         switch (eventType)
  70         {
  71                 case kCFStreamEventHasBytesAvailable:
  72                         NSLog(@"About to read.");
  73                         [connection readStreamHasData];
  74                         break;
  75
  76                 case kCFStreamEventErrorOccurred:
  77                 {
  78                         CFErrorRef error = CFReadStreamCopyError(stream);
  79                         CFReadStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  80                         CFReadStreamClose(stream);
  81                         CFRelease(stream);
  82                         [connection errorEncountered:[[(NSError*)error autorelease] description]];
  83                         break;
  84                 }
  85
  86                 case kCFStreamEventEndEncountered:
  87                         CFReadStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  88                         CFReadStreamClose(stream);
  89                         CFRelease(stream);
  90                         [connection socketDisconnected];
  91                         break;
  92         };
  93 }
  94
  95 void WriteStreamCallback(CFWriteStreamRef stream, CFStreamEventType eventType, void* connectionRaw)
  96 {
  97         DebuggerConnection* connection = (DebuggerConnection*)connectionRaw;
  98         switch (eventType)
  99         {
 100                 case kCFStreamEventCanAcceptBytes:
 101                         [connection sendQueuedWrites];
 102                         break;
 103
 104                 case kCFStreamEventErrorOccurred:
 105                 {
 106                         CFErrorRef error = CFWriteStreamCopyError(stream);
 107                         CFWriteStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 108                         CFWriteStreamClose(stream);
 109                         CFRelease(stream);
 110                         [connection errorEncountered:[[(NSError*)error autorelease] description]];
 111                         break;
 112                 }
 113
 114                 case kCFStreamEventEndEncountered:
 115                         CFWriteStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 116                         CFWriteStreamClose(stream);
 117                         CFRelease(stream);
 118                         [connection socketDisconnected];
 119                         break;
 120         }
 121 }
 122
 123 void SocketAcceptCallback(CFSocketRef socket,
 124                                                   CFSocketCallBackType callbackType,
 125                                                   CFDataRef address,
 126                                                   const void* data,
 127                                                   void* connectionRaw)
 128 {
 129         assert(callbackType == kCFSocketAcceptCallBack);
 130         NSLog(@"SocketAcceptCallback()");
 131
 132         DebuggerConnection* connection = (DebuggerConnection*)connectionRaw;
 133
 134         CFReadStreamRef readStream;
 135         CFWriteStreamRef writeStream;
 136
 137         // Create the streams on the socket.
 138         CFStreamCreatePairWithSocket(kCFAllocatorDefault,
 139                                                                  *(CFSocketNativeHandle*)data,  // Socket handle.
 140                                                                  &readStream,  // Read stream in-pointer.
 141                                                                  &writeStream);  // Write stream in-pointer.
 142
 143         // Create struct to register callbacks for the stream.
 144         CFStreamClientContext context;
 145         context.version = 0;
 146         context.info = connection;
 147         context.retain = NULL;
 148         context.release = NULL;
 149         context.copyDescription = NULL;
 150
 151         // Set the client of the read stream.
 152         CFOptionFlags readFlags =
 153                 kCFStreamEventOpenCompleted |
 154                 kCFStreamEventHasBytesAvailable |
 155                 kCFStreamEventErrorOccurred |
 156                 kCFStreamEventEndEncountered;
 157         if (CFReadStreamSetClient(readStream, readFlags, ReadStreamCallback, &context))
 158                 // Schedule in run loop to do asynchronous communication with the engine.
 159                 CFReadStreamScheduleWithRunLoop(readStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 160         else
 161                 return;
 162
 163         // Open the stream now that it's scheduled on the run loop.
 164         if (!CFReadStreamOpen(readStream))
 165         {
 166                 CFStreamError error = CFReadStreamGetError(readStream);
 167                 NSLog(@"error! %@", error);
 168                 return;
 169         }
 170
 171         // Set the client of the write stream.
 172         CFOptionFlags writeFlags =
 173                 kCFStreamEventOpenCompleted |
 174                 kCFStreamEventCanAcceptBytes |
 175                 kCFStreamEventErrorOccurred |
 176                 kCFStreamEventEndEncountered;
 177         if (CFWriteStreamSetClient(writeStream, writeFlags, WriteStreamCallback, &context))
 178                 // Schedule it in the run loop to receive error information.
 179                 CFWriteStreamScheduleWithRunLoop(writeStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 180         else
 181                 return;
 182
 183         // Open the write stream.
 184         if (!CFWriteStreamOpen(writeStream))
 185         {
 186                 CFStreamError error = CFWriteStreamGetError(writeStream);
 187                 NSLog(@"error! %@", error);
 188                 return;
 189         }
 190
 191         connection.readStream = readStream;
 192         connection.writeStream = writeStream;
 193         [connection socketDidAccept];
 194 }
 195
 196 // GDBpConnection //////////////////////////////////////////////////////////////
 197
 198 @implementation DebuggerConnection
 199 @synthesize socket = socket_;
 200 @synthesize readStream = readStream_;
 201 @synthesize lastReadTransaction = lastReadTransaction_;
 202 @synthesize currentPacket = currentPacket_;
 203 @synthesize writeStream = writeStream_;
 204 @synthesize lastWrittenTransaction = lastWrittenTransaction_;
 205 @synthesize queuedWrites = queuedWrites_;
 206 @synthesize status;
 207 @synthesize delegate;
 208
 209 /**
 210  * Creates a new DebuggerConnection and initializes the socket from the given connection
 211  * paramters.
 212  */
 213 - (id)initWithPort:(NSUInteger)aPort
 214 {
 215         if (self = [super init])
 216         {
 217                 port = aPort;
 218                 connected = NO;
 219
 220                 [[BreakpointManager sharedManager] setConnection:self];
 221
 222                 [self connect];
 223         }
 224         return self;
 225 }
 226
 227 /**
 228  * Deallocates the object
 229  */
 230 - (void)dealloc
 231 {
 232         [self close];
 233         self.currentPacket = nil;
 234
 235         [super dealloc];
 236 }
 237
 238
 239 // Getters /////////////////////////////////////////////////////////////////////
 240 #pragma mark Getters
 241
 242 /**
 243  * Gets the port number
 244  */
 245 - (NSUInteger)port
 246 {
 247         return port;
 248 }
 249
 250 /**
 251  * Returns the name of the remote host
 252  */
 253 - (NSString*)remoteHost
 254 {
 255         if (!connected)
 256         {
 257                 return @"(DISCONNECTED)";
 258         }
 259         // TODO: Either impl or remove.
 260         return @"";
 261 }
 262
 263 /**
 264  * Returns whether or not we have an active connection
 265  */
 266 - (BOOL)isConnected
 267 {
 268         return connected;
 269 }
 270
 271 // Commands ////////////////////////////////////////////////////////////////////
 272 #pragma mark Commands
 273
 274 /**
 275  * Reestablishes communication with the remote debugger so that a new connection doesn't have to be
 276  * created every time you want to debug a page
 277  */
 278 - (void)reconnect
 279 {
 280         [self close];
 281         self.status = @"Connecting";
 282         [self connect];
 283 }
 284
 285 /**
 286  * Tells the debugger to continue running the script. Returns the current stack frame.
 287  */
 288 - (void)run
 289 {
 290         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"run"];
 291 }
 292
 293 /**
 294  * Tells the debugger to step into the current command.
 295  */
 296 - (void)stepIn
 297 {
 298         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_into"];
 299 }
 300
 301 /**
 302  * Tells the debugger to step out of the current context
 303  */
 304 - (void)stepOut
 305 {
 306         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_out"];
 307 }
 308
 309 /**
 310  * Tells the debugger to step over the current function
 311  */
 312 - (void)stepOver
 313 {
 314         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_over"];
 315 }
 316
 317 /**
 318  * Tells the debugger engine to get a specifc property. This also takes in the NSXMLElement
 319  * that requested it so that the child can be attached.
 320  */
 321 - (NSInteger)getProperty:(NSString*)property
 322 {
 323         [self sendCommandWithCallback:@selector(propertiesReceived:) format:@"property_get -n \"%@\"", property];
 324 }
 325
 326 // Breakpoint Management ///////////////////////////////////////////////////////
 327 #pragma mark Breakpoints
 328
 329 /**
 330  * Send an add breakpoint command
 331  */
 332 - (void)addBreakpoint:(Breakpoint*)bp
 333 {
 334         if (!connected)
 335                 return;
 336
 337         NSString* file = [self escapedURIPath:[bp transformedPath]];
 338         NSNumber* transaction = [self sendCommandWithCallback:@selector(breakpointReceived:)
 339                                                                                                    format:@"breakpoint_set -t line -f %@ -n %i", file, [bp line]];
 340         [callbackContext_ setObject:bp forKey:transaction];
 341 }
 342
 343 /**
 344  * Removes a breakpoint
 345  */
 346 - (void)removeBreakpoint:(Breakpoint*)bp
 347 {
 348         if (!connected)
 349         {
 350                 return;
 351         }
 352
 353         [self sendCommandWithCallback:nil format:@"breakpoint_remove -d %i", [bp debuggerId]];
 354 }
 355
 356
 357 // Socket and Stream Callbacks /////////////////////////////////////////////////
 358 #pragma mark Callbacks
 359
 360 /**
 361  * Called by SocketWrapper after the connection is successful. This immediately calls
 362  * -[SocketWrapper receive] to clear the way for communication, though the information
 363  * could be useful server information that we don't use right now.
 364  */
 365 - (void)socketDidAccept
 366 {
 367         connected = YES;
 368         transactionID = 1;
 369         stackFrames_ = [[NSMutableDictionary alloc] init];
 370         self.queuedWrites = [NSMutableArray array];
 371         writeQueueLock_ = [NSRecursiveLock new];
 372         callTable_ = [NSMutableDictionary new];
 373         callbackContext_ = [NSMutableDictionary new];
 374 }
 375
 376 /**
 377  * Receives errors from the SocketWrapper and updates the display
 378  */
 379 - (void)errorEncountered:(NSString*)error
 380 {
 381         [delegate errorEncountered:error];
 382 }
 383
 384 /**
 385  * Creates, connects to, and schedules a CFSocket.
 386  */
 387 - (void)connect
 388 {
 389         // Pass ourselves to the callback so we don't have to use ugly globals.
 390         CFSocketContext context;
 391         context.version = 0;
 392         context.info = self;
 393         context.retain = NULL;
 394         context.release = NULL;
 395         context.copyDescription = NULL;
 396
 397         // Create the address structure.
 398         struct sockaddr_in address;
 399         memset(&address, 0, sizeof(address));
 400         address.sin_len = sizeof(address);
 401         address.sin_family = AF_INET;
 402         address.sin_port = htons(port);
 403         address.sin_addr.s_addr = htonl(INADDR_ANY);
 404
 405         // Create the socket signature.
 406         CFSocketSignature signature;
 407         signature.protocolFamily = PF_INET;
 408         signature.socketType = SOCK_STREAM;
 409         signature.protocol = IPPROTO_TCP;
 410         signature.address = (CFDataRef)[NSData dataWithBytes:&address length:sizeof(address)];
 411
 412         socket_ = CFSocketCreateWithSocketSignature(kCFAllocatorDefault,
 413                                                                                                 &signature,  // Socket signature.
 414                                                                                                 kCFSocketAcceptCallBack,  // Callback types.
 415                                                                                                 SocketAcceptCallback,  // Callout function pointer.
 416                                                                                                 &context);  // Context to pass to callout.
 417         if (!socket_)
 418         {
 419                 [self errorEncountered:@"Could not open socket."];
 420                 return;
 421         }
 422
 423         // Allow old, yet-to-be recycled sockets to be reused.
 424         BOOL yes = YES;
 425         setsockopt(CFSocketGetNative(socket_), SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(BOOL));
 426
 427         // Schedule the socket on the run loop.
 428         CFRunLoopSourceRef source = CFSocketCreateRunLoopSource(kCFAllocatorDefault, socket_, 0);
 429         CFRunLoopAddSource(CFRunLoopGetCurrent(), source, kCFRunLoopCommonModes);
 430         CFRelease(source);
 431
 432         self.status = @"Connecting";
 433 }
 434
 435 /**
 436  * Closes a socket and releases the ref.
 437  */
 438 - (void)close
 439 {
 440         // The socket goes down, so do the streams, which clean themselves up.
 441         CFSocketInvalidate(socket_);
 442         CFRelease(socket_);
 443         [stackFrames_ release];
 444         self.queuedWrites = nil;
 445         [writeQueueLock_ release];
 446         [callTable_ release];
 447         [callbackContext_ release];
 448 }
 449
 450 /**
 451  * Notification that the socket disconnected.
 452  */
 453 - (void)socketDisconnected
 454 {
 455         [self close];
 456         [delegate debuggerDisconnected];
 457 }
 458
 459 /**
 460  * Callback from the CFReadStream that there is data waiting to be read.
 461  */
 462 - (void)readStreamHasData
 463 {
 464         UInt8 buffer[1024];
 465         CFIndex bytesRead = CFReadStreamRead(readStream_, buffer, 1024);
 466         const char* charBuffer = (const char*)buffer;
 467
 468         // We haven't finished reading a packet, so just read more data in.
 469         if (currentPacketIndex_ < packetSize_)
 470         {
 471                 currentPacketIndex_ += bytesRead;
 472                 CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 473                                                                                                                    buffer,
 474                                                                                                                    bytesRead,
 475                                                                                                                    kCFStringEncodingUTF8,
 476                                                                                                                    true);
 477                 [self.currentPacket appendString:(NSString*)bufferString];
 478                 CFRelease(bufferString);
 479         }
 480         // Time to read a new packet.
 481         else
 482         {
 483                 // Read the message header: the size.
 484                 packetSize_ = atoi(charBuffer);
 485                 currentPacketIndex_ = bytesRead - strlen(charBuffer);
 486                 CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 487                                                                                                                    buffer + strlen(charBuffer) + 1,
 488                                                                                                                    bytesRead - strlen(charBuffer) - 1,
 489                                                                                                                    kCFStringEncodingUTF8,
 490                                                                                                                    true);
 491                 self.currentPacket = [NSMutableString stringWithString:(NSString*)bufferString];
 492                 CFRelease(bufferString);
 493         }
 494
 495         // We have finished reading the packet.
 496         if (currentPacketIndex_ >= packetSize_)
 497         {
 498                 packetSize_ = 0;
 499                 currentPacketIndex_ = 0;
 500
 501                 // Test if we can convert it into an NSXMLDocument.
 502                 NSError* error = nil;
 503                 NSXMLDocument* xmlTest = [[NSXMLDocument alloc] initWithXMLString:currentPacket_ options:NSXMLDocumentTidyXML error:&error];
 504                 if (error)
 505                 {
 506                         NSLog(@"Could not parse XML? --- %@", error);
 507                         NSLog(@"Error UserInfo: %@", [error userInfo]);
 508                         NSLog(@"This is the XML Document: %@", currentPacket_);
 509
 510                         // We do not want to starve the write queue, so manually parse out the
 511                         // transaction ID.
 512                         NSRange location = [currentPacket_ rangeOfString:@"transaction_id"];
 513                         if (location.location != NSNotFound)
 514                         {
 515                                 NSUInteger start = location.location + location.length;
 516                                 NSUInteger end = start;
 517
 518                                 NSCharacterSet* numericSet = [NSCharacterSet decimalDigitCharacterSet];
 519
 520                                 // Loop over the characters after the attribute name to extract the ID.
 521                                 while (end < [currentPacket_ length])
 522                                 {
 523                                         unichar c = [currentPacket_ characterAtIndex:end];
 524                                         if ([numericSet characterIsMember:c])
 525                                         {
 526                                                 // If this character is numeric, extend the range to substring.
 527                                                 ++end;
 528                                         }
 529                                         else
 530                                         {
 531                                                 if (start == end)
 532                                                 {
 533                                                         // If this character is nonnumeric and we have nothing in the
 534                                                         // range, skip this character.
 535                                                         ++start;
 536                                                         ++end;
 537                                                 }
 538                                                 else
 539                                                 {
 540                                                         // We've moved past the numeric ID so we should stop searching.
 541                                                         break;
 542                                                 }
 543                                         }
 544                                 }
 545
 546                                 // If we were able to extract the transaction ID, update the last read.
 547                                 NSRange substringRange = NSMakeRange(start, end - start);
 548                                 NSString* transaction = [currentPacket_ substringWithRange:substringRange];
 549                                 if ([transaction length])
 550                                 {
 551                                         lastReadTransaction_ = [transaction intValue];
 552                                         return;
 553                                 }
 554                         }
 555
 556                         // Otherwise, assume +1 and hope it works.
 557                         ++lastReadTransaction_;
 558                         return;
 559                 }
 560                 [self handleResponse:[xmlTest autorelease]];
 561         }
 562 }
 563
 564 /**
 565  * Writes a command into the write stream. If the stream is ready for writing,
 566  * we do so immediately. If not, the command is queued and will be written
 567  * when the stream is ready.
 568  */
 569 - (void)send:(NSString*)command
 570 {
 571         if (lastReadTransaction_ >= lastWrittenTransaction_ && CFWriteStreamCanAcceptBytes(writeStream_))
 572                 [self performSend:command];
 573         else
 574                 [queuedWrites_ addObject:command];
 575 }
 576
 577 /**
 578  * This performs a blocking send. This should ONLY be called when we know we
 579  * have write access to the stream. We will busy wait in case we don't do a full
 580  * send.
 581  */
 582 - (void)performSend:(NSString*)command
 583 {
 584         BOOL done = NO;
 585
 586         char* string = (char*)[command UTF8String];
 587         int stringLength = strlen(string);
 588
 589         // Log the command if TransportDebug is enabled.
 590         if ([[[[NSProcessInfo processInfo] environment] objectForKey:@"TransportDebug"] boolValue])
 591                 NSLog(@"--> %@", command);
 592
 593         // Busy wait while writing. BAADD. Should background this operation.
 594         while (!done)
 595         {
 596                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 597                 {
 598                         // Include the NULL byte in the string when we write.
 599                         int bytesWritten = CFWriteStreamWrite(writeStream_, (UInt8*)string, stringLength + 1);
 600                         if (bytesWritten < 0)
 601                         {
 602                                 NSLog(@"write error");
 603                         }
 604                         // Incomplete write.
 605                         else if (bytesWritten < strlen(string))
 606                         {
 607                                 // Adjust the buffer and wait for another chance to write.
 608                                 stringLength -= bytesWritten;
 609                                 memmove(string, string + bytesWritten, stringLength);
 610                         }
 611                         else
 612                         {
 613                                 done = YES;
 614
 615                                 // We need to scan the string to find the transactionID.
 616                                 NSRange occurrence = [command rangeOfString:@"-i "];
 617                                 if (occurrence.location == NSNotFound)
 618                                 {
 619                                         NSLog(@"sent %@ without a transaction ID", command);
 620                                         continue;
 621                                 }
 622                                 NSString* transaction = [command substringFromIndex:occurrence.location + occurrence.length];
 623                                 lastWrittenTransaction_ = [transaction intValue];
 624                                 NSLog(@"command = %@", command);
 625                                 NSLog(@"read=%d, write=%d", lastReadTransaction_, lastWrittenTransaction_);
 626                         }
 627                 }
 628         }
 629 }
 630
 631 - (void)handleResponse:(NSXMLDocument*)response
 632 {
 633         // Check and see if there's an error.
 634         NSArray* error = [[response rootElement] elementsForName:@"error"];
 635         if ([error count] > 0)
 636         {
 637                 NSLog(@"Xdebug error: %@", error);
 638                 [delegate errorEncountered:[[[[error objectAtIndex:0] children] objectAtIndex:0] stringValue]];
 639         }
 640
 641         // If TransportDebug is enabled, log the response.
 642         if ([[[[NSProcessInfo processInfo] environment] objectForKey:@"TransportDebug"] boolValue])
 643                 NSLog(@"<-- %@", response);
 644
 645         // Get the name of the command from the engine's response.
 646         NSInteger transaction = [self transactionIDFromResponse:response];
 647         if (transaction < lastReadTransaction_)
 648                 NSLog(@"out of date transaction %@", response);
 649
 650         if (transaction != lastWrittenTransaction_)
 651                 NSLog(@"txn doesn't match last written %@", response);
 652
 653         lastReadTransaction_ = transaction;
 654         NSLog(@"read=%d, write=%d", lastReadTransaction_, lastWrittenTransaction_);
 655
 656         if ([[[response rootElement] name] isEqualToString:@"init"])
 657         {
 658                 [self initReceived:response];
 659                 return;
 660         }
 661
 662         NSString* callbackStr = [callTable_ objectForKey:[NSNumber numberWithInt:lastReadTransaction_]];
 663         if (callbackStr)
 664         {
 665                 SEL callback = NSSelectorFromString(callbackStr);
 666                 [self performSelector:callback withObject:response];
 667         }
 668
 669         [self sendQueuedWrites];
 670 }
 671
 672 // Specific Response Handlers //////////////////////////////////////////////////
 673 #pragma mark Response Handlers
 674
 675 /**
 676  * Initial packet received. We've started a brand-new connection to the engine.
 677  */
 678 - (void)initReceived:(NSXMLDocument*)response
 679 {
 680         // Register any breakpoints that exist offline.
 681         for (Breakpoint* bp in [[BreakpointManager sharedManager] breakpoints])
 682                 [self addBreakpoint:bp];
 683
 684         // Load the debugger to make it look active.
 685         [delegate debuggerConnected];
 686
 687         // TODO: update the status.
 688 }
 689
 690 /**
 691  * Receiver for status updates. This just freshens up the UI.
 692  */
 693 - (void)updateStatus:(NSXMLDocument*)response
 694 {
 695         self.status = [[[[response rootElement] attributeForName:@"status"] stringValue] capitalizedString];
 696         if (status == nil || [status isEqualToString:@"Stopped"] || [status isEqualToString:@"Stopping"])
 697         {
 698                 connected = NO;
 699                 [self close];
 700                 [delegate debuggerDisconnected];
 701
 702                 self.status = @"Stopped";
 703         }
 704 }
 705
 706 /**
 707  * Step in/out/over and run all take this path. We first get the status of the
 708  * debugger and then request fresh stack information.
 709  */
 710 - (void)debuggerStep:(NSXMLDocument*)response
 711 {
 712         [self updateStatus:response];
 713         if (!connected)
 714                 return;
 715
 716         // If this is the run command, tell the delegate that a bunch of updates
 717         // are coming. Also remove all existing stack routes and request a new stack.
 718         // TODO: figure out if we can not clobber the stack every time.
 719         NSString* command = [[[response rootElement] attributeForName:@"command"] stringValue];
 720         if (YES || [command isEqualToString:@"run"])
 721         {
 722                 if ([delegate respondsToSelector:@selector(clobberStack)])
 723                         [delegate clobberStack];
 724                 [stackFrames_ removeAllObjects];
 725                 stackFirstTransactionID_ = [[self sendCommandWithCallback:@selector(rebuildStack:) format:@"stack_depth"] intValue];
 726         }
 727 }
 728
 729 /**
 730  * We ask for the stack_depth and now we clobber the stack and start rebuilding
 731  * it.
 732  */
 733 - (void)rebuildStack:(NSXMLDocument*)response
 734 {
 735         NSInteger depth = [[[[response rootElement] attributeForName:@"depth"] stringValue] intValue];
 736
 737         if (stackFirstTransactionID_ == [self transactionIDFromResponse:response])
 738                 stackDepth_ = depth;
 739
 740         // We now need to alloc a bunch of stack frames and get the basic information
 741         // for them.
 742         for (NSInteger i = 0; i < depth; i++)
 743         {
 744                 // Use the transaction ID to create a routing path.
 745                 NSNumber* routingID = [self sendCommandWithCallback:@selector(getStackFrame:) format:@"stack_get -d %d", i];
 746                 [stackFrames_ setObject:[StackFrame alloc] forKey:routingID];
 747         }
 748 }
 749
 750 /**
 751  * The initial rebuild of the stack frame. We now have enough to initialize
 752  * a StackFrame object.
 753  */
 754 - (void)getStackFrame:(NSXMLDocument*)response
 755 {
 756         // Get the routing information.
 757         NSInteger routingID = [self transactionIDFromResponse:response];
 758         if (routingID < stackFirstTransactionID_)
 759                 return;
 760         NSNumber* routingNumber = [NSNumber numberWithInt:routingID];
 761
 762         // Make sure we initialized this frame in our last |-rebuildStack:|.
 763         StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 764         if (!frame)
 765                 return;
 766
 767         NSXMLElement* xmlframe = [[[response rootElement] children] objectAtIndex:0];
 768
 769         // Initialize the stack frame.
 770         [frame initWithIndex:[[[xmlframe attributeForName:@"level"] stringValue] intValue]
 771                         withFilename:[[xmlframe attributeForName:@"filename"] stringValue]
 772                           withSource:nil
 773                                   atLine:[[[xmlframe attributeForName:@"lineno"] stringValue] intValue]
 774                           inFunction:[[xmlframe attributeForName:@"where"] stringValue]
 775                    withVariables:nil];
 776
 777         // Get the source code of the file. Escape % in URL chars.
 778         NSString* escapedFilename = [frame.filename stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 779         NSNumber* transaction = [self sendCommandWithCallback:@selector(setSource:) format:@"source -f %@", escapedFilename];
 780         [callbackContext_ setObject:routingNumber forKey:transaction];
 781
 782         // Get the names of all the contexts.
 783         transaction = [self sendCommandWithCallback:@selector(contextsReceived:) format:@"context_names -d %d", frame.index];
 784         [callbackContext_ setObject:routingNumber forKey:transaction];
 785
 786         if ([delegate respondsToSelector:@selector(newStackFrame:)])
 787                 [delegate newStackFrame:frame];
 788 }
 789
 790 /**
 791  * Callback for setting the source of a file while rebuilding a specific stack
 792  * frame.
 793  */
 794 - (void)setSource:(NSXMLDocument*)response
 795 {
 796         NSNumber* transaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 797         if ([transaction intValue] < stackFirstTransactionID_)
 798                 return;
 799         NSNumber* routingNumber = [callbackContext_ objectForKey:transaction];
 800         if (!routingNumber)
 801                 return;
 802
 803         [callbackContext_ removeObjectForKey:transaction];
 804         StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 805         if (!frame)
 806                 return;
 807
 808         frame.source = [[response rootElement] value];
 809
 810         if ([delegate respondsToSelector:@selector(sourceUpdated:)])
 811                 [delegate sourceUpdated:frame];
 812 }
 813
 814 /**
 815  * Enumerates all the contexts of a given stack frame. We then in turn get the
 816  * contents of each one of these contexts.
 817  */
 818 - (void)contextsReceived:(NSXMLDocument*)response
 819 {
 820         // Get the stack frame's routing ID and use it again.
 821         NSNumber* receivedTransaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 822         if ([receivedTransaction intValue] < stackFirstTransactionID_)
 823                 return;
 824         NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 825         if (!routingID)
 826                 return;
 827
 828         // Get the stack frame by the |routingID|.
 829         StackFrame* frame = [stackFrames_ objectForKey:routingID];
 830
 831         NSXMLElement* contextNames = [response rootElement];
 832         for (NSXMLElement* context in [contextNames children])
 833         {
 834                 NSInteger cid = [[[context attributeForName:@"id"] stringValue] intValue];
 835
 836                 // Fetch each context's variables.
 837                 NSNumber* transaction = [self sendCommandWithCallback:@selector(variablesReceived:)
 838                                                                                                            format:@"context_get -d %d -c %d", frame.index, cid];
 839                 [callbackContext_ setObject:routingID forKey:transaction];
 840         }
 841 }
 842
 843 /**
 844  * Receives the variables from the context and attaches them to the stack frame.
 845  */
 846 - (void)variablesReceived:(NSXMLDocument*)response
 847 {
 848         // Get the stack frame's routing ID and use it again.
 849         NSInteger transaction = [self transactionIDFromResponse:response];
 850         if (transaction < stackFirstTransactionID_)
 851                 return;
 852         NSNumber* receivedTransaction = [NSNumber numberWithInt:transaction];
 853         NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 854         if (!routingID)
 855                 return;
 856
 857         // Get the stack frame by the |routingID|.
 858         StackFrame* frame = [stackFrames_ objectForKey:routingID];
 859
 860         NSMutableArray* variables = [NSMutableArray array];
 861
 862         // Merge the frame's existing variables.
 863         if (frame.variables)
 864                 [variables addObjectsFromArray:frame.variables];
 865
 866         // Add these new variables.
 867         NSArray* addVariables = [[response rootElement] children];
 868         if (addVariables)
 869                 [variables addObjectsFromArray:addVariables];
 870
 871         frame.variables = variables;
 872 }
 873
 874 /**
 875  * Callback from a |-getProperty:| request.
 876  */
 877 - (void)propertiesReceived:(NSXMLDocument*)response
 878 {
 879         NSInteger transaction = [self transactionIDFromResponse:response];
 880
 881         /*
 882          <response>
 883                  <property> <!-- this is the one we requested -->
 884                          <property ... /> <!-- these are what we want -->
 885                  </property>
 886          </repsonse>
 887          */
 888
 889         // Detach all the children so we can insert them into another document.
 890         NSXMLElement* parent = (NSXMLElement*)[[response rootElement] childAtIndex:0];
 891         NSArray* children = [parent children];
 892         [parent setChildren:nil];
 893
 894         [delegate receivedProperties:children forTransaction:transaction];
 895 }
 896
 897 /**
 898  * Callback for setting a breakpoint.
 899  */
 900 - (void)breakpointReceived:(NSXMLDocument*)response
 901 {
 902         NSNumber* transaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 903         Breakpoint* bp = [callbackContext_ objectForKey:transaction];
 904         if (!bp)
 905                 return;
 906
 907         [callbackContext_ removeObjectForKey:callbackContext_];
 908         [bp setDebuggerId:[[[[response rootElement] attributeForName:@"id"] stringValue] intValue]];
 909 }
 910
 911 #pragma mark Private
 912
 913 /**
 914  * This will send a command to the debugger engine. It will append the
 915  * transaction ID automatically. It accepts a NSString command along with a
 916  * a variable number of arguments to substitute into the command, a la
 917  * +[NSString stringWithFormat:]. Returns the transaction ID as a NSNumber.
 918  */
 919 - (NSNumber*)sendCommandWithCallback:(SEL)callback format:(NSString*)format, ...
 920 {
 921         // Collect varargs and format command.
 922         va_list args;
 923         va_start(args, format);
 924         NSString* command = [[NSString alloc] initWithFormat:format arguments:args];
 925         va_end(args);
 926
 927         NSNumber* callbackKey = [NSNumber numberWithInt:transactionID++];
 928         if (callback)
 929                 [callTable_ setObject:NSStringFromSelector(callback) forKey:callbackKey];
 930
 931         [self send:[NSString stringWithFormat:@"%@ -i %@", [command autorelease], callbackKey]];
 932
 933         return callbackKey;
 934 }
 935
 936 /**
 937  * Checks if there are unsent commands in the |queuedWrites_| queue and sends
 938  * them if it's OK to do so. This will not block.
 939  */
 940 - (void)sendQueuedWrites
 941 {
 942         if (!connected)
 943                 return;
 944
 945         [writeQueueLock_ lock];
 946         if (lastReadTransaction_ >= lastWrittenTransaction_ && [queuedWrites_ count] > 0)
 947         {
 948                 NSString* command = [queuedWrites_ objectAtIndex:0];
 949                 NSLog(@"Sending queued write: %@", command);
 950
 951                 // We don't want to block because this is called from the main thread.
 952                 // |-performSend:| busy waits when the stream is not ready. Bail out
 953                 // before we do that becuase busy waiting is BAD.
 954                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 955                 {
 956                         [self performSend:command];
 957                         [queuedWrites_ removeObjectAtIndex:0];
 958                 }
 959         }
 960         [writeQueueLock_ unlock];
 961 }
 962
 963 /**
 964  * Given a file path, this returns a file:// URI and escapes any spaces for the
 965  * debugger engine.
 966  */
 967 - (NSString*)escapedURIPath:(NSString*)path
 968 {
 969         // Custon GDBp paths are fine.
 970         if ([[path substringToIndex:4] isEqualToString:@"gdbp"])
 971                 return path;
 972
 973         // Create a temporary URL that will escape all the nasty characters.
 974         NSURL* url = [NSURL fileURLWithPath:path];
 975         NSString* urlString = [url absoluteString];
 976
 977         // Remove the host because this is a file:// URL;
 978         urlString = [urlString stringByReplacingOccurrencesOfString:[url host] withString:@""];
 979
 980         // Escape % for use in printf-style NSString formatters.
 981         urlString = [urlString stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 982         return urlString;
 983 }
 984
 985 /**
 986  * Returns the transaction_id from an NSXMLDocument.
 987  */
 988 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response
 989 {
 990         return [[[[response rootElement] attributeForName:@"transaction_id"] stringValue] intValue];
 991 }
 992
 993 @end