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 #import "LoggingController.h"
  24
  25 // GDBpConnection (Private) ////////////////////////////////////////////////////
  26
  27 @interface DebuggerConnection ()
  28 @property (readwrite, copy) NSString* status;
  29 @property (assign) CFSocketRef socket;
  30 @property (assign) CFReadStreamRef readStream;
  31 @property NSUInteger lastReadTransaction;
  32 @property (retain) NSMutableString* currentPacket;
  33 @property (assign) CFWriteStreamRef writeStream;
  34 @property NSUInteger lastWrittenTransaction;
  35 @property (retain) NSMutableArray* queuedWrites;
  36
  37 - (void)connect;
  38 - (void)close;
  39 - (void)socketDidAccept;
  40 - (void)socketDisconnected;
  41 - (void)readStreamHasData;
  42 - (void)send:(NSString*)command;
  43 - (void)performSend:(NSString*)command;
  44 - (void)errorEncountered:(NSString*)error;
  45
  46 - (void)handleResponse:(NSXMLDocument*)response;
  47 - (void)initReceived:(NSXMLDocument*)response;
  48 - (void)updateStatus:(NSXMLDocument*)response;
  49 - (void)debuggerStep:(NSXMLDocument*)response;
  50 - (void)rebuildStack:(NSXMLDocument*)response;
  51 - (void)getStackFrame:(NSXMLDocument*)response;
  52 - (void)setSource:(NSXMLDocument*)response;
  53 - (void)contextsReceived:(NSXMLDocument*)response;
  54 - (void)variablesReceived:(NSXMLDocument*)response;
  55 - (void)propertiesReceived:(NSXMLDocument*)response;
  56
  57 - (NSNumber*)sendCommandWithCallback:(SEL)callback format:(NSString*)format, ...;
  58
  59 - (void)sendQueuedWrites;
  60
  61 - (NSString*)escapedURIPath:(NSString*)path;
  62 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response;
  63 @end
  64
  65 // CFNetwork Callbacks /////////////////////////////////////////////////////////
  66
  67 void ReadStreamCallback(CFReadStreamRef stream, CFStreamEventType eventType, void* connectionRaw)
  68 {
  69         DebuggerConnection* connection = (DebuggerConnection*)connectionRaw;
  70         switch (eventType)
  71         {
  72                 case kCFStreamEventHasBytesAvailable:
  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                 [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 // Getters /////////////////////////////////////////////////////////////////////
 239 #pragma mark Getters
 240
 241 /**
 242  * Gets the port number
 243  */
 244 - (NSUInteger)port
 245 {
 246         return port;
 247 }
 248
 249 /**
 250  * Returns the name of the remote host
 251  */
 252 - (NSString*)remoteHost
 253 {
 254         if (!connected)
 255         {
 256                 return @"(DISCONNECTED)";
 257         }
 258         // TODO: Either impl or remove.
 259         return @"";
 260 }
 261
 262 /**
 263  * Returns whether or not we have an active connection
 264  */
 265 - (BOOL)isConnected
 266 {
 267         return connected;
 268 }
 269
 270 // Commands ////////////////////////////////////////////////////////////////////
 271 #pragma mark Commands
 272
 273 /**
 274  * Reestablishes communication with the remote debugger so that a new connection doesn't have to be
 275  * created every time you want to debug a page
 276  */
 277 - (void)reconnect
 278 {
 279         [self close];
 280         self.status = @"Connecting";
 281         [self connect];
 282 }
 283
 284 /**
 285  * Tells the debugger to continue running the script. Returns the current stack frame.
 286  */
 287 - (void)run
 288 {
 289         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"run"];
 290 }
 291
 292 /**
 293  * Tells the debugger to step into the current command.
 294  */
 295 - (void)stepIn
 296 {
 297         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_into"];
 298 }
 299
 300 /**
 301  * Tells the debugger to step out of the current context
 302  */
 303 - (void)stepOut
 304 {
 305         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_out"];
 306 }
 307
 308 /**
 309  * Tells the debugger to step over the current function
 310  */
 311 - (void)stepOver
 312 {
 313         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_over"];
 314 }
 315
 316 /**
 317  * Tells the debugger engine to get a specifc property. This also takes in the NSXMLElement
 318  * that requested it so that the child can be attached.
 319  */
 320 - (NSInteger)getProperty:(NSString*)property
 321 {
 322         [self sendCommandWithCallback:@selector(propertiesReceived:) format:@"property_get -n \"%@\"", property];
 323 }
 324
 325 // Breakpoint Management ///////////////////////////////////////////////////////
 326 #pragma mark Breakpoints
 327
 328 /**
 329  * Send an add breakpoint command
 330  */
 331 - (void)addBreakpoint:(Breakpoint*)bp
 332 {
 333         if (!connected)
 334                 return;
 335
 336         NSString* file = [self escapedURIPath:[bp transformedPath]];
 337         NSNumber* transaction = [self sendCommandWithCallback:@selector(breakpointReceived:)
 338                                                                                                    format:@"breakpoint_set -t line -f %@ -n %i", file, [bp line]];
 339         [callbackContext_ setObject:bp forKey:transaction];
 340 }
 341
 342 /**
 343  * Removes a breakpoint
 344  */
 345 - (void)removeBreakpoint:(Breakpoint*)bp
 346 {
 347         if (!connected)
 348         {
 349                 return;
 350         }
 351
 352         [self sendCommandWithCallback:nil format:@"breakpoint_remove -d %i", [bp debuggerId]];
 353 }
 354
 355
 356 // Socket and Stream Callbacks /////////////////////////////////////////////////
 357 #pragma mark Callbacks
 358
 359 /**
 360  * Called by SocketWrapper after the connection is successful. This immediately calls
 361  * -[SocketWrapper receive] to clear the way for communication, though the information
 362  * could be useful server information that we don't use right now.
 363  */
 364 - (void)socketDidAccept
 365 {
 366         connected = YES;
 367         transactionID = 1;
 368         stackFrames_ = [[NSMutableDictionary alloc] init];
 369         self.queuedWrites = [NSMutableArray array];
 370         writeQueueLock_ = [NSRecursiveLock new];
 371         callTable_ = [NSMutableDictionary new];
 372         callbackContext_ = [NSMutableDictionary new];
 373 }
 374
 375 /**
 376  * Receives errors from the SocketWrapper and updates the display
 377  */
 378 - (void)errorEncountered:(NSString*)error
 379 {
 380         [delegate errorEncountered:error];
 381 }
 382
 383 /**
 384  * Creates, connects to, and schedules a CFSocket.
 385  */
 386 - (void)connect
 387 {
 388         // Pass ourselves to the callback so we don't have to use ugly globals.
 389         CFSocketContext context;
 390         context.version = 0;
 391         context.info = self;
 392         context.retain = NULL;
 393         context.release = NULL;
 394         context.copyDescription = NULL;
 395
 396         // Create the address structure.
 397         struct sockaddr_in address;
 398         memset(&address, 0, sizeof(address));
 399         address.sin_len = sizeof(address);
 400         address.sin_family = AF_INET;
 401         address.sin_port = htons(port);
 402         address.sin_addr.s_addr = htonl(INADDR_ANY);
 403
 404         // Create the socket signature.
 405         CFSocketSignature signature;
 406         signature.protocolFamily = PF_INET;
 407         signature.socketType = SOCK_STREAM;
 408         signature.protocol = IPPROTO_TCP;
 409         signature.address = (CFDataRef)[NSData dataWithBytes:&address length:sizeof(address)];
 410
 411         socket_ = CFSocketCreateWithSocketSignature(kCFAllocatorDefault,
 412                                                                                                 &signature,  // Socket signature.
 413                                                                                                 kCFSocketAcceptCallBack,  // Callback types.
 414                                                                                                 SocketAcceptCallback,  // Callout function pointer.
 415                                                                                                 &context);  // Context to pass to callout.
 416         if (!socket_)
 417         {
 418                 [self errorEncountered:@"Could not open socket."];
 419                 return;
 420         }
 421
 422         // Allow old, yet-to-be recycled sockets to be reused.
 423         BOOL yes = YES;
 424         setsockopt(CFSocketGetNative(socket_), SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(BOOL));
 425
 426         // Schedule the socket on the run loop.
 427         CFRunLoopSourceRef source = CFSocketCreateRunLoopSource(kCFAllocatorDefault, socket_, 0);
 428         CFRunLoopAddSource(CFRunLoopGetCurrent(), source, kCFRunLoopCommonModes);
 429         CFRelease(source);
 430
 431         self.status = @"Connecting";
 432 }
 433
 434 /**
 435  * Closes a socket and releases the ref.
 436  */
 437 - (void)close
 438 {
 439         // The socket goes down, so do the streams, which clean themselves up.
 440         CFSocketInvalidate(socket_);
 441         CFRelease(socket_);
 442         [stackFrames_ release];
 443         self.queuedWrites = nil;
 444         [writeQueueLock_ release];
 445         [callTable_ release];
 446         [callbackContext_ release];
 447 }
 448
 449 /**
 450  * Notification that the socket disconnected.
 451  */
 452 - (void)socketDisconnected
 453 {
 454         [self close];
 455         [delegate debuggerDisconnected];
 456 }
 457
 458 /**
 459  * Callback from the CFReadStream that there is data waiting to be read.
 460  */
 461 - (void)readStreamHasData
 462 {
 463         UInt8 buffer[1024];
 464         CFIndex bytesRead = CFReadStreamRead(readStream_, buffer, 1024);
 465         const char* charBuffer = (const char*)buffer;
 466
 467         // We haven't finished reading a packet, so just read more data in.
 468         if (currentPacketIndex_ < packetSize_)
 469         {
 470                 currentPacketIndex_ += bytesRead;
 471                 CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 472                                                                                                                    buffer,
 473                                                                                                                    bytesRead,
 474                                                                                                                    kCFStringEncodingUTF8,
 475                                                                                                                    true);
 476                 [self.currentPacket appendString:(NSString*)bufferString];
 477                 CFRelease(bufferString);
 478         }
 479         // Time to read a new packet.
 480         else
 481         {
 482                 // Read the message header: the size.
 483                 packetSize_ = atoi(charBuffer);
 484                 currentPacketIndex_ = bytesRead - strlen(charBuffer);
 485                 CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 486                                                                                                                    buffer + strlen(charBuffer) + 1,
 487                                                                                                                    bytesRead - strlen(charBuffer) - 1,
 488                                                                                                                    kCFStringEncodingUTF8,
 489                                                                                                                    true);
 490                 self.currentPacket = [NSMutableString stringWithString:(NSString*)bufferString];
 491                 CFRelease(bufferString);
 492         }
 493
 494         // We have finished reading the packet.
 495         if (currentPacketIndex_ >= packetSize_)
 496         {
 497                 packetSize_ = 0;
 498                 currentPacketIndex_ = 0;
 499
 500                 // Test if we can convert it into an NSXMLDocument.
 501                 NSError* error = nil;
 502                 NSXMLDocument* xmlTest = [[NSXMLDocument alloc] initWithXMLString:currentPacket_ options:NSXMLDocumentTidyXML error:&error];
 503
 504                 // Try to recover if we encountered an error.
 505                 if (error)
 506                 {
 507                         // We do not want to starve the write queue, so manually parse out the
 508                         // transaction ID.
 509                         NSRange location = [currentPacket_ rangeOfString:@"transaction_id"];
 510                         if (location.location != NSNotFound)
 511                         {
 512                                 NSUInteger start = location.location + location.length;
 513                                 NSUInteger end = start;
 514
 515                                 NSCharacterSet* numericSet = [NSCharacterSet decimalDigitCharacterSet];
 516
 517                                 // Loop over the characters after the attribute name to extract the ID.
 518                                 while (end < [currentPacket_ length])
 519                                 {
 520                                         unichar c = [currentPacket_ characterAtIndex:end];
 521                                         if ([numericSet characterIsMember:c])
 522                                         {
 523                                                 // If this character is numeric, extend the range to substring.
 524                                                 ++end;
 525                                         }
 526                                         else
 527                                         {
 528                                                 if (start == end)
 529                                                 {
 530                                                         // If this character is nonnumeric and we have nothing in the
 531                                                         // range, skip this character.
 532                                                         ++start;
 533                                                         ++end;
 534                                                 }
 535                                                 else
 536                                                 {
 537                                                         // We've moved past the numeric ID so we should stop searching.
 538                                                         break;
 539                                                 }
 540                                         }
 541                                 }
 542
 543                                 // If we were able to extract the transaction ID, update the last read.
 544                                 NSRange substringRange = NSMakeRange(start, end - start);
 545                                 NSString* transaction = [currentPacket_ substringWithRange:substringRange];
 546                                 if ([transaction length])
 547                                         lastReadTransaction_ = [transaction intValue];
 548                         }
 549
 550                         // Otherwise, assume +1 and hope it works.
 551                         ++lastReadTransaction_;
 552                 }
 553                 else
 554                 {
 555                         // See if the transaction can be parsed out.
 556                         NSInteger transaction = [self transactionIDFromResponse:xmlTest];
 557                         if (transaction < lastReadTransaction_ || transaction != lastWrittenTransaction_)
 558                         {
 559                                 NSLog(@"tx = %d vs %d", transaction, lastReadTransaction_);
 560                                 NSLog(@"out of date transaction %@", xmlTest);
 561                                 return;
 562                         }
 563
 564                         if (transaction != lastWrittenTransaction_)
 565                                 NSLog(@"txn doesn't match last written %@", xmlTest);
 566
 567                         lastReadTransaction_ = transaction;
 568                 }
 569
 570                 // Log this receive event.
 571                 LoggingController* logger = [(AppDelegate*)[NSApp delegate] loggingController];
 572                 LogEntry* log = [logger recordReceive:currentPacket_];
 573                 log.error = error;
 574                 log.lastWrittenTransactionID = lastWrittenTransaction_;
 575                 log.lastReadTransactionID = lastReadTransaction_;
 576
 577                 // Finally, dispatch the handler for this response.
 578                 [self handleResponse:[xmlTest autorelease]];
 579         }
 580 }
 581
 582 /**
 583  * Writes a command into the write stream. If the stream is ready for writing,
 584  * we do so immediately. If not, the command is queued and will be written
 585  * when the stream is ready.
 586  */
 587 - (void)send:(NSString*)command
 588 {
 589         if (lastReadTransaction_ >= lastWrittenTransaction_ && CFWriteStreamCanAcceptBytes(writeStream_))
 590                 [self performSend:command];
 591         else
 592                 [queuedWrites_ addObject:command];
 593         [self sendQueuedWrites];
 594 }
 595
 596 /**
 597  * This performs a blocking send. This should ONLY be called when we know we
 598  * have write access to the stream. We will busy wait in case we don't do a full
 599  * send.
 600  */
 601 - (void)performSend:(NSString*)command
 602 {
 603         BOOL done = NO;
 604
 605         char* string = (char*)[command UTF8String];
 606         int stringLength = strlen(string);
 607
 608         // Busy wait while writing. BAADD. Should background this operation.
 609         while (!done)
 610         {
 611                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 612                 {
 613                         // Include the NULL byte in the string when we write.
 614                         int bytesWritten = CFWriteStreamWrite(writeStream_, (UInt8*)string, stringLength + 1);
 615                         if (bytesWritten < 0)
 616                         {
 617                                 NSLog(@"write error");
 618                         }
 619                         // Incomplete write.
 620                         else if (bytesWritten < strlen(string))
 621                         {
 622                                 // Adjust the buffer and wait for another chance to write.
 623                                 stringLength -= bytesWritten;
 624                                 memmove(string, string + bytesWritten, stringLength);
 625                         }
 626                         else
 627                         {
 628                                 done = YES;
 629
 630                                 // We need to scan the string to find the transactionID.
 631                                 NSRange occurrence = [command rangeOfString:@"-i "];
 632                                 if (occurrence.location == NSNotFound)
 633                                 {
 634                                         NSLog(@"sent %@ without a transaction ID", command);
 635                                         continue;
 636                                 }
 637                                 NSString* transaction = [command substringFromIndex:occurrence.location + occurrence.length];
 638                                 lastWrittenTransaction_ = [transaction intValue];
 639                         }
 640                 }
 641         }
 642
 643         // Log this trancation.
 644         LoggingController* logger = [(AppDelegate*)[NSApp delegate] loggingController];
 645         LogEntry* log = [logger recordSend:command];
 646         log.lastWrittenTransactionID = lastWrittenTransaction_;
 647         log.lastReadTransactionID = lastReadTransaction_;
 648 }
 649
 650 - (void)handleResponse:(NSXMLDocument*)response
 651 {
 652         // Check and see if there's an error.
 653         NSArray* error = [[response rootElement] elementsForName:@"error"];
 654         if ([error count] > 0)
 655         {
 656                 NSLog(@"Xdebug error: %@", error);
 657                 [delegate errorEncountered:[[[[error objectAtIndex:0] children] objectAtIndex:0] stringValue]];
 658         }
 659
 660         if ([[[response rootElement] name] isEqualToString:@"init"])
 661         {
 662                 [self initReceived:response];
 663                 return;
 664         }
 665
 666         NSString* callbackStr = [callTable_ objectForKey:[NSNumber numberWithInt:lastReadTransaction_]];
 667         if (callbackStr)
 668         {
 669                 SEL callback = NSSelectorFromString(callbackStr);
 670                 [self performSelector:callback withObject:response];
 671         }
 672
 673         [self sendQueuedWrites];
 674 }
 675
 676 // Specific Response Handlers //////////////////////////////////////////////////
 677 #pragma mark Response Handlers
 678
 679 /**
 680  * Initial packet received. We've started a brand-new connection to the engine.
 681  */
 682 - (void)initReceived:(NSXMLDocument*)response
 683 {
 684         // Register any breakpoints that exist offline.
 685         for (Breakpoint* bp in [[BreakpointManager sharedManager] breakpoints])
 686                 [self addBreakpoint:bp];
 687
 688         // Load the debugger to make it look active.
 689         [delegate debuggerConnected];
 690
 691         // TODO: update the status.
 692 }
 693
 694 /**
 695  * Receiver for status updates. This just freshens up the UI.
 696  */
 697 - (void)updateStatus:(NSXMLDocument*)response
 698 {
 699         self.status = [[[[response rootElement] attributeForName:@"status"] stringValue] capitalizedString];
 700         if (status == nil || [status isEqualToString:@"Stopped"] || [status isEqualToString:@"Stopping"])
 701         {
 702                 connected = NO;
 703                 [self close];
 704                 [delegate debuggerDisconnected];
 705
 706                 self.status = @"Stopped";
 707         }
 708 }
 709
 710 /**
 711  * Step in/out/over and run all take this path. We first get the status of the
 712  * debugger and then request fresh stack information.
 713  */
 714 - (void)debuggerStep:(NSXMLDocument*)response
 715 {
 716         [self updateStatus:response];
 717         if (!connected)
 718                 return;
 719
 720         // If this is the run command, tell the delegate that a bunch of updates
 721         // are coming. Also remove all existing stack routes and request a new stack.
 722         // TODO: figure out if we can not clobber the stack every time.
 723         NSString* command = [[[response rootElement] attributeForName:@"command"] stringValue];
 724         if (YES || [command isEqualToString:@"run"])
 725         {
 726                 if ([delegate respondsToSelector:@selector(clobberStack)])
 727                         [delegate clobberStack];
 728                 [stackFrames_ removeAllObjects];
 729                 stackFirstTransactionID_ = [[self sendCommandWithCallback:@selector(rebuildStack:) format:@"stack_depth"] intValue];
 730         }
 731 }
 732
 733 /**
 734  * We ask for the stack_depth and now we clobber the stack and start rebuilding
 735  * it.
 736  */
 737 - (void)rebuildStack:(NSXMLDocument*)response
 738 {
 739         NSInteger depth = [[[[response rootElement] attributeForName:@"depth"] stringValue] intValue];
 740
 741         if (stackFirstTransactionID_ == [self transactionIDFromResponse:response])
 742                 stackDepth_ = depth;
 743
 744         // We now need to alloc a bunch of stack frames and get the basic information
 745         // for them.
 746         for (NSInteger i = 0; i < depth; i++)
 747         {
 748                 // Use the transaction ID to create a routing path.
 749                 NSNumber* routingID = [self sendCommandWithCallback:@selector(getStackFrame:) format:@"stack_get -d %d", i];
 750                 [stackFrames_ setObject:[StackFrame alloc] forKey:routingID];
 751         }
 752 }
 753
 754 /**
 755  * The initial rebuild of the stack frame. We now have enough to initialize
 756  * a StackFrame object.
 757  */
 758 - (void)getStackFrame:(NSXMLDocument*)response
 759 {
 760         // Get the routing information.
 761         NSInteger routingID = [self transactionIDFromResponse:response];
 762         if (routingID < stackFirstTransactionID_)
 763                 return;
 764         NSNumber* routingNumber = [NSNumber numberWithInt:routingID];
 765
 766         // Make sure we initialized this frame in our last |-rebuildStack:|.
 767         StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 768         if (!frame)
 769                 return;
 770
 771         NSXMLElement* xmlframe = [[[response rootElement] children] objectAtIndex:0];
 772
 773         // Initialize the stack frame.
 774         [frame initWithIndex:[[[xmlframe attributeForName:@"level"] stringValue] intValue]
 775                         withFilename:[[xmlframe attributeForName:@"filename"] stringValue]
 776                           withSource:nil
 777                                   atLine:[[[xmlframe attributeForName:@"lineno"] stringValue] intValue]
 778                           inFunction:[[xmlframe attributeForName:@"where"] stringValue]
 779                    withVariables:nil];
 780
 781         // Get the source code of the file. Escape % in URL chars.
 782         NSString* escapedFilename = [frame.filename stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 783         NSNumber* transaction = [self sendCommandWithCallback:@selector(setSource:) format:@"source -f %@", escapedFilename];
 784         [callbackContext_ setObject:routingNumber forKey:transaction];
 785
 786         // Get the names of all the contexts.
 787         transaction = [self sendCommandWithCallback:@selector(contextsReceived:) format:@"context_names -d %d", frame.index];
 788         [callbackContext_ setObject:routingNumber forKey:transaction];
 789
 790         if ([delegate respondsToSelector:@selector(newStackFrame:)])
 791                 [delegate newStackFrame:frame];
 792 }
 793
 794 /**
 795  * Callback for setting the source of a file while rebuilding a specific stack
 796  * frame.
 797  */
 798 - (void)setSource:(NSXMLDocument*)response
 799 {
 800         NSNumber* transaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 801         if ([transaction intValue] < stackFirstTransactionID_)
 802                 return;
 803         NSNumber* routingNumber = [callbackContext_ objectForKey:transaction];
 804         if (!routingNumber)
 805                 return;
 806
 807         [callbackContext_ removeObjectForKey:transaction];
 808         StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 809         if (!frame)
 810                 return;
 811
 812         frame.source = [[response rootElement] value];
 813
 814         if ([delegate respondsToSelector:@selector(sourceUpdated:)])
 815                 [delegate sourceUpdated:frame];
 816 }
 817
 818 /**
 819  * Enumerates all the contexts of a given stack frame. We then in turn get the
 820  * contents of each one of these contexts.
 821  */
 822 - (void)contextsReceived:(NSXMLDocument*)response
 823 {
 824         // Get the stack frame's routing ID and use it again.
 825         NSNumber* receivedTransaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 826         if ([receivedTransaction intValue] < stackFirstTransactionID_)
 827                 return;
 828         NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 829         if (!routingID)
 830                 return;
 831
 832         // Get the stack frame by the |routingID|.
 833         StackFrame* frame = [stackFrames_ objectForKey:routingID];
 834
 835         NSXMLElement* contextNames = [response rootElement];
 836         for (NSXMLElement* context in [contextNames children])
 837         {
 838                 NSInteger cid = [[[context attributeForName:@"id"] stringValue] intValue];
 839
 840                 // Fetch each context's variables.
 841                 NSNumber* transaction = [self sendCommandWithCallback:@selector(variablesReceived:)
 842                                                                                                            format:@"context_get -d %d -c %d", frame.index, cid];
 843                 [callbackContext_ setObject:routingID forKey:transaction];
 844         }
 845 }
 846
 847 /**
 848  * Receives the variables from the context and attaches them to the stack frame.
 849  */
 850 - (void)variablesReceived:(NSXMLDocument*)response
 851 {
 852         // Get the stack frame's routing ID and use it again.
 853         NSInteger transaction = [self transactionIDFromResponse:response];
 854         if (transaction < stackFirstTransactionID_)
 855                 return;
 856         NSNumber* receivedTransaction = [NSNumber numberWithInt:transaction];
 857         NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 858         if (!routingID)
 859                 return;
 860
 861         // Get the stack frame by the |routingID|.
 862         StackFrame* frame = [stackFrames_ objectForKey:routingID];
 863
 864         NSMutableArray* variables = [NSMutableArray array];
 865
 866         // Merge the frame's existing variables.
 867         if (frame.variables)
 868                 [variables addObjectsFromArray:frame.variables];
 869
 870         // Add these new variables.
 871         NSArray* addVariables = [[response rootElement] children];
 872         if (addVariables)
 873                 [variables addObjectsFromArray:addVariables];
 874
 875         frame.variables = variables;
 876 }
 877
 878 /**
 879  * Callback from a |-getProperty:| request.
 880  */
 881 - (void)propertiesReceived:(NSXMLDocument*)response
 882 {
 883         NSInteger transaction = [self transactionIDFromResponse:response];
 884
 885         /*
 886          <response>
 887                  <property> <!-- this is the one we requested -->
 888                          <property ... /> <!-- these are what we want -->
 889                  </property>
 890          </repsonse>
 891          */
 892
 893         // Detach all the children so we can insert them into another document.
 894         NSXMLElement* parent = (NSXMLElement*)[[response rootElement] childAtIndex:0];
 895         NSArray* children = [parent children];
 896         [parent setChildren:nil];
 897
 898         [delegate receivedProperties:children forTransaction:transaction];
 899 }
 900
 901 /**
 902  * Callback for setting a breakpoint.
 903  */
 904 - (void)breakpointReceived:(NSXMLDocument*)response
 905 {
 906         NSNumber* transaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 907         Breakpoint* bp = [callbackContext_ objectForKey:transaction];
 908         if (!bp)
 909                 return;
 910
 911         [callbackContext_ removeObjectForKey:callbackContext_];
 912         [bp setDebuggerId:[[[[response rootElement] attributeForName:@"id"] stringValue] intValue]];
 913 }
 914
 915 #pragma mark Private
 916
 917 /**
 918  * This will send a command to the debugger engine. It will append the
 919  * transaction ID automatically. It accepts a NSString command along with a
 920  * a variable number of arguments to substitute into the command, a la
 921  * +[NSString stringWithFormat:]. Returns the transaction ID as a NSNumber.
 922  */
 923 - (NSNumber*)sendCommandWithCallback:(SEL)callback format:(NSString*)format, ...
 924 {
 925         // Collect varargs and format command.
 926         va_list args;
 927         va_start(args, format);
 928         NSString* command = [[NSString alloc] initWithFormat:format arguments:args];
 929         va_end(args);
 930
 931         NSNumber* callbackKey = [NSNumber numberWithInt:transactionID++];
 932         if (callback)
 933                 [callTable_ setObject:NSStringFromSelector(callback) forKey:callbackKey];
 934
 935         [self send:[NSString stringWithFormat:@"%@ -i %@", [command autorelease], callbackKey]];
 936
 937         return callbackKey;
 938 }
 939
 940 /**
 941  * Checks if there are unsent commands in the |queuedWrites_| queue and sends
 942  * them if it's OK to do so. This will not block.
 943  */
 944 - (void)sendQueuedWrites
 945 {
 946         if (!connected)
 947                 return;
 948
 949         [writeQueueLock_ lock];
 950         if (lastReadTransaction_ >= lastWrittenTransaction_ && [queuedWrites_ count] > 0)
 951         {
 952                 NSString* command = [queuedWrites_ objectAtIndex:0];
 953
 954                 // We don't want to block because this is called from the main thread.
 955                 // |-performSend:| busy waits when the stream is not ready. Bail out
 956                 // before we do that becuase busy waiting is BAD.
 957                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 958                 {
 959                         [self performSend:command];
 960                         [queuedWrites_ removeObjectAtIndex:0];
 961                 }
 962         }
 963         [writeQueueLock_ unlock];
 964 }
 965
 966 /**
 967  * Given a file path, this returns a file:// URI and escapes any spaces for the
 968  * debugger engine.
 969  */
 970 - (NSString*)escapedURIPath:(NSString*)path
 971 {
 972         // Custon GDBp paths are fine.
 973         if ([[path substringToIndex:4] isEqualToString:@"gdbp"])
 974                 return path;
 975
 976         // Create a temporary URL that will escape all the nasty characters.
 977         NSURL* url = [NSURL fileURLWithPath:path];
 978         NSString* urlString = [url absoluteString];
 979
 980         // Remove the host because this is a file:// URL;
 981         urlString = [urlString stringByReplacingOccurrencesOfString:[url host] withString:@""];
 982
 983         // Escape % for use in printf-style NSString formatters.
 984         urlString = [urlString stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 985         return urlString;
 986 }
 987
 988 /**
 989  * Returns the transaction_id from an NSXMLDocument.
 990  */
 991 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response
 992 {
 993         return [[[[response rootElement] attributeForName:@"transaction_id"] stringValue] intValue];
 994 }
 995
 996 @end