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  * Creates an entirely new stack and returns it as an array of StackFrame objects.
 287  */
 288 - (NSArray*)getCurrentStack
 289 {
 290         NSMutableArray* stack = [NSMutableArray array];
 291         NSLog(@"NOTIMPLEMENTED(): %s", _cmd);
 292         return stack;
 293 }
 294
 295 /**
 296  * Tells the debugger to continue running the script. Returns the current stack frame.
 297  */
 298 - (void)run
 299 {
 300         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"run"];
 301 }
 302
 303 /**
 304  * Tells the debugger to step into the current command.
 305  */
 306 - (void)stepIn
 307 {
 308         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_into"];
 309 }
 310
 311 /**
 312  * Tells the debugger to step out of the current context
 313  */
 314 - (void)stepOut
 315 {
 316         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_out"];
 317 }
 318
 319 /**
 320  * Tells the debugger to step over the current function
 321  */
 322 - (void)stepOver
 323 {
 324         [self sendCommandWithCallback:@selector(debuggerStep:) format:@"step_over"];
 325 }
 326
 327 /**
 328  * Tells the debugger engine to get a specifc property. This also takes in the NSXMLElement
 329  * that requested it so that the child can be attached.
 330  */
 331 - (NSInteger)getProperty:(NSString*)property
 332 {
 333         [self sendCommandWithCallback:@selector(propertiesReceived:) format:@"property_get -n \"%@\"", property];
 334 }
 335
 336 // Breakpoint Management ///////////////////////////////////////////////////////
 337 #pragma mark Breakpoints
 338
 339 /**
 340  * Send an add breakpoint command
 341  */
 342 - (void)addBreakpoint:(Breakpoint*)bp
 343 {
 344         if (!connected)
 345                 return;
 346
 347         NSString* file = [self escapedURIPath:[bp transformedPath]];
 348         NSNumber* transaction = [self sendCommandWithCallback:@selector(breakpointReceived:)
 349                                                                                                    format:@"breakpoint_set -t line -f %@ -n %i", file, [bp line]];
 350         [callbackContext_ setObject:bp forKey:transaction];
 351 }
 352
 353 /**
 354  * Removes a breakpoint
 355  */
 356 - (void)removeBreakpoint:(Breakpoint*)bp
 357 {
 358         if (!connected)
 359         {
 360                 return;
 361         }
 362
 363         [self sendCommandWithCallback:nil format:@"breakpoint_remove -d %i", [bp debuggerId]];
 364 }
 365
 366
 367 // Socket and Stream Callbacks /////////////////////////////////////////////////
 368 #pragma mark Callbacks
 369
 370 /**
 371  * Called by SocketWrapper after the connection is successful. This immediately calls
 372  * -[SocketWrapper receive] to clear the way for communication, though the information
 373  * could be useful server information that we don't use right now.
 374  */
 375 - (void)socketDidAccept
 376 {
 377         connected = YES;
 378         transactionID = 1;
 379         stackFrames_ = [[NSMutableDictionary alloc] init];
 380         self.queuedWrites = [NSMutableArray array];
 381         writeQueueLock_ = [NSRecursiveLock new];
 382         callTable_ = [NSMutableDictionary new];
 383         callbackContext_ = [NSMutableDictionary new];
 384 }
 385
 386 /**
 387  * Receives errors from the SocketWrapper and updates the display
 388  */
 389 - (void)errorEncountered:(NSString*)error
 390 {
 391         [delegate errorEncountered:error];
 392 }
 393
 394 /**
 395  * Creates, connects to, and schedules a CFSocket.
 396  */
 397 - (void)connect
 398 {
 399         // Pass ourselves to the callback so we don't have to use ugly globals.
 400         CFSocketContext context;
 401         context.version = 0;
 402         context.info = self;
 403         context.retain = NULL;
 404         context.release = NULL;
 405         context.copyDescription = NULL;
 406
 407         // Create the address structure.
 408         struct sockaddr_in address;
 409         memset(&address, 0, sizeof(address));
 410         address.sin_len = sizeof(address);
 411         address.sin_family = AF_INET;
 412         address.sin_port = htons(port);
 413         address.sin_addr.s_addr = htonl(INADDR_ANY);
 414
 415         // Create the socket signature.
 416         CFSocketSignature signature;
 417         signature.protocolFamily = PF_INET;
 418         signature.socketType = SOCK_STREAM;
 419         signature.protocol = IPPROTO_TCP;
 420         signature.address = (CFDataRef)[NSData dataWithBytes:&address length:sizeof(address)];
 421
 422         socket_ = CFSocketCreateWithSocketSignature(kCFAllocatorDefault,
 423                                                                                                 &signature,  // Socket signature.
 424                                                                                                 kCFSocketAcceptCallBack,  // Callback types.
 425                                                                                                 SocketAcceptCallback,  // Callout function pointer.
 426                                                                                                 &context);  // Context to pass to callout.
 427         if (!socket_)
 428         {
 429                 [self errorEncountered:@"Could not open socket."];
 430                 return;
 431         }
 432
 433         // Allow old, yet-to-be recycled sockets to be reused.
 434         BOOL yes = YES;
 435         setsockopt(CFSocketGetNative(socket_), SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(BOOL));
 436
 437         // Schedule the socket on the run loop.
 438         CFRunLoopSourceRef source = CFSocketCreateRunLoopSource(kCFAllocatorDefault, socket_, 0);
 439         CFRunLoopAddSource(CFRunLoopGetCurrent(), source, kCFRunLoopCommonModes);
 440         CFRelease(source);
 441
 442         self.status = @"Connecting";
 443 }
 444
 445 /**
 446  * Closes a socket and releases the ref.
 447  */
 448 - (void)close
 449 {
 450         // The socket goes down, so do the streams, which clean themselves up.
 451         CFSocketInvalidate(socket_);
 452         CFRelease(socket_);
 453         [stackFrames_ release];
 454         self.queuedWrites = nil;
 455         [writeQueueLock_ release];
 456         [callTable_ release];
 457         [callbackContext_ release];
 458 }
 459
 460 /**
 461  * Notification that the socket disconnected.
 462  */
 463 - (void)socketDisconnected
 464 {
 465         [self close];
 466         [delegate debuggerDisconnected];
 467 }
 468
 469 /**
 470  * Callback from the CFReadStream that there is data waiting to be read.
 471  */
 472 - (void)readStreamHasData
 473 {
 474         UInt8 buffer[1024];
 475         CFIndex bytesRead = CFReadStreamRead(readStream_, buffer, 1024);
 476         const char* charBuffer = (const char*)buffer;
 477
 478         // We haven't finished reading a packet, so just read more data in.
 479         if (currentPacketIndex_ < packetSize_)
 480         {
 481                 currentPacketIndex_ += bytesRead;
 482                 CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 483                                                                                                                    buffer,
 484                                                                                                                    bytesRead,
 485                                                                                                                    kCFStringEncodingUTF8,
 486                                                                                                                    true);
 487                 [self.currentPacket appendString:(NSString*)bufferString];
 488                 CFRelease(bufferString);
 489         }
 490         // Time to read a new packet.
 491         else
 492         {
 493                 // Read the message header: the size.
 494                 packetSize_ = atoi(charBuffer);
 495                 currentPacketIndex_ = bytesRead - strlen(charBuffer);
 496                 CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 497                                                                                                                    buffer + strlen(charBuffer) + 1,
 498                                                                                                                    bytesRead - strlen(charBuffer) - 1,
 499                                                                                                                    kCFStringEncodingUTF8,
 500                                                                                                                    true);
 501                 self.currentPacket = [NSMutableString stringWithString:(NSString*)bufferString];
 502                 CFRelease(bufferString);
 503         }
 504
 505         // We have finished reading the packet.
 506         if (currentPacketIndex_ >= packetSize_)
 507         {
 508                 packetSize_ = 0;
 509                 currentPacketIndex_ = 0;
 510
 511                 // Test if we can convert it into an NSXMLDocument.
 512                 NSError* error = nil;
 513                 NSXMLDocument* xmlTest = [[NSXMLDocument alloc] initWithXMLString:currentPacket_ options:NSXMLDocumentTidyXML error:&error];
 514                 if (error)
 515                 {
 516                         NSLog(@"Could not parse XML? --- %@", error);
 517                         NSLog(@"Error UserInfo: %@", [error userInfo]);
 518                         NSLog(@"This is the XML Document: %@", currentPacket_);
 519
 520                         // We do not want to starve the write queue, so manually parse out the
 521                         // transaction ID.
 522                         NSRange location = [currentPacket_ rangeOfString:@"transaction_id"];
 523                         if (location.location != NSNotFound)
 524                         {
 525                                 NSUInteger start = location.location + location.length;
 526                                 NSUInteger end = start;
 527
 528                                 NSCharacterSet* numericSet = [NSCharacterSet decimalDigitCharacterSet];
 529
 530                                 // Loop over the characters after the attribute name to extract the ID.
 531                                 while (end < [currentPacket_ length])
 532                                 {
 533                                         unichar c = [currentPacket_ characterAtIndex:end];
 534                                         if ([numericSet characterIsMember:c])
 535                                         {
 536                                                 // If this character is numeric, extend the range to substring.
 537                                                 ++end;
 538                                         }
 539                                         else
 540                                         {
 541                                                 if (start == end)
 542                                                 {
 543                                                         // If this character is nonnumeric and we have nothing in the
 544                                                         // range, skip this character.
 545                                                         ++start;
 546                                                         ++end;
 547                                                 }
 548                                                 else
 549                                                 {
 550                                                         // We've moved past the numeric ID so we should stop searching.
 551                                                         break;
 552                                                 }
 553                                         }
 554                                 }
 555
 556                                 // If we were able to extract the transaction ID, update the last read.
 557                                 NSRange substringRange = NSMakeRange(start, end - start);
 558                                 NSString* transaction = [currentPacket_ substringWithRange:substringRange];
 559                                 if ([transaction length])
 560                                 {
 561                                         lastReadTransaction_ = [transaction intValue];
 562                                         return;
 563                                 }
 564                         }
 565
 566                         // Otherwise, assume +1 and hope it works.
 567                         ++lastReadTransaction_;
 568                         return;
 569                 }
 570                 [self handleResponse:[xmlTest autorelease]];
 571         }
 572 }
 573
 574 /**
 575  * Writes a command into the write stream. If the stream is ready for writing,
 576  * we do so immediately. If not, the command is queued and will be written
 577  * when the stream is ready.
 578  */
 579 - (void)send:(NSString*)command
 580 {
 581         if (lastReadTransaction_ >= lastWrittenTransaction_ && CFWriteStreamCanAcceptBytes(writeStream_))
 582                 [self performSend:command];
 583         else
 584                 [queuedWrites_ addObject:command];
 585 }
 586
 587 /**
 588  * This performs a blocking send. This should ONLY be called when we know we
 589  * have write access to the stream. We will busy wait in case we don't do a full
 590  * send.
 591  */
 592 - (void)performSend:(NSString*)command
 593 {
 594         BOOL done = NO;
 595
 596         char* string = (char*)[command UTF8String];
 597         int stringLength = strlen(string);
 598
 599         // Log the command if TransportDebug is enabled.
 600         if ([[[[NSProcessInfo processInfo] environment] objectForKey:@"TransportDebug"] boolValue])
 601                 NSLog(@"--> %@", command);
 602
 603         // Busy wait while writing. BAADD. Should background this operation.
 604         while (!done)
 605         {
 606                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 607                 {
 608                         // Include the NULL byte in the string when we write.
 609                         int bytesWritten = CFWriteStreamWrite(writeStream_, (UInt8*)string, stringLength + 1);
 610                         if (bytesWritten < 0)
 611                         {
 612                                 NSLog(@"write error");
 613                         }
 614                         // Incomplete write.
 615                         else if (bytesWritten < strlen(string))
 616                         {
 617                                 // Adjust the buffer and wait for another chance to write.
 618                                 stringLength -= bytesWritten;
 619                                 memmove(string, string + bytesWritten, stringLength);
 620                         }
 621                         else
 622                         {
 623                                 done = YES;
 624
 625                                 // We need to scan the string to find the transactionID.
 626                                 NSRange occurrence = [command rangeOfString:@"-i "];
 627                                 if (occurrence.location == NSNotFound)
 628                                 {
 629                                         NSLog(@"sent %@ without a transaction ID", command);
 630                                         continue;
 631                                 }
 632                                 NSString* transaction = [command substringFromIndex:occurrence.location + occurrence.length];
 633                                 lastWrittenTransaction_ = [transaction intValue];
 634                                 NSLog(@"command = %@", command);
 635                                 NSLog(@"read=%d, write=%d", lastReadTransaction_, lastWrittenTransaction_);
 636                         }
 637                 }
 638         }
 639 }
 640
 641 - (void)handleResponse:(NSXMLDocument*)response
 642 {
 643         // Check and see if there's an error.
 644         NSArray* error = [[response rootElement] elementsForName:@"error"];
 645         if ([error count] > 0)
 646         {
 647                 NSLog(@"Xdebug error: %@", error);
 648                 [delegate errorEncountered:[[[[error objectAtIndex:0] children] objectAtIndex:0] stringValue]];
 649         }
 650
 651         // If TransportDebug is enabled, log the response.
 652         if ([[[[NSProcessInfo processInfo] environment] objectForKey:@"TransportDebug"] boolValue])
 653                 NSLog(@"<-- %@", response);
 654
 655         // Get the name of the command from the engine's response.
 656         NSInteger transaction = [self transactionIDFromResponse:response];
 657         if (transaction < lastReadTransaction_)
 658                 NSLog(@"out of date transaction %@", response);
 659
 660         if (transaction != lastWrittenTransaction_)
 661                 NSLog(@"txn doesn't match last written %@", response);
 662
 663         lastReadTransaction_ = transaction;
 664         NSLog(@"read=%d, write=%d", lastReadTransaction_, lastWrittenTransaction_);
 665
 666         if ([[[response rootElement] name] isEqualToString:@"init"])
 667         {
 668                 [self initReceived:response];
 669                 return;
 670         }
 671
 672         NSString* callbackStr = [callTable_ objectForKey:[NSNumber numberWithInt:lastReadTransaction_]];
 673         if (callbackStr)
 674         {
 675                 SEL callback = NSSelectorFromString(callbackStr);
 676                 [self performSelector:callback withObject:response];
 677         }
 678
 679         [self sendQueuedWrites];
 680 }
 681
 682 // Specific Response Handlers //////////////////////////////////////////////////
 683 #pragma mark Response Handlers
 684
 685 /**
 686  * Initial packet received. We've started a brand-new connection to the engine.
 687  */
 688 - (void)initReceived:(NSXMLDocument*)response
 689 {
 690         // Register any breakpoints that exist offline.
 691         for (Breakpoint* bp in [[BreakpointManager sharedManager] breakpoints])
 692                 [self addBreakpoint:bp];
 693
 694         // Load the debugger to make it look active.
 695         [delegate debuggerConnected];
 696
 697         // TODO: update the status.
 698 }
 699
 700 /**
 701  * Receiver for status updates. This just freshens up the UI.
 702  */
 703 - (void)updateStatus:(NSXMLDocument*)response
 704 {
 705         self.status = [[[[response rootElement] attributeForName:@"status"] stringValue] capitalizedString];
 706         if (status == nil || [status isEqualToString:@"Stopped"] || [status isEqualToString:@"Stopping"])
 707         {
 708                 connected = NO;
 709                 [self close];
 710                 [delegate debuggerDisconnected];
 711
 712                 self.status = @"Stopped";
 713         }
 714 }
 715
 716 /**
 717  * Step in/out/over and run all take this path. We first get the status of the
 718  * debugger and then request fresh stack information.
 719  */
 720 - (void)debuggerStep:(NSXMLDocument*)response
 721 {
 722         [self sendCommandWithCallback:@selector(updateStatus:) format:@"status"];
 723         NSString* command = [[[response rootElement] attributeForName:@"command"] stringValue];
 724
 725         // If this is the run command, tell the delegate that a bunch of updates
 726         // are coming. Also remove all existing stack routes and request a new stack.
 727         // TODO: figure out if we can not clobber the stack every time.
 728         if (YES || [command isEqualToString:@"run"])
 729         {
 730                 if ([delegate respondsToSelector:@selector(clobberStack)])
 731                         [delegate clobberStack];
 732                 [stackFrames_ removeAllObjects];
 733                 stackFirstTransactionID_ = [[self sendCommandWithCallback:@selector(rebuildStack:) format:@"stack_depth"] intValue];
 734         }
 735 }
 736
 737 /**
 738  * We ask for the stack_depth and now we clobber the stack and start rebuilding
 739  * it.
 740  */
 741 - (void)rebuildStack:(NSXMLDocument*)response
 742 {
 743         NSInteger depth = [[[[response rootElement] attributeForName:@"depth"] stringValue] intValue];
 744
 745         if (stackFirstTransactionID_ == [self transactionIDFromResponse:response])
 746                 stackDepth_ = depth;
 747
 748         // We now need to alloc a bunch of stack frames and get the basic information
 749         // for them.
 750         for (NSInteger i = 0; i < depth; i++)
 751         {
 752                 // Use the transaction ID to create a routing path.
 753                 NSNumber* routingID = [self sendCommandWithCallback:@selector(getStackFrame:) format:@"stack_get -d %d", i];
 754                 [stackFrames_ setObject:[StackFrame alloc] forKey:routingID];
 755         }
 756 }
 757
 758 /**
 759  * The initial rebuild of the stack frame. We now have enough to initialize
 760  * a StackFrame object.
 761  */
 762 - (void)getStackFrame:(NSXMLDocument*)response
 763 {
 764         // Get the routing information.
 765         NSInteger routingID = [self transactionIDFromResponse:response];
 766         if (routingID < stackFirstTransactionID_)
 767                 return;
 768         NSNumber* routingNumber = [NSNumber numberWithInt:routingID];
 769
 770         // Make sure we initialized this frame in our last |-rebuildStack:|.
 771         StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 772         if (!frame)
 773                 return;
 774
 775         NSXMLElement* xmlframe = [[[response rootElement] children] objectAtIndex:0];
 776
 777         // Initialize the stack frame.
 778         [frame initWithIndex:[[[xmlframe attributeForName:@"level"] stringValue] intValue]
 779                         withFilename:[[xmlframe attributeForName:@"filename"] stringValue]
 780                           withSource:nil
 781                                   atLine:[[[xmlframe attributeForName:@"lineno"] stringValue] intValue]
 782                           inFunction:[[xmlframe attributeForName:@"where"] stringValue]
 783                    withVariables:nil];
 784
 785         // Get the source code of the file. Escape % in URL chars.
 786         NSString* escapedFilename = [frame.filename stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 787         NSNumber* transaction = [self sendCommandWithCallback:@selector(setSource:) format:@"source -f %@", escapedFilename];
 788         [callbackContext_ setObject:routingNumber forKey:transaction];
 789
 790         // Get the names of all the contexts.
 791         transaction = [self sendCommandWithCallback:@selector(contextsReceived:) format:@"context_names -d %d", frame.index];
 792         [callbackContext_ setObject:routingNumber forKey:transaction];
 793
 794         if ([delegate respondsToSelector:@selector(newStackFrame:)])
 795                 [delegate newStackFrame:frame];
 796 }
 797
 798 /**
 799  * Callback for setting the source of a file while rebuilding a specific stack
 800  * frame.
 801  */
 802 - (void)setSource:(NSXMLDocument*)response
 803 {
 804         NSNumber* transaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 805         if ([transaction intValue] < stackFirstTransactionID_)
 806                 return;
 807         NSNumber* routingNumber = [callbackContext_ objectForKey:transaction];
 808         if (!routingNumber)
 809                 return;
 810
 811         [callbackContext_ removeObjectForKey:transaction];
 812         StackFrame* frame = [stackFrames_ objectForKey:routingNumber];
 813         if (!frame)
 814                 return;
 815
 816         frame.source = [[response rootElement] value];
 817
 818         if ([delegate respondsToSelector:@selector(sourceUpdated:)])
 819                 [delegate sourceUpdated:frame];
 820 }
 821
 822 /**
 823  * Enumerates all the contexts of a given stack frame. We then in turn get the
 824  * contents of each one of these contexts.
 825  */
 826 - (void)contextsReceived:(NSXMLDocument*)response
 827 {
 828         // Get the stack frame's routing ID and use it again.
 829         NSNumber* receivedTransaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 830         if ([receivedTransaction intValue] < stackFirstTransactionID_)
 831                 return;
 832         NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 833         if (!routingID)
 834                 return;
 835
 836         // Get the stack frame by the |routingID|.
 837         StackFrame* frame = [stackFrames_ objectForKey:routingID];
 838
 839         NSXMLElement* contextNames = [response rootElement];
 840         for (NSXMLElement* context in [contextNames children])
 841         {
 842                 NSInteger cid = [[[context attributeForName:@"id"] stringValue] intValue];
 843
 844                 // Fetch each context's variables.
 845                 NSNumber* transaction = [self sendCommandWithCallback:@selector(variablesReceived:)
 846                                                                                                            format:@"context_get -d %d -c %d", frame.index, cid];
 847                 [callbackContext_ setObject:routingID forKey:transaction];
 848         }
 849 }
 850
 851 /**
 852  * Receives the variables from the context and attaches them to the stack frame.
 853  */
 854 - (void)variablesReceived:(NSXMLDocument*)response
 855 {
 856         // Get the stack frame's routing ID and use it again.
 857         NSInteger transaction = [self transactionIDFromResponse:response];
 858         if (transaction < stackFirstTransactionID_)
 859                 return;
 860         NSNumber* receivedTransaction = [NSNumber numberWithInt:transaction];
 861         NSNumber* routingID = [callbackContext_ objectForKey:receivedTransaction];
 862         if (!routingID)
 863                 return;
 864
 865         // Get the stack frame by the |routingID|.
 866         StackFrame* frame = [stackFrames_ objectForKey:routingID];
 867
 868         NSMutableArray* variables = [NSMutableArray array];
 869
 870         // Merge the frame's existing variables.
 871         if (frame.variables)
 872                 [variables addObjectsFromArray:frame.variables];
 873
 874         // Add these new variables.
 875         NSArray* addVariables = [[response rootElement] children];
 876         if (addVariables)
 877                 [variables addObjectsFromArray:addVariables];
 878
 879         frame.variables = variables;
 880 }
 881
 882 /**
 883  * Callback from a |-getProperty:| request.
 884  */
 885 - (void)propertiesReceived:(NSXMLDocument*)response
 886 {
 887         NSInteger transaction = [self transactionIDFromResponse:response];
 888
 889         /*
 890          <response>
 891                  <property> <!-- this is the one we requested -->
 892                          <property ... /> <!-- these are what we want -->
 893                  </property>
 894          </repsonse>
 895          */
 896
 897         // Detach all the children so we can insert them into another document.
 898         NSXMLElement* parent = (NSXMLElement*)[[response rootElement] childAtIndex:0];
 899         NSArray* children = [parent children];
 900         [parent setChildren:nil];
 901
 902         [delegate receivedProperties:children forTransaction:transaction];
 903 }
 904
 905 /**
 906  * Callback for setting a breakpoint.
 907  */
 908 - (void)breakpointReceived:(NSXMLDocument*)response
 909 {
 910         NSNumber* transaction = [NSNumber numberWithInt:[self transactionIDFromResponse:response]];
 911         Breakpoint* bp = [callbackContext_ objectForKey:transaction];
 912         if (!bp)
 913                 return;
 914
 915         [callbackContext_ removeObjectForKey:callbackContext_];
 916         [bp setDebuggerId:[[[[response rootElement] attributeForName:@"id"] stringValue] intValue]];
 917 }
 918
 919 #pragma mark Private
 920
 921 /**
 922  * This will send a command to the debugger engine. It will append the
 923  * transaction ID automatically. It accepts a NSString command along with a
 924  * a variable number of arguments to substitute into the command, a la
 925  * +[NSString stringWithFormat:]. Returns the transaction ID as a NSNumber.
 926  */
 927 - (NSNumber*)sendCommandWithCallback:(SEL)callback format:(NSString*)format, ...
 928 {
 929         // Collect varargs and format command.
 930         va_list args;
 931         va_start(args, format);
 932         NSString* command = [[NSString alloc] initWithFormat:format arguments:args];
 933         va_end(args);
 934
 935         NSNumber* callbackKey = [NSNumber numberWithInt:transactionID++];
 936         if (callback)
 937                 [callTable_ setObject:NSStringFromSelector(callback) forKey:callbackKey];
 938
 939         [self send:[NSString stringWithFormat:@"%@ -i %@", [command autorelease], callbackKey]];
 940
 941         return callbackKey;
 942 }
 943
 944 /**
 945  * Checks if there are unsent commands in the |queuedWrites_| queue and sends
 946  * them if it's OK to do so. This will not block.
 947  */
 948 - (void)sendQueuedWrites
 949 {
 950         [writeQueueLock_ lock];
 951         if (lastReadTransaction_ >= lastWrittenTransaction_ && [queuedWrites_ count] > 0)
 952         {
 953                 NSString* command = [queuedWrites_ objectAtIndex:0];
 954                 NSLog(@"Sending queued write: %@", command);
 955
 956                 // We don't want to block because this is called from the main thread.
 957                 // |-performSend:| busy waits when the stream is not ready. Bail out
 958                 // before we do that becuase busy waiting is BAD.
 959                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 960                 {
 961                         [self performSend:command];
 962                         [queuedWrites_ removeObjectAtIndex:0];
 963                 }
 964         }
 965         [writeQueueLock_ unlock];
 966 }
 967
 968 /**
 969  * Given a file path, this returns a file:// URI and escapes any spaces for the
 970  * debugger engine.
 971  */
 972 - (NSString*)escapedURIPath:(NSString*)path
 973 {
 974         // Custon GDBp paths are fine.
 975         if ([[path substringToIndex:4] isEqualToString:@"gdbp"])
 976                 return path;
 977
 978         // Create a temporary URL that will escape all the nasty characters.
 979         NSURL* url = [NSURL fileURLWithPath:path];
 980         NSString* urlString = [url absoluteString];
 981
 982         // Remove the host because this is a file:// URL;
 983         urlString = [urlString stringByReplacingOccurrencesOfString:[url host] withString:@""];
 984
 985         // Escape % for use in printf-style NSString formatters.
 986         urlString = [urlString stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 987         return urlString;
 988 }
 989
 990 /**
 991  * Returns the transaction_id from an NSXMLDocument.
 992  */
 993 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response
 994 {
 995         return [[[[response rootElement] attributeForName:@"transaction_id"] stringValue] intValue];
 996 }
 997
 998 @end