Source/NetworkConnection.mm

   1 /*
   2  * MacGDBp
   3  * Copyright (c) 2007 - 2011, 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 "NetworkConnection.h"
  18 #import "NetworkConnectionPrivate.h"
  19
  20 #import "AppDelegate.h"
  21 #import "LoggingController.h"
  22 #include "NetworkCallbackController.h"
  23
  24 // Other Run Loop Callbacks ////////////////////////////////////////////////////
  25
  26 void PerformQuitSignal(void* info)
  27 {
  28   NetworkConnection* obj = (NetworkConnection*)info;
  29   [obj performQuitSignal];
  30 }
  31
  32 ////////////////////////////////////////////////////////////////////////////////
  33
  34 @implementation NetworkConnection
  35
  36 @synthesize port = port_;
  37 @synthesize connected = connected_;
  38 @synthesize delegate = delegate_;
  39
  40 @synthesize readStream = readStream_;
  41 @synthesize lastReadTransaction = lastReadTransaction_;
  42 @synthesize currentPacket = currentPacket_;
  43 @synthesize writeStream = writeStream_;
  44 @synthesize lastWrittenTransaction = lastWrittenTransaction_;
  45 @synthesize queuedWrites = queuedWrites_;
  46
  47 - (id)initWithPort:(NSUInteger)aPort
  48 {
  49   if (self = [super init])
  50   {
  51     port_ = aPort;
  52   }
  53   return self;
  54 }
  55
  56 - (void)dealloc
  57 {
  58   self.currentPacket = nil;
  59   [super dealloc];
  60 }
  61
  62 /**
  63  * Kicks off the socket on another thread.
  64  */
  65 - (void)connect
  66 {
  67   if (thread_ && !connected_) {
  68     // A thread has been detached but the socket has yet to connect. Do not
  69     // spawn a new thread otherwise multiple threads will be blocked on the same
  70     // socket.
  71     return;
  72   }
  73   [NSThread detachNewThreadSelector:@selector(runNetworkThread) toTarget:self withObject:nil];
  74 }
  75
  76 /**
  77  * Creates, connects to, and schedules a CFSocket.
  78  */
  79 - (void)runNetworkThread
  80 {
  81   NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  82
  83   thread_ = [NSThread currentThread];
  84   runLoop_ = [NSRunLoop currentRunLoop];
  85   callbackController_ = new NetworkCallbackController(self);
  86
  87   // Create a source that is used to quit.
  88   CFRunLoopSourceContext quitContext = { 0 };
  89   quitContext.info = self;
  90   quitContext.perform = PerformQuitSignal;
  91   quitSource_ = CFRunLoopSourceCreate(kCFAllocatorDefault, 0, &quitContext);
  92   CFRunLoopAddSource([runLoop_ getCFRunLoop], quitSource_, kCFRunLoopCommonModes);
  93
  94   callbackController_->OpenConnection(port_);
  95
  96   CFRunLoopRun();
  97
  98   thread_ = nil;
  99   runLoop_ = nil;
 100   delete callbackController_;
 101   callbackController_ = NULL;
 102
 103   CFRunLoopSourceInvalidate(quitSource_);
 104   CFRelease(quitSource_);
 105   quitSource_ = NULL;
 106
 107   [pool release];
 108 }
 109
 110 /**
 111  * Called by SocketWrapper after the connection is successful. This immediately calls
 112  * -[SocketWrapper receive] to clear the way for communication, though the information
 113  * could be useful server information that we don't use right now.
 114  */
 115 - (void)socketDidAccept
 116 {
 117   connected_ = YES;
 118   transactionID = 1;
 119   lastReadTransaction_ = 0;
 120   lastWrittenTransaction_ = 0;
 121   self.queuedWrites = [NSMutableArray array];
 122   writeQueueLock_ = [NSRecursiveLock new];
 123   if ([delegate_ respondsToSelector:@selector(connectionDidAccept:)])
 124     [delegate_ performSelectorOnMainThread:@selector(connectionDidAccept:)
 125                                 withObject:self
 126                              waitUntilDone:NO];
 127 }
 128
 129 /**
 130  * Closes a socket and releases the ref.
 131  */
 132 - (void)close
 133 {
 134   if (thread_) {
 135     [thread_ cancel];
 136   }
 137   if (runLoop_ && quitSource_) {
 138     CFRunLoopSourceSignal(quitSource_);
 139     CFRunLoopWakeUp([runLoop_ getCFRunLoop]);
 140   }
 141 }
 142
 143 /**
 144  * Quits the run loop and stops the thread.
 145  */
 146 - (void)performQuitSignal
 147 {
 148   self.queuedWrites = nil;
 149   connected_ = NO;
 150   [writeQueueLock_ release];
 151
 152   if (runLoop_) {
 153     CFRunLoopStop([runLoop_ getCFRunLoop]);
 154   }
 155
 156   callbackController_->CloseConnection();
 157 }
 158
 159 /**
 160  * Notification that the socket disconnected.
 161  */
 162 - (void)socketDisconnected
 163 {
 164   if ([delegate_ respondsToSelector:@selector(connectionDidClose:)])
 165     [delegate_ connectionDidClose:self];
 166 }
 167
 168 /**
 169  * Writes a command into the write stream. If the stream is ready for writing,
 170  * we do so immediately. If not, the command is queued and will be written
 171  * when the stream is ready.
 172  */
 173 - (void)send:(NSString*)command
 174 {
 175   if (lastReadTransaction_ >= lastWrittenTransaction_ && CFWriteStreamCanAcceptBytes(writeStream_)) {
 176     [self performSend:command];
 177   } else {
 178     [writeQueueLock_ lock];
 179     [queuedWrites_ addObject:command];
 180     [writeQueueLock_ unlock];
 181   }
 182   [self sendQueuedWrites];
 183 }
 184
 185 /**
 186  * This will send a command to the debugger engine. It will append the
 187  * transaction ID automatically. It accepts a NSString command along with a
 188  * a variable number of arguments to substitute into the command, a la
 189  * +[NSString stringWithFormat:]. Returns the transaction ID as a NSNumber.
 190  */
 191 - (NSNumber*)sendCommandWithFormat:(NSString*)format, ...
 192 {
 193   // Collect varargs and format command.
 194   va_list args;
 195   va_start(args, format);
 196   NSString* command = [[NSString alloc] initWithFormat:format arguments:args];
 197   va_end(args);
 198
 199   NSNumber* callbackKey = [NSNumber numberWithInt:transactionID++];
 200   NSString* taggedCommand = [NSString stringWithFormat:@"%@ -i %@", [command autorelease], callbackKey];
 201   [self performSelector:@selector(send:)
 202                onThread:thread_
 203              withObject:taggedCommand
 204           waitUntilDone:connected_];
 205
 206   return callbackKey;
 207 }
 208
 209 /**
 210  * Given a file path, this returns a file:// URI and escapes any spaces for the
 211  * debugger engine.
 212  */
 213 - (NSString*)escapedURIPath:(NSString*)path
 214 {
 215   // Custon GDBp paths are fine.
 216   if ([[path substringToIndex:4] isEqualToString:@"gdbp"])
 217     return path;
 218
 219   // Create a temporary URL that will escape all the nasty characters.
 220   NSURL* url = [NSURL fileURLWithPath:path];
 221   NSString* urlString = [url absoluteString];
 222
 223   // Remove the host because this is a file:// URL;
 224   urlString = [urlString stringByReplacingOccurrencesOfString:[url host] withString:@""];
 225
 226   // Escape % for use in printf-style NSString formatters.
 227   urlString = [urlString stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 228   return urlString;
 229 }
 230
 231 /**
 232  * Returns the transaction_id from an NSXMLDocument.
 233  */
 234 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response
 235 {
 236   return [[[[response rootElement] attributeForName:@"transaction_id"] stringValue] intValue];
 237 }
 238
 239 /**
 240  * Scans a command string for the transaction ID component. If it is not found,
 241  * returns NSNotFound.
 242  */
 243 - (NSInteger)transactionIDFromCommand:(NSString*)command
 244 {
 245   NSRange occurrence = [command rangeOfString:@"-i "];
 246   if (occurrence.location == NSNotFound)
 247     return NSNotFound;
 248   NSString* transaction = [command substringFromIndex:occurrence.location + occurrence.length];
 249   return [transaction intValue];
 250 }
 251
 252 // Private /////////////////////////////////////////////////////////////////////
 253 #pragma mark Private
 254
 255 // Delegate Thread-Safe Wrappers ///////////////////////////////////////////////
 256
 257 /**
 258  * Receives errors from the SocketWrapper and updates the display
 259  */
 260 - (void)errorEncountered:(NSString*)error
 261 {
 262   if (![delegate_ respondsToSelector:@selector(errorEncountered:)])
 263     return;
 264   [delegate_ performSelectorOnMainThread:@selector(errorEncountered:)
 265                               withObject:error
 266                            waitUntilDone:NO];
 267 }
 268
 269 - (LogEntry*)recordSend:(NSString*)command
 270 {
 271   LoggingController* logger = [[AppDelegate instance] loggingController];
 272   LogEntry* entry = [LogEntry newSendEntry:command];
 273   entry.lastReadTransactionID = lastReadTransaction_;
 274   entry.lastWrittenTransactionID = lastWrittenTransaction_;
 275   [logger performSelectorOnMainThread:@selector(recordEntry:)
 276                            withObject:entry
 277                         waitUntilDone:NO];
 278   return [entry autorelease];
 279 }
 280
 281 - (LogEntry*)recordReceive:(NSString*)command
 282 {
 283   LoggingController* logger = [[AppDelegate instance] loggingController];
 284   LogEntry* entry = [LogEntry newReceiveEntry:command];
 285   entry.lastReadTransactionID = lastReadTransaction_;
 286   entry.lastWrittenTransactionID = lastWrittenTransaction_;
 287   [logger performSelectorOnMainThread:@selector(recordEntry:)
 288                            withObject:entry
 289                         waitUntilDone:NO];
 290   return [entry autorelease];
 291 }
 292
 293 // Stream Managers /////////////////////////////////////////////////////////////
 294
 295 /**
 296  * Callback from the CFReadStream that there is data waiting to be read.
 297  */
 298 - (void)readStreamHasData
 299 {
 300   const NSUInteger kBufferSize = 1024;
 301   UInt8 buffer[kBufferSize];
 302   CFIndex bufferOffset = 0;  // Starting point in |buffer| to work with.
 303   CFIndex bytesRead = CFReadStreamRead(readStream_, buffer, kBufferSize);
 304   const char* charBuffer = (const char*)buffer;
 305
 306   // The read loop works by going through the buffer until all the bytes have
 307   // been processed.
 308   while (bufferOffset < bytesRead)
 309   {
 310     // Find the NULL separator, or the end of the string.
 311     NSUInteger partLength = 0;
 312     for (NSUInteger i = bufferOffset; i < bytesRead && charBuffer[i] != '\0'; ++i, ++partLength) ;
 313
 314     // If there is not a current packet, set some state.
 315     if (!self.currentPacket)
 316     {
 317       // Read the message header: the size.  This will be |partLength| bytes.
 318       packetSize_ = atoi(charBuffer + bufferOffset);
 319       currentPacketIndex_ = 0;
 320       self.currentPacket = [NSMutableString stringWithCapacity:packetSize_];
 321       bufferOffset += partLength + 1;  // Pass over the NULL byte.
 322       continue;  // Spin the loop to begin reading actual data.
 323     }
 324
 325     // Substring the byte stream and append it to the packet string.
 326     CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 327                                                        buffer + bufferOffset,  // Byte pointer, offset by start index.
 328                                                        partLength,  // Length.
 329                                                        kCFStringEncodingUTF8,
 330                                                        true);
 331     [self.currentPacket appendString:(NSString*)bufferString];
 332     CFRelease(bufferString);
 333
 334     // Advance counters.
 335     currentPacketIndex_ += partLength;
 336     bufferOffset += partLength + 1;
 337
 338     // If this read finished the packet, handle it and reset.
 339     if (currentPacketIndex_ >= packetSize_)
 340     {
 341       [self handlePacket:[[currentPacket_ retain] autorelease]];
 342       self.currentPacket = nil;
 343       packetSize_ = 0;
 344       currentPacketIndex_ = 0;
 345     }
 346   }
 347 }
 348
 349 /**
 350  * Performs the packet handling of a raw string XML packet. From this point on,
 351  * the packets are associated with a transaction and are then dispatched.
 352  */
 353 - (void)handlePacket:(NSString*)packet
 354 {
 355   // Test if we can convert it into an NSXMLDocument.
 356   NSError* error = nil;
 357   NSXMLDocument* xmlTest = [[NSXMLDocument alloc] initWithXMLString:currentPacket_ options:NSXMLDocumentTidyXML error:&error];
 358
 359   // Try to recover if we encountered an error.
 360   if (!xmlTest)
 361   {
 362     // We do not want to starve the write queue, so manually parse out the
 363     // transaction ID.
 364     NSRange location = [currentPacket_ rangeOfString:@"transaction_id"];
 365     if (location.location != NSNotFound)
 366     {
 367       NSUInteger start = location.location + location.length;
 368       NSUInteger end = start;
 369
 370       NSCharacterSet* numericSet = [NSCharacterSet decimalDigitCharacterSet];
 371
 372       // Loop over the characters after the attribute name to extract the ID.
 373       while (end < [currentPacket_ length])
 374       {
 375         unichar c = [currentPacket_ characterAtIndex:end];
 376         if ([numericSet characterIsMember:c])
 377         {
 378           // If this character is numeric, extend the range to substring.
 379           ++end;
 380         }
 381         else
 382         {
 383           if (start == end)
 384           {
 385             // If this character is nonnumeric and we have nothing in the
 386             // range, skip this character.
 387             ++start;
 388             ++end;
 389           }
 390           else
 391           {
 392             // We've moved past the numeric ID so we should stop searching.
 393             break;
 394           }
 395         }
 396       }
 397
 398       // If we were able to extract the transaction ID, update the last read.
 399       NSRange substringRange = NSMakeRange(start, end - start);
 400       NSString* transactionStr = [currentPacket_ substringWithRange:substringRange];
 401       if ([transactionStr length])
 402         lastReadTransaction_ = [transactionStr intValue];
 403     }
 404
 405     // Otherwise, assume +1 and hope it works.
 406     ++lastReadTransaction_;
 407   } else /*if (!reconnect_)*/ {
 408     // See if the transaction can be parsed out.
 409     NSInteger transaction = [self transactionIDFromResponse:xmlTest];
 410     if (transaction < lastReadTransaction_) {
 411       NSLog(@"tx = %d vs %d", transaction, lastReadTransaction_);
 412       NSLog(@"out of date transaction %@", packet);
 413       return;
 414     }
 415
 416     if (transaction != lastWrittenTransaction_)
 417       NSLog(@"txn %d <> %d last written, %d last read", transaction, lastWrittenTransaction_, lastReadTransaction_);
 418
 419     lastReadTransaction_ = transaction;
 420   }
 421
 422   // Log this receive event.
 423   LogEntry* log = [self recordReceive:currentPacket_];
 424   log.error = error;
 425
 426   // Finally, dispatch the handler for this response.
 427   [self handleResponse:[xmlTest autorelease]];
 428 }
 429
 430 - (void)handleResponse:(NSXMLDocument*)response
 431 {
 432   // Check and see if there's an error.
 433   NSArray* error = [[response rootElement] elementsForName:@"error"];
 434   if ([error count] > 0)
 435   {
 436     NSLog(@"Xdebug error: %@", error);
 437     NSString* errorMessage = [[[[error objectAtIndex:0] children] objectAtIndex:0] stringValue];
 438     [self errorEncountered:errorMessage];
 439   }
 440
 441   if ([[[response rootElement] name] isEqualToString:@"init"]) {
 442     connected_ = YES;
 443     [delegate_ performSelectorOnMainThread:@selector(handleInitialResponse:)
 444                                 withObject:response
 445                              waitUntilDone:NO];
 446     return;
 447   }
 448
 449   if ([delegate_ respondsToSelector:@selector(handleResponse:)])
 450     [delegate_ performSelectorOnMainThread:@selector(handleResponse:)
 451                                 withObject:response
 452                              waitUntilDone:NO];
 453
 454   [self sendQueuedWrites];
 455 }
 456
 457 /**
 458  * This performs a blocking send. This should ONLY be called when we know we
 459  * have write access to the stream. We will busy wait in case we don't do a full
 460  * send.
 461  */
 462 - (void)performSend:(NSString*)command
 463 {
 464   // If this is an out-of-date transaction, do not bother sending it.
 465   NSInteger transaction = [self transactionIDFromCommand:command];
 466   if (transaction != NSNotFound && transaction < lastWrittenTransaction_)
 467     return;
 468
 469   BOOL done = NO;
 470
 471   char* string = (char*)[command UTF8String];
 472   size_t stringLength = strlen(string);
 473
 474   // Busy wait while writing. BAADD. Should background this operation.
 475   while (!done)
 476   {
 477     if (CFWriteStreamCanAcceptBytes(writeStream_))
 478     {
 479       // Include the NULL byte in the string when we write.
 480       CFIndex bytesWritten = CFWriteStreamWrite(writeStream_, (UInt8*)string, stringLength + 1);
 481       if (bytesWritten < 0)
 482       {
 483         NSLog(@"write error");
 484       }
 485       // Incomplete write.
 486       else if (bytesWritten < strlen(string))
 487       {
 488         // Adjust the buffer and wait for another chance to write.
 489         stringLength -= bytesWritten;
 490         memmove(string, string + bytesWritten, stringLength);
 491       }
 492       else
 493       {
 494         done = YES;
 495
 496         // We need to scan the string to find the transactionID.
 497         if (transaction == NSNotFound)
 498         {
 499           NSLog(@"sent %@ without a transaction ID", command);
 500           continue;
 501         }
 502         lastWrittenTransaction_ = transaction;
 503       }
 504     }
 505   }
 506
 507   // Log this trancation.
 508   [self recordSend:command];
 509 }
 510
 511 /**
 512  * Checks if there are unsent commands in the |queuedWrites_| queue and sends
 513  * them if it's OK to do so. This will not block.
 514  */
 515 - (void)sendQueuedWrites
 516 {
 517   if (!connected_)
 518     return;
 519
 520   [writeQueueLock_ lock];
 521   if (lastReadTransaction_ >= lastWrittenTransaction_ && [queuedWrites_ count] > 0)
 522   {
 523     NSString* command = [queuedWrites_ objectAtIndex:0];
 524
 525     // We don't want to block because this is called from the main thread.
 526     // |-performSend:| busy waits when the stream is not ready. Bail out
 527     // before we do that becuase busy waiting is BAD.
 528     if (CFWriteStreamCanAcceptBytes(writeStream_))
 529     {
 530       [self performSend:command];
 531       [queuedWrites_ removeObjectAtIndex:0];
 532     }
 533   }
 534   [writeQueueLock_ unlock];
 535 }
 536
 537 @end