Source/ProtocolClient.m

   1 /*
   2  * MacGDBp
   3  * Copyright (c) 2013, 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 "ProtocolClient.h"
  18
  19 @implementation ProtocolClient
  20
  21 - (id)initWithDelegate:(NSObject<ProtocolClientDelegate>*)delegate {
  22   if ((self = [super init])) {
  23     _delegate = delegate;
  24     _delegateThread = [NSThread currentThread];
  25     _lock = [[NSRecursiveLock alloc] init];
  26   }
  27   return self;
  28 }
  29
  30 - (void)dealloc {
  31   [_lock release];
  32   [super dealloc];
  33 }
  34
  35 - (BOOL)isConnected {
  36   return [_messageQueue isConnected];
  37 }
  38
  39 - (void)connectOnPort:(NSUInteger)port {
  40   assert(!_messageQueue);
  41   _messageQueue = [[MessageQueue alloc] initWithPort:port delegate:self];
  42   [_messageQueue connect];
  43 }
  44
  45 - (void)disconnect {
  46   [_messageQueue disconnect];
  47 }
  48
  49 - (NSNumber*)sendCommandWithFormat:(NSString*)format, ... {
  50   // Collect varargs and format command.
  51   va_list args;
  52   va_start(args, format);
  53   NSString* command = [[NSString alloc] initWithFormat:format arguments:args];
  54   va_end(args);
  55
  56   NSNumber* callbackKey = [NSNumber numberWithInt:_nextID++];
  57   NSString* taggedCommand = [NSString stringWithFormat:@"%@ -i %@", [command autorelease], callbackKey];
  58
  59   assert(_messageQueue);
  60   [_messageQueue sendMessage:taggedCommand];
  61   return callbackKey;
  62 }
  63
  64 - (NSNumber*)sendCustomCommandWithFormat:(NSString*)format, ... {
  65   // Collect varargs and format command.
  66   va_list args;
  67   va_start(args, format);
  68   NSString* command = [[[NSString alloc] initWithFormat:format arguments:args] autorelease];
  69   va_end(args);
  70
  71   NSNumber* callbackKey = [NSNumber numberWithInt:_nextID++];
  72   NSString* taggedCommand = [command stringByReplacingOccurrencesOfString:@"{txn}"
  73                                                                withString:[callbackKey stringValue]];
  74
  75   [_messageQueue sendMessage:taggedCommand];
  76   return callbackKey;
  77 }
  78
  79 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response {
  80   return [[[[response rootElement] attributeForName:@"transaction_id"] stringValue] intValue];
  81 }
  82
  83 - (NSInteger)transactionIDFromCommand:(NSString*)command {
  84   NSRange occurrence = [command rangeOfString:@"-i "];
  85   if (occurrence.location == NSNotFound)
  86     return NSNotFound;
  87   NSString* transaction = [command substringFromIndex:occurrence.location + occurrence.length];
  88   return [transaction intValue];
  89 }
  90
  91 // MessageQueueDelegate ////////////////////////////////////////////////////////
  92
  93 - (void)messageQueue:(MessageQueue*)queue error:(NSError*)error {
  94   NSLog(@"error = %@", error);
  95 }
  96
  97 - (void)messageQueueDidConnect:(MessageQueue*)queue {
  98   [_lock lock];
  99   _nextID = 0;
 100   _lastReadID = 0;
 101   _lastWrittenID = 0;
 102   [_lock unlock];
 103
 104   [_delegate debuggerEngineConnected:self];
 105 }
 106
 107 - (void)messageQueueDidDisconnect:(MessageQueue*)queue {
 108   [_messageQueue release];
 109   _messageQueue = nil;
 110   [_delegate debuggerEngineDisconnected:self];
 111 }
 112
 113 // If the write stream is ready, the delegate controls whether or not the next
 114 // pending message should be sent via the result of this method.
 115 - (BOOL)shouldSendMessage {
 116   [_lock lock];
 117   BOOL r = _lastReadID >= _lastWrittenID;
 118   [_lock unlock];
 119   return r;
 120 }
 121
 122 // Callback for when a message has been sent.
 123 - (void)messageQueue:(MessageQueue*)queue didSendMessage:(NSString*)message {
 124   NSInteger tag = [self transactionIDFromCommand:message];
 125   [_lock lock];
 126   _lastWrittenID = tag;
 127   [_lock unlock];
 128 }
 129
 130 // Callback with the message content when one has been receieved.
 131 - (void)messageQueue:(MessageQueue*)queue didReceiveMessage:(NSString*)message {
 132   // Test if we can convert it into an NSXMLDocument.
 133   NSError* error = nil;
 134   NSXMLDocument* xml = [[NSXMLDocument alloc] initWithXMLString:message
 135                                                         options:NSXMLDocumentTidyXML
 136                                                           error:&error];
 137   if (error) {
 138     [self messageQueue:queue error:error];
 139     return;
 140   }
 141
 142   // Validate the transaction.
 143   NSInteger transaction = [self transactionIDFromResponse:xml];
 144   if (transaction < _lastReadID) {
 145     NSLog(@"Transaction #%d is out of date (lastRead = %d). Dropping packet: %@",
 146           transaction, _lastReadID, message);
 147     return;
 148   }
 149   if (transaction != _lastWrittenID) {
 150     NSLog(@"Transaction #%d received out of order. lastRead = %d, lastWritten = %d. Continuing.",
 151           transaction, _lastReadID, _lastWrittenID);
 152   }
 153
 154   _lastReadID = transaction;
 155
 156   [_delegate debuggerEngine:self receivedMessage:xml];
 157 }
 158
 159 @end