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 @interface ProtocolClient (Private)
  20 - (void)postReceivedMessage:(NSXMLDocument*)message;
  21 @end
  22
  23 @implementation ProtocolClient
  24
  25 - (id)initWithDelegate:(NSObject<ProtocolClientDelegate>*)delegate {
  26   if ((self = [super init])) {
  27     _delegate = delegate;
  28     _delegateThread = [NSThread currentThread];
  29     _lock = [[NSRecursiveLock alloc] init];
  30   }
  31   return self;
  32 }
  33
  34 - (void)dealloc {
  35   [_lock release];
  36   [super dealloc];
  37 }
  38
  39 - (BOOL)isConnected {
  40   return [_messageQueue isConnected];
  41 }
  42
  43 - (void)connectOnPort:(NSUInteger)port {
  44   assert(!_messageQueue);
  45   _messageQueue = [[MessageQueue alloc] initWithPort:port delegate:self];
  46   [_messageQueue connect];
  47 }
  48
  49 - (void)disconnect {
  50   [_messageQueue disconnect];
  51 }
  52
  53 - (NSNumber*)sendCommandWithFormat:(NSString*)format, ... {
  54   // Collect varargs and format command.
  55   va_list args;
  56   va_start(args, format);
  57   NSString* command = [[NSString alloc] initWithFormat:format arguments:args];
  58   va_end(args);
  59
  60   NSNumber* callbackKey = [NSNumber numberWithInt:_nextID++];
  61   NSString* taggedCommand = [NSString stringWithFormat:@"%@ -i %@", [command autorelease], callbackKey];
  62
  63   [_messageQueue sendMessage:taggedCommand];
  64   return callbackKey;
  65 }
  66
  67 - (NSNumber*)sendCustomCommandWithFormat:(NSString*)format, ... {
  68   // Collect varargs and format command.
  69   va_list args;
  70   va_start(args, format);
  71   NSString* command = [[[NSString alloc] initWithFormat:format arguments:args] autorelease];
  72   va_end(args);
  73
  74   NSNumber* callbackKey = [NSNumber numberWithInt:_nextID++];
  75   NSString* taggedCommand = [command stringByReplacingOccurrencesOfString:@"{txn}"
  76                                                                withString:[callbackKey stringValue]];
  77
  78   [_messageQueue sendMessage:taggedCommand];
  79   return callbackKey;
  80 }
  81
  82 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response {
  83   return [[[[response rootElement] attributeForName:@"transaction_id"] stringValue] intValue];
  84 }
  85
  86 - (NSInteger)transactionIDFromCommand:(NSString*)command {
  87   NSRange occurrence = [command rangeOfString:@"-i "];
  88   if (occurrence.location == NSNotFound)
  89     return NSNotFound;
  90   NSString* transaction = [command substringFromIndex:occurrence.location + occurrence.length];
  91   return [transaction intValue];
  92 }
  93
  94 // MessageQueueDelegate ////////////////////////////////////////////////////////
  95
  96 - (void)messageQueueError:(NSError*)error {
  97   NSLog(@"error = %@", error);
  98 }
  99
 100 - (void)clientDidConnect:(MessageQueue*)queue {
 101   [_lock lock];
 102   _nextID = 0;
 103   _lastReadID = 0;
 104   _lastWrittenID = 0;
 105   [_lock unlock];
 106
 107   [_delegate performSelector:@selector(debuggerEngineConnected:)
 108                     onThread:_delegateThread
 109                   withObject:self
 110                waitUntilDone:NO];
 111 }
 112
 113 - (void)clientDidDisconnect:(MessageQueue*)queue {
 114   [_delegate performSelector:@selector(debuggerEngineDisconnected:)
 115                     onThread:_delegateThread
 116                   withObject:self
 117                waitUntilDone:NO];
 118 }
 119
 120 // If the write stream is ready, the delegate controls whether or not the next
 121 // pending message should be sent via the result of this method.
 122 - (BOOL)shouldSendMessage {
 123   [_lock lock];
 124   BOOL r = _lastReadID >= _lastWrittenID;
 125   [_lock unlock];
 126   return r;
 127 }
 128
 129 // Callback for when a message has been sent.
 130 - (void)didSendMessage:(NSString*)message {
 131   NSInteger tag = [self transactionIDFromCommand:message];
 132   [_lock lock];
 133   _lastWrittenID = tag;
 134   [_lock unlock];
 135 }
 136
 137 // Callback with the message content when one has been receieved.
 138 - (void)didReceiveMessage:(NSString*)message {
 139   // Test if we can convert it into an NSXMLDocument.
 140   NSError* error = nil;
 141   NSXMLDocument* xml = [[NSXMLDocument alloc] initWithXMLString:message
 142                                                         options:NSXMLDocumentTidyXML
 143                                                           error:&error];
 144   if (error) {
 145     [self messageQueueError:error];
 146     return;
 147   }
 148
 149   // Validate the transaction.
 150   NSInteger transaction = [self transactionIDFromResponse:xml];
 151   if (transaction < _lastReadID) {
 152     NSLog(@"Transaction #%d is out of date (lastRead = %d). Dropping packet: %@",
 153           transaction, _lastReadID, message);
 154     return;
 155   }
 156   if (transaction != _lastWrittenID) {
 157     NSLog(@"Transaction #%d received out of order. lastRead = %d, lastWritten = %d. Continuing.",
 158           transaction, _lastReadID, _lastWrittenID);
 159   }
 160
 161   _lastReadID = transaction;
 162
 163   [self performSelector:@selector(postReceivedMessage:)
 164                onThread:_delegateThread
 165              withObject:xml
 166           waitUntilDone:NO];
 167 }
 168
 169 // Private /////////////////////////////////////////////////////////////////////
 170
 171 - (void)postReceivedMessage:(NSXMLDocument*)message {
 172   [_delegate debuggerEngine:self receivedMessage:message];
 173 }
 174
 175 @end