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   assert(_messageQueue);
  64   [_messageQueue sendMessage:taggedCommand];
  65   return callbackKey;
  66 }
  67
  68 - (NSNumber*)sendCustomCommandWithFormat:(NSString*)format, ... {
  69   // Collect varargs and format command.
  70   va_list args;
  71   va_start(args, format);
  72   NSString* command = [[[NSString alloc] initWithFormat:format arguments:args] autorelease];
  73   va_end(args);
  74
  75   NSNumber* callbackKey = [NSNumber numberWithInt:_nextID++];
  76   NSString* taggedCommand = [command stringByReplacingOccurrencesOfString:@"{txn}"
  77                                                                withString:[callbackKey stringValue]];
  78
  79   [_messageQueue sendMessage:taggedCommand];
  80   return callbackKey;
  81 }
  82
  83 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response {
  84   return [[[[response rootElement] attributeForName:@"transaction_id"] stringValue] intValue];
  85 }
  86
  87 - (NSInteger)transactionIDFromCommand:(NSString*)command {
  88   NSRange occurrence = [command rangeOfString:@"-i "];
  89   if (occurrence.location == NSNotFound)
  90     return NSNotFound;
  91   NSString* transaction = [command substringFromIndex:occurrence.location + occurrence.length];
  92   return [transaction intValue];
  93 }
  94
  95 // MessageQueueDelegate ////////////////////////////////////////////////////////
  96
  97 - (void)messageQueueError:(NSError*)error {
  98   NSLog(@"error = %@", error);
  99 }
 100
 101 - (void)clientDidConnect:(MessageQueue*)queue {
 102   [_lock lock];
 103   _nextID = 0;
 104   _lastReadID = 0;
 105   _lastWrittenID = 0;
 106   [_lock unlock];
 107
 108   [_delegate performSelector:@selector(debuggerEngineConnected:)
 109                     onThread:_delegateThread
 110                   withObject:self
 111                waitUntilDone:NO];
 112 }
 113
 114 - (void)clientDidDisconnect:(MessageQueue*)queue {
 115   [_delegate performSelector:@selector(debuggerEngineDisconnected:)
 116                     onThread:_delegateThread
 117                   withObject:self
 118                waitUntilDone:NO];
 119 }
 120
 121 // If the write stream is ready, the delegate controls whether or not the next
 122 // pending message should be sent via the result of this method.
 123 - (BOOL)shouldSendMessage {
 124   [_lock lock];
 125   BOOL r = _lastReadID >= _lastWrittenID;
 126   [_lock unlock];
 127   return r;
 128 }
 129
 130 // Callback for when a message has been sent.
 131 - (void)didSendMessage:(NSString*)message {
 132   NSInteger tag = [self transactionIDFromCommand:message];
 133   [_lock lock];
 134   _lastWrittenID = tag;
 135   [_lock unlock];
 136 }
 137
 138 // Callback with the message content when one has been receieved.
 139 - (void)didReceiveMessage:(NSString*)message {
 140   // Test if we can convert it into an NSXMLDocument.
 141   NSError* error = nil;
 142   NSXMLDocument* xml = [[NSXMLDocument alloc] initWithXMLString:message
 143                                                         options:NSXMLDocumentTidyXML
 144                                                           error:&error];
 145   if (error) {
 146     [self messageQueueError:error];
 147     return;
 148   }
 149
 150   // Validate the transaction.
 151   NSInteger transaction = [self transactionIDFromResponse:xml];
 152   if (transaction < _lastReadID) {
 153     NSLog(@"Transaction #%d is out of date (lastRead = %d). Dropping packet: %@",
 154           transaction, _lastReadID, message);
 155     return;
 156   }
 157   if (transaction != _lastWrittenID) {
 158     NSLog(@"Transaction #%d received out of order. lastRead = %d, lastWritten = %d. Continuing.",
 159           transaction, _lastReadID, _lastWrittenID);
 160   }
 161
 162   _lastReadID = transaction;
 163
 164   [self performSelector:@selector(postReceivedMessage:)
 165                onThread:_delegateThread
 166              withObject:xml
 167           waitUntilDone:NO
 168                   modes:@[ NSDefaultRunLoopMode ]];
 169 }
 170
 171 // Private /////////////////////////////////////////////////////////////////////
 172
 173 - (void)postReceivedMessage:(NSXMLDocument*)message {
 174   [_delegate debuggerEngine:self receivedMessage:message];
 175 }
 176
 177 @end