Source/MessageQueue.h

   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 <Foundation/Foundation.h>
  18
  19 @protocol MessageQueueDelegate;
  20
  21 // MessageQueue operates a listening socket, that is connected to another
  22 // program with which it exchanges UTF8 string messages. A message contains two
  23 // parts, both terminated by '\0'. The first is an ASCII integer number that is
  24 // the length of the second part. The second part is the actual string message.
  25 @interface MessageQueue : NSObject {
  26  @private
  27   // The port number on which to open a listening socket.
  28   NSUInteger _port;
  29
  30   // The thread and its run loop on which this class primarily operates.
  31   NSThread* _thread;
  32   NSRunLoop* _runLoop;
  33
  34   // Whether or not the message queue is connected to a client.
  35   BOOL _connected;
  36
  37   // A queue of messages that are waiting to be sent.
  38   NSMutableArray* _queue;
  39
  40   // The delegate for this class.
  41   id<MessageQueueDelegate> _delegate;
  42
  43   // The socket that listens for new incoming connections.
  44   CFSocketRef _socket;
  45
  46   // The child socket that has been accepted from |_socket|.
  47   CFSocketNativeHandle _child;
  48
  49   // The read and write streams that are created on the |_child| socket.
  50   CFReadStreamRef _readStream;
  51   CFWriteStreamRef _writeStream;
  52
  53   // When a message is being read, this temporary buffer is used to build up
  54   // the complete message from successive reads.
  55   NSMutableString* _message;
  56   NSUInteger _totalMessageSize;
  57   NSUInteger _messageSize;
  58 }
  59
  60 // Creates a new MessasgeQueue that will listen on |port| and report information
  61 // to its |delegate|.
  62 - (id)initWithPort:(NSUInteger)port delegate:(id<MessageQueueDelegate>)delegate;
  63
  64 // Whether or not the message queue has attached itself to a child.
  65 - (BOOL)isConnected;
  66
  67 // Opens a socket that will listen for connections.
  68 - (void)connect;
  69
  70 // Closes either the listening or child socket and completely disconnects.
  71 - (void)disconnect;
  72
  73 // Enqueues a |message| to be sent to the client. This may be called from any
  74 // thread.
  75 - (void)sendMessage:(NSString*)message;
  76
  77 @end
  78
  79 // Delegate ////////////////////////////////////////////////////////////////////
  80
  81 // The delegate for the message queue. These methods may be called on any thread.
  82 @protocol MessageQueueDelegate <NSObject>
  83 // Callback for any errors that the MessageQueue encounters.
  84 - (void)messageQueueError:(NSError*)error;
  85
  86 // Called when the listening socket has accepted a child socket.
  87 - (void)clientDidConnect:(MessageQueue*)queue;
  88
  89 // Called when the child socket has been disconnected.
  90 - (void)clientDidDisconnect:(MessageQueue*)queue;
  91
  92 // If the write stream is ready, the delegate controls whether or not the next
  93 // pending message should be sent via the result of this method.
  94 - (BOOL)shouldSendMessage;
  95
  96 // Callback for when a message has been sent.
  97 - (void)didSendMessage:(NSString*)message;
  98
  99 // Callback with the message content when one has been receieved.
 100 - (void)didReceiveMessage:(NSString*)message;
 101 @end