BLIP/BLIPWriter.m
author Jens Alfke <jens@mooseyard.com>
Sun Jul 13 10:42:50 2008 -0700 (2008-07-13)
changeset 22 8b883753394a
parent 11 29e8b03c05d4
permissions -rw-r--r--
* Fixed: Responses still pending when a connection closed were not calling their onComplete targets.
* Fixed: BLIPTestClient target failed to build because it didn't link against zlib.
* If TCPListener.bonjourServiceName is changed while the listener is open, it now re-publishes the service with the new name.
* Added a TCPListener.bonjourService property.
* Added a BLIPMessage.representedObject property.
* Fixed a memory leak.
     1 //
     2 //  BLIPFrameWriter.m
     3 //  MYNetwork
     4 //
     5 //  Created by Jens Alfke on 5/18/08.
     6 //  Copyright 2008 Jens Alfke. All rights reserved.
     7 //
     8 
     9 #import "BLIPReader.h"
    10 #import "BLIPWriter.h"
    11 #import "BLIP_Internal.h"
    12 
    13 #import "Logging.h"
    14 #import "Test.h"
    15 
    16 
    17 #define kDefaultFrameSize 4096
    18 
    19 
    20 @implementation BLIPWriter
    21 
    22 
    23 - (void) dealloc
    24 {
    25     [_outBox release];
    26     [super dealloc];
    27 }
    28 
    29 - (void) disconnect
    30 {
    31     [_outBox makeObjectsPerformSelector: @selector(_connectionClosed) withObject: nil];
    32     setObj(&_outBox,nil);
    33     [super disconnect];
    34 }
    35 
    36 @synthesize numRequestsSent=_numRequestsSent;
    37 
    38 
    39 - (BOOL) isBusy
    40 {
    41     return _outBox.count>0 || [super isBusy];
    42 }
    43 
    44 
    45 - (void) _queueMessage: (BLIPMessage*)msg isNew: (BOOL)isNew
    46 {
    47     int n = _outBox.count, index;
    48     if( msg.urgent && n > 1 ) {
    49         // High-priority gets queued after the last existing high-priority message,
    50         // leaving one regular-priority message in between if possible.
    51         for( index=n-1; index>0; index-- ) {
    52             BLIPMessage *otherMsg = [_outBox objectAtIndex: index];
    53             if( [otherMsg urgent] ) {
    54                 index = MIN(index+2, n);
    55                 break;
    56             } else if( isNew && otherMsg._bytesWritten==0 ) {
    57                 // But have to keep message starts in order
    58                 index = index+1;
    59                 break;
    60             }
    61         }
    62         if( index==0 )
    63             index = 1;
    64     } else {
    65         // Regular priority goes at the end of the queue:
    66         index = n;
    67     }
    68     if( ! _outBox )
    69         _outBox = [[NSMutableArray alloc] init];
    70     [_outBox insertObject: msg atIndex: index];
    71     
    72     if( isNew ) {
    73         LogTo(BLIP,@"%@ queuing outgoing %@ at index %i",self,msg,index);
    74         if( n==0 )
    75             [self queueIsEmpty];
    76     }
    77 }
    78 
    79 
    80 - (BOOL) sendMessage: (BLIPMessage*)message
    81 {
    82     Assert(!message.sent,@"message has already been sent");
    83     [self _queueMessage: message isNew: YES];
    84     return YES;
    85 }
    86 
    87 
    88 - (BOOL) sendRequest: (BLIPRequest*)q response: (BLIPResponse*)response
    89 {
    90     if( _shouldClose ) {
    91         Warn(@"%@: Attempt to send a request after the connection has started closing: %@",self,q);
    92         return NO;
    93     }
    94     [q _assignedNumber: ++_numRequestsSent];
    95     if( response ) {
    96         [response _assignedNumber: _numRequestsSent];
    97         [(BLIPReader*)self.reader _addPendingResponse: response];
    98     }
    99     return [self sendMessage: q];
   100 }
   101 
   102 
   103 - (void) queueIsEmpty
   104 {
   105     if( _outBox.count > 0 ) {
   106         // Pop first message in queue:
   107         BLIPMessage *msg = [[_outBox objectAtIndex: 0] retain];
   108         [_outBox removeObjectAtIndex: 0];
   109         
   110         // As an optimization, allow message to send a big frame unless there's a higher-priority
   111         // message right behind it:
   112         size_t frameSize = kDefaultFrameSize;
   113         if( msg.urgent || _outBox.count==0 || ! [[_outBox objectAtIndex: 0] urgent] )
   114             frameSize *= 4;
   115         
   116         if( [msg _writeFrameTo: self maxSize: frameSize] ) {
   117             // add it back so it can send its next frame later:
   118             [self _queueMessage: msg isNew: NO];
   119         }
   120         [msg release];
   121     } else {
   122         LogTo(BLIPVerbose,@"%@: no more work for writer",self);
   123     }
   124 }
   125 
   126 
   127 
   128 @end
   129 
   130 
   131 /*
   132  Copyright (c) 2008, Jens Alfke <jens@mooseyard.com>. All rights reserved.
   133  
   134  Redistribution and use in source and binary forms, with or without modification, are permitted
   135  provided that the following conditions are met:
   136  
   137  * Redistributions of source code must retain the above copyright notice, this list of conditions
   138  and the following disclaimer.
   139  * Redistributions in binary form must reproduce the above copyright notice, this list of conditions
   140  and the following disclaimer in the documentation and/or other materials provided with the
   141  distribution.
   142  
   143  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
   144  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
   145  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRI-
   146  BUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   147  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
   148   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
   149  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 
   150  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   151  */