jens@0: //
jens@0: //  BLIPFrameWriter.m
jens@0: //  MYNetwork
jens@0: //
jens@0: //  Created by Jens Alfke on 5/18/08.
jens@0: //  Copyright 2008 Jens Alfke. All rights reserved.
jens@0: //
jens@0: 
jens@0: #import "BLIPReader.h"
jens@0: #import "BLIPWriter.h"
jens@0: #import "BLIP_Internal.h"
jens@0: 
jens@0: 
jens@0: #define kDefaultFrameSize 4096
jens@0: 
jens@0: 
jens@0: @implementation BLIPWriter
jens@0: 
jens@0: 
jens@0: - (void) dealloc
jens@0: {
jens@0:     [_outBox release];
jens@0:     [super dealloc];
jens@0: }
jens@0: 
jens@0: - (void) disconnect
jens@0: {
jens@0:     [_outBox makeObjectsPerformSelector: @selector(_connectionClosed) withObject: nil];
jens@0:     setObj(&_outBox,nil);
jens@0:     [super disconnect];
jens@0: }
jens@0: 
jens@0: @synthesize numQueriesSent=_numQueriesSent;
jens@0: 
jens@0: 
jens@0: - (BOOL) isBusy
jens@0: {
jens@0:     return _outBox.count>0 || [super isBusy];
jens@0: }
jens@0: 
jens@0: 
jens@0: - (void) _queueMessage: (BLIPMessage*)msg isNew: (BOOL)isNew
jens@0: {
jens@0:     int n = _outBox.count, index;
jens@0:     if( msg.urgent && n > 1 ) {
jens@0:         // High-priority gets queued after the last existing high-priority message,
jens@0:         // leaving one regular-priority message in between if possible.
jens@0:         for( index=n-1; index>0; index-- ) {
jens@0:             BLIPMessage *otherMsg = [_outBox objectAtIndex: index];
jens@0:             if( [otherMsg urgent] ) {
jens@0:                 index = MIN(index+2, n);
jens@0:                 break;
jens@0:             } else if( isNew && otherMsg._bytesWritten==0 ) {
jens@0:                 // But have to keep message starts in order
jens@0:                 index = index+1;
jens@0:                 break;
jens@0:             }
jens@0:         }
jens@0:         if( index==0 )
jens@0:             index = 1;
jens@0:     } else {
jens@0:         // Regular priority goes at the end of the queue:
jens@0:         index = n;
jens@0:     }
jens@0:     if( ! _outBox )
jens@0:         _outBox = [[NSMutableArray alloc] init];
jens@0:     [_outBox insertObject: msg atIndex: index];
jens@0:     
jens@0:     if( isNew ) {
jens@0:         LogTo(BLIP,@"%@ queuing outgoing %@ at index %i",self,msg,index);
jens@0:         if( n==0 )
jens@0:             [self queueIsEmpty];
jens@0:     }
jens@0: }
jens@0: 
jens@0: 
jens@0: - (BOOL) sendMessage: (BLIPMessage*)message
jens@0: {
jens@0:     if( _shouldClose ) {
jens@0:         Warn(@"%@: Attempt to send a message after the connection has started closing",self);
jens@0:         return NO;
jens@0:     }
jens@0:     Assert(!message.sent,@"message has already been sent");
jens@0:     [self _queueMessage: message isNew: YES];
jens@0:     return YES;
jens@0: }
jens@0: 
jens@0: 
jens@0: - (BOOL) sendRequest: (BLIPRequest*)q response: (BLIPResponse*)response
jens@0: {
jens@0:     if( !_shouldClose ) {
jens@0:         [q _assignedNumber: ++_numQueriesSent];
jens@0:         if( response ) {
jens@0:             [response _assignedNumber: _numQueriesSent];
jens@0:             [(BLIPReader*)self.reader _addPendingResponse: response];
jens@0:         }
jens@0:     }
jens@0:     return [self sendMessage: q];
jens@0: }
jens@0: 
jens@0: 
jens@0: - (void) queueIsEmpty
jens@0: {
jens@0:     if( _outBox.count > 0 ) {
jens@0:         // Pop first message in queue:
jens@0:         BLIPMessage *msg = [[_outBox objectAtIndex: 0] retain];
jens@0:         [_outBox removeObjectAtIndex: 0];
jens@0:         
jens@0:         // As an optimization, allow message to send a big frame unless there's a higher-priority
jens@0:         // message right behind it:
jens@0:         size_t frameSize = kDefaultFrameSize;
jens@0:         if( msg.urgent || _outBox.count==0 || ! [[_outBox objectAtIndex: 0] urgent] )
jens@0:             frameSize *= 4;
jens@0:         
jens@0:         if( [msg _writeFrameTo: self maxSize: frameSize] ) {
jens@0:             // add it back so it can send its next frame later:
jens@0:             [self _queueMessage: msg isNew: NO];
jens@0:         }
jens@0:         [msg release];
jens@0:     } else {
jens@0:         LogTo(BLIPVerbose,@"%@: no more work for writer",self);
jens@0:     }
jens@0: }
jens@0: 
jens@0: 
jens@0: 
jens@0: @end
jens@0: 
jens@0: 
jens@0: /*
jens@0:  Copyright (c) 2008, Jens Alfke <jens@mooseyard.com>. All rights reserved.
jens@0:  
jens@0:  Redistribution and use in source and binary forms, with or without modification, are permitted
jens@0:  provided that the following conditions are met:
jens@0:  
jens@0:  * Redistributions of source code must retain the above copyright notice, this list of conditions
jens@0:  and the following disclaimer.
jens@0:  * Redistributions in binary form must reproduce the above copyright notice, this list of conditions
jens@0:  and the following disclaimer in the documentation and/or other materials provided with the
jens@0:  distribution.
jens@0:  
jens@0:  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
jens@0:  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
jens@0:  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRI-
jens@0:  BUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
jens@0:  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
jens@0:   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
jens@0:  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 
jens@0:  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
jens@0:  */