Marsyas  0.6.0-alpha
/usr/src/RPM/BUILD/marsyas-0.6.0/src/marsyas/realtime/packet_queue.h
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00001 /*
00002 ** Copyright (C) 2014 George Tzanetakis <gtzan@cs.uvic.ca>
00003 **
00004 ** This program is free software; you can redistribute it and/or modify
00005 ** it under the terms of the GNU General Public License as published by
00006 ** the Free Software Foundation; either version 2 of the License, or
00007 ** (at your option) any later version.
00008 **
00009 ** This program is distributed in the hope that it will be useful,
00010 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
00011 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00012 ** GNU General Public License for more details.
00013 **
00014 ** You should have received a copy of the GNU General Public License
00015 ** along with this program; if not, write to the Free Software
00016 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
00017 */
00018 
00019 #ifndef MARSYAS_REALTIME_PACKET_QUEUE_INCLUDED
00020 #define MARSYAS_REALTIME_PACKET_QUEUE_INCLUDED
00021 
00022 #include "queue.h"
00023 #include <iostream>
00024 #include <algorithm>
00025 
00026 namespace Marsyas {
00027 namespace RealTime {
00028 
00029 using std::size_t;
00030 
00031 class packet_queue
00032 {
00033 
00034   queue<char> m_byte_queue;
00035 
00036 public:
00037   packet_queue(size_t capacity):
00038     m_byte_queue(capacity)
00039   {}
00040 
00041   void clear() { m_byte_queue.clear(); }
00042 
00043   bool push ( const char *data, size_t count )
00044   {
00045     queue_producer<char> producer(m_byte_queue, sizeof(size_t) + count);
00046 
00047     if (!producer.capacity())
00048       return false;
00049 
00050     producer.write(0, reinterpret_cast<char*>(&count), sizeof(size_t));
00051     producer.write(sizeof(size_t), data, count);
00052 
00053     return true;
00054   }
00055 
00056   size_t pop ( char *data, size_t max_count )
00057   {
00058     size_t count;
00059 
00060     queue_consumer<char> consumer(m_byte_queue, sizeof(size_t));
00061 
00062     if (!consumer.capacity())
00063       return 0;
00064 
00065     consumer.read(0, reinterpret_cast<char*>(&count), sizeof(size_t));
00066 
00067     if (!consumer.reserve(sizeof(size_t) + count))
00068     {
00069       consumer.abort();
00070       return 0;
00071     }
00072 
00073     consumer.read( sizeof(size_t), data, std::min(count, max_count) );
00074 
00075     return count;
00076   }
00077 };
00078 
00079 }
00080 }
00081 
00082 #endif // MARSYAS_REALTIME_PACKET_QUEUE_INCLUDED