libs/evoral/evoral/EventRingBuffer.hpp

   1 /* This file is part of Evoral.
   2  * Copyright (C) 2008 Dave Robillard <http://drobilla.net>
   3  *
   4  * Evoral is free software; you can redistribute it and/or modify it under the
   5  * terms of the GNU General Public License as published by the Free Software
   6  * Foundation; either version 2 of the License, or (at your option) any later
   7  * version.
   8  *
   9  * Evoral is distributed in the hope that it will be useful, but WITHOUT ANY
  10  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  11  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 #ifndef EVORAL_EVENT_RING_BUFFER_HPP
  19 #define EVORAL_EVENT_RING_BUFFER_HPP
  20
  21 #include <glib.h>
  22 #include "evoral/RingBuffer.hpp"
  23 #include "evoral/EventSink.hpp"
  24 #include "evoral/types.hpp"
  25
  26 #include <iostream>
  27 using namespace std;
  28
  29 namespace Evoral {
  30
  31
  32 /** A RingBuffer of events (generic time-stamped binary "blobs").
  33  *
  34  * This packs a timestamp, size, and size bytes of data flat into the buffer.
  35  * Useful for MIDI events, OSC messages, etc.
  36  */
  37 template<typename Time>
  38 class EventRingBuffer : public Evoral::RingBuffer<uint8_t>, public Evoral::EventSink<Time> {
  39 public:
  40
  41         /** @param capacity Ringbuffer capacity in bytes.
  42          */
  43         EventRingBuffer(size_t capacity) : RingBuffer<uint8_t>(capacity)
  44         {}
  45
  46         size_t capacity() const { return _size; }
  47
  48         bool peek_time(Time* time);
  49
  50         uint32_t write(Time  time, EventType  type, uint32_t  size, const uint8_t* buf);
  51         bool     read (Time* time, EventType* type, uint32_t* size,       uint8_t* buf);
  52 };
  53
  54
  55 template<typename Time>
  56 inline bool
  57 EventRingBuffer<Time>::peek_time(Time* time)
  58 {
  59         bool success = RingBuffer<uint8_t>::full_peek(sizeof(Time), (uint8_t*)time);
  60         return success;
  61 }
  62
  63
  64 template<typename Time>
  65 inline bool
  66 EventRingBuffer<Time>::read(Time* time, EventType* type, uint32_t* size, uint8_t* buf)
  67 {
  68         bool success = RingBuffer<uint8_t>::full_read(sizeof(Time), (uint8_t*)time);
  69         if (success)
  70                 success = RingBuffer<uint8_t>::full_read(sizeof(EventType), (uint8_t*)type);
  71         if (success)
  72                 success = RingBuffer<uint8_t>::full_read(sizeof(uint32_t), (uint8_t*)size);
  73         if (success)
  74                 success = RingBuffer<uint8_t>::full_read(*size, buf);
  75
  76         return success;
  77 }
  78
  79
  80 template<typename Time>
  81 inline uint32_t
  82 EventRingBuffer<Time>::write(Time time, EventType type, uint32_t size, const uint8_t* buf)
  83 {
  84         if (write_space() < (sizeof(Time) + sizeof(EventType) + sizeof(uint32_t) + size)) {
  85                 return 0;
  86         } else {
  87                 RingBuffer<uint8_t>::write(sizeof(Time), (uint8_t*)&time);
  88                 RingBuffer<uint8_t>::write(sizeof(EventType), (uint8_t*)&type);
  89                 RingBuffer<uint8_t>::write(sizeof(uint32_t), (uint8_t*)&size);
  90                 RingBuffer<uint8_t>::write(size, buf);
  91                 return size;
  92         }
  93 }
  94
  95
  96 } // namespace Evoral
  97
  98 #endif // EVORAL_EVENT_RING_BUFFER_HPP
  99