rt_midibuffer.h

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/*
 * Copyright (C) 2007-2016 David Robillard <d@drobilla.net>
 * Copyright (C) 2007-2018 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2009-2010 Carl Hetherington <carl@carlh.net>
 * Copyright (C) 2009 Hans Baier <hansfbaier@googlemail.com>
 * Copyright (C) 2014-2016 Robin Gareus <robin@gareus.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#ifndef __ardour_rt_midi_buffer_h__
#define __ardour_rt_midi_buffer_h__
 
#include <map>
 
#include <glibmm/threads.h>
 
#include "evoral/Event.h"
#include "evoral/EventSink.h"
#include "evoral/midi_util.h"
 
#include "ardour/types.h"
 
namespace ARDOUR {
 
class MidiBuffer;
class MidiNoteTracker;
class MidiStateTracker;
 
class LIBARDOUR_API RTMidiBuffer : public Evoral::EventSink<samplepos_t>
{
  private:
        struct Blob {
                uint32_t size;
                uint8_t data[0];
        };
 
  public:
        typedef samplepos_t TimeType;
 
        RTMidiBuffer ();
        ~RTMidiBuffer();
 
        void clear();
        void resize(size_t);
        size_t size() const { return _size; }
        bool empty() const { return _size == 0; }
 
        samplecnt_t span() const;
 
        uint32_t write (TimeType time, Evoral::EventType type, uint32_t size, const uint8_t* buf);
        uint32_t read (MidiBuffer& dst, samplepos_t start, samplepos_t end, MidiNoteTracker& tracker, samplecnt_t offset = 0);
        void track (MidiStateTracker&, samplepos_t start, samplepos_t end);
 
        void dump (uint32_t);
        void reverse ();
        bool reversed() const;
 
        struct Item {
                samplepos_t timestamp;
                union {
                        uint8_t  bytes[4];
                        uint32_t offset;
                };
        };
 
        Item const & operator[](size_t n) const {
                if (n >= _size) {
                        throw std::exception ();
                }
                return _data[n];
        }
 
        uint8_t const * bytes (Item const & item, uint32_t& size) {
                if (!item.bytes[0]) {
                        size = Evoral::midi_event_size (item.bytes[1]);
                        return &item.bytes[1];
                } else {
                        uint32_t offset = item.offset & ~(1<<(CHAR_BIT-1));
                        Blob* blob = reinterpret_cast<Blob*> (&_pool[offset]);
 
                        size = blob->size;
                        return blob->data;
                }
        }
 
        void shift (sampleoffset_t distance) {
                if (_size == 0) {
                        return;
                }
                for (size_t n = 0; n < _size; ++n) {
                        _data[n].timestamp += distance;
                }
        }
 
  private:
        friend struct WriteProtectRender;
 
        /* The main store. Holds Items (timestamp+up to 3 bytes of data OR
         * offset into secondary storage below)
         */
 
        size_t _size;
        size_t _capacity;
        Item*  _data;
        bool   _reversed;
        /* secondary blob storage. Holds Blobs (arbitrary size + data) */
 
        uint32_t alloc_blob (uint32_t size);
        uint32_t store_blob (uint32_t size, uint8_t const * data);
        uint32_t _pool_size;
        uint32_t _pool_capacity;
        uint8_t* _pool;
 
        Glib::Threads::RWLock _lock;
 
  public:
        class WriteProtectRender {
          public:
                WriteProtectRender (RTMidiBuffer& rtm) : lm (rtm._lock, Glib::Threads::NOT_LOCK) {}
                void acquire () { lm.acquire(); }
 
          private:
                Glib::Threads::RWLock::WriterLock lm;
        };
};
 
} // namespace ARDOUR
 
#endif // __ardour_rt_midi_buffer_h__