ardour/libs/ardour/midi_buffer.cc

/*
    Copyright (C) 2006-2007 Paul Davis 
	Author: Dave Robillard
    
    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.,
    675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <iostream>
#include <ardour/midi_buffer.h>

#ifdef __x86_64__
static const int CPU_CACHE_ALIGN = 64;
#else
static const int CPU_CACHE_ALIGN = 16; /* arguably 32 on most arches, but it matters less */
#endif

using namespace std;
using namespace ARDOUR;


// FIXME: mirroring for MIDI buffers?
MidiBuffer::MidiBuffer(size_t capacity)
	: Buffer(DataType::MIDI, capacity)
	, _size(0)
	, _data(0)
{
	if (capacity) {
		resize(_capacity);
		silence(_capacity);
	}
}
	
MidiBuffer::~MidiBuffer()
{
	free(_data);
}

void
MidiBuffer::resize(size_t size)
{
	assert(size > 0);

	if (size < _capacity) {
		return;
	}

	free(_data);

	_size = 0;
	_capacity = size;

#ifdef NO_POSIX_MEMALIGN
	_data = (uint8_t*)malloc(_capacity);
#else
	posix_memalign((void**)&_data, CPU_CACHE_ALIGN, _capacity);
#endif	
	assert(_data);
}

void
MidiBuffer::copy(const MidiBuffer& copy)
{
	assert(_capacity >= copy._size);
	_size = copy._size;
	memcpy(_data, copy._data, copy._size);
}


/** Read events from @a src starting at time @a offset into the START of this buffer, for
 * time duration @a nframes.  Relative time, where 0 = start of buffer.
 *
 * Note that offset and nframes refer to sample time, NOT buffer offsets or event counts.
 */
void
MidiBuffer::read_from(const Buffer& src, nframes_t nframes, nframes_t offset)
{
	assert(src.type() == DataType::MIDI);
	assert(&src != this);

	const MidiBuffer& msrc = (MidiBuffer&)src;
	
	assert(_capacity >= msrc.size());

	if (offset == 0) {
		clear();
		assert(_size == 0);
	}
	
	for (MidiBuffer::const_iterator i = msrc.begin(); i != msrc.end(); ++i) {
		const Evoral::MIDIEvent<TimeType> ev(*i, false);
		/*cout << this << " MidiBuffer::read_from event type: " << int(ev.type())
				<< " time: " << ev.time() << " size: " << ev.size()
				<< " status: " << (int)*ev.buffer() << " buffer size: " << _size << endl;*/
		if (ev.time() < offset) {
			//cout << "MidiBuffer::read_from skipped event before " << offset << endl;
		} else if (ev.time() < (nframes + offset)) {
			//cout << "MidiBuffer::read_from appending event" << endl;
			push_back(ev);
		} else {
			//cerr << "MidiBuffer::read_from skipped event after "
			//	<< nframes << " + " << offset << endl;
		}
	}

	_silent = src.silent();
}


/** Push an event into the buffer.
 *
 * Note that the raw MIDI pointed to by ev will be COPIED and unmodified.
 * That is, the caller still owns it, if it needs freeing it's Not My Problem(TM).
 * Realtime safe.
 * @return false if operation failed (not enough room)
 */
bool
MidiBuffer::push_back(const Evoral::MIDIEvent<TimeType>& ev)
{
	const size_t stamp_size = sizeof(TimeType);
	/*cerr << "MidiBuffer: pushing event " << " size: " << _size 
	    << " event size: " << ev.size() 
	    << " capacity: " << _capacity 
	    << " stamp size: " << stamp_size << " \n";*/
	
	if (_size + stamp_size + ev.size() >= _capacity) {
		cerr << "MidiBuffer::push_back failed (buffer is full)" 
		     << endl;
		return false;
	}

	uint8_t* const write_loc = _data + _size;
	*((TimeType*)write_loc) = ev.time();
	memcpy(write_loc + stamp_size, ev.buffer(), ev.size());

	_size += stamp_size + ev.size();
	_silent = false;
	
	return true;
}


/** Push an event into the buffer.
 *
 * Note that the raw MIDI pointed to by ev will be COPIED and unmodified.
 * That is, the caller still owns it, if it needs freeing it's Not My Problem(TM).
 * Realtime safe.
 * @return false if operation failed (not enough room)
 */
bool
MidiBuffer::push_back(const jack_midi_event_t& ev)
{
	const size_t stamp_size = sizeof(TimeType);
	if (_size + stamp_size + ev.size >= _capacity) {
		cerr << "MidiBuffer::push_back failed (buffer is full)" << endl;
		return false;
	}

	uint8_t* const write_loc = _data + _size;
	*((TimeType*)write_loc) = ev.time;
	memcpy(write_loc + stamp_size, ev.buffer, ev.size);

	_size += stamp_size + ev.size;
	_silent = false;
	
	return true;
}


/** Reserve space for a new event in the buffer.
 *
 * This call is for copying MIDI directly into the buffer, the data location
 * (of sufficient size to write \a size bytes) is returned, or 0 on failure.
 * This call MUST be immediately followed by a write to the returned data
 * location, or the buffer will be corrupted and very nasty things will happen.
 */
uint8_t*
MidiBuffer::reserve(TimeType time, size_t size)
{
	const size_t stamp_size = sizeof(TimeType);
	if (_size + stamp_size + size >= _capacity) {
		return 0;
	}

	// write timestamp
	uint8_t* write_loc = _data + _size;
	*((TimeType*)write_loc) = time;
	
	// move write_loc to begin of MIDI buffer data to write to
	write_loc += stamp_size;

	_size += stamp_size + size;
	_silent = false;
	
	return write_loc;
}


void
MidiBuffer::silence(nframes_t dur, nframes_t offset)
{
	// FIXME use parameters
	if (offset != 0) {
		cerr << "WARNING: MidiBuffer::silence w/ offset != 0 (not implemented)" << endl;
	}

	_size = 0;
	_silent = true;
}

/** Merge \a other into this buffer.  Realtime safe. */
bool
MidiBuffer::merge_in_place(const MidiBuffer &other)
{
	if (other.size() == 0) {
		return true;
	}

	if (_size == 0) {
		copy(other);
		return true;
	}

	if (_size + other.size() > _capacity) {
		cerr << "MidiBuffer::merge failed (no space)" << endl;
		return false;
	}
	
	cerr << "FIXME: MIDI BUFFER IN-PLACE MERGE" << endl;
	return true;
}

/** Clear, and merge \a a and \a b into this buffer.
 *
 * \return true if complete merge was successful
 */
bool
MidiBuffer::merge(const MidiBuffer& a, const MidiBuffer& b)
{
	_size = 0;
	
	if (this == &a) {
	    merge_in_place(b);
	}

	if (this == &b) {
	    merge_in_place(a);
	}
	
	cerr << "FIXME: MIDI BUFFER MERGE" << endl;
	return true;
}