midi_ring_buffer.cc

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/*
    Copyright (C) 2006-2008 Paul Davis

    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 "pbd/compose.h"
#include "pbd/enumwriter.h"
#include "pbd/error.h"

#include "ardour/debug.h"
#include "ardour/midi_ring_buffer.h"
#include "ardour/midi_buffer.h"
#include "ardour/event_type_map.h"

using namespace std;
using namespace PBD;

namespace ARDOUR {

template<typename T>
size_t
MidiRingBuffer<T>::read(MidiBuffer& dst, framepos_t start, framepos_t end, framecnt_t offset, bool stop_on_overflow_in_dst)
{
        if (this->read_space() == 0) {
                return 0;
        }

        T                 ev_time;
        uint32_t          ev_size;
        size_t            count = 0;
        const size_t      prefix_size = sizeof(T) + sizeof(Evoral::EventType) + sizeof(uint32_t);

        while (this->read_space() >= prefix_size) {

                uint8_t peekbuf[prefix_size];

                /* this cannot fail, because we've already verified that there
                   is prefix_space to read
                */
                this->peek (peekbuf, prefix_size);

                ev_time = *(reinterpret_cast<T*>((uintptr_t)peekbuf));
                ev_size = *(reinterpret_cast<uint32_t*>((uintptr_t)(peekbuf + sizeof(T) + sizeof (Evoral::EventType))));

                if (this->read_space() < ev_size) {
                        break;;
                }

                if (ev_time >= end) {
                        DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("MRB event @ %1 past end @ %2\n", ev_time, end));
                        break;
                } else if (ev_time < start) {
                        DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("MRB event @ %1 before start @ %2\n", ev_time, start));
                        break;
                } else {
                        DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("MRB event @ %1 in range %2 .. %3\n", ev_time, start, end));
                }

                ev_time -= start;
                ev_time += offset;

                /* we're good to go ahead and read the data now but since we
                 * have the prefix data already, just skip over that
                 */
                this->increment_read_ptr (prefix_size);

                uint8_t status;
                bool r = this->peek (&status, sizeof(uint8_t)); 
                assert (r); // If this failed, buffer is corrupt, all hope is lost

                /* lets see if we are going to be able to write this event into dst.
                 */
                uint8_t* write_loc = dst.reserve (ev_time, ev_size);
                if (write_loc == 0) {
                        if (stop_on_overflow_in_dst) {
                                DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("MidiRingBuffer: overflow in destination MIDI buffer, stopped after %1 events\n", count));
                                break;
                        }
                        error << "MRB: Unable to reserve space in buffer, event skipped" << endmsg;
                        this->increment_read_ptr (ev_size); // Advance read pointer to next event
                        continue;
                }

                // write MIDI buffer contents
                bool success = read_contents (ev_size, write_loc);

#ifndef NDEBUG
                if (DEBUG::MidiDiskstreamIO && PBD::debug_bits) {
                        DEBUG_STR_DECL(a);
                        DEBUG_STR_APPEND(a, string_compose ("wrote MidiEvent to Buffer (time=%1, start=%2 offset=%3)", ev_time, start, offset));
                        for (size_t i=0; i < ev_size; ++i) {
                                DEBUG_STR_APPEND(a,hex);
                                DEBUG_STR_APPEND(a,"0x");
                                DEBUG_STR_APPEND(a,(int)write_loc[i]);
                                DEBUG_STR_APPEND(a,' ');
                        }
                        DEBUG_STR_APPEND(a,'\n');
                        DEBUG_TRACE (DEBUG::MidiDiskstreamIO, DEBUG_STR(a).str());
                }
#endif

                if (success) {
                        _tracker.track(write_loc);
                        ++count;
                } else {
                        cerr << "WARNING: error reading event contents from MIDI ring" << endl;
                }
        }

        return count;
}

template<typename T>
size_t
MidiRingBuffer<T>::skip_to(framepos_t start)
{
        if (this->read_space() == 0) {
                return 0;
        }

        T                 ev_time;
        uint32_t          ev_size;
        size_t            count = 0;
        const size_t      prefix_size = sizeof(T) + sizeof(Evoral::EventType) + sizeof(uint32_t);

        while (this->read_space() >= prefix_size) {

                uint8_t peekbuf[prefix_size];
                this->peek (peekbuf, prefix_size);

                ev_time = *(reinterpret_cast<T*>((uintptr_t)peekbuf));
                ev_size = *(reinterpret_cast<uint32_t*>((uintptr_t)(peekbuf + sizeof(T) + sizeof (Evoral::EventType))));

                if (ev_time >= start) {
                        return count;
                }

                if (this->read_space() < ev_size) {
                        continue;
                }

                this->increment_read_ptr (prefix_size);

                uint8_t status;
                bool r = this->peek (&status, sizeof(uint8_t));
                assert (r); // If this failed, buffer is corrupt, all hope is lost

                ++count;

                /* TODO investigate and think:
                 *
                 * Does it makes sense to keep track of notes
                 * that are skipped (because they're either too late
                 * (underrun) or never used (read-ahead, loop) ?
                 *
                 * skip_to() is called on the rinbuffer between
                 * disk and process. it seems wrong to track them
                 * (a potential synth never sees skipped notes, either)
                 * but there may be more to this.
                 */

                if (ev_size >= 8) {
                        this->increment_read_ptr (ev_size);
                } else {
                        // we only track note on/off, 8 bytes are plenty.
                        uint8_t write_loc[8];
                        bool success = read_contents (ev_size, write_loc);
                        if (success) {
                                _tracker.track(write_loc);
                        }
                }
        }
        return count;
}



template<typename T>
void
MidiRingBuffer<T>::flush (framepos_t /*start*/, framepos_t end)
{
        const size_t prefix_size = sizeof(T) + sizeof(Evoral::EventType) + sizeof(uint32_t);

        while (this->read_space() >= prefix_size) {
                uint8_t  peekbuf[prefix_size];
                bool     success;
                uint32_t ev_size;
                T        ev_time;

                success = this->peek (peekbuf, prefix_size);
                /* this cannot fail, because we've already verified that there
                   is prefix_space to read
                */
                assert (success);

                ev_time = *(reinterpret_cast<T*>((uintptr_t)peekbuf));
                
                if (ev_time >= end) {
                        break;
                }

                ev_size = *(reinterpret_cast<uint32_t*>((uintptr_t)(peekbuf + sizeof(T) + sizeof (Evoral::EventType))));
                this->increment_read_ptr (prefix_size);
                this->increment_read_ptr (ev_size);
        }
}

template<typename T>
void
MidiRingBuffer<T>::dump(ostream& str)
{
        size_t rspace;

        if ((rspace = this->read_space()) == 0) {
                str << "MRB::dump: empty\n";
                return;
        }

        T                 ev_time;
        Evoral::EventType ev_type;
        uint32_t          ev_size;

        RingBufferNPT<uint8_t>::rw_vector vec;
        RingBufferNPT<uint8_t>::get_read_vector (&vec);

        if (vec.len[0] == 0) {
                return;
        }

        str << this << ": Dump size = " << vec.len[0] + vec.len[1]
            << " r@ " << RingBufferNPT<uint8_t>::get_read_ptr()
            << " w@" << RingBufferNPT<uint8_t>::get_write_ptr() << endl;


        uint8_t *buf = new uint8_t[vec.len[0] + vec.len[1]];
        memcpy (buf, vec.buf[0], vec.len[0]);

        if (vec.len[1]) {
                memcpy (buf+vec.len[1], vec.buf[1], vec.len[1]);
        }

        uint8_t* data = buf;
        const uint8_t* end = buf + vec.len[0] + vec.len[1];

        while (data < end) {

                memcpy (&ev_time, data, sizeof (T));
                data += sizeof (T);
                str << "\ttime " << ev_time;

                if (data >= end) {
                        str << "(incomplete)\n ";
                        break;
                }

                memcpy (&ev_type, data, sizeof (ev_type));
                data += sizeof (ev_type);
                str << " type " << ev_type;

                if (data >= end) {
                        str << "(incomplete)\n";
                        break;
                }

                memcpy (&ev_size, data, sizeof (ev_size));
                data += sizeof (ev_size);
                str << " size " << ev_size;

                if (data >= end) {
                        str << "(incomplete)\n";
                        break;
                }

                for (uint32_t i = 0; i != ev_size && data < end; ++i) {
                        str << ' ' << hex << (int) data[i] << dec;
                }

                data += ev_size;

                str << endl;
        }

        delete [] buf;
}

template<typename T>
void
MidiRingBuffer<T>::reset_tracker ()
{
        _tracker.reset ();
}

template<typename T>
void
MidiRingBuffer<T>::resolve_tracker (MidiBuffer& dst, framepos_t t)
{
        _tracker.resolve_notes (dst, t);
}

template<typename T>
void
MidiRingBuffer<T>::resolve_tracker (Evoral::EventSink<framepos_t>& dst, framepos_t t)
{
        _tracker.resolve_notes(dst, t);
}

template class MidiRingBuffer<framepos_t>;

}  // namespace ARDOUR