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diff --git a/libs/ardour/ardour/midi_ring_buffer.h b/libs/ardour/ardour/midi_ring_buffer.h
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+/*
+ Copyright (C) 2006 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.
+*/
+
+#ifndef __ardour_midi_ring_buffer_h__
+#define __ardour_midi_ring_buffer_h__
+
+#include <iostream>
+#include <algorithm>
+#include <ardour/types.h>
+#include <ardour/buffer.h>
+
+namespace ARDOUR {
+
+
+/* FIXME: this is probably too much inlined code */
+
+
+/** A RingBuffer.
+ * Read/Write realtime safe.
+ * Single-reader Single-writer thread safe.
+ *
+ * This is Raul::RingBuffer, lifted for MIDIRingBuffer to inherit from as it works
+ * a bit differently than PBD::Ringbuffer. This could/should be replaced with
+ * the PBD ringbuffer to decrease code size, but this code is tested and known to
+ * work, so here it sits for now...
+ *
+ * Ignore this class, use MidiRingBuffer.
+ */
+template <typename T>
+class MidiRingBufferBase {
+public:
+
+ /** @param size Size in bytes.
+ */
+ MidiRingBufferBase(size_t size)
+ : _size(size)
+ , _buf(new T[size])
+ {
+ reset();
+ assert(read_space() == 0);
+ assert(write_space() == size - 1);
+ }
+
+ virtual ~MidiRingBufferBase() {
+ delete[] _buf;
+ }
+
+ /** Reset(empty) the ringbuffer.
+ * NOT thread safe.
+ */
+ void reset() {
+ g_atomic_int_set(&_write_ptr, 0);
+ g_atomic_int_set(&_read_ptr, 0);
+ }
+
+ size_t write_space() const {
+
+ const size_t w = g_atomic_int_get(&_write_ptr);
+ const size_t r = g_atomic_int_get(&_read_ptr);
+
+ if (w > r) {
+ return ((r - w + _size) % _size) - 1;
+ } else if (w < r) {
+ return (r - w) - 1;
+ } else {
+ return _size - 1;
+ }
+ }
+
+ size_t read_space() const {
+
+ const size_t w = g_atomic_int_get(&_write_ptr);
+ const size_t r = g_atomic_int_get(&_read_ptr);
+
+ if (w > r) {
+ return w - r;
+ } else {
+ return (w - r + _size) % _size;
+ }
+ }
+
+ size_t capacity() const { return _size; }
+
+ size_t peek(size_t size, T* dst);
+ bool full_peek(size_t size, T* dst);
+
+ size_t read(size_t size, T* dst);
+ bool full_read(size_t size, T* dst);
+
+ bool skip(size_t size);
+
+ void write(size_t size, const T* src);
+
+protected:
+ mutable int _write_ptr;
+ mutable int _read_ptr;
+
+ size_t _size; ///< Size (capacity) in bytes
+ T* _buf; ///< size, event, size, event...
+};
+
+
+/** Peek at the ringbuffer (read w/o advancing read pointer).
+ *
+ * Note that a full read may not be done if the data wraps around.
+ * Caller must check return value and call again if necessary, or use the
+ * full_peek method which does this automatically.
+ */
+template<typename T>
+size_t
+MidiRingBufferBase<T>::peek(size_t size, T* dst)
+{
+ const size_t priv_read_ptr = g_atomic_int_get(&_read_ptr);
+
+ const size_t read_size = (priv_read_ptr + size < _size)
+ ? size
+ : _size - priv_read_ptr;
+
+ memcpy(dst, &_buf[priv_read_ptr], read_size);
+
+ return read_size;
+}
+
+
+template<typename T>
+bool
+MidiRingBufferBase<T>::full_peek(size_t size, T* dst)
+{
+ if (read_space() < size) {
+ return false;
+ }
+
+ const size_t read_size = peek(size, dst);
+
+ if (read_size < size) {
+ peek(size - read_size, dst + read_size);
+ }
+
+ return true;
+}
+
+
+/** Read from the ringbuffer.
+ *
+ * Note that a full read may not be done if the data wraps around.
+ * Caller must check return value and call again if necessary, or use the
+ * full_read method which does this automatically.
+ */
+template<typename T>
+size_t
+MidiRingBufferBase<T>::read(size_t size, T* dst)
+{
+ const size_t priv_read_ptr = g_atomic_int_get(&_read_ptr);
+
+ const size_t read_size = (priv_read_ptr + size < _size)
+ ? size
+ : _size - priv_read_ptr;
+
+ memcpy(dst, &_buf[priv_read_ptr], read_size);
+
+ g_atomic_int_set(&_read_ptr, (priv_read_ptr + read_size) % _size);
+
+ return read_size;
+}
+
+
+template<typename T>
+bool
+MidiRingBufferBase<T>::full_read(size_t size, T* dst)
+{
+ if (read_space() < size) {
+ return false;
+ }
+
+ const size_t read_size = read(size, dst);
+
+ if (read_size < size) {
+ read(size - read_size, dst + read_size);
+ }
+
+ return true;
+}
+
+
+template<typename T>
+bool
+MidiRingBufferBase<T>::skip(size_t size)
+{
+ if (read_space() < size) {
+ std::cerr << "WARNING: Attempt to skip past end of MIDI ring buffer" << std::endl;
+ return false;
+ }
+
+ const size_t priv_read_ptr = g_atomic_int_get(&_read_ptr);
+ g_atomic_int_set(&_read_ptr, (priv_read_ptr + size) % _size);
+
+ return true;
+}
+
+
+template<typename T>
+inline void
+MidiRingBufferBase<T>::write(size_t size, const T* src)
+{
+ const size_t priv_write_ptr = g_atomic_int_get(&_write_ptr);
+
+ if (priv_write_ptr + size <= _size) {
+ memcpy(&_buf[priv_write_ptr], src, size);
+ g_atomic_int_set(&_write_ptr, (priv_write_ptr + size) % _size);
+ } else {
+ const size_t this_size = _size - priv_write_ptr;
+ assert(this_size < size);
+ assert(priv_write_ptr + this_size <= _size);
+ memcpy(&_buf[priv_write_ptr], src, this_size);
+ memcpy(&_buf[0], src+this_size, size - this_size);
+ g_atomic_int_set(&_write_ptr, size - this_size);
+ }
+}
+
+
+/* ******************************************************************** */
+
+
+/** A MIDI RingBuffer.
+ *
+ * This is timestamps and MIDI packed sequentially into a single buffer, similarly
+ * to LV2 MIDI. The buffer looks like this:
+ *
+ * [timestamp][size][size bytes of raw MIDI][timestamp][size][etc..]
+ */
+class MidiRingBuffer : public MidiRingBufferBase<uint8_t> {
+public:
+ /** @param size Size in bytes.
+ */
+ MidiRingBuffer(size_t size)
+ : MidiRingBufferBase<uint8_t>(size), _channel_mask(0x0000FFFF)
+ {}
+
+ size_t write(double time, size_t size, const uint8_t* buf);
+ bool read(double* time, size_t* size, uint8_t* buf);
+
+ bool read_prefix(double* time, size_t* size);
+ bool read_contents(size_t size, uint8_t* buf);
+
+ size_t read(MidiBuffer& dst, nframes_t start, nframes_t end, nframes_t offset=0);
+
+ /** Set the channel filtering mode.
+ * @param mask If mode is FilterChannels, each bit represents a midi channel:
+ * bit 0 = channel 0, bit 1 = channel 1 etc. the read and write methods will only
+ * process events whose channel bit is 1.
+ * If mode is ForceChannel, mask is simply a channel number which all events will
+ * be forced to while reading.
+ */
+ void set_channel_mode(ChannelMode mode, uint16_t mask) {
+ g_atomic_int_set(&_channel_mask, ((uint16_t)mode << 16) | mask);
+ }
+
+ ChannelMode get_channel_mode() const {
+ return static_cast<ChannelMode>((g_atomic_int_get(&_channel_mask) & 0xFFFF0000) >> 16);
+ }
+
+ uint16_t get_channel_mask() const {
+ return static_cast<ChannelMode>((g_atomic_int_get(&_channel_mask) & 0x0000FFFF));
+ }
+
+protected:
+ inline bool is_channel_event(uint8_t event_type_byte) {
+ // mask out channel information
+ event_type_byte &= 0xF0;
+ // midi channel events range from 0x80 to 0xE0
+ return (0x80 <= event_type_byte) && (event_type_byte <= 0xE0);
+ }
+
+private:
+ volatile uint32_t _channel_mask; // 16 bits mode, 16 bits mask
+};
+
+
+inline bool
+MidiRingBuffer::read(double* time, size_t* size, uint8_t* buf)
+{
+ bool success = MidiRingBufferBase<uint8_t>::full_read(sizeof(double), (uint8_t*)time);
+
+ if (success) {
+ success = MidiRingBufferBase<uint8_t>::full_read(sizeof(size_t), (uint8_t*)size);
+ }
+ if (success) {
+ success = MidiRingBufferBase<uint8_t>::full_read(*size, buf);
+ }
+
+ return success;
+}
+
+
+/** Read the time and size of an event. This call MUST be immediately proceeded
+ * by a call to read_contents (or the read pointer will be garabage).
+ */
+inline bool
+MidiRingBuffer::read_prefix(double* time, size_t* size)
+{
+ bool success = MidiRingBufferBase<uint8_t>::full_read(sizeof(double), (uint8_t*)time);
+ if (success) {
+ success = MidiRingBufferBase<uint8_t>::full_read(sizeof(size_t), (uint8_t*)size);
+ }
+
+ return success;
+}
+
+
+/** Read the contenst of an event. This call MUST be immediately preceeded
+ * by a call to read_prefix (or the returned even will be garabage).
+ */
+inline bool
+MidiRingBuffer::read_contents(size_t size, uint8_t* buf)
+{
+ return MidiRingBufferBase<uint8_t>::full_read(size, buf);
+}
+
+
+inline size_t
+MidiRingBuffer::write(double time, size_t size, const uint8_t* buf)
+{
+ /*fprintf(stderr, "MRB %p write (t = %f) ", this, time);
+ for (size_t i = 0; i < size; ++i)
+ fprintf(stderr, "%X", (char)buf[i]);
+ fprintf(stderr, "\n");*/
+
+ assert(size > 0);
+
+ // Don't write event if it doesn't match channel filter
+ if (is_channel_event(buf[0]) && get_channel_mode() == FilterChannels) {
+ uint8_t channel = buf[0] & 0x0F;
+ if ( !(get_channel_mask() & (1L << channel)) ) {
+ return 0;
+ }
+ }
+
+ if (write_space() < (sizeof(double) + sizeof(size_t) + size)) {
+ return 0;
+ } else {
+ MidiRingBufferBase<uint8_t>::write(sizeof(double), (uint8_t*)&time);
+ MidiRingBufferBase<uint8_t>::write(sizeof(size_t), (uint8_t*)&size);
+ if (is_channel_event(buf[0]) && get_channel_mode() == ForceChannel) {
+ assert(size == 2 || size == 3);
+ uint8_t tmp_buf[3];
+ // Force event to channel
+ tmp_buf[0] = (buf[0] & 0xF0) | (get_channel_mask() & 0x0F);
+ tmp_buf[1] = buf[1];
+ if (size == 3) {
+ tmp_buf[2] = buf[2];
+ }
+ MidiRingBufferBase<uint8_t>::write(size, tmp_buf);
+ } else {
+ MidiRingBufferBase<uint8_t>::write(size, buf);
+ }
+ return size;
+ }
+
+}
+
+
+/** Read a block of MIDI events from buffer.
+ *
+ * Timestamps of events returned are relative to start (ie event with stamp 0
+ * occurred at start), with offset added.
+ */
+inline size_t
+MidiRingBuffer::read(MidiBuffer& dst, nframes_t start, nframes_t end, nframes_t offset)
+{
+ if (read_space() == 0)
+ return 0;
+
+ double ev_time;
+ uint32_t ev_size;
+
+ size_t count = 0;
+
+ //printf("---- MRB read %u .. %u + %u\n", start, end, offset);
+
+ while (read_space() > sizeof(double) + sizeof(size_t)) {
+
+ full_peek(sizeof(double), (uint8_t*)&ev_time);
+
+ if (ev_time > end) {
+ break;
+ }
+
+ bool success = MidiRingBufferBase<uint8_t>::full_read(sizeof(double), (uint8_t*)&ev_time);
+ if (success) {
+ success = MidiRingBufferBase<uint8_t>::full_read(sizeof(size_t), (uint8_t*)&ev_size);
+ }
+
+ if (!success) {
+ std::cerr << "MRB: READ ERROR (time/size)" << std::endl;
+ continue;
+ }
+
+ uint8_t status;
+ success = full_peek(sizeof(uint8_t), &status);
+ assert(success); // If this failed, buffer is corrupt, all hope is lost
+
+ // Ignore event if it doesn't match channel filter
+ if (is_channel_event(status) && get_channel_mode() == FilterChannels) {
+ const uint8_t channel = status & 0x0F;
+ if ( !(get_channel_mask() & (1L << channel)) ) {
+ skip(ev_size); // Advance read pointer to next event
+ continue;
+ }
+ }
+
+ if (ev_time >= start) {
+
+ /*std::cerr << "MRB " << this << " - Reading event, time = "
+ << ev_time << " - " << start << " => " << ev_time - start
+ << ", size = " << ev_size << std::endl;*/
+
+ ev_time -= start;
+
+ uint8_t* write_loc = dst.reserve(ev_time, ev_size);
+ if (write_loc == NULL) {
+ std::cerr << "MRB: Unable to reserve space in buffer, event skipped";
+ continue;
+ }
+
+ success = MidiRingBufferBase<uint8_t>::full_read(ev_size, write_loc);
+
+ if (success) {
+ if (is_channel_event(status) && get_channel_mode() == ForceChannel) {
+ write_loc[0] = (write_loc[0] & 0xF0) | (get_channel_mask() & 0x0F);
+ }
+ ++count;
+ //printf("MRB - read event at time %lf\n", ev_time);
+ } else {
+ std::cerr << "MRB: READ ERROR (data)" << std::endl;
+ }
+
+ } else {
+ printf("MRB (start %u) - Skipping event at (too early) time %f\n", start, ev_time);
+ }
+ }
+
+ //printf("(R) read space: %zu\n", read_space());
+
+ return count;
+}
+
+
+} // namespace ARDOUR
+
+#endif // __ardour_midi_ring_buffer_h__
+
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