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-rw-r--r--libs/ardour/ardour/midi_ring_buffer.h322
1 files changed, 209 insertions, 113 deletions
diff --git a/libs/ardour/ardour/midi_ring_buffer.h b/libs/ardour/ardour/midi_ring_buffer.h
index 71f42d7182..86319ad4b2 100644
--- a/libs/ardour/ardour/midi_ring_buffer.h
+++ b/libs/ardour/ardour/midi_ring_buffer.h
@@ -21,61 +21,67 @@
#include <algorithm>
#include <ardour/types.h>
-#include <pbd/ringbufferNPT.h>
#include <ardour/buffer.h>
namespace ARDOUR {
-/** A MIDI RingBuffer
- * (necessary because MIDI events are variable sized so a generic RB won't do).
+
+/** 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...
*
- * ALL publically accessible sizes refer to event COUNTS. What actually goes
- * on in here is none of the callers business :)
+ * Ignore this class, use MidiRingBuffer.
*/
-class MidiRingBuffer {
+template <typename T>
+class MidiRingBufferBase {
public:
- MidiRingBuffer (size_t size)
+
+ /** @param size Size in bytes.
+ */
+ MidiRingBufferBase(size_t size)
: _size(size)
- , _max_event_size(MidiBuffer::max_event_size())
- , _ev_buf(new MidiEvent[size])
- , _raw_buf(new RawMidi[size * _max_event_size])
+ , _buf(new T[size])
{
- reset ();
+ reset();
assert(read_space() == 0);
assert(write_space() == size - 1);
}
- virtual ~MidiRingBuffer() {
- delete[] _ev_buf;
- delete[] _raw_buf;
+ virtual ~MidiRingBufferBase() {
+ delete[] _buf;
}
- void reset () {
- /* !!! NOT THREAD SAFE !!! */
- g_atomic_int_set (&_write_ptr, 0);
- g_atomic_int_set (&_read_ptr, 0);
+ /** 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 () {
- size_t w, r;
+ size_t write_space() const {
- w = g_atomic_int_get (&_write_ptr);
- r = g_atomic_int_get (&_read_ptr);
+ 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) {
+ } else if(w < r) {
return (r - w) - 1;
} else {
return _size - 1;
}
}
- size_t read_space () {
- size_t w, r;
+ size_t read_space() const {
- w = g_atomic_int_get (&_write_ptr);
- r = g_atomic_int_get (&_read_ptr);
+ 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;
@@ -86,139 +92,229 @@ public:
size_t capacity() const { return _size; }
- /** Read one event and appends it to @a out. */
- //size_t read(MidiBuffer& out);
+ 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);
+
+ void write(size_t size, const T* src);
+
+protected:
+ mutable gint _write_ptr;
+ mutable gint _read_ptr;
+
+ size_t _size; ///< Size (capacity) in bytes
+ T* _buf; ///< size, event, size, event...
+};
- /** Write one event (@a in) */
- size_t write(const MidiEvent& in); // deep copies in
- /** Read events all events up to time @a end into @a out, leaving stamps intact.
- * Any events before @a start will be dropped. */
- size_t read(MidiBuffer& out, nframes_t start, nframes_t end);
+/** 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);
- /** Write all events from @a in, applying @a offset to all time stamps */
- size_t write(const MidiBuffer& in, nframes_t offset = 0);
+ 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;
+}
- inline void clear_event(size_t index);
-private:
+template<typename T>
+bool
+MidiRingBufferBase<T>::full_peek(size_t size, T* dst)
+{
+ if (read_space() < size)
+ return false;
- // _event_ indices
- mutable gint _write_ptr;
- mutable gint _read_ptr;
+ const size_t read_size = peek(size, dst);
- size_t _size; // size (capacity) in events
- size_t _max_event_size; // ratio of raw_buf size to ev_buf size
- MidiEvent* _ev_buf; // these point into...
- RawMidi* _raw_buf; // this
+ if (read_size < size)
+ peek(size - read_size, dst + read_size);
-};
+ return true;
+}
-/** Just for sanity checking */
-inline void
-MidiRingBuffer::clear_event(size_t index)
+
+/** 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)
{
- memset(&_ev_buf[index].buffer, 0, _max_event_size);
- _ev_buf[index].time = 0;
- _ev_buf[index].size = 0;
- _ev_buf[index].buffer = 0;
+ 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;
}
-inline size_t
-MidiRingBuffer::write (const MidiEvent& ev)
+
+template<typename T>
+bool
+MidiRingBufferBase<T>::full_read(size_t size, T* dst)
{
- //static nframes_t last_write_time = 0;
+ if (read_space() < size)
+ return false;
+
+ const size_t read_size = read(size, dst);
- assert(ev.size > 0);
+ if (read_size < size)
+ read(size - read_size, dst + read_size);
- size_t priv_write_ptr = g_atomic_int_get(&_write_ptr);
+ return true;
+}
- if (write_space () == 0) {
- return 0;
+
+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 {
- //assert(ev.time >= last_write_time);
+ 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);
+ }
+}
- const size_t raw_index = priv_write_ptr * _max_event_size;
- MidiEvent* const write_ev = &_ev_buf[priv_write_ptr];
- *write_ev = ev;
+/* ******************************************************************** */
+
+
+/** 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<Byte> {
+public:
+
+ /** @param size Size in bytes.
+ */
+ MidiRingBuffer(size_t size)
+ : MidiRingBufferBase<Byte>(size)
+ {}
+
+ size_t write(nframes_t time, size_t size, const Byte* buf);
+ bool read(nframes_t time, size_t* size, Byte* buf);
+
+ size_t read(MidiBuffer& dst, nframes_t start, nframes_t end);
+};
- memcpy(&_raw_buf[raw_index], ev.buffer, ev.size);
- write_ev->buffer = &_raw_buf[raw_index];
- g_atomic_int_set(&_write_ptr, (priv_write_ptr + 1) % _size);
-
- //printf("MRB - wrote %xd %d %d with time %u at index %zu (raw index %zu)\n",
- // write_ev->buffer[0], write_ev->buffer[1], write_ev->buffer[2], write_ev->time,
- // priv_write_ptr, raw_index);
-
- assert(write_ev->size = ev.size);
- //last_write_time = ev.time;
- //printf("(W) read space: %zu\n", read_space());
+inline bool
+MidiRingBuffer::read(nframes_t time, size_t* size, Byte* buf)
+{
+ bool success = MidiRingBufferBase<Byte>::full_read(sizeof(nframes_t), (Byte*)time);
+ if (success)
+ success = MidiRingBufferBase<Byte>::full_read(sizeof(size_t), (Byte*)size);
+ if (success)
+ success = MidiRingBufferBase<Byte>::full_read(*size, buf);
+
+ return success;
+}
+
+
+inline size_t
+MidiRingBuffer::write(nframes_t time, size_t size, const Byte* buf)
+{
+ assert(size > 0);
- return 1;
+ if (write_space() < (sizeof(nframes_t) + sizeof(size_t) + size)) {
+ return 0;
+ } else {
+ MidiRingBufferBase<Byte>::write(sizeof(nframes_t), (Byte*)&time);
+ MidiRingBufferBase<Byte>::write(sizeof(size_t), (Byte*)&size);
+ MidiRingBufferBase<Byte>::write(size, buf);
+ return size;
}
}
+
inline size_t
MidiRingBuffer::read(MidiBuffer& dst, nframes_t start, nframes_t end)
{
if (read_space() == 0)
return 0;
- size_t priv_read_ptr = g_atomic_int_get(&_read_ptr);
- nframes_t time = _ev_buf[priv_read_ptr].time;
- size_t count = 0;
- size_t limit = read_space();
+ MidiEvent ev;
- while (time <= end && limit > 0) {
- MidiEvent* const read_ev = &_ev_buf[priv_read_ptr];
- if (time >= start) {
- dst.push_back(*read_ev);
+ size_t count = 0;
+
+ while (read_space() > sizeof(nframes_t) + sizeof(size_t)) {
+
+ full_peek(sizeof(nframes_t), (Byte*)&ev.time);
+
+ if (ev.time > end)
+ break;
+
+ bool success = MidiRingBufferBase<Byte>::full_read(sizeof(nframes_t), (Byte*)&ev.time);
+ if (success)
+ success = MidiRingBufferBase<Byte>::full_read(sizeof(size_t), (Byte*)&ev.size);
+
+ if (!success) {
+ cerr << "MRB: READ ERROR (time/size)" << endl;
+ continue;
+ }
+
+ if (ev.time >= start) {
+ Byte* write_loc = dst.reserve(ev.time, ev.size);
+ success = MidiRingBufferBase<Byte>::full_read(ev.size, write_loc);
+
+ if (!success)
+ cerr << "MRB: READ ERROR (data)" << endl;
+
//printf("MRB - read %#X %d %d with time %u at index %zu\n",
- // read_ev->buffer[0], read_ev->buffer[1], read_ev->buffer[2], read_ev->time,
+ // ev.buffer[0], ev.buffer[1], ev.buffer[2], ev.time,
// priv_read_ptr);
+ //
} else {
- printf("MRB - SKIPPING - %#X %d %d with time %u at index %zu\n",
- read_ev->buffer[0], read_ev->buffer[1], read_ev->buffer[2], read_ev->time,
- priv_read_ptr);
+ printf("MRB - SKIPPING - %#X %d %d with time %u\n",
+ ev.buffer[0], ev.buffer[1], ev.buffer[2], ev.time);
break;
}
- clear_event(priv_read_ptr);
-
++count;
- --limit;
-
- priv_read_ptr = (priv_read_ptr + 1) % _size;
-
- assert(read_ev->time <= end);
- time = _ev_buf[priv_read_ptr].time;
+
+ assert(ev.time <= end);
}
- g_atomic_int_set(&_read_ptr, priv_read_ptr);
-
//printf("(R) read space: %zu\n", read_space());
return count;
}
-inline size_t
-MidiRingBuffer::write(const MidiBuffer& in, nframes_t offset)
-{
- size_t num_events = in.size();
- size_t to_write = std::min(write_space(), num_events);
-
- // FIXME: double copy :/
- for (size_t i=0; i < to_write; ++i) {
- MidiEvent ev = in[i];
- ev.time += offset;
- write(ev);
- }
-
- return to_write;
-}
} // namespace ARDOUR