Fix dropped MIDI events, especially with record enabled.

I am not precisely sure why the cached iterator was causing this problem, it
shouldn't be invalidated, and the times make sense.  It may be some lock
related issue since the iterator holds a lock on the source.

In any case, this cached iterator was just to avoid repeated linear search of
the model, but since the model has a logarithmic search, instead just scrap all
this problematic persistent state and search for the appropriate start time
every read.  No need to be careful about invalidating when anything changes.

1 files changed, 5 insertions, 33 deletions

diff --git a/libs/ardour/midi_source.cc b/libs/ardour/midi_source.cc
index 655222413a..52c15f94cd 100644
--- a/libs/ardour/midi_source.cc
+++ b/libs/ardour/midi_source.cc
@@ -56,9 +56,7 @@ PBD::Signal1<void,MidiSource*> MidiSource::MidiSourceCreated;
 MidiSource::MidiSource (Session& s, string name, Source::Flag flags)
 	: Source(s, DataType::MIDI, name, flags)
 	, _writing(false)
-	, _model_iter_valid(false)
 	, _length_beats(0.0)
-	, _last_read_end(0)
 	, _capture_length(0)
 	, _capture_loop_length(0)
 {
@@ -67,9 +65,7 @@ MidiSource::MidiSource (Session& s, string name, Source::Flag flags)
 MidiSource::MidiSource (Session& s, const XMLNode& node)
 	: Source(s, node)
 	, _writing(false)
-	, _model_iter_valid(false)
 	, _length_beats(0.0)
-	, _last_read_end(0)
 	, _capture_length(0)
 	, _capture_loop_length(0)
 {
@@ -183,13 +179,6 @@ MidiSource::update_length (framecnt_t)
 	// You're not the boss of me!
 }
 
-void
-MidiSource::invalidate ()
-{
-	_model_iter_valid = false;
-	_model_iter.invalidate();
-}
-
 /** @param filtered A set of parameters whose MIDI messages will not be returned */
 framecnt_t
 MidiSource::midi_read (Evoral::EventSink<framepos_t>& dst, framepos_t source_start,
@@ -205,26 +194,11 @@ MidiSource::midi_read (Evoral::EventSink<framepos_t>& dst, framepos_t source_sta
 							  source_start, start, cnt, tracker, name()));
 
 	if (_model) {
-		Evoral::Sequence<double>::const_iterator& i = _model_iter;
-
-		// If the cached iterator is invalid, search for the first event past start
-		if (_last_read_end == 0 || start != _last_read_end || !_model_iter_valid) {
-			DEBUG_TRACE (DEBUG::MidiSourceIO, string_compose ("*** %1 search for relevant iterator for %1 / %2\n", _name, source_start, start));
-			for (i = _model->begin(0, false, filtered); i != _model->end(); ++i) {
-				if (converter.to(i->time()) >= start) {
-					DEBUG_TRACE (DEBUG::MidiSourceIO, string_compose ("***\tstop iterator search @ %1\n", i->time()));
-					break;
-				}
-			}
-			_model_iter_valid = true;
-		} else {
-			DEBUG_TRACE (DEBUG::MidiSourceIO, string_compose ("*** %1 use cachediterator for %1 / %2\n", _name, source_start, start));
-		}
-
-		_last_read_end = start + cnt;
-
 		// Read events up to end
-		for (; i != _model->end(); ++i) {
+		const double start_beats = converter.from(start);
+		for (Evoral::Sequence<double>::const_iterator i = _model->begin(start_beats, false, filtered);
+		     i != _model->end();
+		     ++i) {
 			const framecnt_t time_frames = converter.to(i->time());
 			if (time_frames < start + cnt) {
 				/* convert event times to session frames by adding on the source start position in session frames */
@@ -265,9 +239,7 @@ MidiSource::midi_write (MidiRingBuffer<framepos_t>& source,
 
 	const framecnt_t ret = write_unlocked (source, source_start, cnt);
 
-	if (cnt == max_framecnt) {
-		_last_read_end = 0;
-	} else {
+	if (cnt != max_framecnt) {
 		_capture_length += cnt;
 	}