Fix repeated linear search on read when cached model iterator reaches end.

git-svn-id: svn://localhost/ardour2/branches/3.0@5853 d708f5d6-7413-0410-9779-e7cbd77b26cf

diff --git a/libs/ardour/midi_source.cc b/libs/ardour/midi_source.cc
index b925c810dad48251f2b34e2738e3ef65c8b75495..86f0b86f95fdf73107bdf5203ee9cb6c6f60ac88 100644 (file)
--- a/libs/ardour/midi_source.cc
+++ b/libs/ardour/midi_source.cc
@@ -51,10 +51,11 @@ using namespace PBD;
 sigc::signal<void,MidiSource *> MidiSource::MidiSourceCreated;
 
 MidiSource::MidiSource (Session& s, string name, Source::Flag flags)
-       : Source (s, DataType::MIDI, name, flags)
+       : Source(s, DataType::MIDI, name, flags)
        , _read_data_count(0)
        , _write_data_count(0)
-       , _writing (false)
+       , _writing(false)
+       , _model_iterator_valid(true)
        , _length_beats(0.0)
        , _last_read_end(0)
        , _last_write_end(0)
@@ -62,10 +63,11 @@ MidiSource::MidiSource (Session& s, string name, Source::Flag flags)
 }
 
 MidiSource::MidiSource (Session& s, const XMLNode& node)
-       : Source (s, node)
+       : Source(s, node)
        , _read_data_count(0)
        , _write_data_count(0)
-       , _writing (false)
+       , _writing(false)
+       , _model_iterator_valid(true)
        , _length_beats(0.0)
        , _last_read_end(0)
        , _last_write_end(0)
@@ -122,7 +124,7 @@ MidiSource::update_length (sframes_t /*pos*/, sframes_t /*cnt*/)
 void
 MidiSource::invalidate ()
 {
-       _model_iter.invalidate();
+       _model_iterator_valid = false;
 }
 
 nframes_t
@@ -136,23 +138,29 @@ MidiSource::midi_read (MidiRingBuffer<nframes_t>& dst, sframes_t source_start,
        BeatsFramesConverter converter(_session, source_start);
 
        if (_model) {
+               //cerr << "READ @ " << start << " * " << cnt << " (source @ " << source_start << " {" << endl;
 #define BEATS_TO_FRAMES(t) (converter.to(t) + stamp_offset - negative_stamp_offset)
 
                Evoral::Sequence<double>::const_iterator& i = _model_iter;
 
-               if (_last_read_end == 0 || start != _last_read_end || !i.valid()) {
+               // If the cached iterator is invalid, search for the first event past start
+               if (_last_read_end == 0 || start != _last_read_end || !_model_iterator_valid) {
                        for (i = _model->begin(); i != _model->end(); ++i) {
                                if (BEATS_TO_FRAMES(i->time()) >= start) {
                                        break;
                                }
                        }
+                       _model_iterator_valid = true;
                }
 
                _last_read_end = start + cnt;
 
+               // Read events up to source_start + start + cnt
                for (; i != _model->end(); ++i) {
                        const sframes_t time_frames = BEATS_TO_FRAMES(i->time());
+                       //cerr << "Read? " << time_frames << " < " << source_start + start + cnt << endl;
                        if (time_frames < source_start + start + cnt) {
+                               //cerr << "Read @ " << time_frames << endl;
                                dst.write(time_frames, i->event_type(), i->size(), i->buffer());
                                if (tracker) {
                                        Evoral::MIDIEvent<Evoral::MusicalTime>& ev (*(Evoral::MIDIEvent<Evoral::MusicalTime>*) (&(*i)));
@@ -163,9 +171,11 @@ MidiSource::midi_read (MidiRingBuffer<nframes_t>& dst, sframes_t source_start,
                                        }
                                }
                        } else {
+                               //cerr << "End" << endl;
                                break;
                        }
                }
+               //cerr << "}" << endl;
                return cnt;
        } else {
                return read_unlocked (dst, source_start, start, cnt, stamp_offset, negative_stamp_offset, tracker);