jack2/common/JackMidiWriteQueue.h

83 lines
2.8 KiB
C++

/*
Copyright (C) 2010 Devin Anderson
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef __JackMidiWriteQueue__
#define __JackMidiWriteQueue__
#include "JackMidiPort.h"
namespace Jack {
/**
* Interface for classes that act as write queues for MIDI messages. Write
* queues are used by processors to transfer data to the next processor.
*/
class SERVER_EXPORT JackMidiWriteQueue {
public:
enum EnqueueResult {
BUFFER_FULL,
BUFFER_TOO_SMALL,
EVENT_EARLY,
EN_ERROR,
OK
};
virtual ~JackMidiWriteQueue();
/**
* Enqueues a data packet in the write queue of `size` bytes contained
* in `buffer` that will be sent the absolute time specified by `time`.
* This method should not block unless 1.) this write queue represents
* the actual outbound MIDI connection, 2.) the MIDI event is being
* sent *now*, meaning that `time` is less than or equal to *now*, and
* 3.) the method is *not* being called in the process thread. The
* method should return `OK` if the event was enqueued, `BUFFER_FULL`
* if the write queue isn't able to accept the event right now,
* `BUFFER_TOO_SMALL` if this write queue will never be able to accept
* the event because the event is too large, `EVENT_EARLY` if this
* queue cannot schedule events ahead of time, and `EN_ERROR` if an error
* occurs that cannot be specified by another return code.
*/
virtual EnqueueResult
EnqueueEvent(jack_nframes_t time, size_t size,
jack_midi_data_t *buffer) = 0;
/**
* A wrapper method for the `EnqueueEvent` method above. The optional
* 'frame_offset' argument is an amount of frames to add to the event's
* time.
*/
inline EnqueueResult
EnqueueEvent(jack_midi_event_t *event, jack_nframes_t frame_offset=0)
{
return EnqueueEvent(event->time + frame_offset, event->size,
event->buffer);
}
};
}
#endif