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/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.internal.midi;
import android.media.midi.MidiReceiver;
import java.io.IOException;
/**
* Add MIDI Events to an EventScheduler
*/
public class MidiEventScheduler extends EventScheduler {
private static final String TAG = "MidiEventScheduler";
// Maintain a pool of scheduled events to reduce memory allocation.
// This pool increases performance by about 14%.
private final static int POOL_EVENT_SIZE = 16;
private MidiReceiver mReceiver = new SchedulingReceiver();
private class SchedulingReceiver extends MidiReceiver {
/**
* Store these bytes in the EventScheduler to be delivered at the specified
* time.
*/
@Override
public void onSend(byte[] msg, int offset, int count, long timestamp)
throws IOException {
MidiEvent event = createScheduledEvent(msg, offset, count, timestamp);
if (event != null) {
add(event);
}
}
@Override
public void onFlush() {
MidiEventScheduler.this.flush();
}
}
public static class MidiEvent extends SchedulableEvent {
public int count = 0;
public byte[] data;
private MidiEvent(int count) {
super(0);
data = new byte[count];
}
private MidiEvent(byte[] msg, int offset, int count, long timestamp) {
super(timestamp);
data = new byte[count];
System.arraycopy(msg, offset, data, 0, count);
this.count = count;
}
@Override
public String toString() {
String text = "Event: ";
for (int i = 0; i < count; i++) {
text += data[i] + ", ";
}
return text;
}
}
/**
* Create an event that contains the message.
*/
private MidiEvent createScheduledEvent(byte[] msg, int offset, int count,
long timestamp) {
MidiEvent event;
if (count > POOL_EVENT_SIZE) {
event = new MidiEvent(msg, offset, count, timestamp);
} else {
event = (MidiEvent) removeEventfromPool();
if (event == null) {
event = new MidiEvent(POOL_EVENT_SIZE);
}
System.arraycopy(msg, offset, event.data, 0, count);
event.count = count;
event.setTimestamp(timestamp);
}
return event;
}
/**
* Return events to a pool so they can be reused.
*
* @param event
*/
@Override
public void addEventToPool(SchedulableEvent event) {
// Make sure the event is suitable for the pool.
if (event instanceof MidiEvent) {
MidiEvent midiEvent = (MidiEvent) event;
if (midiEvent.data.length == POOL_EVENT_SIZE) {
super.addEventToPool(event);
}
}
}
/**
* This MidiReceiver will write date to the scheduling buffer.
* @return the MidiReceiver
*/
public MidiReceiver getReceiver() {
return mReceiver;
}
}
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