/* * Copyright (C) 2016 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 org.mozilla.thirdparty.com.google.android.exoplayer2.upstream; import android.net.Uri; import androidx.annotation.Nullable; import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Assertions; import org.mozilla.thirdparty.com.google.android.exoplayer2.util.PriorityTaskManager; import java.io.IOException; import java.util.List; import java.util.Map; /** * A {@link DataSource} that can be used as part of a task registered with a * {@link PriorityTaskManager}. *
* Calls to {@link #open(DataSpec)} and {@link #read(byte[], int, int)} are allowed to proceed only * if there are no higher priority tasks registered to the {@link PriorityTaskManager}. If there * exists a higher priority task then {@link PriorityTaskManager.PriorityTooLowException} is thrown. *
* Instances of this class are intended to be used as parts of (possibly larger) tasks that are
* registered with the {@link PriorityTaskManager}, and hence do not register as tasks
* themselves.
*/
public final class PriorityDataSource implements DataSource {
private final DataSource upstream;
private final PriorityTaskManager priorityTaskManager;
private final int priority;
/**
* @param upstream The upstream {@link DataSource}.
* @param priorityTaskManager The priority manager to which the task is registered.
* @param priority The priority of the task.
*/
public PriorityDataSource(DataSource upstream, PriorityTaskManager priorityTaskManager,
int priority) {
this.upstream = Assertions.checkNotNull(upstream);
this.priorityTaskManager = Assertions.checkNotNull(priorityTaskManager);
this.priority = priority;
}
@Override
public void addTransferListener(TransferListener transferListener) {
upstream.addTransferListener(transferListener);
}
@Override
public long open(DataSpec dataSpec) throws IOException {
priorityTaskManager.proceedOrThrow(priority);
return upstream.open(dataSpec);
}
@Override
public int read(byte[] buffer, int offset, int max) throws IOException {
priorityTaskManager.proceedOrThrow(priority);
return upstream.read(buffer, offset, max);
}
@Override
@Nullable
public Uri getUri() {
return upstream.getUri();
}
@Override
public Map