1 files changed, 89 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/PriorityDataSource.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/PriorityDataSource.java
new file mode 100644
index 0000000000..18a7fb6238
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/PriorityDataSource.java
@@ -0,0 +1,89 @@
+/*
+ * 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}.
+ * <p>
+ * 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.
+ * <p>
+ * 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 <em>not</em> 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<String, List<String>> getResponseHeaders() {
+    return upstream.getResponseHeaders();
+  }
+
+  @Override
+  public void close() throws IOException {
+    upstream.close();
+  }
+
+}