| /* |
| * Copyright 2019 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 androidx.media2.common; |
| |
| import androidx.annotation.NonNull; |
| |
| import java.io.Closeable; |
| import java.io.IOException; |
| |
| /** |
| * For supplying media data, implement this if your app has special requirements for the way media |
| * data is obtained. |
| * |
| * <p class="note">Methods of this interface may be called on multiple different |
| * threads. There will be a thread synchronization point between each call to ensure that |
| * modifications to the state of your DataSourceCallback are visible to future calls. This means |
| * you don't need to do your own synchronization unless you're modifying the |
| * DataSourceCallback from another thread while it's being used by the media library.</p> |
| * |
| */ |
| public abstract class DataSourceCallback implements Closeable { |
| /** |
| * Called to request data from the given position. |
| * |
| * Implementations should should write up to {@code size} bytes into |
| * {@code buffer}, and return the number of bytes written. |
| * |
| * Return {@code 0} if size is zero (thus no bytes are read). |
| * |
| * Return {@code -1} to indicate that end of stream is reached. |
| * |
| * @param position the position in the media item to read from. |
| * @param buffer the buffer to read the data into. |
| * @param offset the offset within buffer to read the data into. |
| * @param size the number of bytes to read. |
| * @throws IOException on fatal errors. |
| * @return the number of bytes read, or -1 if the end of stream was reached. |
| */ |
| public abstract int readAt(long position, @NonNull byte[] buffer, int offset, int size) |
| throws IOException; |
| |
| /** |
| * Called to get the size of the data source. |
| * |
| * @throws IOException on fatal errors |
| * @return the size of data source in bytes, or -1 if the size is unknown. |
| */ |
| public abstract long getSize() throws IOException; |
| } |