content: /*
   * 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 com.google.android.exoplayer2.upstream;
  
  import android.net.Uri;
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.ParserException;
  import com.google.android.exoplayer2.upstream.Loader.Loadable;
  import com.google.android.exoplayer2.util.Util;
  import java.io.IOException;
  import java.io.InputStream;
  
  /**
   * A {@link Loadable} for objects that can be parsed from binary data using a {@link Parser}.
   *
   * @param <T> The type of the object being loaded.
   */
  public final class ParsingLoadable<T> implements Loadable {
  
    /**
     * Parses an object from loaded data.
     */
    public interface Parser<T> {
  
      /**
       * Parses an object from a response.
       *
       * @param uri The source {@link Uri} of the response, after any redirection.
       * @param inputStream An {@link InputStream} from which the response data can be read.
       * @return The parsed object.
       * @throws ParserException If an error occurs parsing the data.
       * @throws IOException If an error occurs reading data from the stream.
       */
      T parse(Uri uri, InputStream inputStream) throws IOException;
  
    }
  
    /**
     * The {@link DataSpec} that defines the data to be loaded.
     */
    public final DataSpec dataSpec;
    /**
     * The type of the data. One of the {@code DATA_TYPE_*} constants defined in {@link C}. For
     * reporting only.
     */
    public final int type;
  
    private final DataSource dataSource;
    private final Parser<? extends T> parser;
  
    private volatile T result;
    private volatile boolean isCanceled;
    private volatile long bytesLoaded;
  
    /**
     * @param dataSource A {@link DataSource} to use when loading the data.
     * @param uri The {@link Uri} from which the object should be loaded.
     * @param type See {@link #type}.
     * @param parser Parses the object from the response.
     */
    public ParsingLoadable(DataSource dataSource, Uri uri, int type, Parser<? extends T> parser) {
      this(
          dataSource,
          new DataSpec(uri, DataSpec.FLAG_ALLOW_GZIP | DataSpec.FLAG_ALLOW_CACHING_UNKNOWN_LENGTH),
          type,
          parser);
    }
  
    /**
     * @param dataSource A {@link DataSource} to use when loading the data.
     * @param dataSpec The {@link DataSpec} from which the object should be loaded.
     * @param type See {@link #type}.
     * @param parser Parses the object from the response.
     */
    public ParsingLoadable(DataSource dataSource, DataSpec dataSpec, int type,
        Parser<? extends T> parser) {
      this.dataSource = dataSource;
      this.dataSpec = dataSpec;
      this.type = type;
      this.parser = parser;
    }
  
    /**
     * Returns the loaded object, or null if an object has not been loaded.
     */
    public final T getResult() {
      return result;
    }
  
    /**
     * Returns the number of bytes loaded. In the case that the network response was compressed, the
     * value returned is the size of the data <em>after</em> decompression.
     *
     * @return The number of bytes loaded.
     */
    public long bytesLoaded() {
      return bytesLoaded;
    }
  
    @Override
    public final void cancelLoad() {
      // We don't actually cancel anything, but we need to record the cancellation so that
      // isLoadCanceled can return the correct value.
      isCanceled = true;
    }
  
    @Override
    public final boolean isLoadCanceled() {
      return isCanceled;
    }
  
    @Override
    public final void load() throws IOException {
      DataSourceInputStream inputStream = new DataSourceInputStream(dataSource, dataSpec);
      try {
        inputStream.open();
        result = parser.parse(dataSource.getUri(), inputStream);
      } finally {
        bytesLoaded = inputStream.bytesRead();
        Util.closeQuietly(inputStream);
      }
    }
  
  }
  