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.util.Assertions;
  import java.io.IOException;
  
  /**
   * A {@link DataSource} for reading from a byte array.
   */
  public final class ByteArrayDataSource implements DataSource {
  
    private final byte[] data;
  
    private Uri uri;
    private int readPosition;
    private int bytesRemaining;
  
    /**
     * @param data The data to be read.
     */
    public ByteArrayDataSource(byte[] data) {
      Assertions.checkNotNull(data);
      Assertions.checkArgument(data.length > 0);
      this.data = data;
    }
  
    @Override
    public long open(DataSpec dataSpec) throws IOException {
      uri = dataSpec.uri;
      readPosition = (int) dataSpec.position;
      bytesRemaining = (int) ((dataSpec.length == C.LENGTH_UNSET)
          ? (data.length - dataSpec.position) : dataSpec.length);
      if (bytesRemaining <= 0 || readPosition + bytesRemaining > data.length) {
        throw new IOException("Unsatisfiable range: [" + readPosition + ", " + dataSpec.length
            + "], length: " + data.length);
      }
      return bytesRemaining;
    }
  
    @Override
    public int read(byte[] buffer, int offset, int readLength) throws IOException {
      if (readLength == 0) {
        return 0;
      } else if (bytesRemaining == 0) {
        return C.RESULT_END_OF_INPUT;
      }
  
      readLength = Math.min(readLength, bytesRemaining);
      System.arraycopy(data, readPosition, buffer, offset, readLength);
      readPosition += readLength;
      bytesRemaining -= readLength;
      return readLength;
    }
  
    @Override
    public Uri getUri() {
      return uri;
    }
  
    @Override
    public void close() throws IOException {
      uri = null;
    }
  
  }
  