content: /*
   * Copyright (C) 2017 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 android.util.Base64;
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.ParserException;
  import java.io.IOException;
  import java.net.URLDecoder;
  
  /**
   * A {@link DataSource} for reading data URLs, as defined by RFC 2397.
   */
  public final class DataSchemeDataSource implements DataSource {
  
    public static final String SCHEME_DATA = "data";
  
    private DataSpec dataSpec;
    private int bytesRead;
    private byte[] data;
  
    @Override
    public long open(DataSpec dataSpec) throws IOException {
      this.dataSpec = dataSpec;
      Uri uri = dataSpec.uri;
      String scheme = uri.getScheme();
      if (!SCHEME_DATA.equals(scheme)) {
        throw new ParserException("Unsupported scheme: " + scheme);
      }
      String[] uriParts = uri.getSchemeSpecificPart().split(",");
      if (uriParts.length > 2) {
        throw new ParserException("Unexpected URI format: " + uri);
      }
      String dataString = uriParts[1];
      if (uriParts[0].contains(";base64")) {
        try {
          data = Base64.decode(dataString, 0);
        } catch (IllegalArgumentException e) {
          throw new ParserException("Error while parsing Base64 encoded string: " + dataString, e);
        }
      } else {
        // TODO: Add support for other charsets.
        data = URLDecoder.decode(dataString, C.ASCII_NAME).getBytes();
      }
      return data.length;
    }
  
    @Override
    public int read(byte[] buffer, int offset, int readLength) {
      if (readLength == 0) {
        return 0;
      }
      int remainingBytes = data.length - bytesRead;
      if (remainingBytes == 0) {
        return C.RESULT_END_OF_INPUT;
      }
      readLength = Math.min(readLength, remainingBytes);
      System.arraycopy(data, bytesRead, buffer, offset, readLength);
      bytesRead += readLength;
      return readLength;
    }
  
    @Override
    public Uri getUri() {
      return dataSpec != null ? dataSpec.uri : null;
    }
  
    @Override
    public void close() throws IOException {
      dataSpec = null;
      data = null;
    }
  
  }
  