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.android.server.backup.utils;
  
  import static com.android.server.backup.BackupManagerService.TAG;
  
  import android.os.ParcelFileDescriptor;
  import android.util.Slog;
  
  import java.io.DataInputStream;
  import java.io.EOFException;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  
  /**
   * Low-level utility methods for full backup.
   */
  public class FullBackupUtils {
      /**
       * Reads data from pipe and writes it to the stream in chunks of up to 32KB.
       *
       * @param inPipe - pipe to read the data from.
       * @param out - stream to write the data to.
       * @throws IOException - in case of an error.
       */
      public static void routeSocketDataToOutput(ParcelFileDescriptor inPipe, OutputStream out)
              throws IOException {
          // We do not take close() responsibility for the pipe FD
          FileInputStream raw = new FileInputStream(inPipe.getFileDescriptor());
          DataInputStream in = new DataInputStream(raw);
  
          byte[] buffer = new byte[32 * 1024];
          int chunkTotal;
          while ((chunkTotal = in.readInt()) > 0) {
              while (chunkTotal > 0) {
                  int toRead = (chunkTotal > buffer.length) ? buffer.length : chunkTotal;
                  int nRead = in.read(buffer, 0, toRead);
                  if (nRead < 0) {
                      Slog.e(TAG, "Unexpectedly reached end of file while reading data");
                      throw new EOFException();
                  }
                  out.write(buffer, 0, nRead);
                  chunkTotal -= nRead;
              }
          }
      }
  }
  