protected static void writeLzopHeader()

in src/main/java/com/hadoop/compression/lzo/LzopOutputStream.java [44:82]

39 lines of code
4 McCabe index (conditional complexity)


  protected static void writeLzopHeader(OutputStream out,
          LzoCompressor.CompressionStrategy strategy,
          int compressionLevel) throws IOException {
    DataOutputBuffer dob = new DataOutputBuffer();
    try {
      dob.writeShort(LzopCodec.LZOP_VERSION);
      dob.writeShort(LzoCompressor.LZO_LIBRARY_VERSION);
      dob.writeShort(LzopCodec.LZOP_COMPAT_VERSION);
      switch (strategy) {
      case LZO1X_1:
        dob.writeByte(1);
        dob.writeByte(5);
        break;
      case LZO1X_15:
        dob.writeByte(2);
        dob.writeByte(1);
        break;
      case LZO1X_999:
        dob.writeByte(3);
        dob.writeByte((byte) compressionLevel);
        break;
      default:
        throw new IOException("Incompatible lzop strategy: " + strategy);
      }
      dob.writeInt(0);                                    // all flags 0
      dob.writeInt(0x81A4);                               // mode
      dob.writeInt((int)(System.currentTimeMillis() / 1000)); // mtime
      dob.writeInt(0);                                    // gmtdiff ignored
      dob.writeByte(0);                                   // no filename
      Adler32 headerChecksum = new Adler32();
      headerChecksum.update(dob.getData(), 0, dob.getLength());
      int hc = (int)headerChecksum.getValue();
      dob.writeInt(hc);
      out.write(LzopCodec.LZO_MAGIC);
      out.write(dob.getData(), 0, dob.getLength());
    } finally {
      dob.close();
    }
  }