Compression.java 文件源码

public Compressor getCompressor() throws IOException {
  CompressionCodec codec = getCodec();
  if (codec != null) {
    Compressor compressor = CodecPool.getCompressor(codec);
    if (compressor != null) {
      if (compressor.finished()) {
        // Somebody returns the compressor to CodecPool but is still using
        // it.
        LOG.warn("Compressor obtained from CodecPool already finished()");
      } else {
        if(LOG.isDebugEnabled()) {
          LOG.debug("Got a compressor: " + compressor.hashCode());
        }
      }
      /**
       * Following statement is necessary to get around bugs in 0.18 where a
       * compressor is referenced after returned back to the codec pool.
       */
      compressor.reset();
    }
    return compressor;
  }
  return null;
}