Compression.java 文件源码

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

  return null;
}