public Decompressor getDecompressor() {
      CompressionCodec codec = getCodec(conf);
      if (codec != null) {
        Decompressor decompressor = CodecPool.getDecompressor(codec);
        if (LOG.isTraceEnabled())
          LOG.trace("Retrieved decompressor " + decompressor + " from pool.");
        if (decompressor != null) {
          if (decompressor.finished()) {
            // Somebody returns the decompressor to CodecPool but is still using it.
            LOG.warn("Decompressor {} obtained from CodecPool is already finished", decompressor);
          }
          decompressor.reset();
        }
        return decompressor;
      }

      return null;
    }
Creates a compression stream without any additional wrapping into buffering streams.
hbase-common/src/main/java/org/apache/hadoop/hbase/io/compress/Compression.java