code: private boolean readMetaSegment(ReadStream is, int crc)
      throws IOException
    {
      long value = BitsUtil.readLong(is);
      
      crc = Crc32Caucho.generate(crc, value);
  
      int crcFile = BitsUtil.readInt(is);
      
      if (crcFile != crc) {
        log.fine("meta-segment crc mismatch");
        return false;
      }
      
      long address = value & ~0xffff;
      int length = (int) ((value & 0xffff) << 16);
      
      SegmentExtent segment = new SegmentExtent(_segmentId++, address, length);
  
      SegmentMeta segmentMeta = findSegmentMeta(length);
      
      segmentMeta.addSegment(segment);
      
      return true;
    }
docs: metadata for a segment
  
  <pre><code>
  address int48
  length  int16
  crc     int32
  </code></pre>