 of each block (exception for last block of the stream),
    _then_ decoding & encoding ring buffer can have any size, including small ones ( < 64 KB).
  - Decompression buffer is larger than encoding buffer, by a minimum of maxBlockSize more bytes.
    In which case, encoding and decoding buffers do not need to be synchronized,
    and encoding ring buffer can have any size, including small ones ( < 64 KB).

  Whenever these conditions are not possible,
  save the last 64KB of decoded data into a safe buff