misa77 (0.2.0)

misa77 is an LZ-based codec that targets the write-once, read-many niche. In particular, it aims to satisfy the following criteria:

Extremely high decompression throughput (single-threaded).

Modest compression ratios (it has no entropy backend, so one can obviously not compare it to something like zstd, but LZ4 at high effort levels is a good reference point).

Constant memory use, regardless of input size (<= 5 MB across all compression modes, and 0 MB for decompression).

Slow compression is the obvious tradeoff that one makes to achieve the above.

In addition, misa77 has a somewhat synergizing tendency to decompress highly compressed files faster, leading to the following results:

It offers particularly high decompression throughput on highly compressible files.

Even for moderately compressible files, spending more effort during compression to get a more compressed result leads to better decompression throughput (alongside the natural advantage of better ratios).

This makes…