GoKawiilmisa77 (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 high-effort compression particularly attractive for misa77, and inspires some experimental compression modes (refer to src/experimental/) that aim to spend more effort at compression time to produce a compressed stream that is friendlier to the microarchitectures of most CPUs when decompressing said streams.
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