@hackage / snappy-hs

snappy-hs

A pure Haskell implementation of the Snappy compression format.

This library prioritizes portability and simplicity over raw speed. It works reliably across platforms without requiring a C toolchain or dealing with FFI.

Performance

Measured against the native C library (the snappy bindings) on the Google Snappy test corpus, GHC 9.12 / aarch64, library built with -O2:

Decompression runs at roughly C parity (~1-2x) and compression is ~2-3x of C. The gap that remains is GHC's native code generator versus a C compiler, not the algorithm — the encoder mirrors C Snappy's CompressFragment (skip heuristic, word-at-a-time match extension, input-sized hash table). Output is validated to be byte-compatible with the C library in both directions.

Reproduce with cabal bench (criterion, needs the C snappy library installed) or cabal run snappy-bench (pure, no C dependency).

When to use

• You want cross-platform Snappy encode/decode with a pure Haskell dependency stack
• You’d rather avoid C FFI and the build/packaging complexity that comes with it

When not to use

• You need maximum throughput (use the native library or an FFI-based binding instead). You would get a lot of mileage from the library too however.