Encoder comparison
The encoder matrix compares safe Rust OpenZL against the pinned C implementation, with matching graphs, parameters, typed views, frame bytes and corpus. C and Rust compressed sizes are identical; throughput is read against that fixed ratio. The full report includes every file.
Implementations and API mode
The C side uses OpenZL v0.3.0, zstd 1.5.7 and lz4 1.10.0 from the pinned submodules at -O3. The Rust side uses mopenzl and mzstd with the lockfile recorded by the comparison workspace. Prepared contexts and caller output storage are reused. Untimed validation precedes the alternating measurement rounds.
Levels, graphs and corpora
The published graph sweep uses level 6 and format 27. Serial bytes, numeric 16/32-bit inputs and four-byte records are separate views, with only compatible files in each view. Store-on-expansion and checksums follow defaults. There is no published multi-level sweep; changing a node/graph or level requires a fresh matched run. See reproduction.