Move the reusable buffer and compression-context pools behind a Rust
implementation with a narrow C ABI adapter. The scheduler, job table, serial
LDM state, and stream orchestration remain in C until their private layouts
are ported.
Keep context types opaque across Rust modules so the pool bridge does not
depend on private C layout declarations. This also keeps the existing custom
allocator and pool replacement contracts intact.
Test Plan:
- RUSTC_WRAPPER= CARGO_BUILD_RUSTC_WRAPPER= cargo clippy --manifest-path
rust/Cargo.toml --all-targets -- -D warnings
- RUSTC_WRAPPER= CARGO_BUILD_RUSTC_WRAPPER= cargo test --manifest-path
rust/Cargo.toml zstdmt_compress
- make -B -C lib lib-mt
- git diff --cached --check
Move COVER training, frequency mapping, segment selection, optimization,
dictionary shrinking, and best-candidate synchronization into Rust. The
remaining C translation unit is an ABI shim, while the public ZDICT and COVER
symbols stay available to the existing C dictionary-builder callers.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml dict_builder_cover
- cargo check --manifest-path rust/Cargo.toml --no-default-features --features compression,decompression,dict-builder
- cargo clippy --manifest-path rust/Cargo.toml --all-targets -- -D warnings
- make -B -C lib libzstd.a V=1
- git diff --check
Depends-on: Rust compression, entropy, and dictionary-finalization leaves
ddidderr