ZSTD_resolveExternalSequenceValidation() is a pure int identity used while
resolving CCtx parameters. Route its existing C wrapper through a Rust
extern "C" entry point in the parameter module, preserving the int-to-int
ABI and every call-site result. Add boundary coverage for signed int modes.
Test Plan:
- `cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression` -- passed (253 tests)
- `make -B -C lib -j2 lib` -- passed
- required clippy passes for the compression feature, benches, and tests -- passed
- `cargo +nightly fmt --manifest-path rust/Cargo.toml` and `git diff --check` -- passed
The compression-parameter override helper previously lived in C and selectively
copied each nonzero field from a caller-provided override structure. Move that
pure field-wise operation into the Rust compression-parameter module, while
keeping the existing repr(C) structure and pointer-based ABI at both C call
sites. Zero-valued overrides continue to leave the current parameter untouched.
Test Plan:
- `cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression` -- passed (252 tests)
- `make -B -C lib -j2 lib` -- passed
- `make -C tests -j2 fuzzer` and `tests/fuzzer -s4560 -t47 -i48 -v` -- passed
- required clippy passes, nightly fmt, and `git diff --check` -- passed
Keep validation of the applied compression parameters in C and delegate the context-free minimum calculation through a narrow ABI leaf. Preserve the public getter and deprecated block-compression paths.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression
- cargo clippy --manifest-path rust/Cargo.toml --no-default-features --features compression --all-targets
- cargo +nightly fmt --manifest-path rust/Cargo.toml
- make -B -C lib -j2 lib
- make -C tests -j2 fuzzer
- tests/fuzzer -s4560 -t47 -i48 -v
Keep C ownership of the block-state structure while delegating the confirmed-block pointer swap through a narrow two-pointer ABI leaf. Preserve every existing confirmation call site and add direct pointer-swap coverage.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression
- cargo clippy --manifest-path rust/Cargo.toml --no-default-features --features compression --all-targets
- cargo +nightly fmt --manifest-path rust/Cargo.toml
- make -B -C lib -j2 lib
- tests/fuzzer -s4560 -t47 -i48 -v
- make -C tests -j2 test-zstream
Parse attached and separated --patch-from references, preserve the upstream ultra ceiling and conflict checks, and pass the reference path through the existing file-I/O dictionary ABI with patch mode enabled.
Test Plan:
- cargo test --manifest-path rust/cli/Cargo.toml
- cargo clippy --manifest-path rust/cli/Cargo.toml --all-targets
- cargo +nightly fmt --manifest-path rust/Cargo.toml
- make -C tests -j2 check
- small attached/separate patch-from round-trip and rejection smoke
Port the no-delimiter external-sequence block scanner, match splitting, repcode updates, validation, and sequence/literal storage behind a narrow C shim. Preserve trailing bytes as literals when the sequence buffer ends before the requested block, and remove the obsolete C validation wrapper.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression (242 passed)
- cargo clippy --manifest-path rust/Cargo.toml --no-default-features --features compression [--benches|--tests] (clean)
- cargo +nightly fmt --manifest-path rust/Cargo.toml (clean)
- make -B -C lib -j2 lib (passed)
- make -C tests -j2 test-zstream (84 deterministic; 5960 and 8307 randomized passed)
- make -C tests -j2 test-fuzzer (existing test 56 CCtx-reuse mismatch; also fails at 37eb75758)
- make -C tests -j2 test-zstd (existing Rust CLI --patch-from gap)
Port ZSTD_dictNCountRepeat and ZSTD_loadCEntropy to a dedicated Rust compression module. Preserve the existing C-facing ZSTD_loadCEntropy symbol through a narrow shim while keeping dictionary content and compression-context ownership in C.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression
- cargo clippy --manifest-path rust/Cargo.toml --no-default-features --features compression --benches --tests
- make -B -C lib -j2 lib
- make -C tests -j2 test-invalidDictionaries
- make -C tests -j2 test-zstream
Move ZSTD_transferSequences_wBlockDelim's delimiter scan, literal copying, SeqDef storage, validation, and repcode bookkeeping into the Rust compression statistics module. Keep ZSTD_CCtx and block-state ownership in C through a narrow scalar/pointer shim, with ABI layout assertions for ZSTD_SequencePosition.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression
- cargo clippy --manifest-path rust/Cargo.toml --no-default-features --features compression --benches --tests
- make -B -C lib -j2 lib
- make -C tests -j2 test-zstream
Block splitting still estimated literal and sequence section sizes through
three C helpers. Move the pure estimator into zstd_compress_stats.rs so its
histogram, HUF, and FSE cost calculations use the Rust implementations already
behind the compression ABI. Preserve the original literal headers, multi-stream
Huffman surcharge, sequence additional-bit costs, entropy-header accounting,
and fallback estimates; leave C responsible for split recursion and table
ownership.
Test Plan:
- `cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression` -- 229 passed
- `cargo clippy --manifest-path rust/Cargo.toml --no-default-features --features compression` plus benches/tests -- passed before and after formatting
- `cargo +nightly fmt --manifest-path rust/Cargo.toml --all` -- passed
- `make -B -C lib -j2 lib` -- passed
- `make -C tests -j2 test-zstream` -- passed, including 84 deterministic and 15,375 randomized cases
The explicit-delimiter sequence path still calculated each block summary in C,
with a separate AVX2 implementation and scalar fallback. Move that pure scan
to zstd_compress_stats.rs and keep a C wrapper for the existing orchestration.
The Rust leaf preserves delimiter inclusion, literal and match totals, and the
external-sequences error when no delimiter is present, while the C ABI is pinned
with a repr(C) layout check.
Test Plan:
- `cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression` -- 227 passed
- `cargo clippy --manifest-path rust/Cargo.toml --no-default-features --features compression` plus benches/tests -- passed before and after formatting
- `cargo +nightly fmt --manifest-path rust/Cargo.toml --all` -- passed
- `make -B -C lib -j2 lib` -- passed
- `make -C tests -j2 test-zstream` -- passed, including 84 deterministic and 15,464 randomized cases
The external-sequence block path still converted public ZSTD_Sequence values
in C, with separate scalar and AVX2 implementations. Move that pure format
conversion into zstd_compress_stats.rs so both native configurations share one
implementation. Preserve offBase encoding, u16 truncation, the rep-ignored
contract, and the long-length side-band marker; leave C responsible for block
state, repcode resolution, and long-length bookkeeping.
Test Plan:
- `cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression` -- 225 passed
- `cargo clippy --manifest-path rust/Cargo.toml --no-default-features --features compression` plus benches/tests -- passed before and after formatting
- `cargo +nightly fmt --manifest-path rust/Cargo.toml --all` -- passed
- `make -B -C lib -j2 lib` -- passed
- `make -C tests -j2 test-zstream` -- passed, including 84 deterministic and 14,768 randomized cases
Port ZSTD_seqStore_resolveOffCodes and its repcode-resolution helper to Rust. The C shim keeps Repcodes_t and SeqStore_t ownership in the compressor context while Rust preserves long-literal handling, mismatch materialization, and independent decoder/compressor history updates.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression (208 tests)
- cargo clippy --manifest-path rust/Cargo.toml
- cargo clippy --manifest-path rust/Cargo.toml --benches
- cargo clippy --manifest-path rust/Cargo.toml --tests
- make -B -C lib -j2 lib
Replace the shared C raw and one-byte RLE fallback block serializers with Rust ABI leaves. Preserve the zstd block headers, payload copies, capacity errors, and all existing C compressor dispatch and context ownership; share the raw serializer with the Rust one-shot path.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression (208 tests)
- cargo clippy --manifest-path rust/Cargo.toml
- cargo clippy --manifest-path rust/Cargo.toml --benches
- cargo clippy --manifest-path rust/Cargo.toml --tests
- make -B -C lib -j2 lib
Move malloc-backed dictionary file reads into the Rust CLI backend while keeping C responsible for stat metadata, patch-mode size policy, diagnostics, buffer-type selection, and eventual free(). The Rust leaf returns explicit open, size, allocation, and read statuses and publishes only fully read libc allocations.
Test Plan:
- cargo test --manifest-path rust/cli/Cargo.toml (126 tests)
- cargo clippy --manifest-path rust/cli/Cargo.toml
- make -B -C programs -j2 zstd
- make -C tests -j2 test-cli-tests (41 tests)
Port the scalar frame-finalization policy and byte serialization into the Rust compression leaf while keeping checksum finalization, tracing, and the compression context in C. Preserve the init-to-ongoing transition on partial failure and reset the stage only after a successful epilogue.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression
- cargo clippy --manifest-path rust/Cargo.toml
- cargo clippy --manifest-path rust/Cargo.toml --benches
- cargo clippy --manifest-path rust/Cargo.toml --tests
- make -B -C lib -j2 lib
- make -B -C tests -j2 test-zstream (84 deterministic, 6737 and 9012 fuzzer cases)
Route the CLI backend's safe file-removal leaf through a narrow Rust status ABI while preserving C diagnostics, Windows read-only handling, and the existing return convention.
Test Plan: cargo test --manifest-path rust/cli/Cargo.toml; cargo clippy --manifest-path rust/cli/Cargo.toml; cargo clippy --manifest-path rust/cli/Cargo.toml --benches; cargo clippy --manifest-path rust/cli/Cargo.toml --tests; make -B -C programs -j2 zstd; make -C tests -j2 test-cli-tests (41 tests); make -B -C programs -j2 zstd-small zstd-frugal.
Port the external-sequence window, offset, and minimum-match checks through a scalar C ABI leaf while retaining the C caller's control flow and diagnostics.
Test Plan: cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression; cargo clippy --manifest-path rust/Cargo.toml; cargo clippy --manifest-path rust/Cargo.toml --benches; cargo clippy --manifest-path rust/Cargo.toml --tests; make -B -C lib -j2 lib; make -B -C tests -j2 test-zstream (84 deterministic, 7063 and 8665 fuzzer cases).
Move ZSTD_isUpdateAuthorized behind the existing Rust parameter API while retaining the C context-stage checks, diagnostics, and mutation flow.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression (187 tests)
- cargo clippy for library, benches, and tests
- make -B -C lib -j2 lib
Move the CLI's strategy-dependent cycle-log calculation behind a scalar Rust ABI shim while retaining the C assertion and call-site behavior.
Test Plan:
- cargo test --manifest-path rust/cli/Cargo.toml --no-default-features --features cli,compression,decompression,benchmark (116 tests)
- cargo clippy --manifest-path rust/cli/Cargo.toml --all-targets with the full CLI feature set
- make -B -C programs -j2 zstd zstd-small zstd-frugal
- make -C tests -j2 test-cli-tests (41 scenarios)
Move hash-salt mixing and context-reset overflow predicates behind scalar Rust ABI shims. Keep the C-owned match state and window arithmetic in the C wrapper while preserving exact architecture-dependent thresholds.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression (186 tests)
- cargo clippy for library, benches, tests, and CLI all-targets
- make -B -C lib -j2 lib
- make -B -C tests -j2 test-zstream (84 deterministic tests; fuzzers 6451 and 9879 cases)
Move patch-from memory-limit sizing and rejection status selection behind a Rust ABI shim. Keep the C diagnostics and assertion in place, and leave the existing preference unchanged when input sizes are unknown or exceed the window limit.
Test Plan:
- cargo test --manifest-path rust/cli/Cargo.toml --no-default-features --features cli,compression,decompression,benchmark (113 tests)
- cargo clippy --manifest-path rust/cli/Cargo.toml --all-targets with the CLI feature set
- make -B -C programs -j2 zstd zstd-small zstd-frugal
- make -C tests -j2 test-cli-tests (41 scenarios) and make -B -C tests -j2 test-zstream
Move target block-size and block-splitter policy predicates behind narrow Rust ABI shims while retaining the C debug logging, finalized-mode assertion, and surrounding control flow.
Test Plan:
- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression
- cargo clippy --manifest-path rust/Cargo.toml and native library build
- make -B -C tests -j2 test-zstream (84 deterministic tests; fuzzers 6778 and 8299 cases)
Port the single-file and multiple-file summary decisions through the existing FIO context ABI, including the display-level lookup and the original multiple-file assertion invariant. Keep the C wrappers and call sites unchanged.
Test Plan: cargo test --manifest-path rust/cli/Cargo.toml --no-default-features --features cli,compression,decompression,benchmark (108 passed); CLI all-target clippy; make -B -C programs -j2 zstd zstd-small zstd-frugal; make -C tests -j2 test-cli-tests (41 passed).
Move construction of the external-dictionary and active-prefix ranges into a narrow Rust ABI while retaining the C window and logging surface. Preserve byte-range half-open overlap semantics and leave the input-range overlap wrapper available to its other C caller.
Test Plan: cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression (180 passed); root and CLI clippy; make -B -C lib -j2 lib; make -C tests -j2 test-cli-tests (41 passed); make -B -C tests -j2 test-zstream (84 named tests plus 6,845 and 9,628 fuzz cases passed).
Port the 16-cell match-table reduction leaf while preserving the window-index threshold, wrapping subtraction, and btlazy2 unsorted marker. Keep ZSTD_reduceIndex and its strategy-specific table selection in C behind the narrow Rust ABI.
Test Plan: cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression (180 passed); root clippy, bench clippy, and test clippy; make -B -C lib -j2 lib; make -B -C tests -j2 test-zstream (84 named tests plus 6,845 and 9,628 fuzz cases passed).
Mirror fileio.c's private fileInfo_t with a checked repr(C) ABI and aggregate totals, flags, and file counts through an output-pointer shim. Preserve zeroed non-aggregate fields and use wrapping arithmetic for the original integer operations.
Test Plan: cargo test --manifest-path rust/cli/Cargo.toml --no-default-features --features cli,compression,decompression,benchmark (106 passed); cargo clippy --all-targets with the same features; make -B -C programs -j2 zstd zstd-small zstd-frugal; make -C tests -j2 test-cli-tests (41 passed).
Port repcode offBase finalization and explicit-delimiter block sizing through the Rust compression ABI. Preserve wrapped sequence arithmetic, external-sequence error codes, and the no-delimiter target-size policy while keeping the C control flow intact.
Test Plan: cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression (176 passed); cargo clippy root, benches, and tests; make -B -C lib -j2 lib; make -B -C tests -j2 test-zstream (84 named tests plus 6,230 and 8,598 fuzz cases passed).
Move sequence-store byte accounting, chunk derivation, and repcode resolution into the Rust compression module. Move MT raw-sequence buffer conversions into Rust while preserving the existing C adapters and ABI layouts.
Test Plan:\n- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression\n- cargo clippy --manifest-path rust/Cargo.toml\n- cargo clippy --manifest-path rust/Cargo.toml --benches\n- cargo clippy --manifest-path rust/Cargo.toml --tests\n- make -B -C lib -j2 lib\n- make -B -C tests -j2 test-cli-tests
Route file-I/O input/output buffer construction and the LZ4 block-size mapping through Rust ABI leaves while preserving the existing C helper names and public buffer layouts. Add layout, field, and formula coverage.
Test Plan: cargo test --manifest-path rust/cli/Cargo.toml --no-default-features --features cli,compression,decompression,benchmark; cargo clippy --manifest-path rust/cli/Cargo.toml --all-targets --no-default-features --features cli,compression,decompression,benchmark; make -B -C programs -j2 zstd zstd-small zstd-frugal; make -B -C tests -j2 test-cli-tests
Route public CCtx parameter bounds through the Rust policy implementation while keeping build-specific MT limits supplied by the C configuration. Preserve clamping and validation behavior for migrated parameters and add focused Rust coverage.
Test Plan: cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression; cargo clippy --manifest-path rust/Cargo.toml; cargo clippy --manifest-path rust/Cargo.toml --benches; cargo clippy --manifest-path rust/Cargo.toml --tests; make -B -C lib -j2 lib; make -B -C tests -j2 test-cli-tests; make -B -C tests -j2 test-zstream
Move ZSTD_CCtxParams_init_advanced and its default-resolution policy into the Rust parameter API while retaining the C public ABI wrapper. Preserve validation, zeroing, and the existing row-match, block-splitter, LDM, and repcode defaults.
Test Plan:\n- cargo clippy --manifest-path rust/Cargo.toml\n- cargo clippy --manifest-path rust/Cargo.toml --benches\n- cargo clippy --manifest-path rust/Cargo.toml --tests\n- cargo +nightly fmt --manifest-path rust/Cargo.toml --all -- --check\n- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression zstd_compress_params_api\n- make -B -C lib -j2 lib
Move CCtx_params allocation, initialization, and release behind Rust ABI helpers while preserving the public C wrappers and custom allocator contract. Keep parameter bounds and policy in the existing C implementation.
Test Plan:\n- cargo clippy --manifest-path rust/Cargo.toml\n- cargo clippy --manifest-path rust/Cargo.toml --benches\n- cargo clippy --manifest-path rust/Cargo.toml --tests\n- cargo +nightly fmt --manifest-path rust/Cargo.toml --all\n- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression\n- make -B -C lib -j2 lib\n- make -B -C tests -j2 test-rust-lib-smoke\n- make -B -C tests -j2 test-zstream\n- make -B -C tests -j2 test-cli-tests
Move the basename-preserving output-directory helper behind the existing Rust utility ABI. Keep the libc allocation contract and platform separator behavior intact while leaving the C file-I/O engines and higher-level naming policy unchanged.
Test Plan:
- cargo test --manifest-path rust/cli/Cargo.toml (93 passed)
- cargo clippy --manifest-path rust/cli/Cargo.toml --all-targets
- make -B -C tests -j2 test-cli-tests (41 passed)
Implement the CLI trace callbacks and CSV logger in Rust, preserving the ZSTD_Trace ABI, timing fields, parameter reporting, mutex-protected writes, and no-op disabled behavior. Add the module to every Rust CLI archive and exclude the duplicate C trace object from Rust-backed program targets.
Test Plan:
- cargo test --manifest-path rust/cli/Cargo.toml (92 passed)
- cargo clippy --manifest-path rust/cli/Cargo.toml --all-targets
- make -B -C programs -j2 zstd
- Rust trace smoke: programs/zstd -q --trace=/tmp/zstd-rust-trace-smoke.csv -c /tmp/levels-input
- make -B -C tests -j2 test-cli-tests (41 passed)
ddidderr