feat(compress): move CDict constructor policy into Rust

Move regular and by-reference CDict parameter selection and default-level normalization behind a Rust-owned boundary. Keep advanced allocation, private workspace setup, and CDict scalar publication in C callbacks. Test Plan: - ulimit -v 41943040; CARGO_BUILD_JOBS=1 cargo test --manifest-path rust/Cargo.toml --release create_cdict -- --nocapture - ulimit -v 41943040; CARGO_BUILD_JOBS=1 cargo test --manifest-path rust/Cargo.toml --release - ulimit -v 41943040; CARGO_BUILD_JOBS=1 cargo clippy --manifest-path rust/Cargo.toml --release --all-targets -- -D warnings - ulimit -v 41943040; make -B -C programs -j1 zstd - ulimit -v 41943040; make -C tests -j1 test-zstream ZSTREAM_TESTTIME=-T1s
2026-07-19 16:14:34 +02:00
parent 778a7406ad
commit 9f4d92808b
2 changed files with 240 additions and 15 deletions
@@ -19,7 +19,7 @@ use crate::zstd_compress_params::{
    ZSTD_compressionParameters, ZSTD_frameParameters, ZSTD_parameters,
    ZSTD_rust_params_defaultCLevel, ZSTD_rust_params_getCParams,
    ZSTD_rust_params_getParamsInternal, ZSTD_rust_params_shouldAttachDict,
-    ZSTD_CONTENTSIZE_UNKNOWN, ZSTD_RUST_CPM_NO_ATTACH_DICT,
+    ZSTD_CONTENTSIZE_UNKNOWN, ZSTD_RUST_CPM_CREATE_CDICT, ZSTD_RUST_CPM_NO_ATTACH_DICT,
 };
 use crate::zstd_compress_params_api::ZSTD_CCtx_params;
 use crate::zstd_compress_stats::{
@@ -358,6 +358,85 @@ pub unsafe extern "C" fn ZSTD_rust_compressBeginUsingCDictPublic(
    }
 }

+type CreateCDictFn = unsafe extern "C" fn(
+    *mut c_void,
+    *const c_void,
+    usize,
+    c_int,
+    c_int,
+    *const ZSTD_compressionParameters,
+) -> *mut c_void;
+type CreateCDictSetCompressionLevelFn = unsafe extern "C" fn(*mut c_void, *mut c_void, c_int);
+
+/// Explicit projection for the public `ZSTD_createCDict` constructors.
+///
+/// Rust owns create-CDict parameter selection and default-level normalization.
+/// C retains advanced allocation, private workspace setup, and CDict scalar
+/// publication behind callbacks.
+#[repr(C)]
+pub struct ZSTD_rust_createCDictState {
+    callback_context: *mut c_void,
+    exclusion_mask: *const c_uint,
+    create: CreateCDictFn,
+    set_compression_level: CreateCDictSetCompressionLevelFn,
+}
+
+const _: () = {
+    assert!(offset_of!(ZSTD_rust_createCDictState, callback_context) == 0);
+    assert!(offset_of!(ZSTD_rust_createCDictState, exclusion_mask) == size_of::<usize>());
+    assert!(offset_of!(ZSTD_rust_createCDictState, create) == 2 * size_of::<usize>());
+    assert!(
+        offset_of!(ZSTD_rust_createCDictState, set_compression_level) == 3 * size_of::<usize>()
+    );
+    assert!(size_of::<ZSTD_rust_createCDictState>() == size_of::<[usize; 4]>());
+};
+
+/// Select parameters and construct a regular or by-reference CDict.
+#[no_mangle]
+pub unsafe extern "C" fn ZSTD_rust_createCDict(
+    state: *const ZSTD_rust_createCDictState,
+    dict: *const c_void,
+    dict_size: usize,
+    compression_level: c_int,
+    dict_load_method: c_int,
+) -> *mut c_void {
+    if state.is_null() {
+        return ptr::null_mut();
+    }
+    let state = unsafe { &*state };
+    if state.exclusion_mask.is_null() {
+        return ptr::null_mut();
+    }
+    let cparams = ZSTD_rust_params_getParamsInternal(
+        compression_level,
+        ZSTD_CONTENTSIZE_UNKNOWN,
+        dict_size,
+        ZSTD_RUST_CPM_CREATE_CDICT,
+        unsafe { *state.exclusion_mask },
+    )
+    .cParams;
+    let cdict = unsafe {
+        (state.create)(
+            state.callback_context,
+            dict,
+            dict_size,
+            dict_load_method,
+            ZSTD_DCT_AUTO,
+            &cparams,
+        )
+    };
+    if cdict.is_null() {
+        return ptr::null_mut();
+    }
+    let normalized_level = if compression_level == 0 {
+        ZSTD_rust_params_defaultCLevel()
+    } else {
+        compression_level
+    };
+    unsafe { (state.set_compression_level)(state.callback_context, cdict, normalized_level) };
+    cdict
+}
+
 type CompressBeginUsingDictBeginFn =
    unsafe extern "C" fn(*mut c_void, *const c_void, usize, *const c_void, u64) -> usize;

@@ -2655,6 +2734,106 @@ mod tests {
        assert!(probe.events.is_empty());
    }

+    #[derive(Default)]
+    struct CreateCDictProbe {
+        events: Vec<&'static str>,
+        dict: *const c_void,
+        dict_size: usize,
+        dict_load_method: c_int,
+        dict_content_type: c_int,
+        cparams: ZSTD_compressionParameters,
+        cdict_result: *mut c_void,
+        published_cdict: *mut c_void,
+        compression_level: c_int,
+    }
+
+    unsafe extern "C" fn create_cdict_test_create(
+        context: *mut c_void,
+        dict: *const c_void,
+        dict_size: usize,
+        dict_load_method: c_int,
+        dict_content_type: c_int,
+        cparams: *const ZSTD_compressionParameters,
+    ) -> *mut c_void {
+        let probe = unsafe { &mut *context.cast::<CreateCDictProbe>() };
+        probe.events.push("create");
+        probe.dict = dict;
+        probe.dict_size = dict_size;
+        probe.dict_load_method = dict_load_method;
+        probe.dict_content_type = dict_content_type;
+        probe.cparams = unsafe { *cparams };
+        probe.cdict_result
+    }
+
+    unsafe extern "C" fn create_cdict_test_set_compression_level(
+        context: *mut c_void,
+        cdict: *mut c_void,
+        compression_level: c_int,
+    ) {
+        let probe = unsafe { &mut *context.cast::<CreateCDictProbe>() };
+        probe.events.push("set");
+        probe.published_cdict = cdict;
+        probe.compression_level = compression_level;
+    }
+
+    fn create_cdict_test_state(
+        probe: &mut CreateCDictProbe,
+        exclusion_mask: &c_uint,
+    ) -> ZSTD_rust_createCDictState {
+        ZSTD_rust_createCDictState {
+            callback_context: (probe as *mut CreateCDictProbe).cast(),
+            exclusion_mask,
+            create: create_cdict_test_create,
+            set_compression_level: create_cdict_test_set_compression_level,
+        }
+    }
+
+    #[test]
+    fn create_cdict_selects_params_and_normalizes_default_level() {
+        let mut probe = CreateCDictProbe {
+            cdict_result: ptr::dangling_mut(),
+            ..Default::default()
+        };
+        let dict = [1u8, 2, 3, 4];
+        let exclusion_mask = 0;
+        let state = create_cdict_test_state(&mut probe, &exclusion_mask);
+
+        let result = unsafe {
+            ZSTD_rust_createCDict(&state, dict.as_ptr().cast(), dict.len(), 0, ZSTD_DLM_BY_REF)
+        };
+
+        let expected_cparams = ZSTD_rust_params_getParamsInternal(
+            0,
+            ZSTD_CONTENTSIZE_UNKNOWN,
+            dict.len(),
+            ZSTD_RUST_CPM_CREATE_CDICT,
+            exclusion_mask,
+        )
+        .cParams;
+        assert_eq!(result, probe.cdict_result);
+        assert_eq!(probe.events, ["create", "set"]);
+        assert_eq!(probe.dict, dict.as_ptr().cast());
+        assert_eq!(probe.dict_size, dict.len());
+        assert_eq!(probe.dict_load_method, ZSTD_DLM_BY_REF);
+        assert_eq!(probe.dict_content_type, ZSTD_DCT_AUTO);
+        assert_eq!(probe.cparams, expected_cparams);
+        assert_eq!(probe.published_cdict, probe.cdict_result);
+        assert_eq!(probe.compression_level, ZSTD_rust_params_defaultCLevel());
+    }
+
+    #[test]
+    fn create_cdict_stops_before_publication_after_creation_failure() {
+        let mut probe = CreateCDictProbe::default();
+        let exclusion_mask = 0;
+        let state = create_cdict_test_state(&mut probe, &exclusion_mask);
+
+        let result = unsafe { ZSTD_rust_createCDict(&state, ptr::null(), 0, 3, ZSTD_DLM_BY_REF) };
+
+        assert!(result.is_null());
+        assert_eq!(probe.events, ["create"]);
+        assert!(probe.published_cdict.is_null());
+    }
+
    #[derive(Default)]
    struct CompressBeginUsingDictProbe {
        events: Vec<&'static str>,