New xp library symbol : ZSTD_CCtx_setCParams()

Inspired by #3395,
offer a new capability to set all parameters defined in a ZSTD_compressionParameters structure
with a single symbol invocation
to improve user code brevity.

lib/compress/zstd_compress.c

@@ -346,10 +346,13 @@ size_t ZSTD_CCtxParams_init(ZSTD_CCtx_params* cctxParams, int compressionLevel)
 #define ZSTD_NO_CLEVEL 0
 
 /**
- * Initializes the cctxParams from params and compressionLevel.
+ * Initializes `cctxParams` from `params` and `compressionLevel`.
  * @param compressionLevel If params are derived from a compression level then that compression level, otherwise ZSTD_NO_CLEVEL.
  */
-static void ZSTD_CCtxParams_init_internal(ZSTD_CCtx_params* cctxParams, ZSTD_parameters const* params, int compressionLevel)
+static void
+ZSTD_CCtxParams_init_internal(ZSTD_CCtx_params* cctxParams,
+                        const ZSTD_parameters* params,
+                              int compressionLevel)
 {
     assert(!ZSTD_checkCParams(params->cParams));
     ZSTD_memset(cctxParams, 0, sizeof(*cctxParams));
@@ -796,14 +799,14 @@ size_t ZSTD_CCtxParams_setParameter(ZSTD_CCtx_params* CCtxParams,
 
     case ZSTD_c_forceAttachDict : {
         const ZSTD_dictAttachPref_e pref = (ZSTD_dictAttachPref_e)value;
-        BOUNDCHECK(ZSTD_c_forceAttachDict, pref);
+        BOUNDCHECK(ZSTD_c_forceAttachDict, (int)pref);
         CCtxParams->attachDictPref = pref;
         return CCtxParams->attachDictPref;
     }
 
     case ZSTD_c_literalCompressionMode : {
         const ZSTD_paramSwitch_e lcm = (ZSTD_paramSwitch_e)value;
-        BOUNDCHECK(ZSTD_c_literalCompressionMode, lcm);
+        BOUNDCHECK(ZSTD_c_literalCompressionMode, (int)lcm);
         CCtxParams->literalCompressionMode = lcm;
         return CCtxParams->literalCompressionMode;
     }
@@ -1098,6 +1101,14 @@ size_t ZSTD_CCtx_setParametersUsingCCtxParams(
     return 0;
 }
 
+size_t ZSTD_CCtx_setCParams(ZSTD_CCtx* cctx, ZSTD_compressionParameters cparams)
+{
+    FORWARD_IF_ERROR(ZSTD_checkCParams(cparams), "");
+    assert(cctx != NULL);
+    cctx->requestedParams.cParams = cparams;
+    return 0;
+}
+
 size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_CCtx_setPledgedSrcSize to %llu bytes", pledgedSrcSize);

lib/zstd.h

@@ -1740,6 +1740,11 @@ ZSTDLIB_STATIC_API size_t ZSTD_checkCParams(ZSTD_compressionParameters params);
  *  This function never fails (wide contract) */
 ZSTDLIB_STATIC_API ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize);
 
+/*! ZSTD_CCtx_setCParams() :
+ *  Set all parameters provided within @cparams into the working @cctx
+ * @return 0 on success, or an error code (can be checked with ZSTD_isError()) */
+ZSTDLIB_STATIC_API size_t ZSTD_CCtx_setCParams(ZSTD_CCtx* cctx, ZSTD_compressionParameters cparams);
+
 /*! ZSTD_compress_advanced() :
  *  Note : this function is now DEPRECATED.
  *         It can be replaced by ZSTD_compress2(), in combination with ZSTD_CCtx_setParameter() and other parameter setters.
@@ -1747,10 +1752,10 @@ ZSTDLIB_STATIC_API ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressio
 ZSTD_DEPRECATED("use ZSTD_compress2")
 ZSTDLIB_STATIC_API
 size_t ZSTD_compress_advanced(ZSTD_CCtx* cctx,
-                                          void* dst, size_t dstCapacity,
-                                    const void* src, size_t srcSize,
-                                    const void* dict,size_t dictSize,
-                                          ZSTD_parameters params);
+                              void* dst, size_t dstCapacity,
+                        const void* src, size_t srcSize,
+                        const void* dict,size_t dictSize,
+                              ZSTD_parameters params);
 
 /*! ZSTD_compress_usingCDict_advanced() :
  *  Note : this function is now DEPRECATED.

tests/fuzzer.c

@@ -463,9 +463,9 @@ _output_error:
 *   Unit tests
 =============================================*/
 
-static void test_compressBound(int tnb)
+static void test_compressBound(unsigned tnb)
 {
-    DISPLAYLEVEL(3, "test%3i : compressBound : ", tnb);
+    DISPLAYLEVEL(3, "test%3u : compressBound : ", tnb);
 
     /* check ZSTD_compressBound == ZSTD_COMPRESSBOUND
      * for a large range of known valid values */
@@ -485,9 +485,9 @@ static void test_compressBound(int tnb)
     DISPLAYLEVEL(3, "OK \n");
 }
 
-static void test_decompressBound(int tnb)
+static void test_decompressBound(unsigned tnb)
 {
-    DISPLAYLEVEL(3, "test%3i : decompressBound : ", tnb);
+    DISPLAYLEVEL(3, "test%3u : decompressBound : ", tnb);
 
     // Simple compression, with size : should provide size;
     {   const char example[] = "abcd";
@@ -538,6 +538,26 @@ static void test_decompressBound(int tnb)
     DISPLAYLEVEL(3, "OK \n");
 }
 
+static void test_setCParams(unsigned tnb)
+{
+    ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+    ZSTD_compressionParameters cparams;
+    assert(cctx);
+
+    DISPLAYLEVEL(3, "test%3u : ZSTD_CCtx_setCParams : ", tnb);
+
+    /* valid cparams */
+    cparams = ZSTD_getCParams(1, 0, 0);
+    CHECK_Z(ZSTD_CCtx_setCParams(cctx, cparams));
+
+    /* invalid cparams (must fail) */
+    cparams.windowLog = 99;
+    CHECK(ZSTD_isError(ZSTD_CCtx_setCParams(cctx, cparams)));
+
+    free(cctx);
+    DISPLAYLEVEL(3, "OK \n");
+}
+
 static int basicUnitTests(U32 const seed, double compressibility)
 {
     size_t const CNBuffSize = 5 MB;
@@ -588,6 +608,8 @@ static int basicUnitTests(U32 const seed, double compressibility)
 
     test_decompressBound(testNb++);
 
+    test_setCParams(testNb++);
+
     DISPLAYLEVEL(3, "test%3u : ZSTD_adjustCParams : ", testNb++);
     {
         ZSTD_compressionParameters params;