Add ZSTD_CCtx(Param)?_getParameter() function

Closes #1096.

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 36b91030f54b52ed307421034240eab0a4f14e67..13ac747c55a55dda632a0cc23600b5e0d9ff513c 100644 (file)
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -477,6 +477,98 @@ size_t ZSTD_CCtxParam_setParameter(
     }
 }
 
+size_t ZSTD_CCtx_getParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned* value)
+{
+    return ZSTD_CCtxParam_getParameter(&cctx->requestedParams, param, value);
+}
+
+size_t ZSTD_CCtxParam_getParameter(
+        ZSTD_CCtx_params* CCtxParams, ZSTD_cParameter param, unsigned* value)
+{
+    switch(param)
+    {
+    case ZSTD_p_format :
+        *value = CCtxParams->format;
+        break;
+    case ZSTD_p_compressionLevel :
+        *value = CCtxParams->compressionLevel;
+        break;
+    case ZSTD_p_windowLog :
+        *value = CCtxParams->cParams.windowLog;
+        break;
+    case ZSTD_p_hashLog :
+        *value = CCtxParams->cParams.hashLog;
+        break;
+    case ZSTD_p_chainLog :
+        *value = CCtxParams->cParams.chainLog;
+        break;
+    case ZSTD_p_searchLog :
+        *value = CCtxParams->cParams.searchLog;
+        break;
+    case ZSTD_p_minMatch :
+        *value = CCtxParams->cParams.searchLength;
+        break;
+    case ZSTD_p_targetLength :
+        *value = CCtxParams->cParams.targetLength;
+        break;
+    case ZSTD_p_compressionStrategy :
+        *value = (unsigned)CCtxParams->cParams.strategy;
+        break;
+    case ZSTD_p_compressLiterals:
+        *value = !CCtxParams->disableLiteralCompression;
+        break;
+    case ZSTD_p_contentSizeFlag :
+        *value = CCtxParams->fParams.contentSizeFlag;
+        break;
+    case ZSTD_p_checksumFlag :
+        *value = CCtxParams->fParams.checksumFlag;
+        break;
+    case ZSTD_p_dictIDFlag :
+        *value = !CCtxParams->fParams.noDictIDFlag;
+        break;
+    case ZSTD_p_forceMaxWindow :
+        *value = CCtxParams->forceWindow;
+        break;
+    case ZSTD_p_nbWorkers :
+#ifndef ZSTD_MULTITHREAD
+        assert(CCtxParams->nbWorkers == 0);
+#endif
+        *value = CCtxParams->nbWorkers;
+        break;
+    case ZSTD_p_jobSize :
+#ifndef ZSTD_MULTITHREAD
+        return ERROR(parameter_unsupported);
+#else
+        *value = CCtxParams->jobSize;
+        break;
+#endif
+    case ZSTD_p_overlapSizeLog :
+#ifndef ZSTD_MULTITHREAD
+        return ERROR(parameter_unsupported);
+#else
+        *value = CCtxParams->overlapSizeLog;
+        break;
+#endif
+    case ZSTD_p_enableLongDistanceMatching :
+        *value = CCtxParams->ldmParams.enableLdm;
+        break;
+    case ZSTD_p_ldmHashLog :
+        *value = CCtxParams->ldmParams.hashLog;
+        break;
+    case ZSTD_p_ldmMinMatch :
+        *value = CCtxParams->ldmParams.minMatchLength;
+        break;
+    case ZSTD_p_ldmBucketSizeLog :
+        *value = CCtxParams->ldmParams.bucketSizeLog;
+        break;
+    case ZSTD_p_ldmHashEveryLog :
+        *value = CCtxParams->ldmParams.hashEveryLog;
+        break;
+    default: return ERROR(parameter_unsupported);
+    }
+    return 0;
+}
+
 /** ZSTD_CCtx_setParametersUsingCCtxParams() :
  *  just applies `params` into `cctx`
  *  no action is performed, parameters are merely stored.

diff --git a/lib/zstd.h b/lib/zstd.h
index 714155ad043b6473401ca6e617b90c4190c702b7..913c599bb585df8631233b85e512f2e7d3c0a9ad 100644 (file)
--- a/lib/zstd.h
+++ b/lib/zstd.h
@@ -1071,6 +1071,12 @@ typedef enum {
  *            or an error code (which can be tested with ZSTD_isError()). */
 ZSTDLIB_API size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value);
 
+/*! ZSTD_CCtx_getParameter() :
+ * Get the requested value of one compression parameter, selected by enum ZSTD_cParameter.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ */
+ZSTDLIB_API size_t ZSTD_CCtx_getParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned* value);
+
 /*! ZSTD_CCtx_setPledgedSrcSize() :
  *  Total input data size to be compressed as a single frame.
  *  This value will be controlled at the end, and result in error if not respected.
@@ -1238,6 +1244,13 @@ ZSTDLIB_API size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, Z
  */
 ZSTDLIB_API size_t ZSTD_CCtxParam_setParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, unsigned value);
 
+/*! ZSTD_CCtxParam_getParameter() :
+ * Similar to ZSTD_CCtx_getParameter.
+ * Get the requested value of one compression parameter, selected by enum ZSTD_cParameter.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ */
+ZSTDLIB_API size_t ZSTD_CCtxParam_getParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, unsigned* value);
+
 /*! ZSTD_CCtx_setParametersUsingCCtxParams() :
  *  Apply a set of ZSTD_CCtx_params to the compression context.
  *  This can be done even after compression is started,

diff --git a/tests/fuzzer.c b/tests/fuzzer.c
index 589a4aca4368e0b426d6923f30c5ba88db972610..33d27cda79a36c819b4a235f764efa9d9163bdce 100644 (file)
--- a/tests/fuzzer.c
+++ b/tests/fuzzer.c
@@ -117,6 +117,13 @@ static unsigned FUZ_highbit32(U32 v32)
 #define CHECK(fn)  { CHECK_V(err, fn); }
 #define CHECKPLUS(var, fn, more)  { CHECK_V(var, fn); more; }
 
+#define CHECK_EQ(lhs, rhs) {                                      \
+    if ((lhs) != (rhs)) {                                         \
+        DISPLAY("Error L%u => %s != %s ", __LINE__, #lhs, #rhs);  \
+        goto _output_error;                                       \
+    }                                                             \
+}
+
 
 /*=============================================
 *   Memory Tests
@@ -394,6 +401,43 @@ static int basicUnitTests(U32 seed, double compressibility)
     }
     DISPLAYLEVEL(3, "OK \n");
 
+    DISPLAYLEVEL(3, "test%3d : ZSTD_CCtx_getParameter() : ", testNb++);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_outBuffer out = {NULL, 0, 0};
+        ZSTD_inBuffer in = {NULL, 0, 0};
+        unsigned value;
+
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_p_compressionLevel, &value));
+        CHECK_EQ(value, 3);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_p_hashLog, &value));
+        CHECK_EQ(value, 0);
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_p_hashLog, ZSTD_HASHLOG_MIN));
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_p_compressionLevel, &value));
+        CHECK_EQ(value, 3);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_p_hashLog, &value));
+        CHECK_EQ(value, ZSTD_HASHLOG_MIN);
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_p_compressionLevel, 7));
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_p_compressionLevel, &value));
+        CHECK_EQ(value, 7);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_p_hashLog, &value));
+        CHECK_EQ(value, ZSTD_HASHLOG_MIN);
+        /* Start a compression job */
+        ZSTD_compress_generic(cctx, &out, &in, ZSTD_e_continue);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_p_compressionLevel, &value));
+        CHECK_EQ(value, 7);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_p_hashLog, &value));
+        CHECK_EQ(value, ZSTD_HASHLOG_MIN);
+        /* Reset the CCtx */
+        ZSTD_CCtx_reset(cctx);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_p_compressionLevel, &value));
+        CHECK_EQ(value, 7);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_p_hashLog, &value));
+        CHECK_EQ(value, ZSTD_HASHLOG_MIN);
+
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
     DISPLAYLEVEL(3, "test%3d : large window log smaller data : ", testNb++);
     {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
         ZSTD_parameters params = ZSTD_getParams(1, ZSTD_CONTENTSIZE_UNKNOWN, 0);