removed literalCompression directive

in this version, literal compression is always disabled for ZSTD_fast strategy.

Performance parity between ZSTD_compress_advanced() and ZSTD_compress_generic()

diff --git a/doc/zstd_manual.html b/doc/zstd_manual.html
index 3dee74a3d7cfc9c084d9c9cfc4e5e0dc0ea0d8b4..ae2972865af44f06d19c1f1e894a6bd548e8d08c 100644 (file)
--- a/doc/zstd_manual.html
+++ b/doc/zstd_manual.html
@@ -867,12 +867,6 @@ size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long
     </b>/* experimental parameters - no stability guaranteed                   */<b>
     </b>/* =================================================================== */<b>
 
-    ZSTD_p_compressLiterals=1000, </b>/* control huffman compression of literals (enabled) by default.<b>
-                              * disabling it improves speed and decreases compression ratio by a large amount.
-                              * note : this setting is automatically updated when changing compression level.
-                              *        positive compression levels set ZSTD_p_compressLiterals to 1.
-                              *        negative compression levels set ZSTD_p_compressLiterals to 0. */
-
     ZSTD_p_forceMaxWindow=1100, </b>/* Force back-reference distances to remain < windowSize,<b>
                               * even when referencing into Dictionary content (default:0) */
 

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 43c3f27b023767a94a786e6cbf5f30d2edeadf6d..f6bee0b9aaa0ac03dcd4ab4a8e74bfb32a8f1dbd 100644 (file)
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -267,7 +267,6 @@ static int ZSTD_isUpdateAuthorized(ZSTD_cParameter param)
     case ZSTD_p_minMatch:
     case ZSTD_p_targetLength:
     case ZSTD_p_compressionStrategy:
-    case ZSTD_p_compressLiterals:
         return 1;
 
     case ZSTD_p_format:
@@ -318,7 +317,6 @@ size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned v
         if (cctx->cdict) return ERROR(stage_wrong);
         return ZSTD_CCtxParam_setParameter(&cctx->requestedParams, param, value);
 
-    case ZSTD_p_compressLiterals:
     case ZSTD_p_contentSizeFlag:
     case ZSTD_p_checksumFlag:
     case ZSTD_p_dictIDFlag:
@@ -367,7 +365,6 @@ size_t ZSTD_CCtxParam_setParameter(
         int cLevel = (int)value;  /* cast expected to restore negative sign */
         if (cLevel > ZSTD_maxCLevel()) cLevel = ZSTD_maxCLevel();
         if (cLevel) {  /* 0 : does not change current level */
-            CCtxParams->disableLiteralCompression = (cLevel<0);  /* negative levels disable huffman */
             CCtxParams->compressionLevel = cLevel;
         }
         if (CCtxParams->compressionLevel >= 0) return CCtxParams->compressionLevel;
@@ -415,10 +412,6 @@ size_t ZSTD_CCtxParam_setParameter(
         CCtxParams->cParams.strategy = (ZSTD_strategy)value;
         return (size_t)CCtxParams->cParams.strategy;
 
-    case ZSTD_p_compressLiterals:
-        CCtxParams->disableLiteralCompression = !value;
-        return !CCtxParams->disableLiteralCompression;
-
     case ZSTD_p_contentSizeFlag :
         /* Content size written in frame header _when known_ (default:1) */
         DEBUGLOG(4, "set content size flag = %u", (value>0));
@@ -530,9 +523,6 @@ size_t ZSTD_CCtxParam_getParameter(
     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;
@@ -2068,9 +2058,10 @@ MEM_STATIC size_t ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
     /* Compress literals */
     {   const BYTE* const literals = seqStorePtr->litStart;
         size_t const litSize = seqStorePtr->lit - literals;
+        int const disableLiteralCompression = (cctxParams->cParams.strategy == ZSTD_fast) && (cctxParams->cParams.targetLength > 0);
         size_t const cSize = ZSTD_compressLiterals(
                                     &prevEntropy->huf, &nextEntropy->huf,
-                                    cctxParams->cParams.strategy, cctxParams->disableLiteralCompression,
+                                    cctxParams->cParams.strategy, disableLiteralCompression,
                                     op, dstCapacity,
                                     literals, litSize,
                                     workspace, bmi2);
@@ -2967,10 +2958,9 @@ size_t ZSTD_compress_usingDict(ZSTD_CCtx* cctx,
                          const void* dict, size_t dictSize,
                                int compressionLevel)
 {
-    ZSTD_parameters const params = ZSTD_getParams(compressionLevel, srcSize ? srcSize : 1, dict ? dictSize : 0);
+    ZSTD_parameters const params = ZSTD_getParams(compressionLevel, srcSize + (!srcSize), dict ? dictSize : 0);
     ZSTD_CCtx_params cctxParams = ZSTD_assignParamsToCCtxParams(cctx->requestedParams, params);
     assert(params.fParams.contentSizeFlag == 1);
-    ZSTD_CCtxParam_setParameter(&cctxParams, ZSTD_p_compressLiterals, compressionLevel>=0);
     return ZSTD_compress_advanced_internal(cctx, dst, dstCapacity, src, srcSize, dict, dictSize, cctxParams);
 }
 
@@ -3293,8 +3283,7 @@ static size_t ZSTD_resetCStream_internal(ZSTD_CStream* cctx,
                     const ZSTD_CDict* const cdict,
                     ZSTD_CCtx_params const params, unsigned long long const pledgedSrcSize)
 {
-    DEBUGLOG(4, "ZSTD_resetCStream_internal (disableLiteralCompression=%i)",
-                params.disableLiteralCompression);
+    DEBUGLOG(4, "ZSTD_resetCStream_internal");
     /* params are supposed to be fully validated at this point */
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */

diff --git a/lib/compress/zstd_compress_internal.h b/lib/compress/zstd_compress_internal.h
index fd072f309ef29b16aa316500114e0fdf07b9292e..c973c1a8d2c817b22920c5c2bf736812765b80ca 100644 (file)
--- a/lib/compress/zstd_compress_internal.h
+++ b/lib/compress/zstd_compress_internal.h
@@ -181,7 +181,6 @@ struct ZSTD_CCtx_params_s {
     ZSTD_frameParameters fParams;
 
     int compressionLevel;
-    int disableLiteralCompression;
     int forceWindow;           /* force back-references to respect limit of
                                 * 1<<wLog, even for dictionary */
 

diff --git a/lib/compress/zstdmt_compress.c b/lib/compress/zstdmt_compress.c
index 62afdd6c27f3b1a66772e69391f0337c68a478e5..102da896079b53960043991511d51f155262a785 100644 (file)
--- a/lib/compress/zstdmt_compress.c
+++ b/lib/compress/zstdmt_compress.c
@@ -961,7 +961,6 @@ static ZSTD_CCtx_params ZSTDMT_initJobCCtxParams(ZSTD_CCtx_params const params)
     jobParams.cParams = params.cParams;
     jobParams.fParams = params.fParams;
     jobParams.compressionLevel = params.compressionLevel;
-    jobParams.disableLiteralCompression = params.disableLiteralCompression;
 
     return jobParams;
 }
@@ -1222,8 +1221,8 @@ size_t ZSTDMT_initCStream_internal(
         const ZSTD_CDict* cdict, ZSTD_CCtx_params params,
         unsigned long long pledgedSrcSize)
 {
-    DEBUGLOG(4, "ZSTDMT_initCStream_internal (pledgedSrcSize=%u, nbWorkers=%u, cctxPool=%u, disableLiteralCompression=%i)",
-                (U32)pledgedSrcSize, params.nbWorkers, mtctx->cctxPool->totalCCtx, params.disableLiteralCompression);
+    DEBUGLOG(4, "ZSTDMT_initCStream_internal (pledgedSrcSize=%u, nbWorkers=%u, cctxPool=%u)",
+                (U32)pledgedSrcSize, params.nbWorkers, mtctx->cctxPool->totalCCtx);
     /* params are supposed to be fully validated at this point */
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */

diff --git a/lib/zstd.h b/lib/zstd.h
index 8f42ff81b97d812e0390c8d4e36c39140c697538..829c8ad24f93ab3972fb53c6874e38fd1c91fd64 100644 (file)
--- a/lib/zstd.h
+++ b/lib/zstd.h
@@ -1052,12 +1052,6 @@ typedef enum {
     /* experimental parameters - no stability guaranteed                   */
     /* =================================================================== */
 
-    ZSTD_p_compressLiterals=1000, /* control huffman compression of literals (enabled) by default.
-                              * disabling it improves speed and decreases compression ratio by a large amount.
-                              * note : this setting is automatically updated when changing compression level.
-                              *        positive compression levels set ZSTD_p_compressLiterals to 1.
-                              *        negative compression levels set ZSTD_p_compressLiterals to 0. */
-
     ZSTD_p_forceMaxWindow=1100, /* Force back-reference distances to remain < windowSize,
                               * even when referencing into Dictionary content (default:0) */