support targetlen==0 with strategy==ZSTD_fast

to mean "normal compression",
targetlen >= 1 now means "disable huffman compression of literals"

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index f6bee0b9aaa0ac03dcd4ab4a8e74bfb32a8f1dbd..2c566dd395d2c14f9969373f9bb4fe44f6b397c5 100644 (file)
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -689,8 +689,6 @@ size_t ZSTD_checkCParams(ZSTD_compressionParameters cParams)
     CLAMPCHECK(cParams.hashLog, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX);
     CLAMPCHECK(cParams.searchLog, ZSTD_SEARCHLOG_MIN, ZSTD_SEARCHLOG_MAX);
     CLAMPCHECK(cParams.searchLength, ZSTD_SEARCHLENGTH_MIN, ZSTD_SEARCHLENGTH_MAX);
-    if ((U32)(cParams.targetLength) < ZSTD_TARGETLENGTH_MIN)
-        return ERROR(parameter_unsupported);
     if ((U32)(cParams.strategy) > (U32)ZSTD_btultra)
         return ERROR(parameter_unsupported);
     return 0;
@@ -710,7 +708,6 @@ static ZSTD_compressionParameters ZSTD_clampCParams(ZSTD_compressionParameters c
     CLAMP(cParams.hashLog, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX);
     CLAMP(cParams.searchLog, ZSTD_SEARCHLOG_MIN, ZSTD_SEARCHLOG_MAX);
     CLAMP(cParams.searchLength, ZSTD_SEARCHLENGTH_MIN, ZSTD_SEARCHLENGTH_MAX);
-    if ((U32)(cParams.targetLength) < ZSTD_TARGETLENGTH_MIN) cParams.targetLength = ZSTD_TARGETLENGTH_MIN;
     if ((U32)(cParams.strategy) > (U32)ZSTD_btultra) cParams.strategy = ZSTD_btultra;
     return cParams;
 }
@@ -3713,8 +3710,8 @@ static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEV
 {   /* "default" - guarantees a monotonically increasing memory budget */
     /* W,  C,  H,  S,  L, TL, strat */
     { 19, 12, 13,  1,  6,  1, ZSTD_fast    },  /* base for negative levels */
-    { 19, 13, 14,  1,  7,  1, ZSTD_fast    },  /* level  1 */
-    { 19, 15, 16,  1,  6,  1, ZSTD_fast    },  /* level  2 */
+    { 19, 13, 14,  1,  7,  0, ZSTD_fast    },  /* level  1 */
+    { 19, 15, 16,  1,  6,  0, ZSTD_fast    },  /* level  2 */
     { 20, 16, 17,  1,  5,  1, ZSTD_dfast   },  /* level  3 */
     { 20, 18, 18,  1,  5,  1, ZSTD_dfast   },  /* level  4 */
     { 20, 18, 18,  2,  5,  2, ZSTD_greedy  },  /* level  5 */
@@ -3739,7 +3736,7 @@ static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEV
 {   /* for srcSize <= 256 KB */
     /* W,  C,  H,  S,  L,  T, strat */
     { 18, 12, 13,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
-    { 18, 13, 14,  1,  6,  1, ZSTD_fast    },  /* level  1 */
+    { 18, 13, 14,  1,  6,  0, ZSTD_fast    },  /* level  1 */
     { 18, 14, 14,  1,  5,  1, ZSTD_dfast   },  /* level  2 */
     { 18, 16, 16,  1,  4,  1, ZSTD_dfast   },  /* level  3 */
     { 18, 16, 17,  2,  5,  2, ZSTD_greedy  },  /* level  4.*/
@@ -3765,8 +3762,8 @@ static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEV
 {   /* for srcSize <= 128 KB */
     /* W,  C,  H,  S,  L,  T, strat */
     { 17, 12, 12,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
-    { 17, 12, 13,  1,  6,  1, ZSTD_fast    },  /* level  1 */
-    { 17, 13, 15,  1,  5,  1, ZSTD_fast    },  /* level  2 */
+    { 17, 12, 13,  1,  6,  0, ZSTD_fast    },  /* level  1 */
+    { 17, 13, 15,  1,  5,  0, ZSTD_fast    },  /* level  2 */
     { 17, 15, 16,  2,  5,  1, ZSTD_dfast   },  /* level  3 */
     { 17, 17, 17,  2,  4,  1, ZSTD_dfast   },  /* level  4 */
     { 17, 16, 17,  3,  4,  2, ZSTD_greedy  },  /* level  5 */
@@ -3791,8 +3788,8 @@ static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEV
 {   /* for srcSize <= 16 KB */
     /* W,  C,  H,  S,  L,  T, strat */
     { 14, 12, 13,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
-    { 14, 14, 15,  1,  5,  1, ZSTD_fast    },  /* level  1 */
-    { 14, 14, 15,  1,  4,  1, ZSTD_fast    },  /* level  2 */
+    { 14, 14, 15,  1,  5,  0, ZSTD_fast    },  /* level  1 */
+    { 14, 14, 15,  1,  4,  0, ZSTD_fast    },  /* level  2 */
     { 14, 14, 14,  2,  4,  1, ZSTD_dfast   },  /* level  3.*/
     { 14, 14, 14,  4,  4,  2, ZSTD_greedy  },  /* level  4.*/
     { 14, 14, 14,  3,  4,  4, ZSTD_lazy    },  /* level  5.*/

diff --git a/lib/compress/zstd_fast.c b/lib/compress/zstd_fast.c
index 57a70eeeedc99ef0ce1a8c0e84e66add72831bcb..37a715167c62732fcbf5f4215322bafe89c45ec1 100644 (file)
--- a/lib/compress/zstd_fast.c
+++ b/lib/compress/zstd_fast.c
@@ -45,7 +45,7 @@ FORCE_INLINE_TEMPLATE
 size_t ZSTD_compressBlock_fast_generic(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize,
-        U32 const hlog, U32 const stepSize, U32 const mls,
+        U32 const hlog, U32 stepSize, U32 const mls,
         ZSTD_dictMode_e const dictMode)
 {
     U32* const hashTable = ms->hashTable;
@@ -84,6 +84,7 @@ size_t ZSTD_compressBlock_fast_generic(
         || prefixStartIndex >= (U32)(dictEnd - dictBase));
 
     /* init */
+    stepSize += !stepSize;  /* support stepSize of 0 */
     ip += (dictAndPrefixLength == 0);
     if (dictMode == ZSTD_noDict) {
         U32 const maxRep = (U32)(ip - prefixStart);
@@ -264,7 +265,7 @@ size_t ZSTD_compressBlock_fast_dictMatchState(
 static size_t ZSTD_compressBlock_fast_extDict_generic(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize,
-        U32 const hlog, U32 const stepSize, U32 const mls)
+        U32 const hlog, U32 stepSize, U32 const mls)
 {
     U32* hashTable = ms->hashTable;
     const BYTE* const base = ms->window.base;
@@ -281,6 +282,8 @@ static size_t ZSTD_compressBlock_fast_extDict_generic(
     const BYTE* const ilimit = iend - 8;
     U32 offset_1=rep[0], offset_2=rep[1];
 
+    stepSize += !stepSize;   /* support stepSize == 0 */
+
     /* Search Loop */
     while (ip < ilimit) {  /* < instead of <=, because (ip+1) */
         const size_t h = ZSTD_hashPtr(ip, hlog, mls);

diff --git a/lib/zstd.h b/lib/zstd.h
index 829c8ad24f93ab3972fb53c6874e38fd1c91fd64..f8caeb0de4f9e0827942949afe55850950bd1bdf 100644 (file)
--- a/lib/zstd.h
+++ b/lib/zstd.h
@@ -395,7 +395,6 @@ ZSTDLIB_API size_t ZSTD_DStreamOutSize(void);   /*!< recommended size for output
 #define ZSTD_SEARCHLOG_MIN       1
 #define ZSTD_SEARCHLENGTH_MAX    7   /* only for ZSTD_fast, other strategies are limited to 6 */
 #define ZSTD_SEARCHLENGTH_MIN    3   /* only for ZSTD_btopt, other strategies are limited to 4 */
-#define ZSTD_TARGETLENGTH_MIN    1   /* only used by btopt, btultra and btfast */
 #define ZSTD_LDM_MINMATCH_MIN    4
 #define ZSTD_LDM_MINMATCH_MAX 4096
 #define ZSTD_LDM_BUCKETSIZELOG_MAX 8

diff --git a/tests/paramgrill.c b/tests/paramgrill.c
index 44e3cb37bdd7f49e114ebee2b368d83df67b3a74..6208effe4885598443175ff9b7668e3a6e081cd6 100644 (file)
--- a/tests/paramgrill.c
+++ b/tests/paramgrill.c
@@ -598,7 +598,7 @@ static ZSTD_compressionParameters randomParams(void)
         p.searchLog  = (FUZ_rand(&g_rand) % (ZSTD_SEARCHLOG_MAX+1 - ZSTD_SEARCHLOG_MIN)) + ZSTD_SEARCHLOG_MIN;
         p.windowLog  = (FUZ_rand(&g_rand) % (ZSTD_WINDOWLOG_MAX+1 - ZSTD_WINDOWLOG_MIN)) + ZSTD_WINDOWLOG_MIN;
         p.searchLength=(FUZ_rand(&g_rand) % (ZSTD_SEARCHLENGTH_MAX+1 - ZSTD_SEARCHLENGTH_MIN)) + ZSTD_SEARCHLENGTH_MIN;
-        p.targetLength=(FUZ_rand(&g_rand) % (512)) + ZSTD_TARGETLENGTH_MIN;
+        p.targetLength=(FUZ_rand(&g_rand) % (512));
         p.strategy   = (ZSTD_strategy) (FUZ_rand(&g_rand) % (ZSTD_btultra +1));
         validated = !ZSTD_isError(ZSTD_checkCParams(p));
     }