removed limit ZSTD_TARGETLENGTH_MAX

this makes it possible to specify extremely large negative compression levels,
achieving the side effect as "no compression".

It will also be possible to define larger targetlength for ultra compression mode.

There is no adverse side effect due to removing this limit.

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 528291777954556d095051fb716c1aaccbdf544a..2aa26da4cd43a9422138e02d88280927b4e6030e 100644 (file)
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -389,8 +389,7 @@ size_t ZSTD_CCtxParam_setParameter(
         return CCtxParams->cParams.searchLength;
 
     case ZSTD_p_targetLength :
-        if (value>0)   /* 0 => use default */
-            CLAMPCHECK(value, ZSTD_TARGETLENGTH_MIN, ZSTD_TARGETLENGTH_MAX);
+        /* all values are valid. 0 => use default */
         CCtxParams->cParams.targetLength = value;
         return CCtxParams->cParams.targetLength;
 
@@ -590,7 +589,8 @@ 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);
-    CLAMPCHECK(cParams.targetLength, ZSTD_TARGETLENGTH_MIN, ZSTD_TARGETLENGTH_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;
@@ -610,7 +610,7 @@ 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);
-    CLAMP(cParams.targetLength, ZSTD_TARGETLENGTH_MIN, ZSTD_TARGETLENGTH_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;
 }

diff --git a/lib/zstd.h b/lib/zstd.h
index a35091a58ab45667e1a73d5cdb3ec53660d71bb9..6405da602e8f597d5af6695a32a81f10347788eb 100644 (file)
--- a/lib/zstd.h
+++ b/lib/zstd.h
@@ -391,7 +391,6 @@ ZSTDLIB_API size_t ZSTD_DStreamOutSize(void);   /*!< recommended size for output
 #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_TARGETLENGTH_MAX  999   /* 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/programs/zstdcli.c b/programs/zstdcli.c
index bf82843aa7c0d141cfc7bfea36b058e8c895ecd1..c35de7ccfbbd366d907d07eea3cf1d4e8751e625 100644 (file)
--- a/programs/zstdcli.c
+++ b/programs/zstdcli.c
@@ -388,7 +388,7 @@ int main(int argCount, const char* argv[])
     zstd_operation_mode operation = zom_compress;
     ZSTD_compressionParameters compressionParams;
     int cLevel = ZSTDCLI_CLEVEL_DEFAULT;
-    int cLevelLast = -10000;
+    int cLevelLast = -1000000000;
     unsigned recursive = 0;
     unsigned memLimit = 0;
     const char** filenameTable = (const char**)malloc(argCount * sizeof(const char*));   /* argCount >= 1 */