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changed macro LOADCPARAMS by static function ZSTD_cLevelToCParams() 

for improved compiler checks.
Also : ensure most parameters can receive value "0"
to mean "do not change".
dev
Yann Collet 2017-05-12 15:59:48 -07:00
parent b0edb7fb0e
commit add66f816d
3 changed files with 53 additions and 28 deletions
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20
doc/zstd_manual.html
View File

@ -479,31 +479,37 @@ size_t ZSTD_estimateDDictSize(size_t dictSize);
* Special: value 0 means "do not change cLevel". */
ZSTD_p_windowLog, </b>/* Maximum allowed back-reference distance, expressed as power of 2.<b>
* Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
* default value : set through compressionLevel */
* default value : set through compressionLevel.
* Special: value 0 means "do not change windowLog". */
ZSTD_p_hashLog, </b>/* Size of the probe table, as a power of 2.<b>
* Resulting table size is (1 << (hashLog+2)).
* Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX.
* Larger tables improve compression ratio of strategies <= dFast,
* and improve speed of strategies > dFast */
* and improve speed of strategies > dFast.
* Special: value 0 means "do not change hashLog". */
ZSTD_p_chainLog, </b>/* Size of the full-search table, as a power of 2.<b>
* Resulting table size is (1 << (chainLog+2)).
* Larger tables result in better and slower compression.
* This parameter is useless when using "fast" strategy */
* This parameter is useless when using "fast" strategy.
* Special: value 0 means "do not change chainLog". */
ZSTD_p_searchLog, </b>/* Number of search attempts, as a power of 2.<b>
* More attempts result in better and slower compression.
* This parameter is useless when using "fast" and "dFast" strategies */
* This parameter is useless when using "fast" and "dFast" strategies.
* Special: value 0 means "do not change searchLog". */
ZSTD_p_minMatchLength, </b>/* Minimum match size (except for repeat-matches, which limit is hard-coded).<b>
* Larger values make faster compression and decompression, but decrease ratio.
* Must be clamped between ZSTD_SEARCHLENGTH_MIN and ZSTD_SEARCHLENGTH_MAX.
* Note that currently, for all strategies < btopt, effective minimum is 4.
* Note that currently, for all strategies > fast, effective maximum is 6. */
* Note that currently, for all strategies > fast, effective maximum is 6.
* Special: value 0 means "do not change minMatchLength". */
ZSTD_p_targetLength, </b>/* Only useful for strategies >= btopt.<b>
* Length of Match considered "good enough" to stop search.
* Larger values make compression stronger and slower. */
* Larger values make compression stronger and slower.
* Special: value 0 means "do not change targetLength". */
ZSTD_p_compressionStrategy, </b>/* See ZSTD_strategy enum definition.<b>
* Cast selected strategy as unsigned for ZSTD_CCtx_setParameter() compatibility.
* The higher the value of selected strategy, the more complex it is,
* resulting in stronger and slower compression */
* resulting in stronger and slower compression. */
#if 0
ZSTD_p_windowSize, </b>/* Maximum allowed back-reference distance.<b>
* Can be set to a more precise value than windowLog.

41
lib/compress/zstd_compress.c
View File

@ -202,15 +202,23 @@ size_t ZSTD_setCCtxParameter(ZSTD_CCtx* cctx, ZSTD_CCtxParameter param, unsigned
}
}
static void ZSTD_cLevelToCParams(ZSTD_CCtx* cctx)
{
if (cctx->compressionLevel==0) return;
cctx->params.cParams = ZSTD_getCParams(cctx->compressionLevel,
cctx->frameContentSize, 0);
cctx->compressionLevel = 0;
}
size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value)
{
# define CLAMPCHECK(val,min,max) { if ((val<min) | (val>max)) return ERROR(compressionParameter_unsupported); }
# define LOADCPARAMS(cParams) \
if (cctx->compressionLevel!=0) { \
cParams = ZSTD_getCParams( \
cctx->compressionLevel, \
cctx->frameContentSize, 0); /* dictSize unknown at this stage */ \
cctx->compressionLevel = 0; \
# define LOADCPARAMS(cctx) \
if (cctx->compressionLevel!=0) { \
cctx->params.cParams = ZSTD_getCParams( cctx->compressionLevel, \
cctx->frameContentSize, 0); \
cctx->compressionLevel = 0; \
}
@ -223,44 +231,50 @@ size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned v
return 0;
case ZSTD_p_windowLog :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_WINDOWLOG_MIN, ZSTD_WINDOWLOG_MAX);
LOADCPARAMS(cctx->params.cParams);
ZSTD_cLevelToCParams(cctx);
cctx->params.cParams.windowLog = value;
return 0;
case ZSTD_p_hashLog :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX);
LOADCPARAMS(cctx->params.cParams);
ZSTD_cLevelToCParams(cctx);
cctx->params.cParams.hashLog = value;
return 0;
case ZSTD_p_chainLog :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_CHAINLOG_MIN, ZSTD_CHAINLOG_MAX);
LOADCPARAMS(cctx->params.cParams);
ZSTD_cLevelToCParams(cctx);
cctx->params.cParams.chainLog = value;
return 0;
case ZSTD_p_searchLog :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_SEARCHLOG_MIN, ZSTD_SEARCHLOG_MAX);
LOADCPARAMS(cctx->params.cParams);
ZSTD_cLevelToCParams(cctx);
cctx->params.cParams.searchLog = value;
return 0;
case ZSTD_p_minMatchLength :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_SEARCHLENGTH_MIN, ZSTD_SEARCHLENGTH_MAX);
LOADCPARAMS(cctx->params.cParams);
ZSTD_cLevelToCParams(cctx);
cctx->params.cParams.searchLength = value;
return 0;
case ZSTD_p_targetLength :
if (value == 0) return 0; /* special value : 0 means "don't change anything" */
CLAMPCHECK(value, ZSTD_TARGETLENGTH_MIN, ZSTD_TARGETLENGTH_MAX);
LOADCPARAMS(cctx->params.cParams);
ZSTD_cLevelToCParams(cctx);
cctx->params.cParams.targetLength = value;
return 0;
case ZSTD_p_compressionStrategy :
if (value > (unsigned)ZSTD_btultra) return ERROR(compressionParameter_unsupported);
LOADCPARAMS(cctx->params.cParams);
ZSTD_cLevelToCParams(cctx);
cctx->params.cParams.strategy = (ZSTD_strategy)value;
return 0;
@ -325,7 +339,6 @@ ZSTDLIB_API size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict)
@return : 0, or an error code if one value is beyond authorized range */
size_t ZSTD_checkCParams(ZSTD_compressionParameters cParams)
{
# define CLAMPCHECK(val,min,max) { if ((val<min) | (val>max)) return ERROR(compressionParameter_unsupported); }
CLAMPCHECK(cParams.windowLog, ZSTD_WINDOWLOG_MIN, ZSTD_WINDOWLOG_MAX);
CLAMPCHECK(cParams.chainLog, ZSTD_CHAINLOG_MIN, ZSTD_CHAINLOG_MAX);
CLAMPCHECK(cParams.hashLog, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX);

20
lib/zstd.h
View File

@ -593,31 +593,37 @@ typedef enum {
* Special: value 0 means "do not change cLevel". */
ZSTD_p_windowLog, /* Maximum allowed back-reference distance, expressed as power of 2.
* Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
* default value : set through compressionLevel */
* default value : set through compressionLevel.
* Special: value 0 means "do not change windowLog". */
ZSTD_p_hashLog, /* Size of the probe table, as a power of 2.
* Resulting table size is (1 << (hashLog+2)).
* Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX.
* Larger tables improve compression ratio of strategies <= dFast,
* and improve speed of strategies > dFast */
* and improve speed of strategies > dFast.
* Special: value 0 means "do not change hashLog". */
ZSTD_p_chainLog, /* Size of the full-search table, as a power of 2.
* Resulting table size is (1 << (chainLog+2)).
* Larger tables result in better and slower compression.
* This parameter is useless when using "fast" strategy */
* This parameter is useless when using "fast" strategy.
* Special: value 0 means "do not change chainLog". */
ZSTD_p_searchLog, /* Number of search attempts, as a power of 2.
* More attempts result in better and slower compression.
* This parameter is useless when using "fast" and "dFast" strategies */
* This parameter is useless when using "fast" and "dFast" strategies.
* Special: value 0 means "do not change searchLog". */
ZSTD_p_minMatchLength, /* Minimum match size (except for repeat-matches, which limit is hard-coded).
* Larger values make faster compression and decompression, but decrease ratio.
* Must be clamped between ZSTD_SEARCHLENGTH_MIN and ZSTD_SEARCHLENGTH_MAX.
* Note that currently, for all strategies < btopt, effective minimum is 4.
* Note that currently, for all strategies > fast, effective maximum is 6. */
* Note that currently, for all strategies > fast, effective maximum is 6.
* Special: value 0 means "do not change minMatchLength". */
ZSTD_p_targetLength, /* Only useful for strategies >= btopt.
* Length of Match considered "good enough" to stop search.
* Larger values make compression stronger and slower. */
* Larger values make compression stronger and slower.
* Special: value 0 means "do not change targetLength". */
ZSTD_p_compressionStrategy, /* See ZSTD_strategy enum definition.
* Cast selected strategy as unsigned for ZSTD_CCtx_setParameter() compatibility.
* The higher the value of selected strategy, the more complex it is,
* resulting in stronger and slower compression */
* resulting in stronger and slower compression. */
#if 0
ZSTD_p_windowSize, /* Maximum allowed back-reference distance.
* Can be set to a more precise value than windowLog.