mirror of
https://github.com/facebook/zstd.git
synced 2025-01-22 20:03:10 +08:00
fixed paramgrill
This commit is contained in:
Yann Collet
parent
93b8262c02
commit
b7b80e1569
@ -730,12 +730,12 @@ size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long
|
||||
<a name="Chapter20"></a><h2>New advanced API (experimental)</h2><pre></pre>
|
||||
|
||||
<pre><b>typedef enum {
|
||||
</b>/* Question : should we have a format ZSTD_f_auto ?<b>
|
||||
* For the time being, it would mean exactly the same as ZSTD_f_zstd1.
|
||||
* But, in the future, should several formats be supported,
|
||||
</b>/* Opened question : should we have a format ZSTD_f_auto ?<b>
|
||||
* Today, it would mean exactly the same as ZSTD_f_zstd1.
|
||||
* But, in the future, should several formats become supported,
|
||||
* on the compression side, it would mean "default format".
|
||||
* On the decompression side, it would mean "multi format",
|
||||
* and ZSTD_f_zstd1 could be reserved to mean "accept *only* zstd frames".
|
||||
* On the decompression side, it would mean "automatic format detection",
|
||||
* so that ZSTD_f_zstd1 would mean "accept *only* zstd frames".
|
||||
* Since meaning is a little different, another option could be to define different enums for compression and decompression.
|
||||
* This question could be kept for later, when there are actually multiple formats to support,
|
||||
* but there is also the question of pinning enum values, and pinning value `0` is especially important */
|
||||
@ -755,33 +755,34 @@ size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long
|
||||
* Default level is ZSTD_CLEVEL_DEFAULT==3.
|
||||
* Special: value 0 means "do not change cLevel".
|
||||
* Note 1 : it's possible to pass a negative compression level by casting it to unsigned type.
|
||||
* Note 2 : setting compressionLevel automatically updates ZSTD_p_compressLiterals. */
|
||||
* Note 2 : setting a level sets all default values of other compression parameters.
|
||||
* Note 3 : setting compressionLevel automatically updates ZSTD_p_compressLiterals. */
|
||||
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.
|
||||
* Special: value 0 means "do not change windowLog".
|
||||
* Special: value 0 means "use default windowLog".
|
||||
* Note: Using a window size greater than ZSTD_MAXWINDOWSIZE_DEFAULT (default: 2^27)
|
||||
* requires setting the maximum window size at least as large during decompression. */
|
||||
* requires explicitly allowing such window size during decompression stage. */
|
||||
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.
|
||||
* Special: value 0 means "do not change hashLog". */
|
||||
* Special: value 0 means "use default 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.
|
||||
* Special: value 0 means "do not change chainLog". */
|
||||
* Special: value 0 means "use default 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.
|
||||
* Special: value 0 means "do not change searchLog". */
|
||||
* Special: value 0 means "use default searchLog". */
|
||||
ZSTD_p_minMatch, </b>/* Minimum size of searched matches (note : repCode matches can be smaller).<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.
|
||||
* Special: value 0 means "do not change minMatchLength". */
|
||||
* , for all strategies > fast, effective maximum is 6.
|
||||
* Special: value 0 means "use default minMatchLength". */
|
||||
ZSTD_p_targetLength, </b>/* Impact of this field depends on strategy.<b>
|
||||
* For strategies btopt & btultra:
|
||||
* Length of Match considered "good enough" to stop search.
|
||||
@ -789,12 +790,39 @@ size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long
|
||||
* For strategy fast:
|
||||
* Distance between match sampling.
|
||||
* Larger values make compression faster, and weaker.
|
||||
* Special: value 0 means "do not change targetLength". */
|
||||
* Special: value 0 means "use default 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.
|
||||
* Special: value 0 means "do not change strategy". */
|
||||
* Special: value 0 means "use default strategy". */
|
||||
|
||||
ZSTD_p_enableLongDistanceMatching=160, </b>/* Enable long distance matching.<b>
|
||||
* This parameter is designed to improve compression ratio
|
||||
* for large inputs, by finding large matches at long distance.
|
||||
* It increases memory usage and window size.
|
||||
* Note: enabling this parameter increases ZSTD_p_windowLog to 128 MB
|
||||
* except when expressly set to a different value. */
|
||||
ZSTD_p_ldmHashLog, </b>/* Size of the table for long distance matching, as a power of 2.<b>
|
||||
* Larger values increase memory usage and compression ratio,
|
||||
* but decrease compression speed.
|
||||
* Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX
|
||||
* default: windowlog - 7.
|
||||
* Special: value 0 means "automatically determine hashlog". */
|
||||
ZSTD_p_ldmMinMatch, </b>/* Minimum match size for long distance matcher.<b>
|
||||
* Larger/too small values usually decrease compression ratio.
|
||||
* Must be clamped between ZSTD_LDM_MINMATCH_MIN and ZSTD_LDM_MINMATCH_MAX.
|
||||
* Special: value 0 means "use default value" (default: 64). */
|
||||
ZSTD_p_ldmBucketSizeLog, </b>/* Log size of each bucket in the LDM hash table for collision resolution.<b>
|
||||
* Larger values improve collision resolution but decrease compression speed.
|
||||
* The maximum value is ZSTD_LDM_BUCKETSIZELOG_MAX .
|
||||
* Special: value 0 means "use default value" (default: 3). */
|
||||
ZSTD_p_ldmHashEveryLog, </b>/* Frequency of inserting/looking up entries in the LDM hash table.<b>
|
||||
* Must be clamped between 0 and (ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN).
|
||||
* Default is MAX(0, (windowLog - ldmHashLog)), optimizing hash table usage.
|
||||
* Larger values improve compression speed.
|
||||
* Deviating far from default value will likely result in a compression ratio decrease.
|
||||
* Special: value 0 means "automatically determine hashEveryLog". */
|
||||
|
||||
</b>/* frame parameters */<b>
|
||||
ZSTD_p_contentSizeFlag=200, </b>/* Content size will be written into frame header _whenever known_ (default:1)<b>
|
||||
@ -821,7 +849,9 @@ size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long
|
||||
ZSTD_p_overlapSizeLog, </b>/* Size of previous input reloaded at the beginning of each job.<b>
|
||||
* 0 => no overlap, 6(default) => use 1/8th of windowSize, >=9 => use full windowSize */
|
||||
|
||||
</b>/* advanced parameters - may not remain available after API update */<b>
|
||||
</b>/* =================================================================== */<b>
|
||||
</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.
|
||||
@ -832,40 +862,6 @@ size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long
|
||||
ZSTD_p_forceMaxWindow=1100, </b>/* Force back-reference distances to remain < windowSize,<b>
|
||||
* even when referencing into Dictionary content (default:0) */
|
||||
|
||||
ZSTD_p_enableLongDistanceMatching=1200, </b>/* Enable long distance matching.<b>
|
||||
* This parameter is designed to improve the compression
|
||||
* ratio for large inputs with long distance matches.
|
||||
* This increases the memory usage as well as window size.
|
||||
* Note: setting this parameter sets all the LDM parameters
|
||||
* as well as ZSTD_p_windowLog. It should be set after
|
||||
* ZSTD_p_compressionLevel and before ZSTD_p_windowLog and
|
||||
* other LDM parameters. Setting the compression level
|
||||
* after this parameter overrides the window log, though LDM
|
||||
* will remain enabled until explicitly disabled. */
|
||||
ZSTD_p_ldmHashLog, </b>/* Size of the table for long distance matching, as a power of 2.<b>
|
||||
* Larger values increase memory usage and compression ratio, but decrease
|
||||
* compression speed.
|
||||
* Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX
|
||||
* (default: windowlog - 7).
|
||||
* Special: value 0 means "do not change ldmHashLog". */
|
||||
ZSTD_p_ldmMinMatch, </b>/* Minimum size of searched matches for long distance matcher.<b>
|
||||
* Larger/too small values usually decrease compression ratio.
|
||||
* Must be clamped between ZSTD_LDM_MINMATCH_MIN
|
||||
* and ZSTD_LDM_MINMATCH_MAX (default: 64).
|
||||
* Special: value 0 means "do not change ldmMinMatch". */
|
||||
ZSTD_p_ldmBucketSizeLog, </b>/* Log size of each bucket in the LDM hash table for collision resolution.<b>
|
||||
* Larger values usually improve collision resolution but may decrease
|
||||
* compression speed.
|
||||
* The maximum value is ZSTD_LDM_BUCKETSIZELOG_MAX (default: 3).
|
||||
* note : 0 is a valid value */
|
||||
ZSTD_p_ldmHashEveryLog, </b>/* Frequency of inserting/looking up entries in the LDM hash table.<b>
|
||||
* The default is MAX(0, (windowLog - ldmHashLog)) to
|
||||
* optimize hash table usage.
|
||||
* Larger values improve compression speed. Deviating far from the
|
||||
* default value will likely result in a decrease in compression ratio.
|
||||
* Must be clamped between 0 and ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN.
|
||||
* note : 0 is a valid value */
|
||||
|
||||
} ZSTD_cParameter;
|
||||
</b></pre><BR>
|
||||
<pre><b>size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value);
|
||||
@ -1067,7 +1063,7 @@ size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx, const void* dict, size
|
||||
|
||||
</p></pre><BR>
|
||||
|
||||
<pre><b>size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict); </b>/* not implemented */<b>
|
||||
<pre><b>size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);
|
||||
</b><p> Reference a prepared dictionary, to be used to decompress next frames.
|
||||
The dictionary remains active for decompression of future frames using same DCtx.
|
||||
@result : 0, or an error code (which can be tested with ZSTD_isError()).
|
||||
@ -1078,8 +1074,8 @@ size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx, const void* dict, size
|
||||
|
||||
</p></pre><BR>
|
||||
|
||||
<pre><b>size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize); </b>/* not implemented */<b>
|
||||
size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType); </b>/* not implemented */<b>
|
||||
<pre><b>size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize);
|
||||
size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType);
|
||||
</b><p> Reference a prefix (single-usage dictionary) for next compression job.
|
||||
Prefix is **only used once**. It must be explicitly referenced before each frame.
|
||||
If there is a need to use same prefix multiple times, consider embedding it into a ZSTD_DDict instead.
|
||||
|
||||
@ -547,12 +547,12 @@ static ZSTD_compressionParameters randomParams(void)
|
||||
U32 validated = 0;
|
||||
while (!validated) {
|
||||
/* totally random entry */
|
||||
p.chainLog = FUZ_rand(&g_rand) % (ZSTD_CHAINLOG_MAX+1 - ZSTD_CHAINLOG_MIN) + ZSTD_CHAINLOG_MIN;
|
||||
p.hashLog = FUZ_rand(&g_rand) % (ZSTD_HASHLOG_MAX+1 - ZSTD_HASHLOG_MIN) + ZSTD_HASHLOG_MIN;
|
||||
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) % (ZSTD_TARGETLENGTH_MAX+1 - ZSTD_TARGETLENGTH_MIN) + ZSTD_TARGETLENGTH_MIN;
|
||||
p.chainLog = (FUZ_rand(&g_rand) % (ZSTD_CHAINLOG_MAX+1 - ZSTD_CHAINLOG_MIN)) + ZSTD_CHAINLOG_MIN;
|
||||
p.hashLog = (FUZ_rand(&g_rand) % (ZSTD_HASHLOG_MAX+1 - ZSTD_HASHLOG_MIN)) + ZSTD_HASHLOG_MIN;
|
||||
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.strategy = (ZSTD_strategy) (FUZ_rand(&g_rand) % (ZSTD_btultra +1));
|
||||
validated = !ZSTD_isError(ZSTD_checkCParams(p));
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user