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Add ldm options to 'man zstd'

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Stella Lau
2017-09-05 11:27:15 -07:00
parent 67d4a6161c
commit 643d28c701
3 changed files with 123 additions and 10 deletions
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lib/zstd.h
+19 -9
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@@ -979,24 +979,34 @@ typedef enum {
/* advanced parameters - may not remain available after API update */
ZSTD_p_forceMaxWindow=1100, /* Force back-reference distances to remain < windowSize,
* even when referencing into Dictionary content (default:0) */
ZSTD_p_enableLongDistanceMatching, /* Enable long distance matching. This increases the memory
* usage as well as window size. Note: setting this
* parameter resets all the LDM parameters as well as
* ZSTD_p_windowLog. It should be set after
ZSTD_p_enableLongDistanceMatching, /* Enable long distance matching.
* 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, /* Size of the table for long distance matching.
* Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX. */
ZSTD_p_ldmHashLog, /* Size of the table for long distance matching, as a power of 2.
* Larger values increase memory usage and compression ratio, but decrease
* compression speed.
* Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX
* (default: 20). */
ZSTD_p_ldmMinMatch, /* Minimum size of searched matches for long distance matcher.
* Larger/too small values usually decrease compression ratio.
* Must be clamped between ZSTD_LDM_SEARCHLENGTH_MIN
* and ZSTD_LDM_SEARCHLENGTH_MAX. */
ZSTD_p_ldmBucketSizeLog, /* Log size of each bucket in the hash table for collision resolution.
* The maximum value is ZSTD_LDM_BUCKETSIZELOG_MAX. */
* and ZSTD_LDM_SEARCHLENGTH_MAX (default: 64). */
ZSTD_p_ldmBucketSizeLog, /* Log size of each bucket in the LDM hash table for collision resolution.
* Larger values usually improve collision resolution but may decrease
* compression speed.
* The maximum value is ZSTD_LDM_BUCKETSIZELOG_MAX (default: 3). */
ZSTD_p_ldmHashEveryLog, /* Frequency of inserting/looking up entries in the LDM hash table.
* 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. */
} ZSTD_cParameter;