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Adjust Working Context Table Sizes Back Down

dev
W. Felix Handte 2020-08-28 12:38:50 -04:00
parent c09454e28f
commit 7b5d2f72ea
1 changed files with 35 additions and 3 deletions
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38
lib/compress/zstd_compress.c
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@ -872,6 +872,8 @@ static int ZSTD_dedicatedDictSearch_isSupported(
int const compressionLevel,
unsigned long long srcSizeHint,
size_t const dictSize);
static void ZSTD_dedicatedDictSearch_revertCParams(
ZSTD_compressionParameters* cParams);
/**
* Initializes the local dict using the requested parameters.
@ -1661,17 +1663,23 @@ ZSTD_resetCCtx_byAttachingCDict(ZSTD_CCtx* cctx,
U64 pledgedSrcSize,
ZSTD_buffered_policy_e zbuff)
{
{ const ZSTD_compressionParameters* const cdict_cParams = &cdict->matchState.cParams;
{
ZSTD_compressionParameters adjusted_cdict_cParams = cdict->matchState.cParams;
unsigned const windowLog = params.cParams.windowLog;
assert(windowLog != 0);
/* Resize working context table params for input only, since the dict
* has its own tables. */
/* pledgedSrcSize == 0 means 0! */
params.cParams = ZSTD_adjustCParams_internal(*cdict_cParams, pledgedSrcSize, 0);
if (cdict->matchState.dedicatedDictSearch) {
ZSTD_dedicatedDictSearch_revertCParams(&adjusted_cdict_cParams);
}
params.cParams = ZSTD_adjustCParams_internal(adjusted_cdict_cParams, pledgedSrcSize, 0);
params.cParams.windowLog = windowLog;
FORWARD_IF_ERROR(ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
ZSTDcrp_makeClean, zbuff), "");
assert(cctx->appliedParams.cParams.strategy == cdict_cParams->strategy);
assert(cctx->appliedParams.cParams.strategy == adjusted_cdict_cParams.strategy);
}
{ const U32 cdictEnd = (U32)( cdict->matchState.window.nextSrc
@ -4353,6 +4361,30 @@ static int ZSTD_dedicatedDictSearch_isSupported(int const compressionLevel, unsi
return (cParams.strategy >= ZSTD_greedy) && (cParams.strategy <= ZSTD_lazy2);
}
/**
* Reverses the adjustment applied to cparams when enabling dedicated dict
* search. This is used to recover the params set to be used in the working
* context. (Otherwise, those tables would also grow.)
*/
static void ZSTD_dedicatedDictSearch_revertCParams(
ZSTD_compressionParameters* cParams) {
switch (cParams->strategy) {
case ZSTD_fast:
case ZSTD_dfast:
break;
case ZSTD_greedy:
case ZSTD_lazy:
case ZSTD_lazy2:
cParams->hashLog -= ZSTD_LAZY_DDSS_BUCKET_LOG;
break;
case ZSTD_btlazy2:
case ZSTD_btopt:
case ZSTD_btultra:
case ZSTD_btultra2:
break;
}
}
/*! ZSTD_getCParams_internal() :
* @return ZSTD_compressionParameters structure for a selected compression level, srcSize and dictSize.
* Note: srcSizeHint 0 means 0, use ZSTD_CONTENTSIZE_UNKNOWN for unknown.