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Pull Attachment Decision into Separate Function

dev
W. Felix Handte 2018-08-24 13:13:48 -07:00
parent b7fba599ae
commit a6d6bbeae1
1 changed files with 33 additions and 19 deletions
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52
lib/compress/zstd_compress.c
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@ -1302,6 +1302,38 @@ void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx) {
assert(!ZSTD_window_hasExtDict(cctx->blockState.matchState.window));
}
/* These are the approximate sizes for each strategy past which copying the
* dictionary tables into the working context is faster than using them
* in-place.
*/
static const size_t attachDictSizeCutoffs[(unsigned)ZSTD_btultra+1] = {
8 KB, /* unused */
8 KB, /* ZSTD_fast */
16 KB, /* ZSTD_dfast */
32 KB, /* ZSTD_greedy */
32 KB, /* ZSTD_lazy */
32 KB, /* ZSTD_lazy2 */
32 KB, /* ZSTD_btlazy2 */
32 KB, /* ZSTD_btopt */
8 KB /* ZSTD_btultra */
};
static int ZSTD_shouldAttachDict(ZSTD_CCtx* cctx,
const ZSTD_CDict* cdict,
ZSTD_CCtx_params params,
U64 pledgedSrcSize)
{
size_t cutoff = attachDictSizeCutoffs[cdict->matchState.cParams.strategy];
return ( pledgedSrcSize <= cutoff
|| pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
|| params.attachDictPref == ZSTD_dictForceAttach )
&& params.attachDictPref != ZSTD_dictForceCopy
&& !params.forceWindow /* dictMatchState isn't correctly
* handled in _enforceMaxDist */
&& ZSTD_equivalentCParams(cctx->appliedParams.cParams,
cdict->matchState.cParams);
}
static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
const ZSTD_CDict* cdict,
ZSTD_CCtx_params params,
@ -1311,26 +1343,8 @@ static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
/* We have a choice between copying the dictionary context into the working
* context, or referencing the dictionary context from the working context
* in-place. We decide here which strategy to use. */
const U64 attachDictSizeCutoffs[(unsigned)ZSTD_btultra+1] = {
8 KB, /* unused */
8 KB, /* ZSTD_fast */
16 KB, /* ZSTD_dfast */
32 KB, /* ZSTD_greedy */
32 KB, /* ZSTD_lazy */
32 KB, /* ZSTD_lazy2 */
32 KB, /* ZSTD_btlazy2 */
32 KB, /* ZSTD_btopt */
8 KB /* ZSTD_btultra */
};
const ZSTD_compressionParameters *cdict_cParams = &cdict->matchState.cParams;
const int attachDict = ( pledgedSrcSize <= attachDictSizeCutoffs[cdict_cParams->strategy]
|| pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
|| params.attachDictPref == ZSTD_dictForceAttach )
&& params.attachDictPref != ZSTD_dictForceCopy
&& !params.forceWindow /* dictMatchState isn't correctly
* handled in _enforceMaxDist */
&& ZSTD_equivalentCParams(cctx->appliedParams.cParams,
*cdict_cParams);
const int attachDict = ZSTD_shouldAttachDict(cctx, cdict, params, pledgedSrcSize);
DEBUGLOG(4, "ZSTD_resetCCtx_usingCDict (pledgedSrcSize=%u)", (U32)pledgedSrcSize);