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Factor out the logic to build sequences

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This commit is contained in:
Ephraim Park 2019-06-24 15:26:07 -07:00
parent 9007701670
commit f57ac7b09e
1 changed files with 20 additions and 11 deletions
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31
lib/compress/zstd_compress.c
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@ -2732,30 +2732,24 @@ void ZSTD_resetSeqStore(seqStore_t* ssPtr)
ssPtr->longLengthID = 0;
}
static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize)
typedef enum { ZSTDbss_compress, ZSTDbss_noCompress } ZSTD_buildSeqStore_e;
static size_t ZSTD_buildSeqStore(ZSTD_CCtx* zc, const void* src, size_t srcSize)
{
ZSTD_matchState_t* const ms = &zc->blockState.matchState;
size_t cSize;
DEBUGLOG(5, "ZSTD_compressBlock_internal (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u)",
(unsigned)dstCapacity, (unsigned)ms->window.dictLimit, (unsigned)ms->nextToUpdate);
DEBUGLOG(5, "ZSTD_buildSeqStore (srcSize=%zu)", srcSize);
assert(srcSize <= ZSTD_BLOCKSIZE_MAX);
/* Assert that we have correctly flushed the ctx params into the ms's copy */
ZSTD_assertEqualCParams(zc->appliedParams.cParams, ms->cParams);
if (srcSize < MIN_CBLOCK_SIZE+ZSTD_blockHeaderSize+1) {
ZSTD_ldm_skipSequences(&zc->externSeqStore, srcSize, zc->appliedParams.cParams.minMatch);
cSize = 0;
goto out; /* don't even attempt compression below a certain srcSize */
return ZSTDbss_noCompress; /* don't even attempt compression below a certain srcSize */
}
ZSTD_resetSeqStore(&(zc->seqStore));
/* required for optimal parser to read stats from dictionary */
ms->opt.symbolCosts = &zc->blockState.prevCBlock->entropy;
/* tell the optimal parser how we expect to compress literals */
ms->opt.literalCompressionMode = zc->appliedParams.literalCompressionMode;
/* a gap between an attached dict and the current window is not safe,
* they must remain adjacent,
* and when that stops being the case, the dict must be unset */
@ -2809,6 +2803,21 @@ static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
{ const BYTE* const lastLiterals = (const BYTE*)src + srcSize - lastLLSize;
ZSTD_storeLastLiterals(&zc->seqStore, lastLiterals, lastLLSize);
} }
return ZSTDbss_compress;
}
static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize)
{
size_t cSize;
DEBUGLOG(5, "ZSTD_compressBlock_internal (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u)",
(unsigned)dstCapacity, (unsigned)zc->blockState.matchState.window.dictLimit, (unsigned)zc->blockState.matchState.nextToUpdate);
{ const size_t bss = ZSTD_buildSeqStore(zc, src, srcSize);
FORWARD_IF_ERROR(bss);
if (bss == ZSTDbss_noCompress) { cSize = 0; goto out; }
}
/* encode sequences and literals */
cSize = ZSTD_compressSequences(&zc->seqStore,