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integrate fast mode

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This commit is contained in:
Yann Collet
2015-11-05 18:16:59 +01:00
parent 1f44b3f778
commit f12c1304a8
8 changed files with 41 additions and 27 deletions
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lib/zstdhc.c
+5 -1
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@@ -225,10 +225,12 @@ size_t ZSTD_HC_compressBlock_fast_generic(ZSTD_HC_CCtx* ctx,
const U32 hBits = ctx->params.hashLog;
seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const base = ctx->base;
const size_t maxDist = ((size_t)1 << ctx->params.windowLog);
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart + 1;
const BYTE* anchor = istart;
const BYTE* const lowest = (size_t)(istart-base) > maxDist ? istart-maxDist : base;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
@@ -253,7 +255,9 @@ size_t ZSTD_HC_compressBlock_fast_generic(ZSTD_HC_CCtx* ctx,
hashTable[h] = (U32)(ip-base);
if (MEM_read32(ip-offset_2) == MEM_read32(ip)) match = ip-offset_2;
if (MEM_read32(match) != MEM_read32(ip)) { ip += ((ip-anchor) >> g_searchStrength) + 1; offset_2 = offset_1; continue; }
if ( (match < lowest) ||
(MEM_read32(match) != MEM_read32(ip)) )
{ ip += ((ip-anchor) >> g_searchStrength) + 1; offset_2 = offset_1; continue; }
while ((ip>anchor) && (match>base) && (ip[-1] == match[-1])) { ip--; match--; } /* catch up */
{