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fix : ZSTD_compress_generic(,,,ZSTD_e_end) automatically sets pledgedSrcSize

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as per documentation, on ZSTD_setPledgedSrcSize() :
> If all data is provided and consumed in a single round,
> this value (pledgedSrcSize) is overriden by srcSize instead.

This wasn't applied before compression level is transformed into compression parameters.
As a consequence, small input missed compression parameters adaptation.

It seems to work fine now : compression was compared with ZSTD_compress_advanced(),
results were the same.
This commit is contained in:
Yann Collet 2017-11-01 13:15:23 -07:00
parent 61e5a1adfc
commit 428e8b3bf4
2 changed files with 11 additions and 0 deletions
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1
lib/compress/zstd_compress.c
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@ -2814,6 +2814,7 @@ size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
if (cctx->streamStage == zcss_init) {
ZSTD_prefixDict const prefixDict = cctx->prefixDict;
ZSTD_CCtx_params params = cctx->requestedParams;
if (endOp == ZSTD_e_end) cctx->pledgedSrcSizePlusOne = input->size + 1;
params.cParams = ZSTD_getCParamsFromCCtxParams(
cctx->requestedParams, cctx->pledgedSrcSizePlusOne-1, 0 /*dictSize*/);
memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict)); /* single usage */

10
programs/bench.c
View File

@ -286,6 +286,7 @@ static int BMK_benchMem(const void* srcBuffer, size_t srcSize,
U32 nbLoops = 0;
ZSTD_CCtx_setParameter(ctx, ZSTD_p_nbThreads, g_nbThreads);
ZSTD_CCtx_setParameter(ctx, ZSTD_p_compressionLevel, cLevel);
//ZSTD_CCtx_setPledgedSrcSize(ctx, blockTable[0].srcSize); /* estimation, only to help cLevel conversion before applying advanced compression parameters */
ZSTD_CCtx_setParameter(ctx, ZSTD_p_enableLongDistanceMatching, g_ldmFlag);
ZSTD_CCtx_setParameter(ctx, ZSTD_p_ldmMinMatch, g_ldmMinMatch);
ZSTD_CCtx_setParameter(ctx, ZSTD_p_ldmHashLog, g_ldmHashLog);
@ -305,6 +306,14 @@ static int BMK_benchMem(const void* srcBuffer, size_t srcSize,
do {
U32 blockNb;
for (blockNb=0; blockNb<nbBlocks; blockNb++) {
#if 0 /* direct compression function, for occasional comparison */
ZSTD_parameters const params = ZSTD_getParams(cLevel, blockTable[blockNb].srcSize, dictBufferSize);
blockTable[blockNb].cSize = ZSTD_compress_advanced(ctx,
blockTable[blockNb].cPtr, blockTable[blockNb].cRoom,
blockTable[blockNb].srcPtr, blockTable[blockNb].srcSize,
dictBuffer, dictBufferSize,
params);
#else
size_t moreToFlush = 1;
ZSTD_outBuffer out;
ZSTD_inBuffer in;
@ -322,6 +331,7 @@ static int BMK_benchMem(const void* srcBuffer, size_t srcSize,
ZSTD_getErrorName(moreToFlush));
}
blockTable[blockNb].cSize = out.pos;
#endif
}
nbLoops++;
} while (UTIL_clockSpanMicro(clockStart) < clockLoop);