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simplified ZSTD_estimateCCtxSize()

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This commit is contained in:
Yann Collet 2016-07-14 17:05:38 +02:00
parent 69c2cdb45c
commit 8847238cac
2 changed files with 5 additions and 9 deletions
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4
lib/common/zstd.h
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@ -215,7 +215,7 @@ ZSTDLIB_API size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
#define ZSTD_HASHLOG_MAX ZSTD_WINDOWLOG_MAX
#define ZSTD_HASHLOG_MIN 12
#define ZSTD_HASHLOG3_MAX 17
#define ZSTD_HASHLOG3_MIN 15
//#define ZSTD_HASHLOG3_MIN 15
#define ZSTD_SEARCHLOG_MAX (ZSTD_WINDOWLOG_MAX-1)
#define ZSTD_SEARCHLOG_MIN 1
#define ZSTD_SEARCHLENGTH_MAX 7
@ -265,7 +265,7 @@ typedef struct { ZSTD_allocFunction customAlloc; ZSTD_freeFunction customFree; v
/*! ZSTD_estimateCCtxSize() :
* Gives the amount of memory allocated for a ZSTD_CCtx given a set of compression parameters.
* `frameContentSize` is an optional parameter, provide `0` if unknown */
ZSTDLIB_API size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams, unsigned long long frameContentSize);
ZSTDLIB_API size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams);
/*! ZSTD_createCCtx_advanced() :
* Create a ZSTD compression context using external alloc and free functions */

10
lib/compress/zstd_compress.c
View File

@ -249,7 +249,7 @@ ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, u
}
size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams, unsigned long long frameContentSize)
size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams)
{
const size_t blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << cParams.windowLog);
const U32 divider = (cParams.searchLength==3) ? 3 : 4;
@ -258,9 +258,7 @@ size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams, unsigned long l
const size_t chainSize = (cParams.strategy == ZSTD_fast) ? 0 : (1 << cParams.chainLog);
const size_t hSize = ((size_t)1) << cParams.hashLog;
const U32 hashLog3 = (cParams.searchLength>3) ? 0 :
( (!frameContentSize || frameContentSize >= 8192) ? ZSTD_HASHLOG3_MAX :
((frameContentSize >= 2048) ? ZSTD_HASHLOG3_MIN + 1 : ZSTD_HASHLOG3_MIN) );
const U32 hashLog3 = (cParams.searchLength>3) ? 0 : MIN(ZSTD_HASHLOG3_MAX, cParams.windowLog);
const size_t h3Size = ((size_t)1) << hashLog3;
const size_t tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
@ -283,9 +281,7 @@ static size_t ZSTD_resetCCtx_advanced (ZSTD_CCtx* zc,
const size_t tokenSpace = blockSize + 11*maxNbSeq;
const size_t chainSize = (params.cParams.strategy == ZSTD_fast) ? 0 : (1 << params.cParams.chainLog);
const size_t hSize = ((size_t)1) << params.cParams.hashLog;
const U32 hashLog3 = (params.cParams.searchLength>3) ? 0 :
( (!frameContentSize || frameContentSize >= 8192) ? ZSTD_HASHLOG3_MAX :
((frameContentSize >= 2048) ? ZSTD_HASHLOG3_MIN + 1 : ZSTD_HASHLOG3_MIN) );
const U32 hashLog3 = (params.cParams.searchLength>3) ? 0 : MIN(ZSTD_HASHLOG3_MAX, params.cParams.windowLog);
const size_t h3Size = ((size_t)1) << hashLog3;
const size_t tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);