ddidderr/zstd-rs
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updated ZSTD_estimateCCtxSize()

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added a parameter streaming,
to estimate memory allocation size
when the CCtx is used for streaming (CStream).

Note : this function is not able to estimate
memory cost of a potential internal CDict
which can only happen when starting with ZSTD_initCStream_usingDict()
This commit is contained in:
Yann Collet
2017-05-08 17:07:59 -07:00
parent 791d744279
commit fc5145955a
4 changed files with 24 additions and 17 deletions
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lib/compress/zstd_compress.c
+14 -9
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@@ -244,7 +244,7 @@ ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, u
}
size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams)
size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams, unsigned streaming)
{
size_t const blockSize = MIN(ZSTD_BLOCKSIZE_ABSOLUTEMAX, (size_t)1 << cParams.windowLog);
U32 const divider = (cParams.searchLength==3) ? 3 : 4;
@@ -260,12 +260,17 @@ size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams)
+ entropyScratchSpace_size;
size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
size_t const optSpace = ((MaxML+1) + (MaxLL+1) + (MaxOff+1) + (1<<Litbits))*sizeof(U32)
size_t const optBudget = ((MaxML+1) + (MaxLL+1) + (MaxOff+1) + (1<<Litbits))*sizeof(U32)
+ (ZSTD_OPT_NUM+1)*(sizeof(ZSTD_match_t) + sizeof(ZSTD_optimal_t));
size_t const neededSpace = entropySpace + tableSpace + tokenSpace
+ (((cParams.strategy == ZSTD_btopt) || (cParams.strategy == ZSTD_btopt2)) ? optSpace : 0);
size_t const optSpace = ((cParams.strategy == ZSTD_btopt) || (cParams.strategy == ZSTD_btopt2)) ? optBudget : 0;
size_t const neededSpace = entropySpace + tableSpace + tokenSpace + optSpace;
return sizeof(ZSTD_CCtx) + neededSpace;
size_t const inBuffSize = ((size_t)1 << cParams.windowLog) + blockSize;
size_t const outBuffSize = ZSTD_compressBound(blockSize) + 1;
size_t const streamingBudget = inBuffSize + outBuffSize;
size_t const streamingSize = streaming ? streamingBudget : 0;
return sizeof(ZSTD_CCtx) + neededSpace + streamingSize;
}
@@ -3194,23 +3199,23 @@ static size_t ZSTD_initCStream_stage2(ZSTD_CStream* zcs,
unsigned long long pledgedSrcSize)
{
assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
zcs->blockSize = MIN(ZSTD_BLOCKSIZE_ABSOLUTEMAX, (size_t)1 << params.cParams.windowLog);
/* allocate buffers */
{ size_t const neededInBuffSize = (size_t)1 << params.cParams.windowLog;
{ size_t const neededInBuffSize = ((size_t)1 << params.cParams.windowLog) + zcs->blockSize;
if (zcs->inBuffSize < neededInBuffSize) {
zcs->inBuffSize = 0;
ZSTD_free(zcs->inBuff, zcs->customMem);
zcs->inBuff = (char*) ZSTD_malloc(neededInBuffSize, zcs->customMem);
zcs->inBuff = (char*)ZSTD_malloc(neededInBuffSize, zcs->customMem);
if (zcs->inBuff == NULL) return ERROR(memory_allocation);
zcs->inBuffSize = neededInBuffSize;
}
zcs->blockSize = MIN(ZSTD_BLOCKSIZE_ABSOLUTEMAX, neededInBuffSize);
}
if (zcs->outBuffSize < ZSTD_compressBound(zcs->blockSize)+1) {
size_t const outBuffSize = ZSTD_compressBound(zcs->blockSize)+1;
zcs->outBuffSize = 0;
ZSTD_free(zcs->outBuff, zcs->customMem);
zcs->outBuff = (char*) ZSTD_malloc(outBuffSize, zcs->customMem);
zcs->outBuff = (char*)ZSTD_malloc(outBuffSize, zcs->customMem);
if (zcs->outBuff == NULL) return ERROR(memory_allocation);
zcs->outBuffSize = outBuffSize;
}