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Added ZSTD_initStaticCDict()

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This commit is contained in:
Yann Collet
2017-05-25 18:05:49 -07:00
parent 57827f906f
commit cdf7e82222
5 changed files with 145 additions and 37 deletions
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lib/compress/zstd_compress.c
+79 -32
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@@ -3239,7 +3239,6 @@ size_t ZSTD_compress(void* dst, size_t dstCapacity, const void* src, size_t srcS
* Estimate amount of memory that will be needed to create a dictionary with following arguments */
size_t ZSTD_estimateCDictSize(ZSTD_compressionParameters cParams, size_t dictSize, unsigned byReference)
{
cParams = ZSTD_adjustCParams(cParams, 0, dictSize);
return sizeof(ZSTD_CDict) + ZSTD_estimateCCtxSize(cParams)
+ (byReference ? 0 : dictSize);
}
@@ -3258,6 +3257,34 @@ static ZSTD_parameters ZSTD_makeParams(ZSTD_compressionParameters cParams, ZSTD_
return params;
}
static size_t ZSTD_initCDict_internal(
ZSTD_CDict* cdict,
const void* dictBuffer, size_t dictSize, unsigned byReference,
ZSTD_compressionParameters cParams)
{
if ((byReference) || (!dictBuffer) || (!dictSize)) {
cdict->dictBuffer = NULL;
cdict->dictContent = dictBuffer;
} else {
void* const internalBuffer = ZSTD_malloc(dictSize, cdict->refContext->customMem);
if (!internalBuffer) return ERROR(memory_allocation);
memcpy(internalBuffer, dictBuffer, dictSize);
cdict->dictBuffer = internalBuffer;
cdict->dictContent = internalBuffer;
}
cdict->dictContentSize = dictSize;
{ ZSTD_frameParameters const fParams = { 0 /* contentSizeFlag */,
0 /* checksumFlag */, 0 /* noDictIDFlag */ }; /* dummy */
ZSTD_parameters const params = ZSTD_makeParams(cParams, fParams);
CHECK_F( ZSTD_compressBegin_advanced(cdict->refContext,
cdict->dictContent, dictSize,
params, 0 /* srcSize */) );
}
return 0;
}
ZSTD_CDict* ZSTD_createCDict_advanced(const void* dictBuffer, size_t dictSize, unsigned byReference,
ZSTD_compressionParameters cParams, ZSTD_customMem customMem)
{
@@ -3269,44 +3296,19 @@ ZSTD_CDict* ZSTD_createCDict_advanced(const void* dictBuffer, size_t dictSize, u
ZSTD_CCtx* const cctx = ZSTD_createCCtx_advanced(customMem);
if (!cdict || !cctx) {
DEBUGLOG(5, "!cdict || !cctx");
ZSTD_free(cdict, customMem);
ZSTD_freeCCtx(cctx);
return NULL;
}
cdict->refContext = cctx;
if ((byReference) || (!dictBuffer) || (!dictSize)) {
cdict->dictBuffer = NULL;
cdict->dictContent = dictBuffer;
} else {
void* const internalBuffer = ZSTD_malloc(dictSize, customMem);
if (!internalBuffer) {
DEBUGLOG(5, "!internalBuffer");
ZSTD_free(cctx, customMem);
ZSTD_free(cdict, customMem);
return NULL;
}
memcpy(internalBuffer, dictBuffer, dictSize);
cdict->dictBuffer = internalBuffer;
cdict->dictContent = internalBuffer;
if (ZSTD_isError( ZSTD_initCDict_internal(cdict,
dictBuffer, dictSize, byReference,
cParams) )) {
ZSTD_freeCDict(cdict);
return NULL;
}
{ ZSTD_frameParameters const fParams = { 0 /* contentSizeFlag */,
0 /* checksumFlag */, 0 /* noDictIDFlag */ }; /* dummy */
ZSTD_parameters const params = ZSTD_makeParams(cParams, fParams);
size_t const errorCode = ZSTD_compressBegin_advanced(cctx,
cdict->dictContent, dictSize, params, 0);
if (ZSTD_isError(errorCode)) {
DEBUGLOG(5, "ZSTD_compressBegin_advanced error : %s",
ZSTD_getErrorName(errorCode));
ZSTD_free(cdict->dictBuffer, customMem);
ZSTD_free(cdict, customMem);
ZSTD_freeCCtx(cctx);
return NULL;
} }
cdict->refContext = cctx;
cdict->dictContentSize = dictSize;
return cdict;
}
}
@@ -3336,6 +3338,51 @@ size_t ZSTD_freeCDict(ZSTD_CDict* cdict)
}
}
/*! ZSTD_initStaticCDict_advanced() :
* Generate a digested dictionary in provided memory area.
* workspace: The memory area to emplace the dictionary into.
* Provided pointer must 8-bytes aligned.
* It must outlive dictionary usage.
* workspaceSize: Use ZSTD_estimateCDictSize()
* to determine how large workspace must be.
* cParams : use ZSTD_getCParams() to transform a compression level
* into its relevants cParams.
* @return : pointer to ZSTD_CDict*, or NULL if error (size too small)
* Note : there is no corresponding "free" function.
* Since workspace was allocated externally, it must be freed externally.
*/
ZSTD_CDict* ZSTD_initStaticCDict(void* workspace, size_t workspaceSize,
const void* dict, size_t dictSize, unsigned byReference,
ZSTD_compressionParameters cParams)
{
size_t const cctxSize = ZSTD_estimateCCtxSize(cParams);
size_t const neededSize = sizeof(ZSTD_CDict) + (byReference ? 0 : dictSize)
+ cctxSize;
ZSTD_CDict* const cdict = (ZSTD_CDict*) workspace;
void* ptr;
DEBUGLOG(2, "(size_t)workspace & 7 : %u", (U32)(size_t)workspace & 7);
if ((size_t)workspace & 7) return NULL; /* 8-aligned */
DEBUGLOG(2, "(workspaceSize < neededSize) : (%u < %u) => %u",
(U32)workspaceSize, (U32)neededSize, (U32)(workspaceSize < neededSize));
if (workspaceSize < neededSize) return NULL;
if (!byReference) {
memcpy(cdict+1, dict, dictSize);
dict = cdict+1;
ptr = (char*)workspace + sizeof(ZSTD_CDict) + dictSize;
} else {
ptr = cdict+1;
}
cdict->refContext = ZSTD_initStaticCCtx(ptr, cctxSize);
if (ZSTD_isError( ZSTD_initCDict_internal(cdict,
dict, dictSize, 1 /* by Reference */,
cParams) ))
return NULL;
return cdict;
}
static ZSTD_parameters ZSTD_getParamsFromCDict(const ZSTD_CDict* cdict) {
return ZSTD_getParamsFromCCtx(cdict->refContext);
}