Merge pull request #625 from facebook/loadCDict

limited CDict acceptation criteria to be the same as DDict
This commit is contained in:
Yann Collet 2017-03-24 16:06:20 -07:00 committed by GitHub
commit 2238870eb6

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@ -2504,7 +2504,9 @@ size_t ZSTD_compressBlock(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const
return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 0, 0);
}
/*! ZSTD_loadDictionaryContent() :
* @return : 0, or an error code
*/
static size_t ZSTD_loadDictionaryContent(ZSTD_CCtx* zc, const void* src, size_t srcSize)
{
const BYTE* const ip = (const BYTE*) src;
@ -2534,13 +2536,15 @@ static size_t ZSTD_loadDictionaryContent(ZSTD_CCtx* zc, const void* src, size_t
case ZSTD_greedy:
case ZSTD_lazy:
case ZSTD_lazy2:
ZSTD_insertAndFindFirstIndex (zc, iend-HASH_READ_SIZE, zc->params.cParams.searchLength);
if (srcSize >= HASH_READ_SIZE)
ZSTD_insertAndFindFirstIndex(zc, iend-HASH_READ_SIZE, zc->params.cParams.searchLength);
break;
case ZSTD_btlazy2:
case ZSTD_btopt:
case ZSTD_btopt2:
ZSTD_updateTree(zc, iend-HASH_READ_SIZE, iend, 1 << zc->params.cParams.searchLog, zc->params.cParams.searchLength);
if (srcSize >= HASH_READ_SIZE)
ZSTD_updateTree(zc, iend-HASH_READ_SIZE, iend, 1 << zc->params.cParams.searchLog, zc->params.cParams.searchLength);
break;
default:
@ -2567,18 +2571,15 @@ static size_t ZSTD_checkDictNCount(short* normalizedCounter, unsigned dictMaxSym
/* Dictionary format :
Magic == ZSTD_DICT_MAGIC (4 bytes)
HUF_writeCTable(256)
FSE_writeNCount(off)
FSE_writeNCount(ml)
FSE_writeNCount(ll)
RepOffsets
Dictionary content
*/
/*! ZSTD_loadDictEntropyStats() :
@return : size read from dictionary
note : magic number supposed already checked */
static size_t ZSTD_loadDictEntropyStats(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
* See :
* https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#dictionary-format
*/
/*! ZSTD_loadZstdDictionary() :
* @return : 0, or an error code
* assumptions : magic number supposed already checked
* dictSize supposed > 8
*/
static size_t ZSTD_loadZstdDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
{
const BYTE* dictPtr = (const BYTE*)dict;
const BYTE* const dictEnd = dictPtr + dictSize;
@ -2586,7 +2587,11 @@ static size_t ZSTD_loadDictEntropyStats(ZSTD_CCtx* cctx, const void* dict, size_
unsigned offcodeMaxValue = MaxOff;
BYTE scratchBuffer[1<<MAX(MLFSELog,LLFSELog)];
{ size_t const hufHeaderSize = HUF_readCTable(cctx->hufTable, 255, dict, dictSize);
dictPtr += 4; /* skip magic number */
cctx->dictID = cctx->params.fParams.noDictIDFlag ? 0 : MEM_readLE32(dictPtr);
dictPtr += 4;
{ size_t const hufHeaderSize = HUF_readCTable(cctx->hufTable, 255, dictPtr, dictEnd-dictPtr);
if (HUF_isError(hufHeaderSize)) return ERROR(dictionary_corrupted);
dictPtr += hufHeaderSize;
}
@ -2623,43 +2628,44 @@ static size_t ZSTD_loadDictEntropyStats(ZSTD_CCtx* cctx, const void* dict, size_
}
if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted);
cctx->rep[0] = MEM_readLE32(dictPtr+0); if (cctx->rep[0] == 0 || cctx->rep[0] >= dictSize) return ERROR(dictionary_corrupted);
cctx->rep[1] = MEM_readLE32(dictPtr+4); if (cctx->rep[1] == 0 || cctx->rep[1] >= dictSize) return ERROR(dictionary_corrupted);
cctx->rep[2] = MEM_readLE32(dictPtr+8); if (cctx->rep[2] == 0 || cctx->rep[2] >= dictSize) return ERROR(dictionary_corrupted);
cctx->rep[0] = MEM_readLE32(dictPtr+0);
cctx->rep[1] = MEM_readLE32(dictPtr+4);
cctx->rep[2] = MEM_readLE32(dictPtr+8);
dictPtr += 12;
{ U32 offcodeMax = MaxOff;
if ((size_t)(dictEnd - dictPtr) <= ((U32)-1) - 128 KB) {
U32 const maxOffset = (U32)(dictEnd - dictPtr) + 128 KB; /* The maximum offset that must be supported */
/* Calculate minimum offset code required to represent maxOffset */
offcodeMax = ZSTD_highbit32(maxOffset);
{ size_t const dictContentSize = (size_t)(dictEnd - dictPtr);
U32 offcodeMax = MaxOff;
if (dictContentSize <= ((U32)-1) - 128 KB) {
U32 const maxOffset = (U32)dictContentSize + 128 KB; /* The maximum offset that must be supported */
offcodeMax = ZSTD_highbit32(maxOffset); /* Calculate minimum offset code required to represent maxOffset */
}
/* Every possible supported offset <= dictContentSize + 128 KB must be representable */
/* All offset values <= dictContentSize + 128 KB must be representable */
CHECK_F (ZSTD_checkDictNCount(offcodeNCount, offcodeMaxValue, MIN(offcodeMax, MaxOff)));
}
/* All repCodes must be <= dictContentSize and != 0*/
{ U32 u;
for (u=0; u<3; u++) {
if (cctx->rep[u] == 0) return ERROR(dictionary_corrupted);
if (cctx->rep[u] > dictContentSize) return ERROR(dictionary_corrupted);
} }
cctx->flagStaticTables = 1;
cctx->flagStaticHufTable = HUF_repeat_valid;
return dictPtr - (const BYTE*)dict;
cctx->flagStaticTables = 1;
cctx->flagStaticHufTable = HUF_repeat_valid;
return ZSTD_loadDictionaryContent(cctx, dictPtr, dictContentSize);
}
}
/** ZSTD_compress_insertDictionary() :
* @return : 0, or an error code */
static size_t ZSTD_compress_insertDictionary(ZSTD_CCtx* zc, const void* dict, size_t dictSize)
static size_t ZSTD_compress_insertDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
{
if ((dict==NULL) || (dictSize<=8)) return 0;
/* dict as pure content */
if ((MEM_readLE32(dict) != ZSTD_DICT_MAGIC) || (zc->forceRawDict))
return ZSTD_loadDictionaryContent(zc, dict, dictSize);
zc->dictID = zc->params.fParams.noDictIDFlag ? 0 : MEM_readLE32((const char*)dict+4);
if ((MEM_readLE32(dict) != ZSTD_DICT_MAGIC) || (cctx->forceRawDict))
return ZSTD_loadDictionaryContent(cctx, dict, dictSize);
/* known magic number : dict is parsed for entropy stats and content */
{ size_t const loadError = ZSTD_loadDictEntropyStats(zc, (const char*)dict+8 /* skip dictHeader */, dictSize-8);
size_t const eSize = loadError + 8;
if (ZSTD_isError(loadError)) return loadError;
return ZSTD_loadDictionaryContent(zc, (const char*)dict+eSize, dictSize-eSize);
}
/* dict as zstd dictionary */
return ZSTD_loadZstdDictionary(cctx, dict, dictSize);
}
/*! ZSTD_compressBegin_internal() :