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limited CDict acceptation criteria to be the same as DDict

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This commit is contained in:
Yann Collet 2017-03-22 18:09:11 -07:00
parent 35fc66f257
commit bea78e8fc2
1 changed files with 28 additions and 27 deletions
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55
lib/compress/zstd_compress.c
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@ -2567,18 +2567,15 @@ static size_t ZSTD_checkDictNCount(short* normalizedCounter, unsigned dictMaxSym
/* Dictionary format : /* Dictionary format :
Magic == ZSTD_DICT_MAGIC (4 bytes) * See :
HUF_writeCTable(256) * https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#dictionary-format
FSE_writeNCount(off) */
FSE_writeNCount(ml) /*! ZSTD_loadDictionary() :
FSE_writeNCount(ll) * @return : size read from dictionary
RepOffsets * note : magic number supposed already checked
Dictionary content * dictSize supposed > 8
*/ */
/*! ZSTD_loadDictEntropyStats() : static size_t ZSTD_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
@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)
{ {
const BYTE* dictPtr = (const BYTE*)dict; const BYTE* dictPtr = (const BYTE*)dict;
const BYTE* const dictEnd = dictPtr + dictSize; const BYTE* const dictEnd = dictPtr + dictSize;
@ -2586,7 +2583,11 @@ static size_t ZSTD_loadDictEntropyStats(ZSTD_CCtx* cctx, const void* dict, size_
unsigned offcodeMaxValue = MaxOff; unsigned offcodeMaxValue = MaxOff;
BYTE scratchBuffer[1<<MAX(MLFSELog,LLFSELog)]; 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); if (HUF_isError(hufHeaderSize)) return ERROR(dictionary_corrupted);
dictPtr += hufHeaderSize; dictPtr += hufHeaderSize;
} }
@ -2628,15 +2629,20 @@ static size_t ZSTD_loadDictEntropyStats(ZSTD_CCtx* cctx, const void* dict, size_
cctx->rep[2] = MEM_readLE32(dictPtr+8); if (cctx->rep[2] == 0 || cctx->rep[2] >= 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);
dictPtr += 12; dictPtr += 12;
{ U32 offcodeMax = MaxOff; { size_t const dictContentSize = (size_t)(dictEnd - dictPtr);
if ((size_t)(dictEnd - dictPtr) <= ((U32)-1) - 128 KB) { U32 offcodeMax = MaxOff;
U32 const maxOffset = (U32)(dictEnd - dictPtr) + 128 KB; /* The maximum offset that must be supported */ if (dictContentSize <= ((U32)-1) - 128 KB) {
/* Calculate minimum offset code required to represent maxOffset */ U32 const maxOffset = (U32)dictContentSize + 128 KB; /* The maximum offset that must be supported */
offcodeMax = ZSTD_highbit32(maxOffset); 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))); 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->flagStaticTables = 1;
cctx->flagStaticHufTable = HUF_repeat_valid; cctx->flagStaticHufTable = HUF_repeat_valid;
@ -2652,14 +2658,9 @@ static size_t ZSTD_compress_insertDictionary(ZSTD_CCtx* zc, const void* dict, si
/* dict as pure content */ /* dict as pure content */
if ((MEM_readLE32(dict) != ZSTD_DICT_MAGIC) || (zc->forceRawDict)) if ((MEM_readLE32(dict) != ZSTD_DICT_MAGIC) || (zc->forceRawDict))
return ZSTD_loadDictionaryContent(zc, dict, dictSize); return ZSTD_loadDictionaryContent(zc, dict, dictSize);
zc->dictID = zc->params.fParams.noDictIDFlag ? 0 : MEM_readLE32((const char*)dict+4);
/* known magic number : dict is parsed for entropy stats and content */ /* dict as zstd dictionary */
{ size_t const loadError = ZSTD_loadDictEntropyStats(zc, (const char*)dict+8 /* skip dictHeader */, dictSize-8); return ZSTD_loadDictionary(zc, dict, dictSize);
size_t const eSize = loadError + 8;
if (ZSTD_isError(loadError)) return loadError;
return ZSTD_loadDictionaryContent(zc, (const char*)dict+eSize, dictSize-eSize);
}
} }
/*! ZSTD_compressBegin_internal() : /*! ZSTD_compressBegin_internal() :