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Diffstat (limited to 'lib/zstd/decompress/zstd_ddict.c')
| -rw-r--r-- | lib/zstd/decompress/zstd_ddict.c | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/lib/zstd/decompress/zstd_ddict.c b/lib/zstd/decompress/zstd_ddict.c new file mode 100644 index 0000000000..dbbc7919de --- /dev/null +++ b/lib/zstd/decompress/zstd_ddict.c @@ -0,0 +1,241 @@ +/* + * Copyright (c) Yann Collet, Facebook, Inc. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. + */ + +/* zstd_ddict.c : + * concentrates all logic that needs to know the internals of ZSTD_DDict object */ + +/*-******************************************************* +* Dependencies +*********************************************************/ +#include "../common/zstd_deps.h" /* ZSTD_memcpy, ZSTD_memmove, ZSTD_memset */ +#include "../common/cpu.h" /* bmi2 */ +#include "../common/mem.h" /* low level memory routines */ +#define FSE_STATIC_LINKING_ONLY +#include "../common/fse.h" +#define HUF_STATIC_LINKING_ONLY +#include "../common/huf.h" +#include "zstd_decompress_internal.h" +#include "zstd_ddict.h" + + + + +/*-******************************************************* +* Types +*********************************************************/ +struct ZSTD_DDict_s { + void* dictBuffer; + const void* dictContent; + size_t dictSize; + ZSTD_entropyDTables_t entropy; + U32 dictID; + U32 entropyPresent; + ZSTD_customMem cMem; +}; /* typedef'd to ZSTD_DDict within "zstd.h" */ + +const void* ZSTD_DDict_dictContent(const ZSTD_DDict* ddict) +{ + assert(ddict != NULL); + return ddict->dictContent; +} + +size_t ZSTD_DDict_dictSize(const ZSTD_DDict* ddict) +{ + assert(ddict != NULL); + return ddict->dictSize; +} + +void ZSTD_copyDDictParameters(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict) +{ + DEBUGLOG(4, "ZSTD_copyDDictParameters"); + assert(dctx != NULL); + assert(ddict != NULL); + dctx->dictID = ddict->dictID; + dctx->prefixStart = ddict->dictContent; + dctx->virtualStart = ddict->dictContent; + dctx->dictEnd = (const BYTE*)ddict->dictContent + ddict->dictSize; + dctx->previousDstEnd = dctx->dictEnd; +#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + dctx->dictContentBeginForFuzzing = dctx->prefixStart; + dctx->dictContentEndForFuzzing = dctx->previousDstEnd; +#endif + if (ddict->entropyPresent) { + dctx->litEntropy = 1; + dctx->fseEntropy = 1; + dctx->LLTptr = ddict->entropy.LLTable; + dctx->MLTptr = ddict->entropy.MLTable; + dctx->OFTptr = ddict->entropy.OFTable; + dctx->HUFptr = ddict->entropy.hufTable; + dctx->entropy.rep[0] = ddict->entropy.rep[0]; + dctx->entropy.rep[1] = ddict->entropy.rep[1]; + dctx->entropy.rep[2] = ddict->entropy.rep[2]; + } else { + dctx->litEntropy = 0; + dctx->fseEntropy = 0; + } +} + + +static size_t +ZSTD_loadEntropy_intoDDict(ZSTD_DDict* ddict, + ZSTD_dictContentType_e dictContentType) +{ + ddict->dictID = 0; + ddict->entropyPresent = 0; + if (dictContentType == ZSTD_dct_rawContent) return 0; + + if (ddict->dictSize < 8) { + if (dictContentType == ZSTD_dct_fullDict) + return ERROR(dictionary_corrupted); /* only accept specified dictionaries */ + return 0; /* pure content mode */ + } + { U32 const magic = MEM_readLE32(ddict->dictContent); + if (magic != ZSTD_MAGIC_DICTIONARY) { + if (dictContentType == ZSTD_dct_fullDict) + return ERROR(dictionary_corrupted); /* only accept specified dictionaries */ + return 0; /* pure content mode */ + } + } + ddict->dictID = MEM_readLE32((const char*)ddict->dictContent + ZSTD_FRAMEIDSIZE); + + /* load entropy tables */ + RETURN_ERROR_IF(ZSTD_isError(ZSTD_loadDEntropy( + &ddict->entropy, ddict->dictContent, ddict->dictSize)), + dictionary_corrupted, ""); + ddict->entropyPresent = 1; + return 0; +} + + +static size_t ZSTD_initDDict_internal(ZSTD_DDict* ddict, + const void* dict, size_t dictSize, + ZSTD_dictLoadMethod_e dictLoadMethod, + ZSTD_dictContentType_e dictContentType) +{ + if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dict) || (!dictSize)) { + ddict->dictBuffer = NULL; + ddict->dictContent = dict; + if (!dict) dictSize = 0; + } else { + void* const internalBuffer = ZSTD_customMalloc(dictSize, ddict->cMem); + ddict->dictBuffer = internalBuffer; + ddict->dictContent = internalBuffer; + if (!internalBuffer) return ERROR(memory_allocation); + ZSTD_memcpy(internalBuffer, dict, dictSize); + } + ddict->dictSize = dictSize; + ddict->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001); /* cover both little and big endian */ + + /* parse dictionary content */ + FORWARD_IF_ERROR( ZSTD_loadEntropy_intoDDict(ddict, dictContentType) , ""); + + return 0; +} + +ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize, + ZSTD_dictLoadMethod_e dictLoadMethod, + ZSTD_dictContentType_e dictContentType, + ZSTD_customMem customMem) +{ + if ((!customMem.customAlloc) ^ (!customMem.customFree)) return NULL; + + { ZSTD_DDict* const ddict = (ZSTD_DDict*) ZSTD_customMalloc(sizeof(ZSTD_DDict), customMem); + if (ddict == NULL) return NULL; + ddict->cMem = customMem; + { size_t const initResult = ZSTD_initDDict_internal(ddict, + dict, dictSize, + dictLoadMethod, dictContentType); + if (ZSTD_isError(initResult)) { + ZSTD_freeDDict(ddict); + return NULL; + } } + return ddict; + } +} + +/*! ZSTD_createDDict() : +* Create a digested dictionary, to start decompression without startup delay. +* `dict` content is copied inside DDict. +* Consequently, `dict` can be released after `ZSTD_DDict` creation */ +ZSTD_DDict* ZSTD_createDDict(const void* dict, size_t dictSize) +{ + ZSTD_customMem const allocator = { NULL, NULL, NULL }; + return ZSTD_createDDict_advanced(dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto, allocator); +} + +/*! ZSTD_createDDict_byReference() : + * Create a digested dictionary, to start decompression without startup delay. + * Dictionary content is simply referenced, it will be accessed during decompression. + * Warning : dictBuffer must outlive DDict (DDict must be freed before dictBuffer) */ +ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize) +{ + ZSTD_customMem const allocator = { NULL, NULL, NULL }; + return ZSTD_createDDict_advanced(dictBuffer, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto, allocator); +} + + +const ZSTD_DDict* ZSTD_initStaticDDict( + void* sBuffer, size_t sBufferSize, + const void* dict, size_t dictSize, + ZSTD_dictLoadMethod_e dictLoadMethod, + ZSTD_dictContentType_e dictContentType) +{ + size_t const neededSpace = sizeof(ZSTD_DDict) + + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize); + ZSTD_DDict* const ddict = (ZSTD_DDict*)sBuffer; + assert(sBuffer != NULL); + assert(dict != NULL); + if ((size_t)sBuffer & 7) return NULL; /* 8-aligned */ + if (sBufferSize < neededSpace) return NULL; + if (dictLoadMethod == ZSTD_dlm_byCopy) { + ZSTD_memcpy(ddict+1, dict, dictSize); /* local copy */ + dict = ddict+1; + } + if (ZSTD_isError( ZSTD_initDDict_internal(ddict, + dict, dictSize, + ZSTD_dlm_byRef, dictContentType) )) + return NULL; + return ddict; +} + + +size_t ZSTD_freeDDict(ZSTD_DDict* ddict) +{ + if (ddict==NULL) return 0; /* support free on NULL */ + { ZSTD_customMem const cMem = ddict->cMem; + ZSTD_customFree(ddict->dictBuffer, cMem); + ZSTD_customFree(ddict, cMem); + return 0; + } +} + +/*! ZSTD_estimateDDictSize() : + * Estimate amount of memory that will be needed to create a dictionary for decompression. + * Note : dictionary created by reference using ZSTD_dlm_byRef are smaller */ +size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod) +{ + return sizeof(ZSTD_DDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize); +} + +size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict) +{ + if (ddict==NULL) return 0; /* support sizeof on NULL */ + return sizeof(*ddict) + (ddict->dictBuffer ? ddict->dictSize : 0) ; +} + +/*! ZSTD_getDictID_fromDDict() : + * Provides the dictID of the dictionary loaded into `ddict`. + * If @return == 0, the dictionary is not conformant to Zstandard specification, or empty. + * Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */ +unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict) +{ + if (ddict==NULL) return 0; + return ZSTD_getDictID_fromDict(ddict->dictContent, ddict->dictSize); +} |