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