1 /* 2 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. 3 * All rights reserved. 4 * 5 * This source code is licensed under both the BSD-style license (found in the 6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found 7 * in the COPYING file in the root directory of this source tree). 8 * You may select, at your option, one of the above-listed licenses. 9 */ 10 11 /* zstd_ddict.c : 12 * concentrates all logic that needs to know the internals of ZSTD_DDict object */ 13 14 /*-******************************************************* 15 * Dependencies 16 *********************************************************/ 17 #include <string.h> /* memcpy, memmove, memset */ 18 #include "cpu.h" /* bmi2 */ 19 #include "mem.h" /* low level memory routines */ 20 #define FSE_STATIC_LINKING_ONLY 21 #include "fse.h" 22 #define HUF_STATIC_LINKING_ONLY 23 #include "huf.h" 24 #include "zstd_decompress_internal.h" 25 #include "zstd_ddict.h" 26 27 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) 28 # include "zstd_legacy.h" 29 #endif 30 31 32 33 /*-******************************************************* 34 * Types 35 *********************************************************/ 36 struct ZSTD_DDict_s { 37 void* dictBuffer; 38 const void* dictContent; 39 size_t dictSize; 40 ZSTD_entropyDTables_t entropy; 41 U32 dictID; 42 U32 entropyPresent; 43 ZSTD_customMem cMem; 44 }; /* typedef'd to ZSTD_DDict within "zstd.h" */ 45 46 const void* ZSTD_DDict_dictContent(const ZSTD_DDict* ddict) 47 { 48 assert(ddict != NULL); 49 return ddict->dictContent; 50 } 51 52 size_t ZSTD_DDict_dictSize(const ZSTD_DDict* ddict) 53 { 54 assert(ddict != NULL); 55 return ddict->dictSize; 56 } 57 58 void ZSTD_copyDDictParameters(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict) 59 { 60 DEBUGLOG(4, "ZSTD_copyDDictParameters"); 61 assert(dctx != NULL); 62 assert(ddict != NULL); 63 dctx->dictID = ddict->dictID; 64 dctx->prefixStart = ddict->dictContent; 65 dctx->virtualStart = ddict->dictContent; 66 dctx->dictEnd = (const BYTE*)ddict->dictContent + ddict->dictSize; 67 dctx->previousDstEnd = dctx->dictEnd; 68 if (ddict->entropyPresent) { 69 dctx->litEntropy = 1; 70 dctx->fseEntropy = 1; 71 dctx->LLTptr = ddict->entropy.LLTable; 72 dctx->MLTptr = ddict->entropy.MLTable; 73 dctx->OFTptr = ddict->entropy.OFTable; 74 dctx->HUFptr = ddict->entropy.hufTable; 75 dctx->entropy.rep[0] = ddict->entropy.rep[0]; 76 dctx->entropy.rep[1] = ddict->entropy.rep[1]; 77 dctx->entropy.rep[2] = ddict->entropy.rep[2]; 78 } else { 79 dctx->litEntropy = 0; 80 dctx->fseEntropy = 0; 81 } 82 } 83 84 85 static size_t 86 ZSTD_loadEntropy_intoDDict(ZSTD_DDict* ddict, 87 ZSTD_dictContentType_e dictContentType) 88 { 89 ddict->dictID = 0; 90 ddict->entropyPresent = 0; 91 if (dictContentType == ZSTD_dct_rawContent) return 0; 92 93 if (ddict->dictSize < 8) { 94 if (dictContentType == ZSTD_dct_fullDict) 95 return ERROR(dictionary_corrupted); /* only accept specified dictionaries */ 96 return 0; /* pure content mode */ 97 } 98 { U32 const magic = MEM_readLE32(ddict->dictContent); 99 if (magic != ZSTD_MAGIC_DICTIONARY) { 100 if (dictContentType == ZSTD_dct_fullDict) 101 return ERROR(dictionary_corrupted); /* only accept specified dictionaries */ 102 return 0; /* pure content mode */ 103 } 104 } 105 ddict->dictID = MEM_readLE32((const char*)ddict->dictContent + ZSTD_FRAMEIDSIZE); 106 107 /* load entropy tables */ 108 RETURN_ERROR_IF(ZSTD_isError(ZSTD_loadDEntropy( 109 &ddict->entropy, ddict->dictContent, ddict->dictSize)), 110 dictionary_corrupted); 111 ddict->entropyPresent = 1; 112 return 0; 113 } 114 115 116 static size_t ZSTD_initDDict_internal(ZSTD_DDict* ddict, 117 const void* dict, size_t dictSize, 118 ZSTD_dictLoadMethod_e dictLoadMethod, 119 ZSTD_dictContentType_e dictContentType) 120 { 121 if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dict) || (!dictSize)) { 122 ddict->dictBuffer = NULL; 123 ddict->dictContent = dict; 124 if (!dict) dictSize = 0; 125 } else { 126 void* const internalBuffer = ZSTD_malloc(dictSize, ddict->cMem); 127 ddict->dictBuffer = internalBuffer; 128 ddict->dictContent = internalBuffer; 129 if (!internalBuffer) return ERROR(memory_allocation); 130 memcpy(internalBuffer, dict, dictSize); 131 } 132 ddict->dictSize = dictSize; 133 ddict->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001); /* cover both little and big endian */ 134 135 /* parse dictionary content */ 136 FORWARD_IF_ERROR( ZSTD_loadEntropy_intoDDict(ddict, dictContentType) ); 137 138 return 0; 139 } 140 141 ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize, 142 ZSTD_dictLoadMethod_e dictLoadMethod, 143 ZSTD_dictContentType_e dictContentType, 144 ZSTD_customMem customMem) 145 { 146 if (!customMem.customAlloc ^ !customMem.customFree) return NULL; 147 148 { ZSTD_DDict* const ddict = (ZSTD_DDict*) ZSTD_malloc(sizeof(ZSTD_DDict), customMem); 149 if (ddict == NULL) return NULL; 150 ddict->cMem = customMem; 151 { size_t const initResult = ZSTD_initDDict_internal(ddict, 152 dict, dictSize, 153 dictLoadMethod, dictContentType); 154 if (ZSTD_isError(initResult)) { 155 ZSTD_freeDDict(ddict); 156 return NULL; 157 } } 158 return ddict; 159 } 160 } 161 162 /*! ZSTD_createDDict() : 163 * Create a digested dictionary, to start decompression without startup delay. 164 * `dict` content is copied inside DDict. 165 * Consequently, `dict` can be released after `ZSTD_DDict` creation */ 166 ZSTD_DDict* ZSTD_createDDict(const void* dict, size_t dictSize) 167 { 168 ZSTD_customMem const allocator = { NULL, NULL, NULL }; 169 return ZSTD_createDDict_advanced(dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto, allocator); 170 } 171 172 /*! ZSTD_createDDict_byReference() : 173 * Create a digested dictionary, to start decompression without startup delay. 174 * Dictionary content is simply referenced, it will be accessed during decompression. 175 * Warning : dictBuffer must outlive DDict (DDict must be freed before dictBuffer) */ 176 ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize) 177 { 178 ZSTD_customMem const allocator = { NULL, NULL, NULL }; 179 return ZSTD_createDDict_advanced(dictBuffer, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto, allocator); 180 } 181 182 183 const ZSTD_DDict* ZSTD_initStaticDDict( 184 void* sBuffer, size_t sBufferSize, 185 const void* dict, size_t dictSize, 186 ZSTD_dictLoadMethod_e dictLoadMethod, 187 ZSTD_dictContentType_e dictContentType) 188 { 189 size_t const neededSpace = sizeof(ZSTD_DDict) 190 + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize); 191 ZSTD_DDict* const ddict = (ZSTD_DDict*)sBuffer; 192 assert(sBuffer != NULL); 193 assert(dict != NULL); 194 if ((size_t)sBuffer & 7) return NULL; /* 8-aligned */ 195 if (sBufferSize < neededSpace) return NULL; 196 if (dictLoadMethod == ZSTD_dlm_byCopy) { 197 memcpy(ddict+1, dict, dictSize); /* local copy */ 198 dict = ddict+1; 199 } 200 if (ZSTD_isError( ZSTD_initDDict_internal(ddict, 201 dict, dictSize, 202 ZSTD_dlm_byRef, dictContentType) )) 203 return NULL; 204 return ddict; 205 } 206 207 208 size_t ZSTD_freeDDict(ZSTD_DDict* ddict) 209 { 210 if (ddict==NULL) return 0; /* support free on NULL */ 211 { ZSTD_customMem const cMem = ddict->cMem; 212 ZSTD_free(ddict->dictBuffer, cMem); 213 ZSTD_free(ddict, cMem); 214 return 0; 215 } 216 } 217 218 /*! ZSTD_estimateDDictSize() : 219 * Estimate amount of memory that will be needed to create a dictionary for decompression. 220 * Note : dictionary created by reference using ZSTD_dlm_byRef are smaller */ 221 size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod) 222 { 223 return sizeof(ZSTD_DDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize); 224 } 225 226 size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict) 227 { 228 if (ddict==NULL) return 0; /* support sizeof on NULL */ 229 return sizeof(*ddict) + (ddict->dictBuffer ? ddict->dictSize : 0) ; 230 } 231 232 /*! ZSTD_getDictID_fromDDict() : 233 * Provides the dictID of the dictionary loaded into `ddict`. 234 * If @return == 0, the dictionary is not conformant to Zstandard specification, or empty. 235 * Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */ 236 unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict) 237 { 238 if (ddict==NULL) return 0; 239 return ZSTD_getDictID_fromDict(ddict->dictContent, ddict->dictSize); 240 } 241