1 /*
2 * Copyright (c) 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
12 /* zstd_decompress_internal:
13 * objects and definitions shared within lib/decompress modules */
14
15 #ifndef ZSTD_DECOMPRESS_INTERNAL_H
16 #define ZSTD_DECOMPRESS_INTERNAL_H
17
18
19 /*-*******************************************************
20 * Dependencies
21 *********************************************************/
22 #include "../common/mem.h" /* BYTE, U16, U32 */
23 #include "../common/zstd_internal.h" /* constants : MaxLL, MaxML, MaxOff, LLFSELog, etc. */
24
25
26
27 /*-*******************************************************
28 * Constants
29 *********************************************************/
30 static UNUSED_ATTR const U32 LL_base[MaxLL+1] = {
31 0, 1, 2, 3, 4, 5, 6, 7,
32 8, 9, 10, 11, 12, 13, 14, 15,
33 16, 18, 20, 22, 24, 28, 32, 40,
34 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000,
35 0x2000, 0x4000, 0x8000, 0x10000 };
36
37 static UNUSED_ATTR const U32 OF_base[MaxOff+1] = {
38 0, 1, 1, 5, 0xD, 0x1D, 0x3D, 0x7D,
39 0xFD, 0x1FD, 0x3FD, 0x7FD, 0xFFD, 0x1FFD, 0x3FFD, 0x7FFD,
40 0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD,
41 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD, 0x1FFFFFFD, 0x3FFFFFFD, 0x7FFFFFFD };
42
43 static UNUSED_ATTR const U8 OF_bits[MaxOff+1] = {
44 0, 1, 2, 3, 4, 5, 6, 7,
45 8, 9, 10, 11, 12, 13, 14, 15,
46 16, 17, 18, 19, 20, 21, 22, 23,
47 24, 25, 26, 27, 28, 29, 30, 31 };
48
49 static UNUSED_ATTR const U32 ML_base[MaxML+1] = {
50 3, 4, 5, 6, 7, 8, 9, 10,
51 11, 12, 13, 14, 15, 16, 17, 18,
52 19, 20, 21, 22, 23, 24, 25, 26,
53 27, 28, 29, 30, 31, 32, 33, 34,
54 35, 37, 39, 41, 43, 47, 51, 59,
55 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803,
56 0x1003, 0x2003, 0x4003, 0x8003, 0x10003 };
57
58
59 /*-*******************************************************
60 * Decompression types
61 *********************************************************/
62 typedef struct {
63 U32 fastMode;
64 U32 tableLog;
65 } ZSTD_seqSymbol_header;
66
67 typedef struct {
68 U16 nextState;
69 BYTE nbAdditionalBits;
70 BYTE nbBits;
71 U32 baseValue;
72 } ZSTD_seqSymbol;
73
74 #define SEQSYMBOL_TABLE_SIZE(log) (1 + (1 << (log)))
75
76 #define ZSTD_BUILD_FSE_TABLE_WKSP_SIZE (sizeof(S16) * (MaxSeq + 1) + (1u << MaxFSELog) + sizeof(U64))
77 #define ZSTD_BUILD_FSE_TABLE_WKSP_SIZE_U32 ((ZSTD_BUILD_FSE_TABLE_WKSP_SIZE + sizeof(U32) - 1) / sizeof(U32))
78
79 typedef struct {
80 ZSTD_seqSymbol LLTable[SEQSYMBOL_TABLE_SIZE(LLFSELog)]; /* Note : Space reserved for FSE Tables */
81 ZSTD_seqSymbol OFTable[SEQSYMBOL_TABLE_SIZE(OffFSELog)]; /* is also used as temporary workspace while building hufTable during DDict creation */
82 ZSTD_seqSymbol MLTable[SEQSYMBOL_TABLE_SIZE(MLFSELog)]; /* and therefore must be at least HUF_DECOMPRESS_WORKSPACE_SIZE large */
83 HUF_DTable hufTable[HUF_DTABLE_SIZE(HufLog)]; /* can accommodate HUF_decompress4X */
84 U32 rep[ZSTD_REP_NUM];
85 U32 workspace[ZSTD_BUILD_FSE_TABLE_WKSP_SIZE_U32];
86 } ZSTD_entropyDTables_t;
87
88 typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader,
89 ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock,
90 ZSTDds_decompressLastBlock, ZSTDds_checkChecksum,
91 ZSTDds_decodeSkippableHeader, ZSTDds_skipFrame } ZSTD_dStage;
92
93 typedef enum { zdss_init=0, zdss_loadHeader,
94 zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage;
95
96 typedef enum {
97 ZSTD_use_indefinitely = -1, /* Use the dictionary indefinitely */
98 ZSTD_dont_use = 0, /* Do not use the dictionary (if one exists free it) */
99 ZSTD_use_once = 1 /* Use the dictionary once and set to ZSTD_dont_use */
100 } ZSTD_dictUses_e;
101
102 /* Hashset for storing references to multiple ZSTD_DDict within ZSTD_DCtx */
103 typedef struct {
104 const ZSTD_DDict** ddictPtrTable;
105 size_t ddictPtrTableSize;
106 size_t ddictPtrCount;
107 } ZSTD_DDictHashSet;
108
109 #ifndef ZSTD_DECODER_INTERNAL_BUFFER
110 # define ZSTD_DECODER_INTERNAL_BUFFER (1 << 16)
111 #endif
112
113 #define ZSTD_LBMIN 64
114 #define ZSTD_LBMAX (128 << 10)
115
116 /* extra buffer, compensates when dst is not large enough to store litBuffer */
117 #define ZSTD_LITBUFFEREXTRASIZE BOUNDED(ZSTD_LBMIN, ZSTD_DECODER_INTERNAL_BUFFER, ZSTD_LBMAX)
118
119 typedef enum {
120 ZSTD_not_in_dst = 0, /* Stored entirely within litExtraBuffer */
121 ZSTD_in_dst = 1, /* Stored entirely within dst (in memory after current output write) */
122 ZSTD_split = 2 /* Split between litExtraBuffer and dst */
123 } ZSTD_litLocation_e;
124
125 struct ZSTD_DCtx_s
126 {
127 const ZSTD_seqSymbol* LLTptr;
128 const ZSTD_seqSymbol* MLTptr;
129 const ZSTD_seqSymbol* OFTptr;
130 const HUF_DTable* HUFptr;
131 ZSTD_entropyDTables_t entropy;
132 U32 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32]; /* space needed when building huffman tables */
133 const void* previousDstEnd; /* detect continuity */
134 const void* prefixStart; /* start of current segment */
135 const void* virtualStart; /* virtual start of previous segment if it was just before current one */
136 const void* dictEnd; /* end of previous segment */
137 size_t expected;
138 ZSTD_frameHeader fParams;
139 U64 processedCSize;
140 U64 decodedSize;
141 blockType_e bType; /* used in ZSTD_decompressContinue(), store blockType between block header decoding and block decompression stages */
142 ZSTD_dStage stage;
143 U32 litEntropy;
144 U32 fseEntropy;
145 struct xxh64_state xxhState;
146 size_t headerSize;
147 ZSTD_format_e format;
148 ZSTD_forceIgnoreChecksum_e forceIgnoreChecksum; /* User specified: if == 1, will ignore checksums in compressed frame. Default == 0 */
149 U32 validateChecksum; /* if == 1, will validate checksum. Is == 1 if (fParams.checksumFlag == 1) and (forceIgnoreChecksum == 0). */
150 const BYTE* litPtr;
151 ZSTD_customMem customMem;
152 size_t litSize;
153 size_t rleSize;
154 size_t staticSize;
155 #if DYNAMIC_BMI2 != 0
156 int bmi2; /* == 1 if the CPU supports BMI2 and 0 otherwise. CPU support is determined dynamically once per context lifetime. */
157 #endif
158
159 /* dictionary */
160 ZSTD_DDict* ddictLocal;
161 const ZSTD_DDict* ddict; /* set by ZSTD_initDStream_usingDDict(), or ZSTD_DCtx_refDDict() */
162 U32 dictID;
163 int ddictIsCold; /* if == 1 : dictionary is "new" for working context, and presumed "cold" (not in cpu cache) */
164 ZSTD_dictUses_e dictUses;
165 ZSTD_DDictHashSet* ddictSet; /* Hash set for multiple ddicts */
166 ZSTD_refMultipleDDicts_e refMultipleDDicts; /* User specified: if == 1, will allow references to multiple DDicts. Default == 0 (disabled) */
167
168 /* streaming */
169 ZSTD_dStreamStage streamStage;
170 char* inBuff;
171 size_t inBuffSize;
172 size_t inPos;
173 size_t maxWindowSize;
174 char* outBuff;
175 size_t outBuffSize;
176 size_t outStart;
177 size_t outEnd;
178 size_t lhSize;
179 U32 hostageByte;
180 int noForwardProgress;
181 ZSTD_bufferMode_e outBufferMode;
182 ZSTD_outBuffer expectedOutBuffer;
183
184 /* workspace */
185 BYTE* litBuffer;
186 const BYTE* litBufferEnd;
187 ZSTD_litLocation_e litBufferLocation;
188 BYTE litExtraBuffer[ZSTD_LITBUFFEREXTRASIZE + WILDCOPY_OVERLENGTH]; /* literal buffer can be split between storage within dst and within this scratch buffer */
189 BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];
190
191 size_t oversizedDuration;
192
193 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
194 void const* dictContentBeginForFuzzing;
195 void const* dictContentEndForFuzzing;
196 #endif
197
198 /* Tracing */
199 }; /* typedef'd to ZSTD_DCtx within "zstd.h" */
200
201 MEM_STATIC int ZSTD_DCtx_get_bmi2(const struct ZSTD_DCtx_s *dctx) {
202 #if DYNAMIC_BMI2 != 0
203 return dctx->bmi2;
204 #else
205 (void)dctx;
206 return 0;
207 #endif
208 }
209
210 /*-*******************************************************
211 * Shared internal functions
212 *********************************************************/
213
214 /*! ZSTD_loadDEntropy() :
215 * dict : must point at beginning of a valid zstd dictionary.
216 * @return : size of dictionary header (size of magic number + dict ID + entropy tables) */
217 size_t ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy,
218 const void* const dict, size_t const dictSize);
219
220 /*! ZSTD_checkContinuity() :
221 * check if next `dst` follows previous position, where decompression ended.
222 * If yes, do nothing (continue on current segment).
223 * If not, classify previous segment as "external dictionary", and start a new segment.
224 * This function cannot fail. */
225 void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst, size_t dstSize);
226
227
228 #endif /* ZSTD_DECOMPRESS_INTERNAL_H */
229
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