LzmaDec.h (6902B)
1 /* LzmaDec.h -- LZMA Decoder 2 2018-04-21 : Igor Pavlov : Public domain */ 3 4 #ifndef __LZMA_DEC_H 5 #define __LZMA_DEC_H 6 7 #include "7zTypes.h" 8 9 EXTERN_C_BEGIN 10 11 /* #define _LZMA_PROB32 */ 12 /* _LZMA_PROB32 can increase the speed on some CPUs, 13 but memory usage for CLzmaDec::probs will be doubled in that case */ 14 15 typedef 16 #ifdef _LZMA_PROB32 17 UInt32 18 #else 19 UInt16 20 #endif 21 CLzmaProb; 22 23 24 /* ---------- LZMA Properties ---------- */ 25 26 #define LZMA_PROPS_SIZE 5 27 28 typedef struct _CLzmaProps 29 { 30 Byte lc; 31 Byte lp; 32 Byte pb; 33 Byte _pad_; 34 UInt32 dicSize; 35 } CLzmaProps; 36 37 /* LzmaProps_Decode - decodes properties 38 Returns: 39 SZ_OK 40 SZ_ERROR_UNSUPPORTED - Unsupported properties 41 */ 42 43 SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size); 44 45 46 /* ---------- LZMA Decoder state ---------- */ 47 48 /* LZMA_REQUIRED_INPUT_MAX = number of required input bytes for worst case. 49 Num bits = log2((2^11 / 31) ^ 22) + 26 < 134 + 26 = 160; */ 50 51 #define LZMA_REQUIRED_INPUT_MAX 20 52 53 typedef struct 54 { 55 /* Don't change this structure. ASM code can use it. */ 56 CLzmaProps prop; 57 CLzmaProb *probs; 58 CLzmaProb *probs_1664; 59 Byte *dic; 60 SizeT dicBufSize; 61 SizeT dicPos; 62 const Byte *buf; 63 UInt32 range; 64 UInt32 code; 65 UInt32 processedPos; 66 UInt32 checkDicSize; 67 UInt32 reps[4]; 68 UInt32 state; 69 UInt32 remainLen; 70 71 UInt32 numProbs; 72 unsigned tempBufSize; 73 Byte tempBuf[LZMA_REQUIRED_INPUT_MAX]; 74 } CLzmaDec; 75 76 #define LzmaDec_Construct(p) { (p)->dic = NULL; (p)->probs = NULL; } 77 78 void LzmaDec_Init(CLzmaDec *p); 79 80 /* There are two types of LZMA streams: 81 - Stream with end mark. That end mark adds about 6 bytes to compressed size. 82 - Stream without end mark. You must know exact uncompressed size to decompress such stream. */ 83 84 typedef enum 85 { 86 LZMA_FINISH_ANY, /* finish at any point */ 87 LZMA_FINISH_END /* block must be finished at the end */ 88 } ELzmaFinishMode; 89 90 /* ELzmaFinishMode has meaning only if the decoding reaches output limit !!! 91 92 You must use LZMA_FINISH_END, when you know that current output buffer 93 covers last bytes of block. In other cases you must use LZMA_FINISH_ANY. 94 95 If LZMA decoder sees end marker before reaching output limit, it returns SZ_OK, 96 and output value of destLen will be less than output buffer size limit. 97 You can check status result also. 98 99 You can use multiple checks to test data integrity after full decompression: 100 1) Check Result and "status" variable. 101 2) Check that output(destLen) = uncompressedSize, if you know real uncompressedSize. 102 3) Check that output(srcLen) = compressedSize, if you know real compressedSize. 103 You must use correct finish mode in that case. */ 104 105 typedef enum 106 { 107 LZMA_STATUS_NOT_SPECIFIED, /* use main error code instead */ 108 LZMA_STATUS_FINISHED_WITH_MARK, /* stream was finished with end mark. */ 109 LZMA_STATUS_NOT_FINISHED, /* stream was not finished */ 110 LZMA_STATUS_NEEDS_MORE_INPUT, /* you must provide more input bytes */ 111 LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK /* there is probability that stream was finished without end mark */ 112 } ELzmaStatus; 113 114 /* ELzmaStatus is used only as output value for function call */ 115 116 117 /* ---------- Interfaces ---------- */ 118 119 /* There are 3 levels of interfaces: 120 1) Dictionary Interface 121 2) Buffer Interface 122 3) One Call Interface 123 You can select any of these interfaces, but don't mix functions from different 124 groups for same object. */ 125 126 127 /* There are two variants to allocate state for Dictionary Interface: 128 1) LzmaDec_Allocate / LzmaDec_Free 129 2) LzmaDec_AllocateProbs / LzmaDec_FreeProbs 130 You can use variant 2, if you set dictionary buffer manually. 131 For Buffer Interface you must always use variant 1. 132 133 LzmaDec_Allocate* can return: 134 SZ_OK 135 SZ_ERROR_MEM - Memory allocation error 136 SZ_ERROR_UNSUPPORTED - Unsupported properties 137 */ 138 139 SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAllocPtr alloc); 140 void LzmaDec_FreeProbs(CLzmaDec *p, ISzAllocPtr alloc); 141 142 SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAllocPtr alloc); 143 void LzmaDec_Free(CLzmaDec *p, ISzAllocPtr alloc); 144 145 /* ---------- Dictionary Interface ---------- */ 146 147 /* You can use it, if you want to eliminate the overhead for data copying from 148 dictionary to some other external buffer. 149 You must work with CLzmaDec variables directly in this interface. 150 151 STEPS: 152 LzmaDec_Construct() 153 LzmaDec_Allocate() 154 for (each new stream) 155 { 156 LzmaDec_Init() 157 while (it needs more decompression) 158 { 159 LzmaDec_DecodeToDic() 160 use data from CLzmaDec::dic and update CLzmaDec::dicPos 161 } 162 } 163 LzmaDec_Free() 164 */ 165 166 /* LzmaDec_DecodeToDic 167 168 The decoding to internal dictionary buffer (CLzmaDec::dic). 169 You must manually update CLzmaDec::dicPos, if it reaches CLzmaDec::dicBufSize !!! 170 171 finishMode: 172 It has meaning only if the decoding reaches output limit (dicLimit). 173 LZMA_FINISH_ANY - Decode just dicLimit bytes. 174 LZMA_FINISH_END - Stream must be finished after dicLimit. 175 176 Returns: 177 SZ_OK 178 status: 179 LZMA_STATUS_FINISHED_WITH_MARK 180 LZMA_STATUS_NOT_FINISHED 181 LZMA_STATUS_NEEDS_MORE_INPUT 182 LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK 183 SZ_ERROR_DATA - Data error 184 */ 185 186 SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, 187 const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status); 188 189 190 /* ---------- Buffer Interface ---------- */ 191 192 /* It's zlib-like interface. 193 See LzmaDec_DecodeToDic description for information about STEPS and return results, 194 but you must use LzmaDec_DecodeToBuf instead of LzmaDec_DecodeToDic and you don't need 195 to work with CLzmaDec variables manually. 196 197 finishMode: 198 It has meaning only if the decoding reaches output limit (*destLen). 199 LZMA_FINISH_ANY - Decode just destLen bytes. 200 LZMA_FINISH_END - Stream must be finished after (*destLen). 201 */ 202 203 SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, 204 const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status); 205 206 207 /* ---------- One Call Interface ---------- */ 208 209 /* LzmaDecode 210 211 finishMode: 212 It has meaning only if the decoding reaches output limit (*destLen). 213 LZMA_FINISH_ANY - Decode just destLen bytes. 214 LZMA_FINISH_END - Stream must be finished after (*destLen). 215 216 Returns: 217 SZ_OK 218 status: 219 LZMA_STATUS_FINISHED_WITH_MARK 220 LZMA_STATUS_NOT_FINISHED 221 LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK 222 SZ_ERROR_DATA - Data error 223 SZ_ERROR_MEM - Memory allocation error 224 SZ_ERROR_UNSUPPORTED - Unsupported properties 225 SZ_ERROR_INPUT_EOF - It needs more bytes in input buffer (src). 226 */ 227 228 SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, 229 const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode, 230 ELzmaStatus *status, ISzAllocPtr alloc); 231 232 EXTERN_C_END 233 234 #endif