third_party/lzma_sdk/LzmaDec.h

   1 /* LzmaDec.h -- LZMA Decoder
   2 2009-02-07 : Igor Pavlov : Public domain */
   3
   4 #ifndef __LZMA_DEC_H
   5 #define __LZMA_DEC_H
   6
   7 #include "Types.h"
   8
   9 #ifdef __cplusplus
  10 extern "C" {
  11 #endif
  12
  13 /* #define _LZMA_PROB32 */
  14 /* _LZMA_PROB32 can increase the speed on some CPUs,
  15    but memory usage for CLzmaDec::probs will be doubled in that case */
  16
  17 #ifdef _LZMA_PROB32
  18 #define CLzmaProb UInt32
  19 #else
  20 #define CLzmaProb UInt16
  21 #endif
  22
  23
  24 /* ---------- LZMA Properties ---------- */
  25
  26 #define LZMA_PROPS_SIZE 5
  27
  28 typedef struct _CLzmaProps
  29 {
  30   unsigned lc, lp, pb;
  31   UInt32 dicSize;
  32 } CLzmaProps;
  33
  34 /* LzmaProps_Decode - decodes properties
  35 Returns:
  36   SZ_OK
  37   SZ_ERROR_UNSUPPORTED - Unsupported properties
  38 */
  39
  40 SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size);
  41
  42
  43 /* ---------- LZMA Decoder state ---------- */
  44
  45 /* LZMA_REQUIRED_INPUT_MAX = number of required input bytes for worst case.
  46    Num bits = log2((2^11 / 31) ^ 22) + 26 < 134 + 26 = 160; */
  47
  48 #define LZMA_REQUIRED_INPUT_MAX 20
  49
  50 typedef struct
  51 {
  52   CLzmaProps prop;
  53   CLzmaProb *probs;
  54   Byte *dic;
  55   const Byte *buf;
  56   UInt32 range, code;
  57   SizeT dicPos;
  58   SizeT dicBufSize;
  59   UInt32 processedPos;
  60   UInt32 checkDicSize;
  61   unsigned state;
  62   UInt32 reps[4];
  63   unsigned remainLen;
  64   int needFlush;
  65   int needInitState;
  66   UInt32 numProbs;
  67   unsigned tempBufSize;
  68   Byte tempBuf[LZMA_REQUIRED_INPUT_MAX];
  69 } CLzmaDec;
  70
  71 #define LzmaDec_Construct(p) { (p)->dic = 0; (p)->probs = 0; }
  72
  73 void LzmaDec_Init(CLzmaDec *p);
  74
  75 /* There are two types of LZMA streams:
  76      0) Stream with end mark. That end mark adds about 6 bytes to compressed size.
  77      1) Stream without end mark. You must know exact uncompressed size to decompress such stream. */
  78
  79 typedef enum
  80 {
  81   LZMA_FINISH_ANY,   /* finish at any point */
  82   LZMA_FINISH_END    /* block must be finished at the end */
  83 } ELzmaFinishMode;
  84
  85 /* ELzmaFinishMode has meaning only if the decoding reaches output limit !!!
  86
  87    You must use LZMA_FINISH_END, when you know that current output buffer
  88    covers last bytes of block. In other cases you must use LZMA_FINISH_ANY.
  89
  90    If LZMA decoder sees end marker before reaching output limit, it returns SZ_OK,
  91    and output value of destLen will be less than output buffer size limit.
  92    You can check status result also.
  93
  94    You can use multiple checks to test data integrity after full decompression:
  95      1) Check Result and "status" variable.
  96      2) Check that output(destLen) = uncompressedSize, if you know real uncompressedSize.
  97      3) Check that output(srcLen) = compressedSize, if you know real compressedSize.
  98         You must use correct finish mode in that case. */
  99
 100 typedef enum
 101 {
 102   LZMA_STATUS_NOT_SPECIFIED,               /* use main error code instead */
 103   LZMA_STATUS_FINISHED_WITH_MARK,          /* stream was finished with end mark. */
 104   LZMA_STATUS_NOT_FINISHED,                /* stream was not finished */
 105   LZMA_STATUS_NEEDS_MORE_INPUT,            /* you must provide more input bytes */
 106   LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK  /* there is probability that stream was finished without end mark */
 107 } ELzmaStatus;
 108
 109 /* ELzmaStatus is used only as output value for function call */
 110
 111
 112 /* ---------- Interfaces ---------- */
 113
 114 /* There are 3 levels of interfaces:
 115      1) Dictionary Interface
 116      2) Buffer Interface
 117      3) One Call Interface
 118    You can select any of these interfaces, but don't mix functions from different
 119    groups for same object. */
 120
 121
 122 /* There are two variants to allocate state for Dictionary Interface:
 123      1) LzmaDec_Allocate / LzmaDec_Free
 124      2) LzmaDec_AllocateProbs / LzmaDec_FreeProbs
 125    You can use variant 2, if you set dictionary buffer manually.
 126    For Buffer Interface you must always use variant 1.
 127
 128 LzmaDec_Allocate* can return:
 129   SZ_OK
 130   SZ_ERROR_MEM         - Memory allocation error
 131   SZ_ERROR_UNSUPPORTED - Unsupported properties
 132 */
 133
 134 SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc);
 135 void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc);
 136
 137 SRes LzmaDec_Allocate(CLzmaDec *state, const Byte *prop, unsigned propsSize, ISzAlloc *alloc);
 138 void LzmaDec_Free(CLzmaDec *state, ISzAlloc *alloc);
 139
 140 /* ---------- Dictionary Interface ---------- */
 141
 142 /* You can use it, if you want to eliminate the overhead for data copying from
 143    dictionary to some other external buffer.
 144    You must work with CLzmaDec variables directly in this interface.
 145
 146    STEPS:
 147      LzmaDec_Constr()
 148      LzmaDec_Allocate()
 149      for (each new stream)
 150      {
 151        LzmaDec_Init()
 152        while (it needs more decompression)
 153        {
 154          LzmaDec_DecodeToDic()
 155          use data from CLzmaDec::dic and update CLzmaDec::dicPos
 156        }
 157      }
 158      LzmaDec_Free()
 159 */
 160
 161 /* LzmaDec_DecodeToDic
 162
 163    The decoding to internal dictionary buffer (CLzmaDec::dic).
 164    You must manually update CLzmaDec::dicPos, if it reaches CLzmaDec::dicBufSize !!!
 165
 166 finishMode:
 167   It has meaning only if the decoding reaches output limit (dicLimit).
 168   LZMA_FINISH_ANY - Decode just dicLimit bytes.
 169   LZMA_FINISH_END - Stream must be finished after dicLimit.
 170
 171 Returns:
 172   SZ_OK
 173     status:
 174       LZMA_STATUS_FINISHED_WITH_MARK
 175       LZMA_STATUS_NOT_FINISHED
 176       LZMA_STATUS_NEEDS_MORE_INPUT
 177       LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK
 178   SZ_ERROR_DATA - Data error
 179 */
 180
 181 SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit,
 182     const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);
 183
 184
 185 /* ---------- Buffer Interface ---------- */
 186
 187 /* It's zlib-like interface.
 188    See LzmaDec_DecodeToDic description for information about STEPS and return results,
 189    but you must use LzmaDec_DecodeToBuf instead of LzmaDec_DecodeToDic and you don't need
 190    to work with CLzmaDec variables manually.
 191
 192 finishMode:
 193   It has meaning only if the decoding reaches output limit (*destLen).
 194   LZMA_FINISH_ANY - Decode just destLen bytes.
 195   LZMA_FINISH_END - Stream must be finished after (*destLen).
 196 */
 197
 198 SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen,
 199     const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);
 200
 201
 202 /* ---------- One Call Interface ---------- */
 203
 204 /* LzmaDecode
 205
 206 finishMode:
 207   It has meaning only if the decoding reaches output limit (*destLen).
 208   LZMA_FINISH_ANY - Decode just destLen bytes.
 209   LZMA_FINISH_END - Stream must be finished after (*destLen).
 210
 211 Returns:
 212   SZ_OK
 213     status:
 214       LZMA_STATUS_FINISHED_WITH_MARK
 215       LZMA_STATUS_NOT_FINISHED
 216       LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK
 217   SZ_ERROR_DATA - Data error
 218   SZ_ERROR_MEM  - Memory allocation error
 219   SZ_ERROR_UNSUPPORTED - Unsupported properties
 220   SZ_ERROR_INPUT_EOF - It needs more bytes in input buffer (src).
 221 */
 222
 223 SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
 224     const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
 225     ELzmaStatus *status, ISzAlloc *alloc);
 226
 227 #ifdef __cplusplus
 228 }
 229 #endif
 230
 231 #endif