1/* LzmaDec.h -- LZMA Decoder
  22013-01-18 : Igor Pavlov : Public domain */
  3
  4#ifndef __LZMA_DEC_H
  5#define __LZMA_DEC_H
  6
  7#include "7zTypes.h"
  8
  9EXTERN_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#ifdef _LZMA_PROB32
 16#define CLzmaProb UInt32
 17#else
 18#define CLzmaProb UInt16
 19#endif
 20
 21
 22/* ---------- LZMA Properties ---------- */
 23
 24#define LZMA_PROPS_SIZE 5
 25
 26typedef struct _CLzmaProps
 27{
 28  unsigned lc, lp, pb;
 29  UInt32 dicSize;
 30} CLzmaProps;
 31
 32/* LzmaProps_Decode - decodes properties
 33Returns:
 34  SZ_OK
 35  SZ_ERROR_UNSUPPORTED - Unsupported properties
 36*/
 37
 38SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size);
 39
 40
 41/* ---------- LZMA Decoder state ---------- */
 42
 43/* LZMA_REQUIRED_INPUT_MAX = number of required input bytes for worst case.
 44   Num bits = log2((2^11 / 31) ^ 22) + 26 < 134 + 26 = 160; */
 45
 46#define LZMA_REQUIRED_INPUT_MAX 20
 47
 48typedef struct
 49{
 50  CLzmaProps prop;
 51  CLzmaProb *probs;
 52  Byte *dic;
 53  const Byte *buf;
 54  UInt32 range, code;
 55  SizeT dicPos;
 56  SizeT dicBufSize;
 57  UInt32 processedPos;
 58  UInt32 checkDicSize;
 59  unsigned state;
 60  UInt32 reps[4];
 61  unsigned remainLen;
 62  int needFlush;
 63  int needInitState;
 64  UInt32 numProbs;
 65  unsigned tempBufSize;
 66  Byte tempBuf[LZMA_REQUIRED_INPUT_MAX];
 67} CLzmaDec;
 68
 69#define LzmaDec_Construct(p) { (p)->dic = 0; (p)->probs = 0; }
 70
 71void LzmaDec_Init(CLzmaDec *p);
 72
 73/* There are two types of LZMA streams:
 74     0) Stream with end mark. That end mark adds about 6 bytes to compressed size.
 75     1) Stream without end mark. You must know exact uncompressed size to decompress such stream. */
 76
 77typedef enum
 78{
 79  LZMA_FINISH_ANY,   /* finish at any point */
 80  LZMA_FINISH_END    /* block must be finished at the end */
 81} ELzmaFinishMode;
 82
 83/* ELzmaFinishMode has meaning only if the decoding reaches output limit !!!
 84
 85   You must use LZMA_FINISH_END, when you know that current output buffer
 86   covers last bytes of block. In other cases you must use LZMA_FINISH_ANY.
 87
 88   If LZMA decoder sees end marker before reaching output limit, it returns SZ_OK,
 89   and output value of destLen will be less than output buffer size limit.
 90   You can check status result also.
 91
 92   You can use multiple checks to test data integrity after full decompression:
 93     1) Check Result and "status" variable.
 94     2) Check that output(destLen) = uncompressedSize, if you know real uncompressedSize.
 95     3) Check that output(srcLen) = compressedSize, if you know real compressedSize.
 96        You must use correct finish mode in that case. */
 97
 98typedef enum
 99{
100  LZMA_STATUS_NOT_SPECIFIED,               /* use main error code instead */
101  LZMA_STATUS_FINISHED_WITH_MARK,          /* stream was finished with end mark. */
102  LZMA_STATUS_NOT_FINISHED,                /* stream was not finished */
103  LZMA_STATUS_NEEDS_MORE_INPUT,            /* you must provide more input bytes */
104  LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK  /* there is probability that stream was finished without end mark */
105} ELzmaStatus;
106
107/* ELzmaStatus is used only as output value for function call */
108
109
110/* ---------- Interfaces ---------- */
111
112/* There are 3 levels of interfaces:
113     1) Dictionary Interface
114     2) Buffer Interface
115     3) One Call Interface
116   You can select any of these interfaces, but don't mix functions from different
117   groups for same object. */
118
119
120/* There are two variants to allocate state for Dictionary Interface:
121     1) LzmaDec_Allocate / LzmaDec_Free
122     2) LzmaDec_AllocateProbs / LzmaDec_FreeProbs
123   You can use variant 2, if you set dictionary buffer manually.
124   For Buffer Interface you must always use variant 1.
125
126LzmaDec_Allocate* can return:
127  SZ_OK
128  SZ_ERROR_MEM         - Memory allocation error
129  SZ_ERROR_UNSUPPORTED - Unsupported properties
130*/
131   
132SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc);
133void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc);
134
135SRes LzmaDec_Allocate(CLzmaDec *state, const Byte *prop, unsigned propsSize, ISzAlloc *alloc);
136void LzmaDec_Free(CLzmaDec *state, ISzAlloc *alloc);
137
138/* ---------- Dictionary Interface ---------- */
139
140/* You can use it, if you want to eliminate the overhead for data copying from
141   dictionary to some other external buffer.
142   You must work with CLzmaDec variables directly in this interface.
143
144   STEPS:
145     LzmaDec_Constr()
146     LzmaDec_Allocate()
147     for (each new stream)
148     {
149       LzmaDec_Init()
150       while (it needs more decompression)
151       {
152         LzmaDec_DecodeToDic()
153         use data from CLzmaDec::dic and update CLzmaDec::dicPos
154       }
155     }
156     LzmaDec_Free()
157*/
158
159/* LzmaDec_DecodeToDic
160   
161   The decoding to internal dictionary buffer (CLzmaDec::dic).
162   You must manually update CLzmaDec::dicPos, if it reaches CLzmaDec::dicBufSize !!!
163
164finishMode:
165  It has meaning only if the decoding reaches output limit (dicLimit).
166  LZMA_FINISH_ANY - Decode just dicLimit bytes.
167  LZMA_FINISH_END - Stream must be finished after dicLimit.
168
169Returns:
170  SZ_OK
171    status:
172      LZMA_STATUS_FINISHED_WITH_MARK
173      LZMA_STATUS_NOT_FINISHED
174      LZMA_STATUS_NEEDS_MORE_INPUT
175      LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK
176  SZ_ERROR_DATA - Data error
177*/
178
179SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit,
180    const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);
181
182
183/* ---------- Buffer Interface ---------- */
184
185/* It's zlib-like interface.
186   See LzmaDec_DecodeToDic description for information about STEPS and return results,
187   but you must use LzmaDec_DecodeToBuf instead of LzmaDec_DecodeToDic and you don't need
188   to work with CLzmaDec variables manually.
189
190finishMode:
191  It has meaning only if the decoding reaches output limit (*destLen).
192  LZMA_FINISH_ANY - Decode just destLen bytes.
193  LZMA_FINISH_END - Stream must be finished after (*destLen).
194*/
195
196SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen,
197    const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);
198
199
200/* ---------- One Call Interface ---------- */
201
202/* LzmaDecode
203
204finishMode:
205  It has meaning only if the decoding reaches output limit (*destLen).
206  LZMA_FINISH_ANY - Decode just destLen bytes.
207  LZMA_FINISH_END - Stream must be finished after (*destLen).
208
209Returns:
210  SZ_OK
211    status:
212      LZMA_STATUS_FINISHED_WITH_MARK
213      LZMA_STATUS_NOT_FINISHED
214      LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK
215  SZ_ERROR_DATA - Data error
216  SZ_ERROR_MEM  - Memory allocation error
217  SZ_ERROR_UNSUPPORTED - Unsupported properties
218  SZ_ERROR_INPUT_EOF - It needs more bytes in input buffer (src).
219*/
220
221SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
222    const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
223    ELzmaStatus *status, ISzAlloc *alloc);
224
225EXTERN_C_END
226
227#endif