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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
232