xref: /illumos-gate/usr/src/common/lzma/LzmaDec.h (revision 55fea89d)
1 /* LzmaDec.h -- LZMA Decoder
2 2008-10-04 : Igor Pavlov : Public domain */
3 
4 #ifndef __LZMADEC_H
5 #define __LZMADEC_H
6 
7 #include "Types.h"
8 
9 /* #define _LZMA_PROB32 */
10 /* _LZMA_PROB32 can increase the speed on some CPUs,
11    but memory usage for CLzmaDec::probs will be doubled in that case */
12 
13 #ifdef _LZMA_PROB32
14 #define CLzmaProb UInt32
15 #else
16 #define CLzmaProb UInt16
17 #endif
18 
19 
20 /* ---------- LZMA Properties ---------- */
21 
22 #define LZMA_PROPS_SIZE 5
23 
24 typedef struct _CLzmaProps
25 {
26   unsigned lc, lp, pb;
27   UInt32 dicSize;
28 } CLzmaProps;
29 
30 /* LzmaProps_Decode - decodes properties
31 Returns:
32   SZ_OK
33   SZ_ERROR_UNSUPPORTED - Unsupported properties
34 */
35 
36 SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size);
37 
38 
39 /* ---------- LZMA Decoder state ---------- */
40 
41 /* LZMA_REQUIRED_INPUT_MAX = number of required input bytes for worst case.
42    Num bits = log2((2^11 / 31) ^ 22) + 26 < 134 + 26 = 160; */
43 
44 #define LZMA_REQUIRED_INPUT_MAX 20
45 
46 typedef struct
47 {
48   CLzmaProps prop;
49   CLzmaProb *probs;
50   Byte *dic;
51   const Byte *buf;
52   UInt32 range, code;
53   SizeT dicPos;
54   SizeT dicBufSize;
55   UInt32 processedPos;
56   UInt32 checkDicSize;
57   unsigned state;
58   UInt32 reps[4];
59   unsigned remainLen;
60   int needFlush;
61   int needInitState;
62   UInt32 numProbs;
63   unsigned tempBufSize;
64   Byte tempBuf[LZMA_REQUIRED_INPUT_MAX];
65 } CLzmaDec;
66 
67 #define LzmaDec_Construct(p) { (p)->dic = 0; (p)->probs = 0; }
68 
69 void LzmaDec_Init(CLzmaDec *p);
70 
71 /* There are two types of LZMA streams:
72      0) Stream with end mark. That end mark adds about 6 bytes to compressed size.
73      1) Stream without end mark. You must know exact uncompressed size to decompress such stream. */
74 
75 typedef enum
76 {
77   LZMA_FINISH_ANY,   /* finish at any point */
78   LZMA_FINISH_END    /* block must be finished at the end */
79 } ELzmaFinishMode;
80 
81 /* ELzmaFinishMode has meaning only if the decoding reaches output limit !!!
82 
83    You must use LZMA_FINISH_END, when you know that current output buffer
84    covers last bytes of block. In other cases you must use LZMA_FINISH_ANY.
85 
86    If LZMA decoder sees end marker before reaching output limit, it returns SZ_OK,
87    and output value of destLen will be less than output buffer size limit.
88    You can check status result also.
89 
90    You can use multiple checks to test data integrity after full decompression:
91      1) Check Result and "status" variable.
92      2) Check that output(destLen) = uncompressedSize, if you know real uncompressedSize.
93      3) Check that output(srcLen) = compressedSize, if you know real compressedSize.
94         You must use correct finish mode in that case. */
95 
96 typedef enum
97 {
98   LZMA_STATUS_NOT_SPECIFIED,               /* use main error code instead */
99   LZMA_STATUS_FINISHED_WITH_MARK,          /* stream was finished with end mark. */
100   LZMA_STATUS_NOT_FINISHED,                /* stream was not finished */
101   LZMA_STATUS_NEEDS_MORE_INPUT,            /* you must provide more input bytes */
102   LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK  /* there is probability that stream was finished without end mark */
103 } ELzmaStatus;
104 
105 /* ELzmaStatus is used only as output value for function call */
106 
107 
108 /* ---------- Interfaces ---------- */
109 
110 /* There are 3 levels of interfaces:
111      1) Dictionary Interface
112      2) Buffer Interface
113      3) One Call Interface
114    You can select any of these interfaces, but don't mix functions from different
115    groups for same object. */
116 
117 
118 /* There are two variants to allocate state for Dictionary Interface:
119      1) LzmaDec_Allocate / LzmaDec_Free
120      2) LzmaDec_AllocateProbs / LzmaDec_FreeProbs
121    You can use variant 2, if you set dictionary buffer manually.
122    For Buffer Interface you must always use variant 1.
123 
124 LzmaDec_Allocate* can return:
125   SZ_OK
126   SZ_ERROR_MEM         - Memory allocation error
127   SZ_ERROR_UNSUPPORTED - Unsupported properties
128 */
129 
130 SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc);
131 void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc);
132 
133 SRes LzmaDec_Allocate(CLzmaDec *state, const Byte *prop, unsigned propsSize, ISzAlloc *alloc);
134 void LzmaDec_Free(CLzmaDec *state, ISzAlloc *alloc);
135 
136 /* ---------- Dictionary Interface ---------- */
137 
138 /* You can use it, if you want to eliminate the overhead for data copying from
139    dictionary to some other external buffer.
140    You must work with CLzmaDec variables directly in this interface.
141 
142    STEPS:
143      LzmaDec_Constr()
144      LzmaDec_Allocate()
145      for (each new stream)
146      {
147        LzmaDec_Init()
148        while (it needs more decompression)
149        {
150          LzmaDec_DecodeToDic()
151          use data from CLzmaDec::dic and update CLzmaDec::dicPos
152        }
153      }
154      LzmaDec_Free()
155 */
156 
157 /* LzmaDec_DecodeToDic
158 
159    The decoding to internal dictionary buffer (CLzmaDec::dic).
160    You must manually update CLzmaDec::dicPos, if it reaches CLzmaDec::dicBufSize !!!
161 
162 finishMode:
163   It has meaning only if the decoding reaches output limit (dicLimit).
164   LZMA_FINISH_ANY - Decode just dicLimit bytes.
165   LZMA_FINISH_END - Stream must be finished after dicLimit.
166 
167 Returns:
168   SZ_OK
169     status:
170       LZMA_STATUS_FINISHED_WITH_MARK
171       LZMA_STATUS_NOT_FINISHED
172       LZMA_STATUS_NEEDS_MORE_INPUT
173       LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK
174   SZ_ERROR_DATA - Data error
175 */
176 
177 SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit,
178     const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);
179 
180 
181 /* ---------- Buffer Interface ---------- */
182 
183 /* It's zlib-like interface.
184    See LzmaDec_DecodeToDic description for information about STEPS and return results,
185    but you must use LzmaDec_DecodeToBuf instead of LzmaDec_DecodeToDic and you don't need
186    to work with CLzmaDec variables manually.
187 
188 finishMode:
189   It has meaning only if the decoding reaches output limit (*destLen).
190   LZMA_FINISH_ANY - Decode just destLen bytes.
191   LZMA_FINISH_END - Stream must be finished after (*destLen).
192 */
193 
194 SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen,
195     const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);
196 
197 
198 /* ---------- One Call Interface ---------- */
199 
200 /* LzmaDecode
201 
202 finishMode:
203   It has meaning only if the decoding reaches output limit (*destLen).
204   LZMA_FINISH_ANY - Decode just destLen bytes.
205   LZMA_FINISH_END - Stream must be finished after (*destLen).
206 
207 Returns:
208   SZ_OK
209     status:
210       LZMA_STATUS_FINISHED_WITH_MARK
211       LZMA_STATUS_NOT_FINISHED
212       LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK
213   SZ_ERROR_DATA - Data error
214   SZ_ERROR_MEM  - Memory allocation error
215   SZ_ERROR_UNSUPPORTED - Unsupported properties
216   SZ_ERROR_INPUT_EOF - It needs more bytes in input buffer (src).
217 */
218 
219 SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
220     const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
221     ELzmaStatus *status, ISzAlloc *alloc);
222 
223 #endif
224