1/* transforms is a part of ABI, but not API.
2
3 It means that there are some functions that are supposed to be in "common"
4 library, but header itself is not placed into include/brotli. This way,
5 aforementioned functions will be available only to brotli internals.
6 */
7
8#ifndef BROTLI_COMMON_TRANSFORM_H_
9#define BROTLI_COMMON_TRANSFORM_H_
10
11#include <brotli/port.h>
12#include <brotli/types.h>
13
14#if defined(__cplusplus) || defined(c_plusplus)
15extern "C" {
16#endif
17
18enum BrotliWordTransformType {
19 BROTLI_TRANSFORM_IDENTITY = 0,
20 BROTLI_TRANSFORM_OMIT_LAST_1 = 1,
21 BROTLI_TRANSFORM_OMIT_LAST_2 = 2,
22 BROTLI_TRANSFORM_OMIT_LAST_3 = 3,
23 BROTLI_TRANSFORM_OMIT_LAST_4 = 4,
24 BROTLI_TRANSFORM_OMIT_LAST_5 = 5,
25 BROTLI_TRANSFORM_OMIT_LAST_6 = 6,
26 BROTLI_TRANSFORM_OMIT_LAST_7 = 7,
27 BROTLI_TRANSFORM_OMIT_LAST_8 = 8,
28 BROTLI_TRANSFORM_OMIT_LAST_9 = 9,
29 BROTLI_TRANSFORM_UPPERCASE_FIRST = 10,
30 BROTLI_TRANSFORM_UPPERCASE_ALL = 11,
31 BROTLI_TRANSFORM_OMIT_FIRST_1 = 12,
32 BROTLI_TRANSFORM_OMIT_FIRST_2 = 13,
33 BROTLI_TRANSFORM_OMIT_FIRST_3 = 14,
34 BROTLI_TRANSFORM_OMIT_FIRST_4 = 15,
35 BROTLI_TRANSFORM_OMIT_FIRST_5 = 16,
36 BROTLI_TRANSFORM_OMIT_FIRST_6 = 17,
37 BROTLI_TRANSFORM_OMIT_FIRST_7 = 18,
38 BROTLI_TRANSFORM_OMIT_FIRST_8 = 19,
39 BROTLI_TRANSFORM_OMIT_FIRST_9 = 20,
40 BROTLI_TRANSFORM_SHIFT_FIRST = 21,
41 BROTLI_TRANSFORM_SHIFT_ALL = 22,
42 BROTLI_NUM_TRANSFORM_TYPES /* Counts transforms, not a transform itself. */
43};
44
45#define BROTLI_TRANSFORMS_MAX_CUT_OFF BROTLI_TRANSFORM_OMIT_LAST_9
46
47typedef struct BrotliTransforms {
48 uint16_t prefix_suffix_size;
49 /* Last character must be null, so prefix_suffix_size must be at least 1. */
50 const uint8_t* prefix_suffix;
51 const uint16_t* prefix_suffix_map;
52 uint32_t num_transforms;
53 /* Each entry is a [prefix_id, transform, suffix_id] triplet. */
54 const uint8_t* transforms;
55 /* Shift for BROTLI_TRANSFORM_SHIFT_FIRST and BROTLI_TRANSFORM_SHIFT_ALL,
56 must be NULL if and only if no such transforms are present. */
57 const uint8_t* params;
58 /* Indices of transforms like ["", BROTLI_TRANSFORM_OMIT_LAST_#, ""].
59 0-th element corresponds to ["", BROTLI_TRANSFORM_IDENTITY, ""].
60 -1, if cut-off transform does not exist. */
61 int16_t cutOffTransforms[BROTLI_TRANSFORMS_MAX_CUT_OFF + 1];
62} BrotliTransforms;
63
64/* T is BrotliTransforms*; result is uint8_t. */
65#define BROTLI_TRANSFORM_PREFIX_ID(T, I) ((T)->transforms[((I) * 3) + 0])
66#define BROTLI_TRANSFORM_TYPE(T, I) ((T)->transforms[((I) * 3) + 1])
67#define BROTLI_TRANSFORM_SUFFIX_ID(T, I) ((T)->transforms[((I) * 3) + 2])
68
69/* T is BrotliTransforms*; result is const uint8_t*. */
70#define BROTLI_TRANSFORM_PREFIX(T, I) (&(T)->prefix_suffix[ \
71 (T)->prefix_suffix_map[BROTLI_TRANSFORM_PREFIX_ID(T, I)]])
72#define BROTLI_TRANSFORM_SUFFIX(T, I) (&(T)->prefix_suffix[ \
73 (T)->prefix_suffix_map[BROTLI_TRANSFORM_SUFFIX_ID(T, I)]])
74
75BROTLI_COMMON_API const BrotliTransforms* BrotliGetTransforms(void);
76
77BROTLI_COMMON_API int BrotliTransformDictionaryWord(
78 uint8_t* dst, const uint8_t* word, int len,
79 const BrotliTransforms* transforms, int transform_idx);
80
81#if defined(__cplusplus) || defined(c_plusplus)
82} /* extern "C" */
83#endif
84
85#endif /* BROTLI_COMMON_TRANSFORM_H_ */
86