1 | /* Copyright 2015 Google Inc. All Rights Reserved. |
2 | |
3 | Distributed under MIT license. |
4 | See file LICENSE for detail or copy at https://opensource.org/licenses/MIT |
5 | */ |
6 | |
7 | /* Function for fast encoding of an input fragment, independently from the input |
8 | history. This function uses one-pass processing: when we find a backward |
9 | match, we immediately emit the corresponding command and literal codes to |
10 | the bit stream. */ |
11 | |
12 | #ifndef BROTLI_ENC_COMPRESS_FRAGMENT_H_ |
13 | #define BROTLI_ENC_COMPRESS_FRAGMENT_H_ |
14 | |
15 | #include "../common/platform.h" |
16 | #include <brotli/types.h> |
17 | #include "./memory.h" |
18 | |
19 | #if defined(__cplusplus) || defined(c_plusplus) |
20 | extern "C" { |
21 | #endif |
22 | |
23 | /* Compresses "input" string to the "*storage" buffer as one or more complete |
24 | meta-blocks, and updates the "*storage_ix" bit position. |
25 | |
26 | If "is_last" is 1, emits an additional empty last meta-block. |
27 | |
28 | "cmd_depth" and "cmd_bits" contain the command and distance prefix codes |
29 | (see comment in encode.h) used for the encoding of this input fragment. |
30 | If "is_last" is 0, they are updated to reflect the statistics |
31 | of this input fragment, to be used for the encoding of the next fragment. |
32 | |
33 | "*cmd_code_numbits" is the number of bits of the compressed representation |
34 | of the command and distance prefix codes, and "cmd_code" is an array of |
35 | at least "(*cmd_code_numbits + 7) >> 3" size that contains the compressed |
36 | command and distance prefix codes. If "is_last" is 0, these are also |
37 | updated to represent the updated "cmd_depth" and "cmd_bits". |
38 | |
39 | REQUIRES: "input_size" is greater than zero, or "is_last" is 1. |
40 | REQUIRES: "input_size" is less or equal to maximal metablock size (1 << 24). |
41 | REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero. |
42 | REQUIRES: "table_size" is an odd (9, 11, 13, 15) power of two |
43 | OUTPUT: maximal copy distance <= |input_size| |
44 | OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */ |
45 | BROTLI_INTERNAL void BrotliCompressFragmentFast(MemoryManager* m, |
46 | const uint8_t* input, |
47 | size_t input_size, |
48 | BROTLI_BOOL is_last, |
49 | int* table, size_t table_size, |
50 | uint8_t cmd_depth[128], |
51 | uint16_t cmd_bits[128], |
52 | size_t* cmd_code_numbits, |
53 | uint8_t* cmd_code, |
54 | size_t* storage_ix, |
55 | uint8_t* storage); |
56 | |
57 | #if defined(__cplusplus) || defined(c_plusplus) |
58 | } /* extern "C" */ |
59 | #endif |
60 | |
61 | #endif /* BROTLI_ENC_COMPRESS_FRAGMENT_H_ */ |
62 | |