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comparison mupdf-source/thirdparty/brotli/c/enc/compress_fragment.h @ 2:b50eed0cc0ef upstream

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ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4. The directory name has changed: no version number in the expanded directory now.
author Franz Glasner <fzglas.hg@dom66.de>
date Mon, 15 Sep 2025 11:43:07 +0200
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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 <brotli/types.h>
16
17 #include "../common/constants.h"
18 #include "../common/platform.h"
19 #include "entropy_encode.h"
20
21 #if defined(__cplusplus) || defined(c_plusplus)
22 extern "C" {
23 #endif
24
25 typedef struct BrotliOnePassArena {
26 uint8_t lit_depth[256];
27 uint16_t lit_bits[256];
28
29 /* Command and distance prefix codes (each 64 symbols, stored back-to-back)
30 used for the next block. The command prefix code is over a smaller alphabet
31 with the following 64 symbols:
32 0 - 15: insert length code 0, copy length code 0 - 15, same distance
33 16 - 39: insert length code 0, copy length code 0 - 23
34 40 - 63: insert length code 0 - 23, copy length code 0
35 Note that symbols 16 and 40 represent the same code in the full alphabet,
36 but we do not use either of them. */
37 uint8_t cmd_depth[128];
38 uint16_t cmd_bits[128];
39 uint32_t cmd_histo[128];
40
41 /* The compressed form of the command and distance prefix codes for the next
42 block. */
43 uint8_t cmd_code[512];
44 size_t cmd_code_numbits;
45
46 HuffmanTree tree[2 * BROTLI_NUM_LITERAL_SYMBOLS + 1];
47 uint32_t histogram[256];
48 uint8_t tmp_depth[BROTLI_NUM_COMMAND_SYMBOLS];
49 uint16_t tmp_bits[64];
50 } BrotliOnePassArena;
51
52 /* Compresses "input" string to the "*storage" buffer as one or more complete
53 meta-blocks, and updates the "*storage_ix" bit position.
54
55 If "is_last" is 1, emits an additional empty last meta-block.
56
57 "cmd_depth" and "cmd_bits" contain the command and distance prefix codes
58 (see comment in encode.h) used for the encoding of this input fragment.
59 If "is_last" is 0, they are updated to reflect the statistics
60 of this input fragment, to be used for the encoding of the next fragment.
61
62 "*cmd_code_numbits" is the number of bits of the compressed representation
63 of the command and distance prefix codes, and "cmd_code" is an array of
64 at least "(*cmd_code_numbits + 7) >> 3" size that contains the compressed
65 command and distance prefix codes. If "is_last" is 0, these are also
66 updated to represent the updated "cmd_depth" and "cmd_bits".
67
68 REQUIRES: "input_size" is greater than zero, or "is_last" is 1.
69 REQUIRES: "input_size" is less or equal to maximal metablock size (1 << 24).
70 REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero.
71 REQUIRES: "table_size" is an odd (9, 11, 13, 15) power of two
72 OUTPUT: maximal copy distance <= |input_size|
73 OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */
74 BROTLI_INTERNAL void BrotliCompressFragmentFast(BrotliOnePassArena* s,
75 const uint8_t* input,
76 size_t input_size,
77 BROTLI_BOOL is_last,
78 int* table, size_t table_size,
79 size_t* storage_ix,
80 uint8_t* storage);
81
82 #if defined(__cplusplus) || defined(c_plusplus)
83 } /* extern "C" */
84 #endif
85
86 #endif /* BROTLI_ENC_COMPRESS_FRAGMENT_H_ */