Mercurial > hgrepos > Python2 > PyMuPDF

comparison mupdf-source/thirdparty/brotli/c/enc/compress_fragment_two_pass.h @ 3:2c135c81b16c

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
MERGE: upstream PyMuPDF 1.26.4 with MuPDF 1.26.7
author Franz Glasner <fzglas.hg@dom66.de>
date Mon, 15 Sep 2025 11:44:09 +0200
parents b50eed0cc0ef
children
comparison
equal deleted inserted replaced
0:6015a75abc2d 3:2c135c81b16c
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 two-pass processing: in the first pass we save
9 the found backward matches and literal bytes into a buffer, and in the
10 second pass we emit them into the bit stream using prefix codes built based
11 on the actual command and literal byte histograms. */
12
13 #ifndef BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_
14 #define BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_
15
16 #include <brotli/types.h>
17
18 #include "../common/constants.h"
19 #include "../common/platform.h"
20 #include "entropy_encode.h"
21
22 #if defined(__cplusplus) || defined(c_plusplus)
23 extern "C" {
24 #endif
25
26 /* TODO(eustas): turn to macro. */
27 static const size_t kCompressFragmentTwoPassBlockSize = 1 << 17;
28
29 typedef struct BrotliTwoPassArena {
30 uint32_t lit_histo[256];
31 uint8_t lit_depth[256];
32 uint16_t lit_bits[256];
33
34 uint32_t cmd_histo[128];
35 uint8_t cmd_depth[128];
36 uint16_t cmd_bits[128];
37
38 /* BuildAndStoreCommandPrefixCode */
39 HuffmanTree tmp_tree[2 * BROTLI_NUM_LITERAL_SYMBOLS + 1];
40 uint8_t tmp_depth[BROTLI_NUM_COMMAND_SYMBOLS];
41 uint16_t tmp_bits[64];
42 } BrotliTwoPassArena;
43
44 /* Compresses "input" string to the "*storage" buffer as one or more complete
45 meta-blocks, and updates the "*storage_ix" bit position.
46
47 If "is_last" is 1, emits an additional empty last meta-block.
48
49 REQUIRES: "input_size" is greater than zero, or "is_last" is 1.
50 REQUIRES: "input_size" is less or equal to maximal metablock size (1 << 24).
51 REQUIRES: "command_buf" and "literal_buf" point to at least
52 kCompressFragmentTwoPassBlockSize long arrays.
53 REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero.
54 REQUIRES: "table_size" is a power of two
55 OUTPUT: maximal copy distance <= |input_size|
56 OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */
57 BROTLI_INTERNAL void BrotliCompressFragmentTwoPass(BrotliTwoPassArena* s,
58 const uint8_t* input,
59 size_t input_size,
60 BROTLI_BOOL is_last,
61 uint32_t* command_buf,
62 uint8_t* literal_buf,
63 int* table,
64 size_t table_size,
65 size_t* storage_ix,
66 uint8_t* storage);
67
68 #if defined(__cplusplus) || defined(c_plusplus)
69 } /* extern "C" */
70 #endif
71
72 #endif /* BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_ */