Mercurial > hgrepos > Python2 > PyMuPDF

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

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
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
parents
children
comparison
equal deleted inserted replaced
1:1d09e1dec1d9 2:b50eed0cc0ef
1 /* Copyright 2013 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 /* Functions for encoding of integers into prefix codes the amount of extra
8 bits, and the actual values of the extra bits. */
9
10 #ifndef BROTLI_ENC_PREFIX_H_
11 #define BROTLI_ENC_PREFIX_H_
12
13 #include <brotli/types.h>
14
15 #include "../common/constants.h"
16 #include "../common/platform.h"
17 #include "fast_log.h"
18
19 #if defined(__cplusplus) || defined(c_plusplus)
20 extern "C" {
21 #endif
22
23 /* Here distance_code is an intermediate code, i.e. one of the special codes or
24 the actual distance increased by BROTLI_NUM_DISTANCE_SHORT_CODES - 1. */
25 static BROTLI_INLINE void PrefixEncodeCopyDistance(size_t distance_code,
26 size_t num_direct_codes,
27 size_t postfix_bits,
28 uint16_t* code,
29 uint32_t* extra_bits) {
30 if (distance_code < BROTLI_NUM_DISTANCE_SHORT_CODES + num_direct_codes) {
31 *code = (uint16_t)distance_code;
32 *extra_bits = 0;
33 return;
34 } else {
35 size_t dist = ((size_t)1 << (postfix_bits + 2u)) +
36 (distance_code - BROTLI_NUM_DISTANCE_SHORT_CODES - num_direct_codes);
37 size_t bucket = Log2FloorNonZero(dist) - 1;
38 size_t postfix_mask = (1u << postfix_bits) - 1;
39 size_t postfix = dist & postfix_mask;
40 size_t prefix = (dist >> bucket) & 1;
41 size_t offset = (2 + prefix) << bucket;
42 size_t nbits = bucket - postfix_bits;
43 *code = (uint16_t)((nbits << 10) |
44 (BROTLI_NUM_DISTANCE_SHORT_CODES + num_direct_codes +
45 ((2 * (nbits - 1) + prefix) << postfix_bits) + postfix));
46 *extra_bits = (uint32_t)((dist - offset) >> postfix_bits);
47 }
48 }
49
50 #if defined(__cplusplus) || defined(c_plusplus)
51 } /* extern "C" */
52 #endif
53
54 #endif /* BROTLI_ENC_PREFIX_H_ */