Mercurial > hgrepos > Python2 > PyMuPDF

comparison mupdf-source/thirdparty/brotli/c/enc/backward_references_hq.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 /* Function to find backward reference copies. */
8
9 #ifndef BROTLI_ENC_BACKWARD_REFERENCES_HQ_H_
10 #define BROTLI_ENC_BACKWARD_REFERENCES_HQ_H_
11
12 #include <brotli/types.h>
13
14 #include "../common/constants.h"
15 #include "../common/context.h"
16 #include "../common/dictionary.h"
17 #include "../common/platform.h"
18 #include "command.h"
19 #include "hash.h"
20 #include "memory.h"
21 #include "quality.h"
22
23 #if defined(__cplusplus) || defined(c_plusplus)
24 extern "C" {
25 #endif
26
27 BROTLI_INTERNAL void BrotliCreateZopfliBackwardReferences(MemoryManager* m,
28 size_t num_bytes,
29 size_t position, const uint8_t* ringbuffer, size_t ringbuffer_mask,
30 ContextLut literal_context_lut, const BrotliEncoderParams* params,
31 Hasher* hasher, int* dist_cache, size_t* last_insert_len,
32 Command* commands, size_t* num_commands, size_t* num_literals);
33
34 BROTLI_INTERNAL void BrotliCreateHqZopfliBackwardReferences(MemoryManager* m,
35 size_t num_bytes,
36 size_t position, const uint8_t* ringbuffer, size_t ringbuffer_mask,
37 ContextLut literal_context_lut, const BrotliEncoderParams* params,
38 Hasher* hasher, int* dist_cache, size_t* last_insert_len,
39 Command* commands, size_t* num_commands, size_t* num_literals);
40
41 typedef struct ZopfliNode {
42 /* Best length to get up to this byte (not including this byte itself)
43 highest 7 bit is used to reconstruct the length code. */
44 uint32_t length;
45 /* Distance associated with the length. */
46 uint32_t distance;
47 /* Number of literal inserts before this copy; highest 5 bits contain
48 distance short code + 1 (or zero if no short code). */
49 uint32_t dcode_insert_length;
50
51 /* This union holds information used by dynamic-programming. During forward
52 pass |cost| it used to store the goal function. When node is processed its
53 |cost| is invalidated in favor of |shortcut|. On path back-tracing pass
54 |next| is assigned the offset to next node on the path. */
55 union {
56 /* Smallest cost to get to this byte from the beginning, as found so far. */
57 float cost;
58 /* Offset to the next node on the path. Equals to command_length() of the
59 next node on the path. For last node equals to BROTLI_UINT32_MAX */
60 uint32_t next;
61 /* Node position that provides next distance for distance cache. */
62 uint32_t shortcut;
63 } u;
64 } ZopfliNode;
65
66 BROTLI_INTERNAL void BrotliInitZopfliNodes(ZopfliNode* array, size_t length);
67
68 /* Computes the shortest path of commands from position to at most
69 position + num_bytes.
70
71 On return, path->size() is the number of commands found and path[i] is the
72 length of the i-th command (copy length plus insert length).
73 Note that the sum of the lengths of all commands can be less than num_bytes.
74
75 On return, the nodes[0..num_bytes] array will have the following
76 "ZopfliNode array invariant":
77 For each i in [1..num_bytes], if nodes[i].cost < kInfinity, then
78 (1) nodes[i].copy_length() >= 2
79 (2) nodes[i].command_length() <= i and
80 (3) nodes[i - nodes[i].command_length()].cost < kInfinity */
81 BROTLI_INTERNAL size_t BrotliZopfliComputeShortestPath(
82 MemoryManager* m, size_t num_bytes,
83 size_t position, const uint8_t* ringbuffer, size_t ringbuffer_mask,
84 ContextLut literal_context_lut, const BrotliEncoderParams* params,
85 const int* dist_cache, Hasher* hasher, ZopfliNode* nodes);
86
87 BROTLI_INTERNAL void BrotliZopfliCreateCommands(
88 const size_t num_bytes, const size_t block_start, const ZopfliNode* nodes,
89 int* dist_cache, size_t* last_insert_len, const BrotliEncoderParams* params,
90 Command* commands, size_t* num_literals);
91
92 #if defined(__cplusplus) || defined(c_plusplus)
93 } /* extern "C" */
94 #endif
95
96 #endif /* BROTLI_ENC_BACKWARD_REFERENCES_HQ_H_ */