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 #include "./state.h"
8
9 #include <stdlib.h> /* free, malloc */
10
11 #include <brotli/types.h>
12 #include "./huffman.h"
13
14 #if defined(__cplusplus) || defined(c_plusplus)
15 extern "C" {
16 #endif
17
BrotliDecoderStateInit(BrotliDecoderState * s,brotli_alloc_func alloc_func,brotli_free_func free_func,void * opaque)18 BROTLI_BOOL BrotliDecoderStateInit(BrotliDecoderState* s,
19 brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque) {
20 if (!alloc_func) {
21 s->alloc_func = BrotliDefaultAllocFunc;
22 s->free_func = BrotliDefaultFreeFunc;
23 s->memory_manager_opaque = 0;
24 } else {
25 s->alloc_func = alloc_func;
26 s->free_func = free_func;
27 s->memory_manager_opaque = opaque;
28 }
29
30 s->error_code = 0; /* BROTLI_DECODER_NO_ERROR */
31
32 BrotliInitBitReader(&s->br);
33 s->state = BROTLI_STATE_UNINITED;
34 s->large_window = 0;
35 s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NONE;
36 s->substate_uncompressed = BROTLI_STATE_UNCOMPRESSED_NONE;
37 s->substate_decode_uint8 = BROTLI_STATE_DECODE_UINT8_NONE;
38 s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_NONE;
39
40 s->buffer_length = 0;
41 s->loop_counter = 0;
42 s->pos = 0;
43 s->rb_roundtrips = 0;
44 s->partial_pos_out = 0;
45
46 s->block_type_trees = NULL;
47 s->block_len_trees = NULL;
48 s->ringbuffer = NULL;
49 s->ringbuffer_size = 0;
50 s->new_ringbuffer_size = 0;
51 s->ringbuffer_mask = 0;
52
53 s->context_map = NULL;
54 s->context_modes = NULL;
55 s->dist_context_map = NULL;
56 s->context_map_slice = NULL;
57 s->dist_context_map_slice = NULL;
58
59 s->literal_hgroup.codes = NULL;
60 s->literal_hgroup.htrees = NULL;
61 s->insert_copy_hgroup.codes = NULL;
62 s->insert_copy_hgroup.htrees = NULL;
63 s->distance_hgroup.codes = NULL;
64 s->distance_hgroup.htrees = NULL;
65
66 s->is_last_metablock = 0;
67 s->is_uncompressed = 0;
68 s->is_metadata = 0;
69 s->should_wrap_ringbuffer = 0;
70 s->canny_ringbuffer_allocation = 1;
71
72 s->window_bits = 0;
73 s->max_distance = 0;
74 s->dist_rb[0] = 16;
75 s->dist_rb[1] = 15;
76 s->dist_rb[2] = 11;
77 s->dist_rb[3] = 4;
78 s->dist_rb_idx = 0;
79 s->block_type_trees = NULL;
80 s->block_len_trees = NULL;
81
82 s->mtf_upper_bound = 63;
83
84 s->dictionary = BrotliGetDictionary();
85 s->transforms = BrotliGetTransforms();
86
87 return BROTLI_TRUE;
88 }
89
BrotliDecoderStateMetablockBegin(BrotliDecoderState * s)90 void BrotliDecoderStateMetablockBegin(BrotliDecoderState* s) {
91 s->meta_block_remaining_len = 0;
92 s->block_length[0] = 1U << 24;
93 s->block_length[1] = 1U << 24;
94 s->block_length[2] = 1U << 24;
95 s->num_block_types[0] = 1;
96 s->num_block_types[1] = 1;
97 s->num_block_types[2] = 1;
98 s->block_type_rb[0] = 1;
99 s->block_type_rb[1] = 0;
100 s->block_type_rb[2] = 1;
101 s->block_type_rb[3] = 0;
102 s->block_type_rb[4] = 1;
103 s->block_type_rb[5] = 0;
104 s->context_map = NULL;
105 s->context_modes = NULL;
106 s->dist_context_map = NULL;
107 s->context_map_slice = NULL;
108 s->literal_htree = NULL;
109 s->dist_context_map_slice = NULL;
110 s->dist_htree_index = 0;
111 s->context_lookup = NULL;
112 s->literal_hgroup.codes = NULL;
113 s->literal_hgroup.htrees = NULL;
114 s->insert_copy_hgroup.codes = NULL;
115 s->insert_copy_hgroup.htrees = NULL;
116 s->distance_hgroup.codes = NULL;
117 s->distance_hgroup.htrees = NULL;
118 }
119
BrotliDecoderStateCleanupAfterMetablock(BrotliDecoderState * s)120 void BrotliDecoderStateCleanupAfterMetablock(BrotliDecoderState* s) {
121 BROTLI_DECODER_FREE(s, s->context_modes);
122 BROTLI_DECODER_FREE(s, s->context_map);
123 BROTLI_DECODER_FREE(s, s->dist_context_map);
124 BROTLI_DECODER_FREE(s, s->literal_hgroup.htrees);
125 BROTLI_DECODER_FREE(s, s->insert_copy_hgroup.htrees);
126 BROTLI_DECODER_FREE(s, s->distance_hgroup.htrees);
127 }
128
BrotliDecoderStateCleanup(BrotliDecoderState * s)129 void BrotliDecoderStateCleanup(BrotliDecoderState* s) {
130 BrotliDecoderStateCleanupAfterMetablock(s);
131
132 BROTLI_DECODER_FREE(s, s->ringbuffer);
133 BROTLI_DECODER_FREE(s, s->block_type_trees);
134 }
135
BrotliDecoderHuffmanTreeGroupInit(BrotliDecoderState * s,HuffmanTreeGroup * group,uint32_t alphabet_size_max,uint32_t alphabet_size_limit,uint32_t ntrees)136 BROTLI_BOOL BrotliDecoderHuffmanTreeGroupInit(BrotliDecoderState* s,
137 HuffmanTreeGroup* group, uint32_t alphabet_size_max,
138 uint32_t alphabet_size_limit, uint32_t ntrees) {
139 /* 376 = 256 (1-st level table) + 4 + 7 + 15 + 31 + 63 (2-nd level mix-tables)
140 This number is discovered "unlimited" "enough" calculator; it is actually
141 a wee bigger than required in several cases (especially for alphabets with
142 less than 16 symbols). */
143 const size_t max_table_size = alphabet_size_limit + 376;
144 const size_t code_size = sizeof(HuffmanCode) * ntrees * max_table_size;
145 const size_t htree_size = sizeof(HuffmanCode*) * ntrees;
146 /* Pointer alignment is, hopefully, wider than sizeof(HuffmanCode). */
147 HuffmanCode** p = (HuffmanCode**)BROTLI_DECODER_ALLOC(s,
148 code_size + htree_size);
149 group->alphabet_size_max = (uint16_t)alphabet_size_max;
150 group->alphabet_size_limit = (uint16_t)alphabet_size_limit;
151 group->num_htrees = (uint16_t)ntrees;
152 group->htrees = p;
153 group->codes = (HuffmanCode*)(&p[ntrees]);
154 return !!p;
155 }
156
157 #if defined(__cplusplus) || defined(c_plusplus)
158 } /* extern "C" */
159 #endif
160