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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 #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_tree_group = BROTLI_STATE_TREE_GROUP_NONE;
37   s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_NONE;
38   s->substate_uncompressed = BROTLI_STATE_UNCOMPRESSED_NONE;
39   s->substate_huffman = BROTLI_STATE_HUFFMAN_NONE;
40   s->substate_decode_uint8 = BROTLI_STATE_DECODE_UINT8_NONE;
41   s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_NONE;
42 
43   s->buffer_length = 0;
44   s->loop_counter = 0;
45   s->pos = 0;
46   s->rb_roundtrips = 0;
47   s->partial_pos_out = 0;
48 
49   s->block_type_trees = NULL;
50   s->block_len_trees = NULL;
51   s->ringbuffer = NULL;
52   s->ringbuffer_size = 0;
53   s->new_ringbuffer_size = 0;
54   s->ringbuffer_mask = 0;
55 
56   s->context_map = NULL;
57   s->context_modes = NULL;
58   s->dist_context_map = NULL;
59   s->context_map_slice = NULL;
60   s->dist_context_map_slice = NULL;
61 
62   s->sub_loop_counter = 0;
63 
64   s->literal_hgroup.codes = NULL;
65   s->literal_hgroup.htrees = NULL;
66   s->insert_copy_hgroup.codes = NULL;
67   s->insert_copy_hgroup.htrees = NULL;
68   s->distance_hgroup.codes = NULL;
69   s->distance_hgroup.htrees = NULL;
70 
71   s->is_last_metablock = 0;
72   s->is_uncompressed = 0;
73   s->is_metadata = 0;
74   s->should_wrap_ringbuffer = 0;
75   s->canny_ringbuffer_allocation = 1;
76 
77   s->window_bits = 0;
78   s->max_distance = 0;
79   s->dist_rb[0] = 16;
80   s->dist_rb[1] = 15;
81   s->dist_rb[2] = 11;
82   s->dist_rb[3] = 4;
83   s->dist_rb_idx = 0;
84   s->block_type_trees = NULL;
85   s->block_len_trees = NULL;
86 
87   /* Make small negative indexes addressable. */
88   s->symbol_lists = &s->symbols_lists_array[BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1];
89 
90   s->mtf_upper_bound = 63;
91 
92   s->dictionary = BrotliGetDictionary();
93   s->transforms = BrotliGetTransforms();
94 
95   return BROTLI_TRUE;
96 }
97 
BrotliDecoderStateMetablockBegin(BrotliDecoderState * s)98 void BrotliDecoderStateMetablockBegin(BrotliDecoderState* s) {
99   s->meta_block_remaining_len = 0;
100   s->block_length[0] = 1U << 24;
101   s->block_length[1] = 1U << 24;
102   s->block_length[2] = 1U << 24;
103   s->num_block_types[0] = 1;
104   s->num_block_types[1] = 1;
105   s->num_block_types[2] = 1;
106   s->block_type_rb[0] = 1;
107   s->block_type_rb[1] = 0;
108   s->block_type_rb[2] = 1;
109   s->block_type_rb[3] = 0;
110   s->block_type_rb[4] = 1;
111   s->block_type_rb[5] = 0;
112   s->context_map = NULL;
113   s->context_modes = NULL;
114   s->dist_context_map = NULL;
115   s->context_map_slice = NULL;
116   s->literal_htree = NULL;
117   s->dist_context_map_slice = NULL;
118   s->dist_htree_index = 0;
119   s->context_lookup = NULL;
120   s->literal_hgroup.codes = NULL;
121   s->literal_hgroup.htrees = NULL;
122   s->insert_copy_hgroup.codes = NULL;
123   s->insert_copy_hgroup.htrees = NULL;
124   s->distance_hgroup.codes = NULL;
125   s->distance_hgroup.htrees = NULL;
126 }
127 
BrotliDecoderStateCleanupAfterMetablock(BrotliDecoderState * s)128 void BrotliDecoderStateCleanupAfterMetablock(BrotliDecoderState* s) {
129   BROTLI_DECODER_FREE(s, s->context_modes);
130   BROTLI_DECODER_FREE(s, s->context_map);
131   BROTLI_DECODER_FREE(s, s->dist_context_map);
132   BROTLI_DECODER_FREE(s, s->literal_hgroup.htrees);
133   BROTLI_DECODER_FREE(s, s->insert_copy_hgroup.htrees);
134   BROTLI_DECODER_FREE(s, s->distance_hgroup.htrees);
135 }
136 
BrotliDecoderStateCleanup(BrotliDecoderState * s)137 void BrotliDecoderStateCleanup(BrotliDecoderState* s) {
138   BrotliDecoderStateCleanupAfterMetablock(s);
139 
140   BROTLI_DECODER_FREE(s, s->ringbuffer);
141   BROTLI_DECODER_FREE(s, s->block_type_trees);
142 }
143 
BrotliDecoderHuffmanTreeGroupInit(BrotliDecoderState * s,HuffmanTreeGroup * group,uint32_t alphabet_size,uint32_t max_symbol,uint32_t ntrees)144 BROTLI_BOOL BrotliDecoderHuffmanTreeGroupInit(BrotliDecoderState* s,
145     HuffmanTreeGroup* group, uint32_t alphabet_size, uint32_t max_symbol,
146     uint32_t ntrees) {
147   /* Pack two allocations into one */
148   const size_t max_table_size = kMaxHuffmanTableSize[(alphabet_size + 31) >> 5];
149   const size_t code_size = sizeof(HuffmanCode) * ntrees * max_table_size;
150   const size_t htree_size = sizeof(HuffmanCode*) * ntrees;
151   /* Pointer alignment is, hopefully, wider than sizeof(HuffmanCode). */
152   HuffmanCode** p = (HuffmanCode**)BROTLI_DECODER_ALLOC(s,
153       code_size + htree_size);
154   group->alphabet_size = (uint16_t)alphabet_size;
155   group->max_symbol = (uint16_t)max_symbol;
156   group->num_htrees = (uint16_t)ntrees;
157   group->htrees = p;
158   group->codes = (HuffmanCode*)(&p[ntrees]);
159   return !!p;
160 }
161 
162 #if defined(__cplusplus) || defined(c_plusplus)
163 }  /* extern "C" */
164 #endif
165