tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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state.c (5871B)


      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 "../common/dictionary.h"
     10 #include "../common/platform.h"
     11 #include "huffman.h"
     12 
     13 #if defined(__cplusplus) || defined(c_plusplus)
     14 extern "C" {
     15 #endif
     16 
     17 #ifdef BROTLI_REPORTING
     18 /* When BROTLI_REPORTING is defined extra reporting module have to be linked. */
     19 void BrotliDecoderOnStart(const BrotliDecoderState* s);
     20 void BrotliDecoderOnFinish(const BrotliDecoderState* s);
     21 #define BROTLI_DECODER_ON_START(s) BrotliDecoderOnStart(s);
     22 #define BROTLI_DECODER_ON_FINISH(s) BrotliDecoderOnFinish(s);
     23 #else
     24 #if !defined(BROTLI_DECODER_ON_START)
     25 #define BROTLI_DECODER_ON_START(s) (void)(s);
     26 #endif
     27 #if !defined(BROTLI_DECODER_ON_FINISH)
     28 #define BROTLI_DECODER_ON_FINISH(s) (void)(s);
     29 #endif
     30 #endif
     31 
     32 BROTLI_BOOL BrotliDecoderStateInit(BrotliDecoderState* s,
     33    brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque) {
     34  BROTLI_DECODER_ON_START(s);
     35  if (!alloc_func) {
     36    s->alloc_func = BrotliDefaultAllocFunc;
     37    s->free_func = BrotliDefaultFreeFunc;
     38    s->memory_manager_opaque = 0;
     39  } else {
     40    s->alloc_func = alloc_func;
     41    s->free_func = free_func;
     42    s->memory_manager_opaque = opaque;
     43  }
     44 
     45  s->error_code = 0; /* BROTLI_DECODER_NO_ERROR */
     46 
     47  BrotliInitBitReader(&s->br);
     48  s->state = BROTLI_STATE_UNINITED;
     49  s->large_window = 0;
     50  s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NONE;
     51  s->substate_uncompressed = BROTLI_STATE_UNCOMPRESSED_NONE;
     52  s->substate_decode_uint8 = BROTLI_STATE_DECODE_UINT8_NONE;
     53  s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_NONE;
     54 
     55  s->buffer_length = 0;
     56  s->loop_counter = 0;
     57  s->pos = 0;
     58  s->rb_roundtrips = 0;
     59  s->partial_pos_out = 0;
     60  s->used_input = 0;
     61 
     62  s->block_type_trees = NULL;
     63  s->block_len_trees = NULL;
     64  s->ringbuffer = NULL;
     65  s->ringbuffer_size = 0;
     66  s->new_ringbuffer_size = 0;
     67  s->ringbuffer_mask = 0;
     68 
     69  s->context_map = NULL;
     70  s->context_modes = NULL;
     71  s->dist_context_map = NULL;
     72  s->context_map_slice = NULL;
     73  s->dist_context_map_slice = NULL;
     74 
     75  s->literal_hgroup.codes = NULL;
     76  s->literal_hgroup.htrees = NULL;
     77  s->insert_copy_hgroup.codes = NULL;
     78  s->insert_copy_hgroup.htrees = NULL;
     79  s->distance_hgroup.codes = NULL;
     80  s->distance_hgroup.htrees = NULL;
     81 
     82  s->is_last_metablock = 0;
     83  s->is_uncompressed = 0;
     84  s->is_metadata = 0;
     85  s->should_wrap_ringbuffer = 0;
     86  s->canny_ringbuffer_allocation = 1;
     87 
     88  s->window_bits = 0;
     89  s->max_distance = 0;
     90  s->dist_rb[0] = 16;
     91  s->dist_rb[1] = 15;
     92  s->dist_rb[2] = 11;
     93  s->dist_rb[3] = 4;
     94  s->dist_rb_idx = 0;
     95  s->block_type_trees = NULL;
     96  s->block_len_trees = NULL;
     97 
     98  s->mtf_upper_bound = 63;
     99 
    100  s->compound_dictionary = NULL;
    101  s->dictionary =
    102      BrotliSharedDictionaryCreateInstance(alloc_func, free_func, opaque);
    103  if (!s->dictionary) return BROTLI_FALSE;
    104 
    105  s->metadata_start_func = NULL;
    106  s->metadata_chunk_func = NULL;
    107  s->metadata_callback_opaque = 0;
    108 
    109  return BROTLI_TRUE;
    110 }
    111 
    112 void BrotliDecoderStateMetablockBegin(BrotliDecoderState* s) {
    113  s->meta_block_remaining_len = 0;
    114  s->block_length[0] = BROTLI_BLOCK_SIZE_CAP;
    115  s->block_length[1] = BROTLI_BLOCK_SIZE_CAP;
    116  s->block_length[2] = BROTLI_BLOCK_SIZE_CAP;
    117  s->num_block_types[0] = 1;
    118  s->num_block_types[1] = 1;
    119  s->num_block_types[2] = 1;
    120  s->block_type_rb[0] = 1;
    121  s->block_type_rb[1] = 0;
    122  s->block_type_rb[2] = 1;
    123  s->block_type_rb[3] = 0;
    124  s->block_type_rb[4] = 1;
    125  s->block_type_rb[5] = 0;
    126  s->context_map = NULL;
    127  s->context_modes = NULL;
    128  s->dist_context_map = NULL;
    129  s->context_map_slice = NULL;
    130  s->literal_htree = NULL;
    131  s->dist_context_map_slice = NULL;
    132  s->dist_htree_index = 0;
    133  s->context_lookup = NULL;
    134  s->literal_hgroup.codes = NULL;
    135  s->literal_hgroup.htrees = NULL;
    136  s->insert_copy_hgroup.codes = NULL;
    137  s->insert_copy_hgroup.htrees = NULL;
    138  s->distance_hgroup.codes = NULL;
    139  s->distance_hgroup.htrees = NULL;
    140 }
    141 
    142 void BrotliDecoderStateCleanupAfterMetablock(BrotliDecoderState* s) {
    143  BROTLI_DECODER_FREE(s, s->context_modes);
    144  BROTLI_DECODER_FREE(s, s->context_map);
    145  BROTLI_DECODER_FREE(s, s->dist_context_map);
    146  BROTLI_DECODER_FREE(s, s->literal_hgroup.htrees);
    147  BROTLI_DECODER_FREE(s, s->insert_copy_hgroup.htrees);
    148  BROTLI_DECODER_FREE(s, s->distance_hgroup.htrees);
    149 }
    150 
    151 void BrotliDecoderStateCleanup(BrotliDecoderState* s) {
    152  BrotliDecoderStateCleanupAfterMetablock(s);
    153 
    154  BROTLI_DECODER_ON_FINISH(s);
    155 
    156  BROTLI_DECODER_FREE(s, s->compound_dictionary);
    157  BrotliSharedDictionaryDestroyInstance(s->dictionary);
    158  s->dictionary = NULL;
    159  BROTLI_DECODER_FREE(s, s->ringbuffer);
    160  BROTLI_DECODER_FREE(s, s->block_type_trees);
    161 }
    162 
    163 BROTLI_BOOL BrotliDecoderHuffmanTreeGroupInit(BrotliDecoderState* s,
    164    HuffmanTreeGroup* group, brotli_reg_t alphabet_size_max,
    165    brotli_reg_t alphabet_size_limit, brotli_reg_t ntrees) {
    166  /* 376 = 256 (1-st level table) + 4 + 7 + 15 + 31 + 63 (2-nd level mix-tables)
    167     This number is discovered "unlimited" "enough" calculator; it is actually
    168     a wee bigger than required in several cases (especially for alphabets with
    169     less than 16 symbols). */
    170  const size_t max_table_size = alphabet_size_limit + 376;
    171  const size_t code_size = sizeof(HuffmanCode) * ntrees * max_table_size;
    172  const size_t htree_size = sizeof(HuffmanCode*) * ntrees;
    173  /* Pointer alignment is, hopefully, wider than sizeof(HuffmanCode). */
    174  HuffmanCode** p = (HuffmanCode**)BROTLI_DECODER_ALLOC(s,
    175      code_size + htree_size);
    176  group->alphabet_size_max = (uint16_t)alphabet_size_max;
    177  group->alphabet_size_limit = (uint16_t)alphabet_size_limit;
    178  group->num_htrees = (uint16_t)ntrees;
    179  group->htrees = p;
    180  group->codes = p ? (HuffmanCode*)(&p[ntrees]) : NULL;
    181  return !!p;
    182 }
    183 
    184 #if defined(__cplusplus) || defined(c_plusplus)
    185 }  /* extern "C" */
    186 #endif