kc3-lang/brotli/c/dec/state.c

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• Hash : 4b2b2d4f
  Author :
  Date : 2019-04-12T13:57:42
  

  Update (#749)
  
  Update:
  
   * Bazel: fix MSVC configuration
   * C: common: extended documentation and helpers around distance codes
   * C: common: enable BROTLI_DCHECK in "debug" builds
   * C: common: fix implicit trailing zero in `kPrefixSuffix`
   * C: dec: fix possible bit reader discharge for "large-window" mode
   * C: dec: simplify distance decoding via lookup table
   * C: dec: reuse decoder state members memory via union with lookup table
   * C: dec: add decoder state diagram
   * C: enc: clarify access to static dictionary
   * C: enc: improve static dictionary hash
   * C: enc: add "stream offset" parameter for parallel encoding
   * C: enc: reorganize hasher; now Q2-Q3 require exactly 256KiB
             to avoid global TCMalloc lock
   * C: enc: fix rare access to uninitialized data in ring-buffer
   * C: enc: reorganize logging / checks in `write_bits.h`
   * Java: dec: add "large-window" support
   * Java: dec: improve speed
   * Java: dec: debug and 32-bit mode are now activated via system properties
   * Java: dec: demystify some state variables (use better names)
   * Dictionary generator: add single input mode
   * Java: dec: modernize tests
   * Bazel: js: pick working commit for closure rules
  

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• c/dec/state.c

• /* Copyright 2015 Google Inc. All Rights Reserved.
  
     Distributed under MIT license.
     See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
  */
  
  #include "./state.h"
  
  #include <stdlib.h>  /* free, malloc */
  
  #include <brotli/types.h>
  #include "./huffman.h"
  
  #if defined(__cplusplus) || defined(c_plusplus)
  extern "C" {
  #endif
  
  BROTLI_BOOL BrotliDecoderStateInit(BrotliDecoderState* s,
      brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque) {
    if (!alloc_func) {
      s->alloc_func = BrotliDefaultAllocFunc;
      s->free_func = BrotliDefaultFreeFunc;
      s->memory_manager_opaque = 0;
    } else {
      s->alloc_func = alloc_func;
      s->free_func = free_func;
      s->memory_manager_opaque = opaque;
    }
  
    s->error_code = 0; /* BROTLI_DECODER_NO_ERROR */
  
    BrotliInitBitReader(&s->br);
    s->state = BROTLI_STATE_UNINITED;
    s->large_window = 0;
    s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NONE;
    s->substate_uncompressed = BROTLI_STATE_UNCOMPRESSED_NONE;
    s->substate_decode_uint8 = BROTLI_STATE_DECODE_UINT8_NONE;
    s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_NONE;
  
    s->buffer_length = 0;
    s->loop_counter = 0;
    s->pos = 0;
    s->rb_roundtrips = 0;
    s->partial_pos_out = 0;
  
    s->block_type_trees = NULL;
    s->block_len_trees = NULL;
    s->ringbuffer = NULL;
    s->ringbuffer_size = 0;
    s->new_ringbuffer_size = 0;
    s->ringbuffer_mask = 0;
  
    s->context_map = NULL;
    s->context_modes = NULL;
    s->dist_context_map = NULL;
    s->context_map_slice = NULL;
    s->dist_context_map_slice = NULL;
  
    s->literal_hgroup.codes = NULL;
    s->literal_hgroup.htrees = NULL;
    s->insert_copy_hgroup.codes = NULL;
    s->insert_copy_hgroup.htrees = NULL;
    s->distance_hgroup.codes = NULL;
    s->distance_hgroup.htrees = NULL;
  
    s->is_last_metablock = 0;
    s->is_uncompressed = 0;
    s->is_metadata = 0;
    s->should_wrap_ringbuffer = 0;
    s->canny_ringbuffer_allocation = 1;
  
    s->window_bits = 0;
    s->max_distance = 0;
    s->dist_rb[0] = 16;
    s->dist_rb[1] = 15;
    s->dist_rb[2] = 11;
    s->dist_rb[3] = 4;
    s->dist_rb_idx = 0;
    s->block_type_trees = NULL;
    s->block_len_trees = NULL;
  
    s->mtf_upper_bound = 63;
  
    s->dictionary = BrotliGetDictionary();
    s->transforms = BrotliGetTransforms();
  
    return BROTLI_TRUE;
  }
  
  void BrotliDecoderStateMetablockBegin(BrotliDecoderState* s) {
    s->meta_block_remaining_len = 0;
    s->block_length[0] = 1U << 24;
    s->block_length[1] = 1U << 24;
    s->block_length[2] = 1U << 24;
    s->num_block_types[0] = 1;
    s->num_block_types[1] = 1;
    s->num_block_types[2] = 1;
    s->block_type_rb[0] = 1;
    s->block_type_rb[1] = 0;
    s->block_type_rb[2] = 1;
    s->block_type_rb[3] = 0;
    s->block_type_rb[4] = 1;
    s->block_type_rb[5] = 0;
    s->context_map = NULL;
    s->context_modes = NULL;
    s->dist_context_map = NULL;
    s->context_map_slice = NULL;
    s->literal_htree = NULL;
    s->dist_context_map_slice = NULL;
    s->dist_htree_index = 0;
    s->context_lookup = NULL;
    s->literal_hgroup.codes = NULL;
    s->literal_hgroup.htrees = NULL;
    s->insert_copy_hgroup.codes = NULL;
    s->insert_copy_hgroup.htrees = NULL;
    s->distance_hgroup.codes = NULL;
    s->distance_hgroup.htrees = NULL;
  }
  
  void BrotliDecoderStateCleanupAfterMetablock(BrotliDecoderState* s) {
    BROTLI_DECODER_FREE(s, s->context_modes);
    BROTLI_DECODER_FREE(s, s->context_map);
    BROTLI_DECODER_FREE(s, s->dist_context_map);
    BROTLI_DECODER_FREE(s, s->literal_hgroup.htrees);
    BROTLI_DECODER_FREE(s, s->insert_copy_hgroup.htrees);
    BROTLI_DECODER_FREE(s, s->distance_hgroup.htrees);
  }
  
  void BrotliDecoderStateCleanup(BrotliDecoderState* s) {
    BrotliDecoderStateCleanupAfterMetablock(s);
  
    BROTLI_DECODER_FREE(s, s->ringbuffer);
    BROTLI_DECODER_FREE(s, s->block_type_trees);
  }
  
  BROTLI_BOOL BrotliDecoderHuffmanTreeGroupInit(BrotliDecoderState* s,
      HuffmanTreeGroup* group, uint32_t alphabet_size_max,
      uint32_t alphabet_size_limit, uint32_t ntrees) {
    /* Pack two allocations into one */
    const size_t max_table_size =
        kMaxHuffmanTableSize[(alphabet_size_limit + 31) >> 5];
    const size_t code_size = sizeof(HuffmanCode) * ntrees * max_table_size;
    const size_t htree_size = sizeof(HuffmanCode*) * ntrees;
    /* Pointer alignment is, hopefully, wider than sizeof(HuffmanCode). */
    HuffmanCode** p = (HuffmanCode**)BROTLI_DECODER_ALLOC(s,
        code_size + htree_size);
    group->alphabet_size_max = (uint16_t)alphabet_size_max;
    group->alphabet_size_limit = (uint16_t)alphabet_size_limit;
    group->num_htrees = (uint16_t)ntrees;
    group->htrees = p;
    group->codes = (HuffmanCode*)(&p[ntrees]);
    return !!p;
  }
  
  #if defined(__cplusplus) || defined(c_plusplus)
  }  /* extern "C" */
  #endif
  

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