brotli/dec/state.c

/* Copyright 2015 Google Inc. All Rights Reserved.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

#include "./huffman.h"
#include "./state.h"

#include <stdlib.h>
#include <string.h>

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

static void* DefaultAllocFunc(void* opaque, size_t size) {
  BROTLI_UNUSED(opaque);
  return malloc(size);
}

static void DefaultFreeFunc(void* opaque, void* address) {
  BROTLI_UNUSED(opaque);
  free(address);
}

void BrotliStateInit(BrotliState* s) {
  BrotliStateInitWithCustomAllocators(s, 0, 0, 0);
}

void BrotliStateInitWithCustomAllocators(BrotliState* s,
    brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque) {
  if (!alloc_func) {
    s->alloc_func = DefaultAllocFunc;
    s->free_func = DefaultFreeFunc;
    s->memory_manager_opaque = 0;
  } else {
    s->alloc_func = alloc_func;
    s->free_func = free_func;
    s->memory_manager_opaque = opaque;
  }

  BrotliInitBitReader(&s->br);
  s->state = BROTLI_STATE_UNINITED;
  s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NONE;
  s->substate_tree_group = BROTLI_STATE_TREE_GROUP_NONE;
  s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_NONE;
  s->substate_uncompressed = BROTLI_STATE_UNCOMPRESSED_NONE;
  s->substate_huffman = BROTLI_STATE_HUFFMAN_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->context_map = NULL;
  s->context_modes = NULL;
  s->dist_context_map = NULL;
  s->context_map_slice = NULL;
  s->dist_context_map_slice = NULL;

  s->sub_loop_counter = 0;

  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->custom_dict = NULL;
  s->custom_dict_size = 0;

  s->is_last_metablock = 0;
  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;

  /* Make small negative indexes addressable. */
  s->symbol_lists = &s->symbols_lists_array[BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1];

  s->mtf_upper_bound = 255;

  s->legacy_input_buffer = 0;
  s->legacy_output_buffer = 0;
  s->legacy_input_len = 0;
  s->legacy_output_len = 0;
  s->legacy_input_pos = 0;
  s->legacy_output_pos = 0;
}

void BrotliStateMetablockBegin(BrotliState* s) {
  s->meta_block_remaining_len = 0;
  s->block_length[0] = 1U << 28;
  s->block_length[1] = 1U << 28;
  s->block_length[2] = 1U << 28;
  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_index = 0;
  s->literal_htree = NULL;
  s->dist_context_map_slice = NULL;
  s->dist_htree_index = 0;
  s->context_lookup1 = NULL;
  s->context_lookup2 = 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 BrotliStateCleanupAfterMetablock(BrotliState* s) {
  BROTLI_FREE(s, s->context_modes);
  BROTLI_FREE(s, s->context_map);
  BROTLI_FREE(s, s->dist_context_map);

  BrotliHuffmanTreeGroupRelease(s, &s->literal_hgroup);
  BrotliHuffmanTreeGroupRelease(s, &s->insert_copy_hgroup);
  BrotliHuffmanTreeGroupRelease(s, &s->distance_hgroup);
}

void BrotliStateCleanup(BrotliState* s) {
  BrotliStateCleanupAfterMetablock(s);

  BROTLI_FREE(s, s->ringbuffer);
  BROTLI_FREE(s, s->block_type_trees);
  BROTLI_FREE(s, s->legacy_input_buffer);
  BROTLI_FREE(s, s->legacy_output_buffer);
}

int BrotliStateIsStreamStart(const BrotliState* s) {
  return (s->state == BROTLI_STATE_UNINITED &&
      BrotliGetAvailableBits(&s->br) == 0);
}

int BrotliStateIsStreamEnd(const BrotliState* s) {
  return s->state == BROTLI_STATE_DONE;
}

void BrotliHuffmanTreeGroupInit(BrotliState* s, HuffmanTreeGroup* group,
    uint32_t alphabet_size, uint32_t ntrees) {
  /* Pack two allocations into one */
  const size_t code_size =
      sizeof(HuffmanCode) * (size_t)(ntrees * BROTLI_HUFFMAN_MAX_TABLE_SIZE);
  const size_t htree_size = sizeof(HuffmanCode*) * (size_t)ntrees;
  char *p = (char*)BROTLI_ALLOC(s, code_size + htree_size);
  group->alphabet_size = (uint16_t)alphabet_size;
  group->num_htrees = (uint16_t)ntrees;
  group->codes = (HuffmanCode*)p;
  group->htrees = (HuffmanCode**)(p + code_size);
}

void BrotliHuffmanTreeGroupRelease(BrotliState* s, HuffmanTreeGroup* group) {
  BROTLI_FREE(s, group->codes);
  group->htrees = NULL;
}

#if defined(__cplusplus) || defined(c_plusplus)
} /* extern "C" */
#endif