chromium/third_party/brotli/common/shared_dictionary.c

/* Copyright 2017 Google Inc. All Rights Reserved.

   Distributed under MIT license.
   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/

/* Shared Dictionary definition and utilities. */

#include <brotli/shared_dictionary.h>

#include <memory.h>
#include <stdlib.h>  /* malloc, free */
#include <stdio.h>

#include "dictionary.h"
#include "platform.h"
#include "shared_dictionary_internal.h"

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

#define BROTLI_NUM_ENCODED_LENGTHS …

/* Max allowed by spec */
#define BROTLI_MAX_SIZE_BITS …

/* Returns BROTLI_TRUE on success, BROTLI_FALSE on failure. */
static BROTLI_BOOL ReadBool(const uint8_t* encoded, size_t size, size_t* pos,
    BROTLI_BOOL* result) { … }

/* Returns BROTLI_TRUE on success, BROTLI_FALSE on failure. */
static BROTLI_BOOL ReadUint8(const uint8_t* encoded, size_t size, size_t* pos,
    uint8_t* result) { … }

/* Returns BROTLI_TRUE on success, BROTLI_FALSE on failure. */
static BROTLI_BOOL ReadUint16(const uint8_t* encoded, size_t size, size_t* pos,
    uint16_t* result) { … }

/* Reads a varint into a uint32_t, and returns error if it's too large */
/* Returns BROTLI_TRUE on success, BROTLI_FALSE on failure. */
static BROTLI_BOOL ReadVarint32(const uint8_t* encoded, size_t size,
    size_t* pos, uint32_t* result) { … }

/* Returns the total length of word list. */
static size_t BrotliSizeBitsToOffsets(const uint8_t* size_bits_by_length,
    uint32_t* offsets_by_length) { … }

static BROTLI_BOOL ParseWordList(size_t size, const uint8_t* encoded,
    size_t* pos, BrotliDictionary* out) { … }

/* Computes the cutOffTransforms of a BrotliTransforms which already has the
   transforms data correctly filled in. */
static void ComputeCutoffTransforms(BrotliTransforms* transforms) { … }

static BROTLI_BOOL ParsePrefixSuffixTable(size_t size, const uint8_t* encoded,
    size_t* pos, BrotliTransforms* out, uint16_t* out_table,
    size_t* out_table_size) { … }

static BROTLI_BOOL ParseTransformsList(size_t size, const uint8_t* encoded,
    size_t* pos, BrotliTransforms* out, uint16_t* prefix_suffix_table,
    size_t* prefix_suffix_count) { … }

static BROTLI_BOOL DryParseDictionary(const uint8_t* encoded,
    size_t size, uint32_t* num_prefix, BROTLI_BOOL* is_custom_static_dict) { … }

static BROTLI_BOOL ParseDictionary(const uint8_t* encoded, size_t size,
    BrotliSharedDictionary* dict) { … }

/* Decodes shared dictionary and verifies correctness.
   Returns BROTLI_TRUE if dictionary is valid, BROTLI_FALSE otherwise.
   The BrotliSharedDictionary must already have been initialized. If the
   BrotliSharedDictionary already contains data, compound dictionaries
   will be appended, but an error will be returned if it already has
   custom words or transforms.
   TODO(lode): link to RFC for shared brotli once published. */
static BROTLI_BOOL DecodeSharedDictionary(
    const uint8_t* encoded, size_t size, BrotliSharedDictionary* dict) { … }

void BrotliSharedDictionaryDestroyInstance(
    BrotliSharedDictionary* dict) { … }

BROTLI_BOOL BrotliSharedDictionaryAttach(
    BrotliSharedDictionary* dict, BrotliSharedDictionaryType type,
    size_t data_size, const uint8_t data[BROTLI_ARRAY_PARAM(data_size)]) { … }

BrotliSharedDictionary* BrotliSharedDictionaryCreateInstance(
    brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque) { … }

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