brotli/c/enc/compound_dictionary.h
Evgenii Kliuchnikov a8f5813b84 Update
Documentation:
  - add note that brotli is a "stream" format, not an archive-like
  - regenerate .1 with Pandoc
Build:
  - drop legacy "BROTLI_BUILD_PORTABLE" option
  - drop "BROTLI_SANITIZED" definition
Code:
  - c: comb includes
  - c/enc: extract encoder state into separate header
  - c/enc: drop designated q10 codepath
  - c/enc: dealing better with flushing of empty stream
  - fix MSVC compilation
API:
  - py: use library version instead of one in version.h
  - c: add plugable API to report consumed input / produced output
  - c/java: support "lean" prepared dictionaries (without copy of source)
2022-11-17 13:03:09 +00:00

75 lines
2.4 KiB
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
*/
#ifndef BROTLI_ENC_PREPARED_DICTIONARY_H_
#define BROTLI_ENC_PREPARED_DICTIONARY_H_
#include <brotli/shared_dictionary.h>
#include <brotli/types.h>
#include "../common/platform.h"
#include "../common/constants.h"
#include "memory.h"
/* "Fat" prepared dictionary, could be cooked outside of C implementation,
* e.g. on Java side. LZ77 data is copied inside PreparedDictionary struct. */
static const uint32_t kPreparedDictionaryMagic = 0xDEBCEDE0;
static const uint32_t kSharedDictionaryMagic = 0xDEBCEDE1;
static const uint32_t kManagedDictionaryMagic = 0xDEBCEDE2;
/* "Lean" prepared dictionary. LZ77 data is referenced. It is the responsibility
* of caller of "prepare dictionary" to keep the LZ77 data while prepared
* dictionary is in use. */
static const uint32_t kLeanPreparedDictionaryMagic = 0xDEBCEDE3;
static const uint64_t kPreparedDictionaryHashMul64Long =
BROTLI_MAKE_UINT64_T(0x1FE35A7Bu, 0xD3579BD3u);
typedef struct PreparedDictionary {
uint32_t magic;
uint32_t num_items;
uint32_t source_size;
uint32_t hash_bits;
uint32_t bucket_bits;
uint32_t slot_bits;
/* --- Dynamic size members --- */
/* uint32_t slot_offsets[1 << slot_bits]; */
/* uint16_t heads[1 << bucket_bits]; */
/* uint32_t items[variable]; */
/* [maybe] uint8_t* source_ref, depending on magic. */
/* [maybe] uint8_t source[source_size], depending on magic. */
} PreparedDictionary;
BROTLI_INTERNAL PreparedDictionary* CreatePreparedDictionary(MemoryManager* m,
const uint8_t* source, size_t source_size);
BROTLI_INTERNAL void DestroyPreparedDictionary(MemoryManager* m,
PreparedDictionary* dictionary);
typedef struct CompoundDictionary {
/* LZ77 prefix, compound dictionary */
size_t num_chunks;
size_t total_size;
/* Client instances. */
const PreparedDictionary* chunks[SHARED_BROTLI_MAX_COMPOUND_DICTS + 1];
const uint8_t* chunk_source[SHARED_BROTLI_MAX_COMPOUND_DICTS + 1];
size_t chunk_offsets[SHARED_BROTLI_MAX_COMPOUND_DICTS + 1];
size_t num_prepared_instances_;
/* Owned instances. */
PreparedDictionary* prepared_instances_[SHARED_BROTLI_MAX_COMPOUND_DICTS + 1];
} CompoundDictionary;
BROTLI_INTERNAL BROTLI_BOOL AttachPreparedDictionary(
CompoundDictionary* compound, const PreparedDictionary* dictionary);
#endif /* BROTLI_ENC_PREPARED_DICTIONARY */