brotli/dec/decode.h
2016-06-06 11:19:09 +02:00

163 lines
7.8 KiB
C

/* Copyright 2013 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
/* API for Brotli decompression */
#ifndef BROTLI_DEC_DECODE_H_
#define BROTLI_DEC_DECODE_H_
#include "./types.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
typedef struct BrotliStateStruct BrotliState;
typedef enum {
/* Decoding error, e.g. corrupt input or memory allocation problem */
BROTLI_RESULT_ERROR = 0,
/* Decoding successfully completed */
BROTLI_RESULT_SUCCESS = 1,
/* Partially done; should be called again with more input */
BROTLI_RESULT_NEEDS_MORE_INPUT = 2,
/* Partially done; should be called again with more output */
BROTLI_RESULT_NEEDS_MORE_OUTPUT = 3
} BrotliResult;
#define BROTLI_ERROR_CODES_LIST(BROTLI_ERROR_CODE, SEPARATOR) \
BROTLI_ERROR_CODE(_, NO_ERROR, 0) SEPARATOR \
/* Same as BrotliResult values */ \
BROTLI_ERROR_CODE(_, SUCCESS, 1) SEPARATOR \
BROTLI_ERROR_CODE(_, NEEDS_MORE_INPUT, 2) SEPARATOR \
BROTLI_ERROR_CODE(_, NEEDS_MORE_OUTPUT, 3) SEPARATOR \
\
/* Errors caused by invalid input */ \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, EXUBERANT_NIBBLE, -1) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, RESERVED, -2) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, EXUBERANT_META_NIBBLE, -3) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, SIMPLE_HUFFMAN_ALPHABET, -4) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, SIMPLE_HUFFMAN_SAME, -5) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, CL_SPACE, -6) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, HUFFMAN_SPACE, -7) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, CONTEXT_MAP_REPEAT, -8) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, BLOCK_LENGTH_1, -9) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, BLOCK_LENGTH_2, -10) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, TRANSFORM, -11) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, DICTIONARY, -12) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, WINDOW_BITS, -13) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, PADDING_1, -14) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_FORMAT_, PADDING_2, -15) SEPARATOR \
\
/* -16..-20 codes are reserved */ \
\
/* Memory allocation problems */ \
BROTLI_ERROR_CODE(_ERROR_ALLOC_, CONTEXT_MODES, -21) SEPARATOR \
/* Literal, insert and distance trees together */ \
BROTLI_ERROR_CODE(_ERROR_ALLOC_, TREE_GROUPS, -22) SEPARATOR \
/* -23..-24 codes are reserved for distinct tree groups */ \
BROTLI_ERROR_CODE(_ERROR_ALLOC_, CONTEXT_MAP, -25) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_ALLOC_, RING_BUFFER_1, -26) SEPARATOR \
BROTLI_ERROR_CODE(_ERROR_ALLOC_, RING_BUFFER_2, -27) SEPARATOR \
/* -28..-29 codes are reserved for dynamic ringbuffer allocation */ \
BROTLI_ERROR_CODE(_ERROR_ALLOC_, BLOCK_TYPE_TREES, -30) SEPARATOR \
\
/* "Impossible" states */ \
BROTLI_ERROR_CODE(_ERROR_, UNREACHABLE, -31)
typedef enum {
#define _BROTLI_COMMA ,
#define _BROTLI_ERROR_CODE_ENUM_ITEM(PREFIX, NAME, CODE) \
BROTLI ## PREFIX ## NAME = CODE
BROTLI_ERROR_CODES_LIST(_BROTLI_ERROR_CODE_ENUM_ITEM, _BROTLI_COMMA)
#undef _BROTLI_ERROR_CODE_ENUM_ITEM
#undef _BROTLI_COMMA
} BrotliErrorCode;
#define BROTLI_LAST_ERROR_CODE BROTLI_ERROR_UNREACHABLE
/* Creates the instance of BrotliState and initializes it. |alloc_func| and
|free_func| MUST be both zero or both non-zero. In the case they are both
zero, default memory allocators are used. |opaque| is passed to |alloc_func|
and |free_func| when they are called. */
BrotliState* BrotliCreateState(
brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque);
/* Deinitializes and frees BrotliState instance. */
void BrotliDestroyState(BrotliState* state);
/* Sets |*decoded_size| to the decompressed size of the given encoded stream.
This function only works if the encoded buffer has a single meta block,
or if it has two meta-blocks, where the first is uncompressed and the
second is empty.
Returns 1 on success, 0 on failure. */
int BrotliDecompressedSize(size_t encoded_size,
const uint8_t* encoded_buffer,
size_t* decoded_size);
/* Decompresses the data in |encoded_buffer| into |decoded_buffer|, and sets
|*decoded_size| to the decompressed length. */
BrotliResult BrotliDecompressBuffer(size_t encoded_size,
const uint8_t* encoded_buffer,
size_t* decoded_size,
uint8_t* decoded_buffer);
/* Decompresses the data. Supports partial input and output.
Must be called with an allocated input buffer in |*next_in| and an allocated
output buffer in |*next_out|. The values |*available_in| and |*available_out|
must specify the allocated size in |*next_in| and |*next_out| respectively.
After each call, |*available_in| will be decremented by the amount of input
bytes consumed, and the |*next_in| pointer will be incremented by that
amount. Similarly, |*available_out| will be decremented by the amount of
output bytes written, and the |*next_out| pointer will be incremented by that
amount. |total_out|, if it is not a null-pointer, will be set to the number
of bytes decompressed since the last state initialization.
Input is never overconsumed, so |next_in| and |available_in| could be passed
to the next consumer after decoding is complete. */
BrotliResult BrotliDecompressStream(size_t* available_in,
const uint8_t** next_in,
size_t* available_out,
uint8_t** next_out,
size_t* total_out,
BrotliState* s);
/* Fills the new state with a dictionary for LZ77, warming up the ringbuffer,
e.g. for custom static dictionaries for data formats.
Not to be confused with the built-in transformable dictionary of Brotli.
|size| should be less or equal to 2^24 (16MiB), otherwise the dictionary will
be ignored. The dictionary must exist in memory until decoding is done and
is owned by the caller. To use:
1) Allocate and initialize state with BrotliCreateState
2) Use BrotliSetCustomDictionary
3) Use BrotliDecompressStream
4) Clean up and free state with BrotliDestroyState
*/
void BrotliSetCustomDictionary(
size_t size, const uint8_t* dict, BrotliState* s);
/* Returns 1, if s is in a state where we have not read any input bytes yet,
and 0 otherwise */
int BrotliStateIsStreamStart(const BrotliState* s);
/* Returns 1, if s is in a state where we reached the end of the input and
produced all of the output, and 0 otherwise. */
int BrotliStateIsStreamEnd(const BrotliState* s);
/* Returns detailed error code after BrotliDecompressStream returns
BROTLI_RESULT_ERROR. */
BrotliErrorCode BrotliGetErrorCode(const BrotliState* s);
const char* BrotliErrorString(BrotliErrorCode c);
#if defined(__cplusplus) || defined(c_plusplus)
} /* extern "C" */
#endif
#endif /* BROTLI_DEC_DECODE_H_ */