brotli/dec/decode.h
2016-05-20 10:22:03 +02:00

157 lines
6.1 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;
typedef enum {
BROTLI_NO_ERROR = 0,
/* Same as BrotliResult values */
BROTLI_SUCCESS = 1,
BROTLI_NEEDS_MORE_INPUT = 2,
BROTLI_NEEDS_MORE_OUTPUT = 3,
/* Errors caused by invalid input */
BROTLI_ERROR_FORMAT_EXUBERANT_NIBBLE = -1,
BROTLI_ERROR_FORMAT_RESERVED = -2,
BROTLI_ERROR_FORMAT_EXUBERANT_META_NIBBLE = -3,
BROTLI_ERROR_FORMAT_SIMPLE_HUFFMAN_ALPHABET = -4,
BROTLI_ERROR_FORMAT_SIMPLE_HUFFMAN_SAME = -5,
BROTLI_ERROR_FORMAT_CL_SPACE = -6,
BROTLI_ERROR_FORMAT_HUFFMAN_SPACE = -7,
BROTLI_ERROR_FORMAT_CONTEXT_MAP_REPEAT = -8,
BROTLI_ERROR_FORMAT_BLOCK_LENGTH_1 = -9,
BROTLI_ERROR_FORMAT_BLOCK_LENGTH_2 = -10,
BROTLI_ERROR_FORMAT_TRANSFORM = -11,
BROTLI_ERROR_FORMAT_DICTIONARY = -12,
BROTLI_ERROR_FORMAT_WINDOW_BITS = -13,
BROTLI_ERROR_FORMAT_PADDING_1 = -14,
BROTLI_ERROR_FORMAT_PADDING_2 = -15,
/* -16..-20 codes are reserved */
/* Memory allocation problems */
BROTLI_ERROR_ALLOC_CONTEXT_MODES = -21,
BROTLI_ERROR_ALLOC_TREE_GROUPS = -22, /* Literal, insert, distance */
/* -23..-24 codes are reserved for distinct tree groups */
BROTLI_ERROR_ALLOC_CONTEXT_MAP = -25,
BROTLI_ERROR_ALLOC_RING_BUFFER_1 = -26,
BROTLI_ERROR_ALLOC_RING_BUFFER_2 = -27,
/* -28..-29 codes are reserved for dynamic ringbuffer allocation */
BROTLI_ERROR_ALLOC_BLOCK_TYPE_TREES = -30,
/* "Impossible" states */
BROTLI_ERROR_UNREACHABLE_1 = -31,
BROTLI_ERROR_UNREACHABLE_2 = -32,
BROTLI_ERROR_UNREACHABLE_3 = -33,
BROTLI_ERROR_UNREACHABLE_4 = -34,
BROTLI_ERROR_UNREACHABLE_5 = -35,
BROTLI_ERROR_UNREACHABLE_6 = -36
} BrotliErrorCode;
#define BROTLI_LAST_ERROR_CODE BROTLI_ERROR_UNREACHABLE_6
/* 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| will be set to the number of bytes decompressed since
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);
#if defined(__cplusplus) || defined(c_plusplus)
} /* extern "C" */
#endif
#endif /* BROTLI_DEC_DECODE_H_ */