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decode.h(3) Library Functions Manual decode.h(3) NAME decode.h - API for Brotli decompression. SYNOPSIS Macros #define BROTLI_DECODER_ERROR_CODES_LIST(BROTLI_ERROR_CODE, SEPARATOR) Template that evaluates items of BrotliDecoderErrorCode. #define BROTLI_LAST_ERROR_CODE BROTLI_DECODER_ERROR_UNREACHABLE The value of the last error code, negative integer. Typedefs typedef void(* brotli_decoder_metadata_chunk_func) (void *opaque, const uint8_t *data, size_t size) Callback to fire on metadata block chunk becomes available. typedef void(* brotli_decoder_metadata_start_func) (void *opaque, size_t size) Callback to fire on metadata block start. typedef enum BrotliDecoderParameter BrotliDecoderParameter Options to be used with BrotliDecoderSetParameter. typedef struct BrotliDecoderStateStruct BrotliDecoderState Opaque structure that holds decoder state. Enumerations Functions BROTLI_BOOL BrotliDecoderAttachDictionary (BrotliDecoderState *state, BrotliSharedDictionaryType type, size_t data_size, const uint8_t data[data_size]) Adds LZ77 prefix dictionary, adds or replaces built-in static dictionary and transforms. BrotliDecoderState * BrotliDecoderCreateInstance (brotli_alloc_func alloc_func, brotli_free_func free_func, void *opaque) Creates an instance of BrotliDecoderState and initializes it. BrotliDecoderResult BrotliDecoderDecompress (size_t encoded_size, const uint8_t encoded_buffer[encoded_size], size_t *decoded_size, uint8_t decoded_buffer[*decoded_size]) Performs one-shot memory-to-memory decompression. BrotliDecoderResult BrotliDecoderDecompressStream (BrotliDecoderState *state, size_t *available_in, const uint8_t **next_in, size_t *available_out, uint8_t **next_out, size_t *total_out) Decompresses the input stream to the output stream. void BrotliDecoderDestroyInstance (BrotliDecoderState *state) Deinitializes and frees BrotliDecoderState instance. const char * BrotliDecoderErrorString (BrotliDecoderErrorCode c) Converts error code to a c-string. BrotliDecoderErrorCode BrotliDecoderGetErrorCode (const BrotliDecoderState *state) Acquires a detailed error code. BROTLI_BOOL BrotliDecoderHasMoreOutput (const BrotliDecoderState *state) Checks if decoder has more output. BROTLI_BOOL BrotliDecoderIsFinished (const BrotliDecoderState *state) Checks if decoder instance reached the final state. BROTLI_BOOL BrotliDecoderIsUsed (const BrotliDecoderState *state) Checks if instance has already consumed input. void BrotliDecoderSetMetadataCallbacks (BrotliDecoderState *state, brotli_decoder_metadata_start_func start_func, brotli_decoder_metadata_chunk_func chunk_func, void *opaque) Sets callback for receiving metadata blocks. BROTLI_BOOL BrotliDecoderSetParameter (BrotliDecoderState *state, BrotliDecoderParameter param, uint32_t value) Sets the specified parameter to the given decoder instance. const uint8_t * BrotliDecoderTakeOutput (BrotliDecoderState *state, size_t *size) Acquires pointer to internal output buffer. uint32_t BrotliDecoderVersion (void) Gets a decoder library version. Detailed Description API for Brotli decompression. Macro Definition Documentation #define BROTLI_DECODER_ERROR_CODES_LIST(BROTLI_ERROR_CODE, SEPARATOR) Template that evaluates items of BrotliDecoderErrorCode. Example: // Log Brotli error code. switch (brotliDecoderErrorCode) { #define CASE_(PREFIX, NAME, CODE) case BROTLI_DECODER ## PREFIX ## NAME: LOG(INFO) << "error code:" << #NAME; break; #define NEWLINE_ BROTLI_DECODER_ERROR_CODES_LIST(CASE_, NEWLINE_) #undef CASE_ #undef NEWLINE_ default: LOG(FATAL) << "unknown brotli error code"; } #define BROTLI_LAST_ERROR_CODE BROTLI_DECODER_ERROR_UNREACHABLE The value of the last error code, negative integer. All other error code values are in the range from BROTLI_LAST_ERROR_CODE to -1. There are also 4 other possible non-error codes 0 .. 3 in BrotliDecoderErrorCode enumeration. Typedef Documentation typedef void(* brotli_decoder_metadata_chunk_func) (void *opaque, const uint8_t *data, size_t size) Callback to fire on metadata block chunk becomes available. This function can be invoked multiple times per metadata block; block should be considered finished when sum of size matches the announced metadata block size. Chunks contents pointed by data are transient and shouln not be accessed after leaving the callback. Parameters: opaque callback handle data pointer to metadata contents size size of metadata block chunk, at least 1 typedef void(* brotli_decoder_metadata_start_func) (void *opaque, size_t size) Callback to fire on metadata block start. After this callback is fired, if size is not 0, it is followed by brotli_decoder_metadata_chunk_func as more metadata block contents become accessible. Parameters: opaque callback handle size size of metadata block typedef enum BrotliDecoderParameter BrotliDecoderParameter Options to be used with BrotliDecoderSetParameter. typedef struct BrotliDecoderStateStruct BrotliDecoderState Opaque structure that holds decoder state. Allocated and initialized with BrotliDecoderCreateInstance. Cleaned up and deallocated with BrotliDecoderDestroyInstance. Enumeration Type Documentation enum BrotliDecoderErrorCode Error code for detailed logging / production debugging. See BrotliDecoderGetErrorCode and BROTLI_LAST_ERROR_CODE. enum BrotliDecoderParameter Options to be used with BrotliDecoderSetParameter. Enumerator BROTLI_DECODER_PARAM_DISABLE_RING_BUFFER_REALLOCATION Disable 'canny' ring buffer allocation strategy. Ring buffer is allocated according to window size, despite the real size of the content. BROTLI_DECODER_PARAM_LARGE_WINDOW Flag that determines if 'Large Window Brotli' is used. enum BrotliDecoderResult Result type for BrotliDecoderDecompress and BrotliDecoderDecompressStream functions. Enumerator BROTLI_DECODER_RESULT_ERROR Decoding error, e.g. corrupted input or memory allocation problem. BROTLI_DECODER_RESULT_SUCCESS Decoding successfully completed. BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT Partially done; should be called again with more input. BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT Partially done; should be called again with more output. Function Documentation BROTLI_BOOL BrotliDecoderAttachDictionary (BrotliDecoderState * state, BrotliSharedDictionaryType type, size_t data_size, const uint8_t data[data_size]) Adds LZ77 prefix dictionary, adds or replaces built-in static dictionary and transforms. Attached dictionary ownership is not transferred. Data provided to this method should be kept accessible until decoding is finished and decoder instance is destroyed. Note: Dictionaries can NOT be attached after actual decoding is started. Parameters: state decoder instance type dictionary data format data_size length of memory region pointed by data data dictionary data in format corresponding to type Returns: BROTLI_FALSE if dictionary is corrupted, or dictionary count limit is reached BROTLI_TRUE if dictionary is accepted / attached BrotliDecoderState* BrotliDecoderCreateInstance (brotli_alloc_func alloc_func, brotli_free_func free_func, void * opaque) Creates an instance of BrotliDecoderState and initializes it. The instance can be used once for decoding and should then be destroyed with BrotliDecoderDestroyInstance, it cannot be reused for a new decoding session. 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. free_func has to return without doing anything when asked to free a NULL pointer. Parameters: alloc_func custom memory allocation function free_func custom memory free function opaque custom memory manager handle Returns: 0 if instance can not be allocated or initialized pointer to initialized BrotliDecoderState otherwise BrotliDecoderResult BrotliDecoderDecompress (size_t encoded_size, const uint8_t encoded_buffer[encoded_size], size_t * decoded_size, uint8_t decoded_buffer[*decoded_size]) Performs one-shot memory-to-memory decompression. Decompresses the data in encoded_buffer into decoded_buffer, and sets *decoded_size to the decompressed length. Parameters: encoded_size size of encoded_buffer encoded_buffer compressed data buffer with at least encoded_size addressable bytes decoded_size in: size of decoded_buffer; out: length of decompressed data written to decoded_buffer decoded_buffer decompressed data destination buffer Returns: BROTLI_DECODER_RESULT_ERROR if input is corrupted, memory allocation failed, or decoded_buffer is not large enough; BROTLI_DECODER_RESULT_SUCCESS otherwise BrotliDecoderResult BrotliDecoderDecompressStream (BrotliDecoderState * state, size_t * available_in, const uint8_t ** next_in, size_t * available_out, uint8_t ** next_out, size_t * total_out) Decompresses the input stream to the output stream. The values *available_in and *available_out must specify the number of bytes addressable at *next_in and *next_out respectively. When *available_out is 0, next_out is allowed to be NULL. 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. Note: Input is never overconsumed, so next_in and available_in could be passed to the next consumer after decoding is complete. Parameters: state decoder instance available_in in: amount of available input; out: amount of unused input next_in pointer to the next compressed byte available_out in: length of output buffer; out: remaining size of output buffer next_out output buffer cursor; can be NULL if available_out is 0 total_out number of bytes decompressed so far; can be NULL Returns: BROTLI_DECODER_RESULT_ERROR if input is corrupted, memory allocation failed, arguments were invalid, etc.; use BrotliDecoderGetErrorCode to get detailed error code BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT decoding is blocked until more input data is provided BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT decoding is blocked until more output space is provided BROTLI_DECODER_RESULT_SUCCESS decoding is finished, no more input might be consumed and no more output will be produced void BrotliDecoderDestroyInstance (BrotliDecoderState * state) Deinitializes and frees BrotliDecoderState instance. Parameters: state decoder instance to be cleaned up and deallocated BrotliDecoderErrorCode BrotliDecoderGetErrorCode (const BrotliDecoderState * state) Acquires a detailed error code. Should be used only after BrotliDecoderDecompressStream returns BROTLI_DECODER_RESULT_ERROR. See also BrotliDecoderErrorString Parameters: state decoder instance Returns: last saved error code BROTLI_BOOL BrotliDecoderHasMoreOutput (const BrotliDecoderState * state) Checks if decoder has more output. Parameters: state decoder instance Returns: BROTLI_TRUE, if decoder has some unconsumed output BROTLI_FALSE otherwise BROTLI_BOOL BrotliDecoderIsFinished (const BrotliDecoderState * state) Checks if decoder instance reached the final state. Parameters: state decoder instance Returns: BROTLI_TRUE if decoder is in a state where it reached the end of the input and produced all of the output BROTLI_FALSE otherwise BROTLI_BOOL BrotliDecoderIsUsed (const BrotliDecoderState * state) Checks if instance has already consumed input. Instance that returns BROTLI_FALSE is considered 'fresh' and could be reused. Parameters: state decoder instance Returns: BROTLI_TRUE if decoder has already used some input bytes BROTLI_FALSE otherwise void BrotliDecoderSetMetadataCallbacks (BrotliDecoderState * state, brotli_decoder_metadata_start_func start_func, brotli_decoder_metadata_chunk_func chunk_func, void * opaque) Sets callback for receiving metadata blocks. Parameters: state decoder instance start_func callback on metadata block start chunk_func callback on metadata block chunk opaque callback handle BROTLI_BOOL BrotliDecoderSetParameter (BrotliDecoderState * state, BrotliDecoderParameter param, uint32_t value) Sets the specified parameter to the given decoder instance. Parameters: state decoder instance param parameter to set value new parameter value Returns: BROTLI_FALSE if parameter is unrecognized, or value is invalid BROTLI_TRUE if value is accepted const uint8_t* BrotliDecoderTakeOutput (BrotliDecoderState * state, size_t * size) Acquires pointer to internal output buffer. This method is used to make language bindings easier and more efficient: 1. push data to BrotliDecoderDecompressStream, until BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT is reported 2. use BrotliDecoderTakeOutput to peek bytes and copy to language- specific entity Also this could be useful if there is an output stream that is able to consume all the provided data (e.g. when data is saved to file system). Attention: After every call to BrotliDecoderTakeOutput *size bytes of output are considered consumed for all consecutive calls to the instance methods; returned pointer becomes invalidated as well. Note: Decoder output is not guaranteed to be contiguous. This means that after the size-unrestricted call to BrotliDecoderTakeOutput, immediate next call to BrotliDecoderTakeOutput may return more data. Parameters: state decoder instance size in: number of bytes caller is ready to take, 0 if any amount could be handled; out: amount of data pointed by returned pointer and considered consumed; out value is never greater than in value, unless it is 0 Returns: pointer to output data uint32_t BrotliDecoderVersion (void) Gets a decoder library version. Look at BROTLI_MAKE_HEX_VERSION for more information. Author Generated automatically by Doxygen for Brotli from the source code. Brotli August 2021 decode.h(3)
NAME | SYNOPSIS | Detailed Description | Macro Definition Documentation | Typedef Documentation | Enumeration Type Documentation | Function Documentation | Author
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