API for Brotli compression.
Default value for BROTLI_PARAM_MODE parameter.
Default value for BROTLI_PARAM_QUALITY parameter.
Default value for BROTLI_PARAM_LGWIN parameter.
Maximal value for BROTLI_PARAM_LGBLOCK parameter.
Maximal value for BROTLI_PARAM_QUALITY parameter.
Maximal value for BROTLI_PARAM_LGWIN parameter.
Note: equal to BROTLI_MAX_DISTANCE_BITS constant.
Minimal value for BROTLI_PARAM_LGBLOCK parameter.
Minimal value for BROTLI_PARAM_QUALITY parameter.
Minimal value for BROTLI_PARAM_LGWIN parameter.
Options for BROTLI_PARAM_MODE parameter.
Operations that can be performed by streaming encoder.
Options to be used with BrotliEncoderSetParameter.
Opaque structure that holds encoder state. Allocated and initialized with BrotliEncoderCreateInstance. Cleaned up and deallocated with BrotliEncoderDestroyInstance.
Options for BROTLI_PARAM_MODE parameter.
Enumerator
BROTLI_MODE_GENERIC Default compression mode. In this mode compressor does not know anything in advance about the properties of the input.
BROTLI_MODE_TEXT Compression mode for UTF-8 formatted text input.
BROTLI_MODE_FONT Compression mode used in WOFF 2.0.
Operations that can be performed by streaming encoder.
Enumerator
BROTLI_OPERATION_PROCESS Process input. Encoder may postpone producing output, until it has processed enough input.
BROTLI_OPERATION_FLUSH Produce output for all processed input. Actual flush is performed when input stream is depleted and there is enough space in output stream. This means that client should repeat BROTLI_OPERATION_FLUSH operation until available_in becomes 0, and BrotliEncoderHasMoreOutput returns BROTLI_FALSE. If output is acquired via BrotliEncoderTakeOutput, then operation should be repeated after output buffer is drained.
Warning: Until flush is complete, client SHOULD NOT swap, reduce or extend input stream.
When flush is complete, output data will be sufficient for decoder to reproduce all the given input.
BROTLI_OPERATION_FINISH Finalize the stream. Actual finalization is performed when input stream is depleted and there is enough space in output stream. This means that client should repeat BROTLI_OPERATION_FINISH operation until available_in becomes 0, and BrotliEncoderHasMoreOutput returns BROTLI_FALSE. If output is acquired via BrotliEncoderTakeOutput, then operation should be repeated after output buffer is drained.
Warning: Until finalization is complete, client SHOULD NOT swap, reduce or extend input stream.
Helper function BrotliEncoderIsFinished checks if stream is finalized and output fully dumped.
Adding more input data to finalized stream is impossible.
BROTLI_OPERATION_EMIT_METADATA Emit metadata block to stream. Metadata is opaque to Brotli: neither encoder, nor decoder processes this data or relies on it. It may be used to pass some extra information from encoder client to decoder client without interfering with main data stream.
Note: Encoder may emit empty metadata blocks internally, to pad encoded stream to byte boundary.
Warning: Until emitting metadata is complete client SHOULD NOT swap, reduce or extend input stream.
The whole content of input buffer is considered to be the content of metadata block. Do NOT append metadata to input stream, before it is depleted with other operations.
Stream is soft-flushed before metadata block is emitted. Metadata block MUST be no longer than than 16MiB.
Options to be used with BrotliEncoderSetParameter.
Enumerator
BROTLI_PARAM_MODE Tune encoder for specific input. BrotliEncoderMode enumerates all available values.
BROTLI_PARAM_QUALITY The main compression speed-density lever. The higher the quality, the slower the compression. Range is from BROTLI_MIN_QUALITY to BROTLI_MAX_QUALITY.
BROTLI_PARAM_LGWIN Recommended sliding LZ77 window size. Encoder may reduce this value, e.g. if input is much smaller than window size.
Window size is (1 << value) - 16.
Range is from BROTLI_MIN_WINDOW_BITS to BROTLI_MAX_WINDOW_BITS.
BROTLI_PARAM_LGBLOCK Recommended input block size. Encoder may reduce this value, e.g. if input is much smaller than input block size.
Range is from BROTLI_MIN_INPUT_BLOCK_BITS to BROTLI_MAX_INPUT_BLOCK_BITS.
Note: Bigger input block size allows better compression, but consumes more memory. The rough formula of memory used for temporary input storage is 3 << lgBlock.
BROTLI_PARAM_DISABLE_LITERAL_CONTEXT_MODELING Flag that affects usage of 'literal context modeling' format feature. This flag is a 'decoding-speed vs compression ratio' trade-off.
BROTLI_PARAM_SIZE_HINT Estimated total input size for all BrotliEncoderCompressStream calls. The default value is 0, which means that the total input size is unknown.
Performs one-shot memory-to-memory compression. Compresses the data in input_buffer into encoded_buffer, and sets *encoded_size to the compressed length.
Note: If BrotliEncoderMaxCompressedSize(input_size) returns non-zero value, then output is guaranteed to be no longer than that.
Parameters: quality quality parameter value, e.g. BROTLI_DEFAULT_QUALITY lgwin lgwin parameter value, e.g. BROTLI_DEFAULT_WINDOW mode mode parameter value, e.g. BROTLI_DEFAULT_MODE input_size size of input_buffer input_buffer input data buffer with at least input_size addressable bytes encoded_size in: size of encoded_buffer; out: length of compressed data written to encoded_buffer, or 0 if compression fails encoded_buffer compressed data destination buffer
Returns: BROTLI_FALSE in case of compression error
BROTLI_FALSE if output buffer is too small
BROTLI_TRUE otherwise
Compresses input stream to 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.
Internally workflow consists of 3 tasks:
Whenever all 3 tasks can't move forward anymore, or error occurs, this method returns the control flow to caller.
op is used to perform flush, finish the stream, or inject metadata block. See BrotliEncoderOperation for more information.
Flushing the stream means forcing encoding of all input passed to encoder and completing the current output block, so it could be fully decoded by stream decoder. To perform flush set op to BROTLI_OPERATION_FLUSH. Under some circumstances (e.g. lack of output stream capacity) this operation would require several calls to BrotliEncoderCompressStream. The method must be called again until both input stream is depleted and encoder has no more output (see BrotliEncoderHasMoreOutput) after the method is called.
Finishing the stream means encoding of all input passed to encoder and adding specific 'final' marks, so stream decoder could determine that stream is complete. To perform finish set op to BROTLI_OPERATION_FINISH. Under some circumstances (e.g. lack of output stream capacity) this operation would require several calls to BrotliEncoderCompressStream. The method must be called again until both input stream is depleted and encoder has no more output (see BrotliEncoderHasMoreOutput) after the method is called.
Warning: When flushing and finishing, op should not change until operation is complete; input stream should not be swapped, reduced or extended as well.
Parameters: state encoder instance op requested operation available_in in: amount of available input; out: amount of unused input next_in pointer to the next input byte available_out in: length of output buffer; out: remaining size of output buffer next_out compressed output buffer cursor; can be NULL if available_out is 0 total_out number of bytes produced so far; can be NULL
Returns: BROTLI_FALSE if there was an error
BROTLI_TRUE otherwise
Creates an instance of BrotliEncoderState 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.
Parameters: alloc_func custom memory allocation function free_func custom memory fee function opaque custom memory manager handle
Returns: 0 if instance can not be allocated or initialized
pointer to initialized BrotliEncoderState otherwise
Deinitializes and frees BrotliEncoderState instance.
Parameters: state decoder instance to be cleaned up and deallocated
Checks if encoder has more output.
Parameters: state encoder instance
Returns: BROTLI_TRUE, if encoder has some unconsumed output
BROTLI_FALSE otherwise
Checks if encoder instance reached the final state.
Parameters: state encoder instance
Returns: BROTLI_TRUE if encoder is in a state where it reached the end of the input and produced all of the output
BROTLI_FALSE otherwise
Calculates the output size bound for the given input_size.
Warning: Result is not applicable to BrotliEncoderCompressStream output, because every 'flush' adds extra overhead bytes, and some encoder settings (e.g. quality 0 and 1) might imply a 'soft flush' after every chunk of input.
Parameters: input_size size of projected input
Returns: 0 if result does not fit size_t
Sets the specified parameter to the given encoder instance.
Parameters: state encoder instance param parameter to set value new parameter value
Returns: BROTLI_FALSE if parameter is unrecognized, or value is invalid
BROTLI_FALSE if value of parameter can not be changed at current encoder state (e.g. when encoding is started, window size might be already encoded and therefore it is impossible to change it)
BROTLI_TRUE if value is accepted
Warning: invalid values might be accepted in case they would not break encoding process.
Acquires pointer to internal output buffer. This method is used to make language bindings easier and more efficient:
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 BrotliEncoderTakeOutput *size bytes of output are considered consumed for all consecutive calls to the instance methods; returned pointer becomes invalidated as well.
Note: Encoder output is not guaranteed to be contiguous. This means that after the size-unrestricted call to BrotliEncoderTakeOutput, immediate next call to BrotliEncoderTakeOutput may return more data.
Parameters: state encoder 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
Gets an encoder library version. Look at BROTLI_VERSION for more information.
Generated automatically by Doxygen for Brotli from the source code.
