| .TH "encode.h" 3 "August 2021" "Brotli" \" -*- nroff -*- |
| .ad l |
| .nh |
| .SH NAME |
| encode.h \- API for Brotli compression\&. |
| |
| .SH SYNOPSIS |
| .br |
| .PP |
| .SS "Macros" |
| |
| .in +1c |
| .ti -1c |
| .RI "#define \fBBROTLI_DEFAULT_MODE\fP \fBBROTLI_MODE_GENERIC\fP" |
| .br |
| .RI "\fIDefault value for \fBBROTLI_PARAM_MODE\fP parameter\&. \fP" |
| .ti -1c |
| .RI "#define \fBBROTLI_DEFAULT_QUALITY\fP 11" |
| .br |
| .RI "\fIDefault value for \fBBROTLI_PARAM_QUALITY\fP parameter\&. \fP" |
| .ti -1c |
| .RI "#define \fBBROTLI_DEFAULT_WINDOW\fP 22" |
| .br |
| .RI "\fIDefault value for \fBBROTLI_PARAM_LGWIN\fP parameter\&. \fP" |
| .ti -1c |
| .RI "#define \fBBROTLI_LARGE_MAX_WINDOW_BITS\fP 30" |
| .br |
| .RI "\fIMaximal value for \fBBROTLI_PARAM_LGWIN\fP parameter in 'Large Window Brotli' (32-bit)\&. \fP" |
| .ti -1c |
| .RI "#define \fBBROTLI_MAX_INPUT_BLOCK_BITS\fP 24" |
| .br |
| .RI "\fIMaximal value for \fBBROTLI_PARAM_LGBLOCK\fP parameter\&. \fP" |
| .ti -1c |
| .RI "#define \fBBROTLI_MAX_QUALITY\fP 11" |
| .br |
| .RI "\fIMaximal value for \fBBROTLI_PARAM_QUALITY\fP parameter\&. \fP" |
| .ti -1c |
| .RI "#define \fBBROTLI_MAX_WINDOW_BITS\fP 24" |
| .br |
| .RI "\fIMaximal value for \fBBROTLI_PARAM_LGWIN\fP parameter\&. \fP" |
| .ti -1c |
| .RI "#define \fBBROTLI_MIN_INPUT_BLOCK_BITS\fP 16" |
| .br |
| .RI "\fIMinimal value for \fBBROTLI_PARAM_LGBLOCK\fP parameter\&. \fP" |
| .ti -1c |
| .RI "#define \fBBROTLI_MIN_QUALITY\fP 0" |
| .br |
| .RI "\fIMinimal value for \fBBROTLI_PARAM_QUALITY\fP parameter\&. \fP" |
| .ti -1c |
| .RI "#define \fBBROTLI_MIN_WINDOW_BITS\fP 10" |
| .br |
| .RI "\fIMinimal value for \fBBROTLI_PARAM_LGWIN\fP parameter\&. \fP" |
| .in -1c |
| .SS "Typedefs" |
| |
| .in +1c |
| .ti -1c |
| .RI "typedef enum \fBBrotliEncoderMode\fP \fBBrotliEncoderMode\fP" |
| .br |
| .RI "\fIOptions for \fBBROTLI_PARAM_MODE\fP parameter\&. \fP" |
| .ti -1c |
| .RI "typedef enum \fBBrotliEncoderOperation\fP \fBBrotliEncoderOperation\fP" |
| .br |
| .RI "\fIOperations that can be performed by streaming encoder\&. \fP" |
| .ti -1c |
| .RI "typedef enum \fBBrotliEncoderParameter\fP \fBBrotliEncoderParameter\fP" |
| .br |
| .RI "\fIOptions to be used with \fBBrotliEncoderSetParameter\fP\&. \fP" |
| .ti -1c |
| .RI "typedef struct BrotliEncoderStateStruct \fBBrotliEncoderState\fP" |
| .br |
| .RI "\fIOpaque structure that holds encoder state\&. \fP" |
| .in -1c |
| .SS "Enumerations" |
| .SS "Functions" |
| |
| .in +1c |
| .ti -1c |
| .RI "\fBBROTLI_BOOL\fP \fBBrotliEncoderAttachPreparedDictionary\fP (\fBBrotliEncoderState\fP *state, const BrotliEncoderPreparedDictionary *dictionary)" |
| .br |
| .RI "\fIAttaches a prepared dictionary of any type to the encoder\&. \fP" |
| .ti -1c |
| .RI "\fBBROTLI_BOOL\fP \fBBrotliEncoderCompress\fP (int quality, int lgwin, \fBBrotliEncoderMode\fP mode, size_t input_size, const uint8_t input_buffer[input_size], size_t *encoded_size, uint8_t encoded_buffer[*encoded_size])" |
| .br |
| .RI "\fIPerforms one-shot memory-to-memory compression\&. \fP" |
| .ti -1c |
| .RI "\fBBROTLI_BOOL\fP \fBBrotliEncoderCompressStream\fP (\fBBrotliEncoderState\fP *state, \fBBrotliEncoderOperation\fP op, size_t *available_in, const uint8_t **next_in, size_t *available_out, uint8_t **next_out, size_t *total_out)" |
| .br |
| .RI "\fICompresses input stream to output stream\&. \fP" |
| .ti -1c |
| .RI "\fBBrotliEncoderState\fP * \fBBrotliEncoderCreateInstance\fP (\fBbrotli_alloc_func\fP alloc_func, \fBbrotli_free_func\fP free_func, void *opaque)" |
| .br |
| .RI "\fICreates an instance of \fBBrotliEncoderState\fP and initializes it\&. \fP" |
| .ti -1c |
| .RI "void \fBBrotliEncoderDestroyInstance\fP (\fBBrotliEncoderState\fP *state)" |
| .br |
| .RI "\fIDeinitializes and frees \fBBrotliEncoderState\fP instance\&. \fP" |
| .ti -1c |
| .RI "\fBBROTLI_BOOL\fP \fBBrotliEncoderHasMoreOutput\fP (\fBBrotliEncoderState\fP *state)" |
| .br |
| .RI "\fIChecks if encoder has more output\&. \fP" |
| .ti -1c |
| .RI "\fBBROTLI_BOOL\fP \fBBrotliEncoderIsFinished\fP (\fBBrotliEncoderState\fP *state)" |
| .br |
| .RI "\fIChecks if encoder instance reached the final state\&. \fP" |
| .ti -1c |
| .RI "size_t \fBBrotliEncoderMaxCompressedSize\fP (size_t input_size)" |
| .br |
| .RI "\fICalculates the output size bound for the given \fCinput_size\fP\&. \fP" |
| .ti -1c |
| .RI "BrotliEncoderPreparedDictionary * \fBBrotliEncoderPrepareDictionary\fP (BrotliSharedDictionaryType type, size_t data_size, const uint8_t data[data_size], int quality, \fBbrotli_alloc_func\fP alloc_func, \fBbrotli_free_func\fP free_func, void *opaque)" |
| .br |
| .RI "\fIPrepares a shared dictionary from the given file format for the encoder\&. \fP" |
| .ti -1c |
| .RI "\fBBROTLI_BOOL\fP \fBBrotliEncoderSetParameter\fP (\fBBrotliEncoderState\fP *state, \fBBrotliEncoderParameter\fP param, uint32_t value)" |
| .br |
| .RI "\fISets the specified parameter to the given encoder instance\&. \fP" |
| .ti -1c |
| .RI "const uint8_t * \fBBrotliEncoderTakeOutput\fP (\fBBrotliEncoderState\fP *state, size_t *size)" |
| .br |
| .RI "\fIAcquires pointer to internal output buffer\&. \fP" |
| .ti -1c |
| .RI "uint32_t \fBBrotliEncoderVersion\fP (void)" |
| .br |
| .RI "\fIGets an encoder library version\&. \fP" |
| .in -1c |
| .SH "Detailed Description" |
| .PP |
| API for Brotli compression\&. |
| |
| |
| .SH "Macro Definition Documentation" |
| .PP |
| .SS "#define BROTLI_DEFAULT_MODE \fBBROTLI_MODE_GENERIC\fP" |
| |
| .PP |
| Default value for \fBBROTLI_PARAM_MODE\fP parameter\&. |
| .SS "#define BROTLI_DEFAULT_QUALITY 11" |
| |
| .PP |
| Default value for \fBBROTLI_PARAM_QUALITY\fP parameter\&. |
| .SS "#define BROTLI_DEFAULT_WINDOW 22" |
| |
| .PP |
| Default value for \fBBROTLI_PARAM_LGWIN\fP parameter\&. |
| .SS "#define BROTLI_MAX_INPUT_BLOCK_BITS 24" |
| |
| .PP |
| Maximal value for \fBBROTLI_PARAM_LGBLOCK\fP parameter\&. |
| .SS "#define BROTLI_MAX_QUALITY 11" |
| |
| .PP |
| Maximal value for \fBBROTLI_PARAM_QUALITY\fP parameter\&. |
| .SS "#define BROTLI_MAX_WINDOW_BITS 24" |
| |
| .PP |
| Maximal value for \fBBROTLI_PARAM_LGWIN\fP parameter\&. |
| .PP |
| \fBNote:\fP |
| .RS 4 |
| equal to \fCBROTLI_MAX_DISTANCE_BITS\fP constant\&. |
| .RE |
| .PP |
| |
| .SS "#define BROTLI_MIN_INPUT_BLOCK_BITS 16" |
| |
| .PP |
| Minimal value for \fBBROTLI_PARAM_LGBLOCK\fP parameter\&. |
| .SS "#define BROTLI_MIN_QUALITY 0" |
| |
| .PP |
| Minimal value for \fBBROTLI_PARAM_QUALITY\fP parameter\&. |
| .SS "#define BROTLI_MIN_WINDOW_BITS 10" |
| |
| .PP |
| Minimal value for \fBBROTLI_PARAM_LGWIN\fP parameter\&. |
| .SH "Typedef Documentation" |
| .PP |
| .SS "typedef enum \fBBrotliEncoderMode\fP \fBBrotliEncoderMode\fP" |
| |
| .PP |
| Options for \fBBROTLI_PARAM_MODE\fP parameter\&. |
| .SS "typedef enum \fBBrotliEncoderOperation\fP \fBBrotliEncoderOperation\fP" |
| |
| .PP |
| Operations that can be performed by streaming encoder\&. |
| .SS "typedef enum \fBBrotliEncoderParameter\fP \fBBrotliEncoderParameter\fP" |
| |
| .PP |
| Options to be used with \fBBrotliEncoderSetParameter\fP\&. |
| .SS "typedef struct BrotliEncoderStateStruct \fBBrotliEncoderState\fP" |
| |
| .PP |
| Opaque structure that holds encoder state\&. Allocated and initialized with \fBBrotliEncoderCreateInstance\fP\&. Cleaned up and deallocated with \fBBrotliEncoderDestroyInstance\fP\&. |
| .SH "Enumeration Type Documentation" |
| .PP |
| .SS "enum \fBBrotliEncoderMode\fP" |
| |
| .PP |
| Options for \fBBROTLI_PARAM_MODE\fP parameter\&. |
| .PP |
| \fBEnumerator\fP |
| .in +1c |
| .TP |
| \fB\fIBROTLI_MODE_GENERIC \fP\fP |
| Default compression mode\&. In this mode compressor does not know anything in advance about the properties of the input\&. |
| .TP |
| \fB\fIBROTLI_MODE_TEXT \fP\fP |
| Compression mode for UTF-8 formatted text input\&. |
| .TP |
| \fB\fIBROTLI_MODE_FONT \fP\fP |
| Compression mode used in WOFF 2\&.0\&. |
| .SS "enum \fBBrotliEncoderOperation\fP" |
| |
| .PP |
| Operations that can be performed by streaming encoder\&. |
| .PP |
| \fBEnumerator\fP |
| .in +1c |
| .TP |
| \fB\fIBROTLI_OPERATION_PROCESS \fP\fP |
| Process input\&. Encoder may postpone producing output, until it has processed enough input\&. |
| .TP |
| \fB\fIBROTLI_OPERATION_FLUSH \fP\fP |
| 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 \fBBROTLI_OPERATION_FLUSH\fP operation until \fCavailable_in\fP becomes \fC0\fP, and \fBBrotliEncoderHasMoreOutput\fP returns \fBBROTLI_FALSE\fP\&. If output is acquired via \fBBrotliEncoderTakeOutput\fP, then operation should be repeated after output buffer is drained\&. |
| .PP |
| \fBWarning:\fP |
| .RS 4 |
| Until flush is complete, client \fBSHOULD\fP \fBNOT\fP swap, reduce or extend input stream\&. |
| .RE |
| .PP |
| When flush is complete, output data will be sufficient for decoder to reproduce all the given input\&. |
| .TP |
| \fB\fIBROTLI_OPERATION_FINISH \fP\fP |
| 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 \fBBROTLI_OPERATION_FINISH\fP operation until \fCavailable_in\fP becomes \fC0\fP, and \fBBrotliEncoderHasMoreOutput\fP returns \fBBROTLI_FALSE\fP\&. If output is acquired via \fBBrotliEncoderTakeOutput\fP, then operation should be repeated after output buffer is drained\&. |
| .PP |
| \fBWarning:\fP |
| .RS 4 |
| Until finalization is complete, client \fBSHOULD\fP \fBNOT\fP swap, reduce or extend input stream\&. |
| .RE |
| .PP |
| Helper function \fBBrotliEncoderIsFinished\fP checks if stream is finalized and output fully dumped\&. |
| .PP |
| Adding more input data to finalized stream is impossible\&. |
| .TP |
| \fB\fIBROTLI_OPERATION_EMIT_METADATA \fP\fP |
| 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\&. |
| .PP |
| \fBNote:\fP |
| .RS 4 |
| Encoder may emit empty metadata blocks internally, to pad encoded stream to byte boundary\&. |
| .RE |
| .PP |
| \fBWarning:\fP |
| .RS 4 |
| Until emitting metadata is complete client \fBSHOULD\fP \fBNOT\fP swap, reduce or extend input stream\&. |
| .PP |
| The whole content of input buffer is considered to be the content of metadata block\&. Do \fBNOT\fP \fIappend\fP metadata to input stream, before it is depleted with other operations\&. |
| .RE |
| .PP |
| Stream is soft-flushed before metadata block is emitted\&. Metadata block \fBMUST\fP be no longer than than 16MiB\&. |
| .SS "enum \fBBrotliEncoderParameter\fP" |
| |
| .PP |
| Options to be used with \fBBrotliEncoderSetParameter\fP\&. |
| .PP |
| \fBEnumerator\fP |
| .in +1c |
| .TP |
| \fB\fIBROTLI_PARAM_MODE \fP\fP |
| Tune encoder for specific input\&. \fBBrotliEncoderMode\fP enumerates all available values\&. |
| .TP |
| \fB\fIBROTLI_PARAM_QUALITY \fP\fP |
| The main compression speed-density lever\&. The higher the quality, the slower the compression\&. Range is from \fBBROTLI_MIN_QUALITY\fP to \fBBROTLI_MAX_QUALITY\fP\&. |
| .TP |
| \fB\fIBROTLI_PARAM_LGWIN \fP\fP |
| Recommended sliding LZ77 window size\&. Encoder may reduce this value, e\&.g\&. if input is much smaller than window size\&. |
| .PP |
| Window size is \fC(1 << value) - 16\fP\&. |
| .PP |
| Range is from \fBBROTLI_MIN_WINDOW_BITS\fP to \fBBROTLI_MAX_WINDOW_BITS\fP\&. |
| .TP |
| \fB\fIBROTLI_PARAM_LGBLOCK \fP\fP |
| Recommended input block size\&. Encoder may reduce this value, e\&.g\&. if input is much smaller than input block size\&. |
| .PP |
| Range is from \fBBROTLI_MIN_INPUT_BLOCK_BITS\fP to \fBBROTLI_MAX_INPUT_BLOCK_BITS\fP\&. |
| .PP |
| \fBNote:\fP |
| .RS 4 |
| Bigger input block size allows better compression, but consumes more memory\&. |
| .br |
| The rough formula of memory used for temporary input storage is \fC3 << lgBlock\fP\&. |
| .RE |
| .PP |
| |
| .TP |
| \fB\fIBROTLI_PARAM_DISABLE_LITERAL_CONTEXT_MODELING \fP\fP |
| Flag that affects usage of 'literal context modeling' format feature\&. This flag is a 'decoding-speed vs compression ratio' trade-off\&. |
| .TP |
| \fB\fIBROTLI_PARAM_SIZE_HINT \fP\fP |
| Estimated total input size for all \fBBrotliEncoderCompressStream\fP calls\&. The default value is 0, which means that the total input size is unknown\&. |
| .TP |
| \fB\fIBROTLI_PARAM_LARGE_WINDOW \fP\fP |
| Flag that determines if 'Large Window Brotli' is used\&. |
| .TP |
| \fB\fIBROTLI_PARAM_NPOSTFIX \fP\fP |
| Recommended number of postfix bits (NPOSTFIX)\&. Encoder may change this value\&. |
| .PP |
| Range is from 0 to \fBBROTLI_MAX_NPOSTFIX\fP\&. |
| .TP |
| \fB\fIBROTLI_PARAM_NDIRECT \fP\fP |
| Recommended number of direct distance codes (NDIRECT)\&. Encoder may change this value\&. |
| .PP |
| Range is from 0 to (15 << NPOSTFIX) in steps of (1 << NPOSTFIX)\&. |
| .TP |
| \fB\fIBROTLI_PARAM_STREAM_OFFSET \fP\fP |
| Number of bytes of input stream already processed by a different instance\&. |
| .PP |
| \fBNote:\fP |
| .RS 4 |
| It is important to configure all the encoder instances with same parameters (except this one) in order to allow all the encoded parts obey the same restrictions implied by header\&. |
| .RE |
| .PP |
| If offset is not 0, then stream header is omitted\&. In any case output start is byte aligned, so for proper streams stitching 'predecessor' stream must be flushed\&. |
| .PP |
| Range is not artificially limited, but all the values greater or equal to maximal window size have the same effect\&. Values greater than 2**30 are not allowed\&. |
| .SH "Function Documentation" |
| .PP |
| .SS "\fBBROTLI_BOOL\fP BrotliEncoderAttachPreparedDictionary (\fBBrotliEncoderState\fP * state, const BrotliEncoderPreparedDictionary * dictionary)" |
| |
| .PP |
| Attaches a prepared dictionary of any type to the encoder\&. Can be used multiple times to attach multiple dictionaries\&. The dictionary type was determined by BrotliEncoderPrepareDictionary\&. Multiple raw prefix dictionaries and/or max 1 serialized dictionary with custom words can be attached\&. |
| .PP |
| \fBReturns:\fP |
| .RS 4 |
| \fBBROTLI_FALSE\fP in case of error |
| .PP |
| \fBBROTLI_TRUE\fP otherwise |
| .RE |
| .PP |
| |
| .SS "\fBBROTLI_BOOL\fP BrotliEncoderCompress (int quality, int lgwin, \fBBrotliEncoderMode\fP mode, size_t input_size, const uint8_t input_buffer[input_size], size_t * encoded_size, uint8_t encoded_buffer[*encoded_size])" |
| |
| .PP |
| Performs one-shot memory-to-memory compression\&. Compresses the data in \fCinput_buffer\fP into \fCencoded_buffer\fP, and sets \fC*encoded_size\fP to the compressed length\&. |
| .PP |
| \fBNote:\fP |
| .RS 4 |
| If \fBBrotliEncoderMaxCompressedSize\fP(\fCinput_size\fP) returns non-zero value, then output is guaranteed to be no longer than that\&. |
| .PP |
| If \fClgwin\fP is greater than \fBBROTLI_MAX_WINDOW_BITS\fP then resulting stream might be incompatible with RFC 7932; to decode such streams, decoder should be configured with \fBBROTLI_DECODER_PARAM_LARGE_WINDOW\fP = \fC1\fP |
| .RE |
| .PP |
| \fBParameters:\fP |
| .RS 4 |
| \fIquality\fP quality parameter value, e\&.g\&. \fBBROTLI_DEFAULT_QUALITY\fP |
| .br |
| \fIlgwin\fP lgwin parameter value, e\&.g\&. \fBBROTLI_DEFAULT_WINDOW\fP |
| .br |
| \fImode\fP mode parameter value, e\&.g\&. \fBBROTLI_DEFAULT_MODE\fP |
| .br |
| \fIinput_size\fP size of \fCinput_buffer\fP |
| .br |
| \fIinput_buffer\fP input data buffer with at least \fCinput_size\fP addressable bytes |
| .br |
| \fIencoded_size\fP \fBin:\fP size of \fCencoded_buffer\fP; |
| .br |
| \fBout:\fP length of compressed data written to \fCencoded_buffer\fP, or \fC0\fP if compression fails |
| .br |
| \fIencoded_buffer\fP compressed data destination buffer |
| .RE |
| .PP |
| \fBReturns:\fP |
| .RS 4 |
| \fBBROTLI_FALSE\fP in case of compression error |
| .PP |
| \fBBROTLI_FALSE\fP if output buffer is too small |
| .PP |
| \fBBROTLI_TRUE\fP otherwise |
| .RE |
| .PP |
| |
| .SS "\fBBROTLI_BOOL\fP BrotliEncoderCompressStream (\fBBrotliEncoderState\fP * state, \fBBrotliEncoderOperation\fP op, size_t * available_in, const uint8_t ** next_in, size_t * available_out, uint8_t ** next_out, size_t * total_out)" |
| |
| .PP |
| Compresses input stream to output stream\&. The values \fC*available_in\fP and \fC*available_out\fP must specify the number of bytes addressable at \fC*next_in\fP and \fC*next_out\fP respectively\&. When \fC*available_out\fP is \fC0\fP, \fCnext_out\fP is allowed to be \fCNULL\fP\&. |
| .PP |
| After each call, \fC*available_in\fP will be decremented by the amount of input bytes consumed, and the \fC*next_in\fP pointer will be incremented by that amount\&. Similarly, \fC*available_out\fP will be decremented by the amount of output bytes written, and the \fC*next_out\fP pointer will be incremented by that amount\&. |
| .PP |
| \fCtotal_out\fP, if it is not a null-pointer, will be set to the number of bytes compressed since the last \fCstate\fP initialization\&. |
| .PP |
| Internally workflow consists of 3 tasks: |
| .IP "1." 4 |
| (optionally) copy input data to internal buffer |
| .IP "2." 4 |
| actually compress data and (optionally) store it to internal buffer |
| .IP "3." 4 |
| (optionally) copy compressed bytes from internal buffer to output stream |
| .PP |
| .PP |
| Whenever all 3 tasks can't move forward anymore, or error occurs, this method returns the control flow to caller\&. |
| .PP |
| \fCop\fP is used to perform flush, finish the stream, or inject metadata block\&. See \fBBrotliEncoderOperation\fP for more information\&. |
| .PP |
| 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 \fCop\fP to \fBBROTLI_OPERATION_FLUSH\fP\&. Under some circumstances (e\&.g\&. lack of output stream capacity) this operation would require several calls to \fBBrotliEncoderCompressStream\fP\&. The method must be called again until both input stream is depleted and encoder has no more output (see \fBBrotliEncoderHasMoreOutput\fP) after the method is called\&. |
| .PP |
| 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 \fCop\fP to \fBBROTLI_OPERATION_FINISH\fP\&. Under some circumstances (e\&.g\&. lack of output stream capacity) this operation would require several calls to \fBBrotliEncoderCompressStream\fP\&. The method must be called again until both input stream is depleted and encoder has no more output (see \fBBrotliEncoderHasMoreOutput\fP) after the method is called\&. |
| .PP |
| \fBWarning:\fP |
| .RS 4 |
| When flushing and finishing, \fCop\fP should not change until operation is complete; input stream should not be swapped, reduced or extended as well\&. |
| .RE |
| .PP |
| \fBParameters:\fP |
| .RS 4 |
| \fIstate\fP encoder instance |
| .br |
| \fIop\fP requested operation |
| .br |
| \fIavailable_in\fP \fBin:\fP amount of available input; |
| .br |
| \fBout:\fP amount of unused input |
| .br |
| \fInext_in\fP pointer to the next input byte |
| .br |
| \fIavailable_out\fP \fBin:\fP length of output buffer; |
| .br |
| \fBout:\fP remaining size of output buffer |
| .br |
| \fInext_out\fP compressed output buffer cursor; can be \fCNULL\fP if \fCavailable_out\fP is \fC0\fP |
| .br |
| \fItotal_out\fP number of bytes produced so far; can be \fCNULL\fP |
| .RE |
| .PP |
| \fBReturns:\fP |
| .RS 4 |
| \fBBROTLI_FALSE\fP if there was an error |
| .PP |
| \fBBROTLI_TRUE\fP otherwise |
| .RE |
| .PP |
| |
| .SS "\fBBrotliEncoderState\fP* BrotliEncoderCreateInstance (\fBbrotli_alloc_func\fP alloc_func, \fBbrotli_free_func\fP free_func, void * opaque)" |
| |
| .PP |
| Creates an instance of \fBBrotliEncoderState\fP and initializes it\&. \fCalloc_func\fP and \fCfree_func\fP \fBMUST\fP be both zero or both non-zero\&. In the case they are both zero, default memory allocators are used\&. \fCopaque\fP is passed to \fCalloc_func\fP and \fCfree_func\fP when they are called\&. \fCfree_func\fP has to return without doing anything when asked to free a NULL pointer\&. |
| .PP |
| \fBParameters:\fP |
| .RS 4 |
| \fIalloc_func\fP custom memory allocation function |
| .br |
| \fIfree_func\fP custom memory free function |
| .br |
| \fIopaque\fP custom memory manager handle |
| .RE |
| .PP |
| \fBReturns:\fP |
| .RS 4 |
| \fC0\fP if instance can not be allocated or initialized |
| .PP |
| pointer to initialized \fBBrotliEncoderState\fP otherwise |
| .RE |
| .PP |
| |
| .SS "void BrotliEncoderDestroyInstance (\fBBrotliEncoderState\fP * state)" |
| |
| .PP |
| Deinitializes and frees \fBBrotliEncoderState\fP instance\&. |
| .PP |
| \fBParameters:\fP |
| .RS 4 |
| \fIstate\fP decoder instance to be cleaned up and deallocated |
| .RE |
| .PP |
| |
| .SS "\fBBROTLI_BOOL\fP BrotliEncoderHasMoreOutput (\fBBrotliEncoderState\fP * state)" |
| |
| .PP |
| Checks if encoder has more output\&. |
| .PP |
| \fBParameters:\fP |
| .RS 4 |
| \fIstate\fP encoder instance |
| .RE |
| .PP |
| \fBReturns:\fP |
| .RS 4 |
| \fBBROTLI_TRUE\fP, if encoder has some unconsumed output |
| .PP |
| \fBBROTLI_FALSE\fP otherwise |
| .RE |
| .PP |
| |
| .SS "\fBBROTLI_BOOL\fP BrotliEncoderIsFinished (\fBBrotliEncoderState\fP * state)" |
| |
| .PP |
| Checks if encoder instance reached the final state\&. |
| .PP |
| \fBParameters:\fP |
| .RS 4 |
| \fIstate\fP encoder instance |
| .RE |
| .PP |
| \fBReturns:\fP |
| .RS 4 |
| \fBBROTLI_TRUE\fP if encoder is in a state where it reached the end of the input and produced all of the output |
| .PP |
| \fBBROTLI_FALSE\fP otherwise |
| .RE |
| .PP |
| |
| .SS "size_t BrotliEncoderMaxCompressedSize (size_t input_size)" |
| |
| .PP |
| Calculates the output size bound for the given \fCinput_size\fP\&. |
| .PP |
| \fBWarning:\fP |
| .RS 4 |
| Result is only valid if quality is at least \fC2\fP and, in case \fBBrotliEncoderCompressStream\fP was used, no flushes (\fBBROTLI_OPERATION_FLUSH\fP) were performed\&. |
| .RE |
| .PP |
| \fBParameters:\fP |
| .RS 4 |
| \fIinput_size\fP size of projected input |
| .RE |
| .PP |
| \fBReturns:\fP |
| .RS 4 |
| \fC0\fP if result does not fit \fCsize_t\fP |
| .RE |
| .PP |
| |
| .SS "BrotliEncoderPreparedDictionary* BrotliEncoderPrepareDictionary (BrotliSharedDictionaryType type, size_t data_size, const uint8_t data[data_size], int quality, \fBbrotli_alloc_func\fP alloc_func, \fBbrotli_free_func\fP free_func, void * opaque)" |
| |
| .PP |
| Prepares a shared dictionary from the given file format for the encoder\&. \fCalloc_func\fP and \fCfree_func\fP \fBMUST\fP be both zero or both non-zero\&. In the case they are both zero, default memory allocators are used\&. \fCopaque\fP is passed to \fCalloc_func\fP and \fCfree_func\fP when they are called\&. \fCfree_func\fP has to return without doing anything when asked to free a NULL pointer\&. |
| .PP |
| \fBParameters:\fP |
| .RS 4 |
| \fItype\fP type of dictionary stored in data |
| .br |
| \fIdata_size\fP size of \fCdata\fP buffer |
| .br |
| \fIdata\fP pointer to the dictionary data |
| .br |
| \fIquality\fP the maximum Brotli quality to prepare the dictionary for, use BROTLI_MAX_QUALITY by default |
| .br |
| \fIalloc_func\fP custom memory allocation function |
| .br |
| \fIfree_func\fP custom memory free function |
| .br |
| \fIopaque\fP custom memory manager handle |
| .RE |
| .PP |
| |
| .SS "\fBBROTLI_BOOL\fP BrotliEncoderSetParameter (\fBBrotliEncoderState\fP * state, \fBBrotliEncoderParameter\fP param, uint32_t value)" |
| |
| .PP |
| Sets the specified parameter to the given encoder instance\&. |
| .PP |
| \fBParameters:\fP |
| .RS 4 |
| \fIstate\fP encoder instance |
| .br |
| \fIparam\fP parameter to set |
| .br |
| \fIvalue\fP new parameter value |
| .RE |
| .PP |
| \fBReturns:\fP |
| .RS 4 |
| \fBBROTLI_FALSE\fP if parameter is unrecognized, or value is invalid |
| .PP |
| \fBBROTLI_FALSE\fP 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) |
| .PP |
| \fBBROTLI_TRUE\fP if value is accepted |
| .RE |
| .PP |
| \fBWarning:\fP |
| .RS 4 |
| invalid values might be accepted in case they would not break encoding process\&. |
| .RE |
| .PP |
| |
| .SS "const uint8_t* BrotliEncoderTakeOutput (\fBBrotliEncoderState\fP * state, size_t * size)" |
| |
| .PP |
| Acquires pointer to internal output buffer\&. This method is used to make language bindings easier and more efficient: |
| .IP "1." 4 |
| push data to \fBBrotliEncoderCompressStream\fP, until \fBBrotliEncoderHasMoreOutput\fP returns BROTLI_TRUE |
| .IP "2." 4 |
| use \fBBrotliEncoderTakeOutput\fP to peek bytes and copy to language-specific entity |
| .PP |
| .PP |
| 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)\&. |
| .PP |
| \fBAttention:\fP |
| .RS 4 |
| After every call to \fBBrotliEncoderTakeOutput\fP \fC*size\fP bytes of output are considered consumed for all consecutive calls to the instance methods; returned pointer becomes invalidated as well\&. |
| .RE |
| .PP |
| \fBNote:\fP |
| .RS 4 |
| Encoder output is not guaranteed to be contiguous\&. This means that after the size-unrestricted call to \fBBrotliEncoderTakeOutput\fP, immediate next call to \fBBrotliEncoderTakeOutput\fP may return more data\&. |
| .RE |
| .PP |
| \fBParameters:\fP |
| .RS 4 |
| \fIstate\fP encoder instance |
| .br |
| \fIsize\fP \fBin:\fP number of bytes caller is ready to take, \fC0\fP if any amount could be handled; |
| .br |
| \fBout:\fP amount of data pointed by returned pointer and considered consumed; |
| .br |
| out value is never greater than in value, unless it is \fC0\fP |
| .RE |
| .PP |
| \fBReturns:\fP |
| .RS 4 |
| pointer to output data |
| .RE |
| .PP |
| |
| .SS "uint32_t BrotliEncoderVersion (void)" |
| |
| .PP |
| Gets an encoder library version\&. Look at BROTLI_MAKE_HEX_VERSION for more information\&. |
| .SH "Author" |
| .PP |
| Generated automatically by Doxygen for Brotli from the source code\&. |