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Diffstat (limited to 'thirdparty/brotli/include/brotli/encode.h')
| -rw-r--r-- | thirdparty/brotli/include/brotli/encode.h | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/thirdparty/brotli/include/brotli/encode.h b/thirdparty/brotli/include/brotli/encode.h new file mode 100644 index 0000000000..b2c6f61e0f --- /dev/null +++ b/thirdparty/brotli/include/brotli/encode.h @@ -0,0 +1,501 @@ +/* Copyright 2013 Google Inc. All Rights Reserved. + + Distributed under MIT license. + See file LICENSE for detail or copy at https://opensource.org/licenses/MIT +*/ + +/** + * @file + * API for Brotli compression. + */ + +#ifndef BROTLI_ENC_ENCODE_H_ +#define BROTLI_ENC_ENCODE_H_ + +#include <brotli/port.h> +#include <brotli/shared_dictionary.h> +#include <brotli/types.h> + +#if defined(__cplusplus) || defined(c_plusplus) +extern "C" { +#endif + +/** Minimal value for ::BROTLI_PARAM_LGWIN parameter. */ +#define BROTLI_MIN_WINDOW_BITS 10 +/** + * Maximal value for ::BROTLI_PARAM_LGWIN parameter. + * + * @note equal to @c BROTLI_MAX_DISTANCE_BITS constant. + */ +#define BROTLI_MAX_WINDOW_BITS 24 +/** + * Maximal value for ::BROTLI_PARAM_LGWIN parameter + * in "Large Window Brotli" (32-bit). + */ +#define BROTLI_LARGE_MAX_WINDOW_BITS 30 +/** Minimal value for ::BROTLI_PARAM_LGBLOCK parameter. */ +#define BROTLI_MIN_INPUT_BLOCK_BITS 16 +/** Maximal value for ::BROTLI_PARAM_LGBLOCK parameter. */ +#define BROTLI_MAX_INPUT_BLOCK_BITS 24 +/** Minimal value for ::BROTLI_PARAM_QUALITY parameter. */ +#define BROTLI_MIN_QUALITY 0 +/** Maximal value for ::BROTLI_PARAM_QUALITY parameter. */ +#define BROTLI_MAX_QUALITY 11 + +/** Options for ::BROTLI_PARAM_MODE parameter. */ +typedef enum BrotliEncoderMode { + /** + * Default compression mode. + * + * In this mode compressor does not know anything in advance about the + * properties of the input. + */ + BROTLI_MODE_GENERIC = 0, + /** Compression mode for UTF-8 formatted text input. */ + BROTLI_MODE_TEXT = 1, + /** Compression mode used in WOFF 2.0. */ + BROTLI_MODE_FONT = 2 +} BrotliEncoderMode; + +/** Default value for ::BROTLI_PARAM_QUALITY parameter. */ +#define BROTLI_DEFAULT_QUALITY 11 +/** Default value for ::BROTLI_PARAM_LGWIN parameter. */ +#define BROTLI_DEFAULT_WINDOW 22 +/** Default value for ::BROTLI_PARAM_MODE parameter. */ +#define BROTLI_DEFAULT_MODE BROTLI_MODE_GENERIC + +/** Operations that can be performed by streaming encoder. */ +typedef enum BrotliEncoderOperation { + /** + * Process input. + * + * Encoder may postpone producing output, until it has processed enough input. + */ + BROTLI_OPERATION_PROCESS = 0, + /** + * 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 @p available_in becomes @c 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 @b SHOULD @b 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_FLUSH = 1, + /** + * 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 @p available_in becomes @c 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 @b SHOULD @b 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_FINISH = 2, + /** + * 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 @b SHOULD @b NOT swap, + * reduce or extend input stream. + * + * @warning The whole content of input buffer is considered to be the content + * of metadata block. Do @b NOT @e append metadata to input stream, + * before it is depleted with other operations. + * + * Stream is soft-flushed before metadata block is emitted. Metadata block + * @b MUST be no longer than than 16MiB. + */ + BROTLI_OPERATION_EMIT_METADATA = 3 +} BrotliEncoderOperation; + +/** Options to be used with ::BrotliEncoderSetParameter. */ +typedef enum BrotliEncoderParameter { + /** + * Tune encoder for specific input. + * + * ::BrotliEncoderMode enumerates all available values. + */ + BROTLI_PARAM_MODE = 0, + /** + * 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_QUALITY = 1, + /** + * 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_LGWIN = 2, + /** + * 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. \n The rough formula of memory used for temporary input + * storage is `3 << lgBlock`. + */ + BROTLI_PARAM_LGBLOCK = 3, + /** + * Flag that affects usage of "literal context modeling" format feature. + * + * This flag is a "decoding-speed vs compression ratio" trade-off. + */ + BROTLI_PARAM_DISABLE_LITERAL_CONTEXT_MODELING = 4, + /** + * Estimated total input size for all ::BrotliEncoderCompressStream calls. + * + * The default value is 0, which means that the total input size is unknown. + */ + BROTLI_PARAM_SIZE_HINT = 5, + /** + * Flag that determines if "Large Window Brotli" is used. + */ + BROTLI_PARAM_LARGE_WINDOW = 6, + /** + * Recommended number of postfix bits (NPOSTFIX). + * + * Encoder may change this value. + * + * Range is from 0 to ::BROTLI_MAX_NPOSTFIX. + */ + BROTLI_PARAM_NPOSTFIX = 7, + /** + * Recommended number of direct distance codes (NDIRECT). + * + * Encoder may change this value. + * + * Range is from 0 to (15 << NPOSTFIX) in steps of (1 << NPOSTFIX). + */ + BROTLI_PARAM_NDIRECT = 8, + /** + * Number of bytes of input stream already processed by a different instance. + * + * @note 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. + * + * 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. + * + * 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. + */ + BROTLI_PARAM_STREAM_OFFSET = 9 +} BrotliEncoderParameter; + +/** + * Opaque structure that holds encoder state. + * + * Allocated and initialized with ::BrotliEncoderCreateInstance. + * Cleaned up and deallocated with ::BrotliEncoderDestroyInstance. + */ +typedef struct BrotliEncoderStateStruct BrotliEncoderState; + +/** + * Sets the specified parameter to the given encoder instance. + * + * @param state encoder instance + * @param param parameter to set + * @param value new parameter value + * @returns ::BROTLI_FALSE if parameter is unrecognized, or value is invalid + * @returns ::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) + * @returns ::BROTLI_TRUE if value is accepted + * @warning invalid values might be accepted in case they would not break + * encoding process. + */ +BROTLI_ENC_API BROTLI_BOOL BrotliEncoderSetParameter( + BrotliEncoderState* state, BrotliEncoderParameter param, uint32_t value); + +/** + * Creates an instance of ::BrotliEncoderState and initializes it. + * + * @p alloc_func and @p free_func @b MUST be both zero or both non-zero. In the + * case they are both zero, default memory allocators are used. @p opaque is + * passed to @p alloc_func and @p free_func when they are called. @p free_func + * has to return without doing anything when asked to free a NULL pointer. + * + * @param alloc_func custom memory allocation function + * @param free_func custom memory free function + * @param opaque custom memory manager handle + * @returns @c 0 if instance can not be allocated or initialized + * @returns pointer to initialized ::BrotliEncoderState otherwise + */ +BROTLI_ENC_API BrotliEncoderState* BrotliEncoderCreateInstance( + brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque); + +/** + * Deinitializes and frees ::BrotliEncoderState instance. + * + * @param state decoder instance to be cleaned up and deallocated + */ +BROTLI_ENC_API void BrotliEncoderDestroyInstance(BrotliEncoderState* state); + +/* Opaque type for pointer to different possible internal structures containing + dictionary prepared for the encoder */ +typedef struct BrotliEncoderPreparedDictionaryStruct + BrotliEncoderPreparedDictionary; + +/** + * Prepares a shared dictionary from the given file format for the encoder. + * + * @p alloc_func and @p free_func @b MUST be both zero or both non-zero. In the + * case they are both zero, default memory allocators are used. @p opaque is + * passed to @p alloc_func and @p free_func when they are called. @p free_func + * has to return without doing anything when asked to free a NULL pointer. + * + * @param type type of dictionary stored in data + * @param data_size size of @p data buffer + * @param data pointer to the dictionary data + * @param quality the maximum Brotli quality to prepare the dictionary for, + * use BROTLI_MAX_QUALITY by default + * @param alloc_func custom memory allocation function + * @param free_func custom memory free function + * @param opaque custom memory manager handle + */ +BROTLI_ENC_API BrotliEncoderPreparedDictionary* +BrotliEncoderPrepareDictionary(BrotliSharedDictionaryType type, + size_t data_size, const uint8_t data[BROTLI_ARRAY_PARAM(data_size)], + int quality, + brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque); + +BROTLI_ENC_API void BrotliEncoderDestroyPreparedDictionary( + BrotliEncoderPreparedDictionary* dictionary); + +/** + * 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. + * + * @returns ::BROTLI_FALSE in case of error + * @returns ::BROTLI_TRUE otherwise + */ +BROTLI_ENC_API BROTLI_BOOL BrotliEncoderAttachPreparedDictionary( + BrotliEncoderState* state, + const BrotliEncoderPreparedDictionary* dictionary); + +/** + * Calculates the output size bound for the given @p input_size. + * + * @warning Result is only valid if quality is at least @c 2 and, in + * case ::BrotliEncoderCompressStream was used, no flushes + * (::BROTLI_OPERATION_FLUSH) were performed. + * + * @param input_size size of projected input + * @returns @c 0 if result does not fit @c size_t + */ +BROTLI_ENC_API size_t BrotliEncoderMaxCompressedSize(size_t input_size); + +/** + * Performs one-shot memory-to-memory compression. + * + * Compresses the data in @p input_buffer into @p encoded_buffer, and sets + * @p *encoded_size to the compressed length. + * + * @note If ::BrotliEncoderMaxCompressedSize(@p input_size) returns non-zero + * value, then output is guaranteed to be no longer than that. + * + * @note If @p lgwin is greater than ::BROTLI_MAX_WINDOW_BITS then resulting + * stream might be incompatible with RFC 7932; to decode such streams, + * decoder should be configured with + * ::BROTLI_DECODER_PARAM_LARGE_WINDOW = @c 1 + * + * @param quality quality parameter value, e.g. ::BROTLI_DEFAULT_QUALITY + * @param lgwin lgwin parameter value, e.g. ::BROTLI_DEFAULT_WINDOW + * @param mode mode parameter value, e.g. ::BROTLI_DEFAULT_MODE + * @param input_size size of @p input_buffer + * @param input_buffer input data buffer with at least @p input_size + * addressable bytes + * @param[in, out] encoded_size @b in: size of @p encoded_buffer; \n + * @b out: length of compressed data written to + * @p encoded_buffer, or @c 0 if compression fails + * @param encoded_buffer compressed data destination buffer + * @returns ::BROTLI_FALSE in case of compression error + * @returns ::BROTLI_FALSE if output buffer is too small + * @returns ::BROTLI_TRUE otherwise + */ +BROTLI_ENC_API BROTLI_BOOL BrotliEncoderCompress( + int quality, int lgwin, BrotliEncoderMode mode, size_t input_size, + const uint8_t input_buffer[BROTLI_ARRAY_PARAM(input_size)], + size_t* encoded_size, + uint8_t encoded_buffer[BROTLI_ARRAY_PARAM(*encoded_size)]); + +/** + * Compresses input stream to output stream. + * + * The values @p *available_in and @p *available_out must specify the number of + * bytes addressable at @p *next_in and @p *next_out respectively. + * When @p *available_out is @c 0, @p next_out is allowed to be @c NULL. + * + * After each call, @p *available_in will be decremented by the amount of input + * bytes consumed, and the @p *next_in pointer will be incremented by that + * amount. Similarly, @p *available_out will be decremented by the amount of + * output bytes written, and the @p *next_out pointer will be incremented by + * that amount. + * + * @p total_out, if it is not a null-pointer, will be set to the number + * of bytes compressed since the last @p state initialization. + * + * + * + * Internally workflow consists of 3 tasks: + * -# (optionally) copy input data to internal buffer + * -# actually compress data and (optionally) store it to internal buffer + * -# (optionally) copy compressed bytes from internal buffer to output stream + * + * Whenever all 3 tasks can't move forward anymore, or error occurs, this + * method returns the control flow to caller. + * + * @p 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 @p 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 @p 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, @p op should not change until operation + * is complete; input stream should not be swapped, reduced or + * extended as well. + * + * @param state encoder instance + * @param op requested operation + * @param[in, out] available_in @b in: amount of available input; \n + * @b out: amount of unused input + * @param[in, out] next_in pointer to the next input byte + * @param[in, out] available_out @b in: length of output buffer; \n + * @b out: remaining size of output buffer + * @param[in, out] next_out compressed output buffer cursor; + * can be @c NULL if @p available_out is @c 0 + * @param[out] total_out number of bytes produced so far; can be @c NULL + * @returns ::BROTLI_FALSE if there was an error + * @returns ::BROTLI_TRUE otherwise + */ +BROTLI_ENC_API BROTLI_BOOL BrotliEncoderCompressStream( + BrotliEncoderState* state, BrotliEncoderOperation op, size_t* available_in, + const uint8_t** next_in, size_t* available_out, uint8_t** next_out, + size_t* total_out); + +/** + * Checks if encoder instance reached the final state. + * + * @param 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 + * @returns ::BROTLI_FALSE otherwise + */ +BROTLI_ENC_API BROTLI_BOOL BrotliEncoderIsFinished(BrotliEncoderState* state); + +/** + * Checks if encoder has more output. + * + * @param state encoder instance + * @returns ::BROTLI_TRUE, if encoder has some unconsumed output + * @returns ::BROTLI_FALSE otherwise + */ +BROTLI_ENC_API BROTLI_BOOL BrotliEncoderHasMoreOutput( + BrotliEncoderState* state); + +/** + * Acquires pointer to internal output buffer. + * + * This method is used to make language bindings easier and more efficient: + * -# push data to ::BrotliEncoderCompressStream, + * until ::BrotliEncoderHasMoreOutput returns BROTL_TRUE + * -# use ::BrotliEncoderTakeOutput 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 ::BrotliEncoderTakeOutput @p *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. + * + * @param state encoder instance + * @param[in, out] size @b in: number of bytes caller is ready to take, @c 0 if + * any amount could be handled; \n + * @b out: amount of data pointed by returned pointer and + * considered consumed; \n + * out value is never greater than in value, unless it is @c 0 + * @returns pointer to output data + */ +BROTLI_ENC_API const uint8_t* BrotliEncoderTakeOutput( + BrotliEncoderState* state, size_t* size); + +/* Returns the estimated peak memory usage (in bytes) of the BrotliCompress() + function, not counting the memory needed for the input and output. */ +BROTLI_ENC_EXTRA_API size_t BrotliEncoderEstimatePeakMemoryUsage( + int quality, int lgwin, size_t input_size); +/* Returns 0 if dictionary is not valid; otherwise returns allocation size. */ +BROTLI_ENC_EXTRA_API size_t BrotliEncoderGetPreparedDictionarySize( + const BrotliEncoderPreparedDictionary* dictionary); + +/** + * Gets an encoder library version. + * + * Look at BROTLI_VERSION for more information. + */ +BROTLI_ENC_API uint32_t BrotliEncoderVersion(void); + +#if defined(__cplusplus) || defined(c_plusplus) +} /* extern "C" */ +#endif + +#endif /* BROTLI_ENC_ENCODE_H_ */ |