X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=lzma%2Fapi%2Flzma%2Ffilter.h;fp=lzma%2Fapi%2Flzma%2Ffilter.h;h=4e78752b8f795ebc4a699045609ea0758ece1562;hb=32b8a6b26ed8843828e03e505d2256960bda0980;hp=0000000000000000000000000000000000000000;hpb=d48fc23a4bcf8ca3c406d6e8c8a6f8c6b0fa2f1e;p=zpackage diff --git a/lzma/api/lzma/filter.h b/lzma/api/lzma/filter.h new file mode 100644 index 0000000..4e78752 --- /dev/null +++ b/lzma/api/lzma/filter.h @@ -0,0 +1,425 @@ +/** + * \file lzma/filter.h + * \brief Common filter related types and functions + */ + +/* + * Author: Lasse Collin + * + * This file has been put into the public domain. + * You can do whatever you want with this file. + * + * See ../lzma.h for information about liblzma as a whole. + */ + +#ifndef LZMA_H_INTERNAL +# error Never include this file directly. Use instead. +#endif + + +/** + * \brief Maximum number of filters in a chain + * + * A filter chain can have 1-4 filters, of which three are allowed to change + * the size of the data. Usually only one or two filters are needed. + */ +#define LZMA_FILTERS_MAX 4 + + +/** + * \brief Filter options + * + * This structure is used to pass Filter ID and a pointer filter's + * options to liblzma. A few functions work with a single lzma_filter + * structure, while most functions expect a filter chain. + * + * A filter chain is indicated with an array of lzma_filter structures. + * The array is terminated with .id = LZMA_VLI_UNKNOWN. Thus, the filter + * array must have LZMA_FILTERS_MAX + 1 elements (that is, five) to + * be able to hold any arbitrary filter chain. This is important when + * using lzma_block_header_decode() from block.h, because too small + * array would make liblzma write past the end of the filters array. + */ +typedef struct { + /** + * \brief Filter ID + * + * Use constants whose name begin with `LZMA_FILTER_' to specify + * different filters. In an array of lzma_filter structures, use + * LZMA_VLI_UNKNOWN to indicate end of filters. + * + * \note This is not an enum, because on some systems enums + * cannot be 64-bit. + */ + lzma_vli id; + + /** + * \brief Pointer to filter-specific options structure + * + * If the filter doesn't need options, set this to NULL. If id is + * set to LZMA_VLI_UNKNOWN, options is ignored, and thus + * doesn't need be initialized. + */ + void *options; + +} lzma_filter; + + +/** + * \brief Test if the given Filter ID is supported for encoding + * + * Return true if the give Filter ID is supported for encoding by this + * liblzma build. Otherwise false is returned. + * + * There is no way to list which filters are available in this particular + * liblzma version and build. It would be useless, because the application + * couldn't know what kind of options the filter would need. + */ +extern LZMA_API(lzma_bool) lzma_filter_encoder_is_supported(lzma_vli id) + lzma_nothrow lzma_attr_const; + + +/** + * \brief Test if the given Filter ID is supported for decoding + * + * Return true if the give Filter ID is supported for decoding by this + * liblzma build. Otherwise false is returned. + */ +extern LZMA_API(lzma_bool) lzma_filter_decoder_is_supported(lzma_vli id) + lzma_nothrow lzma_attr_const; + + +/** + * \brief Copy the filters array + * + * Copy the Filter IDs and filter-specific options from src to dest. + * Up to LZMA_FILTERS_MAX filters are copied, plus the terminating + * .id == LZMA_VLI_UNKNOWN. Thus, dest should have at least + * LZMA_FILTERS_MAX + 1 elements space unless the caller knows that + * src is smaller than that. + * + * Unless the filter-specific options is NULL, the Filter ID has to be + * supported by liblzma, because liblzma needs to know the size of every + * filter-specific options structure. The filter-specific options are not + * validated. If options is NULL, any unsupported Filter IDs are copied + * without returning an error. + * + * Old filter-specific options in dest are not freed, so dest doesn't + * need to be initialized by the caller in any way. + * + * If an error occurs, memory possibly already allocated by this function + * is always freed. + * + * \return - LZMA_OK + * - LZMA_MEM_ERROR + * - LZMA_OPTIONS_ERROR: Unsupported Filter ID and its options + * is not NULL. + * - LZMA_PROG_ERROR: src or dest is NULL. + */ +extern LZMA_API(lzma_ret) lzma_filters_copy( + const lzma_filter *src, lzma_filter *dest, + const lzma_allocator *allocator) lzma_nothrow; + + +/** + * \brief Calculate approximate memory requirements for raw encoder + * + * This function can be used to calculate the memory requirements for + * Block and Stream encoders too because Block and Stream encoders don't + * need significantly more memory than raw encoder. + * + * \param filters Array of filters terminated with + * .id == LZMA_VLI_UNKNOWN. + * + * \return Number of bytes of memory required for the given + * filter chain when encoding. If an error occurs, + * for example due to unsupported filter chain, + * UINT64_MAX is returned. + */ +extern LZMA_API(uint64_t) lzma_raw_encoder_memusage(const lzma_filter *filters) + lzma_nothrow lzma_attr_pure; + + +/** + * \brief Calculate approximate memory requirements for raw decoder + * + * This function can be used to calculate the memory requirements for + * Block and Stream decoders too because Block and Stream decoders don't + * need significantly more memory than raw decoder. + * + * \param filters Array of filters terminated with + * .id == LZMA_VLI_UNKNOWN. + * + * \return Number of bytes of memory required for the given + * filter chain when decoding. If an error occurs, + * for example due to unsupported filter chain, + * UINT64_MAX is returned. + */ +extern LZMA_API(uint64_t) lzma_raw_decoder_memusage(const lzma_filter *filters) + lzma_nothrow lzma_attr_pure; + + +/** + * \brief Initialize raw encoder + * + * This function may be useful when implementing custom file formats. + * + * \param strm Pointer to properly prepared lzma_stream + * \param filters Array of lzma_filter structures. The end of the + * array must be marked with .id = LZMA_VLI_UNKNOWN. + * + * The `action' with lzma_code() can be LZMA_RUN, LZMA_SYNC_FLUSH (if the + * filter chain supports it), or LZMA_FINISH. + * + * \return - LZMA_OK + * - LZMA_MEM_ERROR + * - LZMA_OPTIONS_ERROR + * - LZMA_PROG_ERROR + */ +extern LZMA_API(lzma_ret) lzma_raw_encoder( + lzma_stream *strm, const lzma_filter *filters) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Initialize raw decoder + * + * The initialization of raw decoder goes similarly to raw encoder. + * + * The `action' with lzma_code() can be LZMA_RUN or LZMA_FINISH. Using + * LZMA_FINISH is not required, it is supported just for convenience. + * + * \return - LZMA_OK + * - LZMA_MEM_ERROR + * - LZMA_OPTIONS_ERROR + * - LZMA_PROG_ERROR + */ +extern LZMA_API(lzma_ret) lzma_raw_decoder( + lzma_stream *strm, const lzma_filter *filters) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Update the filter chain in the encoder + * + * This function is for advanced users only. This function has two slightly + * different purposes: + * + * - After LZMA_FULL_FLUSH when using Stream encoder: Set a new filter + * chain, which will be used starting from the next Block. + * + * - After LZMA_SYNC_FLUSH using Raw, Block, or Stream encoder: Change + * the filter-specific options in the middle of encoding. The actual + * filters in the chain (Filter IDs) cannot be changed. In the future, + * it might become possible to change the filter options without + * using LZMA_SYNC_FLUSH. + * + * While rarely useful, this function may be called also when no data has + * been compressed yet. In that case, this function will behave as if + * LZMA_FULL_FLUSH (Stream encoder) or LZMA_SYNC_FLUSH (Raw or Block + * encoder) had been used right before calling this function. + * + * \return - LZMA_OK + * - LZMA_MEM_ERROR + * - LZMA_MEMLIMIT_ERROR + * - LZMA_OPTIONS_ERROR + * - LZMA_PROG_ERROR + */ +extern LZMA_API(lzma_ret) lzma_filters_update( + lzma_stream *strm, const lzma_filter *filters) lzma_nothrow; + + +/** + * \brief Single-call raw encoder + * + * \param filters Array of lzma_filter structures. The end of the + * array must be marked with .id = LZMA_VLI_UNKNOWN. + * \param allocator lzma_allocator for custom allocator functions. + * Set to NULL to use malloc() and free(). + * \param in Beginning of the input buffer + * \param in_size Size of the input buffer + * \param out Beginning of the output buffer + * \param out_pos The next byte will be written to out[*out_pos]. + * *out_pos is updated only if encoding succeeds. + * \param out_size Size of the out buffer; the first byte into + * which no data is written to is out[out_size]. + * + * \return - LZMA_OK: Encoding was successful. + * - LZMA_BUF_ERROR: Not enough output buffer space. + * - LZMA_OPTIONS_ERROR + * - LZMA_MEM_ERROR + * - LZMA_DATA_ERROR + * - LZMA_PROG_ERROR + * + * \note There is no function to calculate how big output buffer + * would surely be big enough. (lzma_stream_buffer_bound() + * works only for lzma_stream_buffer_encode(); raw encoder + * won't necessarily meet that bound.) + */ +extern LZMA_API(lzma_ret) lzma_raw_buffer_encode( + const lzma_filter *filters, const lzma_allocator *allocator, + const uint8_t *in, size_t in_size, uint8_t *out, + size_t *out_pos, size_t out_size) lzma_nothrow; + + +/** + * \brief Single-call raw decoder + * + * \param filters Array of lzma_filter structures. The end of the + * array must be marked with .id = LZMA_VLI_UNKNOWN. + * \param allocator lzma_allocator for custom allocator functions. + * Set to NULL to use malloc() and free(). + * \param in Beginning of the input buffer + * \param in_pos The next byte will be read from in[*in_pos]. + * *in_pos is updated only if decoding succeeds. + * \param in_size Size of the input buffer; the first byte that + * won't be read is in[in_size]. + * \param out Beginning of the output buffer + * \param out_pos The next byte will be written to out[*out_pos]. + * *out_pos is updated only if encoding succeeds. + * \param out_size Size of the out buffer; the first byte into + * which no data is written to is out[out_size]. + */ +extern LZMA_API(lzma_ret) lzma_raw_buffer_decode( + const lzma_filter *filters, const lzma_allocator *allocator, + const uint8_t *in, size_t *in_pos, size_t in_size, + uint8_t *out, size_t *out_pos, size_t out_size) lzma_nothrow; + + +/** + * \brief Get the size of the Filter Properties field + * + * This function may be useful when implementing custom file formats + * using the raw encoder and decoder. + * + * \param size Pointer to uint32_t to hold the size of the properties + * \param filter Filter ID and options (the size of the properties may + * vary depending on the options) + * + * \return - LZMA_OK + * - LZMA_OPTIONS_ERROR + * - LZMA_PROG_ERROR + * + * \note This function validates the Filter ID, but does not + * necessarily validate the options. Thus, it is possible + * that this returns LZMA_OK while the following call to + * lzma_properties_encode() returns LZMA_OPTIONS_ERROR. + */ +extern LZMA_API(lzma_ret) lzma_properties_size( + uint32_t *size, const lzma_filter *filter) lzma_nothrow; + + +/** + * \brief Encode the Filter Properties field + * + * \param filter Filter ID and options + * \param props Buffer to hold the encoded options. The size of + * buffer must have been already determined with + * lzma_properties_size(). + * + * \return - LZMA_OK + * - LZMA_OPTIONS_ERROR + * - LZMA_PROG_ERROR + * + * \note Even this function won't validate more options than actually + * necessary. Thus, it is possible that encoding the properties + * succeeds but using the same options to initialize the encoder + * will fail. + * + * \note If lzma_properties_size() indicated that the size + * of the Filter Properties field is zero, calling + * lzma_properties_encode() is not required, but it + * won't do any harm either. + */ +extern LZMA_API(lzma_ret) lzma_properties_encode( + const lzma_filter *filter, uint8_t *props) lzma_nothrow; + + +/** + * \brief Decode the Filter Properties field + * + * \param filter filter->id must have been set to the correct + * Filter ID. filter->options doesn't need to be + * initialized (it's not freed by this function). The + * decoded options will be stored to filter->options. + * filter->options is set to NULL if there are no + * properties or if an error occurs. + * \param allocator Custom memory allocator used to allocate the + * options. Set to NULL to use the default malloc(), + * and in case of an error, also free(). + * \param props Input buffer containing the properties. + * \param props_size Size of the properties. This must be the exact + * size; giving too much or too little input will + * return LZMA_OPTIONS_ERROR. + * + * \return - LZMA_OK + * - LZMA_OPTIONS_ERROR + * - LZMA_MEM_ERROR + */ +extern LZMA_API(lzma_ret) lzma_properties_decode( + lzma_filter *filter, const lzma_allocator *allocator, + const uint8_t *props, size_t props_size) lzma_nothrow; + + +/** + * \brief Calculate encoded size of a Filter Flags field + * + * Knowing the size of Filter Flags is useful to know when allocating + * memory to hold the encoded Filter Flags. + * + * \param size Pointer to integer to hold the calculated size + * \param filter Filter ID and associated options whose encoded + * size is to be calculated + * + * \return - LZMA_OK: *size set successfully. Note that this doesn't + * guarantee that filter->options is valid, thus + * lzma_filter_flags_encode() may still fail. + * - LZMA_OPTIONS_ERROR: Unknown Filter ID or unsupported options. + * - LZMA_PROG_ERROR: Invalid options + * + * \note If you need to calculate size of List of Filter Flags, + * you need to loop over every lzma_filter entry. + */ +extern LZMA_API(lzma_ret) lzma_filter_flags_size( + uint32_t *size, const lzma_filter *filter) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Encode Filter Flags into given buffer + * + * In contrast to some functions, this doesn't allocate the needed buffer. + * This is due to how this function is used internally by liblzma. + * + * \param filter Filter ID and options to be encoded + * \param out Beginning of the output buffer + * \param out_pos out[*out_pos] is the next write position. This + * is updated by the encoder. + * \param out_size out[out_size] is the first byte to not write. + * + * \return - LZMA_OK: Encoding was successful. + * - LZMA_OPTIONS_ERROR: Invalid or unsupported options. + * - LZMA_PROG_ERROR: Invalid options or not enough output + * buffer space (you should have checked it with + * lzma_filter_flags_size()). + */ +extern LZMA_API(lzma_ret) lzma_filter_flags_encode(const lzma_filter *filter, + uint8_t *out, size_t *out_pos, size_t out_size) + lzma_nothrow lzma_attr_warn_unused_result; + + +/** + * \brief Decode Filter Flags from given buffer + * + * The decoded result is stored into *filter. The old value of + * filter->options is not free()d. + * + * \return - LZMA_OK + * - LZMA_OPTIONS_ERROR + * - LZMA_MEM_ERROR + * - LZMA_PROG_ERROR + */ +extern LZMA_API(lzma_ret) lzma_filter_flags_decode( + lzma_filter *filter, const lzma_allocator *allocator, + const uint8_t *in, size_t *in_pos, size_t in_size) + lzma_nothrow lzma_attr_warn_unused_result;