mirror of https://git.tukaani.org/xz.git
344 lines
12 KiB
C
344 lines
12 KiB
C
/**
|
|
* \file lzma/filter.h
|
|
* \brief Common filter related types
|
|
*/
|
|
|
|
/*
|
|
* 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 <lzma.h> 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. An array of lzma_filter structures is used to define 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.
|
|
*/
|
|
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.
|
|
*
|
|
* Some filters support changing the options in the middle of
|
|
* the encoding process. These filters store the pointer of the
|
|
* options structure and communicate with the application via
|
|
* modifications of the options structure.
|
|
*/
|
|
void *options;
|
|
|
|
} lzma_filter;
|
|
|
|
|
|
/**
|
|
* \brief Test if the given Filter ID is supported for encoding
|
|
*
|
|
* Returns 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);
|
|
|
|
|
|
/**
|
|
* \brief Test if the given Filter ID is supported for decoding
|
|
*
|
|
* Returns 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);
|
|
|
|
|
|
/**
|
|
* \brief Calculate rough memory requirements for raw encoder
|
|
*
|
|
* \param filters Array of filters terminated with
|
|
* .id == LZMA_VLI_UNKNOWN.
|
|
*
|
|
* \return Rough number of bytes required for the given filter chain
|
|
* when encoding.
|
|
*/
|
|
extern LZMA_API(uint64_t) lzma_raw_encoder_memusage(const lzma_filter *filters)
|
|
lzma_attr_pure;
|
|
|
|
|
|
/**
|
|
* \brief Calculate rough memory requirements for raw decoder
|
|
*
|
|
* \param filters Array of filters terminated with
|
|
* .id == LZMA_VLI_UNKNOWN.
|
|
*
|
|
* \return Rough number of bytes required for the given filter chain
|
|
* when decoding.
|
|
*/
|
|
extern LZMA_API(uint64_t) lzma_raw_decoder_memusage(const lzma_filter *filters)
|
|
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 minimum
|
|
* number of filters is one and the maximum is four.
|
|
*
|
|
* 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_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_attr_warn_unused_result;
|
|
|
|
|
|
/**
|
|
* \brief Single-call raw encoder
|
|
*
|
|
* \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
|
|
*/
|
|
extern LZMA_API(lzma_ret) lzma_raw_buffer_encode(
|
|
const lzma_filter *filters, lzma_allocator *allocator,
|
|
const uint8_t *in, size_t in_size, uint8_t *out,
|
|
size_t *out_pos, size_t out_size);
|
|
|
|
|
|
/**
|
|
* \brief Single-call raw decoder
|
|
*
|
|
* \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, 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);
|
|
|
|
|
|
/**
|
|
* \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 propeties 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);
|
|
|
|
|
|
/**
|
|
* \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 It is OK to skip calling this function if
|
|
* lzma_properties_size() indicated that the size
|
|
* of the Filter Properties field is zero.
|
|
*/
|
|
extern LZMA_API(lzma_ret) lzma_properties_encode(
|
|
const lzma_filter *filter, uint8_t *props);
|
|
|
|
|
|
/**
|
|
* \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, lzma_allocator *allocator,
|
|
const uint8_t *props, size_t props_size);
|
|
|
|
|
|
/**
|
|
* \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 filters Filter ID and associated options whose encoded
|
|
* size is to be calculted
|
|
*
|
|
* \return - LZMA_OK: *size set successfully. Note that this doesn't
|
|
* guarantee that filters->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 *filters)
|
|
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 filters 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 *filters,
|
|
uint8_t *out, size_t *out_pos, size_t out_size)
|
|
lzma_attr_warn_unused_result;
|
|
|
|
|
|
/**
|
|
* \brief Decode Filter Flags from given buffer
|
|
*
|
|
* The decoded result is stored into *filters. filters->options is
|
|
* initialized but the old value 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 *filters, lzma_allocator *allocator,
|
|
const uint8_t *in, size_t *in_pos, size_t in_size)
|
|
lzma_attr_warn_unused_result;
|