diff options
Diffstat (limited to 'src/liblzma/api/lzma/lzma.h')
| -rw-r--r-- | src/liblzma/api/lzma/lzma.h | 222 |
1 files changed, 131 insertions, 91 deletions
diff --git a/src/liblzma/api/lzma/lzma.h b/src/liblzma/api/lzma/lzma.h index 9473f448..5a1cd912 100644 --- a/src/liblzma/api/lzma/lzma.h +++ b/src/liblzma/api/lzma/lzma.h @@ -24,43 +24,11 @@ /** * \brief Filter ID * - * Filter ID of the LZMA filter. This is used as lzma_options_filter.id. + * Filter ID of the LZMA filter. This is used as lzma_filter.id. */ #define LZMA_FILTER_LZMA LZMA_VLI_C(0x40) - -/** - * \brief LZMA compression modes - * - * Currently there are only two modes. Earlier LZMA SDKs had also third - * mode between fast and best. - */ -typedef enum { - LZMA_MODE_INVALID = -1, - /**< - * \brief Invalid mode - * - * Used as array terminator in lzma_available_modes. - */ - - - LZMA_MODE_FAST = 0, - /**< - * \brief Fast compression - * - * Fast mode is usually at its best when combined with - * a hash chain match finder. - */ - - LZMA_MODE_BEST = 2 - /**< - * \brief Best compression ratio - * - * This is usually notably slower than fast mode. Use this - * together with binary tree match finders to expose the - * full potential of the LZMA encoder. - */ -} lzma_mode; +#define LZMA_FILTER_LZMA2 LZMA_VLI_C(0x21) /** @@ -129,6 +97,72 @@ typedef enum { /** + * \brief Test if given match finder is supported + * + * Returns true if the given match finder is supported by this liblzma build. + * Otherwise false is returned. It is safe to call this with a value that + * isn't listed in lzma_match_finder enumeration; the return value will be + * false. + * + * There is no way to list which match finders are available in this + * particular liblzma version and build. It would be useless, because + * a new match finder, which the application developer wasn't aware, + * could require giving additional options to the encoder that the older + * match finders don't need. + */ +extern lzma_bool lzma_mf_is_supported(lzma_match_finder match_finder) + lzma_attr_const; + + +/** + * \brief LZMA compression modes + * + * This selects the function used to analyze the data produced by the match + * finder. + */ +typedef enum { + LZMA_MODE_INVALID = -1, + /**< + * \brief Invalid mode + * + * Used as array terminator in lzma_available_modes. + */ + + LZMA_MODE_FAST = 0, + /**< + * \brief Fast compression + * + * Fast mode is usually at its best when combined with + * a hash chain match finder. + */ + + LZMA_MODE_NORMAL = 1 + /**< + * \brief Normal compression + * + * This is usually notably slower than fast mode. Use this + * together with binary tree match finders to expose the + * full potential of the LZMA encoder. + */ +} lzma_mode; + + +/** + * \brief Test if given compression mode is supported + * + * Returns true if the given compression mode is supported by this liblzma + * build. Otherwise false is returned. It is safe to call this with a value + * that isn't listed in lzma_mode enumeration; the return value will be false. + * + * There is no way to list which modes are available in this particular + * liblzma version and build. It would be useless, because a new compression + * mode, which the application developer wasn't aware, could require giving + * additional options to the encoder that the older modes don't need. + */ +extern lzma_bool lzma_mode_is_available(lzma_mode mode) lzma_attr_const; + + +/** * \brief Options specific to the LZMA method handler */ typedef struct { @@ -157,6 +191,44 @@ typedef struct { # define LZMA_DICTIONARY_SIZE_DEFAULT (UINT32_C(1) << 23) /** + * \brief Pointer to an initial dictionary + * + * It is possible to initialize the LZ77 history window using + * a preset dictionary. Here is a good quote from zlib's + * documentation; this applies to LZMA as is: + * + * "The dictionary should consist of strings (byte sequences) that + * are likely to be encountered later in the data to be compressed, + * with the most commonly used strings preferably put towards the + * end of the dictionary. Using a dictionary is most useful when + * the data to be compressed is short and can be predicted with + * good accuracy; the data can then be compressed better than + * with the default empty dictionary." + * (From deflateSetDictionary() in zlib.h of zlib version 1.2.3) + * + * This feature should be used only in special situations. + * It works correctly only with raw encoding and decoding. + * Currently none of the container formats supported by + * liblzma allow preset dictionary when decoding, thus if + * you create a .lzma file with preset dictionary, it cannot + * be decoded with the regular .lzma decoder functions. + * + * \todo This feature is not implemented yet. + */ + const uint8_t *preset_dictionary; + + /** + * \brief Size of the preset dictionary + * + * Specifies the size of the preset dictionary. If the size is + * bigger than dictionary_size, only the last dictionary_size + * bytes are processed. + * + * This variable is read only when preset_dictionary is not NULL. + */ + uint32_t preset_dictionary_size; + + /** * \brief Number of literal context bits * * How many of the highest bits of the previous uncompressed @@ -203,47 +275,22 @@ typedef struct { # define LZMA_POS_BITS_MAX 4 # define LZMA_POS_BITS_DEFAULT 2 - /** - * \brief Pointer to an initial dictionary - * - * It is possible to initialize the LZ77 history window using - * a preset dictionary. Here is a good quote from zlib's - * documentation; this applies to LZMA as is: - * - * "The dictionary should consist of strings (byte sequences) that - * are likely to be encountered later in the data to be compressed, - * with the most commonly used strings preferably put towards the - * end of the dictionary. Using a dictionary is most useful when - * the data to be compressed is short and can be predicted with - * good accuracy; the data can then be compressed better than - * with the default empty dictionary." - * (From deflateSetDictionary() in zlib.h of zlib version 1.2.3) - * - * This feature should be used only in special situations. - * It works correctly only with raw encoding and decoding. - * Currently none of the container formats supported by - * liblzma allow preset dictionary when decoding, thus if - * you create a .lzma file with preset dictionary, it cannot - * be decoded with the regular .lzma decoder functions. - * - * \todo This feature is not implemented yet. - */ - const uint8_t *preset_dictionary; + /****************************************** + * LZMA options needed only when encoding * + ******************************************/ /** - * \brief Size of the preset dictionary + * \brief Indicate if the options structure is persistent * - * Specifies the size of the preset dictionary. If the size is - * bigger than dictionary_size, only the last dictionary_size - * bytes are processed. + * If this is true, the application must keep this options structure + * available after the LZMA2 encoder has been initialized. With + * persistent structure it is possible to change some encoder options + * in the middle of the encoding process without resetting the encoder. * - * This variable is read only when preset_dictionary is not NULL. + * This option is used only by LZMA2. LZMA1 ignores this and it is + * safeto not initialize this when encoding with LZMA1. */ - uint32_t preset_dictionary_size; - - /****************************************** - * LZMA options needed only when encoding * - ******************************************/ + lzma_bool persistent; /** LZMA compression mode */ lzma_mode mode; @@ -275,6 +322,20 @@ typedef struct { */ uint32_t match_finder_cycles; + /** + * \brief Reserved space for possible future extensions + * + * You should not touch these, because the names of these variables + * may change. These are and will never be used with the currently + * supported options, so it is safe to leave these uninitialized. + */ + uint32_t reserved_int1; + uint32_t reserved_int2; + uint32_t reserved_int3; + uint32_t reserved_int4; + void *reserved_ptr1; + void *reserved_ptr2; + } lzma_options_lzma; @@ -287,27 +348,6 @@ typedef struct { /** - * \brief Available LZMA encoding modes - * - * Pointer to an array containing the list of available encoding modes. - * - * This variable is available only if LZMA encoder has been enabled. - */ -extern const lzma_mode *const lzma_available_modes; - - -/** - * \brief Available match finders - * - * Pointer to an array containing the list of available match finders. - * The last element is LZMA_MF_INVALID. - * - * This variable is available only if LZMA encoder has been enabled. - */ -extern const lzma_match_finder *const lzma_available_match_finders; - - -/** * \brief Table of presets for the LZMA filter * * lzma_preset_lzma[0] is the fastest and lzma_preset_lzma[8] is the slowest. |