* 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.
# error Never include this file directly. Use <lzma.h> instead.
* \brief Default compression preset
* It's not straightforward to recommend a default preset, because in some
* cases keeping the resource usage relatively low is more important that
* getting the maximum compression ratio.
#define LZMA_PRESET_DEFAULT UINT32_C(6)
* \brief Mask for preset level
* This is useful only if you need to extract the level from the preset
* variable. That should be rare.
#define LZMA_PRESET_LEVEL_MASK UINT32_C(0x1F)
* Currently only one flag is defined.
* \brief Extreme compression preset
* This flag modifies the preset to make the encoding significantly slower
* while improving the compression ratio only marginally. This is useful
* when you don't mind wasting time to get as small result as possible.
* This flag doesn't affect the memory usage requirements of the decoder (at
* least not significantly). The memory usage of the encoder may be increased
* a little but only at the lowest preset levels (0-3).
#define LZMA_PRESET_EXTREME (UINT32_C(1) << 31)
* \brief Multithreading options
* Set this to zero if no flags are wanted.
* No flags are currently supported.
* \brief Number of worker threads to use
* \brief Maximum uncompressed size of a Block
* The encoder will start a new .xz Block every block_size bytes.
* Using LZMA_FULL_FLUSH or LZMA_FULL_BARRIER with lzma_code()
* the caller may tell liblzma to start a new Block earlier.
* With LZMA2, a recommended block size is 2-4 times the LZMA2
* dictionary size. With very small dictionaries, it is recommended
* to use at least 1 MiB block size for good compression ratio, even
* if this is more than four times the dictionary size. Note that
* these are only recommendations for typical use cases; feel free
* to use other values. Just keep in mind that using a block size
* less than the LZMA2 dictionary size is waste of RAM.
* Set this to 0 to let liblzma choose the block size depending
* on the compression options. For LZMA2 it will be 3*dict_size
* or 1 MiB, whichever is more.
* For each thread, about 3 * block_size bytes of memory will be
* allocated. This may change in later liblzma versions. If so,
* the memory usage will probably be reduced, not increased.
* \brief Timeout to allow lzma_code() to return early
* Multithreading can make liblzma to consume input and produce
* output in a very bursty way: it may first read a lot of input
* to fill internal buffers, then no input or output occurs for
* In single-threaded mode, lzma_code() won't return until it has
* either consumed all the input or filled the output buffer. If
* this is done in multithreaded mode, it may cause a call
* lzma_code() to take even tens of seconds, which isn't acceptable
* To avoid very long blocking times in lzma_code(), a timeout
* (in milliseconds) may be set here. If lzma_code() would block
* longer than this number of milliseconds, it will return with
* LZMA_OK. Reasonable values are 100 ms or more. The xz command
* If long blocking times are fine for you, set timeout to a special
* value of 0, which will disable the timeout mechanism and will make
* lzma_code() block until all the input is consumed or the output
* buffer has been filled.
* \note Even with a timeout, lzma_code() might sometimes take
* somewhat long time to return. No timing guarantees
* \brief Compression preset (level and possible flags)
* The preset is set just like with lzma_easy_encoder().
* The preset is ignored if filters below is non-NULL.
* \brief Filter chain (alternative to a preset)
* If this is NULL, the preset above is used. Otherwise the preset
* is ignored and the filter chain specified here is used.
const lzma_filter *filters;
* \brief Integrity check type
* See check.h for available checks. The xz command line tool
* defaults to LZMA_CHECK_CRC64, which is a good choice if you
* Reserved space to allow possible future extensions without
* breaking the ABI. 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
lzma_reserved_enum reserved_enum1;
lzma_reserved_enum reserved_enum2;
lzma_reserved_enum reserved_enum3;
* \brief Calculate approximate memory usage of easy encoder
* This function is a wrapper for lzma_raw_encoder_memusage().
* \param preset Compression preset (level and possible flags)
* \return Number of bytes of memory required for the given
* preset when encoding. If an error occurs, for example
* due to unsupported preset, UINT64_MAX is returned.
extern LZMA_API(uint64_t) lzma_easy_encoder_memusage(uint32_t preset)
lzma_nothrow lzma_attr_pure;
* \brief Calculate approximate decoder memory usage of a preset
* This function is a wrapper for lzma_raw_decoder_memusage().
* \param preset Compression preset (level and possible flags)
* \return Number of bytes of memory required to decompress a file
* that was compressed using the given preset. If an error
* occurs, for example due to unsupported preset, UINT64_MAX
extern LZMA_API(uint64_t) lzma_easy_decoder_memusage(uint32_t preset)
lzma_nothrow lzma_attr_pure;
* \brief Initialize .xz Stream encoder using a preset number
* This function is intended for those who just want to use the basic features
* if liblzma (that is, most developers out there).
* \param strm Pointer to lzma_stream that is at least initialized
* \param preset Compression preset to use. A preset consist of level
* number and zero or more flags. Usually flags aren't
* used, so preset is simply a number [0, 9] which match
* the options -0 ... -9 of the xz command line tool.
* Additional flags can be be set using bitwise-or with
* the preset level number, e.g. 6 | LZMA_PRESET_EXTREME.
* \param check Integrity check type to use. See check.h for available
* checks. The xz command line tool defaults to
* LZMA_CHECK_CRC64, which is a good choice if you are
* unsure. LZMA_CHECK_CRC32 is good too as long as the
* uncompressed file is not many gigabytes.
* \return - LZMA_OK: Initialization succeeded. Use lzma_code() to
* - LZMA_MEM_ERROR: Memory allocation failed.
* - LZMA_OPTIONS_ERROR: The given compression preset is not
* supported by this build of liblzma.
* - LZMA_UNSUPPORTED_CHECK: The given check type is not
* supported by this liblzma build.
* - LZMA_PROG_ERROR: One or more of the parameters have values
* that will never be valid. For example, strm == NULL.
* If initialization fails (return value is not LZMA_OK), all the memory
* allocated for *strm by liblzma is always freed. Thus, there is no need
* to call lzma_end() after failed initialization.
* If initialization succeeds, use lzma_code() to do the actual encoding.
* Valid values for `action' (the second argument of lzma_code()) are
* LZMA_RUN, LZMA_SYNC_FLUSH, LZMA_FULL_FLUSH, and LZMA_FINISH. In future,
* there may be compression levels or flags that don't support LZMA_SYNC_FLUSH.
extern LZMA_API(lzma_ret) lzma_easy_encoder(
lzma_stream *strm, uint32_t preset, lzma_check check)
lzma_nothrow lzma_attr_warn_unused_result;
* \brief Single-call .xz Stream encoding using a preset number
* The maximum required output buffer size can be calculated with
* lzma_stream_buffer_bound().
* \param preset Compression preset to use. See the description
* in lzma_easy_encoder().
* \param check Type of the integrity check to calculate from
* \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_UNSUPPORTED_CHECK
extern LZMA_API(lzma_ret) lzma_easy_buffer_encode(
uint32_t preset, lzma_check check,
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 Initialize .xz Stream encoder using a custom filter chain
* \param strm Pointer to properly prepared lzma_stream
* \param filters Array of filters. This must be terminated with
* filters[n].id = LZMA_VLI_UNKNOWN. See filter.h for
* \param check Type of the integrity check to calculate from
* \return - LZMA_OK: Initialization was successful.
* - LZMA_UNSUPPORTED_CHECK
extern LZMA_API(lzma_ret) lzma_stream_encoder(lzma_stream *strm,
const lzma_filter *filters, lzma_check check)
lzma_nothrow lzma_attr_warn_unused_result;
* \brief Calculate approximate memory usage of multithreaded .xz encoder
* Since doing the encoding in threaded mode doesn't affect the memory
* requirements of single-threaded decompressor, you can use
* lzma_easy_decoder_memusage(options->preset) or
* lzma_raw_decoder_memusage(options->filters) to calculate
* the decompressor memory requirements.
* \param options Compression options
* \return Number of bytes of memory required for encoding with the
* given options. If an error occurs, for example due to
* unsupported preset or filter chain, UINT64_MAX is returned.
extern LZMA_API(uint64_t) lzma_stream_encoder_mt_memusage(
const lzma_mt *options) lzma_nothrow lzma_attr_pure;
* \brief Initialize multithreaded .xz Stream encoder
* This provides the functionality of lzma_easy_encoder() and
* lzma_stream_encoder() as a single function for multithreaded use.
* The supported actions for lzma_code() are LZMA_RUN, LZMA_FULL_FLUSH,
* LZMA_FULL_BARRIER, and LZMA_FINISH. Support for LZMA_SYNC_FLUSH might be
* \param strm Pointer to properly prepared lzma_stream
* \param options Pointer to multithreaded compression options
* - LZMA_UNSUPPORTED_CHECK
extern LZMA_API(lzma_ret) lzma_stream_encoder_mt(
lzma_stream *strm, const lzma_mt *options)
lzma_nothrow lzma_attr_warn_unused_result;
* \brief Initialize .lzma encoder (legacy file format)
* The .lzma format is sometimes called the LZMA_Alone format, which is the
* reason for the name of this function. The .lzma format supports only the
* LZMA1 filter. There is no support for integrity checks like CRC32.
* Use this function if and only if you need to create files readable by
* legacy LZMA tools such as LZMA Utils 4.32.x. Moving to the .xz format
* is strongly recommended.
* The valid action values for lzma_code() are LZMA_RUN and LZMA_FINISH.
* No kind of flushing is supported, because the file format doesn't make
extern LZMA_API(lzma_ret) lzma_alone_encoder(
lzma_stream *strm, const lzma_options_lzma *options)
lzma_nothrow lzma_attr_warn_unused_result;
* \brief Calculate output buffer size for single-call Stream encoder
* When trying to compress uncompressible data, the encoded size will be
* slightly bigger than the input data. This function calculates how much
* output buffer space is required to be sure that lzma_stream_buffer_encode()
* doesn't return LZMA_BUF_ERROR.
* The calculated value is not exact, but it is guaranteed to be big enough.
* The actual maximum output space required may be slightly smaller (up to
* about 100 bytes). This should not be a problem in practice.
* If the calculated maximum size doesn't fit into size_t or would make the
* Stream grow past LZMA_VLI_MAX (which should never happen in practice),
* zero is returned to indicate the error.
* \note The limit calculated by this function applies only to
* single-call encoding. Multi-call encoding may (and probably
* will) have larger maximum expansion when encoding
* uncompressible data. Currently there is no function to
* calculate the maximum expansion of multi-call encoding.
extern LZMA_API(size_t) lzma_stream_buffer_bound(size_t uncompressed_size)
* \brief Single-call .xz Stream encoder
* \param filters Array of filters. This must be terminated with
* filters[n].id = LZMA_VLI_UNKNOWN. See filter.h
* \param check Type of the integrity check to calculate from
* \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_UNSUPPORTED_CHECK
extern LZMA_API(lzma_ret) lzma_stream_buffer_encode(
lzma_filter *filters, lzma_check check,
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 lzma_attr_warn_unused_result;
* This flag makes lzma_code() return LZMA_NO_CHECK if the input stream
* being decoded has no integrity check. Note that when used with
* lzma_auto_decoder(), all .lzma files will trigger LZMA_NO_CHECK
* if LZMA_TELL_NO_CHECK is used.
#define LZMA_TELL_NO_CHECK UINT32_C(0x01)
* This flag makes lzma_code() return LZMA_UNSUPPORTED_CHECK if the input
* stream has an integrity check, but the type of the integrity check is not
* supported by this liblzma version or build. Such files can still be
* decoded, but the integrity check cannot be verified.
#define LZMA_TELL_UNSUPPORTED_CHECK UINT32_C(0x02)
* This flag makes lzma_code() return LZMA_GET_CHECK as soon as the type
* of the integrity check is known. The type can then be got with
#define LZMA_TELL_ANY_CHECK UINT32_C(0x04)
* This flag makes lzma_code() not calculate and verify the integrity check
* of the compressed data in .xz files. This means that invalid integrity
* check values won't be detected and LZMA_DATA_ERROR won't be returned in
* This flag only affects the checks of the compressed data itself; the CRC32
* values in the .xz headers will still be verified normally.
* Don't use this flag unless you know what you are doing. Possible reasons
* - Trying to recover data from a corrupt .xz file.
* - Speeding up decompression, which matters mostly with SHA-256
* or with files that have compressed extremely well. It's recommended
* to not use this flag for this purpose unless the file integrity is
* verified externally in some other way.
* Support for this flag was added in liblzma 5.1.4beta.
#define LZMA_IGNORE_CHECK UINT32_C(0x10)
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