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 /* SPDX-License-Identifier: 0BSD */
 
 /**
  * \file        lzma/container.h
  * \brief       File formats
  * \note        Never include this file directly. Use <lzma.h> instead.
  */
 
 /*
  * Author: Lasse Collin
  */
 
 #ifndef LZMA_H_INTERNAL
 #   error Never include this file directly. Use <lzma.h> instead.
 #endif
 
 
 /************
  * Encoding *
  ************/
 
 /**
  * \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)
 
 
 /*
  * Preset flags
  *
  * 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 spending 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
  */
 typedef struct {
     /**
      * \brief       Flags
      *
      * Set this to zero if no flags are wanted.
      *
      * Encoder: No flags are currently supported.
      *
      * Decoder: Bitwise-or of zero or more of the decoder flags:
      * - LZMA_TELL_NO_CHECK
      * - LZMA_TELL_UNSUPPORTED_CHECK
      * - LZMA_TELL_ANY_CHECK
      * - LZMA_IGNORE_CHECK
      * - LZMA_CONCATENATED
      * - LZMA_FAIL_FAST
      */
     uint32_t flags;
 
     /**
      * \brief       Number of worker threads to use
      */
     uint32_t threads;
 
     /**
      * \brief       Encoder only: 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.
      */
     uint64_t block_size;
 
     /**
      * \brief       Timeout to allow lzma_code() to return early
      *
      * Multithreading can make liblzma 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
      * a while.
      *
      * 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
      * in all applications.
      *
      * 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
      * line tool uses 300 ms.
      *
      * If long blocking times are acceptable, set timeout to a special
      * value of 0. This 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
      *              a long time to return. No timing guarantees are made.
      */
     uint32_t timeout;
 
     /**
      * \brief       Encoder only: Compression preset
      *
      * The preset is set just like with lzma_easy_encoder().
      * The preset is ignored if filters below is non-NULL.
      */
     uint32_t preset;
 
     /**
      * \brief       Encoder only: 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       Encoder only: 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
      * are unsure.
      */
     lzma_check check;
 
     /*
      * 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
      * uninitialized.
      */
     /** \private     Reserved member. */
     lzma_reserved_enum reserved_enum1;
 
     /** \private     Reserved member. */
     lzma_reserved_enum reserved_enum2;
 
     /** \private     Reserved member. */
     lzma_reserved_enum reserved_enum3;
 
     /** \private     Reserved member. */
     uint32_t reserved_int1;
 
     /** \private     Reserved member. */
     uint32_t reserved_int2;
 
     /** \private     Reserved member. */
     uint32_t reserved_int3;
 
     /** \private     Reserved member. */
     uint32_t reserved_int4;
 
     /**
      * \brief       Memory usage limit to reduce the number of threads
      *
      * Encoder: Ignored.
      *
      * Decoder:
      *
      * If the number of threads has been set so high that more than
      * memlimit_threading bytes of memory would be needed, the number
      * of threads will be reduced so that the memory usage will not exceed
      * memlimit_threading bytes. However, if memlimit_threading cannot
      * be met even in single-threaded mode, then decoding will continue
      * in single-threaded mode and memlimit_threading may be exceeded
      * even by a large amount. That is, memlimit_threading will never make
      * lzma_code() return LZMA_MEMLIMIT_ERROR. To truly cap the memory
      * usage, see memlimit_stop below.
      *
      * Setting memlimit_threading to UINT64_MAX or a similar huge value
      * means that liblzma is allowed to keep the whole compressed file
      * and the whole uncompressed file in memory in addition to the memory
      * needed by the decompressor data structures used by each thread!
      * In other words, a reasonable value limit must be set here or it
      * will cause problems sooner or later. If you have no idea what
      * a reasonable value could be, try lzma_physmem() / 4 as a starting
      * point. Setting this limit will never prevent decompression of
      * a file; this will only reduce the number of threads.
      *
      * If memlimit_threading is greater than memlimit_stop, then the value
      * of memlimit_stop will be used for both.
      */
     uint64_t memlimit_threading;
 
     /**
      * \brief       Memory usage limit that should never be exceeded
      *
      * Encoder: Ignored.
      *
      * Decoder: If decompressing will need more than this amount of
      * memory even in the single-threaded mode, then lzma_code() will
      * return LZMA_MEMLIMIT_ERROR.
      */
     uint64_t memlimit_stop;
 
     /** \private     Reserved member. */
     uint64_t reserved_int7;
 
     /** \private     Reserved member. */
     uint64_t reserved_int8;
 
     /** \private     Reserved member. */
     void *reserved_ptr1;
 
     /** \private     Reserved member. */
     void *reserved_ptr2;
 
     /** \private     Reserved member. */
     void *reserved_ptr3;
 
     /** \private     Reserved member. */
     void *reserved_ptr4;
 
 } lzma_mt;
 
 
 /**
  * \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 or UINT64_MAX on error.
  */
 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 or UINT64_MAX
  *              on error.
  */
 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
  * of liblzma (that is, most developers out there).
  *
  * 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.
  *
  * \param       strm    Pointer to lzma_stream that is at least initialized
  *                      with LZMA_STREAM_INIT.
  * \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 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      Possible lzma_ret values:
  *              - LZMA_OK: Initialization succeeded. Use lzma_code() to
  *                encode your data.
  *              - 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.
  */
 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
  *                          uncompressed data.
  * \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]  out         Beginning of the output buffer
  * \param[out]  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      Possible lzma_ret values:
  *              - LZMA_OK: Encoding was successful.
  *              - LZMA_BUF_ERROR: Not enough output buffer space.
  *              - LZMA_UNSUPPORTED_CHECK
  *              - LZMA_OPTIONS_ERROR
  *              - LZMA_MEM_ERROR
  *              - LZMA_DATA_ERROR
  *              - LZMA_PROG_ERROR
  */
 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 lzma_stream that is at least initialized
  *                      with LZMA_STREAM_INIT.
  * \param       filters Array of filters terminated with
  *                      .id == LZMA_VLI_UNKNOWN. See filters.h for more
  *                      information.
  * \param       check   Type of the integrity check to calculate from
  *                      uncompressed data.
  *
  * \return      Possible lzma_ret values:
  *              - LZMA_OK: Initialization was successful.
  *              - LZMA_MEM_ERROR
  *              - LZMA_UNSUPPORTED_CHECK
  *              - LZMA_OPTIONS_ERROR
  *              - LZMA_PROG_ERROR
  */
 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
  * added in the future.
  *
  * \param       strm    Pointer to lzma_stream that is at least initialized
  *                      with LZMA_STREAM_INIT.
  * \param       options Pointer to multithreaded compression options
  *
  * \return      Possible lzma_ret values:
  *              - LZMA_OK
  *              - LZMA_MEM_ERROR
  *              - LZMA_UNSUPPORTED_CHECK
  *              - LZMA_OPTIONS_ERROR
  *              - LZMA_PROG_ERROR
  */
 extern LZMA_API(lzma_ret) lzma_stream_encoder_mt(
         lzma_stream *strm, const lzma_mt *options)
         lzma_nothrow lzma_attr_warn_unused_result;
 
 
 /**
  * \brief       Calculate recommended Block size for multithreaded .xz encoder
  *
  * This calculates a recommended Block size for multithreaded encoding given
  * a filter chain. This is used internally by lzma_stream_encoder_mt() to
  * determine the Block size if the block_size member is not set to the
  * special value of 0 in the lzma_mt options struct.
  *
  * If one wishes to change the filters between Blocks, this function is
  * helpful to set the block_size member of the lzma_mt struct before calling
  * lzma_stream_encoder_mt(). Since the block_size member represents the
  * maximum possible Block size for the multithreaded .xz encoder, one can
  * use this function to find the maximum recommended Block size based on
  * all planned filter chains. Otherwise, the multithreaded encoder will
  * base its maximum Block size on the first filter chain used (if the
  * block_size member is not set), which may unnecessarily limit the Block
  * size for a later filter chain.
  *
  * \param       filters   Array of filters terminated with
  *                        .id == LZMA_VLI_UNKNOWN.
  *
  * \return      Recommended Block size in bytes, or UINT64_MAX if
  *              an error occurred.
  */
 extern LZMA_API(uint64_t) lzma_mt_block_size(const lzma_filter *filters)
         lzma_nothrow;
 
 
 /**
  * \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
  * it possible.
  *
  * \param       strm    Pointer to lzma_stream that is at least initialized
  *                      with LZMA_STREAM_INIT.
  * \param       options Pointer to encoder options
  *
  * \return      Possible lzma_ret values:
  *              - LZMA_OK
  *              - LZMA_MEM_ERROR
  *              - LZMA_OPTIONS_ERROR
  *              - LZMA_PROG_ERROR
  */
 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 incompressible 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
  *              incompressible data. Currently there is no function to
  *              calculate the maximum expansion of multi-call encoding.
  *
  * \param       uncompressed_size   Size in bytes of the uncompressed
  *                                  input data
  *
  * \return      Maximum number of bytes needed to store the compressed data.
  */
 extern LZMA_API(size_t) lzma_stream_buffer_bound(size_t uncompressed_size)
         lzma_nothrow;
 
 
 /**
  * \brief       Single-call .xz Stream encoder
  *
  * \param       filters     Array of filters terminated with
  *                          .id == LZMA_VLI_UNKNOWN. See filters.h for more
  *                          information.
  * \param       check       Type of the integrity check to calculate from
  *                          uncompressed data.
  * \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]  out         Beginning of the output buffer
  * \param[out]  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      Possible lzma_ret values:
  *              - LZMA_OK: Encoding was successful.
  *              - LZMA_BUF_ERROR: Not enough output buffer space.
  *              - LZMA_UNSUPPORTED_CHECK
  *              - LZMA_OPTIONS_ERROR
  *              - LZMA_MEM_ERROR
  *              - LZMA_DATA_ERROR
  *              - LZMA_PROG_ERROR
  */
 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;
 
 
 /**
  * \brief       MicroLZMA encoder
  *
  * The MicroLZMA format is a raw LZMA stream whose first byte (always 0x00)
  * has been replaced with bitwise-negation of the LZMA properties (lc/lp/pb).
  * This encoding ensures that the first byte of MicroLZMA stream is never
  * 0x00. There is no end of payload marker and thus the uncompressed size
  * must be stored separately. For the best error detection the dictionary
  * size should be stored separately as well but alternatively one may use
  * the uncompressed size as the dictionary size when decoding.
  *
  * With the MicroLZMA encoder, lzma_code() behaves slightly unusually.
  * The action argument must be LZMA_FINISH and the return value will never be
  * LZMA_OK. Thus the encoding is always done with a single lzma_code() after
  * the initialization. The benefit of the combination of initialization
  * function and lzma_code() is that memory allocations can be re-used for
  * better performance.
  *
  * lzma_code() will try to encode as much input as is possible to fit into
  * the given output buffer. If not all input can be encoded, the stream will
  * be finished without encoding all the input. The caller must check both
  * input and output buffer usage after lzma_code() (total_in and total_out
  * in lzma_stream can be convenient). Often lzma_code() can fill the output
  * buffer completely if there is a lot of input, but sometimes a few bytes
  * may remain unused because the next LZMA symbol would require more space.
  *
  * lzma_stream.avail_out must be at least 6. Otherwise LZMA_PROG_ERROR
  * will be returned.
  *
  * The LZMA dictionary should be reasonably low to speed up the encoder
  * re-initialization. A good value is bigger than the resulting
  * uncompressed size of most of the output chunks. For example, if output
  * size is 4 KiB, dictionary size of 32 KiB or 64 KiB is good. If the
  * data compresses extremely well, even 128 KiB may be useful.
  *
  * The MicroLZMA format and this encoder variant were made with the EROFS
  * file system in mind. This format may be convenient in other embedded
  * uses too where many small streams are needed. XZ Embedded includes a
  * decoder for this format.
  *
  * \param       strm    Pointer to lzma_stream that is at least initialized
  *                      with LZMA_STREAM_INIT.
  * \param       options Pointer to encoder options
  *
  * \return      Possible lzma_ret values:
  *              - LZMA_STREAM_END: All good. Check the amounts of input used
  *                and output produced. Store the amount of input used
  *                (uncompressed size) as it needs to be known to decompress
  *                the data.
  *              - LZMA_OPTIONS_ERROR
  *              - LZMA_MEM_ERROR
  *              - LZMA_PROG_ERROR: In addition to the generic reasons for this
  *                error code, this may also be returned if there isn't enough
  *                output space (6 bytes) to create a valid MicroLZMA stream.
  */
 extern LZMA_API(lzma_ret) lzma_microlzma_encoder(
         lzma_stream *strm, const lzma_options_lzma *options)
         lzma_nothrow;
 
 
 /************
  * Decoding *
  ************/
 
 /**
  * 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
  * lzma_get_check().
  */
 #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
  * such cases.
  *
  * 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
  * to use this flag:
  *
  *   - 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)
 
 
 /**
  * This flag enables decoding of concatenated files with file formats that
  * allow concatenating compressed files as is. From the formats currently
  * supported by liblzma, only the .xz and .lz formats allow concatenated
  * files. Concatenated files are not allowed with the legacy .lzma format.
  *
  * This flag also affects the usage of the 'action' argument for lzma_code().
  * When LZMA_CONCATENATED is used, lzma_code() won't return LZMA_STREAM_END
  * unless LZMA_FINISH is used as 'action'. Thus, the application has to set
  * LZMA_FINISH in the same way as it does when encoding.
  *
  * If LZMA_CONCATENATED is not used, the decoders still accept LZMA_FINISH
  * as 'action' for lzma_code(), but the usage of LZMA_FINISH isn't required.
  */
 #define LZMA_CONCATENATED               UINT32_C(0x08)
 
 
 /**
  * This flag makes the threaded decoder report errors (like LZMA_DATA_ERROR)
  * as soon as they are detected. This saves time when the application has no
  * interest in a partially decompressed truncated or corrupt file. Note that
  * due to timing randomness, if the same truncated or corrupt input is
  * decompressed multiple times with this flag, a different amount of output
  * may be produced by different runs, and even the error code might vary.
  *
  * When using LZMA_FAIL_FAST, it is recommended to use LZMA_FINISH to tell
  * the decoder when no more input will be coming because it can help fast
  * detection and reporting of truncated files. Note that in this situation
  * truncated files might be diagnosed with LZMA_DATA_ERROR instead of
  * LZMA_OK or LZMA_BUF_ERROR!
  *
  * Without this flag the threaded decoder will provide as much output as
  * possible at first and then report the pending error. This default behavior
  * matches the single-threaded decoder and provides repeatable behavior
  * with truncated or corrupt input. There are a few special cases where the
  * behavior can still differ like memory allocation failures (LZMA_MEM_ERROR).
  *
  * Single-threaded decoders currently ignore this flag.
  *
  * Support for this flag was added in liblzma 5.3.3alpha. Note that in older
  * versions this flag isn't supported (LZMA_OPTIONS_ERROR) even by functions
  * that ignore this flag in newer liblzma versions.
  */
 #define LZMA_FAIL_FAST                  UINT32_C(0x20)
 
 
 /**
  * \brief       Initialize .xz Stream decoder
  *
  * \param       strm        Pointer to lzma_stream that is at least initialized
  *                          with LZMA_STREAM_INIT.
  * \param       memlimit    Memory usage limit as bytes. Use UINT64_MAX
  *                          to effectively disable the limiter. liblzma
  *                          5.2.3 and earlier don't allow 0 here and return
  *                          LZMA_PROG_ERROR; later versions treat 0 as if 1
  *                          had been specified.
  * \param       flags       Bitwise-or of zero or more of the decoder flags:
  *                          LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
  *                          LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK,
  *                          LZMA_CONCATENATED, LZMA_FAIL_FAST
  *
  * \return      Possible lzma_ret values:
  *              - LZMA_OK: Initialization was successful.
  *              - LZMA_MEM_ERROR: Cannot allocate memory.
  *              - LZMA_OPTIONS_ERROR: Unsupported flags
  *              - LZMA_PROG_ERROR
  */
 extern LZMA_API(lzma_ret) lzma_stream_decoder(
         lzma_stream *strm, uint64_t memlimit, uint32_t flags)
         lzma_nothrow lzma_attr_warn_unused_result;
 
 
 /**
  * \brief       Initialize multithreaded .xz Stream decoder
  *
  * The decoder can decode multiple Blocks in parallel. This requires that each
  * Block Header contains the Compressed Size and Uncompressed size fields
  * which are added by the multi-threaded encoder, see lzma_stream_encoder_mt().
  *
  * A Stream with one Block will only utilize one thread. A Stream with multiple
  * Blocks but without size information in Block Headers will be processed in
  * single-threaded mode in the same way as done by lzma_stream_decoder().
  * Concatenated Streams are processed one Stream at a time; no inter-Stream
  * parallelization is done.
  *
  * This function behaves like lzma_stream_decoder() when options->threads == 1
  * and options->memlimit_threading <= 1.
  *
  * \param       strm        Pointer to lzma_stream that is at least initialized
  *                          with LZMA_STREAM_INIT.
  * \param       options     Pointer to multithreaded compression options
  *
  * \return      Possible lzma_ret values:
  *              - LZMA_OK: Initialization was successful.
  *              - LZMA_MEM_ERROR: Cannot allocate memory.
  *              - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached.
  *              - LZMA_OPTIONS_ERROR: Unsupported flags.
  *              - LZMA_PROG_ERROR
  */
 extern LZMA_API(lzma_ret) lzma_stream_decoder_mt(
         lzma_stream *strm, const lzma_mt *options)
         lzma_nothrow lzma_attr_warn_unused_result;
 
 
 /**
  * \brief       Decode .xz, .lzma, and .lz (lzip) files with autodetection
  *
  * This decoder autodetects between the .xz, .lzma, and .lz file formats,
  * and calls lzma_stream_decoder(), lzma_alone_decoder(), or
  * lzma_lzip_decoder() once the type of the input file has been detected.
  *
  * Support for .lz was added in 5.4.0.
  *
  * If the flag LZMA_CONCATENATED is used and the input is a .lzma file:
  * For historical reasons concatenated .lzma files aren't supported.
  * If there is trailing data after one .lzma stream, lzma_code() will
  * return LZMA_DATA_ERROR. (lzma_alone_decoder() doesn't have such a check
  * as it doesn't support any decoder flags. It will return LZMA_STREAM_END
  * after one .lzma stream.)
  *
  * \param       strm        Pointer to lzma_stream that is at least initialized
  *                          with LZMA_STREAM_INIT.
  * \param       memlimit    Memory usage limit as bytes. Use UINT64_MAX
  *                          to effectively disable the limiter. liblzma
  *                          5.2.3 and earlier don't allow 0 here and return
  *                          LZMA_PROG_ERROR; later versions treat 0 as if 1
  *                          had been specified.
  * \param       flags       Bitwise-or of zero or more of the decoder flags:
  *                          LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
  *                          LZMA_TELL_ANY_CHECK, LZMA_IGNORE_CHECK,
  *                          LZMA_CONCATENATED, LZMA_FAIL_FAST
  *
  * \return      Possible lzma_ret values:
  *              - LZMA_OK: Initialization was successful.
  *              - LZMA_MEM_ERROR: Cannot allocate memory.
  *              - LZMA_OPTIONS_ERROR: Unsupported flags
  *              - LZMA_PROG_ERROR
  */
 extern LZMA_API(lzma_ret) lzma_auto_decoder(
         lzma_stream *strm, uint64_t memlimit, uint32_t flags)
         lzma_nothrow lzma_attr_warn_unused_result;
 
 
 /**
  * \brief       Initialize .lzma decoder (legacy file format)
  *
  * Valid 'action' arguments to lzma_code() are LZMA_RUN and LZMA_FINISH.
  * There is no need to use LZMA_FINISH, but it's allowed because it may
  * simplify certain types of applications.
  *
  * \param       strm        Pointer to lzma_stream that is at least initialized
  *                          with LZMA_STREAM_INIT.
  * \param       memlimit    Memory usage limit as bytes. Use UINT64_MAX
  *                          to effectively disable the limiter. liblzma
  *                          5.2.3 and earlier don't allow 0 here and return
  *                          LZMA_PROG_ERROR; later versions treat 0 as if 1
  *                          had been specified.
  *
  * \return      Possible lzma_ret values:
  *              - LZMA_OK
  *              - LZMA_MEM_ERROR
  *              - LZMA_PROG_ERROR
  */
 extern LZMA_API(lzma_ret) lzma_alone_decoder(
         lzma_stream *strm, uint64_t memlimit)
         lzma_nothrow lzma_attr_warn_unused_result;
 
 
 /**
  * \brief       Initialize .lz (lzip) decoder (a foreign file format)
  *
  * This decoder supports the .lz format version 0 and the unextended .lz
  * format version 1:
  *
  *   - Files in the format version 0 were produced by lzip 1.3 and older.
  *     Such files aren't common but may be found from file archives
  *     as a few source packages were released in this format. People
  *     might have old personal files in this format too. Decompression
  *     support for the format version 0 was removed in lzip 1.18.
  *
  *   - lzip 1.3 added decompression support for .lz format version 1 files.
  *     Compression support was added in lzip 1.4. In lzip 1.6 the .lz format
  *     version 1 was extended to support the Sync Flush marker. This extension
  *     is not supported by liblzma. lzma_code() will return LZMA_DATA_ERROR
  *     at the location of the Sync Flush marker. In practice files with
  *     the Sync Flush marker are very rare and thus liblzma can decompress
  *     almost all .lz files.
  *
  * Just like with lzma_stream_decoder() for .xz files, LZMA_CONCATENATED
  * should be used when decompressing normal standalone .lz files.
  *
  * The .lz format allows putting non-.lz data at the end of a file after at
  * least one valid .lz member. That is, one can append custom data at the end
  * of a .lz file and the decoder is required to ignore it. In liblzma this
  * is relevant only when LZMA_CONCATENATED is used. In that case lzma_code()
  * will return LZMA_STREAM_END and leave lzma_stream.next_in pointing to
  * the first byte of the non-.lz data. An exception to this is if the first
  * 1-3 bytes of the non-.lz data are identical to the .lz magic bytes
  * (0x4C, 0x5A, 0x49, 0x50; "LZIP" in US-ASCII). In such a case the 1-3 bytes
  * will have been ignored by lzma_code(). If one wishes to locate the non-.lz
  * data reliably, one must ensure that the first byte isn't 0x4C. Actually
  * one should ensure that none of the first four bytes of trailing data are
  * equal to the magic bytes because lzip >= 1.20 requires it by default.
  *
  * \param       strm        Pointer to lzma_stream that is at least initialized
  *                          with LZMA_STREAM_INIT.
  * \param       memlimit    Memory usage limit as bytes. Use UINT64_MAX
  *                          to effectively disable the limiter.
  * \param       flags       Bitwise-or of flags, or zero for no flags.
  *                          All decoder flags listed above are supported
  *                          although only LZMA_CONCATENATED and (in very rare
  *                          cases) LZMA_IGNORE_CHECK are actually useful.
  *                          LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
  *                          and LZMA_FAIL_FAST do nothing. LZMA_TELL_ANY_CHECK
  *                          is supported for consistency only as CRC32 is
  *                          always used in the .lz format.
  *
  * \return      Possible lzma_ret values:
  *              - LZMA_OK: Initialization was successful.
  *              - LZMA_MEM_ERROR: Cannot allocate memory.
  *              - LZMA_OPTIONS_ERROR: Unsupported flags
  *              - LZMA_PROG_ERROR
  */
 extern LZMA_API(lzma_ret) lzma_lzip_decoder(
         lzma_stream *strm, uint64_t memlimit, uint32_t flags)
         lzma_nothrow lzma_attr_warn_unused_result;
 
 
 /**
  * \brief       Single-call .xz Stream decoder
  *
  * \param       memlimit    Pointer to how much memory the decoder is allowed
  *                          to allocate. The value pointed by this pointer is
  *                          modified if and only if LZMA_MEMLIMIT_ERROR is
  *                          returned.
  * \param       flags       Bitwise-or of zero or more of the decoder flags:
  *                          LZMA_TELL_NO_CHECK, LZMA_TELL_UNSUPPORTED_CHECK,
  *                          LZMA_IGNORE_CHECK, LZMA_CONCATENATED,
  *                          LZMA_FAIL_FAST. Note that LZMA_TELL_ANY_CHECK
  *                          is not allowed and will return LZMA_PROG_ERROR.
  * \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]  out         Beginning of the output buffer
  * \param[out]  out_pos     The next byte will be written to out[*out_pos].
  *                          *out_pos is updated only if decoding succeeds.
  * \param       out_size    Size of the out buffer; the first byte into
  *                          which no data is written to is out[out_size].
  *
  * \return      Possible lzma_ret values:
  *              - LZMA_OK: Decoding was successful.
  *              - LZMA_FORMAT_ERROR
  *              - LZMA_OPTIONS_ERROR
  *              - LZMA_DATA_ERROR
  *              - LZMA_NO_CHECK: This can be returned only if using
  *                the LZMA_TELL_NO_CHECK flag.
  *              - LZMA_UNSUPPORTED_CHECK: This can be returned only if using
  *                the LZMA_TELL_UNSUPPORTED_CHECK flag.
  *              - LZMA_MEM_ERROR
  *              - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached.
  *                The minimum required memlimit value was stored to *memlimit.
  *              - LZMA_BUF_ERROR: Output buffer was too small.
  *              - LZMA_PROG_ERROR
  */
 extern LZMA_API(lzma_ret) lzma_stream_buffer_decode(
         uint64_t *memlimit, uint32_t flags,
         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 lzma_attr_warn_unused_result;
 
 
 /**
  * \brief       MicroLZMA decoder
  *
  * See lzma_microlzma_encoder() for more information.
  *
  * The lzma_code() usage with this decoder is completely normal. The
  * special behavior of lzma_code() applies to lzma_microlzma_encoder() only.
  *
  * \param       strm        Pointer to lzma_stream that is at least initialized
  *                          with LZMA_STREAM_INIT.
  * \param       comp_size   Compressed size of the MicroLZMA stream.
  *                          The caller must somehow know this exactly.
  * \param       uncomp_size Uncompressed size of the MicroLZMA stream.
  *                          If the exact uncompressed size isn't known, this
  *                          can be set to a value that is at most as big as
  *                          the exact uncompressed size would be, but then the
  *                          next argument uncomp_size_is_exact must be false.
  * \param       uncomp_size_is_exact
  *                          If true, uncomp_size must be exactly correct.
  *                          This will improve error detection at the end of
  *                          the stream. If the exact uncompressed size isn't
  *                          known, this must be false. uncomp_size must still
  *                          be at most as big as the exact uncompressed size
  *                          is. Setting this to false when the exact size is
  *                          known will work but error detection at the end of
  *                          the stream will be weaker.
  * \param       dict_size   LZMA dictionary size that was used when
  *                          compressing the data. It is OK to use a bigger
  *                          value too but liblzma will then allocate more
  *                          memory than would actually be required and error
  *                          detection will be slightly worse. (Note that with
  *                          the implementation in XZ Embedded it doesn't
  *                          affect the memory usage if one specifies bigger
  *                          dictionary than actually required.)
  *
  * \return      Possible lzma_ret values:
  *              - LZMA_OK
  *              - LZMA_MEM_ERROR
  *              - LZMA_OPTIONS_ERROR
  *              - LZMA_PROG_ERROR
  */
 extern LZMA_API(lzma_ret) lzma_microlzma_decoder(
         lzma_stream *strm, uint64_t comp_size,
         uint64_t uncomp_size, lzma_bool uncomp_size_is_exact,
         uint32_t dict_size) lzma_nothrow;

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