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편집 파일: container.h

/** * \file lzma/container.h * \brief File formats */ /* * 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 /************ * 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 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 */ typedef struct { /** * \brief Flags * * Set this to zero if no flags are wanted. * * No flags are currently supported. */ uint32_t flags; /** * \brief Number of worker threads to use */ uint32_t threads; /** * \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. */ uint64_t block_size; /** * \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 * 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 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 * are made. */ uint32_t timeout; /** * \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. */ uint32_t preset; /** * \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 * 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. */ lzma_reserved_enum reserved_enum1; lzma_reserved_enum reserved_enum2; lzma_reserved_enum reserved_enum3; uint32_t reserved_int1; uint32_t reserved_int2; uint32_t reserved_int3; uint32_t reserved_int4; uint64_t reserved_int5; uint64_t reserved_int6; uint64_t reserved_int7; uint64_t reserved_int8; void *reserved_ptr1; void *reserved_ptr2; void *reserved_ptr3; 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. 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 * is returned. */ 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 * 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 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 * 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. * * 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 * 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 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 * - 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 properly prepared lzma_stream * \param filters Array of filters. This must be terminated with * filters[n].id = LZMA_VLI_UNKNOWN. See filter.h for * more information. * \param check Type of the integrity check to calculate from * uncompressed data. * * \return - 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 properly prepared lzma_stream * \param options Pointer to multithreaded compression options * * \return - 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 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. * * \return - 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 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) lzma_nothrow; /** * \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 * 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 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 * - 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; /************ * 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 format allows 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) /** * \brief Initialize .xz Stream decoder * * \param strm Pointer to properly prepared lzma_stream * \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_CONCATENATED * * \return - 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 Decode .xz Streams and .lzma files with autodetection * * This decoder autodetects between the .xz and .lzma file formats, and * calls lzma_stream_decoder() or lzma_alone_decoder() once the type * of the input file has been detected. * * \param strm Pointer to properly prepared lzma_stream * \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 flags, or zero for no flags. * * \return - 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) * * \param strm Pointer to properly prepared lzma_stream * \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. * * 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. * * \return - 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 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_CONCATENATED. 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 Beginning of the output buffer * \param 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 - 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;