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Diffstat (limited to 'cpukit/libmisc/xz/xz.h')
| -rw-r--r-- | cpukit/libmisc/xz/xz.h | 304 |
1 files changed, 0 insertions, 304 deletions
diff --git a/cpukit/libmisc/xz/xz.h b/cpukit/libmisc/xz/xz.h deleted file mode 100644 index 0a4b38d33c..0000000000 --- a/cpukit/libmisc/xz/xz.h +++ /dev/null @@ -1,304 +0,0 @@ -/* - * XZ decompressor - * - * Authors: Lasse Collin <lasse.collin@tukaani.org> - * Igor Pavlov <http://7-zip.org/> - * - * This file has been put into the public domain. - * You can do whatever you want with this file. - */ - -#ifndef XZ_H -#define XZ_H - -#ifdef __KERNEL__ -# include <linux/stddef.h> -# include <linux/types.h> -#else -# include <stddef.h> -# include <stdint.h> -#endif - -#ifdef __cplusplus -extern "C" { -#endif - -/* In Linux, this is used to make extern functions static when needed. */ -#ifndef XZ_EXTERN -# define XZ_EXTERN extern -#endif - -/** - * enum xz_mode - Operation mode - * - * @XZ_SINGLE: Single-call mode. This uses less RAM than - * than multi-call modes, because the LZMA2 - * dictionary doesn't need to be allocated as - * part of the decoder state. All required data - * structures are allocated at initialization, - * so xz_dec_run() cannot return XZ_MEM_ERROR. - * @XZ_PREALLOC: Multi-call mode with preallocated LZMA2 - * dictionary buffer. All data structures are - * allocated at initialization, so xz_dec_run() - * cannot return XZ_MEM_ERROR. - * @XZ_DYNALLOC: Multi-call mode. The LZMA2 dictionary is - * allocated once the required size has been - * parsed from the stream headers. If the - * allocation fails, xz_dec_run() will return - * XZ_MEM_ERROR. - * - * It is possible to enable support only for a subset of the above - * modes at compile time by defining XZ_DEC_SINGLE, XZ_DEC_PREALLOC, - * or XZ_DEC_DYNALLOC. The xz_dec kernel module is always compiled - * with support for all operation modes, but the preboot code may - * be built with fewer features to minimize code size. - */ -enum xz_mode { - XZ_SINGLE, - XZ_PREALLOC, - XZ_DYNALLOC -}; - -/** - * enum xz_ret - Return codes - * @XZ_OK: Everything is OK so far. More input or more - * output space is required to continue. This - * return code is possible only in multi-call mode - * (XZ_PREALLOC or XZ_DYNALLOC). - * @XZ_STREAM_END: Operation finished successfully. - * @XZ_UNSUPPORTED_CHECK: Integrity check type is not supported. Decoding - * is still possible in multi-call mode by simply - * calling xz_dec_run() again. - * Note that this return value is used only if - * XZ_DEC_ANY_CHECK was defined at build time, - * which is not used in the kernel. Unsupported - * check types return XZ_OPTIONS_ERROR if - * XZ_DEC_ANY_CHECK was not defined at build time. - * @XZ_MEM_ERROR: Allocating memory failed. This return code is - * possible only if the decoder was initialized - * with XZ_DYNALLOC. The amount of memory that was - * tried to be allocated was no more than the - * dict_max argument given to xz_dec_init(). - * @XZ_MEMLIMIT_ERROR: A bigger LZMA2 dictionary would be needed than - * allowed by the dict_max argument given to - * xz_dec_init(). This return value is possible - * only in multi-call mode (XZ_PREALLOC or - * XZ_DYNALLOC); the single-call mode (XZ_SINGLE) - * ignores the dict_max argument. - * @XZ_FORMAT_ERROR: File format was not recognized (wrong magic - * bytes). - * @XZ_OPTIONS_ERROR: This implementation doesn't support the requested - * compression options. In the decoder this means - * that the header CRC32 matches, but the header - * itself specifies something that we don't support. - * @XZ_DATA_ERROR: Compressed data is corrupt. - * @XZ_BUF_ERROR: Cannot make any progress. Details are slightly - * different between multi-call and single-call - * mode; more information below. - * - * In multi-call mode, XZ_BUF_ERROR is returned when two consecutive calls - * to XZ code cannot consume any input and cannot produce any new output. - * This happens when there is no new input available, or the output buffer - * is full while at least one output byte is still pending. Assuming your - * code is not buggy, you can get this error only when decoding a compressed - * stream that is truncated or otherwise corrupt. - * - * In single-call mode, XZ_BUF_ERROR is returned only when the output buffer - * is too small or the compressed input is corrupt in a way that makes the - * decoder produce more output than the caller expected. When it is - * (relatively) clear that the compressed input is truncated, XZ_DATA_ERROR - * is used instead of XZ_BUF_ERROR. - */ -enum xz_ret { - XZ_OK, - XZ_STREAM_END, - XZ_UNSUPPORTED_CHECK, - XZ_MEM_ERROR, - XZ_MEMLIMIT_ERROR, - XZ_FORMAT_ERROR, - XZ_OPTIONS_ERROR, - XZ_DATA_ERROR, - XZ_BUF_ERROR -}; - -/** - * struct xz_buf - Passing input and output buffers to XZ code - * @in: Beginning of the input buffer. This may be NULL if and only - * if in_pos is equal to in_size. - * @in_pos: Current position in the input buffer. This must not exceed - * in_size. - * @in_size: Size of the input buffer - * @out: Beginning of the output buffer. This may be NULL if and only - * if out_pos is equal to out_size. - * @out_pos: Current position in the output buffer. This must not exceed - * out_size. - * @out_size: Size of the output buffer - * - * Only the contents of the output buffer from out[out_pos] onward, and - * the variables in_pos and out_pos are modified by the XZ code. - */ -struct xz_buf { - const uint8_t *in; - size_t in_pos; - size_t in_size; - - uint8_t *out; - size_t out_pos; - size_t out_size; -}; - -/** - * struct xz_dec - Opaque type to hold the XZ decoder state - */ -struct xz_dec; - -/** - * xz_dec_init() - Allocate and initialize a XZ decoder state - * @mode: Operation mode - * @dict_max: Maximum size of the LZMA2 dictionary (history buffer) for - * multi-call decoding. This is ignored in single-call mode - * (mode == XZ_SINGLE). LZMA2 dictionary is always 2^n bytes - * or 2^n + 2^(n-1) bytes (the latter sizes are less common - * in practice), so other values for dict_max don't make sense. - * In the kernel, dictionary sizes of 64 KiB, 128 KiB, 256 KiB, - * 512 KiB, and 1 MiB are probably the only reasonable values, - * except for kernel and initramfs images where a bigger - * dictionary can be fine and useful. - * - * Single-call mode (XZ_SINGLE): xz_dec_run() decodes the whole stream at - * once. The caller must provide enough output space or the decoding will - * fail. The output space is used as the dictionary buffer, which is why - * there is no need to allocate the dictionary as part of the decoder's - * internal state. - * - * Because the output buffer is used as the workspace, streams encoded using - * a big dictionary are not a problem in single-call mode. It is enough that - * the output buffer is big enough to hold the actual uncompressed data; it - * can be smaller than the dictionary size stored in the stream headers. - * - * Multi-call mode with preallocated dictionary (XZ_PREALLOC): dict_max bytes - * of memory is preallocated for the LZMA2 dictionary. This way there is no - * risk that xz_dec_run() could run out of memory, since xz_dec_run() will - * never allocate any memory. Instead, if the preallocated dictionary is too - * small for decoding the given input stream, xz_dec_run() will return - * XZ_MEMLIMIT_ERROR. Thus, it is important to know what kind of data will be - * decoded to avoid allocating excessive amount of memory for the dictionary. - * - * Multi-call mode with dynamically allocated dictionary (XZ_DYNALLOC): - * dict_max specifies the maximum allowed dictionary size that xz_dec_run() - * may allocate once it has parsed the dictionary size from the stream - * headers. This way excessive allocations can be avoided while still - * limiting the maximum memory usage to a sane value to prevent running the - * system out of memory when decompressing streams from untrusted sources. - * - * On success, xz_dec_init() returns a pointer to struct xz_dec, which is - * ready to be used with xz_dec_run(). If memory allocation fails, - * xz_dec_init() returns NULL. - */ -XZ_EXTERN struct xz_dec *xz_dec_init(enum xz_mode mode, uint32_t dict_max); - -/** - * xz_dec_run() - Run the XZ decoder - * @s: Decoder state allocated using xz_dec_init() - * @b: Input and output buffers - * - * The possible return values depend on build options and operation mode. - * See enum xz_ret for details. - * - * Note that if an error occurs in single-call mode (return value is not - * XZ_STREAM_END), b->in_pos and b->out_pos are not modified and the - * contents of the output buffer from b->out[b->out_pos] onward are - * undefined. This is true even after XZ_BUF_ERROR, because with some filter - * chains, there may be a second pass over the output buffer, and this pass - * cannot be properly done if the output buffer is truncated. Thus, you - * cannot give the single-call decoder a too small buffer and then expect to - * get that amount valid data from the beginning of the stream. You must use - * the multi-call decoder if you don't want to uncompress the whole stream. - */ -XZ_EXTERN enum xz_ret xz_dec_run(struct xz_dec *s, struct xz_buf *b); - -/** - * xz_dec_reset() - Reset an already allocated decoder state - * @s: Decoder state allocated using xz_dec_init() - * - * This function can be used to reset the multi-call decoder state without - * freeing and reallocating memory with xz_dec_end() and xz_dec_init(). - * - * In single-call mode, xz_dec_reset() is always called in the beginning of - * xz_dec_run(). Thus, explicit call to xz_dec_reset() is useful only in - * multi-call mode. - */ -XZ_EXTERN void xz_dec_reset(struct xz_dec *s); - -/** - * xz_dec_end() - Free the memory allocated for the decoder state - * @s: Decoder state allocated using xz_dec_init(). If s is NULL, - * this function does nothing. - */ -XZ_EXTERN void xz_dec_end(struct xz_dec *s); - -/* - * Standalone build (userspace build or in-kernel build for boot time use) - * needs a CRC32 implementation. For normal in-kernel use, kernel's own - * CRC32 module is used instead, and users of this module don't need to - * care about the functions below. - */ -#ifndef XZ_INTERNAL_CRC32 -# ifdef __KERNEL__ -# define XZ_INTERNAL_CRC32 0 -# else -# define XZ_INTERNAL_CRC32 1 -# endif -#endif - -/* - * If CRC64 support has been enabled with XZ_USE_CRC64, a CRC64 - * implementation is needed too. - */ -#ifndef XZ_USE_CRC64 -# undef XZ_INTERNAL_CRC64 -# define XZ_INTERNAL_CRC64 0 -#endif -#ifndef XZ_INTERNAL_CRC64 -# ifdef __KERNEL__ -# error Using CRC64 in the kernel has not been implemented. -# else -# define XZ_INTERNAL_CRC64 1 -# endif -#endif - -#if XZ_INTERNAL_CRC32 -/* - * This must be called before any other xz_* function to initialize - * the CRC32 lookup table. - */ -XZ_EXTERN void xz_crc32_init(void); - -/* - * Update CRC32 value using the polynomial from IEEE-802.3. To start a new - * calculation, the third argument must be zero. To continue the calculation, - * the previously returned value is passed as the third argument. - */ -XZ_EXTERN uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc); -#endif - -#if XZ_INTERNAL_CRC64 -/* - * This must be called before any other xz_* function (except xz_crc32_init()) - * to initialize the CRC64 lookup table. - */ -XZ_EXTERN void xz_crc64_init(void); - -/* - * Update CRC64 value using the polynomial from ECMA-182. To start a new - * calculation, the third argument must be zero. To continue the calculation, - * the previously returned value is passed as the third argument. - */ -XZ_EXTERN uint64_t xz_crc64(const uint8_t *buf, size_t size, uint64_t crc); -#endif - -#ifdef __cplusplus -} -#endif - -#endif |