602ce69afb
function old new delta unpack_xz_stream_stdin - 3953 +3953 lzma_main - 2601 +2601 lzma_len - 516 +516 dec_vli - 165 +165 dict_repeat - 103 +103 lzma_reset - 98 +98 fill_temp - 98 +98 crc32_validate - 93 +93 xz_dec_reset - 77 +77 unxz_main - 77 +77 index_update - 47 +47 xz_crc32 - 40 +40 packed_usage 27044 27060 +16 make_new_name_unxz - 14 +14 applet_names 2240 2254 +14 applet_main 1312 1324 +12 applet_nameofs 656 662 +6 unpack_unxz - 5 +5 send_tree 355 360 +5 applet_install_loc 164 166 +2 ------------------------------------------------------------------------------ (add/remove: 15/0 grow/shrink: 6/0 up/down: 7942/0) Total: 7942 bytes text data bss dec hex filename 844032 453 6812 851297 cfd61 busybox_old 852063 453 6812 859328 d1cc0 busybox_unstripped Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
213 lines
8.0 KiB
C
213 lines
8.0 KiB
C
/*
|
|
* 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
|
|
|
|
#ifndef XZ_DEBUG_MSG
|
|
# define XZ_DEBUG_MSG(...) ((void)0)
|
|
#endif
|
|
|
|
/* In Linux, this is used to make extern functions static when needed. */
|
|
#ifndef XZ_EXTERN
|
|
# define XZ_EXTERN extern
|
|
#endif
|
|
|
|
/* In Linux, this is used to mark the functions with __init when needed. */
|
|
#ifndef XZ_FUNC
|
|
# define XZ_FUNC
|
|
#endif
|
|
|
|
/**
|
|
* enum xz_ret - Return codes
|
|
* @XZ_OK: Everything is OK so far. More input or more output
|
|
* space is required to continue.
|
|
* @XZ_STREAM_END: Operation finished successfully.
|
|
* @XZ_MEMLIMIT_ERROR: Not enough memory was preallocated at decoder
|
|
* initialization time.
|
|
* @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_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
|
|
* @dict_max: Maximum size of the LZMA2 dictionary (history buffer) for
|
|
* multi-call decoding, or special value of zero to indicate
|
|
* single-call decoding mode.
|
|
*
|
|
* If dict_max > 0, the decoder is initialized to work in multi-call mode.
|
|
* dict_max number of 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.
|
|
*
|
|
* LZMA2 dictionary is always 2^n bytes or 2^n + 2^(n-1) bytes (the latter
|
|
* sizes are less common in practice). In the kernel, dictionary sizes of
|
|
* 64 KiB, 128 KiB, 256 KiB, 512 KiB, and 1 MiB are probably the only
|
|
* reasonable values.
|
|
*
|
|
* If dict_max == 0, the decoder is initialized to work in single-call mode.
|
|
* In single-call mode, 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. It is enough that the
|
|
* output buffer is is big enough to hold the actual uncompressed data; it
|
|
* can be smaller than the dictionary size stored in the stream headers.
|
|
*
|
|
* On success, xz_dec_init() returns a pointer to struct xz_dec, which is
|
|
* ready to be used with xz_dec_run(). On error, xz_dec_init() returns NULL.
|
|
*/
|
|
XZ_EXTERN struct xz_dec * XZ_FUNC xz_dec_init(uint32_t dict_max);
|
|
|
|
/**
|
|
* xz_dec_run() - Run the XZ decoder
|
|
* @s: Decoder state allocated using xz_dec_init()
|
|
* @b: Input and output buffers
|
|
*
|
|
* In multi-call mode, this function may return any of the values listed in
|
|
* enum xz_ret.
|
|
*
|
|
* In single-call mode, this function never returns XZ_OK. 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.
|
|
*
|
|
* NOTE: In single-call mode, the contents of the output buffer are undefined
|
|
* also after XZ_BUF_ERROR. This is 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_FUNC 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_FUNC 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_FUNC 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.
|
|
*/
|
|
#if !defined(__KERNEL__) || defined(XZ_INTERNAL_CRC32)
|
|
/*
|
|
* This must be called before any other xz_* function to initialize
|
|
* the CRC32 lookup table.
|
|
*/
|
|
#ifndef xz_crc32_init
|
|
XZ_EXTERN void XZ_FUNC xz_crc32_init(uint32_t *crc32_table);
|
|
#endif
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
#ifndef xz_crc32
|
|
XZ_EXTERN uint32_t XZ_FUNC xz_crc32(uint32_t *crc32_table,
|
|
const uint8_t *buf, size_t size, uint32_t crc);
|
|
#endif
|
|
#endif
|
|
#endif
|