xz.h

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/*
 * XZ decompressor
 *
 * Authors: Lasse Collin <[email protected]>
 *          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

/* In Linux, this is used to make extern functions static when needed. */
#ifndef XZ_EXTERN
#   define XZ_EXTERN extern
#endif

enum xz_mode {
    XZ_SINGLE,
    XZ_PREALLOC,
    XZ_DYNALLOC
};

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 {
    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;

XZ_EXTERN struct xz_dec *xz_dec_init(enum xz_mode mode, uint32_t dict_max);

XZ_EXTERN enum xz_ret xz_dec_run(struct xz_dec *s, struct xz_buf *b);

XZ_EXTERN void xz_dec_reset(struct xz_dec *s);

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 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
#endif