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- /****************************************************************************
- * include/lzf.h
- * http://liblzf.plan9.de/
- *
- * Copyright (c) 2000-2008 Marc Alexander Lehmann <schmorp@schmorp.de>
- * This algorithm is believed to be patent-free.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- ****************************************************************************/
- #ifndef __INCLUDE_LZF_H
- #define __INCLUDE_LZF_H
- /****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
- #define LZF_VERSION 0x0105 /* 1.5, API version */
- #define HLOG CONFIG_LIBC_LZF_HLOG
- #define LZF_TYPE0_HDR 0
- #define LZF_TYPE1_HDR 1
- #define LZF_TYPE0_HDR_SIZE 5
- #define LZF_TYPE1_HDR_SIZE 7
- #define LZF_MAX_HDR_SIZE 7
- #define LZF_MIN_HDR_SIZE 5
- /****************************************************************************
- * Public Types
- ****************************************************************************/
- /* LZF headers */
- struct lzf_header_s /* Common data header */
- {
- uint8_t lzf_magic[2]; /* [0]='Z', [1]='V' */
- uint8_t lzf_type; /* LZF_TYPE0_HDR or LZF_TYPE1_HDR */
- };
- struct lzf_type0_header_s /* Uncompressed data header */
- {
- uint8_t lzf_magic[2]; /* [0]='Z', [1]='V' */
- uint8_t lzf_type; /* LZF_TYPE0_HDR */
- uint8_t lzf_len[2]; /* Data length (big-endian) */
- };
- struct lzf_type1_header_s /* Compressed data header */
- {
- uint8_t lzf_magic[2]; /* [0]='Z', [1]='V' */
- uint8_t lzf_type; /* LZF_TYPE1_HDR */
- uint8_t lzf_clen[2]; /* Compressed data length (big-endian) */
- uint8_t lzf_ulen[2]; /* Uncompressed data length (big-endian) */
- };
- /* LZF hash table */
- #if LZF_USE_OFFSETS
- # define LZF_HSLOT_BIAS ((const uint8_t *)in_data)
- typedef unsigned int lzf_hslot_t;
- #else
- # define LZF_HSLOT_BIAS 0
- typedef const uint8_t *lzf_hslot_t;
- #endif
- typedef lzf_hslot_t lzf_state_t[1 << HLOG];
- /****************************************************************************
- * Public Function Prototypes
- ****************************************************************************/
- /****************************************************************************
- * Name: lzf_compress
- *
- * Description:
- * Compress in_len bytes stored at the memory block starting at
- * in_data and write the result to out_data, up to a maximum length
- * of out_len bytes.
- *
- * If the output buffer is not large enough or any error occurs return 0,
- * otherwise return the number of bytes used, which might be considerably
- * more than in_len (but less than 104% of the original size), so it
- * makes sense to always use out_len == in_len - 1), to ensure _some_
- * compression, and store the data uncompressed otherwise (with a flag, of
- * course.
- *
- * lzf_compress might use different algorithms on different systems and
- * even different runs, thus might result in different compressed strings
- * depending on the phase of the moon or similar factors. However, all
- * these strings are architecture-independent and will result in the
- * original data when decompressed using lzf_decompress.
- *
- * The buffers must not be overlapping.
- *
- * Compressed format:
- *
- * 000LLLLL <L+1> ; literal, L+1=1..33 octets
- * LLLooooo oooooooo ; backref L+1=1..7 octets, o+1=1..4096 offset
- * 111ooooo LLLLLLLL oooooooo ; backref L+8 octets, o+1=1..4096 offset
- *
- ****************************************************************************/
- size_t lzf_compress(FAR const void *const in_data,
- unsigned int in_len, FAR void *out_data,
- unsigned int out_len, lzf_state_t htab,
- FAR struct lzf_header_s **reshdr);
- /****************************************************************************
- * Name: lzf_decompress
- *
- * Description:
- * Decompress data compressed with some version of the lzf_compress
- * function and stored at location in_data and length in_len. The result
- * will be stored at out_data up to a maximum of out_len characters.
- *
- * If the output buffer is not large enough to hold the decompressed
- * data, a 0 is returned and errno is set to E2BIG. Otherwise the number
- * of decompressed bytes (i.e. the original length of the data) is
- * returned.
- *
- * If an error in the compressed data is detected, a zero is returned and
- * errno is set to EINVAL.
- *
- * This function is very fast, about as fast as a copying loop.
- *
- ****************************************************************************/
- unsigned int lzf_decompress(FAR const void *const in_data,
- unsigned int in_len, FAR void *out_data,
- unsigned int out_len);
- #endif /* __INCLUDE_LZF_H */
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