LZSS
Contents
LZSS algorithm
LZSS (Lempel-Ziv-Storer-Szymanski) compression is used for the mach_kernel.prelink file.
http://en.wikipedia.org/wiki/Lempel-Ziv-Storer-Szymanski
LZSS de-/compression binary
(Please link here)
LZSS Decompression source
- compression version coming soon
Apple source code
/* * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved. * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ */ /************************************************************** LZSS.C -- A Data Compression Program *************************************************************** 4/6/1989 Haruhiko Okumura Use, distribute, and modify this program freely. Please send me your improved versions. PC-VAN SCIENCE NIFTY-Serve PAF01022 CompuServe 74050,1022 **************************************************************/ /* * lzss.c - Package for decompressing lzss compressed objects * * Copyright (c) 2003 Apple Computer, Inc. * * DRI: Josh de Cesare */ #include <sl.h> #define N 4096 /* size of ring buffer - must be power of 2 */ #define F 18 /* upper limit for match_length */ #define THRESHOLD 2 /* encode string into position and length if match_length is greater than this */ #define NIL N /* index for root of binary search trees */ int decompress_lzss(u_int8_t *dst, u_int8_t *src, u_int32_t srclen) { /* ring buffer of size N, with extra F-1 bytes to aid string comparison */ u_int8_t text_buf[N + F - 1]; u_int8_t *dststart = dst; u_int8_t *srcend = src + srclen; int i, j, k, r, c; unsigned int flags; dst = dststart; srcend = src + srclen; for (i = 0; i < N - F; i++) text_buf[i] = ' '; r = N - F; flags = 0; for ( ; ; ) { if (((flags >>= 1) & 0x100) == 0) { if (src < srcend) c = *src++; else break; flags = c | 0xFF00; /* uses higher byte cleverly */ } /* to count eight */ if (flags & 1) { if (src < srcend) c = *src++; else break; *dst++ = c; text_buf[r++] = c; r &= (N - 1); } else { if (src < srcend) i = *src++; else break; if (src < srcend) j = *src++; else break; i |= ((j & 0xF0) << 4); j = (j & 0x0F) + THRESHOLD; for (k = 0; k <= j; k++) { c = text_buf[(i + k) & (N - 1)]; *dst++ = c; text_buf[r++] = c; r &= (N - 1); } } } return dst - dststart; }