/* * Copyright (c) 2000-2013 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * 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. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * 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_OSREFERENCE_LICENSE_HEADER_END@ */ /* direct-mapped partial matching compressor with simple 22/10 split * * Compresses buffers using a dictionary based match and partial match * (high bits only or full match) scheme. * * Paul Wilson -- wilson@cs.utexas.edu * Scott F. Kaplan -- sfkaplan@cs.utexas.edu * September 1997 */ /* compressed output format, in memory order * 1. a four-word HEADER containing four one-word values: * i. a one-word code saying what algorithm compressed the data * ii. an integer WORD offset into the page saying * where the queue position area starts * iii. an integer WORD offset into the page saying where * the low-bits area starts * iv. an integer WORD offset into the page saying where the * low-bits area ends * * 2. a 64-word TAGS AREA holding one two-bit tag for each word in * the original (1024-word) page, packed 16 per word * * 3. a variable-sized FULL WORDS AREA (always word aligned and an * integral number of words) holding full-word patterns that * were not in the dictionary when encoded (i.e., dictionary misses) * * 4. a variable-sized QUEUE POSITIONS AREA (always word aligned and * an integral number of words) holding four-bit queue positions, * packed eight per word. * * 5. a variable-sized LOW BITS AREA (always word aligned and an * integral number of words) holding ten-bit low-bit patterns * (from partial matches), packed three per word. */ #ifdef __cplusplus extern "C" { #endif #include <mach/vm_param.h> #define WKdm_SCRATCH_BUF_SIZE PAGE_SIZE typedef unsigned int WK_word; void WKdm_decompress_new (WK_word* src_buf, WK_word* dest_buf, WK_word* scratch, unsigned int bytes); int WKdm_compress_new (const WK_word* src_buf, WK_word* dest_buf, WK_word* scratch, unsigned int limit); #ifdef __cplusplus } /* extern "C" */ #endif