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	1	/*
	2	* Copyright (c) 2008 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28	/* compress.c -- compress a memory buffer
	29	* Copyright (C) 1995-2003 Jean-loup Gailly.
	30	* For conditions of distribution and use, see copyright notice in zlib.h
	31	*/
	32
	33	/* @(#) $Id$ */
	34
	35	#define ZLIB_INTERNAL
	36	#if KERNEL
	37	#include <libkern/zlib.h>
	38	#else
	39	#include "zlib.h"
	40	#endif /* KERNEL */
	41
	42	/* ===========================================================================
	43	Compresses the source buffer into the destination buffer. The level
	44	parameter has the same meaning as in deflateInit. sourceLen is the byte
	45	length of the source buffer. Upon entry, destLen is the total size of the
	46	destination buffer, which must be at least 0.1% larger than sourceLen plus
	47	12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
	48
	49	compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
	50	memory, Z_BUF_ERROR if there was not enough room in the output buffer,
	51	Z_STREAM_ERROR if the level parameter is invalid.
	52	*/
	53	int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
	54	Bytef *dest;
	55	uLongf *destLen;
	56	const Bytef *source;
	57	uLong sourceLen;
	58	int level;
	59	{
	60	z_stream stream;
	61	int err;
	62
	63	stream.next_in = (Bytef*)source;
	64	stream.avail_in = (uInt)sourceLen;
	65	#ifdef MAXSEG_64K
	66	/* Check for source > 64K on 16-bit machine: */
	67	if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
	68	#endif
	69	stream.next_out = dest;
	70	stream.avail_out = (uInt)*destLen;
	71	if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
	72
	73	stream.zalloc = (alloc_func)0;
	74	stream.zfree = (free_func)0;
	75	stream.opaque = (voidpf)0;
	76
	77	err = deflateInit(&stream, level);
	78	if (err != Z_OK) return err;
	79
	80	err = deflate(&stream, Z_FINISH);
	81	if (err != Z_STREAM_END) {
	82	deflateEnd(&stream);
	83	return err == Z_OK ? Z_BUF_ERROR : err;
	84	}
	85	*destLen = stream.total_out;
	86
	87	err = deflateEnd(&stream);
	88	return err;
	89	}
	90
	91	/* ===========================================================================
	92	*/
	93	int ZEXPORT compress (dest, destLen, source, sourceLen)
	94	Bytef *dest;
	95	uLongf *destLen;
	96	const Bytef *source;
	97	uLong sourceLen;
	98	{
	99	return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
	100	}
	101
	102	/* ===========================================================================
	103	If the default memLevel or windowBits for deflateInit() is changed, then
	104	this function needs to be updated.
	105	*/
	106	uLong ZEXPORT compressBound (sourceLen)
	107	uLong sourceLen;
	108	{
	109	return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + 11;
	110	}