104 lines
3.7 KiB
C
104 lines
3.7 KiB
C
/*
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* Copyright (c) 2008-2016 Apple Inc. All rights reserved.
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*
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* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
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*
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* This file contains Original Code and/or Modifications of Original Code
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* as defined in and that are subject to the Apple Public Source License
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* Version 2.0 (the 'License'). You may not use this file except in
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* compliance with the License. The rights granted to you under the License
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* may not be used to create, or enable the creation or redistribution of,
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* unlawful or unlicensed copies of an Apple operating system, or to
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* circumvent, violate, or enable the circumvention or violation of, any
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* terms of an Apple operating system software license agreement.
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*
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* Please obtain a copy of the License at
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* http://www.opensource.apple.com/apsl/ and read it before using this file.
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*
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* The Original Code and all software distributed under the License are
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* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
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* Please see the License for the specific language governing rights and
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* limitations under the License.
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*
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* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
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*/
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/* compress.c -- compress a memory buffer
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* Copyright (C) 1995-2003 Jean-loup Gailly.
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* For conditions of distribution and use, see copyright notice in zlib.h
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*/
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/* @(#) $Id$ */
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#define ZLIB_INTERNAL
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#if KERNEL
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#include <libkern/zlib.h>
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#else
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#include "zlib.h"
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#endif /* KERNEL */
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/* ===========================================================================
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Compresses the source buffer into the destination buffer. The level
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parameter has the same meaning as in deflateInit. sourceLen is the byte
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length of the source buffer. Upon entry, destLen is the total size of the
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destination buffer, which must be at least 0.1% larger than sourceLen plus
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12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
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compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
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memory, Z_BUF_ERROR if there was not enough room in the output buffer,
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Z_STREAM_ERROR if the level parameter is invalid.
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*/
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int ZEXPORT
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compress2(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen,
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int level)
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{
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z_stream stream;
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int err;
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stream.next_in = (Bytef*)source;
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stream.avail_in = (uInt)sourceLen;
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#ifdef MAXSEG_64K
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/* Check for source > 64K on 16-bit machine: */
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if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
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#endif
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stream.next_out = dest;
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stream.avail_out = (uInt)*destLen;
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if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
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stream.zalloc = (alloc_func)0;
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stream.zfree = (free_func)0;
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stream.opaque = (voidpf)0;
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err = deflateInit(&stream, level);
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if (err != Z_OK) return err;
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err = deflate(&stream, Z_FINISH);
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if (err != Z_STREAM_END) {
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deflateEnd(&stream);
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return err == Z_OK ? Z_BUF_ERROR : err;
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}
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*destLen = stream.total_out;
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err = deflateEnd(&stream);
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return err;
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}
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/* ===========================================================================
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*/
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int ZEXPORT
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compress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
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{
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return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
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}
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/* ===========================================================================
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If the default memLevel or windowBits for deflateInit() is changed, then
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this function needs to be updated.
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*/
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uLong ZEXPORT
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compressBound(uLong sourceLen)
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{
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return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + 11;
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}
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