45 lines
1.7 KiB
C++
45 lines
1.7 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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/*
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* This file is part of the LibreOffice project.
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*
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* This file incorporates work covered by the following license notice:
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed
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* with this work for additional information regarding copyright
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* ownership. The ASF licenses this file to you under the Apache
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* License, Version 2.0 (the "License"); you may not use this file
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* except in compliance with the License. You may obtain a copy of
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* the License at http://www.apache.org/licenses/LICENSE-2.0 .
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*/
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#include <sal/types.h>
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#include <rtl/crc.h>
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#include <cassert>
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#include <zlib.h>
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// Zlib's crc32() is very fast, so simply use that one instead
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// of implementing this ourselves.
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sal_uInt32 SAL_CALL rtl_crc32 (
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sal_uInt32 Crc,
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const void *Data, sal_uInt32 DatLen) noexcept
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{
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// Check that our types map to zlib correctly.
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static_assert(sizeof(uLong) >= sizeof(sal_uInt32));
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static_assert(sizeof(uInt) >= sizeof(sal_uInt32));
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// Our API says that Crc should be initialized to 0, while
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// zlib says it should be initialized with 'crc32(0,Z_NULL,0)',
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// which however simply returns 0. Ensure this.
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assert(crc32(0, Z_NULL, 0) == 0);
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if (Data)
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Crc = crc32( Crc, static_cast<const Bytef*>(Data), DatLen);
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return Crc;
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}
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/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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