1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 /*
3 * This file is part of the LibreOffice project.
4 *
5 * This Source Code Form is subject to the terms of the Mozilla Public
6 * License, v. 2.0. If a copy of the MPL was not distributed with this
7 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
8 *
9 * This file incorporates work covered by the following license notice:
10 *
11 * Licensed to the Apache Software Foundation (ASF) under one or more
12 * contributor license agreements. See the NOTICE file distributed
13 * with this work for additional information regarding copyright
14 * ownership. The ASF licenses this file to you under the Apache
15 * License, Version 2.0 (the "License"); you may not use this file
16 * except in compliance with the License. You may obtain a copy of
17 * the License at http://www.apache.org/licenses/LICENSE-2.0 .
18 */
19
20 #include <sal/types.h>
21 #include <rtl/crc.h>
22 #include <cassert>
23
24 #include <zlib.h>
25
26 // Zlib's crc32() is very fast, so simply use that one instead
27 // of implementing this ourselves.
28
rtl_crc32(sal_uInt32 Crc,const void * Data,sal_uInt32 DatLen)29 sal_uInt32 SAL_CALL rtl_crc32 (
30 sal_uInt32 Crc,
31 const void *Data, sal_uInt32 DatLen) SAL_THROW_EXTERN_C()
32 {
33 // Check that our types map to zlib correctly.
34 static_assert(sizeof(uLong) >= sizeof(sal_uInt32));
35 static_assert(sizeof(uInt) >= sizeof(sal_uInt32));
36 // Our API says that Crc should be initialized to 0, while
37 // zlib says it should be initialized with 'crc32(0,Z_NULL,0)',
38 // which however simply returns 0. Ensure this.
39 assert(crc32(0, Z_NULL, 0) == 0);
40 if (Data)
41 Crc = crc32( Crc, static_cast<const Bytef*>(Data), DatLen);
42 return Crc;
43 }
44
45 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
46