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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#ifndef _STRINGHASH_HXX
#define _STRINGHASH_HXX
#include <tools/string.hxx>
struct StringEq
{
sal_Bool operator() ( const String *r1,
const String *r2) const
{
return r1->Equals(*r2);
}
};
struct StringEqRef
{
sal_Bool operator() (const String &r1, const String &r2) const
{
return r1.Equals(r2);
}
};
struct StringHash
{
size_t operator() ( const String *rString) const
{
sal_Int32 h, nLen;
h = nLen = rString->Len();
const sal_Unicode *pStr = rString->GetBuffer();
if ( nLen < 16 )
while ( nLen-- > 0 )
h = (h*37) + *(pStr++);
else
{
sal_Int32 nSkip;
const sal_Unicode* pEndStr = pStr+nLen-5;
/* only sample some characters */
/* the first 3, some characters between, and the last 5 */
h = (h*39) + *(pStr++);
h = (h*39) + *(pStr++);
h = (h*39) + *(pStr++);
nSkip = nLen / nLen < 32 ? 4 : 8;
nLen -= 8;
while ( nLen > 0 )
{
h = (h*39) + ( *pStr );
pStr += nSkip;
nLen -= nSkip;
}
h = (h*39) + *(pEndStr++);
h = (h*39) + *(pEndStr++);
h = (h*39) + *(pEndStr++);
h = (h*39) + *(pEndStr++);
h = (h*39) + *(pEndStr++);
}
return h;
}
size_t operator() (const String & rStr) const
{
return (*this)(&rStr);
}
};
struct StringHashRef
{
size_t operator () (const String &rStr) const
{
StringHash aStrHash;
return aStrHash(&rStr);
}
};
#endif // _STRINGHASH_HXX
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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