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/*************************************************************************
*
* OpenOffice.org - a multi-platform office productivity suite
*
* $RCSfile: stringhash.hxx,v $
*
* $Revision: 1.5 $
*
* last change: $Author: rt $ $Date: 2005-09-09 02:10:34 $
*
* The Contents of this file are made available subject to
* the terms of GNU Lesser General Public License Version 2.1.
*
*
* GNU Lesser General Public License Version 2.1
* =============================================
* Copyright 2005 by Sun Microsystems, Inc.
* 901 San Antonio Road, Palo Alto, CA 94303, USA
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
************************************************************************/
#ifndef _STRINGHASH_HXX
#define _STRINGHASH_HXX
#ifndef _STRING_HXX
#include <tools/string.hxx>
#endif
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
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