hxmaputils.cpp

来自「symbian 下的helix player源代码」· C++ 代码 · 共 129 行

/* ***** BEGIN LICENSE BLOCK *****
 * Source last modified: $Id: hxmaputils.cpp,v 1.5.32.3 2004/07/09 01:45:59 hubbe Exp $
 * 
 * Portions Copyright (c) 1995-2004 RealNetworks, Inc. All Rights Reserved.
 * 
 * The contents of this file, and the files included with this file,
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 * Source License (the "RPSL") available at
 * http://www.helixcommunity.org/content/rpsl unless you have licensed
 * the file under the current version of the RealNetworks Community
 * Source License (the "RCSL") available at
 * http://www.helixcommunity.org/content/rcsl, in which case the RCSL
 * will apply. You may also obtain the license terms directly from
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 * to this file, the RCSL.  Please see the applicable RPSL or RCSL for
 * the rights, obligations and limitations governing use of the
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 * 
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 * "GPL") in which case the provisions of the GPL are applicable
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 * 
 * This file is part of the Helix DNA Technology. RealNetworks is the
 * developer of the Original Code and owns the copyrights in the
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 * This file, and the files included with this file, is distributed
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 * ***** END LICENSE BLOCK ***** */

#include "hxmaputils.h"

#include "hlxclib/ctype.h"
#include "hlxclib/string.h"

DECLARE_ITEMVEC_IMP(HlxMap,IntVec_t, int, 0, 0, 0);

ULONG32 HlxMap::StrHashFunc (const char* key, bool bCaseSens)
{
    // XXXSAB: Need something to reasonably distribute strings...anyone
    //         have an idea?
    ULONG32 ret = 0;

    if (key)
    {
        // XOR together sizeof(ULONG32) chunks of the key string...
        static const int wordSize = sizeof(ULONG32);

        const char* keySrc = key;
        int byteLen = strlen(key);
        int wordLen = byteLen / wordSize;
        
        ULONG32 intWord;
        char* pCharWord = (char*)&intWord;

        for (int i = 0; i < wordLen; ++i)
        {
            strncpy (pCharWord, keySrc, wordSize); /* Flawfinder: ignore */
            keySrc += wordSize; byteLen -= wordSize;

            if (! bCaseSens)
            {
                // If case INsensitive, downshift on the way into the
                // hash algorithm.
                char* pCurChar = pCharWord;
                for (int charIdx = 0;
                     charIdx < wordSize;
                     ++charIdx, ++pCurChar)
                {
                    if (isupper(*(pCurChar)))
                        *pCurChar = tolower(*pCurChar);
                }
            }

            ret ^= intWord;
        }

        if (byteLen > 0)
        {
            HX_ASSERT (byteLen < wordSize);
            intWord = 0;
            strncpy (pCharWord, keySrc, byteLen); /* Flawfinder: ignore */

            if (! bCaseSens)
            {
                // If case INsensitive, downshift on the way into the
                // hash algorithm.
                char* pCurChar = pCharWord;
                for (int charIdx = 0;
                     charIdx < byteLen;
                     ++charIdx, ++pCurChar)
                {
                    if (isupper(*(pCurChar)))
                        *pCurChar = tolower(*pCurChar);
                }
            }
            ret ^= intWord;
        }
    }

#ifdef XXXSAB
    printf ("StrHashFunc(\"%s\", %s) -> %d\n",
            key,
            bCaseSens ? "true" : "false",
            ret);
#endif /* XXXSAB */

    return ret;
}