hxmaputils.cpp

著名的 helix realplayer 基于手机 symbian 系统的 播放器全套源代码

/* ***** BEGIN LICENSE BLOCK ***** 
 * Version: RCSL 1.0/RPSL 1.0 
 *  
 * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved. 
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 * Version 1.0 (the "RPSL") available at 
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 * the file under the RealNetworks Community Source License Version 1.0 
 * (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 RealNetworks.  You may not use this file except in 
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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 portions 
 * it created. 
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 * This file, and the files included with this file, is distributed and made 
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#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;
}