static unsigned long hashpjw(char *arKey, unsigned int nKeyLength)
{
    unsigned long h = 0, g;
    char *arEnd=arKey+nKeyLength; 

    while (arKey < arEnd) {
        h = (h << 4) + *arKey++;
        if ((g = (h & 0xF0000000))) {
            h = h ^ (g >> 24);
            h = h ^ g;
        }
    }

    return h;
}

#ifndef NEW_HASH_FUNCTION 

/* Calc hashvalue for a key (區分大小寫)*/
static uint calc_hashnr(const byte *key,uint length)
{
    register uint nr=1, nr2=4; 

    while (length––)
    {
        nr^= (((nr & 63)+nr2)*((uint) (uchar) *key++))+ (nr << 8);
        nr2+=3;
    } 

    return((uint) nr);
} 

/* Calc hashvalue for a key, case indepenently （不區分大小寫） */
static uint calc_hashnr_caseup(const byte *key,uint length)
{
    register uint nr=1, nr2=4; 

    while (length–)
    {
        nr^= (((nr & 63)+nr2)*((uint) (uchar) toupper(*key++)))+ (nr << 8);
        nr2+=3;
    } 

    return((uint) nr);
}

#else
/* 
* Fowler/Noll/Vo hash 
* 
* The basis of the hash algorithm was taken from an idea sent by email to the 
* IEEE Posix P1003.2 mailing list from Phong Vo (kpv@research.att.com) and 
* Glenn Fowler (gsf@research.att.com). Landon Curt Noll (chongo@toad.com) 
* later improved on their algorithm. 
* 
* The magic is in the interesting relationship between the special prime 
* 16777619 (2^24 + 403) and 2^32 and 2^8. 
* 
* This hash produces the fewest collisions of any function that we’ve seen so 
* far, and works well on both numbers and strings. 
*/

//（區分大小寫）
uint calc_hashnr(const byte *key, uint len)
{
    const byte *end=key+len;
    uint hash; 

    for (hash = 0; key < end; key++)
    {
        hash *= 16777619;
        hash ^= (uint) *(uchar*) key;
    } 

    return (hash);
} 

//（不區分大小寫）
uint calc_hashnr_caseup(const byte *key, uint len)
{
    const byte *end=key+len;
    uint hash; 

    for (hash = 0; key < end; key++)
    {
        hash *= 16777619;
        hash ^= (uint) (uchar) toupper(*key);
    } 

    return (hash);
}
#endif

unsigned int hash(char *str)
{
    register unsigned int h;
    register unsigned char *p; 

    for(h=0, p = (unsigned char *)str; *p ; p++)
        h = 31 * h + *p; 

    return h;
}