utils/wvhash.cc

   1 #include "wvhash.h"
   2
   3 // Note: this hash function is case-insensitive since it ignores the
   4 // bit in ASCII that defines case.  You may want to take advantage of this.
   5 unsigned int WvHash(const char *s)
   6 {
   7     unsigned hash = 0, slide, andval;
   8     if (!s) return 0;
   9
  10     slide = sizeof(hash)*8 - 5;
  11     andval = 0x1F << slide;
  12
  13     while (*s)
  14         hash = (hash<<4) ^ (*(s++) & 0x1F) ^ ((hash & andval) >> slide);
  15
  16     return hash;
  17 }
  18
  19 unsigned WvHash(WvStringParm s)
  20 {
  21     return !s ? 0 : WvHash((const char *)s);
  22 }
  23
  24 // FIXME: does this suck?
  25 unsigned WvHash(const int &i)
  26 {
  27     return i;
  28 }
  29
  30
  31 unsigned WvHash(const void *p)
  32 {
  33     return reinterpret_cast<unsigned long>(p);
  34 }
  35