/* ** A simple and fast generic string hasher based on Peter K. Pearson's ** article in CACM 33-6, pp. 677. */ static unsigned char T[] = { 1, 87, 49, 12, 176, 178, 102, 166, 121, 193, 6, 84, 249, 230, 44, 163, 14, 197, 213, 181, 161, 85, 218, 80, 64, 239, 24, 226, 236, 142, 38, 200, 110, 177, 104, 103, 141, 253, 255, 50, 77, 101, 81, 18, 45, 96, 31, 222, 25, 107, 190, 70, 86, 237, 240, 34, 72, 242, 20, 214, 244, 227, 149, 235, 97, 234, 57, 22, 60, 250, 82, 175, 208, 5, 127, 199, 111, 62, 135, 248, 174, 169, 211, 58, 66, 154, 106, 195, 245, 171, 17, 187, 182, 179, 0, 243, 132, 56, 148, 75, 128, 133, 158, 100, 130, 126, 91, 13, 153, 246, 216, 219, 119, 68, 223, 78, 83, 88, 201, 99, 122, 11, 92, 32, 136, 114, 52, 10, 138, 30, 48, 183, 156, 35, 61, 26, 143, 74, 251, 94, 129, 162, 63, 152, 170, 7, 115, 167, 241, 206, 3, 150, 55, 59, 151, 220, 90, 53, 23, 131, 125, 173, 15, 238, 79, 95, 89, 16, 105, 137, 225, 224, 217, 160, 37, 123, 118, 73, 2, 157, 46, 116, 9, 145, 134, 228, 207, 212, 202, 215, 69, 229, 27, 188, 67, 124, 168, 252, 42, 4, 29, 108, 21, 247, 19, 205, 39, 203, 233, 40, 186, 147, 198, 192, 155, 33, 164, 191, 98, 204, 165, 180, 117, 76, 140, 36, 210, 172, 41, 54, 159, 8, 185, 232, 113, 196, 231, 47, 146, 120, 51, 65, 28, 144, 254, 221, 93, 189, 194, 139, 112, 43, 71, 109, 184, 209, }; int hashstr16(const char *s, int maxn) { register unsigned char *p; register unsigned int h1, h2; register int i; if (!*s) return 0; p = (unsigned char *)s; h1 = 0; h2 = p[0]; for(i = maxn; p[1] && --i ; p++) { h1 = T[h1 ^ p[0]]; h2 = T[h2 ^ p[1]]; } return (h1 << 8) | h2; } int hashstr(const char *s, int maxn, int hashs) /* char *s; string to hash */ /* int maxn; maximum number of chars to consider */ /* int hashs; hash table size. */ { register unsigned int h; register unsigned char *p; register int i; if (hashs <= 256) { p = (unsigned char *)s; h = 0; for (i = maxn; *p && --i >= 0; p++) h = T[h ^ *p]; } else { h = hashstr16(s, maxn); } return (unsigned short)h % (unsigned)hashs; /* With 16 bit ints h has to be made positive first! */ } #if 0 /* * whashstr is faster than hashstr, but requires an even power-of-2 table size * I got it from Amylaars driver, he probably wrote it. */ /* char *s; string to hash */ /* int maxn; maximum number of chars to consider */ int whashstr(char *s, int maxn) { register unsigned char h; register unsigned char *p; register int i; for(h = 0, i = maxn, p = (unsigned char *)s; *p && --i >= 0; p++) h = T[h ^ *p]; if (*s) { unsigned short oh = h << 8; for(i = maxn, p = (unsigned char *)s, h = (*p++ + 1)&0xff; *p && --i ; p++) h = T[h ^ *p]; return oh + h; } return h; } int chashstr(char *s, int maxn) { register unsigned char h; register unsigned char *p; register int i; for(h = 0, i = maxn, p = (unsigned char *)s; *p && --i >= 0; p++) h = T[h ^ *p]; return h; } #endif