hashfunctions.c (995B)
1 2 #include "libsheepyObject.h" 3 #include "hashfunctions.h" 4 5 /** 6 * FNV 1-a string hash. 7 */ 8 u32 strHashFNV1A(char *k) { 9 u32 hash = 2166136261U; 10 for (const u8* ptr = (u8*)k; *ptr; ptr++) { 11 hash = (hash ^ *ptr) * 16777619U; 12 } 13 return hash; 14 } 15 16 /** 17 * Integer reversible hash function for 32 bits. 18 * Implementation of the Robert Jenkins "4-byte Integer Hashing", 19 * from http://burtleburtle.net/bob/hash/integer.html 20 */ 21 u32 u32Hash(u32 k) { 22 k -= k << 6; 23 k ^= k >> 17; 24 k -= k << 9; 25 k ^= k << 4; 26 k -= k << 3; 27 k ^= k << 10; 28 k ^= k >> 15; 29 return k; 30 } 31 32 /** 33 * Integer reversible hash function for 64 bits. 34 * Implementation of the Thomas Wang "Integer Hash Function", 35 * from http://web.archive.org/web/20071223173210/http://www.concentric.net/~Ttwang/tech/inthash.htm 36 */ 37 u64 u64Hash(u64 k) { 38 k = ~k + (k << 21); 39 k = k ^ (k >> 24); 40 k = k + (k << 3) + (k << 8); 41 k = k ^ (k >> 14); 42 k = k + (k << 2) + (k << 4); 43 k = k ^ (k >> 28); 44 k = k + (k << 31); 45 return k; 46 } 47