bin/vtfontcvt/fnv_hash.h

   1 /*
   2  * Fowler / Noll / Vo Hash (FNV Hash)
   3  * http://www.isthe.com/chongo/tech/comp/fnv/
   4  *
   5  * This is an implementation of the algorithms posted above.
   6  * This file is placed in the public domain by Peter Wemm.
   7  */
   8 #ifndef _SYS_FNV_HASH_H_
   9 #define _SYS_FNV_HASH_H_
  10
  11 typedef uint32_t Fnv32_t;
  12 typedef uint64_t Fnv64_t;
  13
  14 #define FNV1_32_INIT ((Fnv32_t)33554467UL)
  15 #define FNV1_64_INIT ((Fnv64_t)0xcbf29ce484222325ULL)
  16
  17 #define FNV_32_PRIME ((Fnv32_t)0x01000193UL)
  18 #define FNV_64_PRIME ((Fnv64_t)0x100000001b3ULL)
  19
  20 static __inline Fnv32_t
  21 fnv_32_buf(const void *buf, size_t len, Fnv32_t hval)
  22 {
  23         const uint8_t *s = (const uint8_t *)buf;
  24
  25         while (len-- != 0) {
  26                 hval *= FNV_32_PRIME;
  27                 hval ^= *s++;
  28         }
  29         return (hval);
  30 }
  31
  32 static __inline Fnv32_t
  33 fnv_32_str(const char *str, Fnv32_t hval)
  34 {
  35         const uint8_t *s = (const uint8_t *)str;
  36         Fnv32_t c;
  37
  38         while ((c = *s++) != 0) {
  39                 hval *= FNV_32_PRIME;
  40                 hval ^= c;
  41         }
  42         return (hval);
  43 }
  44
  45 static __inline Fnv64_t
  46 fnv_64_buf(const void *buf, size_t len, Fnv64_t hval)
  47 {
  48         const uint8_t *s = (const uint8_t *)buf;
  49
  50         while (len-- != 0) {
  51                 hval *= FNV_64_PRIME;
  52                 hval ^= *s++;
  53         }
  54         return (hval);
  55 }
  56
  57 static __inline Fnv64_t
  58 fnv_64_str(const char *str, Fnv64_t hval)
  59 {
  60         const uint8_t *s = (const uint8_t *)str;
  61         uint32_t c;
  62
  63         while ((c = *s++) != 0) {
  64                 hval *= FNV_64_PRIME;
  65                 hval ^= c;
  66         }
  67         return (hval);
  68 }
  69 #endif /* _SYS_FNV_HASH_H_ */