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Diffstat (limited to 'amiga/fnv/hash_32a.c')
| -rw-r--r-- | amiga/fnv/hash_32a.c | 144 |
1 files changed, 0 insertions, 144 deletions
diff --git a/amiga/fnv/hash_32a.c b/amiga/fnv/hash_32a.c deleted file mode 100644 index 8b10acf3e..000000000 --- a/amiga/fnv/hash_32a.c +++ /dev/null @@ -1,144 +0,0 @@ -/* - * hash_32 - 32 bit Fowler/Noll/Vo FNV-1a hash code - * - * @(#) $Revision: 5.1 $ - * @(#) $Id: hash_32a.c,v 5.1 2009/06/30 09:13:32 chongo Exp $ - * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_32a.c,v $ - * - *** - * - * Fowler/Noll/Vo hash - * - * The basis of this hash algorithm was taken from an idea sent - * as reviewer comments to the IEEE POSIX P1003.2 committee by: - * - * Phong Vo (http://www.research.att.com/info/kpv/) - * Glenn Fowler (http://www.research.att.com/~gsf/) - * - * In a subsequent ballot round: - * - * Landon Curt Noll (http://www.isthe.com/chongo/) - * - * improved on their algorithm. Some people tried this hash - * and found that it worked rather well. In an EMail message - * to Landon, they named it the ``Fowler/Noll/Vo'' or FNV hash. - * - * FNV hashes are designed to be fast while maintaining a low - * collision rate. The FNV speed allows one to quickly hash lots - * of data while maintaining a reasonable collision rate. See: - * - * http://www.isthe.com/chongo/tech/comp/fnv/index.html - * - * for more details as well as other forms of the FNV hash. - *** - * - * To use the recommended 32 bit FNV-1a hash, pass FNV1_32A_INIT as the - * Fnv32_t hashval argument to fnv_32a_buf() or fnv_32a_str(). - * - *** - * - * Please do not copyright this code. This code is in the public domain. - * - * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, - * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO - * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR - * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF - * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR - * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR - * PERFORMANCE OF THIS SOFTWARE. - * - * By: - * chongo <Landon Curt Noll> /\oo/\ - * http://www.isthe.com/chongo/ - * - * Share and Enjoy! :-) - */ - -#include <stdlib.h> -#include "fnv.h" - - -/* - * 32 bit magic FNV-1a prime - */ -#define FNV_32_PRIME ((Fnv32_t)0x01000193) - - -/* - * fnv_32a_buf - perform a 32 bit Fowler/Noll/Vo FNV-1a hash on a buffer - * - * input: - * buf - start of buffer to hash - * len - length of buffer in octets - * hval - previous hash value or 0 if first call - * - * returns: - * 32 bit hash as a static hash type - * - * NOTE: To use the recommended 32 bit FNV-1a hash, use FNV1_32A_INIT as the - * hval arg on the first call to either fnv_32a_buf() or fnv_32a_str(). - */ -Fnv32_t -fnv_32a_buf(void *buf, size_t len, Fnv32_t hval) -{ - unsigned char *bp = (unsigned char *)buf; /* start of buffer */ - unsigned char *be = bp + len; /* beyond end of buffer */ - - /* - * FNV-1a hash each octet in the buffer - */ - while (bp < be) { - - /* xor the bottom with the current octet */ - hval ^= (Fnv32_t)*bp++; - - /* multiply by the 32 bit FNV magic prime mod 2^32 */ -#if defined(NO_FNV_GCC_OPTIMIZATION) - hval *= FNV_32_PRIME; -#else - hval += (hval<<1) + (hval<<4) + (hval<<7) + (hval<<8) + (hval<<24); -#endif - } - - /* return our new hash value */ - return hval; -} - - -/* - * fnv_32a_str - perform a 32 bit Fowler/Noll/Vo FNV-1a hash on a string - * - * input: - * str - string to hash - * hval - previous hash value or 0 if first call - * - * returns: - * 32 bit hash as a static hash type - * - * NOTE: To use the recommended 32 bit FNV-1a hash, use FNV1_32A_INIT as the - * hval arg on the first call to either fnv_32a_buf() or fnv_32a_str(). - */ -Fnv32_t -fnv_32a_str(char *str, Fnv32_t hval) -{ - unsigned char *s = (unsigned char *)str; /* unsigned string */ - - /* - * FNV-1a hash each octet in the buffer - */ - while (*s) { - - /* xor the bottom with the current octet */ - hval ^= (Fnv32_t)*s++; - - /* multiply by the 32 bit FNV magic prime mod 2^32 */ -#if defined(NO_FNV_GCC_OPTIMIZATION) - hval *= FNV_32_PRIME; -#else - hval += (hval<<1) + (hval<<4) + (hval<<7) + (hval<<8) + (hval<<24); -#endif - } - - /* return our new hash value */ - return hval; -} |