From 3944fd34ec9b7b7bf252c7169a7ebc9b84e95fbf Mon Sep 17 00:00:00 2001 From: kcwu <kcwu@63ad8ddf-47c3-0310-b6dd-a9e9d9715204> Date: Fri, 25 Feb 2005 10:59:22 +0000 Subject: import FNV hash function. rewrite getkeep() for memory saving git-svn-id: http://opensvn.csie.org/pttbbs/trunk/pttbbs@2544 63ad8ddf-47c3-0310-b6dd-a9e9d9715204 --- include/fnv_hash.h | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++ include/pttstruct.h | 3 +- 2 files changed, 108 insertions(+), 2 deletions(-) create mode 100644 include/fnv_hash.h (limited to 'include') diff --git a/include/fnv_hash.h b/include/fnv_hash.h new file mode 100644 index 00000000..9d8851bd --- /dev/null +++ b/include/fnv_hash.h @@ -0,0 +1,107 @@ +/* + * Fowler / Noll / Vo Hash (FNV Hash) + * http://www.isthe.com/chongo/tech/comp/fnv/ + * + * This is an implementation of the algorithms posted above. + * This file is placed in the public domain by Peter Wemm. + * + * $FreeBSD: src/sys/sys/fnv_hash.h,v 1.2 2001/03/20 02:10:18 peter Exp $ + */ + +typedef unsigned int Fnv32_t; +typedef unsigned long long Fnv64_t; + +#define FNV1_32_INIT ((Fnv32_t) 33554467UL) +#define FNV1_64_INIT ((Fnv64_t) 0xcbf29ce484222325ULL) + +#define FNV_32_PRIME ((Fnv32_t) 0x01000193UL) +#define FNV_64_PRIME ((Fnv64_t) 0x100000001b3ULL) + +static __inline Fnv32_t +fnv_32_buf(const void *buf, size_t len, Fnv32_t hval) +{ + const unsigned char *s = (const unsigned char *)buf; + + while (len-- != 0) { + hval *= FNV_32_PRIME; + hval ^= *s++; + } + return hval; +} + +static __inline Fnv32_t +fnv_32_str(const char *str, Fnv32_t hval) +{ + const unsigned char *s = (const unsigned char *)str; + Fnv32_t c; + + while ((c = *s++) != 0) { + hval *= FNV_32_PRIME; + hval ^= c; + } + return hval; +} + +static __inline Fnv32_t +fnv1a_32_str(const char *str, Fnv32_t hval) +{ + const unsigned char *s = (const unsigned char *)str; + Fnv32_t c; + + while ((c = *s++) != 0) { + hval ^= c; + hval *= FNV_32_PRIME; + } + return hval; +} + +static __inline Fnv32_t +fnv1a_32_strcase(const char *str, Fnv32_t hval) +{ + const unsigned char *s = (const unsigned char *)str; + Fnv32_t c; + + while ((c = *s++) != 0) { + hval ^= toupper(c); + hval *= FNV_32_PRIME; + } + return hval; +} + +static __inline Fnv64_t +fnv_64_buf(const void *buf, size_t len, Fnv64_t hval) +{ + const unsigned char *s = (const unsigned char *)buf; + + while (len-- != 0) { + hval *= FNV_64_PRIME; + hval ^= *s++; + } + return hval; +} + +static __inline Fnv64_t +fnv_64_str(const char *str, Fnv64_t hval) +{ + const unsigned char *s = (const unsigned char *)str; + Fnv64_t c; + + while ((c = *s++) != 0) { + hval *= FNV_64_PRIME; + hval ^= c; + } + return hval; +} + +static __inline Fnv64_t +fnv1a_64_strcase(const char *str, Fnv64_t hval) +{ + const unsigned char *s = (const unsigned char *)str; + Fnv64_t c; + + while ((c = *s++) != 0) { + hval ^= toupper(c); + hval *= FNV_64_PRIME; + } + return hval; +} diff --git a/include/pttstruct.h b/include/pttstruct.h index ce5b5382..ca5ed911 100644 --- a/include/pttstruct.h +++ b/include/pttstruct.h @@ -429,10 +429,9 @@ typedef struct crosspost_t { #define SORT_BY_SEX 5 typedef struct keeploc_t { - char *key; + unsigned int hashkey; int top_ln; int crs_ln; - struct keeploc_t *next; } keeploc_t; #define VALID_USHM_ENTRY(X) ((X) >= 0 && (X) < USHM_SIZE) -- cgit v1.2.3