hash字符串 转数字，大全

 1. PHP中出现的字符串Hash函数　　　　static unsigned long hashpjw(char *arKey, unsigned int nKeyLength){ unsigned long h = 0, g; char *arEnd=arKey+nKeyLength; 　　　　 while (arKey < arEnd) { h = (h << 4) + *arKey++; if ((g = (h & 0xF0000000))) { h = h ^ (g >> 24); h = h ^ g; } } return h;}　　　　//2. OpenSSL中出现的字符串Hash函数　　　　unsigned long lh_strhash(char *str){ int i,l; unsigned long ret=0; unsigned short *s; 　　　　 if (str == NULL) return 0; l=(strlen(str)+1)/2; s=(unsigned short *)str; for (i=0; i ret^=(s[i]<<(i&0x0f)); return ret;}/* * The following hash seems to work very well on normal text strings * distributes on %2^n quite well, not as good as MD5, but still good.*/unsigned long lh_strhash(const char *c){ unsigned long ret=0; long n; unsigned long v; int r;　　　　 if ((c == NULL) || (*c == '\0')) return(ret); /* unsigned char b[16]; MD5(c,strlen(c),b); return(b[0]|(b[1]<<8)|(b[2]<<16)|(b[3]<<24 n="0x100;" while="" c="" v="n|(*c);" n="" 0x100="" r="(int)((v">>2)^v)&0x0f; ret=(ret(32-r)); ret&=0xFFFFFFFFL; ret^=v*v; c++; } return((ret>>16)^ret);} 　　　　 　　　　//3. MySql中出现的字符串Hash函数(Mysql中对字符串Hash函数还区分了大小写)　　　　#ifndef NEW_HASH_FUNCTION　　　　/* Calc hashvalue for a key */static uint calc_hashnr(const byte *key,uint length){ register uint nr=1, nr2=4; while (length--) {nr^= (((nr & 63)+nr2)*((uint) (uchar) *key++))+ (nr << 8); nr2+=3; } return((uint) nr);} 　　　　/* Calc hashvalue for a key, case indepenently */static uint calc_hashnr_caseup(const byte *key,uint length){ register uint nr=1, nr2=4; while (length--) {nr^= (((nr & 63)+nr2)*((uint) (uchar) toupper(*key++)))+ (nr << 8); nr2+=3; } return((uint) nr);} 　　　　#else　　　　/* * Fowler/Noll/Vo hash * * The basis of the hash algorithm was taken from an idea sent by email to the * IEEE Posix P1003.2 mailing list from Phong Vo (kpv@research.att.com) and * Glenn Fowler (gsf@research.att.com). Landon Curt Noll (chongo@toad.com) * later improved on their algorithm. * * The magic is in the interesting relationship between the special prime * 16777619 (2^24 + 403) and 2^32 and 2^8. * * This hash produces the fewest collisions of any function that we've seen so * far, and works well on both numbers and strings. */　　　　uint calc_hashnr(const byte *key, uint len){ const byte *end=key+len; uint hash; for (hash = 0; key < end; key++) {hash *= 16777619;hash ^= (uint) *(uchar*) key; } return (hash);} 　　　　uint calc_hashnr_caseup(const byte *key, uint len){ const byte *end=key+len; uint hash; for (hash = 0; key < end; key++) {hash *= 16777619;hash ^= (uint) (uchar) toupper(*key); } return (hash);} 　　　　#endif　　　　 　　　　//4. 一个开源的哈希表源码实现struct entry{ void *k, *v; unsigned int h; struct entry *next;};struct hashtable { unsigned int tablelength; struct entry **table; unsigned int entrycount; unsigned int loadlimit; unsigned int primeindex; unsigned int (*hashfn) (void *k); int (*eqfn) (void *k1, void *k2);};　　static const unsigned int primes[] = { 53, 97, 193, 389, 769, 1543, 3079, 6151, 12289, 24593, 49157, 98317, 196613, 393241, 786433, 1572869, 3145739, 6291469, 12582917, 25165843, 50331653, 100663319, 201326611, 402653189, 805306457, 1610612741};const unsigned int prime_table_length = sizeof(primes)/sizeof(primes[0]);const float max_load_factor = 0.65;　　struct hashtable *create_hashtable(unsigned int minsize, unsigned int (*hashf) (void*), int (*eqf) (void*,void*)){ struct hashtable *h; unsigned int pindex, size = primes[0]; /* Check requested hashtable isn't too large */ if (minsize > (1u << 30)) return NULL; /* Enforce size as prime */ for (pindex=0; pindex < prime_table_length; pindex++) { if (primes[pindex] > minsize) { size=prime[pindex]; break; } } h = (struct hashtable *)malloc(sizeof(struct hashtable)); if (NULL == h) return NULL; /*oom*/ h->table = (struct entry **)malloc(sizeof(struct entry*) * size); if (NULL == h->table) { free(h); return NULL; } /*oom*/ memset(h->table, 0, size * sizeof(struct entry *)); h->tablelength = size; h->primeindex = pindex; h->entrycount = 0; h->hashfn = hashf; h->eqfn = eqf; h->loadlimit = (unsigned int) ceil(size * max_load_factor); return h;}　　unsigned int hash(struct hashtable *h, void *k){ /* Aim to protect against poor hash functions by adding logic here - logic taken from java 1.4 hashtable source */ unsigned int i = h->hashfn(k); i += ~(i << 9); i ^= ((i >> 14) | (i << 18)); /* >>> */ i += (i << 4); i ^= ((i >> 10) | (i << 22)); /* >>> */ return i;}　　 　　5. 另一些字符串Hash函数 　　　　unsigned int hash(char *str){ register unsigned int h; register unsigned char *p;　　　　 for(h=0, p = (unsigned char *)str; *p ; p++) h = 31 * h + *p;　　　　 return h;}　　　　unsigned int hash_func(char *str, int len){ register unsigned int sum = 0; register unsigned int h = 0; register char *p = str;　　　　 while(p - s < len) { register unsigned short a = *(p++); sum ^= a * (p - str); h ^= a / (p - str); } return ((sum << 16) | h) % MAX_PRIME_LESS_THAN_HASH_LEN;}　　　　// RS Hash Function unsigned int RSHash( char *str){ unsigned int b = 378551; unsigned int a = 63689; unsigned int hash = 0;　　　　 while(*str) {hash = hash*a+(*str++); a*= b; } return hash&0x7FFFFFFF;} 　　　　// JS Hash Function unsigned int JSHash( char *str){ unsigned int hash = 1315423911;　　　　 while( *str)hash^=( (hash << 5)+(*str++)+(hash >> 2) ); return (hash & 0x7FFFFFFF );} 　　　　// P. J. Weinberger Hash Function unsigned int PJWHash( char *str){ unsigned int BitsInUnignedInt = (unsigned int)( sizeof(unsigned int)*8 ); unsigned int ThreeQuarters = (unsigned int)( (BitsInUnignedInt*3)/4 ); unsigned int OneEighth = (unsigned int)( BitsInUnignedInt/8 ); unsigned int HighBits = (unsigned int)(0xFFFFFFFF) << (BitsInUnignedInt-OneEighth); unsigned int hash = 0; unsigned int test = 0;　　　　 while( *str) {hash = (hash << OneEighth) + ( *str++ ); if ( (test = hash & HighBits) != 0 )hash = ( (hash^(test >> ThreeQuarters)) & ( ~HighBits )); } return (hash & 0x7FFFFFFF);} 　　　　// ELF Hash Function ，The mostly frequntly used oneunsigned int ELFHash( char * str){ unsigned int hash = 0; unsigned int x = 0;　　　　 while ( *str) {hash = (hash << 4) + ( *str++ ); if ( (x = hash & 0xF0000000L) != 0 ) {hash ^= (x >> 24);hash &= ~x; } } return (hash & 0x7FFFFFFF);} 　　　　// BKDR Hash Function unsigned int BKDRHash( char * str){ unsigned int seed = 131 ; // 31 131 1313 13131 131313 etc.. unsigned int hash = 0 ;　　　　 while ( * str)hash = hash*seed + ( *str++ ); return (hash & 0x7FFFFFFF);} 　　　　// SDBM Hash Function unsigned int SDBMHash( char * str){ unsigned int hash = 0;　　　　 while ( * str)hash = ( *str++ ) + ( hash << 6 ) + (hash << 16 ) - hash; return (hash & 0x7FFFFFFF);} 　　　　// DJB Hash Function unsigned int DJBHash( char * str){ unsigned int hash = 5381 ;　　　　 while ( * str)hash += (hash << 5) + ( *str++ ); return (hash & 0x7FFFFFFF );}　　　　// AP Hash Function unsigned nt APHash( char * str){ unsigned int hash = 0 ; int i;　　　　 for (i = 0; *str; i++ ) { if ( (i & 1) == 0 )hash ^= ((hash << 7 ) ^ ( *str++ ) ^ (hash >> 3)); else hash ^= ( ~((hash << 11 ) ^ ( *str++ ) ^ (hash >> 5 ))); } return (hash & 0x7FFFFFFF );} #日志日期：2007-5-30 星期三(Wednesday) 晴 弘扬正气，明辨是非，人人当有公民意识 新人注册>>登录名： 口令：输入您的评论：(不支持HTML标签)验证码：点击获取验证码 段首缩进两个汉字: 同时转发到微博 本文所属博客：胡言乱语引用地址： 　　 [关 闭] [返回顶部]本站域名:http://wzy_csu0310.blog.tianya.cn/ © 天涯社区