// This is free and unencumbered software released into the public domain under The Unlicense (http://unlicense.org/) // main repo: https://github.com/wangyi-fudan/wyhash // author: 王一 Wang Yi // contributors: Reini Urban, Dietrich Epp, Joshua Haberman, Tommy Ettinger, Daniel Lemire, Otmar Ertl, cocowalla, leo-yuriev, Diego Barrios Romero, paulie-g, dumblob, Yann Collet, ivte-ms, hyb, James Z.M. Gao, easyaspi314 (Devin), TheOneric /* quick example: string s="fjsakfdsjkf"; uint64_t hash=wyhash(s.c_str(), s.size(), 0, _wyp); */ #ifndef wyhash_final_version_3 #define wyhash_final_version_3 #ifndef WYHASH_CONDOM //protections that produce different results: //1: normal valid behavior //2: extra protection against entropy loss (probability=2^-63), aka. "blind multiplication" #define WYHASH_CONDOM 1 #endif #ifndef WYHASH_32BIT_MUM //0: normal version, slow on 32 bit systems //1: faster on 32 bit systems but produces different results, incompatible with wy2u0k function #define WYHASH_32BIT_MUM 0 #endif //includes #include #include #if defined(_MSC_VER) && defined(_M_X64) #include #pragma intrinsic(_umul128) #endif //likely and unlikely macros #if defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__clang__) #define _likely_(x) __builtin_expect(x,1) #define _unlikely_(x) __builtin_expect(x,0) #else #define _likely_(x) (x) #define _unlikely_(x) (x) #endif //128bit multiply function static inline uint64_t _wyrot(uint64_t x) { return (x>>32)|(x<<32); } static inline void _wymum(uint64_t *A, uint64_t *B){ #if(WYHASH_32BIT_MUM) uint64_t hh=(*A>>32)*(*B>>32), hl=(*A>>32)*(uint32_t)*B, lh=(uint32_t)*A*(*B>>32), ll=(uint64_t)(uint32_t)*A*(uint32_t)*B; #if(WYHASH_CONDOM>1) *A^=_wyrot(hl)^hh; *B^=_wyrot(lh)^ll; #else *A=_wyrot(hl)^hh; *B=_wyrot(lh)^ll; #endif #elif defined(__SIZEOF_INT128__) __uint128_t r=*A; r*=*B; #if(WYHASH_CONDOM>1) *A^=(uint64_t)r; *B^=(uint64_t)(r>>64); #else *A=(uint64_t)r; *B=(uint64_t)(r>>64); #endif #elif defined(_MSC_VER) && defined(_M_X64) #if(WYHASH_CONDOM>1) uint64_t a, b; a=_umul128(*A,*B,&b); *A^=a; *B^=b; #else *A=_umul128(*A,*B,B); #endif #else uint64_t ha=*A>>32, hb=*B>>32, la=(uint32_t)*A, lb=(uint32_t)*B, hi, lo; uint64_t rh=ha*hb, rm0=ha*lb, rm1=hb*la, rl=la*lb, t=rl+(rm0<<32), c=t>32)+(rm1>>32)+c; #if(WYHASH_CONDOM>1) *A^=lo; *B^=hi; #else *A=lo; *B=hi; #endif #endif } //multiply and xor mix function, aka MUM static inline uint64_t _wymix(uint64_t A, uint64_t B){ _wymum(&A,&B); return A^B; } //endian macros #ifndef WYHASH_LITTLE_ENDIAN #if defined(_WIN32) || defined(__LITTLE_ENDIAN__) || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) #define WYHASH_LITTLE_ENDIAN 1 #elif defined(__BIG_ENDIAN__) || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) #define WYHASH_LITTLE_ENDIAN 0 #else #warning could not determine endianness! Falling back to little endian. #define WYHASH_LITTLE_ENDIAN 1 #endif #endif //read functions #if (WYHASH_LITTLE_ENDIAN) static inline uint64_t _wyr8(const uint8_t *p) { uint64_t v; memcpy(&v, p, 8); return v;} static inline uint64_t _wyr4(const uint8_t *p) { uint32_t v; memcpy(&v, p, 4); return v;} #elif defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__clang__) static inline uint64_t _wyr8(const uint8_t *p) { uint64_t v; memcpy(&v, p, 8); return __builtin_bswap64(v);} static inline uint64_t _wyr4(const uint8_t *p) { uint32_t v; memcpy(&v, p, 4); return __builtin_bswap32(v);} #elif defined(_MSC_VER) static inline uint64_t _wyr8(const uint8_t *p) { uint64_t v; memcpy(&v, p, 8); return _byteswap_uint64(v);} static inline uint64_t _wyr4(const uint8_t *p) { uint32_t v; memcpy(&v, p, 4); return _byteswap_ulong(v);} #else static inline uint64_t _wyr8(const uint8_t *p) { uint64_t v; memcpy(&v, p, 8); return (((v >> 56) & 0xff)| ((v >> 40) & 0xff00)| ((v >> 24) & 0xff0000)| ((v >> 8) & 0xff000000)| ((v << 8) & 0xff00000000)| ((v << 24) & 0xff0000000000)| ((v << 40) & 0xff000000000000)| ((v << 56) & 0xff00000000000000)); } static inline uint64_t _wyr4(const uint8_t *p) { uint32_t v; memcpy(&v, p, 4); return (((v >> 24) & 0xff)| ((v >> 8) & 0xff00)| ((v << 8) & 0xff0000)| ((v << 24) & 0xff000000)); } #endif #ifdef __BMI2__ #include #endif //wyhash main function; assumes len>0 and that it can read past the end of the input FORCE_INLINE uint64_t wyhash(const void *key, size_t len, uint64_t seed, const uint64_t *secret){ const uint8_t *p = (const uint8_t *)key; seed^=*secret; uint64_t a, b; if (_likely_(len<=16)) { #ifdef __BMI2__ if (len>8) { a = _wyr8(p); b = _bzhi_u64(_wyr8(p+8), (len-8)*8); } else { a = 0; b = _bzhi_u64(_wyr8(p ), len *8); } #else if (len==16) { a = _wyr8(p); b = _wyr8(p+8); } else { if (len>=8) { a = _wyr8(p); p+= 8; } else a = 0; b = _wyr8(p) & (((uint64_t)1)<<((8*len)&63))-1; } #endif } else { size_t i=len; if (_unlikely_(i>48)){ uint64_t see1=seed, see2=seed; do { seed=_wymix(_wyr8(p)^secret[1],_wyr8(p+8)^seed); see1=_wymix(_wyr8(p+16)^secret[2],_wyr8(p+24)^see1); see2=_wymix(_wyr8(p+32)^secret[3],_wyr8(p+40)^see2); p+=48; i-=48; } while (_likely_(i>48)); seed^=see1^see2; } while (_unlikely_(i>16)) { seed=_wymix(_wyr8(p)^secret[1],_wyr8(p+8)^seed); i-=16; p+=16; } a=_wyr8(p+i-16); b=_wyr8(p+i-8); } return _wymix(secret[1]^len,_wymix(a^secret[1],b^seed)); } //the default secret parameters static const uint64_t _wyp[4] = {0xa0761d6478bd642full, 0xe7037ed1a0b428dbull, 0x8ebc6af09c88c6e3ull, 0x589965cc75374cc3ull}; //a useful 64bit-64bit mix function to produce deterministic pseudo random numbers that can pass BigCrush and PractRand static inline uint64_t wyhash64(uint64_t A, uint64_t B){ A^=0xa0761d6478bd642full; B^=0xe7037ed1a0b428dbull; _wymum(&A,&B); return _wymix(A^0xa0761d6478bd642full,B^0xe7037ed1a0b428dbull);} //The wyrand PRNG that pass BigCrush and PractRand static inline uint64_t wyrand(uint64_t *seed){ *seed+=0xa0761d6478bd642full; return _wymix(*seed,*seed^0xe7037ed1a0b428dbull);} //convert any 64 bit pseudo random numbers to uniform distribution [0,1). It can be combined with wyrand, wyhash64 or wyhash. static inline double wy2u01(uint64_t r){ const double _wynorm=1.0/(1ull<<52); return (r>>12)*_wynorm;} //convert any 64 bit pseudo random numbers to APPROXIMATE Gaussian distribution. It can be combined with wyrand, wyhash64 or wyhash. static inline double wy2gau(uint64_t r){ const double _wynorm=1.0/(1ull<<20); return ((r&0x1fffff)+((r>>21)&0x1fffff)+((r>>42)&0x1fffff))*_wynorm-3.0;} #if(!WYHASH_32BIT_MUM) //fast range integer random number generation on [0,k) credit to Daniel Lemire. May not work when WYHASH_32BIT_MUM=1. It can be combined with wyrand, wyhash64 or wyhash. static inline uint64_t wy2u0k(uint64_t r, uint64_t k){ _wymum(&r,&k); return k; } #endif //make your own secret static inline void make_secret(uint64_t seed, uint64_t *secret){ uint8_t c[] = {15, 23, 27, 29, 30, 39, 43, 45, 46, 51, 53, 54, 57, 58, 60, 71, 75, 77, 78, 83, 85, 86, 89, 90, 92, 99, 101, 102, 105, 106, 108, 113, 114, 116, 120, 135, 139, 141, 142, 147, 149, 150, 153, 154, 156, 163, 165, 166, 169, 170, 172, 177, 178, 180, 184, 195, 197, 198, 201, 202, 204, 209, 210, 212, 216, 225, 226, 228, 232, 240 }; for(size_t i=0;i<4;i++){ uint8_t ok; do{ ok=1; secret[i]=0; for(size_t j=0;j<64;j+=8) secret[i]|=((uint64_t)c[wyrand(&seed)%sizeof(c)])< idx(size); // allocate the index of fixed size. idx MUST be zeroed. vector value(size); // we only care about the index, user should maintain his own value vectors. string key="dhskfhdsj" // the object to be inserted into idx size_t pos=wyhashmap(idx.data(), idx.size(), key.c_str(), key.size(), 1); // get the position and insert if(pos */