ref: d181a7286ee394a8a7b6ca7148904e5827ecabcb
dir: /hash.c/
// metrohash64.cpp // // The MIT License (MIT) // // Copyright (c) 2015 J. Andrew Rogers // // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to deal // in the Software without restriction, including without limitation the rights // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell // copies of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in all // copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE // SOFTWARE. // #include <u.h> #include <libc.h> #include <fcall.h> #include <avl.h> #include "dat.h" #include "fns.h" #define _le64toh(x) \ GBIT64((char*)&x) #define ROTATE(x, b) (u64int)( ((x) << (b)) | ( (x) >> (64 - (b))) ) #define HALF_ROUND(a,b,c,d,s,t) \ a += b; c += d; \ b = ROTATE(b, s) ^ a; \ d = ROTATE(d, t) ^ c; \ a = ROTATE(a, 32); #define DOUBLE_ROUND(v0,v1,v2,v3) \ HALF_ROUND(v0,v1,v2,v3,13,16); \ HALF_ROUND(v2,v1,v0,v3,17,21); \ HALF_ROUND(v0,v1,v2,v3,13,16); \ HALF_ROUND(v2,v1,v0,v3,17,21); #define rotate_right(v, k)\ ((v >> k) | (v << (64 - k))) #define read_u64(ptr) \ (*(u64int*)ptr) #define read_u32(ptr) \ (*(u32int*)ptr) #define read_u16(ptr) \ (*(u16int*)ptr) #define read_u8(ptr) \ (*(u8int*)ptr) uvlong metrohash64_1(void * key, u64int len, u32int seed) { static const u64int k0 = 0xC83A91E1; static const u64int k1 = 0x8648DBDB; static const u64int k2 = 0x7BDEC03B; static const u64int k3 = 0x2F5870A5; const uchar * ptr = key; const uchar * const end = ptr + len; u64int hash = ((((u64int) seed) + k2) * k0) + len; if(len >= 32){ u64int v[4]; v[0] = hash; v[1] = hash; v[2] = hash; v[3] = hash; do{ v[0] += read_u64(ptr) * k0; ptr += 8; v[0] = rotate_right(v[0],29) + v[2]; v[1] += read_u64(ptr) * k1; ptr += 8; v[1] = rotate_right(v[1],29) + v[3]; v[2] += read_u64(ptr) * k2; ptr += 8; v[2] = rotate_right(v[2],29) + v[0]; v[3] += read_u64(ptr) * k3; ptr += 8; v[3] = rotate_right(v[3],29) + v[1]; } while(ptr <= (end - 32)); v[2] ^= rotate_right(((v[0] + v[3]) * k0) + v[1], 33) * k1; v[3] ^= rotate_right(((v[1] + v[2]) * k1) + v[0], 33) * k0; v[0] ^= rotate_right(((v[0] + v[2]) * k0) + v[3], 33) * k1; v[1] ^= rotate_right(((v[1] + v[3]) * k1) + v[2], 33) * k0; hash += v[0] ^ v[1]; } if((end - ptr) >= 16){ u64int v0 = hash + (read_u64(ptr) * k0); ptr += 8; v0 = rotate_right(v0,33) * k1; u64int v1 = hash + (read_u64(ptr) * k1); ptr += 8; v1 = rotate_right(v1,33) * k2; v0 ^= rotate_right(v0 * k0, 35) + v1; v1 ^= rotate_right(v1 * k3, 35) + v0; hash += v1; } if((end - ptr) >= 8){ hash += read_u64(ptr) * k3; ptr += 8; hash ^= rotate_right(hash, 33) * k1; } if((end - ptr) >= 4){ hash += read_u32(ptr) * k3; ptr += 4; hash ^= rotate_right(hash, 15) * k1; } if((end - ptr) >= 2){ hash += read_u16(ptr) * k3; ptr += 2; hash ^= rotate_right(hash, 13) * k1; } if((end - ptr) >= 1){ hash += read_u8 (ptr) * k3; hash ^= rotate_right(hash, 25) * k1; } hash ^= rotate_right(hash, 33); hash *= k0; hash ^= rotate_right(hash, 33); return hash; } uvlong bufhash(void *src, usize len) { return metrohash64_1(src, len, 0x6765); } uvlong blkhash(Blk *b) { return metrohash64_1(b->buf, Blksz, 0x6765); } u32int ihash(uvlong x) { x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9ULL; x = (x ^ (x >> 27)) * 0x94d049bb133111ebULL; x = x ^ (x >> 31); return x; }