package xxh3 import "math/bits" // Hash returns the hash of the byte slice. func Hash(b []byte) uint64 { return hashAny(*(*str)(ptr(&b))) } // Hash returns the hash of the string slice. func HashString(s string) uint64 { return hashAny(*(*str)(ptr(&s))) } func hashAny(s str) (acc u64) { p, l := s.p, s.l switch { case l <= 16: switch { case l > 8: // 9-16 inputlo := readU64(p, 0) ^ (key64_024 ^ key64_032) inputhi := readU64(p, ui(l)-8) ^ (key64_040 ^ key64_048) folded := mulFold64(inputlo, inputhi) return xxh3Avalanche(u64(l) + bits.ReverseBytes64(inputlo) + inputhi + folded) case l > 3: // 4-8 input1 := readU32(p, 0) input2 := readU32(p, ui(l)-4) input64 := u64(input2) + u64(input1)<<32 keyed := input64 ^ (key64_008 ^ key64_016) return rrmxmx(keyed, u64(l)) case l == 3: // 3 c12 := u64(readU16(p, 0)) c3 := u64(readU8(p, 2)) acc = c12<<16 + c3 + 3<<8 case l > 1: // 2 c12 := u64(readU16(p, 0)) acc = c12*(1<<24+1)>>8 + 2<<8 case l == 1: // 1 c1 := u64(readU8(p, 0)) acc = c1*(1<<24+1<<16+1) + 1<<8 default: // 0 return 0x2d06800538d394c2 // xxh_avalanche(key64_056 ^ key64_064) } acc ^= u64(key32_000 ^ key32_004) return xxhAvalancheSmall(acc) case l <= 128: acc = u64(l) * prime64_1 if l > 32 { if l > 64 { if l > 96 { acc += mulFold64(readU64(p, 6*8)^key64_096, readU64(p, 7*8)^key64_104) acc += mulFold64(readU64(p, ui(l)-8*8)^key64_112, readU64(p, ui(l)-7*8)^key64_120) } // 96 acc += mulFold64(readU64(p, 4*8)^key64_064, readU64(p, 5*8)^key64_072) acc += mulFold64(readU64(p, ui(l)-6*8)^key64_080, readU64(p, ui(l)-5*8)^key64_088) } // 64 acc += mulFold64(readU64(p, 2*8)^key64_032, readU64(p, 3*8)^key64_040) acc += mulFold64(readU64(p, ui(l)-4*8)^key64_048, readU64(p, ui(l)-3*8)^key64_056) } // 32 acc += mulFold64(readU64(p, 0*8)^key64_000, readU64(p, 1*8)^key64_008) acc += mulFold64(readU64(p, ui(l)-2*8)^key64_016, readU64(p, ui(l)-1*8)^key64_024) return xxh3Avalanche(acc) case l <= 240: acc = u64(l) * prime64_1 acc += mulFold64(readU64(p, 0*16+0)^key64_000, readU64(p, 0*16+8)^key64_008) acc += mulFold64(readU64(p, 1*16+0)^key64_016, readU64(p, 1*16+8)^key64_024) acc += mulFold64(readU64(p, 2*16+0)^key64_032, readU64(p, 2*16+8)^key64_040) acc += mulFold64(readU64(p, 3*16+0)^key64_048, readU64(p, 3*16+8)^key64_056) acc += mulFold64(readU64(p, 4*16+0)^key64_064, readU64(p, 4*16+8)^key64_072) acc += mulFold64(readU64(p, 5*16+0)^key64_080, readU64(p, 5*16+8)^key64_088) acc += mulFold64(readU64(p, 6*16+0)^key64_096, readU64(p, 6*16+8)^key64_104) acc += mulFold64(readU64(p, 7*16+0)^key64_112, readU64(p, 7*16+8)^key64_120) // avalanche acc = xxh3Avalanche(acc) // trailing groups after 128 top := ui(l) &^ 15 for i := ui(8 * 16); i < top; i += 16 { acc += mulFold64(readU64(p, i+0)^readU64(key, i-125), readU64(p, i+8)^readU64(key, i-117)) } // last 16 bytes acc += mulFold64(readU64(p, ui(l)-16)^key64_119, readU64(p, ui(l)-8)^key64_127) return xxh3Avalanche(acc) default: acc = u64(l) * prime64_1 accs := [8]u64{ prime32_3, prime64_1, prime64_2, prime64_3, prime64_4, prime32_2, prime64_5, prime32_1, } if hasAVX512 && l >= avx512Switch { accumAVX512(&accs, p, key, u64(l)) } else if hasAVX2 { accumAVX2(&accs, p, key, u64(l)) } else if hasSSE2 { accumSSE(&accs, p, key, u64(l)) } else { accumScalar(&accs, p, key, u64(l)) } // merge accs acc += mulFold64(accs[0]^key64_011, accs[1]^key64_019) acc += mulFold64(accs[2]^key64_027, accs[3]^key64_035) acc += mulFold64(accs[4]^key64_043, accs[5]^key64_051) acc += mulFold64(accs[6]^key64_059, accs[7]^key64_067) return xxh3Avalanche(acc) } }