mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-11-04 16:29:59 +00:00
127 lines
3.7 KiB
Go
127 lines
3.7 KiB
Go
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)
|
|
}
|
|
}
|