135 lines
4.3 KiB
Go
135 lines
4.3 KiB
Go
package xxh3
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import "math/bits"
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// HashSeed returns the hash of the byte slice with given seed.
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func HashSeed(b []byte, seed uint64) uint64 {
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return hashAnySeed(*(*str)(ptr(&b)), seed)
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}
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// HashStringSeed returns the hash of the string slice with given seed.
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func HashStringSeed(s string, seed uint64) uint64 {
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return hashAnySeed(*(*str)(ptr(&s)), seed)
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}
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func hashAnySeed(s str, seed uint64) (acc u64) {
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p, l := s.p, s.l
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switch {
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case l <= 16:
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switch {
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case l > 8:
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inputlo := readU64(p, 0) ^ (key64_024 ^ key64_032 + seed)
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inputhi := readU64(p, ui(l)-8) ^ (key64_040 ^ key64_048 - seed)
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folded := mulFold64(inputlo, inputhi)
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return xxh3Avalanche(u64(l) + bits.ReverseBytes64(inputlo) + inputhi + folded)
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case l > 3:
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seed ^= u64(bits.ReverseBytes32(u32(seed))) << 32
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input1 := readU32(p, 0)
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input2 := readU32(p, ui(l)-4)
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input64 := u64(input2) + u64(input1)<<32
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keyed := input64 ^ (key64_008 ^ key64_016 - seed)
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return rrmxmx(keyed, u64(l))
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case l == 3: // 3
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c12 := u64(readU16(p, 0))
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c3 := u64(readU8(p, 2))
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acc = c12<<16 + c3 + 3<<8
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case l > 1: // 2
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c12 := u64(readU16(p, 0))
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acc = c12*(1<<24+1)>>8 + 2<<8
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case l == 1: // 1
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c1 := u64(readU8(p, 0))
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acc = c1*(1<<24+1<<16+1) + 1<<8
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default:
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return xxhAvalancheSmall(seed ^ key64_056 ^ key64_064)
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}
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acc ^= u64(key32_000^key32_004) + seed
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return xxhAvalancheSmall(acc)
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case l <= 128:
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acc = u64(l) * prime64_1
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if l > 32 {
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if l > 64 {
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if l > 96 {
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acc += mulFold64(readU64(p, 6*8)^(key64_096+seed), readU64(p, 7*8)^(key64_104-seed))
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acc += mulFold64(readU64(p, ui(l)-8*8)^(key64_112+seed), readU64(p, ui(l)-7*8)^(key64_120-seed))
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} // 96
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acc += mulFold64(readU64(p, 4*8)^(key64_064+seed), readU64(p, 5*8)^(key64_072-seed))
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acc += mulFold64(readU64(p, ui(l)-6*8)^(key64_080+seed), readU64(p, ui(l)-5*8)^(key64_088-seed))
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} // 64
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acc += mulFold64(readU64(p, 2*8)^(key64_032+seed), readU64(p, 3*8)^(key64_040-seed))
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acc += mulFold64(readU64(p, ui(l)-4*8)^(key64_048+seed), readU64(p, ui(l)-3*8)^(key64_056-seed))
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} // 32
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acc += mulFold64(readU64(p, 0*8)^(key64_000+seed), readU64(p, 1*8)^(key64_008-seed))
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acc += mulFold64(readU64(p, ui(l)-2*8)^(key64_016+seed), readU64(p, ui(l)-1*8)^(key64_024-seed))
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return xxh3Avalanche(acc)
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case l <= 240:
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acc = u64(l) * prime64_1
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acc += mulFold64(readU64(p, 0*16+0)^(key64_000+seed), readU64(p, 0*16+8)^(key64_008-seed))
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acc += mulFold64(readU64(p, 1*16+0)^(key64_016+seed), readU64(p, 1*16+8)^(key64_024-seed))
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acc += mulFold64(readU64(p, 2*16+0)^(key64_032+seed), readU64(p, 2*16+8)^(key64_040-seed))
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acc += mulFold64(readU64(p, 3*16+0)^(key64_048+seed), readU64(p, 3*16+8)^(key64_056-seed))
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acc += mulFold64(readU64(p, 4*16+0)^(key64_064+seed), readU64(p, 4*16+8)^(key64_072-seed))
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acc += mulFold64(readU64(p, 5*16+0)^(key64_080+seed), readU64(p, 5*16+8)^(key64_088-seed))
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acc += mulFold64(readU64(p, 6*16+0)^(key64_096+seed), readU64(p, 6*16+8)^(key64_104-seed))
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acc += mulFold64(readU64(p, 7*16+0)^(key64_112+seed), readU64(p, 7*16+8)^(key64_120-seed))
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// avalanche
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acc = xxh3Avalanche(acc)
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// trailing groups after 128
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top := ui(l) &^ 15
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for i := ui(8 * 16); i < top; i += 16 {
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acc += mulFold64(readU64(p, i+0)^(readU64(key, i-125)+seed), readU64(p, i+8)^(readU64(key, i-117)-seed))
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}
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// last 16 bytes
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acc += mulFold64(readU64(p, ui(l)-16)^(key64_119+seed), readU64(p, ui(l)-8)^(key64_127-seed))
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return xxh3Avalanche(acc)
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default:
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acc = u64(l) * prime64_1
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secret := key
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if seed != 0 {
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secret = ptr(&[secretSize]byte{})
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initSecret(secret, seed)
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}
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accs := [8]u64{
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prime32_3, prime64_1, prime64_2, prime64_3,
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prime64_4, prime32_2, prime64_5, prime32_1,
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}
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if hasAVX512 && l >= avx512Switch {
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accumAVX512(&accs, p, secret, u64(l))
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} else if hasAVX2 {
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accumAVX2(&accs, p, secret, u64(l))
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} else if hasSSE2 {
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accumSSE(&accs, p, secret, u64(l))
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} else {
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accumScalarSeed(&accs, p, secret, u64(l))
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}
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// merge accs
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acc += mulFold64(accs[0]^readU64(secret, 11), accs[1]^readU64(secret, 19))
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acc += mulFold64(accs[2]^readU64(secret, 27), accs[3]^readU64(secret, 35))
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acc += mulFold64(accs[4]^readU64(secret, 43), accs[5]^readU64(secret, 51))
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acc += mulFold64(accs[6]^readU64(secret, 59), accs[7]^readU64(secret, 67))
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return xxh3Avalanche(acc)
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}
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}
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