Google's CityHash.
https://github.com/google/cityhash
City implements hash.Hash.
c := NewCity([]byte("...")) // Sum() = Sum64()
c32 := NewCity([]byte("..."), SetSize32()) // Sum() = Sum32()
c64 := NewCity([]byte("..."), SetSize64()) // Sum() = Sum64()
c128 := NewCity([]byte("..."), SetSize128()) // Sum() = Sum128()
c.SetSize32() // Sum() = Sum32()
c.SetSize64() // Sum() = Sum64()
c.SetSize128() // Sum() = Sum128()
c.Set([]byte("...")) // set new []byte
c.Write([]byte("...")) // append []byte
c.Sum32() // uint32
c.Sum64() // uint64
c.Sum64WithSeed(seed) // uint64(with seed)
c.Sum64WithSeeds(seed0, seed1) // uint64(with seeds)
c.Sum128() // Uint128
c.Sum128WithSeed(seed128) // Uint128(with seed)
// Sum() call size bits function.(Sum32() or Sum64() or Sum128())
c.Sum(p) // []byte(buf+p)
c.Sum(nil) // []byte(buf)
c.String() // string(format:%x)
c.Buf()
c.Size()
c.BlockSize()
c.Reset()