djb2, a non-cryptographic hash function

djb2.go

package djb2

// For when you ever need to implement a dictionary hash function,
// that's good enough, simple and fast.
//
// WARNING:
// Not cryptographicly secure!
//
// Source: https://en.wikipedia.org/wiki/DJB2
//
// EXAMPLE
//
//func main() {
//        fmt.Println(djb2("a"))
//        fmt.Println(djb2("b"))
//}

func djb2(s string) int64 {
        var hash int64 = 5381

        for _, c := range s {
                hash = ((hash << 5) + hash) + int64(c)
                // the above line is an optimized version of the following line:
                //hash = hash * 33 + int64(c)
                // which is easier to read and understand...
        }

        return hash
}