golang fnv example

fnv_example.go

package main

import (
	"bufio"
	"fmt"
	"hash/fnv"
	"io"
	"os"
)

func fingerprint(b []byte) uint64 {
	hash := fnv.New64a()
	hash.Write(b)
	return hash.Sum64()
}

func main() {
	var m = make(map[uint64][]byte)
	f, err := os.Open("./words.txt")
	if err != nil {
		fmt.Printf("error opening file: %v\n", err)
		os.Exit(1)
	}
	defer f.Close()

	r := bufio.NewReader(f)
	for {
		line, _, err := r.ReadLine()
		if err == io.EOF {
			break
		}

		n := fingerprint(line)
		if m[n] == nil {
			m[n] = line
		} else {
			fmt.Printf("%s: %d\n", line, n)
		}
	}
}