xxHash 64bit usage example in golang

main.go

package main

import (
	"fmt"
	"hash"
	"io"
	"os"

	"github.com/pierrec/xxHash/xxHash64"
)

func main() {
	h, e := FileHash("file.qcow")
	fmt.Println(h, e)
}

// Regex: ^[a-f0-9]{16}$
func FileHash(filename string) (string, error) {
	var xxh hash.Hash
	xxh = xxHash64.New(0)
	f, err := os.Open(filename)
	if err != nil {
		return "", err
	}
	defer f.Close()
	defer xxh.Reset()
	if _, err := io.Copy(xxh, f); err != nil {
		return "", err
	}
	return hex.EncodeToString(xxh.Sum(nil)), nil
}