UUID generator for Go

This package generates version 4 UUIDs (RFC 4122). It's 35 times faster than other UUID libraries (1, 2), and, unlike those libraries, cannot fail to generate a UUID.

BenchmarkSelf-8         100000000               13.4 ns/op
BenchmarkGofrs-8         2000000               623 ns/op
BenchmarkGoogle-8        2000000               627 ns/op

It's faster and more reliable because it generates UUIDs from an internal CSPRNG. Operating system entropy is only used to seed the generator once. Other libraries read 16 bytes of operating system entropy for each UUID, which is why they're slower and can fail.

API documentation: https://pkg.go.dev/nullprogram.com/x/uuid

Example usage

package main

import (
	"flag"
	"fmt"

	"nullprogram.com/x/uuid"
)

func main() {
	n := flag.Int("n", 1, "number of UUIDs to generate")
	flag.Parse()

	g := uuid.NewGen()
	for i := 0; i < *n; i++ {
		fmt.Println(g.NewV4())
	}
}

Result:

$ ./example -n 4
66ccddf3-be66-455d-8bab-13a20cf57d05
17e7e09c-fafd-4482-999c-7fbd87a1e7a8
b7146884-9678-435e-b76e-9fc8407544e7
cc6f0bf7-9762-456c-890a-3213c6965e95