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iid

Small, globally unique IDs implemented in Go.

GoDoc

Features

  • Can be sorted by creation time
  • Globally unique
  • Small size (can be stored in a 64 bit integer or an 11 byte string)
  • base64url encoded string format: the ids can be used in URLs

ID Format

1 Bit 32 Bit 31 Bit
Not used Timestamp in seconds Cryptographically secure random bytes

The first bit is not used so the ID fits into 64 bit signed integers.

Usage Example

package main

import (
	"github.com/robojones/iid"
	"log"
	"reflect"
)

func main() {
	// Generate new iid
	id := iid.New()
	log.Printf("buffer format: %#v", id)
	
	// Export as base64url string
	str := id.String()
	log.Printf("base64 string: %s", str)
	
	// Import the id from the string
	parsed, err := iid.FromString(str)
	if err != nil {
		panic(err)
	}
	log.Printf("parsed iid from string is identical to the original: %t", reflect.DeepEqual(id, parsed))
	
	// Export as uint64
	i := id.Uint64()
	log.Printf("integer: %d", i)
	
	// Import the id from the integer
	parsed = iid.FromUint64(i)
	log.Printf("parsed iid from uint64 is identical to original: %t", reflect.DeepEqual(id, parsed))
}