antonyis / token

A simple base62 encoded token library for go, ideal for short url services.

Use v2 Instead

Warning: Breaking Changes

Version 2 of this package is ready for production use. You can find it here.

The order of the Base62 characters have been changed in v2 so that the string representation of the Token and the int representation of the token are in the same sort order. This is useful when scaling your app or using NoSQL solutions. Special thanks to @sudhirj for the suggestion.

References

https://instagram-engineering.com/sharding-ids-at-instagram-1cf5a71e5a5c

https://developer.twitter.com/en/docs/basics/twitter-ids.html

https://github.com/ulid/spec

---

This is a simple package for go that generates randomized base62 encoded tokens based on an integer. It's ideal for short url services or for any short, unique, randomized tokens you need to use throughout your app.

How it Works

Token is an alias for uint64.

The Token.Encode() method returns a base62 encoded string based off of the uint64.

Token implements the encoding.TextMarshaler and encoding.TextUnmarshaler interfaces to encode and decode to and from the base62 string representation of the uint64

Basically, the outside world will always see the token as a base62 encoded string, but in your app you will always be able to use the token as a uint64 for fast, indexed, unique, lookups in various databases.

IMPORTANT: Remember to always check for collisions when adding randomized tokens to a database

Example

package main

import (
	"fmt"
	"github.com/marksalpeter/token"
)

type Model struct {
    ID	token.Token `json:"id"`
}

func main() {
	// create a new model
	model := Model {
		ID:	token.New(), // creates a new, random uint64 token
	}
	fmt.Println(model.ID)          // 2751173559858
	fmt.Println(model.ID.Encode()) // Mr1NSSu

	// encode the model as json
	marshaled, err := json.Marshal(&model)
	if err != nil {
		panic(err)
	}
	fmt.Println(string(marshaled)) // {"id":"Mr1NSSu"}

	// decode the model
	var unmarshaled Model
	if err := json.Unmarshal(marshaled, &unmarshaled); err != nil {
		panic(err)
	}
	fmt.Println(unmarshaled.ID)    // 2751173559858

}

Special Mentions

Special thanks to @einsteinx2. The encode and decode functions are ported from a short url project of his and he graciously allowed me to publish them.