README.md

Nano ID

A tiny, secure, URL-friendly, unique string ID generator for Rust

use nanoid::nanoid;

fn main() {
   let id = nanoid!(); //=> "Yo1Tr9F3iF-LFHX9i9GvA"
}

Safe. It uses cryptographically strong random APIs and guarantees a proper distribution of symbols.

Compact. It uses a larger alphabet than UUID (A-Za-z0-9_-) and has a similar number of unique IDs in just 21 symbols instead of 36.

Usage

Install

[dependencies]
nanoid = "0.4.0"

Simple

The main module uses URL-friendly symbols (A-Za-z0-9_-) and returns an ID with 21 characters.

use nanoid::nanoid;

fn main() {
   let id = nanoid!(); //=> "Yo1Tr9F3iF-LFHX9i9GvA"
}

Symbols -,.() are not encoded in the URL. If used at the end of a link they could be identified as a punctuation symbol.

Custom length

If you want to reduce ID length (and increase collisions probability), you can pass the length as an argument generate function:

use nanoid::nanoid;

fn main() {
   let id = nanoid!(10); //=> "IRFa-VaY2b"
}

Custom Alphabet or Length

If you want to change the ID's alphabet or length, you can simply pass the custom alphabet to the nanoid!() macro as the second parameter:

use nanoid::nanoid;

fn main() {
    let alphabet: [char; 16] = [
        '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', 'a', 'b', 'c', 'd', 'e', 'f'
    ];

   let id = nanoid!(10, &alphabet); //=> "4f90d13a42"
}

Alphabet must contain 256 symbols or less. Otherwise, the generator will not be secure.

Custom Random Bytes Generator

You can replace the default safe random generator using the complex module. For instance, to use a seed-based generator.

use nanoid::nanoid;

fn random_byte () -> u8 { 0 }

fn main() {
    fn random (size: usize) -> Vec<u8> {
        let mut bytes: Vec<u8> = vec![0; size];

        for i in 0..size {
            bytes[i] = random_byte();
        }

        bytes
    }

    nanoid!(10, &['a', 'b', 'c', 'd', 'e', 'f'], random); //=> "fbaefaadeb"
}

random function must accept the array size and return an vector with random numbers.

If you want to use the same URL-friendly symbols with format, you can get the default alphabet from the url module:

use nanoid::nanoid;

fn random (size: usize) -> Vec<u8> {
    let result: Vec<u8> = vec![0; size];

    result
}

fn main() {
    nanoid!(10, &nanoid::alphabet::SAFE, random); //=> "93ce_Ltuub"
}

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