metrohash

node-metrohash

Wrapper around MetroHash.

Installation

$ npm install metrohash

API change!

Between v1 and v2, the API for this library has changed to allow for maximum hashing speed.

The biggest change is that a calculated hash is now returned as a (hex-encoded) string instead of a Buffer.

If a Buffer is still required, it's easy to convert the string:

let buffer = Buffer.from(metrohash64('input'), 'hex');

Also, the .hash() methods for the hasher classes have been removed in favor of standalone functions (see below).

Usage

The module exports 2 classes, MetroHash64 and MetroHash128, and two functions, metrohash64 and metrohash128.

The classes are meant for incremental hashing, the functions for standalone hash calculations.

The class constructors and functions accept an optional seed numerical argument, which defaults to 0.

Class interface

const MetroHash64 = require('metrohash').MetroHash64;

// Constructor.
MetroHash64(seed? : number) : this

// Update.
MetroHash64#update(input : String | Buffer) : this

// Finalize and get hash digest.
MetroHash64#digest() : String

(likewise for MetroHash128).

Function interface

const metrohash64 = require('metrohash').metrohash64;

metrohash64(input : String | Buffer, seed? : number) : String

(likewise for metrohash128).

Examples

//// Classes

const MetroHash64 = require('metrohash').MetroHash64;

// Instantiate using seed 123 (`new` is optional).
let hash = new MetroHash64(123);

// Update using a string as input.
hash.update('Hello, World!');

// The same as above:
// hash.update('Hello, ').update('World!');

// Finalize to get the digest as a hex string.
let digest = hash.digest();

//// Functions
const metrohash64 = require('metrohash').metrohash64;

let digest = metrohash64('Hello, World!', 123);

Speed

From v2.0 onwards, MetroHash is pretty fast.