@msgpack/msgpack

What is @msgpack/msgpack?

@msgpack/msgpack is an npm package that provides functionality for encoding and decoding data using the MessagePack format. MessagePack is a binary serialization format that is more efficient than JSON in terms of both size and speed. This package allows you to serialize JavaScript objects into a compact binary format and deserialize them back into JavaScript objects.

What are @msgpack/msgpack's main functionalities?

Encoding Data

This feature allows you to encode a JavaScript object into a MessagePack binary format. The `encode` function takes a JavaScript object and returns a Buffer containing the binary data.

const msgpack = require('@msgpack/msgpack');
const data = { foo: 'bar', num: 42 };
const encoded = msgpack.encode(data);
console.log(encoded);

Decoding Data

This feature allows you to decode a MessagePack binary format back into a JavaScript object. The `decode` function takes a Buffer containing the binary data and returns the original JavaScript object.

const msgpack = require('@msgpack/msgpack');
const encoded = Buffer.from([0x82, 0xa3, 0x66, 0x6f, 0x6f, 0xa3, 0x62, 0x61, 0x72, 0xa3, 0x6e, 0x75, 0x6d, 0x2a]);
const decoded = msgpack.decode(encoded);
console.log(decoded);

Custom Extension Types

This feature allows you to define custom extension types for encoding and decoding. You can use `addExtPacker` to specify how to serialize a custom type and `addExtUnpacker` to specify how to deserialize it.

const msgpack = require('@msgpack/msgpack');
class MyType {
  constructor(value) {
    this.value = value;
  }
}
msgpack.addExtPacker(0x01, MyType, (obj) => msgpack.encode(obj.value));
msgpack.addExtUnpacker(0x01, (data) => new MyType(msgpack.decode(data)));
const myObj = new MyType('custom data');
const encoded = msgpack.encode(myObj);
const decoded = msgpack.decode(encoded);
console.log(decoded);

Other packages similar to @msgpack/msgpack

msgpack-lite

msgpack-lite is another npm package for MessagePack serialization. It is designed to be lightweight and fast, with a focus on performance. Compared to @msgpack/msgpack, msgpack-lite may have fewer features but is optimized for speed and small bundle size.

notepack.io

notepack.io is a fast and small MessagePack implementation for JavaScript. It is designed to be highly efficient and is often used in performance-critical applications. Compared to @msgpack/msgpack, notepack.io is more focused on performance and may offer better speed at the cost of some additional features.

msgpack5

msgpack5 is a pure JavaScript implementation of the MessagePack format. It supports both encoding and decoding, as well as custom extension types. Compared to @msgpack/msgpack, msgpack5 offers similar functionality but may have different performance characteristics and API design.

README

MessagePack for JavaScript

This is the pure-JavaScript implementation of MessagePack, an efficient binary serilization format:

https://msgpack.org/

Stability

This is under development until v1.0.0. Any API will change without notice.

Synopsis

import { deepStrictEqual } from "assert";
import { encode, decode } from "@msgpack/msgpack";

const object = {
  nil: null,
  integer: 1,
  float: Math.PI,
  string: "Hello, world!",
  binary: Uint8Array.from([1, 2, 3]),
  array: [10, 20, 30],
  map: { foo: "bar" },
  timestampExt: new Date(),
};

const encoded = encode(object);
// encoded is an Uint8Array instance

deepStrictEqual(decode(encoded), object);

Install

This library is publised as @msgpack/msgpack in npmjs.com.

npm install @msgpack/msgpack

Encode and Decode

encode(data: unknown, options?): Uint8Array

It encodes data and returns a byte array as Uint8Array.

decode(buffer: ArrayLike<number> | Uint8Array, options?): unknown

It decodes buffer in a byte buffer and returns decoded data as uknown.

decodeAsync(stream: AsyncIterable<ArrayLike<number> | Uint8Array>, options?): Promise<unknown>

It decodes stream in an async iterable of byte arrays and returns decoded data as uknown wrapped in Promise. This function works asyncronously.

Extension Types

To handle MessagePack Extension Types, this library provides ExtensionCodec class.

Here is an example to setup custom extension types that handles Map and Set classes in TypeScript:

import { encode, decode, ExtensionCodec } from "@msgpack/msgpack";

const extensionCodec = new ExtensionCodec();

// Set<T>
extensionCodec.register({
  type: 0,
  encode: (object: unknown): Uint8Array | null => {
    if (object instanceof Set) {
      return encode([...object]);
    } else {
      return null;
    }
  },
  decode: (data: Uint8Array) => {
    const array = decode(data) as Array<any>;
    return new Set(array);
  },
});

// Map<T>
extensionCodec.register({
  type: 1,
  encode: (object: unknown): Uint8Array => {
    if (object instanceof Map) {
      return encode([...object]);
    } else {
      return null;
    }
  },
  decode: (data: Uint8Array) => {
    const array = decode(data) as Array<[unknown, unknown]>;
    return new Map(array);
  },
});

// and later
import { encode, decode } from "@msgpack/msgpack";

const encoded = = encode([new Set<any>(), new Map<any, any>()], { extensionCodec });
const decoded = decode(encoded, { extensionCodec });

Not that extension types for custom objects must be [0, 127], while [-1, -128] is reserved to MessagePack itself.

Prerequsites

• ES5 language features
• Typed Arrays (ES2015; caniuse: typedarrays)
• String.prototype.padStart (ES2017; caniuse: pad-start-end)

You can use polyfills for them.

NodeJS

If you use this library in NodeJS, v10 or later is required.

Benchmark

Benchmark on NodeJS/v12.1.0

operation	op	ms	op/s
buf = Buffer.from(JSON.stringify(obj));	493600	5000	98720
buf = JSON.stringify(obj);	959600	5000	191920
obj = JSON.parse(buf);	346100	5000	69220
buf = require("msgpack-lite").encode(obj);	358300	5000	71660
obj = require("msgpack-lite").decode(buf);	270400	5000	54080
buf = require("@msgpack/msgpack").encode(obj);	594300	5000	118860
obj = require("@msgpack/msgpack").decode(buf);	343100	5000	68620

Distrubition

The NPM package distributed in npmjs.com includes both ES2015+ and ES5 files:

• /dist is compiled into ES2015+
• /dist.es5 is compiled into ES5 and bundled to singile file

If you use NodeJS and/or webpack, their module resolvers use the suitable one automatically.

License

Copyright 2019 The MessagePack Community.

This software is licensed under the ISC license:

https://opensource.org/licenses/ISC

See LICENSE for details.