msgpack-lite

Fast Pure JavaScript MessagePack Encoder and Decoder

Online demo: http://kawanet.github.io/msgpack-lite/

Features

• Pure JavaScript only (No node-gyp nor gcc required)
• Faster than any other pure JavaScript libraries on node.js v4
• Even faster than node-gyp C++ based msgpack library (90% faster on encoding)
• Streaming encoding and decoding interface is also available. It's more faster.
• Ready for Web browsers including Chrome, Firefox, Safari and even IE8
• Tested on Node.js v0.10, v0.12, v4, v5 and v6 as well as Web browsers

Encoding and Decoding MessagePack

var msgpack = require("msgpack-lite");

// encode from JS Object to MessagePack (Buffer)
var buffer = msgpack.encode({"foo": "bar"});

// decode from MessagePack (Buffer) to JS Object
var data = msgpack.decode(buffer); // => {"foo": "bar"}

// if encode/decode receives an invalid argument an error is thrown

Writing to MessagePack Stream

var fs = require("fs");
var msgpack = require("msgpack-lite");

var writeStream = fs.createWriteStream("test.msp");
var encodeStream = msgpack.createEncodeStream();
encodeStream.pipe(writeStream);

// send multiple objects to stream
encodeStream.write({foo: "bar"});
encodeStream.write({baz: "qux"});

// call this once you're done writing to the stream.
encodeStream.end();

Reading from MessagePack Stream

var fs = require("fs");
var msgpack = require("msgpack-lite");

var readStream = fs.createReadStream("test.msp");
var decodeStream = msgpack.createDecodeStream();

// show multiple objects decoded from stream
readStream.pipe(decodeStream).on("data", console.warn);

Decoding MessagePack Bytes Array

var msgpack = require("msgpack-lite");

// decode() accepts Buffer instance per default
msgpack.decode(Buffer([0x81, 0xA3, 0x66, 0x6F, 0x6F, 0xA3, 0x62, 0x61, 0x72]));

// decode() also accepts Array instance
msgpack.decode([0x81, 0xA3, 0x66, 0x6F, 0x6F, 0xA3, 0x62, 0x61, 0x72]);

// decode() accepts raw Uint8Array instance as well
msgpack.decode(new Uint8Array([0x81, 0xA3, 0x66, 0x6F, 0x6F, 0xA3, 0x62, 0x61, 0x72]));

Command Line Interface

A CLI tool bin/msgpack converts data stream from JSON to MessagePack and vice versa.

$ echo '{"foo": "bar"}' | ./bin/msgpack -Jm | od -tx1
0000000    81  a3  66  6f  6f  a3  62  61  72

$ echo '{"foo": "bar"}' | ./bin/msgpack -Jm | ./bin/msgpack -Mj
{"foo":"bar"}

Installation

$ npm install --save msgpack-lite

Tests

Run tests on node.js:

$ make test

Run tests on browsers:

$ make test-browser-local
open the following url in a browser:
http://localhost:4000/__zuul

Browser Build

Browser version msgpack.min.js is also available. 50KB minified, 14KB gziped.

<!--[if lte IE 9]>
<script src="https://cdnjs.cloudflare.com/ajax/libs/es5-shim/4.1.10/es5-shim.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/json3/3.3.2/json3.min.js"></script>
<![endif]-->
<script src="https://rawgit.com/kawanet/msgpack-lite/master/dist/msgpack.min.js"></script>
<script>
// encode from JS Object to MessagePack (Uint8Array)
var buffer = msgpack.encode({foo: "bar"});

// decode from MessagePack (Uint8Array) to JS Object
var array = new Uint8Array([0x81, 0xA3, 0x66, 0x6F, 0x6F, 0xA3, 0x62, 0x61, 0x72]);
var data = msgpack.decode(array);
</script>

MessagePack With Browserify

Step #1: write some code at first.

var msgpack = require("msgpack-lite");
var buffer = msgpack.encode({"foo": "bar"});
var data = msgpack.decode(buffer);
console.warn(data); // => {"foo": "bar"}

Proceed to the next steps if you prefer faster browserify compilation time.

Step #2: add browser property on package.json in your project. This refers the global msgpack object instead of including whole of msgpack-lite source code.

{
  "dependencies": {
    "msgpack-lite": "*"
  },
  "browser": {
    "msgpack-lite": "msgpack-lite/global"
  }
}

Step #3: compile it with browserify and uglifyjs.

browserify src/main.js -o tmp/main.browserify.js -s main
uglifyjs tmp/main.browserify.js -m -c -o js/main.min.js
cp node_modules/msgpack-lite/dist/msgpack.min.js js/msgpack.min.js

Step #4: load msgpack.min.js before your code.

<script src="js/msgpack.min.js"></script>
<script src="js/main.min.js"></script>

Interoperability

It is tested to have basic compatibility with other Node.js MessagePack modules below:

• https://www.npmjs.com/package/msgpack (1.0.2)
• https://www.npmjs.com/package/msgpack-js (0.3.0)
• https://www.npmjs.com/package/msgpack-js-v5 (0.3.0-v5)
• https://www.npmjs.com/package/msgpack-unpack (2.1.1)
• https://github.com/msgpack/msgpack-javascript (msgpack.codec)
• https://www.npmjs.com/package/msgpack5 (3.3.0)
• https://www.npmjs.com/package/notepack (0.0.2)

Benchmarks

A benchmark tool lib/benchmark.js is available to compare encoding/decoding speed (operation per second) with other MessagePack modules. It counts operations of 1KB JSON document in 10 seconds.

$ npm install msgpack msgpack-js msgpack-js-v5 msgpack-unpack msgpack5 notepack
$ npm run benchmark 10

Streaming benchmark tool lib/benchmark-stream.js is also available. It counts milliseconds for 1,000,000 operations of 30 bytes fluentd msgpack fragment. This shows streaming encoding and decoding are super faster.

$ npm run benchmark-stream 2

Test environment: msgpack-lite 0.1.14, Node v4.2.3, Intel(R) Xeon(R) CPU E5-2666 v3 @ 2.90GHz

MessagePack Mapping Table

The following table shows how JavaScript objects (value) will be mapped to MessagePack formats and vice versa.

Note that both null and undefined are mapped to nil 0xC1 type. This means undefined value will be upgraded to null in other words.

Extension Types

The MessagePack specification allows 128 application-specific extension types. The library uses the following types to make round-trip conversion possible for JavaScript native objects.

Other extension types are mapped to built-in ExtBuffer object.

Custom Extension Types (Codecs)

Register a custom extension type number to serialize/deserialize your own class instances.

var msgpack = require("msgpack-lite");

var codec = msgpack.createCodec();
codec.addExtPacker(0x3F, MyVector, myVectorPacker);
codec.addExtUnpacker(0x3F, myVectorUnpacker);

var data = new MyVector(1, 2);
var encoded = msgpack.encode(data, {codec: codec});
var decoded = msgpack.decode(encoded, {codec: codec});

function MyVector(x, y) {
  this.x = x;
  this.y = y;
}

function myVectorPacker(vector) {
  var array = [vector.x, vector.y];
  return msgpack.encode(array); // return Buffer serialized
}

function myVectorUnpacker(buffer) {
  var array = msgpack.decode(buffer);
  return new MyVector(array[0], array[1]); // return Object deserialized
}

The first argument of addExtPacker and addExtUnpacker should be an integer within the range of 0 and 127 (0x0 and 0x7F). myClassPacker is a function that accepts an instance of MyClass, and should return a buffer representing that instance. myClassUnpacker is the opposite: it accepts a buffer and should return an instance of MyClass.

If you pass an array of functions to addExtPacker or addExtUnpacker, the value to be encoded/decoded will pass through each one in order. This allows you to do things like this:

codec.addExtPacker(0x00, Date, [Number, msgpack.encode]);

You can also pass the codec option to msgpack.Decoder(options), msgpack.Encoder(options), msgpack.createEncodeStream(options), and msgpack.createDecodeStream(options).

If you wish to modify the default built-in codec, you can access it at msgpack.codec.preset.

Custom Codec Options

msgpack.createCodec() function accepts some options.

It does NOT have the preset extension types defined when no options given.

var codec = msgpack.createCodec();

preset: It has the preset extension types described above.

var codec = msgpack.createCodec({preset: true});

safe: It runs a validation of the value before writing it into buffer. This is the default behavior for some old browsers which do not support ArrayBuffer object.

var codec = msgpack.createCodec({safe: true});

useraw: It uses raw formats instead of bin and str.

var codec = msgpack.createCodec({useraw: true});

int64: It decodes msgpack's int64/uint64 formats with int64-buffer object.

var codec = msgpack.createCodec({int64: true});

binarraybuffer: It ties msgpack's bin format with ArrayBuffer object, instead of Buffer object.

var codec = msgpack.createCodec({binarraybuffer: true, preset: true});

uint8array: It returns Uint8Array object when encoding, instead of Buffer object.

var codec = msgpack.createCodec({uint8array: true});

usemap: Uses the global JavaScript Map type, if available, to unpack MessagePack map elements.

var codec = msgpack.createCodec({usemap: true});

Compatibility Mode

The compatibility mode respects for msgpack's old spec. Set true to useraw.

// default mode handles both str and bin formats individually
msgpack.encode("Aa"); // => <Buffer a2 41 61> (str format)
msgpack.encode(new Buffer([0x41, 0x61])); // => <Buffer c4 02 41 61> (bin format)

msgpack.decode(new Buffer([0xa2, 0x41, 0x61])); // => 'Aa' (String)
msgpack.decode(new Buffer([0xc4, 0x02, 0x41, 0x61])); // => <Buffer 41 61> (Buffer)

// compatibility mode handles only raw format both for String and Buffer
var options = {codec: msgpack.createCodec({useraw: true})};
msgpack.encode("Aa", options); // => <Buffer a2 41 61> (raw format)
msgpack.encode(new Buffer([0x41, 0x61]), options); // => <Buffer a2 41 61> (raw format)

msgpack.decode(new Buffer([0xa2, 0x41, 0x61]), options); // => <Buffer 41 61> (Buffer)
msgpack.decode(new Buffer([0xa2, 0x41, 0x61]), options).toString(); // => 'Aa' (String)

Repository

• https://github.com/kawanet/msgpack-lite

See Also

• http://msgpack.org/

License

The MIT License (MIT)

Copyright (c) 2015-2016 Yusuke Kawasaki

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.