Overview

pixl-pack is a module for encoding and decoding JavaScript primitive types to/from a binary blob which can be written to files or sent over a network socket. This is vaguely similar to using JSON, except that our output is binary, and we support Buffers. You can pass in many different JavaScript primitives for serialization, including objects and arrays (and buffers inside objects and arrays).

This module uses a proprietary data format. It is not compatible with msgpack.

Features

• Faster than msgpack-lite (see Benchmarks below).
• Supports BigInts.
• Low memory overhead (Buffer decoding does not duplicate memory).
• Stream wrappers included for sending packed objects over streams.

Supported Types

• Buffer
• Object
• Array
• String
• Number
• BigInt
• Boolean
• Null

Usage

Use npm to install the module:

npm install pixl-pack

Here is a simple usage example:

const Pack = require('pixl-pack');

var buf = Pack.encode({
	"foo": "bar",
	"buf": Buffer.from("Now is the time for all good men to come to the aid of their country."),
	"num": 384738.34341,
	"big": 90000002n,
	"bool": true
});

var data = Pack.decode(buf);
console.log( data );

The encode() method encodes any supported primitive type to a binary Buffer, and decode() does the opposite -- it parses a buffer and returns the original primitive type. Both methods are synchronous.

Only basic error checking is performed on decode(). If the data is detected as corrupted, it will throw.

Streams

Stream wrappers are included so you can send pixl-packed objects over IPC, TCP, etc. The wrappers handle all encoding and decoding at each end of the stream, not to mention chunking and reassembling the bits. Call createEncodeStream() to create an encoding stream wrapper, and createDecodeStream() for a decoding stream wrapper.

Here is a streaming example with child processes:

// In the parent process
const Pack = require('pixl-pack');

// spawn worker child
var child = require('child_process').spawn( 
	'node', ['my-worker.js'], 
	{ stdio: ['pipe', 'pipe', 'pipe'] }
);

// connect streams to child's stdio from parent
// (write to child.stdin, read from child.stdout)
var encodeStream = Pack.createEncodeStream();
encodeStream.pipe( child.stdin );

var decodeStream = Pack.createDecodeStream();
child.stdout.pipe( decodeStream );

// send binary object over stream to child's STDIN
encodeStream.write({
	"foo": "bar",
	"buf": Buffer.from("Now is the time for all good men to come to the aid of their country."),
	"num": 384738.34341,
	"big": 90000002n,
	"bool": true
});

// receive response back from child
decodeStream.on('data', function(obj) {
	console.log("Got message from child: ", obj);
	
	// close child's stdin indicating there is no more data to be sent,
	// so child can exit naturally
	child.stdin.end();
});

And in the child process we use the same helper functions to setup the other side of the streams:

// In the child process
const Pack = require('pixl-pack');

// connect streams to our stdio in child
var decodeStream = Pack.createDecodeStream();
process.stdin.pipe( decodeStream );

var encodeStream = Pack.createEncodeStream();
encodeStream.pipe( process.stdout );

// wait for object from parent and send it back with changes
decodeStream.on('data', function(obj) {
	obj.num *= 2;
	obj.message = "Return to sender!";
	
	// send it back
	encodeStream.write(obj);
});

Benchmarks

| Test | msgpack-lite | pixl-pack | |------|--------------|-----------| | Null | 1,046,159 /sec | 6,518,397 /sec | | Boolean | 1,016,273 /sec | 5,556,218 /sec | | String | 784,111 /sec | 1,577,015 /sec | | Buffer | 859,939 /sec | 3,640,740 /sec | | Number | 1,181,587 /sec | 5,430,710 /sec | | Object | 372,714 /sec | 463,397 /sec | | Array | 856,014 /sec | 968,914 /sec |

Benchmarks run on a MacBook Pro 2020 with macOS 10.15.5 and Node v12.13.1.

Benchmark Script

Development

To install pixl-pack for development, run these commands:

git clone https://github.com/jhuckaby/pixl-pack.git
cd pixl-pack

License

The MIT License (MIT)

Copyright (c) 2020 Joseph Huckaby.

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.