worker-task

Move tasks that are computationally heavy or use synchronous io to a worker thread.

Installation

npm i @phylum/worker-task

Please note that node worker threads are currently experimental!

# In order to enable worker thread support, you
# have to pass the following flag to node:
node --experimental-worker ...

Usage

When a worker task is executed, it will create a new worker thread, load the specified entry module and run the exported task in an independent pipeline.

createWorkerTask(filename[, options])

// parent.js
const {createWorkerTask} = require('@phylum/worker-task')

const task = createWorkerTask(path.join(__dirname, 'worker'))

// worker.js
module.exports = async ctx => {
	console.log('Hello World!')
}

• filename <string> - The filename of the worker entry. This can be relative to the current working directory.
• options <object> - An object with the following options:
  • stdin, stdout, stderr, execArgv - See worker options
  • onDispose - Set how to dispose the worker:
    • 'disable' - Default. Disable the worker pipeline.
    • 'terminate' - Terminate the worker thread. (Not recommended)

Serialization

By default, errors are converted to strings using util.inspect(..) before passing them to the parent thread and results are not passed at all. You can use the v8 serialization api by wrapping a value into a Serializable instance. However if the wrapped value is not serializable, an error will be passed to the parent thread.

// worker.js
const {Serializable, raw} = require('@phylum/worker-task')

module.exports = async ctx => {
	return new Serializable({foo: 'bar'})

	// Or use the shorthand function:
	return raw({foo: 'bar'})
}