workerShare

Object sharing between multiple node worker threads and their parents.

class WorkerShare

Class to create workers and share data with them.

constructor(data: Record<string | number, any>)

Creates a workerShare class with the data object. Note the data object must be serializable, so it cannot contain objects within the object.

WorkerShare.data

A proxy of the original data that automatically notifies workers of updates. Should be used when the parent alters the data.

WorkerShare.hire(url: string | URL, workerData)

Creates a new worker at the url listed, subscribing it to the parent's data. Returns the worker.

workerData.input?

Input to be passed into the worker as worker-threads.workerData.input. Note that the value cannot be an Object. If you want to send an object, convert it into JSON and parse the JSON in the worker.

workerData.onMessage(message: any)?

Function called whenever a message is received from the worker that is not data sync.

workerData.onError(error: Error)?

Function called when the worker errors.

workerData.onComplete(exitCode: number)?

Function called when the worker completes, after it is unsubscribed from the parent's data.

workerData.onOnline()?

Function called when the worker is online.

workerData.onMessageError(error: MessageError)?

Function called when the worker throws a message error.

WorkerShare.messageAll(message)

Posts a message to all workers.

WorkerShare.workers

The current amount of workers employed by the class.

WorkerShare.onAllComplete

A function that is executed when all workers have exited. The method takes in no arguments.

function receiveData(onMessageEvent): Record<string|number, any>

Function that should be called by the worker thread to process data. Returns the subscribed data.

onMessageEvent?: (message) => void param

Function called whenever a message is received from the parent that is not data sync.

Installation

npm i workerShare

Using the package

Import the class from workershare in your main thread, and import receiveData in your worker threads. When using the input data in a worker thread, note that it is located at workerData.input so that the initial value of the shared data can also be sent.

Note that only setting a property and deleting it will properly update the parent. Object.defineProperty and Object.setPropertyOf are not caught and transmitted to parent, and direct assignment to the object will unsubscribe the object.

Additionally, as both workerData and the shared data are themselves objects, workerData.input and properties of the shared data cannot be object, it will throw an error. As well, messages sent between the parent and the worker with a sender property set to workerShare will be caught and treated as a data sync message. Message events passed into the worker through the receiveData function's onMessageEvent and WorkerData.hire's onMessage will not receive the message.

The function WorkerShare.prototype.workers can be set with a function of type ()=>void. It will be ran when all workers have exited.

Contribution and License

Contributions are appreciated. Any bugs should be reported as GitHub issues.

If you are contributing or forking the software, note that the tests are not written as unit tests. To properly run the tests, change debug in the main file to true.

This code is licensed under the MIT License.

Copyright © 2025 Last8

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