miozzz / Orc.js

web worker encapsulation

Orc.js

Simple worker encapsulation.

• Creates an Orc worker from a URL
• Orc class maps onmessage event to custom events
• Communication with worker is done through this class

Creating Accesible Methods in the Worker

• In each worker scope there is one instance of an Orc.
• All methods attached to this Orc instance will be easily accesible in the main thread.

// sampleWorker.js

importScripts('scripts/orc.js');

//This method will be accesible in the main thread.
orc.joinArray = function ([params]) {
   return params.join('')
}

orc.sum = function([a,b]){
   return a + b
}
//This method will be NOT accesible in the main thread
doThis = function(params){
   console.log('do this')
   return
}

Calling Methods from the Main Thread

• Methods in the worker thread attached to the orc can be accessible in the main thread.
• You can perform these methods as if the main thread and the worker thread are the same.

let orc = Orc.create('scripts/sampleWorker.js')
    orc.post('joinArray',['a','b','c']) //posts the joinArray method to the worker
    orc.joinArray(['a','b','c'])        //Short version of .post()
    orc.sum(1,2)

Response Handling

Event Style

• Responses from the worker thread can be handled like events through .on() method
• The first parameter is the method to listen for.
• The second parameter is the callback function.

    orc.on('joinArray',function(data){
        console.log(data)
    })
    // Event will fire when orc.joinArray(['a','b','c']) returns from worker thread

Promises

• Responses from the worker thread can be handled like promises
• Every time a method is posted to the worker a unique promise is returned
• This unique promise is resolved when the post returns from the worker thread

    orc.joinArray(['a','b','c']).then((data)=>{
        console.log(data)
    })  

Terminating an Orc

• In the main thread you can terminate an orc by using the terminate method

orc.terminate()

Reserved Method Names

A list of method names that cannot be attached to the orc in the worker thread

• self
• onmessage
• __initialize__
• post
• terminate
• on
• post
• trigger
• listenToWorker
• resolveMessage
• acknowledgeWorker
• events
• promises
• ready