chunked-call

This package helps you split blocking - time consuming operations to chunks that are executed in an asynchronous manner. The package was inspired long time ago, by a StackOverflow Question and main usage should be for systems where multi-threading operations are not available.

Demo

Please visit demo page to see examples.

Usage

Installation

Package is available on npm repository: npm i chunked-call -D

API

// Callback to execution code
declare type IChunkedCallTask = () => boolean;
// Callback on finishing execution
declare type IChunkedCallCallback = () => void;

// Starts Chunked Call
// @task: callback to function that executes until it returns false. 
// @callback: called when execution is finished.
// @limitMs: once execution time exceeded given time, it waits to a next frame
// return: Handler to Chunked Call executor, can be used to terminate execution
function setChunkedCall(task: IChunkedCallTask, callback?: IChunkedCallCallback, limitMs?: number): number;

// Promisified version of setChunkedCall
function setChunkedCallPromise(task: IChunkedCallTask, limitMs?: number): Promise<void>;

// Terminates execution of ongoing chunked call
// @id: Identifier of chunked call gotten from setChunkedCall
// return: True if an execution has been killed successfully, false otherwise.
function killChunkedCall(id: number): boolean;

How to implement chunked-call?

Import required functions

let setChunkedCall = require("chunked-call").setChunkedCall;
let killChunkedCall = require("chunked-call").killChunkedCall;

Case: Loop `for`

// original code:
for (let i = 0; i < array.length; i++) {
    doSomeOperation(array[i]);
}
nextStep();

// becomes:
setChunkedCall(
    (() => {
        let i = 0;
        return () => {
            i++;
            doSomeOperation(array[i]);
            return i < array.length;
        }
    })(), 
    () => nextStep()
);

Case: Loop `while`

// original code:
while (array.length) {
    doSomeOperation(array.pop());
}
nextStep();

// becomes:
setChunkedCall(
    () => {
        if (array.length) {
            doSomeOperation(array.pop());
        }
        return array.length;
    }, 
    () => nextStep()
);

Case: Loop `do-while`

// original code:
do {
    doSomeOperation(array.pop());
}
while (array.length);
nextStep();


// becomes:
setChunkedCall(
    () => {
        doSomeOperation(array.pop());
        return array.length > 0;
    }, 
    () => nextStep()
);

Changelog

1.0.0 - Version uses setTimeout and claerTimeout to schedule next execution
0.0.6 - Added Travis CI
0.0.5 - Updated documentation
0.0.4 - Improve test coverage
0.0.3 - Updated documentation
0.0.2 - First release

License

MIT

trzecieu/chunked-call