Why react application using more memory footprint?

Question

I have one function component in React, and I am also using the KonvaJS npm library. While the function component re-renders it, it increases the memory footprint.

Chrome task manager

My code

import React, { useState, useEffect, useSelector} from "react";
import { Stage as stageKonva } from "konva/lib/Stage";
import { Line as LineKonva } from "konva/lib/shapes/Line";
import { Animation as AnimationKonva } from "konva/lib/Animation";
import { Layer as LayerKonva } from "konva/lib/Layer";
import { Image as ImageKonva } from "konva/lib/shapes/Image";

export const Abc = (data)=>{

   const {  device } = useSelector((state) => ({ device: state.device }));

   useEffect(() => {
      gameStart();
   },[device])

   async function gameStart (){
       var stage = new stageKonva({ container: "gamePanel", width: 300, height: 300});   
       var layer = new LayerKonva(), oldRow = null; stage.add(layer);
       var imageObj1 = new Image(); 
       imageObj1.onload = function () {
         let square = new ImageKonva({ x: 0, y: 0, height: 40, width: 20, image: imageObj1 });
         ------------------------------
         ---------Some code here-------
         ------------------------------
       }
       imageObj1.src = data.image;
   }

    return(<div  id="gamePanel"></div>);       
}

I want to know why the memory footprint is increasing while re-rendering. How to stop that?

Answer 1

You should do a deeper memory profiling and see what is in the memory.

From your code, it is hard to say when you run the effect and how many times.

useEffect(() => {
  gameStart();
},[device])

Probably it is called many times, so it creates many Konva nodes instances in the memory. You can do clean in the effect:

function gameStart (){
  var stage = new stageKonva({ container: "gamePanel", width: 300, height: 300});   
  // some other game code
  return stage;
}

useEffect(() => {
  const stage = gameStart();
  return () => {
    stage.destoy();
  }
},[device])

Destroying just the stage may not be enough. You may need to check animations and other intances.