2.0.0.beta 7 memory leak with nodejs

[albertyou2]

OS: mac os 10.12.6 / centos 6.5 / ubuntu 16.04 ( i had tested under 3 OS)
node canvas : 1.6.7 ( now fabric.js only support 1.x.x)
fabric.js: v2.0.0-beta.7 (the latest version)

Hi @kangax

I found that there is a very bad memory leak issue ( maybe caused by node-canvas ,look at here : Automattic/node-canvas#1003 ) in fabric.js with nodejs.

Here is my test code :
...
{
let canvas = fabric.createCanvasForNode(800, 800);
canvas = null;
}
...
After called this code several times , memory usage grow from 78 MB to 1 GB.

i found a solution here : ( #1997 )
var canvas = fabric.createCanvasForNode();
// blah blah canvas manipulation
canvas.clear();
canvas.dispoose();
// garbage collection should be good now

BUT a new error came out:
TypeError: canvas.dispoose is not a function.

is there any solution in my case?Or fabric.js support node-canvas > 2.0.0.beta5 ?
Thank you very much .

[asturur]

dispoose is not a function. dispose is.
Can you try that?

You have to dispose a canvas since once you create a canvas other 2 gets created ( a cache one and a top layer one, and without disposing maybe they do not get cleared properly )

[albertyou2]

@asturur
Thankyou very much for help!
I have tried "canvas.dispose();" It works fine in sync code like this:
var canvas = fabric.createCanvasForNode();
// blah blah canvas manipulation
canvas.clear();
canvas.dispose();

but i found that it does't work by calling in async code like this:
var canvas = fabric.createCanvasForNode();
canvas.loadFromJSON(jsonObj, () => {
canvas.renderAll();
....
canvas.dispose();
})

Am i missing sth??
Thank you again for helping!

[asturur]

mh.
are you keeping reference to the objects somewhere?
Each object as a canvas reference, if mantained alive will stop the GC from cleaning it away

How can you say is a leak and not resources taken from active stuff? what are you actually doing with the script?