[Tyriar]

This isn't entirely the fault of Electron though, but the convenient data types exposed in a web environment. Beyond the baseline memory of running Chromium, you could use various tricks to keep memory very low such as minimizing GC (eg. declare variable up front, not within loops), use array buffers extensively, shared array buffers to share memory with workers, etc.

[Gaelan]

> eg. declare variable up front, not within loops

I have trouble believing modern JS engines wouldn’t optimize this to the same thing.

[kllrnohj]

Behaviorally they aren't the same thing, so that's not a straightforward mechanical translation. For example if the variable is an object instance then if escape analysis can prove the variable doesn't outlive the loop, then it can be put on the stack & then yes there wouldn't be any benefit to the suggested change. Although deoptimization makes stack allocation more complicated, so JS engines are more conservative here than say JVM runtimes.

But it's really easy for escape analysis to fail, it has to be conservative. So you can end up heap allocating a temporary object every loop iteration quite easily.

[zerkten]

Is there a good guide to these techniques in modern JS? How likely are they to remain viable long-term?

[Tyriar]

Not sure on any particular guide, but I learned a lot from the old #perfmatters push from Chrome, getting a deeper understanding of what the JS engine does when you create an object, where it lives, how it interacts with the garbage collector and so on would be a good thing to learn about. Also it's generally only worth considering optimization for things that store a lot of data like arrays/maps. I don't see why these techniques wouldn't be good in the long term.

I definitely agree that it's easier to make webapps that consumer much more memory than it is using a lower-level language like C++, unless you're being careful.