Experiment with adaptive VTree generation and caching control

[tbranyen]

I think it could be quite interesting to determine at runtime how many VTree objects (including attributes and childNodes) to keep in memory and recycle.

Right now I am working on making it so that every time a VTree is recycled the attributes and childNodes will be fully reset and garbage collected. This helps uncover bugs where a VTree was recycled and just-so-happens to fix an underlying engine issue. Once this is complete, I want to work on a future rendering system that incorporates an adaptive engine for determining the size of objects and instrumenting memory thresholds. This would allow diffHTML to control for environments where memory is low. It would be extremely valuable and distinguish itself from other rendering engines.

TBD:

• Can we estimate the heap size of a VTree including its attributes and childNodes?
• Would implementing memory config limits in bytes vs count be successful for running web apps on lower end hardware?
• Can we balance in real-time which VTrees (if any) are cached fully vs recreated from the DOM each time?

Resources:

• https://stackoverflow.com/questions/1248302/how-to-get-the-size-of-a-javascript-object
• https://www.mattzeunert.com/2017/03/29/v8-object-size.html
• https://developers.google.com/web/updates/2017/12/device-memory
• https://web.dev/monitor-total-page-memory-usage/
• https://developer.mozilla.org/en-US/docs/Web/API/Performance/memory