1476154 - Investigate performance improvements for the frame constructor

Status: NEW

(Core :: Layout, defect, P3)

Description

[Bobby Holley (:bholley)]

This is a placeholder bug for investigation that the layout performance folks will want to do at some point.

The frame constructor is a beast of a component, and a lot of inefficiency lurks behind its complexity. There are four basic areas I can think of where we may be able to improve things:

* Being more precise about change hint handling to avoid unnecessary reconstructs.
* Doing a better job of handling dynamic insertions and removals to avoid unnecessary (or overly-broad) reconstructs.
* Simplifying or micro-optimizing the core algorithms, to either do less work or do it faster.

The first two only apply to dynamic change handling, which is generally an area where our regression tests aren't great, so there may be some pretty dumb stuff there. The last one applies across the board.