Significant Performance Degradation in v2 (2x slower at-least) #1481
Description
Describe the bug
Was just updating to v2 to test it out (went pretty smooth) but found some really severe performance problems. The application I have is quite non-trivial and there is lots of rendering going on but it was running an extremely stable 110-120fps prior but now it very consistently is dropping to less than half of that.
I've got some profiling traces that I've attached (both were running for 10s doing the same operation).
The profiles are here (both old & new, with no app changes in-between except required migrations such as the mouse msg changes)
cpu_and_mem_profiles.zip
I see extremely heavy GC cycles in the new branch as you can see below
CellBuf + ansi parsing seems to be the fault, since it's making tons of copies every frame. Making up more than 50% of the allocations.
Setup
Please complete the following information along with version numbers, if applicable.
I don't feel this is applicable to terminal emulator.
To Reproduce
This should be visible on any document with lots of rendered items.
Source Code
Sadly, I can't provide source code here.
Expected behavior
For allocations and performance to be more inline with previous versions.
Screenshots
I don't feel the video / images would help much here I think the profiles show it pretty explicitly above.
Additional context
Happy to help :D