[labs/observers] WIP: try removing initial update from ResizeController #3773

justinfagnani · 2023-03-30T19:05:09Z

We're getting questions about why ResizeController causes two consecutive host updates. It seems like ResizeObservers already call the observer callback unconditionally, so our code to do that as well made there be two updates. Can we just remove our custom initial call to handleChanges? This would let us remove skipInitial altogether.

wdyt @sorvell ?

changeset-bot · 2023-03-30T19:05:14Z

⚠️ No Changeset found

Latest commit: 25dddb8

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

github-actions · 2023-03-30T19:05:35Z

📊 Tachometer Benchmark Results

Summary

⏱ reactive-element-list

nop-update

lit-html-kitchen-sink: unsure 🔍 -6% - +2% (-1.36ms - +0.53ms)
^{this-change vs tip-of-tree}

render

lit-element-list: 108.97ms - 113.37ms
lit-html-kitchen-sink: unsure 🔍 -5% - +7% (-2.48ms - +3.23ms)
^{this-change vs tip-of-tree}
lit-html-repeat: unsure 🔍 -7% - +6% (-1.06ms - +0.87ms)
^{this-change vs tip-of-tree}
lit-html-template-heavy: unsure 🔍 -3% - +2% (-2.38ms - +1.43ms)
^{this-change vs tip-of-tree}

update

lit-element-list: 1156.04ms - 1175.68ms
lit-html-kitchen-sink: unsure 🔍 -3% - +5% (-3.29ms - +5.27ms)
^{this-change vs tip-of-tree}
lit-html-repeat: unsure 🔍 -13% - +9% (-54.24ms - +35.10ms)
^{this-change vs tip-of-tree}
lit-html-template-heavy: unsure 🔍 -4% - +1% (-6.21ms - +1.96ms)
^{this-change vs tip-of-tree}

update-reflect

lit-element-list: 1122.97ms - 1140.49ms

Results

lit-element-list

Browser: chrome-headless 111.0.5563.110
Sample size: 50
Built by: Benchmarks #4596
Commit: 58721cd

render

Version	Avg time	vs
	108.97ms - 113.37ms	-

update

Version	Avg time	vs
	1156.04ms - 1175.68ms	-

update-reflect

Version	Avg time	vs
	1122.97ms - 1140.49ms	-

lit-html-kitchen-sink

Browser: chrome-headless 111.0.5563.110
Sample size: 30
Built by: Benchmarks #4596
Commit: 58721cd

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	45.33ms - 49.42ms	-	unsure 🔍 -5% - +7% -2.48ms - +3.23ms	unsure 🔍 -3% - +8% -1.22ms - +3.78ms
tip-of-tree tip-of-tree	45.01ms - 48.99ms	unsure 🔍 -7% - +5% -3.23ms - +2.48ms	-	unsure 🔍 -3% - +7% -1.55ms - +3.36ms
previous-release previous-release	44.66ms - 47.53ms	unsure 🔍 -8% - +2% -3.78ms - +1.22ms	unsure 🔍 -7% - +3% -3.36ms - +1.55ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	108.13ms - 114.76ms	-	unsure 🔍 -3% - +5% -3.29ms - +5.27ms	unsure 🔍 -5% - +4% -5.54ms - +4.96ms
tip-of-tree tip-of-tree	107.74ms - 113.16ms	unsure 🔍 -5% - +3% -5.27ms - +3.29ms	-	unsure 🔍 -5% - +3% -6.17ms - +3.60ms
previous-release previous-release	107.67ms - 115.80ms	unsure 🔍 -4% - +5% -4.96ms - +5.54ms	unsure 🔍 -3% - +6% -3.60ms - +6.17ms	-

nop-update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	20.90ms - 21.73ms	-	unsure 🔍 -6% - +2% -1.36ms - +0.53ms	unsure 🔍 -3% - +3% -0.70ms - +0.65ms
tip-of-tree tip-of-tree	20.88ms - 22.58ms	unsure 🔍 -2% - +6% -0.53ms - +1.36ms	-	unsure 🔍 -3% - +7% -0.61ms - +1.40ms
previous-release previous-release	20.80ms - 21.88ms	unsure 🔍 -3% - +3% -0.65ms - +0.70ms	unsure 🔍 -6% - +3% -1.40ms - +0.61ms	-

lit-html-repeat

Browser: chrome-headless 111.0.5563.110
Sample size: 30
Built by: Benchmarks #4596
Commit: 58721cd

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	13.77ms - 15.26ms	-	unsure 🔍 -7% - +6% -1.06ms - +0.87ms	unsure 🔍 -6% - +8% -0.80ms - +1.13ms
tip-of-tree tip-of-tree	14.00ms - 15.22ms	unsure 🔍 -6% - +7% -0.87ms - +1.06ms	-	unsure 🔍 -4% - +8% -0.60ms - +1.12ms
previous-release previous-release	13.75ms - 14.96ms	unsure 🔍 -8% - +5% -1.13ms - +0.80ms	unsure 🔍 -8% - +4% -1.12ms - +0.60ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	359.49ms - 419.24ms	-	unsure 🔍 -13% - +9% -54.24ms - +35.10ms	unsure 🔍 -11% - +10% -43.75ms - +38.45ms
tip-of-tree tip-of-tree	365.72ms - 432.15ms	unsure 🔍 -9% - +14% -35.10ms - +54.24ms	-	unsure 🔍 -9% - +13% -36.66ms - +50.51ms
previous-release previous-release	363.79ms - 420.24ms	unsure 🔍 -10% - +11% -38.45ms - +43.75ms	unsure 🔍 -13% - +9% -50.51ms - +36.66ms	-

lit-html-template-heavy

Browser: chrome-headless 111.0.5563.110
Sample size: 50
Built by: Benchmarks #4596
Commit: 58721cd

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	72.56ms - 75.07ms	-	unsure 🔍 -3% - +2% -2.38ms - +1.43ms	unsure 🔍 -3% - +2% -2.59ms - +1.15ms
tip-of-tree tip-of-tree	72.86ms - 75.72ms	unsure 🔍 -2% - +3% -1.43ms - +2.38ms	-	unsure 🔍 -3% - +2% -2.24ms - +1.74ms
previous-release previous-release	73.15ms - 75.93ms	unsure 🔍 -2% - +4% -1.15ms - +2.59ms	unsure 🔍 -2% - +3% -1.74ms - +2.24ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	155.36ms - 160.78ms	-	unsure 🔍 -4% - +1% -6.21ms - +1.96ms	unsure 🔍 -4% - +2% -5.91ms - +3.45ms
tip-of-tree tip-of-tree	157.14ms - 163.25ms	unsure 🔍 -1% - +4% -1.96ms - +6.21ms	-	unsure 🔍 -3% - +4% -4.00ms - +5.79ms
previous-release previous-release	155.48ms - 163.12ms	unsure 🔍 -2% - +4% -3.45ms - +5.91ms	unsure 🔍 -4% - +2% -5.79ms - +4.00ms	-

⏱ reactive-element-list

Currently running in Benchmarks #4596…

_{tachometer-reporter-action v2 for Benchmarks}

sorvell · 2023-03-30T21:21:35Z

Yeah, I think this stemmed from the fact that the other observers don't have an initial report.

Couple observations. These tests appear to be wrong here since the skipInitial test should be failing. I think it's because we're not waiting until ResizeObserver triggers (fix: maybe just change the await here to be resizeComplete:

lit/packages/labs/observers/src/test/resize-controller_test.ts

Line 78 in 25dddb8

await el.updateComplete;

).

I'd like to preserve the skipInitial setting since we have that on the other observers. To do so we could just do something like in the main observer callback (

lit/packages/labs/observers/src/resize-controller.ts

Line 103 in 25dddb8

this._observer = new ResizeObserver((entries: ResizeObserverEntry[]) => {

):

have a canObserve flag that's true if skipInitial is true
and any processing is gated on that
it becomes true after await host.updateComplete

AndrewJakubowicz · 2023-04-28T21:18:26Z

After fixing the tests and applying the skipInitial setting in the same way that IntersectionController does it, we end up with all tests passing except Safari. This is due to WebKit not calling the callback on observe at the moment. They are working on changing the behavior to match Chrome and Firefox. See: webcompat/web-bugs#117611 (comment)

justinfagnani · 2023-04-28T21:26:59Z

@AndrewJakubowicz is there a way to detect the browser not calling the callback on observe()? Is that initial call synchronous by any chance?

AndrewJakubowicz · 2023-04-28T21:52:57Z

It is not synchronous. The first observe callback runs some time after observe is called.

WIP: try removing initial update

25dddb8

justinfagnani requested a review from sorvell March 30, 2023 19:05

AndrewJakubowicz self-assigned this Apr 26, 2023

[labs/observers] WIP: try removing initial update from ResizeController #3773

Are you sure you want to change the base?

[labs/observers] WIP: try removing initial update from ResizeController #3773

Uh oh!

Conversation

justinfagnani commented Mar 30, 2023

Uh oh!

changeset-bot bot commented Mar 30, 2023

⚠️ No Changeset found

Uh oh!

github-actions bot commented Mar 30, 2023 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

📊 Tachometer Benchmark Results

Summary

nop-update

render

update

update-reflect

Results

render

update

update-reflect

render

update

nop-update

render

update

render

update

Uh oh!

sorvell commented Mar 30, 2023

Uh oh!

AndrewJakubowicz commented Apr 28, 2023

Uh oh!

justinfagnani commented Apr 28, 2023

Uh oh!

AndrewJakubowicz commented Apr 28, 2023

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

github-actions bot commented Mar 30, 2023 •

edited

Loading