[labs/virtualizer] Fix #3815

[graynorton]

No description provided.

[changeset-bot]

🦋 Changeset detected

Latest commit: 486a562

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@lit-labs/virtualizer	Patch

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[github-actions]

📊 Tachometer Benchmark Results

Summary

nop-update

• lit-html-kitchen-sink: unsure 🔍 -10% - -0% (-1.74ms - +0.00ms)
  ^{this-change vs tip-of-tree}

render

• lit-element-list: 75.58ms - 80.96ms
• lit-html-kitchen-sink: unsure 🔍 -7% - +4% (-2.15ms - +1.11ms)
  ^{this-change vs tip-of-tree}
• lit-html-repeat: unsure 🔍 -9% - +1% (-1.00ms - +0.17ms)
  ^{this-change vs tip-of-tree}
• lit-html-template-heavy: unsure 🔍 -4% - +3% (-2.09ms - +1.41ms)
  ^{this-change vs tip-of-tree}
• reactive-element-list: unsure 🔍 -1% - +6% (-0.26ms - +2.96ms)
  ^{this-change vs tip-of-tree}

update

• lit-element-list: 759.75ms - 771.06ms
• lit-html-kitchen-sink: unsure 🔍 -1% - +7% (-0.71ms - +4.80ms)
  ^{this-change vs tip-of-tree}
• lit-html-repeat: unsure 🔍 -2% - +3% (-5.50ms - +7.68ms)
  ^{this-change vs tip-of-tree}
• lit-html-template-heavy: unsure 🔍 -2% - +1% (-1.66ms - +1.17ms)
  ^{this-change vs tip-of-tree}
• reactive-element-list: unsure 🔍 -1% - +1% (-10.96ms - +8.70ms)
  ^{this-change vs tip-of-tree}

update-reflect

• lit-element-list: 738.87ms - 749.81ms
• reactive-element-list: unsure 🔍 -1% - +1% (-9.31ms - +7.49ms)
  ^{this-change vs tip-of-tree}

Results

lit-element-list

• Browser: chrome-headless 112.0.5615.49
• Sample size: 50
• Built by: Benchmarks #4659

• Commit: 1aeaf09

render

Version	Avg time	vs
	75.58ms - 80.96ms	-

update

Version	Avg time	vs
	759.75ms - 771.06ms	-

update-reflect

Version	Avg time	vs
	738.87ms - 749.81ms	-

lit-html-kitchen-sink

• Browser: chrome-headless 112.0.5615.49
• Sample size: 30
• Built by: Benchmarks #4659

• Commit: 1aeaf09

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	28.86ms - 30.67ms	-	unsure 🔍 -7% - +4% -2.15ms - +1.11ms	unsure 🔍 -7% - +3% -2.30ms - +0.98ms
tip-of-tree tip-of-tree	28.92ms - 31.64ms	unsure 🔍 -4% - +7% -1.11ms - +2.15ms	-	unsure 🔍 -7% - +6% -2.07ms - +1.79ms
previous-release previous-release	29.05ms - 31.80ms	unsure 🔍 -3% - +8% -0.98ms - +2.30ms	unsure 🔍 -6% - +7% -1.79ms - +2.07ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	73.67ms - 78.19ms	-	unsure 🔍 -1% - +7% -0.71ms - +4.80ms	unsure 🔍 -4% - +4% -3.42ms - +3.03ms
tip-of-tree tip-of-tree	72.31ms - 75.45ms	unsure 🔍 -6% - +1% -4.80ms - +0.71ms	-	unsure 🔍 -7% - +1% -5.02ms - +0.54ms
previous-release previous-release	73.83ms - 78.42ms	unsure 🔍 -4% - +5% -3.03ms - +3.42ms	unsure 🔍 -1% - +7% -0.54ms - +5.02ms	-

nop-update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	16.51ms - 16.79ms	-	unsure 🔍 -10% - -0% -1.74ms - +0.00ms	faster ✔ 1% - 9% 0.06ms - 1.58ms
tip-of-tree tip-of-tree	16.66ms - 18.38ms	unsure 🔍 -0% - +10% -0.00ms - +1.74ms	-	unsure 🔍 -6% - +7% -1.09ms - +1.19ms
previous-release previous-release	16.72ms - 18.22ms	slower ❌ 0% - 9% 0.06ms - 1.58ms	unsure 🔍 -7% - +6% -1.19ms - +1.09ms	-

lit-html-repeat

• Browser: chrome-headless 112.0.5615.49
• Sample size: 30
• Built by: Benchmarks #4659

• Commit: 1aeaf09

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	10.06ms - 10.89ms	-	unsure 🔍 -9% - +1% -1.00ms - +0.17ms	unsure 🔍 -9% - +4% -0.94ms - +0.46ms
tip-of-tree tip-of-tree	10.48ms - 11.30ms	unsure 🔍 -2% - +10% -0.17ms - +1.00ms	-	unsure 🔍 -5% - +8% -0.52ms - +0.88ms
previous-release previous-release	10.15ms - 11.28ms	unsure 🔍 -4% - +9% -0.46ms - +0.94ms	unsure 🔍 -8% - +5% -0.88ms - +0.52ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	275.80ms - 284.74ms	-	unsure 🔍 -2% - +3% -5.50ms - +7.68ms	unsure 🔍 -4% - +1% -10.49ms - +2.88ms
tip-of-tree tip-of-tree	274.34ms - 284.02ms	unsure 🔍 -3% - +2% -7.68ms - +5.50ms	-	unsure 🔍 -4% - +1% -11.84ms - +2.04ms
previous-release previous-release	279.10ms - 289.05ms	unsure 🔍 -1% - +4% -2.88ms - +10.49ms	unsure 🔍 -1% - +4% -2.04ms - +11.84ms	-

lit-html-template-heavy

• Browser: chrome-headless 112.0.5615.49
• Sample size: 50
• Built by: Benchmarks #4659

• Commit: 1aeaf09

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	53.33ms - 56.29ms	-	unsure 🔍 -4% - +3% -2.09ms - +1.41ms	unsure 🔍 -4% - +3% -2.17ms - +1.40ms
tip-of-tree tip-of-tree	54.22ms - 56.08ms	unsure 🔍 -3% - +4% -1.41ms - +2.09ms	-	unsure 🔍 -3% - +2% -1.40ms - +1.32ms
previous-release previous-release	54.20ms - 56.19ms	unsure 🔍 -3% - +4% -1.40ms - +2.17ms	unsure 🔍 -2% - +3% -1.32ms - +1.40ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	107.03ms - 108.95ms	-	unsure 🔍 -2% - +1% -1.66ms - +1.17ms	unsure 🔍 -2% - +1% -1.70ms - +0.93ms
tip-of-tree tip-of-tree	107.19ms - 109.28ms	unsure 🔍 -1% - +2% -1.17ms - +1.66ms	-	unsure 🔍 -1% - +1% -1.52ms - +1.24ms
previous-release previous-release	107.48ms - 109.27ms	unsure 🔍 -1% - +2% -0.93ms - +1.70ms	unsure 🔍 -1% - +1% -1.24ms - +1.52ms	-

reactive-element-list

• Browser: chrome-headless 112.0.5615.49
• Sample size: 50
• Built by: Benchmarks #4659

• Commit: 1aeaf09

render

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	50.81ms - 53.09ms	-	unsure 🔍 -1% - +6% -0.26ms - +2.96ms	unsure 🔍 -2% - +4% -1.26ms - +1.94ms
tip-of-tree tip-of-tree	49.46ms - 51.74ms	unsure 🔍 -6% - +0% -2.96ms - +0.26ms	-	unsure 🔍 -5% - +1% -2.61ms - +0.60ms
previous-release previous-release	50.48ms - 52.74ms	unsure 🔍 -4% - +2% -1.94ms - +1.26ms	unsure 🔍 -1% - +5% -0.60ms - +2.61ms	-

update

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	787.66ms - 801.41ms	-	unsure 🔍 -1% - +1% -10.96ms - +8.70ms	unsure 🔍 -1% - +1% -10.27ms - +8.73ms
tip-of-tree tip-of-tree	788.63ms - 802.70ms	unsure 🔍 -1% - +1% -8.70ms - +10.96ms	-	unsure 🔍 -1% - +1% -9.25ms - +9.97ms
previous-release previous-release	788.75ms - 801.86ms	unsure 🔍 -1% - +1% -8.73ms - +10.27ms	unsure 🔍 -1% - +1% -9.97ms - +9.25ms	-

update-reflect

Version	Avg time	vs this-change	vs tip-of-tree tip-of-tree	vs previous-release previous-release
this-change	783.53ms - 793.90ms	-	unsure 🔍 -1% - +1% -9.31ms - +7.49ms	unsure 🔍 -1% - +1% -7.56ms - +6.45ms
tip-of-tree tip-of-tree	783.02ms - 796.23ms	unsure 🔍 -1% - +1% -7.49ms - +9.31ms	-	unsure 🔍 -1% - +1% -7.76ms - +8.48ms
previous-release previous-release	784.55ms - 793.99ms	unsure 🔍 -1% - +1% -6.45ms - +7.56ms	unsure 🔍 -1% - +1% -8.48ms - +7.76ms	-

_{tachometer-reporter-action v2 for Benchmarks}

[usergenic]

LGTM!

[justinfagnani]

lgtm

Trying to understand what's going on though, and... it would be great to start adding more explanatory comments as changes are made. I'd like to understand what layoutChildren is doing from a very high level.

[justinfagnani]

@usergenic do you want to merge this?

[usergenic]

@usergenic do you want to merge this?

Yes thanks!