Bug 257478

Summary: Appending an `option` to a `select` forces a style recalc of all options
Product: WebKit Reporter: Ahmad Saleem <ahmad.saleem792>
Component: FormsAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: akeerthi, cdumez, karlcow, rniwa, webkit-bug-importer, wenson_hsieh
Priority: P2 Keywords: InRadar
Version: Safari Technology Preview   
Hardware: Unspecified   
OS: Unspecified   

Description Ahmad Saleem 2023-05-30 04:43:42 PDT 
Hi Team,

Came across this potential opportunities:

Blink Commit: https://chromium.googlesource.com/chromium/src.git/+/19837159fdbebc0033a14887f8436e8edfe75a10

WebKit Source: https://github.com/WebKit/WebKit/blob/22282c4a26cfe887327093bc42513472a26b12fc/Source/WebCore/html/HTMLSelectElement.cpp#L804

Just wanted to raise, if we can get rid of it or it might lead to other bugs?

Thanks!
Comment 1 Ahmad Saleem 2023-05-31 11:21:28 PDT 
Testcase: https://jsfiddle.net/umb93s21/show

Safari Technology Preview 170 (in Private Window):

Description: Measures performance of adding option elements to a multi-selection select element.

Time:
values 6392.009987515606, 6243.90243902439, 6344.485749690196, 6384.039900249391, 6448.362720403023, 6376.089663760897, 6236.297198538367, 6259.168704156507, 6198.547215496368, 6168.674698795207, 6408.010012515703, 6432.160804020101, 6368.159203980042, 6236.297198538367, 6198.547215496314, 6305.418719211879, 6392.009987515606, 6400.000000000058, 6376.089663760897, 6360.248447205084 runs/s
avg 6326.4259764937015 runs/s
median 6364.203825592563 runs/s
stdev 86.99574668297977 runs/s
min 6168.674698795207 runs/s
max 6448.362720403023 runs/s

MiniBrowser (build-webkit --release with Patch):

Description: Measures performance of adding option elements to a multi-selection select element.

Time:
values 11743.119266055042, 11743.11926605506, 11743.119266055046, 11681.877444589309, 11773.981603153745, 11743.11926605506, 11758.530183727034, 11697.127937336842, 11712.418300653637, 11758.530183727005, 11651.495448634645, 11712.41830065365, 11758.530183727034, 11773.981603153745, 11712.418300653595, 11743.119266055019, 11789.473684210527, 11681.877444589365, 11727.748691099505, 11666.66666666675 runs/s
avg 11728.63361534258 runs/s
median 11743.11926605503 runs/s
stdev 38.0371407071838 runs/s
min 11651.495448634645 runs/s
max 11789.473684210527 runs/s
Comment 2 Radar WebKit Bug Importer 2023-06-06 04:44:19 PDT 
<rdar://problem/110314018>
Comment 3 Ahmad Saleem 2023-06-10 15:51:00 PDT 
Description: Measures performance of adding option elements to a multi-selection select element.

Time:
values 13264.248704663229, 11399.491094147596, 11428.571428571442, 11443.167305236264, 11428.571428571442, 11457.800511508965, 11443.167305236297, 11414.01273885349, 11428.571428571442, 11428.571428571402, 11399.491094147583, 11385.006353240153, 11399.491094147555, 11385.006353240153, 11428.57142857143, 11457.800511508978, 11313.131313131313, 11313.131313131287, 11443.167305236191, 11443.167305236218 runs/s
avg 11505.206872276121 runs/s
median 11428.571428571435 runs/s
stdev 415.9965649810432 runs/s
min 11313.131313131287 runs/s
max 13264.248704663229 runs/s

_____________

Description: Measures performance of adding option elements to a multi-selection select element.

Time:
values 11636.36363636364, 11666.666666666666, 11727.748691099483, 11651.495448634576, 11651.49544863459, 11651.495448634576, 11666.666666666639, 11651.49544863459, 11591.203104786533, 11531.531531531531, 11636.363636363663, 11789.473684210527, 11820.580474934008, 11805.006587615228, 11773.981603153745, 11758.530183727034, 11805.006587615284, 11805.00658761534, 11836.195508586554, 11805.006587615284 runs/s
avg 11713.065676654474 runs/s
median 11697.207678883075 runs/s
stdev 89.267576549425 runs/s
min 11531.531531531531 runs/s
max 11836.195508586554 runs/s

_________


Only slight increase on like to like build.