LocalStorage values should be 8-bit strings in memory if possible

[Ben Nham]

LocalStorage values should be 8-bit strings in memory if possible

[Ben Nham]

Created attachment 449739 [details]
Patch

[Chris Dumez]

Comment on attachment 449739 [details]
Patch

r=me

[Radar WebKit Bug Importer]

<rdar://problem/87980407>

[Ben Nham]

Comment on attachment 449739 [details]
Patch

This ended up being only neutral on Membuster. One of the websites in the benchmark has 1.4MB of LocalStorage values in its database. Unfortunately, the values are almost-ASCII but not quite; the site seems to store WebFont css in LocalStorage, and the CSS has a non-ASCII smiley face in it:

@font-face {
  // ...
  src: local('☺︎'),
  // ...
}

See https://www.paulirish.com/2009/bulletproof-font-face-implementation-syntax/#smiley for more details. So the value can't actually be parsed into an 8-bit string and this optimization does nothing for that website.

This is still worth doing though, so I'll land it.

[Yusuke Suzuki]

For this kind of long-living values, making it 8bit as much as possible really makes sense! Nice

[EWS]

Committed r289078 (246784@main): <https://commits.webkit.org/246784@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 449739 [details].