1658207 - [shared fontlist] Family character-map is not always set/used properly to accelerate fallback searches

Status: RESOLVED FIXED

(Core :: Layout: Text and Fonts, defect)

Description

[Jonathan Kew [:jfkthame]]

Doing some profiling of text-intensive actions, I realized that we don't always use the character map in fontlist::Family records correctly to optimize fallback searches, and we don't always set it up when we should as a result of the InitializeFamily message.

(Noticed while profiling pinch-zoom operations in bug 1657440 (edit: actually bug 1656156); the profile showed more time in SearchAllFontsForChar and InitializeFamily than I would have expected. With this fixed, those methods no longer appear as "hotspots" in the profile.)

Comment 1

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1658207 - Set up and use the mCharacterMap in shared Family records more correctly, to accelerate font fallback searches. r=jwatt

Comment 2

[Jonathan Kew [:jfkthame]]

In my local opt (but non-pgo) build, this accelerates reflows when zooming wikipedia.org (which is quite font-fallback-heavy, because of the mix of languages) by at least 20%.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/16346122a824
Set up and use the mCharacterMap in shared Family records more correctly, to accelerate font fallback searches. r=jwatt

Comment 4

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/16346122a824