1947497 - Accessing any usecase requires the entire dependency graph for all usecases to be initialized

Status: RESOLVED FIXED

(Fenix :: Performance, task)

Description

[Jeff Boek [:boek]]

https://searchfox.org/mozilla-central/source/mobile/android/fenix/app/src/main/java/org/mozilla/fenix/components/UseCases.kt

These get initialized immediately in FenixApplication::onCreate

Comment 1

[Segun Famisa [:segun]]

Attachment: Bug 1947497 - Make UseCases & PocketStoriesService lazily initialized

Comment 2

[Segun Famisa [:segun]]

Attachment: app-startup-profile-before.png

Comment 3

[Segun Famisa [:segun]]

Comment on attachment 9465983 [details]
app-startup-profile-before.png

During the Application's onCreate() execution, we make one call to the UseCases container, and that triggers the creation of all the dependencies of that class.

The creation of the UseCases container, then further triggers the creation of AppStore - which uses the PocketUpdatesMiddleware as one of its middlewares. The creation of this class (and its dependencies) takes significant time, and it's not needed at all during startup as seen in this profile - https://share.firefox.dev/3CSiOh0 (also shown in this photo)

Making the dependencies of the UseCases container lazy, and making the PocketStoriesService (in PocketUpdatesMiddleware) lazy helps to remove these unnecessary work from app startup

Comment 4

[Segun Famisa [:segun]]

• Perf compare link

Comment 5

[Segun Famisa [:segun]]

New perf compare link - thanks to :kaya for helping to fix the previous link.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2cc436ba125d
Make UseCases & PocketStoriesService lazily initialized r=android-reviewers,007

Comment 7

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/2cc436ba125d

Comment 8

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/2cc436ba125d