1556833 - Defer write flushing for high-churn LocalStorage keys

Status: NEW

(Core :: Storage: localStorage & sessionStorage, enhancement, P3)

Description

[Andrew Sutherland [:asuth] (he/him)]

In bug 1555660 a user is seeing multiple sites that are idle in terms of user interaction but are constantly churning their localStorage for whatever reason. It would be beneficial to throttle or entirely defer writes to high-churn keys based on user-budget style heuristics.

My discussion in https://bugzilla.mozilla.org/show_bug.cgi?id=1536797#c12 covers potential ways to track and mitigate. Noting that bug 1536797 is actually about the other end of the spectrum: where our delayed writes are too delayed. But both situations are different sides of the same coin; if we can delay the gratuitous high-churn writes further, we can be more timely with non-churn writes.