• epriestley's avatar
    Reduce the frequency of DOM scans to rebuild inlines when scrolling revisions · c666cb9f
    epriestley authored
    Ref T13513. See PHI1734, which raises a concern about the performance of large revisions near the 100-change threshold.
    Currently, `getInlines()` is called whenever the scroll position transitions between two changesets, and it performs a relatively complicated DOM scan to lift inlines out of the document.
    This shows up as taking a small but nontrivial amount of time in Firefox profiles and should be safely memoizable.
    Test Plan:
      - Under Firefox profiling, scrolled through a large revision.
      - Before change: `getInlines()` appeared as the highest-cost thing we're explicitly doing on profiles.
      - After change: `getInlines()` was no longer meaningfully represented on profiles.
      - Created inlines, edited inlines, etc. Didn't identify any broken behavior.
    Maniphest Tasks: T13513
    Differential Revision: https://secure.phabricator.com/D21261