The createCompactList() function runs synchronously during the
module execution burst. Due to it visually changing the page, I
won't defer it with rIC for the time being, although that should
be considered for the future. For this commit, I'm trying to make
it fit the budget of <50ms because ULS is currently usually taking
80ms-180ms on desktop (MacBook/Chrome CPU/4), and that's during
batch execution with other modules as well, thus freezing the
UI thread for much longer than that.
constructor:
* Remove needless clone of jQuery object.
Use $foo instead of $( $foo ).
* Remove creation of 'interlanguageList' and 'compactList' objects
that are immediately removed and re-created by init().
init/getInterlanguageList:
* Use the HTMLElement.lang and HTMLAnchorElement.href properties
directly instead of the DOM getAttribute().
This means stores a full url instead of a relative url, which
should help avoid other bugs in the future.
* Remove needless jQuery() constructor and jQuery.text() call.
Use Node.textContent directly instead.
* Use HTMLElement#querySelectorAll instead of jQuery#find().
init/getCompactList/../filterByLangsInText:
* Avoid jQuery() constructor and jQuery.attr(),
use the HTMLElement.lang property directly.
* Avoid jQuery() selector, call querySelectorAll directly.
init/getCompactList/../getCommonLanguages/../getFrequentLanguageList:
* Avoid temporary array copies from concat() and function overhead
with forEach() and filter().
Instead, keep only a single array, and iterate it once.
init/getCompactList/../filterByBadges (~10m -> ~0.5ms):
* Use one query via $(), instead of two queries $()+find().
* Use $.map() directly instead of map()+fakejQueryObject+toArray().
* Use querySelector(One) for the child instead of $()+find().
* Use HTMLElement.lang property directly.
init/hideOriginal (~5m -> ~0.8ms):
* Use querySelectorAll() directly instead of jQuery find().
* Set HTMLElement.style directly instead of jQuery() css().
init/render/addTrigger:
* Use createElement() and direct properties instead of $(), addClass(),
prop() and text().
* The mw.msg() calls use text() and jqueryMsg#parser which is
expensive.
Use plain() for 'ext-uls-compact-link-info', which doesn't need parsing.
Keep text() for the other message, and document why.
init/listen:
* Use async Deferred#then() instead of sometimes-sync Deferred#done().
Bug: T127328
Change-Id: I424c34fb82c8e95407f7b934e6d42019becbf909