Wp-calypso: Editor: Slow Search on Link to Existing Posts

[supernovia]

Steps to reproduce

1. Starting at URL: wordpress.com/post -- preferably on a large site with many posts
2. Type up a bit of a post, and try to add a link to an existing post.
3. Try searching by title. Scroll through the list.
4. Close it out or insert, then repeat this several times.

What I expected

To be able to quickly find a post and insert a link.

What happened instead

While it works at first, over time, this bogs down considerably. Also, the search results aren't great - users have to scroll down a bit to find posts that should have matched well. One user suggest prioritizing title matches since that's what many folks are searching for.

Browser / OS version

Multiple browsers: switching to another browser helps temporarily, as does clearing local data. But over time it slows down again no matter the browser.

Screenshot / Video

http://www.screencast.com/t/Sqq5S0t5AAu via one of our users

Context / Source

This was brought up in our forums & we've been trying to spot the bug for a while. I couldn't reproduce it, but Timmy tried it on en.blog and was able to get it after a while.

[lancewillett]

+1 I've experienced this a lot on internal P2 sites.

[mahangu]

Reported in #301030-hc as well.

[catehstn]

Experiencing this on my personal site (cate.blog) and also on internal p2s. Would also say that in general Calypso is feeling a bit laggy but shows up very noticeably when trying to add links. Happy to provide a video or run some kind of profiling tool if that would be helpful.

[timmyc]

@catehstn if you could, and wouldn't mind, testing out the same flow with linking in https://calypso.live/?branch=fix/editor/12481 and let us know if it feels faster there? Thanks!

[catehstn]

Hey! Tried it and feels faster. Thanks!

[timmyc]

Thanks for testing @catehstn !

[supernovia]

Just checking in on this - is there anything else we need to do to make it go?

[timmyc]

Thanks for the nudge @supernovia - looks like the branch in #12528 needs some attention, I will try to update that today and find someone to give it the final 👍

[lancewillett]

Re-opening based on a report by @catehstn that the wplink experience is still very slow and laggy for her -- specifically on internal Automattic P2 (the mobile team's "Hogwarts" site).

A bit of anecdotal feedback:

Takes ages to load, unresponsive
can't select my post so ended up finding the link and pasting it over.
my general impression of that component is that it ranges between "unusable" and "meh". It's never snappy.

First load is slowest, second load is faster but still unusable.

My bet is a JS Wrangler doing some benchmarking could find the bottleneck and a fix.

See also https://github.com/Automattic/wp-calypso/pull/12528 as the last time the code was improved, CC @timmyc