tree e97ee606913c022911791d7042b3eeae6ab0a288
parent c02c21e5e92f8f4eb92cc0b2328c24d63d8781df
author Heschi Kreinick <heschi@google.com> 1572894341 -0500
committer Heschi Kreinick <heschi@google.com> 1572903089 +0000

internal/lsp/cache: only refresh imports cache every 30 seconds

Loading completion suggestions can be slow, especially in GOPATH mode
where basically anything can change at any time. As a compromise, cache
everything for 30 seconds. Specifically, after a completion operation
finishes, if the cache is more than 30 seconds old, refresh it
asynchronously. That keeps user-facing latency consistent, without
chewing up CPU when the editor isn't in use. It does mean that if you
walk away for an hour and come back, the first completion may be stale.

In module mode this is relatively benign. The only things the
longer caching affects are the main module and replace targets, and
relevant packages in those will generally be loaded by gopls, so they'll
have full, up-to-date type information regardless.

In GOPATH mode this may be more troublesome, since it affects
everything. In particular, go get -u of a package that isn't imported
yet won't be reflected until the cache period expires. I think that's a
rare enough case not to worry about.

Change-Id: Iaadfd0ff647cda2b1dcdead9254b5492b397e86e
Reviewed-on: https://go-review.googlesource.com/c/tools/+/205163
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>