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>
2 files changed
tree: e97ee606913c022911791d7042b3eeae6ab0a288
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. cover/
  6. go/
  7. godoc/
  8. gopls/
  9. imports/
  10. internal/
  11. playground/
  12. present/
  13. refactor/
  14. .gitattributes
  15. .gitignore
  16. AUTHORS
  17. codereview.cfg
  18. CONTRIBUTING.md
  19. CONTRIBUTORS
  20. go.mod
  21. go.sum
  22. LICENSE
  23. PATENTS
  24. README.md
README.md

Go Tools

This subrepository holds the source for various packages and tools that support the Go programming language.

Some of the tools, godoc and vet for example, are included in binary Go distributions.

Others, including the Go guru and the test coverage tool, can be fetched with go get.

Packages include a type-checker for Go and an implementation of the Static Single Assignment form (SSA) representation for Go programs.

Download/Install

The easiest way to install is to run go get -u golang.org/x/tools/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/tools.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.

The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.