internal/lsp/semantic: avoid doing semantic tokens for large files

LSP (and gopls) support both full-file semantic token requests and
requests for just a range, typically roughly what's visible to the user.
It can be slow to produce the full set for a very large file, so
this code now responds with an error if the file is bigger than
100,000 bytes. After getting this error, vscode, at least,
will stop asking for full requests and use range requests.

Alternatively, server capabilities could say gopls never responds to
full-file requests, but doing that doesn't stop vscode from asking for
them. Another possibility would be to fix a time limit (like 8ms) for
how long to spend generating full-file semantic tokens. That's tricky
to get right, but one could instead generate an error when there
are more than 4,000 semantic tokens (on my laptop, that's about 8ms.)

Large files are unusual; a simple size limit seems adequate for now.

Change-Id: Ieea0d16aad6e37cc4f14b1a6a7116a4e41197aae
Reviewed-on: https://go-review.googlesource.com/c/tools/+/307729
Run-TryBot: Peter Weinberger <pjw@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Peter Weinberger <pjw@google.com>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
3 files changed
tree: ac4a0182cd36000392614b61501f20dda810132d
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. copyright/
  6. cover/
  7. go/
  8. godoc/
  9. gopls/
  10. imports/
  11. internal/
  12. playground/
  13. present/
  14. refactor/
  15. txtar/
  16. .gitattributes
  17. .gitignore
  18. .prettierrc
  19. AUTHORS
  20. codereview.cfg
  21. CONTRIBUTING.md
  22. CONTRIBUTORS
  23. go.mod
  24. go.sum
  25. LICENSE
  26. PATENTS
  27. README.md
README.md

Go Tools

PkgGoDev

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.

JS/CSS Formatting

This repository uses prettier to format JS and CSS files.

The version of prettier used is 1.18.2.

It is encouraged that all JS and CSS code be run through this before submitting a change. However, it is not a strict requirement enforced by CI.

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.