It's too slow to get intellisence in just hello world level project

[tjx666]

Steps:

1. git clone [email protected]:tjx666/study-rust.git
2. open it in vscode in multi-root workspace mode
3. open oop/src/main.rs
4. in my computer, it costs about 30 seconds to get println autocomplete

Version: 1.71.0-insider (Universal)
Commit: 35b971c92d210face8c446a1c6f1e470ad2bcb54
Date: 2022-08-26T09:30:57.123Z
Electron: 19.0.12
Chromium: 102.0.5005.167
Node.js: 16.14.2
V8: 10.2.154.15-electron.0
OS: Darwin x64 21.6.0
Sandboxed: Yes
Rust-Analyzer: v0.4.1184

2022-08-28.22.02.31.mov

[lnicola]

Can you commit and push oop? :-).

[tjx666]

Can you commit and push oop? :-).

Ok. I had commt.

[tjx666]

It's very strange: I just open oop folder, why this extension load all other folders.

[lnicola]

Does it work better after the "Fetching metadata" message goes away? It takes 20 seconds or so.

It's very strange: I just open oop folder, why this extension load all other folders.

If I open oop, it loads fast for me. But if I open the whole Code workspace, it's pretty slow. I think we're mainly calling cargo metadata on each of the projects, we could probably do that in parallel.

[tjx666]

@lnicola The better solution maybe only load the oop workspace. In multi-root workspaces, one workspace should only be load when open the rust file in itself. Because workspaces had nothing relationship between each other.

[lnicola]

Yeah, but we don't do that for some reason, I'm not sure why. Ideally, we'd only load oop and see if it depends on something else from the same workspace.

[flodiebold]

I think that's closely related to #8622 / #7737. As I see it, we don't load projects lazily because 1. it's simpler implementation-wise, but also 2. find references can't work as expected if all projects aren't loaded eagerly. TBH I'm not sure the tradeoff is worth it, maybe we could make the behavior of find references with lazily loaded/unloaded projects clear to users somehow.

[Veykril]

Closing this as related issues have been mentioned / opened that capture the problem more precisely