Debounce workspace symbol searches

[janko]

When I type in a 5-letter word to the project symbol search box, Zed sends 5 workspace/symbol search requests to the language server, each with a new letter added.

I'm primarily writing Ruby, and Ruby LSP is single-threaded. This means that Ruby LSP processes all of these 5 requests synchronously, while Zed seems to only populate the result list once the last response was received.

That's wasteful and makes the project symbol search slow. I'm only interested in that last search request, I don't need the earlier responses, since that's from before I finished typing.

It would be great if Zed had a configuration to debounce the symbol search requests, so that it can send the workspace/symbol request only when I've finished typing, containing the final search query.

[filipwiech]

@janko Nice catch, sounds like a good idea! 👍Seems that Zed at least tries to cancel previous workspace symbol requests if the response hasn't arrived yet, but maybe in some cases that's not enough. Generally Zed tries to be very efficient and AFAIK there's already a lot of clever performance tricks throughout the LSP integration layer, including debouncing in some places (e.g. completions). IMHO you could just open an issue, cannot imagine that the current behavior is intentional. 🙂

[janko]

It seems that Ruby LSP never actually manages to cancel any of the workspace/symbol requests. I found out that proper request cancellation hasn't been fully implemented there yet, so I opened a PR for it – Shopify/ruby-lsp#3791.

I think I'll be good once that's fixed. I don't know if debouncing in the Zed side could improve performance further, it's a bit tricky for me to measure that 😅