Any way to enable lsp for only the selectedTextEditor?

[onriv]

Hi in our plugin the lsp server is some kind performance intensive. We want to see if it's possible limit the lsp server request only for the current focus file, like onriv/lean4ij#35. Checking the requests our lsp server start some heavy operations once the org.eclipse.lsp4j.services.TextDocumentService#didOpen requests is sent.

Is there any way for configuring this? The com.redhat.devtools.lsp4ij.client.features.LSPClientFeatures seems not suitable here. And checking the code LanguageServerWrapper#connect seems not help either.

[angelozerr]

Perhaps by overriding all LSP*feature#isEnabled and get the editor from PsiFile and check if the editor is the current editor?

[onriv]

Yeah indeed. Debugging I found that for the non-slectedfile:

There is still some requests sending to the server like:

[onriv]

Maybe in the case for lean it's kind of prefering to have an option that only after taking the file to front, it's treated as open and sends the didOpen request

[angelozerr]

LSP4IJ sends a didOpen for all opened editor. We could move the logic of didOpen in LSPClientFeatures and even add a method like shouldConnect(PsiFile file) that you could override it to check if didOpen must be sent.

The main problem is that didOpen is mapped with fileOpened event listener which is called for all opened editor.

We should track for your case when editor is selected.

[onriv]

Yeah checking the code. Is the suitable extension point here here?

I am not sure if it's possible turning into things like

if (!wrapper.isEnabled(file)) {
    return CompletableFuture.completedFuture(Collections.emptyList());
}
if (server != null &&
        (afterStartingServerFilter == null || afterStartingServerFilter.test(wrapper.getClientFeatures()))) {
    return wrapper.connect(file, document);
}
return CompletableFuture.completedFuture(null);

and make wrapper.isEnable(file) an extension point.

[onriv]

BTW there is a similar case in our situation: when poping up searching dialog, the file is also treated as opened and send the didOpen request. For avoiding this while implementing the factory LanguageServerFactory, the LanguageServerFactory#isEnabled(project) method turns true if only the real editor is focused. But it has no file argument now.

[angelozerr]

@onriv I have a question. Your performance problem occurs when IJ is starting and opens previously opened editors which starts your ls ?

If it that see #571

Or have you this problem again when IJ is started and you open qeveral editors?

[onriv]

@onriv I have a question. Your performance problem occurs when IJ is starting and opens previously opened editors which starts your ls ?

If it that see #571

Or have you this problem again when IJ is started and you open qeveral editors?

It seems neither. It seems that our language server is indeed cpu intensive for first opening the file:

and hence it may help for only handling current focused editor.

I made a PR minutes ago, please check if it's suitable?
#586

[onriv]

closed with #586