Reduce overhead due to lsp semantic token refresh requests. #69690
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Previously, typing a single character in a razor markup segment would cause 5 semantic token refresh requests, and consequently 12 semantic token range requests for the simple razor page I was testing. This PR reduces that count to 1 semantic token refresh request and 6 semantic token range requests for the same edit. It does this by: 1) Not listening to workspace events if the language server doesn't support semantic tokens. 2) Changing DocumentReloaded handling to detect whether something other than the text has changed on the file, and if not, prevents a refresh message if the file is being tracked. 3) Changing AdditionalDocumentChanged to special case razor files and not send refresh notifications due to their modification.
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Rather than, or as well as, special casing Razor files, should Razor (or the LSP client) do some basic debouncing of the refresh requests? Or would that not be to spec? |
There is debouncing on both the client and server side, and yet we were still experiencing a bunch of the refresh messages and the corresponding semantic token requests. |
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Rather than, or as well as, special casing Razor files, should Razor (or the LSP client) do some basic debouncing of the refresh requests? Or would that not be to spec?
We already debounce on the server - we send max 1 request every 2 seconds (per server). Its also entirely up to the client how it wants to handle the refresh notification. From the spec
Note that the client still has the freedom to delay the re-calculation of the semantic tokens if for example an editor is currently not visible.
| private static bool DisallowsAdditionalDocumentChangedRefreshes(string? filePath) | ||
| { | ||
| var extension = Path.GetExtension(filePath); | ||
| return extension is ".cshtml" or ".razor"; |
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some context for this -
It seems like in general additional files changing could affect semantic tokens (for example if those changes are inputs to a source generator). However, Razor semantic tokens only uses the design time file so we actually don't care of the Razor file changes (they'll already tell us when the design time file changes).
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1 request every 2 seconds and yet each keystroke would cause 5 refresh requests!? wow. |
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@davidwengier -- any concerns with merging? |
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…otnet#69690)" This reverts commit 499a8d2.
Previously, typing a single character in a razor markup segment would cause 5 semantic token refresh requests, and consequently 12 semantic token range requests for the simple razor page I was testing. This PR reduces that count to 1 semantic token refresh request and 6 semantic token range requests for the same edit. It does this by: