Smarter workspaceContains handling?

[bpasero]

Would it be possible to avoid a full workspace scan from every workspaceContains that an extension declares by stopping a search once the first result is found? I know that this should work from the classic file traversal implementation but I am not sure about RipGrep. Maybe there is a command to use RipGrep in such a way that it would just return 0 or 1 when a result is found?

Alternatively we could also do a heuristic: we could first do a quick check of the root level files of the workspace folders and only run the more expensive file search if no files match. I would argue that in most cases the file of interest would actually be in the root folder (e.g. tsconfig.json).

[alexdima]

At the time this was implemented, that was the contract of the DiskSearch.

I don't know if that changed in the meantime.

https://github.com/Microsoft/vscode/blob/de99997ab5715de51a1a9903acf46e487e73f7fa/src/vs/workbench/node/extensionHostMain.ts#L224

		const query: ISearchQuery = {
			folderQueries: this._workspace.folders.map(folder => ({ folder: folder.uri })),
			type: QueryType.File,
			maxResults: 1,
			includePattern: includes
		};

[bpasero]

Ah ok, didn't know about maxResults, @roblourens can maybe clarify if this is supported in RipGrep too.

[roblourens]

It is implemented for text search with ripgrep, but looks to be not implemented for filesearch with rg or find. @chrmarti

[chrmarti]

@roblourens --quiet will tell us if there is a matching file (in ripgrep 0.6.0, we'd need to upgrade from 0.5.2) but not what the match is (which we need for maxResults: 1, but not necessarily for workspaceContains). I don't see any other options we can use, --max-count doesn't do anything with --files.

[roblourens]

We can kill the process as soon as we get the right number of results, this is what text search does.

[chrmarti]

We could optimize this case with an additional flag exists: true and for that pass --quiet. That will avoid all output to stdout and terminate immediately on the first hit. This will need an upgrade of ripgrep we ship though.

[chrmarti]

One way to verify with extension code is by using workspace.findFiles with a low maxResults against a large workspace and make sure it is much faster than without maxResults.