feat(opt-in): kill previous searches when a new search is started

[mikavilpas]

Issue

When typing text, if there are no matches for a ripgrep search, each
keypresses starts a new ripgrep search. This can lead to many searches
being active at the same time. This takes up resources and is not useful
(if the word did not match previously, it will never match with a longer
search string).

Solution

Stop previously running searches when a new search is started. This is
currently disabled by default (soft launch). To opt in, see the README.

If this works well for some time, it might become the default in the
future.

[mikavilpas]

cc @Saghen, I was wondering if repeating searches with longer search strings is a useful feature in blink, or if it would make to also fix it there. It seems like if a short search produces no results, a longer search string might never produce additional results because it always requires a more accurate match.

But I might be wrong 🙂

[Saghen]

@mikavilpas It should be waiting for the current request to finish before sending another in the same context. If the context changes while a request is in-flight, it should call the cancellation functions returned by get_completions before making a new request. It should also only make additional requests within the same context to get_completions if is_incomplete_forward/backward = true and we moved forward or backward in the context. If that's not the case, there's a bug on my end

[mikavilpas]

Ah I see, I think I need to hook into those instead. Thanks for the explanation 👍🏻