👍 Gradually update items in matcher to improve latency of Curator

Author: lambdalisue

denops/fall/event.ts

@@ -31,6 +31,7 @@ export type Event =
   | { type: "collect-processor-succeeded" }
   | { type: "collect-processor-failed"; err: unknown }
   | { type: "match-processor-started" }
+  | { type: "match-processor-updated" }
   | { type: "match-processor-succeeded" }
   | { type: "match-processor-failed"; err: unknown }
   | { type: "visualize-processor-started" }

denops/fall/picker.ts

@@ -348,6 +348,12 @@ export class Picker<T> implements AsyncDisposable {
       case "match-processor-started":
         this.#inputComponent.processing = true;
         break;
+      case "match-processor-updated":
+        this.#inputComponent.processed = this.#matchProcessor.items.length;
+        this.#visualizeProcessor.start(denops, {
+          items: this.#matchProcessor.items,
+        });
+        break;
       case "match-processor-succeeded":
         this.#inputComponent.processing = false;
         this.#inputComponent.processed = this.#matchProcessor.items.length;

denops/fall/processor/match.ts

@@ -67,11 +67,16 @@ export class MatchProcessor<T> {
           : this.#filter.match(denops, { items, query }, { signal }),
         this.#threshold,
       );
-      const matchedItems = [];
+      // Gradually update items when `items` is empty to improve latency
+      // of Curator.
+      const matchedItems = items.length === 0
+        ? (this.#items = [], this.#items)
+        : [];
       for await (const chunk of chunked(iter, this.#chunkSize)) {
         if (this.#paused) await this.#paused.promise;
         signal.throwIfAborted();
         matchedItems.push(...chunk);
+        dispatch({ type: "match-processor-updated" });
         await delay(this.#interval, { signal });
       }
       this.#items = matchedItems;