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frontend/src/lib/utils/mapLimit.ts

@@ -0,0 +1,24 @@
+/**
+ * Map `fn` over `items` with at most `limit` concurrent calls, preserving
+ * result order regardless of completion order.
+ *
+ * Extracted from the files page so batch fan-out paths (delete, drag-move,
+ * upload probing) and the shared resource-actions composable all use the
+ * same bounded-concurrency primitive.
+ */
+export async function mapLimit<T, R>(
+	items: readonly T[],
+	limit: number,
+	fn: (item: T) => Promise<R>
+): Promise<R[]> {
+	const out = new Array<R>(items.length);
+	let next = 0;
+	const worker = async () => {
+		while (next < items.length) {
+			const i = next++;
+			out[i] = await fn(items[i]);
+		}
+	};
+	await Promise.all(Array.from({ length: Math.max(0, Math.min(limit, items.length)) }, worker));
+	return out;
+}