Oxicloud/frontend/src/lib/utils/mapLimit.ts

/**
 * 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;
}