Function mapWithConcurrency

apps/sim/lib/core/utils/concurrency.ts:13–32

(
  items: readonly T[],
  limit: number,
  fn: (item: T, index: number) => Promise<R>
)

 * allSettled-style variant rather than letting a throwing mapper through here.
 */
export async function mapWithConcurrency<T, R>(
  items: readonly T[],
  limit: number,
  fn: (item: T, index: number) => Promise<R>
): Promise<R[]> {
  const results = new Array<R>(items.length)
  const workerCount = Math.max(1, Math.min(limit, items.length))
  let cursor = 0

  const worker = async (): Promise<void> => {
    while (true) {
      const index = cursor++
      if (index >= items.length) return
      results[index] = await fn(items[index], index)
    }
  }

  await Promise.all(Array.from({ length: workerCount }, worker))
  return results
}

/** Default bound for per-row object-storage materialization fan-out. */
export const MATERIALIZE_CONCURRENCY = 20