Class BoundedPubSubArb

packages/effect/src/PubSub.ts:1502–1600

  )

class BoundedPubSubArb<in out A> implements PubSub.Atomic<A> {
  array: Array<A>
  replayIndices: Array<number>
  publisherIndex = 0
  subscribers: Array<number>
  subscriberCount = 0
  subscribersIndex = 0

  readonly capacity: number
  readonly replayBuffer: ReplayBuffer<A> | undefined

  constructor(capacity: number, replayBuffer: ReplayBuffer<A> | undefined) {
    this.capacity = capacity
    this.replayBuffer = replayBuffer
    this.array = Array.from({ length: capacity })
    this.replayIndices = replayBuffer ? Array.from({ length: capacity }) : []
    this.subscribers = Array.from({ length: capacity })
  }

  replayWindow(): PubSub.ReplayWindow<A> {
    return this.replayBuffer ? new ReplayWindowImpl(this.replayBuffer) : emptyReplayWindow
  }

  isEmpty(): boolean {
    return this.publisherIndex === this.subscribersIndex
  }

  isFull(): boolean {
    return this.publisherIndex === this.subscribersIndex + this.capacity
  }

  size(): number {
    return this.publisherIndex - this.subscribersIndex
  }

  publish(value: A): boolean {
    if (this.isFull()) {
      return false
    }
    const replayIndex = this.replayBuffer?.offer(value)
    if (this.subscriberCount !== 0) {
      const index = this.publisherIndex % this.capacity
      this.array[index] = value
      if (replayIndex !== undefined) {
        this.replayIndices[index] = replayIndex
      }
      this.subscribers[index] = this.subscriberCount
      this.publisherIndex += 1
    }
    return true
  }

  publishAll(elements: Iterable<A>): Array<A> {
    if (this.subscriberCount === 0) {
      if (this.replayBuffer) {
        this.replayBuffer.offerAll(elements)
      }
      return []