Class BoundedPubSubSingleSubscription

packages/effect/src/PubSub.ts:1974–2039

}

class BoundedPubSubSingleSubscription<in out A> implements PubSub.BackingSubscription<A> {
  private self: BoundedPubSubSingle<A>
  private subscriberIndex: number
  private unsubscribed: boolean

  constructor(
    self: BoundedPubSubSingle<A>,
    subscriberIndex: number,
    unsubscribed: boolean
  ) {
    this.self = self
    this.subscriberIndex = subscriberIndex
    this.unsubscribed = unsubscribed
  }

  isEmpty(): boolean {
    return (
      this.unsubscribed ||
      this.self.subscribers === 0 ||
      this.subscriberIndex === this.self.publisherIndex
    )
  }

  size() {
    return this.isEmpty() ? 0 : 1
  }

  poll(): A | MutableList.Empty {
    if (this.isEmpty()) {
      return MutableList.Empty
    }
    const elem = this.self.value
    this.self.subscribers -= 1
    if (this.self.subscribers === 0) {
      this.self.value = AbsentValue as unknown as A
    }
    this.subscriberIndex += 1
    return elem
  }

  pollUpTo(n: number): Array<A> {
    if (this.isEmpty() || n < 1) {
      return []
    }
    const a = this.self.value
    this.self.subscribers -= 1
    if (this.self.subscribers === 0) {
      this.self.value = AbsentValue as unknown as A
    }
    this.subscriberIndex += 1
    return [a]
  }

  unsubscribe(): void {
    if (!this.unsubscribed) {
      this.unsubscribed = true
      this.self.subscriberCount -= 1
      if (this.subscriberIndex !== this.self.publisherIndex) {