src/queue.ts

   1 /**
   2  * Queue
   3  */
   4 export class Queue<T> {
   5   private items: Record<number, T>
   6   private head: number
   7   private tail: number
   8
   9   constructor () {
  10     this.items = {}
  11     this.head = 0
  12     this.tail = 0
  13   }
  14
  15   enqueue (item: T): number {
  16     this.items[this.tail] = item
  17     this.tail++
  18     return this.size()
  19   }
  20
  21   dequeue (): T | undefined {
  22     if (this.size() <= 0) return undefined
  23     const item = this.items[this.head]
  24     // eslint-disable-next-line @typescript-eslint/no-dynamic-delete
  25     delete this.items[this.head]
  26     this.head++
  27     if (this.head === this.tail) {
  28       this.head = 0
  29       this.tail = 0
  30     }
  31     return item
  32   }
  33
  34   size (): number {
  35     return this.tail - this.head
  36   }
  37 }