circular-queue-with-array.js

class CQueue {
  constructor(capacity) {
    this.data = [];
    this.capacity = capacity;
    this.size = 0;
    this.front = 0;
    this.rear = 0;
  }

  isFull() {
    return this.size === this.capacity;
  }

  isEmpty() {
    return this.size === 0;
  }

  enqueue(item) {
    if (this.isFull()) return false;

    this.data[this.rear] = item;
    this.rear = (this.rear + 1) % this.capacity;
    this.size++;
    return true;
  }

  dequeue() {
    if (this.isEmpty()) return undefined;

    let item = this.data[this.front];
    this.front = (this.front + 1) % this.capacity;
    this.size--;
    return item;
  }

  front() {
    if (this.isEmpty()) return undefined;

    return this.data[0];
  }

  rear() {
    if (this.isEmpty()) return undefined;

    return this.data[this.size - 1];
  }

  clear() {
    this.data.length = 0;
    this.size = 0;
    this.front = 0;
    this.rear = 0;
  }
}

// Test
const Capacity = 5000000;
const TestCase = 10;

const queue = new CQueue(Capacity);  

const start = performance.now();

for (let tc = 0; tc < TestCase; tc++) {
  for (let i = 0; i < Capacity; i++) {
    queue.enqueue(i);
  }

  for (let i = 0; i < Capacity; i++) {
    queue.dequeue();
  }
}

const end = performance.now();
const duration = (end - start) / TestCase;

console.log(`Duration: ${duration} ms`);