An example that demonstrates the priority queue behavior with 25 events of mixed priorities. We'll enqueue them in a somewhat realistic mixed order, then dequeue them step-by-step while showing: 1) When normal priority order is respected 2) When aging (temporal priority boost) starts kicking in after ~X seconds

priority_queue_demo.js

class PriorityQueue {
  constructor(X = 5) { // X in seconds – events older than this get promoted
    this.high = [];     // edr_security
    this.medium = [];   // scripts_edr
    this.low = [];      // extension
    this.X = X * 1000;  // milliseconds
  }

  enqueue(eventData, type) {
    const event = { 
      id: eventData.id || Date.now(), // just for demo identification
      data: eventData.data || eventData,
      type,
      timestamp: Date.now() 
    };
    if (type === 'edr_security') this.high.push(event);
    else if (type === 'scripts_edr') this.medium.push(event);
    else if (type === 'extension') this.low.push(event);
    else throw new Error('Unknown event type');
  }

  dequeue() {
    const now = Date.now();

    // Promote aged low → medium
    while (this.low.length > 0 && now - this.low[0].timestamp > this.X) {
      const aged = this.low.shift();
      aged.promoted = aged.promoted ? aged.promoted + 1 : 1;
      this.medium.push(aged);
    }

    // Promote aged medium → high
    while (this.medium.length > 0 && now - this.medium[0].timestamp > this.X) {
      const aged = this.medium.shift();
      aged.promoted = aged.promoted ? aged.promoted + 1 : 1;
      this.high.push(aged);
    }

    if (this.high.length > 0) return this.high.shift();
    if (this.medium.length > 0) return this.medium.shift();
    if (this.low.length > 0) return this.low.shift();
    return null;
  }

  isEmpty() { return this.high.length + this.medium.length + this.low.length === 0; }

  size() { return this.high.length + this.medium.length + this.low.length; }
}

// ────────────────────────────────────────────────
//          DEMO WITH 25 EVENTS + AGING
// ────────────────────────────────────────────────

const pq = new PriorityQueue(5); // promote after 5 seconds

// Mock time control (in real app remove this)
let mockTime = Date.now();
const originalNow = Date.now;
Date.now = () => mockTime;

// Helper to add event with shorthand
function add(id, type) {
  pq.enqueue({ id, data: `${type} #${id}` }, type);
}

// Enqueue 25 mixed events (not in perfect order)
add(1, 'edr_security');   // H1
add(2, 'extension');      // L1
add(3, 'scripts_edr');    // M1
add(4, 'edr_security');   // H2
add(5, 'extension');      // L2
add(6, 'extension');      // L3
add(7, 'scripts_edr');    // M2
add(8, 'edr_security');   // H3
add(9, 'extension');      // L4
add(10, 'scripts_edr');   // M3
add(11, 'edr_security');  // H4
add(12, 'extension');     // L5
add(13, 'scripts_edr');   // M4
add(14, 'extension');     // L6
add(15, 'edr_security');  // H5
add(16, 'extension');     // L7
add(17, 'scripts_edr');   // M5
add(18, 'extension');     // L8
add(19, 'edr_security');  // H6
add(20, 'extension');     // L9
add(21, 'scripts_edr');   // M6
add(22, 'extension');     // L10
add(23, 'edr_security');  // H7
add(24, 'scripts_edr');   // M7
add(25, 'extension');     // L11

console.log(`Initial queue size: ${pq.size()}\n`);

// ── Phase 1: Dequeue while time = 0 (no aging yet) ──
console.log("Phase 1 – Fresh queue (no aging):");
for (let i = 1; i <= 7 && !pq.isEmpty(); i++) {
  const e = pq.dequeue();
  console.log(`  ${i}. ${e.type[0].toUpperCase()}  ${e.data}  (age: 0s)`);
}
// → Should get all 7 high-priority events first (H1–H7)

// ── Advance time by 6 seconds → low & medium start promoting ──
mockTime += 6000;
console.log(`\nTime advanced +6s → aging begins\n`);

console.log("Phase 2 – After 6 seconds (low → medium, medium → high):");
let count = 8;
while (!pq.isEmpty() && count <= 18) {
  const e = pq.dequeue();
  const ageSec = Math.round((mockTime - e.timestamp) / 1000);
  const prom = e.promoted ? ` (promoted ×${e.promoted})` : '';
  console.log(`  ${count}. ${e.type[0].toUpperCase()}  ${e.data}  (age: ${ageSec}s${prom})`);
  count++;
}

// ── Advance another 6 seconds (more promotions) ──
mockTime += 6000;
console.log(`\nTime advanced another +6s (total 12s)\n`);

console.log("Phase 3 – Further aging:");
while (!pq.isEmpty()) {
  const e = pq.dequeue();
  const ageSec = Math.round((mockTime - e.timestamp) / 1000);
  const prom = e.promoted ? ` (promoted ×${e.promoted})` : '';
  console.log(`  ${count}. ${e.type[0].toUpperCase()}  ${e.data}  (age: ${ageSec}s${prom})`);
  count++;
}

console.log(`\nFinal queue size: ${pq.size()}`);

// Restore real time
Date.now = originalNow;