/**
* RequestDeduplicator Metrics Demo
*
* This script demonstrates the metrics logging functionality of RequestDeduplicator.
* Run with: npx tsx examples/RequestDeduplicator-metrics-demo.ts
*/
import { RequestDeduplicator } from '../src/utils/RequestDeduplicator.js';
async function simulateApiCall(url: string, delay: number = 100): Promise<string> {
await new Promise(resolve => setTimeout(resolve, delay));
return `Response from ${url}`;
}
async function demonstrateMetrics() {
console.log('🚀 RequestDeduplicator Metrics Demo\n');
// Create deduplicator with metrics logging enabled
const deduplicator = new RequestDeduplicator(5000, {
enableMetricsLogging: true,
logLevel: 'info'
});
console.log('📊 Initial metrics:');
deduplicator.logMetrics();
console.log('');
// Simulate various scenarios
console.log('🔄 Scenario 1: Single requests (should be all misses)');
await deduplicator.dedupe('api1', () => simulateApiCall('/api/users/1'));
await deduplicator.dedupe('api2', () => simulateApiCall('/api/users/2'));
await deduplicator.dedupe('api3', () => simulateApiCall('/api/users/3'));
deduplicator.logMetrics();
console.log('');
console.log('🔄 Scenario 2: Concurrent identical requests (should show hits)');
const promises = [
deduplicator.dedupe('concurrent1', () => simulateApiCall('/api/data', 200)),
deduplicator.dedupe('concurrent1', () => simulateApiCall('/api/data', 200)), // Hit
deduplicator.dedupe('concurrent1', () => simulateApiCall('/api/data', 200)), // Hit
deduplicator.dedupe('concurrent2', () => simulateApiCall('/api/other', 150)),
deduplicator.dedupe('concurrent2', () => simulateApiCall('/api/other', 150)), // Hit
];
await Promise.all(promises);
console.log('After concurrent requests:');
deduplicator.logMetrics();
console.log('');
console.log('🔄 Scenario 3: Mix of new and repeated requests');
await deduplicator.dedupe('new1', () => simulateApiCall('/api/new1'));
await deduplicator.dedupe('new2', () => simulateApiCall('/api/new2'));
console.log('Final metrics:');
deduplicator.logMetrics();
// Show manual stats inspection
console.log('');
console.log('📈 Manual stats inspection:');
const stats = deduplicator.getStats();
console.log(` Total requests: ${stats.totalRequests}`);
console.log(` Hits: ${stats.hits} (${(stats.hitRate * 100).toFixed(1)}%)`);
console.log(` Misses: ${stats.misses}`);
console.log(` Average response time: ${stats.averageResponseTime.toFixed(2)}ms`);
console.log(` Active requests: ${stats.activeRequests}`);
// Reset and show
console.log('');
console.log('🔄 Resetting metrics...');
deduplicator.resetStats();
deduplicator.logMetrics();
}
// Run the demo
demonstrateMetrics().catch(console.error);
