可扩展性设计

// 实现连接池管理
class APIConnectionPool {
  constructor(maxConnections = 10) {
    this.pool = [];
    this.maxConnections = maxConnections;
    this.activeConnections = 0;
  }
  
  async getConnection() {
    if (this.activeConnections < this.maxConnections) {
      this.activeConnections++;
      return this.createConnection();
    }
    
    // 等待可用连接
    return new Promise((resolve) => {
      this.pool.push(resolve);
    });
  }
  
  releaseConnection(conn) {
    if (this.pool.length > 0) {
      const resolve = this.pool.shift();
      resolve(conn);
    } else {
      this.activeConnections--;
    }
  }
  
  createConnection() {
    return {
      apiKey: process.env.API_KEY,
      baseURL: process.env.API_BASE_URL
    };
  }
}