信鸽双十二活动

// 使用懒加载技术优化图片加载
document.addEventListener("DOMContentLoaded", function() {
  const images = document.querySelectorAll("img.lazy");
  const observer = new IntersectionObserver((entries, observer) => {
    entries.forEach(entry => {
      if (entry.isIntersecting) {
        const img = entry.target;
        img.src = img.dataset.src;
        img.classList.remove("lazy");
        observer.unobserve(img);
      }
    });
  });
  images.forEach(img => observer.observe(img));
});

# 使用缓存技术减少数据库查询次数
from functools import lru_cache
import sqlite3

@lru_cache(maxsize=128)
def get_product_info(product_id):
    conn = sqlite3.connect('products.db')
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM products WHERE id=?", (product_id,))
    product_info = cursor.fetchone()
    conn.close()
    return product_info