如何使用PHP开发缓存优化静态资源加载

$cachePath = 'cache/' . md5($resourceUrl) . '.cache';
$cacheDuration = 3600; // 缓存过期时间，单位：秒

if (file_exists($cachePath) && time() - filemtime($cachePath) < $cacheDuration) {
    // 缓存文件存在且未过期，直接输出缓存内容
    echo file_get_contents($cachePath);
} else {
    // 缓存文件不存在或已过期，重新生成缓存
    $content = file_get_contents($resourceUrl);
    file_put_contents($cachePath, $content);
    echo $content;
}

$memcached = new Memcached();
$memcached->addServer('localhost', 11211); // 默认的Memcached服务器地址和端口

$value = $memcached->get($resourceUrl); // 从缓存中读取数据

if ($value) {
    // 缓存存在，直接输出缓存内容
    echo $value;
} else {
    // 缓存不存在，从源地址读取数据并保存到缓存
    $content = file_get_contents($resourceUrl);
    $memcached->set($resourceUrl, $content, $cacheDuration);
    echo $content;
}

$cachePath = 'cache/' . md5($resourceUrl) . '.cache';
if (file_exists($cachePath)) {
    unlink($cachePath);
}

$memcached->delete($resourceUrl);