How to use PHP development cache to optimize static resource loading
Introduction:
In web development, static resources such as images, CSS style sheets and JavaScript Script files etc. tend to take up most of the loading time. For large websites or websites with high concurrent access, how to optimize the loading speed of static resources is an important issue. This article will introduce how to use PHP to develop cache optimization methods for static resource loading, and provide specific code examples.
The basic principle of caching is to save static resources to the server and directly return the cached resources when the client requests it. Avoid duplicate network requests. Caching reduces the load on the server and increases the loading speed of web pages.
PHP provides a variety of methods for caching. Two commonly used methods are introduced below.
2.1 File caching
File caching is to save static resources into files, and then directly return the contents of the files when the client requests it. The specific steps are as follows:
1) Create a cache folder to save cached static resources. For example, you can create a new folder named "cache" in the project root directory.
2) In the PHP code, determine whether the cache file exists. If it exists and has not expired, the cached content will be returned directly; if it does not exist or has expired, the cache file will be regenerated. The following is a sample code:
$cachePath = 'cache/' . md5($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; }
2.2 Memcached Cache
Memcached is a high-performance memory cache system that can save data in memory and increase read speed. The specific steps are as follows:
1) Install and start the Memcached service. You can download the corresponding installation program through the official website (https://memcached.org/) and follow the instructions to install and start.
2) In PHP code, use the Memcached extension to read and save the cache. The following is a sample code:
$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; }
In order to avoid returning old resources after the cache expires, the cache needs to be updated regularly. You can use scheduled tasks or manually trigger where the cache needs to be updated. In addition, when static resources change, the corresponding cache also needs to be cleared. The following is a sample code to clear the cache:
$cachePath = 'cache/' . md5($resourceUrl) . '.cache'; if (file_exists($cachePath)) { unlink($cachePath); } $memcached->delete($resourceUrl);
Summary:
By using PHP for caching to optimize static resource loading, you can significantly improve the loading speed of web pages and reduce network requests and server load. Through file caching or Memcached caching, you can choose the appropriate caching method according to specific needs. At the same time, the cache needs to be updated and cleared regularly to ensure the effectiveness of the cache.
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