CakePHP is a popular PHP framework with a complete cache management system that can improve application performance. But how to clear the cached data once it expires or needs to be updated? This article will detail how to use cache clearing in CakePHP.
CakePHP manages cache through cache key. To clear a single cached data, simply pass its corresponding cache key to the cache engine's delete method.
For example, to clear the cache named "user_list", you can use the following code:
$this->cache->delete('user_list');
This code removes individual cache data from the cache engine. It should be noted that if multiple cache engines are used, the same cache key needs to be passed to all cache engines in order to delete all cache data.
Sometimes, you need to clear multiple cache data, you can use batch clearing. CakePHP provides the clear method, which is used to clear all cache data for the specified cache prefix (cache prefix).
For example, assume there are the following two caches:
$this->cache->write('user_list', $userList); $this->cache->write('post_list', $postList);
Their cache keys are "user_list" and "post_list". To delete both caches at the same time, you can use the following code:
$this->cache->clear('user_');
This code will delete all cache data prefixed with "user_" from all cache engines. In this way, multiple cached data can be cleared in batches.
In CakePHP, you can also set the cache expiration time or cache dependency. CakePHP will automatically clear cache data when the expiration time reaches or dependencies change.
For example, the following code will cache $userList for 60 seconds, and automatically clear the cache when any record of the Users table changes:
$this->cache->write('user_list', $userList, 'default', '+60 seconds', $this->Users);
In the above code, "60 seconds" means cache The time is 60 seconds. "$this->Users" indicates that the cache dependency is the Users table. At this time, when any record in the Users table changes, CakePHP will automatically clear the "user_list" cache.
Sometimes, cached data needs to be updated from the database within a specific interval. You can use the following method to manually force the cache to be refreshed:
// 获取缓存 $userList = $this->cache->read('user_list'); // 如果缓存不存在或已过期,重新获取数据并更新缓存 if (!$userList) { $userList = $this->User->findAll(); $this->cache->write('user_list', $userList); }
This code will first obtain the data from the cache. If the cache does not exist or has expired, it will re-obtain the user list from the database and store it in the cache. . This way you can refresh the cache manually.
Finally, if you need to clear all cached data, you can use the following code:
$this->cache->clear(true);
This code will clear all cached data and Cache configuration will not be cleared. It should be noted that only the administrator of the cache engine has the authority to execute this code, and generally it will not be used in applications.
Summary
In CakePHP, cache clearing is a very important part, which can improve the performance and stability of the application. This article introduces several common cache clearing methods, including clearing a single cache, clearing caches in batches, automatically clearing caches, manually refreshing caches, and clearing all cache data. Use these methods to effectively manage and operate cache data so that applications remain efficient, secure, and stable.
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