Cache object in php to file

Cache is the technology to improve your website speed. To day i will introduce you how to cache the object in you php application. Note: You should't abuse cache, only use it in common object with the same result .

class cache {

    public function __construct() {
        if (!defined('CACHE_PATH'))
            define('CACHE_PATH', __SITE_PATH . '/caches');
    }
}

 Note: You must create cache directory before. The __construct() define CACHE_PATH if it is't defined. To save cache , we create two file that have extenstion is .cache, .info. it is easy to remember , you can change to another extension name if you want.
Below is save cache function

  public function save($id, $time, $content) {
        if (!__ENABLE_CACHE)
            return;
      
        $file_info = CACHE_PATH . "/$id.info";
        $file_cache = CACHE_PATH . "/$id.cache";

        //Equal current time add the long time
        $time = time() + ($time * 60);
         
        $handle = fopen($file_info, 'w+');
        if(!fwrite($handle, $time))
                return false;
        fclose($handle);

        $content =serialize($content);
        
        $handle = fopen($file_cache, 'w+');
        if(!fwrite($handle, $content))
                return false;
        fclose($handle);       
    }

the input parameter is

1. $id to indentify the id cache.
2. $time is the long life is calculated by minutes.
3. $content is object that you want to cache.

The cache file is valid with the long life greater than current time.
The check it we have below function:

  public function isValid($id)
    {
        $file_info = CACHE_PATH . "/$id.info";
        
        if (!file_exists($file_info))
            return false;
         $file_time =file_get_contents($file_info);
         return  (time() < $file_time);        
    }

And this is finally function, get object from cache file.

 public function getCache($id)
    { 
        $file_cache = CACHE_PATH . "/$id.cache";
        if (!file_exists($file_cache))
            die("File $file_cache not found");
        
        $content = file_get_contents($file_cache);
        
        return unserialize($content);
    }

And this is full code

class cache {

    public function __construct() {
        if (!defined('CACHE_PATH'))
            define('CACHE_PATH', __SITE_PATH . '/caches');
    }

    /*
     * $id is the key to save cache
     * $time is calculated by minutes
     * $content is the content will be cached.
     */
    
    public function getCache($id)
    { 
        $file_cache = CACHE_PATH . "/$id.cache";
        if (!file_exists($file_cache))
            die("File $file_cache not found");
        
        $content = file_get_contents($file_cache);
        
        return unserialize($content);
    }

    public function save($id, $time, $content) {
        if (!__ENABLE_CACHE)
            return;
      
        $file_info = CACHE_PATH . "/$id.info";
        $file_cache = CACHE_PATH . "/$id.cache";

        //Equal current time add the long time
        $time = time() + ($time * 60);
         
        $handle = fopen($file_info, 'w+');
        if(!fwrite($handle, $time))
                return false;
        fclose($handle);

        $content =serialize($content);
        
        $handle = fopen($file_cache, 'w+');
        if(!fwrite($handle, $content))
                return false;
        fclose($handle);       
    }
    
    public function isValid($id)
    {
        $file_info = CACHE_PATH . "/$id.info";
        
        if (!file_exists($file_info))
            return false;
         $file_time =file_get_contents($file_info);
         return  (time() < $file_time);        
    }
    
}