File size: 4.04Kb
<?php
class CacheHandler { private $required_variables = array('caching_path','priority_required'); private $caching_path = ""; private $priority_required = 0; function CacheHandler() {
// We need to pull our config data from a configuration file.
// Variables in this file will have to use the following structure:
// $config['cache']['caching_path'] = ...
// $config['cache']['priority_required'] = ...
$config['cache'] = array(
'priority_required' => 50,
'caching_path' => './cache/'
);
$config = $config['cache'];
// At this point, we're sure we have been able to gather some configuration data
// Checking if all the required data have been given.
foreach($this->required_variables as $var)
$this->{$var} = $config[$var]; // Finally: the variable exists.
if(!is_dir($this->caching_path)) mkdir($this->caching_path, 0755);
}
/**
* Save a variable with its cache ending date in a text file (cache file).
* @param string $name Name of the caching file. Has to be unique since you'll pull your data from the cache engine with this variable.
* @param mixed $content Can be any type of variable that you want to cache.
* @param int $duration Time you want to keep the content cached (in SECONDS). If $duration = 0, we'll keep the file cached for ever.
* @return bool Simply returns true if the process has been successful.
*/
function cache_content($name,$content,$duration = 60) {
$filename = $this->caching_path . $this->_encrypt_name($name);
$content = array(
'duration' => $duration,
'creation' => time(),
'content' => $content
);
$content = serialize($content);
$rh = fopen($filename,'w+');
fwrite($rh,$content);
fclose($rh);
return true;
}
/**
* Return the content previously cached with cache_content().
* @param string $name Has to be the same as used when calling cache_content()
* @param int $priority Integer between 0 and 100 to know whether we cache the content or not.
* @return bool False if the cache has expired or doesn't exist (or priority is too low).
*/
function retrieve_cache($name,$priority = 0) {
$filename = $this->caching_path . $this->_encrypt_name($name);
if($priority < $this->priority_required)
return false;
if(!file_exists($filename))
return false;
$content = file_get_contents($filename);
$content = unserialize($content);
if($content['duration'] == 0)
return $content;
else if(time() > $content['creation']+$content['duration'])
return false;
else
return $content['content'];
}
private $has_buffer_started = false;
private $buffer_content = "";
/**
* Start the caching buffer
*/
function start_buffer() {
// we don't need to handle multiple buffers for simple content caching
if(!$this->has_buffer_started){
ob_start();
$this->has_buffer_started = true;
}
}
/**
* Stop the caching buffer
*/
function stop_buffer() {
if($this->has_buffer_started){
$content = ob_get_clean();
$this->buffer_content = $content;
$this->has_buffer_started = false;
}
}
/**
* Cache the content (buffered with start_buffer() and stop_buffer())
* @param string $name Name of the caching file. Has to be unique since you'll pull your data from the cache engine with this variable.
* @param int $duration Time you want to keep the content cached. If $duration = 0, we'll keep the file cached for ever.
* @return bool True if the process has been successful
*/
function cache_buffer($name,$duration = 60) {
// buffer has already been opened and closed
if(!$this->has_buffer_started) {
// simply use the method we already written earlier.
$this->cache_content($name,$this->buffer_content,$duration);
}
}
/**
* Delete a cache file. Usually not used unless you create a cache file with $duration = 0 and want to regenerate the cache.
* @param string $name Name of the caching file.
* @return bool False if file doesn't exist, true if the process has been successful.
*/
function delete_cache($name) {
$filename = $this->caching_path . $this->_encrypt_name($name);
if(!file_exists($filename))
return false;
else
unlink($filename);
return true;
}
/**
* Encrypt the name of a given variable to avoid malformed files.
* @param string $name Cache variable name
* @access private
*/
function _encrypt_name($name) {
return md5($name);
}
}