Current File : /home/emergentqj/antanimora/wp-content/plugins/td-composer/legacy/common/wp_booster/td_remote_cache.php
<?php
/**
* Created by ra.
* Date: 9/24/2015
*/
/**
* Class td_remote_cache - custom cache built for remote requests
*/
class td_remote_cache {
/**
* @var array here we hold the cache - it is loaded and saved to a WordPress option as needed
*/
private static $cache = array();
/**
* @var bool flag used to hook the shutdown action only once
*/
private static $is_shutdown_hooked = false;
/**
* @var bool when this is false, read_cache_meta will not read so it looks like the cache is always empty
*/
private static $is_cache_enabled = true;
/**
* Checks if an item is expired. It does not extend the expiration notice
*
* @param $group - the caching group to use
* @param $item_id - the item id
*
* @return bool
* - true: the item is expired OR is not in cache
* - false: the item is in cache and it's not expired
*/
static function is_expired($group, $item_id) {
self::read_cache_meta();
if (
isset(self::$cache[$group][$item_id])
and time() - self::$cache[$group][$item_id]['timestamp'] < self::$cache[$group][$item_id]['expires'] // timestamp and expires must be present
) {
return false;
}
return true;
}
/**
* Gets an item from the cache. If the item is not in the cache, it will return false
* @param $group - the caching group to use
* @param $item_id - the item id
*
* @return bool|array|string
* - the item (array|string)
* - false if the item is not in the cache. Note that false is not return for expired items, this function does not check if the item is expired
*/
static function get($group, $item_id) {
self::read_cache_meta();
if (isset(self::$cache[$group][$item_id])) {
return self::$cache[$group][$item_id]['value']; // hit
}
return false; // miss
}
/**
* extends the expiration date of an item
* @param $group - the caching group
* @param $item_id - the item id, must be unique in the group
* @param $new_expires_value - new expiration value (WARNING: this will overwride the current expiration value of the item
* it does not append the value to the existing expiration value)
*/
static function extend($group, $item_id, $new_expires_value) {
self::read_cache_meta();
if (isset(self::$cache[$group][$item_id])) {
self::$cache[$group][$item_id]['expires'] = $new_expires_value;
self::$cache[$group][$item_id]['timestamp'] = time();
}
self::schedule_save_cache();
}
/**
* sets an item to the cache. If the item is already present, it will overwrite it
* @param $group - the caching group
* @param $item_id - the item id, must be unique in the group
* @param $item_value - the item (it can be string|array|bool etc)
* @param $expires - in seconds, after how many seconds the item has expired
*/
static function set($group, $item_id, $item_value, $expires) {
self::read_cache_meta();
self::$cache[$group][$item_id] = array (
'value' => $item_value,
'expires' => $expires,
'timestamp' => time()
);
self::schedule_save_cache();
}
/**
* deletes a whole group from the cache. !!!! as of 29/9/2015 is not used
* @param $group
*/
static function delete_group($group) {
self::read_cache_meta();
unset(self::$cache[$group]);
self::schedule_save_cache();
}
/**
* deletes an item from the cache
* @param $group
* @param $item_id
*/
static function delete_item($group, $item_id) {
self::read_cache_meta();
unset(self::$cache[$group][$item_id]);
self::schedule_save_cache();
}
/**
* called by all the functions that use the cache, it reads the caching key from the db only once
*/
private static function read_cache_meta() {
// disable the cache using this method
if (self::$is_cache_enabled === false) {
self::$cache = array();
return;
}
// read the cache only once!
if (empty(self::$cache)) {
self::$cache = get_option(TD_THEME_OPTIONS_NAME . '_remote_cache');
}
}
/**
*
*/
private static function schedule_save_cache() {
// make sure that we hook only once
if (self::$is_shutdown_hooked === false) {
add_action('shutdown', array(__CLASS__, 'on_shutdown_save_cache'));
self::$is_shutdown_hooked = true;
}
}
/**
* @internal
* disables the cache. Warning it also CLEARS the cache
*/
static function _disable_cache() {
delete_option(TD_THEME_OPTIONS_NAME . '_remote_cache');
self::$is_cache_enabled = false;
}
/**
* @internal
* save the cache hook
*/
static function on_shutdown_save_cache() {
update_option(TD_THEME_OPTIONS_NAME . '_remote_cache', self::$cache);
}
}
Mini Shell