silverstripe-framework/Core/Cache.php
2016-09-09 18:43:05 +12:00

192 lines
5.0 KiB
PHP

<?php
namespace SilverStripe\Core;
use Zend_Cache;
use Zend_Cache_Core;
/**
* The `[api:Cache]` class provides a bunch of static functions wrapping the Zend_Cache system
* in something a little more easy to use with the SilverStripe config system.
*
* @see https://docs.silverstripe.org/en/3.4/developer_guides/performance/caching/
*/
class Cache {
/**
* @var array $backends
*/
protected static $backends = array();
/**
* @var array $backend_picks
*/
protected static $backend_picks = array();
/**
* @var array $cache_lifetime
*/
protected static $cache_lifetime = array();
/**
* Initialize the 'default' named cache backend.
*/
protected static function init(){
if (!isset(self::$backends['default'])) {
$cachedir = TEMP_FOLDER . DIRECTORY_SEPARATOR . 'cache';
if (!is_dir($cachedir)) {
mkdir($cachedir);
}
/** @skipUpgrade */
self::$backends['default'] = array(
'File',
array(
'cache_dir' => $cachedir
)
);
self::$cache_lifetime['default'] = array(
'lifetime' => 600,
'priority' => 1
);
}
}
/**
* Add a new named cache backend.
*
* @see http://framework.zend.com/manual/en/zend.cache.html
*
* @param string $name The name of this backend as a freeform string
* @param string $type The Zend_Cache backend ('File' or 'Sqlite' or ...)
* @param array $options The Zend_Cache backend options
*/
public static function add_backend($name, $type, $options = array()) {
self::init();
self::$backends[$name] = array($type, $options);
}
/**
* Pick a named cache backend for a particular named cache.
*
* The priority call with the highest number will be the actual backend
* picked. A backend picked for a specific cache name will always be used
* instead of 'any' if it exists, no matter the priority.
*
* @param string $name The name of the backend, as passed as the first argument to add_backend
* @param string $for The name of the cache to pick this backend for (or 'any' for any backend)
* @param integer $priority The priority of this pick
*/
public static function pick_backend($name, $for, $priority = 1) {
self::init();
$current = -1;
if (isset(self::$backend_picks[$for])) {
$current = self::$backend_picks[$for]['priority'];
}
if ($priority >= $current) {
self::$backend_picks[$for] = array(
'name' => $name,
'priority' => $priority
);
}
}
/**
* Return the cache lifetime for a particular named cache.
*
* @param string $for
*
* @return string
*/
public static function get_cache_lifetime($for) {
if(isset(self::$cache_lifetime[$for])) {
return self::$cache_lifetime[$for];
}
return null;
}
/**
* Set the cache lifetime for a particular named cache
*
* @param string $for The name of the cache to set this lifetime for (or 'any' for all backends)
* @param integer $lifetime The lifetime of an item of the cache, in seconds, or -1 to disable caching
* @param integer $priority The priority. The highest priority setting is used. Unlike backends, 'any' is not
* special in terms of priority.
*/
public static function set_cache_lifetime($for, $lifetime=600, $priority=1) {
self::init();
$current = -1;
if (isset(self::$cache_lifetime[$for])) {
$current = self::$cache_lifetime[$for]['priority'];
}
if ($priority >= $current) {
self::$cache_lifetime[$for] = array(
'lifetime' => $lifetime,
'priority' => $priority
);
}
}
/**
* Build a cache object.
*
* @see http://framework.zend.com/manual/en/zend.cache.html
*
* @param string $for The name of the cache to build
* @param string $frontend (optional) The type of Zend_Cache frontend
* @param array $frontendOptions (optional) Any frontend options to use.
* @return Zend_Cache_Core The cache object
*/
public static function factory($for, $frontend='Output', $frontendOptions=null) {
self::init();
$backend_name = 'default';
$backend_priority = -1;
$cache_lifetime = self::$cache_lifetime['default']['lifetime'];
$lifetime_priority = -1;
foreach(array('any', $for) as $name) {
if(isset(self::$backend_picks[$name])) {
if(self::$backend_picks[$name]['priority'] > $backend_priority) {
$backend_name = self::$backend_picks[$name]['name'];
$backend_priority = self::$backend_picks[$name]['priority'];
}
}
if (isset(self::$cache_lifetime[$name])) {
if(self::$cache_lifetime[$name]['priority'] > $lifetime_priority) {
$cache_lifetime = self::$cache_lifetime[$name]['lifetime'];
$lifetime_priority = self::$cache_lifetime[$name]['priority'];
}
}
}
$backend = self::$backends[$backend_name];
$basicOptions = array('cache_id_prefix' => $for);
if ($cache_lifetime >= 0) {
$basicOptions['lifetime'] = $cache_lifetime;
} else {
$basicOptions['caching'] = false;
}
$frontendOptions = $frontendOptions ? array_merge($basicOptions, $frontendOptions) : $basicOptions;
require_once 'Zend/Cache.php';
return Zend_Cache::factory(
$frontend, $backend[0], $frontendOptions, $backend[1]
);
}
}