PHP比较全面的缓存类

<?php

/*

* Name: wrapperCache

* Notes: wrapper cache for fileCache, memcache/memcached, APC, Xcache and eaccelerator

$cacheObj =wrapperCache::getInstance('memcache',30,array(array('host'=>'localhost')));

echo $cacheObj->cache('key','value');

*/

class wrapperCache {

const DEFAULT_MEMCACHE_PORT = 11211;

const CACHE_TYPE_AUTO = 'auto';

const CACHE_TYPE_EACCELERATOR = 'eaccelerator';

const CACHE_TYPE_APC = 'apc';

const CACHE_TYPE_MEMCACHE = 'memcache';

const CACHE_TYPE_MEMCACHED = 'memcached';

const CACHE_TYPE_FILE = 'filecache';

const CACHE_TYPE_XCACHE = 'xcache';

private $cache_params; //extra params for external caches like path or connection option memcached

public $cache_expire; //seconds that the cache expires

private $cache_type; //type of cache to use

private $cache_external; //external instance of cache, can be fileCache or memcache

private static $instance;//Instance of this class

// Always returns only one instance

public static function getInstance($type=self::CACHE_TYPE_AUTO, $exp_time=3600, $params='cache/'){

if (!isset(self::$instance)) { //doesn't exists the isntance

self::$instance = new self($type, $exp_time, $params); //goes to the constructor

}

return self::$instance;

}

//cache constructor, optional expiring time and cache path

private function __construct($type, $exp_time, $params) {

$this->cache_expire = $exp_time;

$this->cache_params = $params;

$this->setCacheType($type);

}

public function __destruct() {

unset($this->cache_external);

}

// Prevent users to clone the instance

public function __clone(){

$this->cacheError('Clone is not allowed.');

}

//deletes cache from folder

public function clearCache(){

switch($this->cache_type){

case self::CACHE_TYPE_EACCELERATOR :

eaccelerator_clean();

eaccelerator_clear();

break;

case self::CACHE_TYPE_APC :

apc_clear_cache('user');

break;

case self::CACHE_TYPE_XCACHE :

xcache_clear_cache(XC_TYPE_VAR, 0);

break;

case self::CACHE_TYPE_MEMCACHE :

$this->cache_external->flush();

break;

case self::CACHE_TYPE_MEMCACHED :

$this->cache_external->flush();

break;

case self::CACHE_TYPE_FILE:

$this->cache_external->deleteCache();

break;

}

}

//writes or reads the cache

public function cache($key, $value = '', $ttl = '') {

if ($value != '') { //wants to write

if ($ttl == '') $ttl = $this->cache_expire;

$this->put($key, $value, $ttl);

} else return $this->get($key);

//reading value

}

//creates new cache files with the given data, $key== name of the cache, data the info/values to store

private function put($key, $data, $ttl = '') {

if ($ttl == '') $ttl = $this->cache_expire;

switch($this->cache_type){

case self::CACHE_TYPE_EACCELERATOR :

eaccelerator_put($key, serialize($data), $ttl);

break;

case self::CACHE_TYPE_APC :

apc_store($key, $data, $ttl);

break;

case self::CACHE_TYPE_XCACHE :

xcache_set($key, serialize($data), $ttl);

break;

case self::CACHE_TYPE_MEMCACHE :

$data=serialize($data);

$this->cache_external->set($key, $data, false, $ttl);

break;

case self::CACHE_TYPE_MEMCACHED :

$data=serialize($data);

$this->cache_external->set($key, $data, $ttl);

break;

case self::CACHE_TYPE_FILE :

$this->cache_external->cache($key,$data);

break;

}

}

//returns cache for the given key

private function get($key){

switch($this->cache_type){

case self::CACHE_TYPE_EACCELERATOR :

$data = unserialize(eaccelerator_get($key));

break;

case self::CACHE_TYPE_APC :

$data = apc_fetch($key);

break;

case self::CACHE_TYPE_XCACHE :

$data = unserialize(xcache_get($key));

break;

case self::CACHE_TYPE_MEMCACHE :

$data = unserialize($this->cache_external->get($key));

break;

case self::CACHE_TYPE_MEMCACHED :

$data = unserialize($this->cache_external->get($key));

break;

case self::CACHE_TYPE_FILE :

$data = $this->cache_external->cache($key);

break;

}

return $data;

}

//delete key from cache

public function delete($key){

switch($this->cache_type){

case self::CACHE_TYPE_EACCELERATOR :

eaccelerator_rm($key);

break;

case self::CACHE_TYPE_APC :

apc_delete($key);

break;

case self::CACHE_TYPE_XCACHE :

xcache_unset($key);

break;

case self::CACHE_TYPE_MEMCACHE :

$this->cache_external->delete($key);

break;

case self::CACHE_TYPE_MEMCACHED :

$this->cache_external->delete($key);

break;

case self::CACHE_TYPE_FILE :

$this->cache_external->delete($key);

break;

}

}

// Overloading for the Application variables and automatically cached

public function __set($name, $value) {

$this->put($name, $value, $this->cache_expire);

}

public function __get($name) {

return $this->get($name);

}

public function __isset($key) {//echo "Is '$name' set?\n"

if ($this->get($key) !== false) return true;

else return false;

}

public function __unset($name) {//echo "Unsetting '$name'\n";

$this->delete($name);

}

//end overloads

public function getCacheType(){

return $this->cache_type;

}

//sets the cache if its installed if not triggers error

public function setCacheType($type){

$this->cache_type=strtolower($type);

switch($this->cache_type){

case self::CACHE_TYPE_EACCELERATOR :

if (!function_exists('eaccelerator_get')) $this->cacheError('eaccelerator not found');

break;

case self::CACHE_TYPE_APC :

if (!function_exists('apc_fetch')) $this->cacheError('APC not found');

break;

case self::CACHE_TYPE_XCACHE :

if (function_exists('xcache_get')) $this->cacheError('Xcache not found');

break;

case self::CACHE_TYPE_MEMCACHE :

if (class_exists('Memcache')) $this->init_mem();

else $this->cacheError('memcache not found');

break;

case self::CACHE_TYPE_MEMCACHED :

if (class_exists('Memcached')) $this->init_mem(true);

else $this->cacheError('memcached not found');

break;

case self::CACHE_TYPE_FILE :

if (class_exists('fileCache'))$this->init_filecache();

else $this->cacheError('fileCache not found');

break;

case self::CACHE_TYPE_AUTO ://try to auto select a cache system

if (function_exists('eaccelerator_get')) $this->cache_type = self::CACHE_TYPE_EACCELERATOR;

elseif (function_exists('apc_fetch')) $this->cache_type = self::CACHE_TYPE_APC ;

elseif (function_exists('xcache_get')) $this->cache_type = self::CACHE_TYPE_XCACHE;

elseif (class_exists('Memcache')) $this->init_mem();

elseif (class_exists('Memcached')) $this->init_mem(true);

elseif (class_exists('fileCache')) $this->init_filecache();

else $this->cacheError('not any compatible cache was found');

break;

default://not any cache selected or wrong one selected

$msg='Not any cache type selected';

if (isset($type)) $msg='Unrecognized cache type selected <b>'.$type.'</b>';

$this->cacheError($msg);

break;

}

}

private function init_mem($useMemecached = false) { //get instance of the memcache/memcached class

if (is_array($this->cache_params)) {

if ($useMemecached) {

$this->cache_type = self::CACHE_TYPE_MEMCACHED;

$this->cache_external = new Memcached();

} else {

$this->cache_type = self::CACHE_TYPE_MEMCACHE;

$this->cache_external = new Memcache;

}

foreach ($this->cache_params as $server) {

$server['port'] = isset($server['port']) ? (int)$server['port'] : self::DEFAULT_MEMCACHE_PORT;

if ($useMemecached) {

$this->cache_external->addServer($server['host'], $server['port']);

} else {

$server['persistent'] = isset($server['persistent']) ? (bool)$server['persistent'] : true;

$this->cache_external->addServer($server['host'], $server['port'], $server['persistent']);

}

}

} else $this->cacheError($this->cache_type . ' needs an array, example:wrapperCache::getInstance("' . $this->cache_type . '",30,array(array("host"=>"localhost")));');

}

private function init_filecache(){//get instance of the filecache class

$this->cache_type = self::CACHE_TYPE_FILE ;

$this->cache_external = fileCache::getInstance($this->cache_expire, $this->cache_params);

}

public function getAvailableCache($return_format='html'){//returns the available cache

$avCaches = array();

$avCaches[] = array(self::CACHE_TYPE_EACCELERATOR,function_exists('eaccelerator_get'));

$avCaches[] = array(self::CACHE_TYPE_APC, function_exists('apc_fetch')) ;

$avCaches[] = array(self::CACHE_TYPE_XCACHE, function_exists('xcache_get'));

$avCaches[] = array(self::CACHE_TYPE_MEMCACHE, class_exists('Memcache'));

$avCaches[] = array(self::CACHE_TYPE_MEMCACHED, class_exists('Memcached'));

$avCaches[] = array(self::CACHE_TYPE_FILE, class_exists('fileCache'));

if ($return_format == 'html') {

$ret = '<ul>';

foreach ($avCaches as $c) {

$ret .= '<li>' . $c[0] . ' - ';

if ($c[1]) $ret .= 'Found/Compatible';

else $ret .= 'Not Found/Incompatible';

$ret .= '</ll>';

}

return $ret . '</ul>';

} else return $avCaches;

}

private function cacheError($msg){//triggers error

trigger_error('<br /><b>wrapperCache error</b>: '.$msg.

'<br />If you want you can try with \'auto\' for auto select a compatible cache.

<br />Or choose a supported cache from list:'.$this->getAvailableCache(), E_USER_ERROR);

}

}