(PECL memcached >= 0.1.0)
Memcached::get — 检索一个元素
Memcached::get()返回之前存储在key下的元素。如果元素被找到，并且提供
了cas_token参数， 这个参数（译注：这个参数在函数定义中是引用参数，用来传出元素的版本标记，原理
可以查阅乐观锁资料）将会包含该元素的CAS标记值。关于CAS标记值的使用，请查看 Memcached::cas()的说明。
另外，可以通过cache_cb参数设置Read-through caching callback。
key
要检索的元素的key。
cache_cb
通读缓存回掉函数或NULL.
cas_token
检索的元素的CAS标记值。
返回存储在服务端的元素的值或者在其他情况下返回FALSE。
如果key不存在， Memcached::getResultCode()返回Memcached::RES_NOTFOUND。
Example #1 Memcached::get() 示例 #1
<?php
$m = new Memcached();
$m->addServer('localhost', 11211);
$m->set('foo', 100);
var_dump($m->get('foo'));
?>
以上例程会输出：
int(100)
Example #2 Memcached::get() 示例 #2
<?php
$m = new Memcached();
$m->addServer('localhost', 11211);
if (!($ip = $m->get('ip_block'))) {
if ($m->getResultCode() == Memcached::RES_NOTFOUND) {
$ip = array();
$m->set('ip_block', $ip);
} else {
/* log error */
/* ... */
}
}
?>
denis_truffaut[A-T]hotmail[D-O-T]com (2011-01-17 06:01:36)
Note that this function can return NULL as FALSE, so don't make checks with === FALSE as with the old Memcache class, because it won't work. :O
Use the not (!) operator and check the result code with getResultCode() as mentioned in the documentation :)
miha at hribar dot info (2009-07-17 01:31:34)
This method also returns false in case you set the value to false, so in order to have a proper fault mechanism in place you need to check the result code to be certain that a key really does not exist in memcached.
<?php
$Memcached = new Memcached();
$Memcached->addServer('localhost', 11211);
$Memcached->set('key', false);
var_dump($Memcached->get('key')); // boolean false
var_dump($Memcached->getResultCode()); // int 0 which is Memcached::RES_SUCCESS
?>
Or just make sure the values are not false :)