Memcache::delete

(PECL memcache >= 0.2.0)

Memcache::delete — 从服务端删除一个元素

说明

bool Memcache::delete ( string $key [, int $timeout ] )

Memcache::delete()函数通过key删除一个元素。如果参数timeout指定，该元素会在timeout秒后失效。同样也可以使用memcache_delete()函数完成同样功能。

参数

key: 要删除的元素的key。
timeout: 删除该元素的执行时间。如果值为0,则该元素立即删除，如果值为30,元素会在30秒内被删除。

更新日志

版本	说明
Unknown	It's not recommended to use the `timeout` parameter. The behavior differs between memcached versions, but setting to 0 is safe. Other values for this deprecated feature may cause the memcache delete to fail.

返回值

成功时返回 TRUE，或者在失败时返回 FALSE.

范例

Example #1 Memcache::delete() example


<?php

/* procedural API */
$memcache_obj = memcache_connect('memcache_host', 11211);

/* 10秒后key_to_delete对应的值会被从服务端删除 */
memcache_delete($memcache_obj, 'key_to_delete', 10);

/* OO API */
$memcache_obj = new Memcache;
$memcache_obj->connect('memcache_host', 11211);

$memcache_obj->delete('key_to_delete', 10);

?>

参见

Memcache::set() - Store data at the server
Memcache::replace() - 替换已经存在的元素的值

PHP手册 - N: 从服务端删除一个元素

用户评论:

vbaspcppguy at gmail dot com (08-Sep-2010 08:47)

According to the documents, $timeout is not required, but for me if I did not include it regardless of value, it fired an error. I made a simple fix for it. <?php class memcache_tools extends memcache { public function delete($key, $expire=0) { parent::delete($key, $expire); } } ?> This will force it to behave as it should regardless of version.

Anonymous (28-Jul-2010 11:30)

Regardless of whether or not it succeeds, for me on Ubuntu 10.04 it always returns false. Just an FYI, you can't seem to rely on the result.

nibblebot at gmail dot com (09-Jul-2010 04:58)

the Memcache::delete(key) function is broken on several combinations of memcached+pecl-memcache combinations. pecl-memcache 2.2.5 + memcached 1.4.2 - Memcache::delete(key) WORKS pecl-memcache 2.2.5 + memcached 1.4.3 - Memcache::delete(key) DOES NOT WORK pecl-memcache 2.2.5 + memcached 1.4.4 - Memcache::delete(key) WORKS pecl-memcache 2.2.5 + memcached 1.4.5 - Memcache::delete(key) WORKS pecl-memcache 3.0.4 + memcached 1.4.2 - Memcache::delete(key) WORKS pecl-memcache 3.0.4 + memcached 1.4.3 - Memcache::delete(key) DOES NOT WORK pecl-memcache 3.0.4 + memcached 1.4.4 - Memcache::delete(key) DOES NOT WORK pecl-memcache 3.0.4 + memcached 1.4.5 - Memcache::delete(key) DOES NOT WORK

z at zaebal dot com (28-Dec-2009 04:21)

To workaround the "delete" issue just pass zero as timeout parameter.

Wilfried Loche (25-Aug-2009 10:01)

Hi, Be careful about multi memcached servers. It seems logical the get() methods use only one server but, what about the delete() and update() methods? In fact, at least the delete() method perform a delete on the first server it finds! For the test code, you can see it there: http://pecl.php.net/bugs/bug.php?id=16810 Hope this helps someone! Wilfried

Jocke Berg (05-May-2009 11:02)

I was searching for a function/method in this class that would "reset" (or "update", depending on how you look at it) the timeout value for a key. I was searching my butt off when I finally figured; this is the one. Example: You have accessed a web-page including something that should be "in-cache" for way more than 30 days (until the memcache server gets a downtime for some reason). Since the limit for having something in the cache is 30 days, this will be a problem. Simple (yet somewhat non-optimal) solution: <?php //How to "update" the value if($memcache_key_exists){ $memcache_obj->delete('key', (3600*24*30)); } ?> Have fun.