Memcache::delete()

(PECL memcache >= 0.2.0)

从服务端删除一个元素

说明

Memcache::delete(string $key[,int $timeout= 0]): bool

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

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

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

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.

I could not get the delete to work properly, so I ended up trying the 'set' method and setting the timeout value to -1.
<?php
$memcache->set('index', 'deleted', 0, -1);
?>
It solved my problem with the delete method.
(using memcached 1.4.5 and pecl-memcache 3.0.6)

In my case this code does NOT work:
<?php
$memcache->set('index', 'deleted', 0, -1);
?>
because of expire == -1.
I set expire = 1 (and I prefer "replace"):
<?php
$memcache->replace('index', '', 0, 1);
?>

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.