(PECL memcache >= 1.0.0)
Memcache::flush -- memcache_flush — Flush all existing items at the server
Memcache::flush() immediately invalidates all existing items. Memcache::flush() doesn't actually free any ressources, it only marcs all the items as expired, so occupied memory will be overwritten by new items.
This function has no parameters.
Example #1 Memcache::flush() example
<?php
/* procedural API */
$memcache_obj
=
memcache_connect
(
'memcache_host'
,
11211
);
memcache_flush
(
$memcache_obj
);
/* OO API */
$memcache_obj
= new
Memcache
;
$memcache_obj
->
connect
(
'memcache_host'
,
11211
);
$memcache_obj
->
flush
();
?>
Please note that after flushing, you have to wait a certain amount of time (in my case < 1s) to be able to write to Memcached again. If you don't, Memcached::set() will return 1, although your data is in fact not saved.From the memcached mailing list:
"The flush has a one second granularity. The flush will expire all items up to the ones set within the same second."
It is imperative to wait at least one second after flush() command before further actions lique repopulating the cache. Ohterwise new items < 1 second after flush() would be invalidatet instantaneous.
Example:<?php
$memcache->flush();
$time= time()+1; //one second futurewhile(time() < $time) {//sleep}
$memcache->set('key', 'value'); // repopulate the cache?>