Zend_Cache seemed very elegant to me at first, until I tried to make a
customization.
I have some apps that will be using memcached for objects. Thing is,
some of my server farms will have multiple sites and networks, all using
the same pool of memcached servers. Of course all the networks will
cache similar named objects, like 'acl' for instance. So, to avoid
namespace trampling, or rather to "create" namespaces, I thought it'd be
very useful to have cache id prefixes. Now, instead of setting keys in
memecached just called 'obj_name' they'd be 'uniquenetwork_obj_name'.
This allows me to have an acl object for Network1 (network1_acl) and an
acl object for network2 (network2_acl).
I could just go ahead and setup a constant and pass it in along with the
ids into every load(), save(), remove(), etc calls, but that seems like
a lot of unnecessary crap. Instead, it makes a lot more sense to me to
create a new backend option for my "cache id prefix", then have each one
of those methods concat the prefix on to the front of ids automatically
just before the real memcache calls are made.
So, I went about this, and its a real mess. First of all, all options
are hardcoded into the classes and get explicitly checked at object
instantiation. OK, well, I extended Zend_Cache_Backend_Memcached and did
this:
public function __construct($options = array())
{
// add cache id prefix as an allowed option, default nothing
$this->_options['cache_id_prefix'] = null;
// Call parent constructor
parent::__construct($options);
}
Then each one of those methods now look basically like this:
public function load($id, $doNotTestCacheValidity = false)
{
$id = $this->_options['cache_id_prefix'] . $id;
parent::load($id, $doNotTestCacheValidity);
}
Overall, I didn't think that was too big of a deal, but then I realized
that the backends are hardcoded and checked in Zend_Cache, just like the
options, so I'd have to do the same thing for that. What's worse though,
is only the name of the backend is passed in, and then class names are
created and called with a hardcoded 'Zend_Cache_Backend' . $backend. Now
I can't even call my class something different. Now I'd have to create
my class file specifically in the /Zend/Cache/Backend directory, and
call it something like CustomMemcached.
Anyway, overall Zend_Cache is a very nice component with lots of
options, and I appreciate all of them, its just that its very closed.
Maybe that was the intention, and if so, maybe you would accept a patch
file from me to officially add this feature to the memcache backend.
Thanks in advance for reading,
Tony
