Question

I’m trying to understand the difference between regular Memcache and Doctrine’s MemcacheCache.

In my bootstrap I instantiate Memcache like this:

    $memcache = new Memcache;
    $memcache->connect('localhost', 11211);
    \Zend_Registry::set("pdc_memcache_core", $memcache);

I then have the following code for instantiating Doctrine – this is not the full code as I’m just looking at the cachine:

    $doctrineConfig = new \Doctrine\ORM\Configuration();

    $memcacheCore = \Zend_Registry::get("pdc_memcache_core");
    $cache = new \Doctrine\Common\Cache\MemcacheCache;
    $cache->setMemcache($memcacheCore);
    $cache->setNamespace("PDC_");
    \Zend_Registry::set("pdc_memcache", $cache);

    $doctrineConfig->setMetadataCacheImpl($cache);
    $doctrineConfig->setQueryCacheImpl($cache);

I then access the cache like this:

    if (\Zend_Registry::get("pdc_memcache")->contains($cacheKey)) {
        ...
    }

I’m not trying to store Doctrine entities in Memcache – I’m just storing strings and serialised arrays.

Now… is this the correct way to use Memcache with Doctrine? I can see that you use setMemcache to assign the Memcache instance to Doctrine’s MemcacheCache… but would I use MemcacheCache for my own stuff? Or should I use the Memcache instance directly?

Would really appreciate some thoughts on this, as I’m confused by how this is supposed to link together.

Answer 1

It is perfectly ok to use the Memcache Cache of Doctrine Common, thats also the correct way and you also have some abstraction that allows you to consume any Doctrine\Common\Cache\Cache instance. I’m not quite sure you would need that anyway, as you’re working with Zend Framework, and you probably could use the CacheManager or it’s associated CacheManager resource, which both would give you the advantage to make your caching mechanism configurable.