Question

umm… silly question.

I know that one can (and should) use APC cache driver with Doctrine ORM.
But I was just wondering if I can also cache entity manager instance itself?
Is there anything that prevents me from doing this:

    $em = apc_fetch('em');
    if(!$em){
        $cache = new Doctrine\Common\Cache\ApcCache;
        $config = new Doctrine\ORM\Configuration;
        $config->setMetadataCacheImpl($cache);
        $config->setQueryCacheImpl($cache);
        $config->setAutoGenerateProxyClasses(TRUE);
        $config->setProxyNamespace('MyProject\Proxies');
        $config->setProxyDir(APP_PATH . DIRECTORY_SEPARATOR . 'data' . DIRECTORY_SEPARATOR . 'proxy');
        $driverImpl = $config->newDefaultAnnotationDriver('/path/to/lib/MyProject/Entities');
        $config->setMetadataDriverImpl($driverImpl);
        $connectionOptions = array(
            'driver' => 'pdo_sqlite',
            'path' => 'database.sqlite'
        );
        $em = Doctrine\ORM\EntityManager::create($connectionOptions, $config);
        apc_store('em', $em);
    }

Answer 1

Your code should work just fine.
Actually we also do cache EM in our projects. Saves some 300Kb:)