php – Doctrine 2和ORM：如何缓存某个实体的每个查询？

您正在寻找的是second level cache as in Hibernate,它基本上允许您插入一个键值存储,如redis,riak,mongodb等,以便在操作简单的获取操作时快速启动.

在https://github.com/doctrine/doctrine2/pull/580有一项正在进行中的拉动请求,可能会在Doctrine ORM 2.5中登陆,所以请查看那个.

use DoctrineORMEntityRepository;
use DoctrineORMEntityManager;
use DoctrineCommonCacheCache;
use DoctrineCommonCacheArrayCache;

class MyBaseRepo extends EntityRepository
{
    public function __construct(EntityManager $entityManager)
    {
        parent::__construct($entityManager);
        $cache       = $em->getConfiguration()->getHydrationCache();
        $this->cache = $cache ?: new ArrayCache();
    }

    public function find($id)
    {
        if (!$object = $this->tryFetchFromCache($id)) {
            $object = parent::find($id);
            $this->cache->save($this->generateKey($id),$object);
        }

        return $object;
    }

    protected function tryFetchFromCache($id)
    {
        if (!$object = $this->cache->fetch($this->generateCacheKey($id))) {
            return null;
        }

        return $this->getEntityManager()->merge($object);
    }

    public function generateCacheKey($id) { /* ... */ }
}

在引导应用程序时,您可以强制将其作为配置中ORM的基本存储库：

$configuration = new DoctrineORMConfiguration();

$configuration->setDefaultRepositoryClassName('MyMyBaseRepo');

当您的任何实体发生更新/保存时,这也会强制您清除缓存条目：

use DoctrineCommonEventSubscriber;
use DoctrineORMEventOnFlushEventArgs;
use DoctrineORMEvents;

class IssueUpdateSubscriber implements EventSubscriber
{
    public function onFlush(OnFlushEventArgs $args)
    {
        $em  = $args->getEntityManager();
        $uow = $em->getUnitOfWork();

        if (!$cache = $em->getConfiguration()->getHydrationCache()) {
            return;
        }

        $busted = array_merge(
            $uow->getScheduledEntityUpdates(),$uow->getScheduledEntityDeletions(),);

        foreach ($busted as $entityToClear) {
            $className  = get_class($entityToClear);
            $metadata   = $em->getClassMetadata($className);
            $repository = $em->getRepository($className);
            $id         = $metadata->getIdentifierValues($entityToClear);

            $cache->delete($repository->generateCacheKey($id));
        }
    }

    public function getSubscribedEvents()
    {
        return array(Events::onFlush);
    }
}

请注意,此实现不会拦截对给定实体的数据库的所有访问.它不会拦截由代理引起的延迟加载初始化,而且它非常脆弱,所以请设置一些适当的集成测试来支持它.