Doctrine Internals. UnitOfWork

Transcript

1. Presentation title here Doctrine internals UnitOfWork

2. Presentation title here About me https://www.facebook.com/yatsenco https://github.com/anyt about me… Andrey

   Yatsenco • PHP Developer at Oro Inc. • 3 years with Symfony • 6 years with PHP

3. Presentation title here Doctrine Internals. UnitOfWork Introduction • Doctrine is

   the bottleneck for many apps • You know how UnitOfWork is working, you know how doctrine works

4. Presentation title here Doctrine Internals. UnitOfWork UnitOfWork track objects changes

   and commit them transactionally to the Database. Now you don’t manage object loading from the DataBase. UOW do.

5. Presentation title here Doctrine Internals. UnitOfWork UOW use IdentityMap to

   track objects changes and to avoid server round trip It simple two level array storage • First level keys are ClassNames • Second level keys are object IDs.

6. Presentation title here Doctrine Internals. UnitOfWork Doctrine EntityManager is like

   all-in-one decorator on • Repository • UnitOfWork • MetadataFactory • ProxyFactory • etc.

7. Presentation title here Doctrine Internals. UnitOfWork EntityManager -> EntityRepository •

   find • findOneBy • findAll • customFindQueryWithHidration • etc.

8. Presentation title here Doctrine Internals. UnitOfWork EntityManager->UnitOfWork • persist •

   refresh • remove • flush • etc.

9. Presentation title here Doctrine Internals. UnitOfWork EntityManager->UnitOfWork • persist •

   refresh • remove • commit • etc.

10. Presentation title here Doctrine Internals. UnitOfWork Doctrine flow • 1)

    Fetch entities from the database or create new and persist ‘em (Repo|UOW) • 2) Update some of entities directly or using wrapper like Form (uses PropertyAccess) • Remove some, if needed (Forms etc.) • 3) EM->flush() changes (UOW)

11. Presentation title here Doctrine Internals. UnitOfWork 1) Fetching entities from

    the DB • One entity: ◦ find ◦ findOneBy • Several entities: ◦ Lazy/Eager loading ◦ Find partial

12. Presentation title here Doctrine Internals. UnitOfWork 1) Persist • Can

    be omitted if you fetched entities from doctrine • Required only for newly created entities

13. Presentation title here Doctrine Internals. UnitOfWork 2) Update Object changes

    outside Doctrine. • Direct changes • Forms (PropertyAccessor) • etc.

14. Presentation title here Doctrine Internals. UnitOfWork 3) Flush Sync changes

    with the Database

15. Presentation title here Doctrine Internals. UnitOfWork 3) Flush Flow •

    Open DB transaction • Complute change-sets for update • Iterate over scheduled inserts, updates, deletes • Delegate to entity persister SQL generation and execution • Clear UOW on success • Close DB transaction

16. Presentation title here Doctrine Internals. UnitOfWork UnitOfWork through Doctrine Events

    • fetch • persist • remove • flush

17. Presentation title here Doctrine Internals. UnitOfWork Fetch Repo-> find|refresh|getReference|etc. •

    (optional) sync data with DB • Events::loadClassMetadata ◦ If ! Events:onClassMetadataNotFound • hydrate • Events:postLoad

18. Presentation title here Doctrine Internals. UnitOfWork Persist • Events:prePersist •

    Entity ID isn’t exist at this time in most cases • UOW->scheduleForInsert($entity)

19. Presentation title here Doctrine Internals. UnitOfWork Remove • Events::preRemove •

    UOW->scheduleForDelete($entity)

20. Presentation title here Doctrine Internals. UnitOfWork Flush • UOW->commit(null|object|array $entity)

21. Presentation title here Doctrine Internals. UnitOfWork Flush (1) • Events::preFlush

    ◦ $em->flush() can be called safely • compute insert|update|delete changesets • If !changes ◦ Events::onFlush ◦ Events::postFlush ◦ return

22. Presentation title here Doctrine Internals. UnitOfWork Flush (2) • Events::onFlush

    ◦ UOW->getScheduledEntityInsertions() ◦ UOW->getScheduledEntityUpdates() ◦ UOW->getScheduledEntityDeletions() ◦ $em->persist() && UOW- >computeChangeSet() • connection->beginTransaction

23. Presentation title here Doctrine Internals. UnitOfWork Flush (3) • Inserts

    ◦ Persister->insert($entity) ◦ Events::postPersist ▪ entity can’t be updated directly anymore ▪ UOW->scheduleExtraUpdate($entity, array $changeset)

24. Presentation title here Doctrine Internals. UnitOfWork Flush (4) • Updates

    ◦ Events::preUpdate ▪ Entity can’t be updated directly, update changeset using PreUpdateEventArgs ▪ Relations changes not tracked too ◦ UOW->recomputeSingleEntityChangeSet($class, $entity) ◦ Persister->update($entity) ◦ Events::postUpdate ▪ Entity can’t be updated directly anymore ▪ UOW->scheduleExtraUpdate($entity, array $changeset) • UOW->executeExtraUpdates()

25. Presentation title here Doctrine Internals. UnitOfWork Flush (5) • Deletions

    ◦ Persister->delete($entity) ◦ Events::postRemove ▪ nothing to update here

26. Presentation title here Doctrine Internals. UnitOfWork Flush (6) • connection->commit()

    • Events::postFlush ◦ Never call $em->flush() here • UOW->clear(); ◦ Events::onClear • in case of errors ◦ connection->rollback() That’s it.

27. Presentation title here Doctrine Internals. UnitOfWork Let’s talk a little

    bit about performance and how to speed-up doctrine

28. Presentation title here Doctrine Internals. UnitOfWork How to speed-up doctrine

    • Cache ◦ Metadata ◦ Query ◦ result

29. Presentation title here Doctrine Internals. UnitOfWork How to speed-up doctrine

    • Control lazy-loading ◦ Never eager load ◦ Write select queries with joins to needed

30. Presentation title here Doctrine Internals. UnitOfWork How to speed-up doctrine

    • Fetch less ◦ getReference ◦ {partial}

31. Presentation title here Doctrine Internals. UnitOfWork How to speed-up doctrine

    • Hydrate less ◦ arrays instead of objects when you don’t need them or performance is important

32. Presentation title here Doctrine Internals. UnitOfWork How to speed-up doctrine

    • Make flush cheaper ◦ Mark entities as readOnly ◦ Chang tracking policy to DEFERRED_EXPLICIT or NOTIFY ◦ Provide flush arguments (applies objects and arrays)

33. Presentation title here Doctrine Internals. UnitOfWork How to speed-up doctrine

    • Optimize queries

34. Presentation title here Doctrine Internals. UnitOfWork Links: docs • http://www.doctrine-project.org/api/orm/2.0/class-Doctrine.ORM.UnitOfWork.html

    • http://doctrine-orm.readthedocs.io/projects/doctrine-orm/ Patterns • http://martinfowler.com/eaaCatalog/unitOfWork.html • http://martinfowler.com/eaaCatalog/identityMap.html Sergey Zhuravel presentation about Doctrine Events • http://www.slideshare.net/sergeyz/oro-meetups-doctrine-events?qid=7d9177e9-c41c-4642- bdba-e1fa3060bb17&v=&b=&from_search=1

35. Presentation title here ?