One area that was mostly abandoned in applications is the Model layer. Doctrine is a project that brings enterprise support this layer through a powerful ORM implementation. Allied with new support introduced in PHP 5.3, Doctrine 2.0 brings the concept of ORM in PHP to the next level. It introduces a couple of concepts known from other languages and areas, like Annotations, Object Query Languages and Parsers. This talk will introduce these new concepts as well as explain most of its architecture.

1. Enterprise Persistence Layer for PHP

2. • Frontend web developer since 1998
• Moved to backend programming in 2002
• Currently employee of MIH – SWAT team
• Committer of many O.S. projects, including
Zend Framework, Symfony and Doctrine
• Enjoys to play Age of Empires

3. Doctrine is an Object Relational Modeling tool
for PHP, mostly inspired by Hibernate (Java)
and ActiveRecord (Ruby)

4. • Very active community
• Monthly releases
• Current work branches:
– 1.0 (LTS), 1.1, 1.2 (LTS), 2.0 (LTS)

5. • Integrates with many different frameworks:
– Zend Framework
– Symfony
– CodeIgniter
– Kohana
– …
• Supports all drivers supported by PDO

6. • Based on JSR-317 a.k.a. JPA v2.0 (~80%)
• Java…. What?!? #$&*@!
• PHP still lacks of standards
• PHP Standards Group to the rescue!

7. Challenges

8. • No need to extend base class
• New Reflection support
• Benchmarks (˜50000 iterations):
– Setter:
• $o->prop set: 0.35872411727905
• $o->setProp: 0.61513090133667 (71% slower)
• $reflProp->setValue: 0.67149507522583 (87% slower)
– Getter:
• $o->prop get: 0.25784397125244
• $o->getProp: 0.46534395217896 (80% slower)
• $reflProp->getValue: 0.64541401863098 (150% slower)

9. • Optimize hydration of entities
• Garbage Collector – Identity Map
• spl_object_hash
• SplObjectStorage vs. ArrayAccess

10. • Optimize hydration of Entities
• Benchmarks:
– Doctrine 1.1
• 4.3435637950897 for 5000 records
– Doctrine 2.0
• 1.4314442552312 for 5000 records
• 3.4690098762528 for 10000 records

11. • Replication support
• Internal mindset change
• No more weird DSN constructions
• No more shared Identity Maps across multiple
connections

12. • Huge API of public methods
• Lambdas and Closures
• Centralized entry points of methods
• No singleton nightmares!
- I have a problem!
- You can fix it with a singleton.
- Now I have 2 problems…

13. • RDBMS <-> PHP differences
• Clean separation of Platforms via Dialects
• Separation between DB value and PHP value
• Extendable to user land

14. • String processing for DQL
• Implemented a LL(*) parser
• Constructs AST nodes
• TreeWalkers to do compilation DQL -> SQL
• Cache support to prevent overhead

15. • Metadata Mapping
• Extendable mapping drivers
• Should not mess Entities code – VOs
• Cache support to prevent overhead

16. • Real Native SQL support
• Introduction of ResultsetMapping support
• Allow custom columns to be mapped into VOs
• Specific DBMS SQL supported

17. • Commit ordering
• True multigraph implementation
• Topological Sorting
• Prevents cycles
• F*cking incredible fast!

18. Almost 95% of codebase rewritten
Requires PHP 5.3

19. Simplified public API
Smaller footprint

20. Un-necessary clutter removed
No more cyclic references

21. Code heavily decoupled
Extremely extendable

22. • Three main packages:
– Common
– DBAL
– ORM
– Maybe in the future ODM…
• Anyone interested to contribute?

23. • Class Loaders
• Annotations support
• Collection
• Cache
• Event System
• Common LL(*) classes

24. • Class loaders:
– GlobalClassLoader
– IsolatedClassLoader

25. • Annotations EBNF – Yeah baby!
Annotation ::= "@" AnnotationName ["(" [Values] ")”]
AnnotationName ::= QualifiedName | SimpleName
QualifiedName ::= NameSpacePart "" {NameSpacePart ""}*
SimpleName
NameSpacePart ::= identifier
SimpleName ::= identifier
Values ::= Array | Value {"," Value}*
Value ::= PlainValue | FieldAssignment
PlainValue ::= integer | string | float | boolean |
Array | Annotation
FieldAssignment ::= FieldName "=" PlainValue
FieldName ::= identifier
Array ::= "{" ArrayEntry {"," ArrayEntry}* "}”
ArrayEntry ::= Value | KeyValuePair
KeyValuePair ::= Key "=" PlainValue
Key ::= string | integer

26. • Use DBAL independent of ORM
• Powerful Database Abstraction Layer
• Always existed, but it wasn’t advertised
• Can be a separate package in the future

27. • Platforms, Drivers and SchemaManagers
• Nested transactions
• Fully supports:
– Schemas
– Sequences
– Catalogs

30. • Supports:
– One-to-one
– One-to-many
– Many-to-many
• Multigraph
– Unidirectional
– Bidirectional

31. • Simplified bootstrap code

32. • Driver based Metadata
– Annotations
– PHP
– XML
– YAML
– … your own?!

37. • Working with objects

38. • Doctrine Query Language
– Similar do HQL or JPQL
– Automatically makes join restrictions
– Supports inheritance natively
– Can be boosted by usage of a Query Cache
– Easily extendable

39. • Querying
– DQL string
– QueryBuilder object (Criteria)
– Native SQL query

43. • Directed Acyclic Graphs
• Easily extendable
• Several handy tasks to help development
– Schema-tool
– Generate-proxies
– Convert-mapping
– Run-sql
– Run-dql

46. Guilherme Blanco
guilhermeblanco gmail com
+55 16 9215.8480
http://www.doctrine-project.org