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EclipseLink/DesignDocs/232063
Design Specification:
Relationships between non-Cachable and Cachable Entities
Document History
| Date | Author | Version Description & Notes |
|---|---|---|
| 2010/05/27 | Gordon Yorke | Initial creation of this doccumentation |
| 2010/06/23 | Gordon Yorke | Update after initial feedback |
Project overview
Goals:
- Relationships between JPA 2.0 Cachable(false) and Cachable(true) Entities should be supported
Concepts
Currently EclipseLink uses the Isolated Cache functionality to provide @Cacheable(False) requirements. The Isolated Cache functionality was created with security as a primary requirement and Isolated Entities were not allowed to reference Shared Cache Entities. Transitioning Isolated Caches to the JPA 2.0 @Cacheable() requirements means this functionality must adapt and be more flexible as @Cacheable(true) Entities must be able to reference @Cacheable(false) Entities.
Requirements
- Transparent support for relationships from @Cacheable(true) to @Cacheable(false).
- Separate Isolated configuration from @Cacheable(false)
- Create multi-valued configuration option
- SHARED - Entities are fully cached within the IdentityMaps (normal behaviour)
- PROTECTED - Users aways receive cloned versions of these classes but data is cached in shared cache
- ISOLATED - Data is not cached in shared cache ( @Cacheable(false) ) has same isolated behaviour as today
- When the metadata is processed any SHARED Entities that reference PROTECTED or ISOLATED Entities will be elevated to PROTECTED.
- Create multi-valued configuration option
EclipseLink JPA Metadata
- @Cache(isolaton=IsolationType.PROTECTED)
- <cache isolation="PROTECTED"/>
High Level Design
- PROTECTED/ISOLATED Entities will always be cloned when returned
- ISOLATED Entities will not be cached but will be reloaded each time
- ForeignReferenceMappings will track when they reference ISOLATED Entities
- This allows the mapping to determine how and when the relationship should be built.
- Relationships owned by the PROTECTED/SHARED Entity will cache Within the PROTECTED/SHARED Entity in the form of PK(s) values.
- Un-Owned relationships will not be built or cached
Design / Functionality
Design Notes
Testing
API
Config files
Documentation
Open Issues
This section lists the open issues that are still pending that must be decided prior to fully implementing this project's requirements.
| Issue # | Owner | Description / Notes |
|---|---|---|
Decisions
This section lists decisions made. These are intended to document the resolution of open issues or constraints added to the project that are important.
| Issue # | Description / Notes | Decision |
|---|---|---|
Future Considerations
During the research for this project the following items were identified as out of scope but are captured here as potential future enhancements. If agreed upon during the review process these should be logged in the bug system.