Connected Data Objects

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CDO is a free implementation of a Distributed Shared Model on top of the Eclipse Modeling Framework (EMF).

With CDO you can easily enhance your existing EMF models in such a way that they can be stored and subsequently maintained in a central model repository. While object relational mapping against a JDBC data source on the server side is the shipped default CDO provides for pluggable storage adapters that allow you to develop and use different mappers (like Hibernate- or OODB-based). On the client side CDO provides a default integration with EMF, the Eclipse Modeling Framework, although other model integrations on top of the CDO protocol are imaginable as well.

1 Model Integration Features
2 User Interface Features
3 Client Side Features
4 Network Protocol Features
5 Server Side Features
6 DB Store Features
7 Links

[edit] Model Integration Features

EMF integration at model level (as opposed to the edit level)
Support for generated models (just switch two .genmodel properties)
Support for dynamic models (just load .ecore file and commit to repository)
Support for legacy models (for compiled models without access to .genmodel)
Support for the Ecore meta meta model and descendants

[edit] User Interface Features

Eclipse view for working with CDO sessions, transactions, views and resources
Package Manager dialog per session
Eclipse editor for working with resources and objects

[edit] Client Side Features

Multiple sessions to multiple repositories on multiple servers
Multiple transactions per session
Multiple read-only views per session
Multiple audit views per session (an audit is a view that shows a consistent, historical version of a repository)
Multiple resources per view (a view is always associated with its own EMF ResourceSet)
Inter-resource proxy resolution
Multiple root objects per resource
Object state shared among all views of a session
Object graph internally unconnected (unused parts of the graph can easily be reclaimed by the garbage collector)
Only new and modified objects committed in a transaction
Transactions can span multiple resources
Demand loading of objects (resources are populated as they are navigated)
Partial loading of collections (chunk size can be configured per session)
Adaptable pre-fetching of objects (different intelligent usage analyzers are available)
Asynchronous object invalidation (optional)
Clean API to work with sessions, views, transactions and objects
CDOResources are EObjects as well
Objects carry meta information like id, state, version and life span
Support for OSGi environments (headless, Eclipse RCP, ...)
Support for standalone applications (non-OSGi)

[edit] Network Protocol Features

Net4j based binary application protocol
Pluggable transport layer (shipped with NIO socket transport and JVM embedded transport)
Pluggable fail over support
Pluggable authentication (shipped with challenge/response negotiation)
Multiple acceptors per server

[edit] Server Side Features

Pluggable storage adapters
Multiple repositories per server
Multiple models (packages) per repository
Multiple resources (instance documents) per repository
Expressive XML configuration file
Configurable storage adapter per repository (see below)
Configurable caching per repository
Clean API to work with repositories, sessions, views, transactions and revisions
Support for OSGi environments (usually headless)
Support for standalone applications (non-OSGi)