Difference between revisions of "Persistence unified"

(Unified persistence for Eiffel)
(A tentative manifesto)
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===A tentative manifesto===
 
===A tentative manifesto===
The first proposed task is to agree upon a sort of ‘manifesto’ of desirable features of the framework.  
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The first proposed task is to agree upon a sort of ‘manifesto’ of desirable features for the framework.  
  
 
Here is a first proposal:
 
Here is a first proposal:

Revision as of 10:04, 17 August 2007

Unified persistence for Eiffel

This project is about developing a single, integrated and simple persistence framework for Eiffel.

  • Single because nothing else should be needed to access any kind of persistence services.
  • Integrated because aims at integrating both the already existing technologies and frameworks, as far as they deliver the intended benefits, and possibly new ones.
  • Simple because it should be very easy to use, removing all the unnecessary complexity.

A tentative manifesto

The first proposed task is to agree upon a sort of ‘manifesto’ of desirable features for the framework.

Here is a first proposal:

Three abstractions

The framework should provide just three abstractions to the developer: PERSISTENCE_MEDIUM, PERSISTENCE_FORMAT and PERSISTENCE_MANAGER.

Possible specializations of these abstractions could be:

  • FILE_MEDIUM, NETWORK_MEDIUM, RELATIONAL_DB_MEDIUM, CUSTOM_MEDIUM, ...
  • BINARY_FORMAT, STRING_FORMAT, XML_FORMAT, DADL_FORMAT, CUSTOM_FORMAT, ...
  • SERIALIZATION_MANAGER, RDBMS_MANAGER, CUSTOM_MANAGER, ...

Persistence independence

Classes which objects have to be persisted should not be polluted with persistence code, for example adding specific persistence-related attributes or by inhering from some other class that provides persistence services.

  • The access to the persistence services should be as uniform as possible. This can be achieved using the XXX_MANAGER class hierarchy that handles access to specific kinds of persistence stores
  • The different media should be properly incapsulated. This can be achieved using the XXX_MEDIUM class hierarchy
  • The different formats should be properly incapsulated. This can be achieved using the XXX_FORMAT class hierarchy