Package org.silverpeas.core.cache.service

Class VolatileResourceCacheService

  • public class VolatileResourceCacheService
extends Object

    This cache permits to reference some volatile resources (an entity that is being registered into persistence, but not yet validated by the user).
    Elements registered with volatile resource are cleared just after the ending of a user session.

    How it is working:

    • first set the identifier of a Contribution with a volatile identifier. A volatile identifier is generated by this service (newVolatileStringIdentifier() for example). The aim of the volatile identifier is to be unique into the context of the application running and not persisted into repositories or at most persisted temporarily
    • then register the Contribution into the service with register(String, String). By this way and for deletion mainly, the elements (attachments for example) will be managed according the user session.
    • At user session end:
      • If the Contribution has been validated, and so registered into repository, the Contribution has no more a volatile identifier but the one given by its manager. So the volatile identifier registered into the cache is pointing no resources and clean process will do nothing in the end.
      • If the Contribution has not been validated, nothing has been persisted into repository. Resources (attachment for example) linked to the volatile identifier will be deleted just after the ending of the user session.

    This above explanations are for understanding. In reality, there just need to use VolatileIdentifierProvider to get a volatile identifier.

    The system does not know services which have to clean resources linked to volatile contributions (so contribution with volatile identifier indeed).
    But the system is able to call all implementations of VolatileResourceCleaner in order to call the only method VolatileResourceCleaner.cleanVolatileResources(String, String).

    Author:
    Yohann Chastagnier

    • Constructor Detail

      • VolatileResourceCacheService

        public VolatileResourceCacheService()

    • Method Detail

      • clearFrom

        public static void clearFrom​(SessionInfo sessionInfo)
        Clears the volatile cache attached to a user session.
        Parameters:
        sessionInfo - the session of a user.

      • contains

        public boolean contains​(Contribution contribution)
        Indicates if a contribution exists into the volatile cache.
        Parameters:
        contribution - a contribution instance which contains the volatile identifier.
        Returns:
        true if the contribution exists into the volatile cache, false otherwise.

      • couldBeVolatileId

        public boolean couldBeVolatileId​(String id)
        Indicates if the given identifier could be a volatile one.
        It works only with identifiers generated by newVolatileStringIdentifier() method.
        Parameters:
        id - an identifier as string.
        Returns:
        true if the identifier is a volatile one, false otherwise.

      • contains

        public boolean contains​(String volatileId,
                        String componentInstanceId)
        Indicates if a contribution exists into the volatile cache with the given identifiers.
        Parameters:
        volatileId - the volatile identifier.
        componentInstanceId - the identifier of a component instance.
        Returns:
        true if the contribution exists into the volatile cache, false otherwise.

      • clear

        public void clear()
        Clears all the resources referenced into this instance of volatile cache.