While working with the caches and with our own internal content
mapping project I have noticed a slight disconnect between how OCM
handles sessions and how jackrabbit seems to want to handle them. With
the OCM one tends to have a long lived object content manager that is
potentially used by multiple threads. This would mean that the session
would be re-used across multiple reader and writer threads. See http://markmail.org/message/f5lbenhnmdc2vxhx
for details on threading and sessions.
I think this points to the need to have sessions opened and closed
much like in the hibernate model. To accomplish this I think we should
create a ObjectContentManagerFactory which can create the managers so
that each thread can get its own copy. When creating a manager the
factory could use a session factory much like the one that spring has
for JCR (org.springmodules.jcr.JcrSessionFactory). This would allow
sessions to be pooled or created as needed and then be passed to
ObjectContentManagers. The factory could also preload the mapping
classes and other configuration items (like say the cache
implementation factory?). The threads could share a cache (if the
implementation is EhCache or something intelligent) or the cache could
just be a simple hashmap and the assumption would be that the managers
are short lived and the cache is there to eliminate the infinite load
issue.
WDYT?
-paddy
- [OCM] ObjectContentManager and Sessions Padraic Hannon
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