[Zope] How to keep an object in the zodb cache?

24 Jan 2002

      Hi,

I am writing a product which loads a large python structure
object from disk. I don't wish to store this structure in the Zope
Zodb, so I load it in a variable prefixed with _v_.

The code looks like:

class myproduct(SimpleItem.SimpleItem):

    def __init__(self, id, title):
        " initializes a new instance of a myproduct"
        self.id = id
        self.title = title
        self._v_store = None

    def load(self):
        " load store into memory "
        import mystore
        if not hasattr(self, '_v_store') or not self._v_store:
             print "loading store"
             self._v_store = mystore.LoadStore(self.title)

The function self.load() is called from each URL method to ensure
that the store is loaded.

My problem is that after some inactivity in the web server, I can see
that the store is reloaded when a web page is requested, and it takes
some time.

I assume that the object self._v_store has been flushed from the zodb cache
and discarded.

How can I prevent self._v_store from ever beeing flushed from the cache?
Any idea?

Thanks,

Gregory Popovitch