[storm] Zope - Storm Container Implementation

[Gustavo Niemeyer]

Hey Christian,

> i played the last days a bit with storm.zope.
> Unfortunatly there is no Container for zope.storm,
> 
> I´ve looked at the nice z3c.zalchemy [2],
> espacially the container implementation.
> 
> I have taken the container.py from z3c.zalchemy as
> a base for the stormcontainer.py attached to this post.

Very nice! Thanks for publishing it.

> As i´m using grok[1]. I subclass the container from
> grok.Container. But i think this should work in a pure Z3
> Environment too. Maybe subclass from zope.container?
> 
> I´m waiting for your comments.

A few things to perhaps look after:

- store.delete() is actually store.remove()

- The way that commit() is being done in delitem and
  setitem seems dangerous.  It means that as a side-effect
  of removing an item from the container, all the changes
  in the current transaction are persisted.

- You shouldn't have to do flush().  Storm does it
  automatically when needed.

- for id in obj.__storm_object_info__.get('primary_vars'):
      ident += str(id._value)

  You're using private data here, which is not part of the
  exposed API, meaning that it may change without warnings. Also,
  this internal value may not be available by the time you access
  it directly, unlike the actual property.

  Besides these points, this isn't a very good way to extract the
  key, since (1, 23) will yield the same key as (12, 3), for
  instance.


- 	for obj in store.find(self._class):
	    if self._getInstanceKey(obj) == str(id):
		return obj

  That is a *very* expensive way to get an object out of the
  database.  It will walk through all the objects, potentially.
  It should somehow look for the specific key instead.

-- 
Gustavo Niemeyer
http://niemeyer.net