Recent ZODBBrowser versions are very slow

[Marius Gedminas]

139.766s to render a page for /++etc++site/default/PersistentSessionDataContainer which contains a single revision with these attributes:

   __annotations__: <BTrees.OOBTree.OOBTree with oid 0x1b> (2 items)
   __name__: u'PersistentSessionDataContainer'
   __parent__: <zope.site.site.SiteManagementFolder with oid 0x08> (5 items)
   data: <BTrees.OOBTree.OOBTree with oid 0x1c> (2 items)
   resolution: 3000
   timeout: 36000

I suspect (but haven't verified) that the new repr() code is eager-loading historical object revisions, which causes a recursive load of all the btree items, which is totally unnecessary.

[Marius Gedminas (mgedmin)]

Clicking on that OOBTree results in an Apache timeout after 5 minutes, but Zope is still spinning on that request *20122 seconds later*.

[Marius Gedminas (mgedmin)]

Still running 24 hours later. There may be some mutual slowdown since I've got two threads handling the same request, but still, unacceptable.