[ZODB-Dev] ZODB4 and DemoStorage

[Marius Gedminas]

On Tue, Apr 08, 2003 at 10:37:44AM -0400, Barry Warsaw wrote:
> MappingStorage is more like a MemoryMinimalStorage; neither supports
> undo or versions.  MemoryFullStorage as its name implies, supports the
> full storage interface.

OK.  I do not need undo/versions at the moment, but a full functional
testing framework should definitely support them.

> > I have some reservations about it.  Closing the DB also closes the
> > storage, 
> 
> Looking at the code, that's all db.close() does!
> 
> > and I am not sure you just pass the same storage to a new DB
> > instance as if nothing had happened.
> 
> Well, what if you just threw away the DB object without closing it?  I'm
> not 100% sure this is kosher, but it would be interesting to try. :)

It seems to work both with and without db.close().

I have a set of 20 functional tests for our Zope 3 product, and I'm
trying to migrate that to DemoStorage (previously the tests just
recreated the root folder and essential services in setUp).  I see one
interesting failure, which occurs both with db.close and without.
Here's the traceback:

    [...snip...]
    File "/home/users/mg/Zope3/src/zope/app/publication/zopepublication.py", line 163, in afterCall
      get_transaction().commit()
    File "/home/users/mg/Zope3/src/transaction/txn.py", line 62, in commit
      self._manager.commit(self)
    File "/home/users/mg/Zope3/src/transaction/manager.py", line 29, in commit
      r.prepare(txn)
    File "/home/users/mg/Zope3/src/zodb/connection.py", line 307, in prepare
      self._objcommit(obj, txn)
    File "/home/users/mg/Zope3/src/zodb/connection.py", line 450, in _objcommit
      self._commit_store(writer, o, transaction)
    File "/home/users/mg/Zope3/src/zodb/connection.py", line 477, in _commit_store
      transaction)
    File "/home/users/mg/Zope3/src/zodb/storage/demo.py", line 147, in store
      datarec = self._datarec(superself, oid, version)
    File "/home/users/mg/Zope3/src/zodb/storage/demo.py", line 72, in _datarec
      txnrec = it.next()
    File "/home/users/mg/Zope3/src/zodb/storage/bdbfull.py", line 1679, in __getitem__
      return self.next()
    File "/home/users/mg/Zope3/src/zodb/storage/bdbfull.py", line 1716, in next
      it = _RecordsIterator(self._storage, tid, packedp, user, desc, ext)
    File "/home/users/mg/Zope3/src/zodb/storage/bdbfull.py", line 1765, in __init__
      self._extension = pickle.loads(ext)
  TypeError: loads() argument 1 must be string, not unicode

ext is u'' there for some reason.  I'll try to investigate.

Marius Gedminas
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