[ZODB-Dev] class persistence

[Paolo Invernizzi]

Hello zodb-dev,

I was looking at the class persistence module, and there's a problem...

================================
testClassPrepare.py
--------------------------------
from ZODB.FileStorage import DB
from Persistence.Module import PersistentModuleImporter
from Transaction import get_transaction

db = DB("./prova.fs",create=1)
root = db.open().root()
importer = PersistentModuleImporter(root, verbose=1)
importer.module_from_source("foo", """\
from Persistence.Class import PersistentBaseClass

class Foo(PersistentBaseClass):
    def __init__(self):
        self.x = id(self)
    def m(self):
        self.x += 1
        return self.x
""")
get_transaction().commit()

================================
testClassExecute.py
--------------------------------
Python 2.3a0 (#29, Aug 14 2002, 17:43:20) [MSC 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import testClassPrepare
>>>

from ZODB.FileStorage import DB
from Persistence.Module import PersistentModuleImporter
from Transaction import get_transaction

db = DB("./prova.fs",create=0)
root = db.open().root()
importer = PersistentModuleImporter(root, verbose=1)
importer.install()

import foo
obj = foo.Foo()
obj.m()

Python 2.3a0 (#29, Aug 14 2002, 17:43:20) [MSC 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import testClassExecute
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "testClassExecute.py", line 10, in ?
    import foo
  File "D:\cvs\python\dist\src\lib\ihooks.py", line 397, in import_module
    q, tail = self.find_head_package(parent, name)
  File "D:\cvs\python\dist\src\lib\ihooks.py", line 433, in find_head_package
    q = self.import_it(head, qname, parent)
  File "D:\cvs\python\dist\src\lib\ihooks.py", line 486, in import_it
    m = self.loader.load_module(fqname, stuff)
  File "D:\cvs\ZODB4\.\Persistence\Module.py", line 69, in load_module
    assert stuff.__name__ == name, (stuff, stuff.__name__, name)
  File "ZODB\Connection.py", line 247, in setstate
    state = self._unpickle_state(p)
  File "ZODB\Connection.py", line 191, in _unpickle_state
    state = unpickler.load()
  File "ZODB\Connection.py", line 144, in _persistent_load
    object = klass.__new__(klass)
TypeError: __new__() takes exactly 4 arguments (1 given)
>>>


If I've understood all (I'm quite a zope4 newbie!) the problem is the way class are created from metaclasses...
The right direction is towards a Connection/Cache update or towards a
different approach for class persistence? Please point the to the
right path over walk on, as I'm pretty interested if
class-persistence.

I'll also post an help-for-an-advice cry to the persistence-sig ;)


Tnkz in advance!

-- 
Best regards,
 Paolo                          mailto:paoloinvernizzi@dmsware.com