Ack! Deleted the wrong file in the last checkin.

trunk/src/ZODB/referencesf.py

-##############################################################################
-#
-# Copyright (c) 2001, 2002 Zope Corporation and Contributors.
-# All Rights Reserved.
-#
-# This software is subject to the provisions of the Zope Public License,
-# Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
-# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
-# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
-# FOR A PARTICULAR PURPOSE
-#
-##############################################################################
-"""Provide a function that can find object references in pickles
-"""
-import cPickle, cStringIO
-
-def referencesf(p, rootl=None,):
-
-    if rootl is None:
-        rootl = []
-
-    u = cPickle.Unpickler(cStringIO.StringIO(p))
-    l = len(rootl)
-    u.persistent_load = rootl
-    u.noload()
-    try:
-        u.noload()
-    except:
-        # Hm.  We failed to do second load.  Maybe there wasn't a
-        # second pickle.  Let's check:
-        f = cStringIO.StringIO(p)
-        u = cPickle.Unpickler(f)
-        u.persistent_load = []
-        u.noload()
-        if len(p) > f.tell():
-            raise ValueError, 'Error unpickling, %s' % p
-
-
-    # References may be:
-    #
-    # - A tuple, in which case they are an oid and class.
-    #   In this case, just extract the first element, which is
-    #   the oid
-    #
-    # - A list, which is a weak reference. We skip those.
-    #
-    # - Anything else must be an oid. This means that an oid
-    #   may not be a list or a tuple. This is a bit lame.
-    #   We could avoid this lamosity by allowing single-element
-    #   tuples, so that we wrap oids that are lists or tuples in
-    #   tuples.
-    #
-    # - oids may *not* be false.  I'm not sure why. 
-
-    out = []
-    for v in rootl:
-        assert v # Let's see if we ever get empty ones
-        if type(v) is list:
-            # skip wekrefs
-            continue
-        if type(v) is tuple:
-            v = v[0]
-        out.append(v)
-
-    rootl[:] = out
-
-    return rootl