[Zodb-checkins] CVS: ZODB3/bsddb3Storage/bsddb3Storage - Full.py:1.61
Fri, 13 Dec 2002 14:37:03 -0500
Update of /cvs-repository/ZODB3/bsddb3Storage/bsddb3Storage
In directory cvs.zope.org:/tmp/cvs-serv14291
Pass the final crop of ZEO and restore tests. Changes include:
_dorestore(): Adopt the FileStorage semantics for when the transaction
pointed to by prev_txn does not exist. This can happen if we're
restoring to a storage where that transaction has been packed away.
In that case, treat prev_txn as a hint and ignore it. :)
_TransactionsIterator.__len__(): Give this a dummy (and lying)
implementation which is just good enough for Python 2.1.3 support.
=== ZODB3/bsddb3Storage/bsddb3Storage/Full.py 1.60 => 1.61 ===
--- ZODB3/bsddb3Storage/bsddb3Storage/Full.py:1.60 Tue Dec 10 16:41:44 2002
+++ ZODB3/bsddb3Storage/bsddb3Storage/Full.py Fri Dec 13 14:37:01 2002
@@ -575,20 +575,28 @@
# Get the metadata for the previous revision, so that we can dig out
# the non-version revid, but only if there /is/ a previous revision
if prevrevid <> ZERO:
- ovid, onvrevid = unpack(
- '>8s8s', self._metadata[oid+prevrevid][:16])
- if ovid == ZERO:
- # The last revision of this object was made on the
- # non-version, we don't care where the current change is
- # made. But if we're storing this change on a version then
- # the non-version revid will be the previous revid
- if version:
- nvrevid = prevrevid
+ ovid, onvrevid = unpack(
+ '>8s8s', self._metadata[oid+prevrevid][:16])
+ except KeyError:
+ # prev_txn is just a hint. If the transaction it points to
+ # does not exist, perhaps because it's been packed away, just
+ # ignore it. Also, check to see if the data matches. If
+ # not...
+ prevrevid = ZERO
- # We're making another change to this object on this version.
- # The non-version revid is the same as for the previous
- # revision of the object.
- nvrevid = onvrevid
+ if ovid == ZERO:
+ # The last revision of this object was made on the
+ # non-version, we don't care where the current change is
+ # made. But if we're storing this change on a version
+ # then the non-version revid will be the previous revid
+ if version:
+ nvrevid = prevrevid
+ # We're making another change to this object on this
+ # version. The non-version revid is the same as for the
+ # previous revision of the object.
+ nvrevid = onvrevid
# Check for George Bailey Events
if data is None:
lrevid = DNE
@@ -629,8 +637,14 @@
# - data can be None, which indicates a George Bailey object
# (i.e. one who's creation has been transactionally undone).
- # If prev_txn is not None, it should contain the same data as
- # the argument data. If it does, write a backpointer to it.
+ # prev_txn is a backpointer. In the original database, it's possible
+ # that the data was actually living in a previous transaction. This
+ # can happen for transactional undo and other operations, and is used
+ # as a space saving optimization. Under some circumstances the
+ # prev_txn may not actually exist in the target database (i.e. self)
+ # for example, if it's been packed away. In that case, the prev_txn
+ # should be considered just a hint, and is ignored if the transaction
+ # doesn't exist.
if transaction is not self._transaction:
raise POSException.StorageTransactionError(self, transaction)
@@ -1759,6 +1773,11 @@
self._stop = stop
self._closed = False
self._first = True
+ def __len__(self):
+ # This is a lie. It's here only for Python 2.1 support for
+ # list()-ifying these objects.
+ return 0
"""Return the ith item in the sequence of transaction data.