Cache tests from ZEO2 branch

src/ZEO/tests/Cache.py

+"""Tests of the ZEO cache"""
+
+from ZODB.Transaction import Transaction
+from ZODB.tests.MinPO import MinPO
+from ZODB.tests.StorageTestBase import zodb_unpickle
+
+class TransUndoStorageWithCache:
+
+    def checkUndoInvalidation(self):
+        oid = self._storage.new_oid()
+        revid = self._dostore(oid, data=MinPO(23))
+        revid = self._dostore(oid, revid=revid, data=MinPO(24))
+        revid = self._dostore(oid, revid=revid, data=MinPO(25))
+
+        info = self._storage.undoInfo()
+        tid = info[0]['id']
+        # Now start an undo transaction
+        self._transaction.note('undo1')
+        self._storage.tpc_begin(self._transaction)
+
+        oids = self._storage.transactionalUndo(tid, self._transaction)
+
+        # Make sure this doesn't load invalid data into the cache
+        self._storage.load(oid, '')
+        
+        self._storage.tpc_vote(self._transaction)
+        self._storage.tpc_finish(self._transaction)
+
+        assert len(oids) == 1
+        assert oids[0] == oid
+        data, revid = self._storage.load(oid, '')
+        obj = zodb_unpickle(data)
+        assert obj == MinPO(24)
+
+class StorageWithCache:
+
+    def checkAbortVersionInvalidation(self):
+        oid = self._storage.new_oid()
+        revid = self._dostore(oid, data=MinPO(1))
+        revid = self._dostore(oid, revid=revid, data=MinPO(2))
+        revid = self._dostore(oid, revid=revid, data=MinPO(3), version="foo")
+        revid = self._dostore(oid, revid=revid, data=MinPO(4), version="foo")
+        t = Transaction()
+        self._storage.tpc_begin(t)
+        self._storage.abortVersion("foo", t)
+        self._storage.load(oid, "foo")
+        self._storage.tpc_vote(t)
+        self._storage.tpc_finish(t)
+        data, revid = self._storage.load(oid, "foo")
+        obj = zodb_unpickle(data)
+        assert obj == MinPO(2), obj
+
+    def checkCommitVersionInvalidation(self):
+        oid = self._storage.new_oid()
+        revid = self._dostore(oid, data=MinPO(1))
+        revid = self._dostore(oid, revid=revid, data=MinPO(2))
+        revid = self._dostore(oid, revid=revid, data=MinPO(3), version="foo")
+        t = Transaction()
+        self._storage.tpc_begin(t)
+        self._storage.commitVersion("foo", "", t)
+        self._storage.load(oid, "")
+        self._storage.tpc_vote(t)
+        self._storage.tpc_finish(t)
+        data, revid = self._storage.load(oid, "")
+        obj = zodb_unpickle(data)
+        assert obj == MinPO(3), obj