Commit 4f3ad7b0 authored by Chris McDonough's avatar Chris McDonough

Allow tempstorage to participate in MVCC. Also fix minor bug where conflict...

Allow tempstorage to participate in MVCC.  Also fix minor bug where conflict cache could be poisoned by a transaction that failed after store was called.
parent 833a52b9
......@@ -28,6 +28,7 @@ from ZODB import POSException
from ZODB.BaseStorage import BaseStorage
from ZODB.ConflictResolution import ConflictResolvingStorage, ResolvedSerial
import time
import bisect
# keep old object revisions for CONFLICT_CACHE_MAXAGE seconds
CONFLICT_CACHE_MAXAGE = 60
......@@ -135,6 +136,31 @@ class TemporaryStorage(BaseStorage, ConflictResolvingStorage):
finally:
self._lock_release()
def loadBefore(self, oid, tid):
"""Return most recent revision of oid before tid committed
(for MVCC)
."""
# implementation stolen from ZODB.test_storage.MinimalMemoryStorage
self._lock_acquire()
try:
tids = [stid for soid, stid in self._conflict_cache if soid == oid]
if not tids:
raise KeyError, oid
tids.sort()
i = bisect.bisect_left(tids, tid) -1
if i == -1:
return None
start_tid = tids[i]
j = i + 1
if j == len(tids):
end_tid = None
else:
end_tid = tids[j]
data = self.loadSerial(oid, start_tid)
return data, start_tid, end_tid
finally:
self._lock_release()
def store(self, oid, serial, data, version, transaction):
if transaction is not self._transaction:
raise POSException.StorageTransactionError(self, transaction)
......@@ -163,8 +189,6 @@ class TemporaryStorage(BaseStorage, ConflictResolvingStorage):
oserial = serial
newserial=self._tid
self._tmp.append((oid, data))
now = time.time()
self._conflict_cache[(oid, newserial)] = data, now
return serial == oserial and newserial or ResolvedSerial
finally:
self._lock_release()
......@@ -238,6 +262,8 @@ class TemporaryStorage(BaseStorage, ConflictResolvingStorage):
index[oid] = serial
opickle[oid] = data
now = time.time()
self._conflict_cache[(oid, serial)] = data, now
if zeros:
for oid in zeros.keys():
......
......@@ -7,6 +7,11 @@ from ZODB.tests import StorageTestBase, BasicStorage, \
Synchronization, ConflictResolution, \
Corruption, RevisionStorage, MTStorage
from persistent import Persistent
import transaction
from ZODB.DB import DB
from ZODB.POSException import ReadConflictError
class TemporaryStorageTests(
StorageTestBase.StorageTestBase,
## RevisionStorage.RevisionStorage, # not a revision storage, but passes
......@@ -49,6 +54,48 @@ class TemporaryStorageTests(
TemporaryStorage.CONFLICT_CACHE_GCEVERY = old_gcevery
TemporaryStorage.CONFLICT_CACHE_MAXAGE = old_maxage
def doreadconflict(self, db, mvcc):
tm1 = transaction.TransactionManager()
conn = db.open(mvcc=mvcc, transaction_manager=tm1)
r1 = conn.root()
obj = MinPO('root')
r1["p"] = obj
obj = r1["p"]
obj.child1 = MinPO('child1')
tm1.get().commit()
# start a new transaction with a new connection
tm2 = transaction.TransactionManager()
cn2 = db.open(mvcc=mvcc, transaction_manager=tm2)
r2 = cn2.root()
self.assertEqual(r1._p_serial, r2._p_serial)
obj.child2 = MinPO('child2')
tm1.get().commit()
# resume the transaction using cn2
obj = r2["p"]
# An attempt to access obj.child1 should fail with an RCE
# below if conn isn't using mvcc, because r2 was read earlier
# in the transaction and obj was modified by the other
# transaction.
obj.child1
return obj
def checkWithoutMVCCRaisesReadConflict(self):
db = DB(self._storage)
self.assertRaises(ReadConflictError, self.doreadconflict, db, False)
def checkWithMVCCDoesntRaiseReadConflict(self):
db = DB(self._storage)
ob = self.doreadconflict(db, True)
self.assertEquals(ob.__class__, MinPO)
self.assertEquals(getattr(ob, 'child1', MinPO()).value, 'child1')
self.failIf(getattr(ob, 'child2', None))
def test_suite():
suite = unittest.makeSuite(TemporaryStorageTests, 'check')
suite2 = unittest.makeSuite(Corruption.FileStorageCorruptTests, 'check')
......
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