client: drop support for ZODB < 3.10

neo/client/Storage.py

@@ -30,7 +30,7 @@ class Storage(BaseStorage.BaseStorage,
               ConflictResolution.ConflictResolvingStorage):
     """Wrapper class for neoclient."""
 
-    implements(*filter(None, (
+    implements(
         ZODB.interfaces.IStorage,
         # "restore" missing for the moment, but "store" implements this
         # interface.
@@ -41,8 +41,8 @@ class Storage(BaseStorage.BaseStorage,
         # ZODB.interfaces.IStorageIteration,
         ZODB.interfaces.IStorageUndoable,
         ZODB.interfaces.IExternalGC,
-        getattr(ZODB.interfaces, 'ReadVerifyingStorage', None), # BBB ZODB 3.9
-    )))
+        ZODB.interfaces.ReadVerifyingStorage,
+    )
 
     def __init__(self, master_nodes, name, read_only=False,
             compress=None, logfile=None, _app=None, **kw):

neo/client/__init__.py

@@ -100,10 +100,7 @@ if 1:
     # know any legitimate use of DB access outside a transaction.
 
     def afterCompletion(self, *ignored):
-        try:
-            self._readCurrent.clear()
-        except AttributeError: # BBB: ZODB < 3.10
-            pass
+        self._readCurrent.clear()
         # PATCH: do not call sync()
         self._flush_invalidations()
     Connection.afterCompletion = afterCompletion

neo/client/app.py

@@ -641,14 +641,14 @@ class Application(object):
                     # A later serial has already been resolved, skip.
                     resolved_serial_set.update(conflict_serial_set)
                     continue
-                # BBB: On ZODB < 3.10, tryToResolveConflict returns None
-                #      instead of raising ConflictError.
                 try:
                     new_data = tryToResolveConflict(oid, conflict_serial,
                         serial, data)
                 except ConflictError:
-                    new_data = None
-                if new_data is not None:
+                    logging.info('Conflict resolution failed for '
+                        '%r:%r with %r', dump(oid), dump(serial),
+                        dump(conflict_serial))
+                else:
                     logging.info('Conflict resolution succeeded for '
                         '%r:%r with %r', dump(oid), dump(serial),
                         dump(conflict_serial))
@@ -660,10 +660,6 @@ class Application(object):
                     self._store(txn_context, oid, conflict_serial, new_data)
                     append(oid)
                     continue
-                else:
-                    logging.info('Conflict resolution failed for '
-                        '%r:%r with %r', dump(oid), dump(serial),
-                        dump(conflict_serial))
             raise ConflictError(oid=oid, serials=(conflict_serial,
                 serial), data=data)
         return result

neo/tests/client/testClientApp.py

@@ -62,7 +62,7 @@ def resolving_tryToResolveConflict(oid, conflict_serial, serial, data):
     return data
 
 def failing_tryToResolveConflict(oid, conflict_serial, serial, data):
-    return None
+    raise ConflictError
 
 class ClientApplicationTests(NeoUnitTestBase):