Code clean-up, comment fixes

(cherry picked from commit 43029be2)

neo/client/app.py

@@ -669,7 +669,7 @@ class Application(ThreadedApplication):
         txn_context = self._txn_container.pop(transaction)
         if txn_context is None:
             return
-        # We want that the involved nodes abort a transaction after any
+        # We want the involved nodes to abort a transaction after any
         # other packet sent by the client for this transaction. IOW, if we
         # already have a connection with a storage node, potentially with
         # a pending write, aborting only via the master may lead to a race
@@ -698,9 +698,8 @@ class Application(ThreadedApplication):
                                                 txn_context.conn_dict))
             except ConnectionClosed:
                 pass
-        # We don't need to flush queue, as it won't be reused by future
-        # transactions (deleted on next line & indexed by transaction object
-        # instance).
+        # No need to flush queue, as it will be destroyed on return,
+        # along with txn_context.
         self.dispatcher.forget_queue(txn_context.queue, flush_queue=False)
 
     def tpc_finish(self, transaction, f=None):

neo/client/handlers/master.py

@@ -68,11 +68,10 @@ class PrimaryNotificationsHandler(MTEventHandler):
     def answerTransactionFinished(self, conn, _, tid, callback, cache_dict):
         app = self.app
         app.last_tid = tid
-        # Update cache
         cache = app._cache
-        with app._cache_lock:
-            invalidate = app._cache.invalidate
+        invalidate = cache.invalidate
         loading_get = app._loading.get
+        with app._cache_lock:
             for oid, data in cache_dict.iteritems():
                 # Update ex-latest value in cache
                 invalidate(oid, tid)

neo/client/transactions.py

@@ -50,7 +50,7 @@ class Transaction(object):
         self.conflict_dict = {}             # {oid: serial}
         # resolved conflicts
         self.resolved_dict = {}             # {oid: serial}
-        # involved storage nodes; connection is None is connection was lost
+        # involved storage nodes; connection is None if connection was lost
         self.conn_dict = {}                 # {node_id: connection}
 
     def __repr__(self):

neo/master/app.py

@@ -587,7 +587,7 @@ class Application(BaseApplication):
         node.send(Packets.StartOperation(self.backup_tid))
         uuid = node.getUUID()
         assert uuid not in self.storage_starting_set
-        if uuid not in self.storage_ready_dict:
+        assert uuid not in self.storage_ready_dict
         self.storage_starting_set.add(uuid)
 
     def setStorageReady(self, uuid):

neo/storage/handlers/client.py

@@ -34,7 +34,7 @@ class ClientOperationHandler(BaseHandler):
         app = self.app
         if app.operational:
             # Even if in most cases, abortFor is called from both this method
-            # and BaseMasterHandler.notifyPartitionChanges (especially since
+            # and BaseMasterHandler.notifyNodeInformation (especially since
             # storage nodes disconnects unknown clients on their own), these 2
             # handlers also cover distinct scenarios, so neither of them is
             # redundant:

neo/storage/transactions.py

@@ -139,6 +139,7 @@ class TransactionManager(EventQueue):
 
     def replicating(self, offset_list):
         self._replicating.update(offset_list)
+        if __debug__:
             isdisjoint = set(offset_list).isdisjoint
             assert isdisjoint(self._replicated), (offset_list, self._replicated)
             assert isdisjoint(map(self.getPartition, self._store_lock_dict)), (