Use exception for undone creation in client.

git-svn-id: https://svn.erp5.org/repos/neo/trunk@2283 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/client/app.py

@@ -36,7 +36,7 @@ from neo.locking import Lock
 from neo.connection import MTClientConnection, OnTimeout
 from neo.node import NodeManager
 from neo.connector import getConnectorHandler
-from neo.client.exception import NEOStorageError
+from neo.client.exception import NEOStorageError, NEOStorageCreationUndoneError
 from neo.client.exception import NEOStorageNotFoundError, ConnectionClosed
 from neo.exception import NeoException
 from neo.client.handlers import storage, master
@@ -466,6 +466,8 @@ class Application(object):
                 object exists but no data satisfies given parameters
             NEOStorageDoesNotExistError
                 object doesn't exist
+            NEOStorageCreationUndoneError
+                object existed, but its creation was undone
         """
         # TODO:
         # - rename parameters (here and in handlers & packet definitions)
@@ -530,7 +532,7 @@ class Application(object):
             finally:
                 self._cache_lock_release()
         if data == '':
-            data = None
+            raise NEOStorageCreationUndoneError(dump(oid))
         return data, start_serial, end_serial
 
 

neo/client/exception.py

@@ -33,3 +33,9 @@ class NEOStorageDoesNotExistError(NEOStorageNotFoundError):
     """
     pass
 
+class NEOStorageCreationUndoneError(NEOStorageDoesNotExistError):
+    """
+    This error is a refinement of NEOStorageDoesNotExistError: this means that
+    some object existed at some point, but its creation was undone.
+    """
+

neo/client/iterator.py

@@ -17,7 +17,7 @@
 
 from ZODB import BaseStorage
 from neo import util
-
+from neo.client.exception import NEOStorageCreationUndoneError
 
 class Record(BaseStorage.DataRecord):
     """ TBaseStorageransaction record yielded by the Transaction object """
@@ -67,7 +67,10 @@ class Transaction(BaseStorage.TransactionRecord):
         oid = oid_list[oid_index]
         self.oid_index = oid_index + 1
         # load an object
+        try:
             data, _, next_tid = app._load(oid, serial=self.tid)
+        except NEOStorageCreationUndoneError:
+            data = next_tid = None
         record = Record(oid, self.tid, '', data,
             self.prev_serial_dict.get(oid))
         if next_tid is None: