Update a few comments on the protocol, as it is important to define when a...

Update a few comments on the protocol, as it is important to define when a client node may try to resolve a conflict.

git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@64 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/protocol.py

@@ -124,10 +124,14 @@ ASK_NEW_OIDS = 0x0017
 # Answer new object IDs. PM -> C.
 ANSWER_NEW_OIDS = 0x8017
 
-# Ask to store an object. C -> S.
+# Ask to store an object. Send an OID, an original serial, a current
+# transaction ID, and data. C -> S.
 ASK_STORE_OBJECT = 0x0018
 
-# Answer if object has been stored. S -> C.
+# Answer if an object has been stored. If an object is in conflict,
+# a serial of the conflicting transaction is returned. In this case,
+# if this serial is newer than the current transaction ID, a client
+# node must not try to resolve the conflict. S -> C.
 ANSWER_STORE_OBJECT = 0x8018
 
 # Abort a transaction. C -> S

neo/storage/app.py

@@ -227,6 +227,19 @@ class Application(object):
         for node in nm.getClientNodeList():
             nm.remove(node)
 
+        # This is a mapping between transaction IDs and information on
+        # UUIDs of client nodes which issued transactions and objects
+        # which were stored.
+        self.transaction_dict = {}
+
+        # This is a mapping between object IDs and transaction IDs. Used
+        # for locking objects against store operations.
+        self.store_lock_dict = {}
+        
+        # This is a mapping between object IDs and transactions IDs. Used
+        # for locking objects against load operations.
+        self.load_lock_dict = {}
+
         while 1:
             em.poll(1)