Add decorators that implements common patterns used in handlers methods.

git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@503 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/client/handler.py

@@ -20,7 +20,7 @@ import logging
 from neo.handler import EventHandler
 from neo.connection import MTClientConnection
 from neo import protocol
-from neo.protocol import Packet, UnexpectedPacketError, \
+from neo.protocol import Packet, \
         MASTER_NODE_TYPE, STORAGE_NODE_TYPE, CLIENT_NODE_TYPE, \
         INVALID_UUID, RUNNING_STATE, TEMPORARILY_DOWN_STATE, \
         BROKEN_STATE, FEEDING_STATE, DISCARDED_STATE 
@@ -29,6 +29,7 @@ from neo.pt import PartitionTable
 from neo.client.exception import NEOStorageError
 from neo.exception import ElectionFailure
 from neo.util import dump
+from neo.handler import identification_required, restrict_node_types
 
 from ZODB.TimeStamp import TimeStamp
 from ZODB.utils import p64
@@ -153,11 +154,9 @@ class PrimaryBoostrapEventHandler(BaseClientEventHandler):
         finally:
             conn.unlock()
 
+    @identification_required
     def handleAnswerPrimaryMaster(self, conn, packet, primary_uuid, known_master_list):
         uuid = conn.getUUID()
-        if uuid is None:
-            raise UnexpectedPacketError
-
         app = self.app
         node = app.nm.getNodeByUUID(uuid)
         # This must be sent only by master node
@@ -195,11 +194,9 @@ class PrimaryBoostrapEventHandler(BaseClientEventHandler):
                     # Whatever the situation is, I trust this master.
                     app.primary_master_node = primary_node
 
+    @identification_required
     def handleNotifyNodeInformation(self, conn, packet, node_list):
         uuid = conn.getUUID()
-        if uuid is None:
-            raise UnexpectedPacketError
-
         app = self.app
         nm = app.nm
         node = nm.getNodeByUUID(uuid)
@@ -239,6 +236,7 @@ class PrimaryBoostrapEventHandler(BaseClientEventHandler):
 
             n.setState(state)
 
+    @identification_required
     def handleSendPartitionTable(self, conn, packet, ptid, row_list):
         # This handler is in PrimaryBoostrapEventHandler, since this
         # basicaly is an answer to askPrimaryMaster.
@@ -253,9 +251,6 @@ class PrimaryBoostrapEventHandler(BaseClientEventHandler):
         # notifyNodeInformation is valid as asynchrounous event, but
         # sendPartitionTable is only triggered after askPrimaryMaster.
         uuid = conn.getUUID()
-        if uuid is None:
-            raise UnexpectedPacketError
-
         app = self.app
         nm = app.nm
         pt = app.pt

neo/handler.py

@@ -40,6 +40,58 @@ from protocol import ERROR, REQUEST_NODE_IDENTIFICATION, ACCEPT_NODE_IDENTIFICAT
         PROTOCOL_ERROR_CODE, TIMEOUT_ERROR_CODE, BROKEN_NODE_DISALLOWED_CODE, \
         INTERNAL_ERROR_CODE
 
+
+# Some decorators useful to avoid duplication of patterns in handlers
+# FIXME: they may be applied on generic handler
+def identification_required(handler):
+    """ Raise UnexpectedPacketError if the identification has not succeed """
+    def wrapper(self, conn, packet, *args, **kwargs):
+        # check if node identification succeed
+        if conn.getUUID() is None:
+            raise UnexpectedPacketError
+        # identified, call the handler
+        handler(self, conn, packet, *args, **kwargs)
+    return wrapper
+
+def restrict_node_types(*node_types):
+    """ Raise UnexpectedPacketError if the node type is node in the supplied
+    list, if the uuid is None or if the node is not known. This decorator
+    should be applied after identification_required """
+    def inner(handler):
+        def wrapper(self, conn, packet, *args, **kwargs):
+            # check if node type is allowed
+            uuid = conn.getUUID()
+            if uuid is None:
+                raise UnexpectedPacketError
+            node = self.app.nm.getNodeByUUID(uuid)
+            if node is None:
+                raise UnexpectedPacketError
+            if node.getNodeType() not in node_types:
+                raise UnexpectedPacketError
+            # all is ok, call the handler
+            handler(self, conn, packet, *args, **kwargs)
+        return wrapper
+    return inner
+
+def client_connection_required(handler):
+    """ Raise UnexpectedPacketError if the packet comes from a client connection """
+    def wrapper(self, conn, packet, *args, **kwargs):
+        if conn.isServerConnection():
+            raise UnexpectedPacketError
+        # it's a client connection, call the handler
+        handler(self, conn, packet, *args, **kwargs)
+    return wrapper
+
+def server_connection_required(handler):
+    """ Raise UnexpectedPacketError if the packet comes from a server connection """
+    def wrapper(self, conn, packet, *args, **kwargs):
+        if not conn.isServerConnection():
+            raise UnexpectedPacketError
+        # it's a server connection, call the handler
+        handler(self, conn, packet, *args, **kwargs)
+    return wrapper
+
+
 class EventHandler(object):
     """This class handles events."""
     def __init__(self):