add handler for hidden state

git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@535 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/storage/hidden.py

+#
+# Copyright (C) 2006-2009  Nexedi SA
+# 
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+import logging
+
+from neo.handler import EventHandler
+from neo.protocol import Packet, \
+        INVALID_UUID, RUNNING_STATE, BROKEN_STATE, \
+        MASTER_NODE_TYPE, STORAGE_NODE_TYPE, CLIENT_NODE_TYPE, \
+        DOWN_STATE, TEMPORARILY_DOWN_STATE, HIDDEN_STATE
+
+from neo.util import dump
+from neo.node import MasterNode, StorageNode, ClientNode
+from neo.connection import ClientConnection
+from neo.exception import PrimaryFailure
+
+class HiddenEventHandler(EventHandler):
+    """This class implements a generic part of the event handlers."""
+    def __init__(self, app):
+        self.app = app
+        EventHandler.__init__(self)
+
+    def handleAnnouncePrimaryMaster(self, conn, packet):
+        """Theoretically speaking, I should not get this message,
+        because the primary master election must happen when I am
+        not connected to any master node."""
+        uuid = conn.getUUID()
+        if uuid is None:
+            self.handleUnexpectedPacket(conn, packet)
+            return
+
+        app = self.app
+        node = app.nm.getNodeByUUID(uuid)
+        if node is None:
+            raise RuntimeError('I do not know the uuid %r' % dump(uuid))
+
+        if node.getNodeType() != MASTER_NODE_TYPE:
+            self.handleUnexpectedPacket(conn, packet)
+            return
+
+        if app.primary_master_node is None:
+            # Hmm... I am somehow connected to the primary master already.
+            app.primary_master_node = node
+            if not isinstance(conn, ClientConnection):
+                # I do not want a connection from any master node. I rather
+                # want to connect from myself.
+                conn.close()
+        elif app.primary_master_node.getUUID() == uuid:
+            # Yes, I know you are the primary master node.
+            pass
+        else:
+            # It seems that someone else claims taking over the primary
+            # master node...
+            app.primary_master_node = None
+            raise PrimaryFailure('another master node wants to take over')
+
+    def handleNotifyNodeInformation(self, conn, packet, node_list):
+        """Store information on nodes, only if this is sent by a primary
+        master node."""
+        uuid = conn.getUUID()
+        if uuid is None:
+            self.handleUnexpectedPacket(conn, packet)
+            return
+
+        app = self.app
+        node = app.nm.getNodeByUUID(uuid)
+        if node.getNodeType() != MASTER_NODE_TYPE \
+                or app.primary_master_node is None \
+                or app.primary_master_node.getUUID() != uuid:
+            return
+
+        for node_type, ip_address, port, uuid, state in node_list:
+            addr = (ip_address, port)
+
+            if node_type == STORAGE_NODE_TYPE:
+                if uuid == INVALID_UUID:
+                    # No interest.
+                    continue
+
+                if uuid == self.app.uuid:
+                    # This is me, do what the master tell me
+                    if state in (DOWN_STATE, TEMPORARILY_DOWN_STATE, BROKEN_STATE):
+                        conn.close()
+                        self.app.shutdown()
+                    elif state == HIDDEN_STATE:
+                        # I know I'm hidden
+                        continue
+                    else:
+                        # I must be working again                
+                        n = app.nm.getNodeByUUID(uuid)
+                        n.setState(state)
+
+            else:
+                # Do not care of other node
+                pass