controller/switch_conf: introduce a class to manage per-switch configuration

This should be merged into dpset...

Based on the following patch:

From: Isaku Yamahata <yamahata@valinux.co.jp>
Subject: controller/switch_conf: introduce a class to manage per-switch configuration

For tunnel application and generally, it is necessary to associate
configurations to each switches. Such as tunnel port ip address for each
switches.
So introduce a helper class to manage those configurations.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

ryu/controller/conf_switch.py

@@ -0,0 +1,97 @@
+# Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
+# Copyright (C) 2012 Isaku Yamahata <yamahata at private email ne jp>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+
+from ryu.controller import event
+from ryu.lib.dpid import dpid_to_str
+from ryu.base import app_manager
+
+LOG = logging.getLogger(__name__)
+
+
+class EventConfSwitchDelDPID(event.EventBase):
+    def __init__(self, dpid):
+        super(EventConfSwitchDelDPID, self).__init__()
+        self.dpid = dpid
+
+    def __str__(self):
+        return 'EventConfSwitchDelDPID<%s>' % dpid_to_str(self.dpid)
+
+
+class EventConfSwitchSet(event.EventBase):
+    def __init__(self, dpid, key, value):
+        super(EventConfSwitchSet, self).__init__()
+        self.dpid = dpid
+        self.key = key
+        self.value = value
+
+    def __str__(self):
+        return 'EventConfSwitchSet<%s, %s, %s>' % (
+            dpid_to_str(self.dpid), self.key, self.value)
+
+
+class EventConfSwitchDel(event.EventBase):
+    def __init__(self, dpid, key):
+        super(EventConfSwitchDel, self).__init__()
+        self.dpid = dpid
+        self.key = key
+
+    def __str__(self):
+        return 'EventConfSwitchDel<%s, %s>' % (dpid_to_str(self.dpid),
+                                               self.key)
+
+
+class ConfSwitchSet(app_manager.RyuApp):
+    def __init__(self):
+        super(ConfSwitchSet, self).__init__()
+        self.name = 'conf_switch'
+        self.confs = {}
+
+    def dpids(self):
+        return self.confs.keys()
+
+    def del_dpid(self, dpid):
+        del self.confs[dpid]
+        self.send_event_to_observers(EventConfSwitchDelDPID(dpid))
+
+    def keys(self, dpid):
+        return self.confs[dpid].keys()
+
+    def set_key(self, dpid, key, value):
+        conf = self.confs.setdefault(dpid, {})
+        conf[key] = value
+        self.send_event_to_observers(EventConfSwitchSet(dpid, key, value))
+
+    def get_key(self, dpid, key):
+        return self.confs[dpid][key]
+
+    def del_key(self, dpid, key):
+        del self.confs[dpid][key]
+        self.send_event_to_observers(EventConfSwitchDel(dpid, key))
+
+    # methods for TunnelUpdater
+    def __contains__(self, (dpid, key)):
+        """(dpid, key) in <ConfSwitchSet instance>"""
+        return dpid in self.confs and key in self.confs[dpid]
+
+    def find_dpid(self, key, value):
+        for dpid, conf in self.confs.items():
+            if key in conf:
+                if conf[key] == value:
+                    return dpid
+
+        return None