BFD: basic asynchronous session up/down

This is a work-in-progress basic BFD session handling. Only
asynchronous mode is supported at the moment. Setting the session flags
doesn't work.

Change-Id: Idba27f721b5c35be5a66a6d202a63d23ff7ecf6f
Signed-off-by: Klement Sekera <ksekera@cisco.com>

1 files changed, 79 insertions, 0 deletions

diff --git a/test/vpp_object.py b/test/vpp_object.py
new file mode 100644
index 00000000..2b71fc1f
--- /dev/null
+++ b/test/vpp_object.py
@@ -0,0 +1,79 @@
+from abc import ABCMeta, abstractmethod
+
+
+class VppObject(object):
+    """ Abstract vpp object """
+    __metaclass__ = ABCMeta
+
+    def __init__(self):
+        VppObjectRegistry().register(self)
+
+    @abstractmethod
+    def add_vpp_config(self):
+        """ Add the configuration for this object to vpp. """
+        pass
+
+    @abstractmethod
+    def query_vpp_config(self):
+        """Query the vpp configuration.
+
+        :return: True if the object is configured"""
+        pass
+
+    @abstractmethod
+    def remove_vpp_config(self):
+        """ Remove the configuration for this object from vpp. """
+        pass
+
+    @abstractmethod
+    def object_id(self):
+        """ Return a unique string representing this object. """
+        pass
+
+
+class VppObjectRegistry(object):
+    """ Class which handles automatic configuration cleanup. """
+    _shared_state = {}
+
+    def __init__(self):
+        self.__dict__ = self._shared_state
+        if not hasattr(self, "_object_registry"):
+            self._object_registry = []
+        if not hasattr(self, "_object_dict"):
+            self._object_dict = dict()
+
+    def register(self, o):
+        """ Register an object in the registry. """
+        if not o.unique_id() in self._object_dict:
+            self._object_registry.append(o)
+            self._object_dict[o.unique_id()] = o
+        else:
+            print "not adding duplicate %s" % o
+
+    def remove_vpp_config(self, logger):
+        """
+        Remove configuration (if present) from vpp and then remove all objects
+        from the registry.
+        """
+        if not self._object_registry:
+            logger.info("No objects registered for auto-cleanup.")
+            return
+        logger.info("Removing VPP configuration for registered objects")
+        for o in reversed(self._object_registry):
+            if o.query_vpp_config():
+                logger.info("Removing %s", o)
+                o.remove_vpp_config()
+            else:
+                logger.info("Skipping %s, configuration not present", o)
+        failed = []
+        for o in self._object_registry:
+            if o.query_vpp_config():
+                failed.append(o)
+        self._object_registry = []
+        self._object_dict = dict()
+        if failed:
+            logger.error("Couldn't remove configuration for object(s):")
+            for x in failed:
+                logger.error(repr(x))
+            raise Exception("Couldn't remove configuration for object(s): %s" %
+                            (", ".join(str(x) for x in failed)))