From a08b198d889396d25182bb9716817311bcc3be47 Mon Sep 17 00:00:00 2001
From: drebs <drebs@leap.se>
Date: Sun, 9 Jun 2013 14:16:33 -0300
Subject: Add possibility of unregistering in events mechanism.

---
 src/leap/common/events/component.py | 55 +++++++++++++++++++++++++++++++++++--
 1 file changed, 53 insertions(+), 2 deletions(-)

(limited to 'src/leap/common/events/component.py')

diff --git a/src/leap/common/events/component.py b/src/leap/common/events/component.py
index 9932190..029d1ac 100644
--- a/src/leap/common/events/component.py
+++ b/src/leap/common/events/component.py
@@ -56,6 +56,7 @@ class CallbackAlreadyRegistered(Exception):
     """
     Raised when trying to register an already registered callback.
     """
+    pass
 
 
 def ensure_component_daemon():
@@ -111,7 +112,7 @@ def register(signal, callback, uid=None, replace=False, reqcbk=None,
     callback identified by the given uid and replace is False.
 
     :return: the response from server for synch calls or nothing for asynch
-        calls
+        calls.
     :rtype: leap.common.events.events_pb2.EventsResponse or None
     """
     ensure_component_daemon()  # so we can receive registered signals
@@ -140,6 +141,56 @@ def register(signal, callback, uid=None, replace=False, reqcbk=None,
         str(request)[:40])
     return service.register(request, callback=reqcbk, timeout=timeout)
 
+def unregister(signal, uid=None, reqcbk=None, timeout=1000):
+    """
+    Unregister a callback.
+
+    If C{uid} is specified, unregisters only the callback identified by that
+    unique id. Otherwise, unregisters all callbacks
+
+    :param signal: the signal that causes the callback to be launched
+    :type signal: int (see the `events.proto` file)
+    :param uid: a unique id for the callback
+    :type uid: int
+    :param reqcbk: a callback to be called when a response from server is
+        received
+    :type reqcbk: function
+        callback(leap.common.events.events_pb2.EventResponse)
+    :param timeout: the timeout for synch calls
+    :type timeout: int
+
+    :return: the response from server for synch calls or nothing for asynch
+        calls or None if no callback is registered for that signal or uid.
+    :rtype: leap.common.events.events_pb2.EventsResponse or None
+    """
+    if signal not in registered_callbacks or not registered_callbacks[signal]:
+        logger.warning("No callback registered for signal %d." % signal)
+        return None
+    # unregister callback locally
+    cbklist = registered_callbacks[signal]
+    if uid is not None:
+        if filter(lambda (cbkuid, _): cbkuid == uid, cbklist) == []:
+            logger.warning("No callback registered for uid %d." % st)
+            return None
+        registered_callbacks[signal] = filter(lambda(x, y): x != uid, cbklist)
+    else:
+        # exclude all callbacks for given signal
+        registered_callbacks[signal] = []
+    # unregister port in server if there are no more callbacks for this signal
+    if not registered_callbacks[signal]:
+        request = proto.UnregisterRequest()
+        request.event = signal
+        request.port = EventsComponentDaemon.get_instance().get_port()
+        request.mac_method = mac_auth.MacMethod.MAC_NONE
+        request.mac = ""
+        service = RpcService(proto.EventsServerService_Stub,
+                             server.SERVER_PORT, 'localhost')
+        logger.info(
+            "Sending unregistration request to server on port %s: %s",
+            server.SERVER_PORT,
+            str(request)[:40])
+        return service.unregister(request, callback=reqcbk, timeout=timeout)
+
 
 def signal(signal, content="", mac_method="", mac="", reqcbk=None,
            timeout=1000):
@@ -168,7 +219,7 @@ def signal(signal, content="", mac_method="", mac="", reqcbk=None,
     :type timeout: int
 
     :return: the response from server for synch calls or nothing for asynch
-        calls
+        calls.
     :rtype: leap.common.events.events_pb2.EventsResponse or None
     """
     request = proto.SignalRequest()
-- 
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