From 3dbb969b0b020e260c332fe65b0c936c9af1238c Mon Sep 17 00:00:00 2001
From: Stuckinaboot <aspyn@seas.upenn.edu>
Date: Thu, 28 Feb 2019 18:18:58 -0500
Subject: [PATCH] Implement notify feature

---
 libp2p/network/swarm.py | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/libp2p/network/swarm.py b/libp2p/network/swarm.py
index 705ee31..1ecc0df 100644
--- a/libp2p/network/swarm.py
+++ b/libp2p/network/swarm.py
@@ -24,6 +24,9 @@ class Swarm(INetwork):
         self.multiselect = Multiselect()
         self.multiselect_client = MultiselectClient()
 
+        # Create Notifee array
+        self.notifees = []
+
         # Create generic protocol handler
         self.generic_protocol_handler = create_generic_protocol_handler(self)
 
@@ -61,6 +64,7 @@ class Swarm(INetwork):
             # set muxed connection equal to existing muxed connection
             muxed_conn = self.connections[peer_id]
         else:
+            # Dial peer (connection to peer does not yet exist)
             # Transport dials peer (gets back a raw conn)
             raw_conn = await self.transport.dial(multiaddr, self.self_id)
 
@@ -70,6 +74,10 @@ class Swarm(INetwork):
             # Store muxed connection in connections
             self.connections[peer_id] = muxed_conn
 
+            # Call notifiers since event occurred
+            for notifee in self.notifees:
+                notifee.connected(self, muxed_conn)
+
         return muxed_conn
 
     async def new_stream(self, peer_id, protocol_ids):
@@ -100,6 +108,10 @@ class Swarm(INetwork):
         net_stream = NetStream(muxed_stream)
         net_stream.set_protocol(selected_protocol)
 
+        # Call notifiers since event occurred
+        for notifee in self.notifees:
+            notifee.opened_stream(self, net_stream)
+
         return net_stream
 
     async def listen(self, *args):
@@ -137,11 +149,20 @@ class Swarm(INetwork):
                 # Store muxed_conn with peer id
                 self.connections[peer_id] = muxed_conn
 
+                # Call notifiers since event occurred
+                for notifee in self.notifees:
+                    notifee.connected(self, muxed_conn)
+
             try:
                 # Success
                 listener = self.transport.create_listener(conn_handler)
                 self.listeners[str(multiaddr)] = listener
                 await listener.listen(multiaddr)
+
+                # Call notifiers since event occurred
+                for notifee in self.notifees:
+                    notifee.listen(self, multiaddr)
+
                 return True
             except IOError:
                 # Failed. Continue looping.
@@ -150,6 +171,13 @@ class Swarm(INetwork):
         # No multiaddr succeeded
         return False
 
+    def notify(self, notifee):
+        """
+        :param notifee: object implementing Notifee interface
+        """
+        # TODO: Add check to ensure notifee conforms to Notifee interface
+        self.notifees.append(notifee)
+
     def add_transport(self, transport):
         # TODO: Support more than one transport
         self.transport = transport