refactoring of the code to implement IAdvertiser and IDiscoverer

libp2p/host/routed_host.py

@@ -0,0 +1,61 @@
+from libp2p.peer.peerstore import PeerStoreError
+
+from .basic_host import BasicHost
+
+
+class RoutedHost(BasicHost):
+
+    # default options constructor
+    def __init__(self, host, router):
+        super().__init__(host.network)
+        self.host = host
+        self.router = router
+
+    async def advertise(self, service):
+        await self.router.advertise(service)
+
+    async def connect(self, peer_info):
+        """
+        connect ensures there is a connection between this host and the peer with
+        given peer_info.peer_id. connect will absorb the addresses in peer_info into its internal
+        peerstore. If there is not an active connection, connect will issue a
+        dial, and block until a connection is open, or an error is
+        returned.
+
+        :param peer_info: peer_info of the host we want to connect to
+        :type peer_info: peer.peerinfo.PeerInfo
+        """
+        # there is already a connection to this peer
+        if peer_info.peer_id in self.network.connections:
+            return
+
+        # Check if we have some address for that peer
+        # if not, we use the router to get information about the peer
+        peer_info.addrs = await self._find_peer_addrs(peer_info.peer_id)
+
+        # if addrs are given, save them
+        if peer_info.addrs:
+            self.peerstore.add_addrs(peer_info.peer_id, peer_info.addrs, 10)
+
+        # try to connect
+        await super().connect(peer_info)
+
+    def find_peers(self, service):
+        return self.router.find_peers(service)
+
+    async def _find_peer_addrs(self, peer_id):
+        try:
+            addrs = self.peerstore.addrs(peer_id)
+        except PeerStoreError:
+            addrs = None
+
+        if not addrs:
+            peers_info = await self.router.find_peers(peer_id.pretty())
+            if not peers_info:
+                raise KeyError("no address found for this peer_id %s" % str(peer_id))
+            peer_info = peers_info[0]  # todo: handle multiple response
+            if peer_info.peer_id != peer_id:
+                raise RuntimeError('routing failure: provided addrs for different peer')
+            addrs = peer_info.addrs
+
+        return addrs