Merge pull request #50 from zixuanzh/libp2p-new-node

Libp2p new node

host/basic_host.py

@@ -55,6 +55,7 @@ class BasicHost(IHost):
         :param proto_id: protocol id that stream runs on
         :return: true if successful
         """
+        # TODO: host should return a mux stream not a raw stream
         stream = self.network.new_stream(peer_id)
         stream.set_protocol(protocol_id)
         return stream

libp2p/libp2p.py

@@ -2,7 +2,7 @@ from peer.peerstore import PeerStore
 from network.swarm import Swarm
 from host.basic_host import BasicHost
 from transport.upgrader import TransportUpgrader
-from transport.tcp import TCP
+from transport.tcp.tcp import TCP
 from Crypto.PublicKey import RSA
 
 class Libp2p(object):

network/network_interface.py

@@ -3,8 +3,9 @@ from abc import ABC, abstractmethod
 class INetwork(ABC):
 
     @abstractmethod
-    def set_stream_handler(self, stream_handler):
+    def set_stream_handler(self, protocol_id, stream_handler):
         """
+        :param protocol_id: protocol id used on stream
         :param stream_handler: a stream handler instance
         :return: true if successful
         """

network/swarm.py

@@ -1,6 +1,8 @@
 import uuid
 from .network_interface import INetwork
 from .stream.net_stream import NetStream
+from .multiaddr import MultiAddr
+from .connection.raw_connection import RawConnection
 
 class Swarm(INetwork):
 
@@ -10,13 +12,15 @@ class Swarm(INetwork):
         self.upgrader = upgrader
         self.connections = dict()
         self.listeners = dict()
+        self.stream_handlers = dict()
 
-    def set_stream_handler(self, stream_handler):
+    def set_stream_handler(self, protocol_id, stream_handler):
         """
+        :param protocol_id: protocol id used on stream
         :param stream_handler: a stream handler instance
         :return: true if successful
         """
-        pass
+        self.stream_handlers[protocol_id] = stream_handler
 
     def new_stream(self, peer_id, protocol_id):
         """
@@ -64,23 +68,45 @@ class Swarm(INetwork):
         :return: true if at least one success
         """
 
-        # Create a closure C that takes in a multiaddr and 
-        # returns a function object O that takes in a reader and writer.
-        # This function O looks up the stream handler
-        # for the given protocol, creates the net_stream 
-        # for the listener and calls the stream handler function
-        # passing in the net_stream
-
         # For each multiaddr in args
             # Check if a listener for multiaddr exists already
             # If listener already exists, continue
             # Otherwise, do the following:
-                # Pass multiaddr into C and get back function H
-                # listener = transport.create_listener(H)
+                # Pass multiaddr into conn handler
+                # Have conn handler delegate to stream handler
                 # Call listener listen with the multiaddr
                 # Map multiaddr to listener
+        for multiaddr_str in args:
+            if multiaddr_str in self.listeners:
+                return True
 
-        return True
+            multiaddr = MultiAddr(multiaddr_str)
+            multiaddr_dict = multiaddr.to_options()
+
+            def conn_handler(reader, writer):
+                # Upgrade reader/write to a net_stream and pass to appropriate stream handler (using multiaddr)
+                raw_conn = RawConnection(multiaddr_dict.host, multiaddr_dict.port, reader, writer)
+                muxed_conn = self.upgrader.upgrade_connection(raw_conn, False)
+
+                muxed_stream, stream_id, protocol_id = muxed_conn.accept_stream()
+                net_stream = NetStream(muxed_stream)
+                net_stream.set_protocol(protocol_id)
+
+                # Give to stream handler
+                # TODO: handle case when stream handler is set
+                self.stream_handlers[protocol_id](net_stream)
+
+            try:
+                # Success
+                listener = self.transport.create_listener(conn_handler)
+                listener.listen(multiaddr)
+                return True
+            except IOError:
+                # Failed. Continue looping.
+                print("Failed to connect to: " + multiaddr)
+
+        # No multiaddr succeeded
+        return False
 
     def add_transport(self, transport):
         # TODO: Support more than one transport

tests/libp2p/test_libp2p.py

@@ -22,7 +22,7 @@ def test_simple_messages():
     # associate the peer with local ip address (see default parameters of Libp2p())
     hostA.get_peerstore().add_addr("hostB", "/ip4/127.0.0.1/tcp/10000")
 
-    stream = hostA.new_stream("hostB", "/echo/1.0.0")
+    stream = hostA.new_stream("hostB", "/app/1.0.0")
     message = "hello"
     stream.write(message.encode())
 

transport/tcp/tcp.py

@@ -1,7 +1,7 @@
 import asyncio
 from transport.transport_interface import ITransport
 from transport.listener_interface import IListener
-from transport.connection.raw_connection import RawConnection
+from network.connection.raw_connection import RawConnection
 
 class TCP(ITransport):
 
@@ -22,17 +22,16 @@ class TCP(ITransport):
             :return: return True if successful
             """
             # TODO check for exceptions
-            _multiaddr = multiaddr
             if "ipfs" in multiaddr.get_protocols():
                 # ipfs_id = multiaddr.get_ipfs_id()
                 _multiaddr = multiaddr.remove_protocol("ipfs")
 
-            self.multiaddrs.append(_multiaddr)
-            _multiaddr_dict = _multiaddr.to_dict()
-            _loop = asyncio.get_event_loop()
-            _coroutine = asyncio.start_server(self.handler, _multiaddr_dict.host,\
-                _multiaddr_dict.port, loop=_loop)
-            self.server = _loop.run_until_complete(_coroutine)
+            self.multiaddrs.append(multiaddr)
+            multiaddr_dict = _multiaddr.to_options()
+            loop = asyncio.get_event_loop()
+            coroutine = asyncio.start_server(self.handler, multiaddr_dict.host,\
+                multiaddr_dict.port, loop=loop)
+            self.server = loop.run_until_complete(coroutine)
             return True
 
         def get_addrs(self):
@@ -72,7 +71,6 @@ class TCP(ITransport):
         port = _multiaddr_dict.port
         reader, writer = open_conn(host, port)
         return RawConnection(host, port, reader, writer)
-        # TODO dial behavior not fully understood
 
     def create_listener(self, handler_function, options=None):
         """

transport/upgrader.py

@@ -24,5 +24,4 @@ class TransportUpgrader(object):
         # Default to mplex
         
         # TODO do exchange to determine multiplexer
-        
         return MuxedConn(conn, initiator)