Merge pull request #44 from zixuanzh/swarm-new-stream

Swarm new stream

network/stream/net_stream.py

@@ -0,0 +1,42 @@
+import asyncio
+from .net_stream_interface import INetStream
+
+class NetStream(INetStream):
+
+    def __init__(self, muxed_stream):
+        self.muxed_stream = muxed_stream
+
+    def get_protocol(self):
+        """
+        :return: protocol id that stream runs on
+        """
+        return self.protocol_id
+
+    def set_protocol(self, protocol_id):
+        """
+        :param protocol_id: protocol id that stream runs on
+        :return: true if successful
+        """
+        self.protocol_id = protocol_id
+
+    def read(self):
+        """
+        read from stream
+        :return: bytes of input until EOF
+        """
+        return self.muxed_stream.read()
+
+    def write(self, bytes):
+        """
+        write to stream
+        :return: number of bytes written
+        """
+        return self.muxed_stream.write(bytes)
+
+    def close(self):
+        """
+        close stream
+        :return: true if successful
+        """
+        self.muxed_stream.close()
+        return True

network/stream/net_stream_interface.py

@@ -1,6 +1,6 @@
 from abc import ABC, abstractmethod
 
-class IStream(ABC):
+class INetStream(ABC):
 
     def __init__(self, peer_id, multi_addr, connection):
         self.peer_id = peer_id

network/swarm.py

@@ -1,13 +1,15 @@
+import uuid
 from .network_interface import INetwork
-from muxer.mplex.muxed_connection import MuxedConn
-from transport.connection.raw_connection import RawConnection
+from .stream.net_stream import NetStream
 
 class Swarm(INetwork):
 
-    def __init__(self, my_peer_id, peerstore):
+    def __init__(self, my_peer_id, peerstore, upgrader):
         self.my_peer_id = my_peer_id
         self.peerstore = peerstore
-        self.connections = {}
+        self.upgrader = upgrader
+        self.connections = dict()
+        self.listeners = dict()
 
     def set_stream_handler(self, stream_handler):
         """
@@ -18,34 +20,71 @@ class Swarm(INetwork):
 
     def new_stream(self, peer_id, protocol_id):
         """
-        Determine if a connection to peer_id already exists
-        If a connection to peer_id exists, then
-        c = existing connection,
-        otherwise c = new muxed connection to peer_id
-        s = c.open_stream(protocol_id)
-        return s
-
         :param peer_id: peer_id of destination
         :param protocol_id: protocol id
-        :return: stream instance
+        :return: net stream instance
         """
-        muxed_connection = None
+        muxed_conn = None
         if peer_id in self.connections:
-            muxed_connection = self.connections[peer_id]
+            """
+            If muxed connection already exists for peer_id,
+            set muxed connection equal to
+            existing muxed connection
+            """
+            muxed_conn = self.connections[peer_id]
         else:
+            # Get peer info from peer store
             addrs = self.peerstore.addrs(peer_id)
-            stream_ip = addrs.get_protocol_value("ip")
-            stream_port = addrs.get_protocol_value("port")
-            if len(addrs) > 0:
-                conn = RawConnection(stream_ip, stream_port)
-                muxed_connection = MuxedConnection(conn, True)
-            else:
-                raise Exception("No IP and port in addr")
-        return muxed_connection.open_stream(protocol_id, "", peer_id, addrs)
+
+            # Transport dials peer (gets back a raw conn)
+            if not addrs:
+                raise SwarmException("No known addresses to peer")
+            first_addr = addrs[0]
+            raw_conn = self.transport.dial(first_addr)
+
+            # Use upgrader to upgrade raw conn to muxed conn
+            muxed_conn = self.upgrader.upgrade_connection(raw_conn)
+
+            # Store muxed connection in connections
+            self.connections[peer_id] = muxed_conn
+
+        # Use muxed conn to open stream, which returns
+        # a muxed stream
+        stream_id = str(uuid.uuid4())
+        muxed_stream = muxed_conn.open_stream(protocol_id, stream_id, peer_id, first_addr)
+
+        # Create a net stream
+        net_stream = NetStream(muxed_stream)
+
+        return net_stream
 
     def listen(self, *args):
         """
         :param *args: one or many multiaddrs to start listening on
         :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)
+                # Call listener listen with the multiaddr
+                # Map multiaddr to listener
+
+        return True
+
+    def add_transport(self, transport):
+        # TODO: Support more than one transport
+        self.transport = transport
+
+class SwarmException(Exception):
     pass

transport/stream/stream.py

@@ -1,58 +0,0 @@
-import asyncio
-from .stream_interface import IStream
-
-class Stream(IStream):
-
-    def __init__(self, peer_id, multi_addr, connection):
-        IStream.__init__(self, peer_id, multi_addr, connection)
-        self.peer_id = peer_id
-
-        self.multi_addr = multi_addr
-
-        self.stream_ip = multi_addr.get_protocol_value("ip4")
-        self.stream_port = multi_addr.get_protocol_value("tcp")
-
-        self.reader = connection.reader
-        self.writer = connection.writer
-
-        # TODO should construct protocol id from constructor
-        self.protocol_id = None
-
-    def get_protocol(self):
-        """
-        :return: protocol id that stream runs on
-        """
-        return self.protocol_id
-
-    def set_protocol(self, protocol_id):
-        """
-        :param protocol_id: protocol id that stream runs on
-        :return: true if successful
-        """
-        self.protocol_id = protocol_id
-
-    def read(self):
-        """
-        read from stream
-        :return: bytes of input
-        """
-        return self.reader.read(-1)
-
-    def write(self, _bytes):
-        """
-        write to stream
-        :return: number of bytes written
-        """
-        return self.write_to_stream(_bytes)
-
-    async def write_to_stream(self, _bytes):
-        to_return = self.writer.write(_bytes)
-        await self.writer.drain()
-        return to_return
-
-    def close(self):
-        """
-        close stream
-        :return: true if successful
-        """
-        self.writer.close()

transport/upgrader.py

@@ -14,5 +14,11 @@ class TransportUpgrader(object):
     def upgrade_security(self):
         pass
 
-	def upgrade_muxer(self):
+    def upgrade_connection(self, conn):
+        """
+        upgrade raw connection to muxed connection
+        """
+        # For PoC, no security
+        # Default to mplex
         pass
+