py-libp2p/libp2p/transport/tcp/tcp.py
2019-04-30 03:09:05 -04:00

106 lines
3.6 KiB
Python

import asyncio
import multiaddr
from libp2p.network.connection.raw_connection import RawConnection
from libp2p.peer.id import id_b58_encode
from ..listener_interface import IListener
from ..transport_interface import ITransport
class TCP(ITransport):
def __init__(self):
self.listener = self.Listener()
class Listener(IListener):
def __init__(self, handler_function=None):
self.multiaddrs = []
self.server = None
self.handler = handler_function
async def listen(self, multiaddr):
"""
put listener in listening mode and wait for incoming connections
:param multiaddr: multiaddr of peer
:return: return True if successful
"""
_multiaddr = multiaddr
_multiaddr = _multiaddr.decapsulate('/p2p')
coroutine = asyncio.start_server(self.handler,
_multiaddr.value_for_protocol('ip4'),
_multiaddr.value_for_protocol('tcp'))
self.server = await coroutine
socket = self.server.sockets[0]
self.multiaddrs.append(_multiaddr_from_socket(socket))
return True
def get_addrs(self):
"""
retrieve list of addresses the listener is listening on
:return: return list of addrs
"""
# TODO check if server is listening
return self.multiaddrs
def close(self, options=None):
"""
close the listener such that no more connections
can be open on this transport instance
:param options: optional object potential with timeout
a timeout value in ms that fires and destroy all connections
:return: return True if successful
"""
if self.server is None:
return False
self.server.close()
_loop = asyncio.get_event_loop()
_loop.run_until_complete(self.server.wait_closed())
_loop.close()
self.server = None
return True
async def dial(self, multiaddr, self_id, options=None):
"""
dial a transport to peer listening on multiaddr
:param multiaddr: multiaddr of peer
:param self_id: peer_id of the dialer (to send to receiver)
:param options: optional object
:return: True if successful
"""
host = multiaddr.value_for_protocol('ip4')
port = int(multiaddr.value_for_protocol('tcp'))
reader, writer = await asyncio.open_connection(host, port)
# First: send our peer ID so receiver knows it
writer.write(id_b58_encode(self_id).encode())
await writer.drain()
# Await ack for peer id
expected_ack_str = "received peer id"
ack = (await reader.read(len(expected_ack_str))).decode()
if ack != expected_ack_str:
raise Exception("Receiver did not receive peer id")
return RawConnection(host, port, reader, writer, True)
def create_listener(self, handler_function, options=None):
"""
create listener on transport
:param options: optional object with properties the listener must have
:param handler_function: a function called when a new connection is received
that takes a connection as argument which implements interface-connection
:return: a listener object that implements listener_interface.py
"""
return self.Listener(handler_function)
def _multiaddr_from_socket(socket):
return multiaddr.Multiaddr("/ip4/%s/tcp/%s" % socket.getsockname())