py-libp2p/network/swarm.py
2018-11-11 19:37:07 -05:00

91 lines
3.0 KiB
Python

import uuid
from .network_interface import INetwork
from .stream.net_stream import NetStream
class Swarm(INetwork):
def __init__(self, my_peer_id, peerstore, upgrader):
self.my_peer_id = my_peer_id
self.peerstore = peerstore
self.upgrader = upgrader
self.connections = dict()
self.listeners = dict()
def set_stream_handler(self, stream_handler):
"""
:param stream_handler: a stream handler instance
:return: true if successful
"""
pass
def new_stream(self, peer_id, protocol_id):
"""
:param peer_id: peer_id of destination
:param protocol_id: protocol id
:return: net stream instance
"""
muxed_conn = None
if peer_id in self.connections:
"""
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)
# 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, True)
# 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