159 lines
5.6 KiB
Python
159 lines
5.6 KiB
Python
from protocol_muxer.multiselect_client import MultiselectClient
|
|
from protocol_muxer.multiselect import Multiselect
|
|
from .network_interface import INetwork
|
|
from .stream.net_stream import NetStream
|
|
from .connection.raw_connection import RawConnection
|
|
|
|
|
|
class Swarm(INetwork):
|
|
# pylint: disable=too-many-instance-attributes, cell-var-from-loop
|
|
|
|
def __init__(self, peer_id, peerstore, upgrader):
|
|
self.self_id = peer_id
|
|
self.peerstore = peerstore
|
|
self.upgrader = upgrader
|
|
self.connections = dict()
|
|
self.listeners = dict()
|
|
self.stream_handlers = dict()
|
|
self.transport = None
|
|
|
|
# Protocol muxing
|
|
self.multiselect = Multiselect()
|
|
self.multiselect_client = MultiselectClient()
|
|
|
|
def get_peer_id(self):
|
|
return self.self_id
|
|
|
|
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
|
|
"""
|
|
self.multiselect.add_handler(protocol_id, stream_handler)
|
|
return True
|
|
|
|
async def dial_peer(self, peer_id):
|
|
"""
|
|
dial_peer try to create a connection to peer_id
|
|
:param peer_id: peer if we want to dial
|
|
:raises SwarmException: raised when no address if found for peer_id
|
|
:return: muxed connection
|
|
"""
|
|
|
|
# Get peer info from peer store
|
|
addrs = self.peerstore.addrs(peer_id)
|
|
|
|
if not addrs:
|
|
raise SwarmException("No known addresses to peer")
|
|
|
|
# TODO: define logic to choose which address to use, or try them all ?
|
|
multiaddr = addrs[0]
|
|
|
|
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:
|
|
# Transport dials peer (gets back a raw conn)
|
|
raw_conn = await self.transport.dial(multiaddr)
|
|
|
|
# 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
|
|
|
|
return muxed_conn
|
|
|
|
async def new_stream(self, peer_id, protocol_ids):
|
|
"""
|
|
:param peer_id: peer_id of destination
|
|
:param protocol_id: protocol id
|
|
:return: net stream instance
|
|
"""
|
|
# Get peer info from peer store
|
|
addrs = self.peerstore.addrs(peer_id)
|
|
|
|
if not addrs:
|
|
raise SwarmException("No known addresses to peer")
|
|
|
|
multiaddr = addrs[0]
|
|
|
|
muxed_conn = await self.dial_peer(peer_id)
|
|
|
|
# Use muxed conn to open stream, which returns
|
|
# a muxed stream
|
|
# TODO: Remove protocol id from being passed into muxed_conn
|
|
muxed_stream = await muxed_conn.open_stream(protocol_ids[0], peer_id, multiaddr)
|
|
|
|
# Perform protocol muxing to determine protocol to use
|
|
selected_protocol = await self.multiselect_client.select_one_of(protocol_ids, muxed_stream)
|
|
|
|
# Create a net stream with the selected protocol
|
|
net_stream = NetStream(muxed_stream)
|
|
net_stream.set_protocol(selected_protocol)
|
|
|
|
return net_stream
|
|
|
|
async def listen(self, *args):
|
|
"""
|
|
:param *args: one or many multiaddrs to start listening on
|
|
:return: true if at least one success
|
|
|
|
For each multiaddr in args
|
|
Check if a listener for multiaddr exists already
|
|
If listener already exists, continue
|
|
Otherwise:
|
|
Capture multiaddr in conn handler
|
|
Have conn handler delegate to stream handler
|
|
Call listener listen with the multiaddr
|
|
Map multiaddr to listener
|
|
"""
|
|
for multiaddr in args:
|
|
if str(multiaddr) in self.listeners:
|
|
return True
|
|
|
|
async def conn_handler(reader, writer):
|
|
# Upgrade reader/write to a net_stream and pass \
|
|
# to appropriate stream handler (using multiaddr)
|
|
raw_conn = RawConnection(multiaddr.value_for_protocol('ip4'),
|
|
multiaddr.value_for_protocol('tcp'), reader, writer, False)
|
|
muxed_conn = self.upgrader.upgrade_connection(raw_conn)
|
|
|
|
# TODO: Remove protocol id from muxed_conn accept stream or
|
|
# move protocol muxing into accept_stream
|
|
muxed_stream, _, _ = await muxed_conn.accept_stream()
|
|
|
|
# Perform protocol muxing to determine protocol to use
|
|
selected_protocol, handler = await self.multiselect.negotiate(muxed_stream)
|
|
|
|
net_stream = NetStream(muxed_stream)
|
|
net_stream.set_protocol(selected_protocol)
|
|
|
|
# Give to stream handler
|
|
# TODO: handle case when stream handler is set
|
|
# TODO: handle case of multiple protocols over same raw connection
|
|
await handler(net_stream)
|
|
|
|
try:
|
|
# Success
|
|
listener = self.transport.create_listener(conn_handler)
|
|
self.listeners[str(multiaddr)] = listener
|
|
await listener.listen(multiaddr)
|
|
return True
|
|
except IOError:
|
|
# Failed. Continue looping.
|
|
print("Failed to connect to: " + str(multiaddr))
|
|
|
|
# No multiaddr succeeded
|
|
return False
|
|
|
|
def add_transport(self, transport):
|
|
# TODO: Support more than one transport
|
|
self.transport = transport
|
|
|
|
|
|
class SwarmException(Exception):
|
|
pass
|