96 lines
3.6 KiB
Python
96 lines
3.6 KiB
Python
from .pb import rpc_pb2
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from .pubsub_router_interface import IPubsubRouter
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class FloodSub(IPubsubRouter):
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# pylint: disable=no-member
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def __init__(self, protocols):
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self.protocols = protocols
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self.pubsub = None
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def get_protocols(self):
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"""
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:return: the list of protocols supported by the router
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"""
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return self.protocols
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def attach(self, pubsub):
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"""
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Attach is invoked by the PubSub constructor to attach the router to a
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freshly initialized PubSub instance.
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:param pubsub: pubsub instance to attach to
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"""
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self.pubsub = pubsub
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def add_peer(self, peer_id, protocol_id):
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"""
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Notifies the router that a new peer has been connected
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:param peer_id: id of peer to add
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"""
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def remove_peer(self, peer_id):
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"""
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Notifies the router that a peer has been disconnected
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:param peer_id: id of peer to remove
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"""
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def handle_rpc(self, rpc):
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"""
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Invoked to process control messages in the RPC envelope.
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It is invoked after subscriptions and payload messages have been processed
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:param rpc: rpc message
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"""
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async def publish(self, sender_peer_id, rpc_message):
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"""
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Invoked to forward a new message that has been validated.
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This is where the "flooding" part of floodsub happens
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With flooding, routing is almost trivial: for each incoming message,
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forward to all known peers in the topic. There is a bit of logic,
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as the router maintains a timed cache of previous messages,
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so that seen messages are not further forwarded.
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It also never forwards a message back to the source
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or the peer that forwarded the message.
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:param sender_peer_id: peer_id of message sender
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:param rpc_message: pubsub message in RPC string format
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"""
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packet = rpc_pb2.RPC()
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packet.ParseFromString(rpc_message)
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msg_sender = str(sender_peer_id)
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# Deliver to self if self was origin
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# Note: handle_talk checks if self is subscribed to topics in message
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for message in packet.publish:
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decoded_from_id = message.from_id.decode('utf-8')
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if msg_sender == decoded_from_id and msg_sender == str(self.pubsub.host.get_id()):
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await self.pubsub.handle_talk(message)
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# Deliver to self and peers
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for topic in message.topicIDs:
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if topic in self.pubsub.peer_topics:
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for peer_id_in_topic in self.pubsub.peer_topics[topic]:
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# Forward to all known peers in the topic that are not the
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# message sender and are not the message origin
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if peer_id_in_topic not in (msg_sender, decoded_from_id):
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stream = self.pubsub.peers[peer_id_in_topic]
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# create new packet with just publish message
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new_packet = rpc_pb2.RPC()
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new_packet.publish.extend([message])
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await stream.write(new_packet.SerializeToString())
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def join(self, topic):
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"""
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Join notifies the router that we want to receive and
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forward messages in a topic. It is invoked after the
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subscription announcement
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:param topic: topic to join
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"""
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def leave(self, topic):
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"""
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Leave notifies the router that we are no longer interested in a topic.
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It is invoked after the unsubscription announcement.
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:param topic: topic to leave
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"""
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