179 lines
6.3 KiB
Nim
179 lines
6.3 KiB
Nim
## Nim-LibP2P
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## Copyright (c) 2019 Status Research & Development GmbH
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## Licensed under either of
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## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
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## * MIT license ([LICENSE-MIT](LICENSE-MIT))
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## at your option.
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## This file may not be copied, modified, or distributed except according to
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## those terms.
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import sequtils, tables, options, sets, strutils
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import chronos, chronicles
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import pubsub,
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pubsubpeer,
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rpcmsg,
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../../crypto/crypto,
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../../connection,
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../../peerinfo,
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../../peer
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logScope:
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topic = "FloodSub"
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const FloodSubCodec* = "/floodsub/1.0.0"
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type
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FloodSub* = ref object of PubSub
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peers*: Table[string, PubSubPeer] # peerid to peer map
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peerTopics*: Table[string, HashSet[string]] # topic to remote peer map
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proc sendSubs(f: FloodSub,
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peer: PubSubPeer,
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topics: seq[string],
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subscribe: bool) {.async, gcsafe.} =
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## send subscriptions to remote peer
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trace "sending subscriptions", peer = peer.id, subscribe = subscribe
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var msg: RPCMsg
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for t in topics:
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trace "sending topic", peer = peer.id, subscribe = subscribe, topicName = t
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msg.subscriptions.add(SubOpts(topic: t, subscribe: subscribe))
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await peer.send(@[msg])
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proc subscribeTopic(f: FloodSub, topic: string, subscribe: bool, peerId: string) {.gcsafe.} =
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if not f.peerTopics.contains(topic):
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f.peerTopics[topic] = initSet[string]()
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if subscribe:
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trace "adding subscription for topic", peer = peerId, name = topic
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# subscribe the peer to the topic
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f.peerTopics[topic].incl(peerId)
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else:
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trace "removing subscription for topic", peer = peerId, name = topic
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# unsubscribe the peer from the topic
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f.peerTopics[topic].excl(peerId)
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proc rpcHandler(f: FloodSub,
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peer: PubSubPeer,
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rpcMsgs: seq[RPCMsg]) {.async, gcsafe.} =
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## method called by a PubSubPeer every
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## time it receives an RPC message
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##
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## The RPC message might contain subscriptions
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## or messages forwarded to this peer
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##
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trace "processing RPC message", peer = peer.id, msg = rpcMsgs
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for m in rpcMsgs: # for all RPC messages
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trace "processing message", msg = rpcMsgs
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if m.subscriptions.len > 0: # if there are any subscriptions
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for s in m.subscriptions: # subscribe/unsubscribe the peer for each topic
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let id = peer.id
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f.subscribeTopic(s.topic, s.subscribe, id)
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# send subscriptions to every peer
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for p in f.peers.values:
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if p.id != peer.id:
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await p.send(@[RPCMsg(subscriptions: m.subscriptions)])
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var toSendPeers: HashSet[string] = initSet[string]()
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if m.messages.len > 0: # if there are any messages
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for msg in m.messages: # for every message
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for t in msg.topicIDs: # for every topic in the message
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toSendPeers.incl(f.peerTopics[t]) # get all the peers interested in this topic
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if f.topics.contains(t): # check that we're subscribed to it
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for h in f.topics[t].handler:
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await h(t, msg.data) # trigger user provided handler
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# forward the message to all peers interested in it
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for p in toSendPeers:
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if p in f.peers and f.peers[p].id != peer.id:
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await f.peers[p].send(@[RPCMsg(messages: m.messages)])
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proc handleConn(f: FloodSub,
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conn: Connection) {.async, gcsafe.} =
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## handle incoming/outgoing connections
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##
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## this proc will:
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## 1) register a new PubSubPeer for the connection
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## 2) register a handler with the peer;
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## this handler gets called on every rpc message
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## that the peer receives
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## 3) ask the peer to subscribe us to every topic
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## that we're interested in
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##
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if conn.peerInfo.peerId.isNone:
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trace "no valid PeerId for peer"
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return
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# create new pubsub peer
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var peer = newPubSubPeer(conn, proc (peer: PubSubPeer,
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msgs: seq[RPCMsg]) {.async, gcsafe.} =
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# call floodsub rpc handler
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await f.rpcHandler(peer, msgs))
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trace "created new pubsub peer", id = peer.id
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f.peers[peer.id] = peer
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let topics = toSeq(f.topics.keys)
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await f.sendSubs(peer, topics, true)
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let handlerFut = peer.handle() # spawn peer read loop
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handlerFut.addCallback(
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proc(udata: pointer = nil) {.gcsafe.} =
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trace "pubsub peer handler ended, cleaning up",
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peer = conn.peerInfo.peerId.get().pretty
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f.peers.del(peer.id)
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)
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method init(f: FloodSub) =
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proc handler(conn: Connection, proto: string) {.async, gcsafe.} =
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## main protocol handler that gets triggered on every
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## connection for a protocol string
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## e.g. ``/floodsub/1.0.0``, etc...
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##
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await f.handleConn(conn)
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f.handler = handler
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f.codec = FloodSubCodec
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method subscribeToPeer*(f: FloodSub, conn: Connection) {.async, gcsafe.} =
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await f.handleConn(conn)
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method publish*(f: FloodSub,
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topic: string,
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data: seq[byte]) {.async, gcsafe.} =
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await procCall PubSub(f).publish(topic, data)
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trace "about to publish message on topic", name = topic, data = data.toHex()
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if data.len > 0 and topic.len > 0:
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let msg = makeMessage(f.peerInfo.peerId.get(), data, topic)
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if topic in f.peerTopics:
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trace "publishing on topic", name = topic
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for p in f.peerTopics[topic]:
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trace "publishing message", name = topic, peer = p, data = data
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await f.peers[p].send(@[RPCMsg(messages: @[msg])])
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method subscribe*(f: FloodSub,
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topic: string,
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handler: TopicHandler) {.async, gcsafe.} =
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await procCall PubSub(f).subscribe(topic, handler)
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f.subscribeTopic(topic, true, f.peerInfo.peerId.get().pretty)
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for p in f.peers.values:
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await f.sendSubs(p, @[topic], true)
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method unsubscribe*(f: FloodSub,
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topics: seq[TopicPair]) {.async, gcsafe.} =
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await procCall PubSub(f).unsubscribe(topics)
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for p in f.peers.values:
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await f.sendSubs(p, topics.mapIt(it.topic).deduplicate(), false)
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method initPubSub*(f: FloodSub) =
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f.peers = initTable[string, PubSubPeer]()
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f.topics = initTable[string, Topic]()
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f.peerTopics = initTable[string, HashSet[string]]()
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f.init()
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