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