nim-libp2p/libp2p/protocols/pubsub/floodsub.nim

161 lines
4.8 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, sets, strutils
import chronos, chronicles, metrics
import pubsub,
pubsubpeer,
timedcache,
peertable,
rpc/[messages, message],
../../stream/connection,
../../peerid,
../../peerinfo
logScope:
topics = "floodsub"
const FloodSubCodec* = "/floodsub/1.0.0"
type
FloodSub* = ref object of PubSub
floodsub*: PeerTable # topic to remote peer map
seen*: TimedCache[string] # list of messages forwarded to peers
method subscribeTopic*(f: FloodSub,
topic: string,
subscribe: bool,
peer: PubsubPeer) {.gcsafe.} =
procCall PubSub(f).subscribeTopic(topic, subscribe, peer)
if topic notin f.floodsub:
f.floodsub[topic] = initHashSet[PubSubPeer]()
if subscribe:
trace "adding subscription for topic", peer = peer.id, name = topic
# subscribe the peer to the topic
f.floodsub[topic].incl(peer)
else:
trace "removing subscription for topic", peer = peer.id, name = topic
# unsubscribe the peer from the topic
f.floodsub[topic].excl(peer)
method unsubscribePeer*(f: FloodSub, peer: PeerID) =
## handle peer disconnects
##
trace "unsubscribing floodsub peer", peer = $peer
let pubSubPeer = f.peers.getOrDefault(peer)
if pubSubPeer.isNil:
return
for t in toSeq(f.floodsub.keys):
if t in f.floodsub:
f.floodsub[t].excl(pubSubPeer)
procCall PubSub(f).unsubscribePeer(peer)
method rpcHandler*(f: FloodSub,
peer: PubSubPeer,
rpcMsg: RPCMsg) {.async.} =
await procCall PubSub(f).rpcHandler(peer, rpcMsg)
if rpcMsg.messages.len > 0: # if there are any messages
var toSendPeers = initHashSet[PubSubPeer]()
for msg in rpcMsg.messages: # for every message
let msgId = f.msgIdProvider(msg)
logScope: msgId
if msgId notin f.seen:
f.seen.put(msgId) # add the message to the seen cache
if f.verifySignature and not msg.verify(peer.peerId):
trace "dropping message due to failed signature verification"
continue
if not (await f.validate(msg)):
trace "dropping message due to failed validation"
continue
for t in msg.topicIDs: # for every topic in the message
if t in f.floodsub:
toSendPeers.incl(f.floodsub[t]) # get all the peers interested in this topic
await handleData(f, t, msg.data)
# forward the message to all peers interested in it
f.broadcast(
toSeq(toSendPeers),
RPCMsg(messages: rpcMsg.messages))
trace "forwared message to peers", peers = toSendPeers.len
method init*(f: FloodSub) =
proc handler(conn: Connection, proto: string) {.async.} =
## main protocol handler that gets triggered on every
## connection for a protocol string
## e.g. ``/floodsub/1.0.0``, etc...
##
await f.handleConn(conn, proto)
f.handler = handler
f.codec = FloodSubCodec
method publish*(f: FloodSub,
topic: string,
data: seq[byte]): Future[int] {.async.} =
# base returns always 0
discard await procCall PubSub(f).publish(topic, data)
if data.len <= 0 or topic.len <= 0:
trace "topic or data missing, skipping publish"
return 0
if topic notin f.floodsub:
trace "missing peers for topic, skipping publish"
return
trace "publishing on topic", name = topic
inc f.msgSeqno
let
msg = Message.init(f.peerInfo, data, topic, f.msgSeqno, f.sign)
peers = toSeq(f.floodsub.getOrDefault(topic))
# start the future but do not wait yet
f.broadcast(
peers,
RPCMsg(messages: @[msg]))
when defined(libp2p_expensive_metrics):
libp2p_pubsub_messages_published.inc(labelValues = [topic])
trace "published message to peers", peers = peers.len,
msg = msg.shortLog()
return peers.len
method unsubscribe*(f: FloodSub,
topics: seq[TopicPair]) {.async.} =
await procCall PubSub(f).unsubscribe(topics)
for p in f.peers.values:
f.sendSubs(p, topics.mapIt(it.topic).deduplicate(), false)
method unsubscribeAll*(f: FloodSub, topic: string) {.async.} =
await procCall PubSub(f).unsubscribeAll(topic)
for p in f.peers.values:
f.sendSubs(p, @[topic], false)
method initPubSub*(f: FloodSub) =
procCall PubSub(f).initPubSub()
f.floodsub = initTable[string, HashSet[PubSubPeer]]()
f.seen = newTimedCache[string](2.minutes)
f.init()