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

134 lines
4.7 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,
timedcache,
rpc/[messages, message],
../../crypto/crypto,
../../connection,
../../peerinfo,
../../peer
logScope:
topic = "FloodSub"
const FloodSubCodec* = "/floodsub/1.0.0"
type
FloodSub* = ref object of PubSub
floodsub*: Table[string, HashSet[string]] # topic to remote peer map
seen*: TimedCache[string] # list of messages forwarded to peers
method subscribeTopic*(f: FloodSub,
topic: string,
subscribe: bool,
peerId: string) {.gcsafe.} =
procCall PubSub(f).subscribeTopic(topic, subscribe, peerId)
if topic notin f.floodsub:
f.floodsub[topic] = initHashSet[string]()
if subscribe:
trace "adding subscription for topic", peer = peerId, name = topic
# subscribe the peer to the topic
f.floodsub[topic].incl(peerId)
else:
trace "removing subscription for topic", peer = peerId, name = topic
# unsubscribe the peer from the topic
f.floodsub[topic].excl(peerId)
method handleDisconnect*(f: FloodSub, peer: PubSubPeer) {.async.} =
## handle peer disconnects
for t in f.floodsub.keys:
f.floodsub[t].excl(peer.id)
method rpcHandler*(f: FloodSub,
peer: PubSubPeer,
rpcMsgs: seq[RPCMsg]) {.async.} =
await procCall PubSub(f).rpcHandler(peer, rpcMsgs)
for m in rpcMsgs: # for all RPC messages
if m.messages.len > 0: # if there are any messages
var toSendPeers: HashSet[string] = initHashSet[string]()
for msg in m.messages: # for every message
if msg.msgId notin f.seen:
f.seen.put(msg.msgId) # add the message to the seen cache
if not msg.verify(peer.peerInfo):
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
if t in f.topics: # check that we're subscribed to it
for h in f.topics[t].handler:
trace "calling handler for message", msg = msg.msgId,
topicId = t,
localPeer = f.peerInfo.id,
fromPeer = msg.fromPeerId().pretty
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)])
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]) {.async.} =
await procCall PubSub(f).publish(topic, data)
if data.len <= 0 or topic.len <= 0:
trace "topic or data missing, skipping publish"
return
if topic notin f.floodsub:
trace "missing peers for topic, skipping publish"
return
trace "publishing on topic", name = topic
let msg = newMessage(f.peerInfo, data, topic)
for p in f.floodsub[topic]:
trace "publishing message", name = topic, peer = p, data = data
await f.peers[p].send(@[RPCMsg(messages: @[msg])])
method unsubscribe*(f: FloodSub,
topics: seq[TopicPair]) {.async.} =
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.floodsub = initTable[string, HashSet[string]]()
f.seen = newTimedCache[string](2.minutes)
f.init()