nwaku/waku/v2/protocol/waku_relay.nim

96 lines
2.6 KiB
Nim

## Waku Relay module. Thin layer on top of GossipSub.
##
## See https://github.com/vacp2p/specs/blob/master/specs/waku/v2/waku-relay.md
## for spec.
{.push raises: [Defect].}
import
std/[tables, sets],
chronos, chronicles, metrics,
libp2p/protocols/pubsub/[pubsub, gossipsub],
libp2p/protocols/pubsub/rpc/messages,
libp2p/stream/connection
logScope:
topics = "wakurelay"
const
WakuRelayCodec* = "/vac/waku/relay/2.0.0"
type
WakuRelay* = ref object of GossipSub
defaultTopics*: seq[string] # Default configured PubSub topics
method init*(w: WakuRelay) =
debug "init WakuRelay"
proc handler(conn: Connection, proto: string) {.async.} =
## main protocol handler that gets triggered on every
## connection for a protocol string
## e.g. ``/wakusub/0.0.1``, etc...
##
debug "Incoming WakuRelay connection"
try:
await w.handleConn(conn, proto)
except CancelledError:
# This is top-level procedure which will work as separate task, so it
# do not need to propogate CancelledError.
trace "Unexpected cancellation in relay handler", conn
except CatchableError as exc:
trace "WakuRelay handler leaks an error", exc = exc.msg, conn
# XXX: Handler hijack GossipSub here?
w.handler = handler
w.codec = WakuRelayCodec
method initPubSub*(w: WakuRelay) {.raises: [Defect, InitializationError].} =
debug "initWakuRelay"
# after discussions with @sinkingsugar, this is essentially what is needed for
# the libp2p `StrictNoSign` policy
w.anonymize = true
w.verifySignature = false
w.sign = false
procCall GossipSub(w).initPubSub()
w.init()
method subscribe*(w: WakuRelay,
pubSubTopic: string,
handler: TopicHandler) =
debug "subscribe", pubSubTopic=pubSubTopic
procCall GossipSub(w).subscribe(pubSubTopic, handler)
method publish*(w: WakuRelay,
pubSubTopic: string,
message: seq[byte]
): Future[int] {.async.} =
trace "publish", pubSubTopic=pubSubTopic, message=message
return await procCall GossipSub(w).publish(pubSubTopic, message)
method unsubscribe*(w: WakuRelay,
topics: seq[TopicPair]) =
debug "unsubscribe"
procCall GossipSub(w).unsubscribe(topics)
method unsubscribeAll*(w: WakuRelay,
pubSubTopic: string) =
debug "unsubscribeAll"
procCall GossipSub(w).unsubscribeAll(pubSubTopic)
# GossipSub specific methods --------------------------------------------------
method start*(w: WakuRelay) {.async.} =
debug "start"
await procCall GossipSub(w).start()
method stop*(w: WakuRelay) {.async.} =
debug "stop"
await procCall GossipSub(w).stop()