adding pubsub interface to switch

libp2p/switch.nim

@@ -18,10 +18,13 @@ import connection,
        peerinfo,
        multiaddress,
        protocols/identify,
+       protocols/pubsub/pubsub,
        muxers/muxer,
        peer
 
 type
+    NoPubSubException = object of CatchableError
+
     Switch* = ref object of RootObj
       peerInfo*: PeerInfo
       connections*: TableRef[string, Connection]
@@ -33,6 +36,10 @@ type
       identity*: Identify
       streamHandler*: StreamHandler
       secureManagers*: seq[Secure]
+      pubSub*: Option[PubSub]
+
+proc newNoPubSubException(): ref Exception {.inline.} = 
+  result = newException(NoPubSubException, "no pubsub provided!")
 
 proc secure(s: Switch, conn: Connection): Future[Connection] {.async, gcsafe.} = 
   ## secure the incoming connection
@@ -55,17 +62,25 @@ proc identify(s: Switch, conn: Connection) {.async, gcsafe.} =
     if (await s.ms.select(conn, s.identity.codec)):
       let info = await s.identity.identify(conn, conn.peerInfo)
 
-      let id  = if conn.peerInfo.isSome: 
-        conn.peerInfo.get().peerId.pretty 
+      let id  = if conn.peerInfo.peerId.isSome:
+        conn.peerInfo.peerId.get().pretty
         else:
           ""
+
       if id.len > 0 and s.connections.contains(id):
         let connection = s.connections[id]
-        var peerInfo = conn.peerInfo.get()
-        peerInfo.peerId = PeerID.init(info.pubKey) # we might not have a peerId at all
+        var peerInfo = conn.peerInfo
+
+        if info.pubKey.isSome:
+          peerInfo.peerId = some(PeerID.init(info.pubKey.get())) # we might not have a peerId at all
+        
+        if info.addrs.len > 0:
           peerInfo.addrs = info.addrs
+        
+        if info.protos.len > 0:
           peerInfo.protocols = info.protos
-        debug "identify: identified remote peer ", peer = peerInfo.peerId.pretty
+
+        debug "identify: identified remote peer ", peer = peerInfo.peerId.get().pretty
   except IdentityInvalidMsgError as exc:
     debug "identify: invalid message", msg = exc.msg
   except IdentityNoMatchError as exc:
@@ -90,8 +105,7 @@ proc mux(s: Switch, conn: Connection): Future[void] {.async, gcsafe.} =
   # add muxer handler cleanup proc
   handlerFut.addCallback(
       proc(udata: pointer = nil) {.gcsafe.} = 
-        if handlerFut.finished:
-          debug "mux: Muxer handler completed for peer ", peer = conn.peerInfo.get().peerId.pretty
+        debug "mux: Muxer handler completed for peer ", peer = conn.peerInfo.peerId.get().pretty
     )
   await s.identify(stream)
   await stream.close() # close idenity stream
@@ -101,14 +115,14 @@ proc mux(s: Switch, conn: Connection): Future[void] {.async, gcsafe.} =
   # on exit even if there is no peer for it. This shouldn't 
   # happen once secio is in place, but still something to keep
   # in mind
-  if conn.peerInfo.isSome:
-    s.muxed[conn.peerInfo.get().peerId.pretty] = muxer
+  if conn.peerInfo.peerId.isSome:
+    s.muxed[conn.peerInfo.peerId.get().pretty] = muxer
 
 proc handleConn(s: Switch, conn: Connection): Future[Connection] {.async, gcsafe.} =
   result = conn
   ## perform upgrade flow
-  if result.peerInfo.isSome:
-    let id = result.peerInfo.get().peerId.pretty
+  if result.peerInfo.peerId.isSome:
+    let id = result.peerInfo.peerId.get().pretty
     if s.connections.contains(id):
       # if we already have a connection for this peer, 
       # close the incoming connection and return the 
@@ -121,14 +135,22 @@ proc handleConn(s: Switch, conn: Connection): Future[Connection] {.async, gcsafe
   await s.mux(result) # mux it if possible
 
 proc cleanupConn(s: Switch, conn: Connection) {.async, gcsafe.} =
-  if conn.peerInfo.isSome:
-    let id = conn.peerInfo.get().peerId.pretty
+  if conn.peerInfo.peerId.isSome:
+    let id = conn.peerInfo.peerId.get().pretty
     if s.muxed.contains(id):
       await s.muxed[id].close
     
     if s.connections.contains(id):
       await s.connections[id].close()
 
+proc getMuxedStream(s: Switch, peerInfo: PeerInfo): Future[Option[Connection]] {.async, gcsafe.} = 
+  # if there is a muxer for the connection
+  # use it instead to create a muxed stream
+  if s.muxed.contains(peerInfo.peerId.get().pretty):
+    let muxer = s.muxed[peerInfo.peerId.get().pretty]
+    let conn = await muxer.newStream()
+    result = some(conn)
+
 proc dial*(s: Switch, 
            peer: PeerInfo, 
            proto: string = ""): 
@@ -137,13 +159,13 @@ proc dial*(s: Switch,
     for a in peer.addrs: # for each address
       if t.handles(a): # check if it can dial it
         result = await t.dial(a)
-        result.peerInfo = some(peer)
+        # make sure to assign the peer to the connection
+        result.peerInfo = peer
         result = await s.handleConn(result)
 
-        # if there is a muxer for the connection
-        # use it instead to create a muxed stream
-        if s.muxed.contains(peer.peerId.pretty):
-          result = await s.muxed[peer.peerId.pretty].newStream()
+        let stream = await s.getMuxedStream(peer)
+        if stream.isSome:
+          result = stream.get()
 
         debug "dial: attempting to select remote ", proto = proto
         if not (await s.ms.select(result, proto)):
@@ -178,11 +200,35 @@ proc start*(s: Switch) {.async.} =
 proc stop*(s: Switch) {.async.} = 
   await allFutures(s.transports.mapIt(it.close()))
 
+proc subscribeToPeer*(s: Switch, peerInfo: PeerInfo) {.async, gcsafe.} =
+  if s.pubSub.isSome:
+    let conn = await s.dial(peerInfo, s.pubSub.get().codec)
+    await s.pubSub.get().subscribeToPeer(conn)
+
+proc subscribe*(s: Switch, topic: string, handler: TopicHandler): Future[void] {.gcsafe.} = 
+  if s.pubSub.isNone:
+    raise newNoPubSubException()
+  
+  result = s.pubSub.get().subscribe(topic, handler)
+
+proc unsubscribe*(s: Switch, topics: seq[string]): Future[void] {.gcsafe.} = 
+  if s.pubSub.isNone:
+    raise newNoPubSubException()
+  
+  result = s.pubSub.get().unsubscribe(topics)
+
+proc publish*(s: Switch, topic: string, data: seq[byte]): Future[void] {.gcsafe.} = 
+  if s.pubSub.isNone:
+    raise newNoPubSubException()
+
+  result = s.pubSub.get().publish(topic, data)
+
 proc newSwitch*(peerInfo: PeerInfo,
                 transports: seq[Transport],
                 identity: Identify,
                 muxers: Table[string, MuxerProvider],
-                secureManagers: seq[Secure] = @[]): Switch =
+                secureManagers: seq[Secure] = @[],
+                pubSub: Option[PubSub] = none(PubSub)): Switch =
   new result
   result.peerInfo = peerInfo
   result.ms = newMultistream()
@@ -216,3 +262,7 @@ proc newSwitch*(peerInfo: PeerInfo,
     result.secureManagers.add(manager)
 
   result.secureManagers = result.secureManagers.deduplicate()
+
+  if pubSub.isSome:
+    result.pubSub = pubSub
+    result.mount(pubSub.get())