add a logScope to make tracing less ugly (#218)

* add a logScope to make tracing less ugly

* don't crash on nil pointer

libp2p/muxers/mplex/mplex.nim

@@ -81,21 +81,29 @@ method handle*(m: Mplex) {.async, gcsafe.} =
           let channels = m.getChannelList(initiator)
           if id notin channels:
             trace "Channel not found, skipping", id = id,
-                                                initiator = initiator,
-                                                msg = msgType,
-                                                oid = m.oid
+                                                 initiator = initiator,
+                                                 msg = msgType,
+                                                 oid = m.oid
             continue
           channel = channels[id]
 
+        logScope:
+          id = id
+          initiator = initiator
+          msgType = msgType
+          size = data.len
+          oid = m.oid
+
         case msgType:
           of MessageType.New:
             let name = string.fromBytes(data)
             channel = await m.newStreamInternal(false, id, name)
-            trace "created channel", id = id,
-                                    name = name,
-                                    inititator = channel.initiator,
-                                    channoid = channel.oid,
-                                    oid = m.oid
+            logScope:
+              name = channel.name
+              chann_iod = channel.oid
+
+            trace "created channel"
+
             if not isNil(m.streamHandler):
               let stream = newConnection(channel)
               m.conns.add(stream)
@@ -106,6 +114,8 @@ method handle*(m: Mplex) {.async, gcsafe.} =
               proc handler() {.async.} =
                 try:
                   await m.streamHandler(stream)
+                  trace "finished handling stream"
+                  # doAssert(stream.closed, "connection not closed by handler!")
                 except CatchableError as exc:
                   trace "exception in stream handler", exc = exc.msg
                 finally:
@@ -115,53 +125,39 @@ method handle*(m: Mplex) {.async, gcsafe.} =
               fut = handler()
 
           of MessageType.MsgIn, MessageType.MsgOut:
-            trace "pushing data to channel", id = id,
-                                            initiator = initiator,
-                                            msgType = msgType,
-                                            size = data.len,
-                                            name = channel.name,
-                                            channoid = channel.oid,
-                                            oid = m.oid
+            logScope:
+              name = channel.name
+              chann_iod = channel.oid
+
+            trace "pushing data to channel"
 
             if data.len > MaxMsgSize:
               raise newLPStreamLimitError()
             await channel.pushTo(data)
           of MessageType.CloseIn, MessageType.CloseOut:
-            trace "closing channel", id = id,
-                                    initiator = initiator,
-                                    msgType = msgType,
-                                    name = channel.name,
-                                    channoid = channel.oid,
-                                    oid = m.oid
+            logScope:
+              name = channel.name
+              chann_iod = channel.oid
+
+            trace "closing channel"
 
             await channel.closeRemote()
             m.getChannelList(initiator).del(id)
-            trace "deleted channel", id = id,
-                                    initiator = initiator,
-                                    msgType = msgType,
-                                    name = channel.name,
-                                    channoid = channel.oid,
-                                    oid = m.oid
+            trace "deleted channel"
           of MessageType.ResetIn, MessageType.ResetOut:
-            trace "resetting channel", id = id,
-                                      initiator = initiator,
-                                      msgType = msgType,
-                                      name = channel.name,
-                                      channoid = channel.oid,
-                                      oid = m.oid
+            logScope:
+              name = channel.name
+              chann_iod = channel.oid
+
+            trace "resetting channel"
 
             await channel.reset()
             m.getChannelList(initiator).del(id)
-            trace "deleted channel", id = id,
-                                    initiator = initiator,
-                                    msgType = msgType,
-                                    name = channel.name,
-                                    channoid = channel.oid,
-                                    oid = m.oid
+            trace "deleted channel"
             break
     finally:
-        trace "stopping mplex main loop", oid = m.oid
-        await m.close()
+      trace "stopping mplex main loop", oid = m.oid
+      await m.close()
   except CatchableError as exc:
     trace "Exception occurred", exception = exc.msg, oid = m.oid