Revalidate loop fix (#60)

* Sets lower limit in revalidation loop timeout.

* Moves up RevalidateMin

libp2pdht/private/eth/p2p/discoveryv5/protocol.nim

@@ -121,7 +121,8 @@ const
   MaxNodesPerMessage = 3 ## Maximum amount of SPRs per individual Nodes message
   RefreshInterval = 5.minutes ## Interval of launching a random query to
   ## refresh the routing table.
-  RevalidateMax = 10000 ## Revalidation of a peer is done between 0 and this
+  RevalidateMin = 5000
+  RevalidateMax = 10000 ## Revalidation of a peer is done between min and max milliseconds.
   ## value in milliseconds
   IpMajorityInterval = 5.minutes ## Interval for checking the latest IP:Port
   ## majority and updating this when SPR auto update is set.
@@ -937,7 +938,8 @@ proc revalidateLoop(d: Protocol) {.async.} =
   ## message.
   try:
     while true:
-      await sleepAsync(milliseconds(d.rng[].rand(RevalidateMax)))
+      let revalidateTimeout = RevalidateMin + d.rng[].rand(RevalidateMax - RevalidateMin)
+      await sleepAsync(milliseconds(revalidateTimeout))
       let n = d.routingTable.nodeToRevalidate()
       if not n.isNil:
         traceAsyncErrors d.revalidateNode(n)