Tunable max concurrent upgrades

libp2p/builders.nim

@@ -50,6 +50,7 @@ type
     transports: seq[TransportProvider]
     rng: ref HmacDrbgContext
     maxConnections: int
+    maxConcurrentUpgrades: int
     maxIn: int
     sendSignedPeerRecord: bool
     maxOut: int
@@ -73,6 +74,7 @@ proc new*(T: type[SwitchBuilder]): T {.public.} =
     addresses: @[address],
     secureManagers: @[],
     maxConnections: MaxConnections,
+    maxConcurrentUpgrades: ConcurrentUpgrades,
     maxIn: -1,
     maxOut: -1,
     maxConnsPerPeer: MaxConnectionsPerPeer,
@@ -155,6 +157,11 @@ proc withMaxConnections*(b: SwitchBuilder, maxConnections: int): SwitchBuilder {
   b.maxConnections = maxConnections
   b
 
+proc withMaxConcurrentUpgrades*(b: SwitchBuilder, maxConcurrentUpgrades: int): SwitchBuilder {.public.} =
+  ## Maximum concurrent upgrades on the switch. Default to 4
+  b.maxConcurrentUpgrades = maxConcurrentUpgrades
+  b
+
 proc withMaxIn*(b: SwitchBuilder, maxIn: int): SwitchBuilder {.public.} =
   ## Maximum concurrent incoming connections. Should be used with `withMaxOut<#withMaxOut,SwitchBuilder,int>`_
   b.maxIn = maxIn
@@ -253,6 +260,7 @@ proc build*(b: SwitchBuilder): Switch
     connManager = connManager,
     ms = ms,
     nameResolver = b.nameResolver,
+    concurrentUpgrades = b.maxConcurrentUpgrades,
     peerStore = peerStore)
 
   if b.isCircuitRelay:

libp2p/switch.nim

@@ -71,6 +71,7 @@ type
       peerStore*: PeerStore
       nameResolver*: NameResolver
       started: bool
+      concurrentUpgrades: int
 
 proc addConnEventHandler*(s: Switch,
                           handler: ConnEventHandler,
@@ -327,7 +328,8 @@ proc newSwitch*(peerInfo: PeerInfo,
                 connManager: ConnManager,
                 ms: MultistreamSelect,
                 nameResolver: NameResolver = nil,
-                peerStore = PeerStore.new()): Switch
+                peerStore = PeerStore.new(),
+                concurrentUpgrades = ConcurrentUpgrades): Switch
                 {.raises: [Defect, LPError], public.} =
   if secureManagers.len == 0:
     raise newException(LPError, "Provide at least one secure manager")
@@ -339,7 +341,8 @@ proc newSwitch*(peerInfo: PeerInfo,
     connManager: connManager,
     peerStore: peerStore,
     dialer: Dialer.new(peerInfo.peerId, connManager, transports, ms, nameResolver),
-    nameResolver: nameResolver)
+    nameResolver: nameResolver,
+    concurrentUpgrades: ConcurrentUpgrades)
 
   switch.connManager.peerStore = peerStore
   switch.mount(identity)