Add support of TCP_NODELAY option for TCP transport.

Bump version to 2.1.0.

asyncdispatch2.nimble

@@ -1,5 +1,5 @@
 packageName   = "asyncdispatch2"
-version       = "2.0.9"
+version       = "2.1.0"
 author        = "Status Research & Development GmbH"
 description   = "Asyncdispatch2"
 license       = "Apache License 2.0 or MIT"

asyncdispatch2/handles.nim

@@ -13,10 +13,14 @@ when defined(windows):
   import winlean
   const
     asyncInvalidSocket* = AsyncFD(-1)
+    TCP_NODELAY* = 1
+    IPPROTO_TCP* = 6
 else:
   import posix
   const
     asyncInvalidSocket* = AsyncFD(posix.INVALID_SOCKET)
+    TCP_NODELAY* = 1
+    IPPROTO_TCP* = 6
 
 proc setSocketBlocking*(s: SocketHandle, blocking: bool): bool =
   ## Sets blocking mode on socket.

asyncdispatch2/transports/common.nim

@@ -25,7 +25,7 @@ const
 type
   ServerFlags* = enum
     ## Server's flags
-    ReuseAddr, ReusePort, NoAutoRead, GCUserData
+    ReuseAddr, ReusePort, TcpNoDelay, NoAutoRead, GCUserData
 
   TransportAddress* = object
     ## Transport network address

asyncdispatch2/transports/stream.nim

@@ -853,6 +853,14 @@ proc createStreamServer*(host: TransportAddress,
         serverSocket.closeSocket()
       raiseTransportOsError(err)
 
+  if ServerFlags.TcpNoDelay in flags:
+    if not setSockOpt(serverSocket, handles.IPPROTO_TCP,
+                      handles.TCP_NODELAY, 1):
+      let err = osLastError()
+      if sock == asyncInvalidSocket:
+        serverSocket.closeSocket()
+      raiseTransportOsError(err)
+
   toSockAddr(host.address, host.port, saddr, slen)
   if bindAddr(SocketHandle(serverSocket), cast[ptr SockAddr](addr saddr),
               slen) != 0: