lib: refactor to use mapping in cluster master

Cluster master message handler is basically doing the same thing for different message actions which can be avoided. Thus move to method mapping object and doing a single lookup to find the function to execute and it doesnot exists, skip the execution chain. PR-URL: #36250 Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: James M Snell <[email protected]>

Author: yashLadha

lib/internal/cluster/master.js

@@ -248,19 +248,21 @@ cluster.disconnect = function(cb){
 intercom.once('disconnect',cb);
 };
 
+constmethodMessageMapping={
+ close,
+ exitedAfterDisconnect,
+ listening,
+ online,
+ queryServer,
+};
+
 functiononmessage(message,handle){
 constworker=this;
 
-if(message.act==='online')
-online(worker);
-elseif(message.act==='queryServer')
-queryServer(worker,message);
-elseif(message.act==='listening')
-listening(worker,message);
-elseif(message.act==='exitedAfterDisconnect')
-exitedAfterDisconnect(worker,message);
-elseif(message.act==='close')
-close(worker,message);
+constfn=methodMessageMapping[message.act];
+
+if(typeoffn==='function')
+fn(worker,message);
 }
 
 functiononline(worker){