How do I measure the execution time of JavaScript code with callbacks?

Question

I have a piece of JavaScript code that I am executing using the node.js interpreter.

for(var i = 1; i < LIMIT; i++) {   var user = {     id: i,     name: "MongoUser [" + i + "]"   };   db.users.save(user, function(err, saved) {     if(err || !saved) {       console.log("Error");     } else {       console.log("Saved");     }   }); } 

How can I measure the time taken by these database insert operations? I could compute the difference of date values after and before this piece of code but that would be incorrect because of the asynchronous nature of the code.

Answer 1

Use the Node.js console.time() and console.timeEnd():

var i; console.time("dbsave");  for(i = 1; i < LIMIT; i++){     db.users.save({id : i, name : "MongoUser [" + i + "]"}, end); }  end = function(err, saved) {     console.log(( err || !saved )?"Error":"Saved");     if(--i === 1){console.timeEnd("dbsave");} };