add perf

README.md

@@ -689,3 +689,22 @@ func handler(w http.ResponseWriter, r *http.Request, ctn di.Container) {
 # Performance
 
 TODO:
+
+Retrieving an object from a container will always be slower than directly using a variable. That being said, DI tries to minimize the cost of using containers.
+
+## Get parameter
+
+The `Get` method accepts different types as parameter. If possible you should use a `di.Def`...
+
+## Shared objects
+
+- First call, need to create the object. Slower. Need to lock the container to store the object.
+- Next calls are very fast.
+
+## Unshared object
+
+- Fast if no close function (close function requires to store the object in the container, lock the container)
+
+## deep nesting
+
+