Rails has benchmark helper to quickly test the time of execution of a given piece of code. Active Record, Action Controller and Action View libraries provides a benchmark() method to measure the performance of code.

Example: Model(Active Record):

User.benchmark("Creating user") do
  user = user.create("name" => "Jony")
  user.create_stories("content" => "Test")
end

While execution of the above piece of code something like this Creating user (100.3ms) can be seen in the log file.Here benchmark() is a class method of the model User.

Controller(Action Controller):

def process_stories
  self.class.benchmark("Processing stories") do
    @stories = current_user.stories
    Story.cache_story_feeds(@stories, "myfeed-#{current_user.id}")
  end
end

Views(Action View):

    <% benchmark Show story feeds' do %>
          <%= show_story_feeds %>
    <% end %>

In the log file output will be Show story feeds (191.5ms).

This benchmark() method accepts logger level(:debug, :info, :warn, :error) as optional parameter. Default is :info. Thus we can modify the above code as:

<% benchmark Show story feeds' , level: :debug do %>
          <%= show_story_feeds %>
    <% end %>

If we pass silence: true as the third argument all logging activity except the time information for the block will be silenced.