Methods
B
Instance Public methods
benchmark(message = "Benchmarking", options = {})

Allows you to measure the execution time of a block in a template and records the result to the log. Wrap this block around expensive operations or possible bottlenecks to get a time reading for the operation. For example, let's say you thought your file processing method was taking too long; you could wrap it in a benchmark block.

<% benchmark 'Process data files' do %>
  <%= expensive_files_operation %>
<% end %>

That would add something like “Process data files (345.2ms)” to the log, which you can then use to compare timings when optimizing your code.

You may give an optional logger level (:debug, :info, :warn, :error) as the :level option. The default logger level value is :info.

<% benchmark 'Low-level files', level: :debug do %>
  <%= lowlevel_files_operation %>
<% end %>

Finally, you can pass true as the third argument to silence all log activity (other than the timing information) from inside the block. This is great for boiling down a noisy block to just a single statement that produces one log line:

<% benchmark 'Process data files', level: :info, silence: true do %>
  <%= expensive_and_chatty_files_operation %>
<% end %>

Source: show | on GitHub 

# File activesupport/lib/active_support/benchmarkable.rb, line 37
def benchmark(message = "Benchmarking", options = {})
  if logger
    options.assert_valid_keys(:level, :silence)
    options[:level] ||= :info

    result = nil
    ms = Benchmark.ms { result = options[:silence] ? logger.silence { yield } : yield }
    logger.send(options[:level], "%s (%.1fms)" % [ message, ms ])
    result
  else
    yield
  end
end