vendor/rails/actionpack/lib/action_view/helpers/benchmark_helper.rb

   1 require 'benchmark'
   2
   3 module ActionView
   4   module Helpers
   5     # This helper offers a method to measure the execution time of a block
   6     # in a template.
   7     module BenchmarkHelper
   8       # Allows you to measure the execution time of a block
   9       # in a template and records the result to the log. Wrap this block around
  10       # expensive operations or possible bottlenecks to get a time reading
  11       # for the operation.  For example, let's say you thought your file
  12       # processing method was taking too long; you could wrap it in a benchmark block.
  13       #
  14       #  <% benchmark "Process data files" do %>
  15       #    <%= expensive_files_operation %>
  16       #  <% end %>
  17       #
  18       # That would add something like "Process data files (345.2ms)" to the log,
  19       # which you can then use to compare timings when optimizing your code.
  20       #
  21       # You may give an optional logger level as the :level option.
  22       # (:debug, :info, :warn, :error); the default value is :info.
  23       #
  24       #  <% benchmark "Low-level files", :level => :debug do %>
  25       #    <%= lowlevel_files_operation %>
  26       #  <% end %>
  27       #
  28       # Finally, you can pass true as the third argument to silence all log activity
  29       # inside the block. This is great for boiling down a noisy block to just a single statement:
  30       #
  31       #  <% benchmark "Process data files", :level => :info, :silence => true do %>
  32       #    <%= expensive_and_chatty_files_operation %>
  33       #  <% end %>
  34       def benchmark(message = "Benchmarking", options = {})
  35         if controller.logger
  36           if options.is_a?(Symbol)
  37             ActiveSupport::Deprecation.warn("use benchmark('#{message}', :level => :#{options}) instead", caller)
  38             options = { :level => options, :silence => false }
  39           else
  40             options.assert_valid_keys(:level, :silence)
  41             options[:level] ||= :info
  42           end
  43
  44           result = nil
  45           ms = Benchmark.ms { result = options[:silence] ? controller.logger.silence { yield } : yield }
  46           controller.logger.send(options[:level], '%s (%.1fms)' % [ message, ms ])
  47           result
  48         else
  49           yield
  50         end
  51       end
  52     end
  53   end
  54 end