+require 'benchmark'
+
+module ActionView
+ module Helpers
+ # This helper offers a method to measure the execution time of a block
+ # in a template.
+ module BenchmarkHelper
+ # 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 as the :level option.
+ # (:debug, :info, :warn, :error); the default 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
+ # inside the block. This is great for boiling down a noisy block to just a single statement:
+ #
+ # <% benchmark "Process data files", :level => :info, :silence => true do %>
+ # <%= expensive_and_chatty_files_operation %>
+ # <% end %>
+ def benchmark(message = "Benchmarking", options = {})
+ if controller.logger
+ if options.is_a?(Symbol)
+ ActiveSupport::Deprecation.warn("use benchmark('#{message}', :level => :#{options}) instead", caller)
+ options = { :level => options, :silence => false }
+ else
+ options.assert_valid_keys(:level, :silence)
+ options[:level] ||= :info
+ end
+
+ result = nil
+ ms = Benchmark.ms { result = options[:silence] ? controller.logger.silence { yield } : yield }
+ controller.logger.send(options[:level], '%s (%.1fms)' % [ message, ms ])
+ result
+ else
+ yield
+ end
+ end
+ end
+ end
+end