Module: ActionView::Helpers::BenchmarkHelper

Included in:
ActionView::Helpers
Defined in:
lib/action_view/helpers/benchmark_helper.rb

Overview

This helper offers a method to measure the execution time of a block in a template.

Instance Method Summary collapse

Instance Method Details

#benchmark(message = "Benchmarking", options = {}) ⇒ Object

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 %>


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# File 'lib/action_view/helpers/benchmark_helper.rb', line 34

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