CallgrindProfiler

callgrind_profiler.rb

require 'jruby/profiler'
require 'jruby/profiler/callgrind_printer'

module CallgrindProfiler
  def callgrind
    unless JRuby.runtime.instance_config.is_profiling?
      STDERR.puts 'Profiling not enabled, re-run with `ruby --profile.api`'
      return
    end

    return_value = nil

    profile = JRuby::Profiler.profile do
      return_value = yield
    end

    File.open("callgrind.out-#{Time.now.to_i}", 'w') do |file|
      printer = JRuby::Profiler::CallgrindPrinter.new(profile)

      printer.printHeader(file)
      printer.printProfile(file)
      printer.printFooter(file)
    end

    return_value
  end
end