Timing Grape API

timing_grape_api.rb

require 'grape'
require 'logger'
require 'json'

class MyApi < Grape::API
  version 'v1', :using => :path
  format :json

  desc "Returns first / last name"
  get '/:first/:last' do
    env['controller_time'] = Time.now
    { first_name: params[:first], last_name: params[:last] }
  end
end

class Timing
  def initialize(app)
    @app = app
  end
  def call(env)
    pre = Time.now
    status, headers, body = @app.call(env)
    if env['controller_time']
      controller            = env['controller_time']
      post                  = Time.now
      into                  = (controller - pre).round(2)
      outof                 = (post - controller).round(2)
      headers['X-Timing']   = "into=#{into.to_s.inspect}s; outof=#{outof.to_s.inspect}s"
    end
    return status, headers, body
  end
end

app = Rack::Builder.new do
  use Timing
  run MyApi
end

status, headers, body = app.call(
  "REQUEST_METHOD" => "GET",
  "PATH_INFO"      => "/v1/nia/mejia",
  "rack.input"     => StringIO.new,
)
status                                   # => 200
JSON.parse body.to_enum(:each).to_a.join # => {"first_name"=>"nia", "last_name"=>"mejia"}
headers['X-Timing']                      # => "into=\"0.05\"s; outof=\"0.01\"s"