クエリ数をログに出力するSinatra Extension

query_reporter.rb

require 'sinatra/base'

# app.rb で register Sinatra::QueryReporter
module Sinatra
  module QueryReporter
    def self.registered(app)
      query_count = 0
      subscriber = ''

      app.before do
        query_count = 0
        subscriber = ActiveSupport::Notifications.subscribe('sql.active_record') do |*args|
          query_count += 1
        end
      end

      app.after do
        logger.debug, "QueryReporter: #{query_count}"
        ActiveSupport::Notifications.unsubscribe(subscriber)
      end
    end
  end
end