memory_bloat.rb

module Rack
  class MemoryBloat
    def initialize(app, logger)
      @app = app
      @logger = logger
    end

    def call(env)
      memory_usage_before = memory_usage
      result = @app.call(env)
      memory_usage_after = memory_usage
      @logger.info "MemoryBloat: #{memory_usage_after - memory_usage_before} URL: #{Rack::Request.new(env).url}"
      result
    end

    private
    def memory_usage
      `ps -o rss= -p #{$$}`.to_i
    end
  end
end