gistfile1.ex

defmodule Plug.Stats do
  import Plug.Conn

  def init(options) do
    options
  end

  def call(conn, _opts) do
    before_time = :os.timestamp()
    
    Plug.Conn.register_before_send(conn, fn conn -> 

      url = Enum.join(conn.path_info, "/")
      after_time = :os.timestamp()
      diff = :timer.now_diff(after_time, before_time) / 1000
      GenServer.cast(:stats_collector, {:insert, "latency", [value: diff, url: url]})
      GenServer.cast(:stats_collector, {:insert, conn.method, [value: 1, url: url]})

      conn
    end)
    conn


  end
end