Elixir agent for active tracking execution time

time_agent.ex

defmodule TimeAgent do

  def start_link do
    Agent.start_link( fn -> { Map.new, Map.new } end, name: __MODULE__ )
  end
  
  def time_run( m, f, a ) do
    { us, result } = :timer.tc( m, f, a )
    Agent.cast( __MODULE__, __MODULE__, :add_sample, [ to_string(m) <> "." <> to_string(f), us ] )
    result
  end

  def time_run( name, fun ) do
    { us, result } = :timer.tc( fun )
    Agent.cast( __MODULE__, __MODULE__, :add_sample, [ name, us ] )
    result
  end

  def add_sample( { times, counts }, name, us ) do
    {
      Map.update( times, name, us, fn ous -> ous + us end ),
      Map.update( counts, name, 1, fn oct -> oct + 1 end )
    }
  end
  
  def status do
    { times, counts } = Agent.get( __MODULE__, fn state -> state end )
    Enum.map( times, fn { name, time } ->
      c = Map.get( counts, name )
      aus = time / c
      [
	name: name,
	count: c,
	us: [
	  total: time,
	  avg: aus
	],
	s: [
	  total: time / 1000 / 1000,
	  avg: aus / 1000 / 1000
	]
      ]
    end)
  end

  def reset do
    Agent.update( __MODULE__, fn _ -> { Map.new, Map.new } end )
  end
end