ex_stats_agg

"""
MIT License

Copyright (c) 2017 Steven Wagner

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
"""

defmodule Ciroque.Monitoring.StatsAgg do
  @moduledoc """
  Documentation for StatsAgg.


  %{
    group: String.t,
    module: String.t,
    function: String.t,
    most_recent_duration: integer,
    max_duration: integer,
    min_duration: integer,
    avg_duration: integer,
    duration_history: list(integer)
  }

  """

  alias Ciroque.Monitoring.Reducers

  require Logger

  use GenServer

  ## Public Interface

  @type record_function_duration_args_t ::
          %{group: String.t, module: String.t, function: String.t, duration: integer}
          | %{group: String.t, module: String.t, function: String.t, started_at: integer, ended_at: integer}

  def record_function_duration(record_function_duration_args_t = args) do
    GenServer.cast(:ex_stats_agg, {:record_function_duration, args})
  end

  def retrieve_stats(query) when is_list(query) do
    GenServer.call(:ex_stats_agg, {:retrieve_stats, query})
  end

  ## GenServer

  def handle_call({:retrieve_stats, keys}, _from, state) when is_list(keys) do
    case Reducers.retrieve_stats(state, keys) do
      [] -> {:reply, :notfound, state}
      function_stats -> {:reply, function_stats, state}
    end
  end

  def handle_cast({:record_function_duration, record_function_duration_args_t = args}, state) do
    {:noreply, Reducers.put_duration(state, args)}
  end

  def init(state) do
    {:ok, state}
  end

  def start_link() do
    start_link(%{})
  end

  def start_link(state) do
    GenServer.start_link(__MODULE__, state, name: :ex_stats_agg)
  end
end