Initial commit.

README.md

@@ -0,0 +1,26 @@
+# Quantum
+
+[Cron](https://en.wikipedia.org/wiki/Cron)-like job scheduler for [Elixir](http://elixir-lang.org/) applications.
+
+## Setup
+
+To use this plug in your projects, edit your mix.exs file and add the project as a dependency:
+
+```elixir
+defp deps do
+  [
+    { :quantum, ">= 1.0.0" }
+  ]
+end
+```
+
+## Usage
+
+```elixir
+Quantum.cron("0 18-6/2 * * *", fn -> IO.puts("it's late") end)
+Quantum.cron("@daily", &backup/0)
+```
+
+## License
+
+[Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0)

config/config.exs

@@ -0,0 +1,24 @@
+# This file is responsible for configuring your application
+# and its dependencies with the aid of the Mix.Config module.
+use Mix.Config
+
+# This configuration is loaded before any dependency and is restricted
+# to this project. If another project depends on this project, this
+# file won't be loaded nor affect the parent project. For this reason,
+# if you want to provide default values for your application for third-
+# party users, it should be done in your mix.exs file.
+
+# Sample configuration:
+#
+#     config :logger, :console,
+#       level: :info,
+#       format: "$date $time [$level] $metadata$message\n",
+#       metadata: [:user_id]
+
+# It is also possible to import configuration files, relative to this
+# directory. For example, you can emulate configuration per environment
+# by uncommenting the line below and defining dev.exs, test.exs and such.
+# Configuration from the imported file will override the ones defined
+# here (which is why it is important to import them last).
+#
+#     import_config "#{Mix.env}.exs"

lib/quantum.ex

@@ -0,0 +1,109 @@
+defmodule Quantum do
+  use GenServer
+  import Process, only: [send_after: 3]
+
+  @days   ["sun", "mon", "tue", "wed", "thu", "fri", "sat"]
+  @months ["jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"]  
+
+  def start_link(options \\ []) do
+    GenServer.start_link(__MODULE__, %{}, [name: __MODULE__] ++ options)
+  end
+
+  # Public functions ------------------------------------------------------------------------------
+
+  def cron("@yearly",  fun),  do: GenServer.cast(__MODULE__, {"0 0 1 1 *", fun})
+  def cron("@monthly", fun),  do: GenServer.cast(__MODULE__, {"0 0 1 * *", fun})
+  def cron("@weekly",  fun),  do: GenServer.cast(__MODULE__, {"0 0 * * 0", fun})
+  def cron("@daily",   fun),  do: GenServer.cast(__MODULE__, {"0 0 * * *", fun})
+  def cron("@hourly",  fun),  do: GenServer.cast(__MODULE__, {"0 * * * *", fun})
+  def cron(expression, fun),  do: GenServer.cast(__MODULE__, {expression,  fun})
+  def reset,                  do: GenServer.cast(__MODULE__, :reset)
+
+  # Private functions -----------------------------------------------------------------------------
+
+  def init(_) do
+    send_after(self, :tick, 1000)
+    {:ok, %{jobs: [], d: nil, h: nil, m: nil, w: nil}}
+  end
+
+  def handle_info(:tick, state) do
+    send_after(self, :tick, 1000)
+    {d, {h, m, _}} = :calendar.now_to_universal_time(:os.timestamp)
+    if state.d != d do
+      state = %{state | w: rem(:calendar.day_of_the_week(d), 7)}
+    end
+    if state.m != m do
+      state = %{state | d: d, h: h, m: m}
+      Enum.each(state.jobs, fn({e, fun}) -> Task.start(__MODULE__, :execute, [e, fun, state]) end)
+    end
+    {:noreply, state}
+  end
+  def handle_info(_, state), do: {:noreply, state}
+
+  def handle_cast(:reset, state) do
+    {:noreply, %{state | jobs: []}}
+  end
+  def handle_cast({ e, fun }, state) do
+    {:noreply, %{state | jobs: ["#{e |> String.downcase |> translate}": fun] ++ state.jobs}}
+  end
+
+  def execute("* * * * *", fun, _), do: fun.()
+  def execute("0 * * * *", fun, %{m: 0}), do: fun.()
+  def execute("0 0 * * *", fun, %{m: 0, h: 0}), do: fun.()
+  def execute("0 0 1 * *", fun, %{m: 0, h: 0, d: {_, _, 1}}), do: fun.()
+  def execute("0 0 1 1 *", fun, %{m: 0, h: 0, d: {_, 1, 1}}), do: fun.()
+  def execute(e, fun, state) do
+    [m, h, d, n, w] = e |> String.split(" ")
+    {_, cur_mon, cur_day} = state.d
+    cond do
+      !match(m, state.m, 0, 59) -> false
+      !match(h, state.h, 0, 59) -> false
+      !match(d, cur_day, 1, 31) -> false
+      !match(n, cur_mon, 1, 12) -> false
+      !match(w, state.w, 0,  6) -> false
+      true                      -> fun.()
+    end
+  end
+
+  defp translate(e) do
+    {e,_} = List.foldl(@days,   {e,0}, fn(x, acc) -> translate(acc, x) end)
+    {e,_} = List.foldl(@months, {e,1}, fn(x, acc) -> translate(acc, x) end)
+    e
+  end
+  defp translate({e, i}, term), do: {String.replace(e, term, "#{i}"), i+1}
+
+  defp match("*", _, _, _), do: true
+  defp match([], _, _, _), do: false
+  defp match([e|t], v, min, max), do: Enum.any?(parse(e, min, max), &(&1 == v)) or match(t, v, min, max)
+  defp match(e, v, min, max), do: match(e |> String.split(","), v, min, max)
+
+  defp parse("*/" <> _ = e, min, max) do
+    [_,i] = e |> String.split("/")
+    {x,_} = i |> Integer.parse
+    Enum.reject(min..max, &(rem(&1, x) != 0))
+  end
+  defp parse(e, min, max) do
+    [r|i] = e |> String.split("/")
+    [x|y] = r |> String.split("-")
+    {v,_} = x |> Integer.parse
+    parse(v, y, i, min, max) |> Enum.reject(&((&1 < min) or (&1 > max)))
+  end
+  defp parse(v, [], [], _, _), do: [v]
+  defp parse(v, [], i, _, _) do
+    {x,_} = i |> Integer.parse
+    [rem(v,i)]
+  end
+  defp parse(v, y, [], min, max) do
+    {t,_} = y |> Integer.parse
+    if v < t do
+      Enum.to_list(v..t)
+    else
+      Enum.to_list(v..max) ++ Enum.to_list(min..t)
+    end
+  end
+  defp parse(v, y, i, min, max) do
+    {x, _} = i |> Integer.parse
+    parse(v, y, [], min, max) |> Enum.reject(&(rem(&1, x) != 0))
+  end
+
+end

mix.exs

@@ -0,0 +1,45 @@
+defmodule Quantum.Mixfile do
+  use Mix.Project
+
+  def project do
+    [
+      app: :quantum,
+      version: "1.0.0",
+      elixir: "~> 1.0",
+      build_embedded: Mix.env == :prod,
+      start_permanent: Mix.env == :prod,
+      deps: deps,
+      description: "Cronjob scheduler for Elixir applications.",
+      package: package
+    ]
+  end
+
+  # Configuration for the OTP application
+  #
+  # Type `mix help compile.app` for more information
+  def application do
+    [applications: [:logger]]
+  end
+
+  # Dependencies can be Hex packages:
+  #
+  #   {:mydep, "~> 0.3.0"}
+  #
+  # Or git/path repositories:
+  #
+  #   {:mydep, git: "https://github.com/elixir-lang/mydep.git", tag: "0.1.0"}
+  #
+  # Type `mix help deps` for more examples and options
+  defp deps do
+    []
+  end
+
+  defp package do
+    %{
+      contributors: ["Constantin Rack"],
+      licenses: ["Apache License 2.0"],
+      links: %{"Github" => "https://github.com/c-rack/quantum-elixir"}
+    }
+  end
+
+end

test/quantum_test.exs

@@ -0,0 +1,20 @@
+defmodule QuantumTest do
+  use ExUnit.Case
+
+  test "check hourly" do
+    Quantum.execute("0 * * * *", fn -> IO.puts("OK") end, %{ d: { 2015, 12, 31 }, h: 12, m: 0, w: 1 } )
+  end
+
+  test "parse */5" do
+    Quantum.execute("*/5 * * * *", fn -> IO.puts("OK") end, %{ d: { 2015, 12, 31 }, h: 12, m: 0, w: 1 } )
+  end
+
+  test "parse 5" do
+    Quantum.execute("5 * * * *", fn -> IO.puts("OK") end, %{ d: { 2015, 12, 31 }, h: 12, m: 5, w: 1 } )
+  end
+
+  test "counter example" do
+    Quantum.execute("5 * * * *", fn -> IO.puts("FAIL") end, %{ d: { 2015, 12, 31 }, h: 12, m: 0, w: 1 } )
+  end
+
+end

test/test_helper.exs

@@ -0,0 +1 @@
+ExUnit.start()