简单Elixir游戏服设计-玩家进程注册

上回说用Registry 做本地注册（跨服可以用syn，只是稍微麻烦点，需要模拟global注册机制，写个封装模块）。

修改game_server 项目的mix.exs, 增加应用启动

  def application do
    [
      extra_applications: [:logger],
      mod: {GameServer, []}
    ]
  end

修改game_server.ex 实现，如下应用的监控树监管PlayerRegistry进程和PlayerSupervisor。这里可以考虑 :one_for_rest 选项，因为PlayerRegistry 挂了， 恐怕系统都玩不下去。

defmodule GameServer do
  use Application
  def start(_type, _args) do
    children = [
      {Registry, keys: :unique, name: PlayerRegistry},
      PlayerSupervisor
    ]
    Supervisor.start_link(children, strategy: :one_for_one)
  end
end

修改player_server.ex

defmodule PlayerServer do
    use GenServer, restart: :temporary, start: {__MODULE__, :start_link, []}

    def start_link(player) do
        GenServer.start_link(__MODULE__, player, name: register_name(player))
      end

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

    def register_name(%{} = player), do: register_name(player |> Player.get_id)
    def register_name(id), do: {:via, Registry, {PlayerRegistry, id}}
end

修改测试

defmodule PlayerSupervisorTest do
    use ExUnit.Case
    doctest PlayerSupervisor

    setup do
        Application.stop(GameServer)
        Application.start(GameServer)
        %{}
    end

    test "测试PlayerSupervisor启动PlayerServer" do
        assert {:ok, p1} = PlayerSupervisor.start_player(Player.init |> Player.set_id(1))
        assert {:ok, p2} = PlayerSupervisor.start_player(Player.init |> Player.set_id(2))
        assert [{^p1, nil}] = Registry.lookup(PlayerRegistry, 1)
        assert [{^p2, nil}] = Registry.lookup(PlayerRegistry, 2)
    end

end