Add SerialNumber

lib/futu/component/api.ex

@@ -16,24 +16,13 @@ defmodule Futu.Component.Api do
 
       @before_compile unquote(__MODULE__)
 
-      @mapper_module Application.compile_env(:futu, :mapper_module, nil)
-
       @spec map_c2s(any()) :: list()
       def map_c2s(opts \\ [])
       def map_c2s(opts), do: opts
 
       @spec map_s2c(any()) :: any()
       def map_s2c(opts), do: opts
 
-      defp post_process_s2c(s2c, opts) do
-        mapped_s2c = map_s2c(s2c)
-
-        case @mapper_module do
-          nil -> mapped_s2c
-          _ -> apply(@mapper_module, :map, [mapped_s2c, opts])
-        end
-      end
-
       defoverridable map_c2s: 1,
                      map_s2c: 1
     end
@@ -81,7 +70,7 @@ defmodule Futu.Component.Api do
 
         case response do
           %{retType: 0, s2c: s2c} ->
-            {:ok, post_process_s2c(s2c, opts)}
+            {:ok, map_s2c(s2c)}
 
           %{retType: _ret_type, retMsg: ret_msg, errCode: _err_code} ->
             {:error, ret_msg}

lib/futu/gen_server/serial_number.ex

@@ -0,0 +1,26 @@
+defmodule Futu.GenServer.SerialNumber do
+  @moduledoc """
+  Generate incremental numbers
+  """
+  use GenServer
+
+  @spec start_link(list()) :: {:ok, pid()}
+  def start_link(_opts) do
+    GenServer.start_link(__MODULE__, nil)
+  end
+
+  @spec init(nil) :: {:ok, map()}
+  def init(nil) do
+    {:ok, %{sn: os_time()}}
+  end
+
+  def handle_call(:generate, _from, %{sn: sn} = state) do
+    {:reply, sn + 1, %{state | sn: sn + 1}}
+  end
+
+  def handle_call(:get_current_state, _from, %{sn: sn} = state) do
+    {:reply, sn, state}
+  end
+
+  defp os_time(), do: :os.system_time(:millisecond)
+end

test/futu/genserver/serial_number_test.ex

@@ -0,0 +1,20 @@
+defmodule Futu.GenServer.SerialNumberTest do
+  use ExUnit.Case
+  alias Futu.GenServer.SerialNumber
+
+  setup_all do
+    {:ok, pid} = SerialNumber.start_link([])
+    {:ok, pid: pid}
+  end
+
+  describe "generate" do
+    test "increments", %{pid: pid} do
+      sn_1 = GenServer.call(pid, :generate)
+      sn_2 = GenServer.call(pid, :generate)
+      sn_3 = GenServer.call(pid, :generate)
+
+      assert sn_3 > sn_2
+      assert sn_2 > sn_1
+    end
+  end
+end