Elixir：从Elixir任务访问ETS时参数错误

我目前正试图在Elixir中构建一个Redis克隆。作为这项工作的一部分，我使用一个任务来处理get/set请求，并使用ETS来存储键和值

** (ArgumentError) argument error
    (stdlib 3.13.2) :ets.insert(:kv, {"doomspork", "Sean", ["Elixir", "Ruby", "Java"]})

以下是我对相关代码部分采取的步骤：

我创建了一个公共ETS表

根据我尝试插入和读取ETS表中的

不幸的是，这给了我这里描述的错误：

---

您正在尝试在创建ETS之前访问它

init/1

回调在进程启动后在进程内调用，但第一次访问尝试发生在

start

运行的任务中，这可能发生在更早的时候。在您的例子中，这是一个，它根本没有

init/1

回调

只需将

：ets.new（：kv，[：set，：public，：named_table]）

移动到

开始/2

即可

 def init(_) do
    :ets.new(:kv, [:set, :public, :named_table])
  end

 :ets.insert(:kv, {"doomspork", "Sean", ["Elixir", "Ruby", "Java"]})
    IO.inspect(:ets.lookup(:kv, "doomspork"))

[error] Task #PID<0.159.0> started from #PID<0.156.0> terminating
** (ArgumentError) argument error
    (stdlib 3.13.2) :ets.insert(:kv, {"doomspork", "Sean", ["Elixir", "Ruby", "Java"]})
    (redis 1.0.0) lib/server.ex:61: Server.write_line/2
    (redis 1.0.0) lib/server.ex:41: Server.serve/1
    (elixir 1.11.0) lib/task/supervised.ex:90: Task.Supervised.invoke_mfa/2
    (stdlib 3.13.2) proc_lib.erl:226: :proc_lib.init_p_do_apply/3
Function: #Function<0.28410304/0 in Server.loop_acceptor/1>
    Args: []

defmodule Server do
  @moduledoc """
  Your implementation of a Redis server
  """
  use Application
  require Logger

  def start(_type, _args) do
    Supervisor.start_link(
      [{Task.Supervisor, name: Server.TaskSupervisor}, {Task, fn -> Server.listen() end}],
      strategy: :one_for_one
    )
  end

  def init(_) do
    :ets.new(:kv, [:set, :public, :named_table])
  end

  @doc """
  Listen for incoming connections
  """
  def listen() do
    {:ok, socket} = :gen_tcp.listen(6379, [:binary, active: false, reuseaddr: true])
    Logger.info("Accepting connections on 6379")
    loop_acceptor(socket)
  end

  defp loop_acceptor(socket) do
    {:ok, client} = :gen_tcp.accept(socket)
    {:ok, pid} = Task.Supervisor.start_child(Server.TaskSupervisor, fn -> serve(client) end)
    :ok = :gen_tcp.controlling_process(client, pid)
    loop_acceptor(socket)
  end

  defp serve(client) do
    client
    |> read_line()
    |> write_line(client)

    serve(client)
  end

  defp read_line(socket) do
    {:ok, data} = :gen_tcp.recv(socket, 0)
    data
  end

  defp echo(socket, command_arr) do
    echo_statement = Enum.at(command_arr, -2)
    IO.inspect(echo_statement)
    :gen_tcp.send(socket, "+#{echo_statement}\r\n")
  end
  defp write_line(line, socket) do
    command_arr = String.split(line, "\\r\\n")
    command = Enum.at(command_arr, 2) |>String.downcase
    IO.inspect(command_arr)
    IO.inspect(command)
    :ets.insert(:kv, {"doomspork", "Sean", ["Elixir", "Ruby", "Java"]})
    IO.inspect(:ets.lookup(:kv, "doomspork"))
    case command do
      "ping" -> :gen_tcp.send(socket, "+PONG\r\n")
      "set"-> :ets.insert(:kv, {"samplekey", "sampleresp"})
      "get"-> :ets.lookup(:kv, "samplekey")
      "echo"-> echo(socket,command_arr)
      _ -> :gen_tcp.send(socket, "Nah")
    end
  end
end