initial commit

README.md

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+# Pocket
+
+#### An Experimental In Memory Key Value written in Elixir built on top of GenServer and TCP protocol
+
+# Note !!!
+#### this project is only for the purpose of having fun with Elixir's GenServer and Elixir's Map :stuck_out_tongue_winking_eye:
+
+## Installation
+
+the package can be installed
+by adding `pocket` to your list of dependencies in `mix.exs`:
+
+```elixir
+def deps do
+  [
+    {:pocket, "~> 0.1.0", github: "Bhinneka/pocket"}
+  ]
+end
+```
+
+## Usage
+Run iex
+```shell
+$ iex
+iex(1)> Pocket.start([], [])
+```
+
+Open new terminal
+```
+$ telnet 127.0.0.1 9000
+Trying 127.0.0.1...
+Connected to localhost.
+Escape character is '^]'.
+```
+
+Add new value
+```shell
+SET a andi
+OK
+GET a
+andi
+```
+
+
+#### Author
+Wuriyanto github.com/wuriyanto48
+
+##
+
+### Bhinneka.com 2018

config/config.exs

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+# 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
+# 3rd-party users, it should be done in your "mix.exs" file.
+
+# You can configure your application as:
+#
+#     config :pocket, key: :value
+#
+# and access this configuration in your application as:
+#
+#     Application.get_env(:pocket, :key)
+#
+# You can also configure a 3rd-party app:
+#
+#     config :logger, level: :info
+#
+
+# 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/application.ex

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+defmodule Pocket do
+  @moduledoc false
+
+  use Application
+
+  def start(_type, _args) do
+    import Supervisor.Spec, warn: false
+
+    # list options
+    options = [
+      ip: Application.get_env(:extcp, :ip, {127,0,0,1}),
+      port: Application.get_env(:extcp, :port, 9000)
+    ]
+    # List all child processes to be supervised
+    children = [
+      # Starts a worker by calling: Pocket.Worker.start_link(arg)
+      {Pocket.Server, options},
+    ]
+
+    opts = [strategy: :one_for_one, name: Pocket.Supervisor]
+    Supervisor.start_link(children, opts)
+  end
+end

lib/pocket/server.ex

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+defmodule Pocket.Server do
+  @moduledoc """
+  Documentation for Pocket.
+  """
+  use GenServer
+
+  def start_link(options) do
+    GenServer.start_link(__MODULE__, options, [])
+  end
+
+  def init(options) do
+    {:ok, listen_socket} = :gen_tcp.listen(options[:port], [:binary, {:packet, 0}, {:active, true}, {:ip, options[:ip]}])
+    {:ok, _client} = :gen_tcp.accept(listen_socket)
+
+    #initial state with empty Map
+    db = %{}
+
+    {:ok, db}
+  end
+
+  def handle_info({:tcp, client, packet}, db) do
+    IO.inspect db, label: "Incoming packet"
+
+    case handle_input(packet, db) do
+      {:ok, new_db, res} -> :gen_tcp.send(client, "#{res}\n")
+        {:noreply, new_db}
+      {:error, err} -> :gen_tcp.send(client, "Error #{err}")
+        {:noreply, db}
+    end
+
+    # command = String.split(packet) |> Enum.at(0)
+    #   if command === "SET" || command === "GET" do
+    #     if command === "SET" do
+    #       key = String.split(packet) |> Enum.at(1)
+    #       value = String.split(packet) |> Enum.at(2)
+    #       new_db = Map.put_new(db, key, value)
+    #       :gen_tcp.send(client, "OK\n")
+    #       {:noreply, new_db}
+    #     else
+    #       key = String.split(packet) |> Enum.at(1)
+    #       v = Map.get(db, key)
+    #       :gen_tcp.send(client, "#{v}\n")
+    #       {:noreply, db}
+    #     end
+    #   end
+  end
+
+  def handle_info({:tcp_closed, _socket}, db) do
+    IO.inspect "socket closed"
+    {:noreply, db}
+  end
+
+  def handle_info({:tcp_error, socket, reason}, db) do
+    IO.inspect socket, label: "connection error #{reason}"
+    {:noreply, db}
+  end
+
+  defp handle_input(packet, db) when is_binary(packet) do
+      command = String.split(packet) |> Enum.at(0)
+      if command === "SET" || command === "GET" do
+        if command === "SET" do
+          key = String.split(packet) |> Enum.at(1)
+          value = String.split(packet) |> Enum.at(2)
+          new_db = Map.put_new(db, key, value)
+          {:ok, new_db, "OK"}
+        else
+          key = String.split(packet) |> Enum.at(1)
+          v = Map.get(db, key)
+          {:ok, db, v}
+        end
+      end
+  end
+
+  defp handle_input(_, _) do
+    {:error, "invalid command"}
+  end
+end

mix.exs

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+defmodule Pocket.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :pocket,
+      version: "0.1.0",
+      elixir: "~> 1.6",
+      start_permanent: Mix.env() == :prod,
+      deps: deps()
+    ]
+  end
+
+  # Run "mix help compile.app" to learn about applications.
+  def application do
+    [
+      extra_applications: [:logger]
+    ]
+  end
+
+  # Run "mix help deps" to learn about dependencies.
+  defp deps do
+    [
+      # {:dep_from_hexpm, "~> 0.3.0"},
+      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"},
+    ]
+  end
+end

test/pocket_test.exs

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+defmodule PocketTest do
+  use ExUnit.Case
+  doctest Pocket
+
+  test "greets the world" do
+    assert Pocket.hello() == :world
+  end
+end

test/test_helper.exs

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+ExUnit.start()