Add EchoServer example

12 files changed, 191 insertions, 0 deletions

diff --git a/src/code/2/echo_server/.gitignore b/src/code/2/echo_server/.gitignore
new file mode 100644
index 0000000..755b605
--- /dev/null
+++ b/src/code/2/echo_server/.gitignore
@@ -0,0 +1,5 @@
+/_build
+/cover
+/deps
+erl_crash.dump
+*.ez
diff --git a/src/code/2/echo_server/README.md b/src/code/2/echo_server/README.md
new file mode 100644
index 0000000..dee7a73
--- /dev/null
+++ b/src/code/2/echo_server/README.md
@@ -0,0 +1,3 @@
+# EchoServer #
+
+Demo Echo Server
diff --git a/src/code/2/echo_server/config/config.exs b/src/code/2/echo_server/config/config.exs
new file mode 100644
index 0000000..d2d855e
--- /dev/null
+++ b/src/code/2/echo_server/config/config.exs
@@ -0,0 +1 @@
+use Mix.Config
diff --git a/src/code/2/echo_server/lib/echo_server.ex b/src/code/2/echo_server/lib/echo_server.ex
new file mode 100644
index 0000000..7716aec
--- /dev/null
+++ b/src/code/2/echo_server/lib/echo_server.ex
@@ -0,0 +1,8 @@
+defmodule EchoServer do
+  use Application
+
+  def start(_, _) do
+    EchoServer.Supervisor.start_link
+  end
+
+end
diff --git a/src/code/2/echo_server/lib/echo_server/echo.ex b/src/code/2/echo_server/lib/echo_server/echo.ex
new file mode 100644
index 0000000..3a96f29
--- /dev/null
+++ b/src/code/2/echo_server/lib/echo_server/echo.ex
@@ -0,0 +1,36 @@
+defmodule EchoServer.Echo do
+
+  def accept(port) do
+    {:ok, socket} = :gen_tcp.listen(
+      port,
+      [:binary, packet: :line, active: false, reuseaddr: true])
+    loop_acceptor(socket)
+  end
+
+  defp loop_acceptor(socket) do
+    {:ok, client} = :gen_tcp.accept(socket)
+    {:ok, pid} = Task.Supervisor.start_child(
+      EchoServer.TaskSupervisor, fn -> serve(client) end)
+    :ok = :gen_tcp.controlling_process(client, pid)
+    loop_acceptor(socket)
+  end
+
+  defp serve(socket) do
+    socket
+      |> read_line
+      |> (fn(x) -> "> " <> x end).()
+      |> write_line(socket)
+
+    serve(socket)
+  end
+
+  defp read_line(socket) do
+    {:ok, data} = :gen_tcp.recv(socket, 0)
+    data
+  end
+
+  defp write_line(line, socket) do
+    :gen_tcp.send(socket, line)
+  end
+
+end
diff --git a/src/code/2/echo_server/lib/echo_server/supervisor.ex b/src/code/2/echo_server/lib/echo_server/supervisor.ex
new file mode 100644
index 0000000..e770a3a
--- /dev/null
+++ b/src/code/2/echo_server/lib/echo_server/supervisor.ex
@@ -0,0 +1,18 @@
+defmodule EchoServer.Supervisor do
+  use Supervisor
+
+  def start_link do
+    Supervisor.start_link(__MODULE__, [], name: __MODULE__)
+  end
+
+  def init(_) do
+    children = [
+      supervisor(Task.Supervisor, [[name: EchoServer.TaskSupervisor]]),
+      worker(Task, [EchoServer.Echo, :accept, [1337]])
+    ]
+
+    opts = [strategy: :one_for_one]
+    supervise(children, opts)
+  end
+
+end
diff --git a/src/code/2/echo_server/mix.exs b/src/code/2/echo_server/mix.exs
new file mode 100644
index 0000000..d9c2724
--- /dev/null
+++ b/src/code/2/echo_server/mix.exs
@@ -0,0 +1,21 @@
+defmodule EchoServer.Mixfile do
+  use Mix.Project
+
+  def project do
+    [app: :echo_server,
+     version: "0.0.1",
+     elixir: "~> 1.2",
+     build_embedded: Mix.env == :prod,
+     start_permanent: Mix.env == :prod,
+     deps: deps]
+  end
+
+  def application do
+    [mod: {EchoServer, []},
+     applications: [:logger]]
+  end
+
+  defp deps do
+    []
+  end
+end
diff --git a/src/code/2/echo_server/test/echo_server_test.exs b/src/code/2/echo_server/test/echo_server_test.exs
new file mode 100644
index 0000000..9743bf9
--- /dev/null
+++ b/src/code/2/echo_server/test/echo_server_test.exs
@@ -0,0 +1,8 @@
+defmodule EchoServerTest do
+  use ExUnit.Case
+  doctest EchoServer
+
+  test "the truth" do
+    assert 1 + 1 == 2
+  end
+end
diff --git a/src/code/2/echo_server/test/test_helper.exs b/src/code/2/echo_server/test/test_helper.exs
new file mode 100644
index 0000000..869559e
--- /dev/null
+++ b/src/code/2/echo_server/test/test_helper.exs
@@ -0,0 +1 @@
+ExUnit.start()
diff --git a/src/code/2/echo_server_iex.out b/src/code/2/echo_server_iex.out
new file mode 100644
index 0000000..3b9e1d7
--- /dev/null
+++ b/src/code/2/echo_server_iex.out
@@ -0,0 +1,6 @@
+% iex -S mix
+...
+iex(1)> hd Application.started_applications
+{:echo_server,
+ 'echo_server',
+ '0.0.1'}
diff --git a/src/code/2/echo_server_nc.out b/src/code/2/echo_server_nc.out
new file mode 100644
index 0000000..0e9acb9
--- /dev/null
+++ b/src/code/2/echo_server_nc.out
@@ -0,0 +1,5 @@
+% nc localhost 1337
+this is a test
+> this is a test
+I'm testing the echo-ability
+> I'm testing the echo-ability
diff --git a/src/func-w-elixir.tex b/src/func-w-elixir.tex
index eb7b971..8fcb41a 100644
--- a/src/func-w-elixir.tex
+++ b/src/func-w-elixir.tex
@@ -437,6 +437,85 @@ F_1 &= 1
 \lstinputlisting{code/2/pmap.out}
 \end{frame}
 
+\subsubsection{Echo Server}
+\begin{frame}
+\frametitle{Echo Server}
+\begin{itemize}
+\item<2->{Handle connections from clients (\texttt{netcat})}
+\item<3->{Echo back contents of clients messages}
+\end{itemize}
+\end{frame}
+
+\begin{frame}
+\frametitle{\texttt{mix}: Ladle of Elixir\texttt{|>}}
+\begin{itemize}
+\item<1->{Creates Skeleton Projects}
+\item<2->{Compiles Code}
+\item<3->{Runs Test Suites}
+\item<4->{Creates Release}
+\item<5->{Anything you want}
+\end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{\texttt{mix} Output}
+\lstinputlisting{code/2/mix_echo.out}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Elixir\texttt{|>} Applications}
+\lstinputlisting[%
+    numbers=left,
+    title=mix.exs,
+    firstline=13,
+    lastline=16]{code/2/echo_server/mix.exs}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Elixir\texttt{|>} Applications}
+\lstinputlisting[%
+    numbers=left,
+    title=lib/echo\_server.ex]{code/2/echo_server/lib/echo_server.ex}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Elixir\texttt{|>} Supervisors}
+\lstinputlisting[%
+    numbers=left,
+    title=lib/echo\_server/supervisor.ex]
+    {code/2/echo_server/lib/echo_server/supervisor.ex}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Echo Server: Echo}
+\lstinputlisting[%
+    numbers=left,
+    title=lib/echo\_server/echo.ex,
+    firstline=3,
+    lastline=16]
+    {code/2/echo_server/lib/echo_server/echo.ex}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Echo Server: Echo}
+\lstinputlisting[%
+    numbers=left,
+    title=lib/echo\_server/echo.ex,
+    firstline=18,
+    lastline=34]
+    {code/2/echo_server/lib/echo_server/echo.ex}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Echo Server}
+\begin{columns}[c]
+\column{0.5\textwidth{}}
+\lstinputlisting{code/2/echo_server_iex.out}
+\column{0.5\textwidth{}}
+\lstinputlisting[stringstyle=\footnotesize\ttfamily]{code/2/echo_server_nc.out}
+\end{columns}
+\end{frame}
+
 \section*{Going Forward}
 \subsection*{Resources}
 \begin{frame}