[WIP] Beam splitter

.tool-versions

@@ -1,10 +1,3 @@
-# This file contains the recommended versions for developing and running
-# elixir-ls. However, elixir-ls supports a minumum version of Elixir 1.7.0 with
-# OTP 20 and should work with any later releases.
-# Using asdf to manage your elixir and OTP versions is not required, you can
-# use the system-installed version instead.
-#
-# The versions selected here are the versions that are used to build a binary
-# release for distribution
-elixir 1.7.4-otp-20
-erlang 20.3.8.23
+# This is the version that the Elixir-LS distribution will run on.
+elixir 1.10.1-otp-22
+erlang 22.1

apps/elixir_ls_main/.formatter.exs

@@ -0,0 +1,4 @@
+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

apps/elixir_ls_main/.gitignore

@@ -0,0 +1,24 @@
+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where third-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+elixir_ls_main-*.tar
+

apps/elixir_ls_main/README.md

@@ -0,0 +1,5 @@
+# ElixirLsMain
+
+Main Elixir-LS application. Pretty much its sole role is to decide at startup whether
+the language server or debugger are invoked. This way, we can release this as a simple
+single app.

apps/elixir_ls_main/lib/elixir_ls_main/application.ex

@@ -0,0 +1,12 @@
+defmodule ElixirLsMain.Application do
+  use Application
+
+  def start(_type, _args) do
+    task_mod = if System.get_env("ELS_STARTUP_TYPE") == "debugger" do
+      ElixirLS.Debugger.CLI
+    else
+      ElixirLS.LanguageServer.CLI
+    end
+    Task.start_link(&task_mod.main/0)
+  end
+end

apps/elixir_ls_main/mix.exs

@@ -0,0 +1,34 @@
+defmodule ElixirLsMain.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :elixir_ls_main,
+      version: "0.1.0",
+      build_path: "../../_build",
+      config_path: "../../config/config.exs",
+      deps_path: "../../deps",
+      lockfile: "../../mix.lock",
+      elixir: "~> 1.10",
+      start_permanent: Mix.env() == :prod,
+      deps: deps()
+    ]
+  end
+
+  # Run "mix help compile.app" to learn about applications.
+  def application do
+    [
+      mod: {ElixirLsMain.Application, []},
+      extra_applications: [:logger],
+      bundled_applications: [:debugger, :language_server]
+    ]
+  end
+
+  # Run "mix help deps" to learn about dependencies.
+  defp deps do
+    [
+      {:language_server, in_umbrella: true},
+      {:debugger, in_umbrella: true}
+    ]
+  end
+end

apps/elixir_ls_main/priv/debugger.bat

@@ -0,0 +1,10 @@
+REM TODO test me on Win1rand () {
+  od -t xS -N 2 -A n /dev/urandom | tr -d " \n"
+}
+0
+@echo off & setlocal enabledelayedexpansion
+
+set ELS_STARTUP_TYPE=debugger
+set RELEASE_NODE="elixir-ls-!RANDOM!"
+
+@bin/elixir_ls.bat start

apps/elixir_ls_main/priv/debugger.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+# Launches the language server. Very simple wrapper around the generated
+# startup script.
+
+# For now, we assume that this script lives in the root of the unpacked
+# distribution (so that the distribution wrapper script lives in bin/).
+# TODO this is a manual post-install step so we should thinkg about this.
+
+# TODO lots of duplication with language_server.sh here
+
+readlink_f () {
+  cd "$(dirname "$1")" > /dev/null
+  filename="$(basename "$1")"
+  if [ -h "$filename" ]; then
+    readlink_f "$(readlink "$filename")"
+  else
+    echo "`pwd -P`/$filename"
+  fi
+}
+rand () {
+  od -t xS -N 2 -A n /dev/urandom | tr -d " \n"
+}
+
+SCRIPT=$(readlink_f $0)
+SCRIPTPATH=`dirname $SCRIPT`/bin
+
+export RELEASE_NODE=elixir-ls-$(rand)
+
+export ELS_STARTUP_TYPE=debugger
+
+$SCRIPTPATH/elixir_ls start

apps/elixir_ls_main/priv/language_server.bat

@@ -0,0 +1,6 @@
+REM TODO test me on Win10
+@echo off & setlocal enabledelayedexpansion
+
+set RELEASE_NODE="elixir-ls-!RANDOM!"
+
+@bin/elixir_ls.bat start

apps/elixir_ls_main/priv/language_server.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+# Launches the language server. Very simple wrapper around the generated
+# startup script.
+
+# For now, we assume that this script lives in the root of the unpacked
+# distribution (so that the distribution wrapper script lives in bin/).
+# TODO this is a manual post-install step so we should thinkg about this.
+
+readlink_f () {
+  cd "$(dirname "$1")" > /dev/null
+  filename="$(basename "$1")"
+  if [ -h "$filename" ]; then
+    readlink_f "$(readlink "$filename")"
+  else
+    echo "`pwd -P`/$filename"
+  fi
+}
+rand () {
+  od -t xS -N 2 -A n /dev/urandom | tr -d " \n"
+}
+
+SCRIPT=$(readlink_f $0)
+SCRIPTPATH=`dirname $SCRIPT`/bin
+
+export RELEASE_NODE=elixir-ls-$(rand)
+
+$SCRIPTPATH/elixir_ls start

apps/elixir_ls_main/test/test_helper.exs

@@ -0,0 +1 @@
+ExUnit.start()

apps/elixir_ls_utils/lib/application.ex

@@ -0,0 +1,11 @@
+defmodule ElixirLS.Utils.Application do
+  use Application
+
+  def start(_type, _args) do
+    children = [
+      ElixirLS.Utils.EelsRunner
+    ]
+
+    Supervisor.start_link(children, strategy: :one_for_one)
+  end
+end

apps/elixir_ls_utils/lib/eels_runner.ex

@@ -0,0 +1,57 @@
+defmodule ElixirLS.Utils.EelsRunner do
+  @moduledoc """
+  Eels wrapper. This starts an inferior VM that (hopefully) runs the
+  current project's code and forwards commands to it.
+  """
+  use GenServer
+  require Logger
+
+  def start_link([]) do
+    GenServer.start_link(__MODULE__, [], name: __MODULE__)
+  end
+
+  # This might be a bottleneck. A simple optimization would be to stash
+  # the node in ETS and leave the genserver just operate as an ETS owner
+  # process.
+  def exec(module, function, arguments) do
+    GenServer.call(__MODULE__, {:exec, module, function, arguments})
+  end
+
+  def init([]) do
+    {node, cookie} = generate_state()
+    start_eels_vm(node, cookie)
+    exec_ping(node)
+    Logger.info("Eels runner successfully started")
+    {:ok, node}
+  end
+
+  def handle_call(call = {:exec, _module, _function, _arguments}, _from, node) do
+    result = GenServer.call({:eels_server, node}, call)
+    {:reply, result, node}
+  end
+
+  defp generate_state() do
+    max = 2_000_000_000_000 # lots of birthdays need to happen...
+    cookie = :"eels-cookie-#{:rand.uniform(max)}"
+    host = node |> Atom.to_string() |> String.split("@") |> List.last()
+    node = :"eels-#{:rand.uniform(max)}@#{host}"
+    {node, cookie}
+  end
+
+  defp start_eels_vm(node, cookie) do
+    System.put_env("EELS_COOKIE", Atom.to_string(Node.get_cookie()))
+    System.put_env("EELS_NODE", Atom.to_string(node))
+    System.put_env("EELS_VERSION", List.to_string(Keyword.get(Application.spec(:eels), :vsn)))
+    script = Application.app_dir(:elixir_ls_utils) <> "/priv/start_eels"
+    # TODO Should we keep the port around?
+    Port.open({:spawn, script <> " start"}, [])
+    Process.sleep(2_000) # TODO clean up
+    Logger.info("Connected: #{inspect Node.connect(node)}")
+  end
+
+  defp exec_ping(node) do
+    result = GenServer.call({:eels_server, node}, {:exec, Kernel, :node, []})
+    Logger.info("Result = #{inspect result}")
+  end
+
+end

apps/elixir_ls_utils/mix.exs

@@ -20,14 +20,19 @@ defmodule ElixirLS.Utils.Mixfile do
   end
 
   def application do
-    # We must NOT start ANY applications as this is taken care in code.
-    [applications: []]
+    [mod: {ElixirLS.Utils.Application, []},
+     # We include Eels basically just for its source code, so prevent it from starting.
+     included_applications: [:eels]]
   end
 
   defp deps do
     [
       {:jason, "~> 1.1"},
-      {:mix_task_archive_deps, github: "JakeBecker/mix_task_archive_deps"}
+      {:mix_task_archive_deps, github: "JakeBecker/mix_task_archive_deps"},
+      # We include eels as a dependency so that we get it bundled in the release
+      # All we need is its source code but as long as we don't start it, it
+      # won't hurt.
+      {:eels, path: "../../eels"}
     ]
   end
 end

apps/elixir_ls_utils/priv/start_eels

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+# Launches a new Elixir Embedded Language Server, which
+# runs the Elixir/OTP version-specific bits of Elixir-LS
+
+# See ElixirLS.Utils.EelsRunner for details on the environment
+# setup. RELEASE_ROOT is inherited from the release wrapper script
+# that started Elixir-LS; we can use it to find our way around.
+
+exec >/tmp/start_eels.out 2>&1
+
+[ -f "$HOME/.asdf/asdf.sh" ] && . "$HOME/.asdf/asdf.sh"
+
+# Run elixir, asdf-vm makes it the project specific version.
+# TODO Windows version
+elixir --no-halt $RELEASE_ROOT/lib/eels-${EELS_VERSION}/priv/eels_main.exs

eels/.formatter.exs

@@ -0,0 +1,4 @@
+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

eels/.gitignore

@@ -0,0 +1,24 @@
+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where 3rd-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+eels-*.tar
+