write tracer manifast on succesful compile

rebuild if manifest version does not match

Author: lukaszsamson

apps/language_server/lib/language_server/build.ex

@@ -58,7 +58,7 @@ defmodule ElixirLS.LanguageServer.Build do
     :global.trans({__MODULE__, self()}, func)
   end
 
-  defp reload_project do
+  def reload_project do
     mixfile = Path.absname(MixfileHelpers.mix_exs())
 
     if File.exists?(mixfile) do

apps/language_server/lib/language_server/server.ex

@@ -529,6 +529,7 @@ defmodule ElixirLS.LanguageServer.Server do
         "file://" <> _ ->
           root_path = SourceFile.Path.absolute_from_uri(root_uri)
           File.cd!(root_path)
+          Logger.info("cd initialize")
           cwd_uri = SourceFile.Path.to_uri(File.cwd!())
           %{state | root_uri: cwd_uri}
 
@@ -1241,6 +1242,7 @@ defmodule ElixirLS.LanguageServer.Server do
 
       is_nil(prev_project_dir) ->
         File.cd!(project_dir)
+        Logger.info("cd set_project_dir")
         %{state | project_dir: File.cwd!(), mix_project?: File.exists?(MixfileHelpers.mix_exs())}
 
       prev_project_dir != project_dir ->
@@ -1300,11 +1302,21 @@ defmodule ElixirLS.LanguageServer.Server do
     end)
   end
 
-  defp maybe_rebuild(state = %__MODULE__{}) do
+  defp maybe_rebuild(state = %__MODULE__{project_dir: project_dir}) do
     # detect if we are opening a project that has been compiled without a tracer
-    if is_binary(state.project_dir) and state.mix_project and File.dir?(Path.join([project_dir, ".elixir_ls"])) and not Tracer.has_databases?(project_dir) do
-      Logger.info("DETS databases rebuild will be rebuilt")
-      Build.clean(true)
+    if is_binary(project_dir) and state.mix_project? and
+         File.dir?(Path.join([project_dir, ".elixir_ls"])) and
+         not Tracer.manifest_version_current?(project_dir) do
+      Logger.info("DETS databases will be rebuilt")
+      Tracer.clean_dets(project_dir)
+
+      case Build.reload_project() do
+        {:ok, _} ->
+          Build.clean(true)
+
+        _ ->
+          :ok
+      end
     end
   end
 end

apps/language_server/lib/language_server/tracer.ex

@@ -4,6 +4,8 @@ defmodule ElixirLS.LanguageServer.Tracer do
   use GenServer
   require Logger
 
+  @version 1
+
   @tables ~w(modules calls)a
 
   for table <- @tables do
@@ -20,6 +22,10 @@ defmodule ElixirLS.LanguageServer.Tracer do
     GenServer.call(__MODULE__, {:set_project_dir, project_dir})
   end
 
+  def save() do
+    GenServer.cast(__MODULE__, :save)
+  end
+
   defp get_project_dir() do
     case Process.get(:elixir_ls_project_dir) do
       nil ->
@@ -80,6 +86,19 @@ defmodule ElixirLS.LanguageServer.Tracer do
     {:reply, project_dir, state}
   end
 
+  @impl true
+  def handle_cast(:save, %{project_dir: project_dir} = state) do
+    for table <- @tables do
+      table_name = table_name(table)
+
+      sync(table_name)
+    end
+
+    write_manifest(project_dir)
+
+    {:noreply, state}
+  end
+
   @impl true
   def terminate(_reason, state) do
     maybe_close_tables(state)
@@ -95,10 +114,6 @@ defmodule ElixirLS.LanguageServer.Tracer do
     :ok
   end
 
-  def has_databases?(project_dir) do
-    File.exists?(dets_path(project_dir, hd(@tables)))
-  end
-
   defp dets_path(project_dir, table) do
     Path.join([project_dir, ".elixir_ls", "#{table}.dets"])
   end
@@ -270,14 +285,6 @@ defmodule ElixirLS.LanguageServer.Tracer do
     end)
   end
 
-  def save do
-    for table <- @tables do
-      table_name = table_name(table)
-
-      sync(table_name)
-    end
-  end
-
   defp sync(table_name) do
     with :ok <- :dets.from_ets(table_name, table_name),
          :ok <- :dets.sync(table_name) do
@@ -336,4 +343,34 @@ defmodule ElixirLS.LanguageServer.Tracer do
       end
     end
   end
+
+  defp manifest_path(project_dir) do
+    Path.join([project_dir, ".elixir_ls", "tracer_db.manifest"])
+  end
+
+  def write_manifest(project_dir) do
+    path = manifest_path(project_dir)
+    File.rm_rf!(path)
+    File.write!(path, "#{@version}")
+  end
+
+  def read_manifest(project_dir) do
+    with {:ok, text} <- File.read(manifest_path(project_dir)),
+         {version, ""} <- Integer.parse(text) do
+      version
+    else
+      _ -> nil
+    end
+  end
+
+  def manifest_version_current?(project_dir) do
+    read_manifest(project_dir) == @version
+  end
+
+  def clean_dets(project_dir) do
+    for path <-
+          Path.join([project_dir, ".elixir_ls/*.dets"])
+          |> Path.wildcard(),
+        do: File.rm_rf!(path)
+  end
 end

apps/language_server/test/tracer_test.exs

@@ -4,6 +4,7 @@ defmodule ElixirLS.LanguageServer.TracerTest do
   alias ElixirLS.LanguageServer.Test.FixtureHelpers
 
   setup context do
+    File.rm_rf!(FixtureHelpers.get_path(".elixir_ls/tracer_db.manifest"))
     File.rm_rf!(FixtureHelpers.get_path(".elixir_ls/calls.dets"))
     File.rm_rf!(FixtureHelpers.get_path(".elixir_ls/modules.dets"))
     {:ok, _pid} = start_supervised(Tracer)
@@ -206,4 +207,18 @@ defmodule ElixirLS.LanguageServer.TracerTest do
       assert [] == sorted_calls()
     end
   end
+
+  describe "manifest" do
+    test "return nil when not found" do
+      project_path = FixtureHelpers.get_path("")
+      assert nil == Tracer.read_manifest(project_path)
+    end
+
+    test "reads manifest" do
+      project_path = FixtureHelpers.get_path("")
+      Tracer.write_manifest(project_path)
+
+      assert 1 == Tracer.read_manifest(project_path)
+    end
+  end
 end