Automatically back up notebooks without a file (#736)

* Improve file select layout on long paths

* Automatically back up notebooks without a file

* Run formatter

* Add margin when there are no sections

* Add an informative note about autosave directory

* Store autosave path instead of file in the config

* Rename autosave dir to autosave path

* Fix insert mode escape on section headlines

* Show ellipsis on selected file too

* Always create the default directory

* Apply review comments

README.md

@@ -144,6 +144,10 @@ Livebook if said token is supplied as part of the URL.
 
 The following environment variables configure Livebook:
 
+  * LIVEBOOK_AUTOSAVE_PATH - sets the directory where notebooks with no file are
+    saved. Defaults to livebook/notebooks/ under the default user cache location.
+    You can pass "none" to disable this behaviour.
+
   * LIVEBOOK_COOKIE - sets the cookie for running Livebook in a cluster.
     Defaults to a random string that is generated on boot.
 

assets/css/components.css

@@ -2,7 +2,7 @@
   /* Buttons */
 
   .button-base {
-    @apply px-5 py-2 rounded-lg border border-transparent font-medium text-sm;
+    @apply px-5 py-2 rounded-lg border border-transparent font-medium text-sm whitespace-nowrap;
   }
 
   .button-blue {

assets/js/focus_on_update/index.js

@@ -21,6 +21,7 @@ const FocusOnUpdate = {
 
     this.el.focus();
     this.el.selectionStart = this.el.selectionEnd = this.el.value.length;
+    this.el.scrollLeft = this.el.scrollWidth;
   },
 };
 

assets/js/session/index.js

@@ -308,11 +308,12 @@ function handleDocumentKeyDown(hook, event) {
 
       const editor = event.target.closest(".monaco-editor.focused");
 
-      const completionBoxOpen = !!editor.querySelector(
-        ".editor-widget.parameter-hints-widget.visible"
+      const completionBoxOpen = !!(
+        editor &&
+        editor.querySelector(".editor-widget.parameter-hints-widget.visible")
       );
-      const signatureDetailsOpen = !!editor.querySelector(
-        ".editor-widget.suggest-widget.visible"
+      const signatureDetailsOpen = !!(
+        editor && editor.querySelector(".editor-widget.suggest-widget.visible")
       );
 
       // Ignore Escape if it's supposed to close some Monaco input

lib/livebook.ex

@@ -60,6 +60,15 @@ defmodule Livebook do
     configured_file_systems = Livebook.Config.file_systems!("LIVEBOOK_FILE_SYSTEM_")
 
     config :livebook, :file_systems, [local_file_system | configured_file_systems]
+
+    autosave_path =
+      if config_env() == :test do
+        nil
+      else
+        Livebook.Config.autosave_path!("LIVEBOOK_AUTOSAVE_PATH")
+      end
+
+    config :livebook, :autosave_path, autosave_path
   end
 
   @doc """

lib/livebook/config.ex

@@ -71,14 +71,22 @@ defmodule Livebook.Config do
     FileSystem.File.new(file_system)
   end
 
+  @doc """
+  Returns the directory where notebooks with no file should be persisted.
+  """
+  @spec autosave_path() :: String.t() | nil
+  def autosave_path() do
+    Application.fetch_env!(:livebook, :autosave_path)
+  end
+
   ## Parsing
 
   @doc """
   Parses and validates the root path from env.
   """
   def root_path!(env) do
     if root_path = System.get_env(env) do
-      root_path!("LIVEBOOK_ROOT_PATH", root_path)
+      root_path!(env, root_path)
     else
       File.cwd!()
     end
@@ -89,13 +97,62 @@ defmodule Livebook.Config do
   """
   def root_path!(context, root_path) do
     if File.dir?(root_path) do
-      root_path
+      Path.expand(root_path)
     else
       IO.warn("ignoring #{context} because it doesn't point to a directory: #{root_path}")
       File.cwd!()
     end
   end
 
+  @doc """
+  Parses and validates the autosave directory from env.
+  """
+  def autosave_path!(env) do
+    if path = System.get_env(env) do
+      autosave_path!(env, path)
+    else
+      default_autosave_path!()
+    end
+  end
+
+  @doc """
+  Validates `autosave_path` within context.
+  """
+  def autosave_path!(context, path)
+
+  def autosave_path!(_context, "none"), do: nil
+
+  def autosave_path!(context, path) do
+    if writable_directory?(path) do
+      Path.expand(path)
+    else
+      IO.warn("ignoring #{context} because it doesn't point to a writable directory: #{path}")
+      default_autosave_path!()
+    end
+  end
+
+  defp default_autosave_path!() do
+    cache_path = :filename.basedir(:user_cache, "livebook")
+
+    path =
+      if writable_directory?(cache_path) do
+        cache_path
+      else
+        System.tmp_dir!() |> Path.join("livebook")
+      end
+
+    notebooks_path = Path.join(path, "notebooks")
+    File.mkdir_p!(notebooks_path)
+    notebooks_path
+  end
+
+  defp writable_directory?(path) do
+    case File.stat(path) do
+      {:ok, %{type: :directory, access: access}} when access in [:read_write, :write] -> true
+      _ -> false
+    end
+  end
+
   @doc """
   Parses and validates the secret from env.
   """

lib/livebook/session.ex

@@ -973,9 +973,10 @@ defmodule Livebook.Session do
   end
 
   defp maybe_save_notebook_async(state) do
-    if should_save_notebook?(state) do
+    file = notebook_autosave_file(state)
+
+    if file && should_save_notebook?(state) do
       pid = self()
-      file = state.data.file
       content = LiveMarkdown.Export.notebook_to_markdown(state.data.notebook)
 
       {:ok, pid} =
@@ -991,17 +992,46 @@ defmodule Livebook.Session do
   end
 
   defp maybe_save_notebook_sync(state) do
-    if should_save_notebook?(state) do
+    file = notebook_autosave_file(state)
+
+    if file && should_save_notebook?(state) do
       content = LiveMarkdown.Export.notebook_to_markdown(state.data.notebook)
-      result = FileSystem.File.write(state.data.file, content)
+      result = FileSystem.File.write(file, content)
       handle_save_finished(state, result)
     else
       state
     end
   end
 
   defp should_save_notebook?(state) do
-    state.data.file != nil and state.data.dirty and state.save_task_pid == nil
+    state.data.dirty and state.save_task_pid == nil
+  end
+
+  defp notebook_autosave_file(state) do
+    state.data.file || default_notebook_file(state)
+  end
+
+  defp default_notebook_file(session) do
+    if path = Livebook.Config.autosave_path() do
+      dir = path |> FileSystem.Utils.ensure_dir_path() |> FileSystem.File.local()
+      notebook_rel_path = path_with_timestamp(session.session_id, session.created_at)
+      FileSystem.File.resolve(dir, notebook_rel_path)
+    end
+  end
+
+  defp path_with_timestamp(session_id, date_time) do
+    # We want a random, but deterministic part, so we
+    # use a few characters from the session id, which
+    # is random already
+    random_str = String.slice(session_id, 0..3)
+
+    [date_str, time_str, _] =
+      date_time
+      |> DateTime.to_iso8601()
+      |> String.replace(["-", ":"], "_")
+      |> String.split(["T", "."])
+
+    "#{date_str}/#{time_str}_#{random_str}.livemd"
   end
 
   defp handle_save_finished(state, result) do

lib/livebook_cli/server.ex

@@ -19,6 +19,9 @@ defmodule LivebookCLI.Server do
 
     Available options:
 
+      --autosave-path      The directory where notebooks with no file are persisted.
+                           Defaults to livebook/notebooks/ under the default user cache
+                           location. You can pass "none" to disable this behaviour
       --cookie             Sets a cookie for the app distributed node
       --default-runtime    Sets the runtime type that is used by default when none is started
                            explicitly for the given notebook, defaults to standalone
@@ -126,6 +129,7 @@ defmodule LivebookCLI.Server do
   end
 
   @switches [
+    autosave_path: :string,
     cookie: :string,
     default_runtime: :string,
     ip: :string,
@@ -202,6 +206,11 @@ defmodule LivebookCLI.Server do
     opts_to_config(opts, [{:livebook, :default_runtime, default_runtime} | config])
   end
 
+  defp opts_to_config([{:autosave_path, path} | opts], config) do
+    autosave_path = Livebook.Config.autosave_path!("--autosave-path", path)
+    opts_to_config(opts, [{:livebook, :autosave_path, autosave_path} | config])
+  end
+
   defp opts_to_config([_opt | opts], config), do: opts_to_config(opts, config)
 
   defp browser_open(url) do

lib/livebook_web/live/file_select_component.ex

@@ -273,7 +273,7 @@ defmodule LivebookWeb.FileSelectComponent do
           </span>
           <span class={"flex font-medium overflow-hidden whitespace-nowrap #{if(@file_info.is_running, do: "text-green-300", else: "text-gray-500")}"}>
             <%= if @file_info.highlighted != "" do %>
-              <span class={"font-medium #{if(@file_info.is_running, do: "text-green-400", else: "text-gray-900")}"}>
+              <span class={"font-medium overflow-hidden overflow-ellipsis #{if(@file_info.is_running, do: "text-green-400", else: "text-gray-900")}"}>
                 <%= @file_info.highlighted %>
               </span>
             <% end %>

lib/livebook_web/live/home_live.ex

@@ -242,17 +242,19 @@ defmodule LivebookWeb.HomeLive do
      )}
   end
 
+  def handle_event("open_autosave_directory", %{}, socket) do
+    file =
+      Livebook.Config.autosave_path()
+      |> FileSystem.Utils.ensure_dir_path()
+      |> FileSystem.File.local()
+
+    file_info = %{exists: true, access: file_access(file)}
+    {:noreply, assign(socket, file: file, file_info: file_info)}
+  end
+
   @impl true
   def handle_info({:set_file, file, info}, socket) do
-    file_info = %{
-      exists: info.exists,
-      access:
-        case FileSystem.File.access(file) do
-          {:ok, access} -> access
-          {:error, _} -> :none
-        end
-    }
-
+    file_info = %{exists: info.exists, access: file_access(file)}
     {:noreply, assign(socket, file: file, file_info: file_info)}
   end
 
@@ -336,4 +338,11 @@ defmodule LivebookWeb.HomeLive do
     session_opts = Keyword.merge(session_opts, notebook: notebook)
     create_session(socket, session_opts)
   end
+
+  defp file_access(file) do
+    case FileSystem.File.access(file) do
+      {:ok, access} -> access
+      {:error, _} -> :none
+    end
+  end
 end

lib/livebook_web/live/home_live/session_list_component.ex

@@ -12,10 +12,16 @@ defmodule LivebookWeb.HomeLive.SessionListComponent do
 
     sessions = sort_sessions(sessions, socket.assigns.order_by)
 
+    show_autosave_note? =
+      case Livebook.Config.autosave_path() do
+        nil -> false
+        path -> File.ls!(path) != []
+      end
+
     socket =
       socket
       |> assign(assigns)
-      |> assign(:sessions, sessions)
+      |> assign(sessions: sessions, show_autosave_note?: show_autosave_note?)
 
     {:ok, socket}
   end
@@ -47,21 +53,29 @@ defmodule LivebookWeb.HomeLive.SessionListComponent do
           </:content>
         </.menu>
       </div>
-      <.session_list sessions={@sessions} socket={@socket} />
+      <.session_list sessions={@sessions} socket={@socket} show_autosave_note?={@show_autosave_note?} />
     </div>
     """
   end
 
   defp session_list(%{sessions: []} = assigns) do
     ~H"""
-    <div class="p-5 flex space-x-4 items-center border border-gray-200 rounded-lg">
+    <div class="mt-4 p-5 flex space-x-4 items-center border border-gray-200 rounded-lg">
       <div>
         <.remix_icon icon="windy-line" class="text-gray-400 text-xl" />
       </div>
-      <div class="text-gray-600">
-        You do not have any running sessions.
-        <br>
-        Please create a new one by clicking <span class="font-semibold">“New notebook”</span>
+      <div class="flex-grow flex items-center justify-between">
+        <div class="text-gray-600">
+          You do not have any running sessions.
+          <%= if @show_autosave_note? do %>
+            <br>
+            Looking for unsaved notebooks?
+            <a class="font-semibold" href="#" phx-click="open_autosave_directory">Browse them here</a>.
+          <% end %>
+        </div>
+        <button class="button-base button-blue" phx-click="new">
+          New notebook
+        </button>
       </div>
     </div>
     """

lib/livebook_web/live/session_live/persistence_live.ex

@@ -48,7 +48,7 @@ defmodule LivebookWeb.SessionLive.PersistenceLive do
       </h3>
       <div class="w-full flex-col space-y-8">
         <div class="flex">
-          <form phx-change="set_options" onsubmit="return false;" class="flex flex-col space-y-4 items-start">
+          <form phx-change="set_options" onsubmit="return false;" class="flex flex-col space-y-4 items-start max-w-full">
             <div class="flex flex-col space-y-4">
               <.switch_checkbox
                 name="persist_outputs"
@@ -68,15 +68,15 @@ defmodule LivebookWeb.SessionLive.PersistenceLive do
                   ]} />
               </div>
             </div>
-            <div class="flex space-x-2 items-center">
+            <div class="flex space-x-2 items-center max-w-full">
               <span class="text-gray-700 whitespace-nowrap">File:</span>
               <%= if @new_attrs.file do %>
                 <span class="tooltip right" data-tooltip={file_system_label(@new_attrs.file.file_system)}>
                   <span class="flex items-center">
                     [<.file_system_icon file_system={@new_attrs.file.file_system} />]
                   </span>
                 </span>
-                <span class="text-gray-700 whitespace-no-wrap font-medium">
+                <span class="text-gray-700 whitespace-no-wrap font-medium overflow-ellipsis overflow-hidden">
                   <%= @new_attrs.file.path %>
                 </span>
                 <button class="button-base button-gray button-small"