Add Activity Pub endpoints cache

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/mobilizon_web/controllers/activity_pub_controller.ex

@@ -21,53 +21,96 @@ defmodule MobilizonWeb.ActivityPubController do
     "application/activity+json, application/ld+json"
   ]
 
+  @doc """
+  Show an Actor's ActivityPub representation
+  """
+  @spec actor(Plug.Conn.t(), map()) :: Plug.Conn.t()
   def actor(conn, %{"name" => name}) do
-    with %Actor{} = actor <- Actors.get_local_actor_by_name(name) do
-      if conn |> get_req_header("accept") |> is_ap_header() do
-        conn |> render_ap_actor(actor)
-      else
-        conn
-        |> put_resp_content_type("text/html")
-        |> send_file(200, "priv/static/index.html")
-      end
+    if conn |> get_req_header("accept") |> is_ap_header() do
+      render_cached_actor(conn, name)
     else
-      nil -> {:error, :not_found}
+      conn
+      |> put_resp_content_type("text/html")
+      |> send_file(200, "priv/static/index.html")
     end
   end
 
+  @spec render_cached_actor(Plug.Conn.t(), String.t()) :: Plug.Conn.t()
+  defp render_cached_actor(conn, name) do
+    case Cachex.fetch(:activity_pub, "actor_" <> name, &get_local_actor_by_name/1) do
+      {status, %Actor{} = actor} when status in [:ok, :commit] ->
+        conn
+        |> put_resp_header("content-type", "application/activity+json")
+        |> json(ActorView.render("actor.json", %{actor: actor}))
+
+      {:ignore, _} ->
+        {:error, :not_found}
+    end
+  end
+
+  defp get_local_actor_by_name("actor_" <> name) do
+    case Actors.get_local_actor_by_name(name) do
+      nil -> {:ignore, nil}
+      %Actor{} = actor -> {:commit, actor}
+    end
+  end
+
+  # Test if the request has an AP header
   defp is_ap_header(ap_headers) do
     length(@activity_pub_headers -- ap_headers) < 2
   end
 
-  defp render_ap_actor(conn, %Actor{} = actor) do
-    conn
-    |> put_resp_header("content-type", "application/activity+json")
-    |> json(ActorView.render("actor.json", %{actor: actor}))
-  end
-
+  @doc """
+  Renders an Event ActivityPub's representation
+  """
+  @spec event(Plug.Conn.t(), map()) :: Plug.Conn.t()
   def event(conn, %{"uuid" => uuid}) do
-    with %Event{} = event <- Events.get_event_full_by_uuid(uuid),
-         true <- event.visibility in [:public, :unlisted] do
-      conn
-      |> put_resp_header("content-type", "application/activity+json")
-      |> json(ObjectView.render("event.json", %{event: event |> Utils.make_event_data()}))
-    else
-      _ ->
+    case Cachex.fetch(:activity_pub, "event_" <> uuid, &get_event_full_by_uuid/1) do
+      {status, %Event{} = event} when status in [:ok, :commit] ->
+        conn
+        |> put_resp_header("content-type", "application/activity+json")
+        |> json(ObjectView.render("event.json", %{event: event |> Utils.make_event_data()}))
+
+      {:ignore, _} ->
         {:error, :not_found}
     end
   end
 
+  defp get_event_full_by_uuid("event_" <> uuid) do
+    with %Event{} = event <- Events.get_event_full_by_uuid(uuid),
+         true <- event.visibility in [:public, :unlisted] do
+      {:commit, event}
+    else
+      _ -> {:ignore, nil}
+    end
+  end
+
+  @doc """
+  Renders a Comment ActivityPub's representation
+  """
+  @spec comment(Plug.Conn.t(), map()) :: Plug.Conn.t()
   def comment(conn, %{"uuid" => uuid}) do
+    case Cachex.fetch(:activity_pub, "comment_" <> uuid, &get_comment_full_by_uuid/1) do
+      {status, %Comment{} = comment} when status in [:ok, :commit] ->
+        conn
+        |> put_resp_header("content-type", "application/activity+json")
+        |> json(
+          ObjectView.render("comment.json", %{comment: comment |> Utils.make_comment_data()})
+        )
+
+      {:ignore, _} ->
+        {:error, :not_found}
+    end
+  end
+
+  defp get_comment_full_by_uuid("comment_" <> uuid) do
     with %Comment{} = comment <- Events.get_comment_full_from_uuid(uuid) do
       # Comments are always public for now
       # TODO : Make comments maybe restricted
       # true <- comment.public do
-      conn
-      |> put_resp_header("content-type", "application/activity+json")
-      |> json(ObjectView.render("comment.json", %{comment: comment |> Utils.make_comment_data()}))
+      {:commit, comment}
     else
-      _ ->
-        {:error, :not_found}
+      _ -> {:ignore, nil}
     end
   end