Track both content and cache size

lib/music_library/assets.ex

@@ -1,7 +1,9 @@
 defmodule MusicLibrary.Assets do
-  alias MusicLibrary.Assets.Asset
+  alias MusicLibrary.Assets.{Asset, Cache}
   alias MusicLibrary.Repo
 
+  import Ecto.Query
+
   @doc """
   Store any file type - the responsibility to correctly populate format and
   properties is left to the caller.
@@ -28,4 +30,27 @@ defmodule MusicLibrary.Assets do
   def get!(hash) do
     Repo.get!(Asset, hash)
   end
+
+  def total_content_size do
+    q =
+      from p in Asset, select: sum(fragment("length(content)"))
+
+    Repo.one(q)
+  end
+
+  def track_total_content_size do
+    :telemetry.execute(
+      [:music_library, :assets],
+      %{content_size: total_content_size()},
+      %{}
+    )
+  end
+
+  def track_total_cache_size do
+    :telemetry.execute(
+      [:music_library, :assets],
+      %{cache_size: Cache.total_content_size()},
+      %{}
+    )
+  end
 end