Track both content and cache size

lib/music_library/application.ex

@@ -12,11 +12,11 @@ defmodule MusicLibrary.Application do
     _ = Assets.Cache.new()
 
     children = [
-      MusicLibraryWeb.Telemetry,
       MusicLibrary.Vault,
       MusicLibrary.Repo,
       MusicLibrary.ErrorRepo,
       MusicLibrary.BackgroundRepo,
+      MusicLibraryWeb.Telemetry,
       {Oban, Application.fetch_env!(:music_library, Oban)},
       {Ecto.Migrator,
        repos: Application.fetch_env!(:music_library, :ecto_repos), skip: skip_migrations?()},

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

lib/music_library/assets/cache.ex

@@ -23,14 +23,6 @@ defmodule MusicLibrary.Assets.Cache do
     )
   end
 
-  def track_total_content_size do
-    :telemetry.execute(
-      [:music_library, :assets, :cache],
-      %{total_content_size: total_content_size()},
-      %{}
-    )
-  end
-
   def prune(older_than_seconds) do
     threshold =
       DateTime.utc_now()

lib/music_library_web/telemetry.ex

@@ -116,7 +116,8 @@ defmodule MusicLibraryWeb.Telemetry do
       ),
 
       # Assets
-      summary("music_library.assets.cache.total_content_size", unit: {:byte, :kilobyte}),
+      summary("music_library.assets.cache_size", unit: {:byte, :kilobyte}),
+      summary("music_library.assets.content_size", unit: {:byte, :megabyte}),
 
       # VM Metrics
       summary("vm.memory.total", unit: {:byte, :megabyte}),
@@ -128,7 +129,8 @@ defmodule MusicLibraryWeb.Telemetry do
 
   defp periodic_measurements do
     [
-      {MusicLibrary.Assets.Cache, :track_total_content_size, []}
+      {MusicLibrary.Assets, :track_total_cache_size, []},
+      {MusicLibrary.Assets, :track_total_content_size, []}
       # A module, function and arguments to be invoked periodically.
       # This function must call :telemetry.execute/3 and a metric must be added above.
       # {MusicLibraryWeb, :count_users, []}