Cache icon bodies and components

lib/heroicons.ex

@@ -18,12 +18,23 @@ defmodule Heroicons do
   """
 
   # https://github.com/tailwindlabs/heroicons/releases
+
   @latest_version "2.0.10"
 
   @tmp_dir_name "heroicons-elixir"
-
+  use Application
   require Logger
 
+  @doc false
+  def start(_type, _args) do
+    children = [
+      {Heroicons.IconCache, []}
+    ]
+
+    opts = [strategy: :one_for_one, name: Heroicons.Supervisor]
+    Supervisor.start_link(children, opts)
+  end
+
   @doc false
   # Latest known version at the time of publishing.
   def latest_version, do: @latest_version

lib/heroicons/generator.ex

@@ -66,14 +66,13 @@ defmodule Heroicons.Generator do
     attrs = @assigns_to_attrs_mod.assigns_to_attributes(assigns)
     assigns = @assign_mod.assign(assigns, :attrs, attrs)
 
-    EEx.compile_string("<svg {@attrs}" <> Heroicons.IconCache.icon_body(path),
-      engine: Phoenix.LiveView.HTMLEngine,
-      file: __ENV__.file,
-      line: __ENV__.line + 1,
-      module: __ENV__.module,
-      indentation: 0,
-      assigns: assigns
-    )
+    {component, _binding} =
+      Code.eval_quoted(
+        Heroicons.IconCache.fetch_component(path),
+        assigns: assigns
+      )
+
+    component
   end
 
   @doc false
@@ -93,7 +92,7 @@ defmodule Heroicons.Generator do
        "<svg",
        Phoenix.HTML.Safe.to_iodata(attrs),
        " ",
-       Heroicons.IconCache.icon_body(path)
+       Heroicons.IconCache.fetch_body(path)
      ]}
   end
 end

lib/heroicons/icon_cache.ex

@@ -1,8 +1,64 @@
 defmodule Heroicons.IconCache do
-
   @doc "Get's an icon's body from the filesystem"
-  # TODO implement ETS-based caching & benchmark
-  def icon_body(path) do
+  use GenServer
+
+  @name __MODULE__
+
+  def start_link(_), do: GenServer.start_link(__MODULE__, [], name: @name)
+
+  def fetch_component(path) do
+    case :ets.lookup(@name.Components, path) do
+      [{^path, component}] ->
+        component
+
+      [] ->
+        GenServer.call(@name, {:cache_component, path})
+    end
+  end
+
+  def fetch_body(path) do
+    case :ets.lookup(@name, path) do
+      [{^path, body}] ->
+        body
+
+      [] ->
+        GenServer.call(@name, {:cache_body, path})
+    end
+  end
+
+  def init(_) do
+    :ets.new(@name, [:set, :protected, :named_table])
+    :ets.new(@name.Components, [:set, :protected, :named_table])
+
+    {:ok, []}
+  end
+
+  def handle_call({:cache_body, path}, _ref, state) do
+    body = read_body(path)
+
+    :ets.insert_new(@name, {path, body})
+
+    {:reply, body, state}
+  end
+
+  def handle_call({:cache_component, path}, _ref, state) do
+    body = read_body(path)
+
+    component =
+      EEx.compile_string("<svg {@attrs}" <> body,
+        engine: Phoenix.LiveView.HTMLEngine,
+        file: __ENV__.file,
+        line: __ENV__.line + 1,
+        module: __ENV__.module,
+        indentation: 0
+      )
+
+    :ets.insert_new(@name.Components, {path, component})
+
+    {:reply, component, state}
+  end
+
+  defp read_body(path) do
     icon = File.read!(path)
 
     <<"<svg ", body::binary>> = icon

mix.exs

@@ -20,7 +20,8 @@ defmodule HeroiconsElixir.MixProject do
   # Run "mix help compile.app" to learn about applications.
   def application do
     [
-      extra_applications: [:logger]
+      extra_applications: [:logger],
+      mod: {Heroicons, []}
     ]
   end