Move scrubber cache-related functions to Pleroma.HTML

lib/pleroma/html.ex

@@ -27,6 +27,40 @@ defmodule Pleroma.HTML do
   def filter_tags(html, scrubber), do: Scrubber.scrub(html, scrubber)
   def filter_tags(html), do: filter_tags(html, nil)
   def strip_tags(html), do: Scrubber.scrub(html, Scrubber.StripTags)
+
+  def get_cached_scrubbed_html_for_object(content, scrubbers, object) do
+    key = "#{generate_scrubber_signature(scrubbers)}|#{object.id}"
+    Cachex.fetch!(:scrubber_cache, key, fn _key -> ensure_scrubbed_html(content, scrubbers) end)
+  end
+
+  def get_cached_stripped_html_for_object(content, object) do
+    get_cached_scrubbed_html_for_object(content, HtmlSanitizeEx.Scrubber.StripTags, object)
+  end
+
+  def ensure_scrubbed_html(
+        content,
+        scrubbers
+      ) do
+    {:commit, filter_tags(content, scrubbers)}
+  end
+
+  defp generate_scrubber_signature(scrubber) when is_atom(scrubber) do
+    generate_scrubber_signature([scrubber])
+  end
+
+  defp generate_scrubber_signature(scrubbers) do
+    Enum.reduce(scrubbers, "", fn scrubber, signature ->
+      # If a scrubber does not have a version(e.g HtmlSanitizeEx.Scrubber.StripTags) it is assumed it is always 0)
+      version =
+        if Kernel.function_exported?(scrubber, :version, 0) do
+          scrubber.version
+        else
+          0
+        end
+
+      "#{signature}#{to_string(scrubber)}#{version}"
+    end)
+  end
 end
 
 defmodule Pleroma.HTML.Scrubber.TwitterText do