Use Redis for CacheMarkDownField on non AR models

This allows using `CacheMarkdownField` for models that are not backed
by ActiveRecord.

When the including class inherits `ActiveRecord::Base` we include
`Gitlab::MarkdownCache::ActiveRecord::Extension`. This will cause the
markdown fields to be rendered and the generated HTML stored in a
`<field>_html` attribute on the record. We also store the version
used for generating the markdown.

All other classes that include this model will include the
`Gitlab::MarkdownCache::Redis::Extension`. This add the `<field>_html`
attributes to that model and will generate the html in them. The
generated HTML will be cached in redis under the key
`markdown_cache:<class>:<id>`. The class this included in must
therefore respond to `id`.

1 files changed, 4 insertions, 7 deletions

diff --git a/app/models/commit.rb b/app/models/commit.rb
index f412d252e5c..fa0bf36ba49 100644
--- a/app/models/commit.rb
+++ b/app/models/commit.rb
@@ -13,6 +13,7 @@ class Commit
   include StaticModel
   include Presentable
   include ::Gitlab::Utils::StrongMemoize
+  include CacheMarkdownField
 
   attr_mentionable :safe_message, pipeline: :single_line
 
@@ -37,13 +38,9 @@ class Commit
   # Used by GFM to match and present link extensions on node texts and hrefs.
   LINK_EXTENSION_PATTERN = /(patch)/.freeze
 
-  def banzai_render_context(field)
-    pipeline = field == :description ? :commit_description : :single_line
-    context = { pipeline: pipeline, project: self.project }
-    context[:author] = self.author if self.author
-
-    context
-  end
+  cache_markdown_field :title, pipeline: :single_line
+  cache_markdown_field :full_title, pipeline: :single_line
+  cache_markdown_field :description, pipeline: :commit_description
 
   class << self
     def decorate(commits, project)