Add latest changes from gitlab-org/gitlab@13-2-stable-ee

1 files changed, 54 insertions, 0 deletions

diff --git a/lib/gitlab/diff/stats_cache.rb b/lib/gitlab/diff/stats_cache.rb
new file mode 100644
index 00000000000..f38fb21d497
--- /dev/null
+++ b/lib/gitlab/diff/stats_cache.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+#
+module Gitlab
+  module Diff
+    class StatsCache
+      include Gitlab::Metrics::Methods
+      include Gitlab::Utils::StrongMemoize
+
+      EXPIRATION = 1.week
+      VERSION = 1
+
+      def initialize(cachable_key:)
+        @cachable_key = cachable_key
+      end
+
+      def read
+        strong_memoize(:cached_values) do
+          content = cache.fetch(key)
+
+          next unless content
+
+          stats = content.map { |stat| Gitaly::DiffStats.new(stat) }
+
+          Gitlab::Git::DiffStatsCollection.new(stats)
+        end
+      end
+
+      def write_if_empty(stats)
+        return if cache.exist?(key)
+        return unless stats
+
+        cache.write(key, stats.as_json, expires_in: EXPIRATION)
+      end
+
+      def clear
+        cache.delete(key)
+      end
+
+      private
+
+      attr_reader :cachable_key
+
+      def cache
+        Rails.cache
+      end
+
+      def key
+        strong_memoize(:redis_key) do
+          ['diff_stats', cachable_key, VERSION].join(":")
+        end
+      end
+    end
+  end
+end