1 files changed, 55 insertions, 0 deletions
diff --git a/lib/gitlab/set_cache.rb b/lib/gitlab/set_cache.rb
new file mode 100644
index 00000000000..0927a3e64bb
--- /dev/null
+++ b/lib/gitlab/set_cache.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+# Interface to the Redis-backed cache store to keep track of complete cache keys
+# for a ReactiveCache resource.
+module Gitlab
+  class SetCache
+    attr_reader :expires_in
+
+    def initialize(expires_in: 2.weeks)
+      @expires_in = expires_in
+    end
+
+    def cache_key(key)
+      "#{key}:set"
+    end
+
+    def expire(key)
+      with { |redis| redis.del(cache_key(key)) }
+    end
+
+    def exist?(key)
+      with { |redis| redis.exists(cache_key(key)) }
+    end
+
+    def write(key, value)
+      with do |redis|
+        redis.pipelined do
+          redis.sadd(cache_key(key), value)
+
+          redis.expire(cache_key(key), expires_in)
+        end
+      end
+
+      value
+    end
+
+    def read(key)
+      with { |redis| redis.smembers(cache_key(key)) }
+    end
+
+    def include?(key, value)
+      with { |redis| redis.sismember(cache_key(key), value) }
+    end
+
+    def ttl(key)
+      with { |redis| redis.ttl(cache_key(key)) }
+    end
+
+    private
+
+    def with(&blk)
+      Gitlab::Redis::Cache.with(&blk) # rubocop:disable CodeReuse/ActiveRecord
+    end
+  end
+end