Merge branch 'sh-add-thread-memory-cache' into 'master'

Add a memory cache local to the thread to reduce Redis load

Closes #63977

See merge request gitlab-org/gitlab-ce!30233

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/gitlab/thread_memory_cache.rb b/lib/gitlab/thread_memory_cache.rb
new file mode 100644
index 00000000000..7f363dc7feb
--- /dev/null
+++ b/lib/gitlab/thread_memory_cache.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module Gitlab
+  class ThreadMemoryCache
+    THREAD_KEY = :thread_memory_cache
+
+    def self.cache_backend
+      # Note ActiveSupport::Cache::MemoryStore is thread-safe.  Since
+      # each backend is local per thread we probably don't need to worry
+      # about synchronizing access, but this is a drop-in replacement
+      # for ActiveSupport::Cache::RedisStore.
+      Thread.current[THREAD_KEY] ||= ActiveSupport::Cache::MemoryStore.new
+    end
+  end
+end