Add cache to storage_size DB hits

ee/app/models/ee/namespace/root_storage_size.rb

@@ -2,6 +2,10 @@
 
 module EE
   class Namespace::RootStorageSize
+    CURRENT_SIZE_CACHE_KEY = 'root_storage_current_size'
+    LIMIT_CACHE_KEY = 'root_storage_size_limit'
+    EXPIRATION_TIME = 10.minutes
+
     def initialize(root_namespace)
       @root_namespace = root_namespace
     end
@@ -17,12 +21,16 @@ module EE
     end
 
     def current_size
-      @current_size ||= root_namespace.root_storage_statistics&.storage_size
+      @current_size ||= Rails.cache.fetch(['namespaces', root_namespace.id, CURRENT_SIZE_CACHE_KEY], expires_in: EXPIRATION_TIME) do
+        root_namespace.root_storage_statistics&.storage_size
+      end
     end
 
     def limit
-      @limit ||= root_namespace.actual_limits.storage_size_limit.megabytes +
-      root_namespace.additional_purchased_storage_size.megabytes
+      @limit ||= Rails.cache.fetch(['namespaces', root_namespace.id, LIMIT_CACHE_KEY], expires_in: EXPIRATION_TIME) do
+        root_namespace.actual_limits.storage_size_limit.megabytes +
+            root_namespace.additional_purchased_storage_size.megabytes
+      end
     end
 
     private

ee/spec/models/namespace/root_storage_size_spec.rb

@@ -62,6 +62,16 @@ RSpec.describe Namespace::RootStorageSize, type: :model do
     subject { model.current_size }
 
     it { is_expected.to eq(current_size) }
+
+    context 'caches values', :use_clean_rails_memory_store_caching do
+      let(:key) { 'root_storage_current_size' }
+
+      it 'caches the value' do
+        subject
+
+        expect(Rails.cache.read(['namespaces', namespace.id, key])).to eq(current_size)
+      end
+    end
   end
 
   describe '#limit' do
@@ -93,5 +103,20 @@ RSpec.describe Namespace::RootStorageSize, type: :model do
 
       it { is_expected.to eq(0) }
     end
+
+    context 'caches values', :use_clean_rails_memory_store_caching do
+      let(:key) { 'root_storage_size_limit' }
+
+      before do
+        plan_limits.update!(storage_size_limit: 70_000)
+        namespace.update!(additional_purchased_storage_size: 34_000)
+      end
+
+      it 'caches the value' do
+        subject
+
+        expect(Rails.cache.read(['namespaces', namespace.id, key])).to eq(104_000.megabytes)
+      end
+    end
   end
 end