1 files changed, 45 insertions, 0 deletions
diff --git a/lib/gitlab/middleware/memory_report.rb b/lib/gitlab/middleware/memory_report.rb
new file mode 100644
index 00000000000..1c6c771009c
--- /dev/null
+++ b/lib/gitlab/middleware/memory_report.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Middleware
+    class MemoryReport
+      def initialize(app)
+        @app = app
+      end
+
+      def call(env)
+        request = ActionDispatch::Request.new(env)
+
+        return @app.call(env) unless rendering_memory_profiler?(request)
+
+        begin
+          require 'memory_profiler'
+
+          report = MemoryProfiler.report do
+            @app.call(env)
+          end
+
+          report = report_to_string(report)
+          headers = { 'Content-Type' => 'text/plain' }
+
+          [200, headers, [report]]
+        rescue StandardError => e
+          ::Gitlab::ErrorTracking.track_exception(e)
+          [500, { 'Content-Type' => 'text/plain' }, ["Could not generate memory report: #{e}"]]
+        end
+      end
+
+      private
+
+      def rendering_memory_profiler?(request)
+        Rails.env.development? && request.params['performance_bar'] == 'memory'
+      end
+
+      def report_to_string(report)
+        io = StringIO.new
+        report.pretty_print(io, detailed_report: true, scale_bytes: true, normalize_paths: true)
+        io.string
+      end
+    end
+  end
+end