Add measurement to import_rake task

lib/tasks/gitlab/import_export/import.rake

@@ -12,7 +12,7 @@
 namespace :gitlab do
   namespace :import_export do
     desc 'GitLab | Import/Export | EXPERIMENTAL | Import large project archives'
-    task :import, [:username, :namespace_path, :project_path, :archive_path] => :gitlab_environment do |_t, args|
+    task :import, [:username, :namespace_path, :project_path, :archive_path, :measurement_enabled] => :gitlab_environment do |_t, args|
       # Load it here to avoid polluting Rake tasks with Sidekiq test warnings
       require 'sidekiq/testing'
 
@@ -26,7 +26,8 @@ namespace :gitlab do
         namespace_path: args.namespace_path,
         project_path:   args.project_path,
         username:       args.username,
-        file_path:      args.archive_path
+        file_path:      args.archive_path,
+        measurement_enabled: args.measurement_enabled
       ).import
     end
   end
@@ -38,6 +39,7 @@ class GitlabProjectImport
     @file_path    = opts.fetch(:file_path)
     @namespace    = Namespace.find_by_full_path(opts.fetch(:namespace_path))
     @current_user = User.find_by_username(opts.fetch(:username))
+    @measurement_enabled = opts.fetch(:measurement_enabled || false)
   end
 
   def import
@@ -72,6 +74,54 @@ class GitlabProjectImport
     RequestStore.clear!
   end
 
+  def with_count_queries(&block)
+    count = 0
+
+    counter_f = ->(name, started, finished, unique_id, payload) {
+      unless payload[:name].in? %w[CACHE SCHEMA]
+        count += 1
+      end
+    }
+
+    ActiveSupport::Notifications.subscribed(counter_f, "sql.active_record", &block)
+
+    puts "Number of sql calls: #{count}"
+  end
+
+  def with_gc_counter
+    gc_counts_before = GC.stat.select { |k, v| k =~ /count/ }
+    yield
+    gc_counts_after = GC.stat.select { |k, v| k =~ /count/ }
+    stats = gc_counts_before.merge(gc_counts_after) { |k, vb, va| va - vb }
+    puts "Total GC count: #{stats[:count]}"
+    puts "Minor GC count: #{stats[:minor_gc_count]}"
+    puts "Major GC count: #{stats[:major_gc_count]}"
+  end
+
+  def with_measure_time
+    timing = Benchmark.realtime do
+      yield
+    end
+
+    time = Time.at(timing).utc.strftime("%H:%M:%S")
+    puts "Time to finish: #{time}"
+  end
+
+  def with_measuring
+    puts "Measuring enabled..."
+    with_gc_counter do
+      with_count_queries do
+        with_measure_time do
+          yield
+        end
+      end
+    end
+  end
+
+  def measurement_enabled?
+    @measurement_enabled
+  end
+
   # We want to ensure that all Sidekiq jobs are executed
   # synchronously as part of that process.
   # This ensures that all expensive operations do not escape
@@ -80,7 +130,7 @@ class GitlabProjectImport
     Sidekiq::Testing.fake! do
       with_request_store do
         ::Gitlab::GitalyClient.allow_n_plus_1_calls do
-          yield
+          measurement_enabled? ? with_measuring { yield } : yield
         end
       end