Merge branch 'banzai-metrics' into 'master'

Instrument Banzai code

See merge request !3659

config/initializers/metrics.rb

@@ -75,6 +75,29 @@ if Gitlab::Metrics.enabled?
       config.instrument_methods(const)
       config.instrument_instance_methods(const)
     end
+
+    # Instruments all Banzai filters
+    Dir[Rails.root.join('lib', 'banzai', 'filter', '*.rb')].each do |file|
+      klass = File.basename(file, File.extname(file)).camelize
+      const = Banzai::Filter.const_get(klass)
+
+      config.instrument_methods(const)
+      config.instrument_instance_methods(const)
+    end
+
+    config.instrument_methods(Banzai::ReferenceExtractor)
+    config.instrument_instance_methods(Banzai::ReferenceExtractor)
+
+    config.instrument_methods(Banzai::Renderer)
+    config.instrument_methods(Banzai::Querying)
+
+    [Issuable, Mentionable, Participable].each do |klass|
+      config.instrument_instance_methods(klass)
+      config.instrument_instance_methods(klass::ClassMethods)
+    end
+
+    config.instrument_methods(Gitlab::ReferenceExtractor)
+    config.instrument_instance_methods(Gitlab::ReferenceExtractor)
   end
 
   GC::Profiler.enable

lib/banzai/renderer.rb

@@ -19,9 +19,11 @@ module Banzai
       cache_key = full_cache_key(cache_key, context[:pipeline])
 
       if cache_key
+        Gitlab::Metrics.measure(:banzai_cached_render) do
           Rails.cache.fetch(cache_key) do
             cacheless_render(text, context)
           end
+        end
       else
         cacheless_render(text, context)
       end
@@ -64,6 +66,7 @@ module Banzai
     private
 
     def self.cacheless_render(text, context = {})
+      Gitlab::Metrics.measure(:banzai_cacheless_render) do
         result = render_result(text, context)
 
         output = result[:output]
@@ -73,6 +76,7 @@ module Banzai
           output.to_s
         end
       end
+    end
 
     def self.full_cache_key(cache_key, pipeline_name)
       return unless cache_key