Add Gitaly data to the Peek performance bar

app/views/peek/views/_gitaly.html.haml

+- local_assigns.fetch(:view)
+
+%strong
+  %span{ data: { defer_to: "#{view.defer_key}-duration" } } ...
+  \/
+  %span{ data: { defer_to: "#{view.defer_key}-calls" } } ...
+  Gitaly

changelogs/unreleased/zj-peek-gitaly.yml

+---
+title: Add Gitaly metrics to the performance bar
+merge_request:
+author:
+type: other

config/initializers/peek.rb

@@ -16,6 +16,7 @@ Peek.into Peek::Views::Redis
 Peek.into Peek::Views::Sidekiq
 Peek.into Peek::Views::Rblineprof
 Peek.into Peek::Views::GC
+Peek.into Peek::Views::Gitaly
 
 # rubocop:disable Style/ClassAndModuleCamelCase
 class PEEK_DB_CLIENT

lib/gitlab/gitaly_client.rb

@@ -33,6 +33,12 @@ module Gitlab
     MUTEX = Mutex.new
     private_constant :MUTEX
 
+    class << self
+      attr_accessor :query_time
+    end
+
+    self.query_time = 0
+
     def self.stub(name, storage)
       MUTEX.synchronize do
         @stubs ||= {}
@@ -83,11 +89,14 @@ module Gitlab
     # end
     #
     def self.call(storage, service, rpc, request)
+      start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
       enforce_gitaly_request_limits(:call)
 
       kwargs = request_kwargs(storage)
       kwargs = yield(kwargs) if block_given?
       stub(service, storage).__send__(rpc, request, kwargs) # rubocop:disable GitlabSecurity/PublicSend
+    ensure
+      self.query_time += Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
     end
 
     def self.request_kwargs(storage)

lib/peek/views/gitaly.rb

+module Peek
+  module Views
+    class Gitaly < View
+      def duration
+        ::Gitlab::GitalyClient.query_time
+      end
+
+      def calls
+        ::Gitlab::GitalyClient.get_request_count
+      end
+
+      def results
+        { duration: formatted_duration, calls: calls }
+      end
+
+      private
+
+      def formatted_duration
+        ms = duration * 1000
+        if ms >= 1000
+          "%.2fms" % ms
+        else
+          "%.0fms" % ms
+        end
+      end
+
+      def setup_subscribers
+        subscribe 'start_processing.action_controller' do
+          ::Gitlab::GitalyClient.query_time = 0
+        end
+      end
+    end
+  end
+end