From 00ac76cc4ce87954d770abae411c54eb8bf23360 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Coutable?= <remy@rymai.me>
Date: Tue, 4 Jul 2017 16:15:24 +0200
Subject: Cache the allowed user IDs for the performance bar, in Redis for 10
 minutes
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Signed-off-by: Rémy Coutable <remy@rymai.me>
---
 lib/gitlab/performance_bar.rb | 52 +++++++++++++++++++++++++++++--------------
 1 file changed, 35 insertions(+), 17 deletions(-)

(limited to 'lib/gitlab/performance_bar.rb')

diff --git a/lib/gitlab/performance_bar.rb b/lib/gitlab/performance_bar.rb
index 60c8ba5063e..85f4371ec23 100644
--- a/lib/gitlab/performance_bar.rb
+++ b/lib/gitlab/performance_bar.rb
@@ -1,35 +1,53 @@
 module Gitlab
   module PerformanceBar
+    ALLOWED_USER_IDS_KEY = 'performance_bar_allowed_user_ids'.freeze
+    # The time (in seconds) after which a set of allowed user IDs is expired
+    # automatically.
+    ALLOWED_USER_IDS_TIME_TO_LIVE = 10.minutes.to_i
+
     def self.enabled?(current_user = nil)
       Feature.enabled?(:gitlab_performance_bar, current_user)
     end
 
     def self.allowed_user?(user)
-      return false unless allowed_group
+      return false unless allowed_group_name
 
-      if RequestStore.active?
-        RequestStore.fetch('performance_bar:user_member_of_allowed_group') do
-          user_member_of_allowed_group?(user)
-        end
-      else
-        user_member_of_allowed_group?(user)
-      end
+      allowed_user_ids.include?(user.id)
     end
 
-    def self.allowed_group
-      return nil unless Gitlab.config.performance_bar.allowed_group
+    def self.allowed_group_name
+      Gitlab.config.performance_bar.allowed_group
+    end
+
+    def self.allowed_user_ids
+      Gitlab::Redis.with do |redis|
+        if redis.exists(cache_key)
+          redis.smembers(cache_key).map(&:to_i)
+        else
+          group = Group.find_by_full_path(allowed_group_name)
+          # Redis#sadd doesn't accept an empty array, but we still want to use
+          # Redis to let us know that no users are allowed, so we set the
+          # array to [-1] in this case.
+          user_ids =
+            if group
+              GroupMembersFinder.new(group).execute
+                .pluck(:user_id).presence || [-1]
+            else
+              [-1]
+            end
+
+          redis.multi do
+            redis.sadd(cache_key, user_ids)
+            redis.expire(cache_key, ALLOWED_USER_IDS_TIME_TO_LIVE)
+          end
 
-      if RequestStore.active?
-        RequestStore.fetch('performance_bar:allowed_group') do
-          Group.find_by_full_path(Gitlab.config.performance_bar.allowed_group)
+          user_ids
         end
-      else
-        Group.find_by_full_path(Gitlab.config.performance_bar.allowed_group)
       end
     end
 
-    def self.user_member_of_allowed_group?(user)
-      GroupMembersFinder.new(allowed_group).execute.exists?(user_id: user.id)
+    def self.cache_key
+      "#{ALLOWED_USER_IDS_KEY}:#{allowed_group_name}"
     end
   end
 end
-- 
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