Cache the issuable counters for 2 minutes

Signed-off-by: Rémy Coutable <remy@rymai.me>

3 files changed, 41 insertions, 28 deletions

diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index bbc037288db..ebd78bf9888 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -280,29 +280,6 @@ module ApplicationHelper
     end
   end
 
-  def issuables_state_counter_text(state, issuables)
-    titles = {
-      opened: "Open"
-    }
-
-    state_title = titles[state] || state.to_s.humanize
-
-    count =
-      if @issues || @merge_requests
-        issuables_finder = @issues ? issues_finder : merge_requests_finder
-        issuables_finder.params[:state] = state
-        issuables_finder.execute.page(1).total_count
-      end
-
-    html = content_tag(:span, state_title)
-
-    if count.present?
-      html << " " << content_tag(:span, number_with_delimiter(count), class: 'badge')
-    end
-
-    html.html_safe
-  end
-
   def truncate_first_line(message, length = 50)
     truncate(message.each_line.first.chomp, length: length) if message
   end
diff --git a/app/helpers/issuables_helper.rb b/app/helpers/issuables_helper.rb
index 5c04bba323f..8aa1ece017c 100644
--- a/app/helpers/issuables_helper.rb
+++ b/app/helpers/issuables_helper.rb
@@ -94,6 +94,24 @@ module IssuablesHelper
     label_names.join(', ')
   end
 
+  def issuables_state_counter_text(issuable_type, state)
+    titles = {
+      opened: "Open"
+    }
+
+    state_title = titles[state] || state.to_s.humanize
+
+    count =
+      Rails.cache.fetch(issuables_state_counter_cache_key(issuable_type, state), expires_in: 2.minutes) do
+        issuables_count_for_state(issuable_type, state)
+      end
+
+    html = content_tag(:span, state_title)
+    html << " " << content_tag(:span, number_with_delimiter(count), class: 'badge')
+
+    html.html_safe
+  end
+
   private
 
   def sidebar_gutter_collapsed?
@@ -111,4 +129,22 @@ module IssuablesHelper
       issuable.open? ? :opened : :closed
     end
   end
+
+  def issuables_count_for_state(issuable_type, state)
+    issuables_finder = public_send("#{issuable_type}_finder")
+    issuables_finder.params[:state] = state
+
+    issuables_finder.execute.page(1).total_count
+  end
+
+  IRRELEVANT_PARAMS_FOR_CACHE_KEY = %w[utf8 sort page]
+  private_constant :IRRELEVANT_PARAMS_FOR_CACHE_KEY
+
+  def issuables_state_counter_cache_key(issuable_type, state)
+    opts = params.dup
+    opts['state'] = state
+    opts.delete_if { |k, v| IRRELEVANT_PARAMS_FOR_CACHE_KEY.include?(k) }
+
+    hexdigest(['issuables_count', issuable_type, opts.sort].flatten.join('-'))
+  end
 end
diff --git a/app/views/shared/issuable/_nav.html.haml b/app/views/shared/issuable/_nav.html.haml
index 475b99a2a07..5527a2f889a 100644
--- a/app/views/shared/issuable/_nav.html.haml
+++ b/app/views/shared/issuable/_nav.html.haml
@@ -5,21 +5,21 @@
 %ul.nav-links.issues-state-filters
   %li{class: ("active" if params[:state] == 'opened')}
     = link_to page_filter_path(state: 'opened', label: true), title: "Filter by #{page_context_word} that are currently opened." do
-      #{issuables_state_counter_text(:opened, issuables)}
+      #{issuables_state_counter_text(type, :opened)}
 
   - if type == :merge_requests
     %li{class: ("active" if params[:state] == 'merged')}
       = link_to page_filter_path(state: 'merged', label: true), title: 'Filter by merge requests that are currently merged.' do
-        #{issuables_state_counter_text(:merged, issuables)}
+        #{issuables_state_counter_text(type, :merged)}
 
     %li{class: ("active" if params[:state] == 'closed')}
       = link_to page_filter_path(state: 'closed', label: true), title: 'Filter by merge requests that are currently closed and unmerged.' do
-        #{issuables_state_counter_text(:closed, issuables)}
+        #{issuables_state_counter_text(type, :closed)}
   - else
     %li{class: ("active" if params[:state] == 'closed')}
       = link_to page_filter_path(state: 'closed', label: true), title: 'Filter by issues that are currently closed.' do
-        #{issuables_state_counter_text(:closed, issuables)}
+        #{issuables_state_counter_text(type, :closed)}
 
   %li{class: ("active" if params[:state] == 'all')}
     = link_to page_filter_path(state: 'all', label: true), title: "Show all #{page_context_word}." do
-      #{issuables_state_counter_text(:all, issuables)}
+      #{issuables_state_counter_text(type, :all)}