refactor: improve speed of index page rendering with tags

db/migrations/20180122_create_head_pact_publications.rb

@@ -0,0 +1,21 @@
+Sequel.migration do
+  change do
+
+    # This view includes all the latest pacts, as well as the latest pacts
+    # for each tag.
+    # If a pact publication is the latest AND the latest tagged version
+    # there will be two rows in this view for it - one for the top
+    # query,and one for the bottom.
+    create_view(:head_pact_publications,
+      "select lp.*, null as tag_name, 1 as latest
+      from latest_pact_publications lp
+
+      UNION
+
+      select ltp.*, null as latest
+      from latest_tagged_pact_publications ltp
+      "
+    )
+
+  end
+end

lib/pact_broker/index/service.rb

@@ -13,6 +13,9 @@ class Service
       extend PactBroker::Logging
 
       def self.find_index_items options = {}
+        rows = []
+
+        if !options[:tags]
         rows = PactBroker::Matrix::LatestRow
           .select_all_qualified
           .join(:latest_pact_publications, {consumer_id: :consumer_id, provider_id: :provider_id, consumer_version_order: :consumer_version_order})
@@ -21,21 +24,29 @@ def self.find_index_items options = {}
           .order(:consumer_name, :provider_name)
           .eager(:consumer_version_tags)
           .all
+        end
 
         if options[:tags]
-          tagged_rows = PactBroker::Matrix::LatestRow
+          tagged_rows = PactBroker::Matrix::Row
             .select_all_qualified
+            .select_append(:tag_name)
+            .join(:head_pact_publications, {id: :pact_publication_id})
             .eager(:latest_triggered_webhooks)
             .eager(:webhooks)
             .order(:consumer_name, :provider_name)
             .eager(:consumer_version_tags)
-            tagged_rows = tagged_rows.join(:latest_tagged_pact_consumer_version_orders, {consumer_id: :consumer_id, provider_id: :provider_id, latest_consumer_version_order: :consumer_version_order})
 
-          if options[:tags].is_a?(Array)
-            tagged_rows = tagged_rows.where(Sequel[:latest_tagged_pact_consumer_version_orders][:tag_name] => options[:tags])
-          end
+            if options[:tags].is_a?(Array)
+              tagged_rows = tagged_rows.where(Sequel[:head_pact_publications][:tag_name] => options[:tags]).or(Sequel[:head_pact_publications][:tag_name] => nil)
+            end
+
+            tagged_rows = tagged_rows.all
+              .group_by(&:pact_publication_id)
+              .values
+              .collect{|group| [group.first, group.collect{|r| r[:tag_name]}.compact] }
+              .collect{ |(row, tag_names)| row.consumer_head_tag_names = tag_names; row }
 
-          rows = (rows + tagged_rows.all).group_by(&:pact_publication_id).values.collect(&:last)
+          rows = tagged_rows
         end
 
         index_items = []

lib/pact_broker/matrix/row.rb

@@ -59,6 +59,16 @@ def order_by_names_ascending_most_recent_first
         end
       end
 
+      # tags for which this pact publication is the latest of that tag
+      # this is set in the code rather than the database
+      def consumer_head_tag_names
+        @consumer_head_tag_names ||= []
+      end
+
+      def consumer_head_tag_names= consumer_head_tag_names
+        @consumer_head_tag_names = consumer_head_tag_names
+      end
+
       def latest_triggered_webhooks
         @latest_triggered_webhooks ||= []
       end
@@ -76,12 +86,12 @@ def provider
       end
 
       def consumer_version
-        @consumer_version ||= OpenStruct.new(number: consumer_version_number, id: consumer_version_id)
+        @consumer_version ||= OpenStruct.new(number: consumer_version_number, id: consumer_version_id, pacticipant: consumer)
       end
 
       def provider_version
         if provider_version_number
-          @provider_version ||= OpenStruct.new(number: provider_version_number, id: provider_version_id)
+          @provider_version ||= OpenStruct.new(number: provider_version_number, id: provider_version_id, pacticipant: provider)
         end
       end
 
@@ -103,6 +113,7 @@ def latest_verification
             success: success,
             number: verification_number,
             execution_date: verification_executed_at,
+            created_at: verification_executed_at,
             provider_version_number: provider_version_number,
             build_url: verification_build_url,
             provider_version: provider_version