Add latest changes from gitlab-org/gitlab@14-1-stable-eev14.1.0-rc42

4 files changed, 43 insertions, 8 deletions

diff --git a/lib/gitlab/pagination/keyset/column_order_definition.rb b/lib/gitlab/pagination/keyset/column_order_definition.rb
index 0c8ec02a56b..0755af9587b 100644
--- a/lib/gitlab/pagination/keyset/column_order_definition.rb
+++ b/lib/gitlab/pagination/keyset/column_order_definition.rb
@@ -120,7 +120,7 @@ module Gitlab
         AREL_ORDER_CLASSES = { Arel::Nodes::Ascending => :asc, Arel::Nodes::Descending => :desc }.freeze
         ALLOWED_NULLABLE_VALUES = [:not_nullable, :nulls_first, :nulls_last].freeze
 
-        attr_reader :attribute_name, :column_expression, :order_expression, :add_to_projections
+        attr_reader :attribute_name, :column_expression, :order_expression, :add_to_projections, :order_direction
 
         def initialize(attribute_name:, order_expression:, column_expression: nil, reversed_order_expression: nil, nullable: :not_nullable, distinct: true, order_direction: nil, add_to_projections: false)
           @attribute_name = attribute_name
@@ -175,7 +175,7 @@ module Gitlab
 
         private
 
-        attr_reader :reversed_order_expression, :nullable, :distinct, :order_direction
+        attr_reader :reversed_order_expression, :nullable, :distinct
 
         def calculate_reversed_order(order_expression)
           unless AREL_ORDER_CLASSES.has_key?(order_expression.class) # Arel can reverse simple orders
diff --git a/lib/gitlab/pagination/keyset/iterator.rb b/lib/gitlab/pagination/keyset/iterator.rb
index 3bc8c0bf616..c6f0014a0f4 100644
--- a/lib/gitlab/pagination/keyset/iterator.rb
+++ b/lib/gitlab/pagination/keyset/iterator.rb
@@ -4,8 +4,12 @@ module Gitlab
   module Pagination
     module Keyset
       class Iterator
-        def initialize(scope:, use_union_optimization: false)
-          @scope = scope
+        UnsupportedScopeOrder = Class.new(StandardError)
+
+        def initialize(scope:, use_union_optimization: true)
+          @scope, success = Gitlab::Pagination::Keyset::SimpleOrderBuilder.build(scope)
+          raise(UnsupportedScopeOrder, 'The order on the scope does not support keyset pagination') unless success
+
           @order = Gitlab::Pagination::Keyset::Order.extract_keyset_order_object(scope)
           @use_union_optimization = use_union_optimization
         end
diff --git a/lib/gitlab/pagination/keyset/order.rb b/lib/gitlab/pagination/keyset/order.rb
index cef3a7b291a..19d44ee69dd 100644
--- a/lib/gitlab/pagination/keyset/order.rb
+++ b/lib/gitlab/pagination/keyset/order.rb
@@ -139,6 +139,8 @@ module Gitlab
 
           verify_incoming_values!(values)
 
+          return use_composite_row_comparison(values) if composite_row_comparison_possible?
+
           where_values = []
 
           reversed_column_definitions = column_definitions.reverse
@@ -187,6 +189,28 @@ module Gitlab
 
         private
 
+        def composite_row_comparison_possible?
+          !column_definitions.one? &&
+            column_definitions.all?(&:not_nullable?) &&
+            column_definitions.map(&:order_direction).uniq.one? # all columns uses the same order direction
+        end
+
+        # composite row comparison works with NOT NULL columns and may use only one index scan given a proper index setup
+        # Example: (created_at, id) > ('2012-09-18 01:40:01+00', 15)
+        def use_composite_row_comparison(values)
+          columns = Arel::Nodes::Grouping.new(column_definitions.map(&:column_expression))
+          values = Arel::Nodes::Grouping.new(column_definitions.map do |column_definition|
+            value = values[column_definition.attribute_name]
+            Arel::Nodes.build_quoted(value, column_definition.column_expression)
+          end)
+
+          if column_definitions.first.ascending_order?
+            [columns.gt(values)]
+          else
+            [columns.lt(values)]
+          end
+        end
+
         # Adds extra columns to the SELECT clause
         def apply_custom_projections(scope)
           additional_projections = column_definitions.select(&:add_to_projections).map do |column_definition|
diff --git a/lib/gitlab/pagination/offset_pagination.rb b/lib/gitlab/pagination/offset_pagination.rb
index 2805b12d95d..4f8a6ffb2cc 100644
--- a/lib/gitlab/pagination/offset_pagination.rb
+++ b/lib/gitlab/pagination/offset_pagination.rb
@@ -19,11 +19,10 @@ module Gitlab
       private
 
       def paginate_with_limit_optimization(relation)
-        # do not paginate relation if it is already paginated
-        pagination_data = if relation.respond_to?(:current_page) && relation.current_page == params[:page] && relation.limit_value == params[:per_page]
-                            relation
-                          else
+        pagination_data = if needs_pagination?(relation)
                             relation.page(params[:page]).per(params[:per_page])
+                          else
+                            relation
                           end
 
         return pagination_data unless pagination_data.is_a?(ActiveRecord::Relation)
@@ -39,6 +38,14 @@ module Gitlab
         end
       end
 
+      def needs_pagination?(relation)
+        return true unless relation.respond_to?(:current_page)
+        return true if params[:page].present? && relation.current_page != params[:page].to_i
+        return true if params[:per_page].present? && relation.limit_value != params[:per_page].to_i
+
+        false
+      end
+
       def add_default_order(relation)
         if relation.is_a?(ActiveRecord::Relation) && relation.order_values.empty?
           relation = relation.order(:id) # rubocop: disable CodeReuse/ActiveRecord