1 files changed, 61 insertions, 0 deletions
diff --git a/lib/gitlab/ci/config/entry/product/matrix.rb b/lib/gitlab/ci/config/entry/product/matrix.rb
new file mode 100644
index 00000000000..6af809d46c1
--- /dev/null
+++ b/lib/gitlab/ci/config/entry/product/matrix.rb
@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    class Config
+      module Entry
+        ##
+        # Entry that represents matrix style parallel builds.
+        #
+        module Product
+          class Matrix < ::Gitlab::Config::Entry::Node
+            include ::Gitlab::Utils::StrongMemoize
+            include ::Gitlab::Config::Entry::Validatable
+            include ::Gitlab::Config::Entry::Attributable
+
+            validations do
+              validates :config, array_of_hashes: true
+
+              validate on: :composed do
+                limit = Entry::Product::Parallel::PARALLEL_LIMIT
+
+                if number_of_generated_jobs > limit
+                  errors.add(:config, "generates too many jobs (maximum is #{limit})")
+                end
+              end
+            end
+
+            def compose!(deps = nil)
+              super(deps) do
+                @config.each_with_index do |variables, index|
+                  @entries[index] = ::Gitlab::Config::Entry::Factory.new(Entry::Product::Variables)
+                    .value(variables)
+                    .with(parent: self, description: 'matrix variables definition.') # rubocop:disable CodeReuse/ActiveRecord
+                    .create!
+                end
+
+                @entries.each_value do |entry|
+                  entry.compose!(deps)
+                end
+              end
+            end
+
+            def value
+              strong_memoize(:value) do
+                @entries.values.map(&:value)
+              end
+            end
+
+            # rubocop:disable CodeReuse/ActiveRecord
+            def number_of_generated_jobs
+              value.sum do |config|
+                config.values.reduce(1) { |acc, values| acc * values.size }
+              end
+            end
+            # rubocop:enable CodeReuse/ActiveRecord
+          end
+        end
+      end
+    end
+  end
+end