Add latest changes from gitlab-org/gitlab@14-3-stable-eev14.3.0-rc42

1 files changed, 53 insertions, 0 deletions

diff --git a/lib/gitlab/database/migration.rb b/lib/gitlab/database/migration.rb
new file mode 100644
index 00000000000..b2248b0f4eb
--- /dev/null
+++ b/lib/gitlab/database/migration.rb
@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    class Migration
+      module LockRetriesConcern
+        extend ActiveSupport::Concern
+
+        class_methods do
+          def enable_lock_retries!
+            @enable_lock_retries = true # rubocop:disable Gitlab/ModuleWithInstanceVariables
+          end
+
+          def enable_lock_retries?
+            @enable_lock_retries
+          end
+        end
+
+        delegate :enable_lock_retries?, to: :class
+      end
+
+      # This implements a simple versioning scheme for migration helpers.
+      #
+      # We need to be able to version helpers, so we can change their behavior without
+      # altering the behavior of already existing migrations in incompatible ways.
+      #
+      # We can continue to change the behavior of helpers without bumping the version here,
+      # *if* the change is backwards-compatible.
+      #
+      # If not, we would typically override the helper method in a new MigrationHelpers::V[0-9]+
+      # class and create a new entry with a bumped version below.
+      #
+      # We use major version bumps to indicate significant changes and minor version bumps
+      # to indicate backwards-compatible or otherwise minor changes (e.g. a Rails version bump).
+      # However, this hasn't been strictly formalized yet.
+      MIGRATION_CLASSES = {
+        1.0 => Class.new(ActiveRecord::Migration[6.1]) do
+          include LockRetriesConcern
+          include Gitlab::Database::MigrationHelpers::V2
+        end
+      }.freeze
+
+      def self.[](version)
+        MIGRATION_CLASSES[version] || raise(ArgumentError, "Unknown migration version: #{version}")
+      end
+
+      # The current version to be used in new migrations
+      def self.current_version
+        1.0
+      end
+    end
+  end
+end