1 files changed, 64 insertions, 0 deletions
diff --git a/lib/gitlab/database/schema_version_files.rb b/lib/gitlab/database/schema_version_files.rb
new file mode 100644
index 00000000000..27a942404ef
--- /dev/null
+++ b/lib/gitlab/database/schema_version_files.rb
@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    class SchemaVersionFiles
+      SCHEMA_DIRECTORY = 'db/schema_migrations'
+      MIGRATION_DIRECTORIES = %w[db/migrate db/post_migrate].freeze
+      MIGRATION_VERSION_GLOB = '20[0-9][0-9]*'
+
+      def self.touch_all(versions_from_database)
+        versions_from_migration_files = find_versions_from_migration_files
+
+        version_filepaths = find_version_filenames.map { |f| schema_directory.join(f) }
+        FileUtils.rm(version_filepaths)
+
+        versions_to_create = versions_from_database & versions_from_migration_files
+        versions_to_create.each do |version|
+          version_filepath = schema_directory.join(version)
+
+          File.open(version_filepath, 'w') do |file|
+            file << Digest::SHA256.hexdigest(version)
+          end
+        end
+      end
+
+      def self.load_all
+        version_filenames = find_version_filenames
+        return if version_filenames.empty?
+
+        values = version_filenames.map { |vf| "('#{connection.quote_string(vf)}')" }
+        connection.execute(<<~SQL)
+          INSERT INTO schema_migrations (version)
+          VALUES #{values.join(',')}
+          ON CONFLICT DO NOTHING
+        SQL
+      end
+
+      def self.schema_directory
+        @schema_directory ||= Rails.root.join(SCHEMA_DIRECTORY)
+      end
+
+      def self.migration_directories
+        @migration_directories ||= MIGRATION_DIRECTORIES.map { |dir| Rails.root.join(dir) }
+      end
+
+      def self.find_version_filenames
+        Dir.glob(MIGRATION_VERSION_GLOB, base: schema_directory)
+      end
+
+      def self.find_versions_from_migration_files
+        migration_directories.each_with_object([]) do |directory, migration_versions|
+          directory_migrations = Dir.glob(MIGRATION_VERSION_GLOB, base: directory)
+          directory_versions = directory_migrations.map! { |m| m.split('_').first }
+
+          migration_versions.concat(directory_versions)
+        end
+      end
+
+      def self.connection
+        ActiveRecord::Base.connection
+      end
+    end
+  end
+end