gitlab-org--gitlab-foss/lib/gitlab/background_migration/cleanup_concurrent_schema_change.rb
Sean McGivern d3d9077830 Add a helper to rename a column using a background migration
This works the same way as change_column_type_using_background_migration, but
for renaming a column. It takes a table, not a relation, to match its concurrent
counterpart.

Also, generalise the cleanup migrations to reduce code duplication.
2018-06-26 13:54:52 +01:00

52 lines
1.5 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module BackgroundMigration
# Base class for cleaning up concurrent schema changes.
class CleanupConcurrentSchemaChange
include Database::MigrationHelpers
# table - The name of the table the migration is performed for.
# old_column - The name of the old (to drop) column.
# new_column - The name of the new column.
def perform(table, old_column, new_column)
return unless column_exists?(table, new_column)
rows_to_migrate = define_model_for(table)
.where(new_column => nil)
.where
.not(old_column => nil)
if rows_to_migrate.any?
BackgroundMigrationWorker.perform_in(
RESCHEDULE_DELAY,
self.class.name,
[table, old_column, new_column]
)
else
cleanup_concurrent_schema_change(table, old_column, new_column)
end
end
# These methods are necessary so we can re-use the migration helpers in
# this class.
def connection
ActiveRecord::Base.connection
end
def method_missing(name, *args, &block)
connection.__send__(name, *args, &block) # rubocop: disable GitlabSecurity/PublicSend
end
def respond_to_missing?(*args)
connection.respond_to?(*args) || super
end
def define_model_for(table)
Class.new(ActiveRecord::Base) do
self.table_name = table
end
end
end
end
end