This patch modifies the way copy data is shared in order to mitigate potential race conditions
and ensure that the serialised controller stored in the DB is always in a valid state.
The restore controller is now considered the "source of truth" for all information about the
copy operation. Backup controllers can no longer contain information about course copies.
As copy creation is not atomic, it is still possible for copy controllers to become orphaned or
exist in an invalid state. To mitigate this the backup cleanup task has been modified to call
a new helper method copy_helper::cleanup_orphaned_copy_controllers.
Summary of changes in this patch:
- Copy data must now be passed through the restore controller's constructor
- base_controller::get_copy has been deprecated in favour of restore_controller::get_copy
- base_controller::set_copy has been deprecated without replacement
- core_backup\copy\copy has been deprecated, use copy_helper.class.php's copy_helper instead
- backup_cleanup_task will now clean up orphaned controllers from copy operations that went awry
Thanks to Peter Burnett for assiting with testing this patch.
This patch adds better core support for copying courses.
There is now a simplified and dedicated UI for copying
courses. This can be accessed from the course context
menu or course management screens.
All backups are done asynchronously and there can be multiple
copies of a course in flight at once.
When a backup (or restore) is in progress and the user
has another tab open that is taking time to generate and
holding the session lock, a condition arises where
multiple ajax calls are "queued" because the long page
is holding the session lock. When this lock is released,
the queued ajax requests complete. However, as the ajax
requests also lock this can block other requests until they
complete. This patch decreases the frequency of ajax calls
and stops them from holding the session lock.
This patch adds asynchronous backup and restore functionality
to Moodle. This is an optional feature and is not enabled by
default. It can be enabled by site administrators.
Asynchronous backup and restores are actioned by the Moodle
adhoc task API. The progress of backup and restores is
displayedin the Moodle UI. Users can also be sent a message
when a backup or restore operation completes via the
Moodle messaging API.
Franziska Hübler