Delete orphaned session transients

espresso_delete_orphaned_session_transients.php

/**
 * espresso_delete_orphaned_session_transients
 * @param int $expired_session_transient_delete_query_limit
 */
function espresso_delete_orphaned_session_transients( $expired_session_transient_delete_query_limit ) {
	global $wpdb;
	// DELETE ORPHANED SESSION TRANSIENTS
	$SQL = "
		SELECT option_name
		FROM wp_options
		WHERE option_name LIKE '%\_ee\_ssn\_%'
		AND option_name NOT LIKE '%timeout%'
		AND option_name NOT IN (
			SELECT t2.option_name
			FROM wp_options t1
			JOIN wp_options t2 ON t2.option_name = REPLACE( t1.option_name, '_timeout', '' )
			WHERE ( t1.option_name LIKE '\_transient\_timeout\_ee\_ssn\_%' )
		)
		LIMIT 0, {$expired_session_transient_delete_query_limit}
	 ";

	$possibly_orphaned_sessions = $wpdb->get_col( $SQL );
	// valid results?
	if ( ! $possibly_orphaned_sessions instanceof WP_Error && ! empty( $possibly_orphaned_sessions )) {
		// format array of results into something usable within the actual DELETE query's IN clause
		$orphans = array();
		foreach( $possibly_orphaned_sessions as $possibly_orphaned_session ) {
			$orphans[] = "'" . $possibly_orphaned_session . "'";
		}
		$orphans = implode( ', ', $orphans );
		$SQL = "
			DELETE
			FROM {$wpdb->options}
			WHERE option_name
			IN ( $orphans )
		";
		$results = $wpdb->query( $SQL );
		// if something went wrong, then notify the admin
		if ( $results instanceof WP_Error && is_admin() ) {
			EE_Error::add_error( $results->get_error_message(), __FILE__, __FUNCTION__, __LINE__ );
		}
	}
}
add_action( 'FHEE__EE_Session__garbage_collection___end', 'espresso_delete_orphaned_session_transients', 10, 1 );