MDL-73926 backup: Add hook to exclude events for triggering backup

backup/upgrade.txt

@@ -7,6 +7,7 @@ information provided here is intended especially for developers.
   async backups (See MDL-69983).
 * During restore the function create_included_users has been updated to convert backups containing
   legacy MD5 hashed passwords to the new password hashing scheme (See MDL-79134).
+* New get_excluded_events hook for excluding events from automated backup has been implemented (See MDL-73926).
 
 === 4.1 ===
 

backup/util/helper/backup_cron_helper.class.php

@@ -778,18 +778,31 @@ abstract class backup_cron_automated_helper {
      * intentional, since we cannot reliably determine if any modification was made or not.
      */
     protected static function is_course_modified($courseid, $since) {
+        global $DB;
         $logmang = get_log_manager();
         $readers = $logmang->get_readers('core\log\sql_reader');
         $params = array('courseid' => $courseid, 'since' => $since);
 
+        // Exclude events defined by hook.
+        $hook = new \core\hook\backup\get_excluded_events();
+        \core\hook\manager::get_instance()->dispatch($hook);
+        $excludedevents = $hook->get_events();
+
         foreach ($readers as $readerpluginname => $reader) {
             $where = "courseid = :courseid and timecreated > :since and crud <> 'r'";
 
+            $excludeevents = [];
             // Prevent logs of prevous backups causing a false positive.
             if ($readerpluginname != 'logstore_legacy') {
-                $where .= " and target <> 'course_backup'";
+                $excludeevents[] = '\core\event\course_backup_created';
             }
 
+            $excludeevents = array_merge($excludeevents, $excludedevents);
+            if ($excludeevents) {
+                list($notinsql, $notinparams) = $DB->get_in_or_equal($excludeevents, SQL_PARAMS_NAMED, 'eventname', false);
+                $where .= 'AND eventname ' . $notinsql;
+                $params = array_merge($params, $notinparams);
+            }
             if ($reader->get_events_select_exists($where, $params)) {
                 return true;
             }

lib/classes/hook/backup/get_excluded_events.php

@@ -0,0 +1,74 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+namespace core\hook\backup;
+
+use core\hook\described_hook;
+
+/**
+ * Get a list of event names which are excluded to trigger from course changes in automated backup.
+ *
+ * @package    core
+ * @copyright  2023 Tomo Tsuyuki <tomotsuyuki@catalyst-au.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+final class get_excluded_events implements described_hook {
+
+    /**
+     * @var string[] Array of event names.
+     */
+    private $events = [];
+
+    /**
+     * Describes the hook purpose.
+     *
+     * @return string
+     */
+    public static function get_hook_description(): string {
+        return 'Get a list of event names which are excluded to trigger from course changes in automated backup.';
+    }
+
+    /**
+     * List of tags that describe this hook.
+     *
+     * @return string[]
+     */
+    public static function get_hook_tags(): array {
+        return ['backup'];
+    }
+
+    /**
+     * Add an array of event names which are excluded to trigger from course changes in automated backup.
+     * This is set from plugin hook.
+     * e.g. ['\local_course\event\update', '\local_course\event\sync']
+     *
+     * @param string[] $events Array of event name strings
+     * @return void
+     */
+    public function add_events(array $events): void {
+        $this->events = array_merge($this->events, $events);
+    }
+
+    /**
+     * Get an array of event names which are excluded to trigger from course changes in automated backup.
+     * This is called after dispatch for the hook and use values to exclude events for backup.
+     *
+     * @return array
+     */
+    public function get_events(): array {
+        return $this->events;
+    }
+}

version.php

@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2023120700.00;              // YYYYMMDD      = weekly release date of this DEV branch.
+$version  = 2023120700.01;              // YYYYMMDD      = weekly release date of this DEV branch.
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.
 $release  = '4.4dev (Build: 20231207)'; // Human-friendly version name