MDL-64883 mod_chat: convert cron to scheduled task

mod/chat/classes/task/cron_task.php

@@ -0,0 +1,65 @@
+<?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/>.
+
+/**
+ * A scheduled task for chat cron.
+ *
+ * @package    mod_chat
+ * @copyright  2019 Simey Lameze <simey@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+namespace mod_chat\task;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * The main schedule task for the chat module.
+ *
+ * @package   mod_chat
+ * @copyright 2019 Simey Lameze <simey@moodle.com>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class cron_task extends \core\task\scheduled_task {
+
+    /**
+     * Get a descriptive name for this task (shown to admins).
+     *
+     * @return string
+     */
+    public function get_name() {
+        return get_string('crontask', 'mod_chat');
+    }
+
+    /**
+     * Run chat cron.
+     */
+    public function execute() {
+        global $CFG, $DB;
+        require_once($CFG->dirroot . '/mod/chat/lib.php');
+
+        chat_update_chat_times();
+        chat_delete_old_users();
+
+        $timenow = time();
+        $subselect = "SELECT c.keepdays
+                        FROM {chat} c
+                       WHERE c.id = {chat_messages}.chatid";
+        $DB->delete_records_select('chat_messages', "($subselect) > 0 AND timestamp < ?",
+                [$timenow - ($subselect) * DAYSECS]);
+
+        $DB->delete_records_select('chat_messages_current', "timestamp < ?", [$timenow - 8 * HOURSECS]);
+    }
+}

mod/chat/db/tasks.php

@@ -0,0 +1,36 @@
+<?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/>.
+
+/**
+ * Definition of chat scheduled tasks.
+ *
+ * @package   mod_chat
+ * @copyright 2019 Simey Lameze <simey@moodle.com>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+$tasks = array(
+    array(
+        'classname' => '\mod_chat\task\cron_task',
+        'blocking' => 0,
+        'minute' => '*/5',
+        'hour' => '*',
+        'day' => '*',
+        'month' => '*',
+        'dayofweek' => '*'
+    )
+);

mod/chat/lang/en/chat.php

@@ -40,6 +40,7 @@ $string['configservermax'] = 'Max number of clients allowed';
 $string['configserverport'] = 'Port to use on the server for the daemon';
 $string['compact'] = 'Compact';
 $string['coursetheme'] = 'Course theme';
+$string['crontask'] = 'Background processing for chat module';
 $string['currentchats'] = 'Active chat sessions';
 $string['currentusers'] = 'Current users';
 $string['deletesession'] = 'Delete this session';

mod/chat/version.php

@@ -24,7 +24,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2018120300; // The current module version (Date: YYYYMMDDXX).
+$plugin->version   = 2018120301; // The current module version (Date: YYYYMMDDXX).
 $plugin->requires  = 2018112800; // Requires this Moodle version.
 $plugin->component = 'mod_chat'; // Full name of the plugin (used for diagnostics).
 $plugin->cron      = 300;