Issue#209 Remove db calls in get_active of outage

classes/dml/outagedb.php

@@ -211,21 +211,20 @@ class outagedb {
             throw new coding_exception('$time must be null or a positive int.', $time);
         }
 
-        $select = ':datetime2 <= stoptime AND (finished IS NULL OR :datetime3 <= finished)'; // End condition.
-        $select = "(warntime <= :datetime1 AND (${select}))"; // Full select part.
-        $data = $DB->get_records_select(
-            'auth_outage',
-            $select,
-            ['datetime1' => $time, 'datetime2' => $time, 'datetime3' => $time],
-            'starttime ASC, stoptime DESC, title ASC',
-            '*',
-            0,
-            1
-        );
+        // Get cached outage, or null.
+        $outageinfo = get_config('moodle', 'auth_outage_active_outage');
 
-        // Not using $DB->get_record_select instead because there is no 'limit' parameter.
-        // Allowing multiple records still raises an internal error.
-        return (count($data) == 0) ? null : new outage(array_shift($data));
+        if (!$outageinfo) {
+            return null;
+        } else {
+            $outagecache = new outage(json_decode($outageinfo));
+        }
+
+        if ($outagecache && $outagecache->warntime <= $time && $outagecache->stoptime >= $time
+            && (!$outagecache->finished || $outagecache->finished >= $time)) {
+            return  $outagecache;
+        }
+        return null;
     }
 
     /**

classes/local/outage.php

@@ -297,4 +297,12 @@ class outage {
         // Adjust bool fields.
         $this->autostart = ($this->autostart === null) ? null : (bool)$this->autostart;
     }
+
+    /**
+     * Return json encoded outage.
+     * @return string Json string.
+     */
+    public function __toString() {
+        return json_encode(get_object_vars($this));
+    }
 }

classes/local/outagelib.php

@@ -210,6 +210,10 @@ class outagelib {
         } else {
             $ongoingoutage = true;
         }
+
+        // Set json formatted outage string to cache.
+        set_config('auth_outage_active_outage', (string)$outage);
+
         maintenance_static_page::create_from_outage($outage)->generate();
         self::update_climaintenance_code($outage);
         if (!$ongoingoutage || $reenablemaint || is_null($outage)) {