fix: Dramatically increase performance for get_my_slots

lbplanner/classes/enums/WEEKDAY.php

@@ -31,9 +31,8 @@
 use local_lbplanner\polyfill\Enum;
 
 /**
- * All the days of the week.
- * All seven of them.
- * Yup.
+ * ISO 8601 numeric representation of the day of the week.
+ * Same as `(int)DateTime::format('N');`
  */
 class WEEKDAY extends Enum {
     /**

lbplanner/classes/helpers/slot_helper.php

@@ -107,6 +107,42 @@ public static function get_all_slots(): array {
         return $slotsobj;
     }
 
+    /**
+     * Returns a list of all slots relevant for a vintage and range of weekdays.
+     *
+     * @param string $vintage the vintage to filter for
+     * @param int $today the starting day to filter for
+     * @param int $range the range in days
+     * @return slot[] An array of the slots.
+     */
+    public static function get_vintage_time_slots(string $vintage, int $today, int $range): array {
+        global $DB;
+
+        if ($range < 7) {
+            $valid = [];
+            for ($i = $today; $i < ($today + $range); $i++) {
+                array_push($valid, (($i - 1) % 7) + 1);
+            }
+            $insert = " AND slot.weekday IN (" . implode(',', $valid) . ")";
+        } else {
+            $insert = '';
+        }
+
+        $slots = $DB->get_records_sql(
+            'SELECT slot.* FROM {' . self::TABLE_SLOTS . '} as slot ' .
+            'INNER JOIN {' . self::TABLE_SLOT_FILTERS . '} as filter ON slot.id=filter.slotid ' .
+            'WHERE (filter.vintage=? OR filter.vintage=NULL)' . $insert,
+            [$vintage]
+        );
+
+        $slotsobj = [];
+        foreach ($slots as $slot) {
+            array_push($slotsobj, slot::from_db($slot));
+        }
+
+        return $slotsobj;
+    }
+
     /**
      * Returns a list of all slots belonging to a supervisor.
      * @param int $supervisorid userid of the supervisor in question
@@ -306,6 +342,9 @@ public static function filter_slots_for_user(array $allslots, \stdClass $user):
      * @return slot[] the filtered slot array
      */
     public static function filter_slots_for_time(array $allslots, int $range): array {
+        if ($range === 7) {
+            return $allslots;
+        }
         $utctz = new DateTimeZone('UTC');
         $now = new DateTimeImmutable('now', $utctz);
         $slots = [];

lbplanner/services/slots/get_my_slots.php

@@ -17,6 +17,7 @@
 namespace local_lbplanner_services;
 
 use core_external\{external_api, external_function_parameters, external_multiple_structure};
+use DateTimeImmutable;
 use local_lbplanner\helpers\{config_helper, slot_helper};
 use local_lbplanner\model\slot;
 
@@ -43,13 +44,16 @@ public static function get_my_slots_parameters(): external_function_parameters {
     public static function get_my_slots(): array {
         global $USER;
 
-        $allslots = slot_helper::get_all_slots();
+        $dayofweek = (int)(new DateTimeImmutable('today'))->format('N');
+        $allslots = slot_helper::get_vintage_time_slots(
+            $USER->address,
+            $dayofweek,
+            config_helper::get_slot_futuresight()
+        );
 
         $myslots = slot_helper::filter_slots_for_user($allslots, $USER);
 
-        $returnslots = slot_helper::filter_slots_for_time($myslots, config_helper::get_slot_futuresight());
-
-        return array_map(fn(slot $slot) => $slot->prepare_for_api(), $returnslots);
+        return array_map(fn(slot $slot) => $slot->prepare_for_api(), $myslots);
     }
 
     /**