Daily Maintenance: Limit number of logs deleted in a single transacti…

…on (#2533)

* Daily Maintenance: Limit number of logs deleted in a single transaction (#3347)

relates to xibosignage/xibo#3347

- Implemented Batch Deletion with a short pause in between batches.
- Each batch deletes up to a maximum of 10k rows.
- Added a 2-second sleep time in between batches.

lib/Helper/DatabaseLogHandler.php

@@ -1,6 +1,6 @@
 <?php
 /*
- * Copyright (C) 2023 Xibo Signage Ltd
+ * Copyright (C) 2024 Xibo Signage Ltd
  *
  * Xibo - Digital Signage - https://xibosignage.com
  *
@@ -141,9 +141,23 @@ public static function tidyLogs($cutOff)
             if (self::$pdo === null) {
                 self::$pdo = PdoStorageService::newConnection('log');
             }
-            $statement = self::$pdo->prepare('DELETE FROM `log` WHERE logdate < :maxage');
-            $statement->execute(['maxage' => $cutOff]);
-            PdoStorageService::incrementStat('log', 'delete');
+
+            $statement = self::$pdo->prepare('DELETE FROM `log` WHERE logdate < :maxage LIMIT 10000');
+
+            do {
+                // Execute statement
+                $statement->execute(['maxage' => $cutOff]);
+
+                // initialize number of rows deleted
+                $rowsDeleted = $statement->rowCount();
+
+                PdoStorageService::incrementStat('log', 'delete');
+
+                // pause for a second
+                sleep(2);
+
+            } while ($rowsDeleted > 0);
+
         } catch (\PDOException $ignored) {}
     }
 }