From d3aecc718d9a3839d6dca5c9d6dcd3b60495867c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Jakes=CC=8C?= <jan@jakes.pro>
Date: Thu, 31 Oct 2019 14:26:50 +0100
Subject: [PATCH] Add temporary fix for race conditions

[MAILPOET-2436]
---
 lib/Settings/SettingsController.php | 13 +------------
 lib/Settings/SettingsRepository.php | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/lib/Settings/SettingsController.php b/lib/Settings/SettingsController.php
index c91456f8d3..7baf8604e4 100644
--- a/lib/Settings/SettingsController.php
+++ b/lib/Settings/SettingsController.php
@@ -109,7 +109,7 @@ class SettingsController {
       }
     }
     $setting[$last_key] = $value;
-    $this->saveValue($main_key, $this->settings[$main_key]);
+    $this->settings_repository->createOrUpdateByName($main_key, $this->settings[$main_key]);
   }
 
   function delete($key) {
@@ -150,17 +150,6 @@ class SettingsController {
     return $setting ? $setting->getValue() : null;
   }
 
-  private function saveValue($key, $value) {
-    $setting = $this->settings_repository->findOneByName($key);
-    if (!$setting) {
-      $setting = new SettingEntity();
-      $setting->setName($key);
-      $this->settings_repository->persist($setting);
-    }
-    $setting->setValue($value);
-    $this->settings_repository->flush();
-  }
-
   function resetCache() {
     $this->settings = [];
     $this->loaded = false;
diff --git a/lib/Settings/SettingsRepository.php b/lib/Settings/SettingsRepository.php
index 1c18a18c3b..c420ae60e3 100644
--- a/lib/Settings/SettingsRepository.php
+++ b/lib/Settings/SettingsRepository.php
@@ -2,8 +2,10 @@
 
 namespace MailPoet\Settings;
 
+use Carbon\Carbon;
 use MailPoet\Doctrine\Repository;
 use MailPoet\Entities\SettingEntity;
+use MailPoet\WP\Functions as WPFunctions;
 
 /**
  * @method SettingEntity[] findBy(array $criteria, array $order_by = null, int $limit = null, int $offset = null)
@@ -18,6 +20,24 @@ class SettingsRepository extends Repository {
     return $this->doctrine_repository->findOneBy(['name' => $name]);
   }
 
+  function createOrUpdateByName($name, $value) {
+    // Temporarily use low-level INSERT ... ON DUPLICATE KEY UPDATE query to avoid race conditions
+    // between entity fetch and creation with multiple concurrent requests. This will be replaced
+    // by a code solving atomicity of create-or-update on entity (ORM) level in a follow-up ticket.
+    $now = Carbon::createFromTimestamp(WPFunctions::get()->currentTime('timestamp'));
+    $table_name = $this->entity_manager->getClassMetadata(SettingEntity::class)->getTableName();
+    $this->entity_manager->getConnection()->executeUpdate("
+      INSERT INTO $table_name (name, value, created_at, updated_at)
+      VALUES (:name, :value, :now, :now)
+      ON DUPLICATE KEY UPDATE value = :value, updated_at = :now 
+    ", [
+      'name' => $name,
+      'value' => is_array($value) ? serialize($value) : $value,
+      'now' => $now,
+    ]);
+    $this->entity_manager->clear(SettingEntity::class);
+  }
+
   protected function getEntityClassName() {
     return SettingEntity::class;
   }