Allow notification apps to defer and flush the sending

lib/composer/composer/autoload_classmap.php

@@ -408,6 +408,7 @@
     'OCP\\Notification\\AlreadyProcessedException' => $baseDir . '/lib/public/Notification/AlreadyProcessedException.php',
     'OCP\\Notification\\IAction' => $baseDir . '/lib/public/Notification/IAction.php',
     'OCP\\Notification\\IApp' => $baseDir . '/lib/public/Notification/IApp.php',
+    'OCP\\Notification\\IDeferrableApp' => $baseDir . '/lib/public/Notification/IDeferrableApp.php',
     'OCP\\Notification\\IDismissableNotifier' => $baseDir . '/lib/public/Notification/IDismissableNotifier.php',
     'OCP\\Notification\\IManager' => $baseDir . '/lib/public/Notification/IManager.php',
     'OCP\\Notification\\INotification' => $baseDir . '/lib/public/Notification/INotification.php',

lib/composer/composer/autoload_static.php

@@ -437,6 +437,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OCP\\Notification\\AlreadyProcessedException' => __DIR__ . '/../../..' . '/lib/public/Notification/AlreadyProcessedException.php',
         'OCP\\Notification\\IAction' => __DIR__ . '/../../..' . '/lib/public/Notification/IAction.php',
         'OCP\\Notification\\IApp' => __DIR__ . '/../../..' . '/lib/public/Notification/IApp.php',
+        'OCP\\Notification\\IDeferrableApp' => __DIR__ . '/../../..' . '/lib/public/Notification/IDeferrableApp.php',
         'OCP\\Notification\\IDismissableNotifier' => __DIR__ . '/../../..' . '/lib/public/Notification/IDismissableNotifier.php',
         'OCP\\Notification\\IManager' => __DIR__ . '/../../..' . '/lib/public/Notification/IManager.php',
         'OCP\\Notification\\INotification' => __DIR__ . '/../../..' . '/lib/public/Notification/INotification.php',

lib/private/Notification/Manager.php

@@ -31,6 +31,7 @@
 use OCP\ILogger;
 use OCP\Notification\AlreadyProcessedException;
 use OCP\Notification\IApp;
+use OCP\Notification\IDeferrableApp;
 use OCP\Notification\IDismissableNotifier;
 use OCP\Notification\IManager;
 use OCP\Notification\INotification;
@@ -55,6 +56,8 @@ class Manager implements IManager {
 
 	/** @var bool */
 	protected $preparingPushNotification;
+	/** @var bool */
+	protected $deferPushing;
 
 	public function __construct(IValidator $validator,
 								ILogger $logger) {
@@ -65,6 +68,7 @@ public function __construct(IValidator $validator,
 		$this->appClasses = [];
 		$this->notifierClasses = [];
 		$this->preparingPushNotification = false;
+		$this->deferPushing = false;
 	}
 	/**
 	 * @param string $appClass The service must implement IApp, otherwise a
@@ -199,6 +203,46 @@ public function isPreparingPushNotification(): bool {
 		return $this->preparingPushNotification;
 	}
 
+	/**
+	 * The calling app should only "flush" when it got returned true on the defer call
+	 * @return bool
+	 * @since 20.0.0
+	 */
+	public function defer(): bool {
+		$alreadyDeferring = $this->deferPushing;
+		$this->deferPushing = true;
+
+		$apps = $this->getApps();
+
+		foreach ($apps as $app) {
+			if ($app instanceof IDeferrableApp) {
+				$app->defer();
+			}
+		}
+
+		return !$alreadyDeferring;
+	}
+
+	/**
+	 * @since 20.0.0
+	 */
+	public function flush(): void {
+		$apps = $this->getApps();
+
+		foreach ($apps as $app) {
+			if (!$app instanceof IDeferrableApp) {
+				continue;
+			}
+
+			try {
+				$app->flush();
+			} catch (\InvalidArgumentException $e) {
+			}
+		}
+
+		$this->deferPushing = false;
+	}
+
 	/**
 	 * @param INotification $notification
 	 * @throws \InvalidArgumentException When the notification is not valid

lib/public/Notification/IDeferrableApp.php

@@ -0,0 +1,48 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Joas Schilling <coding@schilljs.com>
+ *
+ * @author Joas Schilling <coding@schilljs.com>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCP\Notification;
+
+/**
+ * Interface IDeferrableApp
+ *
+ * @package OCP\Notification
+ * @since 20.0.0
+ */
+interface IDeferrableApp extends IApp {
+	/**
+	 * Start deferring notifications until `flush()` is called
+	 *
+	 * @since 20.0.0
+	 */
+	public function defer(): void;
+
+	/**
+	 * Send all deferred notifications that have been stored since `defer()` was called
+	 *
+	 * @since 20.0.0
+	 */
+	public function flush(): void;
+}

lib/public/Notification/IManager.php

@@ -91,4 +91,21 @@ public function isPreparingPushNotification(): bool;
 	 * @since 18.0.0
 	 */
 	public function dismissNotification(INotification $notification): void;
+
+	/**
+	 * Start deferring notifications until `flush()` is called
+	 *
+	 * The calling app should only "flush" when it got returned true on the defer call,
+	 * otherwise another app is deferring the sending already.
+	 * @return bool
+	 * @since 20.0.0
+	 */
+	public function defer(): bool;
+
+	/**
+	 * Send all deferred notifications that have been stored since `defer()` was called
+	 *
+	 * @since 20.0.0
+	 */
+	public function flush(): void;
 }