expose scheduled tasks to plugins, switch cache_starred_images plugin to use them instead of housekeeping hook

classes/PluginHost.php

@@ -38,6 +38,8 @@ class PluginHost {
 
 	private static ?PluginHost $instance = null;
 
+	private ?Scheduler $scheduler = null;
+
 	const API_VERSION = 2;
 	const PUBLIC_METHOD_DELIMITER = "--";
 
@@ -215,6 +217,7 @@ class PluginHost {
 
 	function __construct() {
 		$this->pdo = Db::pdo();
+		$this->scheduler = new Scheduler('PluginHost Scheduler');
 		$this->storage = [];
 	}
 
@@ -438,6 +441,10 @@ class PluginHost {
 
 		$this->owner_uid = (int) $owner_uid;
 
+		if ($this->owner_uid) {
+			$this->set_scheduler_name("PluginHost Scheduler for UID $owner_uid");
+		}
+
 		foreach ($plugins as $class) {
 			$class = trim($class);
 			$class_file = strtolower(basename(clean($class)));
@@ -907,4 +914,30 @@ class PluginHost {
 		return basename(dirname(dirname($ref->getFileName()))) == "plugins.local";
 	}
 
+	/**
+	 * This exposes sheduled tasks functionality to plugins. For system plugins, tasks registered here are
+	 * executed (if due) during housekeeping. For user plugins, tasks are only run after any feeds owned by
+	 * the user have been processed in an update batch (which means user is not inactive).
+	 *
+	 * This behaviour mirrors that of `HOOK_HOUSE_KEEPING` for user plugins.
+	 *
+	 * @see Scheduler::add_scheduled_task()
+	 * @see Plugin::hook_house_keeping()
+	*/
+	function add_scheduled_task(Plugin $sender, string $task_name, string $cron_expression, Closure $callback): bool {
+		if ($this->is_system($sender))
+			$task_name = get_class($sender) . ':' . $task_name;
+		else
+			$task_name = get_class($sender) . ':' . $task_name . ':' . $this->owner_uid;
+
+		return $this->scheduler->add_scheduled_task($task_name, $cron_expression, $callback);
+	}
+
+	function run_due_tasks() : void {
+		$this->scheduler->run_due_tasks();
+	}
+
+	private function set_scheduler_name(string $name) : void {
+		$this->scheduler->set_name($name);
+	}
 }

classes/RSSUtils.php

@@ -1666,6 +1666,7 @@ class RSSUtils {
 
 		UserHelper::load_user_plugins($owner_uid, $tmph);
 
+		$tmph->run_due_tasks();
 		$tmph->run_hooks(PluginHost::HOOK_HOUSE_KEEPING);
 	}
 
@@ -1794,7 +1795,10 @@ class RSSUtils {
 	static function housekeeping_common(): void {
 		Scheduler::getInstance()->run_due_tasks();
 
-		PluginHost::getInstance()->run_hooks(PluginHost::HOOK_HOUSE_KEEPING);
+		$pluginhost = PluginHost::getInstance();
+
+		$pluginhost->run_due_tasks();
+		$pluginhost->run_hooks(PluginHost::HOOK_HOUSE_KEEPING);
 	}
 
 	static function update_favicon(string $site_url, int $feed): false|string {

classes/Scheduler.php

@@ -7,7 +7,11 @@ class Scheduler {
 	/** @var array<string, mixed> */
 	private array $scheduled_tasks = [];
 
-	function __construct() {
+	private string $name;
+
+	function __construct(string $name = 'Default Scheduler') {
+		$this->set_name($name);
+
 		$this->add_scheduled_task('purge_orphaned_scheduled_tasks', '@weekly',
 			function() {
 				return $this->purge_orphaned_tasks();
@@ -22,6 +26,11 @@ class Scheduler {
 		return self::$instance;
 	}
 
+	/** Sets specific identifier for this instance of Scheduler used in debug logging */
+	public function set_name(string $name) : void {
+		$this->name = $name;
+	}
+
 	/**
 	 * Adds a backend scheduled task which will be executed by updater (if due) during housekeeping.
 	 *
@@ -42,13 +51,13 @@ class Scheduler {
 		$task_name = strtolower($task_name);
 
 		if (isset($this->scheduled_tasks[$task_name])) {
-			user_error("Attempted to override already registered scheduled task $task_name", E_USER_WARNING);
+			user_error("[$this->name] Attempted to override already registered scheduled task $task_name", E_USER_WARNING);
 			return false;
 		} else {
 			try {
 				$cron = new Cron\CronExpression($cron_expression);
 			} catch (InvalidArgumentException $e) {
-				user_error("Attempt to register scheduled task $task_name failed: " . $e->getMessage(), E_USER_WARNING);
+				user_error("[$this->name] Attempt to register scheduled task $task_name failed: " . $e->getMessage(), E_USER_WARNING);
 				return false;
 			}
 
@@ -64,7 +73,7 @@ class Scheduler {
 	 * Execute scheduled tasks which are due to run and record last run timestamps.
 	 */
 	function run_due_tasks() : void {
-		Debug::log('Processing all scheduled tasks...');
+		Debug::log("[$this->name] Processing all scheduled tasks...");
 
 		$tasks_succeeded = 0;
 		$tasks_failed = 0;
@@ -89,7 +98,7 @@ class Scheduler {
 				try {
 					$rc = (int) $task['callback']();
 				} catch (Exception $e) {
-					user_error("Scheduled task $task_name failed with exception: " . $e->getMessage(), E_USER_WARNING);
+					user_error("[$this->name] Scheduled task $task_name failed with exception: " . $e->getMessage(), E_USER_WARNING);
 
 					$rc = self::TASK_RC_EXCEPTION;
 				}
@@ -125,7 +134,7 @@ class Scheduler {
 			}
 		}
 
-		Debug::log("Processing scheduled tasks finished with $tasks_succeeded tasks succeeded and $tasks_failed tasks failed.");
+		Debug::log("[$this->name] Processing scheduled tasks finished with $tasks_succeeded tasks succeeded and $tasks_failed tasks failed.");
 	}
 
 	/**