1 files changed, 128 insertions, 0 deletions
diff --git a/lib/private/InitialStateService.php b/lib/private/InitialStateService.php
new file mode 100644
index 00000000000..300aa238397
--- /dev/null
+++ b/lib/private/InitialStateService.php
@@ -0,0 +1,128 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2019 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC;
+
+use Closure;
+use OC\AppFramework\Bootstrap\Coordinator;
+use OCP\AppFramework\QueryException;
+use OCP\AppFramework\Services\InitialStateProvider;
+use OCP\IInitialStateService;
+use Psr\Container\ContainerInterface;
+use Psr\Log\LoggerInterface;
+
+class InitialStateService implements IInitialStateService {
+
+	/** @var string[][] */
+	private array $states = [];
+
+	/** @var Closure[][] */
+	private array $lazyStates = [];
+
+
+	public function __construct(
+		private LoggerInterface $logger,
+		private Coordinator $bootstrapCoordinator,
+		private ContainerInterface $container,
+	) {
+	}
+
+	public function provideInitialState(string $appName, string $key, $data): void {
+		// Scalars and JsonSerializable are fine
+		if (is_scalar($data) || $data instanceof \JsonSerializable || is_array($data)) {
+			if (!isset($this->states[$appName])) {
+				$this->states[$appName] = [];
+			}
+			try {
+				$this->states[$appName][$key] = json_encode($data, JSON_THROW_ON_ERROR);
+			} catch (\JsonException $e) {
+				$this->logger->error('Invalid ' . $key . ' data provided to provideInitialState by ' . $appName, ['exception' => $e]);
+			}
+			return;
+		}
+
+		$this->logger->warning('Invalid ' . $key . ' data provided to provideInitialState by ' . $appName);
+	}
+
+	public function provideLazyInitialState(string $appName, string $key, Closure $closure): void {
+		if (!isset($this->lazyStates[$appName])) {
+			$this->lazyStates[$appName] = [];
+		}
+		$this->lazyStates[$appName][$key] = $closure;
+	}
+
+	/**
+	 * Invoke all callbacks to populate the `states` property
+	 */
+	private function invokeLazyStateCallbacks(): void {
+		foreach ($this->lazyStates as $app => $lazyStates) {
+			foreach ($lazyStates as $key => $lazyState) {
+				$startTime = microtime(true);
+				$this->provideInitialState($app, $key, $lazyState());
+				$endTime = microtime(true);
+				$duration = $endTime - $startTime;
+				if ($duration > 1) {
+					$this->logger->warning('Lazy initial state provider for {key} took {duration} seconds.', [
+						'app' => $app,
+						'key' => $key,
+						'duration' => round($duration, 2),
+					]);
+				}
+			}
+		}
+		$this->lazyStates = [];
+	}
+
+	/**
+	 * Load the lazy states via the IBootstrap mechanism
+	 */
+	private function loadLazyStates(): void {
+		$context = $this->bootstrapCoordinator->getRegistrationContext();
+
+		if ($context === null) {
+			// To early, nothing to do yet
+			return;
+		}
+
+		$initialStates = $context->getInitialStates();
+		foreach ($initialStates as $initialState) {
+			try {
+				$provider = $this->container->query($initialState->getService());
+			} catch (QueryException $e) {
+				// Log an continue. We can be fault tolerant here.
+				$this->logger->error('Could not load initial state provider dynamically: ' . $e->getMessage(), [
+					'exception' => $e,
+					'app' => $initialState->getAppId(),
+				]);
+				continue;
+			}
+
+			if (!($provider instanceof InitialStateProvider)) {
+				// Log an continue. We can be fault tolerant here.
+				$this->logger->error('Initial state provider is not an InitialStateProvider instance: ' . $initialState->getService(), [
+					'app' => $initialState->getAppId(),
+				]);
+			}
+
+			$this->provideInitialState($initialState->getAppId(), $provider->getKey(), $provider);
+		}
+	}
+
+	public function getInitialStates(): array {
+		$this->invokeLazyStateCallbacks();
+		$this->loadLazyStates();
+
+		$appStates = [];
+		foreach ($this->states as $app => $states) {
+			foreach ($states as $key => $value) {
+				$appStates["$app-$key"] = $value;
+			}
+		}
+		return $appStates;
+	}
+}