1 files changed, 74 insertions, 0 deletions
diff --git a/lib/private/Preview/Storage/Root.php b/lib/private/Preview/Storage/Root.php
new file mode 100644
index 00000000000..41378653962
--- /dev/null
+++ b/lib/private/Preview/Storage/Root.php
@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2020 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\Preview\Storage;
+
+use OC\Files\AppData\AppData;
+use OC\SystemConfig;
+use OCP\Files\IRootFolder;
+use OCP\Files\NotFoundException;
+use OCP\Files\SimpleFS\ISimpleFolder;
+
+class Root extends AppData {
+	private $isMultibucketPreviewDistributionEnabled = false;
+	public function __construct(IRootFolder $rootFolder, SystemConfig $systemConfig) {
+		parent::__construct($rootFolder, $systemConfig, 'preview');
+
+		$this->isMultibucketPreviewDistributionEnabled = $systemConfig->getValue('objectstore.multibucket.preview-distribution', false) === true;
+	}
+
+
+	public function getFolder(string $name): ISimpleFolder {
+		$internalFolder = self::getInternalFolder($name);
+
+		try {
+			return parent::getFolder($internalFolder);
+		} catch (NotFoundException $e) {
+			/*
+			 * The new folder structure is not found.
+			 * Lets try the old one
+			 */
+		}
+
+		try {
+			return parent::getFolder($name);
+		} catch (NotFoundException $e) {
+			/*
+			 * The old folder structure is not found.
+			 * Lets try the multibucket fallback if available
+			 */
+			if ($this->isMultibucketPreviewDistributionEnabled) {
+				return parent::getFolder('old-multibucket/' . $internalFolder);
+			}
+
+			// when there is no further fallback just throw the exception
+			throw $e;
+		}
+	}
+
+	public function newFolder(string $name): ISimpleFolder {
+		$internalFolder = self::getInternalFolder($name);
+		return parent::newFolder($internalFolder);
+	}
+
+	/*
+	 * Do not allow directory listing on this special root
+	 * since it gets to big and time consuming
+	 */
+	public function getDirectoryListing(): array {
+		return [];
+	}
+
+	public static function getInternalFolder(string $name): string {
+		return implode('/', str_split(substr(md5($name), 0, 7))) . '/' . $name;
+	}
+
+	public function getStorageId(): int {
+		return $this->getAppDataRootFolder()->getStorage()->getCache()->getNumericStorageId();
+	}
+}