1 files changed, 292 insertions, 0 deletions
diff --git a/lib/private/Files/Cache/Updater.php b/lib/private/Files/Cache/Updater.php
new file mode 100644
index 00000000000..03681036aa2
--- /dev/null
+++ b/lib/private/Files/Cache/Updater.php
@@ -0,0 +1,292 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OC\Files\Cache;
+
+use Doctrine\DBAL\Exception\DeadlockException;
+use OC\Files\FileInfo;
+use OC\Files\ObjectStore\ObjectStoreStorage;
+use OCP\Files\Cache\ICache;
+use OCP\Files\Cache\ICacheEntry;
+use OCP\Files\Cache\IUpdater;
+use OCP\Files\Storage\IStorage;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Update the cache and propagate changes
+ *
+ */
+class Updater implements IUpdater {
+	/**
+	 * @var bool
+	 */
+	protected $enabled = true;
+
+	/**
+	 * @var \OC\Files\Storage\Storage
+	 */
+	protected $storage;
+
+	/**
+	 * @var \OC\Files\Cache\Propagator
+	 */
+	protected $propagator;
+
+	/**
+	 * @var Scanner
+	 */
+	protected $scanner;
+
+	/**
+	 * @var Cache
+	 */
+	protected $cache;
+
+	private LoggerInterface $logger;
+
+	/**
+	 * @param \OC\Files\Storage\Storage $storage
+	 */
+	public function __construct(\OC\Files\Storage\Storage $storage) {
+		$this->storage = $storage;
+		$this->propagator = $storage->getPropagator();
+		$this->scanner = $storage->getScanner();
+		$this->cache = $storage->getCache();
+		$this->logger = \OC::$server->get(LoggerInterface::class);
+	}
+
+	/**
+	 * Disable updating the cache through this updater
+	 */
+	public function disable() {
+		$this->enabled = false;
+	}
+
+	/**
+	 * Re-enable the updating of the cache through this updater
+	 */
+	public function enable() {
+		$this->enabled = true;
+	}
+
+	/**
+	 * Get the propagator for etags and mtime for the view the updater works on
+	 *
+	 * @return Propagator
+	 */
+	public function getPropagator() {
+		return $this->propagator;
+	}
+
+	/**
+	 * Propagate etag and mtime changes for the parent folders of $path up to the root of the filesystem
+	 *
+	 * @param string $path the path of the file to propagate the changes for
+	 * @param int|null $time the timestamp to set as mtime for the parent folders, if left out the current time is used
+	 */
+	public function propagate($path, $time = null) {
+		if (Scanner::isPartialFile($path)) {
+			return;
+		}
+		$this->propagator->propagateChange($path, $time);
+	}
+
+	/**
+	 * Update the cache for $path and update the size, etag and mtime of the parent folders
+	 *
+	 * @param string $path
+	 * @param int $time
+	 */
+	public function update($path, $time = null, ?int $sizeDifference = null) {
+		if (!$this->enabled or Scanner::isPartialFile($path)) {
+			return;
+		}
+		if (is_null($time)) {
+			$time = time();
+		}
+
+		$data = $this->scanner->scan($path, Scanner::SCAN_SHALLOW, -1, false);
+
+		if (isset($data['oldSize']) && isset($data['size'])) {
+			$sizeDifference = $data['size'] - $data['oldSize'];
+		}
+
+		// encryption is a pita and touches the cache itself
+		if (isset($data['encrypted']) && (bool)$data['encrypted']) {
+			$sizeDifference = null;
+		}
+
+		// scanner didn't provide size info, fallback to full size calculation
+		if ($this->cache instanceof Cache && $sizeDifference === null) {
+			$this->cache->correctFolderSize($path, $data);
+		}
+		$this->correctParentStorageMtime($path);
+		$this->propagator->propagateChange($path, $time, $sizeDifference ?? 0);
+	}
+
+	/**
+	 * Remove $path from the cache and update the size, etag and mtime of the parent folders
+	 *
+	 * @param string $path
+	 */
+	public function remove($path) {
+		if (!$this->enabled or Scanner::isPartialFile($path)) {
+			return;
+		}
+
+		$parent = dirname($path);
+		if ($parent === '.') {
+			$parent = '';
+		}
+
+		$entry = $this->cache->get($path);
+
+		$this->cache->remove($path);
+
+		$this->correctParentStorageMtime($path);
+		if ($entry instanceof ICacheEntry) {
+			$this->propagator->propagateChange($path, time(), -$entry->getSize());
+		} else {
+			$this->propagator->propagateChange($path, time());
+			if ($this->cache instanceof Cache) {
+				$this->cache->correctFolderSize($parent);
+			}
+		}
+	}
+
+	/**
+	 * Rename a file or folder in the cache.
+	 *
+	 * @param IStorage $sourceStorage
+	 * @param string $source
+	 * @param string $target
+	 */
+	public function renameFromStorage(IStorage $sourceStorage, $source, $target) {
+		$this->copyOrRenameFromStorage($sourceStorage, $source, $target, function (ICache $sourceCache) use ($sourceStorage, $source, $target) {
+			// Remove existing cache entry to no reuse the fileId.
+			if ($this->cache->inCache($target)) {
+				$this->cache->remove($target);
+			}
+
+			if ($sourceStorage === $this->storage) {
+				$this->cache->move($source, $target);
+			} else {
+				$this->cache->moveFromCache($sourceCache, $source, $target);
+			}
+		});
+	}
+
+	/**
+	 * Copy a file or folder in the cache.
+	 */
+	public function copyFromStorage(IStorage $sourceStorage, string $source, string $target): void {
+		$this->copyOrRenameFromStorage($sourceStorage, $source, $target, function (ICache $sourceCache, ICacheEntry $sourceInfo) use ($target) {
+			$parent = dirname($target);
+			if ($parent === '.') {
+				$parent = '';
+			}
+			$parentInCache = $this->cache->inCache($parent);
+			if (!$parentInCache) {
+				$parentData = $this->scanner->scan($parent, Scanner::SCAN_SHALLOW, -1, false);
+				$parentInCache = $parentData !== null;
+			}
+			if ($parentInCache) {
+				$this->cache->copyFromCache($sourceCache, $sourceInfo, $target);
+			}
+		});
+	}
+
+	/**
+	 * Utility to copy or rename a file or folder in the cache and update the size, etag and mtime of the parent folders
+	 */
+	private function copyOrRenameFromStorage(IStorage $sourceStorage, string $source, string $target, callable $operation): void {
+		if (!$this->enabled or Scanner::isPartialFile($source) or Scanner::isPartialFile($target)) {
+			return;
+		}
+
+		$time = time();
+
+		$sourceCache = $sourceStorage->getCache();
+		$sourceUpdater = $sourceStorage->getUpdater();
+		$sourcePropagator = $sourceStorage->getPropagator();
+
+		$sourceInfo = $sourceCache->get($source);
+
+		$sourceExtension = pathinfo($source, PATHINFO_EXTENSION);
+		$targetExtension = pathinfo($target, PATHINFO_EXTENSION);
+		$targetIsTrash = preg_match("/^d\d+$/", $targetExtension);
+
+		if ($sourceInfo !== false) {
+			if (!$this->storage->instanceOfStorage(ObjectStoreStorage::class)) {
+				$operation($sourceCache, $sourceInfo);
+			}
+
+			$isDir = $sourceInfo->getMimeType() === FileInfo::MIMETYPE_FOLDER;
+		} else {
+			$isDir = $this->storage->is_dir($target);
+		}
+
+		if ($sourceExtension !== $targetExtension && !$isDir && !$targetIsTrash) {
+			// handle mime type change
+			$mimeType = $this->storage->getMimeType($target);
+			$fileId = $this->cache->getId($target);
+			$this->cache->update($fileId, ['mimetype' => $mimeType]);
+		}
+
+		if ($sourceCache instanceof Cache) {
+			$sourceCache->correctFolderSize($source);
+		}
+		if ($this->cache instanceof Cache) {
+			$this->cache->correctFolderSize($target);
+		}
+		if ($sourceUpdater instanceof Updater) {
+			$sourceUpdater->correctParentStorageMtime($source);
+		}
+		$this->correctParentStorageMtime($target);
+		$this->updateStorageMTimeOnly($target);
+		$sourcePropagator->propagateChange($source, $time);
+		$this->propagator->propagateChange($target, $time);
+	}
+
+	private function updateStorageMTimeOnly($internalPath) {
+		$fileId = $this->cache->getId($internalPath);
+		if ($fileId !== -1) {
+			$mtime = $this->storage->filemtime($internalPath);
+			if ($mtime !== false) {
+				$this->cache->update(
+					$fileId, [
+						'mtime' => null, // this magic tells it to not overwrite mtime
+						'storage_mtime' => $mtime
+					]
+				);
+			}
+		}
+	}
+
+	/**
+	 * update the storage_mtime of the direct parent in the cache to the mtime from the storage
+	 *
+	 * @param string $internalPath
+	 */
+	private function correctParentStorageMtime($internalPath) {
+		$parentId = $this->cache->getParentId($internalPath);
+		$parent = dirname($internalPath);
+		if ($parentId != -1) {
+			$mtime = $this->storage->filemtime($parent);
+			if ($mtime !== false) {
+				try {
+					$this->cache->update($parentId, ['storage_mtime' => $mtime]);
+				} catch (DeadlockException $e) {
+					// ignore the failure.
+					// with failures concurrent updates, someone else would have already done it.
+					// in the worst case the `storage_mtime` isn't updated, which should at most only trigger an extra rescan
+					$this->logger->warning('Error while updating parent storage_mtime, should be safe to ignore', ['exception' => $e]);
+				}
+			}
+		}
+	}
+}