nextcloud / server

lib/private/Files/Cache/Scanner.php

Indentation +506 added lines, -506 removed lines

@@ -57,511 +57,511 @@
  * @package OC\Files\Cache
  */
 class Scanner extends BasicEmitter implements IScanner {
-	/**
-	 * @var \OC\Files\Storage\Storage $storage
-	 */
-	protected $storage;
-
-	/**
-	 * @var string $storageId
-	 */
-	protected $storageId;
-
-	/**
-	 * @var \OC\Files\Cache\Cache $cache
-	 */
-	protected $cache;
-
-	/**
-	 * @var boolean $cacheActive If true, perform cache operations, if false, do not affect cache
-	 */
-	protected $cacheActive;
-
-	/**
-	 * @var bool $useTransactions whether to use transactions
-	 */
-	protected $useTransactions = true;
-
-	/**
-	 * @var \OCP\Lock\ILockingProvider
-	 */
-	protected $lockingProvider;
-
-	public function __construct(\OC\Files\Storage\Storage $storage) {
-		$this->storage = $storage;
-		$this->storageId = $this->storage->getId();
-		$this->cache = $storage->getCache();
-		$this->cacheActive = !\OC::$server->getConfig()->getSystemValue('filesystem_cache_readonly', false);
-		$this->lockingProvider = \OC::$server->getLockingProvider();
-	}
-
-	/**
-	 * Whether to wrap the scanning of a folder in a database transaction
-	 * On default transactions are used
-	 *
-	 * @param bool $useTransactions
-	 */
-	public function setUseTransactions($useTransactions) {
-		$this->useTransactions = $useTransactions;
-	}
-
-	/**
-	 * get all the metadata of a file or folder
-	 * *
-	 *
-	 * @param string $path
-	 * @return array|null an array of metadata of the file
-	 */
-	protected function getData($path) {
-		$data = $this->storage->getMetaData($path);
-		if (is_null($data)) {
-			\OC::$server->get(LoggerInterface::class)->debug("!!! Path '$path' is not accessible or present !!!", ['app' => 'core']);
-		}
-		return $data;
-	}
-
-	/**
-	 * scan a single file and store it in the cache
-	 *
-	 * @param string $file
-	 * @param int $reuseExisting
-	 * @param int $parentId
-	 * @param array|null|false $cacheData existing data in the cache for the file to be scanned
-	 * @param bool $lock set to false to disable getting an additional read lock during scanning
-	 * @param null $data the metadata for the file, as returned by the storage
-	 * @return array|null an array of metadata of the scanned file
-	 * @throws \OCP\Lock\LockedException
-	 */
-	public function scanFile($file, $reuseExisting = 0, $parentId = -1, $cacheData = null, $lock = true, $data = null) {
-		if ($file !== '') {
-			try {
-				$this->storage->verifyPath(dirname($file), basename($file));
-			} catch (\Exception $e) {
-				return null;
-			}
-		}
-		// only proceed if $file is not a partial file, blacklist is handled by the storage
-		if (!self::isPartialFile($file)) {
-
-			// acquire a lock
-			if ($lock) {
-				if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
-					$this->storage->acquireLock($file, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
-				}
-			}
-
-			try {
-				$data = $data ?? $this->getData($file);
-			} catch (ForbiddenException $e) {
-				if ($lock) {
-					if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
-						$this->storage->releaseLock($file, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
-					}
-				}
-
-				return null;
-			}
-
-			try {
-				if ($data) {
-
-					// pre-emit only if it was a file. By that we avoid counting/treating folders as files
-					if ($data['mimetype'] !== 'httpd/unix-directory') {
-						$this->emit('\OC\Files\Cache\Scanner', 'scanFile', [$file, $this->storageId]);
-						\OC_Hook::emit('\OC\Files\Cache\Scanner', 'scan_file', ['path' => $file, 'storage' => $this->storageId]);
-					}
-
-					$parent = dirname($file);
-					if ($parent === '.' || $parent === '/') {
-						$parent = '';
-					}
-					if ($parentId === -1) {
-						$parentId = $this->cache->getParentId($file);
-					}
-
-					// scan the parent if it's not in the cache (id -1) and the current file is not the root folder
-					if ($file && $parentId === -1) {
-						$parentData = $this->scanFile($parent);
-						if (!$parentData) {
-							return null;
-						}
-						$parentId = $parentData['fileid'];
-					}
-					if ($parent) {
-						$data['parent'] = $parentId;
-					}
-					if (is_null($cacheData)) {
-						/** @var CacheEntry $cacheData */
-						$cacheData = $this->cache->get($file);
-					}
-					if ($cacheData && $reuseExisting && isset($cacheData['fileid'])) {
-						// prevent empty etag
-						$etag = empty($cacheData['etag']) ? $data['etag'] : $cacheData['etag'];
-						$fileId = $cacheData['fileid'];
-						$data['fileid'] = $fileId;
-						// only reuse data if the file hasn't explicitly changed
-						if (isset($data['storage_mtime']) && isset($cacheData['storage_mtime']) && $data['storage_mtime'] === $cacheData['storage_mtime']) {
-							$data['mtime'] = $cacheData['mtime'];
-							if (($reuseExisting & self::REUSE_SIZE) && ($data['size'] === -1)) {
-								$data['size'] = $cacheData['size'];
-							}
-							if ($reuseExisting & self::REUSE_ETAG && !$this->storage->instanceOfStorage(IReliableEtagStorage::class)) {
-								$data['etag'] = $etag;
-							}
-						}
-						// Only update metadata that has changed
-						$newData = array_diff_assoc($data, $cacheData->getData());
-					} else {
-						$newData = $data;
-						$fileId = -1;
-					}
-					if (!empty($newData)) {
-						// Reset the checksum if the data has changed
-						$newData['checksum'] = '';
-						$newData['parent'] = $parentId;
-						$data['fileid'] = $this->addToCache($file, $newData, $fileId);
-					}
+    /**
+     * @var \OC\Files\Storage\Storage $storage
+     */
+    protected $storage;
+
+    /**
+     * @var string $storageId
+     */
+    protected $storageId;
+
+    /**
+     * @var \OC\Files\Cache\Cache $cache
+     */
+    protected $cache;
+
+    /**
+     * @var boolean $cacheActive If true, perform cache operations, if false, do not affect cache
+     */
+    protected $cacheActive;
+
+    /**
+     * @var bool $useTransactions whether to use transactions
+     */
+    protected $useTransactions = true;
+
+    /**
+     * @var \OCP\Lock\ILockingProvider
+     */
+    protected $lockingProvider;
+
+    public function __construct(\OC\Files\Storage\Storage $storage) {
+        $this->storage = $storage;
+        $this->storageId = $this->storage->getId();
+        $this->cache = $storage->getCache();
+        $this->cacheActive = !\OC::$server->getConfig()->getSystemValue('filesystem_cache_readonly', false);
+        $this->lockingProvider = \OC::$server->getLockingProvider();
+    }
+
+    /**
+     * Whether to wrap the scanning of a folder in a database transaction
+     * On default transactions are used
+     *
+     * @param bool $useTransactions
+     */
+    public function setUseTransactions($useTransactions) {
+        $this->useTransactions = $useTransactions;
+    }
+
+    /**
+     * get all the metadata of a file or folder
+     * *
+     *
+     * @param string $path
+     * @return array|null an array of metadata of the file
+     */
+    protected function getData($path) {
+        $data = $this->storage->getMetaData($path);
+        if (is_null($data)) {
+            \OC::$server->get(LoggerInterface::class)->debug("!!! Path '$path' is not accessible or present !!!", ['app' => 'core']);
+        }
+        return $data;
+    }
+
+    /**
+     * scan a single file and store it in the cache
+     *
+     * @param string $file
+     * @param int $reuseExisting
+     * @param int $parentId
+     * @param array|null|false $cacheData existing data in the cache for the file to be scanned
+     * @param bool $lock set to false to disable getting an additional read lock during scanning
+     * @param null $data the metadata for the file, as returned by the storage
+     * @return array|null an array of metadata of the scanned file
+     * @throws \OCP\Lock\LockedException
+     */
+    public function scanFile($file, $reuseExisting = 0, $parentId = -1, $cacheData = null, $lock = true, $data = null) {
+        if ($file !== '') {
+            try {
+                $this->storage->verifyPath(dirname($file), basename($file));
+            } catch (\Exception $e) {
+                return null;
+            }
+        }
+        // only proceed if $file is not a partial file, blacklist is handled by the storage
+        if (!self::isPartialFile($file)) {
+
+            // acquire a lock
+            if ($lock) {
+                if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
+                    $this->storage->acquireLock($file, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
+                }
+            }
+
+            try {
+                $data = $data ?? $this->getData($file);
+            } catch (ForbiddenException $e) {
+                if ($lock) {
+                    if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
+                        $this->storage->releaseLock($file, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
+                    }
+                }
+
+                return null;
+            }
+
+            try {
+                if ($data) {
+
+                    // pre-emit only if it was a file. By that we avoid counting/treating folders as files
+                    if ($data['mimetype'] !== 'httpd/unix-directory') {
+                        $this->emit('\OC\Files\Cache\Scanner', 'scanFile', [$file, $this->storageId]);
+                        \OC_Hook::emit('\OC\Files\Cache\Scanner', 'scan_file', ['path' => $file, 'storage' => $this->storageId]);
+                    }
+
+                    $parent = dirname($file);
+                    if ($parent === '.' || $parent === '/') {
+                        $parent = '';
+                    }
+                    if ($parentId === -1) {
+                        $parentId = $this->cache->getParentId($file);
+                    }
+
+                    // scan the parent if it's not in the cache (id -1) and the current file is not the root folder
+                    if ($file && $parentId === -1) {
+                        $parentData = $this->scanFile($parent);
+                        if (!$parentData) {
+                            return null;
+                        }
+                        $parentId = $parentData['fileid'];
+                    }
+                    if ($parent) {
+                        $data['parent'] = $parentId;
+                    }
+                    if (is_null($cacheData)) {
+                        /** @var CacheEntry $cacheData */
+                        $cacheData = $this->cache->get($file);
+                    }
+                    if ($cacheData && $reuseExisting && isset($cacheData['fileid'])) {
+                        // prevent empty etag
+                        $etag = empty($cacheData['etag']) ? $data['etag'] : $cacheData['etag'];
+                        $fileId = $cacheData['fileid'];
+                        $data['fileid'] = $fileId;
+                        // only reuse data if the file hasn't explicitly changed
+                        if (isset($data['storage_mtime']) && isset($cacheData['storage_mtime']) && $data['storage_mtime'] === $cacheData['storage_mtime']) {
+                            $data['mtime'] = $cacheData['mtime'];
+                            if (($reuseExisting & self::REUSE_SIZE) && ($data['size'] === -1)) {
+                                $data['size'] = $cacheData['size'];
+                            }
+                            if ($reuseExisting & self::REUSE_ETAG && !$this->storage->instanceOfStorage(IReliableEtagStorage::class)) {
+                                $data['etag'] = $etag;
+                            }
+                        }
+                        // Only update metadata that has changed
+                        $newData = array_diff_assoc($data, $cacheData->getData());
+                    } else {
+                        $newData = $data;
+                        $fileId = -1;
+                    }
+                    if (!empty($newData)) {
+                        // Reset the checksum if the data has changed
+                        $newData['checksum'] = '';
+                        $newData['parent'] = $parentId;
+                        $data['fileid'] = $this->addToCache($file, $newData, $fileId);
+                    }
 					
-					$data['oldSize'] = ($cacheData && isset($cacheData['size'])) ? $cacheData['size'] : 0;
-
-					if ($cacheData && isset($cacheData['encrypted'])) {
-						$data['encrypted'] = $cacheData['encrypted'];
-					}
-
-					// post-emit only if it was a file. By that we avoid counting/treating folders as files
-					if ($data['mimetype'] !== 'httpd/unix-directory') {
-						$this->emit('\OC\Files\Cache\Scanner', 'postScanFile', [$file, $this->storageId]);
-						\OC_Hook::emit('\OC\Files\Cache\Scanner', 'post_scan_file', ['path' => $file, 'storage' => $this->storageId]);
-					}
-				} else {
-					$this->removeFromCache($file);
-				}
-			} catch (\Exception $e) {
-				if ($lock) {
-					if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
-						$this->storage->releaseLock($file, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
-					}
-				}
-				throw $e;
-			}
-
-			// release the acquired lock
-			if ($lock) {
-				if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
-					$this->storage->releaseLock($file, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
-				}
-			}
-
-			if ($data && !isset($data['encrypted'])) {
-				$data['encrypted'] = false;
-			}
-			return $data;
-		}
-
-		return null;
-	}
-
-	protected function removeFromCache($path) {
-		\OC_Hook::emit('Scanner', 'removeFromCache', ['file' => $path]);
-		$this->emit('\OC\Files\Cache\Scanner', 'removeFromCache', [$path]);
-		if ($this->cacheActive) {
-			$this->cache->remove($path);
-		}
-	}
-
-	/**
-	 * @param string $path
-	 * @param array $data
-	 * @param int $fileId
-	 * @return int the id of the added file
-	 */
-	protected function addToCache($path, $data, $fileId = -1) {
-		if (isset($data['scan_permissions'])) {
-			$data['permissions'] = $data['scan_permissions'];
-		}
-		\OC_Hook::emit('Scanner', 'addToCache', ['file' => $path, 'data' => $data]);
-		$this->emit('\OC\Files\Cache\Scanner', 'addToCache', [$path, $this->storageId, $data]);
-		if ($this->cacheActive) {
-			if ($fileId !== -1) {
-				$this->cache->update($fileId, $data);
-				return $fileId;
-			} else {
-				return $this->cache->insert($path, $data);
-			}
-		} else {
-			return -1;
-		}
-	}
-
-	/**
-	 * @param string $path
-	 * @param array $data
-	 * @param int $fileId
-	 */
-	protected function updateCache($path, $data, $fileId = -1) {
-		\OC_Hook::emit('Scanner', 'addToCache', ['file' => $path, 'data' => $data]);
-		$this->emit('\OC\Files\Cache\Scanner', 'updateCache', [$path, $this->storageId, $data]);
-		if ($this->cacheActive) {
-			if ($fileId !== -1) {
-				$this->cache->update($fileId, $data);
-			} else {
-				$this->cache->put($path, $data);
-			}
-		}
-	}
-
-	/**
-	 * scan a folder and all it's children
-	 *
-	 * @param string $path
-	 * @param bool $recursive
-	 * @param int $reuse
-	 * @param bool $lock set to false to disable getting an additional read lock during scanning
-	 * @return array|null an array of the meta data of the scanned file or folder
-	 */
-	public function scan($path, $recursive = self::SCAN_RECURSIVE, $reuse = -1, $lock = true) {
-		if ($reuse === -1) {
-			$reuse = ($recursive === self::SCAN_SHALLOW) ? self::REUSE_ETAG | self::REUSE_SIZE : self::REUSE_ETAG;
-		}
-		if ($lock) {
-			if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
-				$this->storage->acquireLock('scanner::' . $path, ILockingProvider::LOCK_EXCLUSIVE, $this->lockingProvider);
-				$this->storage->acquireLock($path, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
-			}
-		}
-		try {
-			$data = $this->scanFile($path, $reuse, -1, null, $lock);
-			if ($data && $data['mimetype'] === 'httpd/unix-directory') {
-				$size = $this->scanChildren($path, $recursive, $reuse, $data['fileid'], $lock, $data);
-				$data['size'] = $size;
-			}
-		} finally {
-			if ($lock) {
-				if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
-					$this->storage->releaseLock($path, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
-					$this->storage->releaseLock('scanner::' . $path, ILockingProvider::LOCK_EXCLUSIVE, $this->lockingProvider);
-				}
-			}
-		}
-		return $data;
-	}
-
-	/**
-	 * Get the children currently in the cache
-	 *
-	 * @param int $folderId
-	 * @return array[]
-	 */
-	protected function getExistingChildren($folderId) {
-		$existingChildren = [];
-		$children = $this->cache->getFolderContentsById($folderId);
-		foreach ($children as $child) {
-			$existingChildren[$child['name']] = $child;
-		}
-		return $existingChildren;
-	}
-
-	/**
-	 * scan all the files and folders in a folder
-	 *
-	 * @param string $path
-	 * @param bool $recursive
-	 * @param int $reuse
-	 * @param int $folderId id for the folder to be scanned
-	 * @param bool $lock set to false to disable getting an additional read lock during scanning
-	 * @param array $data the data of the folder before (re)scanning the children
-	 * @return int the size of the scanned folder or -1 if the size is unknown at this stage
-	 */
-	protected function scanChildren($path, $recursive = self::SCAN_RECURSIVE, $reuse = -1, $folderId = null, $lock = true, array $data = []) {
-		if ($reuse === -1) {
-			$reuse = ($recursive === self::SCAN_SHALLOW) ? self::REUSE_ETAG | self::REUSE_SIZE : self::REUSE_ETAG;
-		}
-		$this->emit('\OC\Files\Cache\Scanner', 'scanFolder', [$path, $this->storageId]);
-		$size = 0;
-		if (!is_null($folderId)) {
-			$folderId = $this->cache->getId($path);
-		}
-		$childQueue = $this->handleChildren($path, $recursive, $reuse, $folderId, $lock, $size);
-
-		foreach ($childQueue as $child => $childId) {
-			$childSize = $this->scanChildren($child, $recursive, $reuse, $childId, $lock);
-			if ($childSize === -1) {
-				$size = -1;
-			} elseif ($size !== -1) {
-				$size += $childSize;
-			}
-		}
-		$oldSize = $data['size'] ?? null;
-		if ($this->cacheActive && $oldSize !== $size) {
-			$this->cache->update($folderId, ['size' => $size]);
-		}
-		$this->emit('\OC\Files\Cache\Scanner', 'postScanFolder', [$path, $this->storageId]);
-		return $size;
-	}
-
-	private function handleChildren($path, $recursive, $reuse, $folderId, $lock, &$size) {
-		// we put this in it's own function so it cleans up the memory before we start recursing
-		$existingChildren = $this->getExistingChildren($folderId);
-		$newChildren = iterator_to_array($this->storage->getDirectoryContent($path));
-
-		if (count($existingChildren) === 0 && count($newChildren) === 0) {
-			// no need to do a transaction
-			return [];
-		}
-
-		if ($this->useTransactions) {
-			\OC::$server->getDatabaseConnection()->beginTransaction();
-		}
-
-		$exceptionOccurred = false;
-		$childQueue = [];
-		$newChildNames = [];
-		foreach ($newChildren as $fileMeta) {
-			$permissions = isset($fileMeta['scan_permissions']) ? $fileMeta['scan_permissions'] : $fileMeta['permissions'];
-			if ($permissions === 0) {
-				continue;
-			}
-			$originalFile = $fileMeta['name'];
-			$file = trim(\OC\Files\Filesystem::normalizePath($originalFile), '/');
-			if (trim($originalFile, '/') !== $file) {
-				// encoding mismatch, might require compatibility wrapper
-				\OC::$server->get(LoggerInterface::class)->debug('Scanner: Skipping non-normalized file name "'. $originalFile . '" in path "' . $path . '".', ['app' => 'core']);
-				$this->emit('\OC\Files\Cache\Scanner', 'normalizedNameMismatch', [$path ? $path . '/' . $originalFile : $originalFile]);
-				// skip this entry
-				continue;
-			}
-
-			$newChildNames[] = $file;
-			$child = $path ? $path . '/' . $file : $file;
-			try {
-				$existingData = isset($existingChildren[$file]) ? $existingChildren[$file] : false;
-				$data = $this->scanFile($child, $reuse, $folderId, $existingData, $lock, $fileMeta);
-				if ($data) {
-					if ($data['mimetype'] === 'httpd/unix-directory' && $recursive === self::SCAN_RECURSIVE) {
-						$childQueue[$child] = $data['fileid'];
-					} elseif ($data['mimetype'] === 'httpd/unix-directory' && $recursive === self::SCAN_RECURSIVE_INCOMPLETE && $data['size'] === -1) {
-						// only recurse into folders which aren't fully scanned
-						$childQueue[$child] = $data['fileid'];
-					} elseif ($data['size'] === -1) {
-						$size = -1;
-					} elseif ($size !== -1) {
-						$size += $data['size'];
-					}
-				}
-			} catch (Exception $ex) {
-				// might happen if inserting duplicate while a scanning
-				// process is running in parallel
-				// log and ignore
-				if ($this->useTransactions) {
-					\OC::$server->getDatabaseConnection()->rollback();
-					\OC::$server->getDatabaseConnection()->beginTransaction();
-				}
-				\OC::$server->get(LoggerInterface::class)->debug('Exception while scanning file "' . $child . '"', [
-					'app' => 'core',
-					'exception' => $ex,
-				]);
-				$exceptionOccurred = true;
-			} catch (\OCP\Lock\LockedException $e) {
-				if ($this->useTransactions) {
-					\OC::$server->getDatabaseConnection()->rollback();
-				}
-				throw $e;
-			}
-		}
-		$removedChildren = \array_diff(array_keys($existingChildren), $newChildNames);
-		foreach ($removedChildren as $childName) {
-			$child = $path ? $path . '/' . $childName : $childName;
-			$this->removeFromCache($child);
-		}
-		if ($this->useTransactions) {
-			\OC::$server->getDatabaseConnection()->commit();
-		}
-		if ($exceptionOccurred) {
-			// It might happen that the parallel scan process has already
-			// inserted mimetypes but those weren't available yet inside the transaction
-			// To make sure to have the updated mime types in such cases,
-			// we reload them here
-			\OC::$server->getMimeTypeLoader()->reset();
-		}
-		return $childQueue;
-	}
-
-	/**
-	 * check if the file should be ignored when scanning
-	 * NOTE: files with a '.part' extension are ignored as well!
-	 *       prevents unfinished put requests to be scanned
-	 *
-	 * @param string $file
-	 * @return boolean
-	 */
-	public static function isPartialFile($file) {
-		if (pathinfo($file, PATHINFO_EXTENSION) === 'part') {
-			return true;
-		}
-		if (strpos($file, '.part/') !== false) {
-			return true;
-		}
-
-		return false;
-	}
-
-	/**
-	 * walk over any folders that are not fully scanned yet and scan them
-	 */
-	public function backgroundScan() {
-		if ($this->storage->instanceOfStorage(Jail::class)) {
-			// for jail storage wrappers (shares, groupfolders) we run the background scan on the source storage
-			// this is mainly done because the jail wrapper doesn't implement `getIncomplete` (because it would be inefficient).
-			//
-			// Running the scan on the source storage might scan more than "needed", but the unscanned files outside the jail will
-			// have to be scanned at some point anyway.
-			$unJailedScanner = $this->storage->getUnjailedStorage()->getScanner();
-			$unJailedScanner->backgroundScan();
-		} else {
-			if (!$this->cache->inCache('')) {
-				// if the storage isn't in the cache yet, just scan the root completely
-				$this->runBackgroundScanJob(function () {
-					$this->scan('', self::SCAN_RECURSIVE, self::REUSE_ETAG);
-				}, '');
-			} else {
-				$lastPath = null;
-				// find any path marked as unscanned and run the scanner until no more paths are unscanned (or we get stuck)
-				while (($path = $this->cache->getIncomplete()) !== false && $path !== $lastPath) {
-					$this->runBackgroundScanJob(function () use ($path) {
-						$this->scan($path, self::SCAN_RECURSIVE_INCOMPLETE, self::REUSE_ETAG | self::REUSE_SIZE);
-					}, $path);
-					// FIXME: this won't proceed with the next item, needs revamping of getIncomplete()
-					// to make this possible
-					$lastPath = $path;
-				}
-			}
-		}
-	}
-
-	private function runBackgroundScanJob(callable $callback, $path) {
-		try {
-			$callback();
-			\OC_Hook::emit('Scanner', 'correctFolderSize', ['path' => $path]);
-			if ($this->cacheActive && $this->cache instanceof Cache) {
-				$this->cache->correctFolderSize($path, null, true);
-			}
-		} catch (\OCP\Files\StorageInvalidException $e) {
-			// skip unavailable storages
-		} catch (\OCP\Files\StorageNotAvailableException $e) {
-			// skip unavailable storages
-		} catch (\OCP\Files\ForbiddenException $e) {
-			// skip forbidden storages
-		} catch (\OCP\Lock\LockedException $e) {
-			// skip unavailable storages
-		}
-	}
-
-	/**
-	 * Set whether the cache is affected by scan operations
-	 *
-	 * @param boolean $active The active state of the cache
-	 */
-	public function setCacheActive($active) {
-		$this->cacheActive = $active;
-	}
+                    $data['oldSize'] = ($cacheData && isset($cacheData['size'])) ? $cacheData['size'] : 0;
+
+                    if ($cacheData && isset($cacheData['encrypted'])) {
+                        $data['encrypted'] = $cacheData['encrypted'];
+                    }
+
+                    // post-emit only if it was a file. By that we avoid counting/treating folders as files
+                    if ($data['mimetype'] !== 'httpd/unix-directory') {
+                        $this->emit('\OC\Files\Cache\Scanner', 'postScanFile', [$file, $this->storageId]);
+                        \OC_Hook::emit('\OC\Files\Cache\Scanner', 'post_scan_file', ['path' => $file, 'storage' => $this->storageId]);
+                    }
+                } else {
+                    $this->removeFromCache($file);
+                }
+            } catch (\Exception $e) {
+                if ($lock) {
+                    if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
+                        $this->storage->releaseLock($file, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
+                    }
+                }
+                throw $e;
+            }
+
+            // release the acquired lock
+            if ($lock) {
+                if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
+                    $this->storage->releaseLock($file, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
+                }
+            }
+
+            if ($data && !isset($data['encrypted'])) {
+                $data['encrypted'] = false;
+            }
+            return $data;
+        }
+
+        return null;
+    }
+
+    protected function removeFromCache($path) {
+        \OC_Hook::emit('Scanner', 'removeFromCache', ['file' => $path]);
+        $this->emit('\OC\Files\Cache\Scanner', 'removeFromCache', [$path]);
+        if ($this->cacheActive) {
+            $this->cache->remove($path);
+        }
+    }
+
+    /**
+     * @param string $path
+     * @param array $data
+     * @param int $fileId
+     * @return int the id of the added file
+     */
+    protected function addToCache($path, $data, $fileId = -1) {
+        if (isset($data['scan_permissions'])) {
+            $data['permissions'] = $data['scan_permissions'];
+        }
+        \OC_Hook::emit('Scanner', 'addToCache', ['file' => $path, 'data' => $data]);
+        $this->emit('\OC\Files\Cache\Scanner', 'addToCache', [$path, $this->storageId, $data]);
+        if ($this->cacheActive) {
+            if ($fileId !== -1) {
+                $this->cache->update($fileId, $data);
+                return $fileId;
+            } else {
+                return $this->cache->insert($path, $data);
+            }
+        } else {
+            return -1;
+        }
+    }
+
+    /**
+     * @param string $path
+     * @param array $data
+     * @param int $fileId
+     */
+    protected function updateCache($path, $data, $fileId = -1) {
+        \OC_Hook::emit('Scanner', 'addToCache', ['file' => $path, 'data' => $data]);
+        $this->emit('\OC\Files\Cache\Scanner', 'updateCache', [$path, $this->storageId, $data]);
+        if ($this->cacheActive) {
+            if ($fileId !== -1) {
+                $this->cache->update($fileId, $data);
+            } else {
+                $this->cache->put($path, $data);
+            }
+        }
+    }
+
+    /**
+     * scan a folder and all it's children
+     *
+     * @param string $path
+     * @param bool $recursive
+     * @param int $reuse
+     * @param bool $lock set to false to disable getting an additional read lock during scanning
+     * @return array|null an array of the meta data of the scanned file or folder
+     */
+    public function scan($path, $recursive = self::SCAN_RECURSIVE, $reuse = -1, $lock = true) {
+        if ($reuse === -1) {
+            $reuse = ($recursive === self::SCAN_SHALLOW) ? self::REUSE_ETAG | self::REUSE_SIZE : self::REUSE_ETAG;
+        }
+        if ($lock) {
+            if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
+                $this->storage->acquireLock('scanner::' . $path, ILockingProvider::LOCK_EXCLUSIVE, $this->lockingProvider);
+                $this->storage->acquireLock($path, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
+            }
+        }
+        try {
+            $data = $this->scanFile($path, $reuse, -1, null, $lock);
+            if ($data && $data['mimetype'] === 'httpd/unix-directory') {
+                $size = $this->scanChildren($path, $recursive, $reuse, $data['fileid'], $lock, $data);
+                $data['size'] = $size;
+            }
+        } finally {
+            if ($lock) {
+                if ($this->storage->instanceOfStorage('\OCP\Files\Storage\ILockingStorage')) {
+                    $this->storage->releaseLock($path, ILockingProvider::LOCK_SHARED, $this->lockingProvider);
+                    $this->storage->releaseLock('scanner::' . $path, ILockingProvider::LOCK_EXCLUSIVE, $this->lockingProvider);
+                }
+            }
+        }
+        return $data;
+    }
+
+    /**
+     * Get the children currently in the cache
+     *
+     * @param int $folderId
+     * @return array[]
+     */
+    protected function getExistingChildren($folderId) {
+        $existingChildren = [];
+        $children = $this->cache->getFolderContentsById($folderId);
+        foreach ($children as $child) {
+            $existingChildren[$child['name']] = $child;
+        }
+        return $existingChildren;
+    }
+
+    /**
+     * scan all the files and folders in a folder
+     *
+     * @param string $path
+     * @param bool $recursive
+     * @param int $reuse
+     * @param int $folderId id for the folder to be scanned
+     * @param bool $lock set to false to disable getting an additional read lock during scanning
+     * @param array $data the data of the folder before (re)scanning the children
+     * @return int the size of the scanned folder or -1 if the size is unknown at this stage
+     */
+    protected function scanChildren($path, $recursive = self::SCAN_RECURSIVE, $reuse = -1, $folderId = null, $lock = true, array $data = []) {
+        if ($reuse === -1) {
+            $reuse = ($recursive === self::SCAN_SHALLOW) ? self::REUSE_ETAG | self::REUSE_SIZE : self::REUSE_ETAG;
+        }
+        $this->emit('\OC\Files\Cache\Scanner', 'scanFolder', [$path, $this->storageId]);
+        $size = 0;
+        if (!is_null($folderId)) {
+            $folderId = $this->cache->getId($path);
+        }
+        $childQueue = $this->handleChildren($path, $recursive, $reuse, $folderId, $lock, $size);
+
+        foreach ($childQueue as $child => $childId) {
+            $childSize = $this->scanChildren($child, $recursive, $reuse, $childId, $lock);
+            if ($childSize === -1) {
+                $size = -1;
+            } elseif ($size !== -1) {
+                $size += $childSize;
+            }
+        }
+        $oldSize = $data['size'] ?? null;
+        if ($this->cacheActive && $oldSize !== $size) {
+            $this->cache->update($folderId, ['size' => $size]);
+        }
+        $this->emit('\OC\Files\Cache\Scanner', 'postScanFolder', [$path, $this->storageId]);
+        return $size;
+    }
+
+    private function handleChildren($path, $recursive, $reuse, $folderId, $lock, &$size) {
+        // we put this in it's own function so it cleans up the memory before we start recursing
+        $existingChildren = $this->getExistingChildren($folderId);
+        $newChildren = iterator_to_array($this->storage->getDirectoryContent($path));
+
+        if (count($existingChildren) === 0 && count($newChildren) === 0) {
+            // no need to do a transaction
+            return [];
+        }
+
+        if ($this->useTransactions) {
+            \OC::$server->getDatabaseConnection()->beginTransaction();
+        }
+
+        $exceptionOccurred = false;
+        $childQueue = [];
+        $newChildNames = [];
+        foreach ($newChildren as $fileMeta) {
+            $permissions = isset($fileMeta['scan_permissions']) ? $fileMeta['scan_permissions'] : $fileMeta['permissions'];
+            if ($permissions === 0) {
+                continue;
+            }
+            $originalFile = $fileMeta['name'];
+            $file = trim(\OC\Files\Filesystem::normalizePath($originalFile), '/');
+            if (trim($originalFile, '/') !== $file) {
+                // encoding mismatch, might require compatibility wrapper
+                \OC::$server->get(LoggerInterface::class)->debug('Scanner: Skipping non-normalized file name "'. $originalFile . '" in path "' . $path . '".', ['app' => 'core']);
+                $this->emit('\OC\Files\Cache\Scanner', 'normalizedNameMismatch', [$path ? $path . '/' . $originalFile : $originalFile]);
+                // skip this entry
+                continue;
+            }
+
+            $newChildNames[] = $file;
+            $child = $path ? $path . '/' . $file : $file;
+            try {
+                $existingData = isset($existingChildren[$file]) ? $existingChildren[$file] : false;
+                $data = $this->scanFile($child, $reuse, $folderId, $existingData, $lock, $fileMeta);
+                if ($data) {
+                    if ($data['mimetype'] === 'httpd/unix-directory' && $recursive === self::SCAN_RECURSIVE) {
+                        $childQueue[$child] = $data['fileid'];
+                    } elseif ($data['mimetype'] === 'httpd/unix-directory' && $recursive === self::SCAN_RECURSIVE_INCOMPLETE && $data['size'] === -1) {
+                        // only recurse into folders which aren't fully scanned
+                        $childQueue[$child] = $data['fileid'];
+                    } elseif ($data['size'] === -1) {
+                        $size = -1;
+                    } elseif ($size !== -1) {
+                        $size += $data['size'];
+                    }
+                }
+            } catch (Exception $ex) {
+                // might happen if inserting duplicate while a scanning
+                // process is running in parallel
+                // log and ignore
+                if ($this->useTransactions) {
+                    \OC::$server->getDatabaseConnection()->rollback();
+                    \OC::$server->getDatabaseConnection()->beginTransaction();
+                }
+                \OC::$server->get(LoggerInterface::class)->debug('Exception while scanning file "' . $child . '"', [
+                    'app' => 'core',
+                    'exception' => $ex,
+                ]);
+                $exceptionOccurred = true;
+            } catch (\OCP\Lock\LockedException $e) {
+                if ($this->useTransactions) {
+                    \OC::$server->getDatabaseConnection()->rollback();
+                }
+                throw $e;
+            }
+        }
+        $removedChildren = \array_diff(array_keys($existingChildren), $newChildNames);
+        foreach ($removedChildren as $childName) {
+            $child = $path ? $path . '/' . $childName : $childName;
+            $this->removeFromCache($child);
+        }
+        if ($this->useTransactions) {
+            \OC::$server->getDatabaseConnection()->commit();
+        }
+        if ($exceptionOccurred) {
+            // It might happen that the parallel scan process has already
+            // inserted mimetypes but those weren't available yet inside the transaction
+            // To make sure to have the updated mime types in such cases,
+            // we reload them here
+            \OC::$server->getMimeTypeLoader()->reset();
+        }
+        return $childQueue;
+    }
+
+    /**
+     * check if the file should be ignored when scanning
+     * NOTE: files with a '.part' extension are ignored as well!
+     *       prevents unfinished put requests to be scanned
+     *
+     * @param string $file
+     * @return boolean
+     */
+    public static function isPartialFile($file) {
+        if (pathinfo($file, PATHINFO_EXTENSION) === 'part') {
+            return true;
+        }
+        if (strpos($file, '.part/') !== false) {
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * walk over any folders that are not fully scanned yet and scan them
+     */
+    public function backgroundScan() {
+        if ($this->storage->instanceOfStorage(Jail::class)) {
+            // for jail storage wrappers (shares, groupfolders) we run the background scan on the source storage
+            // this is mainly done because the jail wrapper doesn't implement `getIncomplete` (because it would be inefficient).
+            //
+            // Running the scan on the source storage might scan more than "needed", but the unscanned files outside the jail will
+            // have to be scanned at some point anyway.
+            $unJailedScanner = $this->storage->getUnjailedStorage()->getScanner();
+            $unJailedScanner->backgroundScan();
+        } else {
+            if (!$this->cache->inCache('')) {
+                // if the storage isn't in the cache yet, just scan the root completely
+                $this->runBackgroundScanJob(function () {
+                    $this->scan('', self::SCAN_RECURSIVE, self::REUSE_ETAG);
+                }, '');
+            } else {
+                $lastPath = null;
+                // find any path marked as unscanned and run the scanner until no more paths are unscanned (or we get stuck)
+                while (($path = $this->cache->getIncomplete()) !== false && $path !== $lastPath) {
+                    $this->runBackgroundScanJob(function () use ($path) {
+                        $this->scan($path, self::SCAN_RECURSIVE_INCOMPLETE, self::REUSE_ETAG | self::REUSE_SIZE);
+                    }, $path);
+                    // FIXME: this won't proceed with the next item, needs revamping of getIncomplete()
+                    // to make this possible
+                    $lastPath = $path;
+                }
+            }
+        }
+    }
+
+    private function runBackgroundScanJob(callable $callback, $path) {
+        try {
+            $callback();
+            \OC_Hook::emit('Scanner', 'correctFolderSize', ['path' => $path]);
+            if ($this->cacheActive && $this->cache instanceof Cache) {
+                $this->cache->correctFolderSize($path, null, true);
+            }
+        } catch (\OCP\Files\StorageInvalidException $e) {
+            // skip unavailable storages
+        } catch (\OCP\Files\StorageNotAvailableException $e) {
+            // skip unavailable storages
+        } catch (\OCP\Files\ForbiddenException $e) {
+            // skip forbidden storages
+        } catch (\OCP\Lock\LockedException $e) {
+            // skip unavailable storages
+        }
+    }
+
+    /**
+     * Set whether the cache is affected by scan operations
+     *
+     * @param boolean $active The active state of the cache
+     */
+    public function setCacheActive($active) {
+        $this->cacheActive = $active;
+    }
 }