move log constants to ILogger

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>

38 files changed, 189 insertions, 153 deletions

diff --git a/lib/private/App/AppStore/Fetcher/AppFetcher.php b/lib/private/App/AppStore/Fetcher/AppFetcher.php
index 5203515e09b..cf5839e4994 100644
--- a/lib/private/App/AppStore/Fetcher/AppFetcher.php
+++ b/lib/private/App/AppStore/Fetcher/AppFetcher.php
@@ -101,7 +101,7 @@ class AppFetcher extends Fetcher {
 							$releases[] = $release;
 						}
 					} catch (\InvalidArgumentException $e) {
-						$this->logger->logException($e, ['app' => 'appstoreFetcher', 'level' => Util::WARN]);
+						$this->logger->logException($e, ['app' => 'appstoreFetcher', 'level' => ILogger::WARN]);
 					}
 				}
 			}
diff --git a/lib/private/App/AppStore/Fetcher/Fetcher.php b/lib/private/App/AppStore/Fetcher/Fetcher.php
index 172584c522b..973c4e55e9f 100644
--- a/lib/private/App/AppStore/Fetcher/Fetcher.php
+++ b/lib/private/App/AppStore/Fetcher/Fetcher.php
@@ -171,10 +171,10 @@ abstract class Fetcher {
 			$file->putContent(json_encode($responseJson));
 			return json_decode($file->getContent(), true)['data'];
 		} catch (ConnectException $e) {
-			$this->logger->logException($e, ['app' => 'appstoreFetcher', 'level' => Util::INFO, 'message' => 'Could not connect to appstore']);
+			$this->logger->logException($e, ['app' => 'appstoreFetcher', 'level' => ILogger::INFO, 'message' => 'Could not connect to appstore']);
 			return [];
 		} catch (\Exception $e) {
-			$this->logger->logException($e, ['app' => 'appstoreFetcher', 'level' => Util::INFO]);
+			$this->logger->logException($e, ['app' => 'appstoreFetcher', 'level' => ILogger::INFO]);
 			return [];
 		}
 	}
diff --git a/lib/private/AppFramework/DependencyInjection/DIContainer.php b/lib/private/AppFramework/DependencyInjection/DIContainer.php
index 4dcb94a1d33..37a34106dbe 100644
--- a/lib/private/AppFramework/DependencyInjection/DIContainer.php
+++ b/lib/private/AppFramework/DependencyInjection/DIContainer.php
@@ -57,6 +57,7 @@ use OCP\Files\Folder;
 use OCP\Files\IAppData;
 use OCP\GlobalScale\IConfig;
 use OCP\IL10N;
+use OCP\ILogger;
 use OCP\IRequest;
 use OCP\IServerContainer;
 use OCP\IUserSession;
@@ -375,19 +376,19 @@ class DIContainer extends SimpleContainer implements IAppContainer {
 	public function log($message, $level) {
 		switch($level){
 			case 'debug':
-				$level = \OCP\Util::DEBUG;
+				$level = ILogger::DEBUG;
 				break;
 			case 'info':
-				$level = \OCP\Util::INFO;
+				$level = ILogger::INFO;
 				break;
 			case 'warn':
-				$level = \OCP\Util::WARN;
+				$level = ILogger::WARN;
 				break;
 			case 'fatal':
-				$level = \OCP\Util::FATAL;
+				$level = ILogger::FATAL;
 				break;
 			default:
-				$level = \OCP\Util::ERROR;
+				$level = ILogger::ERROR;
 				break;
 		}
 		\OCP\Util::writeLog($this->getAppName(), $message, $level);
diff --git a/lib/private/AppFramework/Middleware/Security/SecurityMiddleware.php b/lib/private/AppFramework/Middleware/Security/SecurityMiddleware.php
index 7eb730ac2a3..2eedc39c3ab 100644
--- a/lib/private/AppFramework/Middleware/Security/SecurityMiddleware.php
+++ b/lib/private/AppFramework/Middleware/Security/SecurityMiddleware.php
@@ -255,7 +255,7 @@ class SecurityMiddleware extends Middleware {
 			}
 
 			$this->logger->logException($exception, [
-				'level' => \OCP\Util::DEBUG,
+				'level' => ILogger::DEBUG,
 				'app' => 'core',
 			]);
 			return $response;
diff --git a/lib/private/Archive/ZIP.php b/lib/private/Archive/ZIP.php
index fb727aba224..bbfe91ada49 100644
--- a/lib/private/Archive/ZIP.php
+++ b/lib/private/Archive/ZIP.php
@@ -31,6 +31,7 @@
 namespace OC\Archive;
 
 use Icewind\Streams\CallbackWrapper;
+use OCP\ILogger;
 
 class ZIP extends Archive{
 	/**
@@ -47,7 +48,7 @@ class ZIP extends Archive{
 		$this->zip=new \ZipArchive();
 		if($this->zip->open($source, \ZipArchive::CREATE)) {
 		}else{
-			\OCP\Util::writeLog('files_archive', 'Error while opening archive '.$source, \OCP\Util::WARN);
+			\OCP\Util::writeLog('files_archive', 'Error while opening archive '.$source, ILogger::WARN);
 		}
 	}
 	/**
diff --git a/lib/private/Cache/File.php b/lib/private/Cache/File.php
index ab51b54b8c8..7d2d468ec2f 100644
--- a/lib/private/Cache/File.php
+++ b/lib/private/Cache/File.php
@@ -30,6 +30,7 @@ namespace OC\Cache;
 use OC\Files\Filesystem;
 use OC\Files\View;
 use OCP\ICache;
+use OCP\ILogger;
 use OCP\Security\ISecureRandom;
 
 class File implements ICache {
@@ -58,7 +59,7 @@ class File implements ICache {
 			$this->storage = new View('/' . $user->getUID() . '/cache');
 			return $this->storage;
 		} else {
-			\OCP\Util::writeLog('core', 'Can\'t get cache storage, user not logged in', \OCP\Util::ERROR);
+			\OCP\Util::writeLog('core', 'Can\'t get cache storage, user not logged in', ILogger::ERROR);
 			throw new \OC\ForbiddenException('Can\t get cache storage, user not logged in');
 		}
 	}
diff --git a/lib/private/CapabilitiesManager.php b/lib/private/CapabilitiesManager.php
index fb272764597..ceb8205a7bb 100644
--- a/lib/private/CapabilitiesManager.php
+++ b/lib/private/CapabilitiesManager.php
@@ -57,7 +57,7 @@ class CapabilitiesManager {
 			} catch (QueryException $e) {
 				$this->logger->logException($e, [
 					'message' => 'CapabilitiesManager',
-					'level' => \OCP\Util::ERROR,
+					'level' => ILogger::ERROR,
 					'app' => 'core',
 				]);
 				continue;
diff --git a/lib/private/DateTimeZone.php b/lib/private/DateTimeZone.php
index 59da2f601ab..5bd5735226c 100644
--- a/lib/private/DateTimeZone.php
+++ b/lib/private/DateTimeZone.php
@@ -26,6 +26,7 @@ namespace OC;
 
 use OCP\IConfig;
 use OCP\IDateTimeZone;
+use OCP\ILogger;
 use OCP\ISession;
 
 class DateTimeZone implements IDateTimeZone {
@@ -64,7 +65,7 @@ class DateTimeZone implements IDateTimeZone {
 		try {
 			return new \DateTimeZone($timeZone);
 		} catch (\Exception $e) {
-			\OCP\Util::writeLog('datetimezone', 'Failed to created DateTimeZone "' . $timeZone . "'", \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('datetimezone', 'Failed to created DateTimeZone "' . $timeZone . "'", ILogger::DEBUG);
 			return new \DateTimeZone($this->getDefaultTimeZone());
 		}
 	}
@@ -109,7 +110,7 @@ class DateTimeZone implements IDateTimeZone {
 			}
 
 			// No timezone found, fallback to UTC
-			\OCP\Util::writeLog('datetimezone', 'Failed to find DateTimeZone for offset "' . $offset . "'", \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('datetimezone', 'Failed to find DateTimeZone for offset "' . $offset . "'", ILogger::DEBUG);
 			return new \DateTimeZone($this->getDefaultTimeZone());
 		}
 	}
diff --git a/lib/private/Files/Cache/Scanner.php b/lib/private/Files/Cache/Scanner.php
index 8f5f09319dd..e148a25accd 100644
--- a/lib/private/Files/Cache/Scanner.php
+++ b/lib/private/Files/Cache/Scanner.php
@@ -38,6 +38,7 @@ use OC\Files\Filesystem;
 use OC\Hooks\BasicEmitter;
 use OCP\Files\Cache\IScanner;
 use OCP\Files\ForbiddenException;
+use OCP\ILogger;
 use OCP\Lock\ILockingProvider;
 
 /**
@@ -110,7 +111,7 @@ class Scanner extends BasicEmitter implements IScanner {
 	protected function getData($path) {
 		$data = $this->storage->getMetaData($path);
 		if (is_null($data)) {
-			\OCP\Util::writeLog(Scanner::class, "!!! Path '$path' is not accessible or present !!!", \OCP\Util::DEBUG);
+			\OCP\Util::writeLog(Scanner::class, "!!! Path '$path' is not accessible or present !!!", ILogger::DEBUG);
 		}
 		return $data;
 	}
@@ -454,7 +455,7 @@ class Scanner extends BasicEmitter implements IScanner {
 				}
 				\OC::$server->getLogger()->logException($ex, [
 					'message' => 'Exception while scanning file "' . $child . '"',
-					'level' => \OCP\Util::DEBUG,
+					'level' => ILogger::DEBUG,
 					'app' => 'core',
 				]);
 				$exceptionOccurred = true;
diff --git a/lib/private/Files/Filesystem.php b/lib/private/Files/Filesystem.php
index b9f0813c84a..12e59e5ba2d 100644
--- a/lib/private/Files/Filesystem.php
+++ b/lib/private/Files/Filesystem.php
@@ -65,6 +65,7 @@ use OC\Files\Storage\StorageFactory;
 use OC\Lockdown\Filesystem\NullStorage;
 use OCP\Files\Config\IMountProvider;
 use OCP\Files\NotFoundException;
+use OCP\ILogger;
 use OCP\IUserManager;
 
 class Filesystem {
@@ -408,7 +409,7 @@ class Filesystem {
 		$userObject = $userManager->get($user);
 
 		if (is_null($userObject)) {
-			\OCP\Util::writeLog('files', ' Backends provided no user object for ' . $user, \OCP\Util::ERROR);
+			\OCP\Util::writeLog('files', ' Backends provided no user object for ' . $user, ILogger::ERROR);
 			// reset flag, this will make it possible to rethrow the exception if called again
 			unset(self::$usersSetup[$user]);
 			throw new \OC\User\NoUserException('Backends provided no user object for ' . $user);
@@ -418,7 +419,7 @@ class Filesystem {
 		// workaround in case of different casings
 		if ($user !== $realUid) {
 			$stack = json_encode(debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 50));
-			\OCP\Util::writeLog('files', 'initMountPoints() called with wrong user casing. This could be a bug. Expected: "' . $realUid . '" got "' . $user . '". Stack: ' . $stack, \OCP\Util::WARN);
+			\OCP\Util::writeLog('files', 'initMountPoints() called with wrong user casing. This could be a bug. Expected: "' . $realUid . '" got "' . $user . '". Stack: ' . $stack, ILogger::WARN);
 			$user = $realUid;
 
 			// again with the correct casing
diff --git a/lib/private/Files/Mount/MountPoint.php b/lib/private/Files/Mount/MountPoint.php
index 26150de2bd1..36e10bfb45a 100644
--- a/lib/private/Files/Mount/MountPoint.php
+++ b/lib/private/Files/Mount/MountPoint.php
@@ -33,6 +33,7 @@ use \OC\Files\Filesystem;
 use OC\Files\Storage\StorageFactory;
 use OC\Files\Storage\Storage;
 use OCP\Files\Mount\IMountPoint;
+use OCP\ILogger;
 
 class MountPoint implements IMountPoint {
 	/**
@@ -152,12 +153,12 @@ class MountPoint implements IMountPoint {
 					// the root storage could not be initialized, show the user!
 					throw new \Exception('The root storage could not be initialized. Please contact your local administrator.', $exception->getCode(), $exception);
 				} else {
-					\OC::$server->getLogger()->logException($exception, ['level' => \OCP\Util::ERROR]);
+					\OC::$server->getLogger()->logException($exception, ['level' => ILogger::ERROR]);
 				}
 				return;
 			}
 		} else {
-			\OCP\Util::writeLog('core', 'storage backend ' . $this->class . ' not found', \OCP\Util::ERROR);
+			\OCP\Util::writeLog('core', 'storage backend ' . $this->class . ' not found', ILogger::ERROR);
 			$this->invalidStorage = true;
 			return;
 		}
diff --git a/lib/private/Files/Mount/ObjectHomeMountProvider.php b/lib/private/Files/Mount/ObjectHomeMountProvider.php
index 9c09c0737c8..62669020884 100644
--- a/lib/private/Files/Mount/ObjectHomeMountProvider.php
+++ b/lib/private/Files/Mount/ObjectHomeMountProvider.php
@@ -26,6 +26,7 @@ namespace OC\Files\Mount;
 use OCP\Files\Config\IHomeMountProvider;
 use OCP\Files\Storage\IStorageFactory;
 use OCP\IConfig;
+use OCP\ILogger;
 use OCP\IUser;
 
 /**
@@ -79,7 +80,7 @@ class ObjectHomeMountProvider implements IHomeMountProvider {
 
 		// sanity checks
 		if (empty($config['class'])) {
-			\OCP\Util::writeLog('files', 'No class given for objectstore', \OCP\Util::ERROR);
+			\OCP\Util::writeLog('files', 'No class given for objectstore', ILogger::ERROR);
 		}
 		if (!isset($config['arguments'])) {
 			$config['arguments'] = [];
@@ -104,7 +105,7 @@ class ObjectHomeMountProvider implements IHomeMountProvider {
 
 		// sanity checks
 		if (empty($config['class'])) {
-			\OCP\Util::writeLog('files', 'No class given for objectstore', \OCP\Util::ERROR);
+			\OCP\Util::writeLog('files', 'No class given for objectstore', ILogger::ERROR);
 		}
 		if (!isset($config['arguments'])) {
 			$config['arguments'] = [];
diff --git a/lib/private/Files/ObjectStore/S3ConnectionTrait.php b/lib/private/Files/ObjectStore/S3ConnectionTrait.php
index 2556180173a..9565a82ac31 100644
--- a/lib/private/Files/ObjectStore/S3ConnectionTrait.php
+++ b/lib/private/Files/ObjectStore/S3ConnectionTrait.php
@@ -27,6 +27,7 @@ namespace OC\Files\ObjectStore;
 use Aws\ClientResolver;
 use Aws\S3\Exception\S3Exception;
 use Aws\S3\S3Client;
+use OCP\ILogger;
 
 trait S3ConnectionTrait {
 	/** @var array */
@@ -113,7 +114,7 @@ trait S3ConnectionTrait {
 			} catch (S3Exception $e) {
 				$logger->logException($e, [
 					'message' => 'Invalid remote storage.',
-					'level' => \OCP\Util::DEBUG,
+					'level' => ILogger::DEBUG,
 					'app' => 'objectstore',
 				]);
 				throw new \Exception('Creation of bucket "' . $this->bucket . '" failed. ' . $e->getMessage());
diff --git a/lib/private/Files/Storage/Common.php b/lib/private/Files/Storage/Common.php
index c9a91a7c56a..0d0f1da2594 100644
--- a/lib/private/Files/Storage/Common.php
+++ b/lib/private/Files/Storage/Common.php
@@ -54,6 +54,7 @@ use OCP\Files\InvalidPathException;
 use OCP\Files\ReservedWordException;
 use OCP\Files\Storage\ILockingStorage;
 use OCP\Files\Storage\IStorage;
+use OCP\ILogger;
 use OCP\Lock\ILockingProvider;
 use OCP\Lock\LockedException;
 
@@ -453,7 +454,7 @@ abstract class Common implements Storage, ILockingStorage {
 			return false;
 		} catch (\Exception $e) {
 			\OC::$server->getLogger()->info("External storage not available: " . $e->getMessage());
-			\OC::$server->getLogger()->logException($e, ['level' => \OCP\Util::DEBUG]);
+			\OC::$server->getLogger()->logException($e, ['level' => ILogger::DEBUG]);
 			return false;
 		}
 	}
diff --git a/lib/private/Files/Storage/DAV.php b/lib/private/Files/Storage/DAV.php
index b3c2dc00189..1ce7b8acd45 100644
--- a/lib/private/Files/Storage/DAV.php
+++ b/lib/private/Files/Storage/DAV.php
@@ -35,6 +35,7 @@ namespace OC\Files\Storage;
 
 use Exception;
 use GuzzleHttp\Exception\RequestException;
+use OCP\ILogger;
 use Psr\Http\Message\ResponseInterface;
 use Icewind\Streams\CallbackWrapper;
 use OC\Files\Filesystem;
@@ -357,7 +358,7 @@ class DAV extends Common {
 					if ($response->getStatusCode() === Http::STATUS_LOCKED) {
 						throw new \OCP\Lock\LockedException($path);
 					} else {
-						Util::writeLog("webdav client", 'Guzzle get returned status code ' . $response->getStatusCode(), Util::ERROR);
+						Util::writeLog("webdav client", 'Guzzle get returned status code ' . $response->getStatusCode(), ILogger::ERROR);
 					}
 				}
 
diff --git a/lib/private/Files/Storage/Local.php b/lib/private/Files/Storage/Local.php
index a0e20f4cba1..46b53dcf95c 100644
--- a/lib/private/Files/Storage/Local.php
+++ b/lib/private/Files/Storage/Local.php
@@ -42,6 +42,7 @@ namespace OC\Files\Storage;
 use OC\Files\Storage\Wrapper\Jail;
 use OCP\Files\ForbiddenException;
 use OCP\Files\Storage\IStorage;
+use OCP\ILogger;
 
 /**
  * for local filestore, we only have to map the paths
@@ -235,17 +236,17 @@ class Local extends \OC\Files\Storage\Common {
 		$dstParent = dirname($path2);
 
 		if (!$this->isUpdatable($srcParent)) {
-			\OCP\Util::writeLog('core', 'unable to rename, source directory is not writable : ' . $srcParent, \OCP\Util::ERROR);
+			\OCP\Util::writeLog('core', 'unable to rename, source directory is not writable : ' . $srcParent, ILogger::ERROR);
 			return false;
 		}
 
 		if (!$this->isUpdatable($dstParent)) {
-			\OCP\Util::writeLog('core', 'unable to rename, destination directory is not writable : ' . $dstParent, \OCP\Util::ERROR);
+			\OCP\Util::writeLog('core', 'unable to rename, destination directory is not writable : ' . $dstParent, ILogger::ERROR);
 			return false;
 		}
 
 		if (!$this->file_exists($path1)) {
-			\OCP\Util::writeLog('core', 'unable to rename, file does not exists : ' . $path1, \OCP\Util::ERROR);
+			\OCP\Util::writeLog('core', 'unable to rename, file does not exists : ' . $path1, ILogger::ERROR);
 			return false;
 		}
 
@@ -382,7 +383,7 @@ class Local extends \OC\Files\Storage\Common {
 			return $fullPath;
 		}
 
-		\OCP\Util::writeLog('core', "Following symlinks is not allowed ('$fullPath' -> '$realPath' not inside '{$this->realDataDir}')", \OCP\Util::ERROR);
+		\OCP\Util::writeLog('core', "Following symlinks is not allowed ('$fullPath' -> '$realPath' not inside '{$this->realDataDir}')", ILogger::ERROR);
 		throw new ForbiddenException('Following symlinks is not allowed', false);
 	}
 
diff --git a/lib/private/Files/Storage/Wrapper/Encryption.php b/lib/private/Files/Storage/Wrapper/Encryption.php
index 488218e8e74..109de4c4e5c 100644
--- a/lib/private/Files/Storage/Wrapper/Encryption.php
+++ b/lib/private/Files/Storage/Wrapper/Encryption.php
@@ -441,7 +441,7 @@ class Encryption extends Wrapper {
 			} catch (ModuleDoesNotExistsException $e) {
 				$this->logger->logException($e, [
 					'message' => 'Encryption module "' . $encryptionModuleId . '" not found, file will be stored unencrypted',
-					'level' => \OCP\Util::WARN,
+					'level' => ILogger::WARN,
 					'app' => 'core',
 				]);
 			}
diff --git a/lib/private/Files/View.php b/lib/private/Files/View.php
index aaf14b4d7e0..a149cdf0af5 100644
--- a/lib/private/Files/View.php
+++ b/lib/private/Files/View.php
@@ -59,6 +59,7 @@ use OCP\Files\InvalidPathException;
 use OCP\Files\Mount\IMountPoint;
 use OCP\Files\NotFoundException;
 use OCP\Files\ReservedWordException;
+use OCP\ILogger;
 use OCP\IUser;
 use OCP\Lock\ILockingProvider;
 use OCP\Lock\LockedException;
@@ -975,7 +976,7 @@ class View {
 				$hooks[] = 'write';
 				break;
 			default:
-				\OCP\Util::writeLog('core', 'invalid mode (' . $mode . ') for ' . $path, \OCP\Util::ERROR);
+				\OCP\Util::writeLog('core', 'invalid mode (' . $mode . ') for ' . $path, ILogger::ERROR);
 		}
 
 		if ($mode !== 'r' && $mode !== 'w') {
@@ -1463,7 +1464,7 @@ class View {
 							// sometimes when the storage is not available it can be any exception
 							\OC::$server->getLogger()->logException($e, [
 								'message' => 'Exception while scanning storage "' . $subStorage->getId() . '"',
-								'level' => \OCP\Util::ERROR,
+								'level' => ILogger::ERROR,
 								'app' => 'lib',
 							]);
 							continue;
@@ -1752,7 +1753,7 @@ class View {
 		if (!$targetStorage->instanceOfStorage('\OCP\Files\IHomeStorage')) {
 			\OCP\Util::writeLog('files',
 				'It is not allowed to move one mount point into another one',
-				\OCP\Util::DEBUG);
+				ILogger::DEBUG);
 			return false;
 		}
 
@@ -1775,7 +1776,7 @@ class View {
 		if (count($shares) > 0) {
 			\OCP\Util::writeLog('files',
 				'It is not allowed to move one mount point into a shared folder',
-				\OCP\Util::DEBUG);
+				ILogger::DEBUG);
 			return false;
 		}
 
diff --git a/lib/private/Installer.php b/lib/private/Installer.php
index 391e98171cf..b6586eceabe 100644
--- a/lib/private/Installer.php
+++ b/lib/private/Installer.php
@@ -175,7 +175,7 @@ class Installer {
 				$this->downloadApp($appId);
 			} catch (\Exception $e) {
 				$this->logger->logException($e, [
-					'level' => \OCP\Util::ERROR,
+					'level' => ILogger::ERROR,
 					'app' => 'core',
 				]);
 				return false;
@@ -460,7 +460,7 @@ class Installer {
 			OC_Helper::rmdirr($appDir);
 			return true;
 		}else{
-			\OCP\Util::writeLog('core', 'can\'t remove app '.$appId.'. It is not installed.', \OCP\Util::ERROR);
+			\OCP\Util::writeLog('core', 'can\'t remove app '.$appId.'. It is not installed.', ILogger::ERROR);
 
 			return false;
 		}
diff --git a/lib/private/Log.php b/lib/private/Log.php
index e1f9eb213be..ffe8c665c6f 100644
--- a/lib/private/Log.php
+++ b/lib/private/Log.php
@@ -107,7 +107,7 @@ class Log implements ILogger {
 	 * @return void
 	 */
 	public function emergency(string $message, array $context = []) {
-		$this->log(Util::FATAL, $message, $context);
+		$this->log(ILogger::FATAL, $message, $context);
 	}
 
 	/**
@@ -121,7 +121,7 @@ class Log implements ILogger {
 	 * @return void
 	 */
 	public function alert(string $message, array $context = []) {
-		$this->log(Util::ERROR, $message, $context);
+		$this->log(ILogger::ERROR, $message, $context);
 	}
 
 	/**
@@ -134,7 +134,7 @@ class Log implements ILogger {
 	 * @return void
 	 */
 	public function critical(string $message, array $context = []) {
-		$this->log(Util::ERROR, $message, $context);
+		$this->log(ILogger::ERROR, $message, $context);
 	}
 
 	/**
@@ -146,7 +146,7 @@ class Log implements ILogger {
 	 * @return void
 	 */
 	public function error(string $message, array $context = []) {
-		$this->log(Util::ERROR, $message, $context);
+		$this->log(ILogger::ERROR, $message, $context);
 	}
 
 	/**
@@ -160,7 +160,7 @@ class Log implements ILogger {
 	 * @return void
 	 */
 	public function warning(string $message, array $context = []) {
-		$this->log(Util::WARN, $message, $context);
+		$this->log(ILogger::WARN, $message, $context);
 	}
 
 	/**
@@ -171,7 +171,7 @@ class Log implements ILogger {
 	 * @return void
 	 */
 	public function notice(string $message, array $context = []) {
-		$this->log(Util::INFO, $message, $context);
+		$this->log(ILogger::INFO, $message, $context);
 	}
 
 	/**
@@ -184,7 +184,7 @@ class Log implements ILogger {
 	 * @return void
 	 */
 	public function info(string $message, array $context = []) {
-		$this->log(Util::INFO, $message, $context);
+		$this->log(ILogger::INFO, $message, $context);
 	}
 
 	/**
@@ -195,7 +195,7 @@ class Log implements ILogger {
 	 * @return void
 	 */
 	public function debug(string $message, array $context = []) {
-		$this->log(Util::DEBUG, $message, $context);
+		$this->log(ILogger::DEBUG, $message, $context);
 	}
 
 
@@ -260,7 +260,7 @@ class Log implements ILogger {
 
 		// if log condition is satisfied change the required log level to DEBUG
 		if ($this->logConditionSatisfied) {
-			return Util::DEBUG;
+			return ILogger::DEBUG;
 		}
 
 		if (isset($context['app'])) {
@@ -274,11 +274,11 @@ class Log implements ILogger {
 			if (!empty($logCondition)
 				&& isset($logCondition['apps'])
 				&& in_array($app, $logCondition['apps'], true)) {
-				return Util::DEBUG;
+				return ILogger::DEBUG;
 			}
 		}
 
-		return min($this->config->getValue('loglevel', Util::WARN), Util::FATAL);
+		return min($this->config->getValue('loglevel', ILogger::WARN), ILogger::FATAL);
 	}
 
 	/**
@@ -291,7 +291,7 @@ class Log implements ILogger {
 	 */
 	public function logException(\Throwable $exception, array $context = []) {
 		$app = $context['app'] ?? 'no app in context';
-		$level = $context['level'] ?? Util::ERROR;
+		$level = $context['level'] ?? ILogger::ERROR;
 
 		$serializer = new ExceptionSerializer();
 		$data = $serializer->serializeException($exception);
diff --git a/lib/private/Log/File.php b/lib/private/Log/File.php
index 2d7e4b6c14f..755c4729c7a 100644
--- a/lib/private/Log/File.php
+++ b/lib/private/Log/File.php
@@ -37,6 +37,8 @@
 
 namespace OC\Log;
 
+use OCP\ILogger;
+
 /**
  * logging utilities
  *
@@ -159,7 +161,7 @@ class File {
 	 */
 	public static function getEntries($limit=50, $offset=0) {
 		self::init();
-		$minLevel = \OC::$server->getSystemConfig()->getValue("loglevel", \OCP\Util::WARN);
+		$minLevel = \OC::$server->getSystemConfig()->getValue("loglevel", ILogger::WARN);
 		$entries = array();
 		$handle = @fopen(self::$logFile, 'rb');
 		if ($handle) {
diff --git a/lib/private/Log/Rotate.php b/lib/private/Log/Rotate.php
index 97a772b5251..48b96c98a8d 100644
--- a/lib/private/Log/Rotate.php
+++ b/lib/private/Log/Rotate.php
@@ -24,6 +24,7 @@
  */
 
 namespace OC\Log;
+use OCP\ILogger;
 
 /**
  * This rotates the current logfile to a new name, this way the total log usage
@@ -49,6 +50,6 @@ class Rotate extends \OC\BackgroundJob\Job {
 		$rotatedLogfile = $logfile.'.1';
 		rename($logfile, $rotatedLogfile);
 		$msg = 'Log file "'.$logfile.'" was over '.$this->max_log_size.' bytes, moved to "'.$rotatedLogfile.'"';
-		\OCP\Util::writeLog(Rotate::class, $msg, \OCP\Util::WARN);
+		\OCP\Util::writeLog(Rotate::class, $msg, ILogger::WARN);
 	}
 }
diff --git a/lib/private/Log/Syslog.php b/lib/private/Log/Syslog.php
index c6ea0a40350..7b3d931ef31 100644
--- a/lib/private/Log/Syslog.php
+++ b/lib/private/Log/Syslog.php
@@ -25,13 +25,15 @@
 
 namespace OC\Log;
 
+use OCP\ILogger;
+
 class Syslog {
 	static protected $levels = array(
-		\OCP\Util::DEBUG => LOG_DEBUG,
-		\OCP\Util::INFO => LOG_INFO,
-		\OCP\Util::WARN => LOG_WARNING,
-		\OCP\Util::ERROR => LOG_ERR,
-		\OCP\Util::FATAL => LOG_CRIT,
+		ILogger::DEBUG => LOG_DEBUG,
+		ILogger::INFO => LOG_INFO,
+		ILogger::WARN => LOG_WARNING,
+		ILogger::ERROR => LOG_ERR,
+		ILogger::FATAL => LOG_CRIT,
 	);
 
 	/**
diff --git a/lib/private/NaturalSort.php b/lib/private/NaturalSort.php
index 636e5cd0219..470e720c54c 100644
--- a/lib/private/NaturalSort.php
+++ b/lib/private/NaturalSort.php
@@ -27,6 +27,8 @@
 
 namespace OC;
 
+use OCP\ILogger;
+
 class NaturalSort {
 	private static $instance;
 	private $collator;
@@ -41,7 +43,7 @@ class NaturalSort {
 		// or inject an instance of \OC\NaturalSort_DefaultCollator to force using Owncloud's default collator
 		if (isset($injectedCollator)) {
 			$this->collator = $injectedCollator;
-			\OCP\Util::writeLog('core', 'forced use of '.get_class($injectedCollator), \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('core', 'forced use of '.get_class($injectedCollator), ILogger::DEBUG);
 		}
 	}
 
diff --git a/lib/private/Preview/Bitmap.php b/lib/private/Preview/Bitmap.php
index ff6093fcf81..89b56bfc9e8 100644
--- a/lib/private/Preview/Bitmap.php
+++ b/lib/private/Preview/Bitmap.php
@@ -26,6 +26,7 @@
 namespace OC\Preview;
 
 use Imagick;
+use OCP\ILogger;
 
 /**
  * Creates a PNG preview using ImageMagick via the PECL extension
@@ -50,7 +51,7 @@ abstract class Bitmap extends Provider {
 		} catch (\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
 				'message' => 'Imagick says:',
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 			return false;
diff --git a/lib/private/Preview/Office.php b/lib/private/Preview/Office.php
index 6403cf5dd8d..955ab249df2 100644
--- a/lib/private/Preview/Office.php
+++ b/lib/private/Preview/Office.php
@@ -25,6 +25,8 @@
  */
 namespace OC\Preview;
 
+use OCP\ILogger;
+
 abstract class Office extends Provider {
 	private $cmd;
 
@@ -60,7 +62,7 @@ abstract class Office extends Provider {
 			unlink($absPath);
 			unlink($pdfPreview);
 			\OC::$server->getLogger()->logException($e, [
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 			return false;
diff --git a/lib/private/Preview/SVG.php b/lib/private/Preview/SVG.php
index e0abf04d931..e283175c2e2 100644
--- a/lib/private/Preview/SVG.php
+++ b/lib/private/Preview/SVG.php
@@ -24,6 +24,8 @@
  */
 namespace OC\Preview;
 
+use OCP\ILogger;
+
 class SVG extends Provider {
 	/**
 	 * {@inheritDoc}
@@ -54,7 +56,7 @@ class SVG extends Provider {
 			$svg->setImageFormat('png32');
 		} catch (\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 			return false;
diff --git a/lib/private/Settings/Manager.php b/lib/private/Settings/Manager.php
index 7111511eca2..49f699223f6 100644
--- a/lib/private/Settings/Manager.php
+++ b/lib/private/Settings/Manager.php
@@ -150,12 +150,12 @@ class Manager implements IManager {
 				/** @var ISection $section */
 				$section = \OC::$server->query($class);
 			} catch (QueryException $e) {
-				$this->log->logException($e, ['level' => Util::INFO]);
+				$this->log->logException($e, ['level' => ILogger::INFO]);
 				continue;
 			}
 
 			if (!$section instanceof ISection) {
-				$this->log->logException(new \InvalidArgumentException('Invalid settings section registered'), ['level' => Util::INFO]);
+				$this->log->logException(new \InvalidArgumentException('Invalid settings section registered'), ['level' => ILogger::INFO]);
 				continue;
 			}
 
@@ -200,12 +200,12 @@ class Manager implements IManager {
 				/** @var ISettings $setting */
 				$setting = \OC::$server->query($class);
 			} catch (QueryException $e) {
-				$this->log->logException($e, ['level' => Util::INFO]);
+				$this->log->logException($e, ['level' => ILogger::INFO]);
 				continue;
 			}
 
 			if (!$setting instanceof ISettings) {
-				$this->log->logException(new \InvalidArgumentException('Invalid settings setting registered'), ['level' => Util::INFO]);
+				$this->log->logException(new \InvalidArgumentException('Invalid settings setting registered'), ['level' => ILogger::INFO]);
 				continue;
 			}
 
diff --git a/lib/private/Setup/MySQL.php b/lib/private/Setup/MySQL.php
index d3b39007aa9..dd215f96cbe 100644
--- a/lib/private/Setup/MySQL.php
+++ b/lib/private/Setup/MySQL.php
@@ -31,6 +31,7 @@ namespace OC\Setup;
 
 use OC\DB\MySqlTools;
 use OCP\IDBConnection;
+use OCP\ILogger;
 
 class MySQL extends AbstractDatabase {
 	public $dbprettyname = 'MySQL/MariaDB';
@@ -70,7 +71,7 @@ class MySQL extends AbstractDatabase {
 		} catch (\Exception $ex) {
 			$this->logger->logException($ex, [
 				'message' => 'Database creation failed.',
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'mysql.setup',
 			]);
 			return;
@@ -83,7 +84,7 @@ class MySQL extends AbstractDatabase {
 		} catch (\Exception $ex) {
 			$this->logger->logException($ex, [
 				'message' => 'Could not automatically grant privileges, this can be ignored if database user already had privileges.',
-				'level' => \OCP\Util::DEBUG,
+				'level' => ILogger::DEBUG,
 				'app' => 'mysql.setup',
 			]);
 		}
@@ -107,7 +108,7 @@ class MySQL extends AbstractDatabase {
 		catch (\Exception $ex){
 			$this->logger->logException($ex, [
 				'message' => 'Database user creation failed.',
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'mysql.setup',
 			]);
 		}
@@ -162,7 +163,7 @@ class MySQL extends AbstractDatabase {
 		} catch (\Exception $ex) {
 			$this->logger->logException($ex, [
 				'message' => 'Can not create a new MySQL user, will continue with the provided user.',
-				'level' => \OCP\Util::INFO,
+				'level' => ILogger::INFO,
 				'app' => 'mysql.setup',
 			]);
 		}
diff --git a/lib/private/Share/Share.php b/lib/private/Share/Share.php
index 9c82fcc268b..ea00cfaca26 100644
--- a/lib/private/Share/Share.php
+++ b/lib/private/Share/Share.php
@@ -41,6 +41,7 @@ namespace OC\Share;
 
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\IConfig;
+use OCP\ILogger;
 use OCP\Util;
 
 /**
@@ -92,7 +93,7 @@ class Share extends Constants {
 			\OCP\Util::writeLog('OCP\Share',
 				'Sharing backend '.$class.' not registered, '.self::$backendTypes[$itemType]['class']
 				.' is already registered for '.$itemType,
-				\OCP\Util::WARN);
+				ILogger::WARN);
 		}
 		return false;
 	}
@@ -264,7 +265,7 @@ class Share extends Constants {
 		$query = \OC_DB::prepare('SELECT * FROM `*PREFIX*share` WHERE `token` = ?', 1);
 		$result = $query->execute(array($token));
 		if ($result === false) {
-			\OCP\Util::writeLog('OCP\Share', \OC_DB::getErrorMessage() . ', token=' . $token, \OCP\Util::ERROR);
+			\OCP\Util::writeLog('OCP\Share', \OC_DB::getErrorMessage() . ', token=' . $token, ILogger::ERROR);
 		}
 		$row = $result->fetchRow();
 		if ($row === false) {
@@ -335,7 +336,7 @@ class Share extends Constants {
 		if ($backend->isShareTypeAllowed($shareType) === false) {
 			$message = 'Sharing %s failed, because the backend does not allow shares from type %i';
 			$message_t = $l->t('Sharing %s failed, because the backend does not allow shares from type %i', array($itemSourceName, $shareType));
-			\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareType), \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareType), ILogger::DEBUG);
 			throw new \Exception($message_t);
 		}
 
@@ -356,14 +357,14 @@ class Share extends Constants {
 			if (!$path) {
 				$message = 'Sharing %s failed, because the file does not exist';
 				$message_t = $l->t('Sharing %s failed, because the file does not exist', array($itemSourceName));
-				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName), \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName), ILogger::DEBUG);
 				throw new \Exception($message_t);
 			}
 			// verify that the user has share permission
 			if (!\OC\Files\Filesystem::isSharable($path) || \OCP\Util::isSharingDisabledForUser()) {
 				$message = 'You are not allowed to share %s';
 				$message_t = $l->t('You are not allowed to share %s', [$path]);
-				\OCP\Util::writeLog('OCP\Share', sprintf($message, $path), \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('OCP\Share', sprintf($message, $path), ILogger::DEBUG);
 				throw new \Exception($message_t);
 			}
 		}
@@ -376,7 +377,7 @@ class Share extends Constants {
 			foreach ($mounts as $mount) {
 				if ($mount->getStorage()->instanceOfStorage('\OCA\Files_Sharing\ISharedStorage')) {
 					$message = 'Sharing "' . $itemSourceName . '" failed, because it contains files shared with you!';
-					\OCP\Util::writeLog('OCP\Share', $message, \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('OCP\Share', $message, ILogger::DEBUG);
 					throw new \Exception($message);
 				}
 
@@ -408,13 +409,13 @@ class Share extends Constants {
 			if ($shareWith == $uidOwner) {
 				$message = 'Sharing %s failed, because you can not share with yourself';
 				$message_t = $l->t('Sharing %s failed, because you can not share with yourself', [$itemName]);
-				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName), \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName), ILogger::DEBUG);
 				throw new \Exception($message_t);
 			}
 			if (!\OC::$server->getUserManager()->userExists($shareWith)) {
 				$message = 'Sharing %s failed, because the user %s does not exist';
 				$message_t = $l->t('Sharing %s failed, because the user %s does not exist', array($itemSourceName, $shareWith));
-				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), ILogger::DEBUG);
 				throw new \Exception($message_t);
 			}
 			if ($shareWithinGroupOnly) {
@@ -435,7 +436,7 @@ class Share extends Constants {
 					$message = 'Sharing %s failed, because the user '
 						.'%s is not a member of any groups that %s is a member of';
 					$message_t = $l->t('Sharing %s failed, because the user %s is not a member of any groups that %s is a member of', array($itemName, $shareWith, $uidOwner));
-					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemName, $shareWith, $uidOwner), \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemName, $shareWith, $uidOwner), ILogger::DEBUG);
 					throw new \Exception($message_t);
 				}
 			}
@@ -448,7 +449,7 @@ class Share extends Constants {
 				if ($checkExists['uid_owner'] != $uidOwner || $checkExists['share_type'] == $shareType) {
 					$message = 'Sharing %s failed, because this item is already shared with %s';
 					$message_t = $l->t('Sharing %s failed, because this item is already shared with %s', array($itemSourceName, $shareWith));
-					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), ILogger::DEBUG);
 					throw new \Exception($message_t);
 				}
 			}
@@ -460,7 +461,7 @@ class Share extends Constants {
 				if ($checkExists['uid_owner'] != $uidOwner || $checkExists['share_type'] == $shareType) {
 					$message = 'Sharing %s failed, because this item is already shared with user %s';
 					$message_t = $l->t('Sharing %s failed, because this item is already shared with user %s', array($itemSourceName, $shareWith));
-					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), \OCP\Util::ERROR);
+					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), ILogger::ERROR);
 					throw new \Exception($message_t);
 				}
 			}
@@ -468,7 +469,7 @@ class Share extends Constants {
 			if (!\OC::$server->getGroupManager()->groupExists($shareWith)) {
 				$message = 'Sharing %s failed, because the group %s does not exist';
 				$message_t = $l->t('Sharing %s failed, because the group %s does not exist', array($itemSourceName, $shareWith));
-				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), ILogger::DEBUG);
 				throw new \Exception($message_t);
 			}
 			if ($shareWithinGroupOnly) {
@@ -478,7 +479,7 @@ class Share extends Constants {
 					$message = 'Sharing %s failed, because '
 						. '%s is not a member of the group %s';
 					$message_t = $l->t('Sharing %s failed, because %s is not a member of the group %s', array($itemSourceName, $uidOwner, $shareWith));
-					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $uidOwner, $shareWith), \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $uidOwner, $shareWith), ILogger::DEBUG);
 					throw new \Exception($message_t);
 				}
 			}
@@ -490,7 +491,7 @@ class Share extends Constants {
 				if ($checkExists['share_with'] === $shareWith && $checkExists['share_type'] === \OCP\Share::SHARE_TYPE_GROUP) {
 					$message = 'Sharing %s failed, because this item is already shared with %s';
 					$message_t = $l->t('Sharing %s failed, because this item is already shared with %s', array($itemSourceName, $shareWith));
-					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), ILogger::DEBUG);
 					throw new \Exception($message_t);
 				}
 			}
@@ -557,7 +558,7 @@ class Share extends Constants {
 				if (\OCP\Util::isPublicLinkPasswordRequired() && empty($shareWith)) {
 					$message = 'You need to provide a password to create a public link, only protected links are allowed';
 					$message_t = $l->t('You need to provide a password to create a public link, only protected links are allowed');
-					\OCP\Util::writeLog('OCP\Share', $message, \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('OCP\Share', $message, ILogger::DEBUG);
 					throw new \Exception($message_t);
 				}
 
@@ -585,7 +586,7 @@ class Share extends Constants {
 			}
 			$message = 'Sharing %s failed, because sharing with links is not allowed';
 			$message_t = $l->t('Sharing %s failed, because sharing with links is not allowed', array($itemSourceName));
-			\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName), \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName), ILogger::DEBUG);
 			throw new \Exception($message_t);
 		} else if ($shareType === self::SHARE_TYPE_REMOTE) {
 
@@ -596,7 +597,7 @@ class Share extends Constants {
 				$shareWith, $uidOwner, self::FORMAT_NONE, null, 1, true, true)) {
 					$message = 'Sharing %s failed, because this item is already shared with %s';
 					$message_t = $l->t('Sharing %s failed, because this item is already shared with %s', array($itemSourceName, $shareWith));
-					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), ILogger::DEBUG);
 					throw new \Exception($message_t);
 			}
 
@@ -607,7 +608,7 @@ class Share extends Constants {
 			if (Helper::isSameUserOnSameServer($user, $remote, $currentUser, $currentServer)) {
 				$message = 'Not allowed to create a federated share with the same user.';
 				$message_t = $l->t('Not allowed to create a federated share with the same user');
-				\OCP\Util::writeLog('OCP\Share', $message, \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('OCP\Share', $message, ILogger::DEBUG);
 				throw new \Exception($message_t);
 			}
 
@@ -634,7 +635,7 @@ class Share extends Constants {
 			// Future share types need to include their own conditions
 			$message = 'Share type %s is not valid for %s';
 			$message_t = $l->t('Share type %s is not valid for %s', array($shareType, $itemSource));
-			\OCP\Util::writeLog('OCP\Share', sprintf($message, $shareType, $itemSource), \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('OCP\Share', sprintf($message, $shareType, $itemSource), ILogger::DEBUG);
 			throw new \Exception($message_t);
 		}
 
@@ -703,7 +704,7 @@ class Share extends Constants {
 		$result = $query->execute(array($status, $itemType, $itemSource, $shareType, $recipient));
 
 		if($result === false) {
-			\OCP\Util::writeLog('OCP\Share', 'Couldn\'t set send mail status', \OCP\Util::ERROR);
+			\OCP\Util::writeLog('OCP\Share', 'Couldn\'t set send mail status', ILogger::ERROR);
 		}
 	}
 
@@ -740,7 +741,7 @@ class Share extends Constants {
 			if ($date > $maxDate) {
 				$warning = 'Cannot set expiration date. Shares cannot expire later than ' . $maxDays . ' after they have been shared';
 				$warning_t = $l->t('Cannot set expiration date. Shares cannot expire later than %s after they have been shared', array($maxDays));
-				\OCP\Util::writeLog('OCP\Share', $warning, \OCP\Util::WARN);
+				\OCP\Util::writeLog('OCP\Share', $warning, ILogger::WARN);
 				throw new \Exception($warning_t);
 			}
 		}
@@ -748,7 +749,7 @@ class Share extends Constants {
 		if ($date < $today) {
 			$message = 'Cannot set expiration date. Expiration date is in the past';
 			$message_t = $l->t('Cannot set expiration date. Expiration date is in the past');
-			\OCP\Util::writeLog('OCP\Share', $message, \OCP\Util::WARN);
+			\OCP\Util::writeLog('OCP\Share', $message, ILogger::WARN);
 			throw new \Exception($message_t);
 		}
 
@@ -849,20 +850,20 @@ class Share extends Constants {
 				if (!(self::$backends[$itemType] instanceof \OCP\Share_Backend)) {
 					$message = 'Sharing backend %s must implement the interface OCP\Share_Backend';
 					$message_t = $l->t('Sharing backend %s must implement the interface OCP\Share_Backend', array($class));
-					\OCP\Util::writeLog('OCP\Share', sprintf($message, $class), \OCP\Util::ERROR);
+					\OCP\Util::writeLog('OCP\Share', sprintf($message, $class), ILogger::ERROR);
 					throw new \Exception($message_t);
 				}
 				return self::$backends[$itemType];
 			} else {
 				$message = 'Sharing backend %s not found';
 				$message_t = $l->t('Sharing backend %s not found', array($class));
-				\OCP\Util::writeLog('OCP\Share', sprintf($message, $class), \OCP\Util::ERROR);
+				\OCP\Util::writeLog('OCP\Share', sprintf($message, $class), ILogger::ERROR);
 				throw new \Exception($message_t);
 			}
 		}
 		$message = 'Sharing backend for %s not found';
 		$message_t = $l->t('Sharing backend for %s not found', array($itemType));
-		\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemType), \OCP\Util::ERROR);
+		\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemType), ILogger::ERROR);
 		throw new \Exception($message_t);
 	}
 
@@ -1133,7 +1134,7 @@ class Share extends Constants {
 		if ($result === false) {
 			\OCP\Util::writeLog('OCP\Share',
 				\OC_DB::getErrorMessage() . ', select=' . $select . ' where=',
-				\OCP\Util::ERROR);
+				ILogger::ERROR);
 		}
 		$items = array();
 		$targets = array();
@@ -1197,7 +1198,7 @@ class Share extends Constants {
 					if ($result === false) {
 						\OCP\Util::writeLog('OCP\Share', 'Can\'t select parent: ' .
 							\OC_DB::getErrorMessage() . ', select=' . $select . ' where=' . $where,
-							\OCP\Util::ERROR);
+							ILogger::ERROR);
 					} else {
 						$parentRow = $parentResult->fetchRow();
 						$tmpPath = $parentRow['file_target'];
@@ -1668,7 +1669,7 @@ class Share extends Constants {
 				$message = 'Sharing %s failed, because the user %s is the original sharer';
 				$message_t = $l->t('Sharing failed, because the user %s is the original sharer', [$shareWith]);
 
-				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), ILogger::DEBUG);
 				throw new \Exception($message_t);
 			}
 		}
@@ -1680,7 +1681,7 @@ class Share extends Constants {
 					$message = 'Sharing %s failed, because the permissions exceed permissions granted to %s';
 					$message_t = $l->t('Sharing %s failed, because the permissions exceed permissions granted to %s', array($itemSourceName, $uidOwner));
 
-					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $uidOwner), \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $uidOwner), ILogger::DEBUG);
 					throw new \Exception($message_t);
 				} else {
 					// TODO Don't check if inside folder
@@ -1712,7 +1713,7 @@ class Share extends Constants {
 				$message = 'Sharing %s failed, because resharing is not allowed';
 				$message_t = $l->t('Sharing %s failed, because resharing is not allowed', array($itemSourceName));
 
-				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName), \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName), ILogger::DEBUG);
 				throw new \Exception($message_t);
 			}
 		} else {
@@ -1725,7 +1726,7 @@ class Share extends Constants {
 				$message = 'Sharing %s failed, because the sharing backend for '
 					.'%s could not find its source';
 				$message_t = $l->t('Sharing %s failed, because the sharing backend for %s could not find its source', array($itemSource, $itemType));
-				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSource, $itemType), \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSource, $itemType), ILogger::DEBUG);
 				throw new \Exception($message_t);
 			}
 			if ($backend instanceof \OCP\Share_Backend_File_Dependent) {
@@ -1740,7 +1741,7 @@ class Share extends Constants {
 					$message = 'Sharing %s failed, because the file could not be found in the file cache';
 					$message_t = $l->t('Sharing %s failed, because the file could not be found in the file cache', array($itemSource));
 
-					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSource), \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSource), ILogger::DEBUG);
 					throw new \Exception($message_t);
 				}
 			} else {
diff --git a/lib/private/Tags.php b/lib/private/Tags.php
index c78297e5290..10c9affa277 100644
--- a/lib/private/Tags.php
+++ b/lib/private/Tags.php
@@ -47,6 +47,7 @@ namespace OC;
 use OC\Tagging\Tag;
 use OC\Tagging\TagMapper;
 use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\ILogger;
 
 class Tags implements \OCP\ITags {
 
@@ -237,14 +238,14 @@ class Tags implements \OCP\ITags {
 					$entries[$objId][] = $row['category'];
 				}
 				if ($result === null) {
-					\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . \OC::$server->getDatabaseConnection()->getError(), \OCP\Util::ERROR);
+					\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . \OC::$server->getDatabaseConnection()->getError(), ILogger::ERROR);
 					return false;
 				}
 			}
 		} catch(\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
 				'message' => __METHOD__,
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 			return false;
@@ -270,7 +271,7 @@ class Tags implements \OCP\ITags {
 		} elseif(is_string($tag)) {
 			$tag = trim($tag);
 			if($tag === '') {
-				\OCP\Util::writeLog('core', __METHOD__.', Cannot use empty tag names', \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('core', __METHOD__.', Cannot use empty tag names', ILogger::DEBUG);
 				return false;
 			}
 			$tagId = $this->getTagId($tag);
@@ -291,13 +292,13 @@ class Tags implements \OCP\ITags {
 			$stmt = \OC_DB::prepare($sql);
 			$result = $stmt->execute(array($tagId));
 			if ($result === null) {
-				\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . \OC::$server->getDatabaseConnection()->getError(), \OCP\Util::ERROR);
+				\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . \OC::$server->getDatabaseConnection()->getError(), ILogger::ERROR);
 				return false;
 			}
 		} catch(\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
 				'message' => __METHOD__,
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 			return false;
@@ -360,11 +361,11 @@ class Tags implements \OCP\ITags {
 		$name = trim($name);
 
 		if($name === '') {
-			\OCP\Util::writeLog('core', __METHOD__.', Cannot add an empty tag', \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('core', __METHOD__.', Cannot add an empty tag', ILogger::DEBUG);
 			return false;
 		}
 		if($this->userHasTag($name, $this->user)) {
-			\OCP\Util::writeLog('core', __METHOD__.', name: ' . $name. ' exists already', \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('core', __METHOD__.', name: ' . $name. ' exists already', ILogger::DEBUG);
 			return false;
 		}
 		try {
@@ -374,12 +375,12 @@ class Tags implements \OCP\ITags {
 		} catch(\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
 				'message' => __METHOD__,
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 			return false;
 		}
-		\OCP\Util::writeLog('core', __METHOD__.', id: ' . $tag->getId(), \OCP\Util::DEBUG);
+		\OCP\Util::writeLog('core', __METHOD__.', id: ' . $tag->getId(), ILogger::DEBUG);
 		return $tag->getId();
 	}
 
@@ -395,7 +396,7 @@ class Tags implements \OCP\ITags {
 		$to = trim($to);
 
 		if($to === '' || $from === '') {
-			\OCP\Util::writeLog('core', __METHOD__.', Cannot use empty tag names', \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('core', __METHOD__.', Cannot use empty tag names', ILogger::DEBUG);
 			return false;
 		}
 
@@ -405,13 +406,13 @@ class Tags implements \OCP\ITags {
 			$key = $this->getTagByName($from);
 		}
 		if($key === false) {
-			\OCP\Util::writeLog('core', __METHOD__.', tag: ' . $from. ' does not exist', \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('core', __METHOD__.', tag: ' . $from. ' does not exist', ILogger::DEBUG);
 			return false;
 		}
 		$tag = $this->tags[$key];
 
 		if($this->userHasTag($to, $tag->getOwner())) {
-			\OCP\Util::writeLog('core', __METHOD__.', A tag named ' . $to. ' already exists for user ' . $tag->getOwner() . '.', \OCP\Util::DEBUG);
+			\OCP\Util::writeLog('core', __METHOD__.', A tag named ' . $to. ' already exists for user ' . $tag->getOwner() . '.', ILogger::DEBUG);
 			return false;
 		}
 
@@ -421,7 +422,7 @@ class Tags implements \OCP\ITags {
 		} catch(\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
 				'message' => __METHOD__,
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 			return false;
@@ -476,7 +477,7 @@ class Tags implements \OCP\ITags {
 				} catch(\Exception $e) {
 					\OC::$server->getLogger()->logException($e, [
 						'message' => __METHOD__,
-						'level' => \OCP\Util::ERROR,
+						'level' => ILogger::ERROR,
 						'app' => 'core',
 					]);
 				}
@@ -485,7 +486,7 @@ class Tags implements \OCP\ITags {
 			// reload tags to get the proper ids.
 			$this->tags = $this->mapper->loadTags($this->owners, $this->type);
 			\OCP\Util::writeLog('core', __METHOD__.', tags: ' . print_r($this->tags, true),
-				\OCP\Util::DEBUG);
+				ILogger::DEBUG);
 			// Loop through temporarily cached objectid/tagname pairs
 			// and save relations.
 			$tags = $this->tags;
@@ -494,7 +495,7 @@ class Tags implements \OCP\ITags {
 			$dbConnection = \OC::$server->getDatabaseConnection();
 			foreach(self::$relations as $relation) {
 				$tagId = $this->getTagId($relation['tag']);
-				\OCP\Util::writeLog('core', __METHOD__ . 'catid, ' . $relation['tag'] . ' ' . $tagId, \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('core', __METHOD__ . 'catid, ' . $relation['tag'] . ' ' . $tagId, ILogger::DEBUG);
 				if($tagId) {
 					try {
 						$dbConnection->insertIfNotExist(self::RELATION_TABLE,
@@ -506,7 +507,7 @@ class Tags implements \OCP\ITags {
 					} catch(\Exception $e) {
 						\OC::$server->getLogger()->logException($e, [
 							'message' => __METHOD__,
-							'level' => \OCP\Util::ERROR,
+							'level' => ILogger::ERROR,
 							'app' => 'core',
 						]);
 					}
@@ -515,7 +516,7 @@ class Tags implements \OCP\ITags {
 			self::$relations = array(); // reset
 		} else {
 			\OCP\Util::writeLog('core', __METHOD__.', $this->tags is not an array! '
-				. print_r($this->tags, true), \OCP\Util::ERROR);
+				. print_r($this->tags, true), ILogger::ERROR);
 		}
 	}
 
@@ -534,12 +535,12 @@ class Tags implements \OCP\ITags {
 				. 'WHERE `uid` = ?');
 			$result = $stmt->execute(array($arguments['uid']));
 			if ($result === null) {
-				\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . \OC::$server->getDatabaseConnection()->getError(), \OCP\Util::ERROR);
+				\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . \OC::$server->getDatabaseConnection()->getError(), ILogger::ERROR);
 			}
 		} catch(\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
 				'message' => __METHOD__,
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 		}
@@ -554,7 +555,7 @@ class Tags implements \OCP\ITags {
 					} catch(\Exception $e) {
 						\OC::$server->getLogger()->logException($e, [
 							'message' => __METHOD__,
-							'level' => \OCP\Util::ERROR,
+							'level' => ILogger::ERROR,
 							'app' => 'core',
 						]);
 					}
@@ -562,7 +563,7 @@ class Tags implements \OCP\ITags {
 			} catch(\Exception $e) {
 				\OC::$server->getLogger()->logException($e, [
 					'message' => __METHOD__,
-					'level' => \OCP\Util::ERROR,
+					'level' => ILogger::ERROR,
 					'app' => 'core',
 				]);
 			}
@@ -572,12 +573,12 @@ class Tags implements \OCP\ITags {
 				. 'WHERE `uid` = ?');
 			$result = $stmt->execute(array($arguments['uid']));
 			if ($result === null) {
-				\OCP\Util::writeLog('core', __METHOD__. ', DB error: ' . \OC::$server->getDatabaseConnection()->getError(), \OCP\Util::ERROR);
+				\OCP\Util::writeLog('core', __METHOD__. ', DB error: ' . \OC::$server->getDatabaseConnection()->getError(), ILogger::ERROR);
 			}
 		} catch(\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
 				'message' => __METHOD__,
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 		}
@@ -603,13 +604,13 @@ class Tags implements \OCP\ITags {
 			$stmt = \OC_DB::prepare($query);
 			$result = $stmt->execute($updates);
 			if ($result === null) {
-				\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . \OC::$server->getDatabaseConnection()->getError(), \OCP\Util::ERROR);
+				\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . \OC::$server->getDatabaseConnection()->getError(), ILogger::ERROR);
 				return false;
 			}
 		} catch(\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
 				'message' => __METHOD__,
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 			return false;
@@ -628,7 +629,7 @@ class Tags implements \OCP\ITags {
 		} catch(\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
 				'message' => __METHOD__,
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 			return array();
@@ -669,7 +670,7 @@ class Tags implements \OCP\ITags {
 		if(is_string($tag) && !is_numeric($tag)) {
 			$tag = trim($tag);
 			if($tag === '') {
-				\OCP\Util::writeLog('core', __METHOD__.', Cannot add an empty tag', \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('core', __METHOD__.', Cannot add an empty tag', ILogger::DEBUG);
 				return false;
 			}
 			if(!$this->hasTag($tag)) {
@@ -689,7 +690,7 @@ class Tags implements \OCP\ITags {
 		} catch(\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
 				'message' => __METHOD__,
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 			return false;
@@ -708,7 +709,7 @@ class Tags implements \OCP\ITags {
 		if(is_string($tag) && !is_numeric($tag)) {
 			$tag = trim($tag);
 			if($tag === '') {
-				\OCP\Util::writeLog('core', __METHOD__.', Tag name is empty', \OCP\Util::DEBUG);
+				\OCP\Util::writeLog('core', __METHOD__.', Tag name is empty', ILogger::DEBUG);
 				return false;
 			}
 			$tagId =  $this->getTagId($tag);
@@ -724,7 +725,7 @@ class Tags implements \OCP\ITags {
 		} catch(\Exception $e) {
 			\OC::$server->getLogger()->logException($e, [
 				'message' => __METHOD__,
-				'level' => \OCP\Util::ERROR,
+				'level' => ILogger::ERROR,
 				'app' => 'core',
 			]);
 			return false;
@@ -747,7 +748,7 @@ class Tags implements \OCP\ITags {
 		array_filter($names);
 
 		\OCP\Util::writeLog('core', __METHOD__ . ', before: '
-			. print_r($this->tags, true), \OCP\Util::DEBUG);
+			. print_r($this->tags, true), ILogger::DEBUG);
 		foreach($names as $name) {
 			$id = null;
 
@@ -763,7 +764,7 @@ class Tags implements \OCP\ITags {
 				$this->mapper->delete($tag);
 			} else {
 				\OCP\Util::writeLog('core', __METHOD__ . 'Cannot delete tag ' . $name
-					. ': not found.', \OCP\Util::ERROR);
+					. ': not found.', ILogger::ERROR);
 			}
 			if(!is_null($id) && $id !== false) {
 				try {
@@ -774,13 +775,13 @@ class Tags implements \OCP\ITags {
 					if ($result === null) {
 						\OCP\Util::writeLog('core',
 							__METHOD__. 'DB error: ' . \OC::$server->getDatabaseConnection()->getError(),
-							\OCP\Util::ERROR);
+							ILogger::ERROR);
 						return false;
 					}
 				} catch(\Exception $e) {
 					\OC::$server->getLogger()->logException($e, [
 						'message' => __METHOD__,
-						'level' => \OCP\Util::ERROR,
+						'level' => ILogger::ERROR,
 						'app' => 'core',
 					]);
 					return false;
diff --git a/lib/private/Updater.php b/lib/private/Updater.php
index 49a4a1094ed..e6e38798142 100644
--- a/lib/private/Updater.php
+++ b/lib/private/Updater.php
@@ -100,9 +100,9 @@ class Updater extends BasicEmitter {
 		$this->emitRepairEvents();
 		$this->logAllEvents();
 
-		$logLevel = $this->config->getSystemValue('loglevel', Util::WARN);
+		$logLevel = $this->config->getSystemValue('loglevel', ILogger::WARN);
 		$this->emit('\OC\Updater', 'setDebugLogLevel', [ $logLevel, $this->logLevelNames[$logLevel] ]);
-		$this->config->setSystemValue('loglevel', Util::DEBUG);
+		$this->config->setSystemValue('loglevel', ILogger::DEBUG);
 
 		$wasMaintenanceModeEnabled = $this->config->getSystemValue('maintenance', false);
 
diff --git a/lib/private/User/Database.php b/lib/private/User/Database.php
index 001e0c0f4a5..b2c54cd7c7e 100644
--- a/lib/private/User/Database.php
+++ b/lib/private/User/Database.php
@@ -59,6 +59,7 @@ namespace OC\User;
 
 use OC\Cache\CappedMemoryCache;
 use OCP\IDBConnection;
+use OCP\ILogger;
 use OCP\User\Backend\ABackend;
 use OCP\User\Backend\ICheckPasswordBackend;
 use OCP\User\Backend\ICountUsersBackend;
@@ -408,7 +409,7 @@ class Database extends ABackend
 		$query = \OC_DB::prepare('SELECT COUNT(*) FROM `*PREFIX*users`');
 		$result = $query->execute();
 		if ($result === false) {
-			Util::writeLog('core', \OC_DB::getErrorMessage(), Util::ERROR);
+			Util::writeLog('core', \OC_DB::getErrorMessage(), ILogger::ERROR);
 			return false;
 		}
 		return $result->fetchOne();
diff --git a/lib/private/legacy/app.php b/lib/private/legacy/app.php
index 88d5ce1f135..7931eecc502 100644
--- a/lib/private/legacy/app.php
+++ b/lib/private/legacy/app.php
@@ -56,6 +56,7 @@ use OC\DB\MigrationService;
 use OC\Installer;
 use OC\Repair;
 use OCP\App\ManagerEvent;
+use OCP\ILogger;
 
 /**
  * This class manages the apps. It allows them to register and integrate in the
@@ -425,7 +426,7 @@ class OC_App {
 			}
 		}
 
-		\OCP\Util::writeLog('core', 'No application directories are marked as writable.', \OCP\Util::ERROR);
+		\OCP\Util::writeLog('core', 'No application directories are marked as writable.', ILogger::ERROR);
 		return null;
 	}
 
@@ -666,7 +667,7 @@ class OC_App {
 
 		foreach (OC::$APPSROOTS as $apps_dir) {
 			if (!is_readable($apps_dir['path'])) {
-				\OCP\Util::writeLog('core', 'unable to read app folder : ' . $apps_dir['path'], \OCP\Util::WARN);
+				\OCP\Util::writeLog('core', 'unable to read app folder : ' . $apps_dir['path'], ILogger::WARN);
 				continue;
 			}
 			$dh = opendir($apps_dir['path']);
@@ -707,12 +708,12 @@ class OC_App {
 
 				$info = OC_App::getAppInfo($app, false, $langCode);
 				if (!is_array($info)) {
-					\OCP\Util::writeLog('core', 'Could not read app info file for app "' . $app . '"', \OCP\Util::ERROR);
+					\OCP\Util::writeLog('core', 'Could not read app info file for app "' . $app . '"', ILogger::ERROR);
 					continue;
 				}
 
 				if (!isset($info['name'])) {
-					\OCP\Util::writeLog('core', 'App id "' . $app . '" has no name in appinfo', \OCP\Util::ERROR);
+					\OCP\Util::writeLog('core', 'App id "' . $app . '" has no name in appinfo', ILogger::ERROR);
 					continue;
 				}
 
@@ -994,11 +995,11 @@ class OC_App {
 				}
 				return new \OC\Files\View('/' . OC_User::getUser() . '/' . $appId);
 			} else {
-				\OCP\Util::writeLog('core', 'Can\'t get app storage, app ' . $appId . ', user not logged in', \OCP\Util::ERROR);
+				\OCP\Util::writeLog('core', 'Can\'t get app storage, app ' . $appId . ', user not logged in', ILogger::ERROR);
 				return false;
 			}
 		} else {
-			\OCP\Util::writeLog('core', 'Can\'t get app storage, app ' . $appId . ' not enabled', \OCP\Util::ERROR);
+			\OCP\Util::writeLog('core', 'Can\'t get app storage, app ' . $appId . ' not enabled', ILogger::ERROR);
 			return false;
 		}
 	}
diff --git a/lib/private/legacy/db.php b/lib/private/legacy/db.php
index 7c556baeaeb..7e18cbe1875 100644
--- a/lib/private/legacy/db.php
+++ b/lib/private/legacy/db.php
@@ -28,6 +28,8 @@
  *
  */
 
+use OCP\ILogger;
+
 /**
  * This class manages the access to the database. It basically is a wrapper for
  * Doctrine with some adaptions.
@@ -185,7 +187,7 @@ class OC_DB {
 		try {
 			$result = $schemaManager->updateDbFromStructure($file);
 		} catch (Exception $e) {
-			\OCP\Util::writeLog('core', 'Failed to update database structure ('.$e.')', \OCP\Util::FATAL);
+			\OCP\Util::writeLog('core', 'Failed to update database structure ('.$e.')', ILogger::FATAL);
 			throw $e;
 		}
 		return $result;
diff --git a/lib/private/legacy/files.php b/lib/private/legacy/files.php
index 9281c1f7da4..00cd5fbfe51 100644
--- a/lib/private/legacy/files.php
+++ b/lib/private/legacy/files.php
@@ -41,6 +41,7 @@
 
 use OC\Files\View;
 use OC\Streamer;
+use OCP\ILogger;
 use OCP\Lock\ILockingProvider;
 
 /**
@@ -422,7 +423,7 @@ class OC_Files {
 			if (!$handle) {
 				\OCP\Util::writeLog('files',
 					'Can\'t write upload limit to ' . $filename . '. Please check the file permissions',
-					\OCP\Util::WARN);
+					ILogger::WARN);
 				$success = false;
 				continue; // try to update as many files as possible
 			}
diff --git a/lib/private/legacy/user.php b/lib/private/legacy/user.php
index 9c877f22a46..ebb1ff2215b 100644
--- a/lib/private/legacy/user.php
+++ b/lib/private/legacy/user.php
@@ -38,6 +38,8 @@
  *
  */
 
+use OCP\ILogger;
+
 /**
  * This class provides wrapper methods for user management. Multiple backends are
  * supported. User management operations are delegated to the configured backend for
@@ -89,7 +91,7 @@ class OC_User {
 				case 'database':
 				case 'mysql':
 				case 'sqlite':
-					\OCP\Util::writeLog('core', 'Adding user backend ' . $backend . '.', \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('core', 'Adding user backend ' . $backend . '.', ILogger::DEBUG);
 					self::$_usedBackends[$backend] = new \OC\User\Database();
 					\OC::$server->getUserManager()->registerBackend(self::$_usedBackends[$backend]);
 					break;
@@ -98,7 +100,7 @@ class OC_User {
 					\OC::$server->getUserManager()->registerBackend(self::$_usedBackends[$backend]);
 					break;
 				default:
-					\OCP\Util::writeLog('core', 'Adding default user backend ' . $backend . '.', \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('core', 'Adding default user backend ' . $backend . '.', ILogger::DEBUG);
 					$className = 'OC_USER_' . strtoupper($backend);
 					self::$_usedBackends[$backend] = new $className();
 					\OC::$server->getUserManager()->registerBackend(self::$_usedBackends[$backend]);
@@ -143,10 +145,10 @@ class OC_User {
 					self::useBackend($backend);
 					self::$_setupedBackends[] = $i;
 				} else {
-					\OCP\Util::writeLog('core', 'User backend ' . $class . ' already initialized.', \OCP\Util::DEBUG);
+					\OCP\Util::writeLog('core', 'User backend ' . $class . ' already initialized.', ILogger::DEBUG);
 				}
 			} else {
-				\OCP\Util::writeLog('core', 'User backend ' . $class . ' not found.', \OCP\Util::ERROR);
+				\OCP\Util::writeLog('core', 'User backend ' . $class . ' not found.', ILogger::ERROR);
 			}
 		}
 	}
diff --git a/lib/private/legacy/util.php b/lib/private/legacy/util.php
index 3313ccdec91..d3599d14e7a 100644
--- a/lib/private/legacy/util.php
+++ b/lib/private/legacy/util.php
@@ -62,6 +62,7 @@
 
 use OCP\IConfig;
 use OCP\IGroupManager;
+use OCP\ILogger;
 use OCP\IUser;
 
 class OC_Util {
@@ -100,7 +101,7 @@ class OC_Util {
 	private static function initObjectStoreRootFS($config) {
 		// check misconfiguration
 		if (empty($config['class'])) {
-			\OCP\Util::writeLog('files', 'No class given for objectstore', \OCP\Util::ERROR);
+			\OCP\Util::writeLog('files', 'No class given for objectstore', ILogger::ERROR);
 		}
 		if (!isset($config['arguments'])) {
 			$config['arguments'] = array();
@@ -134,7 +135,7 @@ class OC_Util {
 	private static function initObjectStoreMultibucketRootFS($config) {
 		// check misconfiguration
 		if (empty($config['class'])) {
-			\OCP\Util::writeLog('files', 'No class given for objectstore', \OCP\Util::ERROR);
+			\OCP\Util::writeLog('files', 'No class given for objectstore', ILogger::ERROR);
 		}
 		if (!isset($config['arguments'])) {
 			$config['arguments'] = array();
@@ -409,7 +410,7 @@ class OC_Util {
 			\OCP\Util::writeLog(
 				'files_skeleton',
 				'copying skeleton for '.$userId.' from '.$skeletonDirectory.' to '.$userDirectory->getFullPath('/'),
-				\OCP\Util::DEBUG
+				ILogger::DEBUG
 			);
 			self::copyr($skeletonDirectory, $userDirectory);
 			// update the file cache
@@ -1378,7 +1379,7 @@ class OC_Util {
 		// XCache
 		if (function_exists('xcache_clear_cache')) {
 			if (\OC::$server->getIniWrapper()->getBool('xcache.admin.enable_auth')) {
-				\OCP\Util::writeLog('core', 'XCache opcode cache will not be cleared because "xcache.admin.enable_auth" is enabled.', \OCP\Util::WARN);
+				\OCP\Util::writeLog('core', 'XCache opcode cache will not be cleared because "xcache.admin.enable_auth" is enabled.', ILogger::WARN);
 			} else {
 				@xcache_clear_cache(XC_TYPE_PHP, 0);
 			}