nextcloud / server

apps/user_ldap/lib/Migration/Version1120Date20210917155206.php

Indentation +112 added lines, -112 removed lines

@@ -40,116 +40,116 @@
 
 class Version1120Date20210917155206 extends SimpleMigrationStep {
 
-	/** @var IDBConnection */
-	private $dbc;
-	/** @var IUserManager */
-	private $userManager;
-	/** @var LoggerInterface */
-	private $logger;
-
-	public function __construct(IDBConnection $dbc, IUserManager $userManager, LoggerInterface $logger) {
-		$this->dbc = $dbc;
-		$this->userManager = $userManager;
-		$this->logger = $logger;
-	}
-
-	public function getName() {
-		return 'Adjust LDAP user and group id column lengths to match server lengths';
-	}
-
-	/**
-	 * @param IOutput $output
-	 * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
-	 * @param array $options
-	 */
-	public function preSchemaChange(IOutput $output, Closure $schemaClosure, array $options): void {
-		// ensure that there is no user or group id longer than 64char in LDAP table
-		$this->handleIDs('ldap_group_mapping', false);
-		$this->handleIDs('ldap_user_mapping', true);
-	}
-
-	/**
-	 * @param IOutput $output
-	 * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
-	 * @param array $options
-	 * @return null|ISchemaWrapper
-	 */
-	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
-		/** @var ISchemaWrapper $schema */
-		$schema = $schemaClosure();
-
-		$changeSchema = false;
-		foreach (['ldap_user_mapping', 'ldap_group_mapping'] as $tableName) {
-			$table = $schema->getTable($tableName);
-			$column = $table->getColumn('owncloud_name');
-			if ($column->getLength() > 64) {
-				$column->setLength(64);
-				$changeSchema = true;
-			}
-		}
-
-		return $changeSchema ? $schema : null;
-	}
-
-	protected function handleIDs(string $table, bool $emitHooks) {
-		$select = $this->getSelectQuery($table);
-		$update = $this->getUpdateQuery($table);
-
-		$result = $select->executeQuery();
-		while ($row = $result->fetch()) {
-			$newId = hash('sha256', $row['owncloud_name'], false);
-			if ($emitHooks) {
-				$this->emitUnassign($row['owncloud_name'], true);
-			}
-			$update->setParameter('uuid', $row['directory_uuid']);
-			$update->setParameter('newId', $newId);
-			try {
-				$update->executeStatement();
-				if ($emitHooks) {
-					$this->emitUnassign($row['owncloud_name'], false);
-					$this->emitAssign($newId);
-				}
-			} catch (Exception $e) {
-				$this->logger->error('Failed to shorten owncloud_name "{oldId}" to "{newId}" (UUID: "{uuid}" of {table})',
-					[
-						'app' => 'user_ldap',
-						'oldId' => $row['owncloud_name'],
-						'newId' => $newId,
-						'uuid' => $row['directory_uuid'],
-						'table' => $table,
-						'exception' => $e,
-					]
-				);
-			}
-		}
-		$result->closeCursor();
-	}
-
-	protected function getSelectQuery(string $table): IQueryBuilder {
-		$qb = $this->dbc->getQueryBuilder();
-		$qb->select('owncloud_name', 'directory_uuid')
-			->from($table)
-			->where($qb->expr()->gt($qb->func()->octetLength('owncloud_name'), $qb->createNamedParameter('64'), IQueryBuilder::PARAM_INT));
-		return $qb;
-	}
-
-	protected function getUpdateQuery(string $table): IQueryBuilder {
-		$qb = $this->dbc->getQueryBuilder();
-		$qb->update($table)
-			->set('owncloud_name', $qb->createParameter('newId'))
-			->where($qb->expr()->eq('directory_uuid', $qb->createParameter('uuid')));
-		return $qb;
-	}
-
-	protected function emitUnassign(string $oldId, bool $pre): void {
-		if ($this->userManager instanceof PublicEmitter) {
-			$this->userManager->emit('\OC\User', $pre ? 'pre' : 'post' . 'UnassignedUserId', [$oldId]);
-		}
-	}
-
-	protected function emitAssign(string $newId): void {
-		if ($this->userManager instanceof PublicEmitter) {
-			$this->userManager->emit('\OC\User', 'assignedUserId', [$newId]);
-		}
-	}
+    /** @var IDBConnection */
+    private $dbc;
+    /** @var IUserManager */
+    private $userManager;
+    /** @var LoggerInterface */
+    private $logger;
+
+    public function __construct(IDBConnection $dbc, IUserManager $userManager, LoggerInterface $logger) {
+        $this->dbc = $dbc;
+        $this->userManager = $userManager;
+        $this->logger = $logger;
+    }
+
+    public function getName() {
+        return 'Adjust LDAP user and group id column lengths to match server lengths';
+    }
+
+    /**
+     * @param IOutput $output
+     * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+     * @param array $options
+     */
+    public function preSchemaChange(IOutput $output, Closure $schemaClosure, array $options): void {
+        // ensure that there is no user or group id longer than 64char in LDAP table
+        $this->handleIDs('ldap_group_mapping', false);
+        $this->handleIDs('ldap_user_mapping', true);
+    }
+
+    /**
+     * @param IOutput $output
+     * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+     * @param array $options
+     * @return null|ISchemaWrapper
+     */
+    public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+        /** @var ISchemaWrapper $schema */
+        $schema = $schemaClosure();
+
+        $changeSchema = false;
+        foreach (['ldap_user_mapping', 'ldap_group_mapping'] as $tableName) {
+            $table = $schema->getTable($tableName);
+            $column = $table->getColumn('owncloud_name');
+            if ($column->getLength() > 64) {
+                $column->setLength(64);
+                $changeSchema = true;
+            }
+        }
+
+        return $changeSchema ? $schema : null;
+    }
+
+    protected function handleIDs(string $table, bool $emitHooks) {
+        $select = $this->getSelectQuery($table);
+        $update = $this->getUpdateQuery($table);
+
+        $result = $select->executeQuery();
+        while ($row = $result->fetch()) {
+            $newId = hash('sha256', $row['owncloud_name'], false);
+            if ($emitHooks) {
+                $this->emitUnassign($row['owncloud_name'], true);
+            }
+            $update->setParameter('uuid', $row['directory_uuid']);
+            $update->setParameter('newId', $newId);
+            try {
+                $update->executeStatement();
+                if ($emitHooks) {
+                    $this->emitUnassign($row['owncloud_name'], false);
+                    $this->emitAssign($newId);
+                }
+            } catch (Exception $e) {
+                $this->logger->error('Failed to shorten owncloud_name "{oldId}" to "{newId}" (UUID: "{uuid}" of {table})',
+                    [
+                        'app' => 'user_ldap',
+                        'oldId' => $row['owncloud_name'],
+                        'newId' => $newId,
+                        'uuid' => $row['directory_uuid'],
+                        'table' => $table,
+                        'exception' => $e,
+                    ]
+                );
+            }
+        }
+        $result->closeCursor();
+    }
+
+    protected function getSelectQuery(string $table): IQueryBuilder {
+        $qb = $this->dbc->getQueryBuilder();
+        $qb->select('owncloud_name', 'directory_uuid')
+            ->from($table)
+            ->where($qb->expr()->gt($qb->func()->octetLength('owncloud_name'), $qb->createNamedParameter('64'), IQueryBuilder::PARAM_INT));
+        return $qb;
+    }
+
+    protected function getUpdateQuery(string $table): IQueryBuilder {
+        $qb = $this->dbc->getQueryBuilder();
+        $qb->update($table)
+            ->set('owncloud_name', $qb->createParameter('newId'))
+            ->where($qb->expr()->eq('directory_uuid', $qb->createParameter('uuid')));
+        return $qb;
+    }
+
+    protected function emitUnassign(string $oldId, bool $pre): void {
+        if ($this->userManager instanceof PublicEmitter) {
+            $this->userManager->emit('\OC\User', $pre ? 'pre' : 'post' . 'UnassignedUserId', [$oldId]);
+        }
+    }
+
+    protected function emitAssign(string $newId): void {
+        if ($this->userManager instanceof PublicEmitter) {
+            $this->userManager->emit('\OC\User', 'assignedUserId', [$newId]);
+        }
+    }
 }

apps/user_ldap/lib/Migration/Version1141Date20220323143801.php

Indentation +67 added lines, -67 removed lines

@@ -35,79 +35,79 @@
 
 class Version1141Date20220323143801 extends SimpleMigrationStep {
 
-	private IDBConnection $dbc;
+    private IDBConnection $dbc;
 
-	public function __construct(IDBConnection $dbc) {
-		$this->dbc = $dbc;
-	}
+    public function __construct(IDBConnection $dbc) {
+        $this->dbc = $dbc;
+    }
 
-	/**
-	 * @param IOutput $output
-	 * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
-	 * @param array $options
-	 */
-	public function preSchemaChange(IOutput $output, Closure $schemaClosure, array $options): void {
-		foreach (['ldap_user_mapping', 'ldap_group_mapping'] as $tableName) {
-			$qb = $this->dbc->getQueryBuilder();
-			$qb->select('ldap_dn')
-				->from($tableName)
-				->where($qb->expr()->gt($qb->func()->octetLength('ldap_dn'), $qb->createNamedParameter('4000'), IQueryBuilder::PARAM_INT));
+    /**
+     * @param IOutput $output
+     * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+     * @param array $options
+     */
+    public function preSchemaChange(IOutput $output, Closure $schemaClosure, array $options): void {
+        foreach (['ldap_user_mapping', 'ldap_group_mapping'] as $tableName) {
+            $qb = $this->dbc->getQueryBuilder();
+            $qb->select('ldap_dn')
+                ->from($tableName)
+                ->where($qb->expr()->gt($qb->func()->octetLength('ldap_dn'), $qb->createNamedParameter('4000'), IQueryBuilder::PARAM_INT));
 
-			$dnsTooLong = [];
-			$result = $qb->executeQuery();
-			while (($dn = $result->fetchOne()) !== false) {
-				$dnsTooLong[] = $dn;
-			}
-			$result->closeCursor();
-			$this->shortenDNs($dnsTooLong, $tableName);
-		}
-	}
+            $dnsTooLong = [];
+            $result = $qb->executeQuery();
+            while (($dn = $result->fetchOne()) !== false) {
+                $dnsTooLong[] = $dn;
+            }
+            $result->closeCursor();
+            $this->shortenDNs($dnsTooLong, $tableName);
+        }
+    }
 
-	protected function shortenDNs(array $dns, string $table): void {
-		$qb = $this->dbc->getQueryBuilder();
-		$qb->update($table)
-			->set('ldap_dn', $qb->createParameter('shortenedDn'))
-			->where($qb->expr()->eq('ldap_dn', $qb->createParameter('originalDn')));
+    protected function shortenDNs(array $dns, string $table): void {
+        $qb = $this->dbc->getQueryBuilder();
+        $qb->update($table)
+            ->set('ldap_dn', $qb->createParameter('shortenedDn'))
+            ->where($qb->expr()->eq('ldap_dn', $qb->createParameter('originalDn')));
 
-		$pageSize = 1000;
-		$page = 0;
-		do {
-			$subset = array_slice($dns, $page * $pageSize, $pageSize);
-			try {
-				$this->dbc->beginTransaction();
-				foreach ($subset as $dn) {
-					$shortenedDN = mb_substr($dn, 0, 4000);
-					$qb->setParameter('shortenedDn', $shortenedDN);
-					$qb->setParameter('originalDn', $dn);
-					$qb->executeStatement();
-				}
-				$this->dbc->commit();
-			} catch (\Throwable $t) {
-				$this->dbc->rollBack();
-				throw $t;
-			}
-			$page++;
-		} while (count($subset) === $pageSize);
-	}
+        $pageSize = 1000;
+        $page = 0;
+        do {
+            $subset = array_slice($dns, $page * $pageSize, $pageSize);
+            try {
+                $this->dbc->beginTransaction();
+                foreach ($subset as $dn) {
+                    $shortenedDN = mb_substr($dn, 0, 4000);
+                    $qb->setParameter('shortenedDn', $shortenedDN);
+                    $qb->setParameter('originalDn', $dn);
+                    $qb->executeStatement();
+                }
+                $this->dbc->commit();
+            } catch (\Throwable $t) {
+                $this->dbc->rollBack();
+                throw $t;
+            }
+            $page++;
+        } while (count($subset) === $pageSize);
+    }
 
-	/**
-	 * @param IOutput $output
-	 * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
-	 * @param array $options
-	 * @return null|ISchemaWrapper
-	 */
-	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
-		/** @var ISchemaWrapper $schema */
-		$schema = $schemaClosure();
+    /**
+     * @param IOutput $output
+     * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+     * @param array $options
+     * @return null|ISchemaWrapper
+     */
+    public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+        /** @var ISchemaWrapper $schema */
+        $schema = $schemaClosure();
 
-		foreach (['ldap_user_mapping', 'ldap_group_mapping'] as $tableName) {
-			$table = $schema->getTable($tableName);
-			$column = $table->getColumn('ldap_dn');
-			if ($column->getLength() > 4000) {
-				$column->setLength(4000);
-			}
-		}
+        foreach (['ldap_user_mapping', 'ldap_group_mapping'] as $tableName) {
+            $table = $schema->getTable($tableName);
+            $column = $table->getColumn('ldap_dn');
+            if ($column->getLength() > 4000) {
+                $column->setLength(4000);
+            }
+        }
 
-		return $schema;
-	}
+        return $schema;
+    }
 }

lib/private/DB/MigrationService.php

Indentation +619 added lines, -619 removed lines

@@ -46,623 +46,623 @@
 
 class MigrationService {
 
-	/** @var boolean */
-	private $migrationTableCreated;
-	/** @var array */
-	private $migrations;
-	/** @var IOutput */
-	private $output;
-	/** @var Connection */
-	private $connection;
-	/** @var string */
-	private $appName;
-	/** @var bool */
-	private $checkOracle;
-
-	/**
-	 * MigrationService constructor.
-	 *
-	 * @param $appName
-	 * @param Connection $connection
-	 * @param AppLocator $appLocator
-	 * @param IOutput|null $output
-	 * @throws \Exception
-	 */
-	public function __construct($appName, Connection $connection, IOutput $output = null, AppLocator $appLocator = null) {
-		$this->appName = $appName;
-		$this->connection = $connection;
-		$this->output = $output;
-		if (null === $this->output) {
-			$this->output = new SimpleOutput(\OC::$server->get(LoggerInterface::class), $appName);
-		}
-
-		if ($appName === 'core') {
-			$this->migrationsPath = \OC::$SERVERROOT . '/core/Migrations';
-			$this->migrationsNamespace = 'OC\\Core\\Migrations';
-			$this->checkOracle = true;
-		} else {
-			if (null === $appLocator) {
-				$appLocator = new AppLocator();
-			}
-			$appPath = $appLocator->getAppPath($appName);
-			$namespace = App::buildAppNamespace($appName);
-			$this->migrationsPath = "$appPath/lib/Migration";
-			$this->migrationsNamespace = $namespace . '\\Migration';
-
-			$infoParser = new InfoParser();
-			$info = $infoParser->parse($appPath . '/appinfo/info.xml');
-			if (!isset($info['dependencies']['database'])) {
-				$this->checkOracle = true;
-			} else {
-				$this->checkOracle = false;
-				foreach ($info['dependencies']['database'] as $database) {
-					if (\is_string($database) && $database === 'oci') {
-						$this->checkOracle = true;
-					} elseif (\is_array($database) && isset($database['@value']) && $database['@value'] === 'oci') {
-						$this->checkOracle = true;
-					}
-				}
-			}
-		}
-	}
-
-	/**
-	 * Returns the name of the app for which this migration is executed
-	 *
-	 * @return string
-	 */
-	public function getApp() {
-		return $this->appName;
-	}
-
-	/**
-	 * @return bool
-	 * @codeCoverageIgnore - this will implicitly tested on installation
-	 */
-	private function createMigrationTable() {
-		if ($this->migrationTableCreated) {
-			return false;
-		}
-
-		if ($this->connection->tableExists('migrations') && \OC::$server->getConfig()->getAppValue('core', 'vendor', '') !== 'owncloud') {
-			$this->migrationTableCreated = true;
-			return false;
-		}
-
-		$schema = new SchemaWrapper($this->connection);
-
-		/**
-		 * We drop the table when it has different columns or the definition does not
-		 * match. E.g. ownCloud uses a length of 177 for app and 14 for version.
-		 */
-		try {
-			$table = $schema->getTable('migrations');
-			$columns = $table->getColumns();
-
-			if (count($columns) === 2) {
-				try {
-					$column = $table->getColumn('app');
-					$schemaMismatch = $column->getLength() !== 255;
-
-					if (!$schemaMismatch) {
-						$column = $table->getColumn('version');
-						$schemaMismatch = $column->getLength() !== 255;
-					}
-				} catch (SchemaException $e) {
-					// One of the columns is missing
-					$schemaMismatch = true;
-				}
-
-				if (!$schemaMismatch) {
-					// Table exists and schema matches: return back!
-					$this->migrationTableCreated = true;
-					return false;
-				}
-			}
-
-			// Drop the table, when it didn't match our expectations.
-			$this->connection->dropTable('migrations');
-
-			// Recreate the schema after the table was dropped.
-			$schema = new SchemaWrapper($this->connection);
-		} catch (SchemaException $e) {
-			// Table not found, no need to panic, we will create it.
-		}
-
-		$table = $schema->createTable('migrations');
-		$table->addColumn('app', Types::STRING, ['length' => 255]);
-		$table->addColumn('version', Types::STRING, ['length' => 255]);
-		$table->setPrimaryKey(['app', 'version']);
-
-		$this->connection->migrateToSchema($schema->getWrappedSchema());
-
-		$this->migrationTableCreated = true;
-
-		return true;
-	}
-
-	/**
-	 * Returns all versions which have already been applied
-	 *
-	 * @return string[]
-	 * @codeCoverageIgnore - no need to test this
-	 */
-	public function getMigratedVersions() {
-		$this->createMigrationTable();
-		$qb = $this->connection->getQueryBuilder();
-
-		$qb->select('version')
-			->from('migrations')
-			->where($qb->expr()->eq('app', $qb->createNamedParameter($this->getApp())))
-			->orderBy('version');
-
-		$result = $qb->execute();
-		$rows = $result->fetchAll(\PDO::FETCH_COLUMN);
-		$result->closeCursor();
-
-		return $rows;
-	}
-
-	/**
-	 * Returns all versions which are available in the migration folder
-	 *
-	 * @return array
-	 */
-	public function getAvailableVersions() {
-		$this->ensureMigrationsAreLoaded();
-		return array_map('strval', array_keys($this->migrations));
-	}
-
-	protected function findMigrations() {
-		$directory = realpath($this->migrationsPath);
-		if ($directory === false || !file_exists($directory) || !is_dir($directory)) {
-			return [];
-		}
-
-		$iterator = new \RegexIterator(
-			new \RecursiveIteratorIterator(
-				new \RecursiveDirectoryIterator($directory, \FilesystemIterator::SKIP_DOTS),
-				\RecursiveIteratorIterator::LEAVES_ONLY
-			),
-			'#^.+\\/Version[^\\/]{1,255}\\.php$#i',
-			\RegexIterator::GET_MATCH);
-
-		$files = array_keys(iterator_to_array($iterator));
-		uasort($files, function ($a, $b) {
-			preg_match('/^Version(\d+)Date(\d+)\\.php$/', basename($a), $matchA);
-			preg_match('/^Version(\d+)Date(\d+)\\.php$/', basename($b), $matchB);
-			if (!empty($matchA) && !empty($matchB)) {
-				if ($matchA[1] !== $matchB[1]) {
-					return ($matchA[1] < $matchB[1]) ? -1 : 1;
-				}
-				return ($matchA[2] < $matchB[2]) ? -1 : 1;
-			}
-			return (basename($a) < basename($b)) ? -1 : 1;
-		});
-
-		$migrations = [];
-
-		foreach ($files as $file) {
-			$className = basename($file, '.php');
-			$version = (string) substr($className, 7);
-			if ($version === '0') {
-				throw new \InvalidArgumentException(
-					"Cannot load a migrations with the name '$version' because it is a reserved number"
-				);
-			}
-			$migrations[$version] = sprintf('%s\\%s', $this->migrationsNamespace, $className);
-		}
-
-		return $migrations;
-	}
-
-	/**
-	 * @param string $to
-	 * @return string[]
-	 */
-	private function getMigrationsToExecute($to) {
-		$knownMigrations = $this->getMigratedVersions();
-		$availableMigrations = $this->getAvailableVersions();
-
-		$toBeExecuted = [];
-		foreach ($availableMigrations as $v) {
-			if ($to !== 'latest' && $v > $to) {
-				continue;
-			}
-			if ($this->shallBeExecuted($v, $knownMigrations)) {
-				$toBeExecuted[] = $v;
-			}
-		}
-
-		return $toBeExecuted;
-	}
-
-	/**
-	 * @param string $m
-	 * @param string[] $knownMigrations
-	 * @return bool
-	 */
-	private function shallBeExecuted($m, $knownMigrations) {
-		if (in_array($m, $knownMigrations)) {
-			return false;
-		}
-
-		return true;
-	}
-
-	/**
-	 * @param string $version
-	 */
-	private function markAsExecuted($version) {
-		$this->connection->insertIfNotExist('*PREFIX*migrations', [
-			'app' => $this->appName,
-			'version' => $version
-		]);
-	}
-
-	/**
-	 * Returns the name of the table which holds the already applied versions
-	 *
-	 * @return string
-	 */
-	public function getMigrationsTableName() {
-		return $this->connection->getPrefix() . 'migrations';
-	}
-
-	/**
-	 * Returns the namespace of the version classes
-	 *
-	 * @return string
-	 */
-	public function getMigrationsNamespace() {
-		return $this->migrationsNamespace;
-	}
-
-	/**
-	 * Returns the directory which holds the versions
-	 *
-	 * @return string
-	 */
-	public function getMigrationsDirectory() {
-		return $this->migrationsPath;
-	}
-
-	/**
-	 * Return the explicit version for the aliases; current, next, prev, latest
-	 *
-	 * @param string $alias
-	 * @return mixed|null|string
-	 */
-	public function getMigration($alias) {
-		switch ($alias) {
-			case 'current':
-				return $this->getCurrentVersion();
-			case 'next':
-				return $this->getRelativeVersion($this->getCurrentVersion(), 1);
-			case 'prev':
-				return $this->getRelativeVersion($this->getCurrentVersion(), -1);
-			case 'latest':
-				$this->ensureMigrationsAreLoaded();
-
-				$migrations = $this->getAvailableVersions();
-				return @end($migrations);
-		}
-		return '0';
-	}
-
-	/**
-	 * @param string $version
-	 * @param int $delta
-	 * @return null|string
-	 */
-	private function getRelativeVersion($version, $delta) {
-		$this->ensureMigrationsAreLoaded();
-
-		$versions = $this->getAvailableVersions();
-		array_unshift($versions, 0);
-		$offset = array_search($version, $versions, true);
-		if ($offset === false || !isset($versions[$offset + $delta])) {
-			// Unknown version or delta out of bounds.
-			return null;
-		}
-
-		return (string) $versions[$offset + $delta];
-	}
-
-	/**
-	 * @return string
-	 */
-	private function getCurrentVersion() {
-		$m = $this->getMigratedVersions();
-		if (count($m) === 0) {
-			return '0';
-		}
-		$migrations = array_values($m);
-		return @end($migrations);
-	}
-
-	/**
-	 * @param string $version
-	 * @return string
-	 * @throws \InvalidArgumentException
-	 */
-	private function getClass($version) {
-		$this->ensureMigrationsAreLoaded();
-
-		if (isset($this->migrations[$version])) {
-			return $this->migrations[$version];
-		}
-
-		throw new \InvalidArgumentException("Version $version is unknown.");
-	}
-
-	/**
-	 * Allows to set an IOutput implementation which is used for logging progress and messages
-	 *
-	 * @param IOutput $output
-	 */
-	public function setOutput(IOutput $output) {
-		$this->output = $output;
-	}
-
-	/**
-	 * Applies all not yet applied versions up to $to
-	 *
-	 * @param string $to
-	 * @param bool $schemaOnly
-	 * @throws \InvalidArgumentException
-	 */
-	public function migrate($to = 'latest', $schemaOnly = false) {
-		if ($schemaOnly) {
-			$this->migrateSchemaOnly($to);
-			return;
-		}
-
-		// read known migrations
-		$toBeExecuted = $this->getMigrationsToExecute($to);
-		foreach ($toBeExecuted as $version) {
-			try {
-				$this->executeStep($version, $schemaOnly);
-			} catch (\Exception $e) {
-				// The exception itself does not contain the name of the migration,
-				// so we wrap it here, to make debugging easier.
-				throw new \Exception('Database error when running migration ' . $version . ' for app ' . $this->getApp() . PHP_EOL. $e->getMessage(), 0, $e);
-			}
-		}
-	}
-
-	/**
-	 * Applies all not yet applied versions up to $to
-	 *
-	 * @param string $to
-	 * @throws \InvalidArgumentException
-	 */
-	public function migrateSchemaOnly($to = 'latest') {
-		// read known migrations
-		$toBeExecuted = $this->getMigrationsToExecute($to);
-
-		if (empty($toBeExecuted)) {
-			return;
-		}
-
-		$toSchema = null;
-		foreach ($toBeExecuted as $version) {
-			$instance = $this->createInstance($version);
-
-			$toSchema = $instance->changeSchema($this->output, function () use ($toSchema) {
-				return $toSchema ?: new SchemaWrapper($this->connection);
-			}, ['tablePrefix' => $this->connection->getPrefix()]) ?: $toSchema;
-		}
-
-		if ($toSchema instanceof SchemaWrapper) {
-			$targetSchema = $toSchema->getWrappedSchema();
-			if ($this->checkOracle) {
-				$beforeSchema = $this->connection->createSchema();
-				$this->ensureOracleConstraints($beforeSchema, $targetSchema, strlen($this->connection->getPrefix()));
-			}
-			$this->connection->migrateToSchema($targetSchema);
-			$toSchema->performDropTableCalls();
-		}
-
-		foreach ($toBeExecuted as $version) {
-			$this->markAsExecuted($version);
-		}
-	}
-
-	/**
-	 * Get the human readable descriptions for the migration steps to run
-	 *
-	 * @param string $to
-	 * @return string[] [$name => $description]
-	 */
-	public function describeMigrationStep($to = 'latest') {
-		$toBeExecuted = $this->getMigrationsToExecute($to);
-		$description = [];
-		foreach ($toBeExecuted as $version) {
-			$migration = $this->createInstance($version);
-			if ($migration->name()) {
-				$description[$migration->name()] = $migration->description();
-			}
-		}
-		return $description;
-	}
-
-	/**
-	 * @param string $version
-	 * @return IMigrationStep
-	 * @throws \InvalidArgumentException
-	 */
-	protected function createInstance($version) {
-		$class = $this->getClass($version);
-		try {
-			$s = \OC::$server->query($class);
-
-			if (!$s instanceof IMigrationStep) {
-				throw new \InvalidArgumentException('Not a valid migration');
-			}
-		} catch (QueryException $e) {
-			if (class_exists($class)) {
-				$s = new $class();
-			} else {
-				throw new \InvalidArgumentException("Migration step '$class' is unknown");
-			}
-		}
-
-		return $s;
-	}
-
-	/**
-	 * Executes one explicit version
-	 *
-	 * @param string $version
-	 * @param bool $schemaOnly
-	 * @throws \InvalidArgumentException
-	 */
-	public function executeStep($version, $schemaOnly = false) {
-		$instance = $this->createInstance($version);
-
-		if (!$schemaOnly) {
-			$instance->preSchemaChange($this->output, function () {
-				return new SchemaWrapper($this->connection);
-			}, ['tablePrefix' => $this->connection->getPrefix()]);
-		}
-
-		$toSchema = $instance->changeSchema($this->output, function () {
-			return new SchemaWrapper($this->connection);
-		}, ['tablePrefix' => $this->connection->getPrefix()]);
-
-		if ($toSchema instanceof SchemaWrapper) {
-			$targetSchema = $toSchema->getWrappedSchema();
-			if ($this->checkOracle) {
-				$sourceSchema = $this->connection->createSchema();
-				$this->ensureOracleConstraints($sourceSchema, $targetSchema, strlen($this->connection->getPrefix()));
-			}
-			$this->connection->migrateToSchema($targetSchema);
-			$toSchema->performDropTableCalls();
-		}
-
-		if (!$schemaOnly) {
-			$instance->postSchemaChange($this->output, function () {
-				return new SchemaWrapper($this->connection);
-			}, ['tablePrefix' => $this->connection->getPrefix()]);
-		}
-
-		$this->markAsExecuted($version);
-	}
-
-	/**
-	 * Naming constraints:
-	 * - Tables names must be 30 chars or shorter (27 + oc_ prefix)
-	 * - Column names must be 30 chars or shorter
-	 * - Index names must be 30 chars or shorter
-	 * - Sequence names must be 30 chars or shorter
-	 * - Primary key names must be set or the table name 23 chars or shorter
-	 *
-	 * Data constraints:
-	 * - Columns with "NotNull" can not have empty string as default value
-	 * - Columns with "NotNull" can not have number 0 as default value
-	 * - Columns with type "bool" (which is in fact integer of length 1) can not be "NotNull" as it can not store 0/false
-	 *
-	 * @param Schema $sourceSchema
-	 * @param Schema $targetSchema
-	 * @param int $prefixLength
-	 * @throws \Doctrine\DBAL\Exception
-	 */
-	public function ensureOracleConstraints(Schema $sourceSchema, Schema $targetSchema, int $prefixLength) {
-		$sequences = $targetSchema->getSequences();
-
-		foreach ($targetSchema->getTables() as $table) {
-			try {
-				$sourceTable = $sourceSchema->getTable($table->getName());
-			} catch (SchemaException $e) {
-				if (\strlen($table->getName()) - $prefixLength > 27) {
-					throw new \InvalidArgumentException('Table name "' . $table->getName() . '" is too long.');
-				}
-				$sourceTable = null;
-			}
-
-			foreach ($table->getColumns() as $thing) {
-				// If the table doesn't exist OR if the column doesn't exist in the table
-				if (!$sourceTable instanceof Table || !$sourceTable->hasColumn($thing->getName())) {
-					if (\strlen($thing->getName()) > 30) {
-						throw new \InvalidArgumentException('Column name "' . $table->getName() . '"."' . $thing->getName() . '" is too long.');
-					}
-
-					if ($thing->getNotnull() && $thing->getDefault() === ''
-						&& $sourceTable instanceof Table && !$sourceTable->hasColumn($thing->getName())) {
-						throw new \InvalidArgumentException('Column "' . $table->getName() . '"."' . $thing->getName() . '" is NotNull, but has empty string or null as default.');
-					}
-
-					if ($thing->getNotnull() && $thing->getType()->getName() === Types::BOOLEAN) {
-						throw new \InvalidArgumentException('Column "' . $table->getName() . '"."' . $thing->getName() . '" is type Bool and also NotNull, so it can not store "false".');
-					}
-
-					$sourceColumn = null;
-				} else {
-					$sourceColumn = $sourceTable->getColumn($thing->getName());
-				}
-
-				// If the column was just created OR the length changed OR the type changed
-				// we will NOT detect invalid length if the column is not modified
-				if (($sourceColumn === null || $sourceColumn->getLength() !== $thing->getLength() || $sourceColumn->getType()->getName() !== Types::STRING)
-					&& $thing->getLength() > 4000 && $thing->getType()->getName() === Types::STRING) {
-					throw new \InvalidArgumentException('Column "' . $table->getName() . '"."' . $thing->getName() . '" is type String, but exceeding the 4.000 length limit.');
-				}
-			}
-
-			foreach ($table->getIndexes() as $thing) {
-				if ((!$sourceTable instanceof Table || !$sourceTable->hasIndex($thing->getName())) && \strlen($thing->getName()) > 30) {
-					throw new \InvalidArgumentException('Index name "' . $table->getName() . '"."' . $thing->getName() . '" is too long.');
-				}
-			}
-
-			foreach ($table->getForeignKeys() as $thing) {
-				if ((!$sourceTable instanceof Table || !$sourceTable->hasForeignKey($thing->getName())) && \strlen($thing->getName()) > 30) {
-					throw new \InvalidArgumentException('Foreign key name "' . $table->getName() . '"."' . $thing->getName() . '" is too long.');
-				}
-			}
-
-			$primaryKey = $table->getPrimaryKey();
-			if ($primaryKey instanceof Index && (!$sourceTable instanceof Table || !$sourceTable->hasPrimaryKey())) {
-				$indexName = strtolower($primaryKey->getName());
-				$isUsingDefaultName = $indexName === 'primary';
-
-				if ($this->connection->getDatabasePlatform() instanceof PostgreSQL94Platform) {
-					$defaultName = $table->getName() . '_pkey';
-					$isUsingDefaultName = strtolower($defaultName) === $indexName;
-
-					if ($isUsingDefaultName) {
-						$sequenceName = $table->getName() . '_' . implode('_', $primaryKey->getColumns()) . '_seq';
-						$sequences = array_filter($sequences, function (Sequence $sequence) use ($sequenceName) {
-							return $sequence->getName() !== $sequenceName;
-						});
-					}
-				} elseif ($this->connection->getDatabasePlatform() instanceof OraclePlatform) {
-					$defaultName = $table->getName() . '_seq';
-					$isUsingDefaultName = strtolower($defaultName) === $indexName;
-				}
-
-				if (!$isUsingDefaultName && \strlen($indexName) > 30) {
-					throw new \InvalidArgumentException('Primary index name on "' . $table->getName() . '" is too long.');
-				}
-				if ($isUsingDefaultName && \strlen($table->getName()) - $prefixLength >= 23) {
-					throw new \InvalidArgumentException('Primary index name on "' . $table->getName() . '" is too long.');
-				}
-				// } elseif (!$primaryKey instanceof Index && !$sourceTable instanceof Table) {
-				// throw new \InvalidArgumentException('Table "' . $table->getName() . '" has no primary key and therefor will not behave sane in clustered setups.');
-			}
-		}
-
-		foreach ($sequences as $sequence) {
-			if (!$sourceSchema->hasSequence($sequence->getName()) && \strlen($sequence->getName()) > 30) {
-				throw new \InvalidArgumentException('Sequence name "' . $sequence->getName() . '" is too long.');
-			}
-		}
-	}
-
-	private function ensureMigrationsAreLoaded() {
-		if (empty($this->migrations)) {
-			$this->migrations = $this->findMigrations();
-		}
-	}
+    /** @var boolean */
+    private $migrationTableCreated;
+    /** @var array */
+    private $migrations;
+    /** @var IOutput */
+    private $output;
+    /** @var Connection */
+    private $connection;
+    /** @var string */
+    private $appName;
+    /** @var bool */
+    private $checkOracle;
+
+    /**
+     * MigrationService constructor.
+     *
+     * @param $appName
+     * @param Connection $connection
+     * @param AppLocator $appLocator
+     * @param IOutput|null $output
+     * @throws \Exception
+     */
+    public function __construct($appName, Connection $connection, IOutput $output = null, AppLocator $appLocator = null) {
+        $this->appName = $appName;
+        $this->connection = $connection;
+        $this->output = $output;
+        if (null === $this->output) {
+            $this->output = new SimpleOutput(\OC::$server->get(LoggerInterface::class), $appName);
+        }
+
+        if ($appName === 'core') {
+            $this->migrationsPath = \OC::$SERVERROOT . '/core/Migrations';
+            $this->migrationsNamespace = 'OC\\Core\\Migrations';
+            $this->checkOracle = true;
+        } else {
+            if (null === $appLocator) {
+                $appLocator = new AppLocator();
+            }
+            $appPath = $appLocator->getAppPath($appName);
+            $namespace = App::buildAppNamespace($appName);
+            $this->migrationsPath = "$appPath/lib/Migration";
+            $this->migrationsNamespace = $namespace . '\\Migration';
+
+            $infoParser = new InfoParser();
+            $info = $infoParser->parse($appPath . '/appinfo/info.xml');
+            if (!isset($info['dependencies']['database'])) {
+                $this->checkOracle = true;
+            } else {
+                $this->checkOracle = false;
+                foreach ($info['dependencies']['database'] as $database) {
+                    if (\is_string($database) && $database === 'oci') {
+                        $this->checkOracle = true;
+                    } elseif (\is_array($database) && isset($database['@value']) && $database['@value'] === 'oci') {
+                        $this->checkOracle = true;
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * Returns the name of the app for which this migration is executed
+     *
+     * @return string
+     */
+    public function getApp() {
+        return $this->appName;
+    }
+
+    /**
+     * @return bool
+     * @codeCoverageIgnore - this will implicitly tested on installation
+     */
+    private function createMigrationTable() {
+        if ($this->migrationTableCreated) {
+            return false;
+        }
+
+        if ($this->connection->tableExists('migrations') && \OC::$server->getConfig()->getAppValue('core', 'vendor', '') !== 'owncloud') {
+            $this->migrationTableCreated = true;
+            return false;
+        }
+
+        $schema = new SchemaWrapper($this->connection);
+
+        /**
+         * We drop the table when it has different columns or the definition does not
+         * match. E.g. ownCloud uses a length of 177 for app and 14 for version.
+         */
+        try {
+            $table = $schema->getTable('migrations');
+            $columns = $table->getColumns();
+
+            if (count($columns) === 2) {
+                try {
+                    $column = $table->getColumn('app');
+                    $schemaMismatch = $column->getLength() !== 255;
+
+                    if (!$schemaMismatch) {
+                        $column = $table->getColumn('version');
+                        $schemaMismatch = $column->getLength() !== 255;
+                    }
+                } catch (SchemaException $e) {
+                    // One of the columns is missing
+                    $schemaMismatch = true;
+                }
+
+                if (!$schemaMismatch) {
+                    // Table exists and schema matches: return back!
+                    $this->migrationTableCreated = true;
+                    return false;
+                }
+            }
+
+            // Drop the table, when it didn't match our expectations.
+            $this->connection->dropTable('migrations');
+
+            // Recreate the schema after the table was dropped.
+            $schema = new SchemaWrapper($this->connection);
+        } catch (SchemaException $e) {
+            // Table not found, no need to panic, we will create it.
+        }
+
+        $table = $schema->createTable('migrations');
+        $table->addColumn('app', Types::STRING, ['length' => 255]);
+        $table->addColumn('version', Types::STRING, ['length' => 255]);
+        $table->setPrimaryKey(['app', 'version']);
+
+        $this->connection->migrateToSchema($schema->getWrappedSchema());
+
+        $this->migrationTableCreated = true;
+
+        return true;
+    }
+
+    /**
+     * Returns all versions which have already been applied
+     *
+     * @return string[]
+     * @codeCoverageIgnore - no need to test this
+     */
+    public function getMigratedVersions() {
+        $this->createMigrationTable();
+        $qb = $this->connection->getQueryBuilder();
+
+        $qb->select('version')
+            ->from('migrations')
+            ->where($qb->expr()->eq('app', $qb->createNamedParameter($this->getApp())))
+            ->orderBy('version');
+
+        $result = $qb->execute();
+        $rows = $result->fetchAll(\PDO::FETCH_COLUMN);
+        $result->closeCursor();
+
+        return $rows;
+    }
+
+    /**
+     * Returns all versions which are available in the migration folder
+     *
+     * @return array
+     */
+    public function getAvailableVersions() {
+        $this->ensureMigrationsAreLoaded();
+        return array_map('strval', array_keys($this->migrations));
+    }
+
+    protected function findMigrations() {
+        $directory = realpath($this->migrationsPath);
+        if ($directory === false || !file_exists($directory) || !is_dir($directory)) {
+            return [];
+        }
+
+        $iterator = new \RegexIterator(
+            new \RecursiveIteratorIterator(
+                new \RecursiveDirectoryIterator($directory, \FilesystemIterator::SKIP_DOTS),
+                \RecursiveIteratorIterator::LEAVES_ONLY
+            ),
+            '#^.+\\/Version[^\\/]{1,255}\\.php$#i',
+            \RegexIterator::GET_MATCH);
+
+        $files = array_keys(iterator_to_array($iterator));
+        uasort($files, function ($a, $b) {
+            preg_match('/^Version(\d+)Date(\d+)\\.php$/', basename($a), $matchA);
+            preg_match('/^Version(\d+)Date(\d+)\\.php$/', basename($b), $matchB);
+            if (!empty($matchA) && !empty($matchB)) {
+                if ($matchA[1] !== $matchB[1]) {
+                    return ($matchA[1] < $matchB[1]) ? -1 : 1;
+                }
+                return ($matchA[2] < $matchB[2]) ? -1 : 1;
+            }
+            return (basename($a) < basename($b)) ? -1 : 1;
+        });
+
+        $migrations = [];
+
+        foreach ($files as $file) {
+            $className = basename($file, '.php');
+            $version = (string) substr($className, 7);
+            if ($version === '0') {
+                throw new \InvalidArgumentException(
+                    "Cannot load a migrations with the name '$version' because it is a reserved number"
+                );
+            }
+            $migrations[$version] = sprintf('%s\\%s', $this->migrationsNamespace, $className);
+        }
+
+        return $migrations;
+    }
+
+    /**
+     * @param string $to
+     * @return string[]
+     */
+    private function getMigrationsToExecute($to) {
+        $knownMigrations = $this->getMigratedVersions();
+        $availableMigrations = $this->getAvailableVersions();
+
+        $toBeExecuted = [];
+        foreach ($availableMigrations as $v) {
+            if ($to !== 'latest' && $v > $to) {
+                continue;
+            }
+            if ($this->shallBeExecuted($v, $knownMigrations)) {
+                $toBeExecuted[] = $v;
+            }
+        }
+
+        return $toBeExecuted;
+    }
+
+    /**
+     * @param string $m
+     * @param string[] $knownMigrations
+     * @return bool
+     */
+    private function shallBeExecuted($m, $knownMigrations) {
+        if (in_array($m, $knownMigrations)) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * @param string $version
+     */
+    private function markAsExecuted($version) {
+        $this->connection->insertIfNotExist('*PREFIX*migrations', [
+            'app' => $this->appName,
+            'version' => $version
+        ]);
+    }
+
+    /**
+     * Returns the name of the table which holds the already applied versions
+     *
+     * @return string
+     */
+    public function getMigrationsTableName() {
+        return $this->connection->getPrefix() . 'migrations';
+    }
+
+    /**
+     * Returns the namespace of the version classes
+     *
+     * @return string
+     */
+    public function getMigrationsNamespace() {
+        return $this->migrationsNamespace;
+    }
+
+    /**
+     * Returns the directory which holds the versions
+     *
+     * @return string
+     */
+    public function getMigrationsDirectory() {
+        return $this->migrationsPath;
+    }
+
+    /**
+     * Return the explicit version for the aliases; current, next, prev, latest
+     *
+     * @param string $alias
+     * @return mixed|null|string
+     */
+    public function getMigration($alias) {
+        switch ($alias) {
+            case 'current':
+                return $this->getCurrentVersion();
+            case 'next':
+                return $this->getRelativeVersion($this->getCurrentVersion(), 1);
+            case 'prev':
+                return $this->getRelativeVersion($this->getCurrentVersion(), -1);
+            case 'latest':
+                $this->ensureMigrationsAreLoaded();
+
+                $migrations = $this->getAvailableVersions();
+                return @end($migrations);
+        }
+        return '0';
+    }
+
+    /**
+     * @param string $version
+     * @param int $delta
+     * @return null|string
+     */
+    private function getRelativeVersion($version, $delta) {
+        $this->ensureMigrationsAreLoaded();
+
+        $versions = $this->getAvailableVersions();
+        array_unshift($versions, 0);
+        $offset = array_search($version, $versions, true);
+        if ($offset === false || !isset($versions[$offset + $delta])) {
+            // Unknown version or delta out of bounds.
+            return null;
+        }
+
+        return (string) $versions[$offset + $delta];
+    }
+
+    /**
+     * @return string
+     */
+    private function getCurrentVersion() {
+        $m = $this->getMigratedVersions();
+        if (count($m) === 0) {
+            return '0';
+        }
+        $migrations = array_values($m);
+        return @end($migrations);
+    }
+
+    /**
+     * @param string $version
+     * @return string
+     * @throws \InvalidArgumentException
+     */
+    private function getClass($version) {
+        $this->ensureMigrationsAreLoaded();
+
+        if (isset($this->migrations[$version])) {
+            return $this->migrations[$version];
+        }
+
+        throw new \InvalidArgumentException("Version $version is unknown.");
+    }
+
+    /**
+     * Allows to set an IOutput implementation which is used for logging progress and messages
+     *
+     * @param IOutput $output
+     */
+    public function setOutput(IOutput $output) {
+        $this->output = $output;
+    }
+
+    /**
+     * Applies all not yet applied versions up to $to
+     *
+     * @param string $to
+     * @param bool $schemaOnly
+     * @throws \InvalidArgumentException
+     */
+    public function migrate($to = 'latest', $schemaOnly = false) {
+        if ($schemaOnly) {
+            $this->migrateSchemaOnly($to);
+            return;
+        }
+
+        // read known migrations
+        $toBeExecuted = $this->getMigrationsToExecute($to);
+        foreach ($toBeExecuted as $version) {
+            try {
+                $this->executeStep($version, $schemaOnly);
+            } catch (\Exception $e) {
+                // The exception itself does not contain the name of the migration,
+                // so we wrap it here, to make debugging easier.
+                throw new \Exception('Database error when running migration ' . $version . ' for app ' . $this->getApp() . PHP_EOL. $e->getMessage(), 0, $e);
+            }
+        }
+    }
+
+    /**
+     * Applies all not yet applied versions up to $to
+     *
+     * @param string $to
+     * @throws \InvalidArgumentException
+     */
+    public function migrateSchemaOnly($to = 'latest') {
+        // read known migrations
+        $toBeExecuted = $this->getMigrationsToExecute($to);
+
+        if (empty($toBeExecuted)) {
+            return;
+        }
+
+        $toSchema = null;
+        foreach ($toBeExecuted as $version) {
+            $instance = $this->createInstance($version);
+
+            $toSchema = $instance->changeSchema($this->output, function () use ($toSchema) {
+                return $toSchema ?: new SchemaWrapper($this->connection);
+            }, ['tablePrefix' => $this->connection->getPrefix()]) ?: $toSchema;
+        }
+
+        if ($toSchema instanceof SchemaWrapper) {
+            $targetSchema = $toSchema->getWrappedSchema();
+            if ($this->checkOracle) {
+                $beforeSchema = $this->connection->createSchema();
+                $this->ensureOracleConstraints($beforeSchema, $targetSchema, strlen($this->connection->getPrefix()));
+            }
+            $this->connection->migrateToSchema($targetSchema);
+            $toSchema->performDropTableCalls();
+        }
+
+        foreach ($toBeExecuted as $version) {
+            $this->markAsExecuted($version);
+        }
+    }
+
+    /**
+     * Get the human readable descriptions for the migration steps to run
+     *
+     * @param string $to
+     * @return string[] [$name => $description]
+     */
+    public function describeMigrationStep($to = 'latest') {
+        $toBeExecuted = $this->getMigrationsToExecute($to);
+        $description = [];
+        foreach ($toBeExecuted as $version) {
+            $migration = $this->createInstance($version);
+            if ($migration->name()) {
+                $description[$migration->name()] = $migration->description();
+            }
+        }
+        return $description;
+    }
+
+    /**
+     * @param string $version
+     * @return IMigrationStep
+     * @throws \InvalidArgumentException
+     */
+    protected function createInstance($version) {
+        $class = $this->getClass($version);
+        try {
+            $s = \OC::$server->query($class);
+
+            if (!$s instanceof IMigrationStep) {
+                throw new \InvalidArgumentException('Not a valid migration');
+            }
+        } catch (QueryException $e) {
+            if (class_exists($class)) {
+                $s = new $class();
+            } else {
+                throw new \InvalidArgumentException("Migration step '$class' is unknown");
+            }
+        }
+
+        return $s;
+    }
+
+    /**
+     * Executes one explicit version
+     *
+     * @param string $version
+     * @param bool $schemaOnly
+     * @throws \InvalidArgumentException
+     */
+    public function executeStep($version, $schemaOnly = false) {
+        $instance = $this->createInstance($version);
+
+        if (!$schemaOnly) {
+            $instance->preSchemaChange($this->output, function () {
+                return new SchemaWrapper($this->connection);
+            }, ['tablePrefix' => $this->connection->getPrefix()]);
+        }
+
+        $toSchema = $instance->changeSchema($this->output, function () {
+            return new SchemaWrapper($this->connection);
+        }, ['tablePrefix' => $this->connection->getPrefix()]);
+
+        if ($toSchema instanceof SchemaWrapper) {
+            $targetSchema = $toSchema->getWrappedSchema();
+            if ($this->checkOracle) {
+                $sourceSchema = $this->connection->createSchema();
+                $this->ensureOracleConstraints($sourceSchema, $targetSchema, strlen($this->connection->getPrefix()));
+            }
+            $this->connection->migrateToSchema($targetSchema);
+            $toSchema->performDropTableCalls();
+        }
+
+        if (!$schemaOnly) {
+            $instance->postSchemaChange($this->output, function () {
+                return new SchemaWrapper($this->connection);
+            }, ['tablePrefix' => $this->connection->getPrefix()]);
+        }
+
+        $this->markAsExecuted($version);
+    }
+
+    /**
+     * Naming constraints:
+     * - Tables names must be 30 chars or shorter (27 + oc_ prefix)
+     * - Column names must be 30 chars or shorter
+     * - Index names must be 30 chars or shorter
+     * - Sequence names must be 30 chars or shorter
+     * - Primary key names must be set or the table name 23 chars or shorter
+     *
+     * Data constraints:
+     * - Columns with "NotNull" can not have empty string as default value
+     * - Columns with "NotNull" can not have number 0 as default value
+     * - Columns with type "bool" (which is in fact integer of length 1) can not be "NotNull" as it can not store 0/false
+     *
+     * @param Schema $sourceSchema
+     * @param Schema $targetSchema
+     * @param int $prefixLength
+     * @throws \Doctrine\DBAL\Exception
+     */
+    public function ensureOracleConstraints(Schema $sourceSchema, Schema $targetSchema, int $prefixLength) {
+        $sequences = $targetSchema->getSequences();
+
+        foreach ($targetSchema->getTables() as $table) {
+            try {
+                $sourceTable = $sourceSchema->getTable($table->getName());
+            } catch (SchemaException $e) {
+                if (\strlen($table->getName()) - $prefixLength > 27) {
+                    throw new \InvalidArgumentException('Table name "' . $table->getName() . '" is too long.');
+                }
+                $sourceTable = null;
+            }
+
+            foreach ($table->getColumns() as $thing) {
+                // If the table doesn't exist OR if the column doesn't exist in the table
+                if (!$sourceTable instanceof Table || !$sourceTable->hasColumn($thing->getName())) {
+                    if (\strlen($thing->getName()) > 30) {
+                        throw new \InvalidArgumentException('Column name "' . $table->getName() . '"."' . $thing->getName() . '" is too long.');
+                    }
+
+                    if ($thing->getNotnull() && $thing->getDefault() === ''
+                        && $sourceTable instanceof Table && !$sourceTable->hasColumn($thing->getName())) {
+                        throw new \InvalidArgumentException('Column "' . $table->getName() . '"."' . $thing->getName() . '" is NotNull, but has empty string or null as default.');
+                    }
+
+                    if ($thing->getNotnull() && $thing->getType()->getName() === Types::BOOLEAN) {
+                        throw new \InvalidArgumentException('Column "' . $table->getName() . '"."' . $thing->getName() . '" is type Bool and also NotNull, so it can not store "false".');
+                    }
+
+                    $sourceColumn = null;
+                } else {
+                    $sourceColumn = $sourceTable->getColumn($thing->getName());
+                }
+
+                // If the column was just created OR the length changed OR the type changed
+                // we will NOT detect invalid length if the column is not modified
+                if (($sourceColumn === null || $sourceColumn->getLength() !== $thing->getLength() || $sourceColumn->getType()->getName() !== Types::STRING)
+                    && $thing->getLength() > 4000 && $thing->getType()->getName() === Types::STRING) {
+                    throw new \InvalidArgumentException('Column "' . $table->getName() . '"."' . $thing->getName() . '" is type String, but exceeding the 4.000 length limit.');
+                }
+            }
+
+            foreach ($table->getIndexes() as $thing) {
+                if ((!$sourceTable instanceof Table || !$sourceTable->hasIndex($thing->getName())) && \strlen($thing->getName()) > 30) {
+                    throw new \InvalidArgumentException('Index name "' . $table->getName() . '"."' . $thing->getName() . '" is too long.');
+                }
+            }
+
+            foreach ($table->getForeignKeys() as $thing) {
+                if ((!$sourceTable instanceof Table || !$sourceTable->hasForeignKey($thing->getName())) && \strlen($thing->getName()) > 30) {
+                    throw new \InvalidArgumentException('Foreign key name "' . $table->getName() . '"."' . $thing->getName() . '" is too long.');
+                }
+            }
+
+            $primaryKey = $table->getPrimaryKey();
+            if ($primaryKey instanceof Index && (!$sourceTable instanceof Table || !$sourceTable->hasPrimaryKey())) {
+                $indexName = strtolower($primaryKey->getName());
+                $isUsingDefaultName = $indexName === 'primary';
+
+                if ($this->connection->getDatabasePlatform() instanceof PostgreSQL94Platform) {
+                    $defaultName = $table->getName() . '_pkey';
+                    $isUsingDefaultName = strtolower($defaultName) === $indexName;
+
+                    if ($isUsingDefaultName) {
+                        $sequenceName = $table->getName() . '_' . implode('_', $primaryKey->getColumns()) . '_seq';
+                        $sequences = array_filter($sequences, function (Sequence $sequence) use ($sequenceName) {
+                            return $sequence->getName() !== $sequenceName;
+                        });
+                    }
+                } elseif ($this->connection->getDatabasePlatform() instanceof OraclePlatform) {
+                    $defaultName = $table->getName() . '_seq';
+                    $isUsingDefaultName = strtolower($defaultName) === $indexName;
+                }
+
+                if (!$isUsingDefaultName && \strlen($indexName) > 30) {
+                    throw new \InvalidArgumentException('Primary index name on "' . $table->getName() . '" is too long.');
+                }
+                if ($isUsingDefaultName && \strlen($table->getName()) - $prefixLength >= 23) {
+                    throw new \InvalidArgumentException('Primary index name on "' . $table->getName() . '" is too long.');
+                }
+                // } elseif (!$primaryKey instanceof Index && !$sourceTable instanceof Table) {
+                // throw new \InvalidArgumentException('Table "' . $table->getName() . '" has no primary key and therefor will not behave sane in clustered setups.');
+            }
+        }
+
+        foreach ($sequences as $sequence) {
+            if (!$sourceSchema->hasSequence($sequence->getName()) && \strlen($sequence->getName()) > 30) {
+                throw new \InvalidArgumentException('Sequence name "' . $sequence->getName() . '" is too long.');
+            }
+        }
+    }
+
+    private function ensureMigrationsAreLoaded() {
+        if (empty($this->migrations)) {
+            $this->migrations = $this->findMigrations();
+        }
+    }
 }

Spacing +24 added lines, -24 removed lines

@@ -77,7 +77,7 @@ 
 		}
 
 		if ($appName === 'core') {
-			$this->migrationsPath = \OC::$SERVERROOT . '/core/Migrations';
+			$this->migrationsPath = \OC::$SERVERROOT.'/core/Migrations';
 			$this->migrationsNamespace = 'OC\\Core\\Migrations';
 			$this->checkOracle = true;
 		} else {
@@ -87,10 +87,10 @@ 
 			$appPath = $appLocator->getAppPath($appName);
 			$namespace = App::buildAppNamespace($appName);
 			$this->migrationsPath = "$appPath/lib/Migration";
-			$this->migrationsNamespace = $namespace . '\\Migration';
+			$this->migrationsNamespace = $namespace.'\\Migration';
 
 			$infoParser = new InfoParser();
-			$info = $infoParser->parse($appPath . '/appinfo/info.xml');
+			$info = $infoParser->parse($appPath.'/appinfo/info.xml');
 			if (!isset($info['dependencies']['database'])) {
 				$this->checkOracle = true;
 			} else {
@@ -228,7 +228,7 @@ 
 			\RegexIterator::GET_MATCH);
 
 		$files = array_keys(iterator_to_array($iterator));
-		uasort($files, function ($a, $b) {
+		uasort($files, function($a, $b) {
 			preg_match('/^Version(\d+)Date(\d+)\\.php$/', basename($a), $matchA);
 			preg_match('/^Version(\d+)Date(\d+)\\.php$/', basename($b), $matchB);
 			if (!empty($matchA) && !empty($matchB)) {
@@ -306,7 +306,7 @@ 
 	 * @return string
 	 */
 	public function getMigrationsTableName() {
-		return $this->connection->getPrefix() . 'migrations';
+		return $this->connection->getPrefix().'migrations';
 	}
 
 	/**
@@ -426,7 +426,7 @@ 
 			} catch (\Exception $e) {
 				// The exception itself does not contain the name of the migration,
 				// so we wrap it here, to make debugging easier.
-				throw new \Exception('Database error when running migration ' . $version . ' for app ' . $this->getApp() . PHP_EOL. $e->getMessage(), 0, $e);
+				throw new \Exception('Database error when running migration '.$version.' for app '.$this->getApp().PHP_EOL.$e->getMessage(), 0, $e);
 			}
 		}
 	}
@@ -449,7 +449,7 @@ 
 		foreach ($toBeExecuted as $version) {
 			$instance = $this->createInstance($version);
 
-			$toSchema = $instance->changeSchema($this->output, function () use ($toSchema) {
+			$toSchema = $instance->changeSchema($this->output, function() use ($toSchema) {
 				return $toSchema ?: new SchemaWrapper($this->connection);
 			}, ['tablePrefix' => $this->connection->getPrefix()]) ?: $toSchema;
 		}
@@ -522,12 +522,12 @@ 
 		$instance = $this->createInstance($version);
 
 		if (!$schemaOnly) {
-			$instance->preSchemaChange($this->output, function () {
+			$instance->preSchemaChange($this->output, function() {
 				return new SchemaWrapper($this->connection);
 			}, ['tablePrefix' => $this->connection->getPrefix()]);
 		}
 
-		$toSchema = $instance->changeSchema($this->output, function () {
+		$toSchema = $instance->changeSchema($this->output, function() {
 			return new SchemaWrapper($this->connection);
 		}, ['tablePrefix' => $this->connection->getPrefix()]);
 
@@ -542,7 +542,7 @@ 
 		}
 
 		if (!$schemaOnly) {
-			$instance->postSchemaChange($this->output, function () {
+			$instance->postSchemaChange($this->output, function() {
 				return new SchemaWrapper($this->connection);
 			}, ['tablePrefix' => $this->connection->getPrefix()]);
 		}
@@ -576,7 +576,7 @@ 
 				$sourceTable = $sourceSchema->getTable($table->getName());
 			} catch (SchemaException $e) {
 				if (\strlen($table->getName()) - $prefixLength > 27) {
-					throw new \InvalidArgumentException('Table name "' . $table->getName() . '" is too long.');
+					throw new \InvalidArgumentException('Table name "'.$table->getName().'" is too long.');
 				}
 				$sourceTable = null;
 			}
@@ -585,16 +585,16 @@ 
 				// If the table doesn't exist OR if the column doesn't exist in the table
 				if (!$sourceTable instanceof Table || !$sourceTable->hasColumn($thing->getName())) {
 					if (\strlen($thing->getName()) > 30) {
-						throw new \InvalidArgumentException('Column name "' . $table->getName() . '"."' . $thing->getName() . '" is too long.');
+						throw new \InvalidArgumentException('Column name "'.$table->getName().'"."'.$thing->getName().'" is too long.');
 					}
 
 					if ($thing->getNotnull() && $thing->getDefault() === ''
 						&& $sourceTable instanceof Table && !$sourceTable->hasColumn($thing->getName())) {
-						throw new \InvalidArgumentException('Column "' . $table->getName() . '"."' . $thing->getName() . '" is NotNull, but has empty string or null as default.');
+						throw new \InvalidArgumentException('Column "'.$table->getName().'"."'.$thing->getName().'" is NotNull, but has empty string or null as default.');
 					}
 
 					if ($thing->getNotnull() && $thing->getType()->getName() === Types::BOOLEAN) {
-						throw new \InvalidArgumentException('Column "' . $table->getName() . '"."' . $thing->getName() . '" is type Bool and also NotNull, so it can not store "false".');
+						throw new \InvalidArgumentException('Column "'.$table->getName().'"."'.$thing->getName().'" is type Bool and also NotNull, so it can not store "false".');
 					}
 
 					$sourceColumn = null;
@@ -606,19 +606,19 @@ 
 				// we will NOT detect invalid length if the column is not modified
 				if (($sourceColumn === null || $sourceColumn->getLength() !== $thing->getLength() || $sourceColumn->getType()->getName() !== Types::STRING)
 					&& $thing->getLength() > 4000 && $thing->getType()->getName() === Types::STRING) {
-					throw new \InvalidArgumentException('Column "' . $table->getName() . '"."' . $thing->getName() . '" is type String, but exceeding the 4.000 length limit.');
+					throw new \InvalidArgumentException('Column "'.$table->getName().'"."'.$thing->getName().'" is type String, but exceeding the 4.000 length limit.');
 				}
 			}
 
 			foreach ($table->getIndexes() as $thing) {
 				if ((!$sourceTable instanceof Table || !$sourceTable->hasIndex($thing->getName())) && \strlen($thing->getName()) > 30) {
-					throw new \InvalidArgumentException('Index name "' . $table->getName() . '"."' . $thing->getName() . '" is too long.');
+					throw new \InvalidArgumentException('Index name "'.$table->getName().'"."'.$thing->getName().'" is too long.');
 				}
 			}
 
 			foreach ($table->getForeignKeys() as $thing) {
 				if ((!$sourceTable instanceof Table || !$sourceTable->hasForeignKey($thing->getName())) && \strlen($thing->getName()) > 30) {
-					throw new \InvalidArgumentException('Foreign key name "' . $table->getName() . '"."' . $thing->getName() . '" is too long.');
+					throw new \InvalidArgumentException('Foreign key name "'.$table->getName().'"."'.$thing->getName().'" is too long.');
 				}
 			}
 
@@ -628,25 +628,25 @@ 
 				$isUsingDefaultName = $indexName === 'primary';
 
 				if ($this->connection->getDatabasePlatform() instanceof PostgreSQL94Platform) {
-					$defaultName = $table->getName() . '_pkey';
+					$defaultName = $table->getName().'_pkey';
 					$isUsingDefaultName = strtolower($defaultName) === $indexName;
 
 					if ($isUsingDefaultName) {
-						$sequenceName = $table->getName() . '_' . implode('_', $primaryKey->getColumns()) . '_seq';
-						$sequences = array_filter($sequences, function (Sequence $sequence) use ($sequenceName) {
+						$sequenceName = $table->getName().'_'.implode('_', $primaryKey->getColumns()).'_seq';
+						$sequences = array_filter($sequences, function(Sequence $sequence) use ($sequenceName) {
 							return $sequence->getName() !== $sequenceName;
 						});
 					}
 				} elseif ($this->connection->getDatabasePlatform() instanceof OraclePlatform) {
-					$defaultName = $table->getName() . '_seq';
+					$defaultName = $table->getName().'_seq';
 					$isUsingDefaultName = strtolower($defaultName) === $indexName;
 				}
 
 				if (!$isUsingDefaultName && \strlen($indexName) > 30) {
-					throw new \InvalidArgumentException('Primary index name on "' . $table->getName() . '" is too long.');
+					throw new \InvalidArgumentException('Primary index name on "'.$table->getName().'" is too long.');
 				}
 				if ($isUsingDefaultName && \strlen($table->getName()) - $prefixLength >= 23) {
-					throw new \InvalidArgumentException('Primary index name on "' . $table->getName() . '" is too long.');
+					throw new \InvalidArgumentException('Primary index name on "'.$table->getName().'" is too long.');
 				}
 				// } elseif (!$primaryKey instanceof Index && !$sourceTable instanceof Table) {
 				// throw new \InvalidArgumentException('Table "' . $table->getName() . '" has no primary key and therefor will not behave sane in clustered setups.');
@@ -655,7 +655,7 @@ 
 
 		foreach ($sequences as $sequence) {
 			if (!$sourceSchema->hasSequence($sequence->getName()) && \strlen($sequence->getName()) > 30) {
-				throw new \InvalidArgumentException('Sequence name "' . $sequence->getName() . '" is too long.');
+				throw new \InvalidArgumentException('Sequence name "'.$sequence->getName().'" is too long.');
 			}
 		}
 	}