owncloud/core

<?php
/**
 * @author Bart Visscher <bartv@thisnet.nl>
 * @author Jörn Friedrich Dreyer <jfd@butonic.de>
 * @author Lukas Reschke <lukas@statuscode.ch>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin Appelman <icewind@owncloud.com>
 * @author Roeland Jago Douma <rullzer@owncloud.com>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 * @author Vincent Petry <pvince81@owncloud.com>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OC\DB;

use Doctrine\DBAL\Platforms\MySqlPlatform;
use Doctrine\DBAL\Platforms\OraclePlatform;
use Doctrine\DBAL\Platforms\PostgreSqlPlatform;
use Doctrine\DBAL\Platforms\SqlitePlatform;
use Doctrine\DBAL\Schema\Schema;
use OCP\IDBConnection;

class MDB2SchemaManager {
    /** @var \OC\DB\Connection $conn */
    protected $conn;

    /**
     * @param IDBConnection $conn
     */
    public function __construct($conn) {
        $this->conn = $conn;
    }

    /**
     * saves database scheme to xml file
     * @param string $file name of file
     * @return bool
     *
     * TODO: write more documentation
     */
    public function getDbStructure($file) {
        return \OC\DB\MDB2SchemaWriter::saveSchemaToFile($file, $this->conn);
    }

    /**
     * Creates tables from XML file
     * @param string $file file to read structure from
     * @return bool
     *
     * TODO: write more documentation
     */
    public function createDbFromStructure($file) {
        $schemaReader = new MDB2SchemaReader(\OC::$server->getConfig(), $this->conn->getDatabasePlatform());
        $toSchema = new Schema([], [], $this->conn->getSchemaManager()->createSchemaConfig());
        $toSchema = $schemaReader->loadSchemaFromFile($file, $toSchema);
        return $this->executeSchemaChange($toSchema);
    }

    /**
     * @return \OC\DB\Migrator
     */
    public function getMigrator() {
        $random = \OC::$server->getSecureRandom();
        $platform = $this->conn->getDatabasePlatform();
        $config = \OC::$server->getConfig();
        $dispatcher = \OC::$server->getEventDispatcher();
        if ($platform instanceof SqlitePlatform) {
            return new SQLiteMigrator($this->conn, $random, $config, $dispatcher);
        } elseif ($platform instanceof OraclePlatform) {
            return new OracleMigrator($this->conn, $random, $config, $dispatcher);
        } elseif ($platform instanceof MySqlPlatform) {
            return new MySQLMigrator($this->conn, $random, $config, $dispatcher);
        } elseif ($platform instanceof PostgreSqlPlatform) {
            return new PostgreSqlMigrator($this->conn, $random, $config, $dispatcher);
        } else {
            return new Migrator($this->conn, $random, $config, $dispatcher);
        }
    }

    /**
     * Reads database schema from file
     *
     * @param string $file file to read from
     * @return \Doctrine\DBAL\Schema\Schema
     */
    private function readSchemaFromFile($file) {
        $platform = $this->conn->getDatabasePlatform();
        $schemaReader = new MDB2SchemaReader(\OC::$server->getConfig(), $platform);
        $toSchema = new Schema([], [], $this->conn->getSchemaManager()->createSchemaConfig());
        return $schemaReader->loadSchemaFromFile($file, $toSchema);
    }

    /**
     * update the database scheme
     * @param string $file file to read structure from
     * @param bool $generateSql only return the sql needed for the upgrade
     * @return string|boolean
     */
    public function updateDbFromStructure($file, $generateSql = false) {
        $toSchema = $this->readSchemaFromFile($file);
        $migrator = $this->getMigrator();

        if ($generateSql) {
            return $migrator->generateChangeScript($toSchema);
        } else {
            $migrator->migrate($toSchema);
            return true;
        }
    }

    /**
     * @param \Doctrine\DBAL\Schema\Schema $schema
     * @return string
     */
    public function generateChangeScript($schema) {
        $migrator = $this->getMigrator();
        return $migrator->generateChangeScript($schema);
    }

    /**
     * remove all tables defined in a database structure xml file
     *
     * @param string $file the xml file describing the tables
     */
    public function removeDBStructure($file) {
        $schemaReader = new MDB2SchemaReader(\OC::$server->getConfig(), $this->conn->getDatabasePlatform());
        $toSchema = new Schema([], [], $this->conn->getSchemaManager()->createSchemaConfig());
        $fromSchema = $schemaReader->loadSchemaFromFile($file, $toSchema);
        $toSchema = clone $fromSchema;
        /** @var $table \Doctrine\DBAL\Schema\Table */
        foreach ($toSchema->getTables() as $table) {
            $toSchema->dropTable($table->getName());
        }
        $comparator = new \Doctrine\DBAL\Schema\Comparator();
        $schemaDiff = $comparator->compare($fromSchema, $toSchema);
        $this->executeSchemaChange($schemaDiff);
    }

    /**
     * @param \Doctrine\DBAL\Schema\Schema|\Doctrine\DBAL\Schema\SchemaDiff $schema
     * @return bool
     */
    private function executeSchemaChange($schema) {
        $this->conn->beginTransaction();
        foreach ($schema->toSql($this->conn->getDatabasePlatform()) as $sql) {
            $this->conn->query($sql);
        }
        $this->conn->commit();

        if ($this->conn->getDatabasePlatform() instanceof SqlitePlatform) {
            $this->conn->close();
            $this->conn->connect();
        }
        return true;
    }
}