Add a mechanism to try the database migration on a copy of the tables before running...

diff --git a/lib/private/db/migrationexception.php b/lib/private/db/migrationexception.php
new file mode 100644 (file)
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--- /dev/null
+++ b/lib/private/db/migrationexception.php
@@ -0,0 +1,19 @@
+<?php
+/**
+ * Copyright (c) 2014 Robin Appelman <icewind@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\DB;
+
+
+class MigrationException extends \Exception {
+       private $table;
+
+       public function __construct($table, $message) {
+               $this->$table = $table;
+               parent::__construct($message);
+       }
+}

diff --git a/lib/private/db/migrator.php b/lib/private/db/migrator.php
new file mode 100644 (file)
index 0000000..9106066
--- /dev/null
+++ b/lib/private/db/migrator.php
@@ -0,0 +1,139 @@
+<?php
+/**
+ * Copyright (c) 2014 Robin Appelman <icewind@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\DB;
+
+use \Doctrine\DBAL\DBALException;
+use \Doctrine\DBAL\Schema\Table;
+use \Doctrine\DBAL\Schema\Schema;
+use \Doctrine\DBAL\Schema\SchemaConfig;
+
+class Migrator {
+       /**
+        * @var \Doctrine\DBAL\Connection $connection
+        */
+       protected $connection;
+
+       /**
+        * @param \Doctrine\DBAL\Connection $connection
+        */
+       public function __construct(\Doctrine\DBAL\Connection $connection) {
+               $this->connection = $connection;
+       }
+
+       /**
+        * @param \Doctrine\DBAL\Schema\Schema $targetSchema
+        */
+       public function migrate(Schema $targetSchema) {
+               $this->applySchema($targetSchema);
+       }
+
+       /**
+        * @param Schema $targetSchema
+        */
+       public function checkMigrate(Schema $targetSchema) {
+               /**
+                * @var \Doctrine\DBAL\Schema\Table[] $tables
+                */
+               $tables = $targetSchema->getTables();
+
+               $existingTables = $this->connection->getSchemaManager()->listTableNames();
+
+               foreach ($tables as $table) {
+                       // don't need to check for new tables
+                       list(, $tableName) = explode('.', $table->getName());
+                       if (array_search($tableName, $existingTables) !== false) {
+                               $this->checkTableMigrate($table);
+                       }
+               }
+       }
+
+       /**
+        * Check the migration of a table on a copy so we can detect errors before messing with the real table
+        *
+        * @param \Doctrine\DBAL\Schema\Table $table
+        */
+       protected function checkTableMigrate(Table $table) {
+               $name = $table->getName();
+               $tmpName = $name . '_copy_' . uniqid();
+
+               $this->copyTable($name, $tmpName);
+
+               //create the migration schema for the temporary table
+               $tmpTable = new Table($tmpName, $table->getColumns(), $table->getIndexes(), $table->getForeignKeys(), $table->_idGeneratorType, $table->getOptions());
+               $schemaConfig = new SchemaConfig();
+               $schemaConfig->setName($this->connection->getDatabase());
+               $schema = new Schema(array($tmpTable), array(), $schemaConfig);
+
+               try {
+                       $this->applySchema($schema);
+                       $this->dropTable($tmpName);
+               } catch (DBALException $e) {
+                       $this->dropTable($tmpName);
+                       throw new MigrationException($table->getName(), $e->getMessage());
+               }
+       }
+
+       /**
+        * @param \Doctrine\DBAL\Schema\Schema $targetSchema
+        * @param \Doctrine\DBAL\Connection $connection
+        */
+       protected function applySchema(Schema $targetSchema, \Doctrine\DBAL\Connection $connection = null) {
+               if (is_null($connection)) {
+                       $connection = $this->connection;
+               }
+
+               $sourceSchema = $this->connection->getSchemaManager()->createSchema();
+
+               // remove tables we don't know about
+               /** @var $table \Doctrine\DBAL\Schema\Table */
+               foreach ($sourceSchema->getTables() as $table) {
+                       if (!$targetSchema->hasTable($table->getName())) {
+                               $sourceSchema->dropTable($table->getName());
+                       }
+               }
+               // remove sequences we don't know about
+               foreach ($sourceSchema->getSequences() as $table) {
+                       if (!$targetSchema->hasSequence($table->getName())) {
+                               $sourceSchema->dropSequence($table->getName());
+                       }
+               }
+
+               $comparator = new \Doctrine\DBAL\Schema\Comparator();
+               $schemaDiff = $comparator->compare($sourceSchema, $targetSchema);
+
+               foreach ($schemaDiff->changedTables as $tableDiff) {
+                       $tableDiff->name = $this->connection->quoteIdentifier($tableDiff->name);
+               }
+
+               $connection->beginTransaction();
+               foreach ($schemaDiff->toSql($connection->getDatabasePlatform()) as $sql) {
+                       $connection->query($sql);
+               }
+               $connection->commit();
+       }
+
+       /**
+        * @param string $sourceName
+        * @param string $targetName
+        */
+       protected function copyTable($sourceName, $targetName) {
+               $quotedSource = $this->connection->quoteIdentifier($sourceName);
+               $quotedTarget = $this->connection->quoteIdentifier($targetName);
+
+               $this->connection->exec('CREATE TABLE ' . $quotedTarget . ' LIKE ' . $quotedSource);
+               $this->connection->exec('INSERT INTO ' . $quotedTarget . ' SELECT * FROM ' . $quotedSource);
+       }
+
+       /**
+        * @param string $name
+        */
+       protected function dropTable($name) {
+               $this->connection->exec('DROP TABLE ' . $this->connection->quoteIdentifier($name));
+       }
+}

diff --git a/tests/lib/db/migrator.php b/tests/lib/db/migrator.php
new file mode 100644 (file)
index 0000000..ed7c36d
--- /dev/null
+++ b/tests/lib/db/migrator.php
@@ -0,0 +1,84 @@
+<?php
+
+/**
+ * Copyright (c) 2014 Robin Appelman <icewind@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace Test\DB;
+
+use \Doctrine\DBAL\Schema\Schema;
+use \Doctrine\DBAL\Schema\SchemaConfig;
+
+class Migrator extends \PHPUnit_Framework_TestCase {
+       /**
+        * @var \Doctrine\DBAL\Connection $connection
+        */
+       private $connection;
+
+       private $tableName;
+
+       public function setUp() {
+               $this->tableName = 'test_' . uniqid();
+               $this->connection = \OC_DB::getConnection();
+               $this->tableName = $this->connection->getDatabase() . '.' . $this->tableName;
+       }
+
+       public function tearDown() {
+               $this->connection->exec('DROP TABLE ' . $this->tableName);
+       }
+
+       private function getInitialSchema() {
+               $schema = new Schema(array(), array(), $this->getSchemaConfig());
+               $table = $schema->createTable($this->tableName);
+               $table->addColumn('id', 'integer');
+               $table->addColumn('name', 'string');
+               return $schema;
+       }
+
+       private function getNewSchema() {
+               $schema = new Schema(array(), array(), $this->getSchemaConfig());
+               $table = $schema->createTable($this->tableName);
+               $table->addColumn('id', 'integer');
+               $table->addColumn('name', 'string');
+               $table->addUniqueIndex(array('id'));
+               return $schema;
+       }
+
+       private function getSchemaConfig() {
+               $config = new SchemaConfig();
+               $config->setName($this->connection->getDatabase());
+               return $config;
+       }
+
+       /**
+        * @expectedException \OC\DB\MigrationException
+        */
+       public function testDuplicateKeyUpgrade() {
+               $migrator = new \OC\DB\Migrator($this->connection);
+               $migrator->migrate($this->getInitialSchema());
+
+               $this->connection->insert($this->tableName, array('id' => 1, 'name' => 'foo'));
+               $this->connection->insert($this->tableName, array('id' => 2, 'name' => 'bar'));
+               $this->connection->insert($this->tableName, array('id' => 2, 'name' => 'qwerty'));
+
+               $migrator->checkMigrate($this->getNewSchema());
+               $this->fail('checkMigrate should have failed');
+       }
+
+       public function testUpgrade() {
+               $migrator = new \OC\DB\Migrator($this->connection);
+               $migrator->migrate($this->getInitialSchema());
+
+               $this->connection->insert($this->tableName, array('id' => 1, 'name' => 'foo'));
+               $this->connection->insert($this->tableName, array('id' => 2, 'name' => 'bar'));
+               $this->connection->insert($this->tableName, array('id' => 3, 'name' => 'qwerty'));
+
+               $newSchema = $this->getNewSchema();
+               $migrator->checkMigrate($newSchema);
+               $migrator->migrate($newSchema);
+               $this->assertTrue(true);
+       }
+}