shrink ldap_dn column to 4000

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

diff --git a/apps/user_ldap/lib/Migration/Version1141Date20220323143801.php b/apps/user_ldap/lib/Migration/Version1141Date20220323143801.php
new file mode 100644 (file)
index 0000000..8466346
--- /dev/null
+++ b/apps/user_ldap/lib/Migration/Version1141Date20220323143801.php
@@ -0,0 +1,117 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2022 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * 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
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\User_LDAP\Migration;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\IDBConnection;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+class Version1141Date20220323143801 extends SimpleMigrationStep {
+
+       private IDBConnection $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) {
+                       $dnsTooLong = [];
+                       $lengthExpr = $this->dbc->getDatabasePlatform()->getLengthExpression('ldap_dn');
+
+                       $qb = $this->dbc->getQueryBuilder();
+                       $qb->select('ldap_dn')
+                               ->from($tableName)
+                               ->where($qb->expr()->gt($qb->createFunction($lengthExpr), '255', IQueryBuilder::PARAM_INT));
+
+                       $result = $qb->executeQuery();
+                       while(($dn = $result->fetchOne()) !== false) {
+                               if(mb_strlen($dn) > 4000) {
+                                       $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')));
+
+               $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();
+
+               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;
+       }
+}