File indexing completed on 2025-01-26 03:44:37

 <?php
 /*
     SPDX-FileCopyrightText: 2016 Volker Krause <vkrause@kde.org>
 
     SPDX-License-Identifier: MIT
 */
 
 require_once('config.php');
 require_once('restexception.php');
 require_once('utils.php');
 
 /** Handles all database operations. */
 class DataStore {
 
 private $db;
 
 function __construct()
 {
     try {
         $conf = new Config;
         $this->db = new PDO($conf->dsn(), $conf->username(), $conf->password());
     } catch (PDOException $e) {
         throw new RESTException($e->getMessage(), 500);
     }
 }
 
 /** Returns the type of the database driver. */
 public function driver()
 {
     return $this->db->getAttribute(PDO::ATTR_DRIVER_NAME);
 }
 
 /** Access to the PDO handle. */
 public function pdoHandle()
 {
     return $this->db;
 }
 
 /** Prepare a query. */
 public function prepare($queryString)
 {
     try {
         $res = $this->db->prepare($queryString);
         $this->checkError($res);
     } catch (PDOException $e) {
         throw new RESTException($e->getMessage(), 500);
     }
     return $res;
 }
 
 /** Execute a prepared query and check the result for errors. */
 public function execute(PDOStatement $stmt)
 {
     try {
         if (!$stmt->execute()) {
             $err = $stmt->errorInfo();
             $msg = "SQL execution error: SQLSTATE: " . $err[0] . "\nDriver error code: " . $err[1] . "\nDriver error message: " . $err[2];
             throw new RESTException($msg, 500);
         }
     } catch (PDOException $e) {
         throw new RESTException($e->getMessage(), 500);
     }
 }
 
 /** Check database result for errors, and if so, bail out. */
 private function checkError($res)
 {
     if ($res === FALSE) {
         $err = $this->db->errorInfo();
         $msg = "SQLSTATE: " . $err[0] . "\nDriver error code: " . $err[1] . "\nDriver error message: " . $err[2];
         throw new RESTException($msg, 500);
     }
 }
 
 /** Begin transaction. */
 public function beginTransaction()
 {
     $this->db->beginTransaction();
 }
 
 /** Commit transaction. */
 public function commit()
 {
     $this->db->commit();
 }
 
 /** Abort an ongoing transaction. */
 public function rollback()
 {
     $this->db->rollback();
 }
 
 /** Verify the database schema, and fix if needed. */
 public function checkSchema()
 {
     $this->beginTransaction();
     $currentVersion = $this->schemaVersion();
     $schemaFile = __DIR__ . '/schema.json';
     $schemaDefs = json_decode(file_get_contents($schemaFile), true);
     $targetVersion = count($schemaDefs['schema']);
 
     $res = array();
     $res['previousSchemaVersion'] = $currentVersion;
     $res['currentSchemaVersion'] = $targetVersion;
 
     if ($currentVersion == $targetVersion)
         return $res;
     if ($currentVersion > $targetVersion || $currentVersion < 0)
         throw new RESTException('Current schema version is invalid: ' . $currentVersion . '.', 500);
 
     # apply database updates
     error_log('Current schema version: ' . $currentVersion . ' should be: ' . $targetVersion);
     for ($i = $currentVersion; $i < $targetVersion; $i++) {
         error_log("Applying update $i...");
         $this->applySchemaChange($schemaDefs['schema'][$i]);
     }
     $this->commit();
     return $res;
 }
 
 /** Returns the current schema version. */
 private function schemaVersion()
 {
     try {
         $res = $this->db->query('SELECT col_version FROM tbl_version');
         if ($res === FALSE) {
             // restart transaction, so this fail doesn't block the following commands
             $this->rollback();
             $this->beginTransaction();
             return 0;
         }
         foreach ($res as $row)
             return intval($row['col_version']);
     } catch (PDOException $e) {
         // table does not exist yet
     }
     return 0;
 }
 
 /** Applies a list of schema setup commands. */
 private function applySchemaChange($schemaDef)
 {
     if (array_key_exists($this->driver(), $schemaDef))
         $cmds = $schemaDef[$this->driver()];
     else
         $cmds = $schemaDef['sql'];
 
     foreach($cmds as $cmd) {
         $res = $this->db->exec($cmd);
         $this->checkError($res);
     }
     $res = $this->db->exec('UPDATE tbl_version SET col_version = ' . $schemaDef['version']);
     $this->checkError($res);
 }
 
 }
 
 ?>