--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/program/lib/Roundcube/rcube_db.php	Thu Jan 04 15:52:31 2018 -0500
@@ -0,0 +1,1389 @@
+<?php
+
+/**
+ +-----------------------------------------------------------------------+
+ | This file is part of the Roundcube Webmail client                     |
+ | Copyright (C) 2005-2012, The Roundcube Dev Team                       |
+ |                                                                       |
+ | Licensed under the GNU General Public License version 3 or            |
+ | any later version with exceptions for skins & plugins.                |
+ | See the README file for a full license statement.                     |
+ |                                                                       |
+ | PURPOSE:                                                              |
+ |   Database wrapper class that implements PHP PDO functions            |
+ +-----------------------------------------------------------------------+
+ | Author: Aleksander Machniak <alec@alec.pl>                            |
+ +-----------------------------------------------------------------------+
+*/
+
+/**
+ * Database independent query interface.
+ * This is a wrapper for the PHP PDO.
+ *
+ * @package   Framework
+ * @subpackage Database
+ */
+class rcube_db
+{
+    public $db_provider;
+
+    protected $db_dsnw;               // DSN for write operations
+    protected $db_dsnr;               // DSN for read operations
+    protected $db_connected = false;  // Already connected ?
+    protected $db_mode;               // Connection mode
+    protected $dbh;                   // Connection handle
+    protected $dbhs = array();
+    protected $table_connections = array();
+
+    protected $db_error     = false;
+    protected $db_error_msg = '';
+    protected $conn_failure = false;
+    protected $db_index     = 0;
+    protected $last_result;
+    protected $tables;
+    protected $variables;
+
+    protected $options = array(
+        // column/table quotes
+        'identifier_start' => '"',
+        'identifier_end'   => '"',
+        // date/time input format
+        'datetime_format'  => 'Y-m-d H:i:s',
+    );
+
+    const DEBUG_LINE_LENGTH = 4096;
+    const DEFAULT_QUOTE     = '`';
+
+    /**
+     * Factory, returns driver-specific instance of the class
+     *
+     * @param string $db_dsnw DSN for read/write operations
+     * @param string $db_dsnr Optional DSN for read only operations
+     * @param bool   $pconn   Enables persistent connections
+     *
+     * @return rcube_db Object instance
+     */
+    public static function factory($db_dsnw, $db_dsnr = '', $pconn = false)
+    {
+        $driver     = strtolower(substr($db_dsnw, 0, strpos($db_dsnw, ':')));
+        $driver_map = array(
+            'sqlite2' => 'sqlite',
+            'sybase'  => 'mssql',
+            'dblib'   => 'mssql',
+            'mysqli'  => 'mysql',
+            'oci'     => 'oracle',
+            'oci8'    => 'oracle',
+        );
+
+        $driver = isset($driver_map[$driver]) ? $driver_map[$driver] : $driver;
+        $class  = "rcube_db_$driver";
+
+        if (!$driver || !class_exists($class)) {
+            rcube::raise_error(array('code' => 600, 'type' => 'db',
+                'line' => __LINE__, 'file' => __FILE__,
+                'message' => "Configuration error. Unsupported database driver: $driver"),
+                true, true);
+        }
+
+        return new $class($db_dsnw, $db_dsnr, $pconn);
+    }
+
+    /**
+     * Object constructor
+     *
+     * @param string $db_dsnw DSN for read/write operations
+     * @param string $db_dsnr Optional DSN for read only operations
+     * @param bool   $pconn   Enables persistent connections
+     */
+    public function __construct($db_dsnw, $db_dsnr = '', $pconn = false)
+    {
+        if (empty($db_dsnr)) {
+            $db_dsnr = $db_dsnw;
+        }
+
+        $this->db_dsnw  = $db_dsnw;
+        $this->db_dsnr  = $db_dsnr;
+        $this->db_pconn = $pconn;
+
+        $this->db_dsnw_array = self::parse_dsn($db_dsnw);
+        $this->db_dsnr_array = self::parse_dsn($db_dsnr);
+
+        $config = rcube::get_instance()->config;
+
+        $this->options['table_prefix']  = $config->get('db_prefix');
+        $this->options['dsnw_noread']   = $config->get('db_dsnw_noread', false);
+        $this->options['table_dsn_map'] = array_map(array($this, 'table_name'), $config->get('db_table_dsn', array()));
+    }
+
+    /**
+     * Connect to specific database
+     *
+     * @param array  $dsn  DSN for DB connections
+     * @param string $mode Connection mode (r|w)
+     */
+    protected function dsn_connect($dsn, $mode)
+    {
+        $this->db_error     = false;
+        $this->db_error_msg = null;
+
+        // return existing handle
+        if ($this->dbhs[$mode]) {
+            $this->dbh = $this->dbhs[$mode];
+            $this->db_mode = $mode;
+            return $this->dbh;
+        }
+
+        // connect to database
+        if ($dbh = $this->conn_create($dsn)) {
+            $this->dbh          = $dbh;
+            $this->dbhs[$mode]  = $dbh;
+            $this->db_mode      = $mode;
+            $this->db_connected = true;
+        }
+    }
+
+    /**
+     * Create PDO connection
+     */
+    protected function conn_create($dsn)
+    {
+        // Get database specific connection options
+        $dsn_string  = $this->dsn_string($dsn);
+        $dsn_options = $this->dsn_options($dsn);
+
+        // Connect
+        try {
+            // with this check we skip fatal error on PDO object creation
+            if (!class_exists('PDO', false)) {
+                throw new Exception('PDO extension not loaded. See http://php.net/manual/en/intro.pdo.php');
+            }
+
+            $this->conn_prepare($dsn);
+
+            $dbh = new PDO($dsn_string, $dsn['username'], $dsn['password'], $dsn_options);
+
+            // don't throw exceptions or warnings
+            $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT);
+
+            $this->conn_configure($dsn, $dbh);
+        }
+        catch (Exception $e) {
+            $this->db_error     = true;
+            $this->db_error_msg = $e->getMessage();
+
+            rcube::raise_error(array('code' => 500, 'type' => 'db',
+                'line' => __LINE__, 'file' => __FILE__,
+                'message' => $this->db_error_msg), true, false);
+
+            return null;
+        }
+
+        return $dbh;
+    }
+
+    /**
+     * Driver-specific preparation of database connection
+     *
+     * @param array $dsn DSN for DB connections
+     */
+    protected function conn_prepare($dsn)
+    {
+    }
+
+    /**
+     * Driver-specific configuration of database connection
+     *
+     * @param array $dsn DSN for DB connections
+     * @param PDO   $dbh Connection handler
+     */
+    protected function conn_configure($dsn, $dbh)
+    {
+    }
+
+    /**
+     * Connect to appropriate database depending on the operation
+     *
+     * @param string  $mode  Connection mode (r|w)
+     * @param boolean $force Enforce using the given mode
+     */
+    public function db_connect($mode, $force = false)
+    {
+        // previous connection failed, don't attempt to connect again
+        if ($this->conn_failure) {
+            return;
+        }
+
+        // no replication
+        if ($this->db_dsnw == $this->db_dsnr) {
+            $mode = 'w';
+        }
+
+        // Already connected
+        if ($this->db_connected) {
+            // connected to db with the same or "higher" mode (if allowed)
+            if ($this->db_mode == $mode || $this->db_mode == 'w' && !$force && !$this->options['dsnw_noread']) {
+                return;
+            }
+        }
+
+        $dsn = ($mode == 'r') ? $this->db_dsnr_array : $this->db_dsnw_array;
+        $this->dsn_connect($dsn, $mode);
+
+        // use write-master when read-only fails
+        if (!$this->db_connected && $mode == 'r' && $this->is_replicated()) {
+            $this->dsn_connect($this->db_dsnw_array, 'w');
+        }
+
+        $this->conn_failure = !$this->db_connected;
+    }
+
+    /**
+     * Analyze the given SQL statement and select the appropriate connection to use
+     */
+    protected function dsn_select($query)
+    {
+        // no replication
+        if ($this->db_dsnw == $this->db_dsnr) {
+            return 'w';
+        }
+
+        // Read or write ?
+        $mode = preg_match('/^(select|show|set)/i', $query) ? 'r' : 'w';
+
+        $start = '[' . $this->options['identifier_start'] . self::DEFAULT_QUOTE . ']';
+        $end   = '[' . $this->options['identifier_end']   . self::DEFAULT_QUOTE . ']';
+        $regex = '/(?:^|\s)(from|update|into|join)\s+'.$start.'?([a-z0-9._]+)'.$end.'?\s+/i';
+
+        // find tables involved in this query
+        if (preg_match_all($regex, $query, $matches, PREG_SET_ORDER)) {
+            foreach ($matches as $m) {
+                $table = $m[2];
+
+                // always use direct mapping
+                if ($this->options['table_dsn_map'][$table]) {
+                    $mode = $this->options['table_dsn_map'][$table];
+                    break;  // primary table rules
+                }
+                else if ($mode == 'r') {
+                    // connected to db with the same or "higher" mode for this table
+                    $db_mode = $this->table_connections[$table];
+                    if ($db_mode == 'w' && !$this->options['dsnw_noread']) {
+                        $mode = $db_mode;
+                    }
+                }
+            }
+
+            // remember mode chosen (for primary table)
+            $table = $matches[0][2];
+            $this->table_connections[$table] = $mode;
+        }
+
+        return $mode;
+    }
+
+    /**
+     * Activate/deactivate debug mode
+     *
+     * @param boolean $dbg True if SQL queries should be logged
+     */
+    public function set_debug($dbg = true)
+    {
+        $this->options['debug_mode'] = $dbg;
+    }
+
+    /**
+     * Writes debug information/query to 'sql' log file
+     *
+     * @param string $query SQL query
+     */
+    protected function debug($query)
+    {
+        if ($this->options['debug_mode']) {
+            if (($len = strlen($query)) > self::DEBUG_LINE_LENGTH) {
+                $diff  = $len - self::DEBUG_LINE_LENGTH;
+                $query = substr($query, 0, self::DEBUG_LINE_LENGTH)
+                    . "... [truncated $diff bytes]";
+            }
+            rcube::write_log('sql', '[' . (++$this->db_index) . '] ' . $query . ';');
+        }
+    }
+
+    /**
+     * Getter for error state
+     *
+     * @param mixed $result Optional query result
+     *
+     * @return string Error message
+     */
+    public function is_error($result = null)
+    {
+        if ($result !== null) {
+            return $result === false ? $this->db_error_msg : null;
+        }
+
+        return $this->db_error ? $this->db_error_msg : null;
+    }
+
+    /**
+     * Connection state checker
+     *
+     * @return boolean True if in connected state
+     */
+    public function is_connected()
+    {
+        return !is_object($this->dbh) ? false : $this->db_connected;
+    }
+
+    /**
+     * Is database replication configured?
+     *
+     * @return bool Returns true if dsnw != dsnr
+     */
+    public function is_replicated()
+    {
+      return !empty($this->db_dsnr) && $this->db_dsnw != $this->db_dsnr;
+    }
+
+    /**
+     * Get database runtime variables
+     *
+     * @param string $varname Variable name
+     * @param mixed  $default Default value if variable is not set
+     *
+     * @return mixed Variable value or default
+     */
+    public function get_variable($varname, $default = null)
+    {
+        // to be implemented by driver class
+        return rcube::get_instance()->config->get('db_' . $varname, $default);
+    }
+
+    /**
+     * Execute a SQL query
+     *
+     * @param string SQL query to execute
+     * @param mixed  Values to be inserted in query
+     *
+     * @return number  Query handle identifier
+     */
+    public function query()
+    {
+        $params = func_get_args();
+        $query = array_shift($params);
+
+        // Support one argument of type array, instead of n arguments
+        if (count($params) == 1 && is_array($params[0])) {
+            $params = $params[0];
+        }
+
+        return $this->_query($query, 0, 0, $params);
+    }
+
+    /**
+     * Execute a SQL query with limits
+     *
+     * @param string SQL query to execute
+     * @param int    Offset for LIMIT statement
+     * @param int    Number of rows for LIMIT statement
+     * @param mixed  Values to be inserted in query
+     *
+     * @return PDOStatement|bool Query handle or False on error
+     */
+    public function limitquery()
+    {
+        $params  = func_get_args();
+        $query   = array_shift($params);
+        $offset  = array_shift($params);
+        $numrows = array_shift($params);
+
+        return $this->_query($query, $offset, $numrows, $params);
+    }
+
+    /**
+     * Execute a SQL query with limits
+     *
+     * @param string $query   SQL query to execute
+     * @param int    $offset  Offset for LIMIT statement
+     * @param int    $numrows Number of rows for LIMIT statement
+     * @param array  $params  Values to be inserted in query
+     *
+     * @return PDOStatement|bool Query handle or False on error
+     */
+    protected function _query($query, $offset, $numrows, $params)
+    {
+        $query = ltrim($query);
+
+        $this->db_connect($this->dsn_select($query), true);
+
+        // check connection before proceeding
+        if (!$this->is_connected()) {
+            return $this->last_result = false;
+        }
+
+        if ($numrows || $offset) {
+            $query = $this->set_limit($query, $numrows, $offset);
+        }
+
+        // replace self::DEFAULT_QUOTE with driver-specific quoting
+        $query = $this->query_parse($query);
+
+        // Because in Roundcube we mostly use queries that are
+        // executed only once, we will not use prepared queries
+        $pos = 0;
+        $idx = 0;
+
+        if (count($params)) {
+            while ($pos = strpos($query, '?', $pos)) {
+                if ($query[$pos+1] == '?') {  // skip escaped '?'
+                    $pos += 2;
+                }
+                else {
+                    $val = $this->quote($params[$idx++]);
+                    unset($params[$idx-1]);
+                    $query = substr_replace($query, $val, $pos, 1);
+                    $pos += strlen($val);
+                }
+            }
+        }
+
+        $query = rtrim($query, " \t\n\r\0\x0B;");
+
+        // replace escaped '?' and quotes back to normal, see self::quote()
+        $query = str_replace(
+            array('??', self::DEFAULT_QUOTE.self::DEFAULT_QUOTE),
+            array('?', self::DEFAULT_QUOTE),
+            $query
+        );
+
+        // log query
+        $this->debug($query);
+
+        return $this->query_execute($query);
+    }
+
+    /**
+     * Query execution
+     */
+    protected function query_execute($query)
+    {
+        // destroy reference to previous result, required for SQLite driver (#1488874)
+        $this->last_result  = null;
+        $this->db_error_msg = null;
+
+        // send query
+        $result = $this->dbh->query($query);
+
+        if ($result === false) {
+            $result = $this->handle_error($query);
+        }
+
+        return $this->last_result = $result;
+    }
+
+    /**
+     * Parse SQL query and replace identifier quoting
+     *
+     * @param string $query SQL query
+     *
+     * @return string SQL query
+     */
+    protected function query_parse($query)
+    {
+        $start = $this->options['identifier_start'];
+        $end   = $this->options['identifier_end'];
+        $quote = self::DEFAULT_QUOTE;
+
+        if ($start == $quote) {
+            return $query;
+        }
+
+        $pos = 0;
+        $in  = false;
+
+        while ($pos = strpos($query, $quote, $pos)) {
+            if ($query[$pos+1] == $quote) {  // skip escaped quote
+                $pos += 2;
+            }
+            else {
+                if ($in) {
+                    $q  = $end;
+                    $in = false;
+                }
+                else {
+                    $q  = $start;
+                    $in = true;
+                }
+
+                $query = substr_replace($query, $q, $pos, 1);
+                $pos++;
+            }
+        }
+
+        return $query;
+    }
+
+    /**
+     * Helper method to handle DB errors.
+     * This by default logs the error but could be overridden by a driver implementation
+     *
+     * @param string $query Query that triggered the error
+     *
+     * @return mixed Result to be stored and returned
+     */
+    protected function handle_error($query)
+    {
+        $error = $this->dbh->errorInfo();
+
+        if (empty($this->options['ignore_key_errors']) || !in_array($error[0], array('23000', '23505'))) {
+            $this->db_error = true;
+            $this->db_error_msg = sprintf('[%s] %s', $error[1], $error[2]);
+
+            if (empty($this->options['ignore_errors'])) {
+                rcube::raise_error(array(
+                        'code' => 500, 'type' => 'db', 'line' => __LINE__, 'file' => __FILE__,
+                        'message' => $this->db_error_msg . " (SQL Query: $query)"
+                    ), true, false);
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Get number of affected rows for the last query
+     *
+     * @param mixed $result Optional query handle
+     *
+     * @return int Number of (matching) rows
+     */
+    public function affected_rows($result = null)
+    {
+        if ($result || ($result === null && ($result = $this->last_result))) {
+            if ($result !== true) {
+                return $result->rowCount();
+            }
+        }
+
+        return 0;
+    }
+
+    /**
+     * Get number of rows for a SQL query
+     * If no query handle is specified, the last query will be taken as reference
+     *
+     * @param mixed $result Optional query handle
+     *
+     * @return mixed Number of rows or false on failure
+     * @deprecated This method shows very poor performance and should be avoided.
+     */
+    public function num_rows($result = null)
+    {
+        if (($result || ($result === null && ($result = $this->last_result))) && $result !== true) {
+            // repeat query with SELECT COUNT(*) ...
+            if (preg_match('/^SELECT\s+(?:ALL\s+|DISTINCT\s+)?(?:.*?)\s+FROM\s+(.*)$/ims', $result->queryString, $m)) {
+                $query = $this->dbh->query('SELECT COUNT(*) FROM ' . $m[1], PDO::FETCH_NUM);
+                return $query ? intval($query->fetchColumn(0)) : false;
+            }
+            else {
+                $num = count($result->fetchAll());
+                $result->execute();  // re-execute query because there's no seek(0)
+                return $num;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Get last inserted record ID
+     *
+     * @param string $table Table name (to find the incremented sequence)
+     *
+     * @return mixed ID or false on failure
+     */
+    public function insert_id($table = '')
+    {
+        if (!$this->db_connected || $this->db_mode == 'r') {
+            return false;
+        }
+
+        if ($table) {
+            // resolve table name
+            $table = $this->table_name($table);
+        }
+
+        $id = $this->dbh->lastInsertId($table);
+
+        return $id;
+    }
+
+    /**
+     * Get an associative array for one row
+     * If no query handle is specified, the last query will be taken as reference
+     *
+     * @param mixed $result Optional query handle
+     *
+     * @return mixed Array with col values or false on failure
+     */
+    public function fetch_assoc($result = null)
+    {
+        return $this->_fetch_row($result, PDO::FETCH_ASSOC);
+    }
+
+    /**
+     * Get an index array for one row
+     * If no query handle is specified, the last query will be taken as reference
+     *
+     * @param mixed $result Optional query handle
+     *
+     * @return mixed Array with col values or false on failure
+     */
+    public function fetch_array($result = null)
+    {
+        return $this->_fetch_row($result, PDO::FETCH_NUM);
+    }
+
+    /**
+     * Get col values for a result row
+     *
+     * @param mixed $result Optional query handle
+     * @param int   $mode   Fetch mode identifier
+     *
+     * @return mixed Array with col values or false on failure
+     */
+    protected function _fetch_row($result, $mode)
+    {
+        if ($result || ($result === null && ($result = $this->last_result))) {
+            if ($result !== true) {
+                return $result->fetch($mode);
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Adds LIMIT,OFFSET clauses to the query
+     *
+     * @param string $query  SQL query
+     * @param int    $limit  Number of rows
+     * @param int    $offset Offset
+     *
+     * @return string SQL query
+     */
+    protected function set_limit($query, $limit = 0, $offset = 0)
+    {
+        if ($limit) {
+            $query .= ' LIMIT ' . intval($limit);
+        }
+
+        if ($offset) {
+            $query .= ' OFFSET ' . intval($offset);
+        }
+
+        return $query;
+    }
+
+    /**
+     * Returns list of tables in a database
+     *
+     * @return array List of all tables of the current database
+     */
+    public function list_tables()
+    {
+        // get tables if not cached
+        if ($this->tables === null) {
+            $q = $this->query("SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES"
+                . " WHERE TABLE_TYPE = 'BASE TABLE'"
+                . " ORDER BY TABLE_NAME");
+
+            $this->tables = $q ? $q->fetchAll(PDO::FETCH_COLUMN, 0) : array();
+        }
+
+        return $this->tables;
+    }
+
+    /**
+     * Returns list of columns in database table
+     *
+     * @param string $table Table name
+     *
+     * @return array List of table cols
+     */
+    public function list_cols($table)
+    {
+        $q = $this->query('SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = ?',
+            array($table));
+
+        if ($q) {
+            return $q->fetchAll(PDO::FETCH_COLUMN, 0);
+        }
+
+        return array();
+    }
+
+    /**
+     * Start transaction
+     *
+     * @return bool True on success, False on failure
+     */
+    public function startTransaction()
+    {
+        $this->db_connect('w', true);
+
+        // check connection before proceeding
+        if (!$this->is_connected()) {
+            return $this->last_result = false;
+        }
+
+        $this->debug('BEGIN TRANSACTION');
+
+        return $this->last_result = $this->dbh->beginTransaction();
+    }
+
+    /**
+     * Commit transaction
+     *
+     * @return bool True on success, False on failure
+     */
+    public function endTransaction()
+    {
+        $this->db_connect('w', true);
+
+        // check connection before proceeding
+        if (!$this->is_connected()) {
+            return $this->last_result = false;
+        }
+
+        $this->debug('COMMIT TRANSACTION');
+
+        return $this->last_result = $this->dbh->commit();
+    }
+
+    /**
+     * Rollback transaction
+     *
+     * @return bool True on success, False on failure
+     */
+    public function rollbackTransaction()
+    {
+        $this->db_connect('w', true);
+
+        // check connection before proceeding
+        if (!$this->is_connected()) {
+            return $this->last_result = false;
+        }
+
+        $this->debug('ROLLBACK TRANSACTION');
+
+        return $this->last_result = $this->dbh->rollBack();
+    }
+
+    /**
+     * Release resources related to the last query result.
+     * When we know we don't need to access the last query result we can destroy it
+     * and release memory. Useful especially if the query returned big chunk of data.
+     */
+    public function reset()
+    {
+        $this->last_result = null;
+    }
+
+    /**
+     * Terminate database connection.
+     */
+    public function closeConnection()
+    {
+        $this->db_connected = false;
+        $this->db_index     = 0;
+
+        // release statement and connection resources
+        $this->last_result  = null;
+        $this->dbh          = null;
+        $this->dbhs         = array();
+    }
+
+    /**
+     * Formats input so it can be safely used in a query
+     *
+     * @param mixed  $input Value to quote
+     * @param string $type  Type of data (integer, bool, ident)
+     *
+     * @return string Quoted/converted string for use in query
+     */
+    public function quote($input, $type = null)
+    {
+        // handle int directly for better performance
+        if ($type == 'integer' || $type == 'int') {
+            return intval($input);
+        }
+
+        if (is_null($input)) {
+            return 'NULL';
+        }
+
+        if ($input instanceof DateTime) {
+            return $this->quote($input->format($this->options['datetime_format']));
+        }
+
+        if ($type == 'ident') {
+            return $this->quote_identifier($input);
+        }
+
+        // create DB handle if not available
+        if (!$this->dbh) {
+            $this->db_connect('r');
+        }
+
+        if ($this->dbh) {
+            $map = array(
+                'bool'    => PDO::PARAM_BOOL,
+                'integer' => PDO::PARAM_INT,
+            );
+
+            $type = isset($map[$type]) ? $map[$type] : PDO::PARAM_STR;
+
+            return strtr($this->dbh->quote($input, $type),
+                // escape ? and `
+                array('?' => '??', self::DEFAULT_QUOTE => self::DEFAULT_QUOTE.self::DEFAULT_QUOTE)
+            );
+        }
+
+        return 'NULL';
+    }
+
+    /**
+     * Escapes a string so it can be safely used in a query
+     *
+     * @param string $str A string to escape
+     *
+     * @return string Escaped string for use in a query
+     */
+    public function escape($str)
+    {
+        if (is_null($str)) {
+            return 'NULL';
+        }
+
+        return substr($this->quote($str), 1, -1);
+    }
+
+    /**
+     * Quotes a string so it can be safely used as a table or column name
+     *
+     * @param string $str Value to quote
+     *
+     * @return string Quoted string for use in query
+     * @deprecated    Replaced by rcube_db::quote_identifier
+     * @see           rcube_db::quote_identifier
+     */
+    public function quoteIdentifier($str)
+    {
+        return $this->quote_identifier($str);
+    }
+
+    /**
+     * Escapes a string so it can be safely used in a query
+     *
+     * @param string $str A string to escape
+     *
+     * @return string Escaped string for use in a query
+     * @deprecated    Replaced by rcube_db::escape
+     * @see           rcube_db::escape
+     */
+    public function escapeSimple($str)
+    {
+        return $this->escape($str);
+    }
+
+    /**
+     * Quotes a string so it can be safely used as a table or column name
+     *
+     * @param string $str Value to quote
+     *
+     * @return string Quoted string for use in query
+     */
+    public function quote_identifier($str)
+    {
+        $start = $this->options['identifier_start'];
+        $end   = $this->options['identifier_end'];
+        $name  = array();
+
+        foreach (explode('.', $str) as $elem) {
+            $elem = str_replace(array($start, $end), '', $elem);
+            $name[] = $start . $elem . $end;
+        }
+
+        return implode($name, '.');
+    }
+
+    /**
+     * Return SQL function for current time and date
+     *
+     * @param int $interval Optional interval (in seconds) to add/subtract
+     *
+     * @return string SQL function to use in query
+     */
+    public function now($interval = 0)
+    {
+        if ($interval) {
+            $add = ' ' . ($interval > 0 ? '+' : '-') . ' INTERVAL ';
+            $add .= $interval > 0 ? intval($interval) : intval($interval) * -1;
+            $add .= ' SECOND';
+        }
+
+        return "now()" . $add;
+    }
+
+    /**
+     * Return list of elements for use with SQL's IN clause
+     *
+     * @param array  $arr  Input array
+     * @param string $type Type of data (integer, bool, ident)
+     *
+     * @return string Comma-separated list of quoted values for use in query
+     */
+    public function array2list($arr, $type = null)
+    {
+        if (!is_array($arr)) {
+            return $this->quote($arr, $type);
+        }
+
+        foreach ($arr as $idx => $item) {
+            $arr[$idx] = $this->quote($item, $type);
+        }
+
+        return implode(',', $arr);
+    }
+
+    /**
+     * Return SQL statement to convert a field value into a unix timestamp
+     *
+     * This method is deprecated and should not be used anymore due to limitations
+     * of timestamp functions in Mysql (year 2038 problem)
+     *
+     * @param string $field Field name
+     *
+     * @return string  SQL statement to use in query
+     * @deprecated
+     */
+    public function unixtimestamp($field)
+    {
+        return "UNIX_TIMESTAMP($field)";
+    }
+
+    /**
+     * Return SQL statement to convert from a unix timestamp
+     *
+     * @param int $timestamp Unix timestamp
+     *
+     * @return string Date string in db-specific format
+     * @deprecated
+     */
+    public function fromunixtime($timestamp)
+    {
+        return $this->quote(date($this->options['datetime_format'], $timestamp));
+    }
+
+    /**
+     * Return SQL statement for case insensitive LIKE
+     *
+     * @param string $column Field name
+     * @param string $value  Search value
+     *
+     * @return string SQL statement to use in query
+     */
+    public function ilike($column, $value)
+    {
+        return $this->quote_identifier($column).' LIKE '.$this->quote($value);
+    }
+
+    /**
+     * Abstract SQL statement for value concatenation
+     *
+     * @return string SQL statement to be used in query
+     */
+    public function concat(/* col1, col2, ... */)
+    {
+        $args = func_get_args();
+        if (is_array($args[0])) {
+            $args = $args[0];
+        }
+
+        return '(' . join(' || ', $args) . ')';
+    }
+
+    /**
+     * Encodes non-UTF-8 characters in string/array/object (recursive)
+     *
+     * @param mixed $input      Data to fix
+     * @param bool  $serialized Enable serialization
+     *
+     * @return mixed Properly UTF-8 encoded data
+     */
+    public static function encode($input, $serialized = false)
+    {
+        // use Base64 encoding to workaround issues with invalid
+        // or null characters in serialized string (#1489142)
+        if ($serialized) {
+            return base64_encode(serialize($input));
+        }
+
+        if (is_object($input)) {
+            foreach (get_object_vars($input) as $idx => $value) {
+                $input->$idx = self::encode($value);
+            }
+            return $input;
+        }
+        else if (is_array($input)) {
+            foreach ($input as $idx => $value) {
+                $input[$idx] = self::encode($value);
+            }
+
+            return $input;
+        }
+
+        return utf8_encode($input);
+    }
+
+    /**
+     * Decodes encoded UTF-8 string/object/array (recursive)
+     *
+     * @param mixed $input      Input data
+     * @param bool  $serialized Enable serialization
+     *
+     * @return mixed Decoded data
+     */
+    public static function decode($input, $serialized = false)
+    {
+        // use Base64 encoding to workaround issues with invalid
+        // or null characters in serialized string (#1489142)
+        if ($serialized) {
+            // Keep backward compatybility where base64 wasn't used
+            if (strpos(substr($input, 0, 16), ':') !== false) {
+                return self::decode(@unserialize($input));
+            }
+
+            return @unserialize(base64_decode($input));
+        }
+
+        if (is_object($input)) {
+            foreach (get_object_vars($input) as $idx => $value) {
+                $input->$idx = self::decode($value);
+            }
+            return $input;
+        }
+        else if (is_array($input)) {
+            foreach ($input as $idx => $value) {
+                $input[$idx] = self::decode($value);
+            }
+            return $input;
+        }
+
+        return utf8_decode($input);
+    }
+
+    /**
+     * Return correct name for a specific database table
+     *
+     * @param string $table  Table name
+     * @param bool   $quoted Quote table identifier
+     *
+     * @return string Translated table name
+     */
+    public function table_name($table, $quoted = false)
+    {
+        // let plugins alter the table name (#1489837)
+        $plugin = rcube::get_instance()->plugins->exec_hook('db_table_name', array('table' => $table));
+        $table = $plugin['table'];
+
+        // add prefix to the table name if configured
+        if (($prefix = $this->options['table_prefix']) && strpos($table, $prefix) !== 0) {
+            $table = $prefix . $table;
+        }
+
+        if ($quoted) {
+            $table = $this->quote_identifier($table);
+        }
+
+        return $table;
+    }
+
+    /**
+     * Set class option value
+     *
+     * @param string $name  Option name
+     * @param mixed  $value Option value
+     */
+    public function set_option($name, $value)
+    {
+        $this->options[$name] = $value;
+    }
+
+    /**
+     * Set DSN connection to be used for the given table
+     *
+     * @param string $table Table name
+     * @param string $mode  DSN connection ('r' or 'w') to be used
+     */
+    public function set_table_dsn($table, $mode)
+    {
+        $this->options['table_dsn_map'][$this->table_name($table)] = $mode;
+    }
+
+    /**
+     * MDB2 DSN string parser
+     *
+     * @param string $sequence Secuence name
+     *
+     * @return array DSN parameters
+     */
+    public static function parse_dsn($dsn)
+    {
+        if (empty($dsn)) {
+            return null;
+        }
+
+        // Find phptype and dbsyntax
+        if (($pos = strpos($dsn, '://')) !== false) {
+            $str = substr($dsn, 0, $pos);
+            $dsn = substr($dsn, $pos + 3);
+        }
+        else {
+            $str = $dsn;
+            $dsn = null;
+        }
+
+        // Get phptype and dbsyntax
+        // $str => phptype(dbsyntax)
+        if (preg_match('|^(.+?)\((.*?)\)$|', $str, $arr)) {
+            $parsed['phptype']  = $arr[1];
+            $parsed['dbsyntax'] = !$arr[2] ? $arr[1] : $arr[2];
+        }
+        else {
+            $parsed['phptype']  = $str;
+            $parsed['dbsyntax'] = $str;
+        }
+
+        if (empty($dsn)) {
+            return $parsed;
+        }
+
+        // Get (if found): username and password
+        // $dsn => username:password@protocol+hostspec/database
+        if (($at = strrpos($dsn,'@')) !== false) {
+            $str = substr($dsn, 0, $at);
+            $dsn = substr($dsn, $at + 1);
+            if (($pos = strpos($str, ':')) !== false) {
+                $parsed['username'] = rawurldecode(substr($str, 0, $pos));
+                $parsed['password'] = rawurldecode(substr($str, $pos + 1));
+            }
+            else {
+                $parsed['username'] = rawurldecode($str);
+            }
+        }
+
+        // Find protocol and hostspec
+
+        // $dsn => proto(proto_opts)/database
+        if (preg_match('|^([^(]+)\((.*?)\)/?(.*?)$|', $dsn, $match)) {
+            $proto       = $match[1];
+            $proto_opts  = $match[2] ? $match[2] : false;
+            $dsn         = $match[3];
+        }
+        // $dsn => protocol+hostspec/database (old format)
+        else {
+            if (strpos($dsn, '+') !== false) {
+                list($proto, $dsn) = explode('+', $dsn, 2);
+            }
+            if (   strpos($dsn, '//') === 0
+                && strpos($dsn, '/', 2) !== false
+                && $parsed['phptype'] == 'oci8'
+            ) {
+                //oracle's "Easy Connect" syntax:
+                //"username/password@[//]host[:port][/service_name]"
+                //e.g. "scott/tiger@//mymachine:1521/oracle"
+                $proto_opts = $dsn;
+                $pos = strrpos($proto_opts, '/');
+                $dsn = substr($proto_opts, $pos + 1);
+                $proto_opts = substr($proto_opts, 0, $pos);
+            }
+            else if (strpos($dsn, '/') !== false) {
+                list($proto_opts, $dsn) = explode('/', $dsn, 2);
+            }
+            else {
+                $proto_opts = $dsn;
+                $dsn = null;
+            }
+        }
+
+        // process the different protocol options
+        $parsed['protocol'] = $proto ?: 'tcp';
+        $proto_opts = rawurldecode($proto_opts);
+        if (strpos($proto_opts, ':') !== false) {
+            list($proto_opts, $parsed['port']) = explode(':', $proto_opts);
+        }
+        if ($parsed['protocol'] == 'tcp') {
+            $parsed['hostspec'] = $proto_opts;
+        }
+        else if ($parsed['protocol'] == 'unix') {
+            $parsed['socket'] = $proto_opts;
+        }
+
+        // Get dabase if any
+        // $dsn => database
+        if ($dsn) {
+            // /database
+            if (($pos = strpos($dsn, '?')) === false) {
+                $parsed['database'] = rawurldecode($dsn);
+            // /database?param1=value1&param2=value2
+            }
+            else {
+                $parsed['database'] = rawurldecode(substr($dsn, 0, $pos));
+                $dsn = substr($dsn, $pos + 1);
+                if (strpos($dsn, '&') !== false) {
+                    $opts = explode('&', $dsn);
+                }
+                else { // database?param1=value1
+                    $opts = array($dsn);
+                }
+                foreach ($opts as $opt) {
+                    list($key, $value) = explode('=', $opt);
+                    if (!array_key_exists($key, $parsed) || false === $parsed[$key]) {
+                        // don't allow params overwrite
+                        $parsed[$key] = rawurldecode($value);
+                    }
+                }
+            }
+        }
+
+        return $parsed;
+    }
+
+    /**
+     * Returns PDO DSN string from DSN array
+     *
+     * @param array $dsn DSN parameters
+     *
+     * @return string DSN string
+     */
+    protected function dsn_string($dsn)
+    {
+        $params = array();
+        $result = $dsn['phptype'] . ':';
+
+        if ($dsn['hostspec']) {
+            $params[] = 'host=' . $dsn['hostspec'];
+        }
+
+        if ($dsn['port']) {
+            $params[] = 'port=' . $dsn['port'];
+        }
+
+        if ($dsn['database']) {
+            $params[] = 'dbname=' . $dsn['database'];
+        }
+
+        if (!empty($params)) {
+            $result .= implode(';', $params);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Returns driver-specific connection options
+     *
+     * @param array $dsn DSN parameters
+     *
+     * @return array Connection options
+     */
+    protected function dsn_options($dsn)
+    {
+        $result = array();
+
+        if ($this->db_pconn) {
+            $result[PDO::ATTR_PERSISTENT] = true;
+        }
+
+        if (!empty($dsn['prefetch'])) {
+            $result[PDO::ATTR_PREFETCH] = (int) $dsn['prefetch'];
+        }
+
+        if (!empty($dsn['timeout'])) {
+            $result[PDO::ATTR_TIMEOUT] = (int) $dsn['timeout'];
+        }
+
+        return $result;
+    }
+
+    /**
+     * Execute the given SQL script
+     *
+     * @param string $sql SQL queries to execute
+     *
+     * @return boolen True on success, False on error
+     */
+    public function exec_script($sql)
+    {
+        $sql  = $this->fix_table_names($sql);
+        $buff = '';
+        $exec = '';
+
+        foreach (explode("\n", $sql) as $line) {
+            $trimmed = trim($line);
+            if ($trimmed == '' || preg_match('/^--/', $trimmed)) {
+                continue;
+            }
+
+            if ($trimmed == 'GO') {
+                $exec = $buff;
+            }
+            else if ($trimmed[strlen($trimmed)-1] == ';') {
+                $exec = $buff . substr(rtrim($line), 0, -1);
+            }
+
+            if ($exec) {
+                $this->query($exec);
+                $buff = '';
+                $exec = '';
+                if ($this->db_error) {
+                    break;
+                }
+            }
+            else {
+                $buff .= $line . "\n";
+            }
+        }
+
+        return !$this->db_error;
+    }
+
+    /**
+     * Parse SQL file and fix table names according to table prefix
+     */
+    protected function fix_table_names($sql)
+    {
+        if (!$this->options['table_prefix']) {
+            return $sql;
+        }
+
+        $sql = preg_replace_callback(
+            '/((TABLE|TRUNCATE|(?<!ON )UPDATE|INSERT INTO|FROM'
+            . '| ON(?! (DELETE|UPDATE))|REFERENCES|CONSTRAINT|FOREIGN KEY|INDEX)'
+            . '\s+(IF (NOT )?EXISTS )?[`"]*)([^`"\( \r\n]+)/',
+            array($this, 'fix_table_names_callback'),
+            $sql
+        );
+
+        return $sql;
+    }
+
+    /**
+     * Preg_replace callback for fix_table_names()
+     */
+    protected function fix_table_names_callback($matches)
+    {
+        return $matches[1] . $this->options['table_prefix'] . $matches[count($matches)-1];
+    }
+}