--- /cvsroot/moodle/moodle/admin/dbtransfer/lib.php
+++ /cvsroot/moodle/moodle/admin/dbtransfer/lib.php
@@ -0,0 +1,174 @@
+<?php
+require_once($CFG->libdir . '/xmldb/xmldb_structure.php');
+
+abstract class database_exporter {
+    protected $mdb;
+    protected $manager;
+    public function __construct(moodle_database $mdb = null) {
+        if(is_null($mdb)) {
+            global $DB;
+            $mdb = $DB;
+        }
+        $this->mdb = $mdb;
+        $this->manager = $mdb->get_manager();
+    }
+    
+    public function begin_database_export($description = NULL) {
+    }
+    
+    public function begin_table_export(xmldb_table $table) {
+    }
+    
+    public abstract function export_table_data(xmldb_table $table, $data);
+    
+    public function finish_table_export() {
+    }
+    
+    public function finish_database_export(){
+    }
+    
+    public function export_database(xmldb_structure $schema, $description = NULL) {
+        $this->begin_database_export($description);
+        $tables = $schema->getTables();
+        foreach($tables as $table) {
+            $this->export_table($table);
+        }
+        $this->finish_database_export();
+    }
+    
+    public function export_table(xmldb_table $table) {
+        $this->begin_table_export($table);
+        $rs = $this->mdb->get_recordset_sql('SELECT * FROM {' . $table->getName() . '}');
+        foreach($rs as $row) {
+            $this->export_table_data($table, $row);
+        }
+        $this->finish_table_export();
+    }
+}
+
+class DatabaseImporter {
+    protected $mdb;
+    protected $manager;
+    public function __construct(moodle_database $mdb = NULL) {
+        if(is_null($mdb)) {
+            global $DB;
+            $mdb = $DB;
+        }
+        $this->mdb = $mdb;
+        $this->manager = $mdb->get_manager();
+    }
+    
+    public function begin_database_import($version, $timestamp, $description = NULL) {
+    }
+    
+    public function begin_table_import(xmldb_table $table) {
+        if(!$this->manager->table_exists($table)) {
+            $this->manager->create_table($table);
+        }
+    }
+    
+    function import_table_data(xmldb_table $table, $data) {
+        $this->mdb->import_record($table->getName(), $data);
+    }
+    
+    public function finish_table_import() {
+    }
+    
+    public function finish_database_import(){
+    }
+    
+    public function import_database(xmldb_structure $schema, $description = NULL) {
+        $this->begin_database_export($description);
+        $tables = $structure->getTables();
+        foreach($tables as $table) {
+            $this->import_table($table);
+        }
+        $this->finish_database_export();
+    }
+    
+    public function import_table(xmldb_table $table) {
+        $this->begin_table_export($table);
+        $rs = $this->mdb->get_recordset_sql('SELECT * FROM {' . $table->getName() . '}');
+        foreach($rs as $row) {
+            $this->export_table_data($table, $row);
+        }
+        $this->finish_table_export();
+    }
+}
+
+abstract class xml_database_exporter extends database_exporter {
+    protected abstract function output($text);
+    
+    public function begin_database_export($description = NULL) {
+        global $CFG;
+        $this->output('<?xml version="1.0" encoding="utf-8"?>');
+        $this->output('<moodle_database xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
+version="' . $CFG->version . '" timestamp="'. date('c') .'"' . (empty($description) ? '' : ' comment="' . htmlspecialchars($description, ENT_QUOTES) . '"') . '>');
+    }
+
+    public function begin_table_export(xmldb_table $table) {
+        $this->output('<table name="'. $table->getName() . '" schemaHash="' . $table->getHash() . '">');
+    }
+    
+    public function export_table_data(xmldb_table $table, $data) {
+        $this->output('<record>');
+        foreach($data as $key=>$value) {
+            if(is_null($value)) {
+                $this->output('<field name="' . $key . '" value="null" />');
+            } else {
+                $this->output('<field name="' . $key . '">' . htmlspecialchars($value, ENT_NOQUOTES). '</field>');
+            }
+        }
+        $this->output('</record>');
+    }
+    
+    public function finish_table_export() {
+        $this->output('</table>');
+    }
+    
+    public function finish_database_export() {
+        $this->output('</moodle_database>');
+    }
+}
+
+class file_xml_database_exporter extends xml_database_exporter {
+    protected $filepath;
+    protected $file;
+    function __construct($filepath = NULL, moodle_database $mdb = NULL) {
+        parent::__construct($mdb);
+        if(is_null($filepath)) {
+            $filepath = 'php://output';
+        }
+        $this->filepath = $filepath;
+    }
+    
+    public function begin_database_export($description = NULL) {
+        $this->file = fopen($this->filepath, "w");
+        parent::begin_database_export($description);
+    }
+    
+    protected function output($text) {
+        fwrite($this->file, $text);
+    }
+    
+    public function finish_database_export() {
+        parent::finish_database_export();
+        fclose($this->file);
+    }
+}
+
+class string_xml_database_exporter extends xml_database_exporter {
+    protected $data;
+    public function begin_database_export($description = NULL) {
+        $this->data = '';
+        parent::begin_database_export($description);
+    }
+    
+    protected function output($text) {
+        $this->data .= $text;
+    }
+    
+    public function get_output() {
+        return $this->data;
+    }
+}