source: moodle/trunk/fuentes/admin/tool/dbtransfer/locallib.php @ 136

Last change on this file since 136 was 136, checked in by mabarracus, 4 years ago

Ported code to xenial

File size: 7.1 KB
Line 
1<?php
2// This file is part of Moodle - http://moodle.org/
3//
4// Moodle is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8//
9// Moodle is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12// GNU General Public License for more details.
13//
14// You should have received a copy of the GNU General Public License
15// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
16
17/**
18 * Export db content to file.
19 *
20 * @package    tool_dbtransfer
21 * @copyright  2008 Petr Skoda {@link http://skodak.org/}
22 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
23 */
24
25defined('MOODLE_INTERNAL') || die;
26/*
27
28TODO:
29  - exporting to server file >2GB fails in 32bit operating systems - needs warning
30  - we may run out of disk space exporting to server file - we must verify the file is not truncated; read from the end of file?
31  - when sending file >4GB - FAT32 limit, Apache limit, browser limit - needs warning
32  - there must be some form of progress bar during export, transfer - new tracking class could be passed around
33  - command line operation - could work around some 2G/4G limits in PHP; useful for cron full backups
34  - by default allow exporting into empty database only (no tables with the same prefix yet)
35  - all dangerous operation (like deleting of all data) should be confirmed by key found in special file in dataroot
36    (user would need file access to dataroot which might prevent various "accidents")
37  - implement "Export/import running" notification in lib/setup.php (similar to new upgrade flag in config table)
38  - gzip compression when storing xml file - the xml is very verbose and full of repeated tags (zip is not suitable here at all)
39    this could help us keep the files below 2G (expected ratio is > 10:1)
40
41*/
42
43require_once($CFG->libdir.'/adminlib.php');
44require_once($CFG->libdir.'/dtllib.php');
45
46/**
47 * Initiate database export.
48 * @param string $description
49 * @param moodle_database $mdb
50 * @return does not return, calls die()
51 */
52function tool_dbtransfer_export_xml_database($description, $mdb) {
53    core_php_time_limit::raise();
54
55    \core\session\manager::write_close(); // Release session.
56
57    header('Content-Type: application/xhtml+xml; charset=utf-8');
58    header('Content-Disposition: attachment; filename=database.xml');
59    header('Expires: 0');
60    header('Cache-Control: must-revalidate,post-check=0,pre-check=0');
61    header('Pragma: public');
62
63    while(@ob_flush());
64
65    $var = new file_xml_database_exporter('php://output', $mdb);
66    $var->export_database($description);
67
68    // No more output.
69    die;
70}
71
72/**
73 * Initiate database transfer.
74 * @param moodle_database $sourcedb
75 * @param moodle_database $targetdb
76 * @param progress_trace $feedback
77 * @return void
78 */
79function tool_dbtransfer_transfer_database(moodle_database $sourcedb, moodle_database $targetdb, progress_trace $feedback = null) {
80    core_php_time_limit::raise();
81
82    \core\session\manager::write_close(); // Release session.
83
84    $var = new database_mover($sourcedb, $targetdb, true, $feedback);
85    $var->export_database(null);
86
87    tool_dbtransfer_rebuild_target_log_actions($targetdb, $feedback);
88}
89
90/**
91 * Very hacky function for rebuilding of log actions in target database.
92 * @param moodle_database $target
93 * @param progress_trace $feedback
94 * @return void
95 * @throws Exception on conversion error
96 */
97function tool_dbtransfer_rebuild_target_log_actions(moodle_database $target, progress_trace $feedback = null) {
98    global $DB, $CFG;
99    require_once("$CFG->libdir/upgradelib.php");
100
101    $feedback->output(get_string('convertinglogdisplay', 'tool_dbtransfer'));
102
103    $olddb = $DB;
104    $DB = $target;
105    try {
106        $DB->delete_records('log_display', array('component'=>'moodle'));
107        log_update_descriptions('moodle');
108        $plugintypes = core_component::get_plugin_types();
109        foreach ($plugintypes as $type => $location) {
110            $plugs = core_component::get_plugin_list($type);
111            foreach ($plugs as $plug => $fullplug) {
112                $component = $type.'_'.$plug;
113                $DB->delete_records('log_display', array('component'=>$component));
114                log_update_descriptions($component);
115            }
116        }
117    } catch (Exception $e) {
118        $DB = $olddb;
119        throw $e;
120    }
121    $DB = $olddb;
122    $feedback->output(get_string('done', 'core_dbtransfer', null), 1);
123}
124
125/**
126 * Returns list of fully working database drivers present in system.
127 * @return array
128 */
129function tool_dbtransfer_get_drivers() {
130    global $CFG;
131
132    $files = new RegexIterator(new DirectoryIterator("$CFG->libdir/dml"), '|^.*_moodle_database\.php$|');
133    $drivers = array();
134
135    foreach ($files as $file) {
136        $matches = null;
137        preg_match('|^([a-z0-9]+)_([a-z]+)_moodle_database\.php$|', $file->getFilename(), $matches);
138        if (!$matches) {
139            continue;
140        }
141        $dbtype = $matches[1];
142        $dblibrary = $matches[2];
143
144        if ($dbtype === 'sqlite3') {
145            // Blacklist unfinished drivers.
146            continue;
147        }
148
149        $targetdb = moodle_database::get_driver_instance($dbtype, $dblibrary, false);
150        if ($targetdb->driver_installed() !== true) {
151            continue;
152        }
153
154        $driver = $dbtype.'/'.$dblibrary;
155
156        $drivers[$driver] = $targetdb->get_name();
157    };
158
159    return $drivers;
160}
161
162/**
163 * Create CLI maintenance file to prevent all access.
164 */
165function tool_dbtransfer_create_maintenance_file() {
166    global $CFG;
167
168    core_shutdown_manager::register_function('tool_dbtransfer_maintenance_callback');
169
170    $options = new stdClass();
171    $options->trusted = false;
172    $options->noclean = false;
173    $options->smiley = false;
174    $options->filter = false;
175    $options->para = true;
176    $options->newlines = false;
177
178    $message = format_text(get_string('climigrationnotice', 'tool_dbtransfer'), FORMAT_MARKDOWN, $options);
179    $message = bootstrap_renderer::early_error_content($message, '', '', array());
180    $html = <<<OET
181<!DOCTYPE html>
182<html>
183<header><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><header/>
184<body>$message</body>
185</html>
186OET;
187
188    file_put_contents("$CFG->dataroot/climaintenance.html", $html);
189    @chmod("$CFG->dataroot/climaintenance.html", $CFG->filepermissions);
190}
191
192/**
193 * This callback is responsible for unsetting maintenance mode
194 * if the migration is interrupted.
195 */
196function tool_dbtransfer_maintenance_callback() {
197    global $CFG;
198
199    if (empty($CFG->tool_dbransfer_migration_running)) {
200        // Migration was finished properly - keep the maintenance file in place.
201        return;
202    }
203
204    if (file_exists("$CFG->dataroot/climaintenance.html")) {
205        // Failed migration, revert to normal site operation.
206        unlink("$CFG->dataroot/climaintenance.html");
207        error_log('tool_dbtransfer: Interrupted database migration detected, switching off CLI maintenance mode.');
208    }
209}
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