1<?php
2
3namespace dokuwiki;
4
5use dokuwiki\Extension\Event;
6use dokuwiki\Sitemap\Mapper;
7use dokuwiki\Subscriptions\BulkSubscriptionSender;
8use dokuwiki\ChangeLog\ChangeLog;
9
10/**
11 * Class TaskRunner
12 *
13 * Run an asynchronous task.
14 */
15class TaskRunner
16{
17    /**
18     * Run the next task
19     *
20     * @todo refactor to remove dependencies on globals
21     * @triggers INDEXER_TASKS_RUN
22     */
23    public function run()
24    {
25        global $INPUT, $conf, $ID;
26
27        // keep running after browser closes connection
28        @ignore_user_abort(true);
29
30        // check if user abort worked, if yes send output early
31        $defer = !@ignore_user_abort() || $conf['broken_iua'];
32        $output = $INPUT->has('debug') && $conf['allowdebug'];
33        if (!$defer && !$output) {
34            $this->sendGIF();
35        }
36
37        $ID = cleanID($INPUT->str('id'));
38
39        // Catch any possible output (e.g. errors)
40        if (!$output) {
41            ob_start();
42        } else {
43            header('Content-Type: text/plain');
44        }
45
46        // run one of the jobs
47        $tmp = []; // No event data
48        $evt = new Event('INDEXER_TASKS_RUN', $tmp);
49        if ($evt->advise_before()) {
50            if (
51                !(
52                $this->runIndexer() ||
53                $this->runSitemapper() ||
54                $this->sendDigest() ||
55                $this->runTrimRecentChanges() ||
56                $this->runTrimRecentChanges(true))
57            ) {
58                $evt->advise_after();
59            }
60        }
61
62        if (!$output) {
63            ob_end_clean();
64            if ($defer) {
65                $this->sendGIF();
66            }
67        }
68    }
69
70    /**
71     * Just send a 1x1 pixel blank gif to the browser
72     *
73     * @author Andreas Gohr <andi@splitbrain.org>
74     * @author Harry Fuecks <fuecks@gmail.com>
75     */
76    protected function sendGIF()
77    {
78        $img = base64_decode('R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAEALAAAAAABAAEAAAIBTAA7');
79        header('Content-Type: image/gif');
80        header('Content-Length: ' . strlen($img));
81        header('Connection: Close');
82        echo $img;
83        tpl_flush();
84        // Browser should drop connection after this
85        // Thinks it's got the whole image
86    }
87
88    /**
89     * Trims the recent changes cache (or imports the old changelog) as needed.
90     *
91     * @param bool $media_changes   If the media changelog shall be trimmed instead of
92     *                              the page changelog
93     *
94     * @return bool
95     * @triggers TASK_RECENTCHANGES_TRIM
96     * @author Ben Coburn <btcoburn@silicodon.net>
97     */
98    protected function runTrimRecentChanges($media_changes = false)
99    {
100        global $conf;
101
102        echo "runTrimRecentChanges($media_changes): started" . NL;
103
104        $fn = ($media_changes ? $conf['media_changelog'] : $conf['changelog']);
105
106        // Trim the Recent Changes
107        // Trims the recent changes cache to the last $conf['changes_days'] recent
108        // changes or $conf['recent'] items, which ever is larger.
109        // The trimming is only done once a day.
110        if (
111            file_exists($fn) &&
112            (@filemtime($fn . '.trimmed') + 86400) < time() &&
113            !file_exists($fn . '_tmp')
114        ) {
115            @touch($fn . '.trimmed');
116            io_lock($fn);
117            $lines = file($fn);
118            if (count($lines) <= $conf['recent']) {
119                // nothing to trim
120                io_unlock($fn);
121                echo "runTrimRecentChanges($media_changes): finished" . NL;
122                return false;
123            }
124
125            io_saveFile($fn . '_tmp', '');          // presave tmp as 2nd lock
126            $trim_time = time() - $conf['recent_days'] * 86400;
127            $out_lines = [];
128            $old_lines = [];
129            $counter = count($lines);
130            for ($i = 0; $i < $counter; $i++) {
131                $log = ChangeLog::parseLogLine($lines[$i]);
132                if ($log === false) {
133                    continue; // discard junk
134                }
135
136                if ($log['date'] < $trim_time) {
137                    // keep old lines for now (append .$i to prevent key collisions)
138                    $old_lines[$log['date'] . ".$i"] = $lines[$i];
139                } else {
140                    // definitely keep these lines
141                    $out_lines[$log['date'] . ".$i"] = $lines[$i];
142                }
143            }
144
145            if (count($lines) === count($out_lines)) {
146                // nothing to trim
147                @unlink($fn . '_tmp');
148                io_unlock($fn);
149                echo "runTrimRecentChanges($media_changes): finished" . NL;
150                return false;
151            }
152
153            // sort the final result, it shouldn't be necessary,
154            //   however the extra robustness in making the changelog cache self-correcting is worth it
155            ksort($out_lines);
156            $extra = $conf['recent'] - count($out_lines);        // do we need extra lines do bring us up to minimum
157            if ($extra > 0) {
158                ksort($old_lines);
159                $out_lines = array_merge(array_slice($old_lines, -$extra), $out_lines);
160            }
161
162            $eventData = [
163                'isMedia' => $media_changes,
164                'trimmedChangelogLines' => $out_lines,
165                'removedChangelogLines' => $extra > 0 ? array_slice($old_lines, 0, -$extra) : $old_lines,
166            ];
167            Event::createAndTrigger('TASK_RECENTCHANGES_TRIM', $eventData);
168            $out_lines = $eventData['trimmedChangelogLines'];
169
170            // save trimmed changelog
171            io_saveFile($fn . '_tmp', implode('', $out_lines));
172            @unlink($fn);
173            if (!rename($fn . '_tmp', $fn)) {
174                // rename failed so try another way...
175                io_unlock($fn);
176                io_saveFile($fn, implode('', $out_lines));
177                @unlink($fn . '_tmp');
178            } else {
179                io_unlock($fn);
180            }
181            echo "runTrimRecentChanges($media_changes): finished" . NL;
182            return true;
183        }
184
185        // nothing done
186        echo "runTrimRecentChanges($media_changes): finished" . NL;
187        return false;
188    }
189
190
191    /**
192     * Runs the indexer for the current page
193     *
194     * @author Andreas Gohr <andi@splitbrain.org>
195     */
196    protected function runIndexer()
197    {
198        global $ID;
199        echo 'runIndexer(): started' . NL;
200
201        if ((string) $ID === '') {
202            return false;
203        }
204
205        // do the work
206        return idx_addPage($ID, true);
207    }
208
209    /**
210     * Builds a Google Sitemap of all public pages known to the indexer
211     *
212     * The map is placed in the root directory named sitemap.xml.gz - This
213     * file needs to be writable!
214     *
215     * @author Andreas Gohr
216     * @link   https://www.google.com/webmasters/sitemaps/docs/en/about.html
217     */
218    protected function runSitemapper()
219    {
220        echo 'runSitemapper(): started' . NL;
221        $result = Mapper::generate() && Mapper::pingSearchEngines();
222        echo 'runSitemapper(): finished' . NL;
223        return $result;
224    }
225
226    /**
227     * Send digest and list mails for all subscriptions which are in effect for the
228     * current page
229     *
230     * @author Adrian Lang <lang@cosmocode.de>
231     */
232    protected function sendDigest()
233    {
234        global $ID;
235
236        echo 'sendDigest(): started' . NL;
237        if (!actionOK('subscribe')) {
238            echo 'sendDigest(): disabled' . NL;
239            return false;
240        }
241        $sub = new BulkSubscriptionSender();
242        $sent = $sub->sendBulk($ID);
243
244        echo "sendDigest(): sent $sent mails" . NL;
245        echo 'sendDigest(): finished' . NL;
246        return (bool)$sent;
247    }
248}
249