xref: /dokuwiki/inc/ChangeLog/ChangeLog.php (revision e937d00471b8194e1dc5cf14501b68d8840212a3)
1<?php
2
3namespace dokuwiki\ChangeLog;
4
5/**
6 * methods for handling of changelog of pages or media files
7 */
8abstract class ChangeLog
9{
10    /** @var string */
11    protected $id;
12    /** @var int */
13    protected $currentRevision;
14    /** @var int */
15    protected $chunk_size;
16    /** @var array */
17    protected $cache;
18
19    /**
20     * Constructor
21     *
22     * @param string $id page id
23     * @param int $chunk_size maximum block size read from file
24     */
25    public function __construct($id, $chunk_size = 8192)
26    {
27        global $cache_revinfo;
28
29        $this->cache =& $cache_revinfo;
30        if (!isset($this->cache[$id])) {
31            $this->cache[$id] = array();
32        }
33
34        $this->id = $id;
35        $this->setChunkSize($chunk_size);
36        // set property currentRevision and cache prior to getRevisionInfo($currentRev) call
37        $this->getCurrentRevisionInfo();
38    }
39
40    /**
41     * Set chunk size for file reading
42     * Chunk size zero let read whole file at once
43     *
44     * @param int $chunk_size maximum block size read from file
45     */
46    public function setChunkSize($chunk_size)
47    {
48        if (!is_numeric($chunk_size)) $chunk_size = 0;
49
50        $this->chunk_size = (int)max($chunk_size, 0);
51    }
52
53    /**
54     * Returns path to changelog
55     *
56     * @return string path to file
57     */
58    abstract protected function getChangelogFilename();
59
60    /**
61     * Returns path to current page/media
62     *
63     * @return string path to file
64     */
65    abstract protected function getFilename();
66
67    /**
68     * Save revision info to the cache pool
69     *
70     * @return bool
71     */
72    protected function saveRevisionInfo($info)
73    {
74        if (!is_array($info)) return false;
75        //$this->cache[$this->id][$info['date']] ??= $info; // since php 7.4
76        $this->cache[$this->id][$info['date']] = $this->cache[$this->id][$info['date']] ?? $info;
77        return true;
78    }
79
80    /**
81     * Get the changelog information for a specific page id and revision (timestamp)
82     *
83     * Adjacent changelog lines are optimistically parsed and cached to speed up
84     * consecutive calls to getRevisionInfo. For large changelog files, only the chunk
85     * containing the requested changelog line is read.
86     *
87     * @param int $rev revision timestamp
88     * @return bool|array false or array with entries:
89     *      - date:  unix timestamp
90     *      - ip:    IPv4 address (127.0.0.1)
91     *      - type:  log line type
92     *      - id:    page id
93     *      - user:  user name
94     *      - sum:   edit summary (or action reason)
95     *      - extra: extra data (varies by line type)
96     *      - sizechange: change of filesize
97     *
98     * @author Ben Coburn <btcoburn@silicodon.net>
99     * @author Kate Arzamastseva <pshns@ukr.net>
100     */
101    public function getRevisionInfo($rev)
102    {
103        $rev = max(0, $rev);
104        if (!$rev) return false;
105
106        // check if it's already in the memory cache
107        if (isset($this->cache[$this->id]) && isset($this->cache[$this->id][$rev])) {
108            return $this->cache[$this->id][$rev];
109        }
110
111        //read lines from changelog
112        list($fp, $lines) = $this->readloglines($rev);
113        if ($fp) {
114            fclose($fp);
115        }
116        if (empty($lines)) return false;
117
118        // parse and cache changelog lines
119        foreach ($lines as $value) {
120            $info = parseChangelogLine($value);
121            $this->saveRevisionInfo($info);
122        }
123        if (!isset($this->cache[$this->id][$rev])) {
124            return false;
125        }
126        return $this->cache[$this->id][$rev];
127    }
128
129    /**
130     * Return a list of page revisions numbers
131     *
132     * Does not guarantee that the revision exists in the attic,
133     * only that a line with the date exists in the changelog.
134     * By default the current revision is skipped.
135     *
136     * The current revision is automatically skipped when the page exists.
137     * See $INFO['meta']['last_change'] for the current revision.
138     * A negative $first let read the current revision too.
139     *
140     * For efficiency, the log lines are parsed and cached for later
141     * calls to getRevisionInfo. Large changelog files are read
142     * backwards in chunks until the requested number of changelog
143     * lines are recieved.
144     *
145     * @param int $first skip the first n changelog lines
146     * @param int $num number of revisions to return
147     * @return array with the revision timestamps
148     *
149     * @author Ben Coburn <btcoburn@silicodon.net>
150     * @author Kate Arzamastseva <pshns@ukr.net>
151     */
152    public function getRevisions($first, $num)
153    {
154        $revs = array();
155        $lines = array();
156        $count = 0;
157
158        $num = max($num, 0);
159        if ($num == 0) {
160            return $revs;
161        }
162
163        if ($first < 0) {
164            $first = 0;
165        } else {
166            if (file_exists($this->getFilename()) && !$this->isExternalEdition()) {
167                // skip current revision if the page exist and not external edition
168                $first = max($first + 1, 0);
169            }
170        }
171
172        $file = $this->getChangelogFilename();
173
174        if (!file_exists($file)) {
175            return $revs;
176        }
177        if (filesize($file) < $this->chunk_size || $this->chunk_size == 0) {
178            // read whole file
179            $lines = file($file);
180            if ($lines === false) {
181                return $revs;
182            }
183        } else {
184            // read chunks backwards
185            $fp = fopen($file, 'rb'); // "file pointer"
186            if ($fp === false) {
187                return $revs;
188            }
189            fseek($fp, 0, SEEK_END);
190            $tail = ftell($fp);
191
192            // chunk backwards
193            $finger = max($tail - $this->chunk_size, 0);
194            while ($count < $num + $first) {
195                $nl = $this->getNewlinepointer($fp, $finger);
196
197                // was the chunk big enough? if not, take another bite
198                if ($nl > 0 && $tail <= $nl) {
199                    $finger = max($finger - $this->chunk_size, 0);
200                    continue;
201                } else {
202                    $finger = $nl;
203                }
204
205                // read chunk
206                $chunk = '';
207                $read_size = max($tail - $finger, 0); // found chunk size
208                $got = 0;
209                while ($got < $read_size && !feof($fp)) {
210                    $tmp = @fread($fp, max(min($this->chunk_size, $read_size - $got), 0));
211                    if ($tmp === false) {
212                        break;
213                    } //error state
214                    $got += strlen($tmp);
215                    $chunk .= $tmp;
216                }
217                $tmp = explode("\n", $chunk);
218                array_pop($tmp); // remove trailing newline
219
220                // combine with previous chunk
221                $count += count($tmp);
222                $lines = array_merge($tmp, $lines);
223
224                // next chunk
225                if ($finger == 0) {
226                    break;
227                } else { // already read all the lines
228                    $tail = $finger;
229                    $finger = max($tail - $this->chunk_size, 0);
230                }
231            }
232            fclose($fp);
233        }
234
235        // skip parsing extra lines
236        $num = max(min(count($lines) - $first, $num), 0);
237        if ($first > 0 && $num > 0) {
238            $lines = array_slice($lines, max(count($lines) - $first - $num, 0), $num);
239        } else {
240            if ($first > 0 && $num == 0) {
241                $lines = array_slice($lines, 0, max(count($lines) - $first, 0));
242            } elseif ($first == 0 && $num > 0) {
243                $lines = array_slice($lines, max(count($lines) - $num, 0));
244            }
245        }
246
247        // handle lines in reverse order
248        for ($i = count($lines) - 1; $i >= 0; $i--) {
249            $info = parseChangelogLine($lines[$i]);
250            if ($this->saveRevisionInfo($info)) {
251                $revs[] = $info['date'];
252            }
253        }
254
255        return $revs;
256    }
257
258    /**
259     * Get the nth revision left or right handside  for a specific page id and revision (timestamp)
260     *
261     * For large changelog files, only the chunk containing the
262     * reference revision $rev is read and sometimes a next chunck.
263     *
264     * Adjacent changelog lines are optimistically parsed and cached to speed up
265     * consecutive calls to getRevisionInfo.
266     *
267     * @param int $rev revision timestamp used as startdate (doesn't need to be revisionnumber)
268     * @param int $direction give position of returned revision with respect to $rev; positive=next, negative=prev
269     * @return bool|int
270     *      timestamp of the requested revision
271     *      otherwise false
272     */
273    public function getRelativeRevision($rev, $direction)
274    {
275        $rev = max($rev, 0);
276        $direction = (int)$direction;
277
278        //no direction given or last rev, so no follow-up
279        if (!$direction || ($direction > 0 && $this->isCurrentRevision($rev))) {
280            return false;
281        }
282
283        //get lines from changelog
284        list($fp, $lines, $head, $tail, $eof) = $this->readloglines($rev);
285        if (empty($lines)) return false;
286
287        // look for revisions later/earlier than $rev, when founded count till the wanted revision is reached
288        // also parse and cache changelog lines for getRevisionInfo().
289        $revcounter = 0;
290        $relativerev = false;
291        $checkotherchunck = true; //always runs once
292        while (!$relativerev && $checkotherchunck) {
293            $info = array();
294            //parse in normal or reverse order
295            $count = count($lines);
296            if ($direction > 0) {
297                $start = 0;
298                $step = 1;
299            } else {
300                $start = $count - 1;
301                $step = -1;
302            }
303            for ($i = $start; $i >= 0 && $i < $count; $i = $i + $step) {
304                $info = parseChangelogLine($lines[$i]);
305                if ($this->saveRevisionInfo($info)) {
306                    //look for revs older/earlier then reference $rev and select $direction-th one
307                    if (($direction > 0 && $info['date'] > $rev) || ($direction < 0 && $info['date'] < $rev)) {
308                        $revcounter++;
309                        if ($revcounter == abs($direction)) {
310                            $relativerev = $info['date'];
311                        }
312                    }
313                }
314            }
315
316            //true when $rev is found, but not the wanted follow-up.
317            $checkotherchunck = $fp
318                && ($info['date'] == $rev || ($revcounter > 0 && !$relativerev))
319                && !(($tail == $eof && $direction > 0) || ($head == 0 && $direction < 0));
320
321            if ($checkotherchunck) {
322                list($lines, $head, $tail) = $this->readAdjacentChunk($fp, $head, $tail, $direction);
323
324                if (empty($lines)) break;
325            }
326        }
327        if ($fp) {
328            fclose($fp);
329        }
330
331        return $relativerev;
332    }
333
334    /**
335     * Returns revisions around rev1 and rev2
336     * When available it returns $max entries for each revision
337     *
338     * @param int $rev1 oldest revision timestamp
339     * @param int $rev2 newest revision timestamp (0 looks up last revision)
340     * @param int $max maximum number of revisions returned
341     * @return array with two arrays with revisions surrounding rev1 respectively rev2
342     */
343    public function getRevisionsAround($rev1, $rev2, $max = 50)
344    {
345        $max = intval(abs($max) / 2) * 2 + 1;
346        $rev1 = max($rev1, 0);
347        $rev2 = max($rev2, 0);
348
349        if ($rev2) {
350            if ($rev2 < $rev1) {
351                $rev = $rev2;
352                $rev2 = $rev1;
353                $rev1 = $rev;
354            }
355        } else {
356            //empty right side means a removed page. Look up last revision.
357            $rev2 = $this->currentRevision();
358        }
359        //collect revisions around rev2
360        list($revs2, $allrevs, $fp, $lines, $head, $tail) = $this->retrieveRevisionsAround($rev2, $max);
361
362        if (empty($revs2)) return array(array(), array());
363
364        //collect revisions around rev1
365        $index = array_search($rev1, $allrevs);
366        if ($index === false) {
367            //no overlapping revisions
368            list($revs1, , , , ,) = $this->retrieveRevisionsAround($rev1, $max);
369            if (empty($revs1)) $revs1 = array();
370        } else {
371            //revisions overlaps, reuse revisions around rev2
372            $lastrev = array_pop($allrevs); //keep last entry that could be external edit
373            $revs1 = $allrevs;
374            while ($head > 0) {
375                for ($i = count($lines) - 1; $i >= 0; $i--) {
376                    $info = parseChangelogLine($lines[$i]);
377                    if ($this->saveRevisionInfo($info)) {
378                        $revs1[] = $info['date'];
379                        $index++;
380
381                        if ($index > intval($max / 2)) break 2;
382                    }
383                }
384
385                list($lines, $head, $tail) = $this->readAdjacentChunk($fp, $head, $tail, -1);
386            }
387            sort($revs1);
388            $revs1[] = $lastrev; //push back last entry
389
390            //return wanted selection
391            $revs1 = array_slice($revs1, max($index - intval($max / 2), 0), $max);
392        }
393
394        return array(array_reverse($revs1), array_reverse($revs2));
395    }
396
397
398    /**
399     * Checks if the ID has old revisons
400     * @return boolean
401     */
402    public function hasRevisions() {
403        $file = $this->getChangelogFilename();
404        return file_exists($file);
405    }
406
407    /**
408     * Returns lines from changelog.
409     * If file larger than $chuncksize, only chunck is read that could contain $rev.
410     *
411     * When reference timestamp $rev is outside time range of changelog, readloglines() will return
412     * lines in first or last chunk, but they obviously does not contain $rev.
413     *
414     * @param int $rev revision timestamp
415     * @return array|false
416     *     if success returns array(fp, array(changeloglines), $head, $tail, $eof)
417     *     where fp only defined for chuck reading, needs closing.
418     *     otherwise false
419     */
420    protected function readloglines($rev)
421    {
422        $file = $this->getChangelogFilename();
423
424        if (!file_exists($file)) {
425            return false;
426        }
427
428        $fp = null;
429        $head = 0;
430        $tail = 0;
431        $eof = 0;
432
433        if (filesize($file) < $this->chunk_size || $this->chunk_size == 0) {
434            // read whole file
435            $lines = file($file);
436            if ($lines === false) {
437                return false;
438            }
439        } else {
440            // read by chunk
441            $fp = fopen($file, 'rb'); // "file pointer"
442            if ($fp === false) {
443                return false;
444            }
445            $head = 0;
446            fseek($fp, 0, SEEK_END);
447            $eof = ftell($fp);
448            $tail = $eof;
449
450            // find chunk
451            while ($tail - $head > $this->chunk_size) {
452                $finger = $head + intval(($tail - $head) / 2);
453                $finger = $this->getNewlinepointer($fp, $finger);
454                $tmp = fgets($fp);
455                if ($finger == $head || $finger == $tail) {
456                    break;
457                }
458                $info = parseChangelogLine($tmp);
459                $finger_rev = $info['date'];
460
461                if ($finger_rev > $rev) {
462                    $tail = $finger;
463                } else {
464                    $head = $finger;
465                }
466            }
467
468            if ($tail - $head < 1) {
469                // cound not find chunk, assume requested rev is missing
470                fclose($fp);
471                return false;
472            }
473
474            $lines = $this->readChunk($fp, $head, $tail);
475        }
476        return array(
477            $fp,
478            $lines,
479            $head,
480            $tail,
481            $eof,
482        );
483    }
484
485    /**
486     * Read chunk and return array with lines of given chunck.
487     * Has no check if $head and $tail are really at a new line
488     *
489     * @param resource $fp resource filepointer
490     * @param int $head start point chunck
491     * @param int $tail end point chunck
492     * @return array lines read from chunck
493     */
494    protected function readChunk($fp, $head, $tail)
495    {
496        $chunk = '';
497        $chunk_size = max($tail - $head, 0); // found chunk size
498        $got = 0;
499        fseek($fp, $head);
500        while ($got < $chunk_size && !feof($fp)) {
501            $tmp = @fread($fp, max(min($this->chunk_size, $chunk_size - $got), 0));
502            if ($tmp === false) { //error state
503                break;
504            }
505            $got += strlen($tmp);
506            $chunk .= $tmp;
507        }
508        $lines = explode("\n", $chunk);
509        array_pop($lines); // remove trailing newline
510        return $lines;
511    }
512
513    /**
514     * Set pointer to first new line after $finger and return its position
515     *
516     * @param resource $fp filepointer
517     * @param int $finger a pointer
518     * @return int pointer
519     */
520    protected function getNewlinepointer($fp, $finger)
521    {
522        fseek($fp, $finger);
523        $nl = $finger;
524        if ($finger > 0) {
525            fgets($fp); // slip the finger forward to a new line
526            $nl = ftell($fp);
527        }
528        return $nl;
529    }
530
531    /**
532     * Check whether given revision is the current page
533     *
534     * @param int $rev timestamp of current page
535     * @return bool true if $rev is current revision, otherwise false
536     */
537    public function isCurrentRevision($rev)
538    {
539        return $rev == $this->currentRevision();
540    }
541
542    /**
543     * Return an existing revision for a specific date which is
544     * the current one or younger or equal then the date
545     *
546     * @param number $date_at timestamp
547     * @return string revision ('' for current)
548     */
549    public function getLastRevisionAt($date_at)
550    {
551        //requested date_at(timestamp) younger or equal then modified_time($this->id) => load current
552        if (file_exists($this->getFilename()) && $date_at >= @filemtime($this->getFilename())) {
553            return '';
554        } else {
555            if ($rev = $this->getRelativeRevision($date_at + 1, -1)) { //+1 to get also the requested date revision
556                return $rev;
557            } else {
558                return false;
559            }
560        }
561    }
562
563    /**
564     * Returns the next lines of the changelog  of the chunck before head or after tail
565     *
566     * @param resource $fp filepointer
567     * @param int $head position head of last chunk
568     * @param int $tail position tail of last chunk
569     * @param int $direction positive forward, negative backward
570     * @return array with entries:
571     *    - $lines: changelog lines of readed chunk
572     *    - $head: head of chunk
573     *    - $tail: tail of chunk
574     */
575    protected function readAdjacentChunk($fp, $head, $tail, $direction)
576    {
577        if (!$fp) return array(array(), $head, $tail);
578
579        if ($direction > 0) {
580            //read forward
581            $head = $tail;
582            $tail = $head + intval($this->chunk_size * (2 / 3));
583            $tail = $this->getNewlinepointer($fp, $tail);
584        } else {
585            //read backward
586            $tail = $head;
587            $head = max($tail - $this->chunk_size, 0);
588            while (true) {
589                $nl = $this->getNewlinepointer($fp, $head);
590                // was the chunk big enough? if not, take another bite
591                if ($nl > 0 && $tail <= $nl) {
592                    $head = max($head - $this->chunk_size, 0);
593                } else {
594                    $head = $nl;
595                    break;
596                }
597            }
598        }
599
600        //load next chunck
601        $lines = $this->readChunk($fp, $head, $tail);
602        return array($lines, $head, $tail);
603    }
604
605    /**
606     * Collect the $max revisions near to the timestamp $rev
607     *
608     * Ideally, half of retrieved timestamps are older than $rev, another half are newer.
609     * The returned array $requestedrevs may not contain the reference timestamp $rev
610     * when it does not match any revision value recorded in changelog.
611     *
612     * @param int $rev revision timestamp
613     * @param int $max maximum number of revisions to be returned
614     * @return bool|array
615     *     return array with entries:
616     *       - $requestedrevs: array of with $max revision timestamps
617     *       - $revs: all parsed revision timestamps
618     *       - $fp: filepointer only defined for chuck reading, needs closing.
619     *       - $lines: non-parsed changelog lines before the parsed revisions
620     *       - $head: position of first readed changelogline
621     *       - $lasttail: position of end of last readed changelogline
622     *     otherwise false
623     */
624    protected function retrieveRevisionsAround($rev, $max)
625    {
626        $revs = array();
627        $aftercount = $beforecount = 0;
628
629        //get lines from changelog
630        list($fp, $lines, $starthead, $starttail, $eof) = $this->readloglines($rev);
631        if (empty($lines)) return false;
632
633        //parse changelog lines in chunk, and read forward more chunks until $max/2 is reached
634        $head = $starthead;
635        $tail = $starttail;
636        while (count($lines) > 0) {
637            foreach ($lines as $line) {
638                $info = parseChangelogLine($line);
639                if ($this->saveRevisionInfo($info)) {
640                    $revs[] = $info['date'];
641                    if ($info['date'] >= $rev) {
642                        //count revs after reference $rev
643                        $aftercount++;
644                        if ($aftercount == 1) $beforecount = count($revs);
645                    }
646                    //enough revs after reference $rev?
647                    if ($aftercount > intval($max / 2)) break 2;
648                }
649            }
650            //retrieve next chunk
651            list($lines, $head, $tail) = $this->readAdjacentChunk($fp, $head, $tail, 1);
652        }
653        $lasttail = $tail;
654
655        // add a possible revision of external edit, create or deletion
656        if ($lasttail == $eof && $aftercount <= intval($max / 2) && $this->isExternalEdition()) {
657            $revs[] = $this->currentRevision;
658            $aftercount++;
659        }
660
661        if ($aftercount == 0) {
662            //given timestamp $rev is newer than the most recent line in chunk
663            return false; //FIXME: or proceed to collect older revisions?
664        }
665
666        //read more chunks backward until $max/2 is reached and total number of revs is equal to $max
667        $lines = array();
668        $i = 0;
669        if ($aftercount > 0) {
670            $head = $starthead;
671            $tail = $starttail;
672            while ($head > 0) {
673                list($lines, $head, $tail) = $this->readAdjacentChunk($fp, $head, $tail, -1);
674
675                for ($i = count($lines) - 1; $i >= 0; $i--) {
676                    $info = parseChangelogLine($lines[$i]);
677                    if ($this->saveRevisionInfo($info)) {
678                        $revs[] = $info['date'];
679                        $beforecount++;
680                        //enough revs before reference $rev?
681                        if ($beforecount > max(intval($max / 2), $max - $aftercount)) break 2;
682                    }
683                }
684            }
685        }
686        //keep only non-parsed lines
687        $lines = array_slice($lines, 0, $i);
688
689        sort($revs);
690
691        //trunk desired selection
692        $requestedrevs = array_slice($revs, -$max, $max);
693
694        return array($requestedrevs, $revs, $fp, $lines, $head, $lasttail);
695    }
696
697    /**
698     * Get the current revision information, considering external edit, create or deletion
699     *
700     * The "current" revison is the last timestamp of the page in the context of changelog.
701     * However it is often recognised that is in sight now from the DokuWiki user perspective.
702     * The current page is accessible without any revision identifier (eg. doku.php?id=foo),
703     * but it has unique modification time of the source txt file and kept in changelog.
704     * When the page is deleted by saving blank text in the DokuWiki editor, the deletion
705     * time is to be kept as its revision identifier in the changelog.
706     *
707     * External edit will break consistency between the file and changelog. A page source
708     * file might be modified, created or deleted without using DokuWiki editor, instead
709     * by accessing direct to the file stored in data directory via server console.
710     * Such editions are never recorded in changelog. However after external file edit,
711     * now we can see new "current" content of the edited page!
712     *
713     * A tentative revision should be assigned for the external edition to handle whole
714     * revisions successfully in DokuWiki revision list and diff view interface.
715     * As far as the source file of the edition exists, a unique revision can be decided
716     * using function filemtime(), but it could be unknown if the foo.txt file had deleted
717     * or moved to foo.bak file.
718     * In such case, we assume unknown revision as "last timestamp in chagelog" +1
719     * to ensure that current one should be newer than any revisions in changelog.
720     * Another case of external edit: when foo.bak file moved back to foo.txt, the current
721     * one could become older than latest timestamp in changelog. In this case, we should
722     * assume the revison as "last timestamp in chagelog" +1, instead of its timestamp.
723     *
724     * @return bool|array false when page had never existed or array with entries:
725     *      - date:  revision identifier (timestamp or last revision +1)
726     *      - ip:    IPv4 address (127.0.0.1)
727     *      - type:  log line type
728     *      - id:    id of page or media
729     *      - user:  user name
730     *      - sum:   edit summary (or action reason)
731     *      - extra: extra data (varies by line type)
732     *      - sizechange: change of filesize
733     *      - timestamp: timestamp or 'unknown' (key set only for external edition)
734     *
735     * @author  Satoshi Sahara <sahara.satoshi@gmail.com>
736     */
737    public function getCurrentRevisionInfo()
738    {
739        global $lang;
740
741        if (isset($this->currentRevision)) return $this->getRevisionInfo($this->currentRevision);
742
743        // get revision id from the item file timestamp and chagelog
744        $fileRev = @filemtime($this->getFilename()); // false when the file not exist
745        $lastRev = @$this->getRevisions(-1, 1)[0];   // null when failed
746
747        if (!$fileRev && $lastRev === null) {             // has never existed
748            return false;
749        } elseif ($fileRev === $lastRev) {                // not external edit
750            $this->currentRevision = $lastRev;
751            $this->cache[$this->id][$this->currentRevision] += [
752                    'current' => true,
753            ];
754            return $this->getRevisionInfo($this->currentRevision);
755        }
756
757        if (!$fileRev && $lastRev) {                // item file does not exist
758            // check consistency against changelog
759            $revInfo = $this->getRevisionInfo($lastRev);
760            if ($revInfo['type'] == DOKU_CHANGE_TYPE_DELETE) {
761                $this->currentRevision = $lastRev;
762                $this->cache[$this->id][$this->currentRevision] += [
763                    'current' => true,
764                ];
765                return $this->getRevisionInfo($this->currentRevision);
766            }
767
768            // externally deleted
769            $revInfo = [
770                'date' => $lastRev +1,
771                'ip'   => '127.0.0.1',
772                'type' => DOKU_CHANGE_TYPE_DELETE,
773                'id'   => $this->id,
774                'user' => '',
775                'sum'  => $lang['deleted'] .' - '. $lang['external_edit'],
776                'extra' => '',
777                'sizechange' => -io_getSizeFile($this->getFilename($lastRev)),
778                'current' => true,
779                'timestamp' => 'unknown',
780            ];
781
782        } elseif ($fileRev) {                       // item file exist
783            // here, file timestamp is different with last revision in changelog
784            $isJustCreated = is_null($lastRev) || (
785                    $fileRev > $lastRev &&
786                    $this->getRevisionInfo($lastRev)['type'] == DOKU_CHANGE_TYPE_DELETE
787            );
788            $filesize_new = filesize($this->getFilename());
789            $filesize_old = $isJustCreated ? 0 : io_getSizeFile($this->getFilename($lastRev));
790            $sizechange = $filesize_new - $filesize_old;
791
792            if ($isJustCreated) { // lastRev is null
793                $rev = $timestamp = $fileRev;
794                $sum = $lang['created'] .' - '. $lang['external_edit'];
795            } elseif ($fileRev > $lastRev) {
796                $rev = $timestamp = $fileRev;
797                $sum = $lang['external_edit'];
798            } else {
799                // $fileRev is older than $lastRev, externally reverted an old file
800                $rev = max($fileRev, $lastRev +1);
801                $timestamp = 'unknown';
802                $sum = $lang['external_edit'];
803            }
804
805            // externally created or edited
806            $revInfo = [
807                'date' => $rev,
808                'ip'   => '127.0.0.1',
809                'type' => $isJustCreated ? DOKU_CHANGE_TYPE_CREATE : DOKU_CHANGE_TYPE_EDIT,
810                'id'   => $this->id,
811                'user' => '',
812                'sum'  => $sum,
813                'extra' => '',
814                'sizechange' => $sizechange,
815                'current' => true,
816                'timestamp' => $timestamp,
817            ];
818        }
819
820        // cache current revision information of external edition
821        $this->currentRevision = $revInfo['date'];
822        $this->cache[$this->id][$this->currentRevision] = $revInfo;
823        return $this->getRevisionInfo($this->currentRevision);
824    }
825
826    /**
827     * Checks if the revision is external edition
828     * @return boolean
829     */
830    public function isExternalEdition($rev =null)
831    {
832        if ($rev === 'current' || $rev === null) {
833            $revInfo = $this->getCurrentRevisionInfo();
834        } elseif (is_int($rev)) {
835            $revInfo = $this->getRevisionInfo($rev);
836        } elseif (is_array($rev)) {
837            $revInfo =  $rev;
838        }
839        return array_key_exists('timestamp', $revInfo);
840    }
841
842    /**
843     * Return the current revision identifer
844     * @return int|false
845     */
846    public function currentRevision()
847    {
848        if (!isset($this->currentRevision)) {
849            // set ChangeLog::currentRevision property
850            $this->getCurrentRevisionInfo();
851        }
852        return $this->currentRevision;
853    }
854}
855