removed dokuwiki

1 files changed, 0 insertions, 1059 deletions

diff --git a/wiki/inc/changelog.php b/wiki/inc/changelog.php
deleted file mode 100644
index d77b018..0000000
--- a/wiki/inc/changelog.php
+++ /dev/null
@@ -1,1059 +0,0 @@
-<?php
-/**
- * Changelog handling functions
- *
- * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
- * @author     Andreas Gohr <andi@splitbrain.org>
- */
-
-// Constants for known core changelog line types.
-// Use these in place of string literals for more readable code.
-define('DOKU_CHANGE_TYPE_CREATE',       'C');
-define('DOKU_CHANGE_TYPE_EDIT',         'E');
-define('DOKU_CHANGE_TYPE_MINOR_EDIT',   'e');
-define('DOKU_CHANGE_TYPE_DELETE',       'D');
-define('DOKU_CHANGE_TYPE_REVERT',       'R');
-
-/**
- * parses a changelog line into it's components
- *
- * @author Ben Coburn <btcoburn@silicodon.net>
- *
- * @param string $line changelog line
- * @return array|bool parsed line or false
- */
-function parseChangelogLine($line) {
-    $line = rtrim($line, "\n");
-    $tmp = explode("\t", $line);
-    if ($tmp!==false && count($tmp)>1) {
-        $info = array();
-        $info['date']  = (int)$tmp[0]; // unix timestamp
-        $info['ip']    = $tmp[1]; // IPv4 address (127.0.0.1)
-        $info['type']  = $tmp[2]; // log line type
-        $info['id']    = $tmp[3]; // page id
-        $info['user']  = $tmp[4]; // user name
-        $info['sum']   = $tmp[5]; // edit summary (or action reason)
-        $info['extra'] = $tmp[6]; // extra data (varies by line type)
-        if(isset($tmp[7]) && $tmp[7] !== '') { //last item has line-end||
-            $info['sizechange'] = (int) $tmp[7];
-        } else {
-            $info['sizechange'] = null;
-        }
-        return $info;
-    } else {
-        return false;
-    }
-}
-
-/**
- * Add's an entry to the changelog and saves the metadata for the page
- *
- * @param int    $date      Timestamp of the change
- * @param String $id        Name of the affected page
- * @param String $type      Type of the change see DOKU_CHANGE_TYPE_*
- * @param String $summary   Summary of the change
- * @param mixed  $extra     In case of a revert the revision (timestmp) of the reverted page
- * @param array  $flags     Additional flags in a key value array.
- *                             Available flags:
- *                             - ExternalEdit - mark as an external edit.
- * @param null|int $sizechange Change of filesize
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- * @author Esther Brunner <wikidesign@gmail.com>
- * @author Ben Coburn <btcoburn@silicodon.net>
- */
-function addLogEntry($date, $id, $type=DOKU_CHANGE_TYPE_EDIT, $summary='', $extra='', $flags=null, $sizechange = null){
-    global $conf, $INFO;
-    /** @var Input $INPUT */
-    global $INPUT;
-
-    // check for special flags as keys
-    if (!is_array($flags)) { $flags = array(); }
-    $flagExternalEdit = isset($flags['ExternalEdit']);
-
-    $id = cleanid($id);
-    $file = wikiFN($id);
-    $created = @filectime($file);
-    $minor = ($type===DOKU_CHANGE_TYPE_MINOR_EDIT);
-    $wasRemoved = ($type===DOKU_CHANGE_TYPE_DELETE);
-
-    if(!$date) $date = time(); //use current time if none supplied
-    $remote = (!$flagExternalEdit)?clientIP(true):'127.0.0.1';
-    $user   = (!$flagExternalEdit)?$INPUT->server->str('REMOTE_USER'):'';
-    if($sizechange === null) {
-        $sizechange = '';
-    } else {
-        $sizechange = (int) $sizechange;
-    }
-
-    $strip = array("\t", "\n");
-    $logline = array(
-        'date'       => $date,
-        'ip'         => $remote,
-        'type'       => str_replace($strip, '', $type),
-        'id'         => $id,
-        'user'       => $user,
-        'sum'        => utf8_substr(str_replace($strip, '', $summary), 0, 255),
-        'extra'      => str_replace($strip, '', $extra),
-        'sizechange' => $sizechange
-    );
-
-    $wasCreated = ($type===DOKU_CHANGE_TYPE_CREATE);
-    $wasReverted = ($type===DOKU_CHANGE_TYPE_REVERT);
-    // update metadata
-    if (!$wasRemoved) {
-        $oldmeta = p_read_metadata($id);
-        $meta    = array();
-        if ($wasCreated && empty($oldmeta['persistent']['date']['created'])){ // newly created
-            $meta['date']['created'] = $created;
-            if ($user){
-                $meta['creator'] = $INFO['userinfo']['name'];
-                $meta['user']    = $user;
-            }
-        } elseif (($wasCreated || $wasReverted) && !empty($oldmeta['persistent']['date']['created'])) { // re-created / restored
-            $meta['date']['created']  = $oldmeta['persistent']['date']['created'];
-            $meta['date']['modified'] = $created; // use the files ctime here
-            $meta['creator'] = $oldmeta['persistent']['creator'];
-            if ($user) $meta['contributor'][$user] = $INFO['userinfo']['name'];
-        } elseif (!$minor) {   // non-minor modification
-            $meta['date']['modified'] = $date;
-            if ($user) $meta['contributor'][$user] = $INFO['userinfo']['name'];
-        }
-        $meta['last_change'] = $logline;
-        p_set_metadata($id, $meta);
-    }
-
-    // add changelog lines
-    $logline = implode("\t", $logline)."\n";
-    io_saveFile(metaFN($id,'.changes'),$logline,true); //page changelog
-    io_saveFile($conf['changelog'],$logline,true); //global changelog cache
-}
-
-/**
- * Add's an entry to the media changelog
- *
- * @author Michael Hamann <michael@content-space.de>
- * @author Andreas Gohr <andi@splitbrain.org>
- * @author Esther Brunner <wikidesign@gmail.com>
- * @author Ben Coburn <btcoburn@silicodon.net>
- *
- * @param int    $date      Timestamp of the change
- * @param String $id        Name of the affected page
- * @param String $type      Type of the change see DOKU_CHANGE_TYPE_*
- * @param String $summary   Summary of the change
- * @param mixed  $extra     In case of a revert the revision (timestmp) of the reverted page
- * @param array  $flags     Additional flags in a key value array.
- *                             Available flags:
- *                             - (none, so far)
- * @param null|int $sizechange Change of filesize
- */
-function addMediaLogEntry($date, $id, $type=DOKU_CHANGE_TYPE_EDIT, $summary='', $extra='', $flags=null, $sizechange = null){
-    global $conf;
-    /** @var Input $INPUT */
-    global $INPUT;
-
-    $id = cleanid($id);
-
-    if(!$date) $date = time(); //use current time if none supplied
-    $remote = clientIP(true);
-    $user   = $INPUT->server->str('REMOTE_USER');
-    if($sizechange === null) {
-        $sizechange = '';
-    } else {
-        $sizechange = (int) $sizechange;
-    }
-
-    $strip = array("\t", "\n");
-    $logline = array(
-        'date'       => $date,
-        'ip'         => $remote,
-        'type'       => str_replace($strip, '', $type),
-        'id'         => $id,
-        'user'       => $user,
-        'sum'        => utf8_substr(str_replace($strip, '', $summary), 0, 255),
-        'extra'      => str_replace($strip, '', $extra),
-        'sizechange' => $sizechange
-    );
-
-    // add changelog lines
-    $logline = implode("\t", $logline)."\n";
-    io_saveFile($conf['media_changelog'],$logline,true); //global media changelog cache
-    io_saveFile(mediaMetaFN($id,'.changes'),$logline,true); //media file's changelog
-}
-
-/**
- * returns an array of recently changed files using the
- * changelog
- *
- * The following constants can be used to control which changes are
- * included. Add them together as needed.
- *
- * RECENTS_SKIP_DELETED   - don't include deleted pages
- * RECENTS_SKIP_MINORS    - don't include minor changes
- * RECENTS_SKIP_SUBSPACES - don't include subspaces
- * RECENTS_MEDIA_CHANGES  - return media changes instead of page changes
- * RECENTS_MEDIA_PAGES_MIXED  - return both media changes and page changes
- *
- * @param int    $first   number of first entry returned (for paginating
- * @param int    $num     return $num entries
- * @param string $ns      restrict to given namespace
- * @param int    $flags   see above
- * @return array recently changed files
- *
- * @author Ben Coburn <btcoburn@silicodon.net>
- * @author Kate Arzamastseva <pshns@ukr.net>
- */
-function getRecents($first,$num,$ns='',$flags=0){
-    global $conf;
-    $recent = array();
-    $count  = 0;
-
-    if(!$num)
-        return $recent;
-
-    // read all recent changes. (kept short)
-    if ($flags & RECENTS_MEDIA_CHANGES) {
-        $lines = @file($conf['media_changelog']);
-    } else {
-        $lines = @file($conf['changelog']);
-    }
-    $lines_position = count($lines)-1;
-    $media_lines_position = 0;
-    $media_lines = array();
-
-    if ($flags & RECENTS_MEDIA_PAGES_MIXED) {
-        $media_lines = @file($conf['media_changelog']);
-        $media_lines_position = count($media_lines)-1;
-    }
-
-    $seen = array(); // caches seen lines, _handleRecent() skips them
-
-    // handle lines
-    while ($lines_position >= 0 || (($flags & RECENTS_MEDIA_PAGES_MIXED) && $media_lines_position >=0)) {
-        if (empty($rec) && $lines_position >= 0) {
-            $rec = _handleRecent(@$lines[$lines_position], $ns, $flags, $seen);
-            if (!$rec) {
-                $lines_position --;
-                continue;
-            }
-        }
-        if (($flags & RECENTS_MEDIA_PAGES_MIXED) && empty($media_rec) && $media_lines_position >= 0) {
-            $media_rec = _handleRecent(@$media_lines[$media_lines_position], $ns, $flags | RECENTS_MEDIA_CHANGES, $seen);
-            if (!$media_rec) {
-                $media_lines_position --;
-                continue;
-            }
-        }
-        if (($flags & RECENTS_MEDIA_PAGES_MIXED) && @$media_rec['date'] >= @$rec['date']) {
-            $media_lines_position--;
-            $x = $media_rec;
-            $x['media'] = true;
-            $media_rec = false;
-        } else {
-            $lines_position--;
-            $x = $rec;
-            if ($flags & RECENTS_MEDIA_CHANGES) $x['media'] = true;
-            $rec = false;
-        }
-        if(--$first >= 0) continue; // skip first entries
-        $recent[] = $x;
-        $count++;
-        // break when we have enough entries
-        if($count >= $num){ break; }
-    }
-    return $recent;
-}
-
-/**
- * returns an array of files changed since a given time using the
- * changelog
- *
- * The following constants can be used to control which changes are
- * included. Add them together as needed.
- *
- * RECENTS_SKIP_DELETED   - don't include deleted pages
- * RECENTS_SKIP_MINORS    - don't include minor changes
- * RECENTS_SKIP_SUBSPACES - don't include subspaces
- * RECENTS_MEDIA_CHANGES  - return media changes instead of page changes
- *
- * @param int    $from    date of the oldest entry to return
- * @param int    $to      date of the newest entry to return (for pagination, optional)
- * @param string $ns      restrict to given namespace (optional)
- * @param int    $flags   see above (optional)
- * @return array of files
- *
- * @author Michael Hamann <michael@content-space.de>
- * @author Ben Coburn <btcoburn@silicodon.net>
- */
-function getRecentsSince($from,$to=null,$ns='',$flags=0){
-    global $conf;
-    $recent = array();
-
-    if($to && $to < $from)
-        return $recent;
-
-    // read all recent changes. (kept short)
-    if ($flags & RECENTS_MEDIA_CHANGES) {
-        $lines = @file($conf['media_changelog']);
-    } else {
-        $lines = @file($conf['changelog']);
-    }
-    if(!$lines) return $recent;
-
-    // we start searching at the end of the list
-    $lines = array_reverse($lines);
-
-    // handle lines
-    $seen = array(); // caches seen lines, _handleRecent() skips them
-
-    foreach($lines as $line){
-        $rec = _handleRecent($line, $ns, $flags, $seen);
-        if($rec !== false) {
-            if ($rec['date'] >= $from) {
-                if (!$to || $rec['date'] <= $to) {
-                    $recent[] = $rec;
-                }
-            } else {
-                break;
-            }
-        }
-    }
-
-    return array_reverse($recent);
-}
-
-/**
- * Internal function used by getRecents
- *
- * don't call directly
- *
- * @see getRecents()
- * @author Andreas Gohr <andi@splitbrain.org>
- * @author Ben Coburn <btcoburn@silicodon.net>
- *
- * @param string $line   changelog line
- * @param string $ns     restrict to given namespace
- * @param int    $flags  flags to control which changes are included
- * @param array  $seen   listing of seen pages
- * @return array|bool    false or array with info about a change
- */
-function _handleRecent($line,$ns,$flags,&$seen){
-    if(empty($line)) return false;   //skip empty lines
-
-    // split the line into parts
-    $recent = parseChangelogLine($line);
-    if ($recent===false) { return false; }
-
-    // skip seen ones
-    if(isset($seen[$recent['id']])) return false;
-
-    // skip minors
-    if($recent['type']===DOKU_CHANGE_TYPE_MINOR_EDIT && ($flags & RECENTS_SKIP_MINORS)) return false;
-
-    // remember in seen to skip additional sights
-    $seen[$recent['id']] = 1;
-
-    // check if it's a hidden page
-    if(isHiddenPage($recent['id'])) return false;
-
-    // filter namespace
-    if (($ns) && (strpos($recent['id'],$ns.':') !== 0)) return false;
-
-    // exclude subnamespaces
-    if (($flags & RECENTS_SKIP_SUBSPACES) && (getNS($recent['id']) != $ns)) return false;
-
-    // check ACL
-    if ($flags & RECENTS_MEDIA_CHANGES) {
-        $recent['perms'] = auth_quickaclcheck(getNS($recent['id']).':*');
-    } else {
-        $recent['perms'] = auth_quickaclcheck($recent['id']);
-    }
-    if ($recent['perms'] < AUTH_READ) return false;
-
-    // check existance
-    if($flags & RECENTS_SKIP_DELETED){
-        $fn = (($flags & RECENTS_MEDIA_CHANGES) ? mediaFN($recent['id']) : wikiFN($recent['id']));
-        if(!file_exists($fn)) return false;
-    }
-
-    return $recent;
-}
-
-/**
- * Class ChangeLog
- * methods for handling of changelog of pages or media files
- */
-abstract class ChangeLog {
-
-    /** @var string */
-    protected $id;
-    /** @var int */
-    protected $chunk_size;
-    /** @var array */
-    protected $cache;
-
-    /**
-     * Constructor
-     *
-     * @param string $id         page id
-     * @param int $chunk_size maximum block size read from file
-     */
-    public function __construct($id, $chunk_size = 8192) {
-        global $cache_revinfo;
-
-        $this->cache =& $cache_revinfo;
-        if(!isset($this->cache[$id])) {
-            $this->cache[$id] = array();
-        }
-
-        $this->id = $id;
-        $this->setChunkSize($chunk_size);
-
-    }
-
-    /**
-     * Set chunk size for file reading
-     * Chunk size zero let read whole file at once
-     *
-     * @param int $chunk_size maximum block size read from file
-     */
-    public function setChunkSize($chunk_size) {
-        if(!is_numeric($chunk_size)) $chunk_size = 0;
-
-        $this->chunk_size = (int) max($chunk_size, 0);
-    }
-
-    /**
-     * Returns path to changelog
-     *
-     * @return string path to file
-     */
-    abstract protected function getChangelogFilename();
-
-    /**
-     * Returns path to current page/media
-     *
-     * @return string path to file
-     */
-    abstract protected function getFilename();
-
-    /**
-     * Get the changelog information for a specific page id and revision (timestamp)
-     *
-     * Adjacent changelog lines are optimistically parsed and cached to speed up
-     * consecutive calls to getRevisionInfo. For large changelog files, only the chunk
-     * containing the requested changelog line is read.
-     *
-     * @param int $rev        revision timestamp
-     * @return bool|array false or array with entries:
-     *      - date:  unix timestamp
-     *      - ip:    IPv4 address (127.0.0.1)
-     *      - type:  log line type
-     *      - id:    page id
-     *      - user:  user name
-     *      - sum:   edit summary (or action reason)
-     *      - extra: extra data (varies by line type)
-     *
-     * @author Ben Coburn <btcoburn@silicodon.net>
-     * @author Kate Arzamastseva <pshns@ukr.net>
-     */
-    public function getRevisionInfo($rev) {
-        $rev = max($rev, 0);
-
-        // check if it's already in the memory cache
-        if(isset($this->cache[$this->id]) && isset($this->cache[$this->id][$rev])) {
-            return $this->cache[$this->id][$rev];
-        }
-
-        //read lines from changelog
-        list($fp, $lines) = $this->readloglines($rev);
-        if($fp) {
-            fclose($fp);
-        }
-        if(empty($lines)) return false;
-
-        // parse and cache changelog lines
-        foreach($lines as $value) {
-            $tmp = parseChangelogLine($value);
-            if($tmp !== false) {
-                $this->cache[$this->id][$tmp['date']] = $tmp;
-            }
-        }
-        if(!isset($this->cache[$this->id][$rev])) {
-            return false;
-        }
-        return $this->cache[$this->id][$rev];
-    }
-
-    /**
-     * Return a list of page revisions numbers
-     *
-     * Does not guarantee that the revision exists in the attic,
-     * only that a line with the date exists in the changelog.
-     * By default the current revision is skipped.
-     *
-     * The current revision is automatically skipped when the page exists.
-     * See $INFO['meta']['last_change'] for the current revision.
-     * A negative $first let read the current revision too.
-     *
-     * For efficiency, the log lines are parsed and cached for later
-     * calls to getRevisionInfo. Large changelog files are read
-     * backwards in chunks until the requested number of changelog
-     * lines are recieved.
-     *
-     * @param int $first      skip the first n changelog lines
-     * @param int $num        number of revisions to return
-     * @return array with the revision timestamps
-     *
-     * @author Ben Coburn <btcoburn@silicodon.net>
-     * @author Kate Arzamastseva <pshns@ukr.net>
-     */
-    public function getRevisions($first, $num) {
-        $revs = array();
-        $lines = array();
-        $count = 0;
-
-        $num = max($num, 0);
-        if($num == 0) {
-            return $revs;
-        }
-
-        if($first < 0) {
-            $first = 0;
-        } else if(file_exists($this->getFilename())) {
-            // skip current revision if the page exists
-            $first = max($first + 1, 0);
-        }
-
-        $file = $this->getChangelogFilename();
-
-        if(!file_exists($file)) {
-            return $revs;
-        }
-        if(filesize($file) < $this->chunk_size || $this->chunk_size == 0) {
-            // read whole file
-            $lines = file($file);
-            if($lines === false) {
-                return $revs;
-            }
-        } else {
-            // read chunks backwards
-            $fp = fopen($file, 'rb'); // "file pointer"
-            if($fp === false) {
-                return $revs;
-            }
-            fseek($fp, 0, SEEK_END);
-            $tail = ftell($fp);
-
-            // chunk backwards
-            $finger = max($tail - $this->chunk_size, 0);
-            while($count < $num + $first) {
-                $nl = $this->getNewlinepointer($fp, $finger);
-
-                // was the chunk big enough? if not, take another bite
-                if($nl > 0 && $tail <= $nl) {
-                    $finger = max($finger - $this->chunk_size, 0);
-                    continue;
-                } else {
-                    $finger = $nl;
-                }
-
-                // read chunk
-                $chunk = '';
-                $read_size = max($tail - $finger, 0); // found chunk size
-                $got = 0;
-                while($got < $read_size && !feof($fp)) {
-                    $tmp = @fread($fp, max(min($this->chunk_size, $read_size - $got), 0));
-                    if($tmp === false) {
-                        break;
-                    } //error state
-                    $got += strlen($tmp);
-                    $chunk .= $tmp;
-                }
-                $tmp = explode("\n", $chunk);
-                array_pop($tmp); // remove trailing newline
-
-                // combine with previous chunk
-                $count += count($tmp);
-                $lines = array_merge($tmp, $lines);
-
-                // next chunk
-                if($finger == 0) {
-                    break;
-                } // already read all the lines
-                else {
-                    $tail = $finger;
-                    $finger = max($tail - $this->chunk_size, 0);
-                }
-            }
-            fclose($fp);
-        }
-
-        // skip parsing extra lines
-        $num = max(min(count($lines) - $first, $num), 0);
-        if     ($first > 0 && $num > 0)  { $lines = array_slice($lines, max(count($lines) - $first - $num, 0), $num); }
-        else if($first > 0 && $num == 0) { $lines = array_slice($lines, 0, max(count($lines) - $first, 0)); }
-        else if($first == 0 && $num > 0) { $lines = array_slice($lines, max(count($lines) - $num, 0)); }
-
-        // handle lines in reverse order
-        for($i = count($lines) - 1; $i >= 0; $i--) {
-            $tmp = parseChangelogLine($lines[$i]);
-            if($tmp !== false) {
-                $this->cache[$this->id][$tmp['date']] = $tmp;
-                $revs[] = $tmp['date'];
-            }
-        }
-
-        return $revs;
-    }
-
-    /**
-     * Get the nth revision left or right handside  for a specific page id and revision (timestamp)
-     *
-     * For large changelog files, only the chunk containing the
-     * reference revision $rev is read and sometimes a next chunck.
-     *
-     * Adjacent changelog lines are optimistically parsed and cached to speed up
-     * consecutive calls to getRevisionInfo.
-     *
-     * @param int $rev        revision timestamp used as startdate (doesn't need to be revisionnumber)
-     * @param int $direction  give position of returned revision with respect to $rev; positive=next, negative=prev
-     * @return bool|int
-     *      timestamp of the requested revision
-     *      otherwise false
-     */
-    public function getRelativeRevision($rev, $direction) {
-        $rev = max($rev, 0);
-        $direction = (int) $direction;
-
-        //no direction given or last rev, so no follow-up
-        if(!$direction || ($direction > 0 && $this->isCurrentRevision($rev))) {
-            return false;
-        }
-
-        //get lines from changelog
-        list($fp, $lines, $head, $tail, $eof) = $this->readloglines($rev);
-        if(empty($lines)) return false;
-
-        // look for revisions later/earlier then $rev, when founded count till the wanted revision is reached
-        // also parse and cache changelog lines for getRevisionInfo().
-        $revcounter = 0;
-        $relativerev = false;
-        $checkotherchunck = true; //always runs once
-        while(!$relativerev && $checkotherchunck) {
-            $tmp = array();
-            //parse in normal or reverse order
-            $count = count($lines);
-            if($direction > 0) {
-                $start = 0;
-                $step = 1;
-            } else {
-                $start = $count - 1;
-                $step = -1;
-            }
-            for($i = $start; $i >= 0 && $i < $count; $i = $i + $step) {
-                $tmp = parseChangelogLine($lines[$i]);
-                if($tmp !== false) {
-                    $this->cache[$this->id][$tmp['date']] = $tmp;
-                    //look for revs older/earlier then reference $rev and select $direction-th one
-                    if(($direction > 0 && $tmp['date'] > $rev) || ($direction < 0 && $tmp['date'] < $rev)) {
-                        $revcounter++;
-                        if($revcounter == abs($direction)) {
-                            $relativerev = $tmp['date'];
-                        }
-                    }
-                }
-            }
-
-            //true when $rev is found, but not the wanted follow-up.
-            $checkotherchunck = $fp
-                && ($tmp['date'] == $rev || ($revcounter > 0 && !$relativerev))
-                && !(($tail == $eof && $direction > 0) || ($head == 0 && $direction < 0));
-
-            if($checkotherchunck) {
-                list($lines, $head, $tail) = $this->readAdjacentChunk($fp, $head, $tail, $direction);
-
-                if(empty($lines)) break;
-            }
-        }
-        if($fp) {
-            fclose($fp);
-        }
-
-        return $relativerev;
-    }
-
-    /**
-     * Returns revisions around rev1 and rev2
-     * When available it returns $max entries for each revision
-     *
-     * @param int $rev1 oldest revision timestamp
-     * @param int $rev2 newest revision timestamp (0 looks up last revision)
-     * @param int $max maximum number of revisions returned
-     * @return array with two arrays with revisions surrounding rev1 respectively rev2
-     */
-    public function getRevisionsAround($rev1, $rev2, $max = 50) {
-        $max = floor(abs($max) / 2)*2 + 1;
-        $rev1 = max($rev1, 0);
-        $rev2 = max($rev2, 0);
-
-        if($rev2) {
-            if($rev2 < $rev1) {
-                $rev = $rev2;
-                $rev2 = $rev1;
-                $rev1 = $rev;
-            }
-        } else {
-            //empty right side means a removed page. Look up last revision.
-            $revs = $this->getRevisions(-1, 1);
-            $rev2 = $revs[0];
-        }
-        //collect revisions around rev2
-        list($revs2, $allrevs, $fp, $lines, $head, $tail) = $this->retrieveRevisionsAround($rev2, $max);
-
-        if(empty($revs2)) return array(array(), array());
-
-        //collect revisions around rev1
-        $index = array_search($rev1, $allrevs);
-        if($index === false) {
-            //no overlapping revisions
-            list($revs1,,,,,) = $this->retrieveRevisionsAround($rev1, $max);
-            if(empty($revs1)) $revs1 = array();
-        } else {
-            //revisions overlaps, reuse revisions around rev2
-            $revs1 = $allrevs;
-            while($head > 0) {
-                for($i = count($lines) - 1; $i >= 0; $i--) {
-                    $tmp = parseChangelogLine($lines[$i]);
-                    if($tmp !== false) {
-                        $this->cache[$this->id][$tmp['date']] = $tmp;
-                        $revs1[] = $tmp['date'];
-                        $index++;
-
-                        if($index > floor($max / 2)) break 2;
-                    }
-                }
-
-                list($lines, $head, $tail) = $this->readAdjacentChunk($fp, $head, $tail, -1);
-            }
-            sort($revs1);
-            //return wanted selection
-            $revs1 = array_slice($revs1, max($index - floor($max/2), 0), $max);
-        }
-
-        return array(array_reverse($revs1), array_reverse($revs2));
-    }
-
-    /**
-     * Returns lines from changelog.
-     * If file larger than $chuncksize, only chunck is read that could contain $rev.
-     *
-     * @param int $rev   revision timestamp
-     * @return array|false
-     *     if success returns array(fp, array(changeloglines), $head, $tail, $eof)
-     *     where fp only defined for chuck reading, needs closing.
-     *     otherwise false
-     */
-    protected function readloglines($rev) {
-        $file = $this->getChangelogFilename();
-
-        if(!file_exists($file)) {
-            return false;
-        }
-
-        $fp = null;
-        $head = 0;
-        $tail = 0;
-        $eof = 0;
-
-        if(filesize($file) < $this->chunk_size || $this->chunk_size == 0) {
-            // read whole file
-            $lines = file($file);
-            if($lines === false) {
-                return false;
-            }
-        } else {
-            // read by chunk
-            $fp = fopen($file, 'rb'); // "file pointer"
-            if($fp === false) {
-                return false;
-            }
-            $head = 0;
-            fseek($fp, 0, SEEK_END);
-            $eof = ftell($fp);
-            $tail = $eof;
-
-            // find chunk
-            while($tail - $head > $this->chunk_size) {
-                $finger = $head + floor(($tail - $head) / 2.0);
-                $finger = $this->getNewlinepointer($fp, $finger);
-                $tmp = fgets($fp);
-                if($finger == $head || $finger == $tail) {
-                    break;
-                }
-                $tmp = parseChangelogLine($tmp);
-                $finger_rev = $tmp['date'];
-
-                if($finger_rev > $rev) {
-                    $tail = $finger;
-                } else {
-                    $head = $finger;
-                }
-            }
-
-            if($tail - $head < 1) {
-                // cound not find chunk, assume requested rev is missing
-                fclose($fp);
-                return false;
-            }
-
-            $lines = $this->readChunk($fp, $head, $tail);
-        }
-        return array(
-            $fp,
-            $lines,
-            $head,
-            $tail,
-            $eof
-        );
-    }
-
-    /**
-     * Read chunk and return array with lines of given chunck.
-     * Has no check if $head and $tail are really at a new line
-     *
-     * @param resource $fp    resource filepointer
-     * @param int      $head  start point chunck
-     * @param int      $tail  end point chunck
-     * @return array lines read from chunck
-     */
-    protected function readChunk($fp, $head, $tail) {
-        $chunk = '';
-        $chunk_size = max($tail - $head, 0); // found chunk size
-        $got = 0;
-        fseek($fp, $head);
-        while($got < $chunk_size && !feof($fp)) {
-            $tmp = @fread($fp, max(min($this->chunk_size, $chunk_size - $got), 0));
-            if($tmp === false) { //error state
-                break;
-            }
-            $got += strlen($tmp);
-            $chunk .= $tmp;
-        }
-        $lines = explode("\n", $chunk);
-        array_pop($lines); // remove trailing newline
-        return $lines;
-    }
-
-    /**
-     * Set pointer to first new line after $finger and return its position
-     *
-     * @param resource $fp      filepointer
-     * @param int      $finger  a pointer
-     * @return int pointer
-     */
-    protected function getNewlinepointer($fp, $finger) {
-        fseek($fp, $finger);
-        $nl = $finger;
-        if($finger > 0) {
-            fgets($fp); // slip the finger forward to a new line
-            $nl = ftell($fp);
-        }
-        return $nl;
-    }
-
-    /**
-     * Check whether given revision is the current page
-     *
-     * @param int $rev   timestamp of current page
-     * @return bool true if $rev is current revision, otherwise false
-     */
-    public function isCurrentRevision($rev) {
-        return $rev == @filemtime($this->getFilename());
-    }
-
-    /**
-    * Return an existing revision for a specific date which is
-    * the current one or younger or equal then the date
-    *
-    * @param number $date_at timestamp
-    * @return string revision ('' for current)
-    */
-    function getLastRevisionAt($date_at){
-        //requested date_at(timestamp) younger or equal then modified_time($this->id) => load current
-        if(file_exists($this->getFilename()) && $date_at >= @filemtime($this->getFilename())) {
-            return '';
-        } else if ($rev = $this->getRelativeRevision($date_at+1, -1)) { //+1 to get also the requested date revision
-            return $rev;
-        } else {
-            return false;
-        }
-    }
-
-    /**
-     * Returns the next lines of the changelog  of the chunck before head or after tail
-     *
-     * @param resource $fp filepointer
-     * @param int $head position head of last chunk
-     * @param int $tail position tail of last chunk
-     * @param int $direction positive forward, negative backward
-     * @return array with entries:
-     *    - $lines: changelog lines of readed chunk
-     *    - $head: head of chunk
-     *    - $tail: tail of chunk
-     */
-    protected function readAdjacentChunk($fp, $head, $tail, $direction) {
-        if(!$fp) return array(array(), $head, $tail);
-
-        if($direction > 0) {
-            //read forward
-            $head = $tail;
-            $tail = $head + floor($this->chunk_size * (2 / 3));
-            $tail = $this->getNewlinepointer($fp, $tail);
-        } else {
-            //read backward
-            $tail = $head;
-            $head = max($tail - $this->chunk_size, 0);
-            while(true) {
-                $nl = $this->getNewlinepointer($fp, $head);
-                // was the chunk big enough? if not, take another bite
-                if($nl > 0 && $tail <= $nl) {
-                    $head = max($head - $this->chunk_size, 0);
-                } else {
-                    $head = $nl;
-                    break;
-                }
-            }
-        }
-
-        //load next chunck
-        $lines = $this->readChunk($fp, $head, $tail);
-        return array($lines, $head, $tail);
-    }
-
-    /**
-     * Collect the $max revisions near to the timestamp $rev
-     *
-     * @param int $rev revision timestamp
-     * @param int $max maximum number of revisions to be returned
-     * @return bool|array
-     *     return array with entries:
-     *       - $requestedrevs: array of with $max revision timestamps
-     *       - $revs: all parsed revision timestamps
-     *       - $fp: filepointer only defined for chuck reading, needs closing.
-     *       - $lines: non-parsed changelog lines before the parsed revisions
-     *       - $head: position of first readed changelogline
-     *       - $lasttail: position of end of last readed changelogline
-     *     otherwise false
-     */
-    protected function retrieveRevisionsAround($rev, $max) {
-        //get lines from changelog
-        list($fp, $lines, $starthead, $starttail, /* $eof */) = $this->readloglines($rev);
-        if(empty($lines)) return false;
-
-        //parse chunk containing $rev, and read forward more chunks until $max/2 is reached
-        $head = $starthead;
-        $tail = $starttail;
-        $revs = array();
-        $aftercount = $beforecount = 0;
-        while(count($lines) > 0) {
-            foreach($lines as $line) {
-                $tmp = parseChangelogLine($line);
-                if($tmp !== false) {
-                    $this->cache[$this->id][$tmp['date']] = $tmp;
-                    $revs[] = $tmp['date'];
-                    if($tmp['date'] >= $rev) {
-                        //count revs after reference $rev
-                        $aftercount++;
-                        if($aftercount == 1) $beforecount = count($revs);
-                    }
-                    //enough revs after reference $rev?
-                    if($aftercount > floor($max / 2)) break 2;
-                }
-            }
-            //retrieve next chunk
-            list($lines, $head, $tail) = $this->readAdjacentChunk($fp, $head, $tail, 1);
-        }
-        if($aftercount == 0) return false;
-
-        $lasttail = $tail;
-
-        //read additional chuncks backward until $max/2 is reached and total number of revs is equal to $max
-        $lines = array();
-        $i = 0;
-        if($aftercount > 0) {
-            $head = $starthead;
-            $tail = $starttail;
-            while($head > 0) {
-                list($lines, $head, $tail) = $this->readAdjacentChunk($fp, $head, $tail, -1);
-
-                for($i = count($lines) - 1; $i >= 0; $i--) {
-                    $tmp = parseChangelogLine($lines[$i]);
-                    if($tmp !== false) {
-                        $this->cache[$this->id][$tmp['date']] = $tmp;
-                        $revs[] = $tmp['date'];
-                        $beforecount++;
-                        //enough revs before reference $rev?
-                        if($beforecount > max(floor($max / 2), $max - $aftercount)) break 2;
-                    }
-                }
-            }
-        }
-        sort($revs);
-
-        //keep only non-parsed lines
-        $lines = array_slice($lines, 0, $i);
-        //trunk desired selection
-        $requestedrevs = array_slice($revs, -$max, $max);
-
-        return array($requestedrevs, $revs, $fp, $lines, $head, $lasttail);
-    }
-}
-
-/**
- * Class PageChangelog handles changelog of a wiki page
- */
-class PageChangelog extends ChangeLog {
-
-    /**
-     * Returns path to changelog
-     *
-     * @return string path to file
-     */
-    protected function getChangelogFilename() {
-        return metaFN($this->id, '.changes');
-    }
-
-    /**
-     * Returns path to current page/media
-     *
-     * @return string path to file
-     */
-    protected function getFilename() {
-        return wikiFN($this->id);
-    }
-}
-
-/**
- * Class MediaChangelog handles changelog of a media file
- */
-class MediaChangelog extends ChangeLog {
-
-    /**
-     * Returns path to changelog
-     *
-     * @return string path to file
-     */
-    protected function getChangelogFilename() {
-        return mediaMetaFN($this->id, '.changes');
-    }
-
-    /**
-     * Returns path to current page/media
-     *
-     * @return string path to file
-     */
-    protected function getFilename() {
-        return mediaFN($this->id);
-    }
-}