xref: /dokuwiki/inc/ChangeLog/ChangeLogTrait.php (revision 591ebe4523e0e3be14097d6d097eb5796628dcba) 
1<?php
2
3namespace dokuwiki\ChangeLog;
4
5/**
6 * Provides methods for handling of changelog
7 */
8trait ChangeLogTrait
9{
10    /**
11     * Adds an entry to the changelog file
12     *
13     * @return array added logline as revision info
14     */
15    abstract public function addLogEntry(array $info, $timestamp = null);
16
17    /**
18     * Parses a changelog line into it's components
19     *
20     * @author Ben Coburn <btcoburn@silicodon.net>
21     *
22     * @param string $line changelog line
23     * @return array|bool parsed line or false
24     */
25    public static function parseLogLine($line)
26    {
27        $info = explode("\t", rtrim($line, "\n"));
28        if ($info !== false && count($info) > 1) {
29            return $entry = array(
30                'date'  => (int)$info[0], // unix timestamp
31                'ip'    => $info[1], // IPv4 address (127.0.0.1)
32                'type'  => $info[2], // log line type
33                'id'    => $info[3], // page id
34                'user'  => $info[4], // user name
35                'sum'   => $info[5], // edit summary (or action reason)
36                'extra' => $info[6], // extra data (varies by line type)
37                'sizechange' => (isset($info[7]) && $info[7] !== '') ? (int)$info[7] : null, //
38            );
39        } else {
40            return false;
41        }
42    }
43
44    /**
45     * Build a changelog line from it's components
46     *
47     * @param array $info Revision info structure
48     * @param int $timestamp logline date (optional)
49     * @return string changelog line
50     */
51    public static function buildLogLine(array &$info, $timestamp = null)
52    {
53        $strip = ["\t", "\n"];
54        $entry = array(
55            'date'  => $timestamp ?? $info['date'],
56            'ip'    => $info['ip'],
57            'type'  => str_replace($strip, '', $info['type']),
58            'id'    => $info['id'],
59            'user'  => $info['user'],
60            'sum'   => \dokuwiki\Utf8\PhpString::substr(str_replace($strip, '', $info['sum']), 0, 255),
61            'extra' => str_replace($strip, '', $info['extra']),
62            'sizechange' => $info['sizechange'],
63        );
64        $info = $entry;
65        return $line = implode("\t", $entry) ."\n";
66    }
67
68    /**
69     * Returns path to changelog
70     *
71     * @return string path to file
72     */
73    abstract protected function getChangelogFilename();
74
75    /**
76     * Checks if the ID has old revisons
77     * @return boolean
78     */
79    public function hasRevisions()
80    {
81        $logfile = $this->getChangelogFilename();
82        return file_exists($logfile);
83    }
84
85
86    /** @var int */
87    protected $chunk_size;
88
89    /**
90     * Set chunk size for file reading
91     * Chunk size zero let read whole file at once
92     *
93     * @param int $chunk_size maximum block size read from file
94     */
95    public function setChunkSize($chunk_size)
96    {
97        if (!is_numeric($chunk_size)) $chunk_size = 0;
98
99        $this->chunk_size = (int)max($chunk_size, 0);
100    }
101
102    /**
103     * Returns lines from changelog.
104     * If file larger than $chuncksize, only chunck is read that could contain $rev.
105     *
106     * When reference timestamp $rev is outside time range of changelog, readloglines() will return
107     * lines in first or last chunk, but they obviously does not contain $rev.
108     *
109     * @param int $rev revision timestamp
110     * @return array|false
111     *     if success returns array(fp, array(changeloglines), $head, $tail, $eof)
112     *     where fp only defined for chuck reading, needs closing.
113     *     otherwise false
114     */
115    protected function readloglines($rev)
116    {
117        $file = $this->getChangelogFilename();
118
119        if (!file_exists($file)) {
120            return false;
121        }
122
123        $fp = null;
124        $head = 0;
125        $tail = 0;
126        $eof = 0;
127
128        if (filesize($file) < $this->chunk_size || $this->chunk_size == 0) {
129            // read whole file
130            $lines = file($file);
131            if ($lines === false) {
132                return false;
133            }
134        } else {
135            // read by chunk
136            $fp = fopen($file, 'rb'); // "file pointer"
137            if ($fp === false) {
138                return false;
139            }
140            $head = 0;
141            fseek($fp, 0, SEEK_END);
142            $eof = ftell($fp);
143            $tail = $eof;
144
145            // find chunk
146            while ($tail - $head > $this->chunk_size) {
147                $finger = $head + intval(($tail - $head) / 2);
148                $finger = $this->getNewlinepointer($fp, $finger);
149                $tmp = fgets($fp);
150                if ($finger == $head || $finger == $tail) {
151                    break;
152                }
153                $info = $this->parseLogLine($tmp);
154                $finger_rev = $info['date'];
155
156                if ($finger_rev > $rev) {
157                    $tail = $finger;
158                } else {
159                    $head = $finger;
160                }
161            }
162
163            if ($tail - $head < 1) {
164                // cound not find chunk, assume requested rev is missing
165                fclose($fp);
166                return false;
167            }
168
169            $lines = $this->readChunk($fp, $head, $tail);
170        }
171        return array(
172            $fp,
173            $lines,
174            $head,
175            $tail,
176            $eof,
177        );
178    }
179
180    /**
181     * Read chunk and return array with lines of given chunck.
182     * Has no check if $head and $tail are really at a new line
183     *
184     * @param resource $fp resource filepointer
185     * @param int $head start point chunck
186     * @param int $tail end point chunck
187     * @return array lines read from chunck
188     */
189    protected function readChunk($fp, $head, $tail)
190    {
191        $chunk = '';
192        $chunk_size = max($tail - $head, 0); // found chunk size
193        $got = 0;
194        fseek($fp, $head);
195        while ($got < $chunk_size && !feof($fp)) {
196            $tmp = @fread($fp, max(min($this->chunk_size, $chunk_size - $got), 0));
197            if ($tmp === false) { //error state
198                break;
199            }
200            $got += strlen($tmp);
201            $chunk .= $tmp;
202        }
203        $lines = explode("\n", $chunk);
204        array_pop($lines); // remove trailing newline
205        return $lines;
206    }
207
208    /**
209     * Set pointer to first new line after $finger and return its position
210     *
211     * @param resource $fp filepointer
212     * @param int $finger a pointer
213     * @return int pointer
214     */
215    protected function getNewlinepointer($fp, $finger)
216    {
217        fseek($fp, $finger);
218        $nl = $finger;
219        if ($finger > 0) {
220            fgets($fp); // slip the finger forward to a new line
221            $nl = ftell($fp);
222        }
223        return $nl;
224    }
225
226    /**
227     * Returns the next lines of the changelog  of the chunck before head or after tail
228     *
229     * @param resource $fp filepointer
230     * @param int $head position head of last chunk
231     * @param int $tail position tail of last chunk
232     * @param int $direction positive forward, negative backward
233     * @return array with entries:
234     *    - $lines: changelog lines of readed chunk
235     *    - $head: head of chunk
236     *    - $tail: tail of chunk
237     */
238    protected function readAdjacentChunk($fp, $head, $tail, $direction)
239    {
240        if (!$fp) return array(array(), $head, $tail);
241
242        if ($direction > 0) {
243            //read forward
244            $head = $tail;
245            $tail = $head + intval($this->chunk_size * (2 / 3));
246            $tail = $this->getNewlinepointer($fp, $tail);
247        } else {
248            //read backward
249            $tail = $head;
250            $head = max($tail - $this->chunk_size, 0);
251            while (true) {
252                $nl = $this->getNewlinepointer($fp, $head);
253                // was the chunk big enough? if not, take another bite
254                if ($nl > 0 && $tail <= $nl) {
255                    $head = max($head - $this->chunk_size, 0);
256                } else {
257                    $head = $nl;
258                    break;
259                }
260            }
261        }
262
263        //load next chunck
264        $lines = $this->readChunk($fp, $head, $tail);
265        return array($lines, $head, $tail);
266    }
267
268}
269