summaryrefslogtreecommitdiffstats
path: root/wp-includes/Text/Diff.php
blob: eee4e4f8ea531748846593c70975934b1984d41a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
<?php
/**
 * General API for generating and formatting diffs - the differences between
 * two sequences of strings.
 *
 * The original PHP version of this code was written by Geoffrey T. Dairiki
 * <dairiki@dairiki.org>, and is used/adapted with his permission.
 *
 * Copyright 2004 Geoffrey T. Dairiki <dairiki@dairiki.org>
 * Copyright 2004-2010 The Horde Project (http://www.horde.org/)
 *
 * See the enclosed file COPYING for license information (LGPL). If you did
 * not receive this file, see https://opensource.org/license/lgpl-2-1/.
 *
 * @package Text_Diff
 * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
 */
class Text_Diff {

    /**
     * Array of changes.
     *
     * @var array
     */
    var $_edits;

    /**
     * Computes diffs between sequences of strings.
     *
     * @param string $engine     Name of the diffing engine to use.  'auto'
     *                           will automatically select the best.
     * @param array $params      Parameters to pass to the diffing engine.
     *                           Normally an array of two arrays, each
     *                           containing the lines from a file.
     */
    function __construct( $engine, $params )
    {
        // Backward compatibility workaround.
        if (!is_string($engine)) {
            $params = array($engine, $params);
            $engine = 'auto';
        }

        if ($engine == 'auto') {
            $engine = extension_loaded('xdiff') ? 'xdiff' : 'native';
        } else {
            $engine = basename($engine);
        }

        // WP #7391
        require_once dirname(__FILE__).'/Diff/Engine/' . $engine . '.php';
        $class = 'Text_Diff_Engine_' . $engine;
        $diff_engine = new $class();

        $this->_edits = call_user_func_array(array($diff_engine, 'diff'), $params);
    }

	/**
	 * PHP4 constructor.
	 */
	public function Text_Diff( $engine, $params ) {
		self::__construct( $engine, $params );
	}

    /**
     * Returns the array of differences.
     */
    function getDiff()
    {
        return $this->_edits;
    }

    /**
     * returns the number of new (added) lines in a given diff.
     *
     * @since Text_Diff 1.1.0
     *
     * @return int The number of new lines
     */
    function countAddedLines()
    {
        $count = 0;
        foreach ($this->_edits as $edit) {
            if (is_a($edit, 'Text_Diff_Op_add') ||
                is_a($edit, 'Text_Diff_Op_change')) {
                $count += $edit->nfinal();
            }
        }
        return $count;
    }

    /**
     * Returns the number of deleted (removed) lines in a given diff.
     *
     * @since Text_Diff 1.1.0
     *
     * @return int The number of deleted lines
     */
    function countDeletedLines()
    {
        $count = 0;
        foreach ($this->_edits as $edit) {
            if (is_a($edit, 'Text_Diff_Op_delete') ||
                is_a($edit, 'Text_Diff_Op_change')) {
                $count += $edit->norig();
            }
        }
        return $count;
    }

    /**
     * Computes a reversed diff.
     *
     * Example:
     * <code>
     * $diff = new Text_Diff($lines1, $lines2);
     * $rev = $diff->reverse();
     * </code>
     *
     * @return Text_Diff  A Diff object representing the inverse of the
     *                    original diff.  Note that we purposely don't return a
     *                    reference here, since this essentially is a clone()
     *                    method.
     */
    function reverse()
    {
        if (version_compare(zend_version(), '2', '>')) {
            $rev = clone($this);
        } else {
            $rev = $this;
        }
        $rev->_edits = array();
        foreach ($this->_edits as $edit) {
            $rev->_edits[] = $edit->reverse();
        }
        return $rev;
    }

    /**
     * Checks for an empty diff.
     *
     * @return bool True if two sequences were identical.
     */
    function isEmpty()
    {
        foreach ($this->_edits as $edit) {
            if (!is_a($edit, 'Text_Diff_Op_copy')) {
                return false;
            }
        }
        return true;
    }

    /**
     * Computes the length of the Longest Common Subsequence (LCS).
     *
     * This is mostly for diagnostic purposes.
     *
     * @return int The length of the LCS.
     */
    function lcs()
    {
        $lcs = 0;
        foreach ($this->_edits as $edit) {
            if (is_a($edit, 'Text_Diff_Op_copy')) {
                $lcs += count($edit->orig);
            }
        }
        return $lcs;
    }

    /**
     * Gets the original set of lines.
     *
     * This reconstructs the $from_lines parameter passed to the constructor.
     *
     * @return array  The original sequence of strings.
     */
    function getOriginal()
    {
        $lines = array();
        foreach ($this->_edits as $edit) {
            if ($edit->orig) {
                array_splice($lines, count($lines), 0, $edit->orig);
            }
        }
        return $lines;
    }

    /**
     * Gets the final set of lines.
     *
     * This reconstructs the $to_lines parameter passed to the constructor.
     *
     * @return array  The sequence of strings.
     */
    function getFinal()
    {
        $lines = array();
        foreach ($this->_edits as $edit) {
            if ($edit->final) {
                array_splice($lines, count($lines), 0, $edit->final);
            }
        }
        return $lines;
    }

    /**
     * Removes trailing newlines from a line of text. This is meant to be used
     * with array_walk().
     *
     * @param string $line  The line to trim.
     * @param int    $key   The index of the line in the array. Not used.
     */
    static function trimNewlines(&$line, $key)
    {
        $line = str_replace(array("\n", "\r"), '', $line);
    }

    /**
     * Determines the location of the system temporary directory.
     *
     * @access protected
     *
     * @return string  A directory name which can be used for temp files.
     *                 Returns false if one could not be found.
     */
    static function _getTempDir()
    {
        $tmp_locations = array('/tmp', '/var/tmp', 'c:\WUTemp', 'c:\temp',
                               'c:\windows\temp', 'c:\winnt\temp');

        /* Try PHP's upload_tmp_dir directive. */
        $tmp = ini_get('upload_tmp_dir');

        /* Otherwise, try to determine the TMPDIR environment variable. */
        if (!strlen($tmp)) {
            $tmp = getenv('TMPDIR');
        }

        /* If we still cannot determine a value, then cycle through a list of
         * preset possibilities. */
        while (!strlen($tmp) && count($tmp_locations)) {
            $tmp_check = array_shift($tmp_locations);
            if (@is_dir($tmp_check)) {
                $tmp = $tmp_check;
            }
        }

        /* If it is still empty, we have failed, so return false; otherwise
         * return the directory determined. */
        return strlen($tmp) ? $tmp : false;
    }

    /**
     * Checks a diff for validity.
     *
     * This is here only for debugging purposes.
     */
    function _check($from_lines, $to_lines)
    {
        if (serialize($from_lines) != serialize($this->getOriginal())) {
            trigger_error("Reconstructed original does not match", E_USER_ERROR);
        }
        if (serialize($to_lines) != serialize($this->getFinal())) {
            trigger_error("Reconstructed final does not match", E_USER_ERROR);
        }

        $rev = $this->reverse();
        if (serialize($to_lines) != serialize($rev->getOriginal())) {
            trigger_error("Reversed original does not match", E_USER_ERROR);
        }
        if (serialize($from_lines) != serialize($rev->getFinal())) {
            trigger_error("Reversed final does not match", E_USER_ERROR);
        }

        $prevtype = null;
        foreach ($this->_edits as $edit) {
            if ($edit instanceof $prevtype) {
                trigger_error("Edit sequence is non-optimal", E_USER_ERROR);
            }
            $prevtype = get_class($edit);
        }

        return true;
    }

}

/**
 * @package Text_Diff
 * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
 */
class Text_MappedDiff extends Text_Diff {

    /**
     * Computes a diff between sequences of strings.
     *
     * This can be used to compute things like case-insensitive diffs, or diffs
     * which ignore changes in white-space.
     *
     * @param array $from_lines         An array of strings.
     * @param array $to_lines           An array of strings.
     * @param array $mapped_from_lines  This array should have the same size
     *                                  number of elements as $from_lines.  The
     *                                  elements in $mapped_from_lines and
     *                                  $mapped_to_lines are what is actually
     *                                  compared when computing the diff.
     * @param array $mapped_to_lines    This array should have the same number
     *                                  of elements as $to_lines.
     */
    function __construct($from_lines, $to_lines,
                             $mapped_from_lines, $mapped_to_lines)
    {
        assert(count($from_lines) == count($mapped_from_lines));
        assert(count($to_lines) == count($mapped_to_lines));

        parent::Text_Diff($mapped_from_lines, $mapped_to_lines);

        $xi = $yi = 0;
        for ($i = 0; $i < count($this->_edits); $i++) {
            $orig = &$this->_edits[$i]->orig;
            if (is_array($orig)) {
                $orig = array_slice($from_lines, $xi, count($orig));
                $xi += count($orig);
            }

            $final = &$this->_edits[$i]->final;
            if (is_array($final)) {
                $final = array_slice($to_lines, $yi, count($final));
                $yi += count($final);
            }
        }
    }

	/**
	 * PHP4 constructor.
	 */
	public function Text_MappedDiff( $from_lines, $to_lines,
                             $mapped_from_lines, $mapped_to_lines ) {
		self::__construct( $from_lines, $to_lines,
                             $mapped_from_lines, $mapped_to_lines );
	}

}

/**
 * @package Text_Diff
 * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
 *
 * @access private
 */
class Text_Diff_Op {

    var $orig;
    var $final;

    function &reverse()
    {
        trigger_error('Abstract method', E_USER_ERROR);
    }

    function norig()
    {
        return $this->orig ? count($this->orig) : 0;
    }

    function nfinal()
    {
        return $this->final ? count($this->final) : 0;
    }

}

/**
 * @package Text_Diff
 * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
 *
 * @access private
 */
class Text_Diff_Op_copy extends Text_Diff_Op {

	/**
	 * PHP5 constructor.
	 */
    function __construct( $orig, $final = false )
    {
        if (!is_array($final)) {
            $final = $orig;
        }
        $this->orig = $orig;
        $this->final = $final;
    }

	/**
	 * PHP4 constructor.
	 */
	public function Text_Diff_Op_copy( $orig, $final = false ) {
		self::__construct( $orig, $final );
	}

    function &reverse()
    {
        $reverse = new Text_Diff_Op_copy($this->final, $this->orig);
        return $reverse;
    }

}

/**
 * @package Text_Diff
 * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
 *
 * @access private
 */
class Text_Diff_Op_delete extends Text_Diff_Op {

	/**
	 * PHP5 constructor.
	 */
	function __construct( $lines )
    {
        $this->orig = $lines;
        $this->final = false;
    }

	/**
	 * PHP4 constructor.
	 */
	public function Text_Diff_Op_delete( $lines ) {
		self::__construct( $lines );
	}

    function &reverse()
    {
        $reverse = new Text_Diff_Op_add($this->orig);
        return $reverse;
    }

}

/**
 * @package Text_Diff
 * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
 *
 * @access private
 */
class Text_Diff_Op_add extends Text_Diff_Op {

	/**
	 * PHP5 constructor.
	 */
    function __construct( $lines )
    {
        $this->final = $lines;
        $this->orig = false;
    }

	/**
	 * PHP4 constructor.
	 */
	public function Text_Diff_Op_add( $lines ) {
		self::__construct( $lines );
	}

    function &reverse()
    {
        $reverse = new Text_Diff_Op_delete($this->final);
        return $reverse;
    }

}

/**
 * @package Text_Diff
 * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
 *
 * @access private
 */
class Text_Diff_Op_change extends Text_Diff_Op {

	/**
	 * PHP5 constructor.
	 */
    function __construct( $orig, $final )
    {
        $this->orig = $orig;
        $this->final = $final;
    }

	/**
	 * PHP4 constructor.
	 */
	public function Text_Diff_Op_change( $orig, $final ) {
		self::__construct( $orig, $final );
	}

    function &reverse()
    {
        $reverse = new Text_Diff_Op_change($this->final, $this->orig);
        return $reverse;
    }

}