Code Coverage |
||||||||||
Classes and Traits |
Functions and Methods |
Lines |
||||||||
| Total | |
0.00% |
0 / 1 |
|
0.00% |
0 / 5 |
CRAP | |
0.00% |
0 / 352 |
| diff_engine | |
0.00% |
0 / 1 |
|
0.00% |
0 / 5 |
10100.00 | |
0.00% |
0 / 348 |
| diff | |
0.00% |
0 / 1 |
1190.00 | |
0.00% |
0 / 119 |
|||
| _diag | |
0.00% |
0 / 1 |
420.00 | |
0.00% |
0 / 84 |
|||
| _lcs_pos | |
0.00% |
0 / 1 |
30.00 | |
0.00% |
0 / 26 |
|||
| _compareseq | |
0.00% |
0 / 1 |
182.00 | |
0.00% |
0 / 42 |
|||
| _shift_boundaries | |
0.00% |
0 / 1 |
812.00 | |
0.00% |
0 / 77 |
|||
| <?php | |
| /** | |
| * | |
| * This file is part of the phpBB Forum Software package. | |
| * | |
| * @copyright (c) phpBB Limited <https://www.phpbb.com> | |
| * @license GNU General Public License, version 2 (GPL-2.0) | |
| * | |
| * For full copyright and license information, please see | |
| * the docs/CREDITS.txt file. | |
| * | |
| */ | |
| /** | |
| * @ignore | |
| */ | |
| if (!defined('IN_PHPBB')) | |
| { | |
| exit; | |
| } | |
| /** | |
| * Code from pear.php.net, Text_Diff-1.1.0 package | |
| * http://pear.php.net/package/Text_Diff/ (native engine) | |
| * | |
| * Modified by phpBB Limited to meet our coding standards | |
| * and being able to integrate into phpBB | |
| * | |
| * Class used internally by Text_Diff to actually compute the diffs. This | |
| * class is implemented using native PHP code. | |
| * | |
| * The algorithm used here is mostly lifted from the perl module | |
| * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: | |
| * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip | |
| * | |
| * More ideas are taken from: http://www.ics.uci.edu/~eppstein/161/960229.html | |
| * | |
| * Some ideas (and a bit of code) are taken from analyze.c, of GNU | |
| * diffutils-2.7, which can be found at: | |
| * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz | |
| * | |
| * Some ideas (subdivision by NCHUNKS > 2, and some optimizations) are from | |
| * Geoffrey T. Dairiki <dairiki@dairiki.org>. The original PHP version of this | |
| * code was written by him, and is used/adapted with his permission. | |
| * | |
| * Copyright 2004-2008 The Horde Project (http://www.horde.org/) | |
| * | |
| * @author Geoffrey T. Dairiki <dairiki@dairiki.org> | |
| * @package diff | |
| * | |
| * @access private | |
| */ | |
| class diff_engine | |
| { | |
| /** | |
| * If set to true we trim all lines before we compare them. This ensures that sole space/tab changes do not trigger diffs. | |
| */ | |
| var $skip_whitespace_changes = true; | |
| function diff(&$from_lines, &$to_lines, $preserve_cr = true) | |
| { | |
| // Remove empty lines... | |
| // If preserve_cr is true, we basically only change \r\n and bare \r to \n to get the same carriage returns for both files | |
| // If it is false, we try to only use \n once per line and ommit all empty lines to be able to get a proper data diff | |
| if (is_array($from_lines)) | |
| { | |
| $from_lines = implode("\n", $from_lines); | |
| } | |
| if (is_array($to_lines)) | |
| { | |
| $to_lines = implode("\n", $to_lines); | |
| } | |
| if ($preserve_cr) | |
| { | |
| $from_lines = explode("\n", str_replace("\r", "\n", str_replace("\r\n", "\n", $from_lines))); | |
| $to_lines = explode("\n", str_replace("\r", "\n", str_replace("\r\n", "\n", $to_lines))); | |
| } | |
| else | |
| { | |
| $from_lines = explode("\n", preg_replace('#[\n\r]+#', "\n", $from_lines)); | |
| $to_lines = explode("\n", preg_replace('#[\n\r]+#', "\n", $to_lines)); | |
| } | |
| $n_from = count($from_lines); | |
| $n_to = count($to_lines); | |
| $this->xchanged = $this->ychanged = $this->xv = $this->yv = $this->xind = $this->yind = array(); | |
| unset($this->seq, $this->in_seq, $this->lcs); | |
| // Skip leading common lines. | |
| for ($skip = 0; $skip < $n_from && $skip < $n_to; $skip++) | |
| { | |
| if (trim($from_lines[$skip]) !== trim($to_lines[$skip])) | |
| { | |
| break; | |
| } | |
| $this->xchanged[$skip] = $this->ychanged[$skip] = false; | |
| } | |
| // Skip trailing common lines. | |
| $xi = $n_from; | |
| $yi = $n_to; | |
| for ($endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++) | |
| { | |
| if (trim($from_lines[$xi]) !== trim($to_lines[$yi])) | |
| { | |
| break; | |
| } | |
| $this->xchanged[$xi] = $this->ychanged[$yi] = false; | |
| } | |
| // Ignore lines which do not exist in both files. | |
| for ($xi = $skip; $xi < $n_from - $endskip; $xi++) | |
| { | |
| if ($this->skip_whitespace_changes) $xhash[trim($from_lines[$xi])] = 1; else $xhash[$from_lines[$xi]] = 1; | |
| } | |
| for ($yi = $skip; $yi < $n_to - $endskip; $yi++) | |
| { | |
| $line = ($this->skip_whitespace_changes) ? trim($to_lines[$yi]) : $to_lines[$yi]; | |
| if (($this->ychanged[$yi] = empty($xhash[$line]))) | |
| { | |
| continue; | |
| } | |
| $yhash[$line] = 1; | |
| $this->yv[] = $line; | |
| $this->yind[] = $yi; | |
| } | |
| for ($xi = $skip; $xi < $n_from - $endskip; $xi++) | |
| { | |
| $line = ($this->skip_whitespace_changes) ? trim($from_lines[$xi]) : $from_lines[$xi]; | |
| if (($this->xchanged[$xi] = empty($yhash[$line]))) | |
| { | |
| continue; | |
| } | |
| $this->xv[] = $line; | |
| $this->xind[] = $xi; | |
| } | |
| // Find the LCS. | |
| $this->_compareseq(0, count($this->xv), 0, count($this->yv)); | |
| // Merge edits when possible. | |
| if ($this->skip_whitespace_changes) | |
| { | |
| $from_lines_clean = array_map('trim', $from_lines); | |
| $to_lines_clean = array_map('trim', $to_lines); | |
| $this->_shift_boundaries($from_lines_clean, $this->xchanged, $this->ychanged); | |
| $this->_shift_boundaries($to_lines_clean, $this->ychanged, $this->xchanged); | |
| unset($from_lines_clean, $to_lines_clean); | |
| } | |
| else | |
| { | |
| $this->_shift_boundaries($from_lines, $this->xchanged, $this->ychanged); | |
| $this->_shift_boundaries($to_lines, $this->ychanged, $this->xchanged); | |
| } | |
| // Compute the edit operations. | |
| $edits = array(); | |
| $xi = $yi = 0; | |
| while ($xi < $n_from || $yi < $n_to) | |
| { | |
| // Skip matching "snake". | |
| $copy = array(); | |
| while ($xi < $n_from && $yi < $n_to && !$this->xchanged[$xi] && !$this->ychanged[$yi]) | |
| { | |
| $copy[] = $from_lines[$xi++]; | |
| $yi++; | |
| } | |
| if ($copy) | |
| { | |
| $edits[] = new diff_op_copy($copy); | |
| } | |
| // Find deletes & adds. | |
| $delete = array(); | |
| while ($xi < $n_from && $this->xchanged[$xi]) | |
| { | |
| $delete[] = $from_lines[$xi++]; | |
| } | |
| $add = array(); | |
| while ($yi < $n_to && $this->ychanged[$yi]) | |
| { | |
| $add[] = $to_lines[$yi++]; | |
| } | |
| if ($delete && $add) | |
| { | |
| $edits[] = new diff_op_change($delete, $add); | |
| } | |
| else if ($delete) | |
| { | |
| $edits[] = new diff_op_delete($delete); | |
| } | |
| else if ($add) | |
| { | |
| $edits[] = new diff_op_add($add); | |
| } | |
| } | |
| return $edits; | |
| } | |
| /** | |
| * Divides the Largest Common Subsequence (LCS) of the sequences (XOFF, | |
| * XLIM) and (YOFF, YLIM) into NCHUNKS approximately equally sized segments. | |
| * | |
| * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an array of | |
| * NCHUNKS+1 (X, Y) indexes giving the diving points between sub | |
| * sequences. The first sub-sequence is contained in (X0, X1), (Y0, Y1), | |
| * the second in (X1, X2), (Y1, Y2) and so on. Note that (X0, Y0) == | |
| * (XOFF, YOFF) and (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). | |
| * | |
| * This function assumes that the first lines of the specified portions of | |
| * the two files do not match, and likewise that the last lines do not | |
| * match. The caller must trim matching lines from the beginning and end | |
| * of the portions it is going to specify. | |
| */ | |
| function _diag($xoff, $xlim, $yoff, $ylim, $nchunks) | |
| { | |
| $flip = false; | |
| if ($xlim - $xoff > $ylim - $yoff) | |
| { | |
| // Things seems faster (I'm not sure I understand why) when the shortest sequence is in X. | |
| $flip = true; | |
| list($xoff, $xlim, $yoff, $ylim) = array($yoff, $ylim, $xoff, $xlim); | |
| } | |
| if ($flip) | |
| { | |
| for ($i = $ylim - 1; $i >= $yoff; $i--) | |
| { | |
| $ymatches[$this->xv[$i]][] = $i; | |
| } | |
| } | |
| else | |
| { | |
| for ($i = $ylim - 1; $i >= $yoff; $i--) | |
| { | |
| $ymatches[$this->yv[$i]][] = $i; | |
| } | |
| } | |
| $this->lcs = 0; | |
| $this->seq[0]= $yoff - 1; | |
| $this->in_seq = array(); | |
| $ymids[0] = array(); | |
| $numer = $xlim - $xoff + $nchunks - 1; | |
| $x = $xoff; | |
| for ($chunk = 0; $chunk < $nchunks; $chunk++) | |
| { | |
| if ($chunk > 0) | |
| { | |
| for ($i = 0; $i <= $this->lcs; $i++) | |
| { | |
| $ymids[$i][$chunk - 1] = $this->seq[$i]; | |
| } | |
| } | |
| $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $chunk) / $nchunks); | |
| for (; $x < $x1; $x++) | |
| { | |
| $line = $flip ? $this->yv[$x] : $this->xv[$x]; | |
| if (empty($ymatches[$line])) | |
| { | |
| continue; | |
| } | |
| $matches = $ymatches[$line]; | |
| reset($matches); | |
| while ($y = current($matches)) | |
| { | |
| next($matches); | |
| if (empty($this->in_seq[$y])) | |
| { | |
| $k = $this->_lcs_pos($y); | |
| $ymids[$k] = $ymids[$k - 1]; | |
| break; | |
| } | |
| } | |
| // no reset() here | |
| while ($y = current($matches)) | |
| { | |
| next($matches); | |
| if ($y > $this->seq[$k - 1]) | |
| { | |
| // Optimization: this is a common case: next match is just replacing previous match. | |
| $this->in_seq[$this->seq[$k]] = false; | |
| $this->seq[$k] = $y; | |
| $this->in_seq[$y] = 1; | |
| } | |
| else if (empty($this->in_seq[$y])) | |
| { | |
| $k = $this->_lcs_pos($y); | |
| $ymids[$k] = $ymids[$k - 1]; | |
| } | |
| } | |
| } | |
| } | |
| $seps[] = $flip ? array($yoff, $xoff) : array($xoff, $yoff); | |
| $ymid = $ymids[$this->lcs]; | |
| for ($n = 0; $n < $nchunks - 1; $n++) | |
| { | |
| $x1 = $xoff + (int)(($numer + ($xlim - $xoff) * $n) / $nchunks); | |
| $y1 = $ymid[$n] + 1; | |
| $seps[] = $flip ? array($y1, $x1) : array($x1, $y1); | |
| } | |
| $seps[] = $flip ? array($ylim, $xlim) : array($xlim, $ylim); | |
| return array($this->lcs, $seps); | |
| } | |
| function _lcs_pos($ypos) | |
| { | |
| $end = $this->lcs; | |
| if ($end == 0 || $ypos > $this->seq[$end]) | |
| { | |
| $this->seq[++$this->lcs] = $ypos; | |
| $this->in_seq[$ypos] = 1; | |
| return $this->lcs; | |
| } | |
| $beg = 1; | |
| while ($beg < $end) | |
| { | |
| $mid = (int)(($beg + $end) / 2); | |
| if ($ypos > $this->seq[$mid]) | |
| { | |
| $beg = $mid + 1; | |
| } | |
| else | |
| { | |
| $end = $mid; | |
| } | |
| } | |
| $this->in_seq[$this->seq[$end]] = false; | |
| $this->seq[$end] = $ypos; | |
| $this->in_seq[$ypos] = 1; | |
| return $end; | |
| } | |
| /** | |
| * Finds LCS of two sequences. | |
| * | |
| * The results are recorded in the vectors $this->{x,y}changed[], by | |
| * storing a 1 in the element for each line that is an insertion or | |
| * deletion (ie. is not in the LCS). | |
| * | |
| * The subsequence of file 0 is (XOFF, XLIM) and likewise for file 1. | |
| * | |
| * Note that XLIM, YLIM are exclusive bounds. All line numbers are | |
| * origin-0 and discarded lines are not counted. | |
| */ | |
| function _compareseq($xoff, $xlim, $yoff, $ylim) | |
| { | |
| // Slide down the bottom initial diagonal. | |
| while ($xoff < $xlim && $yoff < $ylim && $this->xv[$xoff] == $this->yv[$yoff]) | |
| { | |
| ++$xoff; | |
| ++$yoff; | |
| } | |
| // Slide up the top initial diagonal. | |
| while ($xlim > $xoff && $ylim > $yoff && $this->xv[$xlim - 1] == $this->yv[$ylim - 1]) | |
| { | |
| --$xlim; | |
| --$ylim; | |
| } | |
| if ($xoff == $xlim || $yoff == $ylim) | |
| { | |
| $lcs = 0; | |
| } | |
| else | |
| { | |
| // This is ad hoc but seems to work well. | |
| // $nchunks = sqrt(min($xlim - $xoff, $ylim - $yoff) / 2.5); | |
| // $nchunks = max(2,min(8,(int)$nchunks)); | |
| $nchunks = min(7, $xlim - $xoff, $ylim - $yoff) + 1; | |
| list($lcs, $seps) = $this->_diag($xoff, $xlim, $yoff, $ylim, $nchunks); | |
| } | |
| if ($lcs == 0) | |
| { | |
| // X and Y sequences have no common subsequence: mark all changed. | |
| while ($yoff < $ylim) | |
| { | |
| $this->ychanged[$this->yind[$yoff++]] = 1; | |
| } | |
| while ($xoff < $xlim) | |
| { | |
| $this->xchanged[$this->xind[$xoff++]] = 1; | |
| } | |
| } | |
| else | |
| { | |
| // Use the partitions to split this problem into subproblems. | |
| reset($seps); | |
| $pt1 = $seps[0]; | |
| while ($pt2 = next($seps)) | |
| { | |
| $this->_compareseq($pt1[0], $pt2[0], $pt1[1], $pt2[1]); | |
| $pt1 = $pt2; | |
| } | |
| } | |
| } | |
| /** | |
| * Adjusts inserts/deletes of identical lines to join changes as much as possible. | |
| * | |
| * We do something when a run of changed lines include a line at one end | |
| * and has an excluded, identical line at the other. We are free to | |
| * choose which identical line is included. 'compareseq' usually chooses | |
| * the one at the beginning, but usually it is cleaner to consider the | |
| * following identical line to be the "change". | |
| * | |
| * This is extracted verbatim from analyze.c (GNU diffutils-2.7). | |
| */ | |
| function _shift_boundaries($lines, &$changed, $other_changed) | |
| { | |
| $i = 0; | |
| $j = 0; | |
| $len = count($lines); | |
| $other_len = count($other_changed); | |
| while (1) | |
| { | |
| // Scan forward to find the beginning of another run of | |
| // changes. Also keep track of the corresponding point in the other file. | |
| // | |
| // Throughout this code, $i and $j are adjusted together so that | |
| // the first $i elements of $changed and the first $j elements of | |
| // $other_changed both contain the same number of zeros (unchanged lines). | |
| // | |
| // Furthermore, $j is always kept so that $j == $other_len or $other_changed[$j] == false. | |
| while ($j < $other_len && $other_changed[$j]) | |
| { | |
| $j++; | |
| } | |
| while ($i < $len && ! $changed[$i]) | |
| { | |
| $i++; | |
| $j++; | |
| while ($j < $other_len && $other_changed[$j]) | |
| { | |
| $j++; | |
| } | |
| } | |
| if ($i == $len) | |
| { | |
| break; | |
| } | |
| $start = $i; | |
| // Find the end of this run of changes. | |
| while (++$i < $len && $changed[$i]) | |
| { | |
| continue; | |
| } | |
| do | |
| { | |
| // Record the length of this run of changes, so that we can later determine whether the run has grown. | |
| $runlength = $i - $start; | |
| // Move the changed region back, so long as the previous unchanged line matches the last changed one. | |
| // This merges with previous changed regions. | |
| while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) | |
| { | |
| $changed[--$start] = 1; | |
| $changed[--$i] = false; | |
| while ($start > 0 && $changed[$start - 1]) | |
| { | |
| $start--; | |
| } | |
| while ($other_changed[--$j]) | |
| { | |
| continue; | |
| } | |
| } | |
| // Set CORRESPONDING to the end of the changed run, at the last point where it corresponds to a changed run in the | |
| // other file. CORRESPONDING == LEN means no such point has been found. | |
| $corresponding = $j < $other_len ? $i : $len; | |
| // Move the changed region forward, so long as the first changed line matches the following unchanged one. | |
| // This merges with following changed regions. | |
| // Do this second, so that if there are no merges, the changed region is moved forward as far as possible. | |
| while ($i < $len && $lines[$start] == $lines[$i]) | |
| { | |
| $changed[$start++] = false; | |
| $changed[$i++] = 1; | |
| while ($i < $len && $changed[$i]) | |
| { | |
| $i++; | |
| } | |
| $j++; | |
| if ($j < $other_len && $other_changed[$j]) | |
| { | |
| $corresponding = $i; | |
| while ($j < $other_len && $other_changed[$j]) | |
| { | |
| $j++; | |
| } | |
| } | |
| } | |
| } | |
| while ($runlength != $i - $start); | |
| // If possible, move the fully-merged run of changes back to a corresponding run in the other file. | |
| while ($corresponding < $i) | |
| { | |
| $changed[--$start] = 1; | |
| $changed[--$i] = 0; | |
| while ($other_changed[--$j]) | |
| { | |
| continue; | |
| } | |
| } | |
| } | |
| } | |
| } |