From 96fcbd972bb9e1bfb1398da14539dee447a20e7d Mon Sep 17 00:00:00 2001 From: Meik Sievertsen Date: Sun, 7 Jun 2009 18:00:37 +0000 Subject: moved diff git-svn-id: file:///svn/phpbb/trunk@9556 89ea8834-ac86-4346-8a33-228a782c2dd0 --- phpBB/includes/diff/engine.php | 536 ----------------------------------------- 1 file changed, 536 deletions(-) delete mode 100644 phpBB/includes/diff/engine.php (limited to 'phpBB/includes/diff/engine.php') diff --git a/phpBB/includes/diff/engine.php b/phpBB/includes/diff/engine.php deleted file mode 100644 index eb0dcce395..0000000000 --- a/phpBB/includes/diff/engine.php +++ /dev/null @@ -1,536 +0,0 @@ - 2, and some optimizations) are from -* Geoffrey T. Dairiki . 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 -* @package diff -* -* @access private -*/ -class diff_engine -{ - 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)); - } - - $n_from = sizeof($from_lines); - $n_to = sizeof($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; $skip++) - { - if ($from_lines[$skip] !== $to_lines[$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; $endskip++) - { - if ($from_lines[$xi] !== $to_lines[$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++) - { - $xhash[$from_lines[$xi]] = 1; - } - - for ($yi = $skip; $yi < $n_to - $endskip; $yi++) - { - $line = $to_lines[$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 = $from_lines[$xi]; - - if (($this->xchanged[$xi] = empty($yhash[$line]))) - { - continue; - } - $this->xv[] = $line; - $this->xind[] = $xi; - } - - // Find the LCS. - $this->_compareseq(0, sizeof($this->xv), 0, sizeof($this->yv)); - - // Merge edits when possible. - $this->_shift_boundaries($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 (list(, $y) = each($matches)) - { - if (empty($this->in_seq[$y])) - { - $k = $this->_lcs_pos($y); - $ymids[$k] = $ymids[$k - 1]; - break; - } - } - - // no reset() here - while (list(, $y) = each($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; - - $len = sizeof($lines); - $other_len = sizeof($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; - } - } - } - } -} - -?> \ No newline at end of file -- cgit v1.2.1