diff --git a/code/Diff.php b/code/Diff.php deleted file mode 100755 index 0002ee67..00000000 --- a/code/Diff.php +++ /dev/null @@ -1,861 +0,0 @@ - -// You may copy this code freely under the conditions of the GPL. -// - -// FIXME: possibly remove assert()'s for production version? - -// PHP3 does not have assert() -/** - */ -define('USE_ASSERTS', function_exists('assert')); - -/** - * @package cms - * @subpackage core - * @access private - */ -class _DiffOp { - var $type; - var $orig; - var $final; - - function reverse() { - trigger_error("pure virtual", E_USER_ERROR); - } - - function norig() { - return $this->orig ? sizeof($this->orig) : 0; - } - - function nfinal() { - return $this->final ? sizeof($this->final) : 0; - } -} - -/** - * @package cms - * @subpackage core - * @access private - */ -class _DiffOp_Copy extends _DiffOp { - var $type = 'copy'; - - function _DiffOp_Copy ($orig, $final = false) { - if (!is_array($final)) - $final = $orig; - $this->orig = $orig; - $this->final = $final; - } - - function reverse() { - return new _DiffOp_Copy($this->final, $this->orig); - } -} - -/** - * @package cms - * @subpackage core - * @access private - */ -class _DiffOp_Delete extends _DiffOp { - var $type = 'delete'; - - function _DiffOp_Delete ($lines) { - $this->orig = $lines; - $this->final = false; - } - - function reverse() { - return new _DiffOp_Add($this->orig); - } -} - -/** - * @package cms - * @subpackage core - * @access private - */ -class _DiffOp_Add extends _DiffOp { - var $type = 'add'; - - function _DiffOp_Add ($lines) { - $this->final = $lines; - $this->orig = false; - } - - function reverse() { - return new _DiffOp_Delete($this->final); - } -} - -/** - * @package cms - * @subpackage core - * @access private - */ -class _DiffOp_Change extends _DiffOp { - var $type = 'change'; - - function _DiffOp_Change ($orig, $final) { - $this->orig = $orig; - $this->final = $final; - } - - function reverse() { - return new _DiffOp_Change($this->final, $this->orig); - } -} - - -/** - * Class used internally by Diff to actually compute the diffs. - * - * The algorithm used here is mostly lifted from the perl module - * Algorithm::Diff (version 1.06) by Ned Konz, which is available at: - * http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip - * - * More ideas are taken from: - * http://www.ics.uci.edu/~eppstein/161/960229.html - * - * Some ideas are (and a bit of code) are from from analyze.c, from GNU - * diffutils-2.7, which can be found at: - * ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz - * - * Finally, some ideas (subdivision by NCHUNKS > 2, and some optimizations) - * are my own. - * - * @author Geoffrey T. Dairiki - * @access private - * @package cms - * @subpackage core - */ -class _DiffEngine -{ - function diff ($from_lines, $to_lines) { - $n_from = sizeof($from_lines); - $n_to = sizeof($to_lines); - - $this->xchanged = $this->ychanged = array(); - $this->xv = $this->yv = array(); - $this->xind = $this->yind = array(); - unset($this->seq); - unset($this->in_seq); - unset($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 < $n_to) { - USE_ASSERTS && assert($yi < $n_to || $this->xchanged[$xi]); - USE_ASSERTS && assert($xi < $n_from || $this->ychanged[$yi]); - - // 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) - $edits[] = new _DiffOp_Copy($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) - $edits[] = new _DiffOp_Change($delete, $add); - elseif ($delete) - $edits[] = new _DiffOp_Delete($delete); - elseif ($add) - $edits[] = new _DiffOp_Add($add); - } - return $edits; - } - - - /* Divide the Largest Common Subsequence (LCS) of the sequences - * [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally - * sized segments. - * - * Returns (LCS, PTS). LCS is the length of the LCS. PTS is an - * array of NCHUNKS+1 (X, Y) indexes giving the diving points between - * sub sequences. The first sub-sequence is contained in [X0, X1), - * [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note - * that (X0, Y0) == (XOFF, YOFF) and - * (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM). - * - * This function assumes that the first lines of the specified portions - * of the two files do not match, and likewise that the last lines do not - * match. The caller must trim matching lines from the beginning and end - * of the portions it is going to specify. - */ - function _diag ($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 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($matches); - while (list ($junk, $y) = each($matches)) - if (empty($this->in_seq[$y])) { - $k = $this->_lcs_pos($y); - USE_ASSERTS && assert($k > 0); - $ymids[$k] = $ymids[$k-1]; - break; - } - while (list ($junk, $y) = each($matches)) { - if ($y > $this->seq[$k-1]) { - USE_ASSERTS && assert($y < $this->seq[$k]); - // 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); - USE_ASSERTS && assert($k > 0); - $ymids[$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 = $mid; - } - - USE_ASSERTS && assert($ypos != $this->seq[$end]); - - $this->in_seq[$this->seq[$end]] = false; - $this->seq[$end] = $ypos; - $this->in_seq[$ypos] = 1; - return $end; - } - - /* Find 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 = $pt2; - } - } - } - - /* Adjust inserts/deletes of identical lines to join changes - * as much as possible. - * - * We do something when a run of changed lines include a - * line at one end and has an excluded, identical line at the other. - * We are free to choose which identical line is included. - * 'compareseq' usually chooses the one at the beginning, - * but usually it is cleaner to consider the following identical line - * to be the "change". - * - * This is extracted verbatim from analyze.c (GNU diffutils-2.7). - */ - function _shift_boundaries ($lines, &$changed, $other_changed) { - $i = 0; - $j = 0; - - USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)'); - $len = sizeof($lines); - $other_len = sizeof($other_changed); - - while (1) { - /* - * Scan forwards to find 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]) { - USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); - $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]) - $start--; - USE_ASSERTS && assert('$j > 0'); - while ($other_changed[--$j]) - continue; - USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); - } - - /* - * 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]) - $i++; - - USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]'); - $j++; - if ($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; - USE_ASSERTS && assert('$j > 0'); - while ($other_changed[--$j]) - continue; - USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]'); - } - } - } -} - -/** - * Class representing a 'diff' between two sequences of strings. - * @package cms - * @subpackage core - */ -class Diff -{ - public static $html_cleaner_class = null; - - var $edits; - - /** - * Constructor. - * Computes diff between sequences of strings. - * - * @param $from_lines array An array of strings. - * (Typically these are lines from a file.) - * @param $to_lines array An array of strings. - */ - function Diff($from_lines, $to_lines) { - $eng = new _DiffEngine; - $this->edits = $eng->diff($from_lines, $to_lines); - //$this->_check($from_lines, $to_lines); - } - - /** - * Compute reversed Diff. - * - * SYNOPSIS: - * - * $diff = new Diff($lines1, $lines2); - * $rev = $diff->reverse(); - * @return object A Diff object representing the inverse of the - * original diff. - */ - function reverse () { - $rev = $this; - $rev->edits = array(); - foreach ($this->edits as $edit) { - $rev->edits[] = $edit->reverse(); - } - return $rev; - } - - /** - * Check for empty diff. - * - * @return bool True iff two sequences were identical. - */ - function isEmpty () { - foreach ($this->edits as $edit) { - if ($edit->type != 'copy') - return false; - } - return true; - } - - /** - * Compute the length of the Longest Common Subsequence (LCS). - * - * This is mostly for diagnostic purposed. - * - * @return int The length of the LCS. - */ - function lcs () { - $lcs = 0; - foreach ($this->edits as $edit) { - if ($edit->type == 'copy') - $lcs += sizeof($edit->orig); - } - return $lcs; - } - - /** - * Get the original set of lines. - * - * This reconstructs the $from_lines parameter passed to the - * constructor. - * - * @return array The original sequence of strings. - */ - function orig() { - $lines = array(); - - foreach ($this->edits as $edit) { - if ($edit->orig) - array_splice($lines, sizeof($lines), 0, $edit->orig); - } - return $lines; - } - - /** - * Get the final set of lines. - * - * This reconstructs the $to_lines parameter passed to the - * constructor. - * - * @return array The sequence of strings. - */ - function finaltext() { - $lines = array(); - - foreach ($this->edits as $edit) { - if ($edit->final) - array_splice($lines, sizeof($lines), 0, $edit->final); - } - return $lines; - } - - /** - * Check a Diff for validity. - * - * This is here only for debugging purposes. - */ - function _check ($from_lines, $to_lines) { - if (serialize($from_lines) != serialize($this->orig())) - trigger_error("Reconstructed original doesn't match", E_USER_ERROR); - if (serialize($to_lines) != serialize($this->finaltext())) - trigger_error("Reconstructed final doesn't match", E_USER_ERROR); - - $rev = $this->reverse(); - if (serialize($to_lines) != serialize($rev->orig())) - trigger_error("Reversed original doesn't match", E_USER_ERROR); - if (serialize($from_lines) != serialize($rev->finaltext())) - trigger_error("Reversed final doesn't match", E_USER_ERROR); - - - $prevtype = 'none'; - foreach ($this->edits as $edit) { - if ( $prevtype == $edit->type ) - trigger_error("Edit sequence is non-optimal", E_USER_ERROR); - $prevtype = $edit->type; - } - - $lcs = $this->lcs(); - trigger_error("Diff okay: LCS = $lcs", E_USER_NOTICE); - } - - - - /** - * Attempt to clean invalid HTML, which messes up diffs. - * This cleans code if possible, using an instance of HTMLCleaner - * - * NB: By default, only extremely simple tidying is performed, - * by passing through DomDocument::loadHTML and saveXML - * - * @param string $content HTML content - * @param object $cleaner Optional instance of a HTMLCleaner class to - * use, overriding self::$html_cleaner_class - */ - static function cleanHTML($content, $cleaner=null) { - if (!$cleaner) { - if (class_exists(self::$html_cleaner_class)) { - $cleaner = new self::$html_cleaner_class; - } - } - if ($cleaner) { - $content = $cleaner->cleanHTML($content); - } else { - // At most basic level of cleaning, use DOMDocument to save valid XML. - $doc = new SS_HTMLValue($content); - $content = $doc->getContent(); - } - - // Remove empty and tags because browsers hate them - $content = preg_replace('/<(ins|del)[^>]*\/>/','', $content); - - return $content; - } - - static function compareHTML($from, $to) { - // First split up the content into words and tags - $set1 = self::getHTMLChunks($from); - $set2 = self::getHTMLChunks($to); - - // Diff that - $diff = new Diff($set1, $set2); - - $tagStack[1] = $tagStack[2] = 0; - $rechunked[1] = $rechunked[2] = array(); - - // Go through everything, converting edited tags (and their content) into single chunks. Otherwise - // the generated HTML gets crusty - foreach($diff->edits as $edit) { - switch($edit->type) { - case 'copy': - $lookForTag = false; - $stuffFor[1] = $edit->orig; - $stuffFor[2] = $edit->orig; - break; - - case 'change': - $lookForTag = true; - $stuffFor[1] = $edit->orig; - $stuffFor[2] = $edit->final; - break; - - case 'add': - $lookForTag = true; - $stuffFor[1] = null; - $stuffFor[2] = $edit->final; - break; - - case 'delete': - $lookForTag = true; - $stuffFor[1] = $edit->orig; - $stuffFor[2] = null; - break; - } - - foreach($stuffFor as $listName => $chunks) { - if($chunks) { - foreach($chunks as $item) { - // $tagStack > 0 indicates that we should be tag-building - if($tagStack[$listName]) $rechunked[$listName][sizeof($rechunked[$listName])-1] .= ' ' . $item; - else $rechunked[$listName][] = $item; - - if($lookForTag && isset($item[0]) && $item[0] == "<" && substr($item,0,2) != "edits as $edit) { - switch($edit->type) { - case 'copy': - $content .= " " . implode(" ", $edit->orig) . " "; - break; - - case 'change': - $content .= " " . implode(" ", $edit->final) . " "; - $content .= " " . implode(" ", $edit->orig) . " "; - break; - - case 'add': - $content .= " " . implode(" ", $edit->final) . " "; - break; - - case 'delete': - $content .= " " . implode(" ", $edit->orig) . " "; - break; - } - } - return self::cleanHTML($content); - } - static function getHTMLChunks($content) { - $content = str_replace(array(" ","<", ">"),array(" "," <", "> "),$content); - $candidateChunks = split("[\t\r\n ]+", $content); - while(list($i,$item) = each($candidateChunks)) { - if(isset($item[0]) && $item[0] == "<") { - $newChunk = $item; - while($item[strlen($item)-1] != ">") { - list($i,$item) = each($candidateChunks); - $newChunk .= ' ' . $item; - } - $chunks[] = $newChunk; - } else { - $chunks[] = $item; - } - } - return $chunks; - } - -} - - - - -/** - * Computes diff between sequences of strings. - * @package cms - * @subpackage core - */ -class MappedDiff -extends Diff -{ - /** - * Constructor. - * - * Computes diff between sequences of strings. - * - * This can be used to compute things like - * case-insensitve diffs, or diffs which ignore - * changes in white-space. - * - * @param $from_lines array An array of strings. - * (Typically these are lines from a file.) - * - * @param $to_lines array An array of strings. - * - * @param $mapped_from_lines array 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 $mapped_to_lines array This array should - * have the same number of elements as $to_lines. - */ - function MappedDiff($from_lines, $to_lines, - $mapped_from_lines, $mapped_to_lines) { - - assert(sizeof($from_lines) == sizeof($mapped_from_lines)); - assert(sizeof($to_lines) == sizeof($mapped_to_lines)); - - $this->Diff($mapped_from_lines, $mapped_to_lines); - - $xi = $yi = 0; - // Optimizing loop invariants: - // http://phplens.com/lens/php-book/optimizing-debugging-php.php - for ($i = 0, $max = sizeof($this->edits); $i < $max; $i++) { - $orig = &$this->edits[$i]->orig; - if (is_array($orig)) { - $orig = array_slice($from_lines, $xi, sizeof($orig)); - $xi += sizeof($orig); - } - - $final = &$this->edits[$i]->final; - if (is_array($final)) { - $final = array_slice($to_lines, $yi, sizeof($final)); - $yi += sizeof($final); - } - } - } -} - -?>