X-Git-Url: https://git.heureux-cyclage.org/?a=blobdiff_plain;f=includes%2Fdiff%2FDairikiDiff.php;h=d38319e1ac9c9d1a32b9eab9a328fd773c167a2b;hb=e305dd6ced6360a33b612dfd5d7a1c5f8aeebcc7;hp=6272e7e992a57c7bdb7bd0b9232ae07f69f946fb;hpb=27d3f08d4e41ca5745c80a57afd441f9250db7e1;p=lhc%2Fweb%2Fwiklou.git diff --git a/includes/diff/DairikiDiff.php b/includes/diff/DairikiDiff.php index 6272e7e992..d38319e1ac 100644 --- a/includes/diff/DairikiDiff.php +++ b/includes/diff/DairikiDiff.php @@ -191,524 +191,6 @@ class DiffOpChange extends DiffOp { } } -/** - * 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 (and a bit of code) are 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 - * - * closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations) - * are my own. - * - * Line length limits for robustness added by Tim Starling, 2005-08-31 - * Alternative implementation added by Guy Van den Broeck, 2008-07-30 - * - * @author Geoffrey T. Dairiki, Tim Starling, Guy Van den Broeck - * @private - * @ingroup DifferenceEngine - */ -class DiffEngine { - const MAX_XREF_LENGTH = 10000; - - protected $xchanged, $ychanged; - - protected $xv = [], $yv = []; - protected $xind = [], $yind = []; - - protected $seq = [], $in_seq = []; - - protected $lcs = 0; - - /** - * @param string[] $from_lines - * @param string[] $to_lines - * - * @return DiffOp[] - */ - public function diff( $from_lines, $to_lines ) { - - // Diff and store locally - $this->diffLocal( $from_lines, $to_lines ); - - // Merge edits when possible - $this->shiftBoundaries( $from_lines, $this->xchanged, $this->ychanged ); - $this->shiftBoundaries( $to_lines, $this->ychanged, $this->xchanged ); - - // Compute the edit operations. - $n_from = count( $from_lines ); - $n_to = count( $to_lines ); - - $edits = []; - $xi = $yi = 0; - while ( $xi < $n_from || $yi < $n_to ) { - assert( $yi < $n_to || $this->xchanged[$xi] ); - assert( $xi < $n_from || $this->ychanged[$yi] ); - - // Skip matching "snake". - $copy = []; - while ( $xi < $n_from && $yi < $n_to - && !$this->xchanged[$xi] && !$this->ychanged[$yi] - ) { - $copy[] = $from_lines[$xi++]; - ++$yi; - } - if ( $copy ) { - $edits[] = new DiffOpCopy( $copy ); - } - - // Find deletes & adds. - $delete = []; - while ( $xi < $n_from && $this->xchanged[$xi] ) { - $delete[] = $from_lines[$xi++]; - } - - $add = []; - while ( $yi < $n_to && $this->ychanged[$yi] ) { - $add[] = $to_lines[$yi++]; - } - - if ( $delete && $add ) { - $edits[] = new DiffOpChange( $delete, $add ); - } elseif ( $delete ) { - $edits[] = new DiffOpDelete( $delete ); - } elseif ( $add ) { - $edits[] = new DiffOpAdd( $add ); - } - } - - return $edits; - } - - /** - * @param string[] $from_lines - * @param string[] $to_lines - */ - private function diffLocal( $from_lines, $to_lines ) { - global $wgExternalDiffEngine; - - if ( $wgExternalDiffEngine == 'wikidiff3' ) { - // wikidiff3 - $wikidiff3 = new WikiDiff3(); - $wikidiff3->diff( $from_lines, $to_lines ); - $this->xchanged = $wikidiff3->removed; - $this->ychanged = $wikidiff3->added; - unset( $wikidiff3 ); - } else { - // old diff - $n_from = count( $from_lines ); - $n_to = count( $to_lines ); - $this->xchanged = $this->ychanged = []; - $this->xv = $this->yv = []; - $this->xind = $this->yind = []; - $this->seq = []; - $this->in_seq = []; - $this->lcs = 0; - - // 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++ ) { - $xhash[$this->lineHash( $from_lines[$xi] )] = 1; - } - - for ( $yi = $skip; $yi < $n_to - $endskip; $yi++ ) { - $line = $to_lines[$yi]; - $this->ychanged[$yi] = empty( $xhash[$this->lineHash( $line )] ); - if ( $this->ychanged[$yi] ) { - continue; - } - $yhash[$this->lineHash( $line )] = 1; - $this->yv[] = $line; - $this->yind[] = $yi; - } - for ( $xi = $skip; $xi < $n_from - $endskip; $xi++ ) { - $line = $from_lines[$xi]; - $this->xchanged[$xi] = empty( $yhash[$this->lineHash( $line )] ); - if ( $this->xchanged[$xi] ) { - continue; - } - $this->xv[] = $line; - $this->xind[] = $xi; - } - - // Find the LCS. - $this->compareSeq( 0, count( $this->xv ), 0, count( $this->yv ) ); - } - } - - /** - * Returns the whole line if it's small enough, or the MD5 hash otherwise - * - * @param string $line - * - * @return string - */ - private function lineHash( $line ) { - if ( strlen( $line ) > self::MAX_XREF_LENGTH ) { - return md5( $line ); - } else { - return $line; - } - } - - /** - * 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. - * - * @param int $xoff - * @param int $xlim - * @param int $yoff - * @param int $ylim - * @param int $nchunks - * - * @return array List of two elements, integer and array[]. - */ - private 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 ) = [ $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 = []; - $ymids[0] = []; - - $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 ); - // @codingStandardsIgnoreStart Ignore Squiz.WhiteSpace.SemicolonSpacing.Incorrect - for ( ; $x < $x1; $x++ ) { - // @codingStandardsIgnoreEnd - $line = $flip ? $this->yv[$x] : $this->xv[$x]; - if ( empty( $ymatches[$line] ) ) { - continue; - } - - $k = 0; - $matches = $ymatches[$line]; - reset( $matches ); - while ( list( , $y ) = each( $matches ) ) { - if ( empty( $this->in_seq[$y] ) ) { - $k = $this->lcsPos( $y ); - assert( $k > 0 ); - $ymids[$k] = $ymids[$k - 1]; - break; - } - } - - while ( list( , $y ) = each( $matches ) ) { - if ( $y > $this->seq[$k - 1] ) { - 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; - } elseif ( empty( $this->in_seq[$y] ) ) { - $k = $this->lcsPos( $y ); - assert( $k > 0 ); - $ymids[$k] = $ymids[$k - 1]; - } - } - } - } - - $seps[] = $flip ? [ $yoff, $xoff ] : [ $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 ? [ $y1, $x1 ] : [ $x1, $y1 ]; - } - $seps[] = $flip ? [ $ylim, $xlim ] : [ $xlim, $ylim ]; - - return [ $this->lcs, $seps ]; - } - - /** - * @param int $ypos - * - * @return int - */ - private function lcsPos( $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; - } - } - - 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. - * - * @param int $xoff - * @param int $xlim - * @param int $yoff - * @param int $ylim - */ - private 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). - */ - private function shiftBoundaries( $lines, &$changed, $other_changed ) { - $i = 0; - $j = 0; - - assert( count( $lines ) == count( $changed ) ); - $len = count( $lines ); - $other_len = count( $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] ) { - 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--; - } - assert( $j > 0 ); - while ( $other_changed[--$j] ) { - continue; - } - 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++; - } - - 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; - assert( $j > 0 ); - while ( $other_changed[--$j] ) { - continue; - } - assert( $j >= 0 && !$other_changed[$j] ); - } - } - } -} - /** * Class representing a 'diff' between two sequences of strings. * @todo document @@ -722,6 +204,12 @@ class Diff { */ public $edits; + /** + * @var int If this diff complexity is exceeded, a ComplexityException is thrown + * 0 means no limit. + */ + protected $bailoutComplexity = 0; + /** * Constructor. * Computes diff between sequences of strings. @@ -729,9 +217,11 @@ class Diff { * @param string[] $from_lines An array of strings. * Typically these are lines from a file. * @param string[] $to_lines An array of strings. + * @throws \MediaWiki\Diff\ComplexityException */ public function __construct( $from_lines, $to_lines ) { $eng = new DiffEngine; + $eng->setBailoutComplexity( $this->bailoutComplexity ); $this->edits = $eng->diff( $from_lines, $to_lines ); } @@ -839,236 +329,7 @@ class Diff { } /** - * @todo document, bad name. - * @private - * @ingroup DifferenceEngine + * @deprecated Alias for WordAccumulator, to be soon removed */ -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 string[] $from_lines An array of strings. - * Typically these are lines from a file. - * @param string[] $to_lines An array of strings. - * @param string[] $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 string[] $mapped_to_lines This array should - * have the same number of elements as $to_lines. - */ - public 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::__construct( $mapped_from_lines, $mapped_to_lines ); - - $xi = $yi = 0; - $editCount = count( $this->edits ); - for ( $i = 0; $i < $editCount; $i++ ) { - $orig = &$this->edits[$i]->orig; - if ( is_array( $orig ) ) { - $orig = array_slice( $from_lines, $xi, count( $orig ) ); - $xi += count( $orig ); - } - - $closing = &$this->edits[$i]->closing; - if ( is_array( $closing ) ) { - $closing = array_slice( $to_lines, $yi, count( $closing ) ); - $yi += count( $closing ); - } - } - } -} - -/** - * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3 - */ - -/** - * @todo document - * @private - * @ingroup DifferenceEngine - */ -class HWLDFWordAccumulator { - public $insClass = ' class="diffchange diffchange-inline"'; - public $delClass = ' class="diffchange diffchange-inline"'; - - private $lines = []; - private $line = ''; - private $group = ''; - private $tag = ''; - - /** - * @param string $new_tag - */ - private function flushGroup( $new_tag ) { - if ( $this->group !== '' ) { - if ( $this->tag == 'ins' ) { - $this->line .= "insClass}>" . - htmlspecialchars( $this->group ) . ''; - } elseif ( $this->tag == 'del' ) { - $this->line .= "delClass}>" . - htmlspecialchars( $this->group ) . ''; - } else { - $this->line .= htmlspecialchars( $this->group ); - } - } - $this->group = ''; - $this->tag = $new_tag; - } - - /** - * @param string $new_tag - */ - private function flushLine( $new_tag ) { - $this->flushGroup( $new_tag ); - if ( $this->line != '' ) { - array_push( $this->lines, $this->line ); - } else { - # make empty lines visible by inserting an NBSP - array_push( $this->lines, ' ' ); - } - $this->line = ''; - } - - /** - * @param string[] $words - * @param string $tag - */ - public function addWords( $words, $tag = '' ) { - if ( $tag != $this->tag ) { - $this->flushGroup( $tag ); - } - - foreach ( $words as $word ) { - // new-line should only come as first char of word. - if ( $word == '' ) { - continue; - } - if ( $word[0] == "\n" ) { - $this->flushLine( $tag ); - $word = substr( $word, 1 ); - } - assert( !strstr( $word, "\n" ) ); - $this->group .= $word; - } - } - - /** - * @return string[] - */ - public function getLines() { - $this->flushLine( '~done' ); - - return $this->lines; - } -} - -/** - * @todo document - * @private - * @ingroup DifferenceEngine - */ -class WordLevelDiff extends MappedDiff { - const MAX_LINE_LENGTH = 10000; - - /** - * @param string[] $orig_lines - * @param string[] $closing_lines - */ - public function __construct( $orig_lines, $closing_lines ) { - - list( $orig_words, $orig_stripped ) = $this->split( $orig_lines ); - list( $closing_words, $closing_stripped ) = $this->split( $closing_lines ); - - parent::__construct( $orig_words, $closing_words, - $orig_stripped, $closing_stripped ); - } - - /** - * @param string[] $lines - * - * @return array[] - */ - private function split( $lines ) { - - $words = []; - $stripped = []; - $first = true; - foreach ( $lines as $line ) { - # If the line is too long, just pretend the entire line is one big word - # This prevents resource exhaustion problems - if ( $first ) { - $first = false; - } else { - $words[] = "\n"; - $stripped[] = "\n"; - } - if ( strlen( $line ) > self::MAX_LINE_LENGTH ) { - $words[] = $line; - $stripped[] = $line; - } else { - $m = []; - if ( preg_match_all( '/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs', - $line, $m ) - ) { - foreach ( $m[0] as $word ) { - $words[] = $word; - } - foreach ( $m[1] as $stripped_word ) { - $stripped[] = $stripped_word; - } - } - } - } - - return [ $words, $stripped ]; - } - - /** - * @return string[] - */ - public function orig() { - $orig = new HWLDFWordAccumulator; - - foreach ( $this->edits as $edit ) { - if ( $edit->type == 'copy' ) { - $orig->addWords( $edit->orig ); - } elseif ( $edit->orig ) { - $orig->addWords( $edit->orig, 'del' ); - } - } - $lines = $orig->getLines(); - - return $lines; - } - - /** - * @return string[] - */ - public function closing() { - $closing = new HWLDFWordAccumulator; - - foreach ( $this->edits as $edit ) { - if ( $edit->type == 'copy' ) { - $closing->addWords( $edit->closing ); - } elseif ( $edit->closing ) { - $closing->addWords( $edit->closing, 'ins' ); - } - } - $lines = $closing->getLines(); - - return $lines; - } - +class HWLDFWordAccumulator extends MediaWiki\Diff\WordAccumulator { }