/**
* @param int $i
- * @return string|null
+ * @return string[]|string|null
*/
public function getClosing( $i = null ) {
if ( $i === null ) {
}
}
-/**
- * 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 {
- protected $xchanged, $ychanged;
-
- /**
- * @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 ) {
- $wikidiff3 = new WikiDiff3();
- $wikidiff3->diff( $from_lines, $to_lines );
- $this->xchanged = $wikidiff3->removed;
- $this->ychanged = $wikidiff3->added;
- }
-
- /**
- * 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
*/
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.
* @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 );
}
dépôts / lhc / web / wiklou.git / blobdiff