--- /dev/null
+<?php
+/**
+ * A PHP diff engine for phpwiki. (Taken from phpwiki-1.3.3)
+ *
+ * Copyright © 2000, 2001 Geoffrey T. Dairiki <dairiki@dairiki.org>
+ * You may copy this code freely under the conditions of the GPL.
+ *
+ * @file
+ * @ingroup DifferenceEngine
+ * @defgroup DifferenceEngine DifferenceEngine
+ */
+
+/**
+ * @todo document
+ * @private
+ * @ingroup DifferenceEngine
+ */
+class _DiffOp {
+ var $type;
+ var $orig;
+ var $closing;
+
+ function reverse() {
+ trigger_error( 'pure virtual', E_USER_ERROR );
+ }
+
+ function norig() {
+ return $this->orig ? sizeof( $this->orig ) : 0;
+ }
+
+ function nclosing() {
+ return $this->closing ? sizeof( $this->closing ) : 0;
+ }
+}
+
+/**
+ * @todo document
+ * @private
+ * @ingroup DifferenceEngine
+ */
+class _DiffOp_Copy extends _DiffOp {
+ var $type = 'copy';
+
+ function __construct ( $orig, $closing = false ) {
+ if ( !is_array( $closing ) )
+ $closing = $orig;
+ $this->orig = $orig;
+ $this->closing = $closing;
+ }
+
+ function reverse() {
+ return new _DiffOp_Copy( $this->closing, $this->orig );
+ }
+}
+
+/**
+ * @todo document
+ * @private
+ * @ingroup DifferenceEngine
+ */
+class _DiffOp_Delete extends _DiffOp {
+ var $type = 'delete';
+
+ function __construct ( $lines ) {
+ $this->orig = $lines;
+ $this->closing = false;
+ }
+
+ function reverse() {
+ return new _DiffOp_Add( $this->orig );
+ }
+}
+
+/**
+ * @todo document
+ * @private
+ * @ingroup DifferenceEngine
+ */
+class _DiffOp_Add extends _DiffOp {
+ var $type = 'add';
+
+ function __construct ( $lines ) {
+ $this->closing = $lines;
+ $this->orig = false;
+ }
+
+ function reverse() {
+ return new _DiffOp_Delete( $this->closing );
+ }
+}
+
+/**
+ * @todo document
+ * @private
+ * @ingroup DifferenceEngine
+ */
+class _DiffOp_Change extends _DiffOp {
+ var $type = 'change';
+
+ function __construct ( $orig, $closing ) {
+ $this->orig = $orig;
+ $this->closing = $closing;
+ }
+
+ function reverse() {
+ return new _DiffOp_Change( $this->closing, $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
+ *
+ * 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;
+
+ function diff ( $from_lines, $to_lines ) {
+ wfProfileIn( __METHOD__ );
+
+ // Diff and store locally
+ $this->diff_local( $from_lines, $to_lines );
+
+ // 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.
+ $n_from = sizeof( $from_lines );
+ $n_to = sizeof( $to_lines );
+
+ $edits = array();
+ $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 = 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 );
+ }
+ wfProfileOut( __METHOD__ );
+ return $edits;
+ }
+
+ function diff_local ( $from_lines, $to_lines ) {
+ global $wgExternalDiffEngine;
+ wfProfileIn( __METHOD__ );
+
+ 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 = 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++ ) {
+ $xhash[$this->_line_hash( $from_lines[$xi] )] = 1;
+ }
+
+ for ( $yi = $skip; $yi < $n_to - $endskip; $yi++ ) {
+ $line = $to_lines[$yi];
+ if ( ( $this->ychanged[$yi] = empty( $xhash[$this->_line_hash( $line )] ) ) )
+ continue;
+ $yhash[$this->_line_hash( $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( $yhash[$this->_line_hash( $line )] ) ) )
+ continue;
+ $this->xv[] = $line;
+ $this->xind[] = $xi;
+ }
+
+ // Find the LCS.
+ $this->_compareseq( 0, sizeof( $this->xv ), 0, sizeof( $this->yv ) );
+ }
+ wfProfileOut( __METHOD__ );
+ }
+
+ /**
+ * Returns the whole line if it's small enough, or the MD5 hash otherwise
+ */
+ function _line_hash( $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.
+ */
+ 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( , $y ) = each( $matches ) ) {
+ if ( empty( $this->in_seq[$y] ) ) {
+ $k = $this->_lcs_pos( $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;
+ } else if ( empty( $this->in_seq[$y] ) ) {
+ $k = $this->_lcs_pos( $y );
+ 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;
+ }
+
+ 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 ) {
+ wfProfileIn( __METHOD__ );
+ $i = 0;
+ $j = 0;
+
+ assert( 'sizeof($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] ) {
+ 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]' );
+ }
+ }
+ wfProfileOut( __METHOD__ );
+ }
+}
+
+/**
+ * Class representing a 'diff' between two sequences of strings.
+ * @todo document
+ * @private
+ * @ingroup DifferenceEngine
+ */
+class Diff
+{
+ 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 __construct( $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 closing set of lines.
+ *
+ * This reconstructs the $to_lines parameter passed to the
+ * constructor.
+ *
+ * @return array The sequence of strings.
+ */
+ function closing() {
+ $lines = array();
+
+ foreach ( $this->edits as $edit ) {
+ if ( $edit->closing )
+ array_splice( $lines, sizeof( $lines ), 0, $edit->closing );
+ }
+ return $lines;
+ }
+
+ /**
+ * Check a Diff for validity.
+ *
+ * This is here only for debugging purposes.
+ */
+ function _check ( $from_lines, $to_lines ) {
+ wfProfileIn( __METHOD__ );
+ if ( serialize( $from_lines ) != serialize( $this->orig() ) )
+ trigger_error( "Reconstructed original doesn't match", E_USER_ERROR );
+ if ( serialize( $to_lines ) != serialize( $this->closing() ) )
+ trigger_error( "Reconstructed closing 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->closing() ) )
+ trigger_error( "Reversed closing 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 );
+ wfProfileOut( __METHOD__ );
+ }
+}
+
+/**
+ * @todo document, bad name.
+ * @private
+ * @ingroup DifferenceEngine
+ */
+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 __construct( $from_lines, $to_lines,
+ $mapped_from_lines, $mapped_to_lines ) {
+ wfProfileIn( __METHOD__ );
+
+ assert( sizeof( $from_lines ) == sizeof( $mapped_from_lines ) );
+ assert( sizeof( $to_lines ) == sizeof( $mapped_to_lines ) );
+
+ parent::__construct( $mapped_from_lines, $mapped_to_lines );
+
+ $xi = $yi = 0;
+ for ( $i = 0; $i < sizeof( $this->edits ); $i++ ) {
+ $orig = &$this->edits[$i]->orig;
+ if ( is_array( $orig ) ) {
+ $orig = array_slice( $from_lines, $xi, sizeof( $orig ) );
+ $xi += sizeof( $orig );
+ }
+
+ $closing = &$this->edits[$i]->closing;
+ if ( is_array( $closing ) ) {
+ $closing = array_slice( $to_lines, $yi, sizeof( $closing ) );
+ $yi += sizeof( $closing );
+ }
+ }
+ wfProfileOut( __METHOD__ );
+ }
+}
+
+/**
+ * A class to format Diffs
+ *
+ * This class formats the diff in classic diff format.
+ * It is intended that this class be customized via inheritance,
+ * to obtain fancier outputs.
+ * @todo document
+ * @private
+ * @ingroup DifferenceEngine
+ */
+class DiffFormatter {
+ /**
+ * Number of leading context "lines" to preserve.
+ *
+ * This should be left at zero for this class, but subclasses
+ * may want to set this to other values.
+ */
+ var $leading_context_lines = 0;
+
+ /**
+ * Number of trailing context "lines" to preserve.
+ *
+ * This should be left at zero for this class, but subclasses
+ * may want to set this to other values.
+ */
+ var $trailing_context_lines = 0;
+
+ /**
+ * Format a diff.
+ *
+ * @param $diff object A Diff object.
+ * @return string The formatted output.
+ */
+ function format( $diff ) {
+ wfProfileIn( __METHOD__ );
+
+ $xi = $yi = 1;
+ $block = false;
+ $context = array();
+
+ $nlead = $this->leading_context_lines;
+ $ntrail = $this->trailing_context_lines;
+
+ $this->_start_diff();
+
+ foreach ( $diff->edits as $edit ) {
+ if ( $edit->type == 'copy' ) {
+ if ( is_array( $block ) ) {
+ if ( sizeof( $edit->orig ) <= $nlead + $ntrail ) {
+ $block[] = $edit;
+ }
+ else {
+ if ( $ntrail ) {
+ $context = array_slice( $edit->orig, 0, $ntrail );
+ $block[] = new _DiffOp_Copy( $context );
+ }
+ $this->_block( $x0, $ntrail + $xi - $x0,
+ $y0, $ntrail + $yi - $y0,
+ $block );
+ $block = false;
+ }
+ }
+ $context = $edit->orig;
+ }
+ else {
+ if ( ! is_array( $block ) ) {
+ $context = array_slice( $context, sizeof( $context ) - $nlead );
+ $x0 = $xi - sizeof( $context );
+ $y0 = $yi - sizeof( $context );
+ $block = array();
+ if ( $context )
+ $block[] = new _DiffOp_Copy( $context );
+ }
+ $block[] = $edit;
+ }
+
+ if ( $edit->orig )
+ $xi += sizeof( $edit->orig );
+ if ( $edit->closing )
+ $yi += sizeof( $edit->closing );
+ }
+
+ if ( is_array( $block ) )
+ $this->_block( $x0, $xi - $x0,
+ $y0, $yi - $y0,
+ $block );
+
+ $end = $this->_end_diff();
+ wfProfileOut( __METHOD__ );
+ return $end;
+ }
+
+ function _block( $xbeg, $xlen, $ybeg, $ylen, &$edits ) {
+ wfProfileIn( __METHOD__ );
+ $this->_start_block( $this->_block_header( $xbeg, $xlen, $ybeg, $ylen ) );
+ foreach ( $edits as $edit ) {
+ if ( $edit->type == 'copy' )
+ $this->_context( $edit->orig );
+ elseif ( $edit->type == 'add' )
+ $this->_added( $edit->closing );
+ elseif ( $edit->type == 'delete' )
+ $this->_deleted( $edit->orig );
+ elseif ( $edit->type == 'change' )
+ $this->_changed( $edit->orig, $edit->closing );
+ else
+ trigger_error( 'Unknown edit type', E_USER_ERROR );
+ }
+ $this->_end_block();
+ wfProfileOut( __METHOD__ );
+ }
+
+ function _start_diff() {
+ ob_start();
+ }
+
+ function _end_diff() {
+ $val = ob_get_contents();
+ ob_end_clean();
+ return $val;
+ }
+
+ function _block_header( $xbeg, $xlen, $ybeg, $ylen ) {
+ if ( $xlen > 1 )
+ $xbeg .= "," . ( $xbeg + $xlen - 1 );
+ if ( $ylen > 1 )
+ $ybeg .= "," . ( $ybeg + $ylen - 1 );
+
+ return $xbeg . ( $xlen ? ( $ylen ? 'c' : 'd' ) : 'a' ) . $ybeg;
+ }
+
+ function _start_block( $header ) {
+ echo $header . "\n";
+ }
+
+ function _end_block() {
+ }
+
+ function _lines( $lines, $prefix = ' ' ) {
+ foreach ( $lines as $line )
+ echo "$prefix $line\n";
+ }
+
+ function _context( $lines ) {
+ $this->_lines( $lines );
+ }
+
+ function _added( $lines ) {
+ $this->_lines( $lines, '>' );
+ }
+ function _deleted( $lines ) {
+ $this->_lines( $lines, '<' );
+ }
+
+ function _changed( $orig, $closing ) {
+ $this->_deleted( $orig );
+ echo "---\n";
+ $this->_added( $closing );
+ }
+}
+
+/**
+ * A formatter that outputs unified diffs
+ * @ingroup DifferenceEngine
+ */
+
+class UnifiedDiffFormatter extends DiffFormatter {
+ var $leading_context_lines = 2;
+ var $trailing_context_lines = 2;
+
+ function _added( $lines ) {
+ $this->_lines( $lines, '+' );
+ }
+ function _deleted( $lines ) {
+ $this->_lines( $lines, '-' );
+ }
+ function _changed( $orig, $closing ) {
+ $this->_deleted( $orig );
+ $this->_added( $closing );
+ }
+ function _block_header( $xbeg, $xlen, $ybeg, $ylen ) {
+ return "@@ -$xbeg,$xlen +$ybeg,$ylen @@";
+ }
+}
+
+/**
+ * A pseudo-formatter that just passes along the Diff::$edits array
+ * @ingroup DifferenceEngine
+ */
+class ArrayDiffFormatter extends DiffFormatter {
+ function format( $diff ) {
+ $oldline = 1;
+ $newline = 1;
+ $retval = array();
+ foreach ( $diff->edits as $edit )
+ switch( $edit->type ) {
+ case 'add':
+ foreach ( $edit->closing as $l ) {
+ $retval[] = array(
+ 'action' => 'add',
+ 'new' => $l,
+ 'newline' => $newline++
+ );
+ }
+ break;
+ case 'delete':
+ foreach ( $edit->orig as $l ) {
+ $retval[] = array(
+ 'action' => 'delete',
+ 'old' => $l,
+ 'oldline' => $oldline++,
+ );
+ }
+ break;
+ case 'change':
+ foreach ( $edit->orig as $i => $l ) {
+ $retval[] = array(
+ 'action' => 'change',
+ 'old' => $l,
+ 'new' => @$edit->closing[$i],
+ 'oldline' => $oldline++,
+ 'newline' => $newline++,
+ );
+ }
+ break;
+ case 'copy':
+ $oldline += count( $edit->orig );
+ $newline += count( $edit->orig );
+ }
+ return $retval;
+ }
+}
+
+/**
+ * Additions by Axel Boldt follow, partly taken from diff.php, phpwiki-1.3.3
+ *
+ */
+
+define( 'NBSP', ' ' ); // iso-8859-x non-breaking space.
+
+/**
+ * @todo document
+ * @private
+ * @ingroup DifferenceEngine
+ */
+class _HWLDF_WordAccumulator {
+ function __construct () {
+ $this->_lines = array();
+ $this->_line = '';
+ $this->_group = '';
+ $this->_tag = '';
+ }
+
+ function _flushGroup ( $new_tag ) {
+ if ( $this->_group !== '' ) {
+ if ( $this->_tag == 'ins' )
+ $this->_line .= '<ins class="diffchange diffchange-inline">' .
+ htmlspecialchars ( $this->_group ) . '</ins>';
+ elseif ( $this->_tag == 'del' )
+ $this->_line .= '<del class="diffchange diffchange-inline">' .
+ htmlspecialchars ( $this->_group ) . '</del>';
+ else
+ $this->_line .= htmlspecialchars ( $this->_group );
+ }
+ $this->_group = '';
+ $this->_tag = $new_tag;
+ }
+
+ 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, NBSP );
+ $this->_line = '';
+ }
+
+ 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;
+ }
+ }
+
+ function getLines() {
+ $this->_flushLine( '~done' );
+ return $this->_lines;
+ }
+}
+
+/**
+ * @todo document
+ * @private
+ * @ingroup DifferenceEngine
+ */
+class WordLevelDiff extends MappedDiff {
+ const MAX_LINE_LENGTH = 10000;
+
+ function __construct ( $orig_lines, $closing_lines ) {
+ wfProfileIn( __METHOD__ );
+
+ 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 );
+ wfProfileOut( __METHOD__ );
+ }
+
+ function _split( $lines ) {
+ wfProfileIn( __METHOD__ );
+
+ $words = array();
+ $stripped = array();
+ $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 = array();
+ if ( preg_match_all( '/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs',
+ $line, $m ) )
+ {
+ $words = array_merge( $words, $m[0] );
+ $stripped = array_merge( $stripped, $m[1] );
+ }
+ }
+ }
+ wfProfileOut( __METHOD__ );
+ return array( $words, $stripped );
+ }
+
+ function orig () {
+ wfProfileIn( __METHOD__ );
+ $orig = new _HWLDF_WordAccumulator;
+
+ foreach ( $this->edits as $edit ) {
+ if ( $edit->type == 'copy' )
+ $orig->addWords( $edit->orig );
+ elseif ( $edit->orig )
+ $orig->addWords( $edit->orig, 'del' );
+ }
+ $lines = $orig->getLines();
+ wfProfileOut( __METHOD__ );
+ return $lines;
+ }
+
+ function closing () {
+ wfProfileIn( __METHOD__ );
+ $closing = new _HWLDF_WordAccumulator;
+
+ foreach ( $this->edits as $edit ) {
+ if ( $edit->type == 'copy' )
+ $closing->addWords( $edit->closing );
+ elseif ( $edit->closing )
+ $closing->addWords( $edit->closing, 'ins' );
+ }
+ $lines = $closing->getLines();
+ wfProfileOut( __METHOD__ );
+ return $lines;
+ }
+}
+
+/**
+ * Wikipedia Table style diff formatter.
+ * @todo document
+ * @private
+ * @ingroup DifferenceEngine
+ */
+class TableDiffFormatter extends DiffFormatter {
+ function __construct() {
+ $this->leading_context_lines = 2;
+ $this->trailing_context_lines = 2;
+ }
+
+ public static function escapeWhiteSpace( $msg ) {
+ $msg = preg_replace( '/^ /m', '  ', $msg );
+ $msg = preg_replace( '/ $/m', '  ', $msg );
+ $msg = preg_replace( '/ /', '  ', $msg );
+ return $msg;
+ }
+
+ function _block_header( $xbeg, $xlen, $ybeg, $ylen ) {
+ $r = '<tr><td colspan="2" class="diff-lineno"><!--LINE ' . $xbeg . "--></td>\n" .
+ '<td colspan="2" class="diff-lineno"><!--LINE ' . $ybeg . "--></td></tr>\n";
+ return $r;
+ }
+
+ function _start_block( $header ) {
+ echo $header;
+ }
+
+ function _end_block() {
+ }
+
+ function _lines( $lines, $prefix = ' ', $color = 'white' ) {
+ }
+
+ # HTML-escape parameter before calling this
+ function addedLine( $line ) {
+ return $this->wrapLine( '+', 'diff-addedline', $line );
+ }
+
+ # HTML-escape parameter before calling this
+ function deletedLine( $line ) {
+ return $this->wrapLine( '−', 'diff-deletedline', $line );
+ }
+
+ # HTML-escape parameter before calling this
+ function contextLine( $line ) {
+ return $this->wrapLine( ' ', 'diff-context', $line );
+ }
+
+ private function wrapLine( $marker, $class, $line ) {
+ if ( $line !== '' ) {
+ // The <div> wrapper is needed for 'overflow: auto' style to scroll properly
+ $line = Xml::tags( 'div', null, $this->escapeWhiteSpace( $line ) );
+ }
+ return "<td class='diff-marker'>$marker</td><td class='$class'>$line</td>";
+ }
+
+ function emptyLine() {
+ return '<td colspan="2"> </td>';
+ }
+
+ function _added( $lines ) {
+ foreach ( $lines as $line ) {
+ echo '<tr>' . $this->emptyLine() .
+ $this->addedLine( '<ins class="diffchange">' .
+ htmlspecialchars ( $line ) . '</ins>' ) . "</tr>\n";
+ }
+ }
+
+ function _deleted( $lines ) {
+ foreach ( $lines as $line ) {
+ echo '<tr>' . $this->deletedLine( '<del class="diffchange">' .
+ htmlspecialchars ( $line ) . '</del>' ) .
+ $this->emptyLine() . "</tr>\n";
+ }
+ }
+
+ function _context( $lines ) {
+ foreach ( $lines as $line ) {
+ echo '<tr>' .
+ $this->contextLine( htmlspecialchars ( $line ) ) .
+ $this->contextLine( htmlspecialchars ( $line ) ) . "</tr>\n";
+ }
+ }
+
+ function _changed( $orig, $closing ) {
+ wfProfileIn( __METHOD__ );
+
+ $diff = new WordLevelDiff( $orig, $closing );
+ $del = $diff->orig();
+ $add = $diff->closing();
+
+ # Notice that WordLevelDiff returns HTML-escaped output.
+ # Hence, we will be calling addedLine/deletedLine without HTML-escaping.
+
+ while ( $line = array_shift( $del ) ) {
+ $aline = array_shift( $add );
+ echo '<tr>' . $this->deletedLine( $line ) .
+ $this->addedLine( $aline ) . "</tr>\n";
+ }
+ foreach ( $add as $line ) { # If any leftovers
+ echo '<tr>' . $this->emptyLine() .
+ $this->addedLine( $line ) . "</tr>\n";
+ }
+ wfProfileOut( __METHOD__ );
+ }
+}
scripts.mit.edu / autoinstalls / mediawiki.git / blobdiff