1295 lines
32 KiB
PHP
1295 lines
32 KiB
PHP
<?php
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/**
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* A PHP diff engine for phpwiki. (Taken from phpwiki-1.3.3)
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*
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* Copyright © 2000, 2001 Geoffrey T. Dairiki <dairiki@dairiki.org>
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* You may copy this code freely under the conditions of the GPL.
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*
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* @file
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* @ingroup DifferenceEngine
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* @defgroup DifferenceEngine DifferenceEngine
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*/
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/**
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* @todo document
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* @private
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* @ingroup DifferenceEngine
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*/
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class _DiffOp {
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var $type;
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var $orig;
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var $closing;
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function reverse() {
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trigger_error( 'pure virtual', E_USER_ERROR );
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}
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function norig() {
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||
return $this->orig ? sizeof( $this->orig ) : 0;
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}
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function nclosing() {
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return $this->closing ? sizeof( $this->closing ) : 0;
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}
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}
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/**
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* @todo document
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* @private
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* @ingroup DifferenceEngine
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*/
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class _DiffOp_Copy extends _DiffOp {
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var $type = 'copy';
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function __construct( $orig, $closing = false ) {
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if ( !is_array( $closing ) ) {
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$closing = $orig;
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}
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$this->orig = $orig;
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$this->closing = $closing;
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}
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function reverse() {
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return new _DiffOp_Copy( $this->closing, $this->orig );
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}
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||
}
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/**
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* @todo document
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* @private
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* @ingroup DifferenceEngine
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*/
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class _DiffOp_Delete extends _DiffOp {
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var $type = 'delete';
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function __construct( $lines ) {
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$this->orig = $lines;
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$this->closing = false;
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}
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function reverse() {
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return new _DiffOp_Add( $this->orig );
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}
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}
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/**
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* @todo document
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||
* @private
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* @ingroup DifferenceEngine
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*/
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class _DiffOp_Add extends _DiffOp {
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var $type = 'add';
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function __construct( $lines ) {
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$this->closing = $lines;
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$this->orig = false;
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}
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function reverse() {
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return new _DiffOp_Delete( $this->closing );
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}
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}
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/**
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* @todo document
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* @private
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* @ingroup DifferenceEngine
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*/
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class _DiffOp_Change extends _DiffOp {
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var $type = 'change';
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function __construct( $orig, $closing ) {
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$this->orig = $orig;
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$this->closing = $closing;
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}
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function reverse() {
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return new _DiffOp_Change( $this->closing, $this->orig );
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}
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}
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/**
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* Class used internally by Diff to actually compute the diffs.
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*
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* The algorithm used here is mostly lifted from the perl module
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* Algorithm::Diff (version 1.06) by Ned Konz, which is available at:
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* http://www.perl.com/CPAN/authors/id/N/NE/NEDKONZ/Algorithm-Diff-1.06.zip
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*
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* More ideas are taken from:
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* http://www.ics.uci.edu/~eppstein/161/960229.html
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*
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* Some ideas are (and a bit of code) are from from analyze.c, from GNU
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* diffutils-2.7, which can be found at:
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* ftp://gnudist.gnu.org/pub/gnu/diffutils/diffutils-2.7.tar.gz
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*
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* closingly, some ideas (subdivision by NCHUNKS > 2, and some optimizations)
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* are my own.
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*
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* Line length limits for robustness added by Tim Starling, 2005-08-31
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* Alternative implementation added by Guy Van den Broeck, 2008-07-30
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*
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* @author Geoffrey T. Dairiki, Tim Starling, Guy Van den Broeck
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* @private
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* @ingroup DifferenceEngine
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*/
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class _DiffEngine {
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const MAX_XREF_LENGTH = 10000;
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protected $xchanged, $ychanged;
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protected $xv = array(), $yv = array();
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protected $xind = array(), $yind = array();
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protected $seq = array(), $in_seq = array();
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protected $lcs = 0;
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function diff ( $from_lines, $to_lines ) {
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wfProfileIn( __METHOD__ );
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// Diff and store locally
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$this->diff_local( $from_lines, $to_lines );
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// Merge edits when possible
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$this->_shift_boundaries( $from_lines, $this->xchanged, $this->ychanged );
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$this->_shift_boundaries( $to_lines, $this->ychanged, $this->xchanged );
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// Compute the edit operations.
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$n_from = sizeof( $from_lines );
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$n_to = sizeof( $to_lines );
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$edits = array();
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$xi = $yi = 0;
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while ( $xi < $n_from || $yi < $n_to ) {
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assert( $yi < $n_to || $this->xchanged[$xi] );
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assert( $xi < $n_from || $this->ychanged[$yi] );
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// Skip matching "snake".
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$copy = array();
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while ( $xi < $n_from && $yi < $n_to
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&& !$this->xchanged[$xi] && !$this->ychanged[$yi] ) {
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$copy[] = $from_lines[$xi++];
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++$yi;
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}
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if ( $copy ) {
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$edits[] = new _DiffOp_Copy( $copy );
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}
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// Find deletes & adds.
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$delete = array();
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while ( $xi < $n_from && $this->xchanged[$xi] ) {
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$delete[] = $from_lines[$xi++];
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}
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$add = array();
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while ( $yi < $n_to && $this->ychanged[$yi] ) {
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$add[] = $to_lines[$yi++];
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}
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if ( $delete && $add ) {
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$edits[] = new _DiffOp_Change( $delete, $add );
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} elseif ( $delete ) {
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$edits[] = new _DiffOp_Delete( $delete );
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} elseif ( $add ) {
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$edits[] = new _DiffOp_Add( $add );
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}
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}
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wfProfileOut( __METHOD__ );
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return $edits;
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}
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function diff_local ( $from_lines, $to_lines ) {
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global $wgExternalDiffEngine;
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wfProfileIn( __METHOD__ );
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if ( $wgExternalDiffEngine == 'wikidiff3' ) {
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// wikidiff3
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$wikidiff3 = new WikiDiff3();
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$wikidiff3->diff( $from_lines, $to_lines );
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$this->xchanged = $wikidiff3->removed;
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$this->ychanged = $wikidiff3->added;
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unset( $wikidiff3 );
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} else {
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// old diff
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$n_from = sizeof( $from_lines );
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$n_to = sizeof( $to_lines );
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$this->xchanged = $this->ychanged = array();
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$this->xv = $this->yv = array();
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$this->xind = $this->yind = array();
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unset( $this->seq );
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unset( $this->in_seq );
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unset( $this->lcs );
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// Skip leading common lines.
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for ( $skip = 0; $skip < $n_from && $skip < $n_to; $skip++ ) {
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if ( $from_lines[$skip] !== $to_lines[$skip] ) {
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break;
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}
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$this->xchanged[$skip] = $this->ychanged[$skip] = false;
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}
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// Skip trailing common lines.
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$xi = $n_from; $yi = $n_to;
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for ( $endskip = 0; --$xi > $skip && --$yi > $skip; $endskip++ ) {
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if ( $from_lines[$xi] !== $to_lines[$yi] ) {
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break;
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}
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$this->xchanged[$xi] = $this->ychanged[$yi] = false;
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}
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// Ignore lines which do not exist in both files.
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for ( $xi = $skip; $xi < $n_from - $endskip; $xi++ ) {
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$xhash[$this->_line_hash( $from_lines[$xi] )] = 1;
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}
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for ( $yi = $skip; $yi < $n_to - $endskip; $yi++ ) {
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$line = $to_lines[$yi];
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if ( ( $this->ychanged[$yi] = empty( $xhash[$this->_line_hash( $line )] ) ) ) {
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continue;
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}
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$yhash[$this->_line_hash( $line )] = 1;
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$this->yv[] = $line;
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$this->yind[] = $yi;
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}
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for ( $xi = $skip; $xi < $n_from - $endskip; $xi++ ) {
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$line = $from_lines[$xi];
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if ( ( $this->xchanged[$xi] = empty( $yhash[$this->_line_hash( $line )] ) ) ) {
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continue;
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}
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$this->xv[] = $line;
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$this->xind[] = $xi;
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}
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// Find the LCS.
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$this->_compareseq( 0, sizeof( $this->xv ), 0, sizeof( $this->yv ) );
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}
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wfProfileOut( __METHOD__ );
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}
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/**
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||
* Returns the whole line if it's small enough, or the MD5 hash otherwise
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||
*/
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||
function _line_hash( $line ) {
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||
if ( strlen( $line ) > self::MAX_XREF_LENGTH ) {
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return md5( $line );
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} else {
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return $line;
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||
}
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}
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/**
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* Divide the Largest Common Subsequence (LCS) of the sequences
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* [XOFF, XLIM) and [YOFF, YLIM) into NCHUNKS approximately equally
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* sized segments.
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*
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* Returns (LCS, PTS). LCS is the length of the LCS. PTS is an
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* array of NCHUNKS+1 (X, Y) indexes giving the diving points between
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* sub sequences. The first sub-sequence is contained in [X0, X1),
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* [Y0, Y1), the second in [X1, X2), [Y1, Y2) and so on. Note
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* that (X0, Y0) == (XOFF, YOFF) and
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* (X[NCHUNKS], Y[NCHUNKS]) == (XLIM, YLIM).
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*
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* This function assumes that the first lines of the specified portions
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* of the two files do not match, and likewise that the last lines do not
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* match. The caller must trim matching lines from the beginning and end
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* of the portions it is going to specify.
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*/
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function _diag( $xoff, $xlim, $yoff, $ylim, $nchunks ) {
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$flip = false;
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if ( $xlim - $xoff > $ylim - $yoff ) {
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// Things seems faster (I'm not sure I understand why)
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// when the shortest sequence in X.
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$flip = true;
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list( $xoff, $xlim, $yoff, $ylim ) = array( $yoff, $ylim, $xoff, $xlim );
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}
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if ( $flip ) {
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for ( $i = $ylim - 1; $i >= $yoff; $i-- ) {
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$ymatches[$this->xv[$i]][] = $i;
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}
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} else {
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for ( $i = $ylim - 1; $i >= $yoff; $i-- ) {
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$ymatches[$this->yv[$i]][] = $i;
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}
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}
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||
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$this->lcs = 0;
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$this->seq[0] = $yoff - 1;
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$this->in_seq = array();
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$ymids[0] = array();
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$numer = $xlim - $xoff + $nchunks - 1;
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$x = $xoff;
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for ( $chunk = 0; $chunk < $nchunks; $chunk++ ) {
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if ( $chunk > 0 ) {
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for ( $i = 0; $i <= $this->lcs; $i++ ) {
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$ymids[$i][$chunk -1] = $this->seq[$i];
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}
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}
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$x1 = $xoff + (int)( ( $numer + ( $xlim -$xoff ) * $chunk ) / $nchunks );
|
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for ( ; $x < $x1; $x++ ) {
|
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$line = $flip ? $this->yv[$x] : $this->xv[$x];
|
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if ( empty( $ymatches[$line] ) ) {
|
||
continue;
|
||
}
|
||
$matches = $ymatches[$line];
|
||
reset( $matches );
|
||
while ( list( , $y ) = each( $matches ) ) {
|
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if ( empty( $this->in_seq[$y] ) ) {
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$k = $this->_lcs_pos( $y );
|
||
assert( $k > 0 );
|
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$ymids[$k] = $ymids[$k -1];
|
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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[$k]] = false;
|
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$this->seq[$k] = $y;
|
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$this->in_seq[$y] = 1;
|
||
} elseif ( empty( $this->in_seq[$y] ) ) {
|
||
$k = $this->_lcs_pos( $y );
|
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assert( $k > 0 );
|
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$ymids[$k] = $ymids[$k -1];
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
$seps[] = $flip ? array( $yoff, $xoff ) : array( $xoff, $yoff );
|
||
$ymid = $ymids[$this->lcs];
|
||
for ( $n = 0; $n < $nchunks - 1; $n++ ) {
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$x1 = $xoff + (int)( ( $numer + ( $xlim - $xoff ) * $n ) / $nchunks );
|
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$y1 = $ymid[$n] + 1;
|
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$seps[] = $flip ? array( $y1, $x1 ) : array( $x1, $y1 );
|
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}
|
||
$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 Diff 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' => isset( $edit->closing[$i] ) ? $edit->closing[$i] : null,
|
||
'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__ );
|
||
}
|
||
}
|