6e9b4f0e9c
Per wikitech-l consensus: https://lists.wikimedia.org/pipermail/wikitech-l/2016-February/084821.html Notes: * Disabled CallTimePassByReference due to false positives (T127163) Change-Id: I2c8ce713ce6600a0bb7bf67537c87044c7a45c4b
1074 lines
25 KiB
PHP
1074 lines
25 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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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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* http://www.gnu.org/copyleft/gpl.html
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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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* The base class for all other DiffOp classes.
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*
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* The classes that extend DiffOp are: DiffOpCopy, DiffOpDelete, DiffOpAdd and
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* DiffOpChange. FakeDiffOp also extends DiffOp, but it is not located in this file.
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*
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* @private
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* @ingroup DifferenceEngine
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*/
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abstract class DiffOp {
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/**
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* @var string
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*/
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public $type;
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/**
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* @var string[]
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*/
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public $orig;
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/**
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* @var string[]
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*/
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public $closing;
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/**
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* @return string
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*/
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public function getType() {
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return $this->type;
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}
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/**
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* @return string[]
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*/
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public function getOrig() {
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return $this->orig;
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}
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/**
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* @param int $i
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* @return string|null
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*/
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public function getClosing( $i = null ) {
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if ( $i === null ) {
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return $this->closing;
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}
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if ( array_key_exists( $i, $this->closing ) ) {
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return $this->closing[$i];
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}
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return null;
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}
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abstract public function reverse();
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/**
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* @return int
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*/
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public function norig() {
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return $this->orig ? count( $this->orig ) : 0;
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}
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/**
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* @return int
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*/
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public function nclosing() {
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return $this->closing ? count( $this->closing ) : 0;
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}
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}
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/**
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* Extends DiffOp. Used to mark strings that have been
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* copied from one string array to the other.
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*
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* @private
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* @ingroup DifferenceEngine
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*/
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class DiffOpCopy extends DiffOp {
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public $type = 'copy';
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public 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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/**
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* @return DiffOpCopy
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*/
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public function reverse() {
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return new DiffOpCopy( $this->closing, $this->orig );
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}
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}
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/**
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* Extends DiffOp. Used to mark strings that have been
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* deleted from the first string array.
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*
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* @private
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* @ingroup DifferenceEngine
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*/
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class DiffOpDelete extends DiffOp {
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public $type = 'delete';
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public 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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/**
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* @return DiffOpAdd
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*/
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public function reverse() {
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return new DiffOpAdd( $this->orig );
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}
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}
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/**
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* Extends DiffOp. Used to mark strings that have been
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* added from the first string array.
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*
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* @private
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* @ingroup DifferenceEngine
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*/
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class DiffOpAdd extends DiffOp {
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public $type = 'add';
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public 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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/**
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* @return DiffOpDelete
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*/
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public function reverse() {
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return new DiffOpDelete( $this->closing );
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}
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}
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/**
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* Extends DiffOp. Used to mark strings that have been
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* changed from the first string array (both added and subtracted).
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*
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* @private
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* @ingroup DifferenceEngine
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*/
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class DiffOpChange extends DiffOp {
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public $type = 'change';
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public 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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/**
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* @return DiffOpChange
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*/
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public function reverse() {
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return new DiffOpChange( $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 (and a bit of code) are 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 = [], $yv = [];
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protected $xind = [], $yind = [];
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protected $seq = [], $in_seq = [];
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protected $lcs = 0;
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/**
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* @param string[] $from_lines
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* @param string[] $to_lines
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*
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* @return DiffOp[]
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*/
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public function diff( $from_lines, $to_lines ) {
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// Diff and store locally
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$this->diffLocal( $from_lines, $to_lines );
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// Merge edits when possible
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$this->shiftBoundaries( $from_lines, $this->xchanged, $this->ychanged );
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$this->shiftBoundaries( $to_lines, $this->ychanged, $this->xchanged );
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// Compute the edit operations.
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$n_from = count( $from_lines );
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$n_to = count( $to_lines );
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$edits = [];
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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 = [];
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while ( $xi < $n_from && $yi < $n_to
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&& !$this->xchanged[$xi] && !$this->ychanged[$yi]
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) {
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$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 DiffOpCopy( $copy );
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}
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// Find deletes & adds.
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$delete = [];
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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 = [];
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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 DiffOpChange( $delete, $add );
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} elseif ( $delete ) {
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$edits[] = new DiffOpDelete( $delete );
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} elseif ( $add ) {
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$edits[] = new DiffOpAdd( $add );
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}
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}
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return $edits;
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}
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/**
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* @param string[] $from_lines
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* @param string[] $to_lines
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*/
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private function diffLocal( $from_lines, $to_lines ) {
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global $wgExternalDiffEngine;
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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 = count( $from_lines );
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$n_to = count( $to_lines );
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$this->xchanged = $this->ychanged = [];
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$this->xv = $this->yv = [];
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$this->xind = $this->yind = [];
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$this->seq = [];
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$this->in_seq = [];
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$this->lcs = 0;
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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 = $n_from;
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$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->lineHash( $from_lines[$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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$this->ychanged[$yi] = empty( $xhash[$this->lineHash( $line )] );
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if ( $this->ychanged[$yi] ) {
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continue;
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}
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$yhash[$this->lineHash( $line )] = 1;
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$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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$this->xchanged[$xi] = empty( $yhash[$this->lineHash( $line )] );
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if ( $this->xchanged[$xi] ) {
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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, count( $this->xv ), 0, count( $this->yv ) );
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}
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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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* @param string $line
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*
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* @return string
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*/
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private function lineHash( $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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* @param int $xoff
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* @param int $xlim
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* @param int $yoff
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* @param int $ylim
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* @param int $nchunks
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*
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* @return array List of two elements, integer and array[].
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*/
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private 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 ) = [ $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]][] = $i;
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}
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}
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$this->lcs = 0;
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$this->seq[0] = $yoff - 1;
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$this->in_seq = [];
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$ymids[0] = [];
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$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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// @codingStandardsIgnoreStart Ignore Squiz.WhiteSpace.SemicolonSpacing.Incorrect
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for ( ; $x < $x1; $x++ ) {
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// @codingStandardsIgnoreEnd
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$line = $flip ? $this->yv[$x] : $this->xv[$x];
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if ( empty( $ymatches[$line] ) ) {
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continue;
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}
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$k = 0;
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$matches = $ymatches[$line];
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reset( $matches );
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while ( list( , $y ) = each( $matches ) ) {
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if ( empty( $this->in_seq[$y] ) ) {
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$k = $this->lcsPos( $y );
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assert( '$k > 0' );
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$ymids[$k] = $ymids[$k - 1];
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break;
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}
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}
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while ( list( , $y ) = each( $matches ) ) {
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if ( $y > $this->seq[$k - 1] ) {
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assert( '$y < $this->seq[$k]' );
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// Optimization: this is a common case:
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// next match is just replacing previous match.
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$this->in_seq[$this->seq[$k]] = false;
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$this->seq[$k] = $y;
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$this->in_seq[$y] = 1;
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} elseif ( empty( $this->in_seq[$y] ) ) {
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$k = $this->lcsPos( $y );
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assert( '$k > 0' );
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$ymids[$k] = $ymids[$k - 1];
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}
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}
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}
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}
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$seps[] = $flip ? [ $yoff, $xoff ] : [ $xoff, $yoff ];
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$ymid = $ymids[$this->lcs];
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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 ? [ $y1, $x1 ] : [ $x1, $y1 ];
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}
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$seps[] = $flip ? [ $ylim, $xlim ] : [ $xlim, $ylim ];
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return [ $this->lcs, $seps ];
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}
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/**
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* @param int $ypos
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*
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* @return int
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*/
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private function lcsPos( $ypos ) {
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$end = $this->lcs;
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if ( $end == 0 || $ypos > $this->seq[$end] ) {
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$this->seq[++$this->lcs] = $ypos;
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$this->in_seq[$ypos] = 1;
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return $this->lcs;
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}
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$beg = 1;
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while ( $beg < $end ) {
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$mid = (int)( ( $beg + $end ) / 2 );
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if ( $ypos > $this->seq[$mid] ) {
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$beg = $mid + 1;
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} else {
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$end = $mid;
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}
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}
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assert( '$ypos != $this->seq[$end]' );
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$this->in_seq[$this->seq[$end]] = false;
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$this->seq[$end] = $ypos;
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$this->in_seq[$ypos] = 1;
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return $end;
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}
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/**
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* Find LCS of two sequences.
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*
|
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* The results are recorded in the vectors $this->{x,y}changed[], by
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* storing a 1 in the element for each line that is an insertion
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* or deletion (ie. is not in the LCS).
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*
|
|
* 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
|
|
* @private
|
|
* @ingroup DifferenceEngine
|
|
*/
|
|
class Diff {
|
|
|
|
/**
|
|
* @var DiffOp[]
|
|
*/
|
|
public $edits;
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
public function __construct( $from_lines, $to_lines ) {
|
|
$eng = new DiffEngine;
|
|
$this->edits = $eng->diff( $from_lines, $to_lines );
|
|
}
|
|
|
|
/**
|
|
* @return DiffOp[]
|
|
*/
|
|
public function getEdits() {
|
|
return $this->edits;
|
|
}
|
|
|
|
/**
|
|
* Compute reversed Diff.
|
|
*
|
|
* SYNOPSIS:
|
|
*
|
|
* $diff = new Diff($lines1, $lines2);
|
|
* $rev = $diff->reverse();
|
|
*
|
|
* @return Object A Diff object representing the inverse of the
|
|
* original diff.
|
|
*/
|
|
public function reverse() {
|
|
$rev = $this;
|
|
$rev->edits = [];
|
|
/** @var DiffOp $edit */
|
|
foreach ( $this->edits as $edit ) {
|
|
$rev->edits[] = $edit->reverse();
|
|
}
|
|
|
|
return $rev;
|
|
}
|
|
|
|
/**
|
|
* Check for empty diff.
|
|
*
|
|
* @return bool True if two sequences were identical.
|
|
*/
|
|
public 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.
|
|
*/
|
|
public function lcs() {
|
|
$lcs = 0;
|
|
foreach ( $this->edits as $edit ) {
|
|
if ( $edit->type == 'copy' ) {
|
|
$lcs += count( $edit->orig );
|
|
}
|
|
}
|
|
|
|
return $lcs;
|
|
}
|
|
|
|
/**
|
|
* Get the original set of lines.
|
|
*
|
|
* This reconstructs the $from_lines parameter passed to the
|
|
* constructor.
|
|
*
|
|
* @return string[] The original sequence of strings.
|
|
*/
|
|
public function orig() {
|
|
$lines = [];
|
|
|
|
foreach ( $this->edits as $edit ) {
|
|
if ( $edit->orig ) {
|
|
array_splice( $lines, count( $lines ), 0, $edit->orig );
|
|
}
|
|
}
|
|
|
|
return $lines;
|
|
}
|
|
|
|
/**
|
|
* Get the closing set of lines.
|
|
*
|
|
* This reconstructs the $to_lines parameter passed to the
|
|
* constructor.
|
|
*
|
|
* @return string[] The sequence of strings.
|
|
*/
|
|
public function closing() {
|
|
$lines = [];
|
|
|
|
foreach ( $this->edits as $edit ) {
|
|
if ( $edit->closing ) {
|
|
array_splice( $lines, count( $lines ), 0, $edit->closing );
|
|
}
|
|
}
|
|
|
|
return $lines;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @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 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' ) {
|
|
$this->line .= "<ins{$this->insClass}>" .
|
|
htmlspecialchars( $this->group ) . '</ins>';
|
|
} elseif ( $this->tag == 'del' ) {
|
|
$this->line .= "<del{$this->delClass}>" .
|
|
htmlspecialchars( $this->group ) . '</del>';
|
|
} 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;
|
|
}
|
|
|
|
}
|