MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / includes / diff / WordLevelDiff.php

diff --git a/includes/diff/WordLevelDiff.php b/includes/diff/WordLevelDiff.php
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+<?php
+/**
+ * Copyright © 2000, 2001 Geoffrey T. Dairiki <dairiki@dairiki.org>
+ * You may copy this code freely under the conditions of the GPL.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup DifferenceEngine
+ * @defgroup DifferenceEngine DifferenceEngine
+ */
+
+use MediaWiki\Diff\ComplexityException;
+use MediaWiki\Diff\WordAccumulator;
+
+/**
+ * Performs a word-level diff on several lines
+ *
+ * @ingroup DifferenceEngine
+ */
+class WordLevelDiff extends \Diff {
+       /**
+        * @inheritDoc
+        */
+       protected $bailoutComplexity = 40000000; // Roughly 6K x 6K words changed
+
+       /**
+        * @param string[] $linesBefore
+        * @param string[] $linesAfter
+        */
+       public function __construct( $linesBefore, $linesAfter ) {
+               list( $wordsBefore, $wordsBeforeStripped ) = $this->split( $linesBefore );
+               list( $wordsAfter, $wordsAfterStripped ) = $this->split( $linesAfter );
+
+               try {
+                       parent::__construct( $wordsBeforeStripped, $wordsAfterStripped );
+               } catch ( ComplexityException $ex ) {
+                       // Too hard to diff, just show whole paragraph(s) as changed
+                       $this->edits = [ new DiffOpChange( $linesBefore, $linesAfter ) ];
+               }
+
+               $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( $wordsBefore, $xi, count( $orig ) );
+                               $xi += count( $orig );
+                       }
+
+                       $closing = &$this->edits[$i]->closing;
+                       if ( is_array( $closing ) ) {
+                               $closing = array_slice( $wordsAfter, $yi, count( $closing ) );
+                               $yi += count( $closing );
+                       }
+               }
+       }
+
+       /**
+        * @param string[] $lines
+        *
+        * @return array[]
+        */
+       private function split( $lines ) {
+               $words = [];
+               $stripped = [];
+               $first = true;
+               foreach ( $lines as $line ) {
+                       if ( $first ) {
+                               $first = false;
+                       } else {
+                               $words[] = "\n";
+                               $stripped[] = "\n";
+                       }
+                       $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 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();
+
+               return $lines;
+       }
+
+       /**
+        * @return string[]
+        */
+       public function closing() {
+               $closing = new 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();
+
+               return $lines;
+       }
+
+}