1 files changed, 139 insertions, 0 deletions
diff --git a/www/wiki/includes/diff/WordLevelDiff.php b/www/wiki/includes/diff/WordLevelDiff.php
new file mode 100644
index 00000000..0b318bdb
--- /dev/null
+++ b/www/wiki/includes/diff/WordLevelDiff.php
@@ -0,0 +1,139 @@
+<?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;
+	}
+
+}