Refactor diffs

* Merge MappedDiff into WordLevelDiff
* Rename <something insane>WordAccumulator into WordAccumulator and namespace
* Better variable names

Change-Id: I5847f2bb89402d0537b9e99cccd24c547ce4e4e2

1 files changed, 107 insertions, 0 deletions

diff --git a/includes/diff/WordAccumulator.php b/includes/diff/WordAccumulator.php
new file mode 100644
index 000000000000..a26775ffa80c
--- /dev/null
+++ b/includes/diff/WordAccumulator.php
@@ -0,0 +1,107 @@
+<?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
+ */
+
+namespace MediaWiki\Diff;
+
+/**
+ * Stores, escapes and formats the results of word-level diff
+ *
+ * @private
+ * @ingroup DifferenceEngine
+ */
+class WordAccumulator {
+	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, '&#160;' );
+		}
+		$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;
+	}
+}