From 380b075756a15f82a158be5c3a4283188208c820 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Fri, 2 May 2014 11:13:26 -0700
Subject: [PATCH] Added a script to compare current parser output to cache

* This works on a random set of pages in a namespace and can
  be used to compare different PHP interpreters.
* This can, like any maintenance script, be used with --profiler.

Change-Id: Ica69a3ef27df29af1c6e4dc4c8413b55a03df49e
---
 maintenance/compareParserCache.php | 101 +++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 maintenance/compareParserCache.php

diff --git a/maintenance/compareParserCache.php b/maintenance/compareParserCache.php
new file mode 100644
index 0000000000..97fd3ffcc9
--- /dev/null
+++ b/maintenance/compareParserCache.php
@@ -0,0 +1,101 @@
+<?php
+/**
+ * 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 Maintenance
+ */
+
+require_once __DIR__ . '/Maintenance.php';
+
+/**
+ * @ingroup Maintenance
+ */
+class CompareParserCache extends Maintenance {
+	public function __construct() {
+		parent::__construct();
+		$this->mDescription = "Parse random pages and compare output to cache.";
+		$this->addOption( 'namespace', 'Page namespace number', true, true );
+		$this->addOption( 'maxpages', 'Number of pages to try', true, true );
+	}
+
+	public function execute() {
+		$pages = $this->getOption( 'maxpages' );
+
+		$dbr = $this->getDB( DB_SLAVE );
+
+		$totalsec = 0.0;
+		$scanned = 0;
+		$withcache = 0;
+		while ( $pages-- > 0 ) {
+			$row = $dbr->selectRow( 'page', '*',
+				array(
+					'page_namespace' => $this->getOption( 'namespace' ),
+					'page_is_redirect' => 0,
+					'page_random >= ' . wfRandom()
+				),
+				__METHOD__,
+				array(
+					'ORDER BY' => 'page_random',
+				)
+			);
+
+			if ( !$row ) {
+				continue;
+			}
+			++$scanned;
+
+			$title = Title::newFromRow( $row );
+			$page = WikiPage::factory( $title );
+			$revision = $page->getRevision();
+			$content = $revision->getContent( Revision::RAW );
+
+			$parserOptions = $page->makeParserOptions( 'canonical' );
+
+			$parserOutputOld = ParserCache::singleton()->get( $page, $parserOptions );
+
+			$t1 = microtime( true );
+			$parserOutputNew = $content->getParserOutput(
+				$title, $revision->getId(), $parserOptions, false );
+			$sec = microtime( true ) - $t1;
+			$totalsec += $sec;
+
+			$this->output( "Parsed '{$title->getPrefixedText()}' in $sec seconds.\n" );
+
+			if ( $parserOutputOld ) {
+				$this->output( "Found cache entry found for '{$title->getPrefixedText()}'..." );
+				$oldHtml = trim( preg_replace( '#<!-- .+-->#Us', '', $parserOutputOld->getText() ) );
+				$newHtml = trim( preg_replace( '#<!-- .+-->#Us', '',$parserOutputNew->getText() ) );
+				$diff = wfDiff( $oldHtml, $newHtml );
+				if ( strlen( $diff ) ) {
+					$this->output( "differences found:\n\n$diff\n\n" );
+				} else {
+					$this->output( "No differences found.\n" );
+				}
+				++$withcache;
+			} else {
+				$this->output( "No parser cache entry found for '{$title->getPrefixedText()}'.\n" );
+			}
+		}
+
+		$ave = $scanned ? $totalsec / $scanned : 0;
+		$this->output( "Checked $scanned pages; $withcache had prior cache entries.\n" );
+		$this->output( "Average parse time: $ave sec\n" );
+	}
+}
+
+$maintClass = "CompareParserCache";
+require_once RUN_MAINTENANCE_IF_MAIN;
-- 
2.20.1