From 93b24207c1cb8dac1ff4c810da2ede7ccba987f0 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Fri, 15 Mar 2019 02:24:31 -0700
Subject: [PATCH] Make EditPage::getTemplates avoid page table query spam

This changes TemplatesOnThisPageFormatter to use LinkBatch
and LinkBatch/LinkCache to manage the field.

Change-Id: I523158cdffc599d4d29bab91c98e55085130cee2
---
 includes/TemplatesOnThisPageFormatter.php |  6 +-----
 includes/Title.php                        |  5 +++--
 includes/cache/LinkCache.php              | 20 +++++++++++++++++---
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/includes/TemplatesOnThisPageFormatter.php b/includes/TemplatesOnThisPageFormatter.php
index 494c7bfc86..bca1ef651a 100644
--- a/includes/TemplatesOnThisPageFormatter.php
+++ b/includes/TemplatesOnThisPageFormatter.php
@@ -66,11 +66,7 @@ class TemplatesOnThisPageFormatter {
 		}
 
 		# Do a batch existence check
-		$batch = new LinkBatch;
-		foreach ( $templates as $title ) {
-			$batch->addObj( $title );
-		}
-		$batch->execute();
+		( new LinkBatch( $templates ) )->execute();
 
 		# Construct the HTML
 		$outText = '<div class="mw-templatesUsedExplanation">';
diff --git a/includes/Title.php b/includes/Title.php
index cf76c0d37b..88a7efb8df 100644
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -3255,8 +3255,9 @@ class Title implements LinkTarget, IDBAccessObject {
 		}
 
 		if ( $this->mOldRestrictions === false ) {
-			$this->mOldRestrictions = $dbr->selectField( 'page', 'page_restrictions',
-				[ 'page_id' => $this->getArticleID() ], __METHOD__ );
+			$linkCache = MediaWikiServices::getInstance()->getLinkCache();
+			$linkCache->addLinkObj( $this ); # in case we already had an article ID
+			$this->mOldRestrictions = $linkCache->getGoodLinkFieldObj( $this, 'restrictions' );
 		}
 
 		if ( $this->mOldRestrictions != '' ) {
diff --git a/includes/cache/LinkCache.php b/includes/cache/LinkCache.php
index b3dc00468b..fb416f040a 100644
--- a/includes/cache/LinkCache.php
+++ b/includes/cache/LinkCache.php
@@ -141,6 +141,7 @@ class LinkCache {
 			'revision' => (int)$revision,
 			'model' => $model ? (string)$model : null,
 			'lang' => $lang ? (string)$lang : null,
+			'restrictions' => null
 		] );
 	}
 
@@ -158,8 +159,15 @@ class LinkCache {
 			'length' => intval( $row->page_len ),
 			'redirect' => intval( $row->page_is_redirect ),
 			'revision' => intval( $row->page_latest ),
-			'model' => !empty( $row->page_content_model ) ? strval( $row->page_content_model ) : null,
-			'lang' => !empty( $row->page_lang ) ? strval( $row->page_lang ) : null,
+			'model' => !empty( $row->page_content_model )
+				? strval( $row->page_content_model )
+				: null,
+			'lang' => !empty( $row->page_lang )
+				? strval( $row->page_lang )
+				: null,
+			'restrictions' => !empty( $row->page_restrictions )
+				? strval( $row->page_restrictions )
+				: null
 		] );
 	}
 
@@ -198,7 +206,13 @@ class LinkCache {
 	public static function getSelectFields() {
 		global $wgContentHandlerUseDB, $wgPageLanguageUseDB;
 
-		$fields = [ 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ];
+		$fields = [
+			'page_id',
+			'page_len',
+			'page_is_redirect',
+			'page_latest',
+			'page_restrictions'
+		];
 		if ( $wgContentHandlerUseDB ) {
 			$fields[] = 'page_content_model';
 		}
-- 
2.20.1