From: Jackmcbarn <jackmcbarn@gmail.com>
Date: Tue, 16 Sep 2014 00:07:52 +0000 (-0400)
Subject: Add parser callback to get a page's current revision
X-Git-Tag: 1.31.0-rc.0~13815^2
X-Git-Url: http://git.cyclocoop.org/%22%20.%20generer_url_ecrire%28%22messagerie%22%29%20.%20%22?a=commitdiff_plain;h=edc9f2acd91c0c8e6b31bcef075b57486f0a2071;p=lhc%2Fweb%2Fwiklou.git

Add parser callback to get a page's current revision

Add Parser::fetchCurrentRevisionOfTitle(). By default, this just calls
Revision::newFromTitle, but a callback can be set in ParserOptions that
will override it. Anything that runs as part of a parse should use this
wherever possible.

Bug: 70495
Change-Id: I521f1f68ad819cf0f37e63240806f10c1cceef9c
---

diff --git a/includes/parser/CoreParserFunctions.php b/includes/parser/CoreParserFunctions.php
index eacbecd409..355a3c1216 100644
--- a/includes/parser/CoreParserFunctions.php
+++ b/includes/parser/CoreParserFunctions.php
@@ -1000,11 +1000,6 @@ class CoreParserFunctions {
 	 * @since 1.23
 	 */
 	private static function getCachedRevisionObject( $parser, $title = null ) {
-		static $cache = null;
-		if ( $cache == null ) {
-			$cache = new MapCacheLRU( 50 );
-		}
-
 		if ( is_null( $title ) ) {
 			return null;
 		}
@@ -1024,22 +1019,18 @@ class CoreParserFunctions {
 		// Normalize name for cache
 		$page = $title->getPrefixedDBkey();
 
-		if ( $cache->has( $page ) ) { // cache contains null values
-			return $cache->get( $page );
+		if ( !( $parser->currentRevisionCache && $parser->currentRevisionCache->has( $page ) )
+			&& !$parser->incrementExpensiveFunctionCount() ) {
+			return null;
 		}
-		if ( $parser->incrementExpensiveFunctionCount() ) {
-			$rev = Revision::newFromTitle( $title, false, Revision::READ_NORMAL );
-			$pageID = $rev ? $rev->getPage() : 0;
-			$revID = $rev ? $rev->getId() : 0;
-			$cache->set( $page, $rev ); // maybe null
+		$rev = $parser->fetchCurrentRevisionOfTitle( $title );
+		$pageID = $rev ? $rev->getPage() : 0;
+		$revID = $rev ? $rev->getId() : 0;
 
-			// Register dependency in templatelinks
-			$parser->getOutput()->addTemplate( $title, $pageID, $revID );
+		// Register dependency in templatelinks
+		$parser->getOutput()->addTemplate( $title, $pageID, $revID );
 
-			return $rev;
-		}
-		$cache->set( $page, null );
-		return null;
+		return $rev;
 	}
 
 	/**
diff --git a/includes/parser/Parser.php b/includes/parser/Parser.php
index 8bf400a0cf..bff9c0dc27 100644
--- a/includes/parser/Parser.php
+++ b/includes/parser/Parser.php
@@ -210,6 +210,14 @@ class Parser {
 	 */
 	public $mLangLinkLanguages;
 
+	/**
+	 * @var MapCacheLRU|null
+	 * @since 1.24
+	 *
+	 * A cache of the current revisions of titles. Keys are $title->getPrefixedDbKey()
+	 */
+	public $currentRevisionCache;
+
 	/**
 	 * @var bool Recursive call protection.
 	 * This variable should be treated as if it were private.
@@ -305,6 +313,7 @@ class Parser {
 		$this->mVarCache = array();
 		$this->mUser = null;
 		$this->mLangLinkLanguages = array();
+		$this->currentRevisionCache = null;
 
 		/**
 		 * Prefix for temporary replacement strings for the multipass parser.
@@ -376,6 +385,7 @@ class Parser {
 
 		$this->startParse( $title, $options, self::OT_HTML, $clearState );
 
+		$this->currentRevisionCache = null;
 		$this->mInputSize = strlen( $text );
 		if ( $this->mOptions->getEnableLimitReport() ) {
 			$this->mOutput->resetParseStartTime();
@@ -588,6 +598,7 @@ class Parser {
 		$this->mRevisionUser = $oldRevisionUser;
 		$this->mRevisionSize = $oldRevisionSize;
 		$this->mInputSize = false;
+		$this->currentRevisionCache = null;
 		wfProfileOut( $fname );
 		wfProfileOut( __METHOD__ );
 
@@ -3794,6 +3805,44 @@ class Parser {
 		return array( $dom, $title );
 	}
 
+	/**
+	 * Fetch the current revision of a given title. Note that the revision
+	 * (and even the title) may not exist in the database, so everything
+	 * contributing to the output of the parser should use this method
+	 * where possible, rather than getting the revisions themselves. This
+	 * method also caches its results, so using it benefits performance.
+	 *
+	 * @since 1.24
+	 * @param Title $title
+	 * @return Revision
+	 */
+	public function fetchCurrentRevisionOfTitle( $title ) {
+		$cacheKey = $title->getPrefixedDBkey();
+		if ( !$this->currentRevisionCache ) {
+			$this->currentRevisionCache = new MapCacheLRU( 100 );
+		}
+		if ( !$this->currentRevisionCache->has( $cacheKey ) ) {
+			$this->currentRevisionCache->set( $cacheKey,
+				// Defaults to Parser::statelessFetchRevision()
+				call_user_func( $this->mOptions->getCurrentRevisionCallback(), $title, $this )
+			);
+		}
+		return $this->currentRevisionCache->get( $cacheKey );
+	}
+
+	/**
+	 * Wrapper around Revision::newFromTitle to allow passing additional parameters
+	 * without passing them on to it.
+	 *
+	 * @since 1.24
+	 * @param Title $title
+	 * @param Parser|bool $parser
+	 * @return Revision
+	 */
+	public static function statelessFetchRevision( $title, $parser = false ) {
+		return Revision::newFromTitle( $title );
+	}
+
 	/**
 	 * Fetch the unparsed text of a template and register a reference to it.
 	 * @param Title $title
@@ -3859,9 +3908,13 @@ class Parser {
 				break;
 			}
 			# Get the revision
-			$rev = $id
-				? Revision::newFromId( $id )
-				: Revision::newFromTitle( $title, false, Revision::READ_NORMAL );
+			if ( $id ) {
+				$rev = Revision::newFromId( $id );
+			} elseif ( $parser ) {
+				$rev = $parser->fetchCurrentRevisionOfTitle( $title );
+			} else {
+				$rev = Revision::newFromTitle( $title );
+			}
 			$rev_id = $rev ? $rev->getId() : 0;
 			# If there is no current revision, there is no page
 			if ( $id === false && !$rev ) {
diff --git a/includes/parser/ParserOptions.php b/includes/parser/ParserOptions.php
index 2ca9d505bb..9966a1d79b 100644
--- a/includes/parser/ParserOptions.php
+++ b/includes/parser/ParserOptions.php
@@ -116,6 +116,12 @@ class ParserOptions {
 	 */
 	public $mRemoveComments = true;
 
+	/**
+	 * Callback for current revision fetching. Used as first argument to call_user_func().
+	 */
+	public $mCurrentRevisionCallback =
+		array( 'Parser', 'statelessFetchRevision' );
+
 	/**
 	 * Callback for template fetching. Used as first argument to call_user_func().
 	 */
@@ -282,6 +288,11 @@ class ParserOptions {
 		return $this->mRemoveComments;
 	}
 
+	/* @since 1.24 */
+	public function getCurrentRevisionCallback() {
+		return $this->mCurrentRevisionCallback;
+	}
+
 	public function getTemplateCallback() {
 		return $this->mTemplateCallback;
 	}
@@ -455,6 +466,11 @@ class ParserOptions {
 		return wfSetVar( $this->mRemoveComments, $x );
 	}
 
+	/* @since 1.24 */
+	public function setCurrentRevisionCallback( $x ) {
+		return wfSetVar( $this->mCurrentRevisionCallback, $x );
+	}
+
 	public function setTemplateCallback( $x ) {
 		return wfSetVar( $this->mTemplateCallback, $x );
 	}