FOR UPDATE mode for Article class, and for getArticleID function of Title. Using...

diff --git a/includes/Article.php b/includes/Article.php
index 991eb5b..0e0d866 100644 (file)
--- a/includes/Article.php
+++ b/includes/Article.php
@@ -20,6 +20,7 @@ class Article {
        /* private */ var $mMinorEdit, $mRedirectedFrom;
        /* private */ var $mTouched, $mFileCache, $mTitle;
        /* private */ var $mId, $mTable;
+       /* private */ var $mForUpdate;
 
        function Article( &$title ) {
                $this->mTitle =& $title;
@@ -33,6 +34,7 @@ class Article {
                $this->mTimestamp = $this->mComment = $this->mFileCache = '';
                $this->mCountAdjustment = 0;
                $this->mTouched = '19700101000000';
+               $this->mForUpdate = false;
        }
 
        # Get revision text associated with an old or archive row
@@ -143,7 +145,7 @@ class Article {
                                        $index = $matches[4];
                                        if ( $machineID == 0 ) {
                                                # Current connection
-                                               $db =& wfGetDB( DB_SLAVE );
+                                               $db =& $this->getDB();
                                        } else {
                                                # Alternate connection
                                                $db =& $wgLoadBalancer->getConnection( $machineID );
@@ -157,7 +159,8 @@ class Article {
                                        }
                                        if ( $db->isOpen() ) {
                                                $index = $db->strencode( $index );
-                                               $res = $db->query( "SELECT blob_data FROM $dbName.$tblName WHERE blob_index='$index'", $fname );
+                                               $res = $db->query( "SELECT blob_data FROM $dbName.$tblName " .
+                                                       "WHERE blob_index='$index' " . $this->getSelectOptions(), $fname );
                                                $row = $db->fetchObject( $res );
                                                $text = $row->text_data;
                                        }
@@ -332,7 +335,7 @@ class Article {
        function loadContent( $noredir = false ) {
                global $wgOut, $wgMwRedir, $wgRequest;
 
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr =& $this->getDB();
                # Query variables :P
                $oldid = $wgRequest->getVal( 'oldid' );
                $redirect = $wgRequest->getVal( 'redirect' );
@@ -358,7 +361,8 @@ class Article {
                        $id = $this->getID();
                        if ( 0 == $id ) return;
 
-                       $s = $dbr->getArray( 'cur', $this->getCurContentFields(), array( 'cur_id' => $id ), $fname );
+                       $s = $dbr->selectRow( 'cur', $this->getCurContentFields(), array( 'cur_id' => $id ), $fname, 
+                               $this->getSelectOptions() );
                        if ( $s === false ) {
                                return;
                        }
@@ -382,7 +386,8 @@ class Article {
                                        }
                                        $rid = $rt->getArticleID();
                                        if ( 0 != $rid ) {
-                                               $redirRow = $dbr->getArray( 'cur', $this->getCurContentFields(), array( 'cur_id' => $rid ), $fname );
+                                               $redirRow = $dbr->selectRow( 'cur', $this->getCurContentFields(), 
+                                                       array( 'cur_id' => $rid ), $fname, $this->getSelectOptions() );
 
                                                if ( $redirRow !== false ) {
                                                        $this->mRedirectedFrom = $this->mTitle->getPrefixedText();
@@ -403,7 +408,8 @@ class Article {
                        $this->mTitle->mRestrictions = explode( ',', trim( $s->cur_restrictions ) );
                        $this->mTitle->mRestrictionsLoaded = true;
                } else { # oldid set, retrieve historical version
-                       $s = $dbr->getArray( 'old', $this->getOldContentFields(), array( 'old_id' => $oldid ), $fname );
+                       $s = $dbr->getArray( 'old', $this->getOldContentFields(), array( 'old_id' => $oldid ), 
+                               $fname, $this->getSelectOptions() );
                        if ( $s === false ) {
                                return;
                        }
@@ -436,7 +442,7 @@ class Article {
                $this->mContent = false;
 
                $fname = 'Article::getContentWithout';
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr =& $this->getDB();
 
                if ( ! $oldid ) {       # Retrieve current version
                        $id = $this->getID();
@@ -444,7 +450,8 @@ class Article {
                                return false;
                        }
 
-                       $s = $dbr->getArray( 'cur', $this->getCurContentFields(), array( 'cur_id' => $id ), $fname );
+                       $s = $dbr->selectRow( 'cur', $this->getCurContentFields(), array( 'cur_id' => $id ), 
+                               $fname, $this->getSelectOptions() );
                        if ( $s === false ) {
                                return false;
                        }
@@ -456,7 +463,8 @@ class Article {
                                if( $rt &&  $rt->getInterwiki() == '' && $rt->getNamespace() != NS_SPECIAL ) {
                                        $rid = $rt->getArticleID();
                                        if ( 0 != $rid ) {
-                                               $redirRow = $dbr->getArray( 'cur', $this->getCurContentFields(), array( 'cur_id' => $rid ), $fname );
+                                               $redirRow = $dbr->selectRow( 'cur', $this->getCurContentFields(), 
+                                                       array( 'cur_id' => $rid ), $fname, $this->getSelectOptions() );
 
                                                if ( $redirRow !== false ) {
                                                        $this->mRedirectedFrom = $this->mTitle->getPrefixedText();
@@ -477,7 +485,8 @@ class Article {
                        $this->mTitle->mRestrictions = explode( ",", trim( $s->cur_restrictions ) );
                        $this->mTitle->mRestrictionsLoaded = true;
                } else { # oldid set, retrieve historical version
-                       $s = $dbr->getArray( 'old', $this->getOldContentFields(), array( 'old_id' => $oldid ) );
+                       $s = $dbr->selectRow( 'old', $this->getOldContentFields(), array( 'old_id' => $oldid ), 
+                               $fname, $this->getSelectOptions() );
                        if ( $s === false ) {
                                return false;
                        }
@@ -492,6 +501,33 @@ class Article {
                return $this->mContent;
        }
 
+       # Read/write accessor to select FOR UPDATE
+       function forUpdate( $x = NULL ) {
+               return wfSetVar( $this->mForUpdate, $x );
+       }
+       
+       # Get the database which should be used for reads
+       function &getDB() {
+               if ( $this->mForUpdate ) {
+                       return wfGetDB( DB_MASTER );
+               } else {
+                       return wfGetDB( DB_SLAVE );
+               }
+       }
+
+       # Get options for all SELECT statements
+       # Can pass an option array, to which the class-wide options will be appended
+       function getSelectOptions( $options = '' ) {
+               if ( $this->mForUpdate ) {
+                       if ( $options ) {
+                               $options[] = 'FOR UPDATE';
+                       } else {
+                               $options = 'FOR UPDATE';
+                       }
+               } 
+               return $options;
+       }
+       
        function getID() {
                if( $this->mTitle ) {
                        return $this->mTitle->getArticleID();
@@ -503,8 +539,9 @@ class Article {
        function getCount() {
                if ( -1 == $this->mCounter ) {
                        $id = $this->getID();
-                       $dbr =& wfGetDB( DB_SLAVE );
-                       $this->mCounter = $dbr->getField( 'cur', 'cur_counter', "cur_id={$id}" );
+                       $dbr =& $this->getDB();
+                       $this->mCounter = $dbr->selectField( 'cur', 'cur_counter', "cur_id={$id}", 
+                               'Article::getCount', $this->getSelectOptions() );
                }
                return $this->mCounter;
        }
@@ -529,10 +566,10 @@ class Article {
 
                $fname = 'Article::loadLastEdit';
 
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr =& $this->getDB();
                $s = $dbr->getArray( 'cur',
                  array( 'cur_user','cur_user_text','cur_timestamp', 'cur_comment','cur_minor_edit' ),
-                 array( 'cur_id' => $this->getID() ), $fname );
+                 array( 'cur_id' => $this->getID() ), $fname, $this->getSelectOptions() );
 
                if ( $s !== false ) {
                        $this->mUser = $s->cur_user;
@@ -575,7 +612,7 @@ class Article {
 
                $title = $this->mTitle;
                $contribs = array();
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr =& $this->getDB();
                $oldTable = $dbr->tableName( 'old' );
                $userTable = $dbr->tableName( 'user' );
                $encDBkey = $dbr->strencode( $title->getDBkey() );
@@ -591,9 +628,10 @@ class Article {
                        ORDER BY timestamp DESC";
 
                if ($limit > 0) { $sql .= ' LIMIT '.$limit; }
+               $sql .= ' '. $this->getSelectOptions();
 
                $res = $dbr->query($sql, $fname);
-
+               
                while ( $line = $dbr->fetchObject( $res ) ) {
                        $contribs[] = array($line->old_user, $line->old_user_text, $line->user_real_name);
                }
@@ -612,7 +650,6 @@ class Article {
 
                $fname = 'Article::view';
                wfProfileIn( $fname );
-
                # Get variables from query string
                $oldid = $wgRequest->getVal( 'oldid' );
                $diff = $wgRequest->getVal( 'diff' );
@@ -620,7 +657,6 @@ class Article {
 
                $wgOut->setArticleFlag( true );
                $wgOut->setRobotpolicy( 'index,follow' );
-
                # If we got diff and oldid in the query, we want to see a
                # diff page instead of the article.
 
@@ -635,7 +671,6 @@ class Article {
                        }
                        return;
                }
-
                if ( empty( $oldid ) && $this->checkTouched() ) {
                        if( $wgOut->checkLastModified( $this->mTouched ) ){
                                return;
@@ -646,7 +681,6 @@ class Article {
                                return;
                        }
                }
-
                # Should the parser cache be used?
                if ( $wgEnableParserCache && intval($wgUser->getOption( 'stubthreshold' )) == 0 && empty( $oldid ) ) {
                        $pcache = true;
@@ -660,7 +694,6 @@ class Article {
                                $outputDone = true;
                        }
                }
-
                if ( !$outputDone ) {
                        $text = $this->getContent( false ); # May change mTitle by following a redirect
 
@@ -714,7 +747,6 @@ class Article {
                        }
                }
                $wgOut->setPageTitle( $this->mTitle->getPrefixedText() );
-
                # If we have been passed an &rcid= parameter, we want to give the user a
                # chance to mark this new article as patrolled.
                if ( $wgUseRCPatrol && !is_null ( $rcid ) && $rcid != 0 && $wgUser->getID() != 0 &&
@@ -728,9 +760,10 @@ class Article {
 
                # Put link titles into the link cache
                $wgOut->replaceLinkHolders();
+
                # Add link titles as META keywords
                $wgOut->addMetaTags() ;
-
+                       
                $this->viewUpdates();
                wfProfileOut( $fname );
        }
@@ -1294,7 +1327,7 @@ class Article {
                # determine whether this page has earlier revisions
                # and insert a warning if it does
                # we select the text because it might be useful below
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr =& $this->getDB();
                $ns = $this->mTitle->getNamespace();
                $title = $this->mTitle->getDBkey();
                $old = $dbr->getArray( 'old',
@@ -1302,7 +1335,7 @@ class Article {
                        array(
                                'old_namespace' => $ns,
                                'old_title' => $title,
-                       ), $fname, array( 'ORDER BY' => 'inverse_timestamp' )
+                       ), $fname, $this->getSelectOptions( array( 'ORDER BY' => 'inverse_timestamp' ) )
                );
 
                if( $old !== false && !$confirm ) {
@@ -1317,7 +1350,7 @@ class Article {
                        array(
                                'cur_namespace' => $ns,
                                'cur_title' => $title,
-                       ), $fname
+                       ), $fname, $this->getSelectOptions()
                );
 
                if( $s !== false ) {
@@ -1782,11 +1815,10 @@ class Article {
        # Loads cur_touched and returns a value indicating if it should be used
        function checkTouched() {
                $fname = 'Article::checkTouched';
-
                $id = $this->getID();
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr =& $this->getDB();
                $s = $dbr->getArray( 'cur', array( 'cur_touched', 'cur_is_redirect' ),
-                       array( 'cur_id' => $id ), $fname );
+                       array( 'cur_id' => $id ), $fname, $this->getSelectOptions() );
                if( $s !== false ) {
                        $this->mTouched = wfTimestamp(TS_MW,$s->cur_touched);
                        return !$s->cur_is_redirect;
@@ -1950,7 +1982,7 @@ class Article {
                        return;
                }
 
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr =& $this->getDB();
 
                $basenamespace = $wgTitle->getNamespace() & (~1);
                $cur_clause = array( 'cur_title' => $wgTitle->getDBkey(), 'cur_namespace' => $basenamespace );
@@ -1961,13 +1993,14 @@ class Article {
                $wgOut->setSubtitle( wfMsg( "infosubtitle" ));
 
                # first, see if the page exists at all.
-               $exists = $dbr->selectField( 'cur', 'COUNT(*)', $cur_clause, $fname );
+               $exists = $dbr->selectField( 'cur', 'COUNT(*)', $cur_clause, $fname, $this->getSelectOptions() );
                if ($exists < 1) {
                        $wgOut->addHTML( wfMsg("noarticletext") );
                } else {
-                       $numwatchers = $dbr->selectField( 'watchlist', 'COUNT(*)', $wl_clause, $fname );
+                       $numwatchers = $dbr->selectField( 'watchlist', 'COUNT(*)', $wl_clause, $fname, 
+                               $this->getSelectOptions() );
                        $wgOut->addHTML( "<ul><li>" . wfMsg("numwatchers", $numwatchers) . "</li>" );
-                       $old = $dbr->selectField( 'old', 'COUNT(*)', $old_clause, $fname );
+                       $old = $dbr->selectField( 'old', 'COUNT(*)', $old_clause, $fname, $this->getSelectOptions() );
                        $wgOut->addHTML( "<li>" . wfMsg("numedits", $old + 1) . "</li>");
 
                        # to find number of distinct authors, we need to do some
@@ -1976,31 +2009,35 @@ class Article {
                        # - then, find the number of *other* authors in 'old'
 
                        # find 'cur' author
-                       $cur_author = $dbr->selectField( 'cur', 'cur_user_text', $cur_clause, $fname );
+                       $cur_author = $dbr->selectField( 'cur', 'cur_user_text', $cur_clause, $fname, 
+                               $this->getSelectOptions() );
 
                        # find number of 'old' authors excluding 'cur' author
                        $authors = $dbr->selectField( 'old', 'COUNT(DISTINCT old_user_text)',
-                               $old_clause + array( 'old_user_text<>' . $dbr->addQuotes( $cur_author ) ), $fname ) + 1;
+                               $old_clause + array( 'old_user_text<>' . $dbr->addQuotes( $cur_author ) ), $fname,
+                               $this->getSelectOptions() ) + 1;
 
                        # now for the Talk page ...
                        $cur_clause = array( 'cur_title' => $wgTitle->getDBkey(), 'cur_namespace' => $basenamespace+1 );
                        $old_clause = array( 'old_title' => $wgTitle->getDBkey(), 'old_namespace' => $basenamespace+1 );
 
                        # does it exist?
-                       $exists = $dbr->selectField( 'cur', 'COUNT(*)', $cur_clause, $fname );
+                       $exists = $dbr->selectField( 'cur', 'COUNT(*)', $cur_clause, $fname, $this->getSelectOptions() );
 
                        # number of edits
                        if ($exists > 0) {
-                               $old = $dbr->selectField( 'old', 'COUNT(*)', $old_clause, $fname );
+                               $old = $dbr->selectField( 'old', 'COUNT(*)', $old_clause, $fname, $this->getSelectOptions() );
                                $wgOut->addHTML( "<li>" . wfMsg("numtalkedits", $old + 1) . "</li>");
                        }
                        $wgOut->addHTML( "<li>" . wfMsg("numauthors", $authors) . "</li>" );
 
                        # number of authors
                        if ($exists > 0) {
-                               $cur_author = $dbr->selectField( 'cur', 'cur_user_text', $cur_clause, $fname );
+                               $cur_author = $dbr->selectField( 'cur', 'cur_user_text', $cur_clause, $fname,
+                                       $this->getSelectOptions() );
                                $authors = $dbr->selectField( 'cur', 'COUNT(DISTINCT old_user_text)',
-                                       $old_clause + array( 'old_user_text<>' . $dbr->addQuotes( $cur_author ) ), $fname );
+                                       $old_clause + array( 'old_user_text<>' . $dbr->addQuotes( $cur_author ) ), 
+                                       $fname, $this->getSelectOptions() );
 
                                $wgOut->addHTML( "<li>" . wfMsg("numtalkauthors", $authors) . "</li></ul>" );
                        }

diff --git a/includes/EditPage.php b/includes/EditPage.php
index f6a5793..478fbdf 100644 (file)
--- a/includes/EditPage.php
+++ b/includes/EditPage.php
@@ -153,7 +153,7 @@ class EditPage {
                        }
 
                        # If article is new, insert it.
-                       $aid = $this->mTitle->getArticleID();
+                       $aid = $this->mTitle->getArticleID( GAID_FOR_UPDATE );
                        if ( 0 == $aid ) {
                                # Don't save a new article if it's blank.
                                if ( ( "" == $this->textbox1 ) ||
@@ -168,6 +168,7 @@ class EditPage {
                        # Article exists. Check for edit conflict.
 
                        $this->mArticle->clear(); # Force reload of dates, etc.
+                       $this->mArticle->forUpdate( true ); # Lock the article
 
                        if( ( $this->section != "new" ) &&
                                ($this->mArticle->getTimestamp() != $this->edittime ) ) {
@@ -471,7 +472,6 @@ htmlspecialchars( $wgLang->recodeForEdit( $this->textbox1 ) ) .
                        $wgOut->addHTML($previewhead);
                        $wgOut->addHTML($previewHTML);
                }
-
        }
 
        function blockedIPpage()
@@ -484,10 +484,10 @@ htmlspecialchars( $wgLang->recodeForEdit( $this->textbox1 ) ) .
 
                $id = $wgUser->blockedBy();
                $reason = $wgUser->blockedFor();
-                $ip = $wgIP;
+               $ip = $wgIP;
                
                if ( is_numeric( $id ) ) {
-                       $name = User::whoIs( $id );
+                       $name = User::whoIs( $id );
                } else {
                        $name = $id;
                }

diff --git a/includes/Title.php b/includes/Title.php
index 462bc1a..2b4e562 100644 (file)
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -8,6 +8,9 @@ $wgTitleInterwikiCache = array();
 # * Represents a title, which may contain an interwiki designation or namespace
 # * Can fetch various kinds of data from the database, albeit inefficiently. 
 #
+
+define ( 'GAID_FOR_UPDATE', 1 );
+
 class Title {
        # All member variables should be considered private
        # Please use the accessor functions
@@ -250,7 +253,7 @@ class Title {
                }
                $dbr =& wfGetDB( DB_SLAVE );
                $res = $dbr->select( 'interwiki', array( 'iw_url', 'iw_local' ), array( 'iw_prefix' => $key ), $fname );
-                if(!$res) return "";
+               if(!$res) return "";
                
                $s = $dbr->fetchObject( $res );
                if(!$s) {
@@ -580,12 +583,19 @@ class Title {
        }
 
        # Get the article ID from the link cache
-       # Used very heavily, e.g. in Parser::replaceInternalLinks()
-       function getArticleID() {
+       # $flags is a bit field, may be GAID_FOR_UPDATE to select for update
+       function getArticleID( $flags = 0 ) {
                global $wgLinkCache;
-
-               if ( -1 != $this->mArticleID ) { return $this->mArticleID; }
-               $this->mArticleID = $wgLinkCache->addLinkObj( $this );
+               
+               if ( $flags & GAID_FOR_UPDATE ) {
+                       $oldUpdate = $wgLinkCache->forUpdate( true );
+                       $this->mArticleID = $wgLinkCache->addLinkObj( $this );
+                       $wgLinkCache->forUpdate( $oldUpdate );
+               } else {
+                       if ( -1 == $this->mArticleID ) {
+                               $this->mArticleID = $wgLinkCache->addLinkObj( $this );
+                       }
+               }
                return $this->mArticleID;
        }