Merge "Reduced some master queries by adding flags to Revision functions."

diff --git a/includes/AutoLoader.php b/includes/AutoLoader.php
index d92aa99..83397fd 100644 (file)
--- a/includes/AutoLoader.php
+++ b/includes/AutoLoader.php
@@ -435,6 +435,9 @@ $wgAutoloadLocalClasses = array(
        'IContextSource' => 'includes/context/IContextSource.php',
        'RequestContext' => 'includes/context/RequestContext.php',
 
+       # includes/dao
+       'IDBAccessObject' => 'includes/dao/IDBAccessObject.php',
+
        # includes/db
        'Blob' => 'includes/db/DatabaseUtility.php',
        'ChronologyProtector' => 'includes/db/LBFactory.php',

diff --git a/includes/Revision.php b/includes/Revision.php
index 14bd587..13eaae4 100644 (file)
--- a/includes/Revision.php
+++ b/includes/Revision.php
@@ -23,7 +23,7 @@
 /**
  * @todo document
  */
-class Revision {
+class Revision implements IDBAccessObject {
        protected $mId;
        protected $mPage;
        protected $mUserText;
@@ -47,7 +47,7 @@ class Revision {
        const DELETED_RESTRICTED = 8;
        // Convenience field
        const SUPPRESSED_USER = 12;
-       // Audience options for Revision::getText()
+       // Audience options for accessors
        const FOR_PUBLIC = 1;
        const FOR_THIS_USER = 2;
        const RAW = 3;
@@ -56,11 +56,17 @@ class Revision {
         * Load a page revision from a given revision ID number.
         * Returns null if no such revision can be found.
         *
+        * $flags include:
+        *      IDBAccessObject::LATEST_READ  : Select the data from the master
+        *      IDBAccessObject::LOCKING_READ : Select & lock the data from the master
+        *      IDBAccessObject::AVOID_MASTER : Avoid master queries; data may be stale
+        *
         * @param $id Integer
+        * @param $flags Integer (optional)
         * @return Revision or null
         */
-       public static function newFromId( $id ) {
-               return Revision::newFromConds( array( 'rev_id' => intval( $id ) ) );
+       public static function newFromId( $id, $flags = 0 ) {
+               return self::newFromConds( array( 'rev_id' => intval( $id ) ), $flags );
        }
 
        /**
@@ -68,11 +74,17 @@ class Revision {
         * that's attached to a given title. If not attached
         * to that title, will return null.
         *
+        * $flags include:
+        *      IDBAccessObject::LATEST_READ  : Select the data from the master
+        *      IDBAccessObject::LOCKING_READ : Select & lock the data from the master
+        *      IDBAccessObject::AVOID_MASTER : Avoid master queries; data may be stale
+        *
         * @param $title Title
         * @param $id Integer (optional)
+        * @param $flags Integer Bitfield (optional)
         * @return Revision or null
         */
-       public static function newFromTitle( $title, $id = 0 ) {
+       public static function newFromTitle( $title, $id = 0, $flags = 0 ) {
                $conds = array(
                        'page_namespace' => $title->getNamespace(),
                        'page_title'     => $title->getDBkey()
@@ -80,7 +92,7 @@ class Revision {
                if ( $id ) {
                        // Use the specified ID
                        $conds['rev_id'] = $id;
-               } elseif ( wfGetLB()->getServerCount() > 1 ) {
+               } elseif ( !( $flags & self::AVOID_MASTER ) && wfGetLB()->getServerCount() > 1 ) {
                        // Get the latest revision ID from the master
                        $dbw = wfGetDB( DB_MASTER );
                        $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
@@ -92,7 +104,7 @@ class Revision {
                        // Use a join to get the latest revision
                        $conds[] = 'rev_id=page_latest';
                }
-               return Revision::newFromConds( $conds );
+               return self::newFromConds( $conds, $flags );
        }
 
        /**
@@ -100,15 +112,21 @@ class Revision {
         * that's attached to a given page ID.
         * Returns null if no such revision can be found.
         *
+        * $flags include:
+        *      IDBAccessObject::LATEST_READ  : Select the data from the master
+        *      IDBAccessObject::LOCKING_READ : Select & lock the data from the master
+        *      IDBAccessObject::AVOID_MASTER : Avoid master queries; data may be stale
+        *
         * @param $revId Integer
         * @param $pageId Integer (optional)
+        * @param $flags Integer Bitfield (optional)
         * @return Revision or null
         */
-       public static function newFromPageId( $pageId, $revId = 0 ) {
+       public static function newFromPageId( $pageId, $revId = 0, $flags = 0 ) {
                $conds = array( 'page_id' => $pageId );
                if ( $revId ) {
                        $conds['rev_id'] = $revId;
-               } elseif ( wfGetLB()->getServerCount() > 1 ) {
+               } elseif ( !( $flags & self::AVOID_MASTER ) && wfGetLB()->getServerCount() > 1 ) {
                        // Get the latest revision ID from the master
                        $dbw = wfGetDB( DB_MASTER );
                        $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
@@ -119,7 +137,7 @@ class Revision {
                } else {
                        $conds[] = 'rev_id = page_latest';
                }
-               return Revision::newFromConds( $conds );
+               return self::newFromConds( $conds, $flags );
        }
 
        /**
@@ -175,7 +193,7 @@ class Revision {
         * @return Revision or null
         */
        public static function loadFromId( $db, $id ) {
-               return Revision::loadFromConds( $db, array( 'rev_id' => intval( $id ) ) );
+               return self::loadFromConds( $db, array( 'rev_id' => intval( $id ) ) );
        }
 
        /**
@@ -195,7 +213,7 @@ class Revision {
                } else {
                        $conds[] = 'rev_id=page_latest';
                }
-               return Revision::loadFromConds( $db, $conds );
+               return self::loadFromConds( $db, $conds );
        }
 
        /**
@@ -214,7 +232,7 @@ class Revision {
                } else {
                        $matchId = 'page_latest';
                }
-               return Revision::loadFromConds( $db,
+               return self::loadFromConds( $db,
                        array( "rev_id=$matchId",
                                   'page_namespace' => $title->getNamespace(),
                                   'page_title'     => $title->getDBkey() )
@@ -232,7 +250,7 @@ class Revision {
         * @return Revision or null
         */
        public static function loadFromTimestamp( $db, $title, $timestamp ) {
-               return Revision::loadFromConds( $db,
+               return self::loadFromConds( $db,
                        array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
                                   'page_namespace' => $title->getNamespace(),
                                   'page_title'     => $title->getDBkey() )
@@ -243,14 +261,17 @@ class Revision {
         * Given a set of conditions, fetch a revision.
         *
         * @param $conditions Array
+        * @param $flags integer (optional)
         * @return Revision or null
         */
-       public static function newFromConds( $conditions ) {
-               $db = wfGetDB( DB_SLAVE );
-               $rev = Revision::loadFromConds( $db, $conditions );
-               if( is_null( $rev ) && wfGetLB()->getServerCount() > 1 ) {
-                       $dbw = wfGetDB( DB_MASTER );
-                       $rev = Revision::loadFromConds( $dbw, $conditions );
+       private static function newFromConds( $conditions, $flags = 0 ) {
+               $db = wfGetDB( ( $flags & self::LATEST_READ ) ? DB_MASTER : DB_SLAVE );
+               $rev = self::loadFromConds( $db, $conditions, $flags );
+               if ( is_null( $rev ) && wfGetLB()->getServerCount() > 1 ) {
+                       if ( !( $flags & self::LATEST_READ ) && !( $flags & self::AVOID_MASTER ) ) {
+                               $dbw = wfGetDB( DB_MASTER );
+                               $rev = self::loadFromConds( $dbw, $conditions, $flags );
+                       }
                }
                return $rev;
        }
@@ -261,10 +282,11 @@ class Revision {
         *
         * @param $db DatabaseBase
         * @param $conditions Array
+        * @param $flags integer (optional)
         * @return Revision or null
         */
-       private static function loadFromConds( $db, $conditions ) {
-               $res = Revision::fetchFromConds( $db, $conditions );
+       private static function loadFromConds( $db, $conditions, $flags = 0 ) {
+               $res = self::fetchFromConds( $db, $conditions, $flags );
                if( $res ) {
                        $row = $res->fetchObject();
                        if( $row ) {
@@ -285,7 +307,7 @@ class Revision {
         * @return ResultWrapper
         */
        public static function fetchRevision( $title ) {
-               return Revision::fetchFromConds(
+               return self::fetchFromConds(
                        wfGetDB( DB_SLAVE ),
                        array( 'rev_id=page_latest',
                                   'page_namespace' => $title->getNamespace(),
@@ -300,20 +322,25 @@ class Revision {
         *
         * @param $db DatabaseBase
         * @param $conditions Array
+        * @param $flags integer (optional)
         * @return ResultWrapper
         */
-       private static function fetchFromConds( $db, $conditions ) {
+       private static function fetchFromConds( $db, $conditions, $flags = 0 ) {
                $fields = array_merge(
                        self::selectFields(),
                        self::selectPageFields(),
                        self::selectUserFields()
                );
+               $options = array( 'LIMIT' => 1 );
+               if ( $flags & self::FOR_UPDATE ) {
+                       $options[] = 'FOR UPDATE';
+               }
                return $db->select(
                        array( 'revision', 'page', 'user' ),
                        $fields,
                        $conditions,
                        __METHOD__,
-                       array( 'LIMIT' => 1 ),
+                       $options,
                        array( 'page' => self::pageJoinCond(), 'user' => self::userJoinCond() )
                );
        }
@@ -834,7 +861,7 @@ class Revision {
                if( $this->getTitle() ) {
                        $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
                        if( $prev ) {
-                               return Revision::newFromTitle( $this->getTitle(), $prev );
+                               return self::newFromTitle( $this->getTitle(), $prev );
                        }
                }
                return null;
@@ -849,7 +876,7 @@ class Revision {
                if( $this->getTitle() ) {
                        $next = $this->getTitle()->getNextRevisionID( $this->getId() );
                        if ( $next ) {
-                               return Revision::newFromTitle( $this->getTitle(), $next );
+                               return self::newFromTitle( $this->getTitle(), $next );
                        }
                }
                return null;
@@ -979,7 +1006,7 @@ class Revision {
                                $text = gzdeflate( $text );
                                $flags[] = 'gzip';
                        } else {
-                               wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
+                               wfDebug( __METHOD__ . " -- no zlib support, not compressing\n" );
                        }
                }
                return implode( ',', $flags );
@@ -998,7 +1025,7 @@ class Revision {
                wfProfileIn( __METHOD__ );
 
                $data = $this->mText;
-               $flags = Revision::compressRevisionText( $data );
+               $flags = self::compressRevisionText( $data );
 
                # Write to external storage if required
                if( $wgDefaultExternalStore ) {
@@ -1048,7 +1075,7 @@ class Revision {
                                        ? $this->getPreviousRevisionId( $dbw )
                                        : $this->mParentId,
                                'rev_sha1'       => is_null( $this->mSha1 )
-                                       ? Revision::base36Sha1( $this->mText )
+                                       ? self::base36Sha1( $this->mText )
                                        : $this->mSha1
                        ), __METHOD__
                );
@@ -1272,7 +1299,7 @@ class Revision {
        static function countByTitle( $db, $title ) {
                $id = $title->getArticleID();
                if( $id ) {
-                       return Revision::countByPageId( $db, $id );
+                       return self::countByPageId( $db, $id );
                }
                return 0;
        }

diff --git a/includes/dao/IDBAccessObject.php b/includes/dao/IDBAccessObject.php
new file mode 100644 (file)
index 0000000..cd5dda9
--- /dev/null
+++ b/includes/dao/IDBAccessObject.php
@@ -0,0 +1,32 @@
+<?php
+/**
+ * This file contains database access object related constants.
+ *
+ * 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 Database
+ */
+
+/**
+ * Interface for database access objects
+ */
+interface IDBAccessObject {
+       const LATEST_READ  = 1; // read from the master
+       const FOR_UPDATE   = 2; // lock the rows read
+       const LOCKING_READ = 3; // LATEST_READ | FOR_UPDATE
+       const AVOID_MASTER = 4; // avoiding checking the master
+}

diff --git a/includes/diff/DifferenceEngine.php b/includes/diff/DifferenceEngine.php
index e624ec2..eb3a319 100644 (file)
--- a/includes/diff/DifferenceEngine.php
+++ b/includes/diff/DifferenceEngine.php
@@ -612,7 +612,7 @@ class DifferenceEngine extends ContextSource {
                        return false;
                }
                // Short-circuit
-               // If mOldRev is false, it means that the 
+               // If mOldRev is false, it means that the
                if ( $this->mOldRev === false || ( $this->mOldRev && $this->mNewRev
                        && $this->mOldRev->getID() == $this->mNewRev->getID() ) )
                {
@@ -1019,7 +1019,7 @@ class DifferenceEngine extends ContextSource {
                // Load the new revision object
                $this->mNewRev = $this->mNewid
                        ? Revision::newFromId( $this->mNewid )
-                       : Revision::newFromTitle( $this->getTitle() );
+                       : Revision::newFromTitle( $this->getTitle(), false, Revision::AVOID_MASTER );
 
                if ( !$this->mNewRev instanceof Revision ) {
                        return false;

diff --git a/includes/filerepo/file/LocalFile.php b/includes/filerepo/file/LocalFile.php
index 2f55ec1..67768c4 100644 (file)
--- a/includes/filerepo/file/LocalFile.php
+++ b/includes/filerepo/file/LocalFile.php
@@ -1456,7 +1456,7 @@ class LocalFile extends File {
         */
        function getDescriptionText() {
                global $wgParser;
-               $revision = Revision::newFromTitle( $this->title );
+               $revision = Revision::newFromTitle( $this->title, false, Revision::AVOID_MASTER );
                if ( !$revision ) return false;
                $text = $revision->getText();
                if ( !$text ) return false;

diff --git a/includes/search/SearchEngine.php b/includes/search/SearchEngine.php
index 678c530..a8e0437 100644 (file)
--- a/includes/search/SearchEngine.php
+++ b/includes/search/SearchEngine.php
@@ -756,7 +756,8 @@ class SearchResult {
        protected function initFromTitle( $title ) {
                $this->mTitle = $title;
                if ( !is_null( $this->mTitle ) ) {
-                       $this->mRevision = Revision::newFromTitle( $this->mTitle );
+                       $this->mRevision = Revision::newFromTitle(
+                               $this->mTitle, false, Revision::AVOID_MASTER );
                        if ( $this->mTitle->getNamespace() === NS_FILE )
                                $this->mImage = wfFindFile( $this->mTitle );
                }

diff --git a/includes/specials/SpecialBooksources.php b/includes/specials/SpecialBooksources.php
index bc07d58..87ba0cb 100644 (file)
--- a/includes/specials/SpecialBooksources.php
+++ b/includes/specials/SpecialBooksources.php
@@ -143,7 +143,7 @@ class SpecialBookSources extends SpecialPage {
                $page = $this->msg( 'booksources' )->inContentLanguage()->text();
                $title = Title::makeTitleSafe( NS_PROJECT, $page ); # Show list in content language
                if( is_object( $title ) && $title->exists() ) {
-                       $rev = Revision::newFromTitle( $title );
+                       $rev = Revision::newFromTitle( $title, false, Revision::AVOID_MASTER );
                        $this->getOutput()->addWikiText( str_replace( 'MAGICNUMBER', $this->isbn, $rev->getText() ) );
                        return true;
                }