[JobQueue] Use target wiki configuration for some key functions.

* getQueueTypes() now gets the config of the target wiki.
  Previously, for WMF, if an extension using jobs was not
  on aawiki, those job queues would not be seen by nextJobDB.
* Also fixed nextJobDB.php so that it no longer only considers
  jobs types known to aawiki for picking a DB for default jobs.
* Note that $wgJobTypesExcludedFromDefaultQueue should be global.
* This adds a SiteConfiguration::getConfig() function, which calls
  a new getConfiguration.php script.

Change-Id: I7e6904ead17efa407291f423a2b18e3c866d55fd

diff --git a/includes/SiteConfiguration.php b/includes/SiteConfiguration.php
index 7e96d45..11d7fd6 100644 (file)
--- a/includes/SiteConfiguration.php
+++ b/includes/SiteConfiguration.php
@@ -161,6 +161,12 @@ class SiteConfiguration {
         */
        public $siteParamsCallback = null;
 
+       /**
+        * Configuration cache for getConfig()
+        * @var array
+        */
+       protected $cfgCache = array();
+
        /**
         * Retrieves a configuration setting for a given wiki.
         * @param $settingName String ID of the setting name to retrieve
@@ -486,6 +492,67 @@ class SiteConfiguration {
                return array( $site, $lang );
        }
 
+       /**
+        * Get the resolved (post-setup) configuration of a potentially foreign wiki.
+        * For foreign wikis, this is expensive, and only works if maintenance
+        * scripts are setup to handle the --wiki parameter such as in wiki farms.
+        *
+        * @param string $wiki
+        * @param array|string $settings A setting name or array of setting names
+        * @return Array|mixed Array if $settings is an array, otherwise the value
+        * @throws MWException
+        * @since 1.21
+        */
+       public function getConfig( $wiki, $settings ) {
+               global $IP;
+
+               $multi = is_array( $settings );
+               $settings = (array)$settings;
+               if ( $wiki === wfWikiID() ) { // $wiki is this wiki
+                       $res = array();
+                       foreach ( $settings as $name ) {
+                               if ( !preg_match( '/^wg[A-Z]/', $name ) ) {
+                                       throw new MWException( "Variable '$name' does start with 'wg'." );
+                               } elseif ( !isset( $GLOBALS[$name] ) ) {
+                                       throw new MWException( "Variable '$name' is not set." );
+                               }
+                               $res[$name] = $GLOBALS[$name];
+                       }
+               } else { // $wiki is a foreign wiki
+                       if ( isset( $this->cfgCache[$wiki] ) ) {
+                               $res = array_intersect_key( $this->cfgCache[$wiki], array_flip( $settings ) );
+                               if ( count( $res ) == count( $settings ) ) {
+                                       return $res; // cache hit
+                               }
+                       } elseif ( !in_array( $wiki, $this->wikis ) ) {
+                               throw new MWException( "No such wiki '$wiki'." );
+                       } else {
+                               $this->cfgCache[$wiki] = array();
+                       }
+                       $retVal = 1;
+                       $cmd = wfShellWikiCmd(
+                               "$IP/maintenance/getConfiguration.php",
+                               array(
+                                       '--wiki', $wiki,
+                                       '--settings', implode( ' ', $settings ),
+                                       '--format', 'PHP'
+                               )
+                       );
+                       // ulimit5.sh breaks this call
+                       $data = trim( wfShellExec( $cmd, $retVal, array(), array( 'memory' => 0 ) ) );
+                       if ( $retVal != 0 || !strlen( $data ) ) {
+                               throw new MWException( "Failed to run getConfiguration.php." );
+                       }
+                       $res = unserialize( $data );
+                       if ( !is_array( $res ) ) {
+                               throw new MWException( "Failed to unserialize configuration array." );
+                       }
+                       $this->cfgCache[$wiki] = $this->cfgCache[$wiki] + $res;
+               }
+
+               return $multi ? $res : current( $res );
+       }
+
        /**
         * Returns true if the given vhost is handled locally.
         * @param $vhost String

diff --git a/includes/job/JobQueueGroup.php b/includes/job/JobQueueGroup.php
index 0118853..32c881f 100644 (file)
--- a/includes/job/JobQueueGroup.php
+++ b/includes/job/JobQueueGroup.php
@@ -200,9 +200,7 @@ class JobQueueGroup {
         * @return array List of strings
         */
        public function getQueueTypes() {
-               global $wgJobClasses;
-
-               return array_keys( $wgJobClasses );
+               return array_keys( $this->getCachedConfigVar( 'wgJobClasses' ) );
        }
 
        /**
@@ -284,4 +282,23 @@ class JobQueueGroup {
 
                return $count;
        }
+
+       private function getCachedConfigVar( $name ) {
+               global $wgConf, $wgMemc;
+
+               if ( $this->wiki === wfWikiID() ) {
+                       return $GLOBALS[$name]; // common case
+               } else {
+                       list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
+                       $key = wfForeignMemcKey( $db, $prefix, 'configvalue', $name );
+                       $value = $wgMemc->get( $key ); // ('v' => ...) or false
+                       if ( is_array( $value ) ) {
+                               return $value['v'];
+                       } else {
+                               $value = $wgConf->getConfig( $this->wiki, $name );
+                               $wgMemc->set( $key, array( 'v' => $value ), 86400 + mt_rand( 0, 86400 ) );
+                               return $value;
+                       }
+               }
+       }
 }

diff --git a/maintenance/getConfiguration.php b/maintenance/getConfiguration.php
new file mode 100644 (file)
index 0000000..83b5b02
--- /dev/null
+++ b/maintenance/getConfiguration.php
@@ -0,0 +1,89 @@
+<?php
+/**
+ * Print serialized output of MediaWiki config vars
+ *
+ * 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
+ * @author Tim Starling
+ * @author Antoine Musso
+ */
+
+require_once( __DIR__ . '/Maintenance.php' );
+
+/**
+ * Print serialized output of MediaWiki config vars
+ *
+ * @ingroup Maintenance
+ */
+class GetConfiguration extends Maintenance {
+       public function __construct() {
+               parent::__construct();
+               $this->mDescription = "Get serialized MediaWiki site configuration";
+               $this->addOption( 'settings', 'Space-separated list of wg* variables', true, true );
+               $this->addOption( 'format', 'PHP or JSON', true, true );
+               $this->addOption( 'wiki', 'Wiki ID', true, true );
+       }
+
+       public function execute() {
+               $res = array();
+               foreach ( explode( ' ', $this->getOption( 'settings' ) ) as $name ) {
+                       if ( !preg_match( '/^wg[A-Z]/', $name ) ) {
+                               throw new MWException( "Variable '$name' does start with 'wg'." );
+                       } elseif ( !isset( $GLOBALS[$name] ) ) {
+                               throw new MWException( "Variable '$name' is not set." );
+                       } elseif ( !$this->isAllowedVariable( $GLOBALS[$name] ) ) {
+                               throw new MWException( "Variable '$name' includes non-array, non-scalar, items." );
+                       }
+                       $res[$name] = $GLOBALS[$name];
+               }
+
+               $out = null;
+               switch( $this->getOption( 'format' ) ) {
+                       case 'PHP':
+                               $out = serialize( $res );
+                               break;
+                       case 'JSON':
+                               $out = FormatJson::encode( $res );
+                               break;
+                       default:
+                               throw new MWException( "Invalid serialization format given." );
+               }
+               if ( !is_string( $out ) ) {
+                       throw new MWException( "Failed to serialize the requested settings." );
+               }
+
+               $this->output( $out . "\n" );
+       }
+
+       private function isAllowedVariable( $value ) {
+               if ( is_array( $value ) ) {
+                       foreach ( $value as $k => $v ) {
+                               if ( !$this->isAllowedVariable( $v ) ) {
+                                       return false;
+                               }
+                       }
+                       return true;
+               } elseif ( is_scalar( $value ) ) {
+                       return true;
+               }
+               return false;
+       }
+}
+
+$maintClass = "GetConfiguration";
+require_once( RUN_MAINTENANCE_IF_MAIN );

diff --git a/maintenance/nextJobDB.php b/maintenance/nextJobDB.php
index cf90cf6..6cc8566 100644 (file)
--- a/maintenance/nextJobDB.php
+++ b/maintenance/nextJobDB.php
@@ -37,15 +37,16 @@ class nextJobDB extends Maintenance {
        }
 
        public function execute() {
-               global $wgMemc;
+               global $wgMemc, $wgJobTypesExcludedFromDefaultQueue;
 
                $type = false; // job type required/picked
+
                if ( $this->hasOption( 'types' ) ) {
                        $types = explode( ' ', $this->getOption( 'types' ) );
                } elseif ( $this->hasOption( 'type' ) ) {
                        $types = array( $this->getOption( 'type' ) );
                } else {
-                       $types = JobQueueGroup::singleton()->getDefaultQueueTypes();
+                       $types = false;
                }
 
                // Handle any required periodic queue maintenance
@@ -64,7 +65,10 @@ class nextJobDB extends Maintenance {
                        // Flatten the tree of candidates into a flat list so that a random
                        // item can be selected, weighing each queue (type/db tuple) equally.
                        foreach ( $pendingDBs as $type => $dbs ) {
-                               if ( in_array( $type, $types ) ) {
+                               if (
+                                       ( is_array( $types ) && in_array( $type, $types ) ) ||
+                                       ( $types === false && !in_array( $type, $wgJobTypesExcludedFromDefaultQueue ) )
+                               ) {
                                        foreach ( $dbs as $db ) {
                                                $candidates[] = array( $type, $db );
                                        }