MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / includes / libs / objectcache / ReplicatedBagOStuff.php

diff --git a/includes/libs/objectcache/ReplicatedBagOStuff.php b/includes/libs/objectcache/ReplicatedBagOStuff.php
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+++ b/includes/libs/objectcache/ReplicatedBagOStuff.php
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+<?php
+/**
+ * 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 Cache
+ */
+
+/**
+ * A cache class that directs writes to one set of servers and reads to
+ * another. This assumes that the servers used for reads are setup to replica DB
+ * those that writes go to. This can easily be used with redis for example.
+ *
+ * In the WAN scenario (e.g. multi-datacenter case), this is useful when
+ * writes are rare or they usually take place in the primary datacenter.
+ *
+ * @ingroup Cache
+ * @since 1.26
+ */
+class ReplicatedBagOStuff extends BagOStuff {
+       /** @var BagOStuff */
+       protected $writeStore;
+       /** @var BagOStuff */
+       protected $readStore;
+
+       /**
+        * Constructor. Parameters are:
+        *   - writeFactory : ObjectFactory::getObjectFromSpec array yeilding BagOStuff.
+        *                    This object will be used for writes (e.g. the master DB).
+        *   - readFactory  : ObjectFactory::getObjectFromSpec array yeilding BagOStuff.
+        *                    This object will be used for reads (e.g. a replica DB).
+        *
+        * @param array $params
+        * @throws InvalidArgumentException
+        */
+       public function __construct( $params ) {
+               parent::__construct( $params );
+
+               if ( !isset( $params['writeFactory'] ) ) {
+                       throw new InvalidArgumentException(
+                               __METHOD__ . ': the "writeFactory" parameter is required' );
+               }
+               if ( !isset( $params['readFactory'] ) ) {
+                       throw new InvalidArgumentException(
+                               __METHOD__ . ': the "readFactory" parameter is required' );
+               }
+
+               $opts = [ 'reportDupes' => false ]; // redundant
+               $this->writeStore = ( $params['writeFactory'] instanceof BagOStuff )
+                       ? $params['writeFactory']
+                       : ObjectFactory::getObjectFromSpec( $opts + $params['writeFactory'] );
+               $this->readStore = ( $params['readFactory'] instanceof BagOStuff )
+                       ? $params['readFactory']
+                       : ObjectFactory::getObjectFromSpec( $opts + $params['readFactory'] );
+               $this->attrMap = $this->mergeFlagMaps( [ $this->readStore, $this->writeStore ] );
+       }
+
+       public function setDebug( $debug ) {
+               $this->writeStore->setDebug( $debug );
+               $this->readStore->setDebug( $debug );
+       }
+
+       protected function doGet( $key, $flags = 0 ) {
+               return ( $flags & self::READ_LATEST )
+                       ? $this->writeStore->get( $key, $flags )
+                       : $this->readStore->get( $key, $flags );
+       }
+
+       public function getMulti( array $keys, $flags = 0 ) {
+               return ( $flags & self::READ_LATEST )
+                       ? $this->writeStore->getMulti( $keys, $flags )
+                       : $this->readStore->getMulti( $keys, $flags );
+       }
+
+       public function set( $key, $value, $exptime = 0, $flags = 0 ) {
+               return $this->writeStore->set( $key, $value, $exptime, $flags );
+       }
+
+       public function delete( $key ) {
+               return $this->writeStore->delete( $key );
+       }
+
+       public function add( $key, $value, $exptime = 0 ) {
+               return $this->writeStore->add( $key, $value, $exptime );
+       }
+
+       public function incr( $key, $value = 1 ) {
+               return $this->writeStore->incr( $key, $value );
+       }
+
+       public function decr( $key, $value = 1 ) {
+               return $this->writeStore->decr( $key, $value );
+       }
+
+       public function lock( $key, $timeout = 6, $expiry = 6, $rclass = '' ) {
+               return $this->writeStore->lock( $key, $timeout, $expiry, $rclass );
+       }
+
+       public function unlock( $key ) {
+               return $this->writeStore->unlock( $key );
+       }
+
+       public function merge( $key, callable $callback, $exptime = 0, $attempts = 10, $flags = 0 ) {
+               return $this->writeStore->merge( $key, $callback, $exptime, $attempts, $flags );
+       }
+
+       public function getLastError() {
+               return ( $this->writeStore->getLastError() != self::ERR_NONE )
+                       ? $this->writeStore->getLastError()
+                       : $this->readStore->getLastError();
+       }
+
+       public function clearLastError() {
+               $this->writeStore->clearLastError();
+               $this->readStore->clearLastError();
+       }
+}