1091 lines
32 KiB
PHP
1091 lines
32 KiB
PHP
<?php
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/**
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* Object caching using a SQL database.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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* http://www.gnu.org/copyleft/gpl.html
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*
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* @file
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* @ingroup Cache
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*/
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use MediaWiki\MediaWikiServices;
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use Wikimedia\AtEase\AtEase;
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use Wikimedia\Rdbms\Database;
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use Wikimedia\Rdbms\DBConnectionError;
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use Wikimedia\Rdbms\DBError;
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use Wikimedia\Rdbms\DBQueryError;
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use Wikimedia\Rdbms\IDatabase;
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use Wikimedia\Rdbms\IMaintainableDatabase;
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use Wikimedia\ScopedCallback;
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use Wikimedia\Timestamp\ConvertibleTimestamp;
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use Wikimedia\WaitConditionLoop;
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/**
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* Class to store objects in the database
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*
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* @ingroup Cache
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*/
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class SqlBagOStuff extends MediumSpecificBagOStuff {
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/** @var array[] (server index => server config) */
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protected $serverInfos;
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/** @var string[] (server index => tag/host name) */
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protected $serverTags;
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/** @var int */
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protected $numServerShards;
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/** @var int UNIX timestamp */
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protected $lastGarbageCollect = 0;
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/** @var int */
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protected $purgePeriod = 10;
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/** @var int */
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protected $purgeLimit = 100;
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/** @var int */
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protected $numTableShards = 1;
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/** @var string */
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protected $tableName = 'objectcache';
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/** @var bool */
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protected $replicaOnly = false;
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/** @var array */
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protected $conns;
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/** @var array UNIX timestamps */
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protected $connFailureTimes = [];
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/** @var array Exceptions */
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protected $connFailureErrors = [];
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/** @var int */
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private static $GC_DELAY_SEC = 1;
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/** @var string */
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private static $OP_SET = 'set';
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/** @var string */
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private static $OP_ADD = 'add';
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/** @var string */
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private static $OP_TOUCH = 'touch';
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/** @var string */
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private static $OP_DELETE = 'delete';
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/**
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* Constructor. Parameters are:
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* - server: A server info structure in the format required by each
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* element in $wgDBServers.
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*
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* - servers: An array of server info structures describing a set of database servers
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* to distribute keys to. If this is specified, the "server" option will be
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* ignored. If string keys are used, then they will be used for consistent
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* hashing *instead* of the host name (from the server config). This is useful
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* when a cluster is replicated to another site (with different host names)
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* but each server has a corresponding replica in the other cluster.
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*
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* - purgePeriod: The average number of object cache writes in between
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* garbage collection operations, where expired entries
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* are removed from the database. Or in other words, the
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* reciprocal of the probability of purging on any given
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* write. If this is set to zero, purging will never be done.
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*
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* - purgeLimit: Maximum number of rows to purge at once.
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*
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* - tableName: The table name to use, default is "objectcache".
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*
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* - shards: The number of tables to use for data storage on each server.
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* If this is more than 1, table names will be formed in the style
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* objectcacheNNN where NNN is the shard index, between 0 and
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* shards-1. The number of digits will be the minimum number
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* required to hold the largest shard index. Data will be
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* distributed across all tables by key hash. This is for
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* MySQL bugs 61735 <https://bugs.mysql.com/bug.php?id=61735>
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* and 61736 <https://bugs.mysql.com/bug.php?id=61736>.
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*
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* - replicaOnly: Whether to only use replica DBs and avoid triggering
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* garbage collection logic of expired items. This only
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* makes sense if the primary DB is used and only if get()
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* calls will be used. This is used by ReplicatedBagOStuff.
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* - syncTimeout: Max seconds to wait for replica DBs to catch up for WRITE_SYNC.
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*
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* @param array $params
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*/
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public function __construct( $params ) {
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parent::__construct( $params );
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$this->attrMap[self::ATTR_EMULATION] = self::QOS_EMULATION_SQL;
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$this->attrMap[self::ATTR_SYNCWRITES] = self::QOS_SYNCWRITES_NONE;
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if ( isset( $params['servers'] ) ) {
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$this->serverInfos = [];
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$this->serverTags = [];
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$this->numServerShards = count( $params['servers'] );
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$index = 0;
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foreach ( $params['servers'] as $tag => $info ) {
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$this->serverInfos[$index] = $info;
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if ( is_string( $tag ) ) {
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$this->serverTags[$index] = $tag;
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} else {
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$this->serverTags[$index] = $info['host'] ?? "#$index";
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}
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++$index;
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}
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} elseif ( isset( $params['server'] ) ) {
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$this->serverInfos = [ $params['server'] ];
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$this->numServerShards = count( $this->serverInfos );
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} else {
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// Default to using the main wiki's database servers
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$this->serverInfos = [];
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$this->numServerShards = 1;
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$this->attrMap[self::ATTR_SYNCWRITES] = self::QOS_SYNCWRITES_BE;
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}
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if ( isset( $params['purgePeriod'] ) ) {
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$this->purgePeriod = intval( $params['purgePeriod'] );
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}
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if ( isset( $params['purgeLimit'] ) ) {
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$this->purgeLimit = intval( $params['purgeLimit'] );
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}
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if ( isset( $params['tableName'] ) ) {
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$this->tableName = $params['tableName'];
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}
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if ( isset( $params['shards'] ) ) {
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$this->numTableShards = intval( $params['shards'] );
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}
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// Backwards-compatibility for < 1.34
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$this->replicaOnly = $params['replicaOnly'] ?? ( $params['slaveOnly'] ?? false );
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}
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/**
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* Get a connection to the specified database
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*
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* @param int $shardIndex
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* @return IMaintainableDatabase
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* @throws MWException
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*/
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private function getConnection( $shardIndex ) {
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if ( $shardIndex >= $this->numServerShards ) {
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throw new MWException( __METHOD__ . ": Invalid server index \"$shardIndex\"" );
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}
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# Don't keep timing out trying to connect for each call if the DB is down
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if (
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isset( $this->connFailureErrors[$shardIndex] ) &&
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( $this->getCurrentTime() - $this->connFailureTimes[$shardIndex] ) < 60
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) {
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throw $this->connFailureErrors[$shardIndex];
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}
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if ( $this->serverInfos ) {
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if ( !isset( $this->conns[$shardIndex] ) ) {
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// Use custom database defined by server connection info
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$info = $this->serverInfos[$shardIndex];
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$type = $info['type'] ?? 'mysql';
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$host = $info['host'] ?? '[unknown]';
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$this->logger->debug( __CLASS__ . ": connecting to $host" );
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$conn = Database::factory( $type, $info );
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$conn->clearFlag( DBO_TRX ); // auto-commit mode
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$this->conns[$shardIndex] = $conn;
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// Automatically create the objectcache table for sqlite as needed
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if ( $conn->getType() === 'sqlite' ) {
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$this->initSqliteDatabase( $conn );
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}
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}
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$conn = $this->conns[$shardIndex];
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} else {
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// Use the main LB database
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$lb = MediaWikiServices::getInstance()->getDBLoadBalancer();
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$index = $this->replicaOnly ? DB_REPLICA : DB_MASTER;
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// If the RDBMS has row-level locking, use the autocommit connection to avoid
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// contention and deadlocks. Do not do this if it only has DB-level locking since
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// that would just cause deadlocks.
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$attribs = $lb->getServerAttributes( $lb->getWriterIndex() );
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$flags = $attribs[Database::ATTR_DB_LEVEL_LOCKING] ? 0 : $lb::CONN_TRX_AUTOCOMMIT;
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$conn = $lb->getMaintenanceConnectionRef( $index, [], false, $flags );
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}
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$this->logger->debug( sprintf( "Connection %s will be used for SqlBagOStuff", $conn ) );
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return $conn;
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}
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/**
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* Get the server index and table name for a given key
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* @param string $key
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* @return array Server index and table name
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*/
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private function getTableByKey( $key ) {
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if ( $this->numTableShards > 1 ) {
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$hash = hexdec( substr( md5( $key ), 0, 8 ) ) & 0x7fffffff;
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$tableIndex = $hash % $this->numTableShards;
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} else {
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$tableIndex = 0;
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}
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if ( $this->numServerShards > 1 ) {
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$sortedServers = $this->serverTags;
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ArrayUtils::consistentHashSort( $sortedServers, $key );
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reset( $sortedServers );
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$shardIndex = key( $sortedServers );
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} else {
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$shardIndex = 0;
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}
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return [ $shardIndex, $this->getTableNameByShard( $tableIndex ) ];
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}
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/**
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* Get the table name for a given shard index
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* @param int $index
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* @return string
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*/
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private function getTableNameByShard( $index ) {
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if ( $this->numTableShards > 1 ) {
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$decimals = strlen( $this->numTableShards - 1 );
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return $this->tableName .
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sprintf( "%0{$decimals}d", $index );
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} else {
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return $this->tableName;
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}
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}
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protected function doGet( $key, $flags = 0, &$casToken = null ) {
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$casToken = null;
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$blobs = $this->fetchBlobMulti( [ $key ] );
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if ( array_key_exists( $key, $blobs ) ) {
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$blob = $blobs[$key];
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$value = $this->unserialize( $blob );
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$casToken = ( $value !== false ) ? $blob : null;
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return $value;
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}
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return false;
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}
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protected function doGetMulti( array $keys, $flags = 0 ) {
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$values = [];
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$blobs = $this->fetchBlobMulti( $keys );
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foreach ( $blobs as $key => $blob ) {
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$values[$key] = $this->unserialize( $blob );
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}
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return $values;
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}
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private function fetchBlobMulti( array $keys, $flags = 0 ) {
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$values = []; // array of (key => value)
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$keysByTable = [];
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foreach ( $keys as $key ) {
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list( $shardIndex, $tableName ) = $this->getTableByKey( $key );
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$keysByTable[$shardIndex][$tableName][] = $key;
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}
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$dataRows = [];
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foreach ( $keysByTable as $shardIndex => $serverKeys ) {
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try {
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$db = $this->getConnection( $shardIndex );
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foreach ( $serverKeys as $tableName => $tableKeys ) {
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$res = $db->select( $tableName,
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[ 'keyname', 'value', 'exptime' ],
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[ 'keyname' => $tableKeys ],
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__METHOD__,
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// Approximate write-on-the-fly BagOStuff API via blocking.
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// This approximation fails if a ROLLBACK happens (which is rare).
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// We do not want to flush the TRX as that can break callers.
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$db->trxLevel() ? [ 'LOCK IN SHARE MODE' ] : []
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);
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if ( $res === false ) {
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continue;
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}
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foreach ( $res as $row ) {
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$row->shardIndex = $shardIndex;
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$row->tableName = $tableName;
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$dataRows[$row->keyname] = $row;
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}
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}
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} catch ( DBError $e ) {
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$this->handleReadError( $e, $shardIndex );
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}
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}
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foreach ( $keys as $key ) {
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if ( isset( $dataRows[$key] ) ) { // HIT?
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$row = $dataRows[$key];
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$this->debug( "get: retrieved data; expiry time is " . $row->exptime );
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$db = null; // in case of connection failure
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try {
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$db = $this->getConnection( $row->shardIndex );
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if ( $this->isExpired( $db, $row->exptime ) ) { // MISS
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$this->debug( "get: key has expired" );
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} else { // HIT
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$values[$key] = $db->decodeBlob( $row->value );
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}
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} catch ( DBQueryError $e ) {
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$this->handleWriteError( $e, $db, $row->shardIndex );
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}
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} else { // MISS
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$this->debug( 'get: no matching rows' );
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}
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}
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return $values;
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}
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protected function doSetMulti( array $data, $exptime = 0, $flags = 0 ) {
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return $this->modifyMulti( $data, $exptime, $flags, self::$OP_SET );
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}
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/**
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* @param mixed[]|null[] $data Map of (key => new value or null)
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* @param int $exptime UNIX timestamp, TTL in seconds, or 0 (no expiration)
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* @param int $flags Bitfield of BagOStuff::WRITE_* constants
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* @param string $op Cache operation
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* @return bool
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*/
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private function modifyMulti( array $data, $exptime, $flags, $op ) {
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$keysByTable = [];
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foreach ( $data as $key => $value ) {
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list( $shardIndex, $tableName ) = $this->getTableByKey( $key );
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$keysByTable[$shardIndex][$tableName][] = $key;
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}
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$exptime = $this->getExpirationAsTimestamp( $exptime );
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$result = true;
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/** @noinspection PhpUnusedLocalVariableInspection */
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$silenceScope = $this->silenceTransactionProfiler();
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foreach ( $keysByTable as $shardIndex => $serverKeys ) {
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$db = null; // in case of connection failure
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try {
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$db = $this->getConnection( $shardIndex );
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$this->occasionallyGarbageCollect( $db ); // expire old entries if any
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$dbExpiry = $exptime ? $db->timestamp( $exptime ) : $this->getMaxDateTime( $db );
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} catch ( DBError $e ) {
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$this->handleWriteError( $e, $db, $shardIndex );
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$result = false;
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continue;
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}
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foreach ( $serverKeys as $tableName => $tableKeys ) {
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try {
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$result = $this->updateTableKeys(
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$op,
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$db,
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$tableName,
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$tableKeys,
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$data,
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$dbExpiry
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) && $result;
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} catch ( DBError $e ) {
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$this->handleWriteError( $e, $db, $shardIndex );
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$result = false;
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}
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}
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}
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if ( $this->fieldHasFlags( $flags, self::WRITE_SYNC ) ) {
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$result = $this->waitForReplication() && $result;
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}
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return $result;
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}
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|
|
/**
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* @param string $op
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* @param IDatabase $db
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* @param string $table
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* @param string[] $tableKeys Keys in $data to update
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* @param mixed[]|null[] $data Map of (key => new value or null)
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* @param string $dbExpiry DB-encoded expiry
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* @return bool
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* @throws DBError
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* @throws InvalidArgumentException
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*/
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private function updateTableKeys( $op, $db, $table, $tableKeys, $data, $dbExpiry ) {
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$success = true;
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if ( $op === self::$OP_ADD ) {
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$rows = [];
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foreach ( $tableKeys as $key ) {
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$rows[] = [
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'keyname' => $key,
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'value' => $db->encodeBlob( $this->serialize( $data[$key] ) ),
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'exptime' => $dbExpiry
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];
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}
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$db->delete(
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$table,
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[
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'keyname' => $tableKeys,
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'exptime <= ' . $db->addQuotes( $db->timestamp() )
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],
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__METHOD__
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);
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$db->insert( $table, $rows, __METHOD__, [ 'IGNORE' ] );
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|
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$success = ( $db->affectedRows() == count( $rows ) );
|
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} elseif ( $op === self::$OP_SET ) {
|
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$rows = [];
|
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foreach ( $tableKeys as $key ) {
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$rows[] = [
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'keyname' => $key,
|
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'value' => $db->encodeBlob( $this->serialize( $data[$key] ) ),
|
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'exptime' => $dbExpiry
|
|
];
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}
|
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$db->replace( $table, 'keyname', $rows, __METHOD__ );
|
|
} elseif ( $op === self::$OP_DELETE ) {
|
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$db->delete( $table, [ 'keyname' => $tableKeys ], __METHOD__ );
|
|
} elseif ( $op === self::$OP_TOUCH ) {
|
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$db->update(
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$table,
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[ 'exptime' => $dbExpiry ],
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[
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'keyname' => $tableKeys,
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'exptime > ' . $db->addQuotes( $db->timestamp() )
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],
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__METHOD__
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);
|
|
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$success = ( $db->affectedRows() == count( $tableKeys ) );
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} else {
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throw new InvalidArgumentException( "Invalid operation '$op'" );
|
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}
|
|
|
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return $success;
|
|
}
|
|
|
|
protected function doSet( $key, $value, $exptime = 0, $flags = 0 ) {
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return $this->modifyMulti( [ $key => $value ], $exptime, $flags, self::$OP_SET );
|
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}
|
|
|
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protected function doAdd( $key, $value, $exptime = 0, $flags = 0 ) {
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return $this->modifyMulti( [ $key => $value ], $exptime, $flags, self::$OP_ADD );
|
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}
|
|
|
|
protected function doCas( $casToken, $key, $value, $exptime = 0, $flags = 0 ) {
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list( $shardIndex, $tableName ) = $this->getTableByKey( $key );
|
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$exptime = $this->getExpirationAsTimestamp( $exptime );
|
|
|
|
/** @noinspection PhpUnusedLocalVariableInspection */
|
|
$silenceScope = $this->silenceTransactionProfiler();
|
|
$db = null; // in case of connection failure
|
|
try {
|
|
$db = $this->getConnection( $shardIndex );
|
|
// (T26425) use a replace if the db supports it instead of
|
|
// delete/insert to avoid clashes with conflicting keynames
|
|
$db->update(
|
|
$tableName,
|
|
[
|
|
'keyname' => $key,
|
|
'value' => $db->encodeBlob( $this->serialize( $value ) ),
|
|
'exptime' => $exptime
|
|
? $db->timestamp( $exptime )
|
|
: $this->getMaxDateTime( $db )
|
|
],
|
|
[
|
|
'keyname' => $key,
|
|
'value' => $db->encodeBlob( $casToken ),
|
|
'exptime > ' . $db->addQuotes( $db->timestamp() )
|
|
],
|
|
__METHOD__
|
|
);
|
|
} catch ( DBQueryError $e ) {
|
|
$this->handleWriteError( $e, $db, $shardIndex );
|
|
|
|
return false;
|
|
}
|
|
|
|
$success = (bool)$db->affectedRows();
|
|
if ( $this->fieldHasFlags( $flags, self::WRITE_SYNC ) ) {
|
|
$success = $this->waitForReplication() && $success;
|
|
}
|
|
|
|
return $success;
|
|
}
|
|
|
|
protected function doDeleteMulti( array $keys, $flags = 0 ) {
|
|
return $this->modifyMulti(
|
|
array_fill_keys( $keys, null ),
|
|
0,
|
|
$flags,
|
|
self::$OP_DELETE
|
|
);
|
|
}
|
|
|
|
protected function doDelete( $key, $flags = 0 ) {
|
|
return $this->modifyMulti( [ $key => null ], 0, $flags, self::$OP_DELETE );
|
|
}
|
|
|
|
public function incr( $key, $step = 1, $flags = 0 ) {
|
|
list( $shardIndex, $tableName ) = $this->getTableByKey( $key );
|
|
|
|
$newCount = false;
|
|
/** @noinspection PhpUnusedLocalVariableInspection */
|
|
$silenceScope = $this->silenceTransactionProfiler();
|
|
$db = null; // in case of connection failure
|
|
try {
|
|
$db = $this->getConnection( $shardIndex );
|
|
$encTimestamp = $db->addQuotes( $db->timestamp() );
|
|
$db->update(
|
|
$tableName,
|
|
[ 'value = value + ' . (int)$step ],
|
|
[ 'keyname' => $key, "exptime > $encTimestamp" ],
|
|
__METHOD__
|
|
);
|
|
if ( $db->affectedRows() > 0 ) {
|
|
$newValue = $db->selectField(
|
|
$tableName,
|
|
'value',
|
|
[ 'keyname' => $key, "exptime > $encTimestamp" ],
|
|
__METHOD__
|
|
);
|
|
if ( $this->isInteger( $newValue ) ) {
|
|
$newCount = (int)$newValue;
|
|
}
|
|
}
|
|
} catch ( DBError $e ) {
|
|
$this->handleWriteError( $e, $db, $shardIndex );
|
|
}
|
|
|
|
return $newCount;
|
|
}
|
|
|
|
public function decr( $key, $value = 1, $flags = 0 ) {
|
|
return $this->incr( $key, -$value, $flags );
|
|
}
|
|
|
|
public function changeTTLMulti( array $keys, $exptime, $flags = 0 ) {
|
|
return $this->modifyMulti(
|
|
array_fill_keys( $keys, null ),
|
|
$exptime,
|
|
$flags,
|
|
self::$OP_TOUCH
|
|
);
|
|
}
|
|
|
|
protected function doChangeTTL( $key, $exptime, $flags ) {
|
|
return $this->modifyMulti( [ $key => null ], $exptime, $flags, self::$OP_TOUCH );
|
|
}
|
|
|
|
/**
|
|
* @param IDatabase $db
|
|
* @param string $exptime
|
|
* @return bool
|
|
*/
|
|
private function isExpired( IDatabase $db, $exptime ) {
|
|
return (
|
|
$exptime != $this->getMaxDateTime( $db ) &&
|
|
ConvertibleTimestamp::convert( TS_UNIX, $exptime ) < $this->getCurrentTime()
|
|
);
|
|
}
|
|
|
|
/**
|
|
* @param IDatabase $db
|
|
* @return string
|
|
*/
|
|
private function getMaxDateTime( $db ) {
|
|
if ( (int)$this->getCurrentTime() > 0x7fffffff ) {
|
|
return $db->timestamp( 1 << 62 );
|
|
} else {
|
|
return $db->timestamp( 0x7fffffff );
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @param IDatabase $db
|
|
* @throws DBError
|
|
*/
|
|
private function occasionallyGarbageCollect( IDatabase $db ) {
|
|
if (
|
|
// Random purging is enabled
|
|
$this->purgePeriod &&
|
|
// Only purge on one in every $this->purgePeriod writes
|
|
mt_rand( 0, $this->purgePeriod - 1 ) == 0 &&
|
|
// Avoid repeating the delete within a few seconds
|
|
( $this->getCurrentTime() - $this->lastGarbageCollect ) > self::$GC_DELAY_SEC
|
|
) {
|
|
$garbageCollector = function () use ( $db ) {
|
|
$this->deleteServerObjectsExpiringBefore(
|
|
$db, $this->getCurrentTime(),
|
|
null,
|
|
$this->purgeLimit
|
|
);
|
|
$this->lastGarbageCollect = time();
|
|
};
|
|
if ( $this->asyncHandler ) {
|
|
$this->lastGarbageCollect = $this->getCurrentTime(); // avoid duplicate enqueues
|
|
( $this->asyncHandler )( $garbageCollector );
|
|
} else {
|
|
$garbageCollector();
|
|
}
|
|
}
|
|
}
|
|
|
|
public function expireAll() {
|
|
$this->deleteObjectsExpiringBefore( $this->getCurrentTime() );
|
|
}
|
|
|
|
public function deleteObjectsExpiringBefore(
|
|
$timestamp,
|
|
callable $progress = null,
|
|
$limit = INF
|
|
) {
|
|
/** @noinspection PhpUnusedLocalVariableInspection */
|
|
$silenceScope = $this->silenceTransactionProfiler();
|
|
|
|
$shardIndexes = range( 0, $this->numServerShards - 1 );
|
|
shuffle( $shardIndexes );
|
|
|
|
$ok = true;
|
|
|
|
$keysDeletedCount = 0;
|
|
foreach ( $shardIndexes as $numServersDone => $shardIndex ) {
|
|
$db = null; // in case of connection failure
|
|
try {
|
|
$db = $this->getConnection( $shardIndex );
|
|
$this->deleteServerObjectsExpiringBefore(
|
|
$db,
|
|
$timestamp,
|
|
$progress,
|
|
$limit,
|
|
$numServersDone,
|
|
$keysDeletedCount
|
|
);
|
|
} catch ( DBError $e ) {
|
|
$this->handleWriteError( $e, $db, $shardIndex );
|
|
$ok = false;
|
|
}
|
|
}
|
|
|
|
return $ok;
|
|
}
|
|
|
|
/**
|
|
* @param IDatabase $db
|
|
* @param string|int $timestamp
|
|
* @param callable|null $progressCallback
|
|
* @param int $limit
|
|
* @param int $serversDoneCount
|
|
* @param int &$keysDeletedCount
|
|
* @throws DBError
|
|
*/
|
|
private function deleteServerObjectsExpiringBefore(
|
|
IDatabase $db,
|
|
$timestamp,
|
|
$progressCallback,
|
|
$limit,
|
|
$serversDoneCount = 0,
|
|
&$keysDeletedCount = 0
|
|
) {
|
|
$cutoffUnix = ConvertibleTimestamp::convert( TS_UNIX, $timestamp );
|
|
$shardIndexes = range( 0, $this->numTableShards - 1 );
|
|
shuffle( $shardIndexes );
|
|
|
|
foreach ( $shardIndexes as $numShardsDone => $shardIndex ) {
|
|
$continue = null; // last exptime
|
|
$lag = null; // purge lag
|
|
do {
|
|
$res = $db->select(
|
|
$this->getTableNameByShard( $shardIndex ),
|
|
[ 'keyname', 'exptime' ],
|
|
array_merge(
|
|
[ 'exptime < ' . $db->addQuotes( $db->timestamp( $cutoffUnix ) ) ],
|
|
$continue ? [ 'exptime >= ' . $db->addQuotes( $continue ) ] : []
|
|
),
|
|
__METHOD__,
|
|
[ 'LIMIT' => min( $limit, 100 ), 'ORDER BY' => 'exptime' ]
|
|
);
|
|
|
|
if ( $res->numRows() ) {
|
|
$row = $res->current();
|
|
if ( $lag === null ) {
|
|
$rowExpUnix = ConvertibleTimestamp::convert( TS_UNIX, $row->exptime );
|
|
$lag = max( $cutoffUnix - $rowExpUnix, 1 );
|
|
}
|
|
|
|
$keys = [];
|
|
foreach ( $res as $row ) {
|
|
$keys[] = $row->keyname;
|
|
$continue = $row->exptime;
|
|
}
|
|
|
|
$db->delete(
|
|
$this->getTableNameByShard( $shardIndex ),
|
|
[
|
|
'exptime < ' . $db->addQuotes( $db->timestamp( $cutoffUnix ) ),
|
|
'keyname' => $keys
|
|
],
|
|
__METHOD__
|
|
);
|
|
$keysDeletedCount += $db->affectedRows();
|
|
}
|
|
|
|
if ( is_callable( $progressCallback ) ) {
|
|
if ( $lag ) {
|
|
$continueUnix = ConvertibleTimestamp::convert( TS_UNIX, $continue );
|
|
$remainingLag = $cutoffUnix - $continueUnix;
|
|
$processedLag = max( $lag - $remainingLag, 0 );
|
|
$doneRatio = ( $numShardsDone + $processedLag / $lag ) / $this->numTableShards;
|
|
} else {
|
|
$doneRatio = 1;
|
|
}
|
|
|
|
$overallRatio = ( $doneRatio / $this->numServerShards )
|
|
+ ( $serversDoneCount / $this->numServerShards );
|
|
call_user_func( $progressCallback, $overallRatio * 100 );
|
|
}
|
|
} while ( $res->numRows() && $keysDeletedCount < $limit );
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Delete content of shard tables in every server.
|
|
* Return true if the operation is successful, false otherwise.
|
|
* @return bool
|
|
*/
|
|
public function deleteAll() {
|
|
/** @noinspection PhpUnusedLocalVariableInspection */
|
|
$silenceScope = $this->silenceTransactionProfiler();
|
|
for ( $shardIndex = 0; $shardIndex < $this->numServerShards; $shardIndex++ ) {
|
|
$db = null; // in case of connection failure
|
|
try {
|
|
$db = $this->getConnection( $shardIndex );
|
|
for ( $i = 0; $i < $this->numTableShards; $i++ ) {
|
|
$db->delete( $this->getTableNameByShard( $i ), '*', __METHOD__ );
|
|
}
|
|
} catch ( DBError $e ) {
|
|
$this->handleWriteError( $e, $db, $shardIndex );
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
public function lock( $key, $timeout = 6, $expiry = 6, $rclass = '' ) {
|
|
// Avoid deadlocks and allow lock reentry if specified
|
|
if ( isset( $this->locks[$key] ) ) {
|
|
if ( $rclass != '' && $this->locks[$key]['class'] === $rclass ) {
|
|
++$this->locks[$key]['depth'];
|
|
return true;
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
list( $shardIndex ) = $this->getTableByKey( $key );
|
|
|
|
$db = null; // in case of connection failure
|
|
try {
|
|
$db = $this->getConnection( $shardIndex );
|
|
$ok = $db->lock( $key, __METHOD__, $timeout );
|
|
if ( $ok ) {
|
|
$this->locks[$key] = [ 'class' => $rclass, 'depth' => 1 ];
|
|
}
|
|
|
|
$this->logger->warning(
|
|
__METHOD__ . " failed due to timeout for {key}.",
|
|
[ 'key' => $key, 'timeout' => $timeout ]
|
|
);
|
|
|
|
return $ok;
|
|
} catch ( DBError $e ) {
|
|
$this->handleWriteError( $e, $db, $shardIndex );
|
|
$ok = false;
|
|
}
|
|
|
|
return $ok;
|
|
}
|
|
|
|
public function unlock( $key ) {
|
|
if ( !isset( $this->locks[$key] ) ) {
|
|
return false;
|
|
}
|
|
|
|
if ( --$this->locks[$key]['depth'] <= 0 ) {
|
|
unset( $this->locks[$key] );
|
|
|
|
list( $shardIndex ) = $this->getTableByKey( $key );
|
|
|
|
$db = null; // in case of connection failure
|
|
try {
|
|
$db = $this->getConnection( $shardIndex );
|
|
$ok = $db->unlock( $key, __METHOD__ );
|
|
if ( !$ok ) {
|
|
$this->logger->warning(
|
|
__METHOD__ . ' failed to release lock for {key}.',
|
|
[ 'key' => $key ]
|
|
);
|
|
}
|
|
} catch ( DBError $e ) {
|
|
$this->handleWriteError( $e, $db, $shardIndex );
|
|
$ok = false;
|
|
}
|
|
|
|
return $ok;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Construct a cache key.
|
|
*
|
|
* @since 1.35
|
|
* @param string $keyspace
|
|
* @param array $args
|
|
* @return string
|
|
*/
|
|
public function makeKeyInternal( $keyspace, $args ) {
|
|
// SQL schema for 'objectcache' specifies keys as varchar(255). From that,
|
|
// subtract the number of characters we need for the keyspace and for
|
|
// the separator character needed for each argument. To handle some
|
|
// custom prefixes used by thing like WANObjectCache, limit to 205.
|
|
$keyspace = strtr( $keyspace, ' ', '_' );
|
|
$charsLeft = 205 - strlen( $keyspace ) - count( $args );
|
|
foreach ( $args as &$arg ) {
|
|
$arg = strtr( $arg, [
|
|
' ' => '_', // Avoid unnecessary misses from pre-1.35 code
|
|
':' => '%3A',
|
|
] );
|
|
|
|
// 33 = 32 characters for the MD5 + 1 for the '#' prefix.
|
|
if ( $charsLeft > 33 && strlen( $arg ) > $charsLeft ) {
|
|
$arg = '#' . md5( $arg );
|
|
}
|
|
$charsLeft -= strlen( $arg );
|
|
}
|
|
|
|
if ( $charsLeft < 0 ) {
|
|
return $keyspace . ':BagOStuff-long-key:##' . md5( implode( ':', $args ) );
|
|
}
|
|
return $keyspace . ':' . implode( ':', $args );
|
|
}
|
|
|
|
/**
|
|
* Serialize an object and, if possible, compress the representation.
|
|
* On typical message and page data, this can provide a 3X decrease
|
|
* in storage requirements.
|
|
*
|
|
* @param mixed $data
|
|
* @return string|int
|
|
*/
|
|
protected function serialize( $data ) {
|
|
if ( is_int( $data ) ) {
|
|
return $data;
|
|
}
|
|
|
|
$serial = serialize( $data );
|
|
if ( function_exists( 'gzdeflate' ) ) {
|
|
$serial = gzdeflate( $serial );
|
|
}
|
|
|
|
return $serial;
|
|
}
|
|
|
|
/**
|
|
* Unserialize and, if necessary, decompress an object.
|
|
* @param string $serial
|
|
* @return mixed
|
|
*/
|
|
protected function unserialize( $serial ) {
|
|
if ( $this->isInteger( $serial ) ) {
|
|
return (int)$serial;
|
|
}
|
|
|
|
if ( function_exists( 'gzinflate' ) ) {
|
|
AtEase::suppressWarnings();
|
|
$decomp = gzinflate( $serial );
|
|
AtEase::restoreWarnings();
|
|
|
|
if ( $decomp !== false ) {
|
|
$serial = $decomp;
|
|
}
|
|
}
|
|
|
|
return unserialize( $serial );
|
|
}
|
|
|
|
/**
|
|
* Handle a DBError which occurred during a read operation.
|
|
*
|
|
* @param DBError $exception
|
|
* @param int $shardIndex
|
|
*/
|
|
private function handleReadError( DBError $exception, $shardIndex ) {
|
|
if ( $exception instanceof DBConnectionError ) {
|
|
$this->markServerDown( $exception, $shardIndex );
|
|
}
|
|
|
|
$this->setAndLogDBError( $exception );
|
|
}
|
|
|
|
/**
|
|
* Handle a DBQueryError which occurred during a write operation.
|
|
*
|
|
* @param DBError $exception
|
|
* @param IDatabase|null $db DB handle or null if connection failed
|
|
* @param int $shardIndex
|
|
* @throws Exception
|
|
*/
|
|
private function handleWriteError( DBError $exception, $db, $shardIndex ) {
|
|
if ( !( $db instanceof IDatabase ) ) {
|
|
$this->markServerDown( $exception, $shardIndex );
|
|
}
|
|
|
|
$this->setAndLogDBError( $exception );
|
|
}
|
|
|
|
/**
|
|
* @param DBError $exception
|
|
*/
|
|
private function setAndLogDBError( DBError $exception ) {
|
|
$this->logger->error( "DBError: {$exception->getMessage()}" );
|
|
if ( $exception instanceof DBConnectionError ) {
|
|
$this->setLastError( BagOStuff::ERR_UNREACHABLE );
|
|
$this->logger->debug( __METHOD__ . ": ignoring connection error" );
|
|
} else {
|
|
$this->setLastError( BagOStuff::ERR_UNEXPECTED );
|
|
$this->logger->debug( __METHOD__ . ": ignoring query error" );
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Mark a server down due to a DBConnectionError exception
|
|
*
|
|
* @param DBError $exception
|
|
* @param int $shardIndex
|
|
*/
|
|
private function markServerDown( DBError $exception, $shardIndex ) {
|
|
unset( $this->conns[$shardIndex] ); // bug T103435
|
|
|
|
$now = $this->getCurrentTime();
|
|
if ( isset( $this->connFailureTimes[$shardIndex] ) ) {
|
|
if ( $now - $this->connFailureTimes[$shardIndex] >= 60 ) {
|
|
unset( $this->connFailureTimes[$shardIndex] );
|
|
unset( $this->connFailureErrors[$shardIndex] );
|
|
} else {
|
|
$this->logger->debug( __METHOD__ . ": Server #$shardIndex already down" );
|
|
return;
|
|
}
|
|
}
|
|
$this->logger->info( __METHOD__ . ": Server #$shardIndex down until " . ( $now + 60 ) );
|
|
$this->connFailureTimes[$shardIndex] = $now;
|
|
$this->connFailureErrors[$shardIndex] = $exception;
|
|
}
|
|
|
|
/**
|
|
* @param IMaintainableDatabase $db
|
|
* @throws DBError
|
|
*/
|
|
private function initSqliteDatabase( IMaintainableDatabase $db ) {
|
|
if ( $db->tableExists( 'objectcache' ) ) {
|
|
return;
|
|
}
|
|
// Use one table for SQLite; sharding does not seem to have much benefit
|
|
$db->query( "PRAGMA journal_mode=WAL" ); // this is permanent
|
|
$db->startAtomic( __METHOD__ ); // atomic DDL
|
|
try {
|
|
$encTable = $db->tableName( 'objectcache' );
|
|
$encExptimeIndex = $db->addIdentifierQuotes( $db->tablePrefix() . 'exptime' );
|
|
$db->query(
|
|
"CREATE TABLE $encTable (\n" .
|
|
" keyname BLOB NOT NULL default '' PRIMARY KEY,\n" .
|
|
" value BLOB,\n" .
|
|
" exptime TEXT\n" .
|
|
")",
|
|
__METHOD__
|
|
);
|
|
$db->query( "CREATE INDEX $encExptimeIndex ON $encTable (exptime)" );
|
|
$db->endAtomic( __METHOD__ );
|
|
} catch ( DBError $e ) {
|
|
$db->rollback( __METHOD__ );
|
|
throw $e;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Create the shard tables on all databases (e.g. via eval.php/shell.php)
|
|
*/
|
|
public function createTables() {
|
|
for ( $shardIndex = 0; $shardIndex < $this->numServerShards; $shardIndex++ ) {
|
|
$db = $this->getConnection( $shardIndex );
|
|
if ( in_array( $db->getType(), [ 'mysql', 'postgres' ], true ) ) {
|
|
for ( $i = 0; $i < $this->numTableShards; $i++ ) {
|
|
$encBaseTable = $db->tableName( 'objectcache' );
|
|
$encShardTable = $db->tableName( $this->getTableNameByShard( $i ) );
|
|
$db->query( "CREATE TABLE $encShardTable LIKE $encBaseTable" );
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @return bool Whether the main DB is used, e.g. wfGetDB( DB_MASTER )
|
|
*/
|
|
private function usesMainDB() {
|
|
return !$this->serverInfos;
|
|
}
|
|
|
|
private function waitForReplication() {
|
|
if ( !$this->usesMainDB() ) {
|
|
// Custom DB server list; probably doesn't use replication
|
|
return true;
|
|
}
|
|
|
|
$lb = MediaWikiServices::getInstance()->getDBLoadBalancer();
|
|
if ( $lb->getServerCount() <= 1 ) {
|
|
return true; // no replica DBs
|
|
}
|
|
|
|
// Main LB is used; wait for any replica DBs to catch up
|
|
try {
|
|
$masterPos = $lb->getMasterPos();
|
|
if ( !$masterPos ) {
|
|
return true; // not applicable
|
|
}
|
|
|
|
$loop = new WaitConditionLoop(
|
|
function () use ( $lb, $masterPos ) {
|
|
return $lb->waitForAll( $masterPos, 1 );
|
|
},
|
|
$this->syncTimeout,
|
|
$this->busyCallbacks
|
|
);
|
|
|
|
return ( $loop->invoke() === $loop::CONDITION_REACHED );
|
|
} catch ( DBError $e ) {
|
|
$this->setAndLogDBError( $e );
|
|
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Silence the transaction profiler until the return value falls out of scope
|
|
*
|
|
* @return ScopedCallback|null
|
|
*/
|
|
private function silenceTransactionProfiler() {
|
|
if ( !$this->usesMainDB() ) {
|
|
// Custom DB is configured which either has no TransactionProfiler injected,
|
|
// or has one specific for cache use, which we shouldn't silence
|
|
return null;
|
|
}
|
|
|
|
$trxProfiler = Profiler::instance()->getTransactionProfiler();
|
|
$oldSilenced = $trxProfiler->setSilenced( true );
|
|
return new ScopedCallback( function () use ( $trxProfiler, $oldSilenced ) {
|
|
$trxProfiler->setSilenced( $oldSilenced );
|
|
} );
|
|
}
|
|
}
|