includes/libs/rdbms/lbfactory/LBFactory.php

   1 <?php
   2 /**
   3  * Generator and manager of database load balancing objects
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Database
  22  */
  23
  24 namespace Wikimedia\Rdbms;
  25
  26 use Psr\Log\LoggerInterface;
  27 use Wikimedia\ScopedCallback;
  28 use BagOStuff;
  29 use EmptyBagOStuff;
  30 use WANObjectCache;
  31 use Exception;
  32 use RuntimeException;
  33 use LogicException;
  34
  35 /**
  36  * An interface for generating database load balancers
  37  * @ingroup Database
  38  */
  39 abstract class LBFactory implements ILBFactory {
  40         /** @var ChronologyProtector */
  41         protected $chronProt;
  42         /** @var object|string Class name or object With profileIn/profileOut methods */
  43         protected $profiler;
  44         /** @var TransactionProfiler */
  45         protected $trxProfiler;
  46         /** @var LoggerInterface */
  47         protected $replLogger;
  48         /** @var LoggerInterface */
  49         protected $connLogger;
  50         /** @var LoggerInterface */
  51         protected $queryLogger;
  52         /** @var LoggerInterface */
  53         protected $perfLogger;
  54         /** @var callable Error logger */
  55         protected $errorLogger;
  56         /** @var callable Deprecation logger */
  57         protected $deprecationLogger;
  58         /** @var BagOStuff */
  59         protected $srvCache;
  60         /** @var BagOStuff */
  61         protected $memStash;
  62         /** @var WANObjectCache */
  63         protected $wanCache;
  64
  65         /** @var DatabaseDomain Local domain */
  66         protected $localDomain;
  67         /** @var string Local hostname of the app server */
  68         protected $hostname;
  69         /** @var array Web request information about the client */
  70         protected $requestInfo;
  71
  72         /** @var mixed */
  73         protected $ticket;
  74         /** @var string|bool String if a requested DBO_TRX transaction round is active */
  75         protected $trxRoundId = false;
  76         /** @var string|bool Reason all LBs are read-only or false if not */
  77         protected $readOnlyReason = false;
  78         /** @var callable[] */
  79         protected $replicationWaitCallbacks = [];
  80
  81         /** @var array[] $aliases Map of (table => (dbname, schema, prefix) map) */
  82         protected $tableAliases = [];
  83         /** @var string[] Map of (index alias => index) */
  84         protected $indexAliases = [];
  85
  86         /** @var bool Whether this PHP instance is for a CLI script */
  87         protected $cliMode;
  88         /** @var string Agent name for query profiling */
  89         protected $agent;
  90
  91         /** @var string One of the ROUND_* class constants */
  92         private $trxRoundStage = self::ROUND_CURSORY;
  93
  94         const ROUND_CURSORY = 'cursory';
  95         const ROUND_BEGINNING = 'within-begin';
  96         const ROUND_COMMITTING = 'within-commit';
  97         const ROUND_ROLLING_BACK = 'within-rollback';
  98         const ROUND_COMMIT_CALLBACKS = 'within-commit-callbacks';
  99         const ROUND_ROLLBACK_CALLBACKS = 'within-rollback-callbacks';
 100
 101         private static $loggerFields =
 102                 [ 'replLogger', 'connLogger', 'queryLogger', 'perfLogger' ];
 103
 104         public function __construct( array $conf ) {
 105                 $this->localDomain = isset( $conf['localDomain'] )
 106                         ? DatabaseDomain::newFromId( $conf['localDomain'] )
 107                         : DatabaseDomain::newUnspecified();
 108
 109                 if ( isset( $conf['readOnlyReason'] ) && is_string( $conf['readOnlyReason'] ) ) {
 110                         $this->readOnlyReason = $conf['readOnlyReason'];
 111                 }
 112
 113                 $this->srvCache = $conf['srvCache'] ?? new EmptyBagOStuff();
 114                 $this->memStash = $conf['memStash'] ?? new EmptyBagOStuff();
 115                 $this->wanCache = $conf['wanCache'] ?? WANObjectCache::newEmpty();
 116
 117                 foreach ( self::$loggerFields as $key ) {
 118                         $this->$key = $conf[$key] ?? new \Psr\Log\NullLogger();
 119                 }
 120                 $this->errorLogger = $conf['errorLogger'] ?? function ( Exception $e ) {
 121                         trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING );
 122                 };
 123                 $this->deprecationLogger = $conf['deprecationLogger'] ?? function ( $msg ) {
 124                         trigger_error( $msg, E_USER_DEPRECATED );
 125                 };
 126
 127                 $this->profiler = $conf['profiler'] ?? null;
 128                 $this->trxProfiler = $conf['trxProfiler'] ?? new TransactionProfiler();
 129
 130                 $this->requestInfo = [
 131                         'IPAddress' => $_SERVER[ 'REMOTE_ADDR' ] ?? '',
 132                         'UserAgent' => $_SERVER['HTTP_USER_AGENT'] ?? '',
 133                         'ChronologyProtection' => 'true',
 134                         // phpcs:ignore MediaWiki.Usage.SuperGlobalsUsage.SuperGlobals -- library can't use $wgRequest
 135                         'ChronologyPositionIndex' => $_GET['cpPosIndex'] ?? null
 136                 ];
 137
 138                 $this->cliMode = $conf['cliMode'] ?? ( PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg' );
 139                 $this->hostname = $conf['hostname'] ?? gethostname();
 140                 $this->agent = $conf['agent'] ?? '';
 141
 142                 $this->ticket = mt_rand();
 143         }
 144
 145         public function destroy() {
 146                 $this->shutdown( self::SHUTDOWN_NO_CHRONPROT );
 147                 $this->forEachLBCallMethod( 'disable' );
 148         }
 149
 150         public function shutdown(
 151                 $mode = self::SHUTDOWN_CHRONPROT_SYNC, callable $workCallback = null, &$cpIndex = null
 152         ) {
 153                 $chronProt = $this->getChronologyProtector();
 154                 if ( $mode === self::SHUTDOWN_CHRONPROT_SYNC ) {
 155                         $this->shutdownChronologyProtector( $chronProt, $workCallback, 'sync', $cpIndex );
 156                 } elseif ( $mode === self::SHUTDOWN_CHRONPROT_ASYNC ) {
 157                         $this->shutdownChronologyProtector( $chronProt, null, 'async', $cpIndex );
 158                 }
 159
 160                 $this->commitMasterChanges( __METHOD__ ); // sanity
 161         }
 162
 163         /**
 164          * @see ILBFactory::newMainLB()
 165          * @param bool $domain
 166          * @return ILoadBalancer
 167          */
 168         abstract public function newMainLB( $domain = false );
 169
 170         /**
 171          * @see ILBFactory::getMainLB()
 172          * @param bool $domain
 173          * @return ILoadBalancer
 174          */
 175         abstract public function getMainLB( $domain = false );
 176
 177         /**
 178          * @see ILBFactory::newExternalLB()
 179          * @param string $cluster
 180          * @return ILoadBalancer
 181          */
 182         abstract public function newExternalLB( $cluster );
 183
 184         /**
 185          * @see ILBFactory::getExternalLB()
 186          * @param string $cluster
 187          * @return ILoadBalancer
 188          */
 189         abstract public function getExternalLB( $cluster );
 190
 191         /**
 192          * Call a method of each tracked load balancer
 193          *
 194          * @param string $methodName
 195          * @param array $args
 196          */
 197         protected function forEachLBCallMethod( $methodName, array $args = [] ) {
 198                 $this->forEachLB(
 199                         function ( ILoadBalancer $loadBalancer, $methodName, array $args ) {
 200                                 call_user_func_array( [ $loadBalancer, $methodName ], $args );
 201                         },
 202                         [ $methodName, $args ]
 203                 );
 204         }
 205
 206         public function flushReplicaSnapshots( $fname = __METHOD__ ) {
 207                 $this->forEachLBCallMethod( 'flushReplicaSnapshots', [ $fname ] );
 208         }
 209
 210         final public function commitAll( $fname = __METHOD__, array $options = [] ) {
 211                 $this->commitMasterChanges( $fname, $options );
 212                 $this->forEachLBCallMethod( 'flushMasterSnapshots', [ $fname ] );
 213                 $this->forEachLBCallMethod( 'flushReplicaSnapshots', [ $fname ] );
 214         }
 215
 216         final public function beginMasterChanges( $fname = __METHOD__ ) {
 217                 $this->assertTransactionRoundStage( self::ROUND_CURSORY );
 218                 $this->trxRoundStage = self::ROUND_BEGINNING;
 219                 if ( $this->trxRoundId !== false ) {
 220                         throw new DBTransactionError(
 221                                 null,
 222                                 "$fname: transaction round '{$this->trxRoundId}' already started."
 223                         );
 224                 }
 225                 $this->trxRoundId = $fname;
 226                 // Set DBO_TRX flags on all appropriate DBs
 227                 $this->forEachLBCallMethod( 'beginMasterChanges', [ $fname ] );
 228                 $this->trxRoundStage = self::ROUND_CURSORY;
 229         }
 230
 231         final public function commitMasterChanges( $fname = __METHOD__, array $options = [] ) {
 232                 $this->assertTransactionRoundStage( self::ROUND_CURSORY );
 233                 $this->trxRoundStage = self::ROUND_COMMITTING;
 234                 if ( $this->trxRoundId !== false && $this->trxRoundId !== $fname ) {
 235                         throw new DBTransactionError(
 236                                 null,
 237                                 "$fname: transaction round '{$this->trxRoundId}' still running."
 238                         );
 239                 }
 240                 /** @noinspection PhpUnusedLocalVariableInspection */
 241                 $scope = $this->getScopedPHPBehaviorForCommit(); // try to ignore client aborts
 242                 // Run pre-commit callbacks and suppress post-commit callbacks, aborting on failure
 243                 do {
 244                         $count = 0; // number of callbacks executed this iteration
 245                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$count ) {
 246                                 $count += $lb->finalizeMasterChanges();
 247                         } );
 248                 } while ( $count > 0 );
 249                 $this->trxRoundId = false;
 250                 // Perform pre-commit checks, aborting on failure
 251                 $this->forEachLBCallMethod( 'approveMasterChanges', [ $options ] );
 252                 // Log the DBs and methods involved in multi-DB transactions
 253                 $this->logIfMultiDbTransaction();
 254                 // Actually perform the commit on all master DB connections and revert DBO_TRX
 255                 $this->forEachLBCallMethod( 'commitMasterChanges', [ $fname ] );
 256                 // Run all post-commit callbacks in a separate step
 257                 $this->trxRoundStage = self::ROUND_COMMIT_CALLBACKS;
 258                 $e = $this->executePostTransactionCallbacks();
 259                 $this->trxRoundStage = self::ROUND_CURSORY;
 260                 // Throw any last post-commit callback error
 261                 if ( $e instanceof Exception ) {
 262                         throw $e;
 263                 }
 264         }
 265
 266         final public function rollbackMasterChanges( $fname = __METHOD__ ) {
 267                 $this->trxRoundStage = self::ROUND_ROLLING_BACK;
 268                 $this->trxRoundId = false;
 269                 // Actually perform the rollback on all master DB connections and revert DBO_TRX
 270                 $this->forEachLBCallMethod( 'rollbackMasterChanges', [ $fname ] );
 271                 // Run all post-commit callbacks in a separate step
 272                 $this->trxRoundStage = self::ROUND_ROLLBACK_CALLBACKS;
 273                 $this->executePostTransactionCallbacks();
 274                 $this->trxRoundStage = self::ROUND_CURSORY;
 275         }
 276
 277         /**
 278          * @return Exception|null
 279          */
 280         private function executePostTransactionCallbacks() {
 281                 // Run all post-commit callbacks until new ones stop getting added
 282                 $e = null; // first callback exception
 283                 do {
 284                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$e ) {
 285                                 $ex = $lb->runMasterTransactionIdleCallbacks();
 286                                 $e = $e ?: $ex;
 287                         } );
 288                 } while ( $this->hasMasterChanges() );
 289                 // Run all listener callbacks once
 290                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$e ) {
 291                         $ex = $lb->runMasterTransactionListenerCallbacks();
 292                         $e = $e ?: $ex;
 293                 } );
 294
 295                 return $e;
 296         }
 297
 298         public function hasTransactionRound() {
 299                 return ( $this->trxRoundId !== false );
 300         }
 301
 302         public function isReadyForRoundOperations() {
 303                 return ( $this->trxRoundStage === self::ROUND_CURSORY );
 304         }
 305
 306         /**
 307          * Log query info if multi DB transactions are going to be committed now
 308          */
 309         private function logIfMultiDbTransaction() {
 310                 $callersByDB = [];
 311                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$callersByDB ) {
 312                         $masterName = $lb->getServerName( $lb->getWriterIndex() );
 313                         $callers = $lb->pendingMasterChangeCallers();
 314                         if ( $callers ) {
 315                                 $callersByDB[$masterName] = $callers;
 316                         }
 317                 } );
 318
 319                 if ( count( $callersByDB ) >= 2 ) {
 320                         $dbs = implode( ', ', array_keys( $callersByDB ) );
 321                         $msg = "Multi-DB transaction [{$dbs}]:\n";
 322                         foreach ( $callersByDB as $db => $callers ) {
 323                                 $msg .= "$db: " . implode( '; ', $callers ) . "\n";
 324                         }
 325                         $this->queryLogger->info( $msg );
 326                 }
 327         }
 328
 329         public function hasMasterChanges() {
 330                 $ret = false;
 331                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$ret ) {
 332                         $ret = $ret || $lb->hasMasterChanges();
 333                 } );
 334
 335                 return $ret;
 336         }
 337
 338         public function laggedReplicaUsed() {
 339                 $ret = false;
 340                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$ret ) {
 341                         $ret = $ret || $lb->laggedReplicaUsed();
 342                 } );
 343
 344                 return $ret;
 345         }
 346
 347         public function hasOrMadeRecentMasterChanges( $age = null ) {
 348                 $ret = false;
 349                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $age, &$ret ) {
 350                         $ret = $ret || $lb->hasOrMadeRecentMasterChanges( $age );
 351                 } );
 352                 return $ret;
 353         }
 354
 355         public function waitForReplication( array $opts = [] ) {
 356                 $opts += [
 357                         'domain' => false,
 358                         'cluster' => false,
 359                         'timeout' => $this->cliMode ? 60 : 10,
 360                         'ifWritesSince' => null
 361                 ];
 362
 363                 if ( $opts['domain'] === false && isset( $opts['wiki'] ) ) {
 364                         $opts['domain'] = $opts['wiki']; // b/c
 365                 }
 366
 367                 // Figure out which clusters need to be checked
 368                 /** @var ILoadBalancer[] $lbs */
 369                 $lbs = [];
 370                 if ( $opts['cluster'] !== false ) {
 371                         $lbs[] = $this->getExternalLB( $opts['cluster'] );
 372                 } elseif ( $opts['domain'] !== false ) {
 373                         $lbs[] = $this->getMainLB( $opts['domain'] );
 374                 } else {
 375                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$lbs ) {
 376                                 $lbs[] = $lb;
 377                         } );
 378                         if ( !$lbs ) {
 379                                 return; // nothing actually used
 380                         }
 381                 }
 382
 383                 // Get all the master positions of applicable DBs right now.
 384                 // This can be faster since waiting on one cluster reduces the
 385                 // time needed to wait on the next clusters.
 386                 $masterPositions = array_fill( 0, count( $lbs ), false );
 387                 foreach ( $lbs as $i => $lb ) {
 388                         if ( $lb->getServerCount() <= 1 ) {
 389                                 // T29975 - Don't try to wait for replica DBs if there are none
 390                                 // Prevents permission error when getting master position
 391                                 continue;
 392                         } elseif ( $opts['ifWritesSince']
 393                                 && $lb->lastMasterChangeTimestamp() < $opts['ifWritesSince']
 394                         ) {
 395                                 continue; // no writes since the last wait
 396                         }
 397                         $masterPositions[$i] = $lb->getMasterPos();
 398                 }
 399
 400                 // Run any listener callbacks *after* getting the DB positions. The more
 401                 // time spent in the callbacks, the less time is spent in waitForAll().
 402                 foreach ( $this->replicationWaitCallbacks as $callback ) {
 403                         $callback();
 404                 }
 405
 406                 $failed = [];
 407                 foreach ( $lbs as $i => $lb ) {
 408                         if ( $masterPositions[$i] ) {
 409                                 // The RDBMS may not support getMasterPos()
 410                                 if ( !$lb->waitForAll( $masterPositions[$i], $opts['timeout'] ) ) {
 411                                         $failed[] = $lb->getServerName( $lb->getWriterIndex() );
 412                                 }
 413                         }
 414                 }
 415
 416                 if ( $failed ) {
 417                         throw new DBReplicationWaitError(
 418                                 null,
 419                                 "Could not wait for replica DBs to catch up to " .
 420                                 implode( ', ', $failed )
 421                         );
 422                 }
 423         }
 424
 425         public function setWaitForReplicationListener( $name, callable $callback = null ) {
 426                 if ( $callback ) {
 427                         $this->replicationWaitCallbacks[$name] = $callback;
 428                 } else {
 429                         unset( $this->replicationWaitCallbacks[$name] );
 430                 }
 431         }
 432
 433         public function getEmptyTransactionTicket( $fname ) {
 434                 if ( $this->hasMasterChanges() ) {
 435                         $this->queryLogger->error( __METHOD__ . ": $fname does not have outer scope.\n" .
 436                                 ( new RuntimeException() )->getTraceAsString() );
 437
 438                         return null;
 439                 }
 440
 441                 return $this->ticket;
 442         }
 443
 444         final public function commitAndWaitForReplication( $fname, $ticket, array $opts = [] ) {
 445                 if ( $ticket !== $this->ticket ) {
 446                         $this->perfLogger->error( __METHOD__ . ": $fname does not have outer scope.\n" .
 447                                 ( new RuntimeException() )->getTraceAsString() );
 448
 449                         return;
 450                 }
 451
 452                 // The transaction owner and any caller with the empty transaction ticket can commit
 453                 // so that getEmptyTransactionTicket() callers don't risk seeing DBTransactionError.
 454                 if ( $this->trxRoundId !== false && $fname !== $this->trxRoundId ) {
 455                         $this->queryLogger->info( "$fname: committing on behalf of {$this->trxRoundId}." );
 456                         $fnameEffective = $this->trxRoundId;
 457                 } else {
 458                         $fnameEffective = $fname;
 459                 }
 460
 461                 $this->commitMasterChanges( $fnameEffective );
 462                 $this->waitForReplication( $opts );
 463                 // If a nested caller committed on behalf of $fname, start another empty $fname
 464                 // transaction, leaving the caller with the same empty transaction state as before.
 465                 if ( $fnameEffective !== $fname ) {
 466                         $this->beginMasterChanges( $fnameEffective );
 467                 }
 468         }
 469
 470         public function getChronologyProtectorTouched( $dbName ) {
 471                 return $this->getChronologyProtector()->getTouched( $dbName );
 472         }
 473
 474         public function disableChronologyProtection() {
 475                 $this->getChronologyProtector()->setEnabled( false );
 476         }
 477
 478         /**
 479          * @return ChronologyProtector
 480          */
 481         protected function getChronologyProtector() {
 482                 if ( $this->chronProt ) {
 483                         return $this->chronProt;
 484                 }
 485
 486                 $this->chronProt = new ChronologyProtector(
 487                         $this->memStash,
 488                         [
 489                                 'ip' => $this->requestInfo['IPAddress'],
 490                                 'agent' => $this->requestInfo['UserAgent'],
 491                         ],
 492                         $this->requestInfo['ChronologyPositionIndex']
 493                 );
 494                 $this->chronProt->setLogger( $this->replLogger );
 495
 496                 if ( $this->cliMode ) {
 497                         $this->chronProt->setEnabled( false );
 498                 } elseif ( $this->requestInfo['ChronologyProtection'] === 'false' ) {
 499                         // Request opted out of using position wait logic. This is useful for requests
 500                         // done by the job queue or background ETL that do not have a meaningful session.
 501                         $this->chronProt->setWaitEnabled( false );
 502                 }
 503
 504                 $this->replLogger->debug( __METHOD__ . ': using request info ' .
 505                         json_encode( $this->requestInfo, JSON_PRETTY_PRINT ) );
 506
 507                 return $this->chronProt;
 508         }
 509
 510         /**
 511          * Get and record all of the staged DB positions into persistent memory storage
 512          *
 513          * @param ChronologyProtector $cp
 514          * @param callable|null $workCallback Work to do instead of waiting on syncing positions
 515          * @param string $mode One of (sync, async); whether to wait on remote datacenters
 516          * @param int|null &$cpIndex DB position key write counter; incremented on update
 517          */
 518         protected function shutdownChronologyProtector(
 519                 ChronologyProtector $cp, $workCallback, $mode, &$cpIndex = null
 520         ) {
 521                 // Record all the master positions needed
 522                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $cp ) {
 523                         $cp->shutdownLB( $lb );
 524                 } );
 525                 // Write them to the persistent stash. Try to do something useful by running $work
 526                 // while ChronologyProtector waits for the stash write to replicate to all DCs.
 527                 $unsavedPositions = $cp->shutdown( $workCallback, $mode, $cpIndex );
 528                 if ( $unsavedPositions && $workCallback ) {
 529                         // Invoke callback in case it did not cache the result yet
 530                         $workCallback(); // work now to block for less time in waitForAll()
 531                 }
 532                 // If the positions failed to write to the stash, at least wait on local datacenter
 533                 // replica DBs to catch up before responding. Even if there are several DCs, this increases
 534                 // the chance that the user will see their own changes immediately afterwards. As long
 535                 // as the sticky DC cookie applies (same domain), this is not even an issue.
 536                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $unsavedPositions ) {
 537                         $masterName = $lb->getServerName( $lb->getWriterIndex() );
 538                         if ( isset( $unsavedPositions[$masterName] ) ) {
 539                                 $lb->waitForAll( $unsavedPositions[$masterName] );
 540                         }
 541                 } );
 542         }
 543
 544         /**
 545          * Base parameters to ILoadBalancer::__construct()
 546          * @return array
 547          */
 548         final protected function baseLoadBalancerParams() {
 549                 if ( $this->trxRoundStage === self::ROUND_COMMIT_CALLBACKS ) {
 550                         $initStage = ILoadBalancer::STAGE_POSTCOMMIT_CALLBACKS;
 551                 } elseif ( $this->trxRoundStage === self::ROUND_ROLLBACK_CALLBACKS ) {
 552                         $initStage = ILoadBalancer::STAGE_POSTROLLBACK_CALLBACKS;
 553                 } else {
 554                         $initStage = null;
 555                 }
 556
 557                 return [
 558                         'localDomain' => $this->localDomain,
 559                         'readOnlyReason' => $this->readOnlyReason,
 560                         'srvCache' => $this->srvCache,
 561                         'wanCache' => $this->wanCache,
 562                         'profiler' => $this->profiler,
 563                         'trxProfiler' => $this->trxProfiler,
 564                         'queryLogger' => $this->queryLogger,
 565                         'connLogger' => $this->connLogger,
 566                         'replLogger' => $this->replLogger,
 567                         'errorLogger' => $this->errorLogger,
 568                         'deprecationLogger' => $this->deprecationLogger,
 569                         'hostname' => $this->hostname,
 570                         'cliMode' => $this->cliMode,
 571                         'agent' => $this->agent,
 572                         'chronologyCallback' => function ( ILoadBalancer $lb ) {
 573                                 // Defer ChronologyProtector construction in case setRequestInfo() ends up
 574                                 // being called later (but before the first connection attempt) (T192611)
 575                                 $this->getChronologyProtector()->initLB( $lb );
 576                         },
 577                         'roundStage' => $initStage
 578                 ];
 579         }
 580
 581         /**
 582          * @param ILoadBalancer $lb
 583          */
 584         protected function initLoadBalancer( ILoadBalancer $lb ) {
 585                 if ( $this->trxRoundId !== false ) {
 586                         $lb->beginMasterChanges( $this->trxRoundId ); // set DBO_TRX
 587                 }
 588
 589                 $lb->setTableAliases( $this->tableAliases );
 590                 $lb->setIndexAliases( $this->indexAliases );
 591         }
 592
 593         public function setTableAliases( array $aliases ) {
 594                 $this->tableAliases = $aliases;
 595         }
 596
 597         public function setIndexAliases( array $aliases ) {
 598                 $this->indexAliases = $aliases;
 599         }
 600
 601         public function setDomainPrefix( $prefix ) {
 602                 $this->localDomain = new DatabaseDomain(
 603                         $this->localDomain->getDatabase(),
 604                         null,
 605                         $prefix
 606                 );
 607
 608                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $prefix ) {
 609                         $lb->setDomainPrefix( $prefix );
 610                 } );
 611         }
 612
 613         public function closeAll() {
 614                 $this->forEachLBCallMethod( 'closeAll', [] );
 615         }
 616
 617         public function setAgentName( $agent ) {
 618                 $this->agent = $agent;
 619         }
 620
 621         public function appendShutdownCPIndexAsQuery( $url, $index ) {
 622                 $usedCluster = 0;
 623                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$usedCluster ) {
 624                         $usedCluster |= ( $lb->getServerCount() > 1 );
 625                 } );
 626
 627                 if ( !$usedCluster ) {
 628                         return $url; // no master/replica clusters touched
 629                 }
 630
 631                 return strpos( $url, '?' ) === false ? "$url?cpPosIndex=$index" : "$url&cpPosIndex=$index";
 632         }
 633
 634         /**
 635          * @param int $index Write index
 636          * @param int $time UNIX timestamp
 637          * @return string Timestamp-qualified write index of the form "<index>.<timestamp>"
 638          * @since 1.32
 639          */
 640         public static function makeCookieValueFromCPIndex( $index, $time ) {
 641                 return $index . '@' . $time;
 642         }
 643
 644         /**
 645          * @param string $value String possibly of the form "<index>" or "<index>@<timestamp>"
 646          * @param int $minTimestamp Lowest UNIX timestamp of non-expired values (if present)
 647          * @return int|null Write index or null if $value is empty or expired
 648          * @since 1.32
 649          */
 650         public static function getCPIndexFromCookieValue( $value, $minTimestamp ) {
 651                 if ( !preg_match( '/^(\d+)(?:@(\d+))?$/', $value, $m ) ) {
 652                         return null;
 653                 }
 654
 655                 $index = (int)$m[1];
 656
 657                 if ( isset( $m[2] ) && $m[2] !== '' && (int)$m[2] < $minTimestamp ) {
 658                         return null; // expired
 659                 }
 660
 661                 return ( $index > 0 ) ? $index : null;
 662         }
 663
 664         public function setRequestInfo( array $info ) {
 665                 if ( $this->chronProt ) {
 666                         throw new LogicException( 'ChronologyProtector already initialized.' );
 667                 }
 668
 669                 $this->requestInfo = $info + $this->requestInfo;
 670         }
 671
 672         /**
 673          * @param string $stage
 674          */
 675         private function assertTransactionRoundStage( $stage ) {
 676                 if ( $this->trxRoundStage !== $stage ) {
 677                         throw new DBTransactionError(
 678                                 null,
 679                                 "Transaction round stage must be '$stage' (not '{$this->trxRoundStage}')"
 680                         );
 681                 }
 682         }
 683
 684         /**
 685          * Make PHP ignore user aborts/disconnects until the returned
 686          * value leaves scope. This returns null and does nothing in CLI mode.
 687          *
 688          * @return ScopedCallback|null
 689          */
 690         final protected function getScopedPHPBehaviorForCommit() {
 691                 if ( PHP_SAPI != 'cli' ) { // https://bugs.php.net/bug.php?id=47540
 692                         $old = ignore_user_abort( true ); // avoid half-finished operations
 693                         return new ScopedCallback( function () use ( $old ) {
 694                                 ignore_user_abort( $old );
 695                         } );
 696                 }
 697
 698                 return null;
 699         }
 700
 701         function __destruct() {
 702                 $this->destroy();
 703         }
 704 }
 705
 706 /**
 707  * @deprecated since 1.29
 708  */
 709 class_alias( LBFactory::class, 'LBFactory' );