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 = isset( $conf['srvCache'] ) ? $conf['srvCache'] : new EmptyBagOStuff();
 114                 $this->memStash = isset( $conf['memStash'] ) ? $conf['memStash'] : new EmptyBagOStuff();
 115                 $this->wanCache = isset( $conf['wanCache'] )
 116                         ? $conf['wanCache']
 117                         : WANObjectCache::newEmpty();
 118
 119                 foreach ( self::$loggerFields as $key ) {
 120                         $this->$key = isset( $conf[$key] ) ? $conf[$key] : new \Psr\Log\NullLogger();
 121                 }
 122                 $this->errorLogger = isset( $conf['errorLogger'] )
 123                         ? $conf['errorLogger']
 124                         : function ( Exception $e ) {
 125                                 trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING );
 126                         };
 127                 $this->deprecationLogger = isset( $conf['deprecationLogger'] )
 128                         ? $conf['deprecationLogger']
 129                         : function ( $msg ) {
 130                                 trigger_error( $msg, E_USER_DEPRECATED );
 131                         };
 132
 133                 $this->profiler = isset( $conf['profiler'] ) ? $conf['profiler'] : null;
 134                 $this->trxProfiler = isset( $conf['trxProfiler'] )
 135                         ? $conf['trxProfiler']
 136                         : new TransactionProfiler();
 137
 138                 $this->requestInfo = [
 139                         'IPAddress' => isset( $_SERVER[ 'REMOTE_ADDR' ] ) ? $_SERVER[ 'REMOTE_ADDR' ] : '',
 140                         'UserAgent' => isset( $_SERVER['HTTP_USER_AGENT'] ) ? $_SERVER['HTTP_USER_AGENT'] : '',
 141                         'ChronologyProtection' => 'true',
 142                         // phpcs:ignore MediaWiki.Usage.SuperGlobalsUsage.SuperGlobals -- library can't use $wgRequest
 143                         'ChronologyPositionIndex' => isset( $_GET['cpPosIndex'] ) ? $_GET['cpPosIndex'] : null
 144                 ];
 145
 146                 $this->cliMode = isset( $conf['cliMode'] )
 147                         ? $conf['cliMode']
 148                         : ( PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg' );
 149                 $this->hostname = isset( $conf['hostname'] ) ? $conf['hostname'] : gethostname();
 150                 $this->agent = isset( $conf['agent'] ) ? $conf['agent'] : '';
 151
 152                 $this->ticket = mt_rand();
 153         }
 154
 155         public function destroy() {
 156                 $this->shutdown( self::SHUTDOWN_NO_CHRONPROT );
 157                 $this->forEachLBCallMethod( 'disable' );
 158         }
 159
 160         public function shutdown(
 161                 $mode = self::SHUTDOWN_CHRONPROT_SYNC, callable $workCallback = null, &$cpIndex = null
 162         ) {
 163                 $chronProt = $this->getChronologyProtector();
 164                 if ( $mode === self::SHUTDOWN_CHRONPROT_SYNC ) {
 165                         $this->shutdownChronologyProtector( $chronProt, $workCallback, 'sync', $cpIndex );
 166                 } elseif ( $mode === self::SHUTDOWN_CHRONPROT_ASYNC ) {
 167                         $this->shutdownChronologyProtector( $chronProt, null, 'async', $cpIndex );
 168                 }
 169
 170                 $this->commitMasterChanges( __METHOD__ ); // sanity
 171         }
 172
 173         /**
 174          * @see ILBFactory::newMainLB()
 175          * @param bool $domain
 176          * @return ILoadBalancer
 177          */
 178         abstract public function newMainLB( $domain = false );
 179
 180         /**
 181          * @see ILBFactory::getMainLB()
 182          * @param bool $domain
 183          * @return ILoadBalancer
 184          */
 185         abstract public function getMainLB( $domain = false );
 186
 187         /**
 188          * @see ILBFactory::newExternalLB()
 189          * @param string $cluster
 190          * @return ILoadBalancer
 191          */
 192         abstract public function newExternalLB( $cluster );
 193
 194         /**
 195          * @see ILBFactory::getExternalLB()
 196          * @param string $cluster
 197          * @return ILoadBalancer
 198          */
 199         abstract public function getExternalLB( $cluster );
 200
 201         /**
 202          * Call a method of each tracked load balancer
 203          *
 204          * @param string $methodName
 205          * @param array $args
 206          */
 207         protected function forEachLBCallMethod( $methodName, array $args = [] ) {
 208                 $this->forEachLB(
 209                         function ( ILoadBalancer $loadBalancer, $methodName, array $args ) {
 210                                 call_user_func_array( [ $loadBalancer, $methodName ], $args );
 211                         },
 212                         [ $methodName, $args ]
 213                 );
 214         }
 215
 216         public function flushReplicaSnapshots( $fname = __METHOD__ ) {
 217                 $this->forEachLBCallMethod( 'flushReplicaSnapshots', [ $fname ] );
 218         }
 219
 220         final public function commitAll( $fname = __METHOD__, array $options = [] ) {
 221                 $this->commitMasterChanges( $fname, $options );
 222                 $this->forEachLBCallMethod( 'flushMasterSnapshots', [ $fname ] );
 223                 $this->forEachLBCallMethod( 'flushReplicaSnapshots', [ $fname ] );
 224         }
 225
 226         final public function beginMasterChanges( $fname = __METHOD__ ) {
 227                 $this->assertTransactionRoundStage( self::ROUND_CURSORY );
 228                 $this->trxRoundStage = self::ROUND_BEGINNING;
 229                 if ( $this->trxRoundId !== false ) {
 230                         throw new DBTransactionError(
 231                                 null,
 232                                 "$fname: transaction round '{$this->trxRoundId}' already started."
 233                         );
 234                 }
 235                 $this->trxRoundId = $fname;
 236                 // Set DBO_TRX flags on all appropriate DBs
 237                 $this->forEachLBCallMethod( 'beginMasterChanges', [ $fname ] );
 238                 $this->trxRoundStage = self::ROUND_CURSORY;
 239         }
 240
 241         final public function commitMasterChanges( $fname = __METHOD__, array $options = [] ) {
 242                 $this->assertTransactionRoundStage( self::ROUND_CURSORY );
 243                 $this->trxRoundStage = self::ROUND_COMMITTING;
 244                 if ( $this->trxRoundId !== false && $this->trxRoundId !== $fname ) {
 245                         throw new DBTransactionError(
 246                                 null,
 247                                 "$fname: transaction round '{$this->trxRoundId}' still running."
 248                         );
 249                 }
 250                 /** @noinspection PhpUnusedLocalVariableInspection */
 251                 $scope = $this->getScopedPHPBehaviorForCommit(); // try to ignore client aborts
 252                 // Run pre-commit callbacks and suppress post-commit callbacks, aborting on failure
 253                 do {
 254                         $count = 0; // number of callbacks executed this iteration
 255                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$count ) {
 256                                 $count += $lb->finalizeMasterChanges();
 257                         } );
 258                 } while ( $count > 0 );
 259                 $this->trxRoundId = false;
 260                 // Perform pre-commit checks, aborting on failure
 261                 $this->forEachLBCallMethod( 'approveMasterChanges', [ $options ] );
 262                 // Log the DBs and methods involved in multi-DB transactions
 263                 $this->logIfMultiDbTransaction();
 264                 // Actually perform the commit on all master DB connections and revert DBO_TRX
 265                 $this->forEachLBCallMethod( 'commitMasterChanges', [ $fname ] );
 266                 // Run all post-commit callbacks in a separate step
 267                 $this->trxRoundStage = self::ROUND_COMMIT_CALLBACKS;
 268                 $e = $this->executePostTransactionCallbacks();
 269                 $this->trxRoundStage = self::ROUND_CURSORY;
 270                 // Throw any last post-commit callback error
 271                 if ( $e instanceof Exception ) {
 272                         throw $e;
 273                 }
 274         }
 275
 276         final public function rollbackMasterChanges( $fname = __METHOD__ ) {
 277                 $this->trxRoundStage = self::ROUND_ROLLING_BACK;
 278                 $this->trxRoundId = false;
 279                 // Actually perform the rollback on all master DB connections and revert DBO_TRX
 280                 $this->forEachLBCallMethod( 'rollbackMasterChanges', [ $fname ] );
 281                 // Run all post-commit callbacks in a separate step
 282                 $this->trxRoundStage = self::ROUND_ROLLBACK_CALLBACKS;
 283                 $this->executePostTransactionCallbacks();
 284                 $this->trxRoundStage = self::ROUND_CURSORY;
 285         }
 286
 287         /**
 288          * @return Exception|null
 289          */
 290         private function executePostTransactionCallbacks() {
 291                 // Run all post-commit callbacks until new ones stop getting added
 292                 $e = null; // first callback exception
 293                 do {
 294                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$e ) {
 295                                 $ex = $lb->runMasterTransactionIdleCallbacks();
 296                                 $e = $e ?: $ex;
 297                         } );
 298                 } while ( $this->hasMasterChanges() );
 299                 // Run all listener callbacks once
 300                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$e ) {
 301                         $ex = $lb->runMasterTransactionListenerCallbacks();
 302                         $e = $e ?: $ex;
 303                 } );
 304
 305                 return $e;
 306         }
 307
 308         public function hasTransactionRound() {
 309                 return ( $this->trxRoundId !== false );
 310         }
 311
 312         public function isReadyForRoundOperations() {
 313                 return ( $this->trxRoundStage === self::ROUND_CURSORY );
 314         }
 315
 316         /**
 317          * Log query info if multi DB transactions are going to be committed now
 318          */
 319         private function logIfMultiDbTransaction() {
 320                 $callersByDB = [];
 321                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$callersByDB ) {
 322                         $masterName = $lb->getServerName( $lb->getWriterIndex() );
 323                         $callers = $lb->pendingMasterChangeCallers();
 324                         if ( $callers ) {
 325                                 $callersByDB[$masterName] = $callers;
 326                         }
 327                 } );
 328
 329                 if ( count( $callersByDB ) >= 2 ) {
 330                         $dbs = implode( ', ', array_keys( $callersByDB ) );
 331                         $msg = "Multi-DB transaction [{$dbs}]:\n";
 332                         foreach ( $callersByDB as $db => $callers ) {
 333                                 $msg .= "$db: " . implode( '; ', $callers ) . "\n";
 334                         }
 335                         $this->queryLogger->info( $msg );
 336                 }
 337         }
 338
 339         public function hasMasterChanges() {
 340                 $ret = false;
 341                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$ret ) {
 342                         $ret = $ret || $lb->hasMasterChanges();
 343                 } );
 344
 345                 return $ret;
 346         }
 347
 348         public function laggedReplicaUsed() {
 349                 $ret = false;
 350                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$ret ) {
 351                         $ret = $ret || $lb->laggedReplicaUsed();
 352                 } );
 353
 354                 return $ret;
 355         }
 356
 357         public function hasOrMadeRecentMasterChanges( $age = null ) {
 358                 $ret = false;
 359                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $age, &$ret ) {
 360                         $ret = $ret || $lb->hasOrMadeRecentMasterChanges( $age );
 361                 } );
 362                 return $ret;
 363         }
 364
 365         public function waitForReplication( array $opts = [] ) {
 366                 $opts += [
 367                         'domain' => false,
 368                         'cluster' => false,
 369                         'timeout' => $this->cliMode ? 60 : 10,
 370                         'ifWritesSince' => null
 371                 ];
 372
 373                 if ( $opts['domain'] === false && isset( $opts['wiki'] ) ) {
 374                         $opts['domain'] = $opts['wiki']; // b/c
 375                 }
 376
 377                 // Figure out which clusters need to be checked
 378                 /** @var ILoadBalancer[] $lbs */
 379                 $lbs = [];
 380                 if ( $opts['cluster'] !== false ) {
 381                         $lbs[] = $this->getExternalLB( $opts['cluster'] );
 382                 } elseif ( $opts['domain'] !== false ) {
 383                         $lbs[] = $this->getMainLB( $opts['domain'] );
 384                 } else {
 385                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$lbs ) {
 386                                 $lbs[] = $lb;
 387                         } );
 388                         if ( !$lbs ) {
 389                                 return; // nothing actually used
 390                         }
 391                 }
 392
 393                 // Get all the master positions of applicable DBs right now.
 394                 // This can be faster since waiting on one cluster reduces the
 395                 // time needed to wait on the next clusters.
 396                 $masterPositions = array_fill( 0, count( $lbs ), false );
 397                 foreach ( $lbs as $i => $lb ) {
 398                         if ( $lb->getServerCount() <= 1 ) {
 399                                 // T29975 - Don't try to wait for replica DBs if there are none
 400                                 // Prevents permission error when getting master position
 401                                 continue;
 402                         } elseif ( $opts['ifWritesSince']
 403                                 && $lb->lastMasterChangeTimestamp() < $opts['ifWritesSince']
 404                         ) {
 405                                 continue; // no writes since the last wait
 406                         }
 407                         $masterPositions[$i] = $lb->getMasterPos();
 408                 }
 409
 410                 // Run any listener callbacks *after* getting the DB positions. The more
 411                 // time spent in the callbacks, the less time is spent in waitForAll().
 412                 foreach ( $this->replicationWaitCallbacks as $callback ) {
 413                         $callback();
 414                 }
 415
 416                 $failed = [];
 417                 foreach ( $lbs as $i => $lb ) {
 418                         if ( $masterPositions[$i] ) {
 419                                 // The RDBMS may not support getMasterPos()
 420                                 if ( !$lb->waitForAll( $masterPositions[$i], $opts['timeout'] ) ) {
 421                                         $failed[] = $lb->getServerName( $lb->getWriterIndex() );
 422                                 }
 423                         }
 424                 }
 425
 426                 if ( $failed ) {
 427                         throw new DBReplicationWaitError(
 428                                 null,
 429                                 "Could not wait for replica DBs to catch up to " .
 430                                 implode( ', ', $failed )
 431                         );
 432                 }
 433         }
 434
 435         public function setWaitForReplicationListener( $name, callable $callback = null ) {
 436                 if ( $callback ) {
 437                         $this->replicationWaitCallbacks[$name] = $callback;
 438                 } else {
 439                         unset( $this->replicationWaitCallbacks[$name] );
 440                 }
 441         }
 442
 443         public function getEmptyTransactionTicket( $fname ) {
 444                 if ( $this->hasMasterChanges() ) {
 445                         $this->queryLogger->error( __METHOD__ . ": $fname does not have outer scope.\n" .
 446                                 ( new RuntimeException() )->getTraceAsString() );
 447
 448                         return null;
 449                 }
 450
 451                 return $this->ticket;
 452         }
 453
 454         final public function commitAndWaitForReplication( $fname, $ticket, array $opts = [] ) {
 455                 if ( $ticket !== $this->ticket ) {
 456                         $this->perfLogger->error( __METHOD__ . ": $fname does not have outer scope.\n" .
 457                                 ( new RuntimeException() )->getTraceAsString() );
 458
 459                         return;
 460                 }
 461
 462                 // The transaction owner and any caller with the empty transaction ticket can commit
 463                 // so that getEmptyTransactionTicket() callers don't risk seeing DBTransactionError.
 464                 if ( $this->trxRoundId !== false && $fname !== $this->trxRoundId ) {
 465                         $this->queryLogger->info( "$fname: committing on behalf of {$this->trxRoundId}." );
 466                         $fnameEffective = $this->trxRoundId;
 467                 } else {
 468                         $fnameEffective = $fname;
 469                 }
 470
 471                 $this->commitMasterChanges( $fnameEffective );
 472                 $this->waitForReplication( $opts );
 473                 // If a nested caller committed on behalf of $fname, start another empty $fname
 474                 // transaction, leaving the caller with the same empty transaction state as before.
 475                 if ( $fnameEffective !== $fname ) {
 476                         $this->beginMasterChanges( $fnameEffective );
 477                 }
 478         }
 479
 480         public function getChronologyProtectorTouched( $dbName ) {
 481                 return $this->getChronologyProtector()->getTouched( $dbName );
 482         }
 483
 484         public function disableChronologyProtection() {
 485                 $this->getChronologyProtector()->setEnabled( false );
 486         }
 487
 488         /**
 489          * @return ChronologyProtector
 490          */
 491         protected function getChronologyProtector() {
 492                 if ( $this->chronProt ) {
 493                         return $this->chronProt;
 494                 }
 495
 496                 $this->chronProt = new ChronologyProtector(
 497                         $this->memStash,
 498                         [
 499                                 'ip' => $this->requestInfo['IPAddress'],
 500                                 'agent' => $this->requestInfo['UserAgent'],
 501                         ],
 502                         $this->requestInfo['ChronologyPositionIndex']
 503                 );
 504                 $this->chronProt->setLogger( $this->replLogger );
 505
 506                 if ( $this->cliMode ) {
 507                         $this->chronProt->setEnabled( false );
 508                 } elseif ( $this->requestInfo['ChronologyProtection'] === 'false' ) {
 509                         // Request opted out of using position wait logic. This is useful for requests
 510                         // done by the job queue or background ETL that do not have a meaningful session.
 511                         $this->chronProt->setWaitEnabled( false );
 512                 }
 513
 514                 $this->replLogger->debug( __METHOD__ . ': using request info ' .
 515                         json_encode( $this->requestInfo, JSON_PRETTY_PRINT ) );
 516
 517                 return $this->chronProt;
 518         }
 519
 520         /**
 521          * Get and record all of the staged DB positions into persistent memory storage
 522          *
 523          * @param ChronologyProtector $cp
 524          * @param callable|null $workCallback Work to do instead of waiting on syncing positions
 525          * @param string $mode One of (sync, async); whether to wait on remote datacenters
 526          * @param int|null &$cpIndex DB position key write counter; incremented on update
 527          */
 528         protected function shutdownChronologyProtector(
 529                 ChronologyProtector $cp, $workCallback, $mode, &$cpIndex = null
 530         ) {
 531                 // Record all the master positions needed
 532                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $cp ) {
 533                         $cp->shutdownLB( $lb );
 534                 } );
 535                 // Write them to the persistent stash. Try to do something useful by running $work
 536                 // while ChronologyProtector waits for the stash write to replicate to all DCs.
 537                 $unsavedPositions = $cp->shutdown( $workCallback, $mode, $cpIndex );
 538                 if ( $unsavedPositions && $workCallback ) {
 539                         // Invoke callback in case it did not cache the result yet
 540                         $workCallback(); // work now to block for less time in waitForAll()
 541                 }
 542                 // If the positions failed to write to the stash, at least wait on local datacenter
 543                 // replica DBs to catch up before responding. Even if there are several DCs, this increases
 544                 // the chance that the user will see their own changes immediately afterwards. As long
 545                 // as the sticky DC cookie applies (same domain), this is not even an issue.
 546                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $unsavedPositions ) {
 547                         $masterName = $lb->getServerName( $lb->getWriterIndex() );
 548                         if ( isset( $unsavedPositions[$masterName] ) ) {
 549                                 $lb->waitForAll( $unsavedPositions[$masterName] );
 550                         }
 551                 } );
 552         }
 553
 554         /**
 555          * Base parameters to ILoadBalancer::__construct()
 556          * @return array
 557          */
 558         final protected function baseLoadBalancerParams() {
 559                 if ( $this->trxRoundStage === self::ROUND_COMMIT_CALLBACKS ) {
 560                         $initStage = ILoadBalancer::STAGE_POSTCOMMIT_CALLBACKS;
 561                 } elseif ( $this->trxRoundStage === self::ROUND_ROLLBACK_CALLBACKS ) {
 562                         $initStage = ILoadBalancer::STAGE_POSTROLLBACK_CALLBACKS;
 563                 } else {
 564                         $initStage = null;
 565                 }
 566
 567                 return [
 568                         'localDomain' => $this->localDomain,
 569                         'readOnlyReason' => $this->readOnlyReason,
 570                         'srvCache' => $this->srvCache,
 571                         'wanCache' => $this->wanCache,
 572                         'profiler' => $this->profiler,
 573                         'trxProfiler' => $this->trxProfiler,
 574                         'queryLogger' => $this->queryLogger,
 575                         'connLogger' => $this->connLogger,
 576                         'replLogger' => $this->replLogger,
 577                         'errorLogger' => $this->errorLogger,
 578                         'deprecationLogger' => $this->deprecationLogger,
 579                         'hostname' => $this->hostname,
 580                         'cliMode' => $this->cliMode,
 581                         'agent' => $this->agent,
 582                         'chronologyCallback' => function ( ILoadBalancer $lb ) {
 583                                 // Defer ChronologyProtector construction in case setRequestInfo() ends up
 584                                 // being called later (but before the first connection attempt) (T192611)
 585                                 $this->getChronologyProtector()->initLB( $lb );
 586                         },
 587                         'roundStage' => $initStage
 588                 ];
 589         }
 590
 591         /**
 592          * @param ILoadBalancer $lb
 593          */
 594         protected function initLoadBalancer( ILoadBalancer $lb ) {
 595                 if ( $this->trxRoundId !== false ) {
 596                         $lb->beginMasterChanges( $this->trxRoundId ); // set DBO_TRX
 597                 }
 598
 599                 $lb->setTableAliases( $this->tableAliases );
 600                 $lb->setIndexAliases( $this->indexAliases );
 601         }
 602
 603         public function setTableAliases( array $aliases ) {
 604                 $this->tableAliases = $aliases;
 605         }
 606
 607         public function setIndexAliases( array $aliases ) {
 608                 $this->indexAliases = $aliases;
 609         }
 610
 611         public function setDomainPrefix( $prefix ) {
 612                 $this->localDomain = new DatabaseDomain(
 613                         $this->localDomain->getDatabase(),
 614                         null,
 615                         $prefix
 616                 );
 617
 618                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $prefix ) {
 619                         $lb->setDomainPrefix( $prefix );
 620                 } );
 621         }
 622
 623         public function closeAll() {
 624                 $this->forEachLBCallMethod( 'closeAll', [] );
 625         }
 626
 627         public function setAgentName( $agent ) {
 628                 $this->agent = $agent;
 629         }
 630
 631         public function appendShutdownCPIndexAsQuery( $url, $index ) {
 632                 $usedCluster = 0;
 633                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$usedCluster ) {
 634                         $usedCluster |= ( $lb->getServerCount() > 1 );
 635                 } );
 636
 637                 if ( !$usedCluster ) {
 638                         return $url; // no master/replica clusters touched
 639                 }
 640
 641                 return strpos( $url, '?' ) === false ? "$url?cpPosIndex=$index" : "$url&cpPosIndex=$index";
 642         }
 643
 644         /**
 645          * @param int $index Write index
 646          * @param int $time UNIX timestamp
 647          * @return string Timestamp-qualified write index of the form "<index>.<timestamp>"
 648          * @since 1.32
 649          */
 650         public static function makeCookieValueFromCPIndex( $index, $time ) {
 651                 return $index . '@' . $time;
 652         }
 653
 654         /**
 655          * @param string $value String possibly of the form "<index>" or "<index>@<timestamp>"
 656          * @param int $minTimestamp Lowest UNIX timestamp of non-expired values (if present)
 657          * @return int|null Write index or null if $value is empty or expired
 658          * @since 1.32
 659          */
 660         public static function getCPIndexFromCookieValue( $value, $minTimestamp ) {
 661                 if ( !preg_match( '/^(\d+)(?:@(\d+))?$/', $value, $m ) ) {
 662                         return null;
 663                 }
 664
 665                 $index = (int)$m[1];
 666
 667                 if ( isset( $m[2] ) && $m[2] !== '' && (int)$m[2] < $minTimestamp ) {
 668                         return null; // expired
 669                 }
 670
 671                 return ( $index > 0 ) ? $index : null;
 672         }
 673
 674         public function setRequestInfo( array $info ) {
 675                 if ( $this->chronProt ) {
 676                         throw new LogicException( 'ChronologyProtector already initialized.' );
 677                 }
 678
 679                 $this->requestInfo = $info + $this->requestInfo;
 680         }
 681
 682         /**
 683          * @param string $stage
 684          */
 685         private function assertTransactionRoundStage( $stage ) {
 686                 if ( $this->trxRoundStage !== $stage ) {
 687                         throw new DBTransactionError(
 688                                 null,
 689                                 "Transaction round stage must be '$stage' (not '{$this->trxRoundStage}')"
 690                         );
 691                 }
 692         }
 693
 694         /**
 695          * Make PHP ignore user aborts/disconnects until the returned
 696          * value leaves scope. This returns null and does nothing in CLI mode.
 697          *
 698          * @return ScopedCallback|null
 699          */
 700         final protected function getScopedPHPBehaviorForCommit() {
 701                 if ( PHP_SAPI != 'cli' ) { // https://bugs.php.net/bug.php?id=47540
 702                         $old = ignore_user_abort( true ); // avoid half-finished operations
 703                         return new ScopedCallback( function () use ( $old ) {
 704                                 ignore_user_abort( $old );
 705                         } );
 706                 }
 707
 708                 return null;
 709         }
 710
 711         function __destruct() {
 712                 $this->destroy();
 713         }
 714 }
 715
 716 class_alias( LBFactory::class, 'LBFactory' );