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                         // Headers application can inject via LBFactory::setRequestInfo()
 134                         'ChronologyClientId' => null, // prior $cpClientId value from LBFactory::shutdown()
 135                         'ChronologyPositionIndex' => null // prior $cpIndex value from LBFactory::shutdown()
 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,
 152                 callable $workCallback = null,
 153                 &$cpIndex = null,
 154                 &$cpClientId = null
 155         ) {
 156                 $chronProt = $this->getChronologyProtector();
 157                 if ( $mode === self::SHUTDOWN_CHRONPROT_SYNC ) {
 158                         $this->shutdownChronologyProtector( $chronProt, $workCallback, 'sync', $cpIndex );
 159                 } elseif ( $mode === self::SHUTDOWN_CHRONPROT_ASYNC ) {
 160                         $this->shutdownChronologyProtector( $chronProt, null, 'async', $cpIndex );
 161                 }
 162
 163                 $cpClientId = $chronProt->getClientId();
 164
 165                 $this->commitMasterChanges( __METHOD__ ); // sanity
 166         }
 167
 168         /**
 169          * @see ILBFactory::newMainLB()
 170          * @param bool $domain
 171          * @return ILoadBalancer
 172          */
 173         abstract public function newMainLB( $domain = false );
 174
 175         /**
 176          * @see ILBFactory::getMainLB()
 177          * @param bool $domain
 178          * @return ILoadBalancer
 179          */
 180         abstract public function getMainLB( $domain = false );
 181
 182         /**
 183          * @see ILBFactory::newExternalLB()
 184          * @param string $cluster
 185          * @return ILoadBalancer
 186          */
 187         abstract public function newExternalLB( $cluster );
 188
 189         /**
 190          * @see ILBFactory::getExternalLB()
 191          * @param string $cluster
 192          * @return ILoadBalancer
 193          */
 194         abstract public function getExternalLB( $cluster );
 195
 196         /**
 197          * Call a method of each tracked load balancer
 198          *
 199          * @param string $methodName
 200          * @param array $args
 201          */
 202         protected function forEachLBCallMethod( $methodName, array $args = [] ) {
 203                 $this->forEachLB(
 204                         function ( ILoadBalancer $loadBalancer, $methodName, array $args ) {
 205                                 call_user_func_array( [ $loadBalancer, $methodName ], $args );
 206                         },
 207                         [ $methodName, $args ]
 208                 );
 209         }
 210
 211         public function flushReplicaSnapshots( $fname = __METHOD__ ) {
 212                 $this->forEachLBCallMethod( 'flushReplicaSnapshots', [ $fname ] );
 213         }
 214
 215         final public function commitAll( $fname = __METHOD__, array $options = [] ) {
 216                 $this->commitMasterChanges( $fname, $options );
 217                 $this->forEachLBCallMethod( 'flushMasterSnapshots', [ $fname ] );
 218                 $this->forEachLBCallMethod( 'flushReplicaSnapshots', [ $fname ] );
 219         }
 220
 221         final public function beginMasterChanges( $fname = __METHOD__ ) {
 222                 $this->assertTransactionRoundStage( self::ROUND_CURSORY );
 223                 $this->trxRoundStage = self::ROUND_BEGINNING;
 224                 if ( $this->trxRoundId !== false ) {
 225                         throw new DBTransactionError(
 226                                 null,
 227                                 "$fname: transaction round '{$this->trxRoundId}' already started."
 228                         );
 229                 }
 230                 $this->trxRoundId = $fname;
 231                 // Set DBO_TRX flags on all appropriate DBs
 232                 $this->forEachLBCallMethod( 'beginMasterChanges', [ $fname ] );
 233                 $this->trxRoundStage = self::ROUND_CURSORY;
 234         }
 235
 236         final public function commitMasterChanges( $fname = __METHOD__, array $options = [] ) {
 237                 $this->assertTransactionRoundStage( self::ROUND_CURSORY );
 238                 $this->trxRoundStage = self::ROUND_COMMITTING;
 239                 if ( $this->trxRoundId !== false && $this->trxRoundId !== $fname ) {
 240                         throw new DBTransactionError(
 241                                 null,
 242                                 "$fname: transaction round '{$this->trxRoundId}' still running."
 243                         );
 244                 }
 245                 /** @noinspection PhpUnusedLocalVariableInspection */
 246                 $scope = $this->getScopedPHPBehaviorForCommit(); // try to ignore client aborts
 247                 // Run pre-commit callbacks and suppress post-commit callbacks, aborting on failure
 248                 do {
 249                         $count = 0; // number of callbacks executed this iteration
 250                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$count ) {
 251                                 $count += $lb->finalizeMasterChanges();
 252                         } );
 253                 } while ( $count > 0 );
 254                 $this->trxRoundId = false;
 255                 // Perform pre-commit checks, aborting on failure
 256                 $this->forEachLBCallMethod( 'approveMasterChanges', [ $options ] );
 257                 // Log the DBs and methods involved in multi-DB transactions
 258                 $this->logIfMultiDbTransaction();
 259                 // Actually perform the commit on all master DB connections and revert DBO_TRX
 260                 $this->forEachLBCallMethod( 'commitMasterChanges', [ $fname ] );
 261                 // Run all post-commit callbacks in a separate step
 262                 $this->trxRoundStage = self::ROUND_COMMIT_CALLBACKS;
 263                 $e = $this->executePostTransactionCallbacks();
 264                 $this->trxRoundStage = self::ROUND_CURSORY;
 265                 // Throw any last post-commit callback error
 266                 if ( $e instanceof Exception ) {
 267                         throw $e;
 268                 }
 269         }
 270
 271         final public function rollbackMasterChanges( $fname = __METHOD__ ) {
 272                 $this->trxRoundStage = self::ROUND_ROLLING_BACK;
 273                 $this->trxRoundId = false;
 274                 // Actually perform the rollback on all master DB connections and revert DBO_TRX
 275                 $this->forEachLBCallMethod( 'rollbackMasterChanges', [ $fname ] );
 276                 // Run all post-commit callbacks in a separate step
 277                 $this->trxRoundStage = self::ROUND_ROLLBACK_CALLBACKS;
 278                 $this->executePostTransactionCallbacks();
 279                 $this->trxRoundStage = self::ROUND_CURSORY;
 280         }
 281
 282         /**
 283          * @return Exception|null
 284          */
 285         private function executePostTransactionCallbacks() {
 286                 // Run all post-commit callbacks until new ones stop getting added
 287                 $e = null; // first callback exception
 288                 do {
 289                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$e ) {
 290                                 $ex = $lb->runMasterTransactionIdleCallbacks();
 291                                 $e = $e ?: $ex;
 292                         } );
 293                 } while ( $this->hasMasterChanges() );
 294                 // Run all listener callbacks once
 295                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$e ) {
 296                         $ex = $lb->runMasterTransactionListenerCallbacks();
 297                         $e = $e ?: $ex;
 298                 } );
 299
 300                 return $e;
 301         }
 302
 303         public function hasTransactionRound() {
 304                 return ( $this->trxRoundId !== false );
 305         }
 306
 307         public function isReadyForRoundOperations() {
 308                 return ( $this->trxRoundStage === self::ROUND_CURSORY );
 309         }
 310
 311         /**
 312          * Log query info if multi DB transactions are going to be committed now
 313          */
 314         private function logIfMultiDbTransaction() {
 315                 $callersByDB = [];
 316                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$callersByDB ) {
 317                         $masterName = $lb->getServerName( $lb->getWriterIndex() );
 318                         $callers = $lb->pendingMasterChangeCallers();
 319                         if ( $callers ) {
 320                                 $callersByDB[$masterName] = $callers;
 321                         }
 322                 } );
 323
 324                 if ( count( $callersByDB ) >= 2 ) {
 325                         $dbs = implode( ', ', array_keys( $callersByDB ) );
 326                         $msg = "Multi-DB transaction [{$dbs}]:\n";
 327                         foreach ( $callersByDB as $db => $callers ) {
 328                                 $msg .= "$db: " . implode( '; ', $callers ) . "\n";
 329                         }
 330                         $this->queryLogger->info( $msg );
 331                 }
 332         }
 333
 334         public function hasMasterChanges() {
 335                 $ret = false;
 336                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$ret ) {
 337                         $ret = $ret || $lb->hasMasterChanges();
 338                 } );
 339
 340                 return $ret;
 341         }
 342
 343         public function laggedReplicaUsed() {
 344                 $ret = false;
 345                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$ret ) {
 346                         $ret = $ret || $lb->laggedReplicaUsed();
 347                 } );
 348
 349                 return $ret;
 350         }
 351
 352         public function hasOrMadeRecentMasterChanges( $age = null ) {
 353                 $ret = false;
 354                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $age, &$ret ) {
 355                         $ret = $ret || $lb->hasOrMadeRecentMasterChanges( $age );
 356                 } );
 357                 return $ret;
 358         }
 359
 360         public function waitForReplication( array $opts = [] ) {
 361                 $opts += [
 362                         'domain' => false,
 363                         'cluster' => false,
 364                         'timeout' => $this->cliMode ? 60 : 10,
 365                         'ifWritesSince' => null
 366                 ];
 367
 368                 if ( $opts['domain'] === false && isset( $opts['wiki'] ) ) {
 369                         $opts['domain'] = $opts['wiki']; // b/c
 370                 }
 371
 372                 // Figure out which clusters need to be checked
 373                 /** @var ILoadBalancer[] $lbs */
 374                 $lbs = [];
 375                 if ( $opts['cluster'] !== false ) {
 376                         $lbs[] = $this->getExternalLB( $opts['cluster'] );
 377                 } elseif ( $opts['domain'] !== false ) {
 378                         $lbs[] = $this->getMainLB( $opts['domain'] );
 379                 } else {
 380                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$lbs ) {
 381                                 $lbs[] = $lb;
 382                         } );
 383                         if ( !$lbs ) {
 384                                 return; // nothing actually used
 385                         }
 386                 }
 387
 388                 // Get all the master positions of applicable DBs right now.
 389                 // This can be faster since waiting on one cluster reduces the
 390                 // time needed to wait on the next clusters.
 391                 $masterPositions = array_fill( 0, count( $lbs ), false );
 392                 foreach ( $lbs as $i => $lb ) {
 393                         if ( $lb->getServerCount() <= 1 ) {
 394                                 // T29975 - Don't try to wait for replica DBs if there are none
 395                                 // Prevents permission error when getting master position
 396                                 continue;
 397                         } elseif ( $opts['ifWritesSince']
 398                                 && $lb->lastMasterChangeTimestamp() < $opts['ifWritesSince']
 399                         ) {
 400                                 continue; // no writes since the last wait
 401                         }
 402                         $masterPositions[$i] = $lb->getMasterPos();
 403                 }
 404
 405                 // Run any listener callbacks *after* getting the DB positions. The more
 406                 // time spent in the callbacks, the less time is spent in waitForAll().
 407                 foreach ( $this->replicationWaitCallbacks as $callback ) {
 408                         $callback();
 409                 }
 410
 411                 $failed = [];
 412                 foreach ( $lbs as $i => $lb ) {
 413                         if ( $masterPositions[$i] ) {
 414                                 // The RDBMS may not support getMasterPos()
 415                                 if ( !$lb->waitForAll( $masterPositions[$i], $opts['timeout'] ) ) {
 416                                         $failed[] = $lb->getServerName( $lb->getWriterIndex() );
 417                                 }
 418                         }
 419                 }
 420
 421                 if ( $failed ) {
 422                         throw new DBReplicationWaitError(
 423                                 null,
 424                                 "Could not wait for replica DBs to catch up to " .
 425                                 implode( ', ', $failed )
 426                         );
 427                 }
 428         }
 429
 430         public function setWaitForReplicationListener( $name, callable $callback = null ) {
 431                 if ( $callback ) {
 432                         $this->replicationWaitCallbacks[$name] = $callback;
 433                 } else {
 434                         unset( $this->replicationWaitCallbacks[$name] );
 435                 }
 436         }
 437
 438         public function getEmptyTransactionTicket( $fname ) {
 439                 if ( $this->hasMasterChanges() ) {
 440                         $this->queryLogger->error( __METHOD__ . ": $fname does not have outer scope.\n" .
 441                                 ( new RuntimeException() )->getTraceAsString() );
 442
 443                         return null;
 444                 }
 445
 446                 return $this->ticket;
 447         }
 448
 449         final public function commitAndWaitForReplication( $fname, $ticket, array $opts = [] ) {
 450                 if ( $ticket !== $this->ticket ) {
 451                         $this->perfLogger->error( __METHOD__ . ": $fname does not have outer scope.\n" .
 452                                 ( new RuntimeException() )->getTraceAsString() );
 453
 454                         return;
 455                 }
 456
 457                 // The transaction owner and any caller with the empty transaction ticket can commit
 458                 // so that getEmptyTransactionTicket() callers don't risk seeing DBTransactionError.
 459                 if ( $this->trxRoundId !== false && $fname !== $this->trxRoundId ) {
 460                         $this->queryLogger->info( "$fname: committing on behalf of {$this->trxRoundId}." );
 461                         $fnameEffective = $this->trxRoundId;
 462                 } else {
 463                         $fnameEffective = $fname;
 464                 }
 465
 466                 $this->commitMasterChanges( $fnameEffective );
 467                 $this->waitForReplication( $opts );
 468                 // If a nested caller committed on behalf of $fname, start another empty $fname
 469                 // transaction, leaving the caller with the same empty transaction state as before.
 470                 if ( $fnameEffective !== $fname ) {
 471                         $this->beginMasterChanges( $fnameEffective );
 472                 }
 473         }
 474
 475         public function getChronologyProtectorTouched( $dbName ) {
 476                 return $this->getChronologyProtector()->getTouched( $dbName );
 477         }
 478
 479         public function disableChronologyProtection() {
 480                 $this->getChronologyProtector()->setEnabled( false );
 481         }
 482
 483         /**
 484          * @return ChronologyProtector
 485          */
 486         protected function getChronologyProtector() {
 487                 if ( $this->chronProt ) {
 488                         return $this->chronProt;
 489                 }
 490
 491                 $this->chronProt = new ChronologyProtector(
 492                         $this->memStash,
 493                         [
 494                                 'ip' => $this->requestInfo['IPAddress'],
 495                                 'agent' => $this->requestInfo['UserAgent'],
 496                                 'clientId' => $this->requestInfo['ChronologyClientId']
 497                         ],
 498                         $this->requestInfo['ChronologyPositionIndex']
 499                 );
 500                 $this->chronProt->setLogger( $this->replLogger );
 501
 502                 if ( $this->cliMode ) {
 503                         $this->chronProt->setEnabled( false );
 504                 } elseif ( $this->requestInfo['ChronologyProtection'] === 'false' ) {
 505                         // Request opted out of using position wait logic. This is useful for requests
 506                         // done by the job queue or background ETL that do not have a meaningful session.
 507                         $this->chronProt->setWaitEnabled( false );
 508                 }
 509
 510                 $this->replLogger->debug( __METHOD__ . ': using request info ' .
 511                         json_encode( $this->requestInfo, JSON_PRETTY_PRINT ) );
 512
 513                 return $this->chronProt;
 514         }
 515
 516         /**
 517          * Get and record all of the staged DB positions into persistent memory storage
 518          *
 519          * @param ChronologyProtector $cp
 520          * @param callable|null $workCallback Work to do instead of waiting on syncing positions
 521          * @param string $mode One of (sync, async); whether to wait on remote datacenters
 522          * @param int|null &$cpIndex DB position key write counter; incremented on update
 523          */
 524         protected function shutdownChronologyProtector(
 525                 ChronologyProtector $cp, $workCallback, $mode, &$cpIndex = null
 526         ) {
 527                 // Record all the master positions needed
 528                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $cp ) {
 529                         $cp->shutdownLB( $lb );
 530                 } );
 531                 // Write them to the persistent stash. Try to do something useful by running $work
 532                 // while ChronologyProtector waits for the stash write to replicate to all DCs.
 533                 $unsavedPositions = $cp->shutdown( $workCallback, $mode, $cpIndex );
 534                 if ( $unsavedPositions && $workCallback ) {
 535                         // Invoke callback in case it did not cache the result yet
 536                         $workCallback(); // work now to block for less time in waitForAll()
 537                 }
 538                 // If the positions failed to write to the stash, at least wait on local datacenter
 539                 // replica DBs to catch up before responding. Even if there are several DCs, this increases
 540                 // the chance that the user will see their own changes immediately afterwards. As long
 541                 // as the sticky DC cookie applies (same domain), this is not even an issue.
 542                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $unsavedPositions ) {
 543                         $masterName = $lb->getServerName( $lb->getWriterIndex() );
 544                         if ( isset( $unsavedPositions[$masterName] ) ) {
 545                                 $lb->waitForAll( $unsavedPositions[$masterName] );
 546                         }
 547                 } );
 548         }
 549
 550         /**
 551          * Base parameters to ILoadBalancer::__construct()
 552          * @return array
 553          */
 554         final protected function baseLoadBalancerParams() {
 555                 if ( $this->trxRoundStage === self::ROUND_COMMIT_CALLBACKS ) {
 556                         $initStage = ILoadBalancer::STAGE_POSTCOMMIT_CALLBACKS;
 557                 } elseif ( $this->trxRoundStage === self::ROUND_ROLLBACK_CALLBACKS ) {
 558                         $initStage = ILoadBalancer::STAGE_POSTROLLBACK_CALLBACKS;
 559                 } else {
 560                         $initStage = null;
 561                 }
 562
 563                 return [
 564                         'localDomain' => $this->localDomain,
 565                         'readOnlyReason' => $this->readOnlyReason,
 566                         'srvCache' => $this->srvCache,
 567                         'wanCache' => $this->wanCache,
 568                         'profiler' => $this->profiler,
 569                         'trxProfiler' => $this->trxProfiler,
 570                         'queryLogger' => $this->queryLogger,
 571                         'connLogger' => $this->connLogger,
 572                         'replLogger' => $this->replLogger,
 573                         'errorLogger' => $this->errorLogger,
 574                         'deprecationLogger' => $this->deprecationLogger,
 575                         'hostname' => $this->hostname,
 576                         'cliMode' => $this->cliMode,
 577                         'agent' => $this->agent,
 578                         'chronologyCallback' => function ( ILoadBalancer $lb ) {
 579                                 // Defer ChronologyProtector construction in case setRequestInfo() ends up
 580                                 // being called later (but before the first connection attempt) (T192611)
 581                                 $this->getChronologyProtector()->initLB( $lb );
 582                         },
 583                         'roundStage' => $initStage
 584                 ];
 585         }
 586
 587         /**
 588          * @param ILoadBalancer $lb
 589          */
 590         protected function initLoadBalancer( ILoadBalancer $lb ) {
 591                 if ( $this->trxRoundId !== false ) {
 592                         $lb->beginMasterChanges( $this->trxRoundId ); // set DBO_TRX
 593                 }
 594
 595                 $lb->setTableAliases( $this->tableAliases );
 596                 $lb->setIndexAliases( $this->indexAliases );
 597         }
 598
 599         public function setTableAliases( array $aliases ) {
 600                 $this->tableAliases = $aliases;
 601         }
 602
 603         public function setIndexAliases( array $aliases ) {
 604                 $this->indexAliases = $aliases;
 605         }
 606
 607         public function setDomainPrefix( $prefix ) {
 608                 $this->localDomain = new DatabaseDomain(
 609                         $this->localDomain->getDatabase(),
 610                         null,
 611                         $prefix
 612                 );
 613
 614                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $prefix ) {
 615                         $lb->setDomainPrefix( $prefix );
 616                 } );
 617         }
 618
 619         public function closeAll() {
 620                 $this->forEachLBCallMethod( 'closeAll', [] );
 621         }
 622
 623         public function setAgentName( $agent ) {
 624                 $this->agent = $agent;
 625         }
 626
 627         public function appendShutdownCPIndexAsQuery( $url, $index ) {
 628                 $usedCluster = 0;
 629                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$usedCluster ) {
 630                         $usedCluster |= ( $lb->getServerCount() > 1 );
 631                 } );
 632
 633                 if ( !$usedCluster ) {
 634                         return $url; // no master/replica clusters touched
 635                 }
 636
 637                 return strpos( $url, '?' ) === false ? "$url?cpPosIndex=$index" : "$url&cpPosIndex=$index";
 638         }
 639
 640         /**
 641          * @param int $index Write index
 642          * @param int $time UNIX timestamp; can be used to detect stale cookies (T190082)
 643          * @param string $clientId Agent ID hash from ILBFactory::shutdown()
 644          * @return string Timestamp-qualified write index of the form "<index>@<timestamp>#<hash>"
 645          * @since 1.32
 646          */
 647         public static function makeCookieValueFromCPIndex( $index, $time, $clientId ) {
 648                 return "$index@$time#$clientId";
 649         }
 650
 651         /**
 652          * @param string $value Possible result of LBFactory::makeCookieValueFromCPIndex()
 653          * @param int $minTimestamp Lowest UNIX timestamp of non-expired values (if present)
 654          * @return array (index: int or null, clientId: string or null)
 655          * @since 1.32
 656          */
 657         public static function getCPInfoFromCookieValue( $value, $minTimestamp ) {
 658                 static $placeholder = [ 'index' => null, 'clientId' => null ];
 659
 660                 if ( !preg_match( '/^(\d+)(?:@(\d+))?(?:#([0-9a-f]{32}))?$/', $value, $m ) ) {
 661                         return $placeholder; // invalid
 662                 }
 663
 664                 $index = (int)$m[1];
 665                 if ( $index <= 0 ) {
 666                         return $placeholder; // invalid
 667                 } elseif ( isset( $m[2] ) && $m[2] !== '' && (int)$m[2] < $minTimestamp ) {
 668                         return $placeholder; // expired
 669                 }
 670
 671                 $clientId = ( isset( $m[3] ) && $m[3] !== '' ) ? $m[3] : null;
 672
 673                 return [ 'index' => $index, 'clientId' => $clientId ];
 674         }
 675
 676         public function setRequestInfo( array $info ) {
 677                 if ( $this->chronProt ) {
 678                         throw new LogicException( 'ChronologyProtector already initialized.' );
 679                 }
 680
 681                 $this->requestInfo = $info + $this->requestInfo;
 682         }
 683
 684         /**
 685          * @param string $stage
 686          */
 687         private function assertTransactionRoundStage( $stage ) {
 688                 if ( $this->trxRoundStage !== $stage ) {
 689                         throw new DBTransactionError(
 690                                 null,
 691                                 "Transaction round stage must be '$stage' (not '{$this->trxRoundStage}')"
 692                         );
 693                 }
 694         }
 695
 696         /**
 697          * Make PHP ignore user aborts/disconnects until the returned
 698          * value leaves scope. This returns null and does nothing in CLI mode.
 699          *
 700          * @return ScopedCallback|null
 701          */
 702         final protected function getScopedPHPBehaviorForCommit() {
 703                 if ( PHP_SAPI != 'cli' ) { // https://bugs.php.net/bug.php?id=47540
 704                         $old = ignore_user_abort( true ); // avoid half-finished operations
 705                         return new ScopedCallback( function () use ( $old ) {
 706                                 ignore_user_abort( $old );
 707                         } );
 708                 }
 709
 710                 return null;
 711         }
 712
 713         function __destruct() {
 714                 $this->destroy();
 715         }
 716 }
 717
 718 /**
 719  * @deprecated since 1.29
 720  */
 721 class_alias( LBFactory::class, 'LBFactory' );