includes/libs/rdbms/database/DatabaseMysqlBase.php

   1 <?php
   2 /**
   3  * This is the MySQL database abstraction layer.
   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 namespace Wikimedia\Rdbms;
  24
  25 use DateTime;
  26 use DateTimeZone;
  27 use MediaWiki;
  28 use InvalidArgumentException;
  29 use Exception;
  30 use stdClass;
  31
  32 /**
  33  * Database abstraction object for MySQL.
  34  * Defines methods independent on used MySQL extension.
  35  *
  36  * @ingroup Database
  37  * @since 1.22
  38  * @see Database
  39  */
  40 abstract class DatabaseMysqlBase extends Database {
  41         /** @var MysqlMasterPos */
  42         protected $lastKnownReplicaPos;
  43         /** @var string Method to detect replica DB lag */
  44         protected $lagDetectionMethod;
  45         /** @var array Method to detect replica DB lag */
  46         protected $lagDetectionOptions = [];
  47         /** @var bool bool Whether to use GTID methods */
  48         protected $useGTIDs = false;
  49         /** @var string|null */
  50         protected $sslKeyPath;
  51         /** @var string|null */
  52         protected $sslCertPath;
  53         /** @var string|null */
  54         protected $sslCAPath;
  55         /** @var string[]|null */
  56         protected $sslCiphers;
  57         /** @var string sql_mode value to send on connection */
  58         protected $sqlMode;
  59         /** @var bool Use experimental UTF-8 transmission encoding */
  60         protected $utf8Mode;
  61
  62         /** @var string|null */
  63         private $serverVersion = null;
  64
  65         /**
  66          * Additional $params include:
  67          *   - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
  68          *       pt-heartbeat assumes the table is at heartbeat.heartbeat
  69          *       and uses UTC timestamps in the heartbeat.ts column.
  70          *       (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
  71          *   - lagDetectionOptions : if using pt-heartbeat, this can be set to an array map to change
  72          *       the default behavior. Normally, the heartbeat row with the server
  73          *       ID of this server's master will be used. Set the "conds" field to
  74          *       override the query conditions, e.g. ['shard' => 's1'].
  75          *   - useGTIDs : use GTID methods like MASTER_GTID_WAIT() when possible.
  76          *   - sslKeyPath : path to key file [default: null]
  77          *   - sslCertPath : path to certificate file [default: null]
  78          *   - sslCAPath : parth to certificate authority PEM files [default: null]
  79          *   - sslCiphers : array list of allowable ciphers [default: null]
  80          * @param array $params
  81          */
  82         function __construct( array $params ) {
  83                 $this->lagDetectionMethod = isset( $params['lagDetectionMethod'] )
  84                         ? $params['lagDetectionMethod']
  85                         : 'Seconds_Behind_Master';
  86                 $this->lagDetectionOptions = isset( $params['lagDetectionOptions'] )
  87                         ? $params['lagDetectionOptions']
  88                         : [];
  89                 $this->useGTIDs = !empty( $params['useGTIDs' ] );
  90                 foreach ( [ 'KeyPath', 'CertPath', 'CAPath', 'Ciphers' ] as $name ) {
  91                         $var = "ssl{$name}";
  92                         if ( isset( $params[$var] ) ) {
  93                                 $this->$var = $params[$var];
  94                         }
  95                 }
  96                 $this->sqlMode = isset( $params['sqlMode'] ) ? $params['sqlMode'] : '';
  97                 $this->utf8Mode = !empty( $params['utf8Mode'] );
  98
  99                 parent::__construct( $params );
 100         }
 101
 102         /**
 103          * @return string
 104          */
 105         public function getType() {
 106                 return 'mysql';
 107         }
 108
 109         /**
 110          * @param string $server
 111          * @param string $user
 112          * @param string $password
 113          * @param string $dbName
 114          * @throws Exception|DBConnectionError
 115          * @return bool
 116          */
 117         public function open( $server, $user, $password, $dbName ) {
 118                 # Close/unset connection handle
 119                 $this->close();
 120
 121                 $this->mServer = $server;
 122                 $this->mUser = $user;
 123                 $this->mPassword = $password;
 124                 $this->mDBname = $dbName;
 125
 126                 $this->installErrorHandler();
 127                 try {
 128                         $this->mConn = $this->mysqlConnect( $this->mServer );
 129                 } catch ( Exception $ex ) {
 130                         $this->restoreErrorHandler();
 131                         throw $ex;
 132                 }
 133                 $error = $this->restoreErrorHandler();
 134
 135                 # Always log connection errors
 136                 if ( !$this->mConn ) {
 137                         if ( !$error ) {
 138                                 $error = $this->lastError();
 139                         }
 140                         $this->connLogger->error(
 141                                 "Error connecting to {db_server}: {error}",
 142                                 $this->getLogContext( [
 143                                         'method' => __METHOD__,
 144                                         'error' => $error,
 145                                 ] )
 146                         );
 147                         $this->connLogger->debug( "DB connection error\n" .
 148                                 "Server: $server, User: $user, Password: " .
 149                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 150
 151                         $this->reportConnectionError( $error );
 152                 }
 153
 154                 if ( $dbName != '' ) {
 155                         MediaWiki\suppressWarnings();
 156                         $success = $this->selectDB( $dbName );
 157                         MediaWiki\restoreWarnings();
 158                         if ( !$success ) {
 159                                 $this->queryLogger->error(
 160                                         "Error selecting database {db_name} on server {db_server}",
 161                                         $this->getLogContext( [
 162                                                 'method' => __METHOD__,
 163                                         ] )
 164                                 );
 165                                 $this->queryLogger->debug(
 166                                         "Error selecting database $dbName on server {$this->mServer}" );
 167
 168                                 $this->reportConnectionError( "Error selecting database $dbName" );
 169                         }
 170                 }
 171
 172                 // Tell the server what we're communicating with
 173                 if ( !$this->connectInitCharset() ) {
 174                         $this->reportConnectionError( "Error setting character set" );
 175                 }
 176
 177                 // Abstract over any insane MySQL defaults
 178                 $set = [ 'group_concat_max_len = 262144' ];
 179                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 180                 if ( is_string( $this->sqlMode ) ) {
 181                         $set[] = 'sql_mode = ' . $this->addQuotes( $this->sqlMode );
 182                 }
 183                 // Set any custom settings defined by site config
 184                 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 185                 foreach ( $this->mSessionVars as $var => $val ) {
 186                         // Escape strings but not numbers to avoid MySQL complaining
 187                         if ( !is_int( $val ) && !is_float( $val ) ) {
 188                                 $val = $this->addQuotes( $val );
 189                         }
 190                         $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 191                 }
 192
 193                 if ( $set ) {
 194                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 195                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ) );
 196                         if ( !$success ) {
 197                                 $this->queryLogger->error(
 198                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 199                                         $this->getLogContext( [
 200                                                 'method' => __METHOD__,
 201                                         ] )
 202                                 );
 203                                 $this->reportConnectionError(
 204                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 205                         }
 206                 }
 207
 208                 $this->mOpened = true;
 209
 210                 return true;
 211         }
 212
 213         /**
 214          * Set the character set information right after connection
 215          * @return bool
 216          */
 217         protected function connectInitCharset() {
 218                 if ( $this->utf8Mode ) {
 219                         // Tell the server we're communicating with it in UTF-8.
 220                         // This may engage various charset conversions.
 221                         return $this->mysqlSetCharset( 'utf8' );
 222                 } else {
 223                         return $this->mysqlSetCharset( 'binary' );
 224                 }
 225         }
 226
 227         /**
 228          * Open a connection to a MySQL server
 229          *
 230          * @param string $realServer
 231          * @return mixed Raw connection
 232          * @throws DBConnectionError
 233          */
 234         abstract protected function mysqlConnect( $realServer );
 235
 236         /**
 237          * Set the character set of the MySQL link
 238          *
 239          * @param string $charset
 240          * @return bool
 241          */
 242         abstract protected function mysqlSetCharset( $charset );
 243
 244         /**
 245          * @param ResultWrapper|resource $res
 246          * @throws DBUnexpectedError
 247          */
 248         public function freeResult( $res ) {
 249                 if ( $res instanceof ResultWrapper ) {
 250                         $res = $res->result;
 251                 }
 252                 MediaWiki\suppressWarnings();
 253                 $ok = $this->mysqlFreeResult( $res );
 254                 MediaWiki\restoreWarnings();
 255                 if ( !$ok ) {
 256                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 257                 }
 258         }
 259
 260         /**
 261          * Free result memory
 262          *
 263          * @param resource $res Raw result
 264          * @return bool
 265          */
 266         abstract protected function mysqlFreeResult( $res );
 267
 268         /**
 269          * @param ResultWrapper|resource $res
 270          * @return stdClass|bool
 271          * @throws DBUnexpectedError
 272          */
 273         public function fetchObject( $res ) {
 274                 if ( $res instanceof ResultWrapper ) {
 275                         $res = $res->result;
 276                 }
 277                 MediaWiki\suppressWarnings();
 278                 $row = $this->mysqlFetchObject( $res );
 279                 MediaWiki\restoreWarnings();
 280
 281                 $errno = $this->lastErrno();
 282                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 283                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 284                 // these are the only errors mysql_fetch_object can cause.
 285                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 286                 if ( $errno == 2000 || $errno == 2013 ) {
 287                         throw new DBUnexpectedError(
 288                                 $this,
 289                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 290                         );
 291                 }
 292
 293                 return $row;
 294         }
 295
 296         /**
 297          * Fetch a result row as an object
 298          *
 299          * @param resource $res Raw result
 300          * @return stdClass
 301          */
 302         abstract protected function mysqlFetchObject( $res );
 303
 304         /**
 305          * @param ResultWrapper|resource $res
 306          * @return array|bool
 307          * @throws DBUnexpectedError
 308          */
 309         public function fetchRow( $res ) {
 310                 if ( $res instanceof ResultWrapper ) {
 311                         $res = $res->result;
 312                 }
 313                 MediaWiki\suppressWarnings();
 314                 $row = $this->mysqlFetchArray( $res );
 315                 MediaWiki\restoreWarnings();
 316
 317                 $errno = $this->lastErrno();
 318                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 319                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 320                 // these are the only errors mysql_fetch_array can cause.
 321                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 322                 if ( $errno == 2000 || $errno == 2013 ) {
 323                         throw new DBUnexpectedError(
 324                                 $this,
 325                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 326                         );
 327                 }
 328
 329                 return $row;
 330         }
 331
 332         /**
 333          * Fetch a result row as an associative and numeric array
 334          *
 335          * @param resource $res Raw result
 336          * @return array
 337          */
 338         abstract protected function mysqlFetchArray( $res );
 339
 340         /**
 341          * @throws DBUnexpectedError
 342          * @param ResultWrapper|resource $res
 343          * @return int
 344          */
 345         function numRows( $res ) {
 346                 if ( $res instanceof ResultWrapper ) {
 347                         $res = $res->result;
 348                 }
 349                 MediaWiki\suppressWarnings();
 350                 $n = $this->mysqlNumRows( $res );
 351                 MediaWiki\restoreWarnings();
 352
 353                 // Unfortunately, mysql_num_rows does not reset the last errno.
 354                 // We are not checking for any errors here, since
 355                 // these are no errors mysql_num_rows can cause.
 356                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 357                 // See https://phabricator.wikimedia.org/T44430
 358                 return $n;
 359         }
 360
 361         /**
 362          * Get number of rows in result
 363          *
 364          * @param resource $res Raw result
 365          * @return int
 366          */
 367         abstract protected function mysqlNumRows( $res );
 368
 369         /**
 370          * @param ResultWrapper|resource $res
 371          * @return int
 372          */
 373         public function numFields( $res ) {
 374                 if ( $res instanceof ResultWrapper ) {
 375                         $res = $res->result;
 376                 }
 377
 378                 return $this->mysqlNumFields( $res );
 379         }
 380
 381         /**
 382          * Get number of fields in result
 383          *
 384          * @param resource $res Raw result
 385          * @return int
 386          */
 387         abstract protected function mysqlNumFields( $res );
 388
 389         /**
 390          * @param ResultWrapper|resource $res
 391          * @param int $n
 392          * @return string
 393          */
 394         public function fieldName( $res, $n ) {
 395                 if ( $res instanceof ResultWrapper ) {
 396                         $res = $res->result;
 397                 }
 398
 399                 return $this->mysqlFieldName( $res, $n );
 400         }
 401
 402         /**
 403          * Get the name of the specified field in a result
 404          *
 405          * @param ResultWrapper|resource $res
 406          * @param int $n
 407          * @return string
 408          */
 409         abstract protected function mysqlFieldName( $res, $n );
 410
 411         /**
 412          * mysql_field_type() wrapper
 413          * @param ResultWrapper|resource $res
 414          * @param int $n
 415          * @return string
 416          */
 417         public function fieldType( $res, $n ) {
 418                 if ( $res instanceof ResultWrapper ) {
 419                         $res = $res->result;
 420                 }
 421
 422                 return $this->mysqlFieldType( $res, $n );
 423         }
 424
 425         /**
 426          * Get the type of the specified field in a result
 427          *
 428          * @param ResultWrapper|resource $res
 429          * @param int $n
 430          * @return string
 431          */
 432         abstract protected function mysqlFieldType( $res, $n );
 433
 434         /**
 435          * @param ResultWrapper|resource $res
 436          * @param int $row
 437          * @return bool
 438          */
 439         public function dataSeek( $res, $row ) {
 440                 if ( $res instanceof ResultWrapper ) {
 441                         $res = $res->result;
 442                 }
 443
 444                 return $this->mysqlDataSeek( $res, $row );
 445         }
 446
 447         /**
 448          * Move internal result pointer
 449          *
 450          * @param ResultWrapper|resource $res
 451          * @param int $row
 452          * @return bool
 453          */
 454         abstract protected function mysqlDataSeek( $res, $row );
 455
 456         /**
 457          * @return string
 458          */
 459         public function lastError() {
 460                 if ( $this->mConn ) {
 461                         # Even if it's non-zero, it can still be invalid
 462                         MediaWiki\suppressWarnings();
 463                         $error = $this->mysqlError( $this->mConn );
 464                         if ( !$error ) {
 465                                 $error = $this->mysqlError();
 466                         }
 467                         MediaWiki\restoreWarnings();
 468                 } else {
 469                         $error = $this->mysqlError();
 470                 }
 471                 if ( $error ) {
 472                         $error .= ' (' . $this->mServer . ')';
 473                 }
 474
 475                 return $error;
 476         }
 477
 478         /**
 479          * Returns the text of the error message from previous MySQL operation
 480          *
 481          * @param resource $conn Raw connection
 482          * @return string
 483          */
 484         abstract protected function mysqlError( $conn = null );
 485
 486         /**
 487          * @param string $table
 488          * @param array $uniqueIndexes
 489          * @param array $rows
 490          * @param string $fname
 491          * @return ResultWrapper
 492          */
 493         public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 494                 return $this->nativeReplace( $table, $rows, $fname );
 495         }
 496
 497         /**
 498          * Estimate rows in dataset
 499          * Returns estimated count, based on EXPLAIN output
 500          * Takes same arguments as Database::select()
 501          *
 502          * @param string|array $table
 503          * @param string|array $vars
 504          * @param string|array $conds
 505          * @param string $fname
 506          * @param string|array $options
 507          * @return bool|int
 508          */
 509         public function estimateRowCount( $table, $vars = '*', $conds = '',
 510                 $fname = __METHOD__, $options = []
 511         ) {
 512                 $options['EXPLAIN'] = true;
 513                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 514                 if ( $res === false ) {
 515                         return false;
 516                 }
 517                 if ( !$this->numRows( $res ) ) {
 518                         return 0;
 519                 }
 520
 521                 $rows = 1;
 522                 foreach ( $res as $plan ) {
 523                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 524                 }
 525
 526                 return (int)$rows;
 527         }
 528
 529         public function tableExists( $table, $fname = __METHOD__ ) {
 530                 $table = $this->tableName( $table, 'raw' );
 531                 if ( isset( $this->mSessionTempTables[$table] ) ) {
 532                         return true; // already known to exist and won't show in SHOW TABLES anyway
 533                 }
 534
 535                 // We can't use buildLike() here, because it specifies an escape character
 536                 // other than the backslash, which is the only one supported by SHOW TABLES
 537                 $encLike = $this->escapeLikeInternal( $table, '\\' );
 538
 539                 return $this->query( "SHOW TABLES LIKE '$encLike'", $fname )->numRows() > 0;
 540         }
 541
 542         /**
 543          * @param string $table
 544          * @param string $field
 545          * @return bool|MySQLField
 546          */
 547         public function fieldInfo( $table, $field ) {
 548                 $table = $this->tableName( $table );
 549                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 550                 if ( !$res ) {
 551                         return false;
 552                 }
 553                 $n = $this->mysqlNumFields( $res->result );
 554                 for ( $i = 0; $i < $n; $i++ ) {
 555                         $meta = $this->mysqlFetchField( $res->result, $i );
 556                         if ( $field == $meta->name ) {
 557                                 return new MySQLField( $meta );
 558                         }
 559                 }
 560
 561                 return false;
 562         }
 563
 564         /**
 565          * Get column information from a result
 566          *
 567          * @param resource $res Raw result
 568          * @param int $n
 569          * @return stdClass
 570          */
 571         abstract protected function mysqlFetchField( $res, $n );
 572
 573         /**
 574          * Get information about an index into an object
 575          * Returns false if the index does not exist
 576          *
 577          * @param string $table
 578          * @param string $index
 579          * @param string $fname
 580          * @return bool|array|null False or null on failure
 581          */
 582         public function indexInfo( $table, $index, $fname = __METHOD__ ) {
 583                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 584                 # SHOW INDEX should work for 3.x and up:
 585                 # https://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 586                 $table = $this->tableName( $table );
 587                 $index = $this->indexName( $index );
 588
 589                 $sql = 'SHOW INDEX FROM ' . $table;
 590                 $res = $this->query( $sql, $fname );
 591
 592                 if ( !$res ) {
 593                         return null;
 594                 }
 595
 596                 $result = [];
 597
 598                 foreach ( $res as $row ) {
 599                         if ( $row->Key_name == $index ) {
 600                                 $result[] = $row;
 601                         }
 602                 }
 603
 604                 return empty( $result ) ? false : $result;
 605         }
 606
 607         /**
 608          * @param string $s
 609          * @return string
 610          */
 611         public function strencode( $s ) {
 612                 return $this->mysqlRealEscapeString( $s );
 613         }
 614
 615         /**
 616          * @param string $s
 617          * @return mixed
 618          */
 619         abstract protected function mysqlRealEscapeString( $s );
 620
 621         public function addQuotes( $s ) {
 622                 if ( is_bool( $s ) ) {
 623                         // Parent would transform to int, which does not play nice with MySQL type juggling.
 624                         // When searching for an int in a string column, the strings are cast to int, which
 625                         // means false would match any string not starting with a number.
 626                         $s = (string)(int)$s;
 627                 }
 628                 return parent::addQuotes( $s );
 629         }
 630
 631         /**
 632          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 633          *
 634          * @param string $s
 635          * @return string
 636          */
 637         public function addIdentifierQuotes( $s ) {
 638                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 639                 // Remove NUL bytes and escape backticks by doubling
 640                 return '`' . str_replace( [ "\0", '`' ], [ '', '``' ], $s ) . '`';
 641         }
 642
 643         /**
 644          * @param string $name
 645          * @return bool
 646          */
 647         public function isQuotedIdentifier( $name ) {
 648                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 649         }
 650
 651         public function getLag() {
 652                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 653                         return $this->getLagFromPtHeartbeat();
 654                 } else {
 655                         return $this->getLagFromSlaveStatus();
 656                 }
 657         }
 658
 659         /**
 660          * @return string
 661          */
 662         protected function getLagDetectionMethod() {
 663                 return $this->lagDetectionMethod;
 664         }
 665
 666         /**
 667          * @return bool|int
 668          */
 669         protected function getLagFromSlaveStatus() {
 670                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 671                 $row = $res ? $res->fetchObject() : false;
 672                 if ( $row && strval( $row->Seconds_Behind_Master ) !== '' ) {
 673                         return intval( $row->Seconds_Behind_Master );
 674                 }
 675
 676                 return false;
 677         }
 678
 679         /**
 680          * @return bool|float
 681          */
 682         protected function getLagFromPtHeartbeat() {
 683                 $options = $this->lagDetectionOptions;
 684
 685                 if ( isset( $options['conds'] ) ) {
 686                         // Best method for multi-DC setups: use logical channel names
 687                         $data = $this->getHeartbeatData( $options['conds'] );
 688                 } else {
 689                         // Standard method: use master server ID (works with stock pt-heartbeat)
 690                         $masterInfo = $this->getMasterServerInfo();
 691                         if ( !$masterInfo ) {
 692                                 $this->queryLogger->error(
 693                                         "Unable to query master of {db_server} for server ID",
 694                                         $this->getLogContext( [
 695                                                 'method' => __METHOD__
 696                                         ] )
 697                                 );
 698
 699                                 return false; // could not get master server ID
 700                         }
 701
 702                         $conds = [ 'server_id' => intval( $masterInfo['serverId'] ) ];
 703                         $data = $this->getHeartbeatData( $conds );
 704                 }
 705
 706                 list( $time, $nowUnix ) = $data;
 707                 if ( $time !== null ) {
 708                         // @time is in ISO format like "2015-09-25T16:48:10.000510"
 709                         $dateTime = new DateTime( $time, new DateTimeZone( 'UTC' ) );
 710                         $timeUnix = (int)$dateTime->format( 'U' ) + $dateTime->format( 'u' ) / 1e6;
 711
 712                         return max( $nowUnix - $timeUnix, 0.0 );
 713                 }
 714
 715                 $this->queryLogger->error(
 716                         "Unable to find pt-heartbeat row for {db_server}",
 717                         $this->getLogContext( [
 718                                 'method' => __METHOD__
 719                         ] )
 720                 );
 721
 722                 return false;
 723         }
 724
 725         protected function getMasterServerInfo() {
 726                 $cache = $this->srvCache;
 727                 $key = $cache->makeGlobalKey(
 728                         'mysql',
 729                         'master-info',
 730                         // Using one key for all cluster replica DBs is preferable
 731                         $this->getLBInfo( 'clusterMasterHost' ) ?: $this->getServer()
 732                 );
 733
 734                 return $cache->getWithSetCallback(
 735                         $key,
 736                         $cache::TTL_INDEFINITE,
 737                         function () use ( $cache, $key ) {
 738                                 // Get and leave a lock key in place for a short period
 739                                 if ( !$cache->lock( $key, 0, 10 ) ) {
 740                                         return false; // avoid master connection spike slams
 741                                 }
 742
 743                                 $conn = $this->getLazyMasterHandle();
 744                                 if ( !$conn ) {
 745                                         return false; // something is misconfigured
 746                                 }
 747
 748                                 // Connect to and query the master; catch errors to avoid outages
 749                                 try {
 750                                         $res = $conn->query( 'SELECT @@server_id AS id', __METHOD__ );
 751                                         $row = $res ? $res->fetchObject() : false;
 752                                         $id = $row ? (int)$row->id : 0;
 753                                 } catch ( DBError $e ) {
 754                                         $id = 0;
 755                                 }
 756
 757                                 // Cache the ID if it was retrieved
 758                                 return $id ? [ 'serverId' => $id, 'asOf' => time() ] : false;
 759                         }
 760                 );
 761         }
 762
 763         /**
 764          * @param array $conds WHERE clause conditions to find a row
 765          * @return array (heartbeat `ts` column value or null, UNIX timestamp) for the newest beat
 766          * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
 767          */
 768         protected function getHeartbeatData( array $conds ) {
 769                 // Do not bother starting implicit transactions here
 770                 $this->clearFlag( self::DBO_TRX, self::REMEMBER_PRIOR );
 771                 try {
 772                         $whereSQL = $this->makeList( $conds, self::LIST_AND );
 773                         // Use ORDER BY for channel based queries since that field might not be UNIQUE.
 774                         // Note: this would use "TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6))" but the
 775                         // percision field is not supported in MySQL <= 5.5.
 776                         $res = $this->query(
 777                                 "SELECT ts FROM heartbeat.heartbeat WHERE $whereSQL ORDER BY ts DESC LIMIT 1"
 778                         );
 779                         $row = $res ? $res->fetchObject() : false;
 780                 } finally {
 781                         $this->restoreFlags();
 782                 }
 783
 784                 return [ $row ? $row->ts : null, microtime( true ) ];
 785         }
 786
 787         protected function getApproximateLagStatus() {
 788                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 789                         // Disable caching since this is fast enough and we don't wan't
 790                         // to be *too* pessimistic by having both the cache TTL and the
 791                         // pt-heartbeat interval count as lag in getSessionLagStatus()
 792                         return parent::getApproximateLagStatus();
 793                 }
 794
 795                 $key = $this->srvCache->makeGlobalKey( 'mysql-lag', $this->getServer() );
 796                 $approxLag = $this->srvCache->get( $key );
 797                 if ( !$approxLag ) {
 798                         $approxLag = parent::getApproximateLagStatus();
 799                         $this->srvCache->set( $key, $approxLag, 1 );
 800                 }
 801
 802                 return $approxLag;
 803         }
 804
 805         public function masterPosWait( DBMasterPos $pos, $timeout ) {
 806                 if ( !( $pos instanceof MySQLMasterPos ) ) {
 807                         throw new InvalidArgumentException( "Position not an instance of MySQLMasterPos" );
 808                 }
 809
 810                 if ( $this->getLBInfo( 'is static' ) === true ) {
 811                         return 0; // this is a copy of a read-only dataset with no master DB
 812                 } elseif ( $this->lastKnownReplicaPos && $this->lastKnownReplicaPos->hasReached( $pos ) ) {
 813                         return 0; // already reached this point for sure
 814                 }
 815
 816                 // Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 817                 if ( $this->useGTIDs && $pos->gtids ) {
 818                         // Wait on the GTID set (MariaDB only)
 819                         $gtidArg = $this->addQuotes( implode( ',', $pos->gtids ) );
 820                         $res = $this->doQuery( "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)" );
 821                 } else {
 822                         // Wait on the binlog coordinates
 823                         $encFile = $this->addQuotes( $pos->file );
 824                         $encPos = intval( $pos->pos );
 825                         $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
 826                 }
 827
 828                 $row = $res ? $this->fetchRow( $res ) : false;
 829                 if ( !$row ) {
 830                         throw new DBExpectedError( $this,
 831                                 "MASTER_POS_WAIT() or MASTER_GTID_WAIT() failed: {$this->lastError()}" );
 832                 }
 833
 834                 // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
 835                 $status = ( $row[0] !== null ) ? intval( $row[0] ) : null;
 836                 if ( $status === null ) {
 837                         // T126436: jobs programmed to wait on master positions might be referencing binlogs
 838                         // with an old master hostname. Such calls make MASTER_POS_WAIT() return null. Try
 839                         // to detect this and treat the replica DB as having reached the position; a proper master
 840                         // switchover already requires that the new master be caught up before the switch.
 841                         $replicationPos = $this->getReplicaPos();
 842                         if ( $replicationPos && !$replicationPos->channelsMatch( $pos ) ) {
 843                                 $this->lastKnownReplicaPos = $replicationPos;
 844                                 $status = 0;
 845                         }
 846                 } elseif ( $status >= 0 ) {
 847                         // Remember that this position was reached to save queries next time
 848                         $this->lastKnownReplicaPos = $pos;
 849                 }
 850
 851                 return $status;
 852         }
 853
 854         /**
 855          * Get the position of the master from SHOW SLAVE STATUS
 856          *
 857          * @return MySQLMasterPos|bool
 858          */
 859         public function getReplicaPos() {
 860                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 861                 $row = $this->fetchObject( $res );
 862
 863                 if ( $row ) {
 864                         $pos = isset( $row->Exec_master_log_pos )
 865                                 ? $row->Exec_master_log_pos
 866                                 : $row->Exec_Master_Log_Pos;
 867                         // Also fetch the last-applied GTID set (MariaDB)
 868                         if ( $this->useGTIDs ) {
 869                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_slave_pos'", __METHOD__ );
 870                                 $gtidRow = $this->fetchObject( $res );
 871                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 872                         } else {
 873                                 $gtidSet = '';
 874                         }
 875
 876                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos, $gtidSet );
 877                 } else {
 878                         return false;
 879                 }
 880         }
 881
 882         /**
 883          * Get the position of the master from SHOW MASTER STATUS
 884          *
 885          * @return MySQLMasterPos|bool
 886          */
 887         public function getMasterPos() {
 888                 $res = $this->query( 'SHOW MASTER STATUS', __METHOD__ );
 889                 $row = $this->fetchObject( $res );
 890
 891                 if ( $row ) {
 892                         // Also fetch the last-written GTID set (MariaDB)
 893                         if ( $this->useGTIDs ) {
 894                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_binlog_pos'", __METHOD__ );
 895                                 $gtidRow = $this->fetchObject( $res );
 896                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 897                         } else {
 898                                 $gtidSet = '';
 899                         }
 900
 901                         return new MySQLMasterPos( $row->File, $row->Position, $gtidSet );
 902                 } else {
 903                         return false;
 904                 }
 905         }
 906
 907         public function serverIsReadOnly() {
 908                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'read_only'", __METHOD__ );
 909                 $row = $this->fetchObject( $res );
 910
 911                 return $row ? ( strtolower( $row->Value ) === 'on' ) : false;
 912         }
 913
 914         /**
 915          * @param string $index
 916          * @return string
 917          */
 918         function useIndexClause( $index ) {
 919                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 920         }
 921
 922         /**
 923          * @param string $index
 924          * @return string
 925          */
 926         function ignoreIndexClause( $index ) {
 927                 return "IGNORE INDEX (" . $this->indexName( $index ) . ")";
 928         }
 929
 930         /**
 931          * @return string
 932          */
 933         function lowPriorityOption() {
 934                 return 'LOW_PRIORITY';
 935         }
 936
 937         /**
 938          * @return string
 939          */
 940         public function getSoftwareLink() {
 941                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 942                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 943                 // in libmysql/libmysql.c).
 944                 $version = $this->getServerVersion();
 945                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 946                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 947                 }
 948
 949                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 950                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 951                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 952                 return '[{{int:version-db-mysql-url}} MySQL]';
 953         }
 954
 955         /**
 956          * @return string
 957          */
 958         public function getServerVersion() {
 959                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 960                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 961                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 962                 if ( $this->serverVersion === null ) {
 963                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 964                 }
 965                 return $this->serverVersion;
 966         }
 967
 968         /**
 969          * @param array $options
 970          */
 971         public function setSessionOptions( array $options ) {
 972                 if ( isset( $options['connTimeout'] ) ) {
 973                         $timeout = (int)$options['connTimeout'];
 974                         $this->query( "SET net_read_timeout=$timeout" );
 975                         $this->query( "SET net_write_timeout=$timeout" );
 976                 }
 977         }
 978
 979         /**
 980          * @param string $sql
 981          * @param string $newLine
 982          * @return bool
 983          */
 984         public function streamStatementEnd( &$sql, &$newLine ) {
 985                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 986                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 987                         $this->delimiter = $m[1];
 988                         $newLine = '';
 989                 }
 990
 991                 return parent::streamStatementEnd( $sql, $newLine );
 992         }
 993
 994         /**
 995          * Check to see if a named lock is available. This is non-blocking.
 996          *
 997          * @param string $lockName Name of lock to poll
 998          * @param string $method Name of method calling us
 999          * @return bool
1000          * @since 1.20
1001          */
1002         public function lockIsFree( $lockName, $method ) {
1003                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1004                 $result = $this->query( "SELECT IS_FREE_LOCK($encName) AS lockstatus", $method );
1005                 $row = $this->fetchObject( $result );
1006
1007                 return ( $row->lockstatus == 1 );
1008         }
1009
1010         /**
1011          * @param string $lockName
1012          * @param string $method
1013          * @param int $timeout
1014          * @return bool
1015          */
1016         public function lock( $lockName, $method, $timeout = 5 ) {
1017                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1018                 $result = $this->query( "SELECT GET_LOCK($encName, $timeout) AS lockstatus", $method );
1019                 $row = $this->fetchObject( $result );
1020
1021                 if ( $row->lockstatus == 1 ) {
1022                         parent::lock( $lockName, $method, $timeout ); // record
1023                         return true;
1024                 }
1025
1026                 $this->queryLogger->warning( __METHOD__ . " failed to acquire lock '$lockName'\n" );
1027
1028                 return false;
1029         }
1030
1031         /**
1032          * FROM MYSQL DOCS:
1033          * https://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
1034          * @param string $lockName
1035          * @param string $method
1036          * @return bool
1037          */
1038         public function unlock( $lockName, $method ) {
1039                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1040                 $result = $this->query( "SELECT RELEASE_LOCK($encName) as lockstatus", $method );
1041                 $row = $this->fetchObject( $result );
1042
1043                 if ( $row->lockstatus == 1 ) {
1044                         parent::unlock( $lockName, $method ); // record
1045                         return true;
1046                 }
1047
1048                 $this->queryLogger->warning( __METHOD__ . " failed to release lock '$lockName'\n" );
1049
1050                 return false;
1051         }
1052
1053         private function makeLockName( $lockName ) {
1054                 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1055                 // Newer version enforce a 64 char length limit.
1056                 return ( strlen( $lockName ) > 64 ) ? sha1( $lockName ) : $lockName;
1057         }
1058
1059         public function namedLocksEnqueue() {
1060                 return true;
1061         }
1062
1063         public function tableLocksHaveTransactionScope() {
1064                 return false; // tied to TCP connection
1065         }
1066
1067         protected function doLockTables( array $read, array $write, $method ) {
1068                 $items = [];
1069                 foreach ( $write as $table ) {
1070                         $items[] = $this->tableName( $table ) . ' WRITE';
1071                 }
1072                 foreach ( $read as $table ) {
1073                         $items[] = $this->tableName( $table ) . ' READ';
1074                 }
1075
1076                 $sql = "LOCK TABLES " . implode( ',', $items );
1077                 $this->query( $sql, $method );
1078
1079                 return true;
1080         }
1081
1082         protected function doUnlockTables( $method ) {
1083                 $this->query( "UNLOCK TABLES", $method );
1084
1085                 return true;
1086         }
1087
1088         /**
1089          * @param bool $value
1090          */
1091         public function setBigSelects( $value = true ) {
1092                 if ( $value === 'default' ) {
1093                         if ( $this->mDefaultBigSelects === null ) {
1094                                 # Function hasn't been called before so it must already be set to the default
1095                                 return;
1096                         } else {
1097                                 $value = $this->mDefaultBigSelects;
1098                         }
1099                 } elseif ( $this->mDefaultBigSelects === null ) {
1100                         $this->mDefaultBigSelects =
1101                                 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__ );
1102                 }
1103                 $encValue = $value ? '1' : '0';
1104                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
1105         }
1106
1107         /**
1108          * DELETE where the condition is a join. MySql uses multi-table deletes.
1109          * @param string $delTable
1110          * @param string $joinTable
1111          * @param string $delVar
1112          * @param string $joinVar
1113          * @param array|string $conds
1114          * @param bool|string $fname
1115          * @throws DBUnexpectedError
1116          * @return bool|ResultWrapper
1117          */
1118         public function deleteJoin(
1119                 $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__
1120         ) {
1121                 if ( !$conds ) {
1122                         throw new DBUnexpectedError( $this, __METHOD__ . ' called with empty $conds' );
1123                 }
1124
1125                 $delTable = $this->tableName( $delTable );
1126                 $joinTable = $this->tableName( $joinTable );
1127                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1128
1129                 if ( $conds != '*' ) {
1130                         $sql .= ' AND ' . $this->makeList( $conds, self::LIST_AND );
1131                 }
1132
1133                 return $this->query( $sql, $fname );
1134         }
1135
1136         /**
1137          * @param string $table
1138          * @param array $rows
1139          * @param array $uniqueIndexes
1140          * @param array $set
1141          * @param string $fname
1142          * @return bool
1143          */
1144         public function upsert( $table, array $rows, array $uniqueIndexes,
1145                 array $set, $fname = __METHOD__
1146         ) {
1147                 if ( !count( $rows ) ) {
1148                         return true; // nothing to do
1149                 }
1150
1151                 if ( !is_array( reset( $rows ) ) ) {
1152                         $rows = [ $rows ];
1153                 }
1154
1155                 $table = $this->tableName( $table );
1156                 $columns = array_keys( $rows[0] );
1157
1158                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1159                 $rowTuples = [];
1160                 foreach ( $rows as $row ) {
1161                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1162                 }
1163                 $sql .= implode( ',', $rowTuples );
1164                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, self::LIST_SET );
1165
1166                 return (bool)$this->query( $sql, $fname );
1167         }
1168
1169         /**
1170          * Determines how long the server has been up
1171          *
1172          * @return int
1173          */
1174         public function getServerUptime() {
1175                 $vars = $this->getMysqlStatus( 'Uptime' );
1176
1177                 return (int)$vars['Uptime'];
1178         }
1179
1180         /**
1181          * Determines if the last failure was due to a deadlock
1182          *
1183          * @return bool
1184          */
1185         public function wasDeadlock() {
1186                 return $this->lastErrno() == 1213;
1187         }
1188
1189         /**
1190          * Determines if the last failure was due to a lock timeout
1191          *
1192          * @return bool
1193          */
1194         public function wasLockTimeout() {
1195                 return $this->lastErrno() == 1205;
1196         }
1197
1198         public function wasErrorReissuable() {
1199                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1200         }
1201
1202         /**
1203          * Determines if the last failure was due to the database being read-only.
1204          *
1205          * @return bool
1206          */
1207         public function wasReadOnlyError() {
1208                 return $this->lastErrno() == 1223 ||
1209                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1210         }
1211
1212         public function wasConnectionError( $errno ) {
1213                 return $errno == 2013 || $errno == 2006;
1214         }
1215
1216         /**
1217          * @param string $oldName
1218          * @param string $newName
1219          * @param bool $temporary
1220          * @param string $fname
1221          * @return bool
1222          */
1223         public function duplicateTableStructure(
1224                 $oldName, $newName, $temporary = false, $fname = __METHOD__
1225         ) {
1226                 $tmp = $temporary ? 'TEMPORARY ' : '';
1227                 $newName = $this->addIdentifierQuotes( $newName );
1228                 $oldName = $this->addIdentifierQuotes( $oldName );
1229                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1230
1231                 return $this->query( $query, $fname );
1232         }
1233
1234         /**
1235          * List all tables on the database
1236          *
1237          * @param string $prefix Only show tables with this prefix, e.g. mw_
1238          * @param string $fname Calling function name
1239          * @return array
1240          */
1241         public function listTables( $prefix = null, $fname = __METHOD__ ) {
1242                 $result = $this->query( "SHOW TABLES", $fname );
1243
1244                 $endArray = [];
1245
1246                 foreach ( $result as $table ) {
1247                         $vars = get_object_vars( $table );
1248                         $table = array_pop( $vars );
1249
1250                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1251                                 $endArray[] = $table;
1252                         }
1253                 }
1254
1255                 return $endArray;
1256         }
1257
1258         /**
1259          * @param string $tableName
1260          * @param string $fName
1261          * @return bool|ResultWrapper
1262          */
1263         public function dropTable( $tableName, $fName = __METHOD__ ) {
1264                 if ( !$this->tableExists( $tableName, $fName ) ) {
1265                         return false;
1266                 }
1267
1268                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1269         }
1270
1271         /**
1272          * Get status information from SHOW STATUS in an associative array
1273          *
1274          * @param string $which
1275          * @return array
1276          */
1277         private function getMysqlStatus( $which = "%" ) {
1278                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1279                 $status = [];
1280
1281                 foreach ( $res as $row ) {
1282                         $status[$row->Variable_name] = $row->Value;
1283                 }
1284
1285                 return $status;
1286         }
1287
1288         /**
1289          * Lists VIEWs in the database
1290          *
1291          * @param string $prefix Only show VIEWs with this prefix, eg.
1292          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1293          * @param string $fname Name of calling function
1294          * @return array
1295          * @since 1.22
1296          */
1297         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1298                 // The name of the column containing the name of the VIEW
1299                 $propertyName = 'Tables_in_' . $this->mDBname;
1300
1301                 // Query for the VIEWS
1302                 $res = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1303                 $allViews = [];
1304                 foreach ( $res as $row ) {
1305                         array_push( $allViews, $row->$propertyName );
1306                 }
1307
1308                 if ( is_null( $prefix ) || $prefix === '' ) {
1309                         return $allViews;
1310                 }
1311
1312                 $filteredViews = [];
1313                 foreach ( $allViews as $viewName ) {
1314                         // Does the name of this VIEW start with the table-prefix?
1315                         if ( strpos( $viewName, $prefix ) === 0 ) {
1316                                 array_push( $filteredViews, $viewName );
1317                         }
1318                 }
1319
1320                 return $filteredViews;
1321         }
1322
1323         /**
1324          * Differentiates between a TABLE and a VIEW.
1325          *
1326          * @param string $name Name of the TABLE/VIEW to test
1327          * @param string $prefix
1328          * @return bool
1329          * @since 1.22
1330          */
1331         public function isView( $name, $prefix = null ) {
1332                 return in_array( $name, $this->listViews( $prefix ) );
1333         }
1334
1335         /**
1336          * Allows for index remapping in queries where this is not consistent across DBMS
1337          *
1338          * @param string $index
1339          * @return string
1340          */
1341         protected function indexName( $index ) {
1342                 /**
1343                  * When SQLite indexes were introduced in r45764, it was noted that
1344                  * SQLite requires index names to be unique within the whole database,
1345                  * not just within a schema. As discussed in CR r45819, to avoid the
1346                  * need for a schema change on existing installations, the indexes
1347                  * were implicitly mapped from the new names to the old names.
1348                  *
1349                  * This mapping can be removed if DB patches are introduced to alter
1350                  * the relevant tables in existing installations. Note that because
1351                  * this index mapping applies to table creation, even new installations
1352                  * of MySQL have the old names (except for installations created during
1353                  * a period where this mapping was inappropriately removed, see
1354                  * T154872).
1355                  */
1356                 $renamed = [
1357                         'ar_usertext_timestamp' => 'usertext_timestamp',
1358                         'un_user_id' => 'user_id',
1359                         'un_user_ip' => 'user_ip',
1360                 ];
1361
1362                 if ( isset( $renamed[$index] ) ) {
1363                         return $renamed[$index];
1364                 } else {
1365                         return $index;
1366                 }
1367         }
1368 }
1369
1370 class_alias( DatabaseMysqlBase::class, 'DatabaseMysqlBase' );