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 DBError;
  30 use DBExpectedError;
  31 use DBUnexpectedError;
  32 use DBConnectionError;
  33 use Exception;
  34 use stdClass;
  35
  36 /**
  37  * Database abstraction object for MySQL.
  38  * Defines methods independent on used MySQL extension.
  39  *
  40  * @ingroup Database
  41  * @since 1.22
  42  * @see Database
  43  */
  44 abstract class DatabaseMysqlBase extends Database {
  45         /** @var MysqlMasterPos */
  46         protected $lastKnownReplicaPos;
  47         /** @var string Method to detect replica DB lag */
  48         protected $lagDetectionMethod;
  49         /** @var array Method to detect replica DB lag */
  50         protected $lagDetectionOptions = [];
  51         /** @var bool bool Whether to use GTID methods */
  52         protected $useGTIDs = false;
  53         /** @var string|null */
  54         protected $sslKeyPath;
  55         /** @var string|null */
  56         protected $sslCertPath;
  57         /** @var string|null */
  58         protected $sslCAPath;
  59         /** @var string[]|null */
  60         protected $sslCiphers;
  61         /** @var string sql_mode value to send on connection */
  62         protected $sqlMode;
  63         /** @var bool Use experimental UTF-8 transmission encoding */
  64         protected $utf8Mode;
  65
  66         /** @var string|null */
  67         private $serverVersion = null;
  68
  69         /**
  70          * Additional $params include:
  71          *   - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
  72          *       pt-heartbeat assumes the table is at heartbeat.heartbeat
  73          *       and uses UTC timestamps in the heartbeat.ts column.
  74          *       (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
  75          *   - lagDetectionOptions : if using pt-heartbeat, this can be set to an array map to change
  76          *       the default behavior. Normally, the heartbeat row with the server
  77          *       ID of this server's master will be used. Set the "conds" field to
  78          *       override the query conditions, e.g. ['shard' => 's1'].
  79          *   - useGTIDs : use GTID methods like MASTER_GTID_WAIT() when possible.
  80          *   - sslKeyPath : path to key file [default: null]
  81          *   - sslCertPath : path to certificate file [default: null]
  82          *   - sslCAPath : parth to certificate authority PEM files [default: null]
  83          *   - sslCiphers : array list of allowable ciphers [default: null]
  84          * @param array $params
  85          */
  86         function __construct( array $params ) {
  87                 $this->lagDetectionMethod = isset( $params['lagDetectionMethod'] )
  88                         ? $params['lagDetectionMethod']
  89                         : 'Seconds_Behind_Master';
  90                 $this->lagDetectionOptions = isset( $params['lagDetectionOptions'] )
  91                         ? $params['lagDetectionOptions']
  92                         : [];
  93                 $this->useGTIDs = !empty( $params['useGTIDs' ] );
  94                 foreach ( [ 'KeyPath', 'CertPath', 'CAPath', 'Ciphers' ] as $name ) {
  95                         $var = "ssl{$name}";
  96                         if ( isset( $params[$var] ) ) {
  97                                 $this->$var = $params[$var];
  98                         }
  99                 }
 100                 $this->sqlMode = isset( $params['sqlMode'] ) ? $params['sqlMode'] : '';
 101                 $this->utf8Mode = !empty( $params['utf8Mode'] );
 102
 103                 parent::__construct( $params );
 104         }
 105
 106         /**
 107          * @return string
 108          */
 109         public function getType() {
 110                 return 'mysql';
 111         }
 112
 113         /**
 114          * @param string $server
 115          * @param string $user
 116          * @param string $password
 117          * @param string $dbName
 118          * @throws Exception|DBConnectionError
 119          * @return bool
 120          */
 121         public function open( $server, $user, $password, $dbName ) {
 122                 # Close/unset connection handle
 123                 $this->close();
 124
 125                 $this->mServer = $server;
 126                 $this->mUser = $user;
 127                 $this->mPassword = $password;
 128                 $this->mDBname = $dbName;
 129
 130                 $this->installErrorHandler();
 131                 try {
 132                         $this->mConn = $this->mysqlConnect( $this->mServer );
 133                 } catch ( Exception $ex ) {
 134                         $this->restoreErrorHandler();
 135                         throw $ex;
 136                 }
 137                 $error = $this->restoreErrorHandler();
 138
 139                 # Always log connection errors
 140                 if ( !$this->mConn ) {
 141                         if ( !$error ) {
 142                                 $error = $this->lastError();
 143                         }
 144                         $this->connLogger->error(
 145                                 "Error connecting to {db_server}: {error}",
 146                                 $this->getLogContext( [
 147                                         'method' => __METHOD__,
 148                                         'error' => $error,
 149                                 ] )
 150                         );
 151                         $this->connLogger->debug( "DB connection error\n" .
 152                                 "Server: $server, User: $user, Password: " .
 153                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 154
 155                         $this->reportConnectionError( $error );
 156                 }
 157
 158                 if ( $dbName != '' ) {
 159                         MediaWiki\suppressWarnings();
 160                         $success = $this->selectDB( $dbName );
 161                         MediaWiki\restoreWarnings();
 162                         if ( !$success ) {
 163                                 $this->queryLogger->error(
 164                                         "Error selecting database {db_name} on server {db_server}",
 165                                         $this->getLogContext( [
 166                                                 'method' => __METHOD__,
 167                                         ] )
 168                                 );
 169                                 $this->queryLogger->debug(
 170                                         "Error selecting database $dbName on server {$this->mServer}" );
 171
 172                                 $this->reportConnectionError( "Error selecting database $dbName" );
 173                         }
 174                 }
 175
 176                 // Tell the server what we're communicating with
 177                 if ( !$this->connectInitCharset() ) {
 178                         $this->reportConnectionError( "Error setting character set" );
 179                 }
 180
 181                 // Abstract over any insane MySQL defaults
 182                 $set = [ 'group_concat_max_len = 262144' ];
 183                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 184                 if ( is_string( $this->sqlMode ) ) {
 185                         $set[] = 'sql_mode = ' . $this->addQuotes( $this->sqlMode );
 186                 }
 187                 // Set any custom settings defined by site config
 188                 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 189                 foreach ( $this->mSessionVars as $var => $val ) {
 190                         // Escape strings but not numbers to avoid MySQL complaining
 191                         if ( !is_int( $val ) && !is_float( $val ) ) {
 192                                 $val = $this->addQuotes( $val );
 193                         }
 194                         $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 195                 }
 196
 197                 if ( $set ) {
 198                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 199                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ) );
 200                         if ( !$success ) {
 201                                 $this->queryLogger->error(
 202                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 203                                         $this->getLogContext( [
 204                                                 'method' => __METHOD__,
 205                                         ] )
 206                                 );
 207                                 $this->reportConnectionError(
 208                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 209                         }
 210                 }
 211
 212                 $this->mOpened = true;
 213
 214                 return true;
 215         }
 216
 217         /**
 218          * Set the character set information right after connection
 219          * @return bool
 220          */
 221         protected function connectInitCharset() {
 222                 if ( $this->utf8Mode ) {
 223                         // Tell the server we're communicating with it in UTF-8.
 224                         // This may engage various charset conversions.
 225                         return $this->mysqlSetCharset( 'utf8' );
 226                 } else {
 227                         return $this->mysqlSetCharset( 'binary' );
 228                 }
 229         }
 230
 231         /**
 232          * Open a connection to a MySQL server
 233          *
 234          * @param string $realServer
 235          * @return mixed Raw connection
 236          * @throws DBConnectionError
 237          */
 238         abstract protected function mysqlConnect( $realServer );
 239
 240         /**
 241          * Set the character set of the MySQL link
 242          *
 243          * @param string $charset
 244          * @return bool
 245          */
 246         abstract protected function mysqlSetCharset( $charset );
 247
 248         /**
 249          * @param ResultWrapper|resource $res
 250          * @throws DBUnexpectedError
 251          */
 252         public function freeResult( $res ) {
 253                 if ( $res instanceof ResultWrapper ) {
 254                         $res = $res->result;
 255                 }
 256                 MediaWiki\suppressWarnings();
 257                 $ok = $this->mysqlFreeResult( $res );
 258                 MediaWiki\restoreWarnings();
 259                 if ( !$ok ) {
 260                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 261                 }
 262         }
 263
 264         /**
 265          * Free result memory
 266          *
 267          * @param resource $res Raw result
 268          * @return bool
 269          */
 270         abstract protected function mysqlFreeResult( $res );
 271
 272         /**
 273          * @param ResultWrapper|resource $res
 274          * @return stdClass|bool
 275          * @throws DBUnexpectedError
 276          */
 277         public function fetchObject( $res ) {
 278                 if ( $res instanceof ResultWrapper ) {
 279                         $res = $res->result;
 280                 }
 281                 MediaWiki\suppressWarnings();
 282                 $row = $this->mysqlFetchObject( $res );
 283                 MediaWiki\restoreWarnings();
 284
 285                 $errno = $this->lastErrno();
 286                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 287                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 288                 // these are the only errors mysql_fetch_object can cause.
 289                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 290                 if ( $errno == 2000 || $errno == 2013 ) {
 291                         throw new DBUnexpectedError(
 292                                 $this,
 293                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 294                         );
 295                 }
 296
 297                 return $row;
 298         }
 299
 300         /**
 301          * Fetch a result row as an object
 302          *
 303          * @param resource $res Raw result
 304          * @return stdClass
 305          */
 306         abstract protected function mysqlFetchObject( $res );
 307
 308         /**
 309          * @param ResultWrapper|resource $res
 310          * @return array|bool
 311          * @throws DBUnexpectedError
 312          */
 313         public function fetchRow( $res ) {
 314                 if ( $res instanceof ResultWrapper ) {
 315                         $res = $res->result;
 316                 }
 317                 MediaWiki\suppressWarnings();
 318                 $row = $this->mysqlFetchArray( $res );
 319                 MediaWiki\restoreWarnings();
 320
 321                 $errno = $this->lastErrno();
 322                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 323                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 324                 // these are the only errors mysql_fetch_array can cause.
 325                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 326                 if ( $errno == 2000 || $errno == 2013 ) {
 327                         throw new DBUnexpectedError(
 328                                 $this,
 329                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 330                         );
 331                 }
 332
 333                 return $row;
 334         }
 335
 336         /**
 337          * Fetch a result row as an associative and numeric array
 338          *
 339          * @param resource $res Raw result
 340          * @return array
 341          */
 342         abstract protected function mysqlFetchArray( $res );
 343
 344         /**
 345          * @throws DBUnexpectedError
 346          * @param ResultWrapper|resource $res
 347          * @return int
 348          */
 349         function numRows( $res ) {
 350                 if ( $res instanceof ResultWrapper ) {
 351                         $res = $res->result;
 352                 }
 353                 MediaWiki\suppressWarnings();
 354                 $n = $this->mysqlNumRows( $res );
 355                 MediaWiki\restoreWarnings();
 356
 357                 // Unfortunately, mysql_num_rows does not reset the last errno.
 358                 // We are not checking for any errors here, since
 359                 // these are no errors mysql_num_rows can cause.
 360                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 361                 // See https://phabricator.wikimedia.org/T44430
 362                 return $n;
 363         }
 364
 365         /**
 366          * Get number of rows in result
 367          *
 368          * @param resource $res Raw result
 369          * @return int
 370          */
 371         abstract protected function mysqlNumRows( $res );
 372
 373         /**
 374          * @param ResultWrapper|resource $res
 375          * @return int
 376          */
 377         public function numFields( $res ) {
 378                 if ( $res instanceof ResultWrapper ) {
 379                         $res = $res->result;
 380                 }
 381
 382                 return $this->mysqlNumFields( $res );
 383         }
 384
 385         /**
 386          * Get number of fields in result
 387          *
 388          * @param resource $res Raw result
 389          * @return int
 390          */
 391         abstract protected function mysqlNumFields( $res );
 392
 393         /**
 394          * @param ResultWrapper|resource $res
 395          * @param int $n
 396          * @return string
 397          */
 398         public function fieldName( $res, $n ) {
 399                 if ( $res instanceof ResultWrapper ) {
 400                         $res = $res->result;
 401                 }
 402
 403                 return $this->mysqlFieldName( $res, $n );
 404         }
 405
 406         /**
 407          * Get the name of the specified field in a result
 408          *
 409          * @param ResultWrapper|resource $res
 410          * @param int $n
 411          * @return string
 412          */
 413         abstract protected function mysqlFieldName( $res, $n );
 414
 415         /**
 416          * mysql_field_type() wrapper
 417          * @param ResultWrapper|resource $res
 418          * @param int $n
 419          * @return string
 420          */
 421         public function fieldType( $res, $n ) {
 422                 if ( $res instanceof ResultWrapper ) {
 423                         $res = $res->result;
 424                 }
 425
 426                 return $this->mysqlFieldType( $res, $n );
 427         }
 428
 429         /**
 430          * Get the type of the specified field in a result
 431          *
 432          * @param ResultWrapper|resource $res
 433          * @param int $n
 434          * @return string
 435          */
 436         abstract protected function mysqlFieldType( $res, $n );
 437
 438         /**
 439          * @param ResultWrapper|resource $res
 440          * @param int $row
 441          * @return bool
 442          */
 443         public function dataSeek( $res, $row ) {
 444                 if ( $res instanceof ResultWrapper ) {
 445                         $res = $res->result;
 446                 }
 447
 448                 return $this->mysqlDataSeek( $res, $row );
 449         }
 450
 451         /**
 452          * Move internal result pointer
 453          *
 454          * @param ResultWrapper|resource $res
 455          * @param int $row
 456          * @return bool
 457          */
 458         abstract protected function mysqlDataSeek( $res, $row );
 459
 460         /**
 461          * @return string
 462          */
 463         public function lastError() {
 464                 if ( $this->mConn ) {
 465                         # Even if it's non-zero, it can still be invalid
 466                         MediaWiki\suppressWarnings();
 467                         $error = $this->mysqlError( $this->mConn );
 468                         if ( !$error ) {
 469                                 $error = $this->mysqlError();
 470                         }
 471                         MediaWiki\restoreWarnings();
 472                 } else {
 473                         $error = $this->mysqlError();
 474                 }
 475                 if ( $error ) {
 476                         $error .= ' (' . $this->mServer . ')';
 477                 }
 478
 479                 return $error;
 480         }
 481
 482         /**
 483          * Returns the text of the error message from previous MySQL operation
 484          *
 485          * @param resource $conn Raw connection
 486          * @return string
 487          */
 488         abstract protected function mysqlError( $conn = null );
 489
 490         /**
 491          * @param string $table
 492          * @param array $uniqueIndexes
 493          * @param array $rows
 494          * @param string $fname
 495          * @return ResultWrapper
 496          */
 497         public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 498                 return $this->nativeReplace( $table, $rows, $fname );
 499         }
 500
 501         /**
 502          * Estimate rows in dataset
 503          * Returns estimated count, based on EXPLAIN output
 504          * Takes same arguments as Database::select()
 505          *
 506          * @param string|array $table
 507          * @param string|array $vars
 508          * @param string|array $conds
 509          * @param string $fname
 510          * @param string|array $options
 511          * @return bool|int
 512          */
 513         public function estimateRowCount( $table, $vars = '*', $conds = '',
 514                 $fname = __METHOD__, $options = []
 515         ) {
 516                 $options['EXPLAIN'] = true;
 517                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 518                 if ( $res === false ) {
 519                         return false;
 520                 }
 521                 if ( !$this->numRows( $res ) ) {
 522                         return 0;
 523                 }
 524
 525                 $rows = 1;
 526                 foreach ( $res as $plan ) {
 527                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 528                 }
 529
 530                 return (int)$rows;
 531         }
 532
 533         public function tableExists( $table, $fname = __METHOD__ ) {
 534                 $table = $this->tableName( $table, 'raw' );
 535                 if ( isset( $this->mSessionTempTables[$table] ) ) {
 536                         return true; // already known to exist and won't show in SHOW TABLES anyway
 537                 }
 538
 539                 $encLike = $this->buildLike( $table );
 540
 541                 return $this->query( "SHOW TABLES $encLike", $fname )->numRows() > 0;
 542         }
 543
 544         /**
 545          * @param string $table
 546          * @param string $field
 547          * @return bool|MySQLField
 548          */
 549         public function fieldInfo( $table, $field ) {
 550                 $table = $this->tableName( $table );
 551                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 552                 if ( !$res ) {
 553                         return false;
 554                 }
 555                 $n = $this->mysqlNumFields( $res->result );
 556                 for ( $i = 0; $i < $n; $i++ ) {
 557                         $meta = $this->mysqlFetchField( $res->result, $i );
 558                         if ( $field == $meta->name ) {
 559                                 return new MySQLField( $meta );
 560                         }
 561                 }
 562
 563                 return false;
 564         }
 565
 566         /**
 567          * Get column information from a result
 568          *
 569          * @param resource $res Raw result
 570          * @param int $n
 571          * @return stdClass
 572          */
 573         abstract protected function mysqlFetchField( $res, $n );
 574
 575         /**
 576          * Get information about an index into an object
 577          * Returns false if the index does not exist
 578          *
 579          * @param string $table
 580          * @param string $index
 581          * @param string $fname
 582          * @return bool|array|null False or null on failure
 583          */
 584         public function indexInfo( $table, $index, $fname = __METHOD__ ) {
 585                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 586                 # SHOW INDEX should work for 3.x and up:
 587                 # https://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 588                 $table = $this->tableName( $table );
 589                 $index = $this->indexName( $index );
 590
 591                 $sql = 'SHOW INDEX FROM ' . $table;
 592                 $res = $this->query( $sql, $fname );
 593
 594                 if ( !$res ) {
 595                         return null;
 596                 }
 597
 598                 $result = [];
 599
 600                 foreach ( $res as $row ) {
 601                         if ( $row->Key_name == $index ) {
 602                                 $result[] = $row;
 603                         }
 604                 }
 605
 606                 return empty( $result ) ? false : $result;
 607         }
 608
 609         /**
 610          * @param string $s
 611          * @return string
 612          */
 613         public function strencode( $s ) {
 614                 return $this->mysqlRealEscapeString( $s );
 615         }
 616
 617         /**
 618          * @param string $s
 619          * @return mixed
 620          */
 621         abstract protected function mysqlRealEscapeString( $s );
 622
 623         public function addQuotes( $s ) {
 624                 if ( is_bool( $s ) ) {
 625                         // Parent would transform to int, which does not play nice with MySQL type juggling.
 626                         // When searching for an int in a string column, the strings are cast to int, which
 627                         // means false would match any string not starting with a number.
 628                         $s = (string)(int)$s;
 629                 }
 630                 return parent::addQuotes( $s );
 631         }
 632
 633         /**
 634          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 635          *
 636          * @param string $s
 637          * @return string
 638          */
 639         public function addIdentifierQuotes( $s ) {
 640                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 641                 // Remove NUL bytes and escape backticks by doubling
 642                 return '`' . str_replace( [ "\0", '`' ], [ '', '``' ], $s ) . '`';
 643         }
 644
 645         /**
 646          * @param string $name
 647          * @return bool
 648          */
 649         public function isQuotedIdentifier( $name ) {
 650                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 651         }
 652
 653         public function getLag() {
 654                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 655                         return $this->getLagFromPtHeartbeat();
 656                 } else {
 657                         return $this->getLagFromSlaveStatus();
 658                 }
 659         }
 660
 661         /**
 662          * @return string
 663          */
 664         protected function getLagDetectionMethod() {
 665                 return $this->lagDetectionMethod;
 666         }
 667
 668         /**
 669          * @return bool|int
 670          */
 671         protected function getLagFromSlaveStatus() {
 672                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 673                 $row = $res ? $res->fetchObject() : false;
 674                 if ( $row && strval( $row->Seconds_Behind_Master ) !== '' ) {
 675                         return intval( $row->Seconds_Behind_Master );
 676                 }
 677
 678                 return false;
 679         }
 680
 681         /**
 682          * @return bool|float
 683          */
 684         protected function getLagFromPtHeartbeat() {
 685                 $options = $this->lagDetectionOptions;
 686
 687                 if ( isset( $options['conds'] ) ) {
 688                         // Best method for multi-DC setups: use logical channel names
 689                         $data = $this->getHeartbeatData( $options['conds'] );
 690                 } else {
 691                         // Standard method: use master server ID (works with stock pt-heartbeat)
 692                         $masterInfo = $this->getMasterServerInfo();
 693                         if ( !$masterInfo ) {
 694                                 $this->queryLogger->error(
 695                                         "Unable to query master of {db_server} for server ID",
 696                                         $this->getLogContext( [
 697                                                 'method' => __METHOD__
 698                                         ] )
 699                                 );
 700
 701                                 return false; // could not get master server ID
 702                         }
 703
 704                         $conds = [ 'server_id' => intval( $masterInfo['serverId'] ) ];
 705                         $data = $this->getHeartbeatData( $conds );
 706                 }
 707
 708                 list( $time, $nowUnix ) = $data;
 709                 if ( $time !== null ) {
 710                         // @time is in ISO format like "2015-09-25T16:48:10.000510"
 711                         $dateTime = new DateTime( $time, new DateTimeZone( 'UTC' ) );
 712                         $timeUnix = (int)$dateTime->format( 'U' ) + $dateTime->format( 'u' ) / 1e6;
 713
 714                         return max( $nowUnix - $timeUnix, 0.0 );
 715                 }
 716
 717                 $this->queryLogger->error(
 718                         "Unable to find pt-heartbeat row for {db_server}",
 719                         $this->getLogContext( [
 720                                 'method' => __METHOD__
 721                         ] )
 722                 );
 723
 724                 return false;
 725         }
 726
 727         protected function getMasterServerInfo() {
 728                 $cache = $this->srvCache;
 729                 $key = $cache->makeGlobalKey(
 730                         'mysql',
 731                         'master-info',
 732                         // Using one key for all cluster replica DBs is preferable
 733                         $this->getLBInfo( 'clusterMasterHost' ) ?: $this->getServer()
 734                 );
 735
 736                 return $cache->getWithSetCallback(
 737                         $key,
 738                         $cache::TTL_INDEFINITE,
 739                         function () use ( $cache, $key ) {
 740                                 // Get and leave a lock key in place for a short period
 741                                 if ( !$cache->lock( $key, 0, 10 ) ) {
 742                                         return false; // avoid master connection spike slams
 743                                 }
 744
 745                                 $conn = $this->getLazyMasterHandle();
 746                                 if ( !$conn ) {
 747                                         return false; // something is misconfigured
 748                                 }
 749
 750                                 // Connect to and query the master; catch errors to avoid outages
 751                                 try {
 752                                         $res = $conn->query( 'SELECT @@server_id AS id', __METHOD__ );
 753                                         $row = $res ? $res->fetchObject() : false;
 754                                         $id = $row ? (int)$row->id : 0;
 755                                 } catch ( DBError $e ) {
 756                                         $id = 0;
 757                                 }
 758
 759                                 // Cache the ID if it was retrieved
 760                                 return $id ? [ 'serverId' => $id, 'asOf' => time() ] : false;
 761                         }
 762                 );
 763         }
 764
 765         /**
 766          * @param array $conds WHERE clause conditions to find a row
 767          * @return array (heartbeat `ts` column value or null, UNIX timestamp) for the newest beat
 768          * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
 769          */
 770         protected function getHeartbeatData( array $conds ) {
 771                 // Do not bother starting implicit transactions here
 772                 $this->clearFlag( self::DBO_TRX, self::REMEMBER_PRIOR );
 773                 try {
 774                         $whereSQL = $this->makeList( $conds, self::LIST_AND );
 775                         // Use ORDER BY for channel based queries since that field might not be UNIQUE.
 776                         // Note: this would use "TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6))" but the
 777                         // percision field is not supported in MySQL <= 5.5.
 778                         $res = $this->query(
 779                                 "SELECT ts FROM heartbeat.heartbeat WHERE $whereSQL ORDER BY ts DESC LIMIT 1"
 780                         );
 781                         $row = $res ? $res->fetchObject() : false;
 782                 } finally {
 783                         $this->restoreFlags();
 784                 }
 785
 786                 return [ $row ? $row->ts : null, microtime( true ) ];
 787         }
 788
 789         protected function getApproximateLagStatus() {
 790                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 791                         // Disable caching since this is fast enough and we don't wan't
 792                         // to be *too* pessimistic by having both the cache TTL and the
 793                         // pt-heartbeat interval count as lag in getSessionLagStatus()
 794                         return parent::getApproximateLagStatus();
 795                 }
 796
 797                 $key = $this->srvCache->makeGlobalKey( 'mysql-lag', $this->getServer() );
 798                 $approxLag = $this->srvCache->get( $key );
 799                 if ( !$approxLag ) {
 800                         $approxLag = parent::getApproximateLagStatus();
 801                         $this->srvCache->set( $key, $approxLag, 1 );
 802                 }
 803
 804                 return $approxLag;
 805         }
 806
 807         public function masterPosWait( DBMasterPos $pos, $timeout ) {
 808                 if ( !( $pos instanceof MySQLMasterPos ) ) {
 809                         throw new InvalidArgumentException( "Position not an instance of MySQLMasterPos" );
 810                 }
 811
 812                 if ( $this->getLBInfo( 'is static' ) === true ) {
 813                         return 0; // this is a copy of a read-only dataset with no master DB
 814                 } elseif ( $this->lastKnownReplicaPos && $this->lastKnownReplicaPos->hasReached( $pos ) ) {
 815                         return 0; // already reached this point for sure
 816                 }
 817
 818                 // Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 819                 if ( $this->useGTIDs && $pos->gtids ) {
 820                         // Wait on the GTID set (MariaDB only)
 821                         $gtidArg = $this->addQuotes( implode( ',', $pos->gtids ) );
 822                         $res = $this->doQuery( "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)" );
 823                 } else {
 824                         // Wait on the binlog coordinates
 825                         $encFile = $this->addQuotes( $pos->file );
 826                         $encPos = intval( $pos->pos );
 827                         $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
 828                 }
 829
 830                 $row = $res ? $this->fetchRow( $res ) : false;
 831                 if ( !$row ) {
 832                         throw new DBExpectedError( $this,
 833                                 "MASTER_POS_WAIT() or MASTER_GTID_WAIT() failed: {$this->lastError()}" );
 834                 }
 835
 836                 // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
 837                 $status = ( $row[0] !== null ) ? intval( $row[0] ) : null;
 838                 if ( $status === null ) {
 839                         // T126436: jobs programmed to wait on master positions might be referencing binlogs
 840                         // with an old master hostname. Such calls make MASTER_POS_WAIT() return null. Try
 841                         // to detect this and treat the replica DB as having reached the position; a proper master
 842                         // switchover already requires that the new master be caught up before the switch.
 843                         $replicationPos = $this->getReplicaPos();
 844                         if ( $replicationPos && !$replicationPos->channelsMatch( $pos ) ) {
 845                                 $this->lastKnownReplicaPos = $replicationPos;
 846                                 $status = 0;
 847                         }
 848                 } elseif ( $status >= 0 ) {
 849                         // Remember that this position was reached to save queries next time
 850                         $this->lastKnownReplicaPos = $pos;
 851                 }
 852
 853                 return $status;
 854         }
 855
 856         /**
 857          * Get the position of the master from SHOW SLAVE STATUS
 858          *
 859          * @return MySQLMasterPos|bool
 860          */
 861         public function getReplicaPos() {
 862                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 863                 $row = $this->fetchObject( $res );
 864
 865                 if ( $row ) {
 866                         $pos = isset( $row->Exec_master_log_pos )
 867                                 ? $row->Exec_master_log_pos
 868                                 : $row->Exec_Master_Log_Pos;
 869                         // Also fetch the last-applied GTID set (MariaDB)
 870                         if ( $this->useGTIDs ) {
 871                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_slave_pos'", __METHOD__ );
 872                                 $gtidRow = $this->fetchObject( $res );
 873                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 874                         } else {
 875                                 $gtidSet = '';
 876                         }
 877
 878                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos, $gtidSet );
 879                 } else {
 880                         return false;
 881                 }
 882         }
 883
 884         /**
 885          * Get the position of the master from SHOW MASTER STATUS
 886          *
 887          * @return MySQLMasterPos|bool
 888          */
 889         public function getMasterPos() {
 890                 $res = $this->query( 'SHOW MASTER STATUS', __METHOD__ );
 891                 $row = $this->fetchObject( $res );
 892
 893                 if ( $row ) {
 894                         // Also fetch the last-written GTID set (MariaDB)
 895                         if ( $this->useGTIDs ) {
 896                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_binlog_pos'", __METHOD__ );
 897                                 $gtidRow = $this->fetchObject( $res );
 898                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 899                         } else {
 900                                 $gtidSet = '';
 901                         }
 902
 903                         return new MySQLMasterPos( $row->File, $row->Position, $gtidSet );
 904                 } else {
 905                         return false;
 906                 }
 907         }
 908
 909         public function serverIsReadOnly() {
 910                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'read_only'", __METHOD__ );
 911                 $row = $this->fetchObject( $res );
 912
 913                 return $row ? ( strtolower( $row->Value ) === 'on' ) : false;
 914         }
 915
 916         /**
 917          * @param string $index
 918          * @return string
 919          */
 920         function useIndexClause( $index ) {
 921                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 922         }
 923
 924         /**
 925          * @param string $index
 926          * @return string
 927          */
 928         function ignoreIndexClause( $index ) {
 929                 return "IGNORE INDEX (" . $this->indexName( $index ) . ")";
 930         }
 931
 932         /**
 933          * @return string
 934          */
 935         function lowPriorityOption() {
 936                 return 'LOW_PRIORITY';
 937         }
 938
 939         /**
 940          * @return string
 941          */
 942         public function getSoftwareLink() {
 943                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 944                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 945                 // in libmysql/libmysql.c).
 946                 $version = $this->getServerVersion();
 947                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 948                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 949                 }
 950
 951                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 952                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 953                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 954                 return '[{{int:version-db-mysql-url}} MySQL]';
 955         }
 956
 957         /**
 958          * @return string
 959          */
 960         public function getServerVersion() {
 961                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 962                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 963                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 964                 if ( $this->serverVersion === null ) {
 965                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 966                 }
 967                 return $this->serverVersion;
 968         }
 969
 970         /**
 971          * @param array $options
 972          */
 973         public function setSessionOptions( array $options ) {
 974                 if ( isset( $options['connTimeout'] ) ) {
 975                         $timeout = (int)$options['connTimeout'];
 976                         $this->query( "SET net_read_timeout=$timeout" );
 977                         $this->query( "SET net_write_timeout=$timeout" );
 978                 }
 979         }
 980
 981         /**
 982          * @param string $sql
 983          * @param string $newLine
 984          * @return bool
 985          */
 986         public function streamStatementEnd( &$sql, &$newLine ) {
 987                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 988                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 989                         $this->delimiter = $m[1];
 990                         $newLine = '';
 991                 }
 992
 993                 return parent::streamStatementEnd( $sql, $newLine );
 994         }
 995
 996         /**
 997          * Check to see if a named lock is available. This is non-blocking.
 998          *
 999          * @param string $lockName Name of lock to poll
1000          * @param string $method Name of method calling us
1001          * @return bool
1002          * @since 1.20
1003          */
1004         public function lockIsFree( $lockName, $method ) {
1005                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1006                 $result = $this->query( "SELECT IS_FREE_LOCK($encName) AS lockstatus", $method );
1007                 $row = $this->fetchObject( $result );
1008
1009                 return ( $row->lockstatus == 1 );
1010         }
1011
1012         /**
1013          * @param string $lockName
1014          * @param string $method
1015          * @param int $timeout
1016          * @return bool
1017          */
1018         public function lock( $lockName, $method, $timeout = 5 ) {
1019                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1020                 $result = $this->query( "SELECT GET_LOCK($encName, $timeout) AS lockstatus", $method );
1021                 $row = $this->fetchObject( $result );
1022
1023                 if ( $row->lockstatus == 1 ) {
1024                         parent::lock( $lockName, $method, $timeout ); // record
1025                         return true;
1026                 }
1027
1028                 $this->queryLogger->warning( __METHOD__ . " failed to acquire lock '$lockName'\n" );
1029
1030                 return false;
1031         }
1032
1033         /**
1034          * FROM MYSQL DOCS:
1035          * https://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
1036          * @param string $lockName
1037          * @param string $method
1038          * @return bool
1039          */
1040         public function unlock( $lockName, $method ) {
1041                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1042                 $result = $this->query( "SELECT RELEASE_LOCK($encName) as lockstatus", $method );
1043                 $row = $this->fetchObject( $result );
1044
1045                 if ( $row->lockstatus == 1 ) {
1046                         parent::unlock( $lockName, $method ); // record
1047                         return true;
1048                 }
1049
1050                 $this->queryLogger->warning( __METHOD__ . " failed to release lock '$lockName'\n" );
1051
1052                 return false;
1053         }
1054
1055         private function makeLockName( $lockName ) {
1056                 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1057                 // Newer version enforce a 64 char length limit.
1058                 return ( strlen( $lockName ) > 64 ) ? sha1( $lockName ) : $lockName;
1059         }
1060
1061         public function namedLocksEnqueue() {
1062                 return true;
1063         }
1064
1065         public function tableLocksHaveTransactionScope() {
1066                 return false; // tied to TCP connection
1067         }
1068
1069         protected function doLockTables( array $read, array $write, $method ) {
1070                 $items = [];
1071                 foreach ( $write as $table ) {
1072                         $items[] = $this->tableName( $table ) . ' WRITE';
1073                 }
1074                 foreach ( $read as $table ) {
1075                         $items[] = $this->tableName( $table ) . ' READ';
1076                 }
1077
1078                 $sql = "LOCK TABLES " . implode( ',', $items );
1079                 $this->query( $sql, $method );
1080
1081                 return true;
1082         }
1083
1084         protected function doUnlockTables( $method ) {
1085                 $this->query( "UNLOCK TABLES", $method );
1086
1087                 return true;
1088         }
1089
1090         /**
1091          * @param bool $value
1092          */
1093         public function setBigSelects( $value = true ) {
1094                 if ( $value === 'default' ) {
1095                         if ( $this->mDefaultBigSelects === null ) {
1096                                 # Function hasn't been called before so it must already be set to the default
1097                                 return;
1098                         } else {
1099                                 $value = $this->mDefaultBigSelects;
1100                         }
1101                 } elseif ( $this->mDefaultBigSelects === null ) {
1102                         $this->mDefaultBigSelects =
1103                                 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__ );
1104                 }
1105                 $encValue = $value ? '1' : '0';
1106                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
1107         }
1108
1109         /**
1110          * DELETE where the condition is a join. MySql uses multi-table deletes.
1111          * @param string $delTable
1112          * @param string $joinTable
1113          * @param string $delVar
1114          * @param string $joinVar
1115          * @param array|string $conds
1116          * @param bool|string $fname
1117          * @throws DBUnexpectedError
1118          * @return bool|ResultWrapper
1119          */
1120         public function deleteJoin(
1121                 $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__
1122         ) {
1123                 if ( !$conds ) {
1124                         throw new DBUnexpectedError( $this, __METHOD__ . ' called with empty $conds' );
1125                 }
1126
1127                 $delTable = $this->tableName( $delTable );
1128                 $joinTable = $this->tableName( $joinTable );
1129                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1130
1131                 if ( $conds != '*' ) {
1132                         $sql .= ' AND ' . $this->makeList( $conds, self::LIST_AND );
1133                 }
1134
1135                 return $this->query( $sql, $fname );
1136         }
1137
1138         /**
1139          * @param string $table
1140          * @param array $rows
1141          * @param array $uniqueIndexes
1142          * @param array $set
1143          * @param string $fname
1144          * @return bool
1145          */
1146         public function upsert( $table, array $rows, array $uniqueIndexes,
1147                 array $set, $fname = __METHOD__
1148         ) {
1149                 if ( !count( $rows ) ) {
1150                         return true; // nothing to do
1151                 }
1152
1153                 if ( !is_array( reset( $rows ) ) ) {
1154                         $rows = [ $rows ];
1155                 }
1156
1157                 $table = $this->tableName( $table );
1158                 $columns = array_keys( $rows[0] );
1159
1160                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1161                 $rowTuples = [];
1162                 foreach ( $rows as $row ) {
1163                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1164                 }
1165                 $sql .= implode( ',', $rowTuples );
1166                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, self::LIST_SET );
1167
1168                 return (bool)$this->query( $sql, $fname );
1169         }
1170
1171         /**
1172          * Determines how long the server has been up
1173          *
1174          * @return int
1175          */
1176         public function getServerUptime() {
1177                 $vars = $this->getMysqlStatus( 'Uptime' );
1178
1179                 return (int)$vars['Uptime'];
1180         }
1181
1182         /**
1183          * Determines if the last failure was due to a deadlock
1184          *
1185          * @return bool
1186          */
1187         public function wasDeadlock() {
1188                 return $this->lastErrno() == 1213;
1189         }
1190
1191         /**
1192          * Determines if the last failure was due to a lock timeout
1193          *
1194          * @return bool
1195          */
1196         public function wasLockTimeout() {
1197                 return $this->lastErrno() == 1205;
1198         }
1199
1200         public function wasErrorReissuable() {
1201                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1202         }
1203
1204         /**
1205          * Determines if the last failure was due to the database being read-only.
1206          *
1207          * @return bool
1208          */
1209         public function wasReadOnlyError() {
1210                 return $this->lastErrno() == 1223 ||
1211                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1212         }
1213
1214         public function wasConnectionError( $errno ) {
1215                 return $errno == 2013 || $errno == 2006;
1216         }
1217
1218         /**
1219          * @param string $oldName
1220          * @param string $newName
1221          * @param bool $temporary
1222          * @param string $fname
1223          * @return bool
1224          */
1225         public function duplicateTableStructure(
1226                 $oldName, $newName, $temporary = false, $fname = __METHOD__
1227         ) {
1228                 $tmp = $temporary ? 'TEMPORARY ' : '';
1229                 $newName = $this->addIdentifierQuotes( $newName );
1230                 $oldName = $this->addIdentifierQuotes( $oldName );
1231                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1232
1233                 return $this->query( $query, $fname );
1234         }
1235
1236         /**
1237          * List all tables on the database
1238          *
1239          * @param string $prefix Only show tables with this prefix, e.g. mw_
1240          * @param string $fname Calling function name
1241          * @return array
1242          */
1243         public function listTables( $prefix = null, $fname = __METHOD__ ) {
1244                 $result = $this->query( "SHOW TABLES", $fname );
1245
1246                 $endArray = [];
1247
1248                 foreach ( $result as $table ) {
1249                         $vars = get_object_vars( $table );
1250                         $table = array_pop( $vars );
1251
1252                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1253                                 $endArray[] = $table;
1254                         }
1255                 }
1256
1257                 return $endArray;
1258         }
1259
1260         /**
1261          * @param string $tableName
1262          * @param string $fName
1263          * @return bool|ResultWrapper
1264          */
1265         public function dropTable( $tableName, $fName = __METHOD__ ) {
1266                 if ( !$this->tableExists( $tableName, $fName ) ) {
1267                         return false;
1268                 }
1269
1270                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1271         }
1272
1273         /**
1274          * Get status information from SHOW STATUS in an associative array
1275          *
1276          * @param string $which
1277          * @return array
1278          */
1279         private function getMysqlStatus( $which = "%" ) {
1280                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1281                 $status = [];
1282
1283                 foreach ( $res as $row ) {
1284                         $status[$row->Variable_name] = $row->Value;
1285                 }
1286
1287                 return $status;
1288         }
1289
1290         /**
1291          * Lists VIEWs in the database
1292          *
1293          * @param string $prefix Only show VIEWs with this prefix, eg.
1294          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1295          * @param string $fname Name of calling function
1296          * @return array
1297          * @since 1.22
1298          */
1299         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1300                 // The name of the column containing the name of the VIEW
1301                 $propertyName = 'Tables_in_' . $this->mDBname;
1302
1303                 // Query for the VIEWS
1304                 $res = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1305                 $allViews = [];
1306                 foreach ( $res as $row ) {
1307                         array_push( $allViews, $row->$propertyName );
1308                 }
1309
1310                 if ( is_null( $prefix ) || $prefix === '' ) {
1311                         return $allViews;
1312                 }
1313
1314                 $filteredViews = [];
1315                 foreach ( $allViews as $viewName ) {
1316                         // Does the name of this VIEW start with the table-prefix?
1317                         if ( strpos( $viewName, $prefix ) === 0 ) {
1318                                 array_push( $filteredViews, $viewName );
1319                         }
1320                 }
1321
1322                 return $filteredViews;
1323         }
1324
1325         /**
1326          * Differentiates between a TABLE and a VIEW.
1327          *
1328          * @param string $name Name of the TABLE/VIEW to test
1329          * @param string $prefix
1330          * @return bool
1331          * @since 1.22
1332          */
1333         public function isView( $name, $prefix = null ) {
1334                 return in_array( $name, $this->listViews( $prefix ) );
1335         }
1336
1337         /**
1338          * Allows for index remapping in queries where this is not consistent across DBMS
1339          *
1340          * @param string $index
1341          * @return string
1342          */
1343         protected function indexName( $index ) {
1344                 /**
1345                  * When SQLite indexes were introduced in r45764, it was noted that
1346                  * SQLite requires index names to be unique within the whole database,
1347                  * not just within a schema. As discussed in CR r45819, to avoid the
1348                  * need for a schema change on existing installations, the indexes
1349                  * were implicitly mapped from the new names to the old names.
1350                  *
1351                  * This mapping can be removed if DB patches are introduced to alter
1352                  * the relevant tables in existing installations. Note that because
1353                  * this index mapping applies to table creation, even new installations
1354                  * of MySQL have the old names (except for installations created during
1355                  * a period where this mapping was inappropriately removed, see
1356                  * T154872).
1357                  */
1358                 $renamed = [
1359                         'ar_usertext_timestamp' => 'usertext_timestamp',
1360                         'un_user_id' => 'user_id',
1361                         'un_user_ip' => 'user_ip',
1362                 ];
1363
1364                 if ( isset( $renamed[$index] ) ) {
1365                         return $renamed[$index];
1366                 } else {
1367                         return $index;
1368                 }
1369         }
1370 }
1371
1372 class_alias( DatabaseMysqlBase::class, 'DatabaseMysqlBase' );