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