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
  24 /**
  25  * Database abstraction object for MySQL.
  26  * Defines methods independent on used MySQL extension.
  27  *
  28  * @ingroup Database
  29  * @since 1.22
  30  * @see Database
  31  */
  32 abstract class DatabaseMysqlBase extends DatabaseBase {
  33         /** @var MysqlMasterPos */
  34         protected $lastKnownReplicaPos;
  35         /** @var string Method to detect replica DB lag */
  36         protected $lagDetectionMethod;
  37         /** @var array Method to detect replica DB lag */
  38         protected $lagDetectionOptions = [];
  39         /** @var bool bool Whether to use GTID methods */
  40         protected $useGTIDs = false;
  41         /** @var string|null */
  42         protected $sslKeyPath;
  43         /** @var string|null */
  44         protected $sslCertPath;
  45         /** @var string|null */
  46         protected $sslCAPath;
  47         /** @var string[]|null */
  48         protected $sslCiphers;
  49         /** @var string sql_mode value to send on connection */
  50         protected $sqlMode;
  51         /** @var bool Use experimental UTF-8 transmission encoding */
  52         protected $utf8Mode;
  53
  54         /** @var string|null */
  55         private $serverVersion = null;
  56
  57         /**
  58          * Additional $params include:
  59          *   - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
  60          *       pt-heartbeat assumes the table is at heartbeat.heartbeat
  61          *       and uses UTC timestamps in the heartbeat.ts column.
  62          *       (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
  63          *   - lagDetectionOptions : if using pt-heartbeat, this can be set to an array map to change
  64          *       the default behavior. Normally, the heartbeat row with the server
  65          *       ID of this server's master will be used. Set the "conds" field to
  66          *       override the query conditions, e.g. ['shard' => 's1'].
  67          *   - useGTIDs : use GTID methods like MASTER_GTID_WAIT() when possible.
  68          *   - sslKeyPath : path to key file [default: null]
  69          *   - sslCertPath : path to certificate file [default: null]
  70          *   - sslCAPath : parth to certificate authority PEM files [default: null]
  71          *   - sslCiphers : array list of allowable ciphers [default: null]
  72          * @param array $params
  73          */
  74         function __construct( array $params ) {
  75                 parent::__construct( $params );
  76
  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
  94         /**
  95          * @return string
  96          */
  97         function getType() {
  98                 return 'mysql';
  99         }
 100
 101         /**
 102          * @param string $server
 103          * @param string $user
 104          * @param string $password
 105          * @param string $dbName
 106          * @throws Exception|DBConnectionError
 107          * @return bool
 108          */
 109         function open( $server, $user, $password, $dbName ) {
 110                 # Close/unset connection handle
 111                 $this->close();
 112
 113                 $this->mServer = $server;
 114                 $this->mUser = $user;
 115                 $this->mPassword = $password;
 116                 $this->mDBname = $dbName;
 117
 118                 $this->installErrorHandler();
 119                 try {
 120                         $this->mConn = $this->mysqlConnect( $this->mServer );
 121                 } catch ( Exception $ex ) {
 122                         $this->restoreErrorHandler();
 123                         throw $ex;
 124                 }
 125                 $error = $this->restoreErrorHandler();
 126
 127                 # Always log connection errors
 128                 if ( !$this->mConn ) {
 129                         if ( !$error ) {
 130                                 $error = $this->lastError();
 131                         }
 132                         $this->queryLogger->error(
 133                                 "Error connecting to {db_server}: {error}",
 134                                 $this->getLogContext( [
 135                                         'method' => __METHOD__,
 136                                         'error' => $error,
 137                                 ] )
 138                         );
 139                         $this->queryLogger->debug( "DB connection error\n" .
 140                                 "Server: $server, User: $user, Password: " .
 141                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 142
 143                         $this->reportConnectionError( $error );
 144                 }
 145
 146                 if ( $dbName != '' ) {
 147                         MediaWiki\suppressWarnings();
 148                         $success = $this->selectDB( $dbName );
 149                         MediaWiki\restoreWarnings();
 150                         if ( !$success ) {
 151                                 $this->queryLogger->error(
 152                                         "Error selecting database {db_name} on server {db_server}",
 153                                         $this->getLogContext( [
 154                                                 'method' => __METHOD__,
 155                                         ] )
 156                                 );
 157                                 $this->queryLogger->debug(
 158                                         "Error selecting database $dbName on server {$this->mServer}" );
 159
 160                                 $this->reportConnectionError( "Error selecting database $dbName" );
 161                         }
 162                 }
 163
 164                 // Tell the server what we're communicating with
 165                 if ( !$this->connectInitCharset() ) {
 166                         $this->reportConnectionError( "Error setting character set" );
 167                 }
 168
 169                 // Abstract over any insane MySQL defaults
 170                 $set = [ 'group_concat_max_len = 262144' ];
 171                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 172                 if ( is_string( $this->sqlMode ) ) {
 173                         $set[] = 'sql_mode = ' . $this->addQuotes( $this->sqlMode );
 174                 }
 175                 // Set any custom settings defined by site config
 176                 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 177                 foreach ( $this->mSessionVars as $var => $val ) {
 178                         // Escape strings but not numbers to avoid MySQL complaining
 179                         if ( !is_int( $val ) && !is_float( $val ) ) {
 180                                 $val = $this->addQuotes( $val );
 181                         }
 182                         $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 183                 }
 184
 185                 if ( $set ) {
 186                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 187                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ) );
 188                         if ( !$success ) {
 189                                 $this->queryLogger->error(
 190                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 191                                         $this->getLogContext( [
 192                                                 'method' => __METHOD__,
 193                                         ] )
 194                                 );
 195                                 $this->reportConnectionError(
 196                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 197                         }
 198                 }
 199
 200                 $this->mOpened = true;
 201
 202                 return true;
 203         }
 204
 205         /**
 206          * Set the character set information right after connection
 207          * @return bool
 208          */
 209         protected function connectInitCharset() {
 210                 if ( $this->utf8Mode ) {
 211                         // Tell the server we're communicating with it in UTF-8.
 212                         // This may engage various charset conversions.
 213                         return $this->mysqlSetCharset( 'utf8' );
 214                 } else {
 215                         return $this->mysqlSetCharset( 'binary' );
 216                 }
 217         }
 218
 219         /**
 220          * Open a connection to a MySQL server
 221          *
 222          * @param string $realServer
 223          * @return mixed Raw connection
 224          * @throws DBConnectionError
 225          */
 226         abstract protected function mysqlConnect( $realServer );
 227
 228         /**
 229          * Set the character set of the MySQL link
 230          *
 231          * @param string $charset
 232          * @return bool
 233          */
 234         abstract protected function mysqlSetCharset( $charset );
 235
 236         /**
 237          * @param ResultWrapper|resource $res
 238          * @throws DBUnexpectedError
 239          */
 240         function freeResult( $res ) {
 241                 if ( $res instanceof ResultWrapper ) {
 242                         $res = $res->result;
 243                 }
 244                 MediaWiki\suppressWarnings();
 245                 $ok = $this->mysqlFreeResult( $res );
 246                 MediaWiki\restoreWarnings();
 247                 if ( !$ok ) {
 248                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 249                 }
 250         }
 251
 252         /**
 253          * Free result memory
 254          *
 255          * @param resource $res Raw result
 256          * @return bool
 257          */
 258         abstract protected function mysqlFreeResult( $res );
 259
 260         /**
 261          * @param ResultWrapper|resource $res
 262          * @return stdClass|bool
 263          * @throws DBUnexpectedError
 264          */
 265         function fetchObject( $res ) {
 266                 if ( $res instanceof ResultWrapper ) {
 267                         $res = $res->result;
 268                 }
 269                 MediaWiki\suppressWarnings();
 270                 $row = $this->mysqlFetchObject( $res );
 271                 MediaWiki\restoreWarnings();
 272
 273                 $errno = $this->lastErrno();
 274                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 275                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 276                 // these are the only errors mysql_fetch_object can cause.
 277                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 278                 if ( $errno == 2000 || $errno == 2013 ) {
 279                         throw new DBUnexpectedError(
 280                                 $this,
 281                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 282                         );
 283                 }
 284
 285                 return $row;
 286         }
 287
 288         /**
 289          * Fetch a result row as an object
 290          *
 291          * @param resource $res Raw result
 292          * @return stdClass
 293          */
 294         abstract protected function mysqlFetchObject( $res );
 295
 296         /**
 297          * @param ResultWrapper|resource $res
 298          * @return array|bool
 299          * @throws DBUnexpectedError
 300          */
 301         function fetchRow( $res ) {
 302                 if ( $res instanceof ResultWrapper ) {
 303                         $res = $res->result;
 304                 }
 305                 MediaWiki\suppressWarnings();
 306                 $row = $this->mysqlFetchArray( $res );
 307                 MediaWiki\restoreWarnings();
 308
 309                 $errno = $this->lastErrno();
 310                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 311                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 312                 // these are the only errors mysql_fetch_array can cause.
 313                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 314                 if ( $errno == 2000 || $errno == 2013 ) {
 315                         throw new DBUnexpectedError(
 316                                 $this,
 317                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 318                         );
 319                 }
 320
 321                 return $row;
 322         }
 323
 324         /**
 325          * Fetch a result row as an associative and numeric array
 326          *
 327          * @param resource $res Raw result
 328          * @return array
 329          */
 330         abstract protected function mysqlFetchArray( $res );
 331
 332         /**
 333          * @throws DBUnexpectedError
 334          * @param ResultWrapper|resource $res
 335          * @return int
 336          */
 337         function numRows( $res ) {
 338                 if ( $res instanceof ResultWrapper ) {
 339                         $res = $res->result;
 340                 }
 341                 MediaWiki\suppressWarnings();
 342                 $n = $this->mysqlNumRows( $res );
 343                 MediaWiki\restoreWarnings();
 344
 345                 // Unfortunately, mysql_num_rows does not reset the last errno.
 346                 // We are not checking for any errors here, since
 347                 // these are no errors mysql_num_rows can cause.
 348                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 349                 // See https://phabricator.wikimedia.org/T44430
 350                 return $n;
 351         }
 352
 353         /**
 354          * Get number of rows in result
 355          *
 356          * @param resource $res Raw result
 357          * @return int
 358          */
 359         abstract protected function mysqlNumRows( $res );
 360
 361         /**
 362          * @param ResultWrapper|resource $res
 363          * @return int
 364          */
 365         function numFields( $res ) {
 366                 if ( $res instanceof ResultWrapper ) {
 367                         $res = $res->result;
 368                 }
 369
 370                 return $this->mysqlNumFields( $res );
 371         }
 372
 373         /**
 374          * Get number of fields in result
 375          *
 376          * @param resource $res Raw result
 377          * @return int
 378          */
 379         abstract protected function mysqlNumFields( $res );
 380
 381         /**
 382          * @param ResultWrapper|resource $res
 383          * @param int $n
 384          * @return string
 385          */
 386         function fieldName( $res, $n ) {
 387                 if ( $res instanceof ResultWrapper ) {
 388                         $res = $res->result;
 389                 }
 390
 391                 return $this->mysqlFieldName( $res, $n );
 392         }
 393
 394         /**
 395          * Get the name of the specified field in a result
 396          *
 397          * @param ResultWrapper|resource $res
 398          * @param int $n
 399          * @return string
 400          */
 401         abstract protected function mysqlFieldName( $res, $n );
 402
 403         /**
 404          * mysql_field_type() wrapper
 405          * @param ResultWrapper|resource $res
 406          * @param int $n
 407          * @return string
 408          */
 409         public function fieldType( $res, $n ) {
 410                 if ( $res instanceof ResultWrapper ) {
 411                         $res = $res->result;
 412                 }
 413
 414                 return $this->mysqlFieldType( $res, $n );
 415         }
 416
 417         /**
 418          * Get the type of the specified field in a result
 419          *
 420          * @param ResultWrapper|resource $res
 421          * @param int $n
 422          * @return string
 423          */
 424         abstract protected function mysqlFieldType( $res, $n );
 425
 426         /**
 427          * @param ResultWrapper|resource $res
 428          * @param int $row
 429          * @return bool
 430          */
 431         function dataSeek( $res, $row ) {
 432                 if ( $res instanceof ResultWrapper ) {
 433                         $res = $res->result;
 434                 }
 435
 436                 return $this->mysqlDataSeek( $res, $row );
 437         }
 438
 439         /**
 440          * Move internal result pointer
 441          *
 442          * @param ResultWrapper|resource $res
 443          * @param int $row
 444          * @return bool
 445          */
 446         abstract protected function mysqlDataSeek( $res, $row );
 447
 448         /**
 449          * @return string
 450          */
 451         function lastError() {
 452                 if ( $this->mConn ) {
 453                         # Even if it's non-zero, it can still be invalid
 454                         MediaWiki\suppressWarnings();
 455                         $error = $this->mysqlError( $this->mConn );
 456                         if ( !$error ) {
 457                                 $error = $this->mysqlError();
 458                         }
 459                         MediaWiki\restoreWarnings();
 460                 } else {
 461                         $error = $this->mysqlError();
 462                 }
 463                 if ( $error ) {
 464                         $error .= ' (' . $this->mServer . ')';
 465                 }
 466
 467                 return $error;
 468         }
 469
 470         /**
 471          * Returns the text of the error message from previous MySQL operation
 472          *
 473          * @param resource $conn Raw connection
 474          * @return string
 475          */
 476         abstract protected function mysqlError( $conn = null );
 477
 478         /**
 479          * @param string $table
 480          * @param array $uniqueIndexes
 481          * @param array $rows
 482          * @param string $fname
 483          * @return ResultWrapper
 484          */
 485         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 486                 return $this->nativeReplace( $table, $rows, $fname );
 487         }
 488
 489         /**
 490          * Estimate rows in dataset
 491          * Returns estimated count, based on EXPLAIN output
 492          * Takes same arguments as Database::select()
 493          *
 494          * @param string|array $table
 495          * @param string|array $vars
 496          * @param string|array $conds
 497          * @param string $fname
 498          * @param string|array $options
 499          * @return bool|int
 500          */
 501         public function estimateRowCount( $table, $vars = '*', $conds = '',
 502                 $fname = __METHOD__, $options = []
 503         ) {
 504                 $options['EXPLAIN'] = true;
 505                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 506                 if ( $res === false ) {
 507                         return false;
 508                 }
 509                 if ( !$this->numRows( $res ) ) {
 510                         return 0;
 511                 }
 512
 513                 $rows = 1;
 514                 foreach ( $res as $plan ) {
 515                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 516                 }
 517
 518                 return (int)$rows;
 519         }
 520
 521         /**
 522          * @param string $table
 523          * @param string $field
 524          * @return bool|MySQLField
 525          */
 526         function fieldInfo( $table, $field ) {
 527                 $table = $this->tableName( $table );
 528                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 529                 if ( !$res ) {
 530                         return false;
 531                 }
 532                 $n = $this->mysqlNumFields( $res->result );
 533                 for ( $i = 0; $i < $n; $i++ ) {
 534                         $meta = $this->mysqlFetchField( $res->result, $i );
 535                         if ( $field == $meta->name ) {
 536                                 return new MySQLField( $meta );
 537                         }
 538                 }
 539
 540                 return false;
 541         }
 542
 543         /**
 544          * Get column information from a result
 545          *
 546          * @param resource $res Raw result
 547          * @param int $n
 548          * @return stdClass
 549          */
 550         abstract protected function mysqlFetchField( $res, $n );
 551
 552         /**
 553          * Get information about an index into an object
 554          * Returns false if the index does not exist
 555          *
 556          * @param string $table
 557          * @param string $index
 558          * @param string $fname
 559          * @return bool|array|null False or null on failure
 560          */
 561         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 562                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 563                 # SHOW INDEX should work for 3.x and up:
 564                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 565                 $table = $this->tableName( $table );
 566                 $index = $this->indexName( $index );
 567
 568                 $sql = 'SHOW INDEX FROM ' . $table;
 569                 $res = $this->query( $sql, $fname );
 570
 571                 if ( !$res ) {
 572                         return null;
 573                 }
 574
 575                 $result = [];
 576
 577                 foreach ( $res as $row ) {
 578                         if ( $row->Key_name == $index ) {
 579                                 $result[] = $row;
 580                         }
 581                 }
 582
 583                 return empty( $result ) ? false : $result;
 584         }
 585
 586         /**
 587          * @param string $s
 588          * @return string
 589          */
 590         function strencode( $s ) {
 591                 return $this->mysqlRealEscapeString( $s );
 592         }
 593
 594         /**
 595          * @param string $s
 596          * @return mixed
 597          */
 598         abstract protected function mysqlRealEscapeString( $s );
 599
 600         /**
 601          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 602          *
 603          * @param string $s
 604          * @return string
 605          */
 606         public function addIdentifierQuotes( $s ) {
 607                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 608                 // Remove NUL bytes and escape backticks by doubling
 609                 return '`' . str_replace( [ "\0", '`' ], [ '', '``' ], $s ) . '`';
 610         }
 611
 612         /**
 613          * @param string $name
 614          * @return bool
 615          */
 616         public function isQuotedIdentifier( $name ) {
 617                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 618         }
 619
 620         function getLag() {
 621                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 622                         return $this->getLagFromPtHeartbeat();
 623                 } else {
 624                         return $this->getLagFromSlaveStatus();
 625                 }
 626         }
 627
 628         /**
 629          * @return string
 630          */
 631         protected function getLagDetectionMethod() {
 632                 return $this->lagDetectionMethod;
 633         }
 634
 635         /**
 636          * @return bool|int
 637          */
 638         protected function getLagFromSlaveStatus() {
 639                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 640                 $row = $res ? $res->fetchObject() : false;
 641                 if ( $row && strval( $row->Seconds_Behind_Master ) !== '' ) {
 642                         return intval( $row->Seconds_Behind_Master );
 643                 }
 644
 645                 return false;
 646         }
 647
 648         /**
 649          * @return bool|float
 650          */
 651         protected function getLagFromPtHeartbeat() {
 652                 $options = $this->lagDetectionOptions;
 653
 654                 if ( isset( $options['conds'] ) ) {
 655                         // Best method for multi-DC setups: use logical channel names
 656                         $data = $this->getHeartbeatData( $options['conds'] );
 657                 } else {
 658                         // Standard method: use master server ID (works with stock pt-heartbeat)
 659                         $masterInfo = $this->getMasterServerInfo();
 660                         if ( !$masterInfo ) {
 661                                 $this->queryLogger->error(
 662                                         "Unable to query master of {db_server} for server ID",
 663                                         $this->getLogContext( [
 664                                                 'method' => __METHOD__
 665                                         ] )
 666                                 );
 667
 668                                 return false; // could not get master server ID
 669                         }
 670
 671                         $conds = [ 'server_id' => intval( $masterInfo['serverId'] ) ];
 672                         $data = $this->getHeartbeatData( $conds );
 673                 }
 674
 675                 list( $time, $nowUnix ) = $data;
 676                 if ( $time !== null ) {
 677                         // @time is in ISO format like "2015-09-25T16:48:10.000510"
 678                         $dateTime = new DateTime( $time, new DateTimeZone( 'UTC' ) );
 679                         $timeUnix = (int)$dateTime->format( 'U' ) + $dateTime->format( 'u' ) / 1e6;
 680
 681                         return max( $nowUnix - $timeUnix, 0.0 );
 682                 }
 683
 684                 $this->queryLogger->error(
 685                         "Unable to find pt-heartbeat row for {db_server}",
 686                         $this->getLogContext( [
 687                                 'method' => __METHOD__
 688                         ] )
 689                 );
 690
 691                 return false;
 692         }
 693
 694         protected function getMasterServerInfo() {
 695                 $cache = $this->srvCache;
 696                 $key = $cache->makeGlobalKey(
 697                         'mysql',
 698                         'master-info',
 699                         // Using one key for all cluster replica DBs is preferable
 700                         $this->getLBInfo( 'clusterMasterHost' ) ?: $this->getServer()
 701                 );
 702
 703                 return $cache->getWithSetCallback(
 704                         $key,
 705                         $cache::TTL_INDEFINITE,
 706                         function () use ( $cache, $key ) {
 707                                 // Get and leave a lock key in place for a short period
 708                                 if ( !$cache->lock( $key, 0, 10 ) ) {
 709                                         return false; // avoid master connection spike slams
 710                                 }
 711
 712                                 $conn = $this->getLazyMasterHandle();
 713                                 if ( !$conn ) {
 714                                         return false; // something is misconfigured
 715                                 }
 716
 717                                 // Connect to and query the master; catch errors to avoid outages
 718                                 try {
 719                                         $res = $conn->query( 'SELECT @@server_id AS id', __METHOD__ );
 720                                         $row = $res ? $res->fetchObject() : false;
 721                                         $id = $row ? (int)$row->id : 0;
 722                                 } catch ( DBError $e ) {
 723                                         $id = 0;
 724                                 }
 725
 726                                 // Cache the ID if it was retrieved
 727                                 return $id ? [ 'serverId' => $id, 'asOf' => time() ] : false;
 728                         }
 729                 );
 730         }
 731
 732         /**
 733          * @param array $conds WHERE clause conditions to find a row
 734          * @return array (heartbeat `ts` column value or null, UNIX timestamp) for the newest beat
 735          * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
 736          */
 737         protected function getHeartbeatData( array $conds ) {
 738                 $whereSQL = $this->makeList( $conds, self::LIST_AND );
 739                 // Use ORDER BY for channel based queries since that field might not be UNIQUE.
 740                 // Note: this would use "TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6))" but the
 741                 // percision field is not supported in MySQL <= 5.5.
 742                 $res = $this->query(
 743                         "SELECT ts FROM heartbeat.heartbeat WHERE $whereSQL ORDER BY ts DESC LIMIT 1"
 744                 );
 745                 $row = $res ? $res->fetchObject() : false;
 746
 747                 return [ $row ? $row->ts : null, microtime( true ) ];
 748         }
 749
 750         public function getApproximateLagStatus() {
 751                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 752                         // Disable caching since this is fast enough and we don't wan't
 753                         // to be *too* pessimistic by having both the cache TTL and the
 754                         // pt-heartbeat interval count as lag in getSessionLagStatus()
 755                         return parent::getApproximateLagStatus();
 756                 }
 757
 758                 $key = $this->srvCache->makeGlobalKey( 'mysql-lag', $this->getServer() );
 759                 $approxLag = $this->srvCache->get( $key );
 760                 if ( !$approxLag ) {
 761                         $approxLag = parent::getApproximateLagStatus();
 762                         $this->srvCache->set( $key, $approxLag, 1 );
 763                 }
 764
 765                 return $approxLag;
 766         }
 767
 768         function masterPosWait( DBMasterPos $pos, $timeout ) {
 769                 if ( !( $pos instanceof MySQLMasterPos ) ) {
 770                         throw new InvalidArgumentException( "Position not an instance of MySQLMasterPos" );
 771                 }
 772
 773                 if ( $this->getLBInfo( 'is static' ) === true ) {
 774                         return 0; // this is a copy of a read-only dataset with no master DB
 775                 } elseif ( $this->lastKnownReplicaPos && $this->lastKnownReplicaPos->hasReached( $pos ) ) {
 776                         return 0; // already reached this point for sure
 777                 }
 778
 779                 // Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 780                 if ( $this->useGTIDs && $pos->gtids ) {
 781                         // Wait on the GTID set (MariaDB only)
 782                         $gtidArg = $this->addQuotes( implode( ',', $pos->gtids ) );
 783                         $res = $this->doQuery( "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)" );
 784                 } else {
 785                         // Wait on the binlog coordinates
 786                         $encFile = $this->addQuotes( $pos->file );
 787                         $encPos = intval( $pos->pos );
 788                         $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
 789                 }
 790
 791                 $row = $res ? $this->fetchRow( $res ) : false;
 792                 if ( !$row ) {
 793                         throw new DBExpectedError( $this, "Failed to query MASTER_POS_WAIT()" );
 794                 }
 795
 796                 // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
 797                 $status = ( $row[0] !== null ) ? intval( $row[0] ) : null;
 798                 if ( $status === null ) {
 799                         // T126436: jobs programmed to wait on master positions might be referencing binlogs
 800                         // with an old master hostname. Such calls make MASTER_POS_WAIT() return null. Try
 801                         // to detect this and treat the replica DB as having reached the position; a proper master
 802                         // switchover already requires that the new master be caught up before the switch.
 803                         $replicationPos = $this->getSlavePos();
 804                         if ( $replicationPos && !$replicationPos->channelsMatch( $pos ) ) {
 805                                 $this->lastKnownReplicaPos = $replicationPos;
 806                                 $status = 0;
 807                         }
 808                 } elseif ( $status >= 0 ) {
 809                         // Remember that this position was reached to save queries next time
 810                         $this->lastKnownReplicaPos = $pos;
 811                 }
 812
 813                 return $status;
 814         }
 815
 816         /**
 817          * Get the position of the master from SHOW SLAVE STATUS
 818          *
 819          * @return MySQLMasterPos|bool
 820          */
 821         function getSlavePos() {
 822                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 823                 $row = $this->fetchObject( $res );
 824
 825                 if ( $row ) {
 826                         $pos = isset( $row->Exec_master_log_pos )
 827                                 ? $row->Exec_master_log_pos
 828                                 : $row->Exec_Master_Log_Pos;
 829                         // Also fetch the last-applied GTID set (MariaDB)
 830                         if ( $this->useGTIDs ) {
 831                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_slave_pos'", __METHOD__ );
 832                                 $gtidRow = $this->fetchObject( $res );
 833                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 834                         } else {
 835                                 $gtidSet = '';
 836                         }
 837
 838                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos, $gtidSet );
 839                 } else {
 840                         return false;
 841                 }
 842         }
 843
 844         /**
 845          * Get the position of the master from SHOW MASTER STATUS
 846          *
 847          * @return MySQLMasterPos|bool
 848          */
 849         function getMasterPos() {
 850                 $res = $this->query( 'SHOW MASTER STATUS', __METHOD__ );
 851                 $row = $this->fetchObject( $res );
 852
 853                 if ( $row ) {
 854                         // Also fetch the last-written GTID set (MariaDB)
 855                         if ( $this->useGTIDs ) {
 856                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_binlog_pos'", __METHOD__ );
 857                                 $gtidRow = $this->fetchObject( $res );
 858                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 859                         } else {
 860                                 $gtidSet = '';
 861                         }
 862
 863                         return new MySQLMasterPos( $row->File, $row->Position, $gtidSet );
 864                 } else {
 865                         return false;
 866                 }
 867         }
 868
 869         public function serverIsReadOnly() {
 870                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'read_only'", __METHOD__ );
 871                 $row = $this->fetchObject( $res );
 872
 873                 return $row ? ( strtolower( $row->Value ) === 'on' ) : false;
 874         }
 875
 876         /**
 877          * @param string $index
 878          * @return string
 879          */
 880         function useIndexClause( $index ) {
 881                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 882         }
 883
 884         /**
 885          * @param string $index
 886          * @return string
 887          */
 888         function ignoreIndexClause( $index ) {
 889                 return "IGNORE INDEX (" . $this->indexName( $index ) . ")";
 890         }
 891
 892         /**
 893          * @return string
 894          */
 895         function lowPriorityOption() {
 896                 return 'LOW_PRIORITY';
 897         }
 898
 899         /**
 900          * @return string
 901          */
 902         public function getSoftwareLink() {
 903                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 904                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 905                 // in libmysql/libmysql.c).
 906                 $version = $this->getServerVersion();
 907                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 908                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 909                 }
 910
 911                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 912                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 913                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 914                 return '[{{int:version-db-mysql-url}} MySQL]';
 915         }
 916
 917         /**
 918          * @return string
 919          */
 920         public function getServerVersion() {
 921                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 922                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 923                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 924                 if ( $this->serverVersion === null ) {
 925                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 926                 }
 927                 return $this->serverVersion;
 928         }
 929
 930         /**
 931          * @param array $options
 932          */
 933         public function setSessionOptions( array $options ) {
 934                 if ( isset( $options['connTimeout'] ) ) {
 935                         $timeout = (int)$options['connTimeout'];
 936                         $this->query( "SET net_read_timeout=$timeout" );
 937                         $this->query( "SET net_write_timeout=$timeout" );
 938                 }
 939         }
 940
 941         /**
 942          * @param string $sql
 943          * @param string $newLine
 944          * @return bool
 945          */
 946         public function streamStatementEnd( &$sql, &$newLine ) {
 947                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 948                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 949                         $this->delimiter = $m[1];
 950                         $newLine = '';
 951                 }
 952
 953                 return parent::streamStatementEnd( $sql, $newLine );
 954         }
 955
 956         /**
 957          * Check to see if a named lock is available. This is non-blocking.
 958          *
 959          * @param string $lockName Name of lock to poll
 960          * @param string $method Name of method calling us
 961          * @return bool
 962          * @since 1.20
 963          */
 964         public function lockIsFree( $lockName, $method ) {
 965                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
 966                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 967                 $row = $this->fetchObject( $result );
 968
 969                 return ( $row->lockstatus == 1 );
 970         }
 971
 972         /**
 973          * @param string $lockName
 974          * @param string $method
 975          * @param int $timeout
 976          * @return bool
 977          */
 978         public function lock( $lockName, $method, $timeout = 5 ) {
 979                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
 980                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 981                 $row = $this->fetchObject( $result );
 982
 983                 if ( $row->lockstatus == 1 ) {
 984                         parent::lock( $lockName, $method, $timeout ); // record
 985                         return true;
 986                 }
 987
 988                 $this->queryLogger->debug( __METHOD__ . " failed to acquire lock\n" );
 989
 990                 return false;
 991         }
 992
 993         /**
 994          * FROM MYSQL DOCS:
 995          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 996          * @param string $lockName
 997          * @param string $method
 998          * @return bool
 999          */
1000         public function unlock( $lockName, $method ) {
1001                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
1002                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
1003                 $row = $this->fetchObject( $result );
1004
1005                 if ( $row->lockstatus == 1 ) {
1006                         parent::unlock( $lockName, $method ); // record
1007                         return true;
1008                 }
1009
1010                 $this->queryLogger->debug( __METHOD__ . " failed to release lock\n" );
1011
1012                 return false;
1013         }
1014
1015         private function makeLockName( $lockName ) {
1016                 // http://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1017                 // Newer version enforce a 64 char length limit.
1018                 return ( strlen( $lockName ) > 64 ) ? sha1( $lockName ) : $lockName;
1019         }
1020
1021         public function namedLocksEnqueue() {
1022                 return true;
1023         }
1024
1025         /**
1026          * @param array $read
1027          * @param array $write
1028          * @param string $method
1029          * @param bool $lowPriority
1030          * @return bool
1031          */
1032         public function lockTables( $read, $write, $method, $lowPriority = true ) {
1033                 $items = [];
1034
1035                 foreach ( $write as $table ) {
1036                         $tbl = $this->tableName( $table ) .
1037                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
1038                                 ' WRITE';
1039                         $items[] = $tbl;
1040                 }
1041                 foreach ( $read as $table ) {
1042                         $items[] = $this->tableName( $table ) . ' READ';
1043                 }
1044                 $sql = "LOCK TABLES " . implode( ',', $items );
1045                 $this->query( $sql, $method );
1046
1047                 return true;
1048         }
1049
1050         /**
1051          * @param string $method
1052          * @return bool
1053          */
1054         public function unlockTables( $method ) {
1055                 $this->query( "UNLOCK TABLES", $method );
1056
1057                 return true;
1058         }
1059
1060         /**
1061          * @param bool $value
1062          */
1063         public function setBigSelects( $value = true ) {
1064                 if ( $value === 'default' ) {
1065                         if ( $this->mDefaultBigSelects === null ) {
1066                                 # Function hasn't been called before so it must already be set to the default
1067                                 return;
1068                         } else {
1069                                 $value = $this->mDefaultBigSelects;
1070                         }
1071                 } elseif ( $this->mDefaultBigSelects === null ) {
1072                         $this->mDefaultBigSelects =
1073                                 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__ );
1074                 }
1075                 $encValue = $value ? '1' : '0';
1076                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
1077         }
1078
1079         /**
1080          * DELETE where the condition is a join. MySql uses multi-table deletes.
1081          * @param string $delTable
1082          * @param string $joinTable
1083          * @param string $delVar
1084          * @param string $joinVar
1085          * @param array|string $conds
1086          * @param bool|string $fname
1087          * @throws DBUnexpectedError
1088          * @return bool|ResultWrapper
1089          */
1090         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
1091                 if ( !$conds ) {
1092                         throw new DBUnexpectedError( $this, __METHOD__ . ' called with empty $conds' );
1093                 }
1094
1095                 $delTable = $this->tableName( $delTable );
1096                 $joinTable = $this->tableName( $joinTable );
1097                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1098
1099                 if ( $conds != '*' ) {
1100                         $sql .= ' AND ' . $this->makeList( $conds, self::LIST_AND );
1101                 }
1102
1103                 return $this->query( $sql, $fname );
1104         }
1105
1106         /**
1107          * @param string $table
1108          * @param array $rows
1109          * @param array $uniqueIndexes
1110          * @param array $set
1111          * @param string $fname
1112          * @return bool
1113          */
1114         public function upsert( $table, array $rows, array $uniqueIndexes,
1115                 array $set, $fname = __METHOD__
1116         ) {
1117                 if ( !count( $rows ) ) {
1118                         return true; // nothing to do
1119                 }
1120
1121                 if ( !is_array( reset( $rows ) ) ) {
1122                         $rows = [ $rows ];
1123                 }
1124
1125                 $table = $this->tableName( $table );
1126                 $columns = array_keys( $rows[0] );
1127
1128                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1129                 $rowTuples = [];
1130                 foreach ( $rows as $row ) {
1131                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1132                 }
1133                 $sql .= implode( ',', $rowTuples );
1134                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, self::LIST_SET );
1135
1136                 return (bool)$this->query( $sql, $fname );
1137         }
1138
1139         /**
1140          * Determines how long the server has been up
1141          *
1142          * @return int
1143          */
1144         function getServerUptime() {
1145                 $vars = $this->getMysqlStatus( 'Uptime' );
1146
1147                 return (int)$vars['Uptime'];
1148         }
1149
1150         /**
1151          * Determines if the last failure was due to a deadlock
1152          *
1153          * @return bool
1154          */
1155         function wasDeadlock() {
1156                 return $this->lastErrno() == 1213;
1157         }
1158
1159         /**
1160          * Determines if the last failure was due to a lock timeout
1161          *
1162          * @return bool
1163          */
1164         function wasLockTimeout() {
1165                 return $this->lastErrno() == 1205;
1166         }
1167
1168         function wasErrorReissuable() {
1169                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1170         }
1171
1172         /**
1173          * Determines if the last failure was due to the database being read-only.
1174          *
1175          * @return bool
1176          */
1177         function wasReadOnlyError() {
1178                 return $this->lastErrno() == 1223 ||
1179                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1180         }
1181
1182         function wasConnectionError( $errno ) {
1183                 return $errno == 2013 || $errno == 2006;
1184         }
1185
1186         /**
1187          * Get the underlying binding handle, mConn
1188          *
1189          * Makes sure that mConn is set (disconnects and ping() failure can unset it).
1190          * This catches broken callers than catch and ignore disconnection exceptions.
1191          * Unlike checking isOpen(), this is safe to call inside of open().
1192          *
1193          * @return resource|object
1194          * @throws DBUnexpectedError
1195          * @since 1.26
1196          */
1197         protected function getBindingHandle() {
1198                 if ( !$this->mConn ) {
1199                         throw new DBUnexpectedError(
1200                                 $this,
1201                                 'DB connection was already closed or the connection dropped.'
1202                         );
1203                 }
1204
1205                 return $this->mConn;
1206         }
1207
1208         /**
1209          * @param string $oldName
1210          * @param string $newName
1211          * @param bool $temporary
1212          * @param string $fname
1213          * @return bool
1214          */
1215         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1216                 $tmp = $temporary ? 'TEMPORARY ' : '';
1217                 $newName = $this->addIdentifierQuotes( $newName );
1218                 $oldName = $this->addIdentifierQuotes( $oldName );
1219                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1220
1221                 return $this->query( $query, $fname );
1222         }
1223
1224         /**
1225          * List all tables on the database
1226          *
1227          * @param string $prefix Only show tables with this prefix, e.g. mw_
1228          * @param string $fname Calling function name
1229          * @return array
1230          */
1231         function listTables( $prefix = null, $fname = __METHOD__ ) {
1232                 $result = $this->query( "SHOW TABLES", $fname );
1233
1234                 $endArray = [];
1235
1236                 foreach ( $result as $table ) {
1237                         $vars = get_object_vars( $table );
1238                         $table = array_pop( $vars );
1239
1240                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1241                                 $endArray[] = $table;
1242                         }
1243                 }
1244
1245                 return $endArray;
1246         }
1247
1248         /**
1249          * @param string $tableName
1250          * @param string $fName
1251          * @return bool|ResultWrapper
1252          */
1253         public function dropTable( $tableName, $fName = __METHOD__ ) {
1254                 if ( !$this->tableExists( $tableName, $fName ) ) {
1255                         return false;
1256                 }
1257
1258                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1259         }
1260
1261         /**
1262          * @return array
1263          */
1264         protected function getDefaultSchemaVars() {
1265                 $vars = parent::getDefaultSchemaVars();
1266                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1267                 $vars['wgDBTableOptions'] = str_replace(
1268                         'CHARSET=mysql4',
1269                         'CHARSET=binary',
1270                         $vars['wgDBTableOptions']
1271                 );
1272
1273                 return $vars;
1274         }
1275
1276         /**
1277          * Get status information from SHOW STATUS in an associative array
1278          *
1279          * @param string $which
1280          * @return array
1281          */
1282         function getMysqlStatus( $which = "%" ) {
1283                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1284                 $status = [];
1285
1286                 foreach ( $res as $row ) {
1287                         $status[$row->Variable_name] = $row->Value;
1288                 }
1289
1290                 return $status;
1291         }
1292
1293         /**
1294          * Lists VIEWs in the database
1295          *
1296          * @param string $prefix Only show VIEWs with this prefix, eg.
1297          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1298          * @param string $fname Name of calling function
1299          * @return array
1300          * @since 1.22
1301          */
1302         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1303
1304                 if ( !isset( $this->allViews ) ) {
1305
1306                         // The name of the column containing the name of the VIEW
1307                         $propertyName = 'Tables_in_' . $this->mDBname;
1308
1309                         // Query for the VIEWS
1310                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1311                         $this->allViews = [];
1312                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1313                                 array_push( $this->allViews, $row[$propertyName] );
1314                         }
1315                 }
1316
1317                 if ( is_null( $prefix ) || $prefix === '' ) {
1318                         return $this->allViews;
1319                 }
1320
1321                 $filteredViews = [];
1322                 foreach ( $this->allViews as $viewName ) {
1323                         // Does the name of this VIEW start with the table-prefix?
1324                         if ( strpos( $viewName, $prefix ) === 0 ) {
1325                                 array_push( $filteredViews, $viewName );
1326                         }
1327                 }
1328
1329                 return $filteredViews;
1330         }
1331
1332         /**
1333          * Differentiates between a TABLE and a VIEW.
1334          *
1335          * @param string $name Name of the TABLE/VIEW to test
1336          * @param string $prefix
1337          * @return bool
1338          * @since 1.22
1339          */
1340         public function isView( $name, $prefix = null ) {
1341                 return in_array( $name, $this->listViews( $prefix ) );
1342         }
1343 }
1344