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         function tableExists( $table, $fname = __METHOD__ ) {
 522                 $table = $this->tableName( $table, 'raw' );
 523                 $encLike = $this->buildLike( $table );
 524
 525                 return $this->query( "SHOW TABLES $encLike", $fname )->numRows() > 0;
 526         }
 527
 528         /**
 529          * @param string $table
 530          * @param string $field
 531          * @return bool|MySQLField
 532          */
 533         function fieldInfo( $table, $field ) {
 534                 $table = $this->tableName( $table );
 535                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 536                 if ( !$res ) {
 537                         return false;
 538                 }
 539                 $n = $this->mysqlNumFields( $res->result );
 540                 for ( $i = 0; $i < $n; $i++ ) {
 541                         $meta = $this->mysqlFetchField( $res->result, $i );
 542                         if ( $field == $meta->name ) {
 543                                 return new MySQLField( $meta );
 544                         }
 545                 }
 546
 547                 return false;
 548         }
 549
 550         /**
 551          * Get column information from a result
 552          *
 553          * @param resource $res Raw result
 554          * @param int $n
 555          * @return stdClass
 556          */
 557         abstract protected function mysqlFetchField( $res, $n );
 558
 559         /**
 560          * Get information about an index into an object
 561          * Returns false if the index does not exist
 562          *
 563          * @param string $table
 564          * @param string $index
 565          * @param string $fname
 566          * @return bool|array|null False or null on failure
 567          */
 568         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 569                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 570                 # SHOW INDEX should work for 3.x and up:
 571                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 572                 $table = $this->tableName( $table );
 573                 $index = $this->indexName( $index );
 574
 575                 $sql = 'SHOW INDEX FROM ' . $table;
 576                 $res = $this->query( $sql, $fname );
 577
 578                 if ( !$res ) {
 579                         return null;
 580                 }
 581
 582                 $result = [];
 583
 584                 foreach ( $res as $row ) {
 585                         if ( $row->Key_name == $index ) {
 586                                 $result[] = $row;
 587                         }
 588                 }
 589
 590                 return empty( $result ) ? false : $result;
 591         }
 592
 593         /**
 594          * @param string $s
 595          * @return string
 596          */
 597         function strencode( $s ) {
 598                 return $this->mysqlRealEscapeString( $s );
 599         }
 600
 601         /**
 602          * @param string $s
 603          * @return mixed
 604          */
 605         abstract protected function mysqlRealEscapeString( $s );
 606
 607         /**
 608          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 609          *
 610          * @param string $s
 611          * @return string
 612          */
 613         public function addIdentifierQuotes( $s ) {
 614                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 615                 // Remove NUL bytes and escape backticks by doubling
 616                 return '`' . str_replace( [ "\0", '`' ], [ '', '``' ], $s ) . '`';
 617         }
 618
 619         /**
 620          * @param string $name
 621          * @return bool
 622          */
 623         public function isQuotedIdentifier( $name ) {
 624                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 625         }
 626
 627         function getLag() {
 628                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 629                         return $this->getLagFromPtHeartbeat();
 630                 } else {
 631                         return $this->getLagFromSlaveStatus();
 632                 }
 633         }
 634
 635         /**
 636          * @return string
 637          */
 638         protected function getLagDetectionMethod() {
 639                 return $this->lagDetectionMethod;
 640         }
 641
 642         /**
 643          * @return bool|int
 644          */
 645         protected function getLagFromSlaveStatus() {
 646                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 647                 $row = $res ? $res->fetchObject() : false;
 648                 if ( $row && strval( $row->Seconds_Behind_Master ) !== '' ) {
 649                         return intval( $row->Seconds_Behind_Master );
 650                 }
 651
 652                 return false;
 653         }
 654
 655         /**
 656          * @return bool|float
 657          */
 658         protected function getLagFromPtHeartbeat() {
 659                 $options = $this->lagDetectionOptions;
 660
 661                 if ( isset( $options['conds'] ) ) {
 662                         // Best method for multi-DC setups: use logical channel names
 663                         $data = $this->getHeartbeatData( $options['conds'] );
 664                 } else {
 665                         // Standard method: use master server ID (works with stock pt-heartbeat)
 666                         $masterInfo = $this->getMasterServerInfo();
 667                         if ( !$masterInfo ) {
 668                                 $this->queryLogger->error(
 669                                         "Unable to query master of {db_server} for server ID",
 670                                         $this->getLogContext( [
 671                                                 'method' => __METHOD__
 672                                         ] )
 673                                 );
 674
 675                                 return false; // could not get master server ID
 676                         }
 677
 678                         $conds = [ 'server_id' => intval( $masterInfo['serverId'] ) ];
 679                         $data = $this->getHeartbeatData( $conds );
 680                 }
 681
 682                 list( $time, $nowUnix ) = $data;
 683                 if ( $time !== null ) {
 684                         // @time is in ISO format like "2015-09-25T16:48:10.000510"
 685                         $dateTime = new DateTime( $time, new DateTimeZone( 'UTC' ) );
 686                         $timeUnix = (int)$dateTime->format( 'U' ) + $dateTime->format( 'u' ) / 1e6;
 687
 688                         return max( $nowUnix - $timeUnix, 0.0 );
 689                 }
 690
 691                 $this->queryLogger->error(
 692                         "Unable to find pt-heartbeat row for {db_server}",
 693                         $this->getLogContext( [
 694                                 'method' => __METHOD__
 695                         ] )
 696                 );
 697
 698                 return false;
 699         }
 700
 701         protected function getMasterServerInfo() {
 702                 $cache = $this->srvCache;
 703                 $key = $cache->makeGlobalKey(
 704                         'mysql',
 705                         'master-info',
 706                         // Using one key for all cluster replica DBs is preferable
 707                         $this->getLBInfo( 'clusterMasterHost' ) ?: $this->getServer()
 708                 );
 709
 710                 return $cache->getWithSetCallback(
 711                         $key,
 712                         $cache::TTL_INDEFINITE,
 713                         function () use ( $cache, $key ) {
 714                                 // Get and leave a lock key in place for a short period
 715                                 if ( !$cache->lock( $key, 0, 10 ) ) {
 716                                         return false; // avoid master connection spike slams
 717                                 }
 718
 719                                 $conn = $this->getLazyMasterHandle();
 720                                 if ( !$conn ) {
 721                                         return false; // something is misconfigured
 722                                 }
 723
 724                                 // Connect to and query the master; catch errors to avoid outages
 725                                 try {
 726                                         $res = $conn->query( 'SELECT @@server_id AS id', __METHOD__ );
 727                                         $row = $res ? $res->fetchObject() : false;
 728                                         $id = $row ? (int)$row->id : 0;
 729                                 } catch ( DBError $e ) {
 730                                         $id = 0;
 731                                 }
 732
 733                                 // Cache the ID if it was retrieved
 734                                 return $id ? [ 'serverId' => $id, 'asOf' => time() ] : false;
 735                         }
 736                 );
 737         }
 738
 739         /**
 740          * @param array $conds WHERE clause conditions to find a row
 741          * @return array (heartbeat `ts` column value or null, UNIX timestamp) for the newest beat
 742          * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
 743          */
 744         protected function getHeartbeatData( array $conds ) {
 745                 $whereSQL = $this->makeList( $conds, self::LIST_AND );
 746                 // Use ORDER BY for channel based queries since that field might not be UNIQUE.
 747                 // Note: this would use "TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6))" but the
 748                 // percision field is not supported in MySQL <= 5.5.
 749                 $res = $this->query(
 750                         "SELECT ts FROM heartbeat.heartbeat WHERE $whereSQL ORDER BY ts DESC LIMIT 1"
 751                 );
 752                 $row = $res ? $res->fetchObject() : false;
 753
 754                 return [ $row ? $row->ts : null, microtime( true ) ];
 755         }
 756
 757         public function getApproximateLagStatus() {
 758                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 759                         // Disable caching since this is fast enough and we don't wan't
 760                         // to be *too* pessimistic by having both the cache TTL and the
 761                         // pt-heartbeat interval count as lag in getSessionLagStatus()
 762                         return parent::getApproximateLagStatus();
 763                 }
 764
 765                 $key = $this->srvCache->makeGlobalKey( 'mysql-lag', $this->getServer() );
 766                 $approxLag = $this->srvCache->get( $key );
 767                 if ( !$approxLag ) {
 768                         $approxLag = parent::getApproximateLagStatus();
 769                         $this->srvCache->set( $key, $approxLag, 1 );
 770                 }
 771
 772                 return $approxLag;
 773         }
 774
 775         function masterPosWait( DBMasterPos $pos, $timeout ) {
 776                 if ( !( $pos instanceof MySQLMasterPos ) ) {
 777                         throw new InvalidArgumentException( "Position not an instance of MySQLMasterPos" );
 778                 }
 779
 780                 if ( $this->getLBInfo( 'is static' ) === true ) {
 781                         return 0; // this is a copy of a read-only dataset with no master DB
 782                 } elseif ( $this->lastKnownReplicaPos && $this->lastKnownReplicaPos->hasReached( $pos ) ) {
 783                         return 0; // already reached this point for sure
 784                 }
 785
 786                 // Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 787                 if ( $this->useGTIDs && $pos->gtids ) {
 788                         // Wait on the GTID set (MariaDB only)
 789                         $gtidArg = $this->addQuotes( implode( ',', $pos->gtids ) );
 790                         $res = $this->doQuery( "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)" );
 791                 } else {
 792                         // Wait on the binlog coordinates
 793                         $encFile = $this->addQuotes( $pos->file );
 794                         $encPos = intval( $pos->pos );
 795                         $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
 796                 }
 797
 798                 $row = $res ? $this->fetchRow( $res ) : false;
 799                 if ( !$row ) {
 800                         throw new DBExpectedError( $this, "Failed to query MASTER_POS_WAIT()" );
 801                 }
 802
 803                 // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
 804                 $status = ( $row[0] !== null ) ? intval( $row[0] ) : null;
 805                 if ( $status === null ) {
 806                         // T126436: jobs programmed to wait on master positions might be referencing binlogs
 807                         // with an old master hostname. Such calls make MASTER_POS_WAIT() return null. Try
 808                         // to detect this and treat the replica DB as having reached the position; a proper master
 809                         // switchover already requires that the new master be caught up before the switch.
 810                         $replicationPos = $this->getSlavePos();
 811                         if ( $replicationPos && !$replicationPos->channelsMatch( $pos ) ) {
 812                                 $this->lastKnownReplicaPos = $replicationPos;
 813                                 $status = 0;
 814                         }
 815                 } elseif ( $status >= 0 ) {
 816                         // Remember that this position was reached to save queries next time
 817                         $this->lastKnownReplicaPos = $pos;
 818                 }
 819
 820                 return $status;
 821         }
 822
 823         /**
 824          * Get the position of the master from SHOW SLAVE STATUS
 825          *
 826          * @return MySQLMasterPos|bool
 827          */
 828         function getSlavePos() {
 829                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 830                 $row = $this->fetchObject( $res );
 831
 832                 if ( $row ) {
 833                         $pos = isset( $row->Exec_master_log_pos )
 834                                 ? $row->Exec_master_log_pos
 835                                 : $row->Exec_Master_Log_Pos;
 836                         // Also fetch the last-applied GTID set (MariaDB)
 837                         if ( $this->useGTIDs ) {
 838                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_slave_pos'", __METHOD__ );
 839                                 $gtidRow = $this->fetchObject( $res );
 840                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 841                         } else {
 842                                 $gtidSet = '';
 843                         }
 844
 845                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos, $gtidSet );
 846                 } else {
 847                         return false;
 848                 }
 849         }
 850
 851         /**
 852          * Get the position of the master from SHOW MASTER STATUS
 853          *
 854          * @return MySQLMasterPos|bool
 855          */
 856         function getMasterPos() {
 857                 $res = $this->query( 'SHOW MASTER STATUS', __METHOD__ );
 858                 $row = $this->fetchObject( $res );
 859
 860                 if ( $row ) {
 861                         // Also fetch the last-written GTID set (MariaDB)
 862                         if ( $this->useGTIDs ) {
 863                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_binlog_pos'", __METHOD__ );
 864                                 $gtidRow = $this->fetchObject( $res );
 865                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 866                         } else {
 867                                 $gtidSet = '';
 868                         }
 869
 870                         return new MySQLMasterPos( $row->File, $row->Position, $gtidSet );
 871                 } else {
 872                         return false;
 873                 }
 874         }
 875
 876         public function serverIsReadOnly() {
 877                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'read_only'", __METHOD__ );
 878                 $row = $this->fetchObject( $res );
 879
 880                 return $row ? ( strtolower( $row->Value ) === 'on' ) : false;
 881         }
 882
 883         /**
 884          * @param string $index
 885          * @return string
 886          */
 887         function useIndexClause( $index ) {
 888                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 889         }
 890
 891         /**
 892          * @param string $index
 893          * @return string
 894          */
 895         function ignoreIndexClause( $index ) {
 896                 return "IGNORE INDEX (" . $this->indexName( $index ) . ")";
 897         }
 898
 899         /**
 900          * @return string
 901          */
 902         function lowPriorityOption() {
 903                 return 'LOW_PRIORITY';
 904         }
 905
 906         /**
 907          * @return string
 908          */
 909         public function getSoftwareLink() {
 910                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 911                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 912                 // in libmysql/libmysql.c).
 913                 $version = $this->getServerVersion();
 914                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 915                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 916                 }
 917
 918                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 919                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 920                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 921                 return '[{{int:version-db-mysql-url}} MySQL]';
 922         }
 923
 924         /**
 925          * @return string
 926          */
 927         public function getServerVersion() {
 928                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 929                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 930                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 931                 if ( $this->serverVersion === null ) {
 932                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 933                 }
 934                 return $this->serverVersion;
 935         }
 936
 937         /**
 938          * @param array $options
 939          */
 940         public function setSessionOptions( array $options ) {
 941                 if ( isset( $options['connTimeout'] ) ) {
 942                         $timeout = (int)$options['connTimeout'];
 943                         $this->query( "SET net_read_timeout=$timeout" );
 944                         $this->query( "SET net_write_timeout=$timeout" );
 945                 }
 946         }
 947
 948         /**
 949          * @param string $sql
 950          * @param string $newLine
 951          * @return bool
 952          */
 953         public function streamStatementEnd( &$sql, &$newLine ) {
 954                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 955                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 956                         $this->delimiter = $m[1];
 957                         $newLine = '';
 958                 }
 959
 960                 return parent::streamStatementEnd( $sql, $newLine );
 961         }
 962
 963         /**
 964          * Check to see if a named lock is available. This is non-blocking.
 965          *
 966          * @param string $lockName Name of lock to poll
 967          * @param string $method Name of method calling us
 968          * @return bool
 969          * @since 1.20
 970          */
 971         public function lockIsFree( $lockName, $method ) {
 972                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
 973                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 974                 $row = $this->fetchObject( $result );
 975
 976                 return ( $row->lockstatus == 1 );
 977         }
 978
 979         /**
 980          * @param string $lockName
 981          * @param string $method
 982          * @param int $timeout
 983          * @return bool
 984          */
 985         public function lock( $lockName, $method, $timeout = 5 ) {
 986                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
 987                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 988                 $row = $this->fetchObject( $result );
 989
 990                 if ( $row->lockstatus == 1 ) {
 991                         parent::lock( $lockName, $method, $timeout ); // record
 992                         return true;
 993                 }
 994
 995                 $this->queryLogger->warning( __METHOD__ . " failed to acquire lock '$lockName'\n" );
 996
 997                 return false;
 998         }
 999
1000         /**
1001          * FROM MYSQL DOCS:
1002          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
1003          * @param string $lockName
1004          * @param string $method
1005          * @return bool
1006          */
1007         public function unlock( $lockName, $method ) {
1008                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
1009                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
1010                 $row = $this->fetchObject( $result );
1011
1012                 if ( $row->lockstatus == 1 ) {
1013                         parent::unlock( $lockName, $method ); // record
1014                         return true;
1015                 }
1016
1017                 $this->queryLogger->warning( __METHOD__ . " failed to release lock '$lockName'\n" );
1018
1019                 return false;
1020         }
1021
1022         private function makeLockName( $lockName ) {
1023                 // http://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1024                 // Newer version enforce a 64 char length limit.
1025                 return ( strlen( $lockName ) > 64 ) ? sha1( $lockName ) : $lockName;
1026         }
1027
1028         public function namedLocksEnqueue() {
1029                 return true;
1030         }
1031
1032         /**
1033          * @param array $read
1034          * @param array $write
1035          * @param string $method
1036          * @param bool $lowPriority
1037          * @return bool
1038          */
1039         public function lockTables( $read, $write, $method, $lowPriority = true ) {
1040                 $items = [];
1041
1042                 foreach ( $write as $table ) {
1043                         $tbl = $this->tableName( $table ) .
1044                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
1045                                 ' WRITE';
1046                         $items[] = $tbl;
1047                 }
1048                 foreach ( $read as $table ) {
1049                         $items[] = $this->tableName( $table ) . ' READ';
1050                 }
1051                 $sql = "LOCK TABLES " . implode( ',', $items );
1052                 $this->query( $sql, $method );
1053
1054                 return true;
1055         }
1056
1057         /**
1058          * @param string $method
1059          * @return bool
1060          */
1061         public function unlockTables( $method ) {
1062                 $this->query( "UNLOCK TABLES", $method );
1063
1064                 return true;
1065         }
1066
1067         /**
1068          * @param bool $value
1069          */
1070         public function setBigSelects( $value = true ) {
1071                 if ( $value === 'default' ) {
1072                         if ( $this->mDefaultBigSelects === null ) {
1073                                 # Function hasn't been called before so it must already be set to the default
1074                                 return;
1075                         } else {
1076                                 $value = $this->mDefaultBigSelects;
1077                         }
1078                 } elseif ( $this->mDefaultBigSelects === null ) {
1079                         $this->mDefaultBigSelects =
1080                                 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__ );
1081                 }
1082                 $encValue = $value ? '1' : '0';
1083                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
1084         }
1085
1086         /**
1087          * DELETE where the condition is a join. MySql uses multi-table deletes.
1088          * @param string $delTable
1089          * @param string $joinTable
1090          * @param string $delVar
1091          * @param string $joinVar
1092          * @param array|string $conds
1093          * @param bool|string $fname
1094          * @throws DBUnexpectedError
1095          * @return bool|ResultWrapper
1096          */
1097         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
1098                 if ( !$conds ) {
1099                         throw new DBUnexpectedError( $this, __METHOD__ . ' called with empty $conds' );
1100                 }
1101
1102                 $delTable = $this->tableName( $delTable );
1103                 $joinTable = $this->tableName( $joinTable );
1104                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1105
1106                 if ( $conds != '*' ) {
1107                         $sql .= ' AND ' . $this->makeList( $conds, self::LIST_AND );
1108                 }
1109
1110                 return $this->query( $sql, $fname );
1111         }
1112
1113         /**
1114          * @param string $table
1115          * @param array $rows
1116          * @param array $uniqueIndexes
1117          * @param array $set
1118          * @param string $fname
1119          * @return bool
1120          */
1121         public function upsert( $table, array $rows, array $uniqueIndexes,
1122                 array $set, $fname = __METHOD__
1123         ) {
1124                 if ( !count( $rows ) ) {
1125                         return true; // nothing to do
1126                 }
1127
1128                 if ( !is_array( reset( $rows ) ) ) {
1129                         $rows = [ $rows ];
1130                 }
1131
1132                 $table = $this->tableName( $table );
1133                 $columns = array_keys( $rows[0] );
1134
1135                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1136                 $rowTuples = [];
1137                 foreach ( $rows as $row ) {
1138                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1139                 }
1140                 $sql .= implode( ',', $rowTuples );
1141                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, self::LIST_SET );
1142
1143                 return (bool)$this->query( $sql, $fname );
1144         }
1145
1146         /**
1147          * Determines how long the server has been up
1148          *
1149          * @return int
1150          */
1151         function getServerUptime() {
1152                 $vars = $this->getMysqlStatus( 'Uptime' );
1153
1154                 return (int)$vars['Uptime'];
1155         }
1156
1157         /**
1158          * Determines if the last failure was due to a deadlock
1159          *
1160          * @return bool
1161          */
1162         function wasDeadlock() {
1163                 return $this->lastErrno() == 1213;
1164         }
1165
1166         /**
1167          * Determines if the last failure was due to a lock timeout
1168          *
1169          * @return bool
1170          */
1171         function wasLockTimeout() {
1172                 return $this->lastErrno() == 1205;
1173         }
1174
1175         function wasErrorReissuable() {
1176                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1177         }
1178
1179         /**
1180          * Determines if the last failure was due to the database being read-only.
1181          *
1182          * @return bool
1183          */
1184         function wasReadOnlyError() {
1185                 return $this->lastErrno() == 1223 ||
1186                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1187         }
1188
1189         function wasConnectionError( $errno ) {
1190                 return $errno == 2013 || $errno == 2006;
1191         }
1192
1193         /**
1194          * Get the underlying binding handle, mConn
1195          *
1196          * Makes sure that mConn is set (disconnects and ping() failure can unset it).
1197          * This catches broken callers than catch and ignore disconnection exceptions.
1198          * Unlike checking isOpen(), this is safe to call inside of open().
1199          *
1200          * @return resource|object
1201          * @throws DBUnexpectedError
1202          * @since 1.26
1203          */
1204         protected function getBindingHandle() {
1205                 if ( !$this->mConn ) {
1206                         throw new DBUnexpectedError(
1207                                 $this,
1208                                 'DB connection was already closed or the connection dropped.'
1209                         );
1210                 }
1211
1212                 return $this->mConn;
1213         }
1214
1215         /**
1216          * @param string $oldName
1217          * @param string $newName
1218          * @param bool $temporary
1219          * @param string $fname
1220          * @return bool
1221          */
1222         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1223                 $tmp = $temporary ? 'TEMPORARY ' : '';
1224                 $newName = $this->addIdentifierQuotes( $newName );
1225                 $oldName = $this->addIdentifierQuotes( $oldName );
1226                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1227
1228                 return $this->query( $query, $fname );
1229         }
1230
1231         /**
1232          * List all tables on the database
1233          *
1234          * @param string $prefix Only show tables with this prefix, e.g. mw_
1235          * @param string $fname Calling function name
1236          * @return array
1237          */
1238         function listTables( $prefix = null, $fname = __METHOD__ ) {
1239                 $result = $this->query( "SHOW TABLES", $fname );
1240
1241                 $endArray = [];
1242
1243                 foreach ( $result as $table ) {
1244                         $vars = get_object_vars( $table );
1245                         $table = array_pop( $vars );
1246
1247                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1248                                 $endArray[] = $table;
1249                         }
1250                 }
1251
1252                 return $endArray;
1253         }
1254
1255         /**
1256          * @param string $tableName
1257          * @param string $fName
1258          * @return bool|ResultWrapper
1259          */
1260         public function dropTable( $tableName, $fName = __METHOD__ ) {
1261                 if ( !$this->tableExists( $tableName, $fName ) ) {
1262                         return false;
1263                 }
1264
1265                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1266         }
1267
1268         /**
1269          * @return array
1270          */
1271         protected function getDefaultSchemaVars() {
1272                 $vars = parent::getDefaultSchemaVars();
1273                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1274                 $vars['wgDBTableOptions'] = str_replace(
1275                         'CHARSET=mysql4',
1276                         'CHARSET=binary',
1277                         $vars['wgDBTableOptions']
1278                 );
1279
1280                 return $vars;
1281         }
1282
1283         /**
1284          * Get status information from SHOW STATUS in an associative array
1285          *
1286          * @param string $which
1287          * @return array
1288          */
1289         function getMysqlStatus( $which = "%" ) {
1290                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1291                 $status = [];
1292
1293                 foreach ( $res as $row ) {
1294                         $status[$row->Variable_name] = $row->Value;
1295                 }
1296
1297                 return $status;
1298         }
1299
1300         /**
1301          * Lists VIEWs in the database
1302          *
1303          * @param string $prefix Only show VIEWs with this prefix, eg.
1304          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1305          * @param string $fname Name of calling function
1306          * @return array
1307          * @since 1.22
1308          */
1309         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1310
1311                 if ( !isset( $this->allViews ) ) {
1312
1313                         // The name of the column containing the name of the VIEW
1314                         $propertyName = 'Tables_in_' . $this->mDBname;
1315
1316                         // Query for the VIEWS
1317                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1318                         $this->allViews = [];
1319                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1320                                 array_push( $this->allViews, $row[$propertyName] );
1321                         }
1322                 }
1323
1324                 if ( is_null( $prefix ) || $prefix === '' ) {
1325                         return $this->allViews;
1326                 }
1327
1328                 $filteredViews = [];
1329                 foreach ( $this->allViews as $viewName ) {
1330                         // Does the name of this VIEW start with the table-prefix?
1331                         if ( strpos( $viewName, $prefix ) === 0 ) {
1332                                 array_push( $filteredViews, $viewName );
1333                         }
1334                 }
1335
1336                 return $filteredViews;
1337         }
1338
1339         /**
1340          * Differentiates between a TABLE and a VIEW.
1341          *
1342          * @param string $name Name of the TABLE/VIEW to test
1343          * @param string $prefix
1344          * @return bool
1345          * @since 1.22
1346          */
1347         public function isView( $name, $prefix = null ) {
1348                 return in_array( $name, $this->listViews( $prefix ) );
1349         }
1350 }
1351