includes/libs/rdbms/database/DatabaseMysqlBase.php

   1 <?php
   2 /**
   3  * This is the MySQL database abstraction layer.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Database
  22  */
  23 use Wikimedia\Rdbms\DBMasterPos;
  24 use Wikimedia\Rdbms\MySQLMasterPos;
  25 use Wikimedia\Rdbms\MySQLField;
  26 use Wikimedia\Rdbms\ResultWrapper;
  27
  28 /**
  29  * Database abstraction object for MySQL.
  30  * Defines methods independent on used MySQL extension.
  31  *
  32  * @ingroup Database
  33  * @since 1.22
  34  * @see Database
  35  */
  36 abstract class DatabaseMysqlBase extends Database {
  37         /** @var MysqlMasterPos */
  38         protected $lastKnownReplicaPos;
  39         /** @var string Method to detect replica DB lag */
  40         protected $lagDetectionMethod;
  41         /** @var array Method to detect replica DB lag */
  42         protected $lagDetectionOptions = [];
  43         /** @var bool bool Whether to use GTID methods */
  44         protected $useGTIDs = false;
  45         /** @var string|null */
  46         protected $sslKeyPath;
  47         /** @var string|null */
  48         protected $sslCertPath;
  49         /** @var string|null */
  50         protected $sslCAPath;
  51         /** @var string[]|null */
  52         protected $sslCiphers;
  53         /** @var string sql_mode value to send on connection */
  54         protected $sqlMode;
  55         /** @var bool Use experimental UTF-8 transmission encoding */
  56         protected $utf8Mode;
  57
  58         /** @var string|null */
  59         private $serverVersion = null;
  60
  61         /**
  62          * Additional $params include:
  63          *   - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
  64          *       pt-heartbeat assumes the table is at heartbeat.heartbeat
  65          *       and uses UTC timestamps in the heartbeat.ts column.
  66          *       (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
  67          *   - lagDetectionOptions : if using pt-heartbeat, this can be set to an array map to change
  68          *       the default behavior. Normally, the heartbeat row with the server
  69          *       ID of this server's master will be used. Set the "conds" field to
  70          *       override the query conditions, e.g. ['shard' => 's1'].
  71          *   - useGTIDs : use GTID methods like MASTER_GTID_WAIT() when possible.
  72          *   - sslKeyPath : path to key file [default: null]
  73          *   - sslCertPath : path to certificate file [default: null]
  74          *   - sslCAPath : parth to certificate authority PEM files [default: null]
  75          *   - sslCiphers : array list of allowable ciphers [default: null]
  76          * @param array $params
  77          */
  78         function __construct( array $params ) {
  79                 $this->lagDetectionMethod = isset( $params['lagDetectionMethod'] )
  80                         ? $params['lagDetectionMethod']
  81                         : 'Seconds_Behind_Master';
  82                 $this->lagDetectionOptions = isset( $params['lagDetectionOptions'] )
  83                         ? $params['lagDetectionOptions']
  84                         : [];
  85                 $this->useGTIDs = !empty( $params['useGTIDs' ] );
  86                 foreach ( [ 'KeyPath', 'CertPath', 'CAPath', 'Ciphers' ] as $name ) {
  87                         $var = "ssl{$name}";
  88                         if ( isset( $params[$var] ) ) {
  89                                 $this->$var = $params[$var];
  90                         }
  91                 }
  92                 $this->sqlMode = isset( $params['sqlMode'] ) ? $params['sqlMode'] : '';
  93                 $this->utf8Mode = !empty( $params['utf8Mode'] );
  94
  95                 parent::__construct( $params );
  96         }
  97
  98         /**
  99          * @return string
 100          */
 101         public function getType() {
 102                 return 'mysql';
 103         }
 104
 105         /**
 106          * @param string $server
 107          * @param string $user
 108          * @param string $password
 109          * @param string $dbName
 110          * @throws Exception|DBConnectionError
 111          * @return bool
 112          */
 113         public function open( $server, $user, $password, $dbName ) {
 114                 # Close/unset connection handle
 115                 $this->close();
 116
 117                 $this->mServer = $server;
 118                 $this->mUser = $user;
 119                 $this->mPassword = $password;
 120                 $this->mDBname = $dbName;
 121
 122                 $this->installErrorHandler();
 123                 try {
 124                         $this->mConn = $this->mysqlConnect( $this->mServer );
 125                 } catch ( Exception $ex ) {
 126                         $this->restoreErrorHandler();
 127                         throw $ex;
 128                 }
 129                 $error = $this->restoreErrorHandler();
 130
 131                 # Always log connection errors
 132                 if ( !$this->mConn ) {
 133                         if ( !$error ) {
 134                                 $error = $this->lastError();
 135                         }
 136                         $this->connLogger->error(
 137                                 "Error connecting to {db_server}: {error}",
 138                                 $this->getLogContext( [
 139                                         'method' => __METHOD__,
 140                                         'error' => $error,
 141                                 ] )
 142                         );
 143                         $this->connLogger->debug( "DB connection error\n" .
 144                                 "Server: $server, User: $user, Password: " .
 145                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 146
 147                         $this->reportConnectionError( $error );
 148                 }
 149
 150                 if ( $dbName != '' ) {
 151                         MediaWiki\suppressWarnings();
 152                         $success = $this->selectDB( $dbName );
 153                         MediaWiki\restoreWarnings();
 154                         if ( !$success ) {
 155                                 $this->queryLogger->error(
 156                                         "Error selecting database {db_name} on server {db_server}",
 157                                         $this->getLogContext( [
 158                                                 'method' => __METHOD__,
 159                                         ] )
 160                                 );
 161                                 $this->queryLogger->debug(
 162                                         "Error selecting database $dbName on server {$this->mServer}" );
 163
 164                                 $this->reportConnectionError( "Error selecting database $dbName" );
 165                         }
 166                 }
 167
 168                 // Tell the server what we're communicating with
 169                 if ( !$this->connectInitCharset() ) {
 170                         $this->reportConnectionError( "Error setting character set" );
 171                 }
 172
 173                 // Abstract over any insane MySQL defaults
 174                 $set = [ 'group_concat_max_len = 262144' ];
 175                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 176                 if ( is_string( $this->sqlMode ) ) {
 177                         $set[] = 'sql_mode = ' . $this->addQuotes( $this->sqlMode );
 178                 }
 179                 // Set any custom settings defined by site config
 180                 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 181                 foreach ( $this->mSessionVars as $var => $val ) {
 182                         // Escape strings but not numbers to avoid MySQL complaining
 183                         if ( !is_int( $val ) && !is_float( $val ) ) {
 184                                 $val = $this->addQuotes( $val );
 185                         }
 186                         $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 187                 }
 188
 189                 if ( $set ) {
 190                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 191                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ) );
 192                         if ( !$success ) {
 193                                 $this->queryLogger->error(
 194                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 195                                         $this->getLogContext( [
 196                                                 'method' => __METHOD__,
 197                                         ] )
 198                                 );
 199                                 $this->reportConnectionError(
 200                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 201                         }
 202                 }
 203
 204                 $this->mOpened = true;
 205
 206                 return true;
 207         }
 208
 209         /**
 210          * Set the character set information right after connection
 211          * @return bool
 212          */
 213         protected function connectInitCharset() {
 214                 if ( $this->utf8Mode ) {
 215                         // Tell the server we're communicating with it in UTF-8.
 216                         // This may engage various charset conversions.
 217                         return $this->mysqlSetCharset( 'utf8' );
 218                 } else {
 219                         return $this->mysqlSetCharset( 'binary' );
 220                 }
 221         }
 222
 223         /**
 224          * Open a connection to a MySQL server
 225          *
 226          * @param string $realServer
 227          * @return mixed Raw connection
 228          * @throws DBConnectionError
 229          */
 230         abstract protected function mysqlConnect( $realServer );
 231
 232         /**
 233          * Set the character set of the MySQL link
 234          *
 235          * @param string $charset
 236          * @return bool
 237          */
 238         abstract protected function mysqlSetCharset( $charset );
 239
 240         /**
 241          * @param ResultWrapper|resource $res
 242          * @throws DBUnexpectedError
 243          */
 244         public function freeResult( $res ) {
 245                 if ( $res instanceof ResultWrapper ) {
 246                         $res = $res->result;
 247                 }
 248                 MediaWiki\suppressWarnings();
 249                 $ok = $this->mysqlFreeResult( $res );
 250                 MediaWiki\restoreWarnings();
 251                 if ( !$ok ) {
 252                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 253                 }
 254         }
 255
 256         /**
 257          * Free result memory
 258          *
 259          * @param resource $res Raw result
 260          * @return bool
 261          */
 262         abstract protected function mysqlFreeResult( $res );
 263
 264         /**
 265          * @param ResultWrapper|resource $res
 266          * @return stdClass|bool
 267          * @throws DBUnexpectedError
 268          */
 269         public function fetchObject( $res ) {
 270                 if ( $res instanceof ResultWrapper ) {
 271                         $res = $res->result;
 272                 }
 273                 MediaWiki\suppressWarnings();
 274                 $row = $this->mysqlFetchObject( $res );
 275                 MediaWiki\restoreWarnings();
 276
 277                 $errno = $this->lastErrno();
 278                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 279                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 280                 // these are the only errors mysql_fetch_object can cause.
 281                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 282                 if ( $errno == 2000 || $errno == 2013 ) {
 283                         throw new DBUnexpectedError(
 284                                 $this,
 285                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 286                         );
 287                 }
 288
 289                 return $row;
 290         }
 291
 292         /**
 293          * Fetch a result row as an object
 294          *
 295          * @param resource $res Raw result
 296          * @return stdClass
 297          */
 298         abstract protected function mysqlFetchObject( $res );
 299
 300         /**
 301          * @param ResultWrapper|resource $res
 302          * @return array|bool
 303          * @throws DBUnexpectedError
 304          */
 305         public function fetchRow( $res ) {
 306                 if ( $res instanceof ResultWrapper ) {
 307                         $res = $res->result;
 308                 }
 309                 MediaWiki\suppressWarnings();
 310                 $row = $this->mysqlFetchArray( $res );
 311                 MediaWiki\restoreWarnings();
 312
 313                 $errno = $this->lastErrno();
 314                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 315                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 316                 // these are the only errors mysql_fetch_array can cause.
 317                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 318                 if ( $errno == 2000 || $errno == 2013 ) {
 319                         throw new DBUnexpectedError(
 320                                 $this,
 321                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 322                         );
 323                 }
 324
 325                 return $row;
 326         }
 327
 328         /**
 329          * Fetch a result row as an associative and numeric array
 330          *
 331          * @param resource $res Raw result
 332          * @return array
 333          */
 334         abstract protected function mysqlFetchArray( $res );
 335
 336         /**
 337          * @throws DBUnexpectedError
 338          * @param ResultWrapper|resource $res
 339          * @return int
 340          */
 341         function numRows( $res ) {
 342                 if ( $res instanceof ResultWrapper ) {
 343                         $res = $res->result;
 344                 }
 345                 MediaWiki\suppressWarnings();
 346                 $n = $this->mysqlNumRows( $res );
 347                 MediaWiki\restoreWarnings();
 348
 349                 // Unfortunately, mysql_num_rows does not reset the last errno.
 350                 // We are not checking for any errors here, since
 351                 // these are no errors mysql_num_rows can cause.
 352                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 353                 // See https://phabricator.wikimedia.org/T44430
 354                 return $n;
 355         }
 356
 357         /**
 358          * Get number of rows in result
 359          *
 360          * @param resource $res Raw result
 361          * @return int
 362          */
 363         abstract protected function mysqlNumRows( $res );
 364
 365         /**
 366          * @param ResultWrapper|resource $res
 367          * @return int
 368          */
 369         public function numFields( $res ) {
 370                 if ( $res instanceof ResultWrapper ) {
 371                         $res = $res->result;
 372                 }
 373
 374                 return $this->mysqlNumFields( $res );
 375         }
 376
 377         /**
 378          * Get number of fields in result
 379          *
 380          * @param resource $res Raw result
 381          * @return int
 382          */
 383         abstract protected function mysqlNumFields( $res );
 384
 385         /**
 386          * @param ResultWrapper|resource $res
 387          * @param int $n
 388          * @return string
 389          */
 390         public function fieldName( $res, $n ) {
 391                 if ( $res instanceof ResultWrapper ) {
 392                         $res = $res->result;
 393                 }
 394
 395                 return $this->mysqlFieldName( $res, $n );
 396         }
 397
 398         /**
 399          * Get the name of the specified field in a result
 400          *
 401          * @param ResultWrapper|resource $res
 402          * @param int $n
 403          * @return string
 404          */
 405         abstract protected function mysqlFieldName( $res, $n );
 406
 407         /**
 408          * mysql_field_type() wrapper
 409          * @param ResultWrapper|resource $res
 410          * @param int $n
 411          * @return string
 412          */
 413         public function fieldType( $res, $n ) {
 414                 if ( $res instanceof ResultWrapper ) {
 415                         $res = $res->result;
 416                 }
 417
 418                 return $this->mysqlFieldType( $res, $n );
 419         }
 420
 421         /**
 422          * Get the type of the specified field in a result
 423          *
 424          * @param ResultWrapper|resource $res
 425          * @param int $n
 426          * @return string
 427          */
 428         abstract protected function mysqlFieldType( $res, $n );
 429
 430         /**
 431          * @param ResultWrapper|resource $res
 432          * @param int $row
 433          * @return bool
 434          */
 435         public function dataSeek( $res, $row ) {
 436                 if ( $res instanceof ResultWrapper ) {
 437                         $res = $res->result;
 438                 }
 439
 440                 return $this->mysqlDataSeek( $res, $row );
 441         }
 442
 443         /**
 444          * Move internal result pointer
 445          *
 446          * @param ResultWrapper|resource $res
 447          * @param int $row
 448          * @return bool
 449          */
 450         abstract protected function mysqlDataSeek( $res, $row );
 451
 452         /**
 453          * @return string
 454          */
 455         public function lastError() {
 456                 if ( $this->mConn ) {
 457                         # Even if it's non-zero, it can still be invalid
 458                         MediaWiki\suppressWarnings();
 459                         $error = $this->mysqlError( $this->mConn );
 460                         if ( !$error ) {
 461                                 $error = $this->mysqlError();
 462                         }
 463                         MediaWiki\restoreWarnings();
 464                 } else {
 465                         $error = $this->mysqlError();
 466                 }
 467                 if ( $error ) {
 468                         $error .= ' (' . $this->mServer . ')';
 469                 }
 470
 471                 return $error;
 472         }
 473
 474         /**
 475          * Returns the text of the error message from previous MySQL operation
 476          *
 477          * @param resource $conn Raw connection
 478          * @return string
 479          */
 480         abstract protected function mysqlError( $conn = null );
 481
 482         /**
 483          * @param string $table
 484          * @param array $uniqueIndexes
 485          * @param array $rows
 486          * @param string $fname
 487          * @return ResultWrapper
 488          */
 489         public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 490                 return $this->nativeReplace( $table, $rows, $fname );
 491         }
 492
 493         /**
 494          * Estimate rows in dataset
 495          * Returns estimated count, based on EXPLAIN output
 496          * Takes same arguments as Database::select()
 497          *
 498          * @param string|array $table
 499          * @param string|array $vars
 500          * @param string|array $conds
 501          * @param string $fname
 502          * @param string|array $options
 503          * @return bool|int
 504          */
 505         public function estimateRowCount( $table, $vars = '*', $conds = '',
 506                 $fname = __METHOD__, $options = []
 507         ) {
 508                 $options['EXPLAIN'] = true;
 509                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 510                 if ( $res === false ) {
 511                         return false;
 512                 }
 513                 if ( !$this->numRows( $res ) ) {
 514                         return 0;
 515                 }
 516
 517                 $rows = 1;
 518                 foreach ( $res as $plan ) {
 519                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 520                 }
 521
 522                 return (int)$rows;
 523         }
 524
 525         public function tableExists( $table, $fname = __METHOD__ ) {
 526                 $table = $this->tableName( $table, 'raw' );
 527                 if ( isset( $this->mSessionTempTables[$table] ) ) {
 528                         return true; // already known to exist and won't show in SHOW TABLES anyway
 529                 }
 530
 531                 $encLike = $this->buildLike( $table );
 532
 533                 return $this->query( "SHOW TABLES $encLike", $fname )->numRows() > 0;
 534         }
 535
 536         /**
 537          * @param string $table
 538          * @param string $field
 539          * @return bool|MySQLField
 540          */
 541         public function fieldInfo( $table, $field ) {
 542                 $table = $this->tableName( $table );
 543                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 544                 if ( !$res ) {
 545                         return false;
 546                 }
 547                 $n = $this->mysqlNumFields( $res->result );
 548                 for ( $i = 0; $i < $n; $i++ ) {
 549                         $meta = $this->mysqlFetchField( $res->result, $i );
 550                         if ( $field == $meta->name ) {
 551                                 return new MySQLField( $meta );
 552                         }
 553                 }
 554
 555                 return false;
 556         }
 557
 558         /**
 559          * Get column information from a result
 560          *
 561          * @param resource $res Raw result
 562          * @param int $n
 563          * @return stdClass
 564          */
 565         abstract protected function mysqlFetchField( $res, $n );
 566
 567         /**
 568          * Get information about an index into an object
 569          * Returns false if the index does not exist
 570          *
 571          * @param string $table
 572          * @param string $index
 573          * @param string $fname
 574          * @return bool|array|null False or null on failure
 575          */
 576         public function indexInfo( $table, $index, $fname = __METHOD__ ) {
 577                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 578                 # SHOW INDEX should work for 3.x and up:
 579                 # https://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 580                 $table = $this->tableName( $table );
 581                 $index = $this->indexName( $index );
 582
 583                 $sql = 'SHOW INDEX FROM ' . $table;
 584                 $res = $this->query( $sql, $fname );
 585
 586                 if ( !$res ) {
 587                         return null;
 588                 }
 589
 590                 $result = [];
 591
 592                 foreach ( $res as $row ) {
 593                         if ( $row->Key_name == $index ) {
 594                                 $result[] = $row;
 595                         }
 596                 }
 597
 598                 return empty( $result ) ? false : $result;
 599         }
 600
 601         /**
 602          * @param string $s
 603          * @return string
 604          */
 605         public function strencode( $s ) {
 606                 return $this->mysqlRealEscapeString( $s );
 607         }
 608
 609         /**
 610          * @param string $s
 611          * @return mixed
 612          */
 613         abstract protected function mysqlRealEscapeString( $s );
 614
 615         public function addQuotes( $s ) {
 616                 if ( is_bool( $s ) ) {
 617                         // Parent would transform to int, which does not play nice with MySQL type juggling.
 618                         // When searching for an int in a string column, the strings are cast to int, which
 619                         // means false would match any string not starting with a number.
 620                         $s = (string)(int)$s;
 621                 }
 622                 return parent::addQuotes( $s );
 623         }
 624
 625         /**
 626          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 627          *
 628          * @param string $s
 629          * @return string
 630          */
 631         public function addIdentifierQuotes( $s ) {
 632                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 633                 // Remove NUL bytes and escape backticks by doubling
 634                 return '`' . str_replace( [ "\0", '`' ], [ '', '``' ], $s ) . '`';
 635         }
 636
 637         /**
 638          * @param string $name
 639          * @return bool
 640          */
 641         public function isQuotedIdentifier( $name ) {
 642                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 643         }
 644
 645         public function getLag() {
 646                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 647                         return $this->getLagFromPtHeartbeat();
 648                 } else {
 649                         return $this->getLagFromSlaveStatus();
 650                 }
 651         }
 652
 653         /**
 654          * @return string
 655          */
 656         protected function getLagDetectionMethod() {
 657                 return $this->lagDetectionMethod;
 658         }
 659
 660         /**
 661          * @return bool|int
 662          */
 663         protected function getLagFromSlaveStatus() {
 664                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 665                 $row = $res ? $res->fetchObject() : false;
 666                 if ( $row && strval( $row->Seconds_Behind_Master ) !== '' ) {
 667                         return intval( $row->Seconds_Behind_Master );
 668                 }
 669
 670                 return false;
 671         }
 672
 673         /**
 674          * @return bool|float
 675          */
 676         protected function getLagFromPtHeartbeat() {
 677                 $options = $this->lagDetectionOptions;
 678
 679                 if ( isset( $options['conds'] ) ) {
 680                         // Best method for multi-DC setups: use logical channel names
 681                         $data = $this->getHeartbeatData( $options['conds'] );
 682                 } else {
 683                         // Standard method: use master server ID (works with stock pt-heartbeat)
 684                         $masterInfo = $this->getMasterServerInfo();
 685                         if ( !$masterInfo ) {
 686                                 $this->queryLogger->error(
 687                                         "Unable to query master of {db_server} for server ID",
 688                                         $this->getLogContext( [
 689                                                 'method' => __METHOD__
 690                                         ] )
 691                                 );
 692
 693                                 return false; // could not get master server ID
 694                         }
 695
 696                         $conds = [ 'server_id' => intval( $masterInfo['serverId'] ) ];
 697                         $data = $this->getHeartbeatData( $conds );
 698                 }
 699
 700                 list( $time, $nowUnix ) = $data;
 701                 if ( $time !== null ) {
 702                         // @time is in ISO format like "2015-09-25T16:48:10.000510"
 703                         $dateTime = new DateTime( $time, new DateTimeZone( 'UTC' ) );
 704                         $timeUnix = (int)$dateTime->format( 'U' ) + $dateTime->format( 'u' ) / 1e6;
 705
 706                         return max( $nowUnix - $timeUnix, 0.0 );
 707                 }
 708
 709                 $this->queryLogger->error(
 710                         "Unable to find pt-heartbeat row for {db_server}",
 711                         $this->getLogContext( [
 712                                 'method' => __METHOD__
 713                         ] )
 714                 );
 715
 716                 return false;
 717         }
 718
 719         protected function getMasterServerInfo() {
 720                 $cache = $this->srvCache;
 721                 $key = $cache->makeGlobalKey(
 722                         'mysql',
 723                         'master-info',
 724                         // Using one key for all cluster replica DBs is preferable
 725                         $this->getLBInfo( 'clusterMasterHost' ) ?: $this->getServer()
 726                 );
 727
 728                 return $cache->getWithSetCallback(
 729                         $key,
 730                         $cache::TTL_INDEFINITE,
 731                         function () use ( $cache, $key ) {
 732                                 // Get and leave a lock key in place for a short period
 733                                 if ( !$cache->lock( $key, 0, 10 ) ) {
 734                                         return false; // avoid master connection spike slams
 735                                 }
 736
 737                                 $conn = $this->getLazyMasterHandle();
 738                                 if ( !$conn ) {
 739                                         return false; // something is misconfigured
 740                                 }
 741
 742                                 // Connect to and query the master; catch errors to avoid outages
 743                                 try {
 744                                         $res = $conn->query( 'SELECT @@server_id AS id', __METHOD__ );
 745                                         $row = $res ? $res->fetchObject() : false;
 746                                         $id = $row ? (int)$row->id : 0;
 747                                 } catch ( DBError $e ) {
 748                                         $id = 0;
 749                                 }
 750
 751                                 // Cache the ID if it was retrieved
 752                                 return $id ? [ 'serverId' => $id, 'asOf' => time() ] : false;
 753                         }
 754                 );
 755         }
 756
 757         /**
 758          * @param array $conds WHERE clause conditions to find a row
 759          * @return array (heartbeat `ts` column value or null, UNIX timestamp) for the newest beat
 760          * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
 761          */
 762         protected function getHeartbeatData( array $conds ) {
 763                 // Do not bother starting implicit transactions here
 764                 $this->clearFlag( self::DBO_TRX, self::REMEMBER_PRIOR );
 765                 try {
 766                         $whereSQL = $this->makeList( $conds, self::LIST_AND );
 767                         // Use ORDER BY for channel based queries since that field might not be UNIQUE.
 768                         // Note: this would use "TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6))" but the
 769                         // percision field is not supported in MySQL <= 5.5.
 770                         $res = $this->query(
 771                                 "SELECT ts FROM heartbeat.heartbeat WHERE $whereSQL ORDER BY ts DESC LIMIT 1"
 772                         );
 773                         $row = $res ? $res->fetchObject() : false;
 774                 } finally {
 775                         $this->restoreFlags();
 776                 }
 777
 778                 return [ $row ? $row->ts : null, microtime( true ) ];
 779         }
 780
 781         protected function getApproximateLagStatus() {
 782                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 783                         // Disable caching since this is fast enough and we don't wan't
 784                         // to be *too* pessimistic by having both the cache TTL and the
 785                         // pt-heartbeat interval count as lag in getSessionLagStatus()
 786                         return parent::getApproximateLagStatus();
 787                 }
 788
 789                 $key = $this->srvCache->makeGlobalKey( 'mysql-lag', $this->getServer() );
 790                 $approxLag = $this->srvCache->get( $key );
 791                 if ( !$approxLag ) {
 792                         $approxLag = parent::getApproximateLagStatus();
 793                         $this->srvCache->set( $key, $approxLag, 1 );
 794                 }
 795
 796                 return $approxLag;
 797         }
 798
 799         public function masterPosWait( DBMasterPos $pos, $timeout ) {
 800                 if ( !( $pos instanceof MySQLMasterPos ) ) {
 801                         throw new InvalidArgumentException( "Position not an instance of MySQLMasterPos" );
 802                 }
 803
 804                 if ( $this->getLBInfo( 'is static' ) === true ) {
 805                         return 0; // this is a copy of a read-only dataset with no master DB
 806                 } elseif ( $this->lastKnownReplicaPos && $this->lastKnownReplicaPos->hasReached( $pos ) ) {
 807                         return 0; // already reached this point for sure
 808                 }
 809
 810                 // Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 811                 if ( $this->useGTIDs && $pos->gtids ) {
 812                         // Wait on the GTID set (MariaDB only)
 813                         $gtidArg = $this->addQuotes( implode( ',', $pos->gtids ) );
 814                         $res = $this->doQuery( "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)" );
 815                 } else {
 816                         // Wait on the binlog coordinates
 817                         $encFile = $this->addQuotes( $pos->file );
 818                         $encPos = intval( $pos->pos );
 819                         $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
 820                 }
 821
 822                 $row = $res ? $this->fetchRow( $res ) : false;
 823                 if ( !$row ) {
 824                         throw new DBExpectedError( $this,
 825                                 "MASTER_POS_WAIT() or MASTER_GTID_WAIT() failed: {$this->lastError()}" );
 826                 }
 827
 828                 // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
 829                 $status = ( $row[0] !== null ) ? intval( $row[0] ) : null;
 830                 if ( $status === null ) {
 831                         // T126436: jobs programmed to wait on master positions might be referencing binlogs
 832                         // with an old master hostname. Such calls make MASTER_POS_WAIT() return null. Try
 833                         // to detect this and treat the replica DB as having reached the position; a proper master
 834                         // switchover already requires that the new master be caught up before the switch.
 835                         $replicationPos = $this->getReplicaPos();
 836                         if ( $replicationPos && !$replicationPos->channelsMatch( $pos ) ) {
 837                                 $this->lastKnownReplicaPos = $replicationPos;
 838                                 $status = 0;
 839                         }
 840                 } elseif ( $status >= 0 ) {
 841                         // Remember that this position was reached to save queries next time
 842                         $this->lastKnownReplicaPos = $pos;
 843                 }
 844
 845                 return $status;
 846         }
 847
 848         /**
 849          * Get the position of the master from SHOW SLAVE STATUS
 850          *
 851          * @return MySQLMasterPos|bool
 852          */
 853         public function getReplicaPos() {
 854                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 855                 $row = $this->fetchObject( $res );
 856
 857                 if ( $row ) {
 858                         $pos = isset( $row->Exec_master_log_pos )
 859                                 ? $row->Exec_master_log_pos
 860                                 : $row->Exec_Master_Log_Pos;
 861                         // Also fetch the last-applied GTID set (MariaDB)
 862                         if ( $this->useGTIDs ) {
 863                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_slave_pos'", __METHOD__ );
 864                                 $gtidRow = $this->fetchObject( $res );
 865                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 866                         } else {
 867                                 $gtidSet = '';
 868                         }
 869
 870                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos, $gtidSet );
 871                 } else {
 872                         return false;
 873                 }
 874         }
 875
 876         /**
 877          * Get the position of the master from SHOW MASTER STATUS
 878          *
 879          * @return MySQLMasterPos|bool
 880          */
 881         public function getMasterPos() {
 882                 $res = $this->query( 'SHOW MASTER STATUS', __METHOD__ );
 883                 $row = $this->fetchObject( $res );
 884
 885                 if ( $row ) {
 886                         // Also fetch the last-written GTID set (MariaDB)
 887                         if ( $this->useGTIDs ) {
 888                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_binlog_pos'", __METHOD__ );
 889                                 $gtidRow = $this->fetchObject( $res );
 890                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 891                         } else {
 892                                 $gtidSet = '';
 893                         }
 894
 895                         return new MySQLMasterPos( $row->File, $row->Position, $gtidSet );
 896                 } else {
 897                         return false;
 898                 }
 899         }
 900
 901         public function serverIsReadOnly() {
 902                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'read_only'", __METHOD__ );
 903                 $row = $this->fetchObject( $res );
 904
 905                 return $row ? ( strtolower( $row->Value ) === 'on' ) : false;
 906         }
 907
 908         /**
 909          * @param string $index
 910          * @return string
 911          */
 912         function useIndexClause( $index ) {
 913                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 914         }
 915
 916         /**
 917          * @param string $index
 918          * @return string
 919          */
 920         function ignoreIndexClause( $index ) {
 921                 return "IGNORE INDEX (" . $this->indexName( $index ) . ")";
 922         }
 923
 924         /**
 925          * @return string
 926          */
 927         function lowPriorityOption() {
 928                 return 'LOW_PRIORITY';
 929         }
 930
 931         /**
 932          * @return string
 933          */
 934         public function getSoftwareLink() {
 935                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 936                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 937                 // in libmysql/libmysql.c).
 938                 $version = $this->getServerVersion();
 939                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 940                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 941                 }
 942
 943                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 944                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 945                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 946                 return '[{{int:version-db-mysql-url}} MySQL]';
 947         }
 948
 949         /**
 950          * @return string
 951          */
 952         public function getServerVersion() {
 953                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 954                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 955                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 956                 if ( $this->serverVersion === null ) {
 957                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 958                 }
 959                 return $this->serverVersion;
 960         }
 961
 962         /**
 963          * @param array $options
 964          */
 965         public function setSessionOptions( array $options ) {
 966                 if ( isset( $options['connTimeout'] ) ) {
 967                         $timeout = (int)$options['connTimeout'];
 968                         $this->query( "SET net_read_timeout=$timeout" );
 969                         $this->query( "SET net_write_timeout=$timeout" );
 970                 }
 971         }
 972
 973         /**
 974          * @param string $sql
 975          * @param string $newLine
 976          * @return bool
 977          */
 978         public function streamStatementEnd( &$sql, &$newLine ) {
 979                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 980                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 981                         $this->delimiter = $m[1];
 982                         $newLine = '';
 983                 }
 984
 985                 return parent::streamStatementEnd( $sql, $newLine );
 986         }
 987
 988         /**
 989          * Check to see if a named lock is available. This is non-blocking.
 990          *
 991          * @param string $lockName Name of lock to poll
 992          * @param string $method Name of method calling us
 993          * @return bool
 994          * @since 1.20
 995          */
 996         public function lockIsFree( $lockName, $method ) {
 997                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
 998                 $result = $this->query( "SELECT IS_FREE_LOCK($encName) AS lockstatus", $method );
 999                 $row = $this->fetchObject( $result );
1000
1001                 return ( $row->lockstatus == 1 );
1002         }
1003
1004         /**
1005          * @param string $lockName
1006          * @param string $method
1007          * @param int $timeout
1008          * @return bool
1009          */
1010         public function lock( $lockName, $method, $timeout = 5 ) {
1011                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1012                 $result = $this->query( "SELECT GET_LOCK($encName, $timeout) AS lockstatus", $method );
1013                 $row = $this->fetchObject( $result );
1014
1015                 if ( $row->lockstatus == 1 ) {
1016                         parent::lock( $lockName, $method, $timeout ); // record
1017                         return true;
1018                 }
1019
1020                 $this->queryLogger->warning( __METHOD__ . " failed to acquire lock '$lockName'\n" );
1021
1022                 return false;
1023         }
1024
1025         /**
1026          * FROM MYSQL DOCS:
1027          * https://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
1028          * @param string $lockName
1029          * @param string $method
1030          * @return bool
1031          */
1032         public function unlock( $lockName, $method ) {
1033                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1034                 $result = $this->query( "SELECT RELEASE_LOCK($encName) as lockstatus", $method );
1035                 $row = $this->fetchObject( $result );
1036
1037                 if ( $row->lockstatus == 1 ) {
1038                         parent::unlock( $lockName, $method ); // record
1039                         return true;
1040                 }
1041
1042                 $this->queryLogger->warning( __METHOD__ . " failed to release lock '$lockName'\n" );
1043
1044                 return false;
1045         }
1046
1047         private function makeLockName( $lockName ) {
1048                 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1049                 // Newer version enforce a 64 char length limit.
1050                 return ( strlen( $lockName ) > 64 ) ? sha1( $lockName ) : $lockName;
1051         }
1052
1053         public function namedLocksEnqueue() {
1054                 return true;
1055         }
1056
1057         /**
1058          * @param array $read
1059          * @param array $write
1060          * @param string $method
1061          * @param bool $lowPriority
1062          * @return bool
1063          */
1064         public function lockTables( $read, $write, $method, $lowPriority = true ) {
1065                 $items = [];
1066
1067                 foreach ( $write as $table ) {
1068                         $tbl = $this->tableName( $table ) .
1069                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
1070                                 ' WRITE';
1071                         $items[] = $tbl;
1072                 }
1073                 foreach ( $read as $table ) {
1074                         $items[] = $this->tableName( $table ) . ' READ';
1075                 }
1076                 $sql = "LOCK TABLES " . implode( ',', $items );
1077                 $this->query( $sql, $method );
1078
1079                 return true;
1080         }
1081
1082         /**
1083          * @param string $method
1084          * @return bool
1085          */
1086         public function unlockTables( $method ) {
1087                 $this->query( "UNLOCK TABLES", $method );
1088
1089                 return true;
1090         }
1091
1092         /**
1093          * @param bool $value
1094          */
1095         public function setBigSelects( $value = true ) {
1096                 if ( $value === 'default' ) {
1097                         if ( $this->mDefaultBigSelects === null ) {
1098                                 # Function hasn't been called before so it must already be set to the default
1099                                 return;
1100                         } else {
1101                                 $value = $this->mDefaultBigSelects;
1102                         }
1103                 } elseif ( $this->mDefaultBigSelects === null ) {
1104                         $this->mDefaultBigSelects =
1105                                 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__ );
1106                 }
1107                 $encValue = $value ? '1' : '0';
1108                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
1109         }
1110
1111         /**
1112          * DELETE where the condition is a join. MySql uses multi-table deletes.
1113          * @param string $delTable
1114          * @param string $joinTable
1115          * @param string $delVar
1116          * @param string $joinVar
1117          * @param array|string $conds
1118          * @param bool|string $fname
1119          * @throws DBUnexpectedError
1120          * @return bool|ResultWrapper
1121          */
1122         public function deleteJoin(
1123                 $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__
1124         ) {
1125                 if ( !$conds ) {
1126                         throw new DBUnexpectedError( $this, __METHOD__ . ' called with empty $conds' );
1127                 }
1128
1129                 $delTable = $this->tableName( $delTable );
1130                 $joinTable = $this->tableName( $joinTable );
1131                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1132
1133                 if ( $conds != '*' ) {
1134                         $sql .= ' AND ' . $this->makeList( $conds, self::LIST_AND );
1135                 }
1136
1137                 return $this->query( $sql, $fname );
1138         }
1139
1140         /**
1141          * @param string $table
1142          * @param array $rows
1143          * @param array $uniqueIndexes
1144          * @param array $set
1145          * @param string $fname
1146          * @return bool
1147          */
1148         public function upsert( $table, array $rows, array $uniqueIndexes,
1149                 array $set, $fname = __METHOD__
1150         ) {
1151                 if ( !count( $rows ) ) {
1152                         return true; // nothing to do
1153                 }
1154
1155                 if ( !is_array( reset( $rows ) ) ) {
1156                         $rows = [ $rows ];
1157                 }
1158
1159                 $table = $this->tableName( $table );
1160                 $columns = array_keys( $rows[0] );
1161
1162                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1163                 $rowTuples = [];
1164                 foreach ( $rows as $row ) {
1165                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1166                 }
1167                 $sql .= implode( ',', $rowTuples );
1168                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, self::LIST_SET );
1169
1170                 return (bool)$this->query( $sql, $fname );
1171         }
1172
1173         /**
1174          * Determines how long the server has been up
1175          *
1176          * @return int
1177          */
1178         public function getServerUptime() {
1179                 $vars = $this->getMysqlStatus( 'Uptime' );
1180
1181                 return (int)$vars['Uptime'];
1182         }
1183
1184         /**
1185          * Determines if the last failure was due to a deadlock
1186          *
1187          * @return bool
1188          */
1189         public function wasDeadlock() {
1190                 return $this->lastErrno() == 1213;
1191         }
1192
1193         /**
1194          * Determines if the last failure was due to a lock timeout
1195          *
1196          * @return bool
1197          */
1198         public function wasLockTimeout() {
1199                 return $this->lastErrno() == 1205;
1200         }
1201
1202         public function wasErrorReissuable() {
1203                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1204         }
1205
1206         /**
1207          * Determines if the last failure was due to the database being read-only.
1208          *
1209          * @return bool
1210          */
1211         public function wasReadOnlyError() {
1212                 return $this->lastErrno() == 1223 ||
1213                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1214         }
1215
1216         public function wasConnectionError( $errno ) {
1217                 return $errno == 2013 || $errno == 2006;
1218         }
1219
1220         /**
1221          * @param string $oldName
1222          * @param string $newName
1223          * @param bool $temporary
1224          * @param string $fname
1225          * @return bool
1226          */
1227         public function duplicateTableStructure(
1228                 $oldName, $newName, $temporary = false, $fname = __METHOD__
1229         ) {
1230                 $tmp = $temporary ? 'TEMPORARY ' : '';
1231                 $newName = $this->addIdentifierQuotes( $newName );
1232                 $oldName = $this->addIdentifierQuotes( $oldName );
1233                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1234
1235                 return $this->query( $query, $fname );
1236         }
1237
1238         /**
1239          * List all tables on the database
1240          *
1241          * @param string $prefix Only show tables with this prefix, e.g. mw_
1242          * @param string $fname Calling function name
1243          * @return array
1244          */
1245         public function listTables( $prefix = null, $fname = __METHOD__ ) {
1246                 $result = $this->query( "SHOW TABLES", $fname );
1247
1248                 $endArray = [];
1249
1250                 foreach ( $result as $table ) {
1251                         $vars = get_object_vars( $table );
1252                         $table = array_pop( $vars );
1253
1254                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1255                                 $endArray[] = $table;
1256                         }
1257                 }
1258
1259                 return $endArray;
1260         }
1261
1262         /**
1263          * @param string $tableName
1264          * @param string $fName
1265          * @return bool|ResultWrapper
1266          */
1267         public function dropTable( $tableName, $fName = __METHOD__ ) {
1268                 if ( !$this->tableExists( $tableName, $fName ) ) {
1269                         return false;
1270                 }
1271
1272                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1273         }
1274
1275         /**
1276          * Get status information from SHOW STATUS in an associative array
1277          *
1278          * @param string $which
1279          * @return array
1280          */
1281         private function getMysqlStatus( $which = "%" ) {
1282                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1283                 $status = [];
1284
1285                 foreach ( $res as $row ) {
1286                         $status[$row->Variable_name] = $row->Value;
1287                 }
1288
1289                 return $status;
1290         }
1291
1292         /**
1293          * Lists VIEWs in the database
1294          *
1295          * @param string $prefix Only show VIEWs with this prefix, eg.
1296          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1297          * @param string $fname Name of calling function
1298          * @return array
1299          * @since 1.22
1300          */
1301         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1302                 // The name of the column containing the name of the VIEW
1303                 $propertyName = 'Tables_in_' . $this->mDBname;
1304
1305                 // Query for the VIEWS
1306                 $res = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1307                 $allViews = [];
1308                 foreach ( $res as $row ) {
1309                         array_push( $allViews, $row->$propertyName );
1310                 }
1311
1312                 if ( is_null( $prefix ) || $prefix === '' ) {
1313                         return $allViews;
1314                 }
1315
1316                 $filteredViews = [];
1317                 foreach ( $allViews as $viewName ) {
1318                         // Does the name of this VIEW start with the table-prefix?
1319                         if ( strpos( $viewName, $prefix ) === 0 ) {
1320                                 array_push( $filteredViews, $viewName );
1321                         }
1322                 }
1323
1324                 return $filteredViews;
1325         }
1326
1327         /**
1328          * Differentiates between a TABLE and a VIEW.
1329          *
1330          * @param string $name Name of the TABLE/VIEW to test
1331          * @param string $prefix
1332          * @return bool
1333          * @since 1.22
1334          */
1335         public function isView( $name, $prefix = null ) {
1336                 return in_array( $name, $this->listViews( $prefix ) );
1337         }
1338 }