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