includes/db/DatabaseMysqlBase.php

   1 <?php
   2 /**
   3  * This is the MySQL database abstraction layer.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Database
  22  */
  23
  24 /**
  25  * Database abstraction object for MySQL.
  26  * Defines methods independent on used MySQL extension.
  27  *
  28  * @ingroup Database
  29  * @since 1.22
  30  * @see Database
  31  */
  32 abstract class DatabaseMysqlBase extends Database {
  33         /** @var MysqlMasterPos */
  34         protected $lastKnownSlavePos;
  35         /** @var string Method to detect slave lag */
  36         protected $lagDetectionMethod;
  37         /** @var array Method to detect slave lag */
  38         protected $lagDetectionOptions = [];
  39         /** @var bool bool Whether to use GTID methods */
  40         protected $useGTIDs = false;
  41
  42         /** @var string|null */
  43         private $serverVersion = null;
  44
  45         /**
  46          * Additional $params include:
  47          *   - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
  48          *       pt-heartbeat assumes the table is at heartbeat.heartbeat
  49          *       and uses UTC timestamps in the heartbeat.ts column.
  50          *       (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
  51          *   - lagDetectionOptions : if using pt-heartbeat, this can be set to an array map to change
  52          *       the default behavior. Normally, the heartbeat row with the server
  53          *       ID of this server's master will be used. Set the "conds" field to
  54          *       override the query conditions, e.g. ['shard' => 's1'].
  55          *   - useGTIDs : use GTID methods like MASTER_GTID_WAIT() when possible.
  56          * @param array $params
  57          */
  58         function __construct( array $params ) {
  59                 parent::__construct( $params );
  60
  61                 $this->lagDetectionMethod = isset( $params['lagDetectionMethod'] )
  62                         ? $params['lagDetectionMethod']
  63                         : 'Seconds_Behind_Master';
  64                 $this->lagDetectionOptions = isset( $params['lagDetectionOptions'] )
  65                         ? $params['lagDetectionOptions']
  66                         : [];
  67                 $this->useGTIDs = !empty( $params['useGTIDs' ] );
  68         }
  69
  70         /**
  71          * @return string
  72          */
  73         function getType() {
  74                 return 'mysql';
  75         }
  76
  77         /**
  78          * @param string $server
  79          * @param string $user
  80          * @param string $password
  81          * @param string $dbName
  82          * @throws Exception|DBConnectionError
  83          * @return bool
  84          */
  85         function open( $server, $user, $password, $dbName ) {
  86                 global $wgAllDBsAreLocalhost, $wgSQLMode;
  87
  88                 # Close/unset connection handle
  89                 $this->close();
  90
  91                 # Debugging hack -- fake cluster
  92                 $realServer = $wgAllDBsAreLocalhost ? 'localhost' : $server;
  93                 $this->mServer = $server;
  94                 $this->mUser = $user;
  95                 $this->mPassword = $password;
  96                 $this->mDBname = $dbName;
  97
  98                 $this->installErrorHandler();
  99                 try {
 100                         $this->mConn = $this->mysqlConnect( $realServer );
 101                 } catch ( Exception $ex ) {
 102                         $this->restoreErrorHandler();
 103                         throw $ex;
 104                 }
 105                 $error = $this->restoreErrorHandler();
 106
 107                 # Always log connection errors
 108                 if ( !$this->mConn ) {
 109                         if ( !$error ) {
 110                                 $error = $this->lastError();
 111                         }
 112                         wfLogDBError(
 113                                 "Error connecting to {db_server}: {error}",
 114                                 $this->getLogContext( [
 115                                         'method' => __METHOD__,
 116                                         'error' => $error,
 117                                 ] )
 118                         );
 119                         wfDebug( "DB connection error\n" .
 120                                 "Server: $server, User: $user, Password: " .
 121                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 122
 123                         $this->reportConnectionError( $error );
 124                 }
 125
 126                 if ( $dbName != '' ) {
 127                         MediaWiki\suppressWarnings();
 128                         $success = $this->selectDB( $dbName );
 129                         MediaWiki\restoreWarnings();
 130                         if ( !$success ) {
 131                                 wfLogDBError(
 132                                         "Error selecting database {db_name} on server {db_server}",
 133                                         $this->getLogContext( [
 134                                                 'method' => __METHOD__,
 135                                         ] )
 136                                 );
 137                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 138                                         "from client host " . wfHostname() . "\n" );
 139
 140                                 $this->reportConnectionError( "Error selecting database $dbName" );
 141                         }
 142                 }
 143
 144                 // Tell the server what we're communicating with
 145                 if ( !$this->connectInitCharset() ) {
 146                         $this->reportConnectionError( "Error setting character set" );
 147                 }
 148
 149                 // Abstract over any insane MySQL defaults
 150                 $set = [ 'group_concat_max_len = 262144' ];
 151                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 152                 if ( is_string( $wgSQLMode ) ) {
 153                         $set[] = 'sql_mode = ' . $this->addQuotes( $wgSQLMode );
 154                 }
 155                 // Set any custom settings defined by site config
 156                 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 157                 foreach ( $this->mSessionVars as $var => $val ) {
 158                         // Escape strings but not numbers to avoid MySQL complaining
 159                         if ( !is_int( $val ) && !is_float( $val ) ) {
 160                                 $val = $this->addQuotes( $val );
 161                         }
 162                         $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 163                 }
 164
 165                 if ( $set ) {
 166                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 167                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ) );
 168                         if ( !$success ) {
 169                                 wfLogDBError(
 170                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 171                                         $this->getLogContext( [
 172                                                 'method' => __METHOD__,
 173                                         ] )
 174                                 );
 175                                 $this->reportConnectionError(
 176                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 177                         }
 178                 }
 179
 180                 $this->mOpened = true;
 181
 182                 return true;
 183         }
 184
 185         /**
 186          * Set the character set information right after connection
 187          * @return bool
 188          */
 189         protected function connectInitCharset() {
 190                 global $wgDBmysql5;
 191
 192                 if ( $wgDBmysql5 ) {
 193                         // Tell the server we're communicating with it in UTF-8.
 194                         // This may engage various charset conversions.
 195                         return $this->mysqlSetCharset( 'utf8' );
 196                 } else {
 197                         return $this->mysqlSetCharset( 'binary' );
 198                 }
 199         }
 200
 201         /**
 202          * Open a connection to a MySQL server
 203          *
 204          * @param string $realServer
 205          * @return mixed Raw connection
 206          * @throws DBConnectionError
 207          */
 208         abstract protected function mysqlConnect( $realServer );
 209
 210         /**
 211          * Set the character set of the MySQL link
 212          *
 213          * @param string $charset
 214          * @return bool
 215          */
 216         abstract protected function mysqlSetCharset( $charset );
 217
 218         /**
 219          * @param ResultWrapper|resource $res
 220          * @throws DBUnexpectedError
 221          */
 222         function freeResult( $res ) {
 223                 if ( $res instanceof ResultWrapper ) {
 224                         $res = $res->result;
 225                 }
 226                 MediaWiki\suppressWarnings();
 227                 $ok = $this->mysqlFreeResult( $res );
 228                 MediaWiki\restoreWarnings();
 229                 if ( !$ok ) {
 230                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 231                 }
 232         }
 233
 234         /**
 235          * Free result memory
 236          *
 237          * @param resource $res Raw result
 238          * @return bool
 239          */
 240         abstract protected function mysqlFreeResult( $res );
 241
 242         /**
 243          * @param ResultWrapper|resource $res
 244          * @return stdClass|bool
 245          * @throws DBUnexpectedError
 246          */
 247         function fetchObject( $res ) {
 248                 if ( $res instanceof ResultWrapper ) {
 249                         $res = $res->result;
 250                 }
 251                 MediaWiki\suppressWarnings();
 252                 $row = $this->mysqlFetchObject( $res );
 253                 MediaWiki\restoreWarnings();
 254
 255                 $errno = $this->lastErrno();
 256                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 257                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 258                 // these are the only errors mysql_fetch_object can cause.
 259                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 260                 if ( $errno == 2000 || $errno == 2013 ) {
 261                         throw new DBUnexpectedError(
 262                                 $this,
 263                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 264                         );
 265                 }
 266
 267                 return $row;
 268         }
 269
 270         /**
 271          * Fetch a result row as an object
 272          *
 273          * @param resource $res Raw result
 274          * @return stdClass
 275          */
 276         abstract protected function mysqlFetchObject( $res );
 277
 278         /**
 279          * @param ResultWrapper|resource $res
 280          * @return array|bool
 281          * @throws DBUnexpectedError
 282          */
 283         function fetchRow( $res ) {
 284                 if ( $res instanceof ResultWrapper ) {
 285                         $res = $res->result;
 286                 }
 287                 MediaWiki\suppressWarnings();
 288                 $row = $this->mysqlFetchArray( $res );
 289                 MediaWiki\restoreWarnings();
 290
 291                 $errno = $this->lastErrno();
 292                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 293                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 294                 // these are the only errors mysql_fetch_array can cause.
 295                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 296                 if ( $errno == 2000 || $errno == 2013 ) {
 297                         throw new DBUnexpectedError(
 298                                 $this,
 299                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 300                         );
 301                 }
 302
 303                 return $row;
 304         }
 305
 306         /**
 307          * Fetch a result row as an associative and numeric array
 308          *
 309          * @param resource $res Raw result
 310          * @return array
 311          */
 312         abstract protected function mysqlFetchArray( $res );
 313
 314         /**
 315          * @throws DBUnexpectedError
 316          * @param ResultWrapper|resource $res
 317          * @return int
 318          */
 319         function numRows( $res ) {
 320                 if ( $res instanceof ResultWrapper ) {
 321                         $res = $res->result;
 322                 }
 323                 MediaWiki\suppressWarnings();
 324                 $n = $this->mysqlNumRows( $res );
 325                 MediaWiki\restoreWarnings();
 326
 327                 // Unfortunately, mysql_num_rows does not reset the last errno.
 328                 // We are not checking for any errors here, since
 329                 // these are no errors mysql_num_rows can cause.
 330                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 331                 // See https://phabricator.wikimedia.org/T44430
 332                 return $n;
 333         }
 334
 335         /**
 336          * Get number of rows in result
 337          *
 338          * @param resource $res Raw result
 339          * @return int
 340          */
 341         abstract protected function mysqlNumRows( $res );
 342
 343         /**
 344          * @param ResultWrapper|resource $res
 345          * @return int
 346          */
 347         function numFields( $res ) {
 348                 if ( $res instanceof ResultWrapper ) {
 349                         $res = $res->result;
 350                 }
 351
 352                 return $this->mysqlNumFields( $res );
 353         }
 354
 355         /**
 356          * Get number of fields in result
 357          *
 358          * @param resource $res Raw result
 359          * @return int
 360          */
 361         abstract protected function mysqlNumFields( $res );
 362
 363         /**
 364          * @param ResultWrapper|resource $res
 365          * @param int $n
 366          * @return string
 367          */
 368         function fieldName( $res, $n ) {
 369                 if ( $res instanceof ResultWrapper ) {
 370                         $res = $res->result;
 371                 }
 372
 373                 return $this->mysqlFieldName( $res, $n );
 374         }
 375
 376         /**
 377          * Get the name of the specified field in a result
 378          *
 379          * @param ResultWrapper|resource $res
 380          * @param int $n
 381          * @return string
 382          */
 383         abstract protected function mysqlFieldName( $res, $n );
 384
 385         /**
 386          * mysql_field_type() wrapper
 387          * @param ResultWrapper|resource $res
 388          * @param int $n
 389          * @return string
 390          */
 391         public function fieldType( $res, $n ) {
 392                 if ( $res instanceof ResultWrapper ) {
 393                         $res = $res->result;
 394                 }
 395
 396                 return $this->mysqlFieldType( $res, $n );
 397         }
 398
 399         /**
 400          * Get the type of the specified field in a result
 401          *
 402          * @param ResultWrapper|resource $res
 403          * @param int $n
 404          * @return string
 405          */
 406         abstract protected function mysqlFieldType( $res, $n );
 407
 408         /**
 409          * @param ResultWrapper|resource $res
 410          * @param int $row
 411          * @return bool
 412          */
 413         function dataSeek( $res, $row ) {
 414                 if ( $res instanceof ResultWrapper ) {
 415                         $res = $res->result;
 416                 }
 417
 418                 return $this->mysqlDataSeek( $res, $row );
 419         }
 420
 421         /**
 422          * Move internal result pointer
 423          *
 424          * @param ResultWrapper|resource $res
 425          * @param int $row
 426          * @return bool
 427          */
 428         abstract protected function mysqlDataSeek( $res, $row );
 429
 430         /**
 431          * @return string
 432          */
 433         function lastError() {
 434                 if ( $this->mConn ) {
 435                         # Even if it's non-zero, it can still be invalid
 436                         MediaWiki\suppressWarnings();
 437                         $error = $this->mysqlError( $this->mConn );
 438                         if ( !$error ) {
 439                                 $error = $this->mysqlError();
 440                         }
 441                         MediaWiki\restoreWarnings();
 442                 } else {
 443                         $error = $this->mysqlError();
 444                 }
 445                 if ( $error ) {
 446                         $error .= ' (' . $this->mServer . ')';
 447                 }
 448
 449                 return $error;
 450         }
 451
 452         /**
 453          * Returns the text of the error message from previous MySQL operation
 454          *
 455          * @param resource $conn Raw connection
 456          * @return string
 457          */
 458         abstract protected function mysqlError( $conn = null );
 459
 460         /**
 461          * @param string $table
 462          * @param array $uniqueIndexes
 463          * @param array $rows
 464          * @param string $fname
 465          * @return ResultWrapper
 466          */
 467         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 468                 return $this->nativeReplace( $table, $rows, $fname );
 469         }
 470
 471         /**
 472          * Estimate rows in dataset
 473          * Returns estimated count, based on EXPLAIN output
 474          * Takes same arguments as Database::select()
 475          *
 476          * @param string|array $table
 477          * @param string|array $vars
 478          * @param string|array $conds
 479          * @param string $fname
 480          * @param string|array $options
 481          * @return bool|int
 482          */
 483         public function estimateRowCount( $table, $vars = '*', $conds = '',
 484                 $fname = __METHOD__, $options = []
 485         ) {
 486                 $options['EXPLAIN'] = true;
 487                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 488                 if ( $res === false ) {
 489                         return false;
 490                 }
 491                 if ( !$this->numRows( $res ) ) {
 492                         return 0;
 493                 }
 494
 495                 $rows = 1;
 496                 foreach ( $res as $plan ) {
 497                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 498                 }
 499
 500                 return (int)$rows;
 501         }
 502
 503         /**
 504          * @param string $table
 505          * @param string $field
 506          * @return bool|MySQLField
 507          */
 508         function fieldInfo( $table, $field ) {
 509                 $table = $this->tableName( $table );
 510                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 511                 if ( !$res ) {
 512                         return false;
 513                 }
 514                 $n = $this->mysqlNumFields( $res->result );
 515                 for ( $i = 0; $i < $n; $i++ ) {
 516                         $meta = $this->mysqlFetchField( $res->result, $i );
 517                         if ( $field == $meta->name ) {
 518                                 return new MySQLField( $meta );
 519                         }
 520                 }
 521
 522                 return false;
 523         }
 524
 525         /**
 526          * Get column information from a result
 527          *
 528          * @param resource $res Raw result
 529          * @param int $n
 530          * @return stdClass
 531          */
 532         abstract protected function mysqlFetchField( $res, $n );
 533
 534         /**
 535          * Get information about an index into an object
 536          * Returns false if the index does not exist
 537          *
 538          * @param string $table
 539          * @param string $index
 540          * @param string $fname
 541          * @return bool|array|null False or null on failure
 542          */
 543         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 544                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 545                 # SHOW INDEX should work for 3.x and up:
 546                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 547                 $table = $this->tableName( $table );
 548                 $index = $this->indexName( $index );
 549
 550                 $sql = 'SHOW INDEX FROM ' . $table;
 551                 $res = $this->query( $sql, $fname );
 552
 553                 if ( !$res ) {
 554                         return null;
 555                 }
 556
 557                 $result = [];
 558
 559                 foreach ( $res as $row ) {
 560                         if ( $row->Key_name == $index ) {
 561                                 $result[] = $row;
 562                         }
 563                 }
 564
 565                 return empty( $result ) ? false : $result;
 566         }
 567
 568         /**
 569          * @param string $s
 570          * @return string
 571          */
 572         function strencode( $s ) {
 573                 return $this->mysqlRealEscapeString( $s );
 574         }
 575
 576         /**
 577          * @param string $s
 578          * @return mixed
 579          */
 580         abstract protected function mysqlRealEscapeString( $s );
 581
 582         /**
 583          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 584          *
 585          * @param string $s
 586          * @return string
 587          */
 588         public function addIdentifierQuotes( $s ) {
 589                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 590                 // Remove NUL bytes and escape backticks by doubling
 591                 return '`' . str_replace( [ "\0", '`' ], [ '', '``' ], $s ) . '`';
 592         }
 593
 594         /**
 595          * @param string $name
 596          * @return bool
 597          */
 598         public function isQuotedIdentifier( $name ) {
 599                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 600         }
 601
 602         function reconnect() {
 603                 $this->closeConnection();
 604                 $this->mOpened = false;
 605                 $this->mConn = false;
 606                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 607
 608                 return true;
 609         }
 610
 611         function getLag() {
 612                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 613                         return $this->getLagFromPtHeartbeat();
 614                 } else {
 615                         return $this->getLagFromSlaveStatus();
 616                 }
 617         }
 618
 619         /**
 620          * @return string
 621          */
 622         protected function getLagDetectionMethod() {
 623                 return $this->lagDetectionMethod;
 624         }
 625
 626         /**
 627          * @return bool|int
 628          */
 629         protected function getLagFromSlaveStatus() {
 630                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 631                 $row = $res ? $res->fetchObject() : false;
 632                 if ( $row && strval( $row->Seconds_Behind_Master ) !== '' ) {
 633                         return intval( $row->Seconds_Behind_Master );
 634                 }
 635
 636                 return false;
 637         }
 638
 639         /**
 640          * @return bool|float
 641          */
 642         protected function getLagFromPtHeartbeat() {
 643                 $options = $this->lagDetectionOptions;
 644
 645                 if ( isset( $options['conds'] ) ) {
 646                         // Best method for multi-DC setups: use logical channel names
 647                         $data = $this->getHeartbeatData( $options['conds'] );
 648                 } else {
 649                         // Standard method: use master server ID (works with stock pt-heartbeat)
 650                         $masterInfo = $this->getMasterServerInfo();
 651                         if ( !$masterInfo ) {
 652                                 wfLogDBError(
 653                                         "Unable to query master of {db_server} for server ID",
 654                                         $this->getLogContext( [
 655                                                 'method' => __METHOD__
 656                                         ] )
 657                                 );
 658
 659                                 return false; // could not get master server ID
 660                         }
 661
 662                         $conds = [ 'server_id' => intval( $masterInfo['serverId'] ) ];
 663                         $data = $this->getHeartbeatData( $conds );
 664                 }
 665
 666                 list( $time, $nowUnix ) = $data;
 667                 if ( $time !== null ) {
 668                         // @time is in ISO format like "2015-09-25T16:48:10.000510"
 669                         $dateTime = new DateTime( $time, new DateTimeZone( 'UTC' ) );
 670                         $timeUnix = (int)$dateTime->format( 'U' ) + $dateTime->format( 'u' ) / 1e6;
 671
 672                         return max( $nowUnix - $timeUnix, 0.0 );
 673                 }
 674
 675                 wfLogDBError(
 676                         "Unable to find pt-heartbeat row for {db_server}",
 677                         $this->getLogContext( [
 678                                 'method' => __METHOD__
 679                         ] )
 680                 );
 681
 682                 return false;
 683         }
 684
 685         protected function getMasterServerInfo() {
 686                 $cache = $this->srvCache;
 687                 $key = $cache->makeGlobalKey(
 688                         'mysql',
 689                         'master-info',
 690                         // Using one key for all cluster slaves is preferable
 691                         $this->getLBInfo( 'clusterMasterHost' ) ?: $this->getServer()
 692                 );
 693
 694                 return $cache->getWithSetCallback(
 695                         $key,
 696                         $cache::TTL_INDEFINITE,
 697                         function () use ( $cache, $key ) {
 698                                 // Get and leave a lock key in place for a short period
 699                                 if ( !$cache->lock( $key, 0, 10 ) ) {
 700                                         return false; // avoid master connection spike slams
 701                                 }
 702
 703                                 $conn = $this->getLazyMasterHandle();
 704                                 if ( !$conn ) {
 705                                         return false; // something is misconfigured
 706                                 }
 707
 708                                 // Connect to and query the master; catch errors to avoid outages
 709                                 try {
 710                                         $res = $conn->query( 'SELECT @@server_id AS id', __METHOD__ );
 711                                         $row = $res ? $res->fetchObject() : false;
 712                                         $id = $row ? (int)$row->id : 0;
 713                                 } catch ( DBError $e ) {
 714                                         $id = 0;
 715                                 }
 716
 717                                 // Cache the ID if it was retrieved
 718                                 return $id ? [ 'serverId' => $id, 'asOf' => time() ] : false;
 719                         }
 720                 );
 721         }
 722
 723         /**
 724          * @param array $conds WHERE clause conditions to find a row
 725          * @return array (heartbeat `ts` column value or null, UNIX timestamp) for the newest beat
 726          * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
 727          */
 728         protected function getHeartbeatData( array $conds ) {
 729                 $whereSQL = $this->makeList( $conds, LIST_AND );
 730                 // Use ORDER BY for channel based queries since that field might not be UNIQUE.
 731                 // Note: this would use "TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6))" but the
 732                 // percision field is not supported in MySQL <= 5.5.
 733                 $res = $this->query(
 734                         "SELECT ts FROM heartbeat.heartbeat WHERE $whereSQL ORDER BY ts DESC LIMIT 1"
 735                 );
 736                 $row = $res ? $res->fetchObject() : false;
 737
 738                 return [ $row ? $row->ts : null, microtime( true ) ];
 739         }
 740
 741         public function getApproximateLagStatus() {
 742                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 743                         // Disable caching since this is fast enough and we don't wan't
 744                         // to be *too* pessimistic by having both the cache TTL and the
 745                         // pt-heartbeat interval count as lag in getSessionLagStatus()
 746                         return parent::getApproximateLagStatus();
 747                 }
 748
 749                 $key = $this->srvCache->makeGlobalKey( 'mysql-lag', $this->getServer() );
 750                 $approxLag = $this->srvCache->get( $key );
 751                 if ( !$approxLag ) {
 752                         $approxLag = parent::getApproximateLagStatus();
 753                         $this->srvCache->set( $key, $approxLag, 1 );
 754                 }
 755
 756                 return $approxLag;
 757         }
 758
 759         function masterPosWait( DBMasterPos $pos, $timeout ) {
 760                 if ( !( $pos instanceof MySQLMasterPos ) ) {
 761                         throw new InvalidArgumentException( "Position not an instance of MySQLMasterPos" );
 762                 }
 763
 764                 if ( $this->getLBInfo( 'is static' ) === true ) {
 765                         return 0; // this is a copy of a read-only dataset with no master DB
 766                 } elseif ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 767                         return 0; // already reached this point for sure
 768                 }
 769
 770                 // Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 771                 if ( $this->useGTIDs && $pos->gtids ) {
 772                         // Wait on the GTID set (MariaDB only)
 773                         $gtidArg = $this->addQuotes( implode( ',', $pos->gtids ) );
 774                         $res = $this->doQuery( "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)" );
 775                 } else {
 776                         // Wait on the binlog coordinates
 777                         $encFile = $this->addQuotes( $pos->file );
 778                         $encPos = intval( $pos->pos );
 779                         $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
 780                 }
 781
 782                 $row = $res ? $this->fetchRow( $res ) : false;
 783                 if ( !$row ) {
 784                         throw new DBExpectedError( $this, "Failed to query MASTER_POS_WAIT()" );
 785                 }
 786
 787                 // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
 788                 $status = ( $row[0] !== null ) ? intval( $row[0] ) : null;
 789                 if ( $status === null ) {
 790                         // T126436: jobs programmed to wait on master positions might be referencing binlogs
 791                         // with an old master hostname. Such calls make MASTER_POS_WAIT() return null. Try
 792                         // to detect this and treat the slave as having reached the position; a proper master
 793                         // switchover already requires that the new master be caught up before the switch.
 794                         $slavePos = $this->getSlavePos();
 795                         if ( $slavePos && !$slavePos->channelsMatch( $pos ) ) {
 796                                 $this->lastKnownSlavePos = $slavePos;
 797                                 $status = 0;
 798                         }
 799                 } elseif ( $status >= 0 ) {
 800                         // Remember that this position was reached to save queries next time
 801                         $this->lastKnownSlavePos = $pos;
 802                 }
 803
 804                 return $status;
 805         }
 806
 807         /**
 808          * Get the position of the master from SHOW SLAVE STATUS
 809          *
 810          * @return MySQLMasterPos|bool
 811          */
 812         function getSlavePos() {
 813                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 814                 $row = $this->fetchObject( $res );
 815
 816                 if ( $row ) {
 817                         $pos = isset( $row->Exec_master_log_pos )
 818                                 ? $row->Exec_master_log_pos
 819                                 : $row->Exec_Master_Log_Pos;
 820                         // Also fetch the last-applied GTID set (MariaDB)
 821                         if ( $this->useGTIDs ) {
 822                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_slave_pos'", __METHOD__ );
 823                                 $gtidRow = $this->fetchObject( $res );
 824                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 825                         } else {
 826                                 $gtidSet = '';
 827                         }
 828
 829                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos, $gtidSet );
 830                 } else {
 831                         return false;
 832                 }
 833         }
 834
 835         /**
 836          * Get the position of the master from SHOW MASTER STATUS
 837          *
 838          * @return MySQLMasterPos|bool
 839          */
 840         function getMasterPos() {
 841                 $res = $this->query( 'SHOW MASTER STATUS', __METHOD__ );
 842                 $row = $this->fetchObject( $res );
 843
 844                 if ( $row ) {
 845                         // Also fetch the last-written GTID set (MariaDB)
 846                         if ( $this->useGTIDs ) {
 847                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_binlog_pos'", __METHOD__ );
 848                                 $gtidRow = $this->fetchObject( $res );
 849                                 $gtidSet = $gtidRow ? $gtidRow->Value : '';
 850                         } else {
 851                                 $gtidSet = '';
 852                         }
 853
 854                         return new MySQLMasterPos( $row->File, $row->Position, $gtidSet );
 855                 } else {
 856                         return false;
 857                 }
 858         }
 859
 860         public function serverIsReadOnly() {
 861                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'read_only'", __METHOD__ );
 862                 $row = $this->fetchObject( $res );
 863
 864                 return $row ? ( strtolower( $row->Value ) === 'on' ) : false;
 865         }
 866
 867         /**
 868          * @param string $index
 869          * @return string
 870          */
 871         function useIndexClause( $index ) {
 872                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 873         }
 874
 875         /**
 876          * @return string
 877          */
 878         function lowPriorityOption() {
 879                 return 'LOW_PRIORITY';
 880         }
 881
 882         /**
 883          * @return string
 884          */
 885         public function getSoftwareLink() {
 886                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 887                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 888                 // in libmysql/libmysql.c).
 889                 $version = $this->getServerVersion();
 890                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 891                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 892                 }
 893
 894                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 895                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 896                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 897                 return '[{{int:version-db-mysql-url}} MySQL]';
 898         }
 899
 900         /**
 901          * @return string
 902          */
 903         public function getServerVersion() {
 904                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 905                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 906                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 907                 if ( $this->serverVersion === null ) {
 908                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 909                 }
 910                 return $this->serverVersion;
 911         }
 912
 913         /**
 914          * @param array $options
 915          */
 916         public function setSessionOptions( array $options ) {
 917                 if ( isset( $options['connTimeout'] ) ) {
 918                         $timeout = (int)$options['connTimeout'];
 919                         $this->query( "SET net_read_timeout=$timeout" );
 920                         $this->query( "SET net_write_timeout=$timeout" );
 921                 }
 922         }
 923
 924         /**
 925          * @param string $sql
 926          * @param string $newLine
 927          * @return bool
 928          */
 929         public function streamStatementEnd( &$sql, &$newLine ) {
 930                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 931                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 932                         $this->delimiter = $m[1];
 933                         $newLine = '';
 934                 }
 935
 936                 return parent::streamStatementEnd( $sql, $newLine );
 937         }
 938
 939         /**
 940          * Check to see if a named lock is available. This is non-blocking.
 941          *
 942          * @param string $lockName Name of lock to poll
 943          * @param string $method Name of method calling us
 944          * @return bool
 945          * @since 1.20
 946          */
 947         public function lockIsFree( $lockName, $method ) {
 948                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
 949                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 950                 $row = $this->fetchObject( $result );
 951
 952                 return ( $row->lockstatus == 1 );
 953         }
 954
 955         /**
 956          * @param string $lockName
 957          * @param string $method
 958          * @param int $timeout
 959          * @return bool
 960          */
 961         public function lock( $lockName, $method, $timeout = 5 ) {
 962                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
 963                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 964                 $row = $this->fetchObject( $result );
 965
 966                 if ( $row->lockstatus == 1 ) {
 967                         parent::lock( $lockName, $method, $timeout ); // record
 968                         return true;
 969                 }
 970
 971                 wfDebug( __METHOD__ . " failed to acquire lock\n" );
 972
 973                 return false;
 974         }
 975
 976         /**
 977          * FROM MYSQL DOCS:
 978          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 979          * @param string $lockName
 980          * @param string $method
 981          * @return bool
 982          */
 983         public function unlock( $lockName, $method ) {
 984                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
 985                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 986                 $row = $this->fetchObject( $result );
 987
 988                 if ( $row->lockstatus == 1 ) {
 989                         parent::unlock( $lockName, $method ); // record
 990                         return true;
 991                 }
 992
 993                 wfDebug( __METHOD__ . " failed to release lock\n" );
 994
 995                 return false;
 996         }
 997
 998         private function makeLockName( $lockName ) {
 999                 // http://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1000                 // Newer version enforce a 64 char length limit.
1001                 return ( strlen( $lockName ) > 64 ) ? sha1( $lockName ) : $lockName;
1002         }
1003
1004         public function namedLocksEnqueue() {
1005                 return true;
1006         }
1007
1008         /**
1009          * @param array $read
1010          * @param array $write
1011          * @param string $method
1012          * @param bool $lowPriority
1013          * @return bool
1014          */
1015         public function lockTables( $read, $write, $method, $lowPriority = true ) {
1016                 $items = [];
1017
1018                 foreach ( $write as $table ) {
1019                         $tbl = $this->tableName( $table ) .
1020                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
1021                                 ' WRITE';
1022                         $items[] = $tbl;
1023                 }
1024                 foreach ( $read as $table ) {
1025                         $items[] = $this->tableName( $table ) . ' READ';
1026                 }
1027                 $sql = "LOCK TABLES " . implode( ',', $items );
1028                 $this->query( $sql, $method );
1029
1030                 return true;
1031         }
1032
1033         /**
1034          * @param string $method
1035          * @return bool
1036          */
1037         public function unlockTables( $method ) {
1038                 $this->query( "UNLOCK TABLES", $method );
1039
1040                 return true;
1041         }
1042
1043         /**
1044          * Get search engine class. All subclasses of this
1045          * need to implement this if they wish to use searching.
1046          *
1047          * @return string
1048          */
1049         public function getSearchEngine() {
1050                 return 'SearchMySQL';
1051         }
1052
1053         /**
1054          * @param bool $value
1055          */
1056         public function setBigSelects( $value = true ) {
1057                 if ( $value === 'default' ) {
1058                         if ( $this->mDefaultBigSelects === null ) {
1059                                 # Function hasn't been called before so it must already be set to the default
1060                                 return;
1061                         } else {
1062                                 $value = $this->mDefaultBigSelects;
1063                         }
1064                 } elseif ( $this->mDefaultBigSelects === null ) {
1065                         $this->mDefaultBigSelects =
1066                                 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__ );
1067                 }
1068                 $encValue = $value ? '1' : '0';
1069                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
1070         }
1071
1072         /**
1073          * DELETE where the condition is a join. MySql uses multi-table deletes.
1074          * @param string $delTable
1075          * @param string $joinTable
1076          * @param string $delVar
1077          * @param string $joinVar
1078          * @param array|string $conds
1079          * @param bool|string $fname
1080          * @throws DBUnexpectedError
1081          * @return bool|ResultWrapper
1082          */
1083         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
1084                 if ( !$conds ) {
1085                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
1086                 }
1087
1088                 $delTable = $this->tableName( $delTable );
1089                 $joinTable = $this->tableName( $joinTable );
1090                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1091
1092                 if ( $conds != '*' ) {
1093                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1094                 }
1095
1096                 return $this->query( $sql, $fname );
1097         }
1098
1099         /**
1100          * @param string $table
1101          * @param array $rows
1102          * @param array $uniqueIndexes
1103          * @param array $set
1104          * @param string $fname
1105          * @return bool
1106          */
1107         public function upsert( $table, array $rows, array $uniqueIndexes,
1108                 array $set, $fname = __METHOD__
1109         ) {
1110                 if ( !count( $rows ) ) {
1111                         return true; // nothing to do
1112                 }
1113
1114                 if ( !is_array( reset( $rows ) ) ) {
1115                         $rows = [ $rows ];
1116                 }
1117
1118                 $table = $this->tableName( $table );
1119                 $columns = array_keys( $rows[0] );
1120
1121                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1122                 $rowTuples = [];
1123                 foreach ( $rows as $row ) {
1124                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1125                 }
1126                 $sql .= implode( ',', $rowTuples );
1127                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
1128
1129                 return (bool)$this->query( $sql, $fname );
1130         }
1131
1132         /**
1133          * Determines how long the server has been up
1134          *
1135          * @return int
1136          */
1137         function getServerUptime() {
1138                 $vars = $this->getMysqlStatus( 'Uptime' );
1139
1140                 return (int)$vars['Uptime'];
1141         }
1142
1143         /**
1144          * Determines if the last failure was due to a deadlock
1145          *
1146          * @return bool
1147          */
1148         function wasDeadlock() {
1149                 return $this->lastErrno() == 1213;
1150         }
1151
1152         /**
1153          * Determines if the last failure was due to a lock timeout
1154          *
1155          * @return bool
1156          */
1157         function wasLockTimeout() {
1158                 return $this->lastErrno() == 1205;
1159         }
1160
1161         function wasErrorReissuable() {
1162                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1163         }
1164
1165         /**
1166          * Determines if the last failure was due to the database being read-only.
1167          *
1168          * @return bool
1169          */
1170         function wasReadOnlyError() {
1171                 return $this->lastErrno() == 1223 ||
1172                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1173         }
1174
1175         function wasConnectionError( $errno ) {
1176                 return $errno == 2013 || $errno == 2006;
1177         }
1178
1179         /**
1180          * Get the underlying binding handle, mConn
1181          *
1182          * Makes sure that mConn is set (disconnects and ping() failure can unset it).
1183          * This catches broken callers than catch and ignore disconnection exceptions.
1184          * Unlike checking isOpen(), this is safe to call inside of open().
1185          *
1186          * @return resource|object
1187          * @throws DBUnexpectedError
1188          * @since 1.26
1189          */
1190         protected function getBindingHandle() {
1191                 if ( !$this->mConn ) {
1192                         throw new DBUnexpectedError(
1193                                 $this,
1194                                 'DB connection was already closed or the connection dropped.'
1195                         );
1196                 }
1197
1198                 return $this->mConn;
1199         }
1200
1201         /**
1202          * @param string $oldName
1203          * @param string $newName
1204          * @param bool $temporary
1205          * @param string $fname
1206          * @return bool
1207          */
1208         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1209                 $tmp = $temporary ? 'TEMPORARY ' : '';
1210                 $newName = $this->addIdentifierQuotes( $newName );
1211                 $oldName = $this->addIdentifierQuotes( $oldName );
1212                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1213
1214                 return $this->query( $query, $fname );
1215         }
1216
1217         /**
1218          * List all tables on the database
1219          *
1220          * @param string $prefix Only show tables with this prefix, e.g. mw_
1221          * @param string $fname Calling function name
1222          * @return array
1223          */
1224         function listTables( $prefix = null, $fname = __METHOD__ ) {
1225                 $result = $this->query( "SHOW TABLES", $fname );
1226
1227                 $endArray = [];
1228
1229                 foreach ( $result as $table ) {
1230                         $vars = get_object_vars( $table );
1231                         $table = array_pop( $vars );
1232
1233                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1234                                 $endArray[] = $table;
1235                         }
1236                 }
1237
1238                 return $endArray;
1239         }
1240
1241         /**
1242          * @param string $tableName
1243          * @param string $fName
1244          * @return bool|ResultWrapper
1245          */
1246         public function dropTable( $tableName, $fName = __METHOD__ ) {
1247                 if ( !$this->tableExists( $tableName, $fName ) ) {
1248                         return false;
1249                 }
1250
1251                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1252         }
1253
1254         /**
1255          * @return array
1256          */
1257         protected function getDefaultSchemaVars() {
1258                 $vars = parent::getDefaultSchemaVars();
1259                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1260                 $vars['wgDBTableOptions'] = str_replace(
1261                         'CHARSET=mysql4',
1262                         'CHARSET=binary',
1263                         $vars['wgDBTableOptions']
1264                 );
1265
1266                 return $vars;
1267         }
1268
1269         /**
1270          * Get status information from SHOW STATUS in an associative array
1271          *
1272          * @param string $which
1273          * @return array
1274          */
1275         function getMysqlStatus( $which = "%" ) {
1276                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1277                 $status = [];
1278
1279                 foreach ( $res as $row ) {
1280                         $status[$row->Variable_name] = $row->Value;
1281                 }
1282
1283                 return $status;
1284         }
1285
1286         /**
1287          * Lists VIEWs in the database
1288          *
1289          * @param string $prefix Only show VIEWs with this prefix, eg.
1290          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1291          * @param string $fname Name of calling function
1292          * @return array
1293          * @since 1.22
1294          */
1295         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1296
1297                 if ( !isset( $this->allViews ) ) {
1298
1299                         // The name of the column containing the name of the VIEW
1300                         $propertyName = 'Tables_in_' . $this->mDBname;
1301
1302                         // Query for the VIEWS
1303                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1304                         $this->allViews = [];
1305                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1306                                 array_push( $this->allViews, $row[$propertyName] );
1307                         }
1308                 }
1309
1310                 if ( is_null( $prefix ) || $prefix === '' ) {
1311                         return $this->allViews;
1312                 }
1313
1314                 $filteredViews = [];
1315                 foreach ( $this->allViews as $viewName ) {
1316                         // Does the name of this VIEW start with the table-prefix?
1317                         if ( strpos( $viewName, $prefix ) === 0 ) {
1318                                 array_push( $filteredViews, $viewName );
1319                         }
1320                 }
1321
1322                 return $filteredViews;
1323         }
1324
1325         /**
1326          * Differentiates between a TABLE and a VIEW.
1327          *
1328          * @param string $name Name of the TABLE/VIEW to test
1329          * @param string $prefix
1330          * @return bool
1331          * @since 1.22
1332          */
1333         public function isView( $name, $prefix = null ) {
1334                 return in_array( $name, $this->listViews( $prefix ) );
1335         }
1336 }
1337
1338 /**
1339  * Utility class.
1340  * @ingroup Database
1341  */
1342 class MySQLField implements Field {
1343         private $name, $tablename, $default, $max_length, $nullable,
1344                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary,
1345                 $is_numeric, $is_blob, $is_unsigned, $is_zerofill;
1346
1347         function __construct( $info ) {
1348                 $this->name = $info->name;
1349                 $this->tablename = $info->table;
1350                 $this->default = $info->def;
1351                 $this->max_length = $info->max_length;
1352                 $this->nullable = !$info->not_null;
1353                 $this->is_pk = $info->primary_key;
1354                 $this->is_unique = $info->unique_key;
1355                 $this->is_multiple = $info->multiple_key;
1356                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1357                 $this->type = $info->type;
1358                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1359                 $this->is_numeric = isset( $info->numeric ) ? $info->numeric : false;
1360                 $this->is_blob = isset( $info->blob ) ? $info->blob : false;
1361                 $this->is_unsigned = isset( $info->unsigned ) ? $info->unsigned : false;
1362                 $this->is_zerofill = isset( $info->zerofill ) ? $info->zerofill : false;
1363         }
1364
1365         /**
1366          * @return string
1367          */
1368         function name() {
1369                 return $this->name;
1370         }
1371
1372         /**
1373          * @return string
1374          */
1375         function tableName() {
1376                 return $this->tablename;
1377         }
1378
1379         /**
1380          * @return string
1381          */
1382         function type() {
1383                 return $this->type;
1384         }
1385
1386         /**
1387          * @return bool
1388          */
1389         function isNullable() {
1390                 return $this->nullable;
1391         }
1392
1393         function defaultValue() {
1394                 return $this->default;
1395         }
1396
1397         /**
1398          * @return bool
1399          */
1400         function isKey() {
1401                 return $this->is_key;
1402         }
1403
1404         /**
1405          * @return bool
1406          */
1407         function isMultipleKey() {
1408                 return $this->is_multiple;
1409         }
1410
1411         /**
1412          * @return bool
1413          */
1414         function isBinary() {
1415                 return $this->binary;
1416         }
1417
1418         /**
1419          * @return bool
1420          */
1421         function isNumeric() {
1422                 return $this->is_numeric;
1423         }
1424
1425         /**
1426          * @return bool
1427          */
1428         function isBlob() {
1429                 return $this->is_blob;
1430         }
1431
1432         /**
1433          * @return bool
1434          */
1435         function isUnsigned() {
1436                 return $this->is_unsigned;
1437         }
1438
1439         /**
1440          * @return bool
1441          */
1442         function isZerofill() {
1443                 return $this->is_zerofill;
1444         }
1445 }
1446
1447 /**
1448  * DBMasterPos class for MySQL/MariaDB
1449  *
1450  * Note that master positions and sync logic here make some assumptions:
1451  *  - Binlog-based usage assumes single-source replication and non-hierarchical replication.
1452  *  - GTID-based usage allows getting/syncing with multi-source replication. It is assumed
1453  *    that GTID sets are complete (e.g. include all domains on the server).
1454  */
1455 class MySQLMasterPos implements DBMasterPos {
1456         /** @var string Binlog file */
1457         public $file;
1458         /** @var int Binglog file position */
1459         public $pos;
1460         /** @var string[] GTID list */
1461         public $gtids = [];
1462         /** @var float UNIX timestamp */
1463         public $asOfTime = 0.0;
1464
1465         /**
1466          * @param string $file Binlog file name
1467          * @param integer $pos Binlog position
1468          * @param string $gtid Comma separated GTID set [optional]
1469          */
1470         function __construct( $file, $pos, $gtid = '' ) {
1471                 $this->file = $file;
1472                 $this->pos = $pos;
1473                 $this->gtids = array_map( 'trim', explode( ',', $gtid ) );
1474                 $this->asOfTime = microtime( true );
1475         }
1476
1477         /**
1478          * @return string <binlog file>/<position>, e.g db1034-bin.000976/843431247
1479          */
1480         function __toString() {
1481                 return "{$this->file}/{$this->pos}";
1482         }
1483
1484         function asOfTime() {
1485                 return $this->asOfTime;
1486         }
1487
1488         function hasReached( DBMasterPos $pos ) {
1489                 if ( !( $pos instanceof self ) ) {
1490                         throw new InvalidArgumentException( "Position not an instance of " . __CLASS__ );
1491                 }
1492
1493                 // Prefer GTID comparisons, which work with multi-tier replication
1494                 $thisPosByDomain = $this->getGtidCoordinates();
1495                 $thatPosByDomain = $pos->getGtidCoordinates();
1496                 if ( $thisPosByDomain && $thatPosByDomain ) {
1497                         $reached = true;
1498                         // Check that this has positions GTE all of those in $pos for all domains in $pos
1499                         foreach ( $thatPosByDomain as $domain => $thatPos ) {
1500                                 $thisPos = isset( $thisPosByDomain[$domain] ) ? $thisPosByDomain[$domain] : -1;
1501                                 $reached = $reached && ( $thatPos <= $thisPos );
1502                         }
1503
1504                         return $reached;
1505                 }
1506
1507                 // Fallback to the binlog file comparisons
1508                 $thisBinPos = $this->getBinlogCoordinates();
1509                 $thatBinPos = $pos->getBinlogCoordinates();
1510                 if ( $thisBinPos && $thatBinPos && $thisBinPos['binlog'] === $thatBinPos['binlog'] ) {
1511                         return ( $thisBinPos['pos'] >= $thatBinPos['pos'] );
1512                 }
1513
1514                 // Comparing totally different binlogs does not make sense
1515                 return false;
1516         }
1517
1518         function channelsMatch( DBMasterPos $pos ) {
1519                 if ( !( $pos instanceof self ) ) {
1520                         throw new InvalidArgumentException( "Position not an instance of " . __CLASS__ );
1521                 }
1522
1523                 // Prefer GTID comparisons, which work with multi-tier replication
1524                 $thisPosDomains = array_keys( $this->getGtidCoordinates() );
1525                 $thatPosDomains = array_keys( $pos->getGtidCoordinates() );
1526                 if ( $thisPosDomains && $thatPosDomains ) {
1527                         // Check that this has GTIDs for all domains in $pos
1528                         return !array_diff( $thatPosDomains, $thisPosDomains );
1529                 }
1530
1531                 // Fallback to the binlog file comparisons
1532                 $thisBinPos = $this->getBinlogCoordinates();
1533                 $thatBinPos = $pos->getBinlogCoordinates();
1534
1535                 return ( $thisBinPos && $thatBinPos && $thisBinPos['binlog'] === $thatBinPos['binlog'] );
1536         }
1537
1538         /**
1539          * @note: this returns false for multi-source replication GTID sets
1540          * @see https://mariadb.com/kb/en/mariadb/gtid
1541          * @see https://dev.mysql.com/doc/refman/5.6/en/replication-gtids-concepts.html
1542          * @return array Map of (domain => integer position) or false
1543          */
1544         protected function getGtidCoordinates() {
1545                 $gtidInfos = [];
1546                 foreach ( $this->gtids as $gtid ) {
1547                         $m = [];
1548                         // MariaDB style: <domain>-<server id>-<sequence number>
1549                         if ( preg_match( '!^(\d+)-\d+-(\d+)$!', $gtid, $m ) ) {
1550                                 $gtidInfos[(int)$m[1]] = (int)$m[2];
1551                         // MySQL style: <UUID domain>:<sequence number>
1552                         } elseif ( preg_match( '!^(\w{8}-\w{4}-\w{4}-\w{4}-\w{12}):(\d+)$!', $gtid, $m ) ) {
1553                                 $gtidInfos[$m[1]] = (int)$m[2];
1554                         } else {
1555                                 $gtidInfos = [];
1556                                 break; // unrecognized GTID
1557                         }
1558
1559                 }
1560
1561                 return $gtidInfos;
1562         }
1563
1564         /**
1565          * @see http://dev.mysql.com/doc/refman/5.7/en/show-master-status.html
1566          * @see http://dev.mysql.com/doc/refman/5.7/en/show-slave-status.html
1567          * @return array|bool (binlog, (integer file number, integer position)) or false
1568          */
1569         protected function getBinlogCoordinates() {
1570                 $m = [];
1571                 if ( preg_match( '!^(.+)\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1572                         return [ 'binlog' => $m[1], 'pos' => [ (int)$m[2], (int)$m[3] ] ];
1573                 }
1574
1575                 return false;
1576         }
1577 }