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
  40         /** @var string|null */
  41         private $serverVersion = null;
  42
  43         /**
  44          * Additional $params include:
  45          *   - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
  46          *                          pt-heartbeat assumes the table is at heartbeat.heartbeat
  47          *                          and uses UTC timestamps in the heartbeat.ts column.
  48          *                          (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
  49          *   - lagDetectionOptions : if using pt-heartbeat, this can be set to an array map to change
  50          *                           the default behavior. Normally, the heartbeat row with the server
  51          *                           ID of this server's master will be used. Set the "conds" field to
  52          *                           override the query conditions, e.g. ['shard' => 's1'].
  53          * @param array $params
  54          */
  55         function __construct( array $params ) {
  56                 parent::__construct( $params );
  57
  58                 $this->lagDetectionMethod = isset( $params['lagDetectionMethod'] )
  59                         ? $params['lagDetectionMethod']
  60                         : 'Seconds_Behind_Master';
  61                 $this->lagDetectionOptions = isset( $params['lagDetectionOptions'] )
  62                         ? $params['lagDetectionOptions']
  63                         : [];
  64         }
  65
  66         /**
  67          * @return string
  68          */
  69         function getType() {
  70                 return 'mysql';
  71         }
  72
  73         /**
  74          * @param string $server
  75          * @param string $user
  76          * @param string $password
  77          * @param string $dbName
  78          * @throws Exception|DBConnectionError
  79          * @return bool
  80          */
  81         function open( $server, $user, $password, $dbName ) {
  82                 global $wgAllDBsAreLocalhost, $wgSQLMode;
  83
  84                 # Close/unset connection handle
  85                 $this->close();
  86
  87                 # Debugging hack -- fake cluster
  88                 $realServer = $wgAllDBsAreLocalhost ? 'localhost' : $server;
  89                 $this->mServer = $server;
  90                 $this->mUser = $user;
  91                 $this->mPassword = $password;
  92                 $this->mDBname = $dbName;
  93
  94                 $this->installErrorHandler();
  95                 try {
  96                         $this->mConn = $this->mysqlConnect( $realServer );
  97                 } catch ( Exception $ex ) {
  98                         $this->restoreErrorHandler();
  99                         throw $ex;
 100                 }
 101                 $error = $this->restoreErrorHandler();
 102
 103                 # Always log connection errors
 104                 if ( !$this->mConn ) {
 105                         if ( !$error ) {
 106                                 $error = $this->lastError();
 107                         }
 108                         wfLogDBError(
 109                                 "Error connecting to {db_server}: {error}",
 110                                 $this->getLogContext( [
 111                                         'method' => __METHOD__,
 112                                         'error' => $error,
 113                                 ] )
 114                         );
 115                         wfDebug( "DB connection error\n" .
 116                                 "Server: $server, User: $user, Password: " .
 117                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 118
 119                         $this->reportConnectionError( $error );
 120                 }
 121
 122                 if ( $dbName != '' ) {
 123                         MediaWiki\suppressWarnings();
 124                         $success = $this->selectDB( $dbName );
 125                         MediaWiki\restoreWarnings();
 126                         if ( !$success ) {
 127                                 wfLogDBError(
 128                                         "Error selecting database {db_name} on server {db_server}",
 129                                         $this->getLogContext( [
 130                                                 'method' => __METHOD__,
 131                                         ] )
 132                                 );
 133                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 134                                         "from client host " . wfHostname() . "\n" );
 135
 136                                 $this->reportConnectionError( "Error selecting database $dbName" );
 137                         }
 138                 }
 139
 140                 // Tell the server what we're communicating with
 141                 if ( !$this->connectInitCharset() ) {
 142                         $this->reportConnectionError( "Error setting character set" );
 143                 }
 144
 145                 // Abstract over any insane MySQL defaults
 146                 $set = [ 'group_concat_max_len = 262144' ];
 147                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 148                 if ( is_string( $wgSQLMode ) ) {
 149                         $set[] = 'sql_mode = ' . $this->addQuotes( $wgSQLMode );
 150                 }
 151                 // Set any custom settings defined by site config
 152                 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 153                 foreach ( $this->mSessionVars as $var => $val ) {
 154                         // Escape strings but not numbers to avoid MySQL complaining
 155                         if ( !is_int( $val ) && !is_float( $val ) ) {
 156                                 $val = $this->addQuotes( $val );
 157                         }
 158                         $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 159                 }
 160
 161                 if ( $set ) {
 162                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 163                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ) );
 164                         if ( !$success ) {
 165                                 wfLogDBError(
 166                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 167                                         $this->getLogContext( [
 168                                                 'method' => __METHOD__,
 169                                         ] )
 170                                 );
 171                                 $this->reportConnectionError(
 172                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 173                         }
 174                 }
 175
 176                 $this->mOpened = true;
 177
 178                 return true;
 179         }
 180
 181         /**
 182          * Set the character set information right after connection
 183          * @return bool
 184          */
 185         protected function connectInitCharset() {
 186                 global $wgDBmysql5;
 187
 188                 if ( $wgDBmysql5 ) {
 189                         // Tell the server we're communicating with it in UTF-8.
 190                         // This may engage various charset conversions.
 191                         return $this->mysqlSetCharset( 'utf8' );
 192                 } else {
 193                         return $this->mysqlSetCharset( 'binary' );
 194                 }
 195         }
 196
 197         /**
 198          * Open a connection to a MySQL server
 199          *
 200          * @param string $realServer
 201          * @return mixed Raw connection
 202          * @throws DBConnectionError
 203          */
 204         abstract protected function mysqlConnect( $realServer );
 205
 206         /**
 207          * Set the character set of the MySQL link
 208          *
 209          * @param string $charset
 210          * @return bool
 211          */
 212         abstract protected function mysqlSetCharset( $charset );
 213
 214         /**
 215          * @param ResultWrapper|resource $res
 216          * @throws DBUnexpectedError
 217          */
 218         function freeResult( $res ) {
 219                 if ( $res instanceof ResultWrapper ) {
 220                         $res = $res->result;
 221                 }
 222                 MediaWiki\suppressWarnings();
 223                 $ok = $this->mysqlFreeResult( $res );
 224                 MediaWiki\restoreWarnings();
 225                 if ( !$ok ) {
 226                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 227                 }
 228         }
 229
 230         /**
 231          * Free result memory
 232          *
 233          * @param resource $res Raw result
 234          * @return bool
 235          */
 236         abstract protected function mysqlFreeResult( $res );
 237
 238         /**
 239          * @param ResultWrapper|resource $res
 240          * @return stdClass|bool
 241          * @throws DBUnexpectedError
 242          */
 243         function fetchObject( $res ) {
 244                 if ( $res instanceof ResultWrapper ) {
 245                         $res = $res->result;
 246                 }
 247                 MediaWiki\suppressWarnings();
 248                 $row = $this->mysqlFetchObject( $res );
 249                 MediaWiki\restoreWarnings();
 250
 251                 $errno = $this->lastErrno();
 252                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 253                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 254                 // these are the only errors mysql_fetch_object can cause.
 255                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 256                 if ( $errno == 2000 || $errno == 2013 ) {
 257                         throw new DBUnexpectedError(
 258                                 $this,
 259                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 260                         );
 261                 }
 262
 263                 return $row;
 264         }
 265
 266         /**
 267          * Fetch a result row as an object
 268          *
 269          * @param resource $res Raw result
 270          * @return stdClass
 271          */
 272         abstract protected function mysqlFetchObject( $res );
 273
 274         /**
 275          * @param ResultWrapper|resource $res
 276          * @return array|bool
 277          * @throws DBUnexpectedError
 278          */
 279         function fetchRow( $res ) {
 280                 if ( $res instanceof ResultWrapper ) {
 281                         $res = $res->result;
 282                 }
 283                 MediaWiki\suppressWarnings();
 284                 $row = $this->mysqlFetchArray( $res );
 285                 MediaWiki\restoreWarnings();
 286
 287                 $errno = $this->lastErrno();
 288                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 289                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 290                 // these are the only errors mysql_fetch_array can cause.
 291                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 292                 if ( $errno == 2000 || $errno == 2013 ) {
 293                         throw new DBUnexpectedError(
 294                                 $this,
 295                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 296                         );
 297                 }
 298
 299                 return $row;
 300         }
 301
 302         /**
 303          * Fetch a result row as an associative and numeric array
 304          *
 305          * @param resource $res Raw result
 306          * @return array
 307          */
 308         abstract protected function mysqlFetchArray( $res );
 309
 310         /**
 311          * @throws DBUnexpectedError
 312          * @param ResultWrapper|resource $res
 313          * @return int
 314          */
 315         function numRows( $res ) {
 316                 if ( $res instanceof ResultWrapper ) {
 317                         $res = $res->result;
 318                 }
 319                 MediaWiki\suppressWarnings();
 320                 $n = $this->mysqlNumRows( $res );
 321                 MediaWiki\restoreWarnings();
 322
 323                 // Unfortunately, mysql_num_rows does not reset the last errno.
 324                 // We are not checking for any errors here, since
 325                 // these are no errors mysql_num_rows can cause.
 326                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 327                 // See https://phabricator.wikimedia.org/T44430
 328                 return $n;
 329         }
 330
 331         /**
 332          * Get number of rows in result
 333          *
 334          * @param resource $res Raw result
 335          * @return int
 336          */
 337         abstract protected function mysqlNumRows( $res );
 338
 339         /**
 340          * @param ResultWrapper|resource $res
 341          * @return int
 342          */
 343         function numFields( $res ) {
 344                 if ( $res instanceof ResultWrapper ) {
 345                         $res = $res->result;
 346                 }
 347
 348                 return $this->mysqlNumFields( $res );
 349         }
 350
 351         /**
 352          * Get number of fields in result
 353          *
 354          * @param resource $res Raw result
 355          * @return int
 356          */
 357         abstract protected function mysqlNumFields( $res );
 358
 359         /**
 360          * @param ResultWrapper|resource $res
 361          * @param int $n
 362          * @return string
 363          */
 364         function fieldName( $res, $n ) {
 365                 if ( $res instanceof ResultWrapper ) {
 366                         $res = $res->result;
 367                 }
 368
 369                 return $this->mysqlFieldName( $res, $n );
 370         }
 371
 372         /**
 373          * Get the name of the specified field in a result
 374          *
 375          * @param ResultWrapper|resource $res
 376          * @param int $n
 377          * @return string
 378          */
 379         abstract protected function mysqlFieldName( $res, $n );
 380
 381         /**
 382          * mysql_field_type() wrapper
 383          * @param ResultWrapper|resource $res
 384          * @param int $n
 385          * @return string
 386          */
 387         public function fieldType( $res, $n ) {
 388                 if ( $res instanceof ResultWrapper ) {
 389                         $res = $res->result;
 390                 }
 391
 392                 return $this->mysqlFieldType( $res, $n );
 393         }
 394
 395         /**
 396          * Get the type of the specified field in a result
 397          *
 398          * @param ResultWrapper|resource $res
 399          * @param int $n
 400          * @return string
 401          */
 402         abstract protected function mysqlFieldType( $res, $n );
 403
 404         /**
 405          * @param ResultWrapper|resource $res
 406          * @param int $row
 407          * @return bool
 408          */
 409         function dataSeek( $res, $row ) {
 410                 if ( $res instanceof ResultWrapper ) {
 411                         $res = $res->result;
 412                 }
 413
 414                 return $this->mysqlDataSeek( $res, $row );
 415         }
 416
 417         /**
 418          * Move internal result pointer
 419          *
 420          * @param ResultWrapper|resource $res
 421          * @param int $row
 422          * @return bool
 423          */
 424         abstract protected function mysqlDataSeek( $res, $row );
 425
 426         /**
 427          * @return string
 428          */
 429         function lastError() {
 430                 if ( $this->mConn ) {
 431                         # Even if it's non-zero, it can still be invalid
 432                         MediaWiki\suppressWarnings();
 433                         $error = $this->mysqlError( $this->mConn );
 434                         if ( !$error ) {
 435                                 $error = $this->mysqlError();
 436                         }
 437                         MediaWiki\restoreWarnings();
 438                 } else {
 439                         $error = $this->mysqlError();
 440                 }
 441                 if ( $error ) {
 442                         $error .= ' (' . $this->mServer . ')';
 443                 }
 444
 445                 return $error;
 446         }
 447
 448         /**
 449          * Returns the text of the error message from previous MySQL operation
 450          *
 451          * @param resource $conn Raw connection
 452          * @return string
 453          */
 454         abstract protected function mysqlError( $conn = null );
 455
 456         /**
 457          * @param string $table
 458          * @param array $uniqueIndexes
 459          * @param array $rows
 460          * @param string $fname
 461          * @return ResultWrapper
 462          */
 463         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 464                 return $this->nativeReplace( $table, $rows, $fname );
 465         }
 466
 467         /**
 468          * Estimate rows in dataset
 469          * Returns estimated count, based on EXPLAIN output
 470          * Takes same arguments as Database::select()
 471          *
 472          * @param string|array $table
 473          * @param string|array $vars
 474          * @param string|array $conds
 475          * @param string $fname
 476          * @param string|array $options
 477          * @return bool|int
 478          */
 479         public function estimateRowCount( $table, $vars = '*', $conds = '',
 480                 $fname = __METHOD__, $options = []
 481         ) {
 482                 $options['EXPLAIN'] = true;
 483                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 484                 if ( $res === false ) {
 485                         return false;
 486                 }
 487                 if ( !$this->numRows( $res ) ) {
 488                         return 0;
 489                 }
 490
 491                 $rows = 1;
 492                 foreach ( $res as $plan ) {
 493                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 494                 }
 495
 496                 return (int)$rows;
 497         }
 498
 499         /**
 500          * @param string $table
 501          * @param string $field
 502          * @return bool|MySQLField
 503          */
 504         function fieldInfo( $table, $field ) {
 505                 $table = $this->tableName( $table );
 506                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 507                 if ( !$res ) {
 508                         return false;
 509                 }
 510                 $n = $this->mysqlNumFields( $res->result );
 511                 for ( $i = 0; $i < $n; $i++ ) {
 512                         $meta = $this->mysqlFetchField( $res->result, $i );
 513                         if ( $field == $meta->name ) {
 514                                 return new MySQLField( $meta );
 515                         }
 516                 }
 517
 518                 return false;
 519         }
 520
 521         /**
 522          * Get column information from a result
 523          *
 524          * @param resource $res Raw result
 525          * @param int $n
 526          * @return stdClass
 527          */
 528         abstract protected function mysqlFetchField( $res, $n );
 529
 530         /**
 531          * Get information about an index into an object
 532          * Returns false if the index does not exist
 533          *
 534          * @param string $table
 535          * @param string $index
 536          * @param string $fname
 537          * @return bool|array|null False or null on failure
 538          */
 539         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 540                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 541                 # SHOW INDEX should work for 3.x and up:
 542                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 543                 $table = $this->tableName( $table );
 544                 $index = $this->indexName( $index );
 545
 546                 $sql = 'SHOW INDEX FROM ' . $table;
 547                 $res = $this->query( $sql, $fname );
 548
 549                 if ( !$res ) {
 550                         return null;
 551                 }
 552
 553                 $result = [];
 554
 555                 foreach ( $res as $row ) {
 556                         if ( $row->Key_name == $index ) {
 557                                 $result[] = $row;
 558                         }
 559                 }
 560
 561                 return empty( $result ) ? false : $result;
 562         }
 563
 564         /**
 565          * @param string $s
 566          * @return string
 567          */
 568         function strencode( $s ) {
 569                 $sQuoted = $this->mysqlRealEscapeString( $s );
 570
 571                 if ( $sQuoted === false ) {
 572                         $this->ping();
 573                         $sQuoted = $this->mysqlRealEscapeString( $s );
 574                 }
 575
 576                 return $sQuoted;
 577         }
 578
 579         /**
 580          * @param string $s
 581          * @return mixed
 582          */
 583         abstract protected function mysqlRealEscapeString( $s );
 584
 585         /**
 586          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 587          *
 588          * @param string $s
 589          * @return string
 590          */
 591         public function addIdentifierQuotes( $s ) {
 592                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 593                 // Remove NUL bytes and escape backticks by doubling
 594                 return '`' . str_replace( [ "\0", '`' ], [ '', '``' ], $s ) . '`';
 595         }
 596
 597         /**
 598          * @param string $name
 599          * @return bool
 600          */
 601         public function isQuotedIdentifier( $name ) {
 602                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 603         }
 604
 605         /**
 606          * @return bool
 607          */
 608         function ping() {
 609                 $ping = $this->mysqlPing();
 610                 if ( $ping ) {
 611                         // Connection was good or lost but reconnected...
 612                         // @note: mysqlnd (php 5.6+) does not support this (PHP bug 52561)
 613                         return true;
 614                 }
 615
 616                 // Try a full disconnect/reconnect cycle if ping() failed
 617                 $this->closeConnection();
 618                 $this->mOpened = false;
 619                 $this->mConn = false;
 620                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 621
 622                 return true;
 623         }
 624
 625         /**
 626          * Ping a server connection or reconnect if there is no connection
 627          *
 628          * @return bool
 629          */
 630         abstract protected function mysqlPing();
 631
 632         function getLag() {
 633                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 634                         return $this->getLagFromPtHeartbeat();
 635                 } else {
 636                         return $this->getLagFromSlaveStatus();
 637                 }
 638         }
 639
 640         /**
 641          * @return string
 642          */
 643         protected function getLagDetectionMethod() {
 644                 return $this->lagDetectionMethod;
 645         }
 646
 647         /**
 648          * @return bool|int
 649          */
 650         protected function getLagFromSlaveStatus() {
 651                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 652                 $row = $res ? $res->fetchObject() : false;
 653                 if ( $row && strval( $row->Seconds_Behind_Master ) !== '' ) {
 654                         return intval( $row->Seconds_Behind_Master );
 655                 }
 656
 657                 return false;
 658         }
 659
 660         /**
 661          * @return bool|float
 662          */
 663         protected function getLagFromPtHeartbeat() {
 664                 $options = $this->lagDetectionOptions;
 665
 666                 if ( isset( $options['conds'] ) ) {
 667                         // Best method for multi-DC setups: use logical channel names
 668                         $data = $this->getHeartbeatData( $options['conds'] );
 669                 } else {
 670                         // Standard method: use master server ID (works with stock pt-heartbeat)
 671                         $masterInfo = $this->getMasterServerInfo();
 672                         if ( !$masterInfo ) {
 673                                 wfLogDBError(
 674                                         "Unable to query master of {db_server} for server ID",
 675                                         $this->getLogContext( [
 676                                                 'method' => __METHOD__
 677                                         ] )
 678                                 );
 679
 680                                 return false; // could not get master server ID
 681                         }
 682
 683                         $conds = [ 'server_id' => intval( $masterInfo['serverId'] ) ];
 684                         $data = $this->getHeartbeatData( $conds );
 685                 }
 686
 687                 list( $time, $nowUnix ) = $data;
 688                 if ( $time !== null ) {
 689                         // @time is in ISO format like "2015-09-25T16:48:10.000510"
 690                         $dateTime = new DateTime( $time, new DateTimeZone( 'UTC' ) );
 691                         $timeUnix = (int)$dateTime->format( 'U' ) + $dateTime->format( 'u' ) / 1e6;
 692
 693                         return max( $nowUnix - $timeUnix, 0.0 );
 694                 }
 695
 696                 wfLogDBError(
 697                         "Unable to find pt-heartbeat row for {db_server}",
 698                         $this->getLogContext( [
 699                                 'method' => __METHOD__
 700                         ] )
 701                 );
 702
 703                 return false;
 704         }
 705
 706         protected function getMasterServerInfo() {
 707                 $cache = $this->srvCache;
 708                 $key = $cache->makeGlobalKey(
 709                         'mysql',
 710                         'master-info',
 711                         // Using one key for all cluster slaves is preferable
 712                         $this->getLBInfo( 'clusterMasterHost' ) ?: $this->getServer()
 713                 );
 714
 715                 return $cache->getWithSetCallback(
 716                         $key,
 717                         $cache::TTL_INDEFINITE,
 718                         function () use ( $cache, $key ) {
 719                                 // Get and leave a lock key in place for a short period
 720                                 if ( !$cache->lock( $key, 0, 10 ) ) {
 721                                         return false; // avoid master connection spike slams
 722                                 }
 723
 724                                 $conn = $this->getLazyMasterHandle();
 725                                 if ( !$conn ) {
 726                                         return false; // something is misconfigured
 727                                 }
 728
 729                                 // Connect to and query the master; catch errors to avoid outages
 730                                 try {
 731                                         $res = $conn->query( 'SELECT @@server_id AS id', __METHOD__ );
 732                                         $row = $res ? $res->fetchObject() : false;
 733                                         $id = $row ? (int)$row->id : 0;
 734                                 } catch ( DBError $e ) {
 735                                         $id = 0;
 736                                 }
 737
 738                                 // Cache the ID if it was retrieved
 739                                 return $id ? [ 'serverId' => $id, 'asOf' => time() ] : false;
 740                         }
 741                 );
 742         }
 743
 744         /**
 745          * @param array $conds WHERE clause conditions to find a row
 746          * @return array (heartbeat `ts` column value or null, UNIX timestamp) for the newest beat
 747          * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
 748          */
 749         protected function getHeartbeatData( array $conds ) {
 750                 $whereSQL = $this->makeList( $conds, LIST_AND );
 751                 // Use ORDER BY for channel based queries since that field might not be UNIQUE.
 752                 // Note: this would use "TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6))" but the
 753                 // percision field is not supported in MySQL <= 5.5.
 754                 $res = $this->query(
 755                         "SELECT ts FROM heartbeat.heartbeat WHERE $whereSQL ORDER BY ts DESC LIMIT 1"
 756                 );
 757                 $row = $res ? $res->fetchObject() : false;
 758
 759                 return [ $row ? $row->ts : null, microtime( true ) ];
 760         }
 761
 762         public function getApproximateLagStatus() {
 763                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 764                         // Disable caching since this is fast enough and we don't wan't
 765                         // to be *too* pessimistic by having both the cache TTL and the
 766                         // pt-heartbeat interval count as lag in getSessionLagStatus()
 767                         return parent::getApproximateLagStatus();
 768                 }
 769
 770                 $key = $this->srvCache->makeGlobalKey( 'mysql-lag', $this->getServer() );
 771                 $approxLag = $this->srvCache->get( $key );
 772                 if ( !$approxLag ) {
 773                         $approxLag = parent::getApproximateLagStatus();
 774                         $this->srvCache->set( $key, $approxLag, 1 );
 775                 }
 776
 777                 return $approxLag;
 778         }
 779
 780         function masterPosWait( DBMasterPos $pos, $timeout ) {
 781                 if ( !( $pos instanceof MySQLMasterPos ) ) {
 782                         throw new InvalidArgumentException( "Position not an instance of MySQLMasterPos" );
 783                 }
 784
 785                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 786                         return 0;
 787                 }
 788
 789                 # Commit any open transactions
 790                 $this->commit( __METHOD__, 'flush' );
 791
 792                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 793                 $encFile = $this->addQuotes( $pos->file );
 794                 $encPos = intval( $pos->pos );
 795                 $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
 796
 797                 $row = $res ? $this->fetchRow( $res ) : false;
 798                 if ( !$row ) {
 799                         throw new DBExpectedError( $this, "Failed to query MASTER_POS_WAIT()" );
 800                 }
 801
 802                 // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
 803                 $status = ( $row[0] !== null ) ? intval( $row[0] ) : null;
 804                 if ( $status === null ) {
 805                         // T126436: jobs programmed to wait on master positions might be referencing binlogs
 806                         // with an old master hostname. Such calls make MASTER_POS_WAIT() return null. Try
 807                         // to detect this and treat the slave as having reached the position; a proper master
 808                         // switchover already requires that the new master be caught up before the switch.
 809                         $slavePos = $this->getSlavePos();
 810                         if ( $slavePos && !$slavePos->channelsMatch( $pos ) ) {
 811                                 $this->lastKnownSlavePos = $slavePos;
 812                                 $status = 0;
 813                         }
 814                 } elseif ( $status >= 0 ) {
 815                         // Remember that this position was reached to save queries next time
 816                         $this->lastKnownSlavePos = $pos;
 817                 }
 818
 819                 return $status;
 820         }
 821
 822         /**
 823          * Get the position of the master from SHOW SLAVE STATUS
 824          *
 825          * @return MySQLMasterPos|bool
 826          */
 827         function getSlavePos() {
 828                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 829                 $row = $this->fetchObject( $res );
 830
 831                 if ( $row ) {
 832                         $pos = isset( $row->Exec_master_log_pos )
 833                                 ? $row->Exec_master_log_pos
 834                                 : $row->Exec_Master_Log_Pos;
 835
 836                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 837                 } else {
 838                         return false;
 839                 }
 840         }
 841
 842         /**
 843          * Get the position of the master from SHOW MASTER STATUS
 844          *
 845          * @return MySQLMasterPos|bool
 846          */
 847         function getMasterPos() {
 848                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 849                 $row = $this->fetchObject( $res );
 850
 851                 if ( $row ) {
 852                         return new MySQLMasterPos( $row->File, $row->Position );
 853                 } else {
 854                         return false;
 855                 }
 856         }
 857
 858         /**
 859          * @param string $index
 860          * @return string
 861          */
 862         function useIndexClause( $index ) {
 863                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 864         }
 865
 866         /**
 867          * @return string
 868          */
 869         function lowPriorityOption() {
 870                 return 'LOW_PRIORITY';
 871         }
 872
 873         /**
 874          * @return string
 875          */
 876         public function getSoftwareLink() {
 877                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 878                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 879                 // in libmysql/libmysql.c).
 880                 $version = $this->getServerVersion();
 881                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 882                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 883                 }
 884
 885                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 886                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 887                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 888                 return '[{{int:version-db-mysql-url}} MySQL]';
 889         }
 890
 891         /**
 892          * @return string
 893          */
 894         public function getServerVersion() {
 895                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 896                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 897                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 898                 if ( $this->serverVersion === null ) {
 899                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 900                 }
 901                 return $this->serverVersion;
 902         }
 903
 904         /**
 905          * @param array $options
 906          */
 907         public function setSessionOptions( array $options ) {
 908                 if ( isset( $options['connTimeout'] ) ) {
 909                         $timeout = (int)$options['connTimeout'];
 910                         $this->query( "SET net_read_timeout=$timeout" );
 911                         $this->query( "SET net_write_timeout=$timeout" );
 912                 }
 913         }
 914
 915         /**
 916          * @param string $sql
 917          * @param string $newLine
 918          * @return bool
 919          */
 920         public function streamStatementEnd( &$sql, &$newLine ) {
 921                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 922                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 923                         $this->delimiter = $m[1];
 924                         $newLine = '';
 925                 }
 926
 927                 return parent::streamStatementEnd( $sql, $newLine );
 928         }
 929
 930         /**
 931          * Check to see if a named lock is available. This is non-blocking.
 932          *
 933          * @param string $lockName Name of lock to poll
 934          * @param string $method Name of method calling us
 935          * @return bool
 936          * @since 1.20
 937          */
 938         public function lockIsFree( $lockName, $method ) {
 939                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
 940                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 941                 $row = $this->fetchObject( $result );
 942
 943                 return ( $row->lockstatus == 1 );
 944         }
 945
 946         /**
 947          * @param string $lockName
 948          * @param string $method
 949          * @param int $timeout
 950          * @return bool
 951          */
 952         public function lock( $lockName, $method, $timeout = 5 ) {
 953                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
 954                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 955                 $row = $this->fetchObject( $result );
 956
 957                 if ( $row->lockstatus == 1 ) {
 958                         parent::lock( $lockName, $method, $timeout ); // record
 959                         return true;
 960                 }
 961
 962                 wfDebug( __METHOD__ . " failed to acquire lock\n" );
 963
 964                 return false;
 965         }
 966
 967         /**
 968          * FROM MYSQL DOCS:
 969          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 970          * @param string $lockName
 971          * @param string $method
 972          * @return bool
 973          */
 974         public function unlock( $lockName, $method ) {
 975                 $lockName = $this->addQuotes( $this->makeLockName( $lockName ) );
 976                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 977                 $row = $this->fetchObject( $result );
 978
 979                 if ( $row->lockstatus == 1 ) {
 980                         parent::unlock( $lockName, $method ); // record
 981                         return true;
 982                 }
 983
 984                 wfDebug( __METHOD__ . " failed to release lock\n" );
 985
 986                 return false;
 987         }
 988
 989         private function makeLockName( $lockName ) {
 990                 // http://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
 991                 // Newer version enforce a 64 char length limit.
 992                 return ( strlen( $lockName ) > 64 ) ? sha1( $lockName ) : $lockName;
 993         }
 994
 995         public function namedLocksEnqueue() {
 996                 return true;
 997         }
 998
 999         /**
1000          * @param array $read
1001          * @param array $write
1002          * @param string $method
1003          * @param bool $lowPriority
1004          * @return bool
1005          */
1006         public function lockTables( $read, $write, $method, $lowPriority = true ) {
1007                 $items = [];
1008
1009                 foreach ( $write as $table ) {
1010                         $tbl = $this->tableName( $table ) .
1011                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
1012                                 ' WRITE';
1013                         $items[] = $tbl;
1014                 }
1015                 foreach ( $read as $table ) {
1016                         $items[] = $this->tableName( $table ) . ' READ';
1017                 }
1018                 $sql = "LOCK TABLES " . implode( ',', $items );
1019                 $this->query( $sql, $method );
1020
1021                 return true;
1022         }
1023
1024         /**
1025          * @param string $method
1026          * @return bool
1027          */
1028         public function unlockTables( $method ) {
1029                 $this->query( "UNLOCK TABLES", $method );
1030
1031                 return true;
1032         }
1033
1034         /**
1035          * Get search engine class. All subclasses of this
1036          * need to implement this if they wish to use searching.
1037          *
1038          * @return string
1039          */
1040         public function getSearchEngine() {
1041                 return 'SearchMySQL';
1042         }
1043
1044         /**
1045          * @param bool $value
1046          */
1047         public function setBigSelects( $value = true ) {
1048                 if ( $value === 'default' ) {
1049                         if ( $this->mDefaultBigSelects === null ) {
1050                                 # Function hasn't been called before so it must already be set to the default
1051                                 return;
1052                         } else {
1053                                 $value = $this->mDefaultBigSelects;
1054                         }
1055                 } elseif ( $this->mDefaultBigSelects === null ) {
1056                         $this->mDefaultBigSelects =
1057                                 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__ );
1058                 }
1059                 $encValue = $value ? '1' : '0';
1060                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
1061         }
1062
1063         /**
1064          * DELETE where the condition is a join. MySql uses multi-table deletes.
1065          * @param string $delTable
1066          * @param string $joinTable
1067          * @param string $delVar
1068          * @param string $joinVar
1069          * @param array|string $conds
1070          * @param bool|string $fname
1071          * @throws DBUnexpectedError
1072          * @return bool|ResultWrapper
1073          */
1074         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
1075                 if ( !$conds ) {
1076                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
1077                 }
1078
1079                 $delTable = $this->tableName( $delTable );
1080                 $joinTable = $this->tableName( $joinTable );
1081                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1082
1083                 if ( $conds != '*' ) {
1084                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1085                 }
1086
1087                 return $this->query( $sql, $fname );
1088         }
1089
1090         /**
1091          * @param string $table
1092          * @param array $rows
1093          * @param array $uniqueIndexes
1094          * @param array $set
1095          * @param string $fname
1096          * @return bool
1097          */
1098         public function upsert( $table, array $rows, array $uniqueIndexes,
1099                 array $set, $fname = __METHOD__
1100         ) {
1101                 if ( !count( $rows ) ) {
1102                         return true; // nothing to do
1103                 }
1104
1105                 if ( !is_array( reset( $rows ) ) ) {
1106                         $rows = [ $rows ];
1107                 }
1108
1109                 $table = $this->tableName( $table );
1110                 $columns = array_keys( $rows[0] );
1111
1112                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1113                 $rowTuples = [];
1114                 foreach ( $rows as $row ) {
1115                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1116                 }
1117                 $sql .= implode( ',', $rowTuples );
1118                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
1119
1120                 return (bool)$this->query( $sql, $fname );
1121         }
1122
1123         /**
1124          * Determines how long the server has been up
1125          *
1126          * @return int
1127          */
1128         function getServerUptime() {
1129                 $vars = $this->getMysqlStatus( 'Uptime' );
1130
1131                 return (int)$vars['Uptime'];
1132         }
1133
1134         /**
1135          * Determines if the last failure was due to a deadlock
1136          *
1137          * @return bool
1138          */
1139         function wasDeadlock() {
1140                 return $this->lastErrno() == 1213;
1141         }
1142
1143         /**
1144          * Determines if the last failure was due to a lock timeout
1145          *
1146          * @return bool
1147          */
1148         function wasLockTimeout() {
1149                 return $this->lastErrno() == 1205;
1150         }
1151
1152         /**
1153          * Determines if the last query error was something that should be dealt
1154          * with by pinging the connection and reissuing the query
1155          *
1156          * @return bool
1157          */
1158         function wasErrorReissuable() {
1159                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1160         }
1161
1162         /**
1163          * Determines if the last failure was due to the database being read-only.
1164          *
1165          * @return bool
1166          */
1167         function wasReadOnlyError() {
1168                 return $this->lastErrno() == 1223 ||
1169                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1170         }
1171
1172         function wasConnectionError( $errno ) {
1173                 return $errno == 2013 || $errno == 2006;
1174         }
1175
1176         /**
1177          * Get the underlying binding handle, mConn
1178          *
1179          * Makes sure that mConn is set (disconnects and ping() failure can unset it).
1180          * This catches broken callers than catch and ignore disconnection exceptions.
1181          * Unlike checking isOpen(), this is safe to call inside of open().
1182          *
1183          * @return resource|object
1184          * @throws DBUnexpectedError
1185          * @since 1.26
1186          */
1187         protected function getBindingHandle() {
1188                 if ( !$this->mConn ) {
1189                         throw new DBUnexpectedError(
1190                                 $this,
1191                                 'DB connection was already closed or the connection dropped.'
1192                         );
1193                 }
1194
1195                 return $this->mConn;
1196         }
1197
1198         /**
1199          * @param string $oldName
1200          * @param string $newName
1201          * @param bool $temporary
1202          * @param string $fname
1203          * @return bool
1204          */
1205         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1206                 $tmp = $temporary ? 'TEMPORARY ' : '';
1207                 $newName = $this->addIdentifierQuotes( $newName );
1208                 $oldName = $this->addIdentifierQuotes( $oldName );
1209                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1210
1211                 return $this->query( $query, $fname );
1212         }
1213
1214         /**
1215          * List all tables on the database
1216          *
1217          * @param string $prefix Only show tables with this prefix, e.g. mw_
1218          * @param string $fname Calling function name
1219          * @return array
1220          */
1221         function listTables( $prefix = null, $fname = __METHOD__ ) {
1222                 $result = $this->query( "SHOW TABLES", $fname );
1223
1224                 $endArray = [];
1225
1226                 foreach ( $result as $table ) {
1227                         $vars = get_object_vars( $table );
1228                         $table = array_pop( $vars );
1229
1230                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1231                                 $endArray[] = $table;
1232                         }
1233                 }
1234
1235                 return $endArray;
1236         }
1237
1238         /**
1239          * @param string $tableName
1240          * @param string $fName
1241          * @return bool|ResultWrapper
1242          */
1243         public function dropTable( $tableName, $fName = __METHOD__ ) {
1244                 if ( !$this->tableExists( $tableName, $fName ) ) {
1245                         return false;
1246                 }
1247
1248                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1249         }
1250
1251         /**
1252          * @return array
1253          */
1254         protected function getDefaultSchemaVars() {
1255                 $vars = parent::getDefaultSchemaVars();
1256                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1257                 $vars['wgDBTableOptions'] = str_replace(
1258                         'CHARSET=mysql4',
1259                         'CHARSET=binary',
1260                         $vars['wgDBTableOptions']
1261                 );
1262
1263                 return $vars;
1264         }
1265
1266         /**
1267          * Get status information from SHOW STATUS in an associative array
1268          *
1269          * @param string $which
1270          * @return array
1271          */
1272         function getMysqlStatus( $which = "%" ) {
1273                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1274                 $status = [];
1275
1276                 foreach ( $res as $row ) {
1277                         $status[$row->Variable_name] = $row->Value;
1278                 }
1279
1280                 return $status;
1281         }
1282
1283         /**
1284          * Lists VIEWs in the database
1285          *
1286          * @param string $prefix Only show VIEWs with this prefix, eg.
1287          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1288          * @param string $fname Name of calling function
1289          * @return array
1290          * @since 1.22
1291          */
1292         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1293
1294                 if ( !isset( $this->allViews ) ) {
1295
1296                         // The name of the column containing the name of the VIEW
1297                         $propertyName = 'Tables_in_' . $this->mDBname;
1298
1299                         // Query for the VIEWS
1300                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1301                         $this->allViews = [];
1302                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1303                                 array_push( $this->allViews, $row[$propertyName] );
1304                         }
1305                 }
1306
1307                 if ( is_null( $prefix ) || $prefix === '' ) {
1308                         return $this->allViews;
1309                 }
1310
1311                 $filteredViews = [];
1312                 foreach ( $this->allViews as $viewName ) {
1313                         // Does the name of this VIEW start with the table-prefix?
1314                         if ( strpos( $viewName, $prefix ) === 0 ) {
1315                                 array_push( $filteredViews, $viewName );
1316                         }
1317                 }
1318
1319                 return $filteredViews;
1320         }
1321
1322         /**
1323          * Differentiates between a TABLE and a VIEW.
1324          *
1325          * @param string $name Name of the TABLE/VIEW to test
1326          * @param string $prefix
1327          * @return bool
1328          * @since 1.22
1329          */
1330         public function isView( $name, $prefix = null ) {
1331                 return in_array( $name, $this->listViews( $prefix ) );
1332         }
1333 }
1334
1335 /**
1336  * Utility class.
1337  * @ingroup Database
1338  */
1339 class MySQLField implements Field {
1340         private $name, $tablename, $default, $max_length, $nullable,
1341                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary,
1342                 $is_numeric, $is_blob, $is_unsigned, $is_zerofill;
1343
1344         function __construct( $info ) {
1345                 $this->name = $info->name;
1346                 $this->tablename = $info->table;
1347                 $this->default = $info->def;
1348                 $this->max_length = $info->max_length;
1349                 $this->nullable = !$info->not_null;
1350                 $this->is_pk = $info->primary_key;
1351                 $this->is_unique = $info->unique_key;
1352                 $this->is_multiple = $info->multiple_key;
1353                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1354                 $this->type = $info->type;
1355                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1356                 $this->is_numeric = isset( $info->numeric ) ? $info->numeric : false;
1357                 $this->is_blob = isset( $info->blob ) ? $info->blob : false;
1358                 $this->is_unsigned = isset( $info->unsigned ) ? $info->unsigned : false;
1359                 $this->is_zerofill = isset( $info->zerofill ) ? $info->zerofill : false;
1360         }
1361
1362         /**
1363          * @return string
1364          */
1365         function name() {
1366                 return $this->name;
1367         }
1368
1369         /**
1370          * @return string
1371          */
1372         function tableName() {
1373                 return $this->tablename;
1374         }
1375
1376         /**
1377          * @return string
1378          */
1379         function type() {
1380                 return $this->type;
1381         }
1382
1383         /**
1384          * @return bool
1385          */
1386         function isNullable() {
1387                 return $this->nullable;
1388         }
1389
1390         function defaultValue() {
1391                 return $this->default;
1392         }
1393
1394         /**
1395          * @return bool
1396          */
1397         function isKey() {
1398                 return $this->is_key;
1399         }
1400
1401         /**
1402          * @return bool
1403          */
1404         function isMultipleKey() {
1405                 return $this->is_multiple;
1406         }
1407
1408         /**
1409          * @return bool
1410          */
1411         function isBinary() {
1412                 return $this->binary;
1413         }
1414
1415         /**
1416          * @return bool
1417          */
1418         function isNumeric() {
1419                 return $this->is_numeric;
1420         }
1421
1422         /**
1423          * @return bool
1424          */
1425         function isBlob() {
1426                 return $this->is_blob;
1427         }
1428
1429         /**
1430          * @return bool
1431          */
1432         function isUnsigned() {
1433                 return $this->is_unsigned;
1434         }
1435
1436         /**
1437          * @return bool
1438          */
1439         function isZerofill() {
1440                 return $this->is_zerofill;
1441         }
1442 }
1443
1444 class MySQLMasterPos implements DBMasterPos {
1445         /** @var string */
1446         public $file;
1447         /** @var int Position */
1448         public $pos;
1449         /** @var float UNIX timestamp */
1450         public $asOfTime = 0.0;
1451
1452         function __construct( $file, $pos ) {
1453                 $this->file = $file;
1454                 $this->pos = $pos;
1455                 $this->asOfTime = microtime( true );
1456         }
1457
1458         function asOfTime() {
1459                 return $this->asOfTime;
1460         }
1461
1462         function hasReached( DBMasterPos $pos ) {
1463                 if ( !( $pos instanceof self ) ) {
1464                         throw new InvalidArgumentException( "Position not an instance of " . __CLASS__ );
1465                 }
1466
1467                 $thisPos = $this->getCoordinates();
1468                 $thatPos = $pos->getCoordinates();
1469
1470                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1471         }
1472
1473         function channelsMatch( DBMasterPos $pos ) {
1474                 if ( !( $pos instanceof self ) ) {
1475                         throw new InvalidArgumentException( "Position not an instance of " . __CLASS__ );
1476                 }
1477
1478                 $thisBinlog = $this->getBinlogName();
1479                 $thatBinlog = $pos->getBinlogName();
1480
1481                 return ( $thisBinlog !== false && $thisBinlog === $thatBinlog );
1482         }
1483
1484         function __toString() {
1485                 // e.g db1034-bin.000976/843431247
1486                 return "{$this->file}/{$this->pos}";
1487         }
1488
1489         /**
1490          * @return string|bool
1491          */
1492         protected function getBinlogName() {
1493                 $m = [];
1494                 if ( preg_match( '!^(.+)\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1495                         return $m[1];
1496                 }
1497
1498                 return false;
1499         }
1500
1501         /**
1502          * @return array|bool (int, int)
1503          */
1504         protected function getCoordinates() {
1505                 $m = [];
1506                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1507                         return [ (int)$m[1], (int)$m[2] ];
1508                 }
1509
1510                 return false;
1511         }
1512 }