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 DatabaseBase {
  33         /** @var MysqlMasterPos */
  34         protected $lastKnownSlavePos;
  35         /** @var string Method to detect slave lag */
  36         protected $lagDetectionMethod;
  37
  38         /** @var BagOStuff APC cache */
  39         protected $srvCache;
  40
  41         /** @var string|null */
  42         private $serverVersion = null;
  43
  44         /**
  45          * Additional $params include:
  46          *   - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
  47          *                          pt-heartbeat assumes the table is at heartbeat.heartbeat
  48          *                          and uses UTC timestamps in the heartbeat.ts column.
  49          *                          (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
  50          * @param array $params
  51          */
  52         function __construct( array $params ) {
  53                 parent::__construct( $params );
  54
  55                 $this->lagDetectionMethod = isset( $params['lagDetectionMethod'] )
  56                         ? $params['lagDetectionMethod']
  57                         : 'Seconds_Behind_Master';
  58
  59                 $this->srvCache = ObjectCache::newAccelerator( 'hash' );
  60         }
  61
  62         /**
  63          * @return string
  64          */
  65         function getType() {
  66                 return 'mysql';
  67         }
  68
  69         /**
  70          * @param string $server
  71          * @param string $user
  72          * @param string $password
  73          * @param string $dbName
  74          * @throws Exception|DBConnectionError
  75          * @return bool
  76          */
  77         function open( $server, $user, $password, $dbName ) {
  78                 global $wgAllDBsAreLocalhost, $wgSQLMode;
  79
  80                 # Close/unset connection handle
  81                 $this->close();
  82
  83                 # Debugging hack -- fake cluster
  84                 $realServer = $wgAllDBsAreLocalhost ? 'localhost' : $server;
  85                 $this->mServer = $server;
  86                 $this->mUser = $user;
  87                 $this->mPassword = $password;
  88                 $this->mDBname = $dbName;
  89
  90                 $this->installErrorHandler();
  91                 try {
  92                         $this->mConn = $this->mysqlConnect( $realServer );
  93                 } catch ( Exception $ex ) {
  94                         $this->restoreErrorHandler();
  95                         throw $ex;
  96                 }
  97                 $error = $this->restoreErrorHandler();
  98
  99                 # Always log connection errors
 100                 if ( !$this->mConn ) {
 101                         if ( !$error ) {
 102                                 $error = $this->lastError();
 103                         }
 104                         wfLogDBError(
 105                                 "Error connecting to {db_server}: {error}",
 106                                 $this->getLogContext( array(
 107                                         'method' => __METHOD__,
 108                                         'error' => $error,
 109                                 ) )
 110                         );
 111                         wfDebug( "DB connection error\n" .
 112                                 "Server: $server, User: $user, Password: " .
 113                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 114
 115                         $this->reportConnectionError( $error );
 116                 }
 117
 118                 if ( $dbName != '' ) {
 119                         MediaWiki\suppressWarnings();
 120                         $success = $this->selectDB( $dbName );
 121                         MediaWiki\restoreWarnings();
 122                         if ( !$success ) {
 123                                 wfLogDBError(
 124                                         "Error selecting database {db_name} on server {db_server}",
 125                                         $this->getLogContext( array(
 126                                                 'method' => __METHOD__,
 127                                         ) )
 128                                 );
 129                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 130                                         "from client host " . wfHostname() . "\n" );
 131
 132                                 $this->reportConnectionError( "Error selecting database $dbName" );
 133                         }
 134                 }
 135
 136                 // Tell the server what we're communicating with
 137                 if ( !$this->connectInitCharset() ) {
 138                         $this->reportConnectionError( "Error setting character set" );
 139                 }
 140
 141                 // Abstract over any insane MySQL defaults
 142                 $set = array( 'group_concat_max_len = 262144' );
 143                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 144                 if ( is_string( $wgSQLMode ) ) {
 145                         $set[] = 'sql_mode = ' . $this->addQuotes( $wgSQLMode );
 146                 }
 147                 // Set any custom settings defined by site config
 148                 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 149                 foreach ( $this->mSessionVars as $var => $val ) {
 150                         // Escape strings but not numbers to avoid MySQL complaining
 151                         if ( !is_int( $val ) && !is_float( $val ) ) {
 152                                 $val = $this->addQuotes( $val );
 153                         }
 154                         $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 155                 }
 156
 157                 if ( $set ) {
 158                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 159                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ) );
 160                         if ( !$success ) {
 161                                 wfLogDBError(
 162                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 163                                         $this->getLogContext( array(
 164                                                 'method' => __METHOD__,
 165                                         ) )
 166                                 );
 167                                 $this->reportConnectionError(
 168                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 169                         }
 170                 }
 171
 172                 $this->mOpened = true;
 173
 174                 return true;
 175         }
 176
 177         /**
 178          * Set the character set information right after connection
 179          * @return bool
 180          */
 181         protected function connectInitCharset() {
 182                 global $wgDBmysql5;
 183
 184                 if ( $wgDBmysql5 ) {
 185                         // Tell the server we're communicating with it in UTF-8.
 186                         // This may engage various charset conversions.
 187                         return $this->mysqlSetCharset( 'utf8' );
 188                 } else {
 189                         return $this->mysqlSetCharset( 'binary' );
 190                 }
 191         }
 192
 193         /**
 194          * Open a connection to a MySQL server
 195          *
 196          * @param string $realServer
 197          * @return mixed Raw connection
 198          * @throws DBConnectionError
 199          */
 200         abstract protected function mysqlConnect( $realServer );
 201
 202         /**
 203          * Set the character set of the MySQL link
 204          *
 205          * @param string $charset
 206          * @return bool
 207          */
 208         abstract protected function mysqlSetCharset( $charset );
 209
 210         /**
 211          * @param ResultWrapper|resource $res
 212          * @throws DBUnexpectedError
 213          */
 214         function freeResult( $res ) {
 215                 if ( $res instanceof ResultWrapper ) {
 216                         $res = $res->result;
 217                 }
 218                 MediaWiki\suppressWarnings();
 219                 $ok = $this->mysqlFreeResult( $res );
 220                 MediaWiki\restoreWarnings();
 221                 if ( !$ok ) {
 222                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 223                 }
 224         }
 225
 226         /**
 227          * Free result memory
 228          *
 229          * @param resource $res Raw result
 230          * @return bool
 231          */
 232         abstract protected function mysqlFreeResult( $res );
 233
 234         /**
 235          * @param ResultWrapper|resource $res
 236          * @return stdClass|bool
 237          * @throws DBUnexpectedError
 238          */
 239         function fetchObject( $res ) {
 240                 if ( $res instanceof ResultWrapper ) {
 241                         $res = $res->result;
 242                 }
 243                 MediaWiki\suppressWarnings();
 244                 $row = $this->mysqlFetchObject( $res );
 245                 MediaWiki\restoreWarnings();
 246
 247                 $errno = $this->lastErrno();
 248                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 249                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 250                 // these are the only errors mysql_fetch_object can cause.
 251                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 252                 if ( $errno == 2000 || $errno == 2013 ) {
 253                         throw new DBUnexpectedError(
 254                                 $this,
 255                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 256                         );
 257                 }
 258
 259                 return $row;
 260         }
 261
 262         /**
 263          * Fetch a result row as an object
 264          *
 265          * @param resource $res Raw result
 266          * @return stdClass
 267          */
 268         abstract protected function mysqlFetchObject( $res );
 269
 270         /**
 271          * @param ResultWrapper|resource $res
 272          * @return array|bool
 273          * @throws DBUnexpectedError
 274          */
 275         function fetchRow( $res ) {
 276                 if ( $res instanceof ResultWrapper ) {
 277                         $res = $res->result;
 278                 }
 279                 MediaWiki\suppressWarnings();
 280                 $row = $this->mysqlFetchArray( $res );
 281                 MediaWiki\restoreWarnings();
 282
 283                 $errno = $this->lastErrno();
 284                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 285                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 286                 // these are the only errors mysql_fetch_array can cause.
 287                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 288                 if ( $errno == 2000 || $errno == 2013 ) {
 289                         throw new DBUnexpectedError(
 290                                 $this,
 291                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 292                         );
 293                 }
 294
 295                 return $row;
 296         }
 297
 298         /**
 299          * Fetch a result row as an associative and numeric array
 300          *
 301          * @param resource $res Raw result
 302          * @return array
 303          */
 304         abstract protected function mysqlFetchArray( $res );
 305
 306         /**
 307          * @throws DBUnexpectedError
 308          * @param ResultWrapper|resource $res
 309          * @return int
 310          */
 311         function numRows( $res ) {
 312                 if ( $res instanceof ResultWrapper ) {
 313                         $res = $res->result;
 314                 }
 315                 MediaWiki\suppressWarnings();
 316                 $n = $this->mysqlNumRows( $res );
 317                 MediaWiki\restoreWarnings();
 318
 319                 // Unfortunately, mysql_num_rows does not reset the last errno.
 320                 // We are not checking for any errors here, since
 321                 // these are no errors mysql_num_rows can cause.
 322                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 323                 // See https://phabricator.wikimedia.org/T44430
 324                 return $n;
 325         }
 326
 327         /**
 328          * Get number of rows in result
 329          *
 330          * @param resource $res Raw result
 331          * @return int
 332          */
 333         abstract protected function mysqlNumRows( $res );
 334
 335         /**
 336          * @param ResultWrapper|resource $res
 337          * @return int
 338          */
 339         function numFields( $res ) {
 340                 if ( $res instanceof ResultWrapper ) {
 341                         $res = $res->result;
 342                 }
 343
 344                 return $this->mysqlNumFields( $res );
 345         }
 346
 347         /**
 348          * Get number of fields in result
 349          *
 350          * @param resource $res Raw result
 351          * @return int
 352          */
 353         abstract protected function mysqlNumFields( $res );
 354
 355         /**
 356          * @param ResultWrapper|resource $res
 357          * @param int $n
 358          * @return string
 359          */
 360         function fieldName( $res, $n ) {
 361                 if ( $res instanceof ResultWrapper ) {
 362                         $res = $res->result;
 363                 }
 364
 365                 return $this->mysqlFieldName( $res, $n );
 366         }
 367
 368         /**
 369          * Get the name of the specified field in a result
 370          *
 371          * @param ResultWrapper|resource $res
 372          * @param int $n
 373          * @return string
 374          */
 375         abstract protected function mysqlFieldName( $res, $n );
 376
 377         /**
 378          * mysql_field_type() wrapper
 379          * @param ResultWrapper|resource $res
 380          * @param int $n
 381          * @return string
 382          */
 383         public function fieldType( $res, $n ) {
 384                 if ( $res instanceof ResultWrapper ) {
 385                         $res = $res->result;
 386                 }
 387
 388                 return $this->mysqlFieldType( $res, $n );
 389         }
 390
 391         /**
 392          * Get the type of the specified field in a result
 393          *
 394          * @param ResultWrapper|resource $res
 395          * @param int $n
 396          * @return string
 397          */
 398         abstract protected function mysqlFieldType( $res, $n );
 399
 400         /**
 401          * @param ResultWrapper|resource $res
 402          * @param int $row
 403          * @return bool
 404          */
 405         function dataSeek( $res, $row ) {
 406                 if ( $res instanceof ResultWrapper ) {
 407                         $res = $res->result;
 408                 }
 409
 410                 return $this->mysqlDataSeek( $res, $row );
 411         }
 412
 413         /**
 414          * Move internal result pointer
 415          *
 416          * @param ResultWrapper|resource $res
 417          * @param int $row
 418          * @return bool
 419          */
 420         abstract protected function mysqlDataSeek( $res, $row );
 421
 422         /**
 423          * @return string
 424          */
 425         function lastError() {
 426                 if ( $this->mConn ) {
 427                         # Even if it's non-zero, it can still be invalid
 428                         MediaWiki\suppressWarnings();
 429                         $error = $this->mysqlError( $this->mConn );
 430                         if ( !$error ) {
 431                                 $error = $this->mysqlError();
 432                         }
 433                         MediaWiki\restoreWarnings();
 434                 } else {
 435                         $error = $this->mysqlError();
 436                 }
 437                 if ( $error ) {
 438                         $error .= ' (' . $this->mServer . ')';
 439                 }
 440
 441                 return $error;
 442         }
 443
 444         /**
 445          * Returns the text of the error message from previous MySQL operation
 446          *
 447          * @param resource $conn Raw connection
 448          * @return string
 449          */
 450         abstract protected function mysqlError( $conn = null );
 451
 452         /**
 453          * @param string $table
 454          * @param array $uniqueIndexes
 455          * @param array $rows
 456          * @param string $fname
 457          * @return ResultWrapper
 458          */
 459         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 460                 return $this->nativeReplace( $table, $rows, $fname );
 461         }
 462
 463         /**
 464          * Estimate rows in dataset
 465          * Returns estimated count, based on EXPLAIN output
 466          * Takes same arguments as Database::select()
 467          *
 468          * @param string|array $table
 469          * @param string|array $vars
 470          * @param string|array $conds
 471          * @param string $fname
 472          * @param string|array $options
 473          * @return bool|int
 474          */
 475         public function estimateRowCount( $table, $vars = '*', $conds = '',
 476                 $fname = __METHOD__, $options = array()
 477         ) {
 478                 $options['EXPLAIN'] = true;
 479                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 480                 if ( $res === false ) {
 481                         return false;
 482                 }
 483                 if ( !$this->numRows( $res ) ) {
 484                         return 0;
 485                 }
 486
 487                 $rows = 1;
 488                 foreach ( $res as $plan ) {
 489                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 490                 }
 491
 492                 return (int)$rows;
 493         }
 494
 495         /**
 496          * @param string $table
 497          * @param string $field
 498          * @return bool|MySQLField
 499          */
 500         function fieldInfo( $table, $field ) {
 501                 $table = $this->tableName( $table );
 502                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 503                 if ( !$res ) {
 504                         return false;
 505                 }
 506                 $n = $this->mysqlNumFields( $res->result );
 507                 for ( $i = 0; $i < $n; $i++ ) {
 508                         $meta = $this->mysqlFetchField( $res->result, $i );
 509                         if ( $field == $meta->name ) {
 510                                 return new MySQLField( $meta );
 511                         }
 512                 }
 513
 514                 return false;
 515         }
 516
 517         /**
 518          * Get column information from a result
 519          *
 520          * @param resource $res Raw result
 521          * @param int $n
 522          * @return stdClass
 523          */
 524         abstract protected function mysqlFetchField( $res, $n );
 525
 526         /**
 527          * Get information about an index into an object
 528          * Returns false if the index does not exist
 529          *
 530          * @param string $table
 531          * @param string $index
 532          * @param string $fname
 533          * @return bool|array|null False or null on failure
 534          */
 535         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 536                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 537                 # SHOW INDEX should work for 3.x and up:
 538                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 539                 $table = $this->tableName( $table );
 540                 $index = $this->indexName( $index );
 541
 542                 $sql = 'SHOW INDEX FROM ' . $table;
 543                 $res = $this->query( $sql, $fname );
 544
 545                 if ( !$res ) {
 546                         return null;
 547                 }
 548
 549                 $result = array();
 550
 551                 foreach ( $res as $row ) {
 552                         if ( $row->Key_name == $index ) {
 553                                 $result[] = $row;
 554                         }
 555                 }
 556
 557                 return empty( $result ) ? false : $result;
 558         }
 559
 560         /**
 561          * @param string $s
 562          * @return string
 563          */
 564         function strencode( $s ) {
 565                 $sQuoted = $this->mysqlRealEscapeString( $s );
 566
 567                 if ( $sQuoted === false ) {
 568                         $this->ping();
 569                         $sQuoted = $this->mysqlRealEscapeString( $s );
 570                 }
 571
 572                 return $sQuoted;
 573         }
 574
 575         /**
 576          * @param string $s
 577          * @return mixed
 578          */
 579         abstract protected function mysqlRealEscapeString( $s );
 580
 581         /**
 582          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 583          *
 584          * @param string $s
 585          * @return string
 586          */
 587         public function addIdentifierQuotes( $s ) {
 588                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 589                 // Remove NUL bytes and escape backticks by doubling
 590                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s ) . '`';
 591         }
 592
 593         /**
 594          * @param string $name
 595          * @return bool
 596          */
 597         public function isQuotedIdentifier( $name ) {
 598                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 599         }
 600
 601         /**
 602          * @return bool
 603          */
 604         function ping() {
 605                 $ping = $this->mysqlPing();
 606                 if ( $ping ) {
 607                         // Connection was good or lost but reconnected...
 608                         // @note: mysqlnd (php 5.6+) does not support this (PHP bug 52561)
 609                         return true;
 610                 }
 611
 612                 // Try a full disconnect/reconnect cycle if ping() failed
 613                 $this->closeConnection();
 614                 $this->mOpened = false;
 615                 $this->mConn = false;
 616                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 617
 618                 return true;
 619         }
 620
 621         /**
 622          * Ping a server connection or reconnect if there is no connection
 623          *
 624          * @return bool
 625          */
 626         abstract protected function mysqlPing();
 627
 628         /**
 629          * Returns slave lag.
 630          *
 631          * This will do a SHOW SLAVE STATUS
 632          *
 633          * @return int
 634          */
 635         function getLag() {
 636                 if ( $this->lagDetectionMethod === 'pt-heartbeat' ) {
 637                         return $this->getLagFromPtHeartbeat();
 638                 } else {
 639                         return $this->getLagFromSlaveStatus();
 640                 }
 641         }
 642
 643         /**
 644          * @return bool|int
 645          */
 646         protected function getLagFromSlaveStatus() {
 647                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 648                 $row = $res ? $res->fetchObject() : false;
 649                 if ( $row && strval( $row->Seconds_Behind_Master ) !== '' ) {
 650                         return intval( $row->Seconds_Behind_Master );
 651                 }
 652
 653                 return false;
 654         }
 655
 656         /**
 657          * @return bool|float
 658          */
 659         protected function getLagFromPtHeartbeat() {
 660                 $key = wfMemcKey( 'mysql', 'master-server-id', $this->getServer() );
 661                 $masterId = intval( $this->srvCache->get( $key ) );
 662                 if ( !$masterId ) {
 663                         $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 664                         $row = $res ? $res->fetchObject() : false;
 665                         if ( $row && strval( $row->Master_Server_Id ) !== '' ) {
 666                                 $masterId = intval( $row->Master_Server_Id );
 667                                 $this->srvCache->set( $key, $masterId, 30 );
 668                         }
 669                 }
 670
 671                 if ( !$masterId ) {
 672                         return false;
 673                 }
 674
 675                 $res = $this->query(
 676                         "SELECT TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6)) AS Lag " .
 677                         "FROM heartbeat.heartbeat WHERE server_id = $masterId"
 678                 );
 679                 $row = $res ? $res->fetchObject() : false;
 680                 if ( $row ) {
 681                         return max( floatval( $row->Lag ) / 1e6, 0.0 );
 682                 }
 683
 684                 return false;
 685         }
 686
 687         /**
 688          * Wait for the slave to catch up to a given master position.
 689          * @todo Return values for this and base class are rubbish
 690          *
 691          * @param DBMasterPos|MySQLMasterPos $pos
 692          * @param int $timeout The maximum number of seconds to wait for synchronisation
 693          * @return int Zero if the slave was past that position already,
 694          *   greater than zero if we waited for some period of time, less than
 695          *   zero if we timed out.
 696          */
 697         function masterPosWait( DBMasterPos $pos, $timeout ) {
 698                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 699                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 700                 }
 701
 702                 # Commit any open transactions
 703                 $this->commit( __METHOD__, 'flush' );
 704
 705                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 706                 $encFile = $this->addQuotes( $pos->file );
 707                 $encPos = intval( $pos->pos );
 708                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 709                 $res = $this->doQuery( $sql );
 710
 711                 $status = false;
 712                 if ( $res && $row = $this->fetchRow( $res ) ) {
 713                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 714                         if ( ctype_digit( $status ) ) { // success
 715                                 $this->lastKnownSlavePos = $pos;
 716                         }
 717                 }
 718
 719                 return $status;
 720         }
 721
 722         /**
 723          * Get the position of the master from SHOW SLAVE STATUS
 724          *
 725          * @return MySQLMasterPos|bool
 726          */
 727         function getSlavePos() {
 728                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 729                 $row = $this->fetchObject( $res );
 730
 731                 if ( $row ) {
 732                         $pos = isset( $row->Exec_master_log_pos )
 733                                 ? $row->Exec_master_log_pos
 734                                 : $row->Exec_Master_Log_Pos;
 735
 736                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 737                 } else {
 738                         return false;
 739                 }
 740         }
 741
 742         /**
 743          * Get the position of the master from SHOW MASTER STATUS
 744          *
 745          * @return MySQLMasterPos|bool
 746          */
 747         function getMasterPos() {
 748                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 749                 $row = $this->fetchObject( $res );
 750
 751                 if ( $row ) {
 752                         return new MySQLMasterPos( $row->File, $row->Position );
 753                 } else {
 754                         return false;
 755                 }
 756         }
 757
 758         /**
 759          * @param string $index
 760          * @return string
 761          */
 762         function useIndexClause( $index ) {
 763                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 764         }
 765
 766         /**
 767          * @return string
 768          */
 769         function lowPriorityOption() {
 770                 return 'LOW_PRIORITY';
 771         }
 772
 773         /**
 774          * @return string
 775          */
 776         public function getSoftwareLink() {
 777                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 778                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 779                 // in libmysql/libmysql.c).
 780                 $version = $this->getServerVersion();
 781                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 782                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 783                 }
 784
 785                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 786                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 787                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 788                 return '[{{int:version-db-mysql-url}} MySQL]';
 789         }
 790
 791         /**
 792          * @return string
 793          */
 794         public function getServerVersion() {
 795                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 796                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 797                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 798                 if ( $this->serverVersion === null ) {
 799                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 800                 }
 801                 return $this->serverVersion;
 802         }
 803
 804         /**
 805          * @param array $options
 806          */
 807         public function setSessionOptions( array $options ) {
 808                 if ( isset( $options['connTimeout'] ) ) {
 809                         $timeout = (int)$options['connTimeout'];
 810                         $this->query( "SET net_read_timeout=$timeout" );
 811                         $this->query( "SET net_write_timeout=$timeout" );
 812                 }
 813         }
 814
 815         /**
 816          * @param string $sql
 817          * @param string $newLine
 818          * @return bool
 819          */
 820         public function streamStatementEnd( &$sql, &$newLine ) {
 821                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 822                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 823                         $this->delimiter = $m[1];
 824                         $newLine = '';
 825                 }
 826
 827                 return parent::streamStatementEnd( $sql, $newLine );
 828         }
 829
 830         /**
 831          * Check to see if a named lock is available. This is non-blocking.
 832          *
 833          * @param string $lockName Name of lock to poll
 834          * @param string $method Name of method calling us
 835          * @return bool
 836          * @since 1.20
 837          */
 838         public function lockIsFree( $lockName, $method ) {
 839                 $lockName = $this->addQuotes( $lockName );
 840                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 841                 $row = $this->fetchObject( $result );
 842
 843                 return ( $row->lockstatus == 1 );
 844         }
 845
 846         /**
 847          * @param string $lockName
 848          * @param string $method
 849          * @param int $timeout
 850          * @return bool
 851          */
 852         public function lock( $lockName, $method, $timeout = 5 ) {
 853                 $lockName = $this->addQuotes( $lockName );
 854                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 855                 $row = $this->fetchObject( $result );
 856
 857                 if ( $row->lockstatus == 1 ) {
 858                         return true;
 859                 } else {
 860                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 861
 862                         return false;
 863                 }
 864         }
 865
 866         /**
 867          * FROM MYSQL DOCS:
 868          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 869          * @param string $lockName
 870          * @param string $method
 871          * @return bool
 872          */
 873         public function unlock( $lockName, $method ) {
 874                 $lockName = $this->addQuotes( $lockName );
 875                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 876                 $row = $this->fetchObject( $result );
 877
 878                 return ( $row->lockstatus == 1 );
 879         }
 880
 881         public function namedLocksEnqueue() {
 882                 return true;
 883         }
 884
 885         /**
 886          * @param array $read
 887          * @param array $write
 888          * @param string $method
 889          * @param bool $lowPriority
 890          * @return bool
 891          */
 892         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 893                 $items = array();
 894
 895                 foreach ( $write as $table ) {
 896                         $tbl = $this->tableName( $table ) .
 897                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 898                                 ' WRITE';
 899                         $items[] = $tbl;
 900                 }
 901                 foreach ( $read as $table ) {
 902                         $items[] = $this->tableName( $table ) . ' READ';
 903                 }
 904                 $sql = "LOCK TABLES " . implode( ',', $items );
 905                 $this->query( $sql, $method );
 906
 907                 return true;
 908         }
 909
 910         /**
 911          * @param string $method
 912          * @return bool
 913          */
 914         public function unlockTables( $method ) {
 915                 $this->query( "UNLOCK TABLES", $method );
 916
 917                 return true;
 918         }
 919
 920         /**
 921          * Get search engine class. All subclasses of this
 922          * need to implement this if they wish to use searching.
 923          *
 924          * @return string
 925          */
 926         public function getSearchEngine() {
 927                 return 'SearchMySQL';
 928         }
 929
 930         /**
 931          * @param bool $value
 932          */
 933         public function setBigSelects( $value = true ) {
 934                 if ( $value === 'default' ) {
 935                         if ( $this->mDefaultBigSelects === null ) {
 936                                 # Function hasn't been called before so it must already be set to the default
 937                                 return;
 938                         } else {
 939                                 $value = $this->mDefaultBigSelects;
 940                         }
 941                 } elseif ( $this->mDefaultBigSelects === null ) {
 942                         $this->mDefaultBigSelects =
 943                                 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__ );
 944                 }
 945                 $encValue = $value ? '1' : '0';
 946                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 947         }
 948
 949         /**
 950          * DELETE where the condition is a join. MySql uses multi-table deletes.
 951          * @param string $delTable
 952          * @param string $joinTable
 953          * @param string $delVar
 954          * @param string $joinVar
 955          * @param array|string $conds
 956          * @param bool|string $fname
 957          * @throws DBUnexpectedError
 958          * @return bool|ResultWrapper
 959          */
 960         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 961                 if ( !$conds ) {
 962                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 963                 }
 964
 965                 $delTable = $this->tableName( $delTable );
 966                 $joinTable = $this->tableName( $joinTable );
 967                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 968
 969                 if ( $conds != '*' ) {
 970                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 971                 }
 972
 973                 return $this->query( $sql, $fname );
 974         }
 975
 976         /**
 977          * @param string $table
 978          * @param array $rows
 979          * @param array $uniqueIndexes
 980          * @param array $set
 981          * @param string $fname
 982          * @return bool
 983          */
 984         public function upsert( $table, array $rows, array $uniqueIndexes,
 985                 array $set, $fname = __METHOD__
 986         ) {
 987                 if ( !count( $rows ) ) {
 988                         return true; // nothing to do
 989                 }
 990
 991                 if ( !is_array( reset( $rows ) ) ) {
 992                         $rows = array( $rows );
 993                 }
 994
 995                 $table = $this->tableName( $table );
 996                 $columns = array_keys( $rows[0] );
 997
 998                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
 999                 $rowTuples = array();
1000                 foreach ( $rows as $row ) {
1001                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1002                 }
1003                 $sql .= implode( ',', $rowTuples );
1004                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
1005
1006                 return (bool)$this->query( $sql, $fname );
1007         }
1008
1009         /**
1010          * Determines how long the server has been up
1011          *
1012          * @return int
1013          */
1014         function getServerUptime() {
1015                 $vars = $this->getMysqlStatus( 'Uptime' );
1016
1017                 return (int)$vars['Uptime'];
1018         }
1019
1020         /**
1021          * Determines if the last failure was due to a deadlock
1022          *
1023          * @return bool
1024          */
1025         function wasDeadlock() {
1026                 return $this->lastErrno() == 1213;
1027         }
1028
1029         /**
1030          * Determines if the last failure was due to a lock timeout
1031          *
1032          * @return bool
1033          */
1034         function wasLockTimeout() {
1035                 return $this->lastErrno() == 1205;
1036         }
1037
1038         /**
1039          * Determines if the last query error was something that should be dealt
1040          * with by pinging the connection and reissuing the query
1041          *
1042          * @return bool
1043          */
1044         function wasErrorReissuable() {
1045                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1046         }
1047
1048         /**
1049          * Determines if the last failure was due to the database being read-only.
1050          *
1051          * @return bool
1052          */
1053         function wasReadOnlyError() {
1054                 return $this->lastErrno() == 1223 ||
1055                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1056         }
1057
1058         function wasConnectionError( $errno ) {
1059                 return $errno == 2013 || $errno == 2006;
1060         }
1061
1062         /**
1063          * Get the underlying binding handle, mConn
1064          *
1065          * Makes sure that mConn is set (disconnects and ping() failure can unset it).
1066          * This catches broken callers than catch and ignore disconnection exceptions.
1067          * Unlike checking isOpen(), this is safe to call inside of open().
1068          *
1069          * @return resource|object
1070          * @throws DBUnexpectedError
1071          * @since 1.26
1072          */
1073         protected function getBindingHandle() {
1074                 if ( !$this->mConn ) {
1075                         throw new DBUnexpectedError(
1076                                 $this,
1077                                 'DB connection was already closed or the connection dropped.'
1078                         );
1079                 }
1080
1081                 return $this->mConn;
1082         }
1083
1084         /**
1085          * @param string $oldName
1086          * @param string $newName
1087          * @param bool $temporary
1088          * @param string $fname
1089          * @return bool
1090          */
1091         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1092                 $tmp = $temporary ? 'TEMPORARY ' : '';
1093                 $newName = $this->addIdentifierQuotes( $newName );
1094                 $oldName = $this->addIdentifierQuotes( $oldName );
1095                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1096
1097                 return $this->query( $query, $fname );
1098         }
1099
1100         /**
1101          * List all tables on the database
1102          *
1103          * @param string $prefix Only show tables with this prefix, e.g. mw_
1104          * @param string $fname Calling function name
1105          * @return array
1106          */
1107         function listTables( $prefix = null, $fname = __METHOD__ ) {
1108                 $result = $this->query( "SHOW TABLES", $fname );
1109
1110                 $endArray = array();
1111
1112                 foreach ( $result as $table ) {
1113                         $vars = get_object_vars( $table );
1114                         $table = array_pop( $vars );
1115
1116                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1117                                 $endArray[] = $table;
1118                         }
1119                 }
1120
1121                 return $endArray;
1122         }
1123
1124         /**
1125          * @param string $tableName
1126          * @param string $fName
1127          * @return bool|ResultWrapper
1128          */
1129         public function dropTable( $tableName, $fName = __METHOD__ ) {
1130                 if ( !$this->tableExists( $tableName, $fName ) ) {
1131                         return false;
1132                 }
1133
1134                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1135         }
1136
1137         /**
1138          * @return array
1139          */
1140         protected function getDefaultSchemaVars() {
1141                 $vars = parent::getDefaultSchemaVars();
1142                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1143                 $vars['wgDBTableOptions'] = str_replace(
1144                         'CHARSET=mysql4',
1145                         'CHARSET=binary',
1146                         $vars['wgDBTableOptions']
1147                 );
1148
1149                 return $vars;
1150         }
1151
1152         /**
1153          * Get status information from SHOW STATUS in an associative array
1154          *
1155          * @param string $which
1156          * @return array
1157          */
1158         function getMysqlStatus( $which = "%" ) {
1159                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1160                 $status = array();
1161
1162                 foreach ( $res as $row ) {
1163                         $status[$row->Variable_name] = $row->Value;
1164                 }
1165
1166                 return $status;
1167         }
1168
1169         /**
1170          * Lists VIEWs in the database
1171          *
1172          * @param string $prefix Only show VIEWs with this prefix, eg.
1173          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1174          * @param string $fname Name of calling function
1175          * @return array
1176          * @since 1.22
1177          */
1178         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1179
1180                 if ( !isset( $this->allViews ) ) {
1181
1182                         // The name of the column containing the name of the VIEW
1183                         $propertyName = 'Tables_in_' . $this->mDBname;
1184
1185                         // Query for the VIEWS
1186                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1187                         $this->allViews = array();
1188                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1189                                 array_push( $this->allViews, $row[$propertyName] );
1190                         }
1191                 }
1192
1193                 if ( is_null( $prefix ) || $prefix === '' ) {
1194                         return $this->allViews;
1195                 }
1196
1197                 $filteredViews = array();
1198                 foreach ( $this->allViews as $viewName ) {
1199                         // Does the name of this VIEW start with the table-prefix?
1200                         if ( strpos( $viewName, $prefix ) === 0 ) {
1201                                 array_push( $filteredViews, $viewName );
1202                         }
1203                 }
1204
1205                 return $filteredViews;
1206         }
1207
1208         /**
1209          * Differentiates between a TABLE and a VIEW.
1210          *
1211          * @param string $name Name of the TABLE/VIEW to test
1212          * @param string $prefix
1213          * @return bool
1214          * @since 1.22
1215          */
1216         public function isView( $name, $prefix = null ) {
1217                 return in_array( $name, $this->listViews( $prefix ) );
1218         }
1219 }
1220
1221 /**
1222  * Utility class.
1223  * @ingroup Database
1224  */
1225 class MySQLField implements Field {
1226         private $name, $tablename, $default, $max_length, $nullable,
1227                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary,
1228                 $is_numeric, $is_blob, $is_unsigned, $is_zerofill;
1229
1230         function __construct( $info ) {
1231                 $this->name = $info->name;
1232                 $this->tablename = $info->table;
1233                 $this->default = $info->def;
1234                 $this->max_length = $info->max_length;
1235                 $this->nullable = !$info->not_null;
1236                 $this->is_pk = $info->primary_key;
1237                 $this->is_unique = $info->unique_key;
1238                 $this->is_multiple = $info->multiple_key;
1239                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1240                 $this->type = $info->type;
1241                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1242                 $this->is_numeric = isset( $info->numeric ) ? $info->numeric : false;
1243                 $this->is_blob = isset( $info->blob ) ? $info->blob : false;
1244                 $this->is_unsigned = isset( $info->unsigned ) ? $info->unsigned : false;
1245                 $this->is_zerofill = isset( $info->zerofill ) ? $info->zerofill : false;
1246         }
1247
1248         /**
1249          * @return string
1250          */
1251         function name() {
1252                 return $this->name;
1253         }
1254
1255         /**
1256          * @return string
1257          */
1258         function tableName() {
1259                 return $this->tablename;
1260         }
1261
1262         /**
1263          * @return string
1264          */
1265         function type() {
1266                 return $this->type;
1267         }
1268
1269         /**
1270          * @return bool
1271          */
1272         function isNullable() {
1273                 return $this->nullable;
1274         }
1275
1276         function defaultValue() {
1277                 return $this->default;
1278         }
1279
1280         /**
1281          * @return bool
1282          */
1283         function isKey() {
1284                 return $this->is_key;
1285         }
1286
1287         /**
1288          * @return bool
1289          */
1290         function isMultipleKey() {
1291                 return $this->is_multiple;
1292         }
1293
1294         /**
1295          * @return bool
1296          */
1297         function isBinary() {
1298                 return $this->binary;
1299         }
1300
1301         /**
1302          * @return bool
1303          */
1304         function isNumeric() {
1305                 return $this->is_numeric;
1306         }
1307
1308         /**
1309          * @return bool
1310          */
1311         function isBlob() {
1312                 return $this->is_blob;
1313         }
1314
1315         /**
1316          * @return bool
1317          */
1318         function isUnsigned() {
1319                 return $this->is_unsigned;
1320         }
1321
1322         /**
1323          * @return bool
1324          */
1325         function isZerofill() {
1326                 return $this->is_zerofill;
1327         }
1328 }
1329
1330 class MySQLMasterPos implements DBMasterPos {
1331         /** @var string */
1332         public $file;
1333         /** @var int Position */
1334         public $pos;
1335         /** @var float UNIX timestamp */
1336         public $asOfTime = 0.0;
1337
1338         function __construct( $file, $pos ) {
1339                 $this->file = $file;
1340                 $this->pos = $pos;
1341                 $this->asOfTime = microtime( true );
1342         }
1343
1344         function __toString() {
1345                 // e.g db1034-bin.000976/843431247
1346                 return "{$this->file}/{$this->pos}";
1347         }
1348
1349         /**
1350          * @return array|bool (int, int)
1351          */
1352         protected function getCoordinates() {
1353                 $m = array();
1354                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1355                         return array( (int)$m[1], (int)$m[2] );
1356                 }
1357
1358                 return false;
1359         }
1360
1361         function hasReached( MySQLMasterPos $pos ) {
1362                 $thisPos = $this->getCoordinates();
1363                 $thatPos = $pos->getCoordinates();
1364
1365                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1366         }
1367
1368         function asOfTime() {
1369                 return $this->asOfTime;
1370         }
1371 }