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
  36         /** @var null|int */
  37         protected $mFakeSlaveLag = null;
  38
  39         protected $mFakeMaster = false;
  40
  41         /** @var string|null */
  42         private $serverVersion = null;
  43
  44         /**
  45          * @return string
  46          */
  47         function getType() {
  48                 return 'mysql';
  49         }
  50
  51         /**
  52          * @param string $server
  53          * @param string $user
  54          * @param string $password
  55          * @param string $dbName
  56          * @throws Exception|DBConnectionError
  57          * @return bool
  58          */
  59         function open( $server, $user, $password, $dbName ) {
  60                 global $wgAllDBsAreLocalhost, $wgSQLMode;
  61
  62                 # Debugging hack -- fake cluster
  63                 if ( $wgAllDBsAreLocalhost ) {
  64                         $realServer = 'localhost';
  65                 } else {
  66                         $realServer = $server;
  67                 }
  68                 $this->close();
  69                 $this->mServer = $server;
  70                 $this->mUser = $user;
  71                 $this->mPassword = $password;
  72                 $this->mDBname = $dbName;
  73
  74                 # The kernel's default SYN retransmission period is far too slow for us,
  75                 # so we use a short timeout plus a manual retry. Retrying means that a small
  76                 # but finite rate of SYN packet loss won't cause user-visible errors.
  77                 $this->mConn = false;
  78                 $this->installErrorHandler();
  79                 try {
  80                         $this->mConn = $this->mysqlConnect( $realServer );
  81                 } catch ( Exception $ex ) {
  82                         $this->restoreErrorHandler();
  83                         throw $ex;
  84                 }
  85                 $error = $this->restoreErrorHandler();
  86
  87                 # Always log connection errors
  88                 if ( !$this->mConn ) {
  89                         if ( !$error ) {
  90                                 $error = $this->lastError();
  91                         }
  92                         wfLogDBError(
  93                                 "Error connecting to {db_server}: {error}",
  94                                 $this->getLogContext( array(
  95                                         'method' => __METHOD__,
  96                                         'error' => $error,
  97                                 ) )
  98                         );
  99                         wfDebug( "DB connection error\n" .
 100                                 "Server: $server, User: $user, Password: " .
 101                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 102
 103                         $this->reportConnectionError( $error );
 104                 }
 105
 106                 if ( $dbName != '' ) {
 107                         wfSuppressWarnings();
 108                         $success = $this->selectDB( $dbName );
 109                         wfRestoreWarnings();
 110                         if ( !$success ) {
 111                                 wfLogDBError(
 112                                         "Error selecting database {db_name} on server {db_server}",
 113                                         $this->getLogContext( array(
 114                                                 'method' => __METHOD__,
 115                                         ) )
 116                                 );
 117                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 118                                         "from client host " . wfHostname() . "\n" );
 119
 120                                 $this->reportConnectionError( "Error selecting database $dbName" );
 121                         }
 122                 }
 123
 124                 // Tell the server what we're communicating with
 125                 if ( !$this->connectInitCharset() ) {
 126                         $this->reportConnectionError( "Error setting character set" );
 127                 }
 128
 129                 // Abstract over any insane MySQL defaults
 130                 $set = array( 'group_concat_max_len = 262144' );
 131                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 132                 if ( is_string( $wgSQLMode ) ) {
 133                         $set[] = 'sql_mode = ' . $this->addQuotes( $wgSQLMode );
 134                 }
 135                 // Set any custom settings defined by site config
 136                 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 137                 foreach ( $this->mSessionVars as $var => $val ) {
 138                         // Escape strings but not numbers to avoid MySQL complaining
 139                         if ( !is_int( $val ) && !is_float( $val ) ) {
 140                                 $val = $this->addQuotes( $val );
 141                         }
 142                         $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 143                 }
 144
 145                 if ( $set ) {
 146                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 147                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ), __METHOD__ );
 148                         if ( !$success ) {
 149                                 wfLogDBError(
 150                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 151                                         $this->getLogContext( array(
 152                                                 'method' => __METHOD__,
 153                                         ) )
 154                                 );
 155                                 $this->reportConnectionError(
 156                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 157                         }
 158                 }
 159
 160                 $this->mOpened = true;
 161
 162                 return true;
 163         }
 164
 165         /**
 166          * Set the character set information right after connection
 167          * @return bool
 168          */
 169         protected function connectInitCharset() {
 170                 global $wgDBmysql5;
 171
 172                 if ( $wgDBmysql5 ) {
 173                         // Tell the server we're communicating with it in UTF-8.
 174                         // This may engage various charset conversions.
 175                         return $this->mysqlSetCharset( 'utf8' );
 176                 } else {
 177                         return $this->mysqlSetCharset( 'binary' );
 178                 }
 179         }
 180
 181         /**
 182          * Open a connection to a MySQL server
 183          *
 184          * @param string $realServer
 185          * @return mixed Raw connection
 186          * @throws DBConnectionError
 187          */
 188         abstract protected function mysqlConnect( $realServer );
 189
 190         /**
 191          * Set the character set of the MySQL link
 192          *
 193          * @param string $charset
 194          * @return bool
 195          */
 196         abstract protected function mysqlSetCharset( $charset );
 197
 198         /**
 199          * @param ResultWrapper|resource $res
 200          * @throws DBUnexpectedError
 201          */
 202         function freeResult( $res ) {
 203                 if ( $res instanceof ResultWrapper ) {
 204                         $res = $res->result;
 205                 }
 206                 wfSuppressWarnings();
 207                 $ok = $this->mysqlFreeResult( $res );
 208                 wfRestoreWarnings();
 209                 if ( !$ok ) {
 210                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 211                 }
 212         }
 213
 214         /**
 215          * Free result memory
 216          *
 217          * @param resource $res Raw result
 218          * @return bool
 219          */
 220         abstract protected function mysqlFreeResult( $res );
 221
 222         /**
 223          * @param ResultWrapper|resource $res
 224          * @return stdClass|bool
 225          * @throws DBUnexpectedError
 226          */
 227         function fetchObject( $res ) {
 228                 if ( $res instanceof ResultWrapper ) {
 229                         $res = $res->result;
 230                 }
 231                 wfSuppressWarnings();
 232                 $row = $this->mysqlFetchObject( $res );
 233                 wfRestoreWarnings();
 234
 235                 $errno = $this->lastErrno();
 236                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 237                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 238                 // these are the only errors mysql_fetch_object can cause.
 239                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 240                 if ( $errno == 2000 || $errno == 2013 ) {
 241                         throw new DBUnexpectedError(
 242                                 $this,
 243                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 244                         );
 245                 }
 246
 247                 return $row;
 248         }
 249
 250         /**
 251          * Fetch a result row as an object
 252          *
 253          * @param resource $res Raw result
 254          * @return stdClass
 255          */
 256         abstract protected function mysqlFetchObject( $res );
 257
 258         /**
 259          * @param ResultWrapper|resource $res
 260          * @return array|bool
 261          * @throws DBUnexpectedError
 262          */
 263         function fetchRow( $res ) {
 264                 if ( $res instanceof ResultWrapper ) {
 265                         $res = $res->result;
 266                 }
 267                 wfSuppressWarnings();
 268                 $row = $this->mysqlFetchArray( $res );
 269                 wfRestoreWarnings();
 270
 271                 $errno = $this->lastErrno();
 272                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 273                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 274                 // these are the only errors mysql_fetch_array can cause.
 275                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 276                 if ( $errno == 2000 || $errno == 2013 ) {
 277                         throw new DBUnexpectedError(
 278                                 $this,
 279                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 280                         );
 281                 }
 282
 283                 return $row;
 284         }
 285
 286         /**
 287          * Fetch a result row as an associative and numeric array
 288          *
 289          * @param resource $res Raw result
 290          * @return array
 291          */
 292         abstract protected function mysqlFetchArray( $res );
 293
 294         /**
 295          * @throws DBUnexpectedError
 296          * @param ResultWrapper|resource $res
 297          * @return int
 298          */
 299         function numRows( $res ) {
 300                 if ( $res instanceof ResultWrapper ) {
 301                         $res = $res->result;
 302                 }
 303                 wfSuppressWarnings();
 304                 $n = $this->mysqlNumRows( $res );
 305                 wfRestoreWarnings();
 306
 307                 // Unfortunately, mysql_num_rows does not reset the last errno.
 308                 // We are not checking for any errors here, since
 309                 // these are no errors mysql_num_rows can cause.
 310                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 311                 // See https://bugzilla.wikimedia.org/42430
 312                 return $n;
 313         }
 314
 315         /**
 316          * Get number of rows in result
 317          *
 318          * @param resource $res Raw result
 319          * @return int
 320          */
 321         abstract protected function mysqlNumRows( $res );
 322
 323         /**
 324          * @param ResultWrapper|resource $res
 325          * @return int
 326          */
 327         function numFields( $res ) {
 328                 if ( $res instanceof ResultWrapper ) {
 329                         $res = $res->result;
 330                 }
 331
 332                 return $this->mysqlNumFields( $res );
 333         }
 334
 335         /**
 336          * Get number of fields in result
 337          *
 338          * @param resource $res Raw result
 339          * @return int
 340          */
 341         abstract protected function mysqlNumFields( $res );
 342
 343         /**
 344          * @param ResultWrapper|resource $res
 345          * @param int $n
 346          * @return string
 347          */
 348         function fieldName( $res, $n ) {
 349                 if ( $res instanceof ResultWrapper ) {
 350                         $res = $res->result;
 351                 }
 352
 353                 return $this->mysqlFieldName( $res, $n );
 354         }
 355
 356         /**
 357          * Get the name of the specified field in a result
 358          *
 359          * @param ResultWrapper|resource $res
 360          * @param int $n
 361          * @return string
 362          */
 363         abstract protected function mysqlFieldName( $res, $n );
 364
 365         /**
 366          * mysql_field_type() wrapper
 367          * @param ResultWrapper|resource $res
 368          * @param int $n
 369          * @return string
 370          */
 371         public function fieldType( $res, $n ) {
 372                 if ( $res instanceof ResultWrapper ) {
 373                         $res = $res->result;
 374                 }
 375
 376                 return $this->mysqlFieldType( $res, $n );
 377         }
 378
 379         /**
 380          * Get the type of the specified field in a result
 381          *
 382          * @param ResultWrapper|resource $res
 383          * @param int $n
 384          * @return string
 385          */
 386         abstract protected function mysqlFieldType( $res, $n );
 387
 388         /**
 389          * @param ResultWrapper|resource $res
 390          * @param int $row
 391          * @return bool
 392          */
 393         function dataSeek( $res, $row ) {
 394                 if ( $res instanceof ResultWrapper ) {
 395                         $res = $res->result;
 396                 }
 397
 398                 return $this->mysqlDataSeek( $res, $row );
 399         }
 400
 401         /**
 402          * Move internal result pointer
 403          *
 404          * @param ResultWrapper|resource $res
 405          * @param int $row
 406          * @return bool
 407          */
 408         abstract protected function mysqlDataSeek( $res, $row );
 409
 410         /**
 411          * @return string
 412          */
 413         function lastError() {
 414                 if ( $this->mConn ) {
 415                         # Even if it's non-zero, it can still be invalid
 416                         wfSuppressWarnings();
 417                         $error = $this->mysqlError( $this->mConn );
 418                         if ( !$error ) {
 419                                 $error = $this->mysqlError();
 420                         }
 421                         wfRestoreWarnings();
 422                 } else {
 423                         $error = $this->mysqlError();
 424                 }
 425                 if ( $error ) {
 426                         $error .= ' (' . $this->mServer . ')';
 427                 }
 428
 429                 return $error;
 430         }
 431
 432         /**
 433          * Returns the text of the error message from previous MySQL operation
 434          *
 435          * @param resource $conn Raw connection
 436          * @return string
 437          */
 438         abstract protected function mysqlError( $conn = null );
 439
 440         /**
 441          * @param string $table
 442          * @param array $uniqueIndexes
 443          * @param array $rows
 444          * @param string $fname
 445          * @return ResultWrapper
 446          */
 447         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 448                 return $this->nativeReplace( $table, $rows, $fname );
 449         }
 450
 451         /**
 452          * Estimate rows in dataset
 453          * Returns estimated count, based on EXPLAIN output
 454          * Takes same arguments as Database::select()
 455          *
 456          * @param string|array $table
 457          * @param string|array $vars
 458          * @param string|array $conds
 459          * @param string $fname
 460          * @param string|array $options
 461          * @return bool|int
 462          */
 463         public function estimateRowCount( $table, $vars = '*', $conds = '',
 464                 $fname = __METHOD__, $options = array()
 465         ) {
 466                 $options['EXPLAIN'] = true;
 467                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 468                 if ( $res === false ) {
 469                         return false;
 470                 }
 471                 if ( !$this->numRows( $res ) ) {
 472                         return 0;
 473                 }
 474
 475                 $rows = 1;
 476                 foreach ( $res as $plan ) {
 477                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 478                 }
 479
 480                 return (int)$rows;
 481         }
 482
 483         /**
 484          * @param string $table
 485          * @param string $field
 486          * @return bool|MySQLField
 487          */
 488         function fieldInfo( $table, $field ) {
 489                 $table = $this->tableName( $table );
 490                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 491                 if ( !$res ) {
 492                         return false;
 493                 }
 494                 $n = $this->mysqlNumFields( $res->result );
 495                 for ( $i = 0; $i < $n; $i++ ) {
 496                         $meta = $this->mysqlFetchField( $res->result, $i );
 497                         if ( $field == $meta->name ) {
 498                                 return new MySQLField( $meta );
 499                         }
 500                 }
 501
 502                 return false;
 503         }
 504
 505         /**
 506          * Get column information from a result
 507          *
 508          * @param resource $res Raw result
 509          * @param int $n
 510          * @return stdClass
 511          */
 512         abstract protected function mysqlFetchField( $res, $n );
 513
 514         /**
 515          * Get information about an index into an object
 516          * Returns false if the index does not exist
 517          *
 518          * @param string $table
 519          * @param string $index
 520          * @param string $fname
 521          * @return bool|array|null False or null on failure
 522          */
 523         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 524                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 525                 # SHOW INDEX should work for 3.x and up:
 526                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 527                 $table = $this->tableName( $table );
 528                 $index = $this->indexName( $index );
 529
 530                 $sql = 'SHOW INDEX FROM ' . $table;
 531                 $res = $this->query( $sql, $fname );
 532
 533                 if ( !$res ) {
 534                         return null;
 535                 }
 536
 537                 $result = array();
 538
 539                 foreach ( $res as $row ) {
 540                         if ( $row->Key_name == $index ) {
 541                                 $result[] = $row;
 542                         }
 543                 }
 544
 545                 return empty( $result ) ? false : $result;
 546         }
 547
 548         /**
 549          * @param string $s
 550          * @return string
 551          */
 552         function strencode( $s ) {
 553                 $sQuoted = $this->mysqlRealEscapeString( $s );
 554
 555                 if ( $sQuoted === false ) {
 556                         $this->ping();
 557                         $sQuoted = $this->mysqlRealEscapeString( $s );
 558                 }
 559
 560                 return $sQuoted;
 561         }
 562
 563         /**
 564          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 565          *
 566          * @param string $s
 567          * @return string
 568          */
 569         public function addIdentifierQuotes( $s ) {
 570                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 571                 // Remove NUL bytes and escape backticks by doubling
 572                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s ) . '`';
 573         }
 574
 575         /**
 576          * @param string $name
 577          * @return bool
 578          */
 579         public function isQuotedIdentifier( $name ) {
 580                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 581         }
 582
 583         /**
 584          * @return bool
 585          */
 586         function ping() {
 587                 $ping = $this->mysqlPing();
 588                 if ( $ping ) {
 589                         return true;
 590                 }
 591
 592                 $this->closeConnection();
 593                 $this->mOpened = false;
 594                 $this->mConn = false;
 595                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 596
 597                 return true;
 598         }
 599
 600         /**
 601          * Ping a server connection or reconnect if there is no connection
 602          *
 603          * @return bool
 604          */
 605         abstract protected function mysqlPing();
 606
 607         /**
 608          * Set lag time in seconds for a fake slave
 609          *
 610          * @param int $lag
 611          */
 612         public function setFakeSlaveLag( $lag ) {
 613                 $this->mFakeSlaveLag = $lag;
 614         }
 615
 616         /**
 617          * Make this connection a fake master
 618          *
 619          * @param bool $enabled
 620          */
 621         public function setFakeMaster( $enabled = true ) {
 622                 $this->mFakeMaster = $enabled;
 623         }
 624
 625         /**
 626          * Returns slave lag.
 627          *
 628          * This will do a SHOW SLAVE STATUS
 629          *
 630          * @return int
 631          */
 632         function getLag() {
 633                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 634                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 635
 636                         return $this->mFakeSlaveLag;
 637                 }
 638
 639                 return $this->getLagFromSlaveStatus();
 640         }
 641
 642         /**
 643          * @return bool|int
 644          */
 645         function getLagFromSlaveStatus() {
 646                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 647                 if ( !$res ) {
 648                         return false;
 649                 }
 650                 $row = $res->fetchObject();
 651                 if ( !$row ) {
 652                         return false;
 653                 }
 654                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 655                         return false;
 656                 } else {
 657                         return intval( $row->Seconds_Behind_Master );
 658                 }
 659         }
 660
 661         /**
 662          * Wait for the slave to catch up to a given master position.
 663          * @todo Return values for this and base class are rubbish
 664          *
 665          * @param DBMasterPos|MySQLMasterPos $pos
 666          * @param int $timeout The maximum number of seconds to wait for synchronisation
 667          * @return int Zero if the slave was past that position already,
 668          *   greater than zero if we waited for some period of time, less than
 669          *   zero if we timed out.
 670          */
 671         function masterPosWait( DBMasterPos $pos, $timeout ) {
 672                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 673                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 674                 }
 675
 676                 # Commit any open transactions
 677                 $this->commit( __METHOD__, 'flush' );
 678
 679                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 680                         $wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
 681
 682                         if ( $wait > $timeout * 1e6 ) {
 683                                 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
 684
 685                                 return -1;
 686                         } elseif ( $wait > 0 ) {
 687                                 wfDebug( "Fake slave waiting $wait us\n" );
 688                                 usleep( $wait );
 689
 690                                 return 1;
 691                         } else {
 692                                 wfDebug( "Fake slave up to date ($wait us)\n" );
 693
 694                                 return 0;
 695                         }
 696                 }
 697
 698                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 699                 $encFile = $this->addQuotes( $pos->file );
 700                 $encPos = intval( $pos->pos );
 701                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 702                 $res = $this->doQuery( $sql );
 703
 704                 $status = false;
 705                 if ( $res && $row = $this->fetchRow( $res ) ) {
 706                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 707                         if ( ctype_digit( $status ) ) { // success
 708                                 $this->lastKnownSlavePos = $pos;
 709                         }
 710                 }
 711
 712                 return $status;
 713         }
 714
 715         /**
 716          * Get the position of the master from SHOW SLAVE STATUS
 717          *
 718          * @return MySQLMasterPos|bool
 719          */
 720         function getSlavePos() {
 721                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 722                         $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
 723                         wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
 724
 725                         return $pos;
 726                 }
 727
 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                 if ( $this->mFakeMaster ) {
 749                         return new MySQLMasterPos( 'fake', microtime( true ) );
 750                 }
 751
 752                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 753                 $row = $this->fetchObject( $res );
 754
 755                 if ( $row ) {
 756                         return new MySQLMasterPos( $row->File, $row->Position );
 757                 } else {
 758                         return false;
 759                 }
 760         }
 761
 762         /**
 763          * @param string $index
 764          * @return string
 765          */
 766         function useIndexClause( $index ) {
 767                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 768         }
 769
 770         /**
 771          * @return string
 772          */
 773         function lowPriorityOption() {
 774                 return 'LOW_PRIORITY';
 775         }
 776
 777         /**
 778          * @return string
 779          */
 780         public function getSoftwareLink() {
 781                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 782                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 783                 // in libmysql/libmysql.c).
 784                 $version = $this->getServerVersion();
 785                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 786                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 787                 }
 788
 789                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 790                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 791                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 792                 return '[{{int:version-db-mysql-url}} MySQL]';
 793         }
 794
 795         /**
 796          * @return string
 797          */
 798         public function getServerVersion() {
 799                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 800                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 801                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 802                 if ( $this->serverVersion === null ) {
 803                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 804                 }
 805                 return $this->serverVersion;
 806         }
 807
 808         /**
 809          * @param array $options
 810          */
 811         public function setSessionOptions( array $options ) {
 812                 if ( isset( $options['connTimeout'] ) ) {
 813                         $timeout = (int)$options['connTimeout'];
 814                         $this->query( "SET net_read_timeout=$timeout" );
 815                         $this->query( "SET net_write_timeout=$timeout" );
 816                 }
 817         }
 818
 819         /**
 820          * @param string $sql
 821          * @param string $newLine
 822          * @return bool
 823          */
 824         public function streamStatementEnd( &$sql, &$newLine ) {
 825                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 826                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 827                         $this->delimiter = $m[1];
 828                         $newLine = '';
 829                 }
 830
 831                 return parent::streamStatementEnd( $sql, $newLine );
 832         }
 833
 834         /**
 835          * Check to see if a named lock is available. This is non-blocking.
 836          *
 837          * @param string $lockName Name of lock to poll
 838          * @param string $method Name of method calling us
 839          * @return bool
 840          * @since 1.20
 841          */
 842         public function lockIsFree( $lockName, $method ) {
 843                 $lockName = $this->addQuotes( $lockName );
 844                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 845                 $row = $this->fetchObject( $result );
 846
 847                 return ( $row->lockstatus == 1 );
 848         }
 849
 850         /**
 851          * @param string $lockName
 852          * @param string $method
 853          * @param int $timeout
 854          * @return bool
 855          */
 856         public function lock( $lockName, $method, $timeout = 5 ) {
 857                 $lockName = $this->addQuotes( $lockName );
 858                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 859                 $row = $this->fetchObject( $result );
 860
 861                 if ( $row->lockstatus == 1 ) {
 862                         return true;
 863                 } else {
 864                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 865
 866                         return false;
 867                 }
 868         }
 869
 870         /**
 871          * FROM MYSQL DOCS:
 872          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 873          * @param string $lockName
 874          * @param string $method
 875          * @return bool
 876          */
 877         public function unlock( $lockName, $method ) {
 878                 $lockName = $this->addQuotes( $lockName );
 879                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 880                 $row = $this->fetchObject( $result );
 881
 882                 return ( $row->lockstatus == 1 );
 883         }
 884
 885         public function namedLocksEnqueue() {
 886                 return true;
 887         }
 888
 889         /**
 890          * @param array $read
 891          * @param array $write
 892          * @param string $method
 893          * @param bool $lowPriority
 894          * @return bool
 895          */
 896         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 897                 $items = array();
 898
 899                 foreach ( $write as $table ) {
 900                         $tbl = $this->tableName( $table ) .
 901                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 902                                 ' WRITE';
 903                         $items[] = $tbl;
 904                 }
 905                 foreach ( $read as $table ) {
 906                         $items[] = $this->tableName( $table ) . ' READ';
 907                 }
 908                 $sql = "LOCK TABLES " . implode( ',', $items );
 909                 $this->query( $sql, $method );
 910
 911                 return true;
 912         }
 913
 914         /**
 915          * @param string $method
 916          * @return bool
 917          */
 918         public function unlockTables( $method ) {
 919                 $this->query( "UNLOCK TABLES", $method );
 920
 921                 return true;
 922         }
 923
 924         /**
 925          * Get search engine class. All subclasses of this
 926          * need to implement this if they wish to use searching.
 927          *
 928          * @return string
 929          */
 930         public function getSearchEngine() {
 931                 return 'SearchMySQL';
 932         }
 933
 934         /**
 935          * @param bool $value
 936          */
 937         public function setBigSelects( $value = true ) {
 938                 if ( $value === 'default' ) {
 939                         if ( $this->mDefaultBigSelects === null ) {
 940                                 # Function hasn't been called before so it must already be set to the default
 941                                 return;
 942                         } else {
 943                                 $value = $this->mDefaultBigSelects;
 944                         }
 945                 } elseif ( $this->mDefaultBigSelects === null ) {
 946                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 947                 }
 948                 $encValue = $value ? '1' : '0';
 949                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 950         }
 951
 952         /**
 953          * DELETE where the condition is a join. MySql uses multi-table deletes.
 954          * @param string $delTable
 955          * @param string $joinTable
 956          * @param string $delVar
 957          * @param string $joinVar
 958          * @param array|string $conds
 959          * @param bool|string $fname
 960          * @throws DBUnexpectedError
 961          * @return bool|ResultWrapper
 962          */
 963         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 964                 if ( !$conds ) {
 965                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 966                 }
 967
 968                 $delTable = $this->tableName( $delTable );
 969                 $joinTable = $this->tableName( $joinTable );
 970                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 971
 972                 if ( $conds != '*' ) {
 973                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 974                 }
 975
 976                 return $this->query( $sql, $fname );
 977         }
 978
 979         /**
 980          * @param string $table
 981          * @param array $rows
 982          * @param array $uniqueIndexes
 983          * @param array $set
 984          * @param string $fname
 985          * @return bool
 986          */
 987         public function upsert( $table, array $rows, array $uniqueIndexes,
 988                 array $set, $fname = __METHOD__
 989         ) {
 990                 if ( !count( $rows ) ) {
 991                         return true; // nothing to do
 992                 }
 993
 994                 if ( !is_array( reset( $rows ) ) ) {
 995                         $rows = array( $rows );
 996                 }
 997
 998                 $table = $this->tableName( $table );
 999                 $columns = array_keys( $rows[0] );
1000
1001                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1002                 $rowTuples = array();
1003                 foreach ( $rows as $row ) {
1004                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1005                 }
1006                 $sql .= implode( ',', $rowTuples );
1007                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
1008
1009                 return (bool)$this->query( $sql, $fname );
1010         }
1011
1012         /**
1013          * Determines how long the server has been up
1014          *
1015          * @return int
1016          */
1017         function getServerUptime() {
1018                 $vars = $this->getMysqlStatus( 'Uptime' );
1019
1020                 return (int)$vars['Uptime'];
1021         }
1022
1023         /**
1024          * Determines if the last failure was due to a deadlock
1025          *
1026          * @return bool
1027          */
1028         function wasDeadlock() {
1029                 return $this->lastErrno() == 1213;
1030         }
1031
1032         /**
1033          * Determines if the last failure was due to a lock timeout
1034          *
1035          * @return bool
1036          */
1037         function wasLockTimeout() {
1038                 return $this->lastErrno() == 1205;
1039         }
1040
1041         /**
1042          * Determines if the last query error was something that should be dealt
1043          * with by pinging the connection and reissuing the query
1044          *
1045          * @return bool
1046          */
1047         function wasErrorReissuable() {
1048                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1049         }
1050
1051         /**
1052          * Determines if the last failure was due to the database being read-only.
1053          *
1054          * @return bool
1055          */
1056         function wasReadOnlyError() {
1057                 return $this->lastErrno() == 1223 ||
1058                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1059         }
1060
1061         /**
1062          * @param string $oldName
1063          * @param string $newName
1064          * @param bool $temporary
1065          * @param string $fname
1066          * @return bool
1067          */
1068         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1069                 $tmp = $temporary ? 'TEMPORARY ' : '';
1070                 $newName = $this->addIdentifierQuotes( $newName );
1071                 $oldName = $this->addIdentifierQuotes( $oldName );
1072                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1073
1074                 return $this->query( $query, $fname );
1075         }
1076
1077         /**
1078          * List all tables on the database
1079          *
1080          * @param string $prefix Only show tables with this prefix, e.g. mw_
1081          * @param string $fname Calling function name
1082          * @return array
1083          */
1084         function listTables( $prefix = null, $fname = __METHOD__ ) {
1085                 $result = $this->query( "SHOW TABLES", $fname );
1086
1087                 $endArray = array();
1088
1089                 foreach ( $result as $table ) {
1090                         $vars = get_object_vars( $table );
1091                         $table = array_pop( $vars );
1092
1093                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1094                                 $endArray[] = $table;
1095                         }
1096                 }
1097
1098                 return $endArray;
1099         }
1100
1101         /**
1102          * @param string $tableName
1103          * @param string $fName
1104          * @return bool|ResultWrapper
1105          */
1106         public function dropTable( $tableName, $fName = __METHOD__ ) {
1107                 if ( !$this->tableExists( $tableName, $fName ) ) {
1108                         return false;
1109                 }
1110
1111                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1112         }
1113
1114         /**
1115          * @return array
1116          */
1117         protected function getDefaultSchemaVars() {
1118                 $vars = parent::getDefaultSchemaVars();
1119                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1120                 $vars['wgDBTableOptions'] = str_replace(
1121                         'CHARSET=mysql4',
1122                         'CHARSET=binary',
1123                         $vars['wgDBTableOptions']
1124                 );
1125
1126                 return $vars;
1127         }
1128
1129         /**
1130          * Get status information from SHOW STATUS in an associative array
1131          *
1132          * @param string $which
1133          * @return array
1134          */
1135         function getMysqlStatus( $which = "%" ) {
1136                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1137                 $status = array();
1138
1139                 foreach ( $res as $row ) {
1140                         $status[$row->Variable_name] = $row->Value;
1141                 }
1142
1143                 return $status;
1144         }
1145
1146         /**
1147          * Lists VIEWs in the database
1148          *
1149          * @param string $prefix Only show VIEWs with this prefix, eg.
1150          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1151          * @param string $fname Name of calling function
1152          * @return array
1153          * @since 1.22
1154          */
1155         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1156
1157                 if ( !isset( $this->allViews ) ) {
1158
1159                         // The name of the column containing the name of the VIEW
1160                         $propertyName = 'Tables_in_' . $this->mDBname;
1161
1162                         // Query for the VIEWS
1163                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1164                         $this->allViews = array();
1165                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1166                                 array_push( $this->allViews, $row[$propertyName] );
1167                         }
1168                 }
1169
1170                 if ( is_null( $prefix ) || $prefix === '' ) {
1171                         return $this->allViews;
1172                 }
1173
1174                 $filteredViews = array();
1175                 foreach ( $this->allViews as $viewName ) {
1176                         // Does the name of this VIEW start with the table-prefix?
1177                         if ( strpos( $viewName, $prefix ) === 0 ) {
1178                                 array_push( $filteredViews, $viewName );
1179                         }
1180                 }
1181
1182                 return $filteredViews;
1183         }
1184
1185         /**
1186          * Differentiates between a TABLE and a VIEW.
1187          *
1188          * @param string $name Name of the TABLE/VIEW to test
1189          * @param string $prefix
1190          * @return bool
1191          * @since 1.22
1192          */
1193         public function isView( $name, $prefix = null ) {
1194                 return in_array( $name, $this->listViews( $prefix ) );
1195         }
1196 }
1197
1198 /**
1199  * Utility class.
1200  * @ingroup Database
1201  */
1202 class MySQLField implements Field {
1203         private $name, $tablename, $default, $max_length, $nullable,
1204                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary,
1205                 $is_numeric, $is_blob, $is_unsigned, $is_zerofill;
1206
1207         function __construct( $info ) {
1208                 $this->name = $info->name;
1209                 $this->tablename = $info->table;
1210                 $this->default = $info->def;
1211                 $this->max_length = $info->max_length;
1212                 $this->nullable = !$info->not_null;
1213                 $this->is_pk = $info->primary_key;
1214                 $this->is_unique = $info->unique_key;
1215                 $this->is_multiple = $info->multiple_key;
1216                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1217                 $this->type = $info->type;
1218                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1219                 $this->is_numeric = isset( $info->numeric ) ? $info->numeric : false;
1220                 $this->is_blob = isset( $info->blob ) ? $info->blob : false;
1221                 $this->is_unsigned = isset( $info->unsigned ) ? $info->unsigned : false;
1222                 $this->is_zerofill = isset( $info->zerofill ) ? $info->zerofill : false;
1223         }
1224
1225         /**
1226          * @return string
1227          */
1228         function name() {
1229                 return $this->name;
1230         }
1231
1232         /**
1233          * @return string
1234          */
1235         function tableName() {
1236                 return $this->tableName;
1237         }
1238
1239         /**
1240          * @return string
1241          */
1242         function type() {
1243                 return $this->type;
1244         }
1245
1246         /**
1247          * @return bool
1248          */
1249         function isNullable() {
1250                 return $this->nullable;
1251         }
1252
1253         function defaultValue() {
1254                 return $this->default;
1255         }
1256
1257         /**
1258          * @return bool
1259          */
1260         function isKey() {
1261                 return $this->is_key;
1262         }
1263
1264         /**
1265          * @return bool
1266          */
1267         function isMultipleKey() {
1268                 return $this->is_multiple;
1269         }
1270
1271         /**
1272          * @return bool
1273          */
1274         function isBinary() {
1275                 return $this->binary;
1276         }
1277
1278         /**
1279          * @return bool
1280          */
1281         function isNumeric() {
1282                 return $this->is_numeric;
1283         }
1284
1285         /**
1286          * @return bool
1287          */
1288         function isBlob() {
1289                 return $this->is_blob;
1290         }
1291
1292         /**
1293          * @return bool
1294          */
1295         function isUnsigned() {
1296                 return $this->is_unsigned;
1297         }
1298
1299         /**
1300          * @return bool
1301          */
1302         function isZerofill() {
1303                 return $this->is_zerofill;
1304         }
1305 }
1306
1307 class MySQLMasterPos implements DBMasterPos {
1308         /** @var string */
1309         public $file;
1310         /** @var int Position */
1311         public $pos;
1312         /** @var float UNIX timestamp */
1313         public $asOfTime = 0.0;
1314
1315         function __construct( $file, $pos ) {
1316                 $this->file = $file;
1317                 $this->pos = $pos;
1318                 $this->asOfTime = microtime( true );
1319         }
1320
1321         function __toString() {
1322                 // e.g db1034-bin.000976/843431247
1323                 return "{$this->file}/{$this->pos}";
1324         }
1325
1326         /**
1327          * @return array|bool (int, int)
1328          */
1329         protected function getCoordinates() {
1330                 $m = array();
1331                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1332                         return array( (int)$m[1], (int)$m[2] );
1333                 }
1334
1335                 return false;
1336         }
1337
1338         function hasReached( MySQLMasterPos $pos ) {
1339                 $thisPos = $this->getCoordinates();
1340                 $thatPos = $pos->getCoordinates();
1341
1342                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1343         }
1344
1345         function asOfTime() {
1346                 return $this->asOfTime;
1347         }
1348 }