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         /**
  42          * @return string
  43          */
  44         function getType() {
  45                 return 'mysql';
  46         }
  47
  48         /**
  49          * @param string $server
  50          * @param string $user
  51          * @param string $password
  52          * @param string $dbName
  53          * @throws Exception|DBConnectionError
  54          * @return bool
  55          */
  56         function open( $server, $user, $password, $dbName ) {
  57                 global $wgAllDBsAreLocalhost, $wgSQLMode;
  58                 wfProfileIn( __METHOD__ );
  59
  60                 # Debugging hack -- fake cluster
  61                 if ( $wgAllDBsAreLocalhost ) {
  62                         $realServer = 'localhost';
  63                 } else {
  64                         $realServer = $server;
  65                 }
  66                 $this->close();
  67                 $this->mServer = $server;
  68                 $this->mUser = $user;
  69                 $this->mPassword = $password;
  70                 $this->mDBname = $dbName;
  71
  72                 wfProfileIn( "dbconnect-$server" );
  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 $ex ) {
  82                         wfProfileOut( "dbconnect-$server" );
  83                         wfProfileOut( __METHOD__ );
  84                         $this->restoreErrorHandler();
  85                         throw $ex;
  86                 }
  87                 $error = $this->restoreErrorHandler();
  88
  89                 wfProfileOut( "dbconnect-$server" );
  90
  91                 # Always log connection errors
  92                 if ( !$this->mConn ) {
  93                         if ( !$error ) {
  94                                 $error = $this->lastError();
  95                         }
  96                         wfLogDBError( "Error connecting to {$this->mServer}: $error" );
  97                         wfDebug( "DB connection error\n" .
  98                                 "Server: $server, User: $user, Password: " .
  99                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 100
 101                         wfProfileOut( __METHOD__ );
 102
 103                         $this->reportConnectionError( $error );
 104                 }
 105
 106                 if ( $dbName != '' ) {
 107                         wfSuppressWarnings();
 108                         $success = $this->selectDB( $dbName );
 109                         wfRestoreWarnings();
 110                         if ( !$success ) {
 111                                 wfLogDBError( "Error selecting database $dbName on server {$this->mServer}" );
 112                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 113                                         "from client host " . wfHostname() . "\n" );
 114
 115                                 wfProfileOut( __METHOD__ );
 116
 117                                 $this->reportConnectionError( "Error selecting database $dbName" );
 118                         }
 119                 }
 120
 121                 // Tell the server what we're communicating with
 122                 if ( !$this->connectInitCharset() ) {
 123                         $this->reportConnectionError( "Error setting character set" );
 124                 }
 125
 126                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 127                 if ( is_string( $wgSQLMode ) ) {
 128                         $mode = $this->addQuotes( $wgSQLMode );
 129                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 130                         $success = $this->doQuery( "SET sql_mode = $mode", __METHOD__ );
 131                         if ( !$success ) {
 132                                 wfLogDBError( "Error setting sql_mode to $mode on server {$this->mServer}" );
 133                                 wfProfileOut( __METHOD__ );
 134                                 $this->reportConnectionError( "Error setting sql_mode to $mode" );
 135                         }
 136                 }
 137
 138                 $this->mOpened = true;
 139                 wfProfileOut( __METHOD__ );
 140
 141                 return true;
 142         }
 143
 144         /**
 145          * Set the character set information right after connection
 146          * @return bool
 147          */
 148         protected function connectInitCharset() {
 149                 global $wgDBmysql5;
 150
 151                 if ( $wgDBmysql5 ) {
 152                         // Tell the server we're communicating with it in UTF-8.
 153                         // This may engage various charset conversions.
 154                         return $this->mysqlSetCharset( 'utf8' );
 155                 } else {
 156                         return $this->mysqlSetCharset( 'binary' );
 157                 }
 158         }
 159
 160         /**
 161          * Open a connection to a MySQL server
 162          *
 163          * @param string $realServer
 164          * @return mixed Raw connection
 165          * @throws DBConnectionError
 166          */
 167         abstract protected function mysqlConnect( $realServer );
 168
 169         /**
 170          * Set the character set of the MySQL link
 171          *
 172          * @param string $charset
 173          * @return bool
 174          */
 175         abstract protected function mysqlSetCharset( $charset );
 176
 177         /**
 178          * @param ResultWrapper|resource $res
 179          * @throws DBUnexpectedError
 180          */
 181         function freeResult( $res ) {
 182                 if ( $res instanceof ResultWrapper ) {
 183                         $res = $res->result;
 184                 }
 185                 wfSuppressWarnings();
 186                 $ok = $this->mysqlFreeResult( $res );
 187                 wfRestoreWarnings();
 188                 if ( !$ok ) {
 189                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 190                 }
 191         }
 192
 193         /**
 194          * Free result memory
 195          *
 196          * @param resource $res Raw result
 197          * @return bool
 198          */
 199         abstract protected function mysqlFreeResult( $res );
 200
 201         /**
 202          * @param ResultWrapper|resource $res
 203          * @return stdClass|bool
 204          * @throws DBUnexpectedError
 205          */
 206         function fetchObject( $res ) {
 207                 if ( $res instanceof ResultWrapper ) {
 208                         $res = $res->result;
 209                 }
 210                 wfSuppressWarnings();
 211                 $row = $this->mysqlFetchObject( $res );
 212                 wfRestoreWarnings();
 213
 214                 $errno = $this->lastErrno();
 215                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 216                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 217                 // these are the only errors mysql_fetch_object can cause.
 218                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 219                 if ( $errno == 2000 || $errno == 2013 ) {
 220                         throw new DBUnexpectedError(
 221                                 $this,
 222                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 223                         );
 224                 }
 225
 226                 return $row;
 227         }
 228
 229         /**
 230          * Fetch a result row as an object
 231          *
 232          * @param resource $res Raw result
 233          * @return stdClass
 234          */
 235         abstract protected function mysqlFetchObject( $res );
 236
 237         /**
 238          * @param ResultWrapper|resource $res
 239          * @return array|bool
 240          * @throws DBUnexpectedError
 241          */
 242         function fetchRow( $res ) {
 243                 if ( $res instanceof ResultWrapper ) {
 244                         $res = $res->result;
 245                 }
 246                 wfSuppressWarnings();
 247                 $row = $this->mysqlFetchArray( $res );
 248                 wfRestoreWarnings();
 249
 250                 $errno = $this->lastErrno();
 251                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 252                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 253                 // these are the only errors mysql_fetch_array can cause.
 254                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 255                 if ( $errno == 2000 || $errno == 2013 ) {
 256                         throw new DBUnexpectedError(
 257                                 $this,
 258                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 259                         );
 260                 }
 261
 262                 return $row;
 263         }
 264
 265         /**
 266          * Fetch a result row as an associative and numeric array
 267          *
 268          * @param resource $res Raw result
 269          * @return array
 270          */
 271         abstract protected function mysqlFetchArray( $res );
 272
 273         /**
 274          * @throws DBUnexpectedError
 275          * @param ResultWrapper|resource $res
 276          * @return int
 277          */
 278         function numRows( $res ) {
 279                 if ( $res instanceof ResultWrapper ) {
 280                         $res = $res->result;
 281                 }
 282                 wfSuppressWarnings();
 283                 $n = $this->mysqlNumRows( $res );
 284                 wfRestoreWarnings();
 285
 286                 // Unfortunately, mysql_num_rows does not reset the last errno.
 287                 // We are not checking for any errors here, since
 288                 // these are no errors mysql_num_rows can cause.
 289                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 290                 // See https://bugzilla.wikimedia.org/42430
 291                 return $n;
 292         }
 293
 294         /**
 295          * Get number of rows in result
 296          *
 297          * @param resource $res Raw result
 298          * @return int
 299          */
 300         abstract protected function mysqlNumRows( $res );
 301
 302         /**
 303          * @param ResultWrapper|resource $res
 304          * @return int
 305          */
 306         function numFields( $res ) {
 307                 if ( $res instanceof ResultWrapper ) {
 308                         $res = $res->result;
 309                 }
 310
 311                 return $this->mysqlNumFields( $res );
 312         }
 313
 314         /**
 315          * Get number of fields in result
 316          *
 317          * @param resource $res Raw result
 318          * @return int
 319          */
 320         abstract protected function mysqlNumFields( $res );
 321
 322         /**
 323          * @param ResultWrapper|resource $res
 324          * @param int $n
 325          * @return string
 326          */
 327         function fieldName( $res, $n ) {
 328                 if ( $res instanceof ResultWrapper ) {
 329                         $res = $res->result;
 330                 }
 331
 332                 return $this->mysqlFieldName( $res, $n );
 333         }
 334
 335         /**
 336          * Get the name of the specified field in a result
 337          *
 338          * @param ResultWrapper|resource $res
 339          * @param int $n
 340          * @return string
 341          */
 342         abstract protected function mysqlFieldName( $res, $n );
 343
 344         /**
 345          * mysql_field_type() wrapper
 346          * @param ResultWrapper|resource $res
 347          * @param int $n
 348          * @return string
 349          */
 350         public function fieldType( $res, $n ) {
 351                 if ( $res instanceof ResultWrapper ) {
 352                         $res = $res->result;
 353                 }
 354
 355                 return $this->mysqlFieldType( $res, $n );
 356         }
 357
 358         /**
 359          * Get the type of the specified field in a result
 360          *
 361          * @param ResultWrapper|resource $res
 362          * @param int $n
 363          * @return string
 364          */
 365         abstract protected function mysqlFieldType( $res, $n );
 366
 367         /**
 368          * @param ResultWrapper|resource $res
 369          * @param int $row
 370          * @return bool
 371          */
 372         function dataSeek( $res, $row ) {
 373                 if ( $res instanceof ResultWrapper ) {
 374                         $res = $res->result;
 375                 }
 376
 377                 return $this->mysqlDataSeek( $res, $row );
 378         }
 379
 380         /**
 381          * Move internal result pointer
 382          *
 383          * @param ResultWrapper|resource $res
 384          * @param int $row
 385          * @return bool
 386          */
 387         abstract protected function mysqlDataSeek( $res, $row );
 388
 389         /**
 390          * @return string
 391          */
 392         function lastError() {
 393                 if ( $this->mConn ) {
 394                         # Even if it's non-zero, it can still be invalid
 395                         wfSuppressWarnings();
 396                         $error = $this->mysqlError( $this->mConn );
 397                         if ( !$error ) {
 398                                 $error = $this->mysqlError();
 399                         }
 400                         wfRestoreWarnings();
 401                 } else {
 402                         $error = $this->mysqlError();
 403                 }
 404                 if ( $error ) {
 405                         $error .= ' (' . $this->mServer . ')';
 406                 }
 407
 408                 return $error;
 409         }
 410
 411         /**
 412          * Returns the text of the error message from previous MySQL operation
 413          *
 414          * @param resource $conn Raw connection
 415          * @return string
 416          */
 417         abstract protected function mysqlError( $conn = null );
 418
 419         /**
 420          * @param string $table
 421          * @param array $uniqueIndexes
 422          * @param array $rows
 423          * @param string $fname
 424          * @return ResultWrapper
 425          */
 426         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 427                 return $this->nativeReplace( $table, $rows, $fname );
 428         }
 429
 430         /**
 431          * Estimate rows in dataset
 432          * Returns estimated count, based on EXPLAIN output
 433          * Takes same arguments as Database::select()
 434          *
 435          * @param string|array $table
 436          * @param string|array $vars
 437          * @param string|array $conds
 438          * @param string $fname
 439          * @param string|array $options
 440          * @return bool|int
 441          */
 442         public function estimateRowCount( $table, $vars = '*', $conds = '',
 443                 $fname = __METHOD__, $options = array()
 444         ) {
 445                 $options['EXPLAIN'] = true;
 446                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 447                 if ( $res === false ) {
 448                         return false;
 449                 }
 450                 if ( !$this->numRows( $res ) ) {
 451                         return 0;
 452                 }
 453
 454                 $rows = 1;
 455                 foreach ( $res as $plan ) {
 456                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 457                 }
 458
 459                 return $rows;
 460         }
 461
 462         /**
 463          * @param string $table
 464          * @param string $field
 465          * @return bool|MySQLField
 466          */
 467         function fieldInfo( $table, $field ) {
 468                 $table = $this->tableName( $table );
 469                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 470                 if ( !$res ) {
 471                         return false;
 472                 }
 473                 $n = $this->mysqlNumFields( $res->result );
 474                 for ( $i = 0; $i < $n; $i++ ) {
 475                         $meta = $this->mysqlFetchField( $res->result, $i );
 476                         if ( $field == $meta->name ) {
 477                                 return new MySQLField( $meta );
 478                         }
 479                 }
 480
 481                 return false;
 482         }
 483
 484         /**
 485          * Get column information from a result
 486          *
 487          * @param resource $res Raw result
 488          * @param int $n
 489          * @return stdClass
 490          */
 491         abstract protected function mysqlFetchField( $res, $n );
 492
 493         /**
 494          * Get information about an index into an object
 495          * Returns false if the index does not exist
 496          *
 497          * @param string $table
 498          * @param string $index
 499          * @param string $fname
 500          * @return bool|array|null False or null on failure
 501          */
 502         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 503                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 504                 # SHOW INDEX should work for 3.x and up:
 505                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 506                 $table = $this->tableName( $table );
 507                 $index = $this->indexName( $index );
 508
 509                 $sql = 'SHOW INDEX FROM ' . $table;
 510                 $res = $this->query( $sql, $fname );
 511
 512                 if ( !$res ) {
 513                         return null;
 514                 }
 515
 516                 $result = array();
 517
 518                 foreach ( $res as $row ) {
 519                         if ( $row->Key_name == $index ) {
 520                                 $result[] = $row;
 521                         }
 522                 }
 523
 524                 return empty( $result ) ? false : $result;
 525         }
 526
 527         /**
 528          * @param string $s
 529          * @return string
 530          */
 531         function strencode( $s ) {
 532                 $sQuoted = $this->mysqlRealEscapeString( $s );
 533
 534                 if ( $sQuoted === false ) {
 535                         $this->ping();
 536                         $sQuoted = $this->mysqlRealEscapeString( $s );
 537                 }
 538
 539                 return $sQuoted;
 540         }
 541
 542         /**
 543          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 544          *
 545          * @param string $s
 546          * @return string
 547          */
 548         public function addIdentifierQuotes( $s ) {
 549                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 550                 // Remove NUL bytes and escape backticks by doubling
 551                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s ) . '`';
 552         }
 553
 554         /**
 555          * @param string $name
 556          * @return bool
 557          */
 558         public function isQuotedIdentifier( $name ) {
 559                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 560         }
 561
 562         /**
 563          * @return bool
 564          */
 565         function ping() {
 566                 $ping = $this->mysqlPing();
 567                 if ( $ping ) {
 568                         return true;
 569                 }
 570
 571                 $this->closeConnection();
 572                 $this->mOpened = false;
 573                 $this->mConn = false;
 574                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 575
 576                 return true;
 577         }
 578
 579         /**
 580          * Ping a server connection or reconnect if there is no connection
 581          *
 582          * @return bool
 583          */
 584         abstract protected function mysqlPing();
 585
 586         /**
 587          * Set lag time in seconds for a fake slave
 588          *
 589          * @param int $lag
 590          */
 591         public function setFakeSlaveLag( $lag ) {
 592                 $this->mFakeSlaveLag = $lag;
 593         }
 594
 595         /**
 596          * Make this connection a fake master
 597          *
 598          * @param bool $enabled
 599          */
 600         public function setFakeMaster( $enabled = true ) {
 601                 $this->mFakeMaster = $enabled;
 602         }
 603
 604         /**
 605          * Returns slave lag.
 606          *
 607          * This will do a SHOW SLAVE STATUS
 608          *
 609          * @return int
 610          */
 611         function getLag() {
 612                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 613                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 614
 615                         return $this->mFakeSlaveLag;
 616                 }
 617
 618                 return $this->getLagFromSlaveStatus();
 619         }
 620
 621         /**
 622          * @return bool|int
 623          */
 624         function getLagFromSlaveStatus() {
 625                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 626                 if ( !$res ) {
 627                         return false;
 628                 }
 629                 $row = $res->fetchObject();
 630                 if ( !$row ) {
 631                         return false;
 632                 }
 633                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 634                         return false;
 635                 } else {
 636                         return intval( $row->Seconds_Behind_Master );
 637                 }
 638         }
 639
 640         /**
 641          * Wait for the slave to catch up to a given master position.
 642          * @todo Return values for this and base class are rubbish
 643          *
 644          * @param DBMasterPos|MySQLMasterPos $pos
 645          * @param int $timeout The maximum number of seconds to wait for synchronisation
 646          * @return int Zero if the slave was past that position already,
 647          *   greater than zero if we waited for some period of time, less than
 648          *   zero if we timed out.
 649          */
 650         function masterPosWait( DBMasterPos $pos, $timeout ) {
 651                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 652                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 653                 }
 654
 655                 wfProfileIn( __METHOD__ );
 656                 # Commit any open transactions
 657                 $this->commit( __METHOD__, 'flush' );
 658
 659                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 660                         $wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
 661
 662                         if ( $wait > $timeout * 1e6 ) {
 663                                 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
 664                                 wfProfileOut( __METHOD__ );
 665
 666                                 return -1;
 667                         } elseif ( $wait > 0 ) {
 668                                 wfDebug( "Fake slave waiting $wait us\n" );
 669                                 usleep( $wait );
 670                                 wfProfileOut( __METHOD__ );
 671
 672                                 return 1;
 673                         } else {
 674                                 wfDebug( "Fake slave up to date ($wait us)\n" );
 675                                 wfProfileOut( __METHOD__ );
 676
 677                                 return 0;
 678                         }
 679                 }
 680
 681                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 682                 $encFile = $this->addQuotes( $pos->file );
 683                 $encPos = intval( $pos->pos );
 684                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 685                 $res = $this->doQuery( $sql );
 686
 687                 $status = false;
 688                 if ( $res && $row = $this->fetchRow( $res ) ) {
 689                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 690                         if ( ctype_digit( $status ) ) { // success
 691                                 $this->lastKnownSlavePos = $pos;
 692                         }
 693                 }
 694
 695                 wfProfileOut( __METHOD__ );
 696
 697                 return $status;
 698         }
 699
 700         /**
 701          * Get the position of the master from SHOW SLAVE STATUS
 702          *
 703          * @return MySQLMasterPos|bool
 704          */
 705         function getSlavePos() {
 706                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 707                         $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
 708                         wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
 709
 710                         return $pos;
 711                 }
 712
 713                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 714                 $row = $this->fetchObject( $res );
 715
 716                 if ( $row ) {
 717                         $pos = isset( $row->Exec_master_log_pos )
 718                                 ? $row->Exec_master_log_pos
 719                                 : $row->Exec_Master_Log_Pos;
 720
 721                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 722                 } else {
 723                         return false;
 724                 }
 725         }
 726
 727         /**
 728          * Get the position of the master from SHOW MASTER STATUS
 729          *
 730          * @return MySQLMasterPos|bool
 731          */
 732         function getMasterPos() {
 733                 if ( $this->mFakeMaster ) {
 734                         return new MySQLMasterPos( 'fake', microtime( true ) );
 735                 }
 736
 737                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 738                 $row = $this->fetchObject( $res );
 739
 740                 if ( $row ) {
 741                         return new MySQLMasterPos( $row->File, $row->Position );
 742                 } else {
 743                         return false;
 744                 }
 745         }
 746
 747         /**
 748          * @param string $index
 749          * @return string
 750          */
 751         function useIndexClause( $index ) {
 752                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 753         }
 754
 755         /**
 756          * @return string
 757          */
 758         function lowPriorityOption() {
 759                 return 'LOW_PRIORITY';
 760         }
 761
 762         /**
 763          * @return string
 764          */
 765         public function getSoftwareLink() {
 766                 // MariaDB includes its name in its version string (sent when the connection is opened),
 767                 // and this is how MariaDB's version of the mysql command-line client identifies MariaDB
 768                 // servers (see the mariadb_connection() function in libmysql/libmysql.c).
 769                 $version = $this->getServerVersion();
 770                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 771                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 772                 }
 773
 774                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 775                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 776                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 777                 return '[{{int:version-db-mysql-url}} MySQL]';
 778         }
 779
 780         /**
 781          * @param array $options
 782          */
 783         public function setSessionOptions( array $options ) {
 784                 if ( isset( $options['connTimeout'] ) ) {
 785                         $timeout = (int)$options['connTimeout'];
 786                         $this->query( "SET net_read_timeout=$timeout" );
 787                         $this->query( "SET net_write_timeout=$timeout" );
 788                 }
 789         }
 790
 791         /**
 792          * @param string $sql
 793          * @param string $newLine
 794          * @return bool
 795          */
 796         public function streamStatementEnd( &$sql, &$newLine ) {
 797                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 798                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 799                         $this->delimiter = $m[1];
 800                         $newLine = '';
 801                 }
 802
 803                 return parent::streamStatementEnd( $sql, $newLine );
 804         }
 805
 806         /**
 807          * Check to see if a named lock is available. This is non-blocking.
 808          *
 809          * @param string $lockName name of lock to poll
 810          * @param string $method name of method calling us
 811          * @return bool
 812          * @since 1.20
 813          */
 814         public function lockIsFree( $lockName, $method ) {
 815                 $lockName = $this->addQuotes( $lockName );
 816                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 817                 $row = $this->fetchObject( $result );
 818
 819                 return ( $row->lockstatus == 1 );
 820         }
 821
 822         /**
 823          * @param string $lockName
 824          * @param string $method
 825          * @param int $timeout
 826          * @return bool
 827          */
 828         public function lock( $lockName, $method, $timeout = 5 ) {
 829                 $lockName = $this->addQuotes( $lockName );
 830                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 831                 $row = $this->fetchObject( $result );
 832
 833                 if ( $row->lockstatus == 1 ) {
 834                         return true;
 835                 } else {
 836                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 837
 838                         return false;
 839                 }
 840         }
 841
 842         /**
 843          * FROM MYSQL DOCS:
 844          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 845          * @param string $lockName
 846          * @param string $method
 847          * @return bool
 848          */
 849         public function unlock( $lockName, $method ) {
 850                 $lockName = $this->addQuotes( $lockName );
 851                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 852                 $row = $this->fetchObject( $result );
 853
 854                 return ( $row->lockstatus == 1 );
 855         }
 856
 857         /**
 858          * @param array $read
 859          * @param array $write
 860          * @param string $method
 861          * @param bool $lowPriority
 862          * @return bool
 863          */
 864         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 865                 $items = array();
 866
 867                 foreach ( $write as $table ) {
 868                         $tbl = $this->tableName( $table ) .
 869                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 870                                 ' WRITE';
 871                         $items[] = $tbl;
 872                 }
 873                 foreach ( $read as $table ) {
 874                         $items[] = $this->tableName( $table ) . ' READ';
 875                 }
 876                 $sql = "LOCK TABLES " . implode( ',', $items );
 877                 $this->query( $sql, $method );
 878
 879                 return true;
 880         }
 881
 882         /**
 883          * @param string $method
 884          * @return bool
 885          */
 886         public function unlockTables( $method ) {
 887                 $this->query( "UNLOCK TABLES", $method );
 888
 889                 return true;
 890         }
 891
 892         /**
 893          * Get search engine class. All subclasses of this
 894          * need to implement this if they wish to use searching.
 895          *
 896          * @return string
 897          */
 898         public function getSearchEngine() {
 899                 return 'SearchMySQL';
 900         }
 901
 902         /**
 903          * @param bool $value
 904          * @return mixed null|bool|ResultWrapper
 905          */
 906         public function setBigSelects( $value = true ) {
 907                 if ( $value === 'default' ) {
 908                         if ( $this->mDefaultBigSelects === null ) {
 909                                 # Function hasn't been called before so it must already be set to the default
 910                                 return;
 911                         } else {
 912                                 $value = $this->mDefaultBigSelects;
 913                         }
 914                 } elseif ( $this->mDefaultBigSelects === null ) {
 915                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 916                 }
 917                 $encValue = $value ? '1' : '0';
 918                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 919         }
 920
 921         /**
 922          * DELETE where the condition is a join. MySql uses multi-table deletes.
 923          * @param string $delTable
 924          * @param string $joinTable
 925          * @param string $delVar
 926          * @param string $joinVar
 927          * @param array|string $conds
 928          * @param bool|string $fname
 929          * @throws DBUnexpectedError
 930          * @return bool|ResultWrapper
 931          */
 932         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 933                 if ( !$conds ) {
 934                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 935                 }
 936
 937                 $delTable = $this->tableName( $delTable );
 938                 $joinTable = $this->tableName( $joinTable );
 939                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 940
 941                 if ( $conds != '*' ) {
 942                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 943                 }
 944
 945                 return $this->query( $sql, $fname );
 946         }
 947
 948         /**
 949          * @param string $table
 950          * @param array $rows
 951          * @param array $uniqueIndexes
 952          * @param array $set
 953          * @param string $fname
 954          * @return bool
 955          */
 956         public function upsert( $table, array $rows, array $uniqueIndexes,
 957                 array $set, $fname = __METHOD__
 958         ) {
 959                 if ( !count( $rows ) ) {
 960                         return true; // nothing to do
 961                 }
 962
 963                 if ( !is_array( reset( $rows ) ) ) {
 964                         $rows = array( $rows );
 965                 }
 966
 967                 $table = $this->tableName( $table );
 968                 $columns = array_keys( $rows[0] );
 969
 970                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
 971                 $rowTuples = array();
 972                 foreach ( $rows as $row ) {
 973                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
 974                 }
 975                 $sql .= implode( ',', $rowTuples );
 976                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
 977
 978                 return (bool)$this->query( $sql, $fname );
 979         }
 980
 981         /**
 982          * Determines how long the server has been up
 983          *
 984          * @return int
 985          */
 986         function getServerUptime() {
 987                 $vars = $this->getMysqlStatus( 'Uptime' );
 988
 989                 return (int)$vars['Uptime'];
 990         }
 991
 992         /**
 993          * Determines if the last failure was due to a deadlock
 994          *
 995          * @return bool
 996          */
 997         function wasDeadlock() {
 998                 return $this->lastErrno() == 1213;
 999         }
1000
1001         /**
1002          * Determines if the last failure was due to a lock timeout
1003          *
1004          * @return bool
1005          */
1006         function wasLockTimeout() {
1007                 return $this->lastErrno() == 1205;
1008         }
1009
1010         /**
1011          * Determines if the last query error was something that should be dealt
1012          * with by pinging the connection and reissuing the query
1013          *
1014          * @return bool
1015          */
1016         function wasErrorReissuable() {
1017                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1018         }
1019
1020         /**
1021          * Determines if the last failure was due to the database being read-only.
1022          *
1023          * @return bool
1024          */
1025         function wasReadOnlyError() {
1026                 return $this->lastErrno() == 1223 ||
1027                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1028         }
1029
1030         /**
1031          * @param string $oldName
1032          * @param string $newName
1033          * @param bool $temporary
1034          * @param string $fname
1035          * @return bool
1036          */
1037         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1038                 $tmp = $temporary ? 'TEMPORARY ' : '';
1039                 $newName = $this->addIdentifierQuotes( $newName );
1040                 $oldName = $this->addIdentifierQuotes( $oldName );
1041                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1042
1043                 return $this->query( $query, $fname );
1044         }
1045
1046         /**
1047          * List all tables on the database
1048          *
1049          * @param string $prefix Only show tables with this prefix, e.g. mw_
1050          * @param string $fname Calling function name
1051          * @return array
1052          */
1053         function listTables( $prefix = null, $fname = __METHOD__ ) {
1054                 $result = $this->query( "SHOW TABLES", $fname );
1055
1056                 $endArray = array();
1057
1058                 foreach ( $result as $table ) {
1059                         $vars = get_object_vars( $table );
1060                         $table = array_pop( $vars );
1061
1062                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1063                                 $endArray[] = $table;
1064                         }
1065                 }
1066
1067                 return $endArray;
1068         }
1069
1070         /**
1071          * @param string $tableName
1072          * @param string $fName
1073          * @return bool|ResultWrapper
1074          */
1075         public function dropTable( $tableName, $fName = __METHOD__ ) {
1076                 if ( !$this->tableExists( $tableName, $fName ) ) {
1077                         return false;
1078                 }
1079
1080                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1081         }
1082
1083         /**
1084          * @return array
1085          */
1086         protected function getDefaultSchemaVars() {
1087                 $vars = parent::getDefaultSchemaVars();
1088                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1089                 $vars['wgDBTableOptions'] = str_replace(
1090                         'CHARSET=mysql4',
1091                         'CHARSET=binary',
1092                         $vars['wgDBTableOptions']
1093                 );
1094
1095                 return $vars;
1096         }
1097
1098         /**
1099          * Get status information from SHOW STATUS in an associative array
1100          *
1101          * @param string $which
1102          * @return array
1103          */
1104         function getMysqlStatus( $which = "%" ) {
1105                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1106                 $status = array();
1107
1108                 foreach ( $res as $row ) {
1109                         $status[$row->Variable_name] = $row->Value;
1110                 }
1111
1112                 return $status;
1113         }
1114
1115         /**
1116          * Lists VIEWs in the database
1117          *
1118          * @param string $prefix Only show VIEWs with this prefix, eg.
1119          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1120          * @param string $fname Name of calling function
1121          * @return array
1122          * @since 1.22
1123          */
1124         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1125
1126                 if ( !isset( $this->allViews ) ) {
1127
1128                         // The name of the column containing the name of the VIEW
1129                         $propertyName = 'Tables_in_' . $this->mDBname;
1130
1131                         // Query for the VIEWS
1132                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1133                         $this->allViews = array();
1134                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1135                                 array_push( $this->allViews, $row[$propertyName] );
1136                         }
1137                 }
1138
1139                 if ( is_null( $prefix ) || $prefix === '' ) {
1140                         return $this->allViews;
1141                 }
1142
1143                 $filteredViews = array();
1144                 foreach ( $this->allViews as $viewName ) {
1145                         // Does the name of this VIEW start with the table-prefix?
1146                         if ( strpos( $viewName, $prefix ) === 0 ) {
1147                                 array_push( $filteredViews, $viewName );
1148                         }
1149                 }
1150
1151                 return $filteredViews;
1152         }
1153
1154         /**
1155          * Differentiates between a TABLE and a VIEW.
1156          *
1157          * @param string $name Name of the TABLE/VIEW to test
1158          * @param string $prefix
1159          * @return bool
1160          * @since 1.22
1161          */
1162         public function isView( $name, $prefix = null ) {
1163                 return in_array( $name, $this->listViews( $prefix ) );
1164         }
1165 }
1166
1167 /**
1168  * Utility class.
1169  * @ingroup Database
1170  */
1171 class MySQLField implements Field {
1172         private $name, $tablename, $default, $max_length, $nullable,
1173                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary;
1174
1175         function __construct( $info ) {
1176                 $this->name = $info->name;
1177                 $this->tablename = $info->table;
1178                 $this->default = $info->def;
1179                 $this->max_length = $info->max_length;
1180                 $this->nullable = !$info->not_null;
1181                 $this->is_pk = $info->primary_key;
1182                 $this->is_unique = $info->unique_key;
1183                 $this->is_multiple = $info->multiple_key;
1184                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1185                 $this->type = $info->type;
1186                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1187         }
1188
1189         /**
1190          * @return string
1191          */
1192         function name() {
1193                 return $this->name;
1194         }
1195
1196         /**
1197          * @return string
1198          */
1199         function tableName() {
1200                 return $this->tableName;
1201         }
1202
1203         /**
1204          * @return string
1205          */
1206         function type() {
1207                 return $this->type;
1208         }
1209
1210         /**
1211          * @return bool
1212          */
1213         function isNullable() {
1214                 return $this->nullable;
1215         }
1216
1217         function defaultValue() {
1218                 return $this->default;
1219         }
1220
1221         /**
1222          * @return bool
1223          */
1224         function isKey() {
1225                 return $this->is_key;
1226         }
1227
1228         /**
1229          * @return bool
1230          */
1231         function isMultipleKey() {
1232                 return $this->is_multiple;
1233         }
1234
1235         function isBinary() {
1236                 return $this->binary;
1237         }
1238 }
1239
1240 class MySQLMasterPos implements DBMasterPos {
1241         /** @var string */
1242         public $file;
1243
1244         /** @var int timestamp */
1245         public $pos;
1246
1247         function __construct( $file, $pos ) {
1248                 $this->file = $file;
1249                 $this->pos = $pos;
1250         }
1251
1252         function __toString() {
1253                 // e.g db1034-bin.000976/843431247
1254                 return "{$this->file}/{$this->pos}";
1255         }
1256
1257         /**
1258          * @return array|bool (int, int)
1259          */
1260         protected function getCoordinates() {
1261                 $m = array();
1262                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1263                         return array( (int)$m[1], (int)$m[2] );
1264                 }
1265
1266                 return false;
1267         }
1268
1269         function hasReached( MySQLMasterPos $pos ) {
1270                 $thisPos = $this->getCoordinates();
1271                 $thatPos = $pos->getCoordinates();
1272
1273                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1274         }
1275 }