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
 136                 if ( $set ) {
 137                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 138                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ), __METHOD__ );
 139                         if ( !$success ) {
 140                                 wfLogDBError(
 141                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 142                                         $this->getLogContext( array(
 143                                                 'method' => __METHOD__,
 144                                         ) )
 145                                 );
 146                                 $this->reportConnectionError(
 147                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 148                         }
 149                 }
 150
 151                 $this->mOpened = true;
 152
 153                 return true;
 154         }
 155
 156         /**
 157          * Set the character set information right after connection
 158          * @return bool
 159          */
 160         protected function connectInitCharset() {
 161                 global $wgDBmysql5;
 162
 163                 if ( $wgDBmysql5 ) {
 164                         // Tell the server we're communicating with it in UTF-8.
 165                         // This may engage various charset conversions.
 166                         return $this->mysqlSetCharset( 'utf8' );
 167                 } else {
 168                         return $this->mysqlSetCharset( 'binary' );
 169                 }
 170         }
 171
 172         /**
 173          * Open a connection to a MySQL server
 174          *
 175          * @param string $realServer
 176          * @return mixed Raw connection
 177          * @throws DBConnectionError
 178          */
 179         abstract protected function mysqlConnect( $realServer );
 180
 181         /**
 182          * Set the character set of the MySQL link
 183          *
 184          * @param string $charset
 185          * @return bool
 186          */
 187         abstract protected function mysqlSetCharset( $charset );
 188
 189         /**
 190          * @param ResultWrapper|resource $res
 191          * @throws DBUnexpectedError
 192          */
 193         function freeResult( $res ) {
 194                 if ( $res instanceof ResultWrapper ) {
 195                         $res = $res->result;
 196                 }
 197                 wfSuppressWarnings();
 198                 $ok = $this->mysqlFreeResult( $res );
 199                 wfRestoreWarnings();
 200                 if ( !$ok ) {
 201                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 202                 }
 203         }
 204
 205         /**
 206          * Free result memory
 207          *
 208          * @param resource $res Raw result
 209          * @return bool
 210          */
 211         abstract protected function mysqlFreeResult( $res );
 212
 213         /**
 214          * @param ResultWrapper|resource $res
 215          * @return stdClass|bool
 216          * @throws DBUnexpectedError
 217          */
 218         function fetchObject( $res ) {
 219                 if ( $res instanceof ResultWrapper ) {
 220                         $res = $res->result;
 221                 }
 222                 wfSuppressWarnings();
 223                 $row = $this->mysqlFetchObject( $res );
 224                 wfRestoreWarnings();
 225
 226                 $errno = $this->lastErrno();
 227                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 228                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 229                 // these are the only errors mysql_fetch_object can cause.
 230                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 231                 if ( $errno == 2000 || $errno == 2013 ) {
 232                         throw new DBUnexpectedError(
 233                                 $this,
 234                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 235                         );
 236                 }
 237
 238                 return $row;
 239         }
 240
 241         /**
 242          * Fetch a result row as an object
 243          *
 244          * @param resource $res Raw result
 245          * @return stdClass
 246          */
 247         abstract protected function mysqlFetchObject( $res );
 248
 249         /**
 250          * @param ResultWrapper|resource $res
 251          * @return array|bool
 252          * @throws DBUnexpectedError
 253          */
 254         function fetchRow( $res ) {
 255                 if ( $res instanceof ResultWrapper ) {
 256                         $res = $res->result;
 257                 }
 258                 wfSuppressWarnings();
 259                 $row = $this->mysqlFetchArray( $res );
 260                 wfRestoreWarnings();
 261
 262                 $errno = $this->lastErrno();
 263                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 264                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 265                 // these are the only errors mysql_fetch_array can cause.
 266                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 267                 if ( $errno == 2000 || $errno == 2013 ) {
 268                         throw new DBUnexpectedError(
 269                                 $this,
 270                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 271                         );
 272                 }
 273
 274                 return $row;
 275         }
 276
 277         /**
 278          * Fetch a result row as an associative and numeric array
 279          *
 280          * @param resource $res Raw result
 281          * @return array
 282          */
 283         abstract protected function mysqlFetchArray( $res );
 284
 285         /**
 286          * @throws DBUnexpectedError
 287          * @param ResultWrapper|resource $res
 288          * @return int
 289          */
 290         function numRows( $res ) {
 291                 if ( $res instanceof ResultWrapper ) {
 292                         $res = $res->result;
 293                 }
 294                 wfSuppressWarnings();
 295                 $n = $this->mysqlNumRows( $res );
 296                 wfRestoreWarnings();
 297
 298                 // Unfortunately, mysql_num_rows does not reset the last errno.
 299                 // We are not checking for any errors here, since
 300                 // these are no errors mysql_num_rows can cause.
 301                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 302                 // See https://bugzilla.wikimedia.org/42430
 303                 return $n;
 304         }
 305
 306         /**
 307          * Get number of rows in result
 308          *
 309          * @param resource $res Raw result
 310          * @return int
 311          */
 312         abstract protected function mysqlNumRows( $res );
 313
 314         /**
 315          * @param ResultWrapper|resource $res
 316          * @return int
 317          */
 318         function numFields( $res ) {
 319                 if ( $res instanceof ResultWrapper ) {
 320                         $res = $res->result;
 321                 }
 322
 323                 return $this->mysqlNumFields( $res );
 324         }
 325
 326         /**
 327          * Get number of fields in result
 328          *
 329          * @param resource $res Raw result
 330          * @return int
 331          */
 332         abstract protected function mysqlNumFields( $res );
 333
 334         /**
 335          * @param ResultWrapper|resource $res
 336          * @param int $n
 337          * @return string
 338          */
 339         function fieldName( $res, $n ) {
 340                 if ( $res instanceof ResultWrapper ) {
 341                         $res = $res->result;
 342                 }
 343
 344                 return $this->mysqlFieldName( $res, $n );
 345         }
 346
 347         /**
 348          * Get the name of the specified field in a result
 349          *
 350          * @param ResultWrapper|resource $res
 351          * @param int $n
 352          * @return string
 353          */
 354         abstract protected function mysqlFieldName( $res, $n );
 355
 356         /**
 357          * mysql_field_type() wrapper
 358          * @param ResultWrapper|resource $res
 359          * @param int $n
 360          * @return string
 361          */
 362         public function fieldType( $res, $n ) {
 363                 if ( $res instanceof ResultWrapper ) {
 364                         $res = $res->result;
 365                 }
 366
 367                 return $this->mysqlFieldType( $res, $n );
 368         }
 369
 370         /**
 371          * Get the type of the specified field in a result
 372          *
 373          * @param ResultWrapper|resource $res
 374          * @param int $n
 375          * @return string
 376          */
 377         abstract protected function mysqlFieldType( $res, $n );
 378
 379         /**
 380          * @param ResultWrapper|resource $res
 381          * @param int $row
 382          * @return bool
 383          */
 384         function dataSeek( $res, $row ) {
 385                 if ( $res instanceof ResultWrapper ) {
 386                         $res = $res->result;
 387                 }
 388
 389                 return $this->mysqlDataSeek( $res, $row );
 390         }
 391
 392         /**
 393          * Move internal result pointer
 394          *
 395          * @param ResultWrapper|resource $res
 396          * @param int $row
 397          * @return bool
 398          */
 399         abstract protected function mysqlDataSeek( $res, $row );
 400
 401         /**
 402          * @return string
 403          */
 404         function lastError() {
 405                 if ( $this->mConn ) {
 406                         # Even if it's non-zero, it can still be invalid
 407                         wfSuppressWarnings();
 408                         $error = $this->mysqlError( $this->mConn );
 409                         if ( !$error ) {
 410                                 $error = $this->mysqlError();
 411                         }
 412                         wfRestoreWarnings();
 413                 } else {
 414                         $error = $this->mysqlError();
 415                 }
 416                 if ( $error ) {
 417                         $error .= ' (' . $this->mServer . ')';
 418                 }
 419
 420                 return $error;
 421         }
 422
 423         /**
 424          * Returns the text of the error message from previous MySQL operation
 425          *
 426          * @param resource $conn Raw connection
 427          * @return string
 428          */
 429         abstract protected function mysqlError( $conn = null );
 430
 431         /**
 432          * @param string $table
 433          * @param array $uniqueIndexes
 434          * @param array $rows
 435          * @param string $fname
 436          * @return ResultWrapper
 437          */
 438         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 439                 return $this->nativeReplace( $table, $rows, $fname );
 440         }
 441
 442         /**
 443          * Estimate rows in dataset
 444          * Returns estimated count, based on EXPLAIN output
 445          * Takes same arguments as Database::select()
 446          *
 447          * @param string|array $table
 448          * @param string|array $vars
 449          * @param string|array $conds
 450          * @param string $fname
 451          * @param string|array $options
 452          * @return bool|int
 453          */
 454         public function estimateRowCount( $table, $vars = '*', $conds = '',
 455                 $fname = __METHOD__, $options = array()
 456         ) {
 457                 $options['EXPLAIN'] = true;
 458                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 459                 if ( $res === false ) {
 460                         return false;
 461                 }
 462                 if ( !$this->numRows( $res ) ) {
 463                         return 0;
 464                 }
 465
 466                 $rows = 1;
 467                 foreach ( $res as $plan ) {
 468                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 469                 }
 470
 471                 return $rows;
 472         }
 473
 474         /**
 475          * @param string $table
 476          * @param string $field
 477          * @return bool|MySQLField
 478          */
 479         function fieldInfo( $table, $field ) {
 480                 $table = $this->tableName( $table );
 481                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 482                 if ( !$res ) {
 483                         return false;
 484                 }
 485                 $n = $this->mysqlNumFields( $res->result );
 486                 for ( $i = 0; $i < $n; $i++ ) {
 487                         $meta = $this->mysqlFetchField( $res->result, $i );
 488                         if ( $field == $meta->name ) {
 489                                 return new MySQLField( $meta );
 490                         }
 491                 }
 492
 493                 return false;
 494         }
 495
 496         /**
 497          * Get column information from a result
 498          *
 499          * @param resource $res Raw result
 500          * @param int $n
 501          * @return stdClass
 502          */
 503         abstract protected function mysqlFetchField( $res, $n );
 504
 505         /**
 506          * Get information about an index into an object
 507          * Returns false if the index does not exist
 508          *
 509          * @param string $table
 510          * @param string $index
 511          * @param string $fname
 512          * @return bool|array|null False or null on failure
 513          */
 514         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 515                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 516                 # SHOW INDEX should work for 3.x and up:
 517                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 518                 $table = $this->tableName( $table );
 519                 $index = $this->indexName( $index );
 520
 521                 $sql = 'SHOW INDEX FROM ' . $table;
 522                 $res = $this->query( $sql, $fname );
 523
 524                 if ( !$res ) {
 525                         return null;
 526                 }
 527
 528                 $result = array();
 529
 530                 foreach ( $res as $row ) {
 531                         if ( $row->Key_name == $index ) {
 532                                 $result[] = $row;
 533                         }
 534                 }
 535
 536                 return empty( $result ) ? false : $result;
 537         }
 538
 539         /**
 540          * @param string $s
 541          * @return string
 542          */
 543         function strencode( $s ) {
 544                 $sQuoted = $this->mysqlRealEscapeString( $s );
 545
 546                 if ( $sQuoted === false ) {
 547                         $this->ping();
 548                         $sQuoted = $this->mysqlRealEscapeString( $s );
 549                 }
 550
 551                 return $sQuoted;
 552         }
 553
 554         /**
 555          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 556          *
 557          * @param string $s
 558          * @return string
 559          */
 560         public function addIdentifierQuotes( $s ) {
 561                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 562                 // Remove NUL bytes and escape backticks by doubling
 563                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s ) . '`';
 564         }
 565
 566         /**
 567          * @param string $name
 568          * @return bool
 569          */
 570         public function isQuotedIdentifier( $name ) {
 571                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 572         }
 573
 574         /**
 575          * @return bool
 576          */
 577         function ping() {
 578                 $ping = $this->mysqlPing();
 579                 if ( $ping ) {
 580                         return true;
 581                 }
 582
 583                 $this->closeConnection();
 584                 $this->mOpened = false;
 585                 $this->mConn = false;
 586                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 587
 588                 return true;
 589         }
 590
 591         /**
 592          * Ping a server connection or reconnect if there is no connection
 593          *
 594          * @return bool
 595          */
 596         abstract protected function mysqlPing();
 597
 598         /**
 599          * Set lag time in seconds for a fake slave
 600          *
 601          * @param int $lag
 602          */
 603         public function setFakeSlaveLag( $lag ) {
 604                 $this->mFakeSlaveLag = $lag;
 605         }
 606
 607         /**
 608          * Make this connection a fake master
 609          *
 610          * @param bool $enabled
 611          */
 612         public function setFakeMaster( $enabled = true ) {
 613                 $this->mFakeMaster = $enabled;
 614         }
 615
 616         /**
 617          * Returns slave lag.
 618          *
 619          * This will do a SHOW SLAVE STATUS
 620          *
 621          * @return int
 622          */
 623         function getLag() {
 624                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 625                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 626
 627                         return $this->mFakeSlaveLag;
 628                 }
 629
 630                 return $this->getLagFromSlaveStatus();
 631         }
 632
 633         /**
 634          * @return bool|int
 635          */
 636         function getLagFromSlaveStatus() {
 637                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 638                 if ( !$res ) {
 639                         return false;
 640                 }
 641                 $row = $res->fetchObject();
 642                 if ( !$row ) {
 643                         return false;
 644                 }
 645                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 646                         return false;
 647                 } else {
 648                         return intval( $row->Seconds_Behind_Master );
 649                 }
 650         }
 651
 652         /**
 653          * Wait for the slave to catch up to a given master position.
 654          * @todo Return values for this and base class are rubbish
 655          *
 656          * @param DBMasterPos|MySQLMasterPos $pos
 657          * @param int $timeout The maximum number of seconds to wait for synchronisation
 658          * @return int Zero if the slave was past that position already,
 659          *   greater than zero if we waited for some period of time, less than
 660          *   zero if we timed out.
 661          */
 662         function masterPosWait( DBMasterPos $pos, $timeout ) {
 663                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 664                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 665                 }
 666
 667                 # Commit any open transactions
 668                 $this->commit( __METHOD__, 'flush' );
 669
 670                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 671                         $wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
 672
 673                         if ( $wait > $timeout * 1e6 ) {
 674                                 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
 675
 676                                 return -1;
 677                         } elseif ( $wait > 0 ) {
 678                                 wfDebug( "Fake slave waiting $wait us\n" );
 679                                 usleep( $wait );
 680
 681                                 return 1;
 682                         } else {
 683                                 wfDebug( "Fake slave up to date ($wait us)\n" );
 684
 685                                 return 0;
 686                         }
 687                 }
 688
 689                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 690                 $encFile = $this->addQuotes( $pos->file );
 691                 $encPos = intval( $pos->pos );
 692                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 693                 $res = $this->doQuery( $sql );
 694
 695                 $status = false;
 696                 if ( $res && $row = $this->fetchRow( $res ) ) {
 697                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 698                         if ( ctype_digit( $status ) ) { // success
 699                                 $this->lastKnownSlavePos = $pos;
 700                         }
 701                 }
 702
 703                 return $status;
 704         }
 705
 706         /**
 707          * Get the position of the master from SHOW SLAVE STATUS
 708          *
 709          * @return MySQLMasterPos|bool
 710          */
 711         function getSlavePos() {
 712                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 713                         $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
 714                         wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
 715
 716                         return $pos;
 717                 }
 718
 719                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 720                 $row = $this->fetchObject( $res );
 721
 722                 if ( $row ) {
 723                         $pos = isset( $row->Exec_master_log_pos )
 724                                 ? $row->Exec_master_log_pos
 725                                 : $row->Exec_Master_Log_Pos;
 726
 727                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 728                 } else {
 729                         return false;
 730                 }
 731         }
 732
 733         /**
 734          * Get the position of the master from SHOW MASTER STATUS
 735          *
 736          * @return MySQLMasterPos|bool
 737          */
 738         function getMasterPos() {
 739                 if ( $this->mFakeMaster ) {
 740                         return new MySQLMasterPos( 'fake', microtime( true ) );
 741                 }
 742
 743                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 744                 $row = $this->fetchObject( $res );
 745
 746                 if ( $row ) {
 747                         return new MySQLMasterPos( $row->File, $row->Position );
 748                 } else {
 749                         return false;
 750                 }
 751         }
 752
 753         /**
 754          * @param string $index
 755          * @return string
 756          */
 757         function useIndexClause( $index ) {
 758                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 759         }
 760
 761         /**
 762          * @return string
 763          */
 764         function lowPriorityOption() {
 765                 return 'LOW_PRIORITY';
 766         }
 767
 768         /**
 769          * @return string
 770          */
 771         public function getSoftwareLink() {
 772                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 773                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 774                 // in libmysql/libmysql.c).
 775                 $version = $this->getServerVersion();
 776                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 777                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 778                 }
 779
 780                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 781                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 782                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 783                 return '[{{int:version-db-mysql-url}} MySQL]';
 784         }
 785
 786         /**
 787          * @return string
 788          */
 789         public function getServerVersion() {
 790                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 791                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 792                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 793                 if ( $this->serverVersion === null ) {
 794                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 795                 }
 796                 return $this->serverVersion;
 797         }
 798
 799         /**
 800          * @param array $options
 801          */
 802         public function setSessionOptions( array $options ) {
 803                 if ( isset( $options['connTimeout'] ) ) {
 804                         $timeout = (int)$options['connTimeout'];
 805                         $this->query( "SET net_read_timeout=$timeout" );
 806                         $this->query( "SET net_write_timeout=$timeout" );
 807                 }
 808         }
 809
 810         /**
 811          * @param string $sql
 812          * @param string $newLine
 813          * @return bool
 814          */
 815         public function streamStatementEnd( &$sql, &$newLine ) {
 816                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 817                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 818                         $this->delimiter = $m[1];
 819                         $newLine = '';
 820                 }
 821
 822                 return parent::streamStatementEnd( $sql, $newLine );
 823         }
 824
 825         /**
 826          * Check to see if a named lock is available. This is non-blocking.
 827          *
 828          * @param string $lockName Name of lock to poll
 829          * @param string $method Name of method calling us
 830          * @return bool
 831          * @since 1.20
 832          */
 833         public function lockIsFree( $lockName, $method ) {
 834                 $lockName = $this->addQuotes( $lockName );
 835                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 836                 $row = $this->fetchObject( $result );
 837
 838                 return ( $row->lockstatus == 1 );
 839         }
 840
 841         /**
 842          * @param string $lockName
 843          * @param string $method
 844          * @param int $timeout
 845          * @return bool
 846          */
 847         public function lock( $lockName, $method, $timeout = 5 ) {
 848                 $lockName = $this->addQuotes( $lockName );
 849                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 850                 $row = $this->fetchObject( $result );
 851
 852                 if ( $row->lockstatus == 1 ) {
 853                         return true;
 854                 } else {
 855                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 856
 857                         return false;
 858                 }
 859         }
 860
 861         /**
 862          * FROM MYSQL DOCS:
 863          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 864          * @param string $lockName
 865          * @param string $method
 866          * @return bool
 867          */
 868         public function unlock( $lockName, $method ) {
 869                 $lockName = $this->addQuotes( $lockName );
 870                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 871                 $row = $this->fetchObject( $result );
 872
 873                 return ( $row->lockstatus == 1 );
 874         }
 875
 876         /**
 877          * @param array $read
 878          * @param array $write
 879          * @param string $method
 880          * @param bool $lowPriority
 881          * @return bool
 882          */
 883         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 884                 $items = array();
 885
 886                 foreach ( $write as $table ) {
 887                         $tbl = $this->tableName( $table ) .
 888                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 889                                 ' WRITE';
 890                         $items[] = $tbl;
 891                 }
 892                 foreach ( $read as $table ) {
 893                         $items[] = $this->tableName( $table ) . ' READ';
 894                 }
 895                 $sql = "LOCK TABLES " . implode( ',', $items );
 896                 $this->query( $sql, $method );
 897
 898                 return true;
 899         }
 900
 901         /**
 902          * @param string $method
 903          * @return bool
 904          */
 905         public function unlockTables( $method ) {
 906                 $this->query( "UNLOCK TABLES", $method );
 907
 908                 return true;
 909         }
 910
 911         /**
 912          * Get search engine class. All subclasses of this
 913          * need to implement this if they wish to use searching.
 914          *
 915          * @return string
 916          */
 917         public function getSearchEngine() {
 918                 return 'SearchMySQL';
 919         }
 920
 921         /**
 922          * @param bool $value
 923          */
 924         public function setBigSelects( $value = true ) {
 925                 if ( $value === 'default' ) {
 926                         if ( $this->mDefaultBigSelects === null ) {
 927                                 # Function hasn't been called before so it must already be set to the default
 928                                 return;
 929                         } else {
 930                                 $value = $this->mDefaultBigSelects;
 931                         }
 932                 } elseif ( $this->mDefaultBigSelects === null ) {
 933                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 934                 }
 935                 $encValue = $value ? '1' : '0';
 936                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 937         }
 938
 939         /**
 940          * DELETE where the condition is a join. MySql uses multi-table deletes.
 941          * @param string $delTable
 942          * @param string $joinTable
 943          * @param string $delVar
 944          * @param string $joinVar
 945          * @param array|string $conds
 946          * @param bool|string $fname
 947          * @throws DBUnexpectedError
 948          * @return bool|ResultWrapper
 949          */
 950         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 951                 if ( !$conds ) {
 952                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 953                 }
 954
 955                 $delTable = $this->tableName( $delTable );
 956                 $joinTable = $this->tableName( $joinTable );
 957                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 958
 959                 if ( $conds != '*' ) {
 960                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 961                 }
 962
 963                 return $this->query( $sql, $fname );
 964         }
 965
 966         /**
 967          * @param string $table
 968          * @param array $rows
 969          * @param array $uniqueIndexes
 970          * @param array $set
 971          * @param string $fname
 972          * @return bool
 973          */
 974         public function upsert( $table, array $rows, array $uniqueIndexes,
 975                 array $set, $fname = __METHOD__
 976         ) {
 977                 if ( !count( $rows ) ) {
 978                         return true; // nothing to do
 979                 }
 980
 981                 if ( !is_array( reset( $rows ) ) ) {
 982                         $rows = array( $rows );
 983                 }
 984
 985                 $table = $this->tableName( $table );
 986                 $columns = array_keys( $rows[0] );
 987
 988                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
 989                 $rowTuples = array();
 990                 foreach ( $rows as $row ) {
 991                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
 992                 }
 993                 $sql .= implode( ',', $rowTuples );
 994                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
 995
 996                 return (bool)$this->query( $sql, $fname );
 997         }
 998
 999         /**
1000          * Determines how long the server has been up
1001          *
1002          * @return int
1003          */
1004         function getServerUptime() {
1005                 $vars = $this->getMysqlStatus( 'Uptime' );
1006
1007                 return (int)$vars['Uptime'];
1008         }
1009
1010         /**
1011          * Determines if the last failure was due to a deadlock
1012          *
1013          * @return bool
1014          */
1015         function wasDeadlock() {
1016                 return $this->lastErrno() == 1213;
1017         }
1018
1019         /**
1020          * Determines if the last failure was due to a lock timeout
1021          *
1022          * @return bool
1023          */
1024         function wasLockTimeout() {
1025                 return $this->lastErrno() == 1205;
1026         }
1027
1028         /**
1029          * Determines if the last query error was something that should be dealt
1030          * with by pinging the connection and reissuing the query
1031          *
1032          * @return bool
1033          */
1034         function wasErrorReissuable() {
1035                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1036         }
1037
1038         /**
1039          * Determines if the last failure was due to the database being read-only.
1040          *
1041          * @return bool
1042          */
1043         function wasReadOnlyError() {
1044                 return $this->lastErrno() == 1223 ||
1045                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1046         }
1047
1048         /**
1049          * @param string $oldName
1050          * @param string $newName
1051          * @param bool $temporary
1052          * @param string $fname
1053          * @return bool
1054          */
1055         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1056                 $tmp = $temporary ? 'TEMPORARY ' : '';
1057                 $newName = $this->addIdentifierQuotes( $newName );
1058                 $oldName = $this->addIdentifierQuotes( $oldName );
1059                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1060
1061                 return $this->query( $query, $fname );
1062         }
1063
1064         /**
1065          * List all tables on the database
1066          *
1067          * @param string $prefix Only show tables with this prefix, e.g. mw_
1068          * @param string $fname Calling function name
1069          * @return array
1070          */
1071         function listTables( $prefix = null, $fname = __METHOD__ ) {
1072                 $result = $this->query( "SHOW TABLES", $fname );
1073
1074                 $endArray = array();
1075
1076                 foreach ( $result as $table ) {
1077                         $vars = get_object_vars( $table );
1078                         $table = array_pop( $vars );
1079
1080                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1081                                 $endArray[] = $table;
1082                         }
1083                 }
1084
1085                 return $endArray;
1086         }
1087
1088         /**
1089          * @param string $tableName
1090          * @param string $fName
1091          * @return bool|ResultWrapper
1092          */
1093         public function dropTable( $tableName, $fName = __METHOD__ ) {
1094                 if ( !$this->tableExists( $tableName, $fName ) ) {
1095                         return false;
1096                 }
1097
1098                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1099         }
1100
1101         /**
1102          * @return array
1103          */
1104         protected function getDefaultSchemaVars() {
1105                 $vars = parent::getDefaultSchemaVars();
1106                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1107                 $vars['wgDBTableOptions'] = str_replace(
1108                         'CHARSET=mysql4',
1109                         'CHARSET=binary',
1110                         $vars['wgDBTableOptions']
1111                 );
1112
1113                 return $vars;
1114         }
1115
1116         /**
1117          * Get status information from SHOW STATUS in an associative array
1118          *
1119          * @param string $which
1120          * @return array
1121          */
1122         function getMysqlStatus( $which = "%" ) {
1123                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1124                 $status = array();
1125
1126                 foreach ( $res as $row ) {
1127                         $status[$row->Variable_name] = $row->Value;
1128                 }
1129
1130                 return $status;
1131         }
1132
1133         /**
1134          * Lists VIEWs in the database
1135          *
1136          * @param string $prefix Only show VIEWs with this prefix, eg.
1137          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1138          * @param string $fname Name of calling function
1139          * @return array
1140          * @since 1.22
1141          */
1142         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1143
1144                 if ( !isset( $this->allViews ) ) {
1145
1146                         // The name of the column containing the name of the VIEW
1147                         $propertyName = 'Tables_in_' . $this->mDBname;
1148
1149                         // Query for the VIEWS
1150                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1151                         $this->allViews = array();
1152                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1153                                 array_push( $this->allViews, $row[$propertyName] );
1154                         }
1155                 }
1156
1157                 if ( is_null( $prefix ) || $prefix === '' ) {
1158                         return $this->allViews;
1159                 }
1160
1161                 $filteredViews = array();
1162                 foreach ( $this->allViews as $viewName ) {
1163                         // Does the name of this VIEW start with the table-prefix?
1164                         if ( strpos( $viewName, $prefix ) === 0 ) {
1165                                 array_push( $filteredViews, $viewName );
1166                         }
1167                 }
1168
1169                 return $filteredViews;
1170         }
1171
1172         /**
1173          * Differentiates between a TABLE and a VIEW.
1174          *
1175          * @param string $name Name of the TABLE/VIEW to test
1176          * @param string $prefix
1177          * @return bool
1178          * @since 1.22
1179          */
1180         public function isView( $name, $prefix = null ) {
1181                 return in_array( $name, $this->listViews( $prefix ) );
1182         }
1183 }
1184
1185 /**
1186  * Utility class.
1187  * @ingroup Database
1188  */
1189 class MySQLField implements Field {
1190         private $name, $tablename, $default, $max_length, $nullable,
1191                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary;
1192
1193         function __construct( $info ) {
1194                 $this->name = $info->name;
1195                 $this->tablename = $info->table;
1196                 $this->default = $info->def;
1197                 $this->max_length = $info->max_length;
1198                 $this->nullable = !$info->not_null;
1199                 $this->is_pk = $info->primary_key;
1200                 $this->is_unique = $info->unique_key;
1201                 $this->is_multiple = $info->multiple_key;
1202                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1203                 $this->type = $info->type;
1204                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1205         }
1206
1207         /**
1208          * @return string
1209          */
1210         function name() {
1211                 return $this->name;
1212         }
1213
1214         /**
1215          * @return string
1216          */
1217         function tableName() {
1218                 return $this->tableName;
1219         }
1220
1221         /**
1222          * @return string
1223          */
1224         function type() {
1225                 return $this->type;
1226         }
1227
1228         /**
1229          * @return bool
1230          */
1231         function isNullable() {
1232                 return $this->nullable;
1233         }
1234
1235         function defaultValue() {
1236                 return $this->default;
1237         }
1238
1239         /**
1240          * @return bool
1241          */
1242         function isKey() {
1243                 return $this->is_key;
1244         }
1245
1246         /**
1247          * @return bool
1248          */
1249         function isMultipleKey() {
1250                 return $this->is_multiple;
1251         }
1252
1253         function isBinary() {
1254                 return $this->binary;
1255         }
1256 }
1257
1258 class MySQLMasterPos implements DBMasterPos {
1259         /** @var string */
1260         public $file;
1261         /** @var int Position */
1262         public $pos;
1263         /** @var float UNIX timestamp */
1264         public $asOfTime = 0.0;
1265
1266         function __construct( $file, $pos ) {
1267                 $this->file = $file;
1268                 $this->pos = $pos;
1269                 $this->asOfTime = microtime( true );
1270         }
1271
1272         function __toString() {
1273                 // e.g db1034-bin.000976/843431247
1274                 return "{$this->file}/{$this->pos}";
1275         }
1276
1277         /**
1278          * @return array|bool (int, int)
1279          */
1280         protected function getCoordinates() {
1281                 $m = array();
1282                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1283                         return array( (int)$m[1], (int)$m[2] );
1284                 }
1285
1286                 return false;
1287         }
1288
1289         function hasReached( MySQLMasterPos $pos ) {
1290                 $thisPos = $this->getCoordinates();
1291                 $thatPos = $pos->getCoordinates();
1292
1293                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1294         }
1295
1296         function asOfTime() {
1297                 return $this->asOfTime;
1298         }
1299 }