includes/db/DatabaseMysql.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  * Inherit all methods and properties of Database::Database()
  27  *
  28  * @ingroup Database
  29  * @see Database
  30  */
  31 class DatabaseMysql extends DatabaseBase {
  32
  33         /**
  34          * @return string
  35          */
  36         function getType() {
  37                 return 'mysql';
  38         }
  39
  40         /**
  41          * @param $sql string
  42          * @return resource
  43          */
  44         protected function doQuery( $sql ) {
  45                 if ( $this->bufferResults() ) {
  46                         $ret = mysql_query( $sql, $this->mConn );
  47                 } else {
  48                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
  49                 }
  50                 return $ret;
  51         }
  52
  53         /**
  54          * @param $server string
  55          * @param $user string
  56          * @param $password string
  57          * @param $dbName string
  58          * @return bool
  59          * @throws DBConnectionError
  60          */
  61         function open( $server, $user, $password, $dbName ) {
  62                 global $wgAllDBsAreLocalhost, $wgDBmysql5, $wgSQLMode;
  63                 wfProfileIn( __METHOD__ );
  64
  65                 # Load mysql.so if we don't have it
  66                 wfDl( 'mysql' );
  67
  68                 # Fail now
  69                 # Otherwise we get a suppressed fatal error, which is very hard to track down
  70                 if ( !function_exists( 'mysql_connect' ) ) {
  71                         wfProfileOut( __METHOD__ );
  72                         throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
  73                 }
  74
  75                 # Debugging hack -- fake cluster
  76                 if ( $wgAllDBsAreLocalhost ) {
  77                         $realServer = 'localhost';
  78                 } else {
  79                         $realServer = $server;
  80                 }
  81                 $this->close();
  82                 $this->mServer = $server;
  83                 $this->mUser = $user;
  84                 $this->mPassword = $password;
  85                 $this->mDBname = $dbName;
  86
  87                 $connFlags = 0;
  88                 if ( $this->mFlags & DBO_SSL ) {
  89                         $connFlags |= MYSQL_CLIENT_SSL;
  90                 }
  91                 if ( $this->mFlags & DBO_COMPRESS ) {
  92                         $connFlags |= MYSQL_CLIENT_COMPRESS;
  93                 }
  94
  95                 wfProfileIn( "dbconnect-$server" );
  96
  97                 # The kernel's default SYN retransmission period is far too slow for us,
  98                 # so we use a short timeout plus a manual retry. Retrying means that a small
  99                 # but finite rate of SYN packet loss won't cause user-visible errors.
 100                 $this->mConn = false;
 101                 if ( ini_get( 'mysql.connect_timeout' ) <= 3 ) {
 102                         $numAttempts = 2;
 103                 } else {
 104                         $numAttempts = 1;
 105                 }
 106                 $this->installErrorHandler();
 107                 for ( $i = 0; $i < $numAttempts && !$this->mConn; $i++ ) {
 108                         if ( $i > 1 ) {
 109                                 usleep( 1000 );
 110                         }
 111                         if ( $this->mFlags & DBO_PERSISTENT ) {
 112                                 $this->mConn = mysql_pconnect( $realServer, $user, $password, $connFlags );
 113                         } else {
 114                                 # Create a new connection...
 115                                 $this->mConn = mysql_connect( $realServer, $user, $password, true, $connFlags );
 116                         }
 117                         #if ( $this->mConn === false ) {
 118                                 #$iplus = $i + 1;
 119                                 #wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
 120                         #}
 121                 }
 122                 $error = $this->restoreErrorHandler();
 123
 124                 wfProfileOut( "dbconnect-$server" );
 125
 126                 # Always log connection errors
 127                 if ( !$this->mConn ) {
 128                         if ( !$error ) {
 129                                 $error = $this->lastError();
 130                         }
 131                         wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
 132                         wfDebug( "DB connection error\n" .
 133                                 "Server: $server, User: $user, Password: " .
 134                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 135
 136                         wfProfileOut( __METHOD__ );
 137                         return $this->reportConnectionError( $error );
 138                 }
 139
 140                 if ( $dbName != '' ) {
 141                         wfSuppressWarnings();
 142                         $success = mysql_select_db( $dbName, $this->mConn );
 143                         wfRestoreWarnings();
 144                         if ( !$success ) {
 145                                 wfLogDBError( "Error selecting database $dbName on server {$this->mServer}\n" );
 146                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 147                                         "from client host " . wfHostname() . "\n" );
 148
 149                                 wfProfileOut( __METHOD__ );
 150                                 return $this->reportConnectionError( "Error selecting database $dbName" );
 151                         }
 152                 }
 153
 154                 // Tell the server we're communicating with it in UTF-8.
 155                 // This may engage various charset conversions.
 156                 if ( $wgDBmysql5 ) {
 157                         $this->query( 'SET NAMES utf8', __METHOD__ );
 158                 } else {
 159                         $this->query( 'SET NAMES binary', __METHOD__ );
 160                 }
 161                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 162                 if ( is_string( $wgSQLMode ) ) {
 163                         $mode = $this->addQuotes( $wgSQLMode );
 164                         $this->query( "SET sql_mode = $mode", __METHOD__ );
 165                 }
 166
 167                 $this->mOpened = true;
 168                 wfProfileOut( __METHOD__ );
 169                 return true;
 170         }
 171
 172         /**
 173          * @return bool
 174          */
 175         protected function closeConnection() {
 176                 return mysql_close( $this->mConn );
 177         }
 178
 179         /**
 180          * @param $res ResultWrapper
 181          * @throws DBUnexpectedError
 182          */
 183         function freeResult( $res ) {
 184                 if ( $res instanceof ResultWrapper ) {
 185                         $res = $res->result;
 186                 }
 187                 wfSuppressWarnings();
 188                 $ok = mysql_free_result( $res );
 189                 wfRestoreWarnings();
 190                 if ( !$ok ) {
 191                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 192                 }
 193         }
 194
 195         /**
 196          * @param $res ResultWrapper
 197          * @return object|bool
 198          * @throws DBUnexpectedError
 199          */
 200         function fetchObject( $res ) {
 201                 if ( $res instanceof ResultWrapper ) {
 202                         $res = $res->result;
 203                 }
 204                 wfSuppressWarnings();
 205                 $row = mysql_fetch_object( $res );
 206                 wfRestoreWarnings();
 207
 208                 $errno = $this->lastErrno();
 209                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 210                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 211                 // these are the only errors mysql_fetch_object can cause.
 212                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 213                 if ( $errno == 2000 || $errno == 2013 ) {
 214                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 215                 }
 216                 return $row;
 217         }
 218
 219         /**
 220          * @param $res ResultWrapper
 221          * @return array|bool
 222          * @throws DBUnexpectedError
 223          */
 224         function fetchRow( $res ) {
 225                 if ( $res instanceof ResultWrapper ) {
 226                         $res = $res->result;
 227                 }
 228                 wfSuppressWarnings();
 229                 $row = mysql_fetch_array( $res );
 230                 wfRestoreWarnings();
 231
 232                 $errno = $this->lastErrno();
 233                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 234                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 235                 // these are the only errors mysql_fetch_object can cause.
 236                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 237                 if ( $errno == 2000 || $errno == 2013 ) {
 238                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 239                 }
 240                 return $row;
 241         }
 242
 243         /**
 244          * @throws DBUnexpectedError
 245          * @param $res ResultWrapper
 246          * @return int
 247          */
 248         function numRows( $res ) {
 249                 if ( $res instanceof ResultWrapper ) {
 250                         $res = $res->result;
 251                 }
 252                 wfSuppressWarnings();
 253                 $n = mysql_num_rows( $res );
 254                 wfRestoreWarnings();
 255                 // Unfortunately, mysql_num_rows does not reset the last errno.
 256                 // We are not checking for any errors here, since
 257                 // these are no errors mysql_num_rows can cause.
 258                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 259                 // See https://bugzilla.wikimedia.org/42430
 260                 return $n;
 261         }
 262
 263         /**
 264          * @param $res ResultWrapper
 265          * @return int
 266          */
 267         function numFields( $res ) {
 268                 if ( $res instanceof ResultWrapper ) {
 269                         $res = $res->result;
 270                 }
 271                 return mysql_num_fields( $res );
 272         }
 273
 274         /**
 275          * @param $res ResultWrapper
 276          * @param $n string
 277          * @return string
 278          */
 279         function fieldName( $res, $n ) {
 280                 if ( $res instanceof ResultWrapper ) {
 281                         $res = $res->result;
 282                 }
 283                 return mysql_field_name( $res, $n );
 284         }
 285
 286         /**
 287          * @return int
 288          */
 289         function insertId() {
 290                 return mysql_insert_id( $this->mConn );
 291         }
 292
 293         /**
 294          * @param $res ResultWrapper
 295          * @param $row
 296          * @return bool
 297          */
 298         function dataSeek( $res, $row ) {
 299                 if ( $res instanceof ResultWrapper ) {
 300                         $res = $res->result;
 301                 }
 302                 return mysql_data_seek( $res, $row );
 303         }
 304
 305         /**
 306          * @return int
 307          */
 308         function lastErrno() {
 309                 if ( $this->mConn ) {
 310                         return mysql_errno( $this->mConn );
 311                 } else {
 312                         return mysql_errno();
 313                 }
 314         }
 315
 316         /**
 317          * @return string
 318          */
 319         function lastError() {
 320                 if ( $this->mConn ) {
 321                         # Even if it's non-zero, it can still be invalid
 322                         wfSuppressWarnings();
 323                         $error = mysql_error( $this->mConn );
 324                         if ( !$error ) {
 325                                 $error = mysql_error();
 326                         }
 327                         wfRestoreWarnings();
 328                 } else {
 329                         $error = mysql_error();
 330                 }
 331                 if ( $error ) {
 332                         $error .= ' (' . $this->mServer . ')';
 333                 }
 334                 return $error;
 335         }
 336
 337         /**
 338          * @return int
 339          */
 340         function affectedRows() {
 341                 return mysql_affected_rows( $this->mConn );
 342         }
 343
 344         /**
 345          * @param $table string
 346          * @param $uniqueIndexes
 347          * @param $rows array
 348          * @param $fname string
 349          * @return ResultWrapper
 350          */
 351         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 352                 return $this->nativeReplace( $table, $rows, $fname );
 353         }
 354
 355         /**
 356          * @param string $table
 357          * @param array $rows
 358          * @param array $uniqueIndexes
 359          * @param array $set
 360          * @param string $fname
 361          * @param array $options
 362          * @return bool
 363          */
 364         public function upsert(
 365                 $table, array $rows, array $uniqueIndexes, array $set, $fname = __METHOD__
 366         ) {
 367                 if ( !count( $rows ) ) {
 368                         return true; // nothing to do
 369                 }
 370                 $rows = is_array( reset( $rows ) ) ? $rows : array( $rows );
 371
 372                 $table = $this->tableName( $table );
 373                 $columns = array_keys( $rows[0] );
 374
 375                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
 376                 $rowTuples = array();
 377                 foreach ( $rows as $row ) {
 378                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
 379                 }
 380                 $sql .= implode( ',', $rowTuples );
 381                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
 382
 383                 return (bool)$this->query( $sql, $fname );
 384         }
 385
 386         /**
 387          * Estimate rows in dataset
 388          * Returns estimated count, based on EXPLAIN output
 389          * Takes same arguments as Database::select()
 390          *
 391          * @param $table string|array
 392          * @param $vars string|array
 393          * @param $conds string|array
 394          * @param $fname string
 395          * @param $options string|array
 396          * @return int
 397          */
 398         public function estimateRowCount( $table, $vars = '*', $conds = '', $fname = __METHOD__, $options = array() ) {
 399                 $options['EXPLAIN'] = true;
 400                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 401                 if ( $res === false ) {
 402                         return false;
 403                 }
 404                 if ( !$this->numRows( $res ) ) {
 405                         return 0;
 406                 }
 407
 408                 $rows = 1;
 409                 foreach ( $res as $plan ) {
 410                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 411                 }
 412                 return $rows;
 413         }
 414
 415         /**
 416          * @param $table string
 417          * @param $field string
 418          * @return bool|MySQLField
 419          */
 420         function fieldInfo( $table, $field ) {
 421                 $table = $this->tableName( $table );
 422                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 423                 if ( !$res ) {
 424                         return false;
 425                 }
 426                 $n = mysql_num_fields( $res->result );
 427                 for ( $i = 0; $i < $n; $i++ ) {
 428                         $meta = mysql_fetch_field( $res->result, $i );
 429                         if ( $field == $meta->name ) {
 430                                 return new MySQLField( $meta );
 431                         }
 432                 }
 433                 return false;
 434         }
 435
 436         /**
 437          * Get information about an index into an object
 438          * Returns false if the index does not exist
 439          *
 440          * @param $table string
 441          * @param $index string
 442          * @param $fname string
 443          * @return bool|array|null False or null on failure
 444          */
 445         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 446                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 447                 # SHOW INDEX should work for 3.x and up:
 448                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 449                 $table = $this->tableName( $table );
 450                 $index = $this->indexName( $index );
 451
 452                 $sql = 'SHOW INDEX FROM ' . $table;
 453                 $res = $this->query( $sql, $fname );
 454
 455                 if ( !$res ) {
 456                         return null;
 457                 }
 458
 459                 $result = array();
 460
 461                 foreach ( $res as $row ) {
 462                         if ( $row->Key_name == $index ) {
 463                                 $result[] = $row;
 464                         }
 465                 }
 466                 return empty( $result ) ? false : $result;
 467         }
 468
 469         /**
 470          * @param $db
 471          * @return bool
 472          */
 473         function selectDB( $db ) {
 474                 $this->mDBname = $db;
 475                 return mysql_select_db( $db, $this->mConn );
 476         }
 477
 478         /**
 479          * @param $s string
 480          *
 481          * @return string
 482          */
 483         function strencode( $s ) {
 484                 $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 485
 486                 if ( $sQuoted === false ) {
 487                         $this->ping();
 488                         $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 489                 }
 490                 return $sQuoted;
 491         }
 492
 493         /**
 494          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 495          *
 496          * @param $s string
 497          *
 498          * @return string
 499          */
 500         public function addIdentifierQuotes( $s ) {
 501                 return "`" . $this->strencode( $s ) . "`";
 502         }
 503
 504         /**
 505          * @param $name string
 506          * @return bool
 507          */
 508         public function isQuotedIdentifier( $name ) {
 509                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 510         }
 511
 512         /**
 513          * @return bool
 514          */
 515         function ping() {
 516                 $ping = mysql_ping( $this->mConn );
 517                 if ( $ping ) {
 518                         return true;
 519                 }
 520
 521                 mysql_close( $this->mConn );
 522                 $this->mOpened = false;
 523                 $this->mConn = false;
 524                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 525                 return true;
 526         }
 527
 528         /**
 529          * Returns slave lag.
 530          *
 531          * This will do a SHOW SLAVE STATUS
 532          *
 533          * @return int
 534          */
 535         function getLag() {
 536                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 537                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 538                         return $this->mFakeSlaveLag;
 539                 }
 540
 541                 return $this->getLagFromSlaveStatus();
 542         }
 543
 544         /**
 545          * @return bool|int
 546          */
 547         function getLagFromSlaveStatus() {
 548                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 549                 if ( !$res ) {
 550                         return false;
 551                 }
 552                 $row = $res->fetchObject();
 553                 if ( !$row ) {
 554                         return false;
 555                 }
 556                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 557                         return false;
 558                 } else {
 559                         return intval( $row->Seconds_Behind_Master );
 560                 }
 561         }
 562
 563         /**
 564          * @deprecated in 1.19, use getLagFromSlaveStatus
 565          *
 566          * @return bool|int
 567          */
 568         function getLagFromProcesslist() {
 569                 wfDeprecated( __METHOD__, '1.19' );
 570                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 571                 if ( !$res ) {
 572                         return false;
 573                 }
 574                 # Find slave SQL thread
 575                 foreach ( $res as $row ) {
 576                         /* This should work for most situations - when default db
 577                          * for thread is not specified, it had no events executed,
 578                          * and therefore it doesn't know yet how lagged it is.
 579                          *
 580                          * Relay log I/O thread does not select databases.
 581                          */
 582                         if ( $row->User == 'system user' &&
 583                                 $row->State != 'Waiting for master to send event' &&
 584                                 $row->State != 'Connecting to master' &&
 585                                 $row->State != 'Queueing master event to the relay log' &&
 586                                 $row->State != 'Waiting for master update' &&
 587                                 $row->State != 'Requesting binlog dump' &&
 588                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 589                                 $row->State != 'Reconnecting after a failed master event read' &&
 590                                 $row->State != 'Registering slave on master'
 591                                 ) {
 592                                 # This is it, return the time (except -ve)
 593                                 if ( $row->Time > 0x7fffffff ) {
 594                                         return false;
 595                                 } else {
 596                                         return $row->Time;
 597                                 }
 598                         }
 599                 }
 600                 return false;
 601         }
 602
 603         /**
 604          * Wait for the slave to catch up to a given master position.
 605          *
 606          * @param $pos DBMasterPos object
 607          * @param $timeout Integer: the maximum number of seconds to wait for synchronisation
 608          * @return bool|string
 609          */
 610         function masterPosWait( DBMasterPos $pos, $timeout ) {
 611                 $fname = __METHOD__;
 612                 wfProfileIn( $fname );
 613
 614                 # Commit any open transactions
 615                 if ( $this->mTrxLevel ) {
 616                         $this->commit( $fname );
 617                 }
 618
 619                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 620                         $status = parent::masterPosWait( $pos, $timeout );
 621                         wfProfileOut( $fname );
 622                         return $status;
 623                 }
 624
 625                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 626                 $encFile = $this->addQuotes( $pos->file );
 627                 $encPos = intval( $pos->pos );
 628                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 629                 $res = $this->doQuery( $sql );
 630
 631                 if ( $res && $row = $this->fetchRow( $res ) ) {
 632                         wfProfileOut( $fname );
 633                         return $row[0];
 634                 }
 635                 wfProfileOut( $fname );
 636                 return false;
 637         }
 638
 639         /**
 640          * Get the position of the master from SHOW SLAVE STATUS
 641          *
 642          * @return MySQLMasterPos|bool
 643          */
 644         function getSlavePos() {
 645                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 646                         return parent::getSlavePos();
 647                 }
 648
 649                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 650                 $row = $this->fetchObject( $res );
 651
 652                 if ( $row ) {
 653                         $pos = isset( $row->Exec_master_log_pos ) ? $row->Exec_master_log_pos : $row->Exec_Master_Log_Pos;
 654                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 655                 } else {
 656                         return false;
 657                 }
 658         }
 659
 660         /**
 661          * Get the position of the master from SHOW MASTER STATUS
 662          *
 663          * @return MySQLMasterPos|bool
 664          */
 665         function getMasterPos() {
 666                 if ( $this->mFakeMaster ) {
 667                         return parent::getMasterPos();
 668                 }
 669
 670                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 671                 $row = $this->fetchObject( $res );
 672
 673                 if ( $row ) {
 674                         return new MySQLMasterPos( $row->File, $row->Position );
 675                 } else {
 676                         return false;
 677                 }
 678         }
 679
 680         /**
 681          * @return string
 682          */
 683         function getServerVersion() {
 684                 return mysql_get_server_info( $this->mConn );
 685         }
 686
 687         /**
 688          * @param $index
 689          * @return string
 690          */
 691         function useIndexClause( $index ) {
 692                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 693         }
 694
 695         /**
 696          * @return string
 697          */
 698         function lowPriorityOption() {
 699                 return 'LOW_PRIORITY';
 700         }
 701
 702         /**
 703          * @return string
 704          */
 705         public function getSoftwareLink() {
 706                 return '[http://www.mysql.com/ MySQL]';
 707         }
 708
 709         /**
 710          * @param $options array
 711          */
 712         public function setSessionOptions( array $options ) {
 713                 if ( isset( $options['connTimeout'] ) ) {
 714                         $timeout = (int)$options['connTimeout'];
 715                         $this->query( "SET net_read_timeout=$timeout" );
 716                         $this->query( "SET net_write_timeout=$timeout" );
 717                 }
 718         }
 719
 720         public function streamStatementEnd( &$sql, &$newLine ) {
 721                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 722                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 723                         $this->delimiter = $m[1];
 724                         $newLine = '';
 725                 }
 726                 return parent::streamStatementEnd( $sql, $newLine );
 727         }
 728
 729         /**
 730          * Check to see if a named lock is available. This is non-blocking.
 731          *
 732          * @param string $lockName name of lock to poll
 733          * @param string $method name of method calling us
 734          * @return Boolean
 735          * @since 1.20
 736          */
 737         public function lockIsFree( $lockName, $method ) {
 738                 $lockName = $this->addQuotes( $lockName );
 739                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 740                 $row = $this->fetchObject( $result );
 741                 return ( $row->lockstatus == 1 );
 742         }
 743
 744         /**
 745          * @param $lockName string
 746          * @param $method string
 747          * @param $timeout int
 748          * @return bool
 749          */
 750         public function lock( $lockName, $method, $timeout = 5 ) {
 751                 $lockName = $this->addQuotes( $lockName );
 752                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 753                 $row = $this->fetchObject( $result );
 754
 755                 if ( $row->lockstatus == 1 ) {
 756                         return true;
 757                 } else {
 758                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 759                         return false;
 760                 }
 761         }
 762
 763         /**
 764          * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 765          * @param $lockName string
 766          * @param $method string
 767          * @return bool
 768          */
 769         public function unlock( $lockName, $method ) {
 770                 $lockName = $this->addQuotes( $lockName );
 771                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 772                 $row = $this->fetchObject( $result );
 773                 return ( $row->lockstatus == 1 );
 774         }
 775
 776         /**
 777          * @param $read array
 778          * @param $write array
 779          * @param $method string
 780          * @param $lowPriority bool
 781          * @return bool
 782          */
 783         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 784                 $items = array();
 785
 786                 foreach ( $write as $table ) {
 787                         $tbl = $this->tableName( $table ) .
 788                                         ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 789                                         ' WRITE';
 790                         $items[] = $tbl;
 791                 }
 792                 foreach ( $read as $table ) {
 793                         $items[] = $this->tableName( $table ) . ' READ';
 794                 }
 795                 $sql = "LOCK TABLES " . implode( ',', $items );
 796                 $this->query( $sql, $method );
 797                 return true;
 798         }
 799
 800         /**
 801          * @param $method string
 802          * @return bool
 803          */
 804         public function unlockTables( $method ) {
 805                 $this->query( "UNLOCK TABLES", $method );
 806                 return true;
 807         }
 808
 809         /**
 810          * Get search engine class. All subclasses of this
 811          * need to implement this if they wish to use searching.
 812          *
 813          * @return String
 814          */
 815         public function getSearchEngine() {
 816                 return 'SearchMySQL';
 817         }
 818
 819         /**
 820          * @param bool $value
 821          * @return mixed
 822          */
 823         public function setBigSelects( $value = true ) {
 824                 if ( $value === 'default' ) {
 825                         if ( $this->mDefaultBigSelects === null ) {
 826                                 # Function hasn't been called before so it must already be set to the default
 827                                 return;
 828                         } else {
 829                                 $value = $this->mDefaultBigSelects;
 830                         }
 831                 } elseif ( $this->mDefaultBigSelects === null ) {
 832                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 833                 }
 834                 $encValue = $value ? '1' : '0';
 835                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 836         }
 837
 838         /**
 839          * DELETE where the condition is a join. MySql uses multi-table deletes.
 840          * @param $delTable string
 841          * @param $joinTable string
 842          * @param $delVar string
 843          * @param $joinVar string
 844          * @param $conds array|string
 845          * @param bool|string $fname bool
 846          * @throws DBUnexpectedError
 847          * @return bool|ResultWrapper
 848          */
 849         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 850                 if ( !$conds ) {
 851                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 852                 }
 853
 854                 $delTable = $this->tableName( $delTable );
 855                 $joinTable = $this->tableName( $joinTable );
 856                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 857
 858                 if ( $conds != '*' ) {
 859                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 860                 }
 861
 862                 return $this->query( $sql, $fname );
 863         }
 864
 865         /**
 866          * Determines how long the server has been up
 867          *
 868          * @return int
 869          */
 870         function getServerUptime() {
 871                 $vars = $this->getMysqlStatus( 'Uptime' );
 872                 return (int)$vars['Uptime'];
 873         }
 874
 875         /**
 876          * Determines if the last failure was due to a deadlock
 877          *
 878          * @return bool
 879          */
 880         function wasDeadlock() {
 881                 return $this->lastErrno() == 1213;
 882         }
 883
 884         /**
 885          * Determines if the last failure was due to a lock timeout
 886          *
 887          * @return bool
 888          */
 889         function wasLockTimeout() {
 890                 return $this->lastErrno() == 1205;
 891         }
 892
 893         /**
 894          * Determines if the last query error was something that should be dealt
 895          * with by pinging the connection and reissuing the query
 896          *
 897          * @return bool
 898          */
 899         function wasErrorReissuable() {
 900                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
 901         }
 902
 903         /**
 904          * Determines if the last failure was due to the database being read-only.
 905          *
 906          * @return bool
 907          */
 908         function wasReadOnlyError() {
 909                 return $this->lastErrno() == 1223 ||
 910                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
 911         }
 912
 913         /**
 914          * @param $oldName
 915          * @param $newName
 916          * @param $temporary bool
 917          * @param $fname string
 918          */
 919         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 920                 $tmp = $temporary ? 'TEMPORARY ' : '';
 921                 $newName = $this->addIdentifierQuotes( $newName );
 922                 $oldName = $this->addIdentifierQuotes( $oldName );
 923                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
 924                 $this->query( $query, $fname );
 925         }
 926
 927         /**
 928          * List all tables on the database
 929          *
 930          * @param string $prefix Only show tables with this prefix, e.g. mw_
 931          * @param string $fname calling function name
 932          * @return array
 933          */
 934         function listTables( $prefix = null, $fname = __METHOD__ ) {
 935                 $result = $this->query( "SHOW TABLES", $fname );
 936
 937                 $endArray = array();
 938
 939                 foreach ( $result as $table ) {
 940                         $vars = get_object_vars( $table );
 941                         $table = array_pop( $vars );
 942
 943                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
 944                                 $endArray[] = $table;
 945                         }
 946                 }
 947
 948                 return $endArray;
 949         }
 950
 951         /**
 952          * @param $tableName
 953          * @param $fName string
 954          * @return bool|ResultWrapper
 955          */
 956         public function dropTable( $tableName, $fName = __METHOD__ ) {
 957                 if ( !$this->tableExists( $tableName, $fName ) ) {
 958                         return false;
 959                 }
 960                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
 961         }
 962
 963         /**
 964          * @return array
 965          */
 966         protected function getDefaultSchemaVars() {
 967                 $vars = parent::getDefaultSchemaVars();
 968                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
 969                 $vars['wgDBTableOptions'] = str_replace( 'CHARSET=mysql4', 'CHARSET=binary', $vars['wgDBTableOptions'] );
 970                 return $vars;
 971         }
 972
 973         /**
 974          * Get status information from SHOW STATUS in an associative array
 975          *
 976          * @param $which string
 977          * @return array
 978          */
 979         function getMysqlStatus( $which = "%" ) {
 980                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
 981                 $status = array();
 982
 983                 foreach ( $res as $row ) {
 984                         $status[$row->Variable_name] = $row->Value;
 985                 }
 986
 987                 return $status;
 988         }
 989
 990 }
 991
 992 /**
 993  * Utility class.
 994  * @ingroup Database
 995  */
 996 class MySQLField implements Field {
 997         private $name, $tablename, $default, $max_length, $nullable,
 998                 $is_pk, $is_unique, $is_multiple, $is_key, $type;
 999
1000         function __construct( $info ) {
1001                 $this->name = $info->name;
1002                 $this->tablename = $info->table;
1003                 $this->default = $info->def;
1004                 $this->max_length = $info->max_length;
1005                 $this->nullable = !$info->not_null;
1006                 $this->is_pk = $info->primary_key;
1007                 $this->is_unique = $info->unique_key;
1008                 $this->is_multiple = $info->multiple_key;
1009                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1010                 $this->type = $info->type;
1011         }
1012
1013         /**
1014          * @return string
1015          */
1016         function name() {
1017                 return $this->name;
1018         }
1019
1020         /**
1021          * @return string
1022          */
1023         function tableName() {
1024                 return $this->tableName;
1025         }
1026
1027         /**
1028          * @return string
1029          */
1030         function type() {
1031                 return $this->type;
1032         }
1033
1034         /**
1035          * @return bool
1036          */
1037         function isNullable() {
1038                 return $this->nullable;
1039         }
1040
1041         function defaultValue() {
1042                 return $this->default;
1043         }
1044
1045         /**
1046          * @return bool
1047          */
1048         function isKey() {
1049                 return $this->is_key;
1050         }
1051
1052         /**
1053          * @return bool
1054          */
1055         function isMultipleKey() {
1056                 return $this->is_multiple;
1057         }
1058 }
1059
1060 class MySQLMasterPos implements DBMasterPos {
1061         var $file, $pos;
1062
1063         function __construct( $file, $pos ) {
1064                 $this->file = $file;
1065                 $this->pos = $pos;
1066         }
1067
1068         function __toString() {
1069                 return "{$this->file}/{$this->pos}";
1070         }
1071 }