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                 # Close/unset connection handle
  63                 $this->close();
  64
  65                 # Debugging hack -- fake cluster
  66                 $realServer = $wgAllDBsAreLocalhost ? 'localhost' : $server;
  67                 $this->mServer = $server;
  68                 $this->mUser = $user;
  69                 $this->mPassword = $password;
  70                 $this->mDBname = $dbName;
  71
  72                 $this->installErrorHandler();
  73                 try {
  74                         $this->mConn = $this->mysqlConnect( $realServer );
  75                 } catch ( Exception $ex ) {
  76                         $this->restoreErrorHandler();
  77                         throw $ex;
  78                 }
  79                 $error = $this->restoreErrorHandler();
  80
  81                 # Always log connection errors
  82                 if ( !$this->mConn ) {
  83                         if ( !$error ) {
  84                                 $error = $this->lastError();
  85                         }
  86                         wfLogDBError(
  87                                 "Error connecting to {db_server}: {error}",
  88                                 $this->getLogContext( array(
  89                                         'method' => __METHOD__,
  90                                         'error' => $error,
  91                                 ) )
  92                         );
  93                         wfDebug( "DB connection error\n" .
  94                                 "Server: $server, User: $user, Password: " .
  95                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
  96
  97                         $this->reportConnectionError( $error );
  98                 }
  99
 100                 if ( $dbName != '' ) {
 101                         MediaWiki\suppressWarnings();
 102                         $success = $this->selectDB( $dbName );
 103                         MediaWiki\restoreWarnings();
 104                         if ( !$success ) {
 105                                 wfLogDBError(
 106                                         "Error selecting database {db_name} on server {db_server}",
 107                                         $this->getLogContext( array(
 108                                                 'method' => __METHOD__,
 109                                         ) )
 110                                 );
 111                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 112                                         "from client host " . wfHostname() . "\n" );
 113
 114                                 $this->reportConnectionError( "Error selecting database $dbName" );
 115                         }
 116                 }
 117
 118                 // Tell the server what we're communicating with
 119                 if ( !$this->connectInitCharset() ) {
 120                         $this->reportConnectionError( "Error setting character set" );
 121                 }
 122
 123                 // Abstract over any insane MySQL defaults
 124                 $set = array( 'group_concat_max_len = 262144' );
 125                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 126                 if ( is_string( $wgSQLMode ) ) {
 127                         $set[] = 'sql_mode = ' . $this->addQuotes( $wgSQLMode );
 128                 }
 129                 // Set any custom settings defined by site config
 130                 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 131                 foreach ( $this->mSessionVars as $var => $val ) {
 132                         // Escape strings but not numbers to avoid MySQL complaining
 133                         if ( !is_int( $val ) && !is_float( $val ) ) {
 134                                 $val = $this->addQuotes( $val );
 135                         }
 136                         $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 137                 }
 138
 139                 if ( $set ) {
 140                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 141                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ), __METHOD__ );
 142                         if ( !$success ) {
 143                                 wfLogDBError(
 144                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 145                                         $this->getLogContext( array(
 146                                                 'method' => __METHOD__,
 147                                         ) )
 148                                 );
 149                                 $this->reportConnectionError(
 150                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 151                         }
 152                 }
 153
 154                 $this->mOpened = true;
 155
 156                 return true;
 157         }
 158
 159         /**
 160          * Set the character set information right after connection
 161          * @return bool
 162          */
 163         protected function connectInitCharset() {
 164                 global $wgDBmysql5;
 165
 166                 if ( $wgDBmysql5 ) {
 167                         // Tell the server we're communicating with it in UTF-8.
 168                         // This may engage various charset conversions.
 169                         return $this->mysqlSetCharset( 'utf8' );
 170                 } else {
 171                         return $this->mysqlSetCharset( 'binary' );
 172                 }
 173         }
 174
 175         /**
 176          * Open a connection to a MySQL server
 177          *
 178          * @param string $realServer
 179          * @return mixed Raw connection
 180          * @throws DBConnectionError
 181          */
 182         abstract protected function mysqlConnect( $realServer );
 183
 184         /**
 185          * Set the character set of the MySQL link
 186          *
 187          * @param string $charset
 188          * @return bool
 189          */
 190         abstract protected function mysqlSetCharset( $charset );
 191
 192         /**
 193          * @param ResultWrapper|resource $res
 194          * @throws DBUnexpectedError
 195          */
 196         function freeResult( $res ) {
 197                 if ( $res instanceof ResultWrapper ) {
 198                         $res = $res->result;
 199                 }
 200                 MediaWiki\suppressWarnings();
 201                 $ok = $this->mysqlFreeResult( $res );
 202                 MediaWiki\restoreWarnings();
 203                 if ( !$ok ) {
 204                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 205                 }
 206         }
 207
 208         /**
 209          * Free result memory
 210          *
 211          * @param resource $res Raw result
 212          * @return bool
 213          */
 214         abstract protected function mysqlFreeResult( $res );
 215
 216         /**
 217          * @param ResultWrapper|resource $res
 218          * @return stdClass|bool
 219          * @throws DBUnexpectedError
 220          */
 221         function fetchObject( $res ) {
 222                 if ( $res instanceof ResultWrapper ) {
 223                         $res = $res->result;
 224                 }
 225                 MediaWiki\suppressWarnings();
 226                 $row = $this->mysqlFetchObject( $res );
 227                 MediaWiki\restoreWarnings();
 228
 229                 $errno = $this->lastErrno();
 230                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 231                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 232                 // these are the only errors mysql_fetch_object can cause.
 233                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 234                 if ( $errno == 2000 || $errno == 2013 ) {
 235                         throw new DBUnexpectedError(
 236                                 $this,
 237                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 238                         );
 239                 }
 240
 241                 return $row;
 242         }
 243
 244         /**
 245          * Fetch a result row as an object
 246          *
 247          * @param resource $res Raw result
 248          * @return stdClass
 249          */
 250         abstract protected function mysqlFetchObject( $res );
 251
 252         /**
 253          * @param ResultWrapper|resource $res
 254          * @return array|bool
 255          * @throws DBUnexpectedError
 256          */
 257         function fetchRow( $res ) {
 258                 if ( $res instanceof ResultWrapper ) {
 259                         $res = $res->result;
 260                 }
 261                 MediaWiki\suppressWarnings();
 262                 $row = $this->mysqlFetchArray( $res );
 263                 MediaWiki\restoreWarnings();
 264
 265                 $errno = $this->lastErrno();
 266                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 267                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 268                 // these are the only errors mysql_fetch_array can cause.
 269                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 270                 if ( $errno == 2000 || $errno == 2013 ) {
 271                         throw new DBUnexpectedError(
 272                                 $this,
 273                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 274                         );
 275                 }
 276
 277                 return $row;
 278         }
 279
 280         /**
 281          * Fetch a result row as an associative and numeric array
 282          *
 283          * @param resource $res Raw result
 284          * @return array
 285          */
 286         abstract protected function mysqlFetchArray( $res );
 287
 288         /**
 289          * @throws DBUnexpectedError
 290          * @param ResultWrapper|resource $res
 291          * @return int
 292          */
 293         function numRows( $res ) {
 294                 if ( $res instanceof ResultWrapper ) {
 295                         $res = $res->result;
 296                 }
 297                 MediaWiki\suppressWarnings();
 298                 $n = $this->mysqlNumRows( $res );
 299                 MediaWiki\restoreWarnings();
 300
 301                 // Unfortunately, mysql_num_rows does not reset the last errno.
 302                 // We are not checking for any errors here, since
 303                 // these are no errors mysql_num_rows can cause.
 304                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 305                 // See https://bugzilla.wikimedia.org/42430
 306                 return $n;
 307         }
 308
 309         /**
 310          * Get number of rows in result
 311          *
 312          * @param resource $res Raw result
 313          * @return int
 314          */
 315         abstract protected function mysqlNumRows( $res );
 316
 317         /**
 318          * @param ResultWrapper|resource $res
 319          * @return int
 320          */
 321         function numFields( $res ) {
 322                 if ( $res instanceof ResultWrapper ) {
 323                         $res = $res->result;
 324                 }
 325
 326                 return $this->mysqlNumFields( $res );
 327         }
 328
 329         /**
 330          * Get number of fields in result
 331          *
 332          * @param resource $res Raw result
 333          * @return int
 334          */
 335         abstract protected function mysqlNumFields( $res );
 336
 337         /**
 338          * @param ResultWrapper|resource $res
 339          * @param int $n
 340          * @return string
 341          */
 342         function fieldName( $res, $n ) {
 343                 if ( $res instanceof ResultWrapper ) {
 344                         $res = $res->result;
 345                 }
 346
 347                 return $this->mysqlFieldName( $res, $n );
 348         }
 349
 350         /**
 351          * Get the name of the specified field in a result
 352          *
 353          * @param ResultWrapper|resource $res
 354          * @param int $n
 355          * @return string
 356          */
 357         abstract protected function mysqlFieldName( $res, $n );
 358
 359         /**
 360          * mysql_field_type() wrapper
 361          * @param ResultWrapper|resource $res
 362          * @param int $n
 363          * @return string
 364          */
 365         public function fieldType( $res, $n ) {
 366                 if ( $res instanceof ResultWrapper ) {
 367                         $res = $res->result;
 368                 }
 369
 370                 return $this->mysqlFieldType( $res, $n );
 371         }
 372
 373         /**
 374          * Get the type of the specified field in a result
 375          *
 376          * @param ResultWrapper|resource $res
 377          * @param int $n
 378          * @return string
 379          */
 380         abstract protected function mysqlFieldType( $res, $n );
 381
 382         /**
 383          * @param ResultWrapper|resource $res
 384          * @param int $row
 385          * @return bool
 386          */
 387         function dataSeek( $res, $row ) {
 388                 if ( $res instanceof ResultWrapper ) {
 389                         $res = $res->result;
 390                 }
 391
 392                 return $this->mysqlDataSeek( $res, $row );
 393         }
 394
 395         /**
 396          * Move internal result pointer
 397          *
 398          * @param ResultWrapper|resource $res
 399          * @param int $row
 400          * @return bool
 401          */
 402         abstract protected function mysqlDataSeek( $res, $row );
 403
 404         /**
 405          * @return string
 406          */
 407         function lastError() {
 408                 if ( $this->mConn ) {
 409                         # Even if it's non-zero, it can still be invalid
 410                         MediaWiki\suppressWarnings();
 411                         $error = $this->mysqlError( $this->mConn );
 412                         if ( !$error ) {
 413                                 $error = $this->mysqlError();
 414                         }
 415                         MediaWiki\restoreWarnings();
 416                 } else {
 417                         $error = $this->mysqlError();
 418                 }
 419                 if ( $error ) {
 420                         $error .= ' (' . $this->mServer . ')';
 421                 }
 422
 423                 return $error;
 424         }
 425
 426         /**
 427          * Returns the text of the error message from previous MySQL operation
 428          *
 429          * @param resource $conn Raw connection
 430          * @return string
 431          */
 432         abstract protected function mysqlError( $conn = null );
 433
 434         /**
 435          * @param string $table
 436          * @param array $uniqueIndexes
 437          * @param array $rows
 438          * @param string $fname
 439          * @return ResultWrapper
 440          */
 441         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 442                 return $this->nativeReplace( $table, $rows, $fname );
 443         }
 444
 445         /**
 446          * Estimate rows in dataset
 447          * Returns estimated count, based on EXPLAIN output
 448          * Takes same arguments as Database::select()
 449          *
 450          * @param string|array $table
 451          * @param string|array $vars
 452          * @param string|array $conds
 453          * @param string $fname
 454          * @param string|array $options
 455          * @return bool|int
 456          */
 457         public function estimateRowCount( $table, $vars = '*', $conds = '',
 458                 $fname = __METHOD__, $options = array()
 459         ) {
 460                 $options['EXPLAIN'] = true;
 461                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 462                 if ( $res === false ) {
 463                         return false;
 464                 }
 465                 if ( !$this->numRows( $res ) ) {
 466                         return 0;
 467                 }
 468
 469                 $rows = 1;
 470                 foreach ( $res as $plan ) {
 471                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 472                 }
 473
 474                 return (int)$rows;
 475         }
 476
 477         /**
 478          * @param string $table
 479          * @param string $field
 480          * @return bool|MySQLField
 481          */
 482         function fieldInfo( $table, $field ) {
 483                 $table = $this->tableName( $table );
 484                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 485                 if ( !$res ) {
 486                         return false;
 487                 }
 488                 $n = $this->mysqlNumFields( $res->result );
 489                 for ( $i = 0; $i < $n; $i++ ) {
 490                         $meta = $this->mysqlFetchField( $res->result, $i );
 491                         if ( $field == $meta->name ) {
 492                                 return new MySQLField( $meta );
 493                         }
 494                 }
 495
 496                 return false;
 497         }
 498
 499         /**
 500          * Get column information from a result
 501          *
 502          * @param resource $res Raw result
 503          * @param int $n
 504          * @return stdClass
 505          */
 506         abstract protected function mysqlFetchField( $res, $n );
 507
 508         /**
 509          * Get information about an index into an object
 510          * Returns false if the index does not exist
 511          *
 512          * @param string $table
 513          * @param string $index
 514          * @param string $fname
 515          * @return bool|array|null False or null on failure
 516          */
 517         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 518                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 519                 # SHOW INDEX should work for 3.x and up:
 520                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 521                 $table = $this->tableName( $table );
 522                 $index = $this->indexName( $index );
 523
 524                 $sql = 'SHOW INDEX FROM ' . $table;
 525                 $res = $this->query( $sql, $fname );
 526
 527                 if ( !$res ) {
 528                         return null;
 529                 }
 530
 531                 $result = array();
 532
 533                 foreach ( $res as $row ) {
 534                         if ( $row->Key_name == $index ) {
 535                                 $result[] = $row;
 536                         }
 537                 }
 538
 539                 return empty( $result ) ? false : $result;
 540         }
 541
 542         /**
 543          * @param string $s
 544          * @return string
 545          */
 546         function strencode( $s ) {
 547                 $sQuoted = $this->mysqlRealEscapeString( $s );
 548
 549                 if ( $sQuoted === false ) {
 550                         $this->ping();
 551                         $sQuoted = $this->mysqlRealEscapeString( $s );
 552                 }
 553
 554                 return $sQuoted;
 555         }
 556
 557         /**
 558          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 559          *
 560          * @param string $s
 561          * @return string
 562          */
 563         public function addIdentifierQuotes( $s ) {
 564                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 565                 // Remove NUL bytes and escape backticks by doubling
 566                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s ) . '`';
 567         }
 568
 569         /**
 570          * @param string $name
 571          * @return bool
 572          */
 573         public function isQuotedIdentifier( $name ) {
 574                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 575         }
 576
 577         /**
 578          * @return bool
 579          */
 580         function ping() {
 581                 $ping = $this->mysqlPing();
 582                 if ( $ping ) {
 583                         // Connection was good or lost but reconnected...
 584                         // @note: mysqlnd (php 5.6+) does not support this (PHP bug 52561)
 585                         return true;
 586                 }
 587
 588                 // Try a full disconnect/reconnect cycle if ping() failed
 589                 $this->closeConnection();
 590                 $this->mOpened = false;
 591                 $this->mConn = false;
 592                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 593
 594                 return true;
 595         }
 596
 597         /**
 598          * Ping a server connection or reconnect if there is no connection
 599          *
 600          * @return bool
 601          */
 602         abstract protected function mysqlPing();
 603
 604         /**
 605          * Set lag time in seconds for a fake slave
 606          *
 607          * @param int $lag
 608          */
 609         public function setFakeSlaveLag( $lag ) {
 610                 $this->mFakeSlaveLag = $lag;
 611         }
 612
 613         /**
 614          * Make this connection a fake master
 615          *
 616          * @param bool $enabled
 617          */
 618         public function setFakeMaster( $enabled = true ) {
 619                 $this->mFakeMaster = $enabled;
 620         }
 621
 622         /**
 623          * Returns slave lag.
 624          *
 625          * This will do a SHOW SLAVE STATUS
 626          *
 627          * @return int
 628          */
 629         function getLag() {
 630                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 631                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 632
 633                         return $this->mFakeSlaveLag;
 634                 }
 635
 636                 return $this->getLagFromSlaveStatus();
 637         }
 638
 639         /**
 640          * @return bool|int
 641          */
 642         function getLagFromSlaveStatus() {
 643                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 644                 if ( !$res ) {
 645                         return false;
 646                 }
 647                 $row = $res->fetchObject();
 648                 if ( !$row ) {
 649                         return false;
 650                 }
 651                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 652                         return false;
 653                 } else {
 654                         return intval( $row->Seconds_Behind_Master );
 655                 }
 656         }
 657
 658         /**
 659          * Wait for the slave to catch up to a given master position.
 660          * @todo Return values for this and base class are rubbish
 661          *
 662          * @param DBMasterPos|MySQLMasterPos $pos
 663          * @param int $timeout The maximum number of seconds to wait for synchronisation
 664          * @return int Zero if the slave was past that position already,
 665          *   greater than zero if we waited for some period of time, less than
 666          *   zero if we timed out.
 667          */
 668         function masterPosWait( DBMasterPos $pos, $timeout ) {
 669                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 670                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 671                 }
 672
 673                 # Commit any open transactions
 674                 $this->commit( __METHOD__, 'flush' );
 675
 676                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 677                         $wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
 678
 679                         if ( $wait > $timeout * 1e6 ) {
 680                                 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
 681
 682                                 return -1;
 683                         } elseif ( $wait > 0 ) {
 684                                 wfDebug( "Fake slave waiting $wait us\n" );
 685                                 usleep( $wait );
 686
 687                                 return 1;
 688                         } else {
 689                                 wfDebug( "Fake slave up to date ($wait us)\n" );
 690
 691                                 return 0;
 692                         }
 693                 }
 694
 695                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 696                 $encFile = $this->addQuotes( $pos->file );
 697                 $encPos = intval( $pos->pos );
 698                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 699                 $res = $this->doQuery( $sql );
 700
 701                 $status = false;
 702                 if ( $res && $row = $this->fetchRow( $res ) ) {
 703                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 704                         if ( ctype_digit( $status ) ) { // success
 705                                 $this->lastKnownSlavePos = $pos;
 706                         }
 707                 }
 708
 709                 return $status;
 710         }
 711
 712         /**
 713          * Get the position of the master from SHOW SLAVE STATUS
 714          *
 715          * @return MySQLMasterPos|bool
 716          */
 717         function getSlavePos() {
 718                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 719                         $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
 720                         wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
 721
 722                         return $pos;
 723                 }
 724
 725                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 726                 $row = $this->fetchObject( $res );
 727
 728                 if ( $row ) {
 729                         $pos = isset( $row->Exec_master_log_pos )
 730                                 ? $row->Exec_master_log_pos
 731                                 : $row->Exec_Master_Log_Pos;
 732
 733                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 734                 } else {
 735                         return false;
 736                 }
 737         }
 738
 739         /**
 740          * Get the position of the master from SHOW MASTER STATUS
 741          *
 742          * @return MySQLMasterPos|bool
 743          */
 744         function getMasterPos() {
 745                 if ( $this->mFakeMaster ) {
 746                         return new MySQLMasterPos( 'fake', microtime( true ) );
 747                 }
 748
 749                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 750                 $row = $this->fetchObject( $res );
 751
 752                 if ( $row ) {
 753                         return new MySQLMasterPos( $row->File, $row->Position );
 754                 } else {
 755                         return false;
 756                 }
 757         }
 758
 759         /**
 760          * @param string $index
 761          * @return string
 762          */
 763         function useIndexClause( $index ) {
 764                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 765         }
 766
 767         /**
 768          * @return string
 769          */
 770         function lowPriorityOption() {
 771                 return 'LOW_PRIORITY';
 772         }
 773
 774         /**
 775          * @return string
 776          */
 777         public function getSoftwareLink() {
 778                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 779                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 780                 // in libmysql/libmysql.c).
 781                 $version = $this->getServerVersion();
 782                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 783                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 784                 }
 785
 786                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 787                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 788                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 789                 return '[{{int:version-db-mysql-url}} MySQL]';
 790         }
 791
 792         /**
 793          * @return string
 794          */
 795         public function getServerVersion() {
 796                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 797                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 798                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 799                 if ( $this->serverVersion === null ) {
 800                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 801                 }
 802                 return $this->serverVersion;
 803         }
 804
 805         /**
 806          * @param array $options
 807          */
 808         public function setSessionOptions( array $options ) {
 809                 if ( isset( $options['connTimeout'] ) ) {
 810                         $timeout = (int)$options['connTimeout'];
 811                         $this->query( "SET net_read_timeout=$timeout" );
 812                         $this->query( "SET net_write_timeout=$timeout" );
 813                 }
 814         }
 815
 816         /**
 817          * @param string $sql
 818          * @param string $newLine
 819          * @return bool
 820          */
 821         public function streamStatementEnd( &$sql, &$newLine ) {
 822                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 823                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 824                         $this->delimiter = $m[1];
 825                         $newLine = '';
 826                 }
 827
 828                 return parent::streamStatementEnd( $sql, $newLine );
 829         }
 830
 831         /**
 832          * Check to see if a named lock is available. This is non-blocking.
 833          *
 834          * @param string $lockName Name of lock to poll
 835          * @param string $method Name of method calling us
 836          * @return bool
 837          * @since 1.20
 838          */
 839         public function lockIsFree( $lockName, $method ) {
 840                 $lockName = $this->addQuotes( $lockName );
 841                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 842                 $row = $this->fetchObject( $result );
 843
 844                 return ( $row->lockstatus == 1 );
 845         }
 846
 847         /**
 848          * @param string $lockName
 849          * @param string $method
 850          * @param int $timeout
 851          * @return bool
 852          */
 853         public function lock( $lockName, $method, $timeout = 5 ) {
 854                 $lockName = $this->addQuotes( $lockName );
 855                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 856                 $row = $this->fetchObject( $result );
 857
 858                 if ( $row->lockstatus == 1 ) {
 859                         return true;
 860                 } else {
 861                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 862
 863                         return false;
 864                 }
 865         }
 866
 867         /**
 868          * FROM MYSQL DOCS:
 869          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 870          * @param string $lockName
 871          * @param string $method
 872          * @return bool
 873          */
 874         public function unlock( $lockName, $method ) {
 875                 $lockName = $this->addQuotes( $lockName );
 876                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 877                 $row = $this->fetchObject( $result );
 878
 879                 return ( $row->lockstatus == 1 );
 880         }
 881
 882         public function namedLocksEnqueue() {
 883                 return true;
 884         }
 885
 886         /**
 887          * @param array $read
 888          * @param array $write
 889          * @param string $method
 890          * @param bool $lowPriority
 891          * @return bool
 892          */
 893         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 894                 $items = array();
 895
 896                 foreach ( $write as $table ) {
 897                         $tbl = $this->tableName( $table ) .
 898                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 899                                 ' WRITE';
 900                         $items[] = $tbl;
 901                 }
 902                 foreach ( $read as $table ) {
 903                         $items[] = $this->tableName( $table ) . ' READ';
 904                 }
 905                 $sql = "LOCK TABLES " . implode( ',', $items );
 906                 $this->query( $sql, $method );
 907
 908                 return true;
 909         }
 910
 911         /**
 912          * @param string $method
 913          * @return bool
 914          */
 915         public function unlockTables( $method ) {
 916                 $this->query( "UNLOCK TABLES", $method );
 917
 918                 return true;
 919         }
 920
 921         /**
 922          * Get search engine class. All subclasses of this
 923          * need to implement this if they wish to use searching.
 924          *
 925          * @return string
 926          */
 927         public function getSearchEngine() {
 928                 return 'SearchMySQL';
 929         }
 930
 931         /**
 932          * @param bool $value
 933          */
 934         public function setBigSelects( $value = true ) {
 935                 if ( $value === 'default' ) {
 936                         if ( $this->mDefaultBigSelects === null ) {
 937                                 # Function hasn't been called before so it must already be set to the default
 938                                 return;
 939                         } else {
 940                                 $value = $this->mDefaultBigSelects;
 941                         }
 942                 } elseif ( $this->mDefaultBigSelects === null ) {
 943                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__ );
 944                 }
 945                 $encValue = $value ? '1' : '0';
 946                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 947         }
 948
 949         /**
 950          * DELETE where the condition is a join. MySql uses multi-table deletes.
 951          * @param string $delTable
 952          * @param string $joinTable
 953          * @param string $delVar
 954          * @param string $joinVar
 955          * @param array|string $conds
 956          * @param bool|string $fname
 957          * @throws DBUnexpectedError
 958          * @return bool|ResultWrapper
 959          */
 960         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 961                 if ( !$conds ) {
 962                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 963                 }
 964
 965                 $delTable = $this->tableName( $delTable );
 966                 $joinTable = $this->tableName( $joinTable );
 967                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 968
 969                 if ( $conds != '*' ) {
 970                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 971                 }
 972
 973                 return $this->query( $sql, $fname );
 974         }
 975
 976         /**
 977          * @param string $table
 978          * @param array $rows
 979          * @param array $uniqueIndexes
 980          * @param array $set
 981          * @param string $fname
 982          * @return bool
 983          */
 984         public function upsert( $table, array $rows, array $uniqueIndexes,
 985                 array $set, $fname = __METHOD__
 986         ) {
 987                 if ( !count( $rows ) ) {
 988                         return true; // nothing to do
 989                 }
 990
 991                 if ( !is_array( reset( $rows ) ) ) {
 992                         $rows = array( $rows );
 993                 }
 994
 995                 $table = $this->tableName( $table );
 996                 $columns = array_keys( $rows[0] );
 997
 998                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
 999                 $rowTuples = array();
1000                 foreach ( $rows as $row ) {
1001                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1002                 }
1003                 $sql .= implode( ',', $rowTuples );
1004                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
1005
1006                 return (bool)$this->query( $sql, $fname );
1007         }
1008
1009         /**
1010          * Determines how long the server has been up
1011          *
1012          * @return int
1013          */
1014         function getServerUptime() {
1015                 $vars = $this->getMysqlStatus( 'Uptime' );
1016
1017                 return (int)$vars['Uptime'];
1018         }
1019
1020         /**
1021          * Determines if the last failure was due to a deadlock
1022          *
1023          * @return bool
1024          */
1025         function wasDeadlock() {
1026                 return $this->lastErrno() == 1213;
1027         }
1028
1029         /**
1030          * Determines if the last failure was due to a lock timeout
1031          *
1032          * @return bool
1033          */
1034         function wasLockTimeout() {
1035                 return $this->lastErrno() == 1205;
1036         }
1037
1038         /**
1039          * Determines if the last query error was something that should be dealt
1040          * with by pinging the connection and reissuing the query
1041          *
1042          * @return bool
1043          */
1044         function wasErrorReissuable() {
1045                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1046         }
1047
1048         /**
1049          * Determines if the last failure was due to the database being read-only.
1050          *
1051          * @return bool
1052          */
1053         function wasReadOnlyError() {
1054                 return $this->lastErrno() == 1223 ||
1055                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1056         }
1057
1058         function wasConnectionError( $errno ) {
1059                 return $errno == 2013 || $errno == 2006;
1060         }
1061
1062         /**
1063          * Get the underlying binding handle, mConn
1064          *
1065          * Makes sure that mConn is set (disconnects and ping() failure can unset it).
1066          * This catches broken callers than catch and ignore disconnection exceptions.
1067          * Unlike checking isOpen(), this is safe to call inside of open().
1068          *
1069          * @return resource|object
1070          * @throws DBUnexpectedError
1071          * @since 1.26
1072          */
1073         protected function getBindingHandle() {
1074                 if ( !$this->mConn ) {
1075                         throw new DBUnexpectedError(
1076                                 $this,
1077                                 'DB connection was already closed or the connection dropped.'
1078                         );
1079                 }
1080
1081                 return $this->mConn;
1082         }
1083
1084         /**
1085          * @param string $oldName
1086          * @param string $newName
1087          * @param bool $temporary
1088          * @param string $fname
1089          * @return bool
1090          */
1091         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1092                 $tmp = $temporary ? 'TEMPORARY ' : '';
1093                 $newName = $this->addIdentifierQuotes( $newName );
1094                 $oldName = $this->addIdentifierQuotes( $oldName );
1095                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1096
1097                 return $this->query( $query, $fname );
1098         }
1099
1100         /**
1101          * List all tables on the database
1102          *
1103          * @param string $prefix Only show tables with this prefix, e.g. mw_
1104          * @param string $fname Calling function name
1105          * @return array
1106          */
1107         function listTables( $prefix = null, $fname = __METHOD__ ) {
1108                 $result = $this->query( "SHOW TABLES", $fname );
1109
1110                 $endArray = array();
1111
1112                 foreach ( $result as $table ) {
1113                         $vars = get_object_vars( $table );
1114                         $table = array_pop( $vars );
1115
1116                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1117                                 $endArray[] = $table;
1118                         }
1119                 }
1120
1121                 return $endArray;
1122         }
1123
1124         /**
1125          * @param string $tableName
1126          * @param string $fName
1127          * @return bool|ResultWrapper
1128          */
1129         public function dropTable( $tableName, $fName = __METHOD__ ) {
1130                 if ( !$this->tableExists( $tableName, $fName ) ) {
1131                         return false;
1132                 }
1133
1134                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1135         }
1136
1137         /**
1138          * @return array
1139          */
1140         protected function getDefaultSchemaVars() {
1141                 $vars = parent::getDefaultSchemaVars();
1142                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1143                 $vars['wgDBTableOptions'] = str_replace(
1144                         'CHARSET=mysql4',
1145                         'CHARSET=binary',
1146                         $vars['wgDBTableOptions']
1147                 );
1148
1149                 return $vars;
1150         }
1151
1152         /**
1153          * Get status information from SHOW STATUS in an associative array
1154          *
1155          * @param string $which
1156          * @return array
1157          */
1158         function getMysqlStatus( $which = "%" ) {
1159                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1160                 $status = array();
1161
1162                 foreach ( $res as $row ) {
1163                         $status[$row->Variable_name] = $row->Value;
1164                 }
1165
1166                 return $status;
1167         }
1168
1169         /**
1170          * Lists VIEWs in the database
1171          *
1172          * @param string $prefix Only show VIEWs with this prefix, eg.
1173          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1174          * @param string $fname Name of calling function
1175          * @return array
1176          * @since 1.22
1177          */
1178         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1179
1180                 if ( !isset( $this->allViews ) ) {
1181
1182                         // The name of the column containing the name of the VIEW
1183                         $propertyName = 'Tables_in_' . $this->mDBname;
1184
1185                         // Query for the VIEWS
1186                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1187                         $this->allViews = array();
1188                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1189                                 array_push( $this->allViews, $row[$propertyName] );
1190                         }
1191                 }
1192
1193                 if ( is_null( $prefix ) || $prefix === '' ) {
1194                         return $this->allViews;
1195                 }
1196
1197                 $filteredViews = array();
1198                 foreach ( $this->allViews as $viewName ) {
1199                         // Does the name of this VIEW start with the table-prefix?
1200                         if ( strpos( $viewName, $prefix ) === 0 ) {
1201                                 array_push( $filteredViews, $viewName );
1202                         }
1203                 }
1204
1205                 return $filteredViews;
1206         }
1207
1208         /**
1209          * Differentiates between a TABLE and a VIEW.
1210          *
1211          * @param string $name Name of the TABLE/VIEW to test
1212          * @param string $prefix
1213          * @return bool
1214          * @since 1.22
1215          */
1216         public function isView( $name, $prefix = null ) {
1217                 return in_array( $name, $this->listViews( $prefix ) );
1218         }
1219 }
1220
1221 /**
1222  * Utility class.
1223  * @ingroup Database
1224  */
1225 class MySQLField implements Field {
1226         private $name, $tablename, $default, $max_length, $nullable,
1227                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary,
1228                 $is_numeric, $is_blob, $is_unsigned, $is_zerofill;
1229
1230         function __construct( $info ) {
1231                 $this->name = $info->name;
1232                 $this->tablename = $info->table;
1233                 $this->default = $info->def;
1234                 $this->max_length = $info->max_length;
1235                 $this->nullable = !$info->not_null;
1236                 $this->is_pk = $info->primary_key;
1237                 $this->is_unique = $info->unique_key;
1238                 $this->is_multiple = $info->multiple_key;
1239                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1240                 $this->type = $info->type;
1241                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1242                 $this->is_numeric = isset( $info->numeric ) ? $info->numeric : false;
1243                 $this->is_blob = isset( $info->blob ) ? $info->blob : false;
1244                 $this->is_unsigned = isset( $info->unsigned ) ? $info->unsigned : false;
1245                 $this->is_zerofill = isset( $info->zerofill ) ? $info->zerofill : false;
1246         }
1247
1248         /**
1249          * @return string
1250          */
1251         function name() {
1252                 return $this->name;
1253         }
1254
1255         /**
1256          * @return string
1257          */
1258         function tableName() {
1259                 return $this->tableName;
1260         }
1261
1262         /**
1263          * @return string
1264          */
1265         function type() {
1266                 return $this->type;
1267         }
1268
1269         /**
1270          * @return bool
1271          */
1272         function isNullable() {
1273                 return $this->nullable;
1274         }
1275
1276         function defaultValue() {
1277                 return $this->default;
1278         }
1279
1280         /**
1281          * @return bool
1282          */
1283         function isKey() {
1284                 return $this->is_key;
1285         }
1286
1287         /**
1288          * @return bool
1289          */
1290         function isMultipleKey() {
1291                 return $this->is_multiple;
1292         }
1293
1294         /**
1295          * @return bool
1296          */
1297         function isBinary() {
1298                 return $this->binary;
1299         }
1300
1301         /**
1302          * @return bool
1303          */
1304         function isNumeric() {
1305                 return $this->is_numeric;
1306         }
1307
1308         /**
1309          * @return bool
1310          */
1311         function isBlob() {
1312                 return $this->is_blob;
1313         }
1314
1315         /**
1316          * @return bool
1317          */
1318         function isUnsigned() {
1319                 return $this->is_unsigned;
1320         }
1321
1322         /**
1323          * @return bool
1324          */
1325         function isZerofill() {
1326                 return $this->is_zerofill;
1327         }
1328 }
1329
1330 class MySQLMasterPos implements DBMasterPos {
1331         /** @var string */
1332         public $file;
1333         /** @var int Position */
1334         public $pos;
1335         /** @var float UNIX timestamp */
1336         public $asOfTime = 0.0;
1337
1338         function __construct( $file, $pos ) {
1339                 $this->file = $file;
1340                 $this->pos = $pos;
1341                 $this->asOfTime = microtime( true );
1342         }
1343
1344         function __toString() {
1345                 // e.g db1034-bin.000976/843431247
1346                 return "{$this->file}/{$this->pos}";
1347         }
1348
1349         /**
1350          * @return array|bool (int, int)
1351          */
1352         protected function getCoordinates() {
1353                 $m = array();
1354                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1355                         return array( (int)$m[1], (int)$m[2] );
1356                 }
1357
1358                 return false;
1359         }
1360
1361         function hasReached( MySQLMasterPos $pos ) {
1362                 $thisPos = $this->getCoordinates();
1363                 $thatPos = $pos->getCoordinates();
1364
1365                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1366         }
1367
1368         function asOfTime() {
1369                 return $this->asOfTime;
1370         }
1371 }