includes/db/DatabaseMysql.php

   1 <?php
   2 /**
   3  * This is the MySQL database abstraction layer.
   4  *
   5  * @file
   6  * @ingroup Database
   7  */
   8
   9 /**
  10  * Database abstraction object for mySQL
  11  * Inherit all methods and properties of Database::Database()
  12  *
  13  * @ingroup Database
  14  * @see Database
  15  */
  16 class DatabaseMysql extends DatabaseBase {
  17         function getType() {
  18                 return 'mysql';
  19         }
  20
  21         /*private*/ function doQuery( $sql ) {
  22                 if( $this->bufferResults() ) {
  23                         $ret = mysql_query( $sql, $this->mConn );
  24                 } else {
  25                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
  26                 }
  27                 return $ret;
  28         }
  29
  30         function open( $server, $user, $password, $dbName ) {
  31                 global $wgAllDBsAreLocalhost;
  32                 wfProfileIn( __METHOD__ );
  33
  34                 # Load mysql.so if we don't have it
  35                 wfDl( 'mysql' );
  36
  37                 # Fail now
  38                 # Otherwise we get a suppressed fatal error, which is very hard to track down
  39                 if ( !function_exists( 'mysql_connect' ) ) {
  40                         throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
  41                 }
  42
  43                 # Debugging hack -- fake cluster
  44                 if ( $wgAllDBsAreLocalhost ) {
  45                         $realServer = 'localhost';
  46                 } else {
  47                         $realServer = $server;
  48                 }
  49                 $this->close();
  50                 $this->mServer = $server;
  51                 $this->mUser = $user;
  52                 $this->mPassword = $password;
  53                 $this->mDBname = $dbName;
  54
  55                 wfProfileIn("dbconnect-$server");
  56
  57                 # The kernel's default SYN retransmission period is far too slow for us,
  58                 # so we use a short timeout plus a manual retry. Retrying means that a small
  59                 # but finite rate of SYN packet loss won't cause user-visible errors.
  60                 $this->mConn = false;
  61                 if ( ini_get( 'mysql.connect_timeout' ) <= 3 ) {
  62                         $numAttempts = 2;
  63                 } else {
  64                         $numAttempts = 1;
  65                 }
  66                 $this->installErrorHandler();
  67                 for ( $i = 0; $i < $numAttempts && !$this->mConn; $i++ ) {
  68                         if ( $i > 1 ) {
  69                                 usleep( 1000 );
  70                         }
  71                         if ( $this->mFlags & DBO_PERSISTENT ) {
  72                                 $this->mConn = mysql_pconnect( $realServer, $user, $password );
  73                         } else {
  74                                 # Create a new connection...
  75                                 $this->mConn = mysql_connect( $realServer, $user, $password, true );
  76                         }
  77                         #if ( $this->mConn === false ) {
  78                                 #$iplus = $i + 1;
  79                                 #wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
  80                         #}
  81                 }
  82                 $phpError = $this->restoreErrorHandler();
  83                 # Always log connection errors
  84                 if ( !$this->mConn ) {
  85                         $error = $this->lastError();
  86                         if ( !$error ) {
  87                                 $error = $phpError;
  88                         }
  89                         wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
  90                         wfDebug( "DB connection error\n" );
  91                         wfDebug( "Server: $server, User: $user, Password: " .
  92                                 substr( $password, 0, 3 ) . "..., error: " . mysql_error() . "\n" );
  93                 }
  94
  95                 wfProfileOut("dbconnect-$server");
  96
  97                 if ( $dbName != '' && $this->mConn !== false ) {
  98                         $success = @/**/mysql_select_db( $dbName, $this->mConn );
  99                         if ( !$success ) {
 100                                 $error = "Error selecting database $dbName on server {$this->mServer} " .
 101                                         "from client host " . wfHostname() . "\n";
 102                                 wfLogDBError(" Error selecting database $dbName on server {$this->mServer} \n");
 103                                 wfDebug( $error );
 104                         }
 105                 } else {
 106                         # Delay USE query
 107                         $success = (bool)$this->mConn;
 108                 }
 109
 110                 if ( $success ) {
 111                         $version = $this->getServerVersion();
 112                         if ( version_compare( $version, '4.1' ) >= 0 ) {
 113                                 // Tell the server we're communicating with it in UTF-8.
 114                                 // This may engage various charset conversions.
 115                                 global $wgDBmysql5;
 116                                 if( $wgDBmysql5 ) {
 117                                         $this->query( 'SET NAMES utf8', __METHOD__ );
 118                                 } else {
 119                                         $this->query( 'SET NAMES binary', __METHOD__ );
 120                                 }
 121                                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 122                                 global $wgSQLMode;
 123                                 if ( is_string( $wgSQLMode ) ) {
 124                                         $mode = $this->addQuotes( $wgSQLMode );
 125                                         $this->query( "SET sql_mode = $mode", __METHOD__ );
 126                                 }
 127                         }
 128
 129                         // Turn off strict mode if it is on
 130                 } else {
 131                         $this->reportConnectionError( $phpError );
 132                 }
 133
 134                 $this->mOpened = $success;
 135                 wfProfileOut( __METHOD__ );
 136                 return $success;
 137         }
 138
 139         function close() {
 140                 $this->mOpened = false;
 141                 if ( $this->mConn ) {
 142                         if ( $this->trxLevel() ) {
 143                                 $this->commit();
 144                         }
 145                         return mysql_close( $this->mConn );
 146                 } else {
 147                         return true;
 148                 }
 149         }
 150
 151         function freeResult( $res ) {
 152                 if ( $res instanceof ResultWrapper ) {
 153                         $res = $res->result;
 154                 }
 155                 if ( !@/**/mysql_free_result( $res ) ) {
 156                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 157                 }
 158         }
 159
 160         function fetchObject( $res ) {
 161                 if ( $res instanceof ResultWrapper ) {
 162                         $res = $res->result;
 163                 }
 164                 @/**/$row = mysql_fetch_object( $res );
 165                 if( $this->lastErrno() ) {
 166                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 167                 }
 168                 return $row;
 169         }
 170
 171         function fetchRow( $res ) {
 172                 if ( $res instanceof ResultWrapper ) {
 173                         $res = $res->result;
 174                 }
 175                 @/**/$row = mysql_fetch_array( $res );
 176                 if ( $this->lastErrno() ) {
 177                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 178                 }
 179                 return $row;
 180         }
 181
 182         function numRows( $res ) {
 183                 if ( $res instanceof ResultWrapper ) {
 184                         $res = $res->result;
 185                 }
 186                 @/**/$n = mysql_num_rows( $res );
 187                 if( $this->lastErrno() ) {
 188                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 189                 }
 190                 return $n;
 191         }
 192
 193         function numFields( $res ) {
 194                 if ( $res instanceof ResultWrapper ) {
 195                         $res = $res->result;
 196                 }
 197                 return mysql_num_fields( $res );
 198         }
 199
 200         function fieldName( $res, $n ) {
 201                 if ( $res instanceof ResultWrapper ) {
 202                         $res = $res->result;
 203                 }
 204                 return mysql_field_name( $res, $n );
 205         }
 206
 207         function insertId() { return mysql_insert_id( $this->mConn ); }
 208
 209         function dataSeek( $res, $row ) {
 210                 if ( $res instanceof ResultWrapper ) {
 211                         $res = $res->result;
 212                 }
 213                 return mysql_data_seek( $res, $row );
 214         }
 215
 216         function lastErrno() {
 217                 if ( $this->mConn ) {
 218                         return mysql_errno( $this->mConn );
 219                 } else {
 220                         return mysql_errno();
 221                 }
 222         }
 223
 224         function lastError() {
 225                 if ( $this->mConn ) {
 226                         # Even if it's non-zero, it can still be invalid
 227                         wfSuppressWarnings();
 228                         $error = mysql_error( $this->mConn );
 229                         if ( !$error ) {
 230                                 $error = mysql_error();
 231                         }
 232                         wfRestoreWarnings();
 233                 } else {
 234                         $error = mysql_error();
 235                 }
 236                 if( $error ) {
 237                         $error .= ' (' . $this->mServer . ')';
 238                 }
 239                 return $error;
 240         }
 241
 242         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 243
 244         /**
 245          * Estimate rows in dataset
 246          * Returns estimated count, based on EXPLAIN output
 247          * Takes same arguments as Database::select()
 248          */
 249         public function estimateRowCount( $table, $vars='*', $conds='', $fname = 'DatabaseMysql::estimateRowCount', $options = array() ) {
 250                 $options['EXPLAIN'] = true;
 251                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 252                 if ( $res === false ) {
 253                         return false;
 254                 }
 255                 if ( !$this->numRows( $res ) ) {
 256                         return 0;
 257                 }
 258
 259                 $rows = 1;
 260                 foreach ( $res as $plan ) {
 261                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 262                 }
 263                 return $rows;
 264         }
 265
 266         function fieldInfo( $table, $field ) {
 267                 $table = $this->tableName( $table );
 268                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 269                 if ( !$res ) {
 270                         return false;
 271                 }
 272                 $n = mysql_num_fields( $res->result );
 273                 for( $i = 0; $i < $n; $i++ ) {
 274                         $meta = mysql_fetch_field( $res->result, $i );
 275                         if( $field == $meta->name ) {
 276                                 return new MySQLField($meta);
 277                         }
 278                 }
 279                 return false;
 280         }
 281
 282         /**
 283          * Get information about an index into an object
 284          * Returns false if the index does not exist
 285          */
 286         function indexInfo( $table, $index, $fname = 'DatabaseMysql::indexInfo' ) {
 287                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 288                 # SHOW INDEX should work for 3.x and up:
 289                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 290                 $table = $this->tableName( $table );
 291                 $index = $this->indexName( $index );
 292                 $sql = 'SHOW INDEX FROM ' . $table;
 293                 $res = $this->query( $sql, $fname );
 294
 295                 if ( !$res ) {
 296                         return null;
 297                 }
 298
 299                 $result = array();
 300
 301                 foreach ( $res as $row ) {
 302                         if ( $row->Key_name == $index ) {
 303                                 $result[] = $row;
 304                         }
 305                 }
 306
 307                 return empty( $result ) ? false : $result;
 308         }
 309
 310         function selectDB( $db ) {
 311                 $this->mDBname = $db;
 312                 return mysql_select_db( $db, $this->mConn );
 313         }
 314
 315         function strencode( $s ) {
 316                 $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 317
 318                 if($sQuoted === false) {
 319                         $this->ping();
 320                         $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 321                 }
 322                 return $sQuoted;
 323         }
 324
 325         /**
 326          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 327          */
 328         public function addIdentifierQuotes( $s ) {
 329                 return "`" . $this->strencode( $s ) . "`";
 330         }
 331
 332         function ping() {
 333                 $ping = mysql_ping( $this->mConn );
 334                 if ( $ping ) {
 335                         return true;
 336                 }
 337
 338                 mysql_close( $this->mConn );
 339                 $this->mOpened = false;
 340                 $this->mConn = false;
 341                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 342                 return true;
 343         }
 344
 345         /**
 346          * Returns slave lag.
 347          * At the moment, this will only work if the DB user has the PROCESS privilege
 348          * @result int
 349          */
 350         function getLag() {
 351                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 352                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 353                         return $this->mFakeSlaveLag;
 354                 }
 355                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 356                 if( !$res ) {
 357                         return false;
 358                 }
 359                 # Find slave SQL thread
 360                 foreach( $res as $row ) {
 361                         /* This should work for most situations - when default db
 362                          * for thread is not specified, it had no events executed,
 363                          * and therefore it doesn't know yet how lagged it is.
 364                          *
 365                          * Relay log I/O thread does not select databases.
 366                          */
 367                         if ( $row->User == 'system user' &&
 368                                 $row->State != 'Waiting for master to send event' &&
 369                                 $row->State != 'Connecting to master' &&
 370                                 $row->State != 'Queueing master event to the relay log' &&
 371                                 $row->State != 'Waiting for master update' &&
 372                                 $row->State != 'Requesting binlog dump' &&
 373                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 374                                 $row->State != 'Reconnecting after a failed master event read' &&
 375                                 $row->State != 'Registering slave on master'
 376                                 ) {
 377                                 # This is it, return the time (except -ve)
 378                                 if ( $row->Time > 0x7fffffff ) {
 379                                         return false;
 380                                 } else {
 381                                         return $row->Time;
 382                                 }
 383                         }
 384                 }
 385                 return false;
 386         }
 387
 388         function getServerVersion() {
 389                 return mysql_get_server_info( $this->mConn );
 390         }
 391
 392         function useIndexClause( $index ) {
 393                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 394         }
 395
 396         function lowPriorityOption() {
 397                 return 'LOW_PRIORITY';
 398         }
 399
 400         public static function getSoftwareLink() {
 401                 return '[http://www.mysql.com/ MySQL]';
 402         }
 403
 404         function standardSelectDistinct() {
 405                 return false;
 406         }
 407
 408         public function setTimeout( $timeout ) {
 409                 $this->query( "SET net_read_timeout=$timeout" );
 410                 $this->query( "SET net_write_timeout=$timeout" );
 411         }
 412
 413         public function lock( $lockName, $method, $timeout = 5 ) {
 414                 $lockName = $this->addQuotes( $lockName );
 415                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 416                 $row = $this->fetchObject( $result );
 417
 418                 if( $row->lockstatus == 1 ) {
 419                         return true;
 420                 } else {
 421                         wfDebug( __METHOD__." failed to acquire lock\n" );
 422                         return false;
 423                 }
 424         }
 425
 426         /**
 427          * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 428          */
 429         public function unlock( $lockName, $method ) {
 430                 $lockName = $this->addQuotes( $lockName );
 431                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 432                 $row = $this->fetchObject( $result );
 433                 return $row->lockstatus;
 434         }
 435
 436         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 437                 $items = array();
 438
 439                 foreach( $write as $table ) {
 440                         $tbl = $this->tableName( $table ) .
 441                                         ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 442                                         ' WRITE';
 443                         $items[] = $tbl;
 444                 }
 445                 foreach( $read as $table ) {
 446                         $items[] = $this->tableName( $table ) . ' READ';
 447                 }
 448                 $sql = "LOCK TABLES " . implode( ',', $items );
 449                 $this->query( $sql, $method );
 450         }
 451
 452         public function unlockTables( $method ) {
 453                 $this->query( "UNLOCK TABLES", $method );
 454         }
 455
 456         /**
 457          * Get search engine class. All subclasses of this
 458          * need to implement this if they wish to use searching.
 459          *
 460          * @return String
 461          */
 462         public function getSearchEngine() {
 463                 return 'SearchMySQL';
 464         }
 465
 466         public function setBigSelects( $value = true ) {
 467                 if ( $value === 'default' ) {
 468                         if ( $this->mDefaultBigSelects === null ) {
 469                                 # Function hasn't been called before so it must already be set to the default
 470                                 return;
 471                         } else {
 472                                 $value = $this->mDefaultBigSelects;
 473                         }
 474                 } elseif ( $this->mDefaultBigSelects === null ) {
 475                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 476                 }
 477                 $encValue = $value ? '1' : '0';
 478                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 479         }
 480
 481
 482         /**
 483          * Determines if the last failure was due to a deadlock
 484          */
 485         function wasDeadlock() {
 486                 return $this->lastErrno() == 1213;
 487         }
 488
 489         /**
 490          * Determines if the last query error was something that should be dealt
 491          * with by pinging the connection and reissuing the query
 492          */
 493         function wasErrorReissuable() {
 494                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
 495         }
 496
 497         /**
 498          * Determines if the last failure was due to the database being read-only.
 499          */
 500         function wasReadOnlyError() {
 501                 return $this->lastErrno() == 1223 ||
 502                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
 503         }
 504
 505         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseMysql::duplicateTableStructure' ) {
 506                 $tmp = $temporary ? 'TEMPORARY ' : '';
 507                 if ( strcmp( $this->getServerVersion(), '4.1' ) < 0 ) {
 508                         # Hack for MySQL versions < 4.1, which don't support
 509                         # "CREATE TABLE ... LIKE". Note that
 510                         # "CREATE TEMPORARY TABLE ... SELECT * FROM ... LIMIT 0"
 511                         # would not create the indexes we need....
 512                         #
 513                         # Note that we don't bother changing around the prefixes here be-
 514                         # cause we know we're using MySQL anyway.
 515
 516                         $res = $this->query( "SHOW CREATE TABLE $oldName" );
 517                         $row = $this->fetchRow( $res );
 518                         $oldQuery = $row[1];
 519                         $query = preg_replace( '/CREATE TABLE `(.*?)`/',
 520                                 "CREATE $tmp TABLE `$newName`", $oldQuery );
 521                         if ($oldQuery === $query) {
 522                                 # Couldn't do replacement
 523                                 throw new MWException( "could not create temporary table $newName" );
 524                         }
 525                 } else {
 526                         $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
 527                 }
 528                 $this->query( $query, $fname );
 529         }
 530
 531         /**
 532          * List all tables on the database
 533          *
 534          * @param $prefix Only show tables with this prefix, e.g. mw_
 535          * @param $fname String: calling function name
 536          */
 537         function listTables( $prefix = null, $fname = 'DatabaseMysql::listTables' ) {
 538                 $result = $this->query( "SHOW TABLES", $fname);
 539
 540                 $endArray = array();
 541
 542                 foreach( $result as $table ) {
 543                         $vars = get_object_vars($table);
 544                         $table = array_pop( $vars );
 545
 546                         if( empty( $prefix ) || strpos( $table, $prefix ) === 0 ) {
 547                                 $endArray[] = $table;
 548                         }
 549                 }
 550
 551                 return $endArray;
 552         }
 553
 554         public function dropTable( $tableName, $fName = 'DatabaseMysql::dropTable' ) {
 555                 if( !$this->tableExists( $tableName ) ) {
 556                         return false;
 557                 }
 558                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
 559         }
 560
 561 }
 562
 563 /**
 564  * Legacy support: Database == DatabaseMysql
 565  */
 566 class Database extends DatabaseMysql {}
 567
 568 /**
 569  * Utility class.
 570  * @ingroup Database
 571  */
 572 class MySQLField implements Field {
 573         private $name, $tablename, $default, $max_length, $nullable,
 574                 $is_pk, $is_unique, $is_multiple, $is_key, $type;
 575
 576         function __construct ( $info ) {
 577                 $this->name = $info->name;
 578                 $this->tablename = $info->table;
 579                 $this->default = $info->def;
 580                 $this->max_length = $info->max_length;
 581                 $this->nullable = !$info->not_null;
 582                 $this->is_pk = $info->primary_key;
 583                 $this->is_unique = $info->unique_key;
 584                 $this->is_multiple = $info->multiple_key;
 585                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
 586                 $this->type = $info->type;
 587         }
 588
 589         function name() {
 590                 return $this->name;
 591         }
 592
 593         function tableName() {
 594                 return $this->tableName;
 595         }
 596
 597         function type() {
 598                 return $this->type;
 599         }
 600
 601         function isNullable() {
 602                 return $this->nullable;
 603         }
 604
 605         function defaultValue() {
 606                 return $this->default;
 607         }
 608
 609         function isKey() {
 610                 return $this->is_key;
 611         }
 612
 613         function isMultipleKey() {
 614                 return $this->is_multiple;
 615         }
 616 }
 617
 618 class MySQLMasterPos {
 619         var $file, $pos;
 620
 621         function __construct( $file, $pos ) {
 622                 $this->file = $file;
 623                 $this->pos = $pos;
 624         }
 625
 626         function __toString() {
 627                 return "{$this->file}/{$this->pos}";
 628         }
 629 }