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         public function isQuotedIdentifier( $name ) {
 333                 return $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 334         }
 335
 336         function ping() {
 337                 $ping = mysql_ping( $this->mConn );
 338                 if ( $ping ) {
 339                         return true;
 340                 }
 341
 342                 mysql_close( $this->mConn );
 343                 $this->mOpened = false;
 344                 $this->mConn = false;
 345                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 346                 return true;
 347         }
 348
 349         /**
 350          * Returns slave lag.
 351          * At the moment, this will only work if the DB user has the PROCESS privilege
 352          * @result int
 353          */
 354         function getLag() {
 355                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 356                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 357                         return $this->mFakeSlaveLag;
 358                 }
 359                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 360                 if( !$res ) {
 361                         return false;
 362                 }
 363                 # Find slave SQL thread
 364                 foreach( $res as $row ) {
 365                         /* This should work for most situations - when default db
 366                          * for thread is not specified, it had no events executed,
 367                          * and therefore it doesn't know yet how lagged it is.
 368                          *
 369                          * Relay log I/O thread does not select databases.
 370                          */
 371                         if ( $row->User == 'system user' &&
 372                                 $row->State != 'Waiting for master to send event' &&
 373                                 $row->State != 'Connecting to master' &&
 374                                 $row->State != 'Queueing master event to the relay log' &&
 375                                 $row->State != 'Waiting for master update' &&
 376                                 $row->State != 'Requesting binlog dump' &&
 377                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 378                                 $row->State != 'Reconnecting after a failed master event read' &&
 379                                 $row->State != 'Registering slave on master'
 380                                 ) {
 381                                 # This is it, return the time (except -ve)
 382                                 if ( $row->Time > 0x7fffffff ) {
 383                                         return false;
 384                                 } else {
 385                                         return $row->Time;
 386                                 }
 387                         }
 388                 }
 389                 return false;
 390         }
 391
 392         function getServerVersion() {
 393                 return mysql_get_server_info( $this->mConn );
 394         }
 395
 396         function useIndexClause( $index ) {
 397                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 398         }
 399
 400         function lowPriorityOption() {
 401                 return 'LOW_PRIORITY';
 402         }
 403
 404         public static function getSoftwareLink() {
 405                 return '[http://www.mysql.com/ MySQL]';
 406         }
 407
 408         function standardSelectDistinct() {
 409                 return false;
 410         }
 411
 412         public function setTimeout( $timeout ) {
 413                 $this->query( "SET net_read_timeout=$timeout" );
 414                 $this->query( "SET net_write_timeout=$timeout" );
 415         }
 416
 417         public function lock( $lockName, $method, $timeout = 5 ) {
 418                 $lockName = $this->addQuotes( $lockName );
 419                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 420                 $row = $this->fetchObject( $result );
 421
 422                 if( $row->lockstatus == 1 ) {
 423                         return true;
 424                 } else {
 425                         wfDebug( __METHOD__." failed to acquire lock\n" );
 426                         return false;
 427                 }
 428         }
 429
 430         /**
 431          * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 432          */
 433         public function unlock( $lockName, $method ) {
 434                 $lockName = $this->addQuotes( $lockName );
 435                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 436                 $row = $this->fetchObject( $result );
 437                 return $row->lockstatus;
 438         }
 439
 440         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 441                 $items = array();
 442
 443                 foreach( $write as $table ) {
 444                         $tbl = $this->tableName( $table ) .
 445                                         ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 446                                         ' WRITE';
 447                         $items[] = $tbl;
 448                 }
 449                 foreach( $read as $table ) {
 450                         $items[] = $this->tableName( $table ) . ' READ';
 451                 }
 452                 $sql = "LOCK TABLES " . implode( ',', $items );
 453                 $this->query( $sql, $method );
 454         }
 455
 456         public function unlockTables( $method ) {
 457                 $this->query( "UNLOCK TABLES", $method );
 458         }
 459
 460         /**
 461          * Get search engine class. All subclasses of this
 462          * need to implement this if they wish to use searching.
 463          *
 464          * @return String
 465          */
 466         public function getSearchEngine() {
 467                 return 'SearchMySQL';
 468         }
 469
 470         public function setBigSelects( $value = true ) {
 471                 if ( $value === 'default' ) {
 472                         if ( $this->mDefaultBigSelects === null ) {
 473                                 # Function hasn't been called before so it must already be set to the default
 474                                 return;
 475                         } else {
 476                                 $value = $this->mDefaultBigSelects;
 477                         }
 478                 } elseif ( $this->mDefaultBigSelects === null ) {
 479                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 480                 }
 481                 $encValue = $value ? '1' : '0';
 482                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 483         }
 484
 485         /**
 486          * Determines if the last failure was due to a deadlock
 487          */
 488         function wasDeadlock() {
 489                 return $this->lastErrno() == 1213;
 490         }
 491
 492         /**
 493          * Determines if the last query error was something that should be dealt
 494          * with by pinging the connection and reissuing the query
 495          */
 496         function wasErrorReissuable() {
 497                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
 498         }
 499
 500         /**
 501          * Determines if the last failure was due to the database being read-only.
 502          */
 503         function wasReadOnlyError() {
 504                 return $this->lastErrno() == 1223 ||
 505                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
 506         }
 507
 508         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseMysql::duplicateTableStructure' ) {
 509                 $tmp = $temporary ? 'TEMPORARY ' : '';
 510                 if ( strcmp( $this->getServerVersion(), '4.1' ) < 0 ) {
 511                         # Hack for MySQL versions < 4.1, which don't support
 512                         # "CREATE TABLE ... LIKE". Note that
 513                         # "CREATE TEMPORARY TABLE ... SELECT * FROM ... LIMIT 0"
 514                         # would not create the indexes we need....
 515                         #
 516                         # Note that we don't bother changing around the prefixes here be-
 517                         # cause we know we're using MySQL anyway.
 518
 519                         $res = $this->query( 'SHOW CREATE TABLE ' . $this->addIdentifierQuotes( $oldName ) );
 520                         $row = $this->fetchRow( $res );
 521                         $oldQuery = $row[1];
 522                         $query = preg_replace( '/CREATE TABLE `(.*?)`/',
 523                                 "CREATE $tmp TABLE " . $this->addIdentifierQuotes( $newName ), $oldQuery );
 524                         if ($oldQuery === $query) {
 525                                 # Couldn't do replacement
 526                                 throw new MWException( "could not create temporary table $newName" );
 527                         }
 528                 } else {
 529                         $newName = $this->addIdentifierQuotes( $newName );
 530                         $oldName = $this->addIdentifierQuotes( $oldName );
 531                         $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
 532                 }
 533                 $this->query( $query, $fname );
 534         }
 535
 536         /**
 537          * List all tables on the database
 538          *
 539          * @param $prefix Only show tables with this prefix, e.g. mw_
 540          * @param $fname String: calling function name
 541          */
 542         function listTables( $prefix = null, $fname = 'DatabaseMysql::listTables' ) {
 543                 $result = $this->query( "SHOW TABLES", $fname);
 544
 545                 $endArray = array();
 546
 547                 foreach( $result as $table ) {
 548                         $vars = get_object_vars($table);
 549                         $table = array_pop( $vars );
 550
 551                         if( !$prefix || strpos( $table, $prefix ) === 0 ) {
 552                                 $endArray[] = $table;
 553                         }
 554                 }
 555
 556                 return $endArray;
 557         }
 558
 559         public function dropTable( $tableName, $fName = 'DatabaseMysql::dropTable' ) {
 560                 if( !$this->tableExists( $tableName ) ) {
 561                         return false;
 562                 }
 563                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
 564         }
 565
 566         protected function getDefaultSchemaVars() {
 567                 $vars = parent::getDefaultSchemaVars();
 568                 $vars['wgDBTableOptions'] = $GLOBALS['wgDBTableOptions'];
 569                 return $vars;
 570         }
 571 }
 572
 573 /**
 574  * Legacy support: Database == DatabaseMysql
 575  */
 576 class Database extends DatabaseMysql {}
 577
 578 /**
 579  * Utility class.
 580  * @ingroup Database
 581  */
 582 class MySQLField implements Field {
 583         private $name, $tablename, $default, $max_length, $nullable,
 584                 $is_pk, $is_unique, $is_multiple, $is_key, $type;
 585
 586         function __construct ( $info ) {
 587                 $this->name = $info->name;
 588                 $this->tablename = $info->table;
 589                 $this->default = $info->def;
 590                 $this->max_length = $info->max_length;
 591                 $this->nullable = !$info->not_null;
 592                 $this->is_pk = $info->primary_key;
 593                 $this->is_unique = $info->unique_key;
 594                 $this->is_multiple = $info->multiple_key;
 595                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
 596                 $this->type = $info->type;
 597         }
 598
 599         function name() {
 600                 return $this->name;
 601         }
 602
 603         function tableName() {
 604                 return $this->tableName;
 605         }
 606
 607         function type() {
 608                 return $this->type;
 609         }
 610
 611         function isNullable() {
 612                 return $this->nullable;
 613         }
 614
 615         function defaultValue() {
 616                 return $this->default;
 617         }
 618
 619         function isKey() {
 620                 return $this->is_key;
 621         }
 622
 623         function isMultipleKey() {
 624                 return $this->is_multiple;
 625         }
 626 }
 627
 628 class MySQLMasterPos {
 629         var $file, $pos;
 630
 631         function __construct( $file, $pos ) {
 632                 $this->file = $file;
 633                 $this->pos = $pos;
 634         }
 635
 636         function __toString() {
 637                 return "{$this->file}/{$this->pos}";
 638         }
 639 }