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