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 ( $res === false )
 257                         return false;
 258                 if ( !$this->numRows( $res ) ) {
 259                         $this->freeResult($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
 268                 $this->freeResult($res);
 269                 return $rows;
 270         }
 271
 272         function fieldInfo( $table, $field ) {
 273                 $table = $this->tableName( $table );
 274                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 275                 if ( !$res ) {
 276                         return false;
 277                 }
 278                 $n = mysql_num_fields( $res->result );
 279                 for( $i = 0; $i < $n; $i++ ) {
 280                         $meta = mysql_fetch_field( $res->result, $i );
 281                         if( $field == $meta->name ) {
 282                                 return new MySQLField($meta);
 283                         }
 284                 }
 285                 return false;
 286         }
 287
 288         function selectDB( $db ) {
 289                 $this->mDBname = $db;
 290                 return mysql_select_db( $db, $this->mConn );
 291         }
 292
 293         function strencode( $s ) {
 294                 $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 295
 296                 if($sQuoted === false) {
 297                         $this->ping();
 298                         $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 299                 }
 300                 return $sQuoted;
 301         }
 302
 303         function ping() {
 304                 $ping = mysql_ping( $this->mConn );
 305                 if ( $ping ) {
 306                         return true;
 307                 }
 308
 309                 mysql_close( $this->mConn );
 310                 $this->mOpened = false;
 311                 $this->mConn = false;
 312                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 313                 return true;
 314         }
 315
 316         /**
 317          * Returns slave lag.
 318          * At the moment, this will only work if the DB user has the PROCESS privilege
 319          * @result int
 320          */
 321         function getLag() {
 322                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 323                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 324                         return $this->mFakeSlaveLag;
 325                 }
 326                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 327                 # Find slave SQL thread
 328                 while ( $row = $this->fetchObject( $res ) ) {
 329                         /* This should work for most situations - when default db
 330                          * for thread is not specified, it had no events executed,
 331                          * and therefore it doesn't know yet how lagged it is.
 332                          *
 333                          * Relay log I/O thread does not select databases.
 334                          */
 335                         if ( $row->User == 'system user' &&
 336                                 $row->State != 'Waiting for master to send event' &&
 337                                 $row->State != 'Connecting to master' &&
 338                                 $row->State != 'Queueing master event to the relay log' &&
 339                                 $row->State != 'Waiting for master update' &&
 340                                 $row->State != 'Requesting binlog dump' &&
 341                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 342                                 $row->State != 'Reconnecting after a failed master event read' &&
 343                                 $row->State != 'Registering slave on master'
 344                                 ) {
 345                                 # This is it, return the time (except -ve)
 346                                 if ( $row->Time > 0x7fffffff ) {
 347                                         return false;
 348                                 } else {
 349                                         return $row->Time;
 350                                 }
 351                         }
 352                 }
 353                 return false;
 354         }
 355
 356         function getServerVersion() {
 357                 return mysql_get_server_info( $this->mConn );
 358         }
 359
 360         function useIndexClause( $index ) {
 361                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 362         }
 363
 364         function lowPriorityOption() {
 365                 return 'LOW_PRIORITY';
 366         }
 367
 368         function getSoftwareLink() {
 369                 return '[http://www.mysql.com/ MySQL]';
 370         }
 371
 372         function standardSelectDistinct() {
 373                 return false;
 374         }
 375
 376         public function setTimeout( $timeout ) {
 377                 $this->query( "SET net_read_timeout=$timeout" );
 378                 $this->query( "SET net_write_timeout=$timeout" );
 379         }
 380
 381         public function lock( $lockName, $method, $timeout = 5 ) {
 382                 $lockName = $this->addQuotes( $lockName );
 383                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 384                 $row = $this->fetchObject( $result );
 385                 $this->freeResult( $result );
 386
 387                 if( $row->lockstatus == 1 ) {
 388                         return true;
 389                 } else {
 390                         wfDebug( __METHOD__." failed to acquire lock\n" );
 391                         return false;
 392                 }
 393         }
 394
 395         /**
 396          * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 397          */
 398         public function unlock( $lockName, $method ) {
 399                 $lockName = $this->addQuotes( $lockName );
 400                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 401                 $row = $this->fetchObject( $result );
 402                 return $row->lockstatus;
 403         }
 404
 405         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 406                 $items = array();
 407
 408                 foreach( $write as $table ) {
 409                         $tbl = $this->tableName( $table ) .
 410                                         ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 411                                         ' WRITE';
 412                         $items[] = $tbl;
 413                 }
 414                 foreach( $read as $table ) {
 415                         $items[] = $this->tableName( $table ) . ' READ';
 416                 }
 417                 $sql = "LOCK TABLES " . implode( ',', $items );
 418                 $this->query( $sql, $method );
 419         }
 420
 421         public function unlockTables( $method ) {
 422                 $this->query( "UNLOCK TABLES", $method );
 423         }
 424
 425         /**
 426          * Get search engine class. All subclasses of this
 427          * need to implement this if they wish to use searching.
 428          *
 429          * @return String
 430          */
 431         public function getSearchEngine() {
 432                 return 'SearchMySQL';
 433         }
 434
 435         public function setBigSelects( $value = true ) {
 436                 if ( $value === 'default' ) {
 437                         if ( $this->mDefaultBigSelects === null ) {
 438                                 # Function hasn't been called before so it must already be set to the default
 439                                 return;
 440                         } else {
 441                                 $value = $this->mDefaultBigSelects;
 442                         }
 443                 } elseif ( $this->mDefaultBigSelects === null ) {
 444                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 445                 }
 446                 $encValue = $value ? '1' : '0';
 447                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 448         }
 449
 450
 451         /**
 452          * Determines if the last failure was due to a deadlock
 453          */
 454         function wasDeadlock() {
 455                 return $this->lastErrno() == 1213;
 456         }
 457
 458         /**
 459          * Determines if the last query error was something that should be dealt
 460          * with by pinging the connection and reissuing the query
 461          */
 462         function wasErrorReissuable() {
 463                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
 464         }
 465
 466         /**
 467          * Determines if the last failure was due to the database being read-only.
 468          */
 469         function wasReadOnlyError() {
 470                 return $this->lastErrno() == 1223 ||
 471                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
 472         }
 473
 474         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseMysql::duplicateTableStructure' ) {
 475                 $tmp = $temporary ? 'TEMPORARY ' : '';
 476                 if ( strcmp( $this->getServerVersion(), '4.1' ) < 0 ) {
 477                         # Hack for MySQL versions < 4.1, which don't support
 478                         # "CREATE TABLE ... LIKE". Note that
 479                         # "CREATE TEMPORARY TABLE ... SELECT * FROM ... LIMIT 0"
 480                         # would not create the indexes we need....
 481                         #
 482                         # Note that we don't bother changing around the prefixes here be-
 483                         # cause we know we're using MySQL anyway.
 484
 485                         $res = $this->query( "SHOW CREATE TABLE $oldName" );
 486                         $row = $this->fetchRow( $res );
 487                         $oldQuery = $row[1];
 488                         $query = preg_replace( '/CREATE TABLE `(.*?)`/',
 489                                 "CREATE $tmp TABLE `$newName`", $oldQuery );
 490                         if ($oldQuery === $query) {
 491                                 # Couldn't do replacement
 492                                 throw new MWException( "could not create temporary table $newName" );
 493                         }
 494                 } else {
 495                         $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
 496                 }
 497                 $this->query( $query, $fname );
 498         }
 499
 500 }
 501
 502 /**
 503  * Legacy support: Database == DatabaseMysql
 504  */
 505 class Database extends DatabaseMysql {}
 506
 507 class MySQLMasterPos {
 508         var $file, $pos;
 509
 510         function __construct( $file, $pos ) {
 511                 $this->file = $file;
 512                 $this->pos = $pos;
 513         }
 514
 515         function __toString() {
 516                 return "{$this->file}/{$this->pos}";
 517         }
 518 }