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                 $success = false;
  56
  57                 wfProfileIn("dbconnect-$server");
  58
  59                 # The kernel's default SYN retransmission period is far too slow for us,
  60                 # so we use a short timeout plus a manual retry. Retrying means that a small
  61                 # but finite rate of SYN packet loss won't cause user-visible errors.
  62                 $this->mConn = false;
  63                 if ( ini_get( 'mysql.connect_timeout' ) <= 3 ) {
  64                         $numAttempts = 2;
  65                 } else {
  66                         $numAttempts = 1;
  67                 }
  68                 $this->installErrorHandler();
  69                 for ( $i = 0; $i < $numAttempts && !$this->mConn; $i++ ) {
  70                         if ( $i > 1 ) {
  71                                 usleep( 1000 );
  72                         }
  73                         if ( $this->mFlags & DBO_PERSISTENT ) {
  74                                 $this->mConn = mysql_pconnect( $realServer, $user, $password );
  75                         } else {
  76                                 # Create a new connection...
  77                                 $this->mConn = mysql_connect( $realServer, $user, $password, true );
  78                         }
  79                         #if ( $this->mConn === false ) {
  80                                 #$iplus = $i + 1;
  81                                 #wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
  82                         #}
  83                 }
  84                 $phpError = $this->restoreErrorHandler();
  85                 # Always log connection errors
  86                 if ( !$this->mConn ) {
  87                         $error = $this->lastError();
  88                         if ( !$error ) {
  89                                 $error = $phpError;
  90                         }
  91                         wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
  92                         wfDebug( "DB connection error\n" );
  93                         wfDebug( "Server: $server, User: $user, Password: " .
  94                                 substr( $password, 0, 3 ) . "..., error: " . mysql_error() . "\n" );
  95                         $success = false;
  96                 }
  97
  98                 wfProfileOut("dbconnect-$server");
  99
 100                 if ( $dbName != '' && $this->mConn !== false ) {
 101                         $success = @/**/mysql_select_db( $dbName, $this->mConn );
 102                         if ( !$success ) {
 103                                 $error = "Error selecting database $dbName on server {$this->mServer} " .
 104                                         "from client host " . wfHostname() . "\n";
 105                                 wfLogDBError(" Error selecting database $dbName on server {$this->mServer} \n");
 106                                 wfDebug( $error );
 107                         }
 108                 } else {
 109                         # Delay USE query
 110                         $success = (bool)$this->mConn;
 111                 }
 112
 113                 if ( $success ) {
 114                         $version = $this->getServerVersion();
 115                         if ( version_compare( $version, '4.1' ) >= 0 ) {
 116                                 // Tell the server we're communicating with it in UTF-8.
 117                                 // This may engage various charset conversions.
 118                                 global $wgDBmysql5;
 119                                 if( $wgDBmysql5 ) {
 120                                         $this->query( 'SET NAMES utf8', __METHOD__ );
 121                                 } else {
 122                                         $this->query( 'SET NAMES binary', __METHOD__ );
 123                                 }
 124                                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 125                                 global $wgSQLMode;
 126                                 if ( is_string( $wgSQLMode ) ) {
 127                                         $mode = $this->addQuotes( $wgSQLMode );
 128                                         $this->query( "SET sql_mode = $mode", __METHOD__ );
 129                                 }
 130                         }
 131
 132                         // Turn off strict mode if it is on
 133                 } else {
 134                         $this->reportConnectionError( $phpError );
 135                 }
 136
 137                 $this->mOpened = $success;
 138                 wfProfileOut( __METHOD__ );
 139                 return $success;
 140         }
 141
 142         function close() {
 143                 $this->mOpened = false;
 144                 if ( $this->mConn ) {
 145                         if ( $this->trxLevel() ) {
 146                                 $this->commit();
 147                         }
 148                         return mysql_close( $this->mConn );
 149                 } else {
 150                         return true;
 151                 }
 152         }
 153
 154         function freeResult( $res ) {
 155                 if ( $res instanceof ResultWrapper ) {
 156                         $res = $res->result;
 157                 }
 158                 if ( !@/**/mysql_free_result( $res ) ) {
 159                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 160                 }
 161         }
 162
 163         function fetchObject( $res ) {
 164                 if ( $res instanceof ResultWrapper ) {
 165                         $res = $res->result;
 166                 }
 167                 @/**/$row = mysql_fetch_object( $res );
 168                 if( $this->lastErrno() ) {
 169                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 170                 }
 171                 return $row;
 172         }
 173
 174         function fetchRow( $res ) {
 175                 if ( $res instanceof ResultWrapper ) {
 176                         $res = $res->result;
 177                 }
 178                 @/**/$row = mysql_fetch_array( $res );
 179                 if ( $this->lastErrno() ) {
 180                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 181                 }
 182                 return $row;
 183         }
 184
 185         function numRows( $res ) {
 186                 if ( $res instanceof ResultWrapper ) {
 187                         $res = $res->result;
 188                 }
 189                 @/**/$n = mysql_num_rows( $res );
 190                 if( $this->lastErrno() ) {
 191                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 192                 }
 193                 return $n;
 194         }
 195
 196         function numFields( $res ) {
 197                 if ( $res instanceof ResultWrapper ) {
 198                         $res = $res->result;
 199                 }
 200                 return mysql_num_fields( $res );
 201         }
 202
 203         function fieldName( $res, $n ) {
 204                 if ( $res instanceof ResultWrapper ) {
 205                         $res = $res->result;
 206                 }
 207                 return mysql_field_name( $res, $n );
 208         }
 209
 210         function insertId() { return mysql_insert_id( $this->mConn ); }
 211
 212         function dataSeek( $res, $row ) {
 213                 if ( $res instanceof ResultWrapper ) {
 214                         $res = $res->result;
 215                 }
 216                 return mysql_data_seek( $res, $row );
 217         }
 218
 219         function lastErrno() {
 220                 if ( $this->mConn ) {
 221                         return mysql_errno( $this->mConn );
 222                 } else {
 223                         return mysql_errno();
 224                 }
 225         }
 226
 227         function lastError() {
 228                 if ( $this->mConn ) {
 229                         # Even if it's non-zero, it can still be invalid
 230                         wfSuppressWarnings();
 231                         $error = mysql_error( $this->mConn );
 232                         if ( !$error ) {
 233                                 $error = mysql_error();
 234                         }
 235                         wfRestoreWarnings();
 236                 } else {
 237                         $error = mysql_error();
 238                 }
 239                 if( $error ) {
 240                         $error .= ' (' . $this->mServer . ')';
 241                 }
 242                 return $error;
 243         }
 244
 245         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 246
 247         /**
 248          * Estimate rows in dataset
 249          * Returns estimated count, based on EXPLAIN output
 250          * Takes same arguments as Database::select()
 251          */
 252         public function estimateRowCount( $table, $vars='*', $conds='', $fname = 'Database::estimateRowCount', $options = array() ) {
 253                 $options['EXPLAIN'] = true;
 254                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 255                 if ( $res === false ) {
 256                         return false;
 257                 }
 258                 if ( !$this->numRows( $res ) ) {
 259                         return 0;
 260                 }
 261
 262                 $rows = 1;
 263                 foreach ( $res as $plan ) {
 264                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 265                 }
 266                 return $rows;
 267         }
 268
 269         function fieldInfo( $table, $field ) {
 270                 $table = $this->tableName( $table );
 271                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 272                 if ( !$res ) {
 273                         return false;
 274                 }
 275                 $n = mysql_num_fields( $res->result );
 276                 for( $i = 0; $i < $n; $i++ ) {
 277                         $meta = mysql_fetch_field( $res->result, $i );
 278                         if( $field == $meta->name ) {
 279                                 return new MySQLField($meta);
 280                         }
 281                 }
 282                 return false;
 283         }
 284
 285         function selectDB( $db ) {
 286                 $this->mDBname = $db;
 287                 return mysql_select_db( $db, $this->mConn );
 288         }
 289
 290         function strencode( $s ) {
 291                 $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 292
 293                 if($sQuoted === false) {
 294                         $this->ping();
 295                         $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 296                 }
 297                 return $sQuoted;
 298         }
 299
 300         function ping() {
 301                 $ping = mysql_ping( $this->mConn );
 302                 if ( $ping ) {
 303                         return true;
 304                 }
 305
 306                 mysql_close( $this->mConn );
 307                 $this->mOpened = false;
 308                 $this->mConn = false;
 309                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 310                 return true;
 311         }
 312
 313         /**
 314          * Returns slave lag.
 315          * At the moment, this will only work if the DB user has the PROCESS privilege
 316          * @result int
 317          */
 318         function getLag() {
 319                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 320                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 321                         return $this->mFakeSlaveLag;
 322                 }
 323                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 324                 if( !$res ) {
 325                         return false;
 326                 }
 327                 # Find slave SQL thread
 328                 foreach( $res as $row ) {
 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         public static 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
 386                 if( $row->lockstatus == 1 ) {
 387                         return true;
 388                 } else {
 389                         wfDebug( __METHOD__." failed to acquire lock\n" );
 390                         return false;
 391                 }
 392         }
 393
 394         /**
 395          * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 396          */
 397         public function unlock( $lockName, $method ) {
 398                 $lockName = $this->addQuotes( $lockName );
 399                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 400                 $row = $this->fetchObject( $result );
 401                 return $row->lockstatus;
 402         }
 403
 404         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 405                 $items = array();
 406
 407                 foreach( $write as $table ) {
 408                         $tbl = $this->tableName( $table ) .
 409                                         ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 410                                         ' WRITE';
 411                         $items[] = $tbl;
 412                 }
 413                 foreach( $read as $table ) {
 414                         $items[] = $this->tableName( $table ) . ' READ';
 415                 }
 416                 $sql = "LOCK TABLES " . implode( ',', $items );
 417                 $this->query( $sql, $method );
 418         }
 419
 420         public function unlockTables( $method ) {
 421                 $this->query( "UNLOCK TABLES", $method );
 422         }
 423
 424         /**
 425          * Get search engine class. All subclasses of this
 426          * need to implement this if they wish to use searching.
 427          *
 428          * @return String
 429          */
 430         public function getSearchEngine() {
 431                 return 'SearchMySQL';
 432         }
 433
 434         public function setBigSelects( $value = true ) {
 435                 if ( $value === 'default' ) {
 436                         if ( $this->mDefaultBigSelects === null ) {
 437                                 # Function hasn't been called before so it must already be set to the default
 438                                 return;
 439                         } else {
 440                                 $value = $this->mDefaultBigSelects;
 441                         }
 442                 } elseif ( $this->mDefaultBigSelects === null ) {
 443                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 444                 }
 445                 $encValue = $value ? '1' : '0';
 446                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 447         }
 448
 449
 450         /**
 451          * Determines if the last failure was due to a deadlock
 452          */
 453         function wasDeadlock() {
 454                 return $this->lastErrno() == 1213;
 455         }
 456
 457         /**
 458          * Determines if the last query error was something that should be dealt
 459          * with by pinging the connection and reissuing the query
 460          */
 461         function wasErrorReissuable() {
 462                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
 463         }
 464
 465         /**
 466          * Determines if the last failure was due to the database being read-only.
 467          */
 468         function wasReadOnlyError() {
 469                 return $this->lastErrno() == 1223 ||
 470                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
 471         }
 472
 473         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseMysql::duplicateTableStructure' ) {
 474                 $tmp = $temporary ? 'TEMPORARY ' : '';
 475                 if ( strcmp( $this->getServerVersion(), '4.1' ) < 0 ) {
 476                         # Hack for MySQL versions < 4.1, which don't support
 477                         # "CREATE TABLE ... LIKE". Note that
 478                         # "CREATE TEMPORARY TABLE ... SELECT * FROM ... LIMIT 0"
 479                         # would not create the indexes we need....
 480                         #
 481                         # Note that we don't bother changing around the prefixes here be-
 482                         # cause we know we're using MySQL anyway.
 483
 484                         $res = $this->query( "SHOW CREATE TABLE $oldName" );
 485                         $row = $this->fetchRow( $res );
 486                         $oldQuery = $row[1];
 487                         $query = preg_replace( '/CREATE TABLE `(.*?)`/',
 488                                 "CREATE $tmp TABLE `$newName`", $oldQuery );
 489                         if ($oldQuery === $query) {
 490                                 # Couldn't do replacement
 491                                 throw new MWException( "could not create temporary table $newName" );
 492                         }
 493                 } else {
 494                         $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
 495                 }
 496                 $this->query( $query, $fname );
 497         }
 498
 499 }
 500
 501 /**
 502  * Legacy support: Database == DatabaseMysql
 503  */
 504 class Database extends DatabaseMysql {}
 505
 506 class MySQLMasterPos {
 507         var $file, $pos;
 508
 509         function __construct( $file, $pos ) {
 510                 $this->file = $file;
 511                 $this->pos = $pos;
 512         }
 513
 514         function __toString() {
 515                 return "{$this->file}/{$this->pos}";
 516         }
 517 }