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                 while( $plan = $this->fetchObject( $res ) ) {
 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                 # Find slave SQL thread
 325                 while ( $row = $this->fetchObject( $res ) ) {
 326                         /* This should work for most situations - when default db
 327                          * for thread is not specified, it had no events executed,
 328                          * and therefore it doesn't know yet how lagged it is.
 329                          *
 330                          * Relay log I/O thread does not select databases.
 331                          */
 332                         if ( $row->User == 'system user' &&
 333                                 $row->State != 'Waiting for master to send event' &&
 334                                 $row->State != 'Connecting to master' &&
 335                                 $row->State != 'Queueing master event to the relay log' &&
 336                                 $row->State != 'Waiting for master update' &&
 337                                 $row->State != 'Requesting binlog dump' &&
 338                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 339                                 $row->State != 'Reconnecting after a failed master event read' &&
 340                                 $row->State != 'Registering slave on master'
 341                                 ) {
 342                                 # This is it, return the time (except -ve)
 343                                 if ( $row->Time > 0x7fffffff ) {
 344                                         return false;
 345                                 } else {
 346                                         return $row->Time;
 347                                 }
 348                         }
 349                 }
 350                 return false;
 351         }
 352
 353         /**
 354          * INSERT ... ON DUPE UPDATE wrapper, inserts an array into a table, optionally updating if
 355          * duplicate primary key found
 356          *
 357          * $a may be a single associative array, or an array of these with numeric keys, for
 358          * multi-row insert.
 359          *
 360          * Usually aborts on failure
 361          * If errors are explicitly ignored, returns success
 362          *
 363          * @param $table   String: table name (prefix auto-added)
 364          * @param $a       Array: Array of rows to insert
 365          * @param $fname   String: Calling function name (use __METHOD__) for logs/profiling
 366          * @param $onDupeUpdate   Array: Associative array of fields to update on duplicate
 367          *
 368          * @return bool
 369          */
 370         function insertOrUpdate( $table, $a, $fname = 'DatabaseBase::insertOrUpdate', $onDupeUpdate = array() ) {
 371                 # No rows to insert, easy just return now
 372                 if ( !count( $a ) ) {
 373                         return true;
 374                 }
 375
 376                 $table = $this->tableName( $table );
 377
 378                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 379                         $multi = true;
 380                         $keys = array_keys( $a[0] );
 381                 } else {
 382                         $multi = false;
 383                         $keys = array_keys( $a );
 384                 }
 385
 386                 $sql = "INSERT INTO $table (" . implode( ',', $keys ) . ') VALUES ';
 387
 388                 if ( $multi ) {
 389                         $first = true;
 390                         foreach ( $a as $row ) {
 391                                 if ( $first ) {
 392                                         $first = false;
 393                                 } else {
 394                                         $sql .= ',';
 395                                 }
 396                                 $sql .= '(' . $this->makeList( $row ) . ')';
 397                         }
 398                 } else {
 399                         $sql .= '(' . $this->makeList( $a ) . ')';
 400                 }
 401
 402                 if ( count( $onDupeUpdate ) ) {
 403                         $sql .= ' ON DUPLICATE KEY UPDATE ' . $this->makeList( $onDupeUpdate, LIST_SET );
 404                 }
 405
 406                 return (bool)$this->query( $sql, $fname );
 407         }
 408
 409         function getServerVersion() {
 410                 return mysql_get_server_info( $this->mConn );
 411         }
 412
 413         function useIndexClause( $index ) {
 414                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 415         }
 416
 417         function lowPriorityOption() {
 418                 return 'LOW_PRIORITY';
 419         }
 420
 421         public static function getSoftwareLink() {
 422                 return '[http://www.mysql.com/ MySQL]';
 423         }
 424
 425         function standardSelectDistinct() {
 426                 return false;
 427         }
 428
 429         public function setTimeout( $timeout ) {
 430                 $this->query( "SET net_read_timeout=$timeout" );
 431                 $this->query( "SET net_write_timeout=$timeout" );
 432         }
 433
 434         public function lock( $lockName, $method, $timeout = 5 ) {
 435                 $lockName = $this->addQuotes( $lockName );
 436                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 437                 $row = $this->fetchObject( $result );
 438
 439                 if( $row->lockstatus == 1 ) {
 440                         return true;
 441                 } else {
 442                         wfDebug( __METHOD__." failed to acquire lock\n" );
 443                         return false;
 444                 }
 445         }
 446
 447         /**
 448          * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 449          */
 450         public function unlock( $lockName, $method ) {
 451                 $lockName = $this->addQuotes( $lockName );
 452                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 453                 $row = $this->fetchObject( $result );
 454                 return $row->lockstatus;
 455         }
 456
 457         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 458                 $items = array();
 459
 460                 foreach( $write as $table ) {
 461                         $tbl = $this->tableName( $table ) .
 462                                         ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 463                                         ' WRITE';
 464                         $items[] = $tbl;
 465                 }
 466                 foreach( $read as $table ) {
 467                         $items[] = $this->tableName( $table ) . ' READ';
 468                 }
 469                 $sql = "LOCK TABLES " . implode( ',', $items );
 470                 $this->query( $sql, $method );
 471         }
 472
 473         public function unlockTables( $method ) {
 474                 $this->query( "UNLOCK TABLES", $method );
 475         }
 476
 477         /**
 478          * Get search engine class. All subclasses of this
 479          * need to implement this if they wish to use searching.
 480          *
 481          * @return String
 482          */
 483         public function getSearchEngine() {
 484                 return 'SearchMySQL';
 485         }
 486
 487         public function setBigSelects( $value = true ) {
 488                 if ( $value === 'default' ) {
 489                         if ( $this->mDefaultBigSelects === null ) {
 490                                 # Function hasn't been called before so it must already be set to the default
 491                                 return;
 492                         } else {
 493                                 $value = $this->mDefaultBigSelects;
 494                         }
 495                 } elseif ( $this->mDefaultBigSelects === null ) {
 496                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 497                 }
 498                 $encValue = $value ? '1' : '0';
 499                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 500         }
 501
 502
 503         /**
 504          * Determines if the last failure was due to a deadlock
 505          */
 506         function wasDeadlock() {
 507                 return $this->lastErrno() == 1213;
 508         }
 509
 510         /**
 511          * Determines if the last query error was something that should be dealt
 512          * with by pinging the connection and reissuing the query
 513          */
 514         function wasErrorReissuable() {
 515                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
 516         }
 517
 518         /**
 519          * Determines if the last failure was due to the database being read-only.
 520          */
 521         function wasReadOnlyError() {
 522                 return $this->lastErrno() == 1223 ||
 523                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
 524         }
 525
 526         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseMysql::duplicateTableStructure' ) {
 527                 $tmp = $temporary ? 'TEMPORARY ' : '';
 528                 if ( strcmp( $this->getServerVersion(), '4.1' ) < 0 ) {
 529                         # Hack for MySQL versions < 4.1, which don't support
 530                         # "CREATE TABLE ... LIKE". Note that
 531                         # "CREATE TEMPORARY TABLE ... SELECT * FROM ... LIMIT 0"
 532                         # would not create the indexes we need....
 533                         #
 534                         # Note that we don't bother changing around the prefixes here be-
 535                         # cause we know we're using MySQL anyway.
 536
 537                         $res = $this->query( "SHOW CREATE TABLE $oldName" );
 538                         $row = $this->fetchRow( $res );
 539                         $oldQuery = $row[1];
 540                         $query = preg_replace( '/CREATE TABLE `(.*?)`/',
 541                                 "CREATE $tmp TABLE `$newName`", $oldQuery );
 542                         if ($oldQuery === $query) {
 543                                 # Couldn't do replacement
 544                                 throw new MWException( "could not create temporary table $newName" );
 545                         }
 546                 } else {
 547                         $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
 548                 }
 549                 $this->query( $query, $fname );
 550         }
 551
 552 }
 553
 554 /**
 555  * Legacy support: Database == DatabaseMysql
 556  */
 557 class Database extends DatabaseMysql {}
 558
 559 class MySQLMasterPos {
 560         var $file, $pos;
 561
 562         function __construct( $file, $pos ) {
 563                 $this->file = $file;
 564                 $this->pos = $pos;
 565         }
 566
 567         function __toString() {
 568                 return "{$this->file}/{$this->pos}";
 569         }
 570 }