includes/db/DatabaseMysql.php

   1 <?php
   2 /**
   3  * This is the MySQL database abstraction layer.
   4  *
   5  * @file
   6  * @ingroup Database
   7  */
   8
   9 /**
  10  * Database abstraction object for mySQL
  11  * Inherit all methods and properties of Database::Database()
  12  *
  13  * @ingroup Database
  14  * @see Database
  15  */
  16 class DatabaseMysql extends DatabaseBase {
  17         function getType() {
  18                 return 'mysql';
  19         }
  20
  21         /*private*/ function doQuery( $sql ) {
  22                 if( $this->bufferResults() ) {
  23                         $ret = mysql_query( $sql, $this->mConn );
  24                 } else {
  25                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
  26                 }
  27                 return $ret;
  28         }
  29
  30         function open( $server, $user, $password, $dbName ) {
  31                 global $wgAllDBsAreLocalhost;
  32                 wfProfileIn( __METHOD__ );
  33
  34                 # Load mysql.so if we don't have it
  35                 wfDl( 'mysql' );
  36
  37                 # Fail now
  38                 # Otherwise we get a suppressed fatal error, which is very hard to track down
  39                 if ( !function_exists( 'mysql_connect' ) ) {
  40                         throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
  41                 }
  42
  43                 # Debugging hack -- fake cluster
  44                 if ( $wgAllDBsAreLocalhost ) {
  45                         $realServer = 'localhost';
  46                 } else {
  47                         $realServer = $server;
  48                 }
  49                 $this->close();
  50                 $this->mServer = $server;
  51                 $this->mUser = $user;
  52                 $this->mPassword = $password;
  53                 $this->mDBname = $dbName;
  54
  55                 wfProfileIn("dbconnect-$server");
  56
  57                 # The kernel's default SYN retransmission period is far too slow for us,
  58                 # so we use a short timeout plus a manual retry. Retrying means that a small
  59                 # but finite rate of SYN packet loss won't cause user-visible errors.
  60                 $this->mConn = false;
  61                 if ( ini_get( 'mysql.connect_timeout' ) <= 3 ) {
  62                         $numAttempts = 2;
  63                 } else {
  64                         $numAttempts = 1;
  65                 }
  66                 $this->installErrorHandler();
  67                 for ( $i = 0; $i < $numAttempts && !$this->mConn; $i++ ) {
  68                         if ( $i > 1 ) {
  69                                 usleep( 1000 );
  70                         }
  71                         if ( $this->mFlags & DBO_PERSISTENT ) {
  72                                 $this->mConn = mysql_pconnect( $realServer, $user, $password );
  73                         } else {
  74                                 # Create a new connection...
  75                                 $this->mConn = mysql_connect( $realServer, $user, $password, true );
  76                         }
  77                         #if ( $this->mConn === false ) {
  78                                 #$iplus = $i + 1;
  79                                 #wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
  80                         #}
  81                 }
  82                 $phpError = $this->restoreErrorHandler();
  83                 # Always log connection errors
  84                 if ( !$this->mConn ) {
  85                         $error = $this->lastError();
  86                         if ( !$error ) {
  87                                 $error = $phpError;
  88                         }
  89                         wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
  90                         wfDebug( "DB connection error\n" );
  91                         wfDebug( "Server: $server, User: $user, Password: " .
  92                                 substr( $password, 0, 3 ) . "..., error: " . mysql_error() . "\n" );
  93                 }
  94
  95                 wfProfileOut("dbconnect-$server");
  96
  97                 if ( $dbName != '' && $this->mConn !== false ) {
  98                         $success = @/**/mysql_select_db( $dbName, $this->mConn );
  99                         if ( !$success ) {
 100                                 $error = "Error selecting database $dbName on server {$this->mServer} " .
 101                                         "from client host " . wfHostname() . "\n";
 102                                 wfLogDBError(" Error selecting database $dbName on server {$this->mServer} \n");
 103                                 wfDebug( $error );
 104                         }
 105                 } else {
 106                         # Delay USE query
 107                         $success = (bool)$this->mConn;
 108                 }
 109
 110                 if ( $success ) {
 111                         $version = $this->getServerVersion();
 112                         if ( version_compare( $version, '4.1' ) >= 0 ) {
 113                                 // Tell the server we're communicating with it in UTF-8.
 114                                 // This may engage various charset conversions.
 115                                 global $wgDBmysql5;
 116                                 if( $wgDBmysql5 ) {
 117                                         $this->query( 'SET NAMES utf8', __METHOD__ );
 118                                 } else {
 119                                         $this->query( 'SET NAMES binary', __METHOD__ );
 120                                 }
 121                                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 122                                 global $wgSQLMode;
 123                                 if ( is_string( $wgSQLMode ) ) {
 124                                         $mode = $this->addQuotes( $wgSQLMode );
 125                                         $this->query( "SET sql_mode = $mode", __METHOD__ );
 126                                 }
 127                         }
 128
 129                         // Turn off strict mode if it is on
 130                 } else {
 131                         $this->reportConnectionError( $phpError );
 132                 }
 133
 134                 $this->mOpened = $success;
 135                 wfProfileOut( __METHOD__ );
 136                 return $success;
 137         }
 138
 139         function close() {
 140                 $this->mOpened = false;
 141                 if ( $this->mConn ) {
 142                         if ( $this->trxLevel() ) {
 143                                 $this->commit();
 144                         }
 145                         return mysql_close( $this->mConn );
 146                 } else {
 147                         return true;
 148                 }
 149         }
 150
 151         function freeResult( $res ) {
 152                 if ( $res instanceof ResultWrapper ) {
 153                         $res = $res->result;
 154                 }
 155                 if ( !@/**/mysql_free_result( $res ) ) {
 156                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 157                 }
 158         }
 159
 160         function fetchObject( $res ) {
 161                 if ( $res instanceof ResultWrapper ) {
 162                         $res = $res->result;
 163                 }
 164                 @/**/$row = mysql_fetch_object( $res );
 165                 if( $this->lastErrno() ) {
 166                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 167                 }
 168                 return $row;
 169         }
 170
 171         function fetchRow( $res ) {
 172                 if ( $res instanceof ResultWrapper ) {
 173                         $res = $res->result;
 174                 }
 175                 @/**/$row = mysql_fetch_array( $res );
 176                 if ( $this->lastErrno() ) {
 177                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 178                 }
 179                 return $row;
 180         }
 181
 182         function numRows( $res ) {
 183                 if ( $res instanceof ResultWrapper ) {
 184                         $res = $res->result;
 185                 }
 186                 @/**/$n = mysql_num_rows( $res );
 187                 if( $this->lastErrno() ) {
 188                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 189                 }
 190                 return $n;
 191         }
 192
 193         function numFields( $res ) {
 194                 if ( $res instanceof ResultWrapper ) {
 195                         $res = $res->result;
 196                 }
 197                 return mysql_num_fields( $res );
 198         }
 199
 200         function fieldName( $res, $n ) {
 201                 if ( $res instanceof ResultWrapper ) {
 202                         $res = $res->result;
 203                 }
 204                 return mysql_field_name( $res, $n );
 205         }
 206
 207         function insertId() { return mysql_insert_id( $this->mConn ); }
 208
 209         function dataSeek( $res, $row ) {
 210                 if ( $res instanceof ResultWrapper ) {
 211                         $res = $res->result;
 212                 }
 213                 return mysql_data_seek( $res, $row );
 214         }
 215
 216         function lastErrno() {
 217                 if ( $this->mConn ) {
 218                         return mysql_errno( $this->mConn );
 219                 } else {
 220                         return mysql_errno();
 221                 }
 222         }
 223
 224         function lastError() {
 225                 if ( $this->mConn ) {
 226                         # Even if it's non-zero, it can still be invalid
 227                         wfSuppressWarnings();
 228                         $error = mysql_error( $this->mConn );
 229                         if ( !$error ) {
 230                                 $error = mysql_error();
 231                         }
 232                         wfRestoreWarnings();
 233                 } else {
 234                         $error = mysql_error();
 235                 }
 236                 if( $error ) {
 237                         $error .= ' (' . $this->mServer . ')';
 238                 }
 239                 return $error;
 240         }
 241
 242         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 243
 244         /**
 245          * Estimate rows in dataset
 246          * Returns estimated count, based on EXPLAIN output
 247          * Takes same arguments as Database::select()
 248          */
 249         public function estimateRowCount( $table, $vars='*', $conds='', $fname = 'DatabaseMysql::estimateRowCount', $options = array() ) {
 250                 $options['EXPLAIN'] = true;
 251                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 252                 if ( $res === false ) {
 253                         return false;
 254                 }
 255                 if ( !$this->numRows( $res ) ) {
 256                         return 0;
 257                 }
 258
 259                 $rows = 1;
 260                 foreach ( $res as $plan ) {
 261                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 262                 }
 263                 return $rows;
 264         }
 265
 266         function fieldInfo( $table, $field ) {
 267                 $table = $this->tableName( $table );
 268                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 269                 if ( !$res ) {
 270                         return false;
 271                 }
 272                 $n = mysql_num_fields( $res->result );
 273                 for( $i = 0; $i < $n; $i++ ) {
 274                         $meta = mysql_fetch_field( $res->result, $i );
 275                         if( $field == $meta->name ) {
 276                                 return new MySQLField($meta);
 277                         }
 278                 }
 279                 return false;
 280         }
 281
 282         /**
 283          * Get information about an index into an object
 284          * Returns false if the index does not exist
 285          */
 286         function indexInfo( $table, $index, $fname = 'DatabaseMysql::indexInfo' ) {
 287                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 288                 # SHOW INDEX should work for 3.x and up:
 289                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 290                 $table = $this->tableName( $table );
 291                 $index = $this->indexName( $index );
 292                 $sql = 'SHOW INDEX FROM ' . $table;
 293                 $res = $this->query( $sql, $fname );
 294
 295                 if ( !$res ) {
 296                         return null;
 297                 }
 298
 299                 $result = array();
 300
 301                 foreach ( $res as $row ) {
 302                         if ( $row->Key_name == $index ) {
 303                                 $result[] = $row;
 304                         }
 305                 }
 306
 307                 return empty( $result ) ? false : $result;
 308         }
 309
 310         function selectDB( $db ) {
 311                 $this->mDBname = $db;
 312                 return mysql_select_db( $db, $this->mConn );
 313         }
 314
 315         function strencode( $s ) {
 316                 $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 317
 318                 if($sQuoted === false) {
 319                         $this->ping();
 320                         $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 321                 }
 322                 return $sQuoted;
 323         }
 324
 325         function ping() {
 326                 $ping = mysql_ping( $this->mConn );
 327                 if ( $ping ) {
 328                         return true;
 329                 }
 330
 331                 mysql_close( $this->mConn );
 332                 $this->mOpened = false;
 333                 $this->mConn = false;
 334                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 335                 return true;
 336         }
 337
 338         /**
 339          * Returns slave lag.
 340          * At the moment, this will only work if the DB user has the PROCESS privilege
 341          * @result int
 342          */
 343         function getLag() {
 344                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 345                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 346                         return $this->mFakeSlaveLag;
 347                 }
 348                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 349                 if( !$res ) {
 350                         return false;
 351                 }
 352                 # Find slave SQL thread
 353                 foreach( $res as $row ) {
 354                         /* This should work for most situations - when default db
 355                          * for thread is not specified, it had no events executed,
 356                          * and therefore it doesn't know yet how lagged it is.
 357                          *
 358                          * Relay log I/O thread does not select databases.
 359                          */
 360                         if ( $row->User == 'system user' &&
 361                                 $row->State != 'Waiting for master to send event' &&
 362                                 $row->State != 'Connecting to master' &&
 363                                 $row->State != 'Queueing master event to the relay log' &&
 364                                 $row->State != 'Waiting for master update' &&
 365                                 $row->State != 'Requesting binlog dump' &&
 366                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 367                                 $row->State != 'Reconnecting after a failed master event read' &&
 368                                 $row->State != 'Registering slave on master'
 369                                 ) {
 370                                 # This is it, return the time (except -ve)
 371                                 if ( $row->Time > 0x7fffffff ) {
 372                                         return false;
 373                                 } else {
 374                                         return $row->Time;
 375                                 }
 376                         }
 377                 }
 378                 return false;
 379         }
 380
 381         function getServerVersion() {
 382                 return mysql_get_server_info( $this->mConn );
 383         }
 384
 385         function useIndexClause( $index ) {
 386                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 387         }
 388
 389         function lowPriorityOption() {
 390                 return 'LOW_PRIORITY';
 391         }
 392
 393         public static function getSoftwareLink() {
 394                 return '[http://www.mysql.com/ MySQL]';
 395         }
 396
 397         function standardSelectDistinct() {
 398                 return false;
 399         }
 400
 401         public function setTimeout( $timeout ) {
 402                 $this->query( "SET net_read_timeout=$timeout" );
 403                 $this->query( "SET net_write_timeout=$timeout" );
 404         }
 405
 406         public function lock( $lockName, $method, $timeout = 5 ) {
 407                 $lockName = $this->addQuotes( $lockName );
 408                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 409                 $row = $this->fetchObject( $result );
 410
 411                 if( $row->lockstatus == 1 ) {
 412                         return true;
 413                 } else {
 414                         wfDebug( __METHOD__." failed to acquire lock\n" );
 415                         return false;
 416                 }
 417         }
 418
 419         /**
 420          * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 421          */
 422         public function unlock( $lockName, $method ) {
 423                 $lockName = $this->addQuotes( $lockName );
 424                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 425                 $row = $this->fetchObject( $result );
 426                 return $row->lockstatus;
 427         }
 428
 429         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 430                 $items = array();
 431
 432                 foreach( $write as $table ) {
 433                         $tbl = $this->tableName( $table ) .
 434                                         ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 435                                         ' WRITE';
 436                         $items[] = $tbl;
 437                 }
 438                 foreach( $read as $table ) {
 439                         $items[] = $this->tableName( $table ) . ' READ';
 440                 }
 441                 $sql = "LOCK TABLES " . implode( ',', $items );
 442                 $this->query( $sql, $method );
 443         }
 444
 445         public function unlockTables( $method ) {
 446                 $this->query( "UNLOCK TABLES", $method );
 447         }
 448
 449         /**
 450          * Get search engine class. All subclasses of this
 451          * need to implement this if they wish to use searching.
 452          *
 453          * @return String
 454          */
 455         public function getSearchEngine() {
 456                 return 'SearchMySQL';
 457         }
 458
 459         public function setBigSelects( $value = true ) {
 460                 if ( $value === 'default' ) {
 461                         if ( $this->mDefaultBigSelects === null ) {
 462                                 # Function hasn't been called before so it must already be set to the default
 463                                 return;
 464                         } else {
 465                                 $value = $this->mDefaultBigSelects;
 466                         }
 467                 } elseif ( $this->mDefaultBigSelects === null ) {
 468                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 469                 }
 470                 $encValue = $value ? '1' : '0';
 471                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 472         }
 473
 474         public function unixTimestamp( $field ) {
 475                 return "UNIX_TIMESTAMP($field)";
 476         }
 477
 478         /**
 479          * Determines if the last failure was due to a deadlock
 480          */
 481         function wasDeadlock() {
 482                 return $this->lastErrno() == 1213;
 483         }
 484
 485         /**
 486          * Determines if the last query error was something that should be dealt
 487          * with by pinging the connection and reissuing the query
 488          */
 489         function wasErrorReissuable() {
 490                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
 491         }
 492
 493         /**
 494          * Determines if the last failure was due to the database being read-only.
 495          */
 496         function wasReadOnlyError() {
 497                 return $this->lastErrno() == 1223 ||
 498                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
 499         }
 500
 501         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseMysql::duplicateTableStructure' ) {
 502                 $tmp = $temporary ? 'TEMPORARY ' : '';
 503                 if ( strcmp( $this->getServerVersion(), '4.1' ) < 0 ) {
 504                         # Hack for MySQL versions < 4.1, which don't support
 505                         # "CREATE TABLE ... LIKE". Note that
 506                         # "CREATE TEMPORARY TABLE ... SELECT * FROM ... LIMIT 0"
 507                         # would not create the indexes we need....
 508                         #
 509                         # Note that we don't bother changing around the prefixes here be-
 510                         # cause we know we're using MySQL anyway.
 511
 512                         $res = $this->query( "SHOW CREATE TABLE $oldName" );
 513                         $row = $this->fetchRow( $res );
 514                         $oldQuery = $row[1];
 515                         $query = preg_replace( '/CREATE TABLE `(.*?)`/',
 516                                 "CREATE $tmp TABLE `$newName`", $oldQuery );
 517                         if ($oldQuery === $query) {
 518                                 # Couldn't do replacement
 519                                 throw new MWException( "could not create temporary table $newName" );
 520                         }
 521                 } else {
 522                         $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
 523                 }
 524                 $this->query( $query, $fname );
 525         }
 526
 527 }
 528
 529 /**
 530  * Legacy support: Database == DatabaseMysql
 531  */
 532 class Database extends DatabaseMysql {}
 533
 534 /**
 535  * Utility class.
 536  * @ingroup Database
 537  */
 538 class MySQLField implements Field {
 539         private $name, $tablename, $default, $max_length, $nullable,
 540                 $is_pk, $is_unique, $is_multiple, $is_key, $type;
 541
 542         function __construct ( $info ) {
 543                 $this->name = $info->name;
 544                 $this->tablename = $info->table;
 545                 $this->default = $info->def;
 546                 $this->max_length = $info->max_length;
 547                 $this->nullable = !$info->not_null;
 548                 $this->is_pk = $info->primary_key;
 549                 $this->is_unique = $info->unique_key;
 550                 $this->is_multiple = $info->multiple_key;
 551                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
 552                 $this->type = $info->type;
 553         }
 554
 555         function name() {
 556                 return $this->name;
 557         }
 558
 559         function tableName() {
 560                 return $this->tableName;
 561         }
 562
 563         function type() {
 564                 return $this->type;
 565         }
 566
 567         function isNullable() {
 568                 return $this->nullable;
 569         }
 570
 571         function defaultValue() {
 572                 return $this->default;
 573         }
 574
 575         function isKey() {
 576                 return $this->is_key;
 577         }
 578
 579         function isMultipleKey() {
 580                 return $this->is_multiple;
 581         }
 582 }
 583
 584 class MySQLMasterPos {
 585         var $file, $pos;
 586
 587         function __construct( $file, $pos ) {
 588                 $this->file = $file;
 589                 $this->pos = $pos;
 590         }
 591
 592         function __toString() {
 593                 return "{$this->file}/{$this->pos}";
 594         }
 595 }