includes/Database.php

   1 <?php
   2 # $Id$
   3 # This file deals with MySQL interface functions
   4 # and query specifics/optimisations
   5 #
   6 require_once( "CacheManager.php" );
   7
   8 define( "DB_READ", -1 );
   9 define( "DB_WRITE", -2 );
  10 define( "DB_LAST", -3 );
  11
  12 define( "LIST_COMMA", 0 );
  13 define( "LIST_AND", 1 );
  14 define( "LIST_SET", 2 );
  15
  16 class Database {
  17
  18 #------------------------------------------------------------------------------
  19 # Variables
  20 #------------------------------------------------------------------------------
  21         /* private */ var $mLastQuery = "";
  22         /* private */ var $mBufferResults = true;
  23         /* private */ var $mIgnoreErrors = false;
  24
  25         /* private */ var $mServer, $mUser, $mPassword, $mConn, $mDBname;
  26         /* private */ var $mOut, $mDebug, $mOpened = false;
  27
  28         /* private */ var $mFailFunction;
  29
  30 #------------------------------------------------------------------------------
  31 # Accessors
  32 #------------------------------------------------------------------------------
  33         # Set functions
  34         # These set a variable and return the previous state
  35
  36         # Fail function, takes a Database as a parameter
  37         # Set to false for default, 1 for ignore errors
  38         function setFailFunction( $function ) { return wfSetVar( $this->mFailFunction, $function ); }
  39
  40         # Output page, used for reporting errors
  41         # FALSE means discard output
  42         function &setOutputPage( &$out ) { return wfSetRef( $this->mOut, $out ); }
  43
  44         # Boolean, controls output of large amounts of debug information
  45         function setDebug( $debug ) { return wfSetVar( $this->mDebug, $debug ); }
  46
  47         # Turns buffering of SQL result sets on (true) or off (false). Default is
  48         # "on" and it should not be changed without good reasons.
  49         function setBufferResults( $buffer ) { return wfSetVar( $this->mBufferResults, $buffer ); }
  50
  51         # Turns on (false) or off (true) the automatic generation and sending
  52         # of a "we're sorry, but there has been a database error" page on
  53         # database errors. Default is on (false). When turned off, the
  54         # code should use wfLastErrno() and wfLastError() to handle the
  55         # situation as appropriate.
  56         function setIgnoreErrors( $ignoreErrors ) { return wfSetVar( $this->mIgnoreErrors, $ignoreErrors ); }
  57
  58         # Get functions
  59
  60         function lastQuery() { return $this->mLastQuery; }
  61         function isOpen() { return $this->mOpened; }
  62
  63 #------------------------------------------------------------------------------
  64 # Other functions
  65 #------------------------------------------------------------------------------
  66
  67         function Database()
  68         {
  69                 global $wgOut;
  70                 # Can't get a reference if it hasn't been set yet
  71                 if ( !isset( $wgOut ) ) {
  72                         $wgOut = NULL;
  73                 }
  74                 $this->mOut =& $wgOut;
  75
  76         }
  77
  78         /* static */ function newFromParams( $server, $user, $password, $dbName,
  79                 $failFunction = false, $debug = false, $bufferResults = true, $ignoreErrors = false )
  80         {
  81                 $db = new Database;
  82                 $db->mFailFunction = $failFunction;
  83                 $db->mIgnoreErrors = $ignoreErrors;
  84                 $db->mDebug = $debug;
  85                 $db->mBufferResults = $bufferResults;
  86                 $db->open( $server, $user, $password, $dbName );
  87                 return $db;
  88         }
  89
  90         # Usually aborts on failure
  91         # If the failFunction is set to a non-zero integer, returns success
  92         function open( $server, $user, $password, $dbName )
  93         {
  94                 global $wgEmergencyContact;
  95
  96                 $this->close();
  97                 $this->mServer = $server;
  98                 $this->mUser = $user;
  99                 $this->mPassword = $password;
 100                 $this->mDBname = $dbName;
 101
 102                 $success = false;
 103
 104                 @$this->mConn = mysql_connect( $server, $user, $password );
 105                 if ( $dbName != "" ) {
 106                         if ( $this->mConn !== false ) {
 107                                 $success = @mysql_select_db( $dbName, $this->mConn );
 108                                 if ( !$success ) {
 109                                         wfDebug( "Error selecting database \"$dbName\": " . $this->lastError() . "\n" );
 110                                 }
 111                         } else {
 112                                 wfDebug( "DB connection error\n" );
 113                                 wfDebug( "Server: $server, User: $user, Password: " .
 114                                         substr( $password, 0, 3 ) . "...\n" );
 115                                 $success = false;
 116                         }
 117                 } else {
 118                         # Delay USE query
 119                         $success = !!$this->mConn;
 120                 }
 121
 122                 if ( !$success ) {
 123                         $this->reportConnectionError();
 124                         $this->close();
 125                 }
 126                 $this->mOpened = $success;
 127                 return $success;
 128         }
 129
 130         # Closes a database connection, if it is open
 131         # Returns success, true if already closed
 132         function close()
 133         {
 134                 $this->mOpened = false;
 135                 if ( $this->mConn ) {
 136                         return mysql_close( $this->mConn );
 137                 } else {
 138                         return true;
 139                 }
 140         }
 141
 142         /* private */ function reportConnectionError( $msg = "")
 143         {
 144                 if ( $this->mFailFunction ) {
 145                         if ( !is_int( $this->mFailFunction ) ) {
 146                                 $this->$mFailFunction( $this );
 147                         }
 148                 } else {
 149                         wfEmergencyAbort( $this );
 150                 }
 151         }
 152
 153         # Usually aborts on failure
 154         # If errors are explicitly ignored, returns success
 155         function query( $sql, $fname = "" )
 156         {
 157                 global $wgProfiling;
 158
 159                 if ( $wgProfiling ) {
 160                         # generalizeSQL will probably cut down the query to reasonable
 161                         # logging size most of the time. The substr is really just a sanity check.
 162                         $profName = "query: " . substr( Database::generalizeSQL( $sql ), 0, 255 );
 163                         wfProfileIn( $profName );
 164                 }
 165
 166                 $this->mLastQuery = $sql;
 167
 168                 if ( $this->mDebug ) {
 169                         $sqlx = substr( $sql, 0, 500 );
 170                         $sqlx = wordwrap(strtr($sqlx,"\t\n","  "));
 171                         wfDebug( "SQL: $sqlx\n" );
 172                 }
 173                 if( $this->mBufferResults ) {
 174                         $ret = mysql_query( $sql, $this->mConn );
 175                 } else {
 176                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 177                 }
 178
 179                 if ( false === $ret ) {
 180                         $error = mysql_error( $this->mConn );
 181                         $errno = mysql_errno( $this->mConn );
 182                         if( $this->mIgnoreErrors ) {
 183                                 wfDebug("SQL ERROR (ignored): " . $error . "\n");
 184                         } else {
 185                                 wfDebug("SQL ERROR: " . $error . "\n");
 186                                 if ( $this->mOut ) {
 187                                         // this calls wfAbruptExit()
 188                                         $this->mOut->databaseError( $fname, $sql, $error, $errno );
 189                                 }
 190                         }
 191                 }
 192
 193                 if ( $wgProfiling ) {
 194                         wfProfileOut( $profName );
 195                 }
 196                 return $ret;
 197         }
 198
 199         function freeResult( $res ) {
 200                 if ( !@mysql_free_result( $res ) ) {
 201                         wfDebugDieBacktrace( "Unable to free MySQL result\n" );
 202                 }
 203         }
 204         function fetchObject( $res ) {
 205                 @$row = mysql_fetch_object( $res );
 206                 # FIXME: HACK HACK HACK HACK debug
 207                 if( mysql_errno() ) {
 208                         wfDebugDieBacktrace( "SQL error: " . htmlspecialchars( mysql_error() ) );
 209                 }
 210                 return $row;
 211         }
 212
 213         function fetchRow( $res ) {
 214                 @$row = mysql_fetch_array( $res );
 215                 if (mysql_errno() ) {
 216                         wfDebugDieBacktrace( "SQL error: " . htmlspecialchars( mysql_error() ) );
 217                 }
 218                 return $row;
 219         }
 220
 221         function numRows( $res ) {
 222                 @$n = mysql_num_rows( $res );
 223                 if( mysql_errno() ) {
 224                         wfDebugDieBacktrace( "SQL error: " . htmlspecialchars( mysql_error() ) );
 225                 }
 226                 return $n;
 227         }
 228         function numFields( $res ) { return mysql_num_fields( $res ); }
 229         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 230         function insertId() { return mysql_insert_id( $this->mConn ); }
 231         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 232         function lastErrno() { return mysql_errno(); }
 233         function lastError() { return mysql_error(); }
 234         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 235
 236         # Simple UPDATE wrapper
 237         # Usually aborts on failure
 238         # If errors are explicitly ignored, returns success
 239         function set( $table, $var, $value, $cond, $fname = "Database::set" )
 240         {
 241                 $sql = "UPDATE $table SET $var = '" .
 242                   wfStrencode( $value ) . "' WHERE ($cond)";
 243                 return !!$this->query( $sql, DB_WRITE, $fname );
 244         }
 245
 246         # Simple SELECT wrapper, returns a single field, input must be encoded
 247         # Usually aborts on failure
 248         # If errors are explicitly ignored, returns FALSE on failure
 249         function get( $table, $var, $cond, $fname = "Database::get" )
 250         {
 251                 $sql = "SELECT $var FROM $table WHERE ($cond)";
 252                 $result = $this->query( $sql, DB_READ, $fname );
 253
 254                 $ret = "";
 255                 if ( mysql_num_rows( $result ) > 0 ) {
 256                         $s = mysql_fetch_object( $result );
 257                         $ret = $s->$var;
 258                         mysql_free_result( $result );
 259                 }
 260                 return $ret;
 261         }
 262
 263         # More complex SELECT wrapper, single row only
 264         # Aborts or returns FALSE on error
 265         # Takes an array of selected variables, and a condition map, which is ANDed
 266         # e.g. getArray( "cur", array( "cur_id" ), array( "cur_namespace" => 0, "cur_title" => "Astronomy" ) )
 267         #   would return an object where $obj->cur_id is the ID of the Astronomy article
 268         function getArray( $table, $vars, $conds, $fname = "Database::getArray" )
 269         {
 270                 $vars = implode( ",", $vars );
 271                 $where = Database::makeList( $conds, LIST_AND );
 272                 $sql = "SELECT $vars FROM $table WHERE $where LIMIT 1";
 273                 $res = $this->query( $sql, $fname );
 274                 if ( $res === false || !$this->numRows( $res ) ) {
 275                         return false;
 276                 }
 277                 $obj = $this->fetchObject( $res );
 278                 $this->freeResult( $res );
 279                 return $obj;
 280         }
 281
 282         # Removes most variables from an SQL query and replaces them with X or N for numbers.
 283         # It's only slightly flawed. Don't use for anything important.
 284         /* static */ function generalizeSQL( $sql )
 285         {
 286                 # This does the same as the regexp below would do, but in such a way
 287                 # as to avoid crashing php on some large strings.
 288                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
 289
 290                 $sql = str_replace ( "\\\\", "", $sql);
 291                 $sql = str_replace ( "\\'", "", $sql);
 292                 $sql = str_replace ( "\\\"", "", $sql);
 293                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
 294                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
 295
 296                 # All newlines, tabs, etc replaced by single space
 297                 $sql = preg_replace ( "/\s+/", " ", $sql);
 298
 299                 # All numbers => N
 300                 $sql = preg_replace ('/-?[0-9]+/s', "N", $sql);
 301
 302                 return $sql;
 303         }
 304
 305         # Determines whether a field exists in a table
 306         # Usually aborts on failure
 307         # If errors are explicitly ignored, returns NULL on failure
 308         function fieldExists( $table, $field, $fname = "Database::fieldExists" )
 309         {
 310                 $res = $this->query( "DESCRIBE $table", DB_READ, $fname );
 311                 if ( !$res ) {
 312                         return NULL;
 313                 }
 314
 315                 $found = false;
 316
 317                 while ( $row = $this->fetchObject( $res ) ) {
 318                         if ( $row->Field == $field ) {
 319                                 $found = true;
 320                                 break;
 321                         }
 322                 }
 323                 return $found;
 324         }
 325
 326         # Determines whether an index exists
 327         # Usually aborts on failure
 328         # If errors are explicitly ignored, returns NULL on failure
 329         function indexExists( $table, $index, $fname = "Database::indexExists" )
 330         {
 331                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 332                 # SHOW INDEX should work for 3.x and up:
 333                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 334                 $sql = "SHOW INDEX FROM $table";
 335                 $res = $this->query( $sql, DB_READ, $fname );
 336                 if ( !$res ) {
 337                         return NULL;
 338                 }
 339
 340                 $found = false;
 341
 342                 while ( $row = $this->fetchObject( $res ) ) {
 343                         if ( $row->Key_name == $index ) {
 344                                 $found = true;
 345                                 break;
 346                         }
 347                 }
 348                 return $found;
 349         }
 350
 351         function tableExists( $table )
 352         {
 353                 $old = $this->mIgnoreErrors;
 354                 $this->mIgnoreErrors = true;
 355                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
 356                 $this->mIgnoreErrors = $old;
 357                 if( $res ) {
 358                         $this->freeResult( $res );
 359                         return true;
 360                 } else {
 361                         return false;
 362                 }
 363         }
 364
 365         function fieldInfo( $table, $field )
 366         {
 367                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
 368                 $n = mysql_num_fields( $res );
 369                 for( $i = 0; $i < $n; $i++ ) {
 370                         $meta = mysql_fetch_field( $res, $i );
 371                         if( $field == $meta->name ) {
 372                                 return $meta;
 373                         }
 374                 }
 375                 return false;
 376         }
 377
 378         # INSERT wrapper, inserts an array into a table
 379         # Keys are field names, values are values
 380         # Usually aborts on failure
 381         # If errors are explicitly ignored, returns success
 382         function insertArray( $table, $a, $fname = "Database::insertArray" )
 383         {
 384                 $sql1 = "INSERT INTO $table (";
 385                 $sql2 = "VALUES (" . Database::makeList( $a );
 386                 $first = true;
 387                 foreach ( $a as $field => $value ) {
 388                         if ( !$first ) {
 389                                 $sql1 .= ",";
 390                         }
 391                         $first = false;
 392                         $sql1 .= $field;
 393                 }
 394                 $sql = "$sql1) $sql2)";
 395                 return !!$this->query( $sql, $fname );
 396         }
 397
 398         # A cross between insertArray and getArray, takes a condition array and a SET array
 399         function updateArray( $table, $values, $conds, $fname = "Database::updateArray" )
 400         {
 401                 $sql = "UPDATE $table SET " . $this->makeList( $values, LIST_SET );
 402                 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
 403                 $this->query( $sql, $fname );
 404         }
 405
 406         # Makes a wfStrencoded list from an array
 407         # $mode: LIST_COMMA - comma separated, no field names
 408         #        LIST_AND   - ANDed WHERE clause (without the WHERE)
 409         #        LIST_SET   - comma separated with field names, like a SET clause
 410         /* static */ function makeList( $a, $mode = LIST_COMMA )
 411         {
 412                 $first = true;
 413                 $list = "";
 414                 foreach ( $a as $field => $value ) {
 415                         if ( !$first ) {
 416                                 if ( $mode == LIST_AND ) {
 417                                         $list .= " AND ";
 418                                 } else {
 419                                         $list .= ",";
 420                                 }
 421                         } else {
 422                                 $first = false;
 423                         }
 424                         if ( $mode == LIST_AND || $mode == LIST_SET ) {
 425                                 $list .= "$field=";
 426                         }
 427                         if ( !is_numeric( $value ) ) {
 428                                 $list .= "'" . wfStrencode( $value ) . "'";
 429                         } else {
 430                                 $list .= $value;
 431                         }
 432                 }
 433                 return $list;
 434         }
 435
 436         function selectDB( $db )
 437         {
 438                 $this->mDBname = $db;
 439                 mysql_select_db( $db, $this->mConn );
 440         }
 441
 442         function startTimer( $timeout )
 443         {
 444                 global $IP;
 445
 446                 $tid = mysql_thread_id( $this->mConn );
 447                 exec( "php $IP/killthread.php $timeout $tid &>/dev/null &" );
 448         }
 449
 450         function stopTimer()
 451         {
 452         }
 453
 454 }
 455
 456 #------------------------------------------------------------------------------
 457 # Global functions
 458 #------------------------------------------------------------------------------
 459
 460 /* Standard fail function, called by default when a connection cannot be established
 461    Displays the file cache if possible */
 462 function wfEmergencyAbort( &$conn ) {
 463         global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding, $wgSiteNotice, $wgOutputEncoding;
 464
 465         if( !headers_sent() ) {
 466                 header( "HTTP/1.0 500 Internal Server Error" );
 467                 header( "Content-type: text/html; charset=$wgOutputEncoding" );
 468                 /* Don't cache error pages!  They cause no end of trouble... */
 469                 header( "Cache-control: none" );
 470                 header( "Pragma: nocache" );
 471         }
 472         $msg = $wgSiteNotice;
 473         if($msg == "") $msg = wfMsgNoDB( "noconnect" );
 474         $text = $msg;
 475
 476         if($wgUseFileCache) {
 477                 if($wgTitle) {
 478                         $t =& $wgTitle;
 479                 } else {
 480                         if($title) {
 481                                 $t = Title::newFromURL( $title );
 482                         } elseif (@$_REQUEST['search']) {
 483                                 $search = $_REQUEST['search'];
 484                                 echo wfMsgNoDB( "searchdisabled" );
 485                                 echo wfMsgNoDB( "googlesearch", htmlspecialchars( $search ), $wgInputEncoding );
 486                                 wfAbruptExit();
 487                         } else {
 488                                 $t = Title::newFromText( wfMsgNoDB( "mainpage" ) );
 489                         }
 490                 }
 491
 492                 $cache = new CacheManager( $t );
 493                 if( $cache->isFileCached() ) {
 494                         $msg = "<p style='color: red'><b>$msg<br />\n" .
 495                                 wfMsgNoDB( "cachederror" ) . "</b></p>\n";
 496
 497                         $tag = "<div id='article'>";
 498                         $text = str_replace(
 499                                 $tag,
 500                                 $tag . $msg,
 501                                 $cache->fetchPageText() );
 502                 }
 503         }
 504
 505         echo $text;
 506         wfAbruptExit();
 507 }
 508
 509 function wfStrencode( $s )
 510 {
 511         return addslashes( $s );
 512 }
 513
 514 # Ideally we'd be using actual time fields in the db
 515 function wfTimestamp2Unix( $ts ) {
 516         return gmmktime( ( (int)substr( $ts, 8, 2) ),
 517                   (int)substr( $ts, 10, 2 ), (int)substr( $ts, 12, 2 ),
 518                   (int)substr( $ts, 4, 2 ), (int)substr( $ts, 6, 2 ),
 519                   (int)substr( $ts, 0, 4 ) );
 520 }
 521
 522 function wfUnix2Timestamp( $unixtime ) {
 523         return gmdate( "YmdHis", $unixtime );
 524 }
 525
 526 function wfTimestampNow() {
 527         # return NOW
 528         return gmdate( "YmdHis" );
 529 }
 530
 531 # Sorting hack for MySQL 3, which doesn't use index sorts for DESC
 532 function wfInvertTimestamp( $ts ) {
 533         return strtr(
 534                 $ts,
 535                 "0123456789",
 536                 "9876543210"
 537         );
 538 }
 539
 540 function wfLimitResult( $limit, $offset ) {
 541         return " LIMIT ".(is_numeric($offset)?"{$offset},":"")."{$limit} ";
 542 }
 543
 544 ?>