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( "LIST_COMMA", 0 );
   9 define( "LIST_AND", 1 );
  10 define( "LIST_SET", 2 );
  11
  12 class Database {
  13
  14 #------------------------------------------------------------------------------
  15 # Variables
  16 #------------------------------------------------------------------------------
  17         /* private */ var $mLastQuery = "";
  18         /* private */ var $mBufferResults = true;
  19         /* private */ var $mIgnoreErrors = false;
  20
  21         /* private */ var $mServer, $mUser, $mPassword, $mConn, $mDBname;
  22         /* private */ var $mOut, $mDebug, $mOpened = false;
  23
  24         /* private */ var $mFailFunction;
  25
  26 #------------------------------------------------------------------------------
  27 # Accessors
  28 #------------------------------------------------------------------------------
  29         # Set functions
  30         # These set a variable and return the previous state
  31
  32         # Fail function, takes a Database as a parameter
  33         # Set to false for default, 1 for ignore errors
  34         function setFailFunction( $function ) { return wfSetVar( $this->mFailFunction, $function ); }
  35
  36         # Output page, used for reporting errors
  37         # FALSE means discard output
  38         function &setOutputPage( &$out ) { $this->mOut =& $out; }
  39
  40         # Boolean, controls output of large amounts of debug information
  41         function setDebug( $debug ) { return wfSetVar( $this->mDebug, $debug ); }
  42
  43         # Turns buffering of SQL result sets on (true) or off (false). Default is
  44         # "on" and it should not be changed without good reasons.
  45         function setBufferResults( $buffer ) { return wfSetVar( $this->mBufferResults, $buffer ); }
  46
  47         # Turns on (false) or off (true) the automatic generation and sending
  48         # of a "we're sorry, but there has been a database error" page on
  49         # database errors. Default is on (false). When turned off, the
  50         # code should use wfLastErrno() and wfLastError() to handle the
  51         # situation as appropriate.
  52         function setIgnoreErrors( $ignoreErrors ) { return wfSetVar( $this->mIgnoreErrors, $ignoreErrors ); }
  53
  54         # Get functions
  55
  56         function lastQuery() { return $this->mLastQuery; }
  57         function isOpen() { return $this->mOpened; }
  58
  59 #------------------------------------------------------------------------------
  60 # Other functions
  61 #------------------------------------------------------------------------------
  62
  63         function Database()
  64         {
  65                 global $wgOut;
  66                 # Can't get a reference if it hasn't been set yet
  67                 if ( !isset( $wgOut ) ) {
  68                         $wgOut = NULL;
  69                 }
  70                 $this->mOut =& $wgOut;
  71
  72         }
  73
  74         /* static */ function newFromParams( $server, $user, $password, $dbName,
  75                 $failFunction = false, $debug = false, $bufferResults = true, $ignoreErrors = false )
  76         {
  77                 $db = new Database;
  78                 $db->mFailFunction = $failFunction;
  79                 $db->mIgnoreErrors = $ignoreErrors;
  80                 $db->mDebug = $debug;
  81                 $db->mBufferResults = $bufferResults;
  82                 $db->open( $server, $user, $password, $dbName );
  83                 return $db;
  84         }
  85
  86         # Usually aborts on failure
  87         # If the failFunction is set to a non-zero integer, returns success
  88         function open( $server, $user, $password, $dbName )
  89         {
  90                 global $wgEmergencyContact;
  91
  92                 # Test for missing mysql.so
  93                 # Otherwise we get a suppressed fatal error, which is very hard to track down
  94                 if ( !function_exists( 'mysql_connect' ) ) {
  95                         die( "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
  96                 }
  97
  98                 $this->close();
  99                 $this->mServer = $server;
 100                 $this->mUser = $user;
 101                 $this->mPassword = $password;
 102                 $this->mDBname = $dbName;
 103
 104                 $success = false;
 105
 106                 @$this->mConn = mysql_connect( $server, $user, $password );
 107                 if ( $dbName != "" ) {
 108                         if ( $this->mConn !== false ) {
 109                                 $success = @mysql_select_db( $dbName, $this->mConn );
 110                                 if ( !$success ) {
 111                                         wfDebug( "Error selecting database \"$dbName\": " . $this->lastError() . "\n" );
 112                                 }
 113                         } else {
 114                                 wfDebug( "DB connection error\n" );
 115                                 wfDebug( "Server: $server, User: $user, Password: " .
 116                                         substr( $password, 0, 3 ) . "...\n" );
 117                                 $success = false;
 118                         }
 119                 } else {
 120                         # Delay USE query
 121                         $success = !!$this->mConn;
 122                 }
 123
 124                 if ( !$success ) {
 125                         $this->reportConnectionError();
 126                         $this->close();
 127                 }
 128                 $this->mOpened = $success;
 129                 return $success;
 130         }
 131
 132         # Closes a database connection, if it is open
 133         # Returns success, true if already closed
 134         function close()
 135         {
 136                 $this->mOpened = false;
 137                 if ( $this->mConn ) {
 138                         return mysql_close( $this->mConn );
 139                 } else {
 140                         return true;
 141                 }
 142         }
 143
 144         /* private */ function reportConnectionError( $msg = "")
 145         {
 146                 if ( $this->mFailFunction ) {
 147                         if ( !is_int( $this->mFailFunction ) ) {
 148                                 $ff = $this->mFailFunction;
 149                                 $ff( $this, mysql_error() );
 150                         }
 151                 } else {
 152                         wfEmergencyAbort( $this, mysql_error() );
 153                 }
 154         }
 155
 156         # Usually aborts on failure
 157         # If errors are explicitly ignored, returns success
 158         function query( $sql, $fname = "" )
 159         {
 160                 global $wgProfiling, $wgCommandLineMode;
 161
 162                 if ( $wgProfiling ) {
 163                         # generalizeSQL will probably cut down the query to reasonable
 164                         # logging size most of the time. The substr is really just a sanity check.
 165                         $profName = "query: " . substr( Database::generalizeSQL( $sql ), 0, 255 );
 166                         wfProfileIn( $profName );
 167                 }
 168
 169                 $this->mLastQuery = $sql;
 170
 171                 if ( $this->mDebug ) {
 172                         $sqlx = substr( $sql, 0, 500 );
 173                         $sqlx = wordwrap(strtr($sqlx,"\t\n","  "));
 174                         wfDebug( "SQL: $sqlx\n" );
 175                 }
 176                 if( $this->mBufferResults ) {
 177                         $ret = mysql_query( $sql, $this->mConn );
 178                 } else {
 179                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 180                 }
 181
 182                 if ( false === $ret ) {
 183                         $error = mysql_error( $this->mConn );
 184                         $errno = mysql_errno( $this->mConn );
 185                         if( $this->mIgnoreErrors ) {
 186                                 wfDebug("SQL ERROR (ignored): " . $error . "\n");
 187                         } else {
 188                                 $sql1line = str_replace( "\n", "\\n", $sql );
 189                                 wfLogDBError("$errno\t$error\t$sql1line\n");
 190                                 wfDebug("SQL ERROR: " . $error . "\n");
 191                                 if ( $wgCommandLineMode ) {
 192                                         wfDebugDieBacktrace( "A database error has occurred\n" .
 193                                           "Query: $sql\n" .
 194                                           "Function: $fname\n" .
 195                                           "Error: $errno $error\n"
 196                                         );
 197                                 } elseif ( $this->mOut ) {
 198                                         // this calls wfAbruptExit()
 199                                         $this->mOut->databaseError( $fname, $sql, $error, $errno );
 200                                 }
 201                         }
 202                 }
 203
 204                 if ( $wgProfiling ) {
 205                         wfProfileOut( $profName );
 206                 }
 207                 return $ret;
 208         }
 209
 210         function freeResult( $res ) {
 211                 if ( !@mysql_free_result( $res ) ) {
 212                         wfDebugDieBacktrace( "Unable to free MySQL result\n" );
 213                 }
 214         }
 215         function fetchObject( $res ) {
 216                 @$row = mysql_fetch_object( $res );
 217                 # FIXME: HACK HACK HACK HACK debug
 218                 if( mysql_errno() ) {
 219                         wfDebugDieBacktrace( "SQL error: " . htmlspecialchars( mysql_error() ) );
 220                 }
 221                 return $row;
 222         }
 223
 224         function fetchRow( $res ) {
 225                 @$row = mysql_fetch_array( $res );
 226                 if (mysql_errno() ) {
 227                         wfDebugDieBacktrace( "SQL error: " . htmlspecialchars( mysql_error() ) );
 228                 }
 229                 return $row;
 230         }
 231
 232         function numRows( $res ) {
 233                 @$n = mysql_num_rows( $res );
 234                 if( mysql_errno() ) {
 235                         wfDebugDieBacktrace( "SQL error: " . htmlspecialchars( mysql_error() ) );
 236                 }
 237                 return $n;
 238         }
 239         function numFields( $res ) { return mysql_num_fields( $res ); }
 240         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 241         function insertId() { return mysql_insert_id( $this->mConn ); }
 242         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 243         function lastErrno() { return mysql_errno(); }
 244         function lastError() { return mysql_error(); }
 245         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 246
 247         # Simple UPDATE wrapper
 248         # Usually aborts on failure
 249         # If errors are explicitly ignored, returns success
 250         function set( $table, $var, $value, $cond, $fname = "Database::set" )
 251         {
 252                 $sql = "UPDATE $table SET $var = '" .
 253                   wfStrencode( $value ) . "' WHERE ($cond)";
 254                 return !!$this->query( $sql, DB_WRITE, $fname );
 255         }
 256
 257         # Simple SELECT wrapper, returns a single field, input must be encoded
 258         # Usually aborts on failure
 259         # If errors are explicitly ignored, returns FALSE on failure
 260         function get( $table, $var, $cond, $fname = "Database::get" )
 261         {
 262                 $sql = "SELECT $var FROM $table WHERE ($cond)";
 263                 $result = $this->query( $sql, DB_READ, $fname );
 264
 265                 $ret = "";
 266                 if ( mysql_num_rows( $result ) > 0 ) {
 267                         $s = mysql_fetch_object( $result );
 268                         $ret = $s->$var;
 269                         mysql_free_result( $result );
 270                 }
 271                 return $ret;
 272         }
 273
 274         # More complex SELECT wrapper, single row only
 275         # Aborts or returns FALSE on error
 276         # Takes an array of selected variables, and a condition map, which is ANDed
 277         # e.g. getArray( "cur", array( "cur_id" ), array( "cur_namespace" => 0, "cur_title" => "Astronomy" ) )
 278         #   would return an object where $obj->cur_id is the ID of the Astronomy article
 279         function getArray( $table, $vars, $conds, $fname = "Database::getArray" )
 280         {
 281                 $vars = implode( ",", $vars );
 282                 if ( $conds !== false ) {
 283                         $where = Database::makeList( $conds, LIST_AND );
 284                         $sql = "SELECT $vars FROM $table WHERE $where LIMIT 1";
 285                 } else {
 286                         $sql = "SELECT $vars FROM $table LIMIT 1";
 287                 }
 288                 $res = $this->query( $sql, $fname );
 289                 if ( $res === false || !$this->numRows( $res ) ) {
 290                         return false;
 291                 }
 292                 $obj = $this->fetchObject( $res );
 293                 $this->freeResult( $res );
 294                 return $obj;
 295         }
 296
 297         # Removes most variables from an SQL query and replaces them with X or N for numbers.
 298         # It's only slightly flawed. Don't use for anything important.
 299         /* static */ function generalizeSQL( $sql )
 300         {
 301                 # This does the same as the regexp below would do, but in such a way
 302                 # as to avoid crashing php on some large strings.
 303                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
 304
 305                 $sql = str_replace ( "\\\\", "", $sql);
 306                 $sql = str_replace ( "\\'", "", $sql);
 307                 $sql = str_replace ( "\\\"", "", $sql);
 308                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
 309                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
 310
 311                 # All newlines, tabs, etc replaced by single space
 312                 $sql = preg_replace ( "/\s+/", " ", $sql);
 313
 314                 # All numbers => N
 315                 $sql = preg_replace ('/-?[0-9]+/s', "N", $sql);
 316
 317                 return $sql;
 318         }
 319
 320         # Determines whether a field exists in a table
 321         # Usually aborts on failure
 322         # If errors are explicitly ignored, returns NULL on failure
 323         function fieldExists( $table, $field, $fname = "Database::fieldExists" )
 324         {
 325                 $res = $this->query( "DESCRIBE $table", DB_READ, $fname );
 326                 if ( !$res ) {
 327                         return NULL;
 328                 }
 329
 330                 $found = false;
 331
 332                 while ( $row = $this->fetchObject( $res ) ) {
 333                         if ( $row->Field == $field ) {
 334                                 $found = true;
 335                                 break;
 336                         }
 337                 }
 338                 return $found;
 339         }
 340
 341         # Determines whether an index exists
 342         # Usually aborts on failure
 343         # If errors are explicitly ignored, returns NULL on failure
 344         function indexExists( $table, $index, $fname = "Database::indexExists" )
 345         {
 346                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 347                 # SHOW INDEX should work for 3.x and up:
 348                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 349                 $sql = "SHOW INDEX FROM $table";
 350                 $res = $this->query( $sql, DB_READ, $fname );
 351                 if ( !$res ) {
 352                         return NULL;
 353                 }
 354
 355                 $found = false;
 356
 357                 while ( $row = $this->fetchObject( $res ) ) {
 358                         if ( $row->Key_name == $index ) {
 359                                 $found = true;
 360                                 break;
 361                         }
 362                 }
 363                 return $found;
 364         }
 365
 366         function tableExists( $table )
 367         {
 368                 $old = $this->mIgnoreErrors;
 369                 $this->mIgnoreErrors = true;
 370                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
 371                 $this->mIgnoreErrors = $old;
 372                 if( $res ) {
 373                         $this->freeResult( $res );
 374                         return true;
 375                 } else {
 376                         return false;
 377                 }
 378         }
 379
 380         function fieldInfo( $table, $field )
 381         {
 382                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
 383                 $n = mysql_num_fields( $res );
 384                 for( $i = 0; $i < $n; $i++ ) {
 385                         $meta = mysql_fetch_field( $res, $i );
 386                         if( $field == $meta->name ) {
 387                                 return $meta;
 388                         }
 389                 }
 390                 return false;
 391         }
 392
 393         # INSERT wrapper, inserts an array into a table
 394         # Keys are field names, values are values
 395         # Usually aborts on failure
 396         # If errors are explicitly ignored, returns success
 397         function insertArray( $table, $a, $fname = "Database::insertArray" )
 398         {
 399                 $sql1 = "INSERT INTO $table (";
 400                 $sql2 = "VALUES (" . Database::makeList( $a );
 401                 $first = true;
 402                 foreach ( $a as $field => $value ) {
 403                         if ( !$first ) {
 404                                 $sql1 .= ",";
 405                         }
 406                         $first = false;
 407                         $sql1 .= $field;
 408                 }
 409                 $sql = "$sql1) $sql2)";
 410                 return !!$this->query( $sql, $fname );
 411         }
 412
 413         # A cross between insertArray and getArray, takes a condition array and a SET array
 414         function updateArray( $table, $values, $conds, $fname = "Database::updateArray" )
 415         {
 416                 $sql = "UPDATE $table SET " . $this->makeList( $values, LIST_SET );
 417                 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
 418                 $this->query( $sql, $fname );
 419         }
 420
 421         # Makes a wfStrencoded list from an array
 422         # $mode: LIST_COMMA - comma separated, no field names
 423         #        LIST_AND   - ANDed WHERE clause (without the WHERE)
 424         #        LIST_SET   - comma separated with field names, like a SET clause
 425         /* static */ function makeList( $a, $mode = LIST_COMMA )
 426         {
 427                 $first = true;
 428                 $list = "";
 429                 foreach ( $a as $field => $value ) {
 430                         if ( !$first ) {
 431                                 if ( $mode == LIST_AND ) {
 432                                         $list .= " AND ";
 433                                 } else {
 434                                         $list .= ",";
 435                                 }
 436                         } else {
 437                                 $first = false;
 438                         }
 439                         if ( $mode == LIST_AND || $mode == LIST_SET ) {
 440                                 $list .= "$field=";
 441                         }
 442                         if ( !is_numeric( $value ) ) {
 443                                 $list .= "'" . wfStrencode( $value ) . "'";
 444                         } else {
 445                                 $list .= $value;
 446                         }
 447                 }
 448                 return $list;
 449         }
 450
 451         function selectDB( $db )
 452         {
 453                 $this->mDBname = $db;
 454                 mysql_select_db( $db, $this->mConn );
 455         }
 456
 457         function startTimer( $timeout )
 458         {
 459                 global $IP;
 460
 461                 $tid = mysql_thread_id( $this->mConn );
 462                 exec( "php $IP/killthread.php $timeout $tid &>/dev/null &" );
 463         }
 464
 465         function stopTimer()
 466         {
 467         }
 468 }
 469
 470 #------------------------------------------------------------------------------
 471 # Global functions
 472 #------------------------------------------------------------------------------
 473
 474 /* Standard fail function, called by default when a connection cannot be established
 475    Displays the file cache if possible */
 476 function wfEmergencyAbort( &$conn, $error ) {
 477         global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding, $wgSiteNotice, $wgOutputEncoding;
 478
 479         if( !headers_sent() ) {
 480                 header( "HTTP/1.0 500 Internal Server Error" );
 481                 header( "Content-type: text/html; charset=$wgOutputEncoding" );
 482                 /* Don't cache error pages!  They cause no end of trouble... */
 483                 header( "Cache-control: none" );
 484                 header( "Pragma: nocache" );
 485         }
 486         $msg = $wgSiteNotice;
 487         if($msg == "") $msg = wfMsgNoDB( "noconnect", $error );
 488         $text = $msg;
 489
 490         if($wgUseFileCache) {
 491                 if($wgTitle) {
 492                         $t =& $wgTitle;
 493                 } else {
 494                         if($title) {
 495                                 $t = Title::newFromURL( $title );
 496                         } elseif (@$_REQUEST['search']) {
 497                                 $search = $_REQUEST['search'];
 498                                 echo wfMsgNoDB( "searchdisabled" );
 499                                 echo wfMsgNoDB( "googlesearch", htmlspecialchars( $search ), $wgInputEncoding );
 500                                 wfAbruptExit();
 501                         } else {
 502                                 $t = Title::newFromText( wfMsgNoDB( "mainpage" ) );
 503                         }
 504                 }
 505
 506                 $cache = new CacheManager( $t );
 507                 if( $cache->isFileCached() ) {
 508                         $msg = "<p style='color: red'><b>$msg<br />\n" .
 509                                 wfMsgNoDB( "cachederror" ) . "</b></p>\n";
 510
 511                         $tag = "<div id='article'>";
 512                         $text = str_replace(
 513                                 $tag,
 514                                 $tag . $msg,
 515                                 $cache->fetchPageText() );
 516                 }
 517         }
 518
 519         echo $text;
 520         wfAbruptExit();
 521 }
 522
 523 function wfStrencode( $s )
 524 {
 525         return addslashes( $s );
 526 }
 527
 528 function wfLimitResult( $limit, $offset ) {
 529         return " LIMIT ".(is_numeric($offset)?"{$offset},":"")."{$limit} ";
 530 }
 531
 532
 533 ?>