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                                 wfDebug("SQL ERROR: " . $error . "\n");
 189                                 if ( $wgCommandLineMode ) {
 190                                         wfDebugDieBacktrace( "A database error has occurred\n" .
 191                                           "Query: $sql\n" .
 192                                           "Function: $fname\n" .
 193                                           "Error: $errno $error\n"
 194                                         );
 195                                 } elseif ( $this->mOut ) {
 196                                         // this calls wfAbruptExit()
 197                                         $this->mOut->databaseError( $fname, $sql, $error, $errno );
 198                                 }
 199                         }
 200                 }
 201
 202                 if ( $wgProfiling ) {
 203                         wfProfileOut( $profName );
 204                 }
 205                 return $ret;
 206         }
 207
 208         function freeResult( $res ) {
 209                 if ( !@mysql_free_result( $res ) ) {
 210                         wfDebugDieBacktrace( "Unable to free MySQL result\n" );
 211                 }
 212         }
 213         function fetchObject( $res ) {
 214                 @$row = mysql_fetch_object( $res );
 215                 # FIXME: HACK HACK HACK HACK debug
 216                 if( mysql_errno() ) {
 217                         wfDebugDieBacktrace( "SQL error: " . htmlspecialchars( mysql_error() ) );
 218                 }
 219                 return $row;
 220         }
 221
 222         function fetchRow( $res ) {
 223                 @$row = mysql_fetch_array( $res );
 224                 if (mysql_errno() ) {
 225                         wfDebugDieBacktrace( "SQL error: " . htmlspecialchars( mysql_error() ) );
 226                 }
 227                 return $row;
 228         }
 229
 230         function numRows( $res ) {
 231                 @$n = mysql_num_rows( $res );
 232                 if( mysql_errno() ) {
 233                         wfDebugDieBacktrace( "SQL error: " . htmlspecialchars( mysql_error() ) );
 234                 }
 235                 return $n;
 236         }
 237         function numFields( $res ) { return mysql_num_fields( $res ); }
 238         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 239         function insertId() { return mysql_insert_id( $this->mConn ); }
 240         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 241         function lastErrno() { return mysql_errno(); }
 242         function lastError() { return mysql_error(); }
 243         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 244
 245         # Simple UPDATE wrapper
 246         # Usually aborts on failure
 247         # If errors are explicitly ignored, returns success
 248         function set( $table, $var, $value, $cond, $fname = "Database::set" )
 249         {
 250                 $sql = "UPDATE $table SET $var = '" .
 251                   wfStrencode( $value ) . "' WHERE ($cond)";
 252                 return !!$this->query( $sql, DB_WRITE, $fname );
 253         }
 254
 255         # Simple SELECT wrapper, returns a single field, input must be encoded
 256         # Usually aborts on failure
 257         # If errors are explicitly ignored, returns FALSE on failure
 258         function get( $table, $var, $cond, $fname = "Database::get" )
 259         {
 260                 $sql = "SELECT $var FROM $table WHERE ($cond)";
 261                 $result = $this->query( $sql, DB_READ, $fname );
 262
 263                 $ret = "";
 264                 if ( mysql_num_rows( $result ) > 0 ) {
 265                         $s = mysql_fetch_object( $result );
 266                         $ret = $s->$var;
 267                         mysql_free_result( $result );
 268                 }
 269                 return $ret;
 270         }
 271
 272         # More complex SELECT wrapper, single row only
 273         # Aborts or returns FALSE on error
 274         # Takes an array of selected variables, and a condition map, which is ANDed
 275         # e.g. getArray( "cur", array( "cur_id" ), array( "cur_namespace" => 0, "cur_title" => "Astronomy" ) )
 276         #   would return an object where $obj->cur_id is the ID of the Astronomy article
 277         function getArray( $table, $vars, $conds, $fname = "Database::getArray" )
 278         {
 279                 $vars = implode( ",", $vars );
 280                 if ( $conds !== false ) {
 281                         $where = Database::makeList( $conds, LIST_AND );
 282                         $sql = "SELECT $vars FROM $table WHERE $where LIMIT 1";
 283                 } else {
 284                         $sql = "SELECT $vars FROM $table LIMIT 1";
 285                 }
 286                 $res = $this->query( $sql, $fname );
 287                 if ( $res === false || !$this->numRows( $res ) ) {
 288                         return false;
 289                 }
 290                 $obj = $this->fetchObject( $res );
 291                 $this->freeResult( $res );
 292                 return $obj;
 293         }
 294
 295         # Removes most variables from an SQL query and replaces them with X or N for numbers.
 296         # It's only slightly flawed. Don't use for anything important.
 297         /* static */ function generalizeSQL( $sql )
 298         {
 299                 # This does the same as the regexp below would do, but in such a way
 300                 # as to avoid crashing php on some large strings.
 301                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
 302
 303                 $sql = str_replace ( "\\\\", "", $sql);
 304                 $sql = str_replace ( "\\'", "", $sql);
 305                 $sql = str_replace ( "\\\"", "", $sql);
 306                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
 307                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
 308
 309                 # All newlines, tabs, etc replaced by single space
 310                 $sql = preg_replace ( "/\s+/", " ", $sql);
 311
 312                 # All numbers => N
 313                 $sql = preg_replace ('/-?[0-9]+/s', "N", $sql);
 314
 315                 return $sql;
 316         }
 317
 318         # Determines whether a field exists in a table
 319         # Usually aborts on failure
 320         # If errors are explicitly ignored, returns NULL on failure
 321         function fieldExists( $table, $field, $fname = "Database::fieldExists" )
 322         {
 323                 $res = $this->query( "DESCRIBE $table", DB_READ, $fname );
 324                 if ( !$res ) {
 325                         return NULL;
 326                 }
 327
 328                 $found = false;
 329
 330                 while ( $row = $this->fetchObject( $res ) ) {
 331                         if ( $row->Field == $field ) {
 332                                 $found = true;
 333                                 break;
 334                         }
 335                 }
 336                 return $found;
 337         }
 338
 339         # Determines whether an index exists
 340         # Usually aborts on failure
 341         # If errors are explicitly ignored, returns NULL on failure
 342         function indexExists( $table, $index, $fname = "Database::indexExists" )
 343         {
 344                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 345                 # SHOW INDEX should work for 3.x and up:
 346                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 347                 $sql = "SHOW INDEX FROM $table";
 348                 $res = $this->query( $sql, DB_READ, $fname );
 349                 if ( !$res ) {
 350                         return NULL;
 351                 }
 352
 353                 $found = false;
 354
 355                 while ( $row = $this->fetchObject( $res ) ) {
 356                         if ( $row->Key_name == $index ) {
 357                                 $found = true;
 358                                 break;
 359                         }
 360                 }
 361                 return $found;
 362         }
 363
 364         function tableExists( $table )
 365         {
 366                 $old = $this->mIgnoreErrors;
 367                 $this->mIgnoreErrors = true;
 368                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
 369                 $this->mIgnoreErrors = $old;
 370                 if( $res ) {
 371                         $this->freeResult( $res );
 372                         return true;
 373                 } else {
 374                         return false;
 375                 }
 376         }
 377
 378         function fieldInfo( $table, $field )
 379         {
 380                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
 381                 $n = mysql_num_fields( $res );
 382                 for( $i = 0; $i < $n; $i++ ) {
 383                         $meta = mysql_fetch_field( $res, $i );
 384                         if( $field == $meta->name ) {
 385                                 return $meta;
 386                         }
 387                 }
 388                 return false;
 389         }
 390
 391         # INSERT wrapper, inserts an array into a table
 392         # Keys are field names, values are values
 393         # Usually aborts on failure
 394         # If errors are explicitly ignored, returns success
 395         function insertArray( $table, $a, $fname = "Database::insertArray" )
 396         {
 397                 $sql1 = "INSERT INTO $table (";
 398                 $sql2 = "VALUES (" . Database::makeList( $a );
 399                 $first = true;
 400                 foreach ( $a as $field => $value ) {
 401                         if ( !$first ) {
 402                                 $sql1 .= ",";
 403                         }
 404                         $first = false;
 405                         $sql1 .= $field;
 406                 }
 407                 $sql = "$sql1) $sql2)";
 408                 return !!$this->query( $sql, $fname );
 409         }
 410
 411         # A cross between insertArray and getArray, takes a condition array and a SET array
 412         function updateArray( $table, $values, $conds, $fname = "Database::updateArray" )
 413         {
 414                 $sql = "UPDATE $table SET " . $this->makeList( $values, LIST_SET );
 415                 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
 416                 $this->query( $sql, $fname );
 417         }
 418
 419         # Makes a wfStrencoded list from an array
 420         # $mode: LIST_COMMA - comma separated, no field names
 421         #        LIST_AND   - ANDed WHERE clause (without the WHERE)
 422         #        LIST_SET   - comma separated with field names, like a SET clause
 423         /* static */ function makeList( $a, $mode = LIST_COMMA )
 424         {
 425                 $first = true;
 426                 $list = "";
 427                 foreach ( $a as $field => $value ) {
 428                         if ( !$first ) {
 429                                 if ( $mode == LIST_AND ) {
 430                                         $list .= " AND ";
 431                                 } else {
 432                                         $list .= ",";
 433                                 }
 434                         } else {
 435                                 $first = false;
 436                         }
 437                         if ( $mode == LIST_AND || $mode == LIST_SET ) {
 438                                 $list .= "$field=";
 439                         }
 440                         if ( !is_numeric( $value ) ) {
 441                                 $list .= "'" . wfStrencode( $value ) . "'";
 442                         } else {
 443                                 $list .= $value;
 444                         }
 445                 }
 446                 return $list;
 447         }
 448
 449         function selectDB( $db )
 450         {
 451                 $this->mDBname = $db;
 452                 mysql_select_db( $db, $this->mConn );
 453         }
 454
 455         function startTimer( $timeout )
 456         {
 457                 global $IP;
 458
 459                 $tid = mysql_thread_id( $this->mConn );
 460                 exec( "php $IP/killthread.php $timeout $tid &>/dev/null &" );
 461         }
 462
 463         function stopTimer()
 464         {
 465         }
 466
 467 }
 468
 469 #------------------------------------------------------------------------------
 470 # Global functions
 471 #------------------------------------------------------------------------------
 472
 473 /* Standard fail function, called by default when a connection cannot be established
 474    Displays the file cache if possible */
 475 function wfEmergencyAbort( &$conn, $error ) {
 476         global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding, $wgSiteNotice, $wgOutputEncoding;
 477
 478         if( !headers_sent() ) {
 479                 header( "HTTP/1.0 500 Internal Server Error" );
 480                 header( "Content-type: text/html; charset=$wgOutputEncoding" );
 481                 /* Don't cache error pages!  They cause no end of trouble... */
 482                 header( "Cache-control: none" );
 483                 header( "Pragma: nocache" );
 484         }
 485         $msg = $wgSiteNotice;
 486         if($msg == "") $msg = wfMsgNoDB( "noconnect", $error );
 487         $text = $msg;
 488
 489         if($wgUseFileCache) {
 490                 if($wgTitle) {
 491                         $t =& $wgTitle;
 492                 } else {
 493                         if($title) {
 494                                 $t = Title::newFromURL( $title );
 495                         } elseif (@$_REQUEST['search']) {
 496                                 $search = $_REQUEST['search'];
 497                                 echo wfMsgNoDB( "searchdisabled" );
 498                                 echo wfMsgNoDB( "googlesearch", htmlspecialchars( $search ), $wgInputEncoding );
 499                                 wfAbruptExit();
 500                         } else {
 501                                 $t = Title::newFromText( wfMsgNoDB( "mainpage" ) );
 502                         }
 503                 }
 504
 505                 $cache = new CacheManager( $t );
 506                 if( $cache->isFileCached() ) {
 507                         $msg = "<p style='color: red'><b>$msg<br />\n" .
 508                                 wfMsgNoDB( "cachederror" ) . "</b></p>\n";
 509
 510                         $tag = "<div id='article'>";
 511                         $text = str_replace(
 512                                 $tag,
 513                                 $tag . $msg,
 514                                 $cache->fetchPageText() );
 515                 }
 516         }
 517
 518         echo $text;
 519         wfAbruptExit();
 520 }
 521
 522 function wfStrencode( $s )
 523 {
 524         return addslashes( $s );
 525 }
 526
 527 # Ideally we'd be using actual time fields in the db
 528 function wfTimestamp2Unix( $ts ) {
 529         return gmmktime( ( (int)substr( $ts, 8, 2) ),
 530                   (int)substr( $ts, 10, 2 ), (int)substr( $ts, 12, 2 ),
 531                   (int)substr( $ts, 4, 2 ), (int)substr( $ts, 6, 2 ),
 532                   (int)substr( $ts, 0, 4 ) );
 533 }
 534
 535 function wfUnix2Timestamp( $unixtime ) {
 536         return gmdate( "YmdHis", $unixtime );
 537 }
 538
 539 function wfTimestampNow() {
 540         # return NOW
 541         return gmdate( "YmdHis" );
 542 }
 543
 544 # Sorting hack for MySQL 3, which doesn't use index sorts for DESC
 545 function wfInvertTimestamp( $ts ) {
 546         return strtr(
 547                 $ts,
 548                 "0123456789",
 549                 "9876543210"
 550         );
 551 }
 552
 553 function wfLimitResult( $limit, $offset ) {
 554         return " LIMIT ".(is_numeric($offset)?"{$offset},":"")."{$limit} ";
 555 }
 556
 557 ?>