includes/db/DatabaseSqlite.php

   1 <?php
   2 /**
   3  * This is the SQLite database abstraction layer.
   4  * See maintenance/sqlite/README for development notes and other specific information
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  * @ingroup Database
  23  */
  24
  25 /**
  26  * @ingroup Database
  27  */
  28 class DatabaseSqlite extends DatabaseBase {
  29         /** @var bool Whether full text is enabled */
  30         private static $fulltextEnabled = null;
  31
  32         /** @var string File name for SQLite database file */
  33         public $mDatabaseFile;
  34
  35         /** @var int The number of rows affected as an integer */
  36         protected $mAffectedRows;
  37
  38         /** @var resource */
  39         protected $mLastResult;
  40
  41         /** @var PDO */
  42         protected $mConn;
  43
  44         /** @var FSLockManager (hopefully on the same server as the DB) */
  45         protected $lockMgr;
  46
  47         function __construct( array $p ) {
  48                 global $wgSharedDB, $wgSQLiteDataDir;
  49
  50                 $this->mDBname = $p['dbname'];
  51                 parent::__construct( $p );
  52                 // parent doesn't open when $user is false, but we can work with $dbName
  53                 if ( $p['dbname'] && !$this->isOpen() ) {
  54                         if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  55                                 if ( $wgSharedDB ) {
  56                                         $this->attachDatabase( $wgSharedDB );
  57                                 }
  58                         }
  59                 }
  60
  61                 $this->lockMgr = new FSLockManager( array( 'lockDirectory' => "$wgSQLiteDataDir/locks" ) );
  62         }
  63
  64         /**
  65          * @return string
  66          */
  67         function getType() {
  68                 return 'sqlite';
  69         }
  70
  71         /**
  72          * @todo Check if it should be true like parent class
  73          *
  74          * @return bool
  75          */
  76         function implicitGroupby() {
  77                 return false;
  78         }
  79
  80         /** Open an SQLite database and return a resource handle to it
  81          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  82          *
  83          * @param string $server
  84          * @param string $user
  85          * @param string $pass
  86          * @param string $dbName
  87          *
  88          * @throws DBConnectionError
  89          * @return PDO
  90          */
  91         function open( $server, $user, $pass, $dbName ) {
  92                 global $wgSQLiteDataDir;
  93
  94                 $this->close();
  95                 $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
  96                 if ( !is_readable( $fileName ) ) {
  97                         $this->mConn = false;
  98                         throw new DBConnectionError( $this, "SQLite database not accessible" );
  99                 }
 100                 $this->openFile( $fileName );
 101
 102                 return $this->mConn;
 103         }
 104
 105         /**
 106          * Opens a database file
 107          *
 108          * @param string $fileName
 109          * @throws DBConnectionError
 110          * @return PDO|bool SQL connection or false if failed
 111          */
 112         function openFile( $fileName ) {
 113                 $err = false;
 114
 115                 $this->mDatabaseFile = $fileName;
 116                 try {
 117                         if ( $this->mFlags & DBO_PERSISTENT ) {
 118                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 119                                         array( PDO::ATTR_PERSISTENT => true ) );
 120                         } else {
 121                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 122                         }
 123                 } catch ( PDOException $e ) {
 124                         $err = $e->getMessage();
 125                 }
 126
 127                 if ( !$this->mConn ) {
 128                         wfDebug( "DB connection error: $err\n" );
 129                         throw new DBConnectionError( $this, $err );
 130                 }
 131
 132                 $this->mOpened = !!$this->mConn;
 133                 if ( $this->mOpened ) {
 134                         # Set error codes only, don't raise exceptions
 135                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 136                         # Enforce LIKE to be case sensitive, just like MySQL
 137                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 138
 139                         return $this->mConn;
 140                 }
 141
 142                 return false;
 143         }
 144
 145         /**
 146          * Does not actually close the connection, just destroys the reference for GC to do its work
 147          * @return bool
 148          */
 149         protected function closeConnection() {
 150                 $this->mConn = null;
 151
 152                 return true;
 153         }
 154
 155         /**
 156          * Generates a database file name. Explicitly public for installer.
 157          * @param string $dir Directory where database resides
 158          * @param string $dbName Database name
 159          * @return string
 160          */
 161         public static function generateFileName( $dir, $dbName ) {
 162                 return "$dir/$dbName.sqlite";
 163         }
 164
 165         /**
 166          * Check if the searchindext table is FTS enabled.
 167          * @return bool False if not enabled.
 168          */
 169         function checkForEnabledSearch() {
 170                 if ( self::$fulltextEnabled === null ) {
 171                         self::$fulltextEnabled = false;
 172                         $table = $this->tableName( 'searchindex' );
 173                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 174                         if ( $res ) {
 175                                 $row = $res->fetchRow();
 176                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 177                         }
 178                 }
 179
 180                 return self::$fulltextEnabled;
 181         }
 182
 183         /**
 184          * Returns version of currently supported SQLite fulltext search module or false if none present.
 185          * @return string
 186          */
 187         static function getFulltextSearchModule() {
 188                 static $cachedResult = null;
 189                 if ( $cachedResult !== null ) {
 190                         return $cachedResult;
 191                 }
 192                 $cachedResult = false;
 193                 $table = 'dummy_search_test';
 194
 195                 $db = new DatabaseSqliteStandalone( ':memory:' );
 196
 197                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 198                         $cachedResult = 'FTS3';
 199                 }
 200                 $db->close();
 201
 202                 return $cachedResult;
 203         }
 204
 205         /**
 206          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 207          * for details.
 208          *
 209          * @param string $name Database name to be used in queries like
 210          *   SELECT foo FROM dbname.table
 211          * @param bool|string $file Database file name. If omitted, will be generated
 212          *   using $name and $wgSQLiteDataDir
 213          * @param string $fname Calling function name
 214          * @return ResultWrapper
 215          */
 216         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 217                 global $wgSQLiteDataDir;
 218                 if ( !$file ) {
 219                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 220                 }
 221                 $file = $this->addQuotes( $file );
 222
 223                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 224         }
 225
 226         /**
 227          * @see DatabaseBase::isWriteQuery()
 228          *
 229          * @param string $sql
 230          * @return bool
 231          */
 232         function isWriteQuery( $sql ) {
 233                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 234         }
 235
 236         /**
 237          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 238          *
 239          * @param string $sql
 240          * @return bool|ResultWrapper
 241          */
 242         protected function doQuery( $sql ) {
 243                 $res = $this->mConn->query( $sql );
 244                 if ( $res === false ) {
 245                         return false;
 246                 } else {
 247                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 248                         $this->mAffectedRows = $r->rowCount();
 249                         $res = new ResultWrapper( $this, $r->fetchAll() );
 250                 }
 251
 252                 return $res;
 253         }
 254
 255         /**
 256          * @param ResultWrapper|mixed $res
 257          */
 258         function freeResult( $res ) {
 259                 if ( $res instanceof ResultWrapper ) {
 260                         $res->result = null;
 261                 } else {
 262                         $res = null;
 263                 }
 264         }
 265
 266         /**
 267          * @param ResultWrapper|array $res
 268          * @return stdClass|bool
 269          */
 270         function fetchObject( $res ) {
 271                 if ( $res instanceof ResultWrapper ) {
 272                         $r =& $res->result;
 273                 } else {
 274                         $r =& $res;
 275                 }
 276
 277                 $cur = current( $r );
 278                 if ( is_array( $cur ) ) {
 279                         next( $r );
 280                         $obj = new stdClass;
 281                         foreach ( $cur as $k => $v ) {
 282                                 if ( !is_numeric( $k ) ) {
 283                                         $obj->$k = $v;
 284                                 }
 285                         }
 286
 287                         return $obj;
 288                 }
 289
 290                 return false;
 291         }
 292
 293         /**
 294          * @param ResultWrapper|mixed $res
 295          * @return array|bool
 296          */
 297         function fetchRow( $res ) {
 298                 if ( $res instanceof ResultWrapper ) {
 299                         $r =& $res->result;
 300                 } else {
 301                         $r =& $res;
 302                 }
 303                 $cur = current( $r );
 304                 if ( is_array( $cur ) ) {
 305                         next( $r );
 306
 307                         return $cur;
 308                 }
 309
 310                 return false;
 311         }
 312
 313         /**
 314          * The PDO::Statement class implements the array interface so count() will work
 315          *
 316          * @param ResultWrapper|array $res
 317          * @return int
 318          */
 319         function numRows( $res ) {
 320                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 321
 322                 return count( $r );
 323         }
 324
 325         /**
 326          * @param ResultWrapper $res
 327          * @return int
 328          */
 329         function numFields( $res ) {
 330                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 331                 if ( is_array( $r ) && count( $r ) > 0 ) {
 332                         // The size of the result array is twice the number of fields. (Bug: 65578)
 333                         return count( $r[0] ) / 2;
 334                 } else {
 335                         // If the result is empty return 0
 336                         return 0;
 337                 }
 338         }
 339
 340         /**
 341          * @param ResultWrapper $res
 342          * @param int $n
 343          * @return bool
 344          */
 345         function fieldName( $res, $n ) {
 346                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 347                 if ( is_array( $r ) ) {
 348                         $keys = array_keys( $r[0] );
 349
 350                         return $keys[$n];
 351                 }
 352
 353                 return false;
 354         }
 355
 356         /**
 357          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 358          *
 359          * @param string $name
 360          * @param string $format
 361          * @return string
 362          */
 363         function tableName( $name, $format = 'quoted' ) {
 364                 // table names starting with sqlite_ are reserved
 365                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 366                         return $name;
 367                 }
 368
 369                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 370         }
 371
 372         /**
 373          * Index names have DB scope
 374          *
 375          * @param string $index
 376          * @return string
 377          */
 378         function indexName( $index ) {
 379                 return $index;
 380         }
 381
 382         /**
 383          * This must be called after nextSequenceVal
 384          *
 385          * @return int
 386          */
 387         function insertId() {
 388                 // PDO::lastInsertId yields a string :(
 389                 return intval( $this->mConn->lastInsertId() );
 390         }
 391
 392         /**
 393          * @param ResultWrapper|array $res
 394          * @param int $row
 395          */
 396         function dataSeek( $res, $row ) {
 397                 if ( $res instanceof ResultWrapper ) {
 398                         $r =& $res->result;
 399                 } else {
 400                         $r =& $res;
 401                 }
 402                 reset( $r );
 403                 if ( $row > 0 ) {
 404                         for ( $i = 0; $i < $row; $i++ ) {
 405                                 next( $r );
 406                         }
 407                 }
 408         }
 409
 410         /**
 411          * @return string
 412          */
 413         function lastError() {
 414                 if ( !is_object( $this->mConn ) ) {
 415                         return "Cannot return last error, no db connection";
 416                 }
 417                 $e = $this->mConn->errorInfo();
 418
 419                 return isset( $e[2] ) ? $e[2] : '';
 420         }
 421
 422         /**
 423          * @return string
 424          */
 425         function lastErrno() {
 426                 if ( !is_object( $this->mConn ) ) {
 427                         return "Cannot return last error, no db connection";
 428                 } else {
 429                         $info = $this->mConn->errorInfo();
 430
 431                         return $info[1];
 432                 }
 433         }
 434
 435         /**
 436          * @return int
 437          */
 438         function affectedRows() {
 439                 return $this->mAffectedRows;
 440         }
 441
 442         /**
 443          * Returns information about an index
 444          * Returns false if the index does not exist
 445          * - if errors are explicitly ignored, returns NULL on failure
 446          *
 447          * @param string $table
 448          * @param string $index
 449          * @param string $fname
 450          * @return array
 451          */
 452         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 453                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 454                 $res = $this->query( $sql, $fname );
 455                 if ( !$res ) {
 456                         return null;
 457                 }
 458                 if ( $res->numRows() == 0 ) {
 459                         return false;
 460                 }
 461                 $info = array();
 462                 foreach ( $res as $row ) {
 463                         $info[] = $row->name;
 464                 }
 465
 466                 return $info;
 467         }
 468
 469         /**
 470          * @param string $table
 471          * @param string $index
 472          * @param string $fname
 473          * @return bool|null
 474          */
 475         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 476                 $row = $this->selectRow( 'sqlite_master', '*',
 477                         array(
 478                                 'type' => 'index',
 479                                 'name' => $this->indexName( $index ),
 480                         ), $fname );
 481                 if ( !$row || !isset( $row->sql ) ) {
 482                         return null;
 483                 }
 484
 485                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 486                 $indexPos = strpos( $row->sql, 'INDEX' );
 487                 if ( $indexPos === false ) {
 488                         return null;
 489                 }
 490                 $firstPart = substr( $row->sql, 0, $indexPos );
 491                 $options = explode( ' ', $firstPart );
 492
 493                 return in_array( 'UNIQUE', $options );
 494         }
 495
 496         /**
 497          * Filter the options used in SELECT statements
 498          *
 499          * @param array $options
 500          * @return array
 501          */
 502         function makeSelectOptions( $options ) {
 503                 foreach ( $options as $k => $v ) {
 504                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 505                                 $options[$k] = '';
 506                         }
 507                 }
 508
 509                 return parent::makeSelectOptions( $options );
 510         }
 511
 512         /**
 513          * @param array $options
 514          * @return string
 515          */
 516         protected function makeUpdateOptionsArray( $options ) {
 517                 $options = parent::makeUpdateOptionsArray( $options );
 518                 $options = self::fixIgnore( $options );
 519
 520                 return $options;
 521         }
 522
 523         /**
 524          * @param array $options
 525          * @return array
 526          */
 527         static function fixIgnore( $options ) {
 528                 # SQLite uses OR IGNORE not just IGNORE
 529                 foreach ( $options as $k => $v ) {
 530                         if ( $v == 'IGNORE' ) {
 531                                 $options[$k] = 'OR IGNORE';
 532                         }
 533                 }
 534
 535                 return $options;
 536         }
 537
 538         /**
 539          * @param array $options
 540          * @return string
 541          */
 542         function makeInsertOptions( $options ) {
 543                 $options = self::fixIgnore( $options );
 544
 545                 return parent::makeInsertOptions( $options );
 546         }
 547
 548         /**
 549          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 550          * @param string $table
 551          * @param array $a
 552          * @param string $fname
 553          * @param array $options
 554          * @return bool
 555          */
 556         function insert( $table, $a, $fname = __METHOD__, $options = array() ) {
 557                 if ( !count( $a ) ) {
 558                         return true;
 559                 }
 560
 561                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 562                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 563                         $ret = true;
 564                         foreach ( $a as $v ) {
 565                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 566                                         $ret = false;
 567                                 }
 568                         }
 569                 } else {
 570                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 571                 }
 572
 573                 return $ret;
 574         }
 575
 576         /**
 577          * @param string $table
 578          * @param array $uniqueIndexes Unused
 579          * @param string|array $rows
 580          * @param string $fname
 581          * @return bool|ResultWrapper
 582          */
 583         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 584                 if ( !count( $rows ) ) {
 585                         return true;
 586                 }
 587
 588                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 589                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 590                         $ret = true;
 591                         foreach ( $rows as $v ) {
 592                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 593                                         $ret = false;
 594                                 }
 595                         }
 596                 } else {
 597                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 598                 }
 599
 600                 return $ret;
 601         }
 602
 603         /**
 604          * Returns the size of a text field, or -1 for "unlimited"
 605          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 606          *
 607          * @param string $table
 608          * @param string $field
 609          * @return int
 610          */
 611         function textFieldSize( $table, $field ) {
 612                 return -1;
 613         }
 614
 615         /**
 616          * @return bool
 617          */
 618         function unionSupportsOrderAndLimit() {
 619                 return false;
 620         }
 621
 622         /**
 623          * @param string $sqls
 624          * @param bool $all Whether to "UNION ALL" or not
 625          * @return string
 626          */
 627         function unionQueries( $sqls, $all ) {
 628                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 629
 630                 return implode( $glue, $sqls );
 631         }
 632
 633         /**
 634          * @return bool
 635          */
 636         function wasDeadlock() {
 637                 return $this->lastErrno() == 5; // SQLITE_BUSY
 638         }
 639
 640         /**
 641          * @return bool
 642          */
 643         function wasErrorReissuable() {
 644                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 645         }
 646
 647         /**
 648          * @return bool
 649          */
 650         function wasReadOnlyError() {
 651                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 652         }
 653
 654         /**
 655          * @return string Wikitext of a link to the server software's web site
 656          */
 657         public function getSoftwareLink() {
 658                 return "[{{int:version-db-sqlite-url}} SQLite]";
 659         }
 660
 661         /**
 662          * @return string Version information from the database
 663          */
 664         function getServerVersion() {
 665                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 666
 667                 return $ver;
 668         }
 669
 670         /**
 671          * @return string User-friendly database information
 672          */
 673         public function getServerInfo() {
 674                 return wfMessage( self::getFulltextSearchModule()
 675                         ? 'sqlite-has-fts'
 676                         : 'sqlite-no-fts', $this->getServerVersion() )->text();
 677         }
 678
 679         /**
 680          * Get information about a given field
 681          * Returns false if the field does not exist.
 682          *
 683          * @param string $table
 684          * @param string $field
 685          * @return SQLiteField|bool False on failure
 686          */
 687         function fieldInfo( $table, $field ) {
 688                 $tableName = $this->tableName( $table );
 689                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 690                 $res = $this->query( $sql, __METHOD__ );
 691                 foreach ( $res as $row ) {
 692                         if ( $row->name == $field ) {
 693                                 return new SQLiteField( $row, $tableName );
 694                         }
 695                 }
 696
 697                 return false;
 698         }
 699
 700         /**
 701          * @param string $s
 702          * @return string
 703          */
 704         function strencode( $s ) {
 705                 return substr( $this->addQuotes( $s ), 1, -1 );
 706         }
 707
 708         /**
 709          * @param string $b
 710          * @return Blob
 711          */
 712         function encodeBlob( $b ) {
 713                 return new Blob( $b );
 714         }
 715
 716         /**
 717          * @param Blob|string $b
 718          * @return string
 719          */
 720         function decodeBlob( $b ) {
 721                 if ( $b instanceof Blob ) {
 722                         $b = $b->fetch();
 723                 }
 724
 725                 return $b;
 726         }
 727
 728         /**
 729          * @param Blob|string $s
 730          * @return string
 731          */
 732         function addQuotes( $s ) {
 733                 if ( $s instanceof Blob ) {
 734                         return "x'" . bin2hex( $s->fetch() ) . "'";
 735                 } elseif ( is_bool( $s ) ) {
 736                         return (int)$s;
 737                 } elseif ( strpos( $s, "\0" ) !== false ) {
 738                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 739                         // This is a known limitation of SQLite's mprintf function which PDO should work around,
 740                         // but doesn't. I have reported this to php.net as bug #63419:
 741                         // https://bugs.php.net/bug.php?id=63419
 742                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 743                         // https://bugs.php.net/bug.php?id=62361
 744                         // There is an additional bug regarding sorting this data after insert
 745                         // on older versions of sqlite shipped with ubuntu 12.04
 746                         // https://bugzilla.wikimedia.org/show_bug.cgi?id=72367
 747                         wfDebugLog( __CLASS__, __FUNCTION__ . ': Quoting value containing null byte. For consistency all binary data should have been first processed with self::encodeBlob()' );
 748                         return "x'" . bin2hex( $s ) . "'";
 749                 } else {
 750                         return $this->mConn->quote( $s );
 751                 }
 752         }
 753
 754         /**
 755          * @return string
 756          */
 757         function buildLike() {
 758                 $params = func_get_args();
 759                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 760                         $params = $params[0];
 761                 }
 762
 763                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 764         }
 765
 766         /**
 767          * @return string
 768          */
 769         public function getSearchEngine() {
 770                 return "SearchSqlite";
 771         }
 772
 773         /**
 774          * No-op version of deadlockLoop
 775          *
 776          * @return mixed
 777          */
 778         public function deadlockLoop( /*...*/ ) {
 779                 $args = func_get_args();
 780                 $function = array_shift( $args );
 781
 782                 return call_user_func_array( $function, $args );
 783         }
 784
 785         /**
 786          * @param string $s
 787          * @return string
 788          */
 789         protected function replaceVars( $s ) {
 790                 $s = parent::replaceVars( $s );
 791                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 792                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 793
 794                         // binary/varbinary column type -> blob
 795                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 796                         // no such thing as unsigned
 797                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 798                         // INT -> INTEGER
 799                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 800                         // floating point types -> REAL
 801                         $s = preg_replace(
 802                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 803                                 'REAL',
 804                                 $s
 805                         );
 806                         // varchar -> TEXT
 807                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 808                         // TEXT normalization
 809                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 810                         // BLOB normalization
 811                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 812                         // BOOL -> INTEGER
 813                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 814                         // DATETIME -> TEXT
 815                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 816                         // No ENUM type
 817                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 818                         // binary collation type -> nothing
 819                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 820                         // auto_increment -> autoincrement
 821                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 822                         // No explicit options
 823                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 824                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 825                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 826                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 827                         // No truncated indexes
 828                         $s = preg_replace( '/\(\d+\)/', '', $s );
 829                         // No FULLTEXT
 830                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 831                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 832                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 833                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 834                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 835                         // INSERT IGNORE --> INSERT OR IGNORE
 836                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 837                 }
 838
 839                 return $s;
 840         }
 841
 842         public function lock( $lockName, $method, $timeout = 5 ) {
 843                 global $wgSQLiteDataDir;
 844
 845                 if ( !is_dir( "$wgSQLiteDataDir/locks" ) ) { // create dir as needed
 846                         if ( !is_writable( $wgSQLiteDataDir ) || !mkdir( "$wgSQLiteDataDir/locks" ) ) {
 847                                 throw new DBError( "Cannot create directory \"$wgSQLiteDataDir/locks\"." );
 848                         }
 849                 }
 850
 851                 return $this->lockMgr->lock( array( $lockName ), LockManager::LOCK_EX, $timeout )->isOK();
 852         }
 853
 854         public function unlock( $lockName, $method ) {
 855                 return $this->lockMgr->unlock( array( $lockName ), LockManager::LOCK_EX )->isOK();
 856         }
 857
 858         /**
 859          * Build a concatenation list to feed into a SQL query
 860          *
 861          * @param string[] $stringList
 862          * @return string
 863          */
 864         function buildConcat( $stringList ) {
 865                 return '(' . implode( ') || (', $stringList ) . ')';
 866         }
 867
 868         public function buildGroupConcatField(
 869                 $delim, $table, $field, $conds = '', $join_conds = array()
 870         ) {
 871                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 872
 873                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, array(), $join_conds ) . ')';
 874         }
 875
 876         /**
 877          * @throws MWException
 878          * @param string $oldName
 879          * @param string $newName
 880          * @param bool $temporary
 881          * @param string $fname
 882          * @return bool|ResultWrapper
 883          */
 884         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 885                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 886                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 887                 $obj = $this->fetchObject( $res );
 888                 if ( !$obj ) {
 889                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 890                 }
 891                 $sql = $obj->sql;
 892                 $sql = preg_replace(
 893                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 894                         $this->addIdentifierQuotes( $newName ),
 895                         $sql,
 896                         1
 897                 );
 898                 if ( $temporary ) {
 899                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 900                                 wfDebug( "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 901                         } else {
 902                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 903                         }
 904                 }
 905
 906                 return $this->query( $sql, $fname );
 907         }
 908
 909         /**
 910          * List all tables on the database
 911          *
 912          * @param string $prefix Only show tables with this prefix, e.g. mw_
 913          * @param string $fname Calling function name
 914          *
 915          * @return array
 916          */
 917         function listTables( $prefix = null, $fname = __METHOD__ ) {
 918                 $result = $this->select(
 919                         'sqlite_master',
 920                         'name',
 921                         "type='table'"
 922                 );
 923
 924                 $endArray = array();
 925
 926                 foreach ( $result as $table ) {
 927                         $vars = get_object_vars( $table );
 928                         $table = array_pop( $vars );
 929
 930                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
 931                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
 932                                         $endArray[] = $table;
 933                                 }
 934                         }
 935                 }
 936
 937                 return $endArray;
 938         }
 939 } // end DatabaseSqlite class
 940
 941 /**
 942  * This class allows simple acccess to a SQLite database independently from main database settings
 943  * @ingroup Database
 944  */
 945 class DatabaseSqliteStandalone extends DatabaseSqlite {
 946         public function __construct( $fileName, $flags = 0 ) {
 947                 global $wgSQLiteDataDir;
 948
 949                 $this->mTrxAtomicLevels = new SplStack;
 950                 $this->lockMgr = new FSLockManager( array( 'lockDirectory' => "$wgSQLiteDataDir/locks" ) );
 951
 952                 $this->mFlags = $flags;
 953                 $this->tablePrefix( null );
 954                 $this->openFile( $fileName );
 955         }
 956 }
 957
 958 /**
 959  * @ingroup Database
 960  */
 961 class SQLiteField implements Field {
 962         private $info, $tableName;
 963
 964         function __construct( $info, $tableName ) {
 965                 $this->info = $info;
 966                 $this->tableName = $tableName;
 967         }
 968
 969         function name() {
 970                 return $this->info->name;
 971         }
 972
 973         function tableName() {
 974                 return $this->tableName;
 975         }
 976
 977         function defaultValue() {
 978                 if ( is_string( $this->info->dflt_value ) ) {
 979                         // Typically quoted
 980                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 981                                 return str_replace( "''", "'", $this->info->dflt_value );
 982                         }
 983                 }
 984
 985                 return $this->info->dflt_value;
 986         }
 987
 988         /**
 989          * @return bool
 990          */
 991         function isNullable() {
 992                 return !$this->info->notnull;
 993         }
 994
 995         function type() {
 996                 return $this->info->type;
 997         }
 998 } // end SQLiteField