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( $p = null ) {
  48                 global $wgSharedDB, $wgSQLiteDataDir;
  49
  50                 if ( !is_array( $p ) ) { // legacy calling pattern
  51                         wfDeprecated( __METHOD__ . " method called without parameter array.", "1.22" );
  52                         $args = func_get_args();
  53                         $p = array(
  54                                 'host' => isset( $args[0] ) ? $args[0] : false,
  55                                 'user' => isset( $args[1] ) ? $args[1] : false,
  56                                 'password' => isset( $args[2] ) ? $args[2] : false,
  57                                 'dbname' => isset( $args[3] ) ? $args[3] : false,
  58                                 'flags' => isset( $args[4] ) ? $args[4] : 0,
  59                                 'tablePrefix' => isset( $args[5] ) ? $args[5] : 'get from global',
  60                                 'schema' => 'get from global',
  61                                 'foreign' => isset( $args[6] ) ? $args[6] : false
  62                         );
  63                 }
  64                 $this->mDBname = $p['dbname'];
  65                 parent::__construct( $p );
  66                 // parent doesn't open when $user is false, but we can work with $dbName
  67                 if ( $p['dbname'] && !$this->isOpen() ) {
  68                         if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  69                                 if ( $wgSharedDB ) {
  70                                         $this->attachDatabase( $wgSharedDB );
  71                                 }
  72                         }
  73                 }
  74
  75                 $this->lockMgr = new FSLockManager( array( 'lockDirectory' => "$wgSQLiteDataDir/locks" ) );
  76         }
  77
  78         /**
  79          * @return string
  80          */
  81         function getType() {
  82                 return 'sqlite';
  83         }
  84
  85         /**
  86          * @todo Check if it should be true like parent class
  87          *
  88          * @return bool
  89          */
  90         function implicitGroupby() {
  91                 return false;
  92         }
  93
  94         /** Open an SQLite database and return a resource handle to it
  95          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  96          *
  97          * @param string $server
  98          * @param string $user
  99          * @param string $pass
 100          * @param string $dbName
 101          *
 102          * @throws DBConnectionError
 103          * @return PDO
 104          */
 105         function open( $server, $user, $pass, $dbName ) {
 106                 global $wgSQLiteDataDir;
 107
 108                 $this->close();
 109                 $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
 110                 if ( !is_readable( $fileName ) ) {
 111                         $this->mConn = false;
 112                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 113                 }
 114                 $this->openFile( $fileName );
 115
 116                 return $this->mConn;
 117         }
 118
 119         /**
 120          * Opens a database file
 121          *
 122          * @param string $fileName
 123          * @throws DBConnectionError
 124          * @return PDO|bool SQL connection or false if failed
 125          */
 126         function openFile( $fileName ) {
 127                 $err = false;
 128
 129                 $this->mDatabaseFile = $fileName;
 130                 try {
 131                         if ( $this->mFlags & DBO_PERSISTENT ) {
 132                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 133                                         array( PDO::ATTR_PERSISTENT => true ) );
 134                         } else {
 135                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 136                         }
 137                 } catch ( PDOException $e ) {
 138                         $err = $e->getMessage();
 139                 }
 140
 141                 if ( !$this->mConn ) {
 142                         wfDebug( "DB connection error: $err\n" );
 143                         throw new DBConnectionError( $this, $err );
 144                 }
 145
 146                 $this->mOpened = !!$this->mConn;
 147                 # set error codes only, don't raise exceptions
 148                 if ( $this->mOpened ) {
 149                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 150                         # Enforce LIKE to be case sensitive, just like MySQL
 151                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 152
 153                         return $this->mConn;
 154                 }
 155
 156                 return false;
 157         }
 158
 159         /**
 160          * Does not actually close the connection, just destroys the reference for GC to do its work
 161          * @return bool
 162          */
 163         protected function closeConnection() {
 164                 $this->mConn = null;
 165
 166                 return true;
 167         }
 168
 169         /**
 170          * Generates a database file name. Explicitly public for installer.
 171          * @param string $dir Directory where database resides
 172          * @param string $dbName Database name
 173          * @return string
 174          */
 175         public static function generateFileName( $dir, $dbName ) {
 176                 return "$dir/$dbName.sqlite";
 177         }
 178
 179         /**
 180          * Check if the searchindext table is FTS enabled.
 181          * @return bool False if not enabled.
 182          */
 183         function checkForEnabledSearch() {
 184                 if ( self::$fulltextEnabled === null ) {
 185                         self::$fulltextEnabled = false;
 186                         $table = $this->tableName( 'searchindex' );
 187                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 188                         if ( $res ) {
 189                                 $row = $res->fetchRow();
 190                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 191                         }
 192                 }
 193
 194                 return self::$fulltextEnabled;
 195         }
 196
 197         /**
 198          * Returns version of currently supported SQLite fulltext search module or false if none present.
 199          * @return string
 200          */
 201         static function getFulltextSearchModule() {
 202                 static $cachedResult = null;
 203                 if ( $cachedResult !== null ) {
 204                         return $cachedResult;
 205                 }
 206                 $cachedResult = false;
 207                 $table = 'dummy_search_test';
 208
 209                 $db = new DatabaseSqliteStandalone( ':memory:' );
 210
 211                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 212                         $cachedResult = 'FTS3';
 213                 }
 214                 $db->close();
 215
 216                 return $cachedResult;
 217         }
 218
 219         /**
 220          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 221          * for details.
 222          *
 223          * @param string $name Database name to be used in queries like
 224          *   SELECT foo FROM dbname.table
 225          * @param bool|string $file Database file name. If omitted, will be generated
 226          *   using $name and $wgSQLiteDataDir
 227          * @param string $fname Calling function name
 228          * @return ResultWrapper
 229          */
 230         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 231                 global $wgSQLiteDataDir;
 232                 if ( !$file ) {
 233                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 234                 }
 235                 $file = $this->addQuotes( $file );
 236
 237                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 238         }
 239
 240         /**
 241          * @see DatabaseBase::isWriteQuery()
 242          *
 243          * @param string $sql
 244          * @return bool
 245          */
 246         function isWriteQuery( $sql ) {
 247                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 248         }
 249
 250         /**
 251          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 252          *
 253          * @param string $sql
 254          * @return bool|ResultWrapper
 255          */
 256         protected function doQuery( $sql ) {
 257                 $res = $this->mConn->query( $sql );
 258                 if ( $res === false ) {
 259                         return false;
 260                 } else {
 261                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 262                         $this->mAffectedRows = $r->rowCount();
 263                         $res = new ResultWrapper( $this, $r->fetchAll() );
 264                 }
 265
 266                 return $res;
 267         }
 268
 269         /**
 270          * @param ResultWrapper|mixed $res
 271          */
 272         function freeResult( $res ) {
 273                 if ( $res instanceof ResultWrapper ) {
 274                         $res->result = null;
 275                 } else {
 276                         $res = null;
 277                 }
 278         }
 279
 280         /**
 281          * @param ResultWrapper|array $res
 282          * @return stdClass|bool
 283          */
 284         function fetchObject( $res ) {
 285                 if ( $res instanceof ResultWrapper ) {
 286                         $r =& $res->result;
 287                 } else {
 288                         $r =& $res;
 289                 }
 290
 291                 $cur = current( $r );
 292                 if ( is_array( $cur ) ) {
 293                         next( $r );
 294                         $obj = new stdClass;
 295                         foreach ( $cur as $k => $v ) {
 296                                 if ( !is_numeric( $k ) ) {
 297                                         $obj->$k = $v;
 298                                 }
 299                         }
 300
 301                         return $obj;
 302                 }
 303
 304                 return false;
 305         }
 306
 307         /**
 308          * @param ResultWrapper|mixed $res
 309          * @return array|bool
 310          */
 311         function fetchRow( $res ) {
 312                 if ( $res instanceof ResultWrapper ) {
 313                         $r =& $res->result;
 314                 } else {
 315                         $r =& $res;
 316                 }
 317                 $cur = current( $r );
 318                 if ( is_array( $cur ) ) {
 319                         next( $r );
 320
 321                         return $cur;
 322                 }
 323
 324                 return false;
 325         }
 326
 327         /**
 328          * The PDO::Statement class implements the array interface so count() will work
 329          *
 330          * @param ResultWrapper|array $res
 331          * @return int
 332          */
 333         function numRows( $res ) {
 334                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 335
 336                 return count( $r );
 337         }
 338
 339         /**
 340          * @param ResultWrapper $res
 341          * @return int
 342          */
 343         function numFields( $res ) {
 344                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 345                 if ( is_array( $r ) && count( $r ) > 0 ) {
 346                         // The size of the result array is twice the number of fields. (Bug: 65578)
 347                         return count( $r[0] ) / 2;
 348                 } else {
 349                         // If the result is empty return 0
 350                         return 0;
 351                 }
 352         }
 353
 354         /**
 355          * @param ResultWrapper $res
 356          * @param int $n
 357          * @return bool
 358          */
 359         function fieldName( $res, $n ) {
 360                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 361                 if ( is_array( $r ) ) {
 362                         $keys = array_keys( $r[0] );
 363
 364                         return $keys[$n];
 365                 }
 366
 367                 return false;
 368         }
 369
 370         /**
 371          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 372          *
 373          * @param string $name
 374          * @param string $format
 375          * @return string
 376          */
 377         function tableName( $name, $format = 'quoted' ) {
 378                 // table names starting with sqlite_ are reserved
 379                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 380                         return $name;
 381                 }
 382
 383                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 384         }
 385
 386         /**
 387          * Index names have DB scope
 388          *
 389          * @param string $index
 390          * @return string
 391          */
 392         function indexName( $index ) {
 393                 return $index;
 394         }
 395
 396         /**
 397          * This must be called after nextSequenceVal
 398          *
 399          * @return int
 400          */
 401         function insertId() {
 402                 // PDO::lastInsertId yields a string :(
 403                 return intval( $this->mConn->lastInsertId() );
 404         }
 405
 406         /**
 407          * @param ResultWrapper|array $res
 408          * @param int $row
 409          */
 410         function dataSeek( $res, $row ) {
 411                 if ( $res instanceof ResultWrapper ) {
 412                         $r =& $res->result;
 413                 } else {
 414                         $r =& $res;
 415                 }
 416                 reset( $r );
 417                 if ( $row > 0 ) {
 418                         for ( $i = 0; $i < $row; $i++ ) {
 419                                 next( $r );
 420                         }
 421                 }
 422         }
 423
 424         /**
 425          * @return string
 426          */
 427         function lastError() {
 428                 if ( !is_object( $this->mConn ) ) {
 429                         return "Cannot return last error, no db connection";
 430                 }
 431                 $e = $this->mConn->errorInfo();
 432
 433                 return isset( $e[2] ) ? $e[2] : '';
 434         }
 435
 436         /**
 437          * @return string
 438          */
 439         function lastErrno() {
 440                 if ( !is_object( $this->mConn ) ) {
 441                         return "Cannot return last error, no db connection";
 442                 } else {
 443                         $info = $this->mConn->errorInfo();
 444
 445                         return $info[1];
 446                 }
 447         }
 448
 449         /**
 450          * @return int
 451          */
 452         function affectedRows() {
 453                 return $this->mAffectedRows;
 454         }
 455
 456         /**
 457          * Returns information about an index
 458          * Returns false if the index does not exist
 459          * - if errors are explicitly ignored, returns NULL on failure
 460          *
 461          * @param string $table
 462          * @param string $index
 463          * @param string $fname
 464          * @return array
 465          */
 466         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 467                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 468                 $res = $this->query( $sql, $fname );
 469                 if ( !$res ) {
 470                         return null;
 471                 }
 472                 if ( $res->numRows() == 0 ) {
 473                         return false;
 474                 }
 475                 $info = array();
 476                 foreach ( $res as $row ) {
 477                         $info[] = $row->name;
 478                 }
 479
 480                 return $info;
 481         }
 482
 483         /**
 484          * @param string $table
 485          * @param string $index
 486          * @param string $fname
 487          * @return bool|null
 488          */
 489         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 490                 $row = $this->selectRow( 'sqlite_master', '*',
 491                         array(
 492                                 'type' => 'index',
 493                                 'name' => $this->indexName( $index ),
 494                         ), $fname );
 495                 if ( !$row || !isset( $row->sql ) ) {
 496                         return null;
 497                 }
 498
 499                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 500                 $indexPos = strpos( $row->sql, 'INDEX' );
 501                 if ( $indexPos === false ) {
 502                         return null;
 503                 }
 504                 $firstPart = substr( $row->sql, 0, $indexPos );
 505                 $options = explode( ' ', $firstPart );
 506
 507                 return in_array( 'UNIQUE', $options );
 508         }
 509
 510         /**
 511          * Filter the options used in SELECT statements
 512          *
 513          * @param array $options
 514          * @return array
 515          */
 516         function makeSelectOptions( $options ) {
 517                 foreach ( $options as $k => $v ) {
 518                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 519                                 $options[$k] = '';
 520                         }
 521                 }
 522
 523                 return parent::makeSelectOptions( $options );
 524         }
 525
 526         /**
 527          * @param array $options
 528          * @return string
 529          */
 530         protected function makeUpdateOptionsArray( $options ) {
 531                 $options = parent::makeUpdateOptionsArray( $options );
 532                 $options = self::fixIgnore( $options );
 533
 534                 return $options;
 535         }
 536
 537         /**
 538          * @param array $options
 539          * @return array
 540          */
 541         static function fixIgnore( $options ) {
 542                 # SQLite uses OR IGNORE not just IGNORE
 543                 foreach ( $options as $k => $v ) {
 544                         if ( $v == 'IGNORE' ) {
 545                                 $options[$k] = 'OR IGNORE';
 546                         }
 547                 }
 548
 549                 return $options;
 550         }
 551
 552         /**
 553          * @param array $options
 554          * @return string
 555          */
 556         function makeInsertOptions( $options ) {
 557                 $options = self::fixIgnore( $options );
 558
 559                 return parent::makeInsertOptions( $options );
 560         }
 561
 562         /**
 563          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 564          * @param string $table
 565          * @param array $a
 566          * @param string $fname
 567          * @param array $options
 568          * @return bool
 569          */
 570         function insert( $table, $a, $fname = __METHOD__, $options = array() ) {
 571                 if ( !count( $a ) ) {
 572                         return true;
 573                 }
 574
 575                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 576                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 577                         $ret = true;
 578                         foreach ( $a as $v ) {
 579                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 580                                         $ret = false;
 581                                 }
 582                         }
 583                 } else {
 584                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 585                 }
 586
 587                 return $ret;
 588         }
 589
 590         /**
 591          * @param string $table
 592          * @param array $uniqueIndexes Unused
 593          * @param string|array $rows
 594          * @param string $fname
 595          * @return bool|ResultWrapper
 596          */
 597         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 598                 if ( !count( $rows ) ) {
 599                         return true;
 600                 }
 601
 602                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 603                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 604                         $ret = true;
 605                         foreach ( $rows as $v ) {
 606                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 607                                         $ret = false;
 608                                 }
 609                         }
 610                 } else {
 611                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 612                 }
 613
 614                 return $ret;
 615         }
 616
 617         /**
 618          * Returns the size of a text field, or -1 for "unlimited"
 619          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 620          *
 621          * @param string $table
 622          * @param string $field
 623          * @return int
 624          */
 625         function textFieldSize( $table, $field ) {
 626                 return -1;
 627         }
 628
 629         /**
 630          * @return bool
 631          */
 632         function unionSupportsOrderAndLimit() {
 633                 return false;
 634         }
 635
 636         /**
 637          * @param string $sqls
 638          * @param bool $all Whether to "UNION ALL" or not
 639          * @return string
 640          */
 641         function unionQueries( $sqls, $all ) {
 642                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 643
 644                 return implode( $glue, $sqls );
 645         }
 646
 647         /**
 648          * @return bool
 649          */
 650         function wasDeadlock() {
 651                 return $this->lastErrno() == 5; // SQLITE_BUSY
 652         }
 653
 654         /**
 655          * @return bool
 656          */
 657         function wasErrorReissuable() {
 658                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 659         }
 660
 661         /**
 662          * @return bool
 663          */
 664         function wasReadOnlyError() {
 665                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 666         }
 667
 668         /**
 669          * @return string Wikitext of a link to the server software's web site
 670          */
 671         public function getSoftwareLink() {
 672                 return "[{{int:version-db-sqlite-url}} SQLite]";
 673         }
 674
 675         /**
 676          * @return string Version information from the database
 677          */
 678         function getServerVersion() {
 679                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 680
 681                 return $ver;
 682         }
 683
 684         /**
 685          * @return string User-friendly database information
 686          */
 687         public function getServerInfo() {
 688                 return wfMessage( self::getFulltextSearchModule()
 689                         ? 'sqlite-has-fts'
 690                         : 'sqlite-no-fts', $this->getServerVersion() )->text();
 691         }
 692
 693         /**
 694          * Get information about a given field
 695          * Returns false if the field does not exist.
 696          *
 697          * @param string $table
 698          * @param string $field
 699          * @return SQLiteField|bool False on failure
 700          */
 701         function fieldInfo( $table, $field ) {
 702                 $tableName = $this->tableName( $table );
 703                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 704                 $res = $this->query( $sql, __METHOD__ );
 705                 foreach ( $res as $row ) {
 706                         if ( $row->name == $field ) {
 707                                 return new SQLiteField( $row, $tableName );
 708                         }
 709                 }
 710
 711                 return false;
 712         }
 713
 714         protected function doBegin( $fname = '' ) {
 715                 if ( $this->mTrxLevel == 1 ) {
 716                         $this->commit( __METHOD__ );
 717                 }
 718                 try {
 719                         $this->mConn->beginTransaction();
 720                 } catch ( PDOException $e ) {
 721                         throw new DBUnexpectedError( $this, 'Error in BEGIN query: ' . $e->getMessage() );
 722                 }
 723                 $this->mTrxLevel = 1;
 724         }
 725
 726         protected function doCommit( $fname = '' ) {
 727                 if ( $this->mTrxLevel == 0 ) {
 728                         return;
 729                 }
 730                 try {
 731                         $this->mConn->commit();
 732                 } catch ( PDOException $e ) {
 733                         throw new DBUnexpectedError( $this, 'Error in COMMIT query: ' . $e->getMessage() );
 734                 }
 735                 $this->mTrxLevel = 0;
 736         }
 737
 738         protected function doRollback( $fname = '' ) {
 739                 if ( $this->mTrxLevel == 0 ) {
 740                         return;
 741                 }
 742                 $this->mConn->rollBack();
 743                 $this->mTrxLevel = 0;
 744         }
 745
 746         /**
 747          * @param string $s
 748          * @return string
 749          */
 750         function strencode( $s ) {
 751                 return substr( $this->addQuotes( $s ), 1, -1 );
 752         }
 753
 754         /**
 755          * @param string $b
 756          * @return Blob
 757          */
 758         function encodeBlob( $b ) {
 759                 return new Blob( $b );
 760         }
 761
 762         /**
 763          * @param Blob|string $b
 764          * @return string
 765          */
 766         function decodeBlob( $b ) {
 767                 if ( $b instanceof Blob ) {
 768                         $b = $b->fetch();
 769                 }
 770
 771                 return $b;
 772         }
 773
 774         /**
 775          * @param Blob|string $s
 776          * @return string
 777          */
 778         function addQuotes( $s ) {
 779                 if ( $s instanceof Blob ) {
 780                         return "x'" . bin2hex( $s->fetch() ) . "'";
 781                 } elseif ( is_bool( $s ) ) {
 782                         return (int)$s;
 783                 } elseif ( strpos( $s, "\0" ) !== false ) {
 784                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 785                         // This is a known limitation of SQLite's mprintf function which PDO should work around,
 786                         // but doesn't. I have reported this to php.net as bug #63419:
 787                         // https://bugs.php.net/bug.php?id=63419
 788                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 789                         // https://bugs.php.net/bug.php?id=62361
 790                         // There is an additional bug regarding sorting this data after insert
 791                         // on older versions of sqlite shipped with ubuntu 12.04
 792                         // https://bugzilla.wikimedia.org/show_bug.cgi?id=72367
 793                         wfDebugLog( __CLASS__, __FUNCTION__ . ': Quoting value containing null byte. For consistency all binary data should have been first processed with self::encodeBlob()' );
 794                         return "x'" . bin2hex( $s ) . "'";
 795                 } else {
 796                         return $this->mConn->quote( $s );
 797                 }
 798         }
 799
 800         /**
 801          * @return string
 802          */
 803         function buildLike() {
 804                 $params = func_get_args();
 805                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 806                         $params = $params[0];
 807                 }
 808
 809                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 810         }
 811
 812         /**
 813          * @return string
 814          */
 815         public function getSearchEngine() {
 816                 return "SearchSqlite";
 817         }
 818
 819         /**
 820          * No-op version of deadlockLoop
 821          *
 822          * @return mixed
 823          */
 824         public function deadlockLoop( /*...*/ ) {
 825                 $args = func_get_args();
 826                 $function = array_shift( $args );
 827
 828                 return call_user_func_array( $function, $args );
 829         }
 830
 831         /**
 832          * @param string $s
 833          * @return string
 834          */
 835         protected function replaceVars( $s ) {
 836                 $s = parent::replaceVars( $s );
 837                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 838                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 839
 840                         // binary/varbinary column type -> blob
 841                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 842                         // no such thing as unsigned
 843                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 844                         // INT -> INTEGER
 845                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 846                         // floating point types -> REAL
 847                         $s = preg_replace(
 848                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 849                                 'REAL',
 850                                 $s
 851                         );
 852                         // varchar -> TEXT
 853                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 854                         // TEXT normalization
 855                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 856                         // BLOB normalization
 857                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 858                         // BOOL -> INTEGER
 859                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 860                         // DATETIME -> TEXT
 861                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 862                         // No ENUM type
 863                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 864                         // binary collation type -> nothing
 865                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 866                         // auto_increment -> autoincrement
 867                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 868                         // No explicit options
 869                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 870                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 871                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 872                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 873                         // No truncated indexes
 874                         $s = preg_replace( '/\(\d+\)/', '', $s );
 875                         // No FULLTEXT
 876                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 877                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 878                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 879                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 880                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 881                         // INSERT IGNORE --> INSERT OR IGNORE
 882                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 883                 }
 884
 885                 return $s;
 886         }
 887
 888         public function lock( $lockName, $method, $timeout = 5 ) {
 889                 global $wgSQLiteDataDir;
 890
 891                 if ( !is_dir( "$wgSQLiteDataDir/locks" ) ) { // create dir as needed
 892                         if ( !is_writable( $wgSQLiteDataDir ) || !mkdir( "$wgSQLiteDataDir/locks" ) ) {
 893                                 throw new DBError( "Cannot create directory \"$wgSQLiteDataDir/locks\"." );
 894                         }
 895                 }
 896
 897                 return $this->lockMgr->lock( array( $lockName ), LockManager::LOCK_EX, $timeout )->isOK();
 898         }
 899
 900         public function unlock( $lockName, $method ) {
 901                 return $this->lockMgr->unlock( array( $lockName ), LockManager::LOCK_EX )->isOK();
 902         }
 903
 904         /**
 905          * Build a concatenation list to feed into a SQL query
 906          *
 907          * @param string[] $stringList
 908          * @return string
 909          */
 910         function buildConcat( $stringList ) {
 911                 return '(' . implode( ') || (', $stringList ) . ')';
 912         }
 913
 914         public function buildGroupConcatField(
 915                 $delim, $table, $field, $conds = '', $join_conds = array()
 916         ) {
 917                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 918
 919                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, array(), $join_conds ) . ')';
 920         }
 921
 922         /**
 923          * @throws MWException
 924          * @param string $oldName
 925          * @param string $newName
 926          * @param bool $temporary
 927          * @param string $fname
 928          * @return bool|ResultWrapper
 929          */
 930         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 931                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 932                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 933                 $obj = $this->fetchObject( $res );
 934                 if ( !$obj ) {
 935                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 936                 }
 937                 $sql = $obj->sql;
 938                 $sql = preg_replace(
 939                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 940                         $this->addIdentifierQuotes( $newName ),
 941                         $sql,
 942                         1
 943                 );
 944                 if ( $temporary ) {
 945                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 946                                 wfDebug( "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 947                         } else {
 948                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 949                         }
 950                 }
 951
 952                 return $this->query( $sql, $fname );
 953         }
 954
 955         /**
 956          * List all tables on the database
 957          *
 958          * @param string $prefix Only show tables with this prefix, e.g. mw_
 959          * @param string $fname Calling function name
 960          *
 961          * @return array
 962          */
 963         function listTables( $prefix = null, $fname = __METHOD__ ) {
 964                 $result = $this->select(
 965                         'sqlite_master',
 966                         'name',
 967                         "type='table'"
 968                 );
 969
 970                 $endArray = array();
 971
 972                 foreach ( $result as $table ) {
 973                         $vars = get_object_vars( $table );
 974                         $table = array_pop( $vars );
 975
 976                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
 977                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
 978                                         $endArray[] = $table;
 979                                 }
 980                         }
 981                 }
 982
 983                 return $endArray;
 984         }
 985 } // end DatabaseSqlite class
 986
 987 /**
 988  * This class allows simple acccess to a SQLite database independently from main database settings
 989  * @ingroup Database
 990  */
 991 class DatabaseSqliteStandalone extends DatabaseSqlite {
 992         public function __construct( $fileName, $flags = 0 ) {
 993                 $this->mFlags = $flags;
 994                 $this->tablePrefix( null );
 995                 $this->openFile( $fileName );
 996         }
 997 }
 998
 999 /**
1000  * @ingroup Database
1001  */
1002 class SQLiteField implements Field {
1003         private $info, $tableName;
1004
1005         function __construct( $info, $tableName ) {
1006                 $this->info = $info;
1007                 $this->tableName = $tableName;
1008         }
1009
1010         function name() {
1011                 return $this->info->name;
1012         }
1013
1014         function tableName() {
1015                 return $this->tableName;
1016         }
1017
1018         function defaultValue() {
1019                 if ( is_string( $this->info->dflt_value ) ) {
1020                         // Typically quoted
1021                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
1022                                 return str_replace( "''", "'", $this->info->dflt_value );
1023                         }
1024                 }
1025
1026                 return $this->info->dflt_value;
1027         }
1028
1029         /**
1030          * @return bool
1031          */
1032         function isNullable() {
1033                 return !$this->info->notnull;
1034         }
1035
1036         function type() {
1037                 return $this->info->type;
1038         }
1039 } // end SQLiteField