includes/libs/rdbms/database/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 Database {
  29         /** @var bool Whether full text is enabled */
  30         private static $fulltextEnabled = null;
  31
  32         /** @var string Directory */
  33         protected $dbDir;
  34         /** @var string File name for SQLite database file */
  35         protected $dbPath;
  36         /** @var string Transaction mode */
  37         protected $trxMode;
  38
  39         /** @var int The number of rows affected as an integer */
  40         protected $mAffectedRows;
  41         /** @var resource */
  42         protected $mLastResult;
  43
  44         /** @var $mConn PDO */
  45         protected $mConn;
  46
  47         /** @var FSLockManager (hopefully on the same server as the DB) */
  48         protected $lockMgr;
  49
  50         /**
  51          * Additional params include:
  52          *   - dbDirectory : directory containing the DB and the lock file directory
  53          *                   [defaults to $wgSQLiteDataDir]
  54          *   - dbFilePath  : use this to force the path of the DB file
  55          *   - trxMode     : one of (deferred, immediate, exclusive)
  56          * @param array $p
  57          */
  58         function __construct( array $p ) {
  59                 if ( isset( $p['dbFilePath'] ) ) {
  60                         parent::__construct( $p );
  61                         // Standalone .sqlite file mode.
  62                         // Super doesn't open when $user is false, but we can work with $dbName,
  63                         // which is derived from the file path in this case.
  64                         $this->openFile( $p['dbFilePath'] );
  65                         $lockDomain = md5( $p['dbFilePath'] );
  66                 } elseif ( !isset( $p['dbDirectory'] ) ) {
  67                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
  68                 } else {
  69                         $this->dbDir = $p['dbDirectory'];
  70                         $this->mDBname = $p['dbname'];
  71                         $lockDomain = $this->mDBname;
  72                         // Stock wiki mode using standard file names per DB.
  73                         parent::__construct( $p );
  74                         // Super doesn't open when $user is false, but we can work with $dbName
  75                         if ( $p['dbname'] && !$this->isOpen() ) {
  76                                 if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  77                                         $done = [];
  78                                         foreach ( $this->tableAliases as $params ) {
  79                                                 if ( isset( $done[$params['dbname']] ) ) {
  80                                                         continue;
  81                                                 }
  82                                                 $this->attachDatabase( $params['dbname'] );
  83                                                 $done[$params['dbname']] = 1;
  84                                         }
  85                                 }
  86                         }
  87                 }
  88
  89                 $this->trxMode = isset( $p['trxMode'] ) ? strtoupper( $p['trxMode'] ) : null;
  90                 if ( $this->trxMode &&
  91                         !in_array( $this->trxMode, [ 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ] )
  92                 ) {
  93                         $this->trxMode = null;
  94                         $this->queryLogger->warning( "Invalid SQLite transaction mode provided." );
  95                 }
  96
  97                 $this->lockMgr = new FSLockManager( [
  98                         'domain' => $lockDomain,
  99                         'lockDirectory' => "{$this->dbDir}/locks"
 100                 ] );
 101         }
 102
 103         /**
 104          * @param string $filename
 105          * @param array $p Options map; supports:
 106          *   - flags       : (same as __construct counterpart)
 107          *   - trxMode     : (same as __construct counterpart)
 108          *   - dbDirectory : (same as __construct counterpart)
 109          * @return DatabaseSqlite
 110          * @since 1.25
 111          */
 112         public static function newStandaloneInstance( $filename, array $p = [] ) {
 113                 $p['dbFilePath'] = $filename;
 114                 $p['schema'] = false;
 115                 $p['tablePrefix'] = '';
 116
 117                 return Database::factory( 'sqlite', $p );
 118         }
 119
 120         /**
 121          * @return string
 122          */
 123         function getType() {
 124                 return 'sqlite';
 125         }
 126
 127         /**
 128          * @todo Check if it should be true like parent class
 129          *
 130          * @return bool
 131          */
 132         function implicitGroupby() {
 133                 return false;
 134         }
 135
 136         /** Open an SQLite database and return a resource handle to it
 137          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
 138          *
 139          * @param string $server
 140          * @param string $user
 141          * @param string $pass
 142          * @param string $dbName
 143          *
 144          * @throws DBConnectionError
 145          * @return bool
 146          */
 147         function open( $server, $user, $pass, $dbName ) {
 148                 $this->close();
 149                 $fileName = self::generateFileName( $this->dbDir, $dbName );
 150                 if ( !is_readable( $fileName ) ) {
 151                         $this->mConn = false;
 152                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 153                 }
 154                 $this->openFile( $fileName );
 155
 156                 return (bool)$this->mConn;
 157         }
 158
 159         /**
 160          * Opens a database file
 161          *
 162          * @param string $fileName
 163          * @throws DBConnectionError
 164          * @return PDO|bool SQL connection or false if failed
 165          */
 166         protected function openFile( $fileName ) {
 167                 $err = false;
 168
 169                 $this->dbPath = $fileName;
 170                 try {
 171                         if ( $this->mFlags & self::DBO_PERSISTENT ) {
 172                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 173                                         [ PDO::ATTR_PERSISTENT => true ] );
 174                         } else {
 175                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 176                         }
 177                 } catch ( PDOException $e ) {
 178                         $err = $e->getMessage();
 179                 }
 180
 181                 if ( !$this->mConn ) {
 182                         $this->queryLogger->debug( "DB connection error: $err\n" );
 183                         throw new DBConnectionError( $this, $err );
 184                 }
 185
 186                 $this->mOpened = !!$this->mConn;
 187                 if ( $this->mOpened ) {
 188                         # Set error codes only, don't raise exceptions
 189                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 190                         # Enforce LIKE to be case sensitive, just like MySQL
 191                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 192
 193                         return $this->mConn;
 194                 }
 195
 196                 return false;
 197         }
 198
 199         /**
 200          * @return string SQLite DB file path
 201          * @since 1.25
 202          */
 203         public function getDbFilePath() {
 204                 return $this->dbPath;
 205         }
 206
 207         /**
 208          * Does not actually close the connection, just destroys the reference for GC to do its work
 209          * @return bool
 210          */
 211         protected function closeConnection() {
 212                 $this->mConn = null;
 213
 214                 return true;
 215         }
 216
 217         /**
 218          * Generates a database file name. Explicitly public for installer.
 219          * @param string $dir Directory where database resides
 220          * @param string $dbName Database name
 221          * @return string
 222          */
 223         public static function generateFileName( $dir, $dbName ) {
 224                 return "$dir/$dbName.sqlite";
 225         }
 226
 227         /**
 228          * Check if the searchindext table is FTS enabled.
 229          * @return bool False if not enabled.
 230          */
 231         function checkForEnabledSearch() {
 232                 if ( self::$fulltextEnabled === null ) {
 233                         self::$fulltextEnabled = false;
 234                         $table = $this->tableName( 'searchindex' );
 235                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 236                         if ( $res ) {
 237                                 $row = $res->fetchRow();
 238                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 239                         }
 240                 }
 241
 242                 return self::$fulltextEnabled;
 243         }
 244
 245         /**
 246          * Returns version of currently supported SQLite fulltext search module or false if none present.
 247          * @return string
 248          */
 249         static function getFulltextSearchModule() {
 250                 static $cachedResult = null;
 251                 if ( $cachedResult !== null ) {
 252                         return $cachedResult;
 253                 }
 254                 $cachedResult = false;
 255                 $table = 'dummy_search_test';
 256
 257                 $db = self::newStandaloneInstance( ':memory:' );
 258                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 259                         $cachedResult = 'FTS3';
 260                 }
 261                 $db->close();
 262
 263                 return $cachedResult;
 264         }
 265
 266         /**
 267          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 268          * for details.
 269          *
 270          * @param string $name Database name to be used in queries like
 271          *   SELECT foo FROM dbname.table
 272          * @param bool|string $file Database file name. If omitted, will be generated
 273          *   using $name and configured data directory
 274          * @param string $fname Calling function name
 275          * @return ResultWrapper
 276          */
 277         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 278                 if ( !$file ) {
 279                         $file = self::generateFileName( $this->dbDir, $name );
 280                 }
 281                 $file = $this->addQuotes( $file );
 282
 283                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 284         }
 285
 286         function isWriteQuery( $sql ) {
 287                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 288         }
 289
 290         /**
 291          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 292          *
 293          * @param string $sql
 294          * @return bool|ResultWrapper
 295          */
 296         protected function doQuery( $sql ) {
 297                 $res = $this->mConn->query( $sql );
 298                 if ( $res === false ) {
 299                         return false;
 300                 }
 301
 302                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 303                 $this->mAffectedRows = $r->rowCount();
 304                 $res = new ResultWrapper( $this, $r->fetchAll() );
 305
 306                 return $res;
 307         }
 308
 309         /**
 310          * @param ResultWrapper|mixed $res
 311          */
 312         function freeResult( $res ) {
 313                 if ( $res instanceof ResultWrapper ) {
 314                         $res->result = null;
 315                 } else {
 316                         $res = null;
 317                 }
 318         }
 319
 320         /**
 321          * @param ResultWrapper|array $res
 322          * @return stdClass|bool
 323          */
 324         function fetchObject( $res ) {
 325                 if ( $res instanceof ResultWrapper ) {
 326                         $r =& $res->result;
 327                 } else {
 328                         $r =& $res;
 329                 }
 330
 331                 $cur = current( $r );
 332                 if ( is_array( $cur ) ) {
 333                         next( $r );
 334                         $obj = new stdClass;
 335                         foreach ( $cur as $k => $v ) {
 336                                 if ( !is_numeric( $k ) ) {
 337                                         $obj->$k = $v;
 338                                 }
 339                         }
 340
 341                         return $obj;
 342                 }
 343
 344                 return false;
 345         }
 346
 347         /**
 348          * @param ResultWrapper|mixed $res
 349          * @return array|bool
 350          */
 351         function fetchRow( $res ) {
 352                 if ( $res instanceof ResultWrapper ) {
 353                         $r =& $res->result;
 354                 } else {
 355                         $r =& $res;
 356                 }
 357                 $cur = current( $r );
 358                 if ( is_array( $cur ) ) {
 359                         next( $r );
 360
 361                         return $cur;
 362                 }
 363
 364                 return false;
 365         }
 366
 367         /**
 368          * The PDO::Statement class implements the array interface so count() will work
 369          *
 370          * @param ResultWrapper|array $res
 371          * @return int
 372          */
 373         function numRows( $res ) {
 374                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 375
 376                 return count( $r );
 377         }
 378
 379         /**
 380          * @param ResultWrapper $res
 381          * @return int
 382          */
 383         function numFields( $res ) {
 384                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 385                 if ( is_array( $r ) && count( $r ) > 0 ) {
 386                         // The size of the result array is twice the number of fields. (Bug: 65578)
 387                         return count( $r[0] ) / 2;
 388                 } else {
 389                         // If the result is empty return 0
 390                         return 0;
 391                 }
 392         }
 393
 394         /**
 395          * @param ResultWrapper $res
 396          * @param int $n
 397          * @return bool
 398          */
 399         function fieldName( $res, $n ) {
 400                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 401                 if ( is_array( $r ) ) {
 402                         $keys = array_keys( $r[0] );
 403
 404                         return $keys[$n];
 405                 }
 406
 407                 return false;
 408         }
 409
 410         /**
 411          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 412          *
 413          * @param string $name
 414          * @param string $format
 415          * @return string
 416          */
 417         function tableName( $name, $format = 'quoted' ) {
 418                 // table names starting with sqlite_ are reserved
 419                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 420                         return $name;
 421                 }
 422
 423                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 424         }
 425
 426         /**
 427          * This must be called after nextSequenceVal
 428          *
 429          * @return int
 430          */
 431         function insertId() {
 432                 // PDO::lastInsertId yields a string :(
 433                 return intval( $this->mConn->lastInsertId() );
 434         }
 435
 436         /**
 437          * @param ResultWrapper|array $res
 438          * @param int $row
 439          */
 440         function dataSeek( $res, $row ) {
 441                 if ( $res instanceof ResultWrapper ) {
 442                         $r =& $res->result;
 443                 } else {
 444                         $r =& $res;
 445                 }
 446                 reset( $r );
 447                 if ( $row > 0 ) {
 448                         for ( $i = 0; $i < $row; $i++ ) {
 449                                 next( $r );
 450                         }
 451                 }
 452         }
 453
 454         /**
 455          * @return string
 456          */
 457         function lastError() {
 458                 if ( !is_object( $this->mConn ) ) {
 459                         return "Cannot return last error, no db connection";
 460                 }
 461                 $e = $this->mConn->errorInfo();
 462
 463                 return isset( $e[2] ) ? $e[2] : '';
 464         }
 465
 466         /**
 467          * @return string
 468          */
 469         function lastErrno() {
 470                 if ( !is_object( $this->mConn ) ) {
 471                         return "Cannot return last error, no db connection";
 472                 } else {
 473                         $info = $this->mConn->errorInfo();
 474
 475                         return $info[1];
 476                 }
 477         }
 478
 479         /**
 480          * @return int
 481          */
 482         function affectedRows() {
 483                 return $this->mAffectedRows;
 484         }
 485
 486         /**
 487          * Returns information about an index
 488          * Returns false if the index does not exist
 489          * - if errors are explicitly ignored, returns NULL on failure
 490          *
 491          * @param string $table
 492          * @param string $index
 493          * @param string $fname
 494          * @return array|false
 495          */
 496         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 497                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 498                 $res = $this->query( $sql, $fname );
 499                 if ( !$res || $res->numRows() == 0 ) {
 500                         return false;
 501                 }
 502                 $info = [];
 503                 foreach ( $res as $row ) {
 504                         $info[] = $row->name;
 505                 }
 506
 507                 return $info;
 508         }
 509
 510         /**
 511          * @param string $table
 512          * @param string $index
 513          * @param string $fname
 514          * @return bool|null
 515          */
 516         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 517                 $row = $this->selectRow( 'sqlite_master', '*',
 518                         [
 519                                 'type' => 'index',
 520                                 'name' => $this->indexName( $index ),
 521                         ], $fname );
 522                 if ( !$row || !isset( $row->sql ) ) {
 523                         return null;
 524                 }
 525
 526                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 527                 $indexPos = strpos( $row->sql, 'INDEX' );
 528                 if ( $indexPos === false ) {
 529                         return null;
 530                 }
 531                 $firstPart = substr( $row->sql, 0, $indexPos );
 532                 $options = explode( ' ', $firstPart );
 533
 534                 return in_array( 'UNIQUE', $options );
 535         }
 536
 537         /**
 538          * Filter the options used in SELECT statements
 539          *
 540          * @param array $options
 541          * @return array
 542          */
 543         function makeSelectOptions( $options ) {
 544                 foreach ( $options as $k => $v ) {
 545                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 546                                 $options[$k] = '';
 547                         }
 548                 }
 549
 550                 return parent::makeSelectOptions( $options );
 551         }
 552
 553         /**
 554          * @param array $options
 555          * @return string
 556          */
 557         protected function makeUpdateOptionsArray( $options ) {
 558                 $options = parent::makeUpdateOptionsArray( $options );
 559                 $options = self::fixIgnore( $options );
 560
 561                 return $options;
 562         }
 563
 564         /**
 565          * @param array $options
 566          * @return array
 567          */
 568         static function fixIgnore( $options ) {
 569                 # SQLite uses OR IGNORE not just IGNORE
 570                 foreach ( $options as $k => $v ) {
 571                         if ( $v == 'IGNORE' ) {
 572                                 $options[$k] = 'OR IGNORE';
 573                         }
 574                 }
 575
 576                 return $options;
 577         }
 578
 579         /**
 580          * @param array $options
 581          * @return string
 582          */
 583         function makeInsertOptions( $options ) {
 584                 $options = self::fixIgnore( $options );
 585
 586                 return parent::makeInsertOptions( $options );
 587         }
 588
 589         /**
 590          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 591          * @param string $table
 592          * @param array $a
 593          * @param string $fname
 594          * @param array $options
 595          * @return bool
 596          */
 597         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 598                 if ( !count( $a ) ) {
 599                         return true;
 600                 }
 601
 602                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 603                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 604                         $ret = true;
 605                         foreach ( $a as $v ) {
 606                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 607                                         $ret = false;
 608                                 }
 609                         }
 610                 } else {
 611                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 612                 }
 613
 614                 return $ret;
 615         }
 616
 617         /**
 618          * @param string $table
 619          * @param array $uniqueIndexes Unused
 620          * @param string|array $rows
 621          * @param string $fname
 622          * @return bool|ResultWrapper
 623          */
 624         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 625                 if ( !count( $rows ) ) {
 626                         return true;
 627                 }
 628
 629                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 630                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 631                         $ret = true;
 632                         foreach ( $rows as $v ) {
 633                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 634                                         $ret = false;
 635                                 }
 636                         }
 637                 } else {
 638                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 639                 }
 640
 641                 return $ret;
 642         }
 643
 644         /**
 645          * Returns the size of a text field, or -1 for "unlimited"
 646          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 647          *
 648          * @param string $table
 649          * @param string $field
 650          * @return int
 651          */
 652         function textFieldSize( $table, $field ) {
 653                 return -1;
 654         }
 655
 656         /**
 657          * @return bool
 658          */
 659         function unionSupportsOrderAndLimit() {
 660                 return false;
 661         }
 662
 663         /**
 664          * @param string $sqls
 665          * @param bool $all Whether to "UNION ALL" or not
 666          * @return string
 667          */
 668         function unionQueries( $sqls, $all ) {
 669                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 670
 671                 return implode( $glue, $sqls );
 672         }
 673
 674         /**
 675          * @return bool
 676          */
 677         function wasDeadlock() {
 678                 return $this->lastErrno() == 5; // SQLITE_BUSY
 679         }
 680
 681         /**
 682          * @return bool
 683          */
 684         function wasErrorReissuable() {
 685                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 686         }
 687
 688         /**
 689          * @return bool
 690          */
 691         function wasReadOnlyError() {
 692                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 693         }
 694
 695         /**
 696          * @return string Wikitext of a link to the server software's web site
 697          */
 698         public function getSoftwareLink() {
 699                 return "[{{int:version-db-sqlite-url}} SQLite]";
 700         }
 701
 702         /**
 703          * @return string Version information from the database
 704          */
 705         function getServerVersion() {
 706                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 707
 708                 return $ver;
 709         }
 710
 711         /**
 712          * Get information about a given field
 713          * Returns false if the field does not exist.
 714          *
 715          * @param string $table
 716          * @param string $field
 717          * @return SQLiteField|bool False on failure
 718          */
 719         function fieldInfo( $table, $field ) {
 720                 $tableName = $this->tableName( $table );
 721                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 722                 $res = $this->query( $sql, __METHOD__ );
 723                 foreach ( $res as $row ) {
 724                         if ( $row->name == $field ) {
 725                                 return new SQLiteField( $row, $tableName );
 726                         }
 727                 }
 728
 729                 return false;
 730         }
 731
 732         protected function doBegin( $fname = '' ) {
 733                 if ( $this->trxMode ) {
 734                         $this->query( "BEGIN {$this->trxMode}", $fname );
 735                 } else {
 736                         $this->query( 'BEGIN', $fname );
 737                 }
 738                 $this->mTrxLevel = 1;
 739         }
 740
 741         /**
 742          * @param string $s
 743          * @return string
 744          */
 745         function strencode( $s ) {
 746                 return substr( $this->addQuotes( $s ), 1, -1 );
 747         }
 748
 749         /**
 750          * @param string $b
 751          * @return Blob
 752          */
 753         function encodeBlob( $b ) {
 754                 return new Blob( $b );
 755         }
 756
 757         /**
 758          * @param Blob|string $b
 759          * @return string
 760          */
 761         function decodeBlob( $b ) {
 762                 if ( $b instanceof Blob ) {
 763                         $b = $b->fetch();
 764                 }
 765
 766                 return $b;
 767         }
 768
 769         /**
 770          * @param string|int|null|bool|Blob $s
 771          * @return string|int
 772          */
 773         function addQuotes( $s ) {
 774                 if ( $s instanceof Blob ) {
 775                         return "x'" . bin2hex( $s->fetch() ) . "'";
 776                 } elseif ( is_bool( $s ) ) {
 777                         return (int)$s;
 778                 } elseif ( strpos( $s, "\0" ) !== false ) {
 779                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 780                         // This is a known limitation of SQLite's mprintf function which PDO
 781                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 782                         // https://bugs.php.net/bug.php?id=63419
 783                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 784                         // https://bugs.php.net/bug.php?id=62361
 785                         // There is an additional bug regarding sorting this data after insert
 786                         // on older versions of sqlite shipped with ubuntu 12.04
 787                         // https://phabricator.wikimedia.org/T74367
 788                         $this->queryLogger->debug(
 789                                 __FUNCTION__ .
 790                                 ': Quoting value containing null byte. ' .
 791                                 'For consistency all binary data should have been ' .
 792                                 'first processed with self::encodeBlob()'
 793                         );
 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          * @param string $field Field or column to cast
 814          * @return string
 815          * @since 1.28
 816          */
 817         public function buildStringCast( $field ) {
 818                 return 'CAST ( ' . $field . ' AS TEXT )';
 819         }
 820
 821         /**
 822          * No-op version of deadlockLoop
 823          *
 824          * @return mixed
 825          */
 826         public function deadlockLoop( /*...*/ ) {
 827                 $args = func_get_args();
 828                 $function = array_shift( $args );
 829
 830                 return call_user_func_array( $function, $args );
 831         }
 832
 833         /**
 834          * @param string $s
 835          * @return string
 836          */
 837         protected function replaceVars( $s ) {
 838                 $s = parent::replaceVars( $s );
 839                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 840                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 841
 842                         // binary/varbinary column type -> blob
 843                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 844                         // no such thing as unsigned
 845                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 846                         // INT -> INTEGER
 847                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 848                         // floating point types -> REAL
 849                         $s = preg_replace(
 850                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 851                                 'REAL',
 852                                 $s
 853                         );
 854                         // varchar -> TEXT
 855                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 856                         // TEXT normalization
 857                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 858                         // BLOB normalization
 859                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 860                         // BOOL -> INTEGER
 861                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 862                         // DATETIME -> TEXT
 863                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 864                         // No ENUM type
 865                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 866                         // binary collation type -> nothing
 867                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 868                         // auto_increment -> autoincrement
 869                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 870                         // No explicit options
 871                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 872                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 873                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 874                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 875                         // No truncated indexes
 876                         $s = preg_replace( '/\(\d+\)/', '', $s );
 877                         // No FULLTEXT
 878                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 879                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 880                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 881                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 882                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 883                         // INSERT IGNORE --> INSERT OR IGNORE
 884                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 885                 }
 886
 887                 return $s;
 888         }
 889
 890         public function lock( $lockName, $method, $timeout = 5 ) {
 891                 if ( !is_dir( "{$this->dbDir}/locks" ) ) { // create dir as needed
 892                         if ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) ) {
 893                                 throw new DBError( $this, "Cannot create directory \"{$this->dbDir}/locks\"." );
 894                         }
 895                 }
 896
 897                 return $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout )->isOK();
 898         }
 899
 900         public function unlock( $lockName, $method ) {
 901                 return $this->lockMgr->unlock( [ $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 = []
 916         ) {
 917                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 918
 919                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
 920         }
 921
 922         /**
 923          * @param string $oldName
 924          * @param string $newName
 925          * @param bool $temporary
 926          * @param string $fname
 927          * @return bool|ResultWrapper
 928          * @throws RuntimeException
 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 RuntimeException( "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                                 $this->queryLogger->debug(
 947                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 948                         } else {
 949                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 950                         }
 951                 }
 952
 953                 $res = $this->query( $sql, $fname );
 954
 955                 // Take over indexes
 956                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
 957                 foreach ( $indexList as $index ) {
 958                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
 959                                 continue;
 960                         }
 961
 962                         if ( $index->unique ) {
 963                                 $sql = 'CREATE UNIQUE INDEX';
 964                         } else {
 965                                 $sql = 'CREATE INDEX';
 966                         }
 967                         // Try to come up with a new index name, given indexes have database scope in SQLite
 968                         $indexName = $newName . '_' . $index->name;
 969                         $sql .= ' ' . $indexName . ' ON ' . $newName;
 970
 971                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
 972                         $fields = [];
 973                         foreach ( $indexInfo as $indexInfoRow ) {
 974                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
 975                         }
 976
 977                         $sql .= '(' . implode( ',', $fields ) . ')';
 978
 979                         $this->query( $sql );
 980                 }
 981
 982                 return $res;
 983         }
 984
 985         /**
 986          * List all tables on the database
 987          *
 988          * @param string $prefix Only show tables with this prefix, e.g. mw_
 989          * @param string $fname Calling function name
 990          *
 991          * @return array
 992          */
 993         function listTables( $prefix = null, $fname = __METHOD__ ) {
 994                 $result = $this->select(
 995                         'sqlite_master',
 996                         'name',
 997                         "type='table'"
 998                 );
 999
1000                 $endArray = [];
1001
1002                 foreach ( $result as $table ) {
1003                         $vars = get_object_vars( $table );
1004                         $table = array_pop( $vars );
1005
1006                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1007                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1008                                         $endArray[] = $table;
1009                                 }
1010                         }
1011                 }
1012
1013                 return $endArray;
1014         }
1015
1016         /**
1017          * Override due to no CASCADE support
1018          *
1019          * @param string $tableName
1020          * @param string $fName
1021          * @return bool|ResultWrapper
1022          * @throws DBReadOnlyError
1023          */
1024         public function dropTable( $tableName, $fName = __METHOD__ ) {
1025                 if ( !$this->tableExists( $tableName, $fName ) ) {
1026                         return false;
1027                 }
1028                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1029
1030                 return $this->query( $sql, $fName );
1031         }
1032
1033         protected function requiresDatabaseUser() {
1034                 return false; // just a file
1035         }
1036
1037         /**
1038          * @return string
1039          */
1040         public function __toString() {
1041                 return 'SQLite ' . (string)$this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
1042         }
1043 }