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
  35         /** @var string File name for SQLite database file */
  36         protected $dbPath;
  37
  38         /** @var string Transaction mode */
  39         protected $trxMode;
  40
  41         /** @var int The number of rows affected as an integer */
  42         protected $mAffectedRows;
  43
  44         /** @var resource */
  45         protected $mLastResult;
  46
  47         /** @var $mConn PDO */
  48
  49         /** @var FSLockManager (hopefully on the same server as the DB) */
  50         protected $lockMgr;
  51
  52         /**
  53          * Additional params include:
  54          *   - dbDirectory : directory containing the DB and the lock file directory
  55          *                   [defaults to $wgSQLiteDataDir]
  56          *   - dbFilePath  : use this to force the path of the DB file
  57          *   - trxMode     : one of (deferred, immediate, exclusive)
  58          * @param array $p
  59          */
  60         function __construct( array $p ) {
  61                 if ( isset( $p['dbFilePath'] ) ) {
  62                         parent::__construct( $p );
  63                         // Standalone .sqlite file mode.
  64                         // Super doesn't open when $user is false, but we can work with $dbName,
  65                         // which is derived from the file path in this case.
  66                         $this->openFile( $p['dbFilePath'] );
  67                         $lockDomain = md5( $p['dbFilePath'] );
  68                 } elseif ( !isset( $p['dbDirectory'] ) ) {
  69                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
  70                 } else {
  71                         $this->dbDir = $p['dbDirectory'];
  72                         $this->mDBname = $p['dbname'];
  73                         $lockDomain = $this->mDBname;
  74                         // Stock wiki mode using standard file names per DB.
  75                         parent::__construct( $p );
  76                         // Super doesn't open when $user is false, but we can work with $dbName
  77                         if ( $p['dbname'] && !$this->isOpen() ) {
  78                                 if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  79                                         $done = [];
  80                                         foreach ( $this->tableAliases as $params ) {
  81                                                 if ( isset( $done[$params['dbname']] ) ) {
  82                                                         continue;
  83                                                 }
  84                                                 $this->attachDatabase( $params['dbname'] );
  85                                                 $done[$params['dbname']] = 1;
  86                                         }
  87                                 }
  88                         }
  89                 }
  90
  91                 $this->trxMode = isset( $p['trxMode'] ) ? strtoupper( $p['trxMode'] ) : null;
  92                 if ( $this->trxMode &&
  93                         !in_array( $this->trxMode, [ 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ] )
  94                 ) {
  95                         $this->trxMode = null;
  96                         $this->queryLogger->warning( "Invalid SQLite transaction mode provided." );
  97                 }
  98
  99                 $this->lockMgr = new FSLockManager( [
 100                         'domain' => $lockDomain,
 101                         'lockDirectory' => "{$this->dbDir}/locks"
 102                 ] );
 103         }
 104
 105         /**
 106          * @param string $filename
 107          * @param array $p Options map; supports:
 108          *   - flags       : (same as __construct counterpart)
 109          *   - trxMode     : (same as __construct counterpart)
 110          *   - dbDirectory : (same as __construct counterpart)
 111          * @return DatabaseSqlite
 112          * @since 1.25
 113          */
 114         public static function newStandaloneInstance( $filename, array $p = [] ) {
 115                 $p['dbFilePath'] = $filename;
 116                 $p['schema'] = false;
 117                 $p['tablePrefix'] = '';
 118
 119                 return Database::factory( 'sqlite', $p );
 120         }
 121
 122         /**
 123          * @return string
 124          */
 125         function getType() {
 126                 return 'sqlite';
 127         }
 128
 129         /**
 130          * @todo Check if it should be true like parent class
 131          *
 132          * @return bool
 133          */
 134         function implicitGroupby() {
 135                 return false;
 136         }
 137
 138         /** Open an SQLite database and return a resource handle to it
 139          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
 140          *
 141          * @param string $server
 142          * @param string $user
 143          * @param string $pass
 144          * @param string $dbName
 145          *
 146          * @throws DBConnectionError
 147          * @return PDO
 148          */
 149         function open( $server, $user, $pass, $dbName ) {
 150                 $this->close();
 151                 $fileName = self::generateFileName( $this->dbDir, $dbName );
 152                 if ( !is_readable( $fileName ) ) {
 153                         $this->mConn = false;
 154                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 155                 }
 156                 $this->openFile( $fileName );
 157
 158                 return $this->mConn;
 159         }
 160
 161         /**
 162          * Opens a database file
 163          *
 164          * @param string $fileName
 165          * @throws DBConnectionError
 166          * @return PDO|bool SQL connection or false if failed
 167          */
 168         protected function openFile( $fileName ) {
 169                 $err = false;
 170
 171                 $this->dbPath = $fileName;
 172                 try {
 173                         if ( $this->mFlags & self::DBO_PERSISTENT ) {
 174                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 175                                         [ PDO::ATTR_PERSISTENT => true ] );
 176                         } else {
 177                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 178                         }
 179                 } catch ( PDOException $e ) {
 180                         $err = $e->getMessage();
 181                 }
 182
 183                 if ( !$this->mConn ) {
 184                         $this->queryLogger->debug( "DB connection error: $err\n" );
 185                         throw new DBConnectionError( $this, $err );
 186                 }
 187
 188                 $this->mOpened = !!$this->mConn;
 189                 if ( $this->mOpened ) {
 190                         # Set error codes only, don't raise exceptions
 191                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 192                         # Enforce LIKE to be case sensitive, just like MySQL
 193                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 194
 195                         return $this->mConn;
 196                 }
 197
 198                 return false;
 199         }
 200
 201         /**
 202          * @return string SQLite DB file path
 203          * @since 1.25
 204          */
 205         public function getDbFilePath() {
 206                 return $this->dbPath;
 207         }
 208
 209         /**
 210          * Does not actually close the connection, just destroys the reference for GC to do its work
 211          * @return bool
 212          */
 213         protected function closeConnection() {
 214                 $this->mConn = null;
 215
 216                 return true;
 217         }
 218
 219         /**
 220          * Generates a database file name. Explicitly public for installer.
 221          * @param string $dir Directory where database resides
 222          * @param string $dbName Database name
 223          * @return string
 224          */
 225         public static function generateFileName( $dir, $dbName ) {
 226                 return "$dir/$dbName.sqlite";
 227         }
 228
 229         /**
 230          * Check if the searchindext table is FTS enabled.
 231          * @return bool False if not enabled.
 232          */
 233         function checkForEnabledSearch() {
 234                 if ( self::$fulltextEnabled === null ) {
 235                         self::$fulltextEnabled = false;
 236                         $table = $this->tableName( 'searchindex' );
 237                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 238                         if ( $res ) {
 239                                 $row = $res->fetchRow();
 240                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 241                         }
 242                 }
 243
 244                 return self::$fulltextEnabled;
 245         }
 246
 247         /**
 248          * Returns version of currently supported SQLite fulltext search module or false if none present.
 249          * @return string
 250          */
 251         static function getFulltextSearchModule() {
 252                 static $cachedResult = null;
 253                 if ( $cachedResult !== null ) {
 254                         return $cachedResult;
 255                 }
 256                 $cachedResult = false;
 257                 $table = 'dummy_search_test';
 258
 259                 $db = self::newStandaloneInstance( ':memory:' );
 260                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 261                         $cachedResult = 'FTS3';
 262                 }
 263                 $db->close();
 264
 265                 return $cachedResult;
 266         }
 267
 268         /**
 269          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 270          * for details.
 271          *
 272          * @param string $name Database name to be used in queries like
 273          *   SELECT foo FROM dbname.table
 274          * @param bool|string $file Database file name. If omitted, will be generated
 275          *   using $name and configured data directory
 276          * @param string $fname Calling function name
 277          * @return ResultWrapper
 278          */
 279         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 280                 if ( !$file ) {
 281                         $file = self::generateFileName( $this->dbDir, $name );
 282                 }
 283                 $file = $this->addQuotes( $file );
 284
 285                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 286         }
 287
 288         function isWriteQuery( $sql ) {
 289                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 290         }
 291
 292         /**
 293          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 294          *
 295          * @param string $sql
 296          * @return bool|ResultWrapper
 297          */
 298         protected function doQuery( $sql ) {
 299                 $res = $this->mConn->query( $sql );
 300                 if ( $res === false ) {
 301                         return false;
 302                 }
 303
 304                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 305                 $this->mAffectedRows = $r->rowCount();
 306                 $res = new ResultWrapper( $this, $r->fetchAll() );
 307
 308                 return $res;
 309         }
 310
 311         /**
 312          * @param ResultWrapper|mixed $res
 313          */
 314         function freeResult( $res ) {
 315                 if ( $res instanceof ResultWrapper ) {
 316                         $res->result = null;
 317                 } else {
 318                         $res = null;
 319                 }
 320         }
 321
 322         /**
 323          * @param ResultWrapper|array $res
 324          * @return stdClass|bool
 325          */
 326         function fetchObject( $res ) {
 327                 if ( $res instanceof ResultWrapper ) {
 328                         $r =& $res->result;
 329                 } else {
 330                         $r =& $res;
 331                 }
 332
 333                 $cur = current( $r );
 334                 if ( is_array( $cur ) ) {
 335                         next( $r );
 336                         $obj = new stdClass;
 337                         foreach ( $cur as $k => $v ) {
 338                                 if ( !is_numeric( $k ) ) {
 339                                         $obj->$k = $v;
 340                                 }
 341                         }
 342
 343                         return $obj;
 344                 }
 345
 346                 return false;
 347         }
 348
 349         /**
 350          * @param ResultWrapper|mixed $res
 351          * @return array|bool
 352          */
 353         function fetchRow( $res ) {
 354                 if ( $res instanceof ResultWrapper ) {
 355                         $r =& $res->result;
 356                 } else {
 357                         $r =& $res;
 358                 }
 359                 $cur = current( $r );
 360                 if ( is_array( $cur ) ) {
 361                         next( $r );
 362
 363                         return $cur;
 364                 }
 365
 366                 return false;
 367         }
 368
 369         /**
 370          * The PDO::Statement class implements the array interface so count() will work
 371          *
 372          * @param ResultWrapper|array $res
 373          * @return int
 374          */
 375         function numRows( $res ) {
 376                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 377
 378                 return count( $r );
 379         }
 380
 381         /**
 382          * @param ResultWrapper $res
 383          * @return int
 384          */
 385         function numFields( $res ) {
 386                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 387                 if ( is_array( $r ) && count( $r ) > 0 ) {
 388                         // The size of the result array is twice the number of fields. (Bug: 65578)
 389                         return count( $r[0] ) / 2;
 390                 } else {
 391                         // If the result is empty return 0
 392                         return 0;
 393                 }
 394         }
 395
 396         /**
 397          * @param ResultWrapper $res
 398          * @param int $n
 399          * @return bool
 400          */
 401         function fieldName( $res, $n ) {
 402                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 403                 if ( is_array( $r ) ) {
 404                         $keys = array_keys( $r[0] );
 405
 406                         return $keys[$n];
 407                 }
 408
 409                 return false;
 410         }
 411
 412         /**
 413          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 414          *
 415          * @param string $name
 416          * @param string $format
 417          * @return string
 418          */
 419         function tableName( $name, $format = 'quoted' ) {
 420                 // table names starting with sqlite_ are reserved
 421                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 422                         return $name;
 423                 }
 424
 425                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 426         }
 427
 428         /**
 429          * This must be called after nextSequenceVal
 430          *
 431          * @return int
 432          */
 433         function insertId() {
 434                 // PDO::lastInsertId yields a string :(
 435                 return intval( $this->mConn->lastInsertId() );
 436         }
 437
 438         /**
 439          * @param ResultWrapper|array $res
 440          * @param int $row
 441          */
 442         function dataSeek( $res, $row ) {
 443                 if ( $res instanceof ResultWrapper ) {
 444                         $r =& $res->result;
 445                 } else {
 446                         $r =& $res;
 447                 }
 448                 reset( $r );
 449                 if ( $row > 0 ) {
 450                         for ( $i = 0; $i < $row; $i++ ) {
 451                                 next( $r );
 452                         }
 453                 }
 454         }
 455
 456         /**
 457          * @return string
 458          */
 459         function lastError() {
 460                 if ( !is_object( $this->mConn ) ) {
 461                         return "Cannot return last error, no db connection";
 462                 }
 463                 $e = $this->mConn->errorInfo();
 464
 465                 return isset( $e[2] ) ? $e[2] : '';
 466         }
 467
 468         /**
 469          * @return string
 470          */
 471         function lastErrno() {
 472                 if ( !is_object( $this->mConn ) ) {
 473                         return "Cannot return last error, no db connection";
 474                 } else {
 475                         $info = $this->mConn->errorInfo();
 476
 477                         return $info[1];
 478                 }
 479         }
 480
 481         /**
 482          * @return int
 483          */
 484         function affectedRows() {
 485                 return $this->mAffectedRows;
 486         }
 487
 488         /**
 489          * Returns information about an index
 490          * Returns false if the index does not exist
 491          * - if errors are explicitly ignored, returns NULL on failure
 492          *
 493          * @param string $table
 494          * @param string $index
 495          * @param string $fname
 496          * @return array
 497          */
 498         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 499                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 500                 $res = $this->query( $sql, $fname );
 501                 if ( !$res ) {
 502                         return null;
 503                 }
 504                 if ( $res->numRows() == 0 ) {
 505                         return false;
 506                 }
 507                 $info = [];
 508                 foreach ( $res as $row ) {
 509                         $info[] = $row->name;
 510                 }
 511
 512                 return $info;
 513         }
 514
 515         /**
 516          * @param string $table
 517          * @param string $index
 518          * @param string $fname
 519          * @return bool|null
 520          */
 521         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 522                 $row = $this->selectRow( 'sqlite_master', '*',
 523                         [
 524                                 'type' => 'index',
 525                                 'name' => $this->indexName( $index ),
 526                         ], $fname );
 527                 if ( !$row || !isset( $row->sql ) ) {
 528                         return null;
 529                 }
 530
 531                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 532                 $indexPos = strpos( $row->sql, 'INDEX' );
 533                 if ( $indexPos === false ) {
 534                         return null;
 535                 }
 536                 $firstPart = substr( $row->sql, 0, $indexPos );
 537                 $options = explode( ' ', $firstPart );
 538
 539                 return in_array( 'UNIQUE', $options );
 540         }
 541
 542         /**
 543          * Filter the options used in SELECT statements
 544          *
 545          * @param array $options
 546          * @return array
 547          */
 548         function makeSelectOptions( $options ) {
 549                 foreach ( $options as $k => $v ) {
 550                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 551                                 $options[$k] = '';
 552                         }
 553                 }
 554
 555                 return parent::makeSelectOptions( $options );
 556         }
 557
 558         /**
 559          * @param array $options
 560          * @return string
 561          */
 562         protected function makeUpdateOptionsArray( $options ) {
 563                 $options = parent::makeUpdateOptionsArray( $options );
 564                 $options = self::fixIgnore( $options );
 565
 566                 return $options;
 567         }
 568
 569         /**
 570          * @param array $options
 571          * @return array
 572          */
 573         static function fixIgnore( $options ) {
 574                 # SQLite uses OR IGNORE not just IGNORE
 575                 foreach ( $options as $k => $v ) {
 576                         if ( $v == 'IGNORE' ) {
 577                                 $options[$k] = 'OR IGNORE';
 578                         }
 579                 }
 580
 581                 return $options;
 582         }
 583
 584         /**
 585          * @param array $options
 586          * @return string
 587          */
 588         function makeInsertOptions( $options ) {
 589                 $options = self::fixIgnore( $options );
 590
 591                 return parent::makeInsertOptions( $options );
 592         }
 593
 594         /**
 595          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 596          * @param string $table
 597          * @param array $a
 598          * @param string $fname
 599          * @param array $options
 600          * @return bool
 601          */
 602         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 603                 if ( !count( $a ) ) {
 604                         return true;
 605                 }
 606
 607                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 608                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 609                         $ret = true;
 610                         foreach ( $a as $v ) {
 611                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 612                                         $ret = false;
 613                                 }
 614                         }
 615                 } else {
 616                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 617                 }
 618
 619                 return $ret;
 620         }
 621
 622         /**
 623          * @param string $table
 624          * @param array $uniqueIndexes Unused
 625          * @param string|array $rows
 626          * @param string $fname
 627          * @return bool|ResultWrapper
 628          */
 629         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 630                 if ( !count( $rows ) ) {
 631                         return true;
 632                 }
 633
 634                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 635                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 636                         $ret = true;
 637                         foreach ( $rows as $v ) {
 638                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 639                                         $ret = false;
 640                                 }
 641                         }
 642                 } else {
 643                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 644                 }
 645
 646                 return $ret;
 647         }
 648
 649         /**
 650          * Returns the size of a text field, or -1 for "unlimited"
 651          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 652          *
 653          * @param string $table
 654          * @param string $field
 655          * @return int
 656          */
 657         function textFieldSize( $table, $field ) {
 658                 return -1;
 659         }
 660
 661         /**
 662          * @return bool
 663          */
 664         function unionSupportsOrderAndLimit() {
 665                 return false;
 666         }
 667
 668         /**
 669          * @param string $sqls
 670          * @param bool $all Whether to "UNION ALL" or not
 671          * @return string
 672          */
 673         function unionQueries( $sqls, $all ) {
 674                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 675
 676                 return implode( $glue, $sqls );
 677         }
 678
 679         /**
 680          * @return bool
 681          */
 682         function wasDeadlock() {
 683                 return $this->lastErrno() == 5; // SQLITE_BUSY
 684         }
 685
 686         /**
 687          * @return bool
 688          */
 689         function wasErrorReissuable() {
 690                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 691         }
 692
 693         /**
 694          * @return bool
 695          */
 696         function wasReadOnlyError() {
 697                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 698         }
 699
 700         /**
 701          * @return string Wikitext of a link to the server software's web site
 702          */
 703         public function getSoftwareLink() {
 704                 return "[{{int:version-db-sqlite-url}} SQLite]";
 705         }
 706
 707         /**
 708          * @return string Version information from the database
 709          */
 710         function getServerVersion() {
 711                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 712
 713                 return $ver;
 714         }
 715
 716         /**
 717          * Get information about a given field
 718          * Returns false if the field does not exist.
 719          *
 720          * @param string $table
 721          * @param string $field
 722          * @return SQLiteField|bool False on failure
 723          */
 724         function fieldInfo( $table, $field ) {
 725                 $tableName = $this->tableName( $table );
 726                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 727                 $res = $this->query( $sql, __METHOD__ );
 728                 foreach ( $res as $row ) {
 729                         if ( $row->name == $field ) {
 730                                 return new SQLiteField( $row, $tableName );
 731                         }
 732                 }
 733
 734                 return false;
 735         }
 736
 737         protected function doBegin( $fname = '' ) {
 738                 if ( $this->trxMode ) {
 739                         $this->query( "BEGIN {$this->trxMode}", $fname );
 740                 } else {
 741                         $this->query( 'BEGIN', $fname );
 742                 }
 743                 $this->mTrxLevel = 1;
 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 string|int|null|bool|Blob $s
 776          * @return string|int
 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
 786                         // should work around, 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://phabricator.wikimedia.org/T74367
 793                         $this->queryLogger->debug(
 794                                 __FUNCTION__ .
 795                                 ': Quoting value containing null byte. ' .
 796                                 'For consistency all binary data should have been ' .
 797                                 'first processed with self::encodeBlob()'
 798                         );
 799                         return "x'" . bin2hex( $s ) . "'";
 800                 } else {
 801                         return $this->mConn->quote( $s );
 802                 }
 803         }
 804
 805         /**
 806          * @return string
 807          */
 808         function buildLike() {
 809                 $params = func_get_args();
 810                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 811                         $params = $params[0];
 812                 }
 813
 814                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 815         }
 816
 817         /**
 818          * @param string $field Field or column to cast
 819          * @return string
 820          * @since 1.28
 821          */
 822         public function buildStringCast( $field ) {
 823                 return 'CAST ( ' . $field . ' AS TEXT )';
 824         }
 825
 826         /**
 827          * No-op version of deadlockLoop
 828          *
 829          * @return mixed
 830          */
 831         public function deadlockLoop( /*...*/ ) {
 832                 $args = func_get_args();
 833                 $function = array_shift( $args );
 834
 835                 return call_user_func_array( $function, $args );
 836         }
 837
 838         /**
 839          * @param string $s
 840          * @return string
 841          */
 842         protected function replaceVars( $s ) {
 843                 $s = parent::replaceVars( $s );
 844                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 845                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 846
 847                         // binary/varbinary column type -> blob
 848                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 849                         // no such thing as unsigned
 850                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 851                         // INT -> INTEGER
 852                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 853                         // floating point types -> REAL
 854                         $s = preg_replace(
 855                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 856                                 'REAL',
 857                                 $s
 858                         );
 859                         // varchar -> TEXT
 860                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 861                         // TEXT normalization
 862                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 863                         // BLOB normalization
 864                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 865                         // BOOL -> INTEGER
 866                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 867                         // DATETIME -> TEXT
 868                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 869                         // No ENUM type
 870                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 871                         // binary collation type -> nothing
 872                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 873                         // auto_increment -> autoincrement
 874                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 875                         // No explicit options
 876                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 877                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 878                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 879                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 880                         // No truncated indexes
 881                         $s = preg_replace( '/\(\d+\)/', '', $s );
 882                         // No FULLTEXT
 883                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 884                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 885                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 886                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 887                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 888                         // INSERT IGNORE --> INSERT OR IGNORE
 889                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 890                 }
 891
 892                 return $s;
 893         }
 894
 895         public function lock( $lockName, $method, $timeout = 5 ) {
 896                 if ( !is_dir( "{$this->dbDir}/locks" ) ) { // create dir as needed
 897                         if ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) ) {
 898                                 throw new DBError( $this, "Cannot create directory \"{$this->dbDir}/locks\"." );
 899                         }
 900                 }
 901
 902                 return $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout )->isOK();
 903         }
 904
 905         public function unlock( $lockName, $method ) {
 906                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isOK();
 907         }
 908
 909         /**
 910          * Build a concatenation list to feed into a SQL query
 911          *
 912          * @param string[] $stringList
 913          * @return string
 914          */
 915         function buildConcat( $stringList ) {
 916                 return '(' . implode( ') || (', $stringList ) . ')';
 917         }
 918
 919         public function buildGroupConcatField(
 920                 $delim, $table, $field, $conds = '', $join_conds = []
 921         ) {
 922                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 923
 924                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
 925         }
 926
 927         /**
 928          * @param string $oldName
 929          * @param string $newName
 930          * @param bool $temporary
 931          * @param string $fname
 932          * @return bool|ResultWrapper
 933          * @throws RuntimeException
 934          */
 935         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 936                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 937                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 938                 $obj = $this->fetchObject( $res );
 939                 if ( !$obj ) {
 940                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
 941                 }
 942                 $sql = $obj->sql;
 943                 $sql = preg_replace(
 944                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 945                         $this->addIdentifierQuotes( $newName ),
 946                         $sql,
 947                         1
 948                 );
 949                 if ( $temporary ) {
 950                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 951                                 $this->queryLogger->debug(
 952                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 953                         } else {
 954                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 955                         }
 956                 }
 957
 958                 $res = $this->query( $sql, $fname );
 959
 960                 // Take over indexes
 961                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
 962                 foreach ( $indexList as $index ) {
 963                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
 964                                 continue;
 965                         }
 966
 967                         if ( $index->unique ) {
 968                                 $sql = 'CREATE UNIQUE INDEX';
 969                         } else {
 970                                 $sql = 'CREATE INDEX';
 971                         }
 972                         // Try to come up with a new index name, given indexes have database scope in SQLite
 973                         $indexName = $newName . '_' . $index->name;
 974                         $sql .= ' ' . $indexName . ' ON ' . $newName;
 975
 976                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
 977                         $fields = [];
 978                         foreach ( $indexInfo as $indexInfoRow ) {
 979                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
 980                         }
 981
 982                         $sql .= '(' . implode( ',', $fields ) . ')';
 983
 984                         $this->query( $sql );
 985                 }
 986
 987                 return $res;
 988         }
 989
 990         /**
 991          * List all tables on the database
 992          *
 993          * @param string $prefix Only show tables with this prefix, e.g. mw_
 994          * @param string $fname Calling function name
 995          *
 996          * @return array
 997          */
 998         function listTables( $prefix = null, $fname = __METHOD__ ) {
 999                 $result = $this->select(
1000                         'sqlite_master',
1001                         'name',
1002                         "type='table'"
1003                 );
1004
1005                 $endArray = [];
1006
1007                 foreach ( $result as $table ) {
1008                         $vars = get_object_vars( $table );
1009                         $table = array_pop( $vars );
1010
1011                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1012                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1013                                         $endArray[] = $table;
1014                                 }
1015                         }
1016                 }
1017
1018                 return $endArray;
1019         }
1020
1021         /**
1022          * Override due to no CASCADE support
1023          *
1024          * @param string $tableName
1025          * @param string $fName
1026          * @return bool|ResultWrapper
1027          * @throws DBReadOnlyError
1028          */
1029         public function dropTable( $tableName, $fName = __METHOD__ ) {
1030                 if ( !$this->tableExists( $tableName, $fName ) ) {
1031                         return false;
1032                 }
1033                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1034
1035                 return $this->query( $sql, $fName );
1036         }
1037
1038         protected function requiresDatabaseUser() {
1039                 return false; // just a file
1040         }
1041
1042         /**
1043          * @return string
1044          */
1045         public function __toString() {
1046                 return 'SQLite ' . (string)$this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
1047         }
1048 }