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 DatabaseBase {
  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 PDO */
  48         protected $mConn;
  49
  50         /** @var FSLockManager (hopefully on the same server as the DB) */
  51         protected $lockMgr;
  52
  53         /**
  54          * Additional params include:
  55          *   - dbDirectory : directory containing the DB and the lock file directory
  56          *                   [defaults to $wgSQLiteDataDir]
  57          *   - dbFilePath  : use this to force the path of the DB file
  58          *   - trxMode     : one of (deferred, immediate, exclusive)
  59          * @param array $p
  60          */
  61         function __construct( array $p ) {
  62                 if ( isset( $p['dbFilePath'] ) ) {
  63                         parent::__construct( $p );
  64                         // Standalone .sqlite file mode.
  65                         // Super doesn't open when $user is false, but we can work with $dbName,
  66                         // which is derived from the file path in this case.
  67                         $this->openFile( $p['dbFilePath'] );
  68                         $lockDomain = md5( $p['dbFilePath'] );
  69                 } elseif ( !isset( $p['dbDirectory'] ) ) {
  70                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
  71                 } else {
  72                         $this->dbDir = $p['dbDirectory'];
  73                         $this->mDBname = $p['dbname'];
  74                         $lockDomain = $this->mDBname;
  75                         // Stock wiki mode using standard file names per DB.
  76                         parent::__construct( $p );
  77                         // Super doesn't open when $user is false, but we can work with $dbName
  78                         if ( $p['dbname'] && !$this->isOpen() ) {
  79                                 if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  80                                         $done = [];
  81                                         foreach ( $this->tableAliases as $params ) {
  82                                                 if ( isset( $done[$params['dbname']] ) ) {
  83                                                         continue;
  84                                                 }
  85                                                 $this->attachDatabase( $params['dbname'] );
  86                                                 $done[$params['dbname']] = 1;
  87                                         }
  88                                 }
  89                         }
  90                 }
  91
  92                 $this->trxMode = isset( $p['trxMode'] ) ? strtoupper( $p['trxMode'] ) : null;
  93                 if ( $this->trxMode &&
  94                         !in_array( $this->trxMode, [ 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ] )
  95                 ) {
  96                         $this->trxMode = null;
  97                         $this->queryLogger->warning( "Invalid SQLite transaction mode provided." );
  98                 }
  99
 100                 $this->lockMgr = new FSLockManager( [
 101                         'domain' => $lockDomain,
 102                         'lockDirectory' => "{$this->dbDir}/locks"
 103                 ] );
 104         }
 105
 106         /**
 107          * @param string $filename
 108          * @param array $p Options map; supports:
 109          *   - flags       : (same as __construct counterpart)
 110          *   - trxMode     : (same as __construct counterpart)
 111          *   - dbDirectory : (same as __construct counterpart)
 112          * @return DatabaseSqlite
 113          * @since 1.25
 114          */
 115         public static function newStandaloneInstance( $filename, array $p = [] ) {
 116                 $p['dbFilePath'] = $filename;
 117                 $p['schema'] = false;
 118                 $p['tablePrefix'] = '';
 119
 120                 return DatabaseBase::factory( 'sqlite', $p );
 121         }
 122
 123         /**
 124          * @return string
 125          */
 126         function getType() {
 127                 return 'sqlite';
 128         }
 129
 130         /**
 131          * @todo Check if it should be true like parent class
 132          *
 133          * @return bool
 134          */
 135         function implicitGroupby() {
 136                 return false;
 137         }
 138
 139         /** Open an SQLite database and return a resource handle to it
 140          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
 141          *
 142          * @param string $server
 143          * @param string $user
 144          * @param string $pass
 145          * @param string $dbName
 146          *
 147          * @throws DBConnectionError
 148          * @return PDO
 149          */
 150         function open( $server, $user, $pass, $dbName ) {
 151                 $this->close();
 152                 $fileName = self::generateFileName( $this->dbDir, $dbName );
 153                 if ( !is_readable( $fileName ) ) {
 154                         $this->mConn = false;
 155                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 156                 }
 157                 $this->openFile( $fileName );
 158
 159                 return $this->mConn;
 160         }
 161
 162         /**
 163          * Opens a database file
 164          *
 165          * @param string $fileName
 166          * @throws DBConnectionError
 167          * @return PDO|bool SQL connection or false if failed
 168          */
 169         protected function openFile( $fileName ) {
 170                 $err = false;
 171
 172                 $this->dbPath = $fileName;
 173                 try {
 174                         if ( $this->mFlags & DBO_PERSISTENT ) {
 175                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 176                                         [ PDO::ATTR_PERSISTENT => true ] );
 177                         } else {
 178                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 179                         }
 180                 } catch ( PDOException $e ) {
 181                         $err = $e->getMessage();
 182                 }
 183
 184                 if ( !$this->mConn ) {
 185                         $this->queryLogger->debug( "DB connection error: $err\n" );
 186                         throw new DBConnectionError( $this, $err );
 187                 }
 188
 189                 $this->mOpened = !!$this->mConn;
 190                 if ( $this->mOpened ) {
 191                         # Set error codes only, don't raise exceptions
 192                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 193                         # Enforce LIKE to be case sensitive, just like MySQL
 194                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 195
 196                         return $this->mConn;
 197                 }
 198
 199                 return false;
 200         }
 201
 202         /**
 203          * @return string SQLite DB file path
 204          * @since 1.25
 205          */
 206         public function getDbFilePath() {
 207                 return $this->dbPath;
 208         }
 209
 210         /**
 211          * Does not actually close the connection, just destroys the reference for GC to do its work
 212          * @return bool
 213          */
 214         protected function closeConnection() {
 215                 $this->mConn = null;
 216
 217                 return true;
 218         }
 219
 220         /**
 221          * Generates a database file name. Explicitly public for installer.
 222          * @param string $dir Directory where database resides
 223          * @param string $dbName Database name
 224          * @return string
 225          */
 226         public static function generateFileName( $dir, $dbName ) {
 227                 return "$dir/$dbName.sqlite";
 228         }
 229
 230         /**
 231          * Check if the searchindext table is FTS enabled.
 232          * @return bool False if not enabled.
 233          */
 234         function checkForEnabledSearch() {
 235                 if ( self::$fulltextEnabled === null ) {
 236                         self::$fulltextEnabled = false;
 237                         $table = $this->tableName( 'searchindex' );
 238                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 239                         if ( $res ) {
 240                                 $row = $res->fetchRow();
 241                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 242                         }
 243                 }
 244
 245                 return self::$fulltextEnabled;
 246         }
 247
 248         /**
 249          * Returns version of currently supported SQLite fulltext search module or false if none present.
 250          * @return string
 251          */
 252         static function getFulltextSearchModule() {
 253                 static $cachedResult = null;
 254                 if ( $cachedResult !== null ) {
 255                         return $cachedResult;
 256                 }
 257                 $cachedResult = false;
 258                 $table = 'dummy_search_test';
 259
 260                 $db = self::newStandaloneInstance( ':memory:' );
 261                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 262                         $cachedResult = 'FTS3';
 263                 }
 264                 $db->close();
 265
 266                 return $cachedResult;
 267         }
 268
 269         /**
 270          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 271          * for details.
 272          *
 273          * @param string $name Database name to be used in queries like
 274          *   SELECT foo FROM dbname.table
 275          * @param bool|string $file Database file name. If omitted, will be generated
 276          *   using $name and configured data directory
 277          * @param string $fname Calling function name
 278          * @return ResultWrapper
 279          */
 280         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 281                 if ( !$file ) {
 282                         $file = self::generateFileName( $this->dbDir, $name );
 283                 }
 284                 $file = $this->addQuotes( $file );
 285
 286                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 287         }
 288
 289         function isWriteQuery( $sql ) {
 290                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 291         }
 292
 293         /**
 294          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 295          *
 296          * @param string $sql
 297          * @return bool|ResultWrapper
 298          */
 299         protected function doQuery( $sql ) {
 300                 $res = $this->mConn->query( $sql );
 301                 if ( $res === false ) {
 302                         return false;
 303                 }
 304
 305                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 306                 $this->mAffectedRows = $r->rowCount();
 307                 $res = new ResultWrapper( $this, $r->fetchAll() );
 308
 309                 return $res;
 310         }
 311
 312         /**
 313          * @param ResultWrapper|mixed $res
 314          */
 315         function freeResult( $res ) {
 316                 if ( $res instanceof ResultWrapper ) {
 317                         $res->result = null;
 318                 } else {
 319                         $res = null;
 320                 }
 321         }
 322
 323         /**
 324          * @param ResultWrapper|array $res
 325          * @return stdClass|bool
 326          */
 327         function fetchObject( $res ) {
 328                 if ( $res instanceof ResultWrapper ) {
 329                         $r =& $res->result;
 330                 } else {
 331                         $r =& $res;
 332                 }
 333
 334                 $cur = current( $r );
 335                 if ( is_array( $cur ) ) {
 336                         next( $r );
 337                         $obj = new stdClass;
 338                         foreach ( $cur as $k => $v ) {
 339                                 if ( !is_numeric( $k ) ) {
 340                                         $obj->$k = $v;
 341                                 }
 342                         }
 343
 344                         return $obj;
 345                 }
 346
 347                 return false;
 348         }
 349
 350         /**
 351          * @param ResultWrapper|mixed $res
 352          * @return array|bool
 353          */
 354         function fetchRow( $res ) {
 355                 if ( $res instanceof ResultWrapper ) {
 356                         $r =& $res->result;
 357                 } else {
 358                         $r =& $res;
 359                 }
 360                 $cur = current( $r );
 361                 if ( is_array( $cur ) ) {
 362                         next( $r );
 363
 364                         return $cur;
 365                 }
 366
 367                 return false;
 368         }
 369
 370         /**
 371          * The PDO::Statement class implements the array interface so count() will work
 372          *
 373          * @param ResultWrapper|array $res
 374          * @return int
 375          */
 376         function numRows( $res ) {
 377                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 378
 379                 return count( $r );
 380         }
 381
 382         /**
 383          * @param ResultWrapper $res
 384          * @return int
 385          */
 386         function numFields( $res ) {
 387                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 388                 if ( is_array( $r ) && count( $r ) > 0 ) {
 389                         // The size of the result array is twice the number of fields. (Bug: 65578)
 390                         return count( $r[0] ) / 2;
 391                 } else {
 392                         // If the result is empty return 0
 393                         return 0;
 394                 }
 395         }
 396
 397         /**
 398          * @param ResultWrapper $res
 399          * @param int $n
 400          * @return bool
 401          */
 402         function fieldName( $res, $n ) {
 403                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 404                 if ( is_array( $r ) ) {
 405                         $keys = array_keys( $r[0] );
 406
 407                         return $keys[$n];
 408                 }
 409
 410                 return false;
 411         }
 412
 413         /**
 414          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 415          *
 416          * @param string $name
 417          * @param string $format
 418          * @return string
 419          */
 420         function tableName( $name, $format = 'quoted' ) {
 421                 // table names starting with sqlite_ are reserved
 422                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 423                         return $name;
 424                 }
 425
 426                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 427         }
 428
 429         /**
 430          * This must be called after nextSequenceVal
 431          *
 432          * @return int
 433          */
 434         function insertId() {
 435                 // PDO::lastInsertId yields a string :(
 436                 return intval( $this->mConn->lastInsertId() );
 437         }
 438
 439         /**
 440          * @param ResultWrapper|array $res
 441          * @param int $row
 442          */
 443         function dataSeek( $res, $row ) {
 444                 if ( $res instanceof ResultWrapper ) {
 445                         $r =& $res->result;
 446                 } else {
 447                         $r =& $res;
 448                 }
 449                 reset( $r );
 450                 if ( $row > 0 ) {
 451                         for ( $i = 0; $i < $row; $i++ ) {
 452                                 next( $r );
 453                         }
 454                 }
 455         }
 456
 457         /**
 458          * @return string
 459          */
 460         function lastError() {
 461                 if ( !is_object( $this->mConn ) ) {
 462                         return "Cannot return last error, no db connection";
 463                 }
 464                 $e = $this->mConn->errorInfo();
 465
 466                 return isset( $e[2] ) ? $e[2] : '';
 467         }
 468
 469         /**
 470          * @return string
 471          */
 472         function lastErrno() {
 473                 if ( !is_object( $this->mConn ) ) {
 474                         return "Cannot return last error, no db connection";
 475                 } else {
 476                         $info = $this->mConn->errorInfo();
 477
 478                         return $info[1];
 479                 }
 480         }
 481
 482         /**
 483          * @return int
 484          */
 485         function affectedRows() {
 486                 return $this->mAffectedRows;
 487         }
 488
 489         /**
 490          * Returns information about an index
 491          * Returns false if the index does not exist
 492          * - if errors are explicitly ignored, returns NULL on failure
 493          *
 494          * @param string $table
 495          * @param string $index
 496          * @param string $fname
 497          * @return array
 498          */
 499         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 500                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 501                 $res = $this->query( $sql, $fname );
 502                 if ( !$res ) {
 503                         return null;
 504                 }
 505                 if ( $res->numRows() == 0 ) {
 506                         return false;
 507                 }
 508                 $info = [];
 509                 foreach ( $res as $row ) {
 510                         $info[] = $row->name;
 511                 }
 512
 513                 return $info;
 514         }
 515
 516         /**
 517          * @param string $table
 518          * @param string $index
 519          * @param string $fname
 520          * @return bool|null
 521          */
 522         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 523                 $row = $this->selectRow( 'sqlite_master', '*',
 524                         [
 525                                 'type' => 'index',
 526                                 'name' => $this->indexName( $index ),
 527                         ], $fname );
 528                 if ( !$row || !isset( $row->sql ) ) {
 529                         return null;
 530                 }
 531
 532                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 533                 $indexPos = strpos( $row->sql, 'INDEX' );
 534                 if ( $indexPos === false ) {
 535                         return null;
 536                 }
 537                 $firstPart = substr( $row->sql, 0, $indexPos );
 538                 $options = explode( ' ', $firstPart );
 539
 540                 return in_array( 'UNIQUE', $options );
 541         }
 542
 543         /**
 544          * Filter the options used in SELECT statements
 545          *
 546          * @param array $options
 547          * @return array
 548          */
 549         function makeSelectOptions( $options ) {
 550                 foreach ( $options as $k => $v ) {
 551                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 552                                 $options[$k] = '';
 553                         }
 554                 }
 555
 556                 return parent::makeSelectOptions( $options );
 557         }
 558
 559         /**
 560          * @param array $options
 561          * @return string
 562          */
 563         protected function makeUpdateOptionsArray( $options ) {
 564                 $options = parent::makeUpdateOptionsArray( $options );
 565                 $options = self::fixIgnore( $options );
 566
 567                 return $options;
 568         }
 569
 570         /**
 571          * @param array $options
 572          * @return array
 573          */
 574         static function fixIgnore( $options ) {
 575                 # SQLite uses OR IGNORE not just IGNORE
 576                 foreach ( $options as $k => $v ) {
 577                         if ( $v == 'IGNORE' ) {
 578                                 $options[$k] = 'OR IGNORE';
 579                         }
 580                 }
 581
 582                 return $options;
 583         }
 584
 585         /**
 586          * @param array $options
 587          * @return string
 588          */
 589         function makeInsertOptions( $options ) {
 590                 $options = self::fixIgnore( $options );
 591
 592                 return parent::makeInsertOptions( $options );
 593         }
 594
 595         /**
 596          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 597          * @param string $table
 598          * @param array $a
 599          * @param string $fname
 600          * @param array $options
 601          * @return bool
 602          */
 603         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 604                 if ( !count( $a ) ) {
 605                         return true;
 606                 }
 607
 608                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 609                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 610                         $ret = true;
 611                         foreach ( $a as $v ) {
 612                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 613                                         $ret = false;
 614                                 }
 615                         }
 616                 } else {
 617                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 618                 }
 619
 620                 return $ret;
 621         }
 622
 623         /**
 624          * @param string $table
 625          * @param array $uniqueIndexes Unused
 626          * @param string|array $rows
 627          * @param string $fname
 628          * @return bool|ResultWrapper
 629          */
 630         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 631                 if ( !count( $rows ) ) {
 632                         return true;
 633                 }
 634
 635                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 636                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 637                         $ret = true;
 638                         foreach ( $rows as $v ) {
 639                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 640                                         $ret = false;
 641                                 }
 642                         }
 643                 } else {
 644                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 645                 }
 646
 647                 return $ret;
 648         }
 649
 650         /**
 651          * Returns the size of a text field, or -1 for "unlimited"
 652          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 653          *
 654          * @param string $table
 655          * @param string $field
 656          * @return int
 657          */
 658         function textFieldSize( $table, $field ) {
 659                 return -1;
 660         }
 661
 662         /**
 663          * @return bool
 664          */
 665         function unionSupportsOrderAndLimit() {
 666                 return false;
 667         }
 668
 669         /**
 670          * @param string $sqls
 671          * @param bool $all Whether to "UNION ALL" or not
 672          * @return string
 673          */
 674         function unionQueries( $sqls, $all ) {
 675                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 676
 677                 return implode( $glue, $sqls );
 678         }
 679
 680         /**
 681          * @return bool
 682          */
 683         function wasDeadlock() {
 684                 return $this->lastErrno() == 5; // SQLITE_BUSY
 685         }
 686
 687         /**
 688          * @return bool
 689          */
 690         function wasErrorReissuable() {
 691                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 692         }
 693
 694         /**
 695          * @return bool
 696          */
 697         function wasReadOnlyError() {
 698                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 699         }
 700
 701         /**
 702          * @return string Wikitext of a link to the server software's web site
 703          */
 704         public function getSoftwareLink() {
 705                 return "[{{int:version-db-sqlite-url}} SQLite]";
 706         }
 707
 708         /**
 709          * @return string Version information from the database
 710          */
 711         function getServerVersion() {
 712                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 713
 714                 return $ver;
 715         }
 716
 717         /**
 718          * Get information about a given field
 719          * Returns false if the field does not exist.
 720          *
 721          * @param string $table
 722          * @param string $field
 723          * @return SQLiteField|bool False on failure
 724          */
 725         function fieldInfo( $table, $field ) {
 726                 $tableName = $this->tableName( $table );
 727                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 728                 $res = $this->query( $sql, __METHOD__ );
 729                 foreach ( $res as $row ) {
 730                         if ( $row->name == $field ) {
 731                                 return new SQLiteField( $row, $tableName );
 732                         }
 733                 }
 734
 735                 return false;
 736         }
 737
 738         protected function doBegin( $fname = '' ) {
 739                 if ( $this->trxMode ) {
 740                         $this->query( "BEGIN {$this->trxMode}", $fname );
 741                 } else {
 742                         $this->query( 'BEGIN', $fname );
 743                 }
 744                 $this->mTrxLevel = 1;
 745         }
 746
 747         /**
 748          * @param string $s
 749          * @return string
 750          */
 751         function strencode( $s ) {
 752                 return substr( $this->addQuotes( $s ), 1, -1 );
 753         }
 754
 755         /**
 756          * @param string $b
 757          * @return Blob
 758          */
 759         function encodeBlob( $b ) {
 760                 return new Blob( $b );
 761         }
 762
 763         /**
 764          * @param Blob|string $b
 765          * @return string
 766          */
 767         function decodeBlob( $b ) {
 768                 if ( $b instanceof Blob ) {
 769                         $b = $b->fetch();
 770                 }
 771
 772                 return $b;
 773         }
 774
 775         /**
 776          * @param string|int|null|bool|Blob $s
 777          * @return string|int
 778          */
 779         function addQuotes( $s ) {
 780                 if ( $s instanceof Blob ) {
 781                         return "x'" . bin2hex( $s->fetch() ) . "'";
 782                 } elseif ( is_bool( $s ) ) {
 783                         return (int)$s;
 784                 } elseif ( strpos( $s, "\0" ) !== false ) {
 785                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 786                         // This is a known limitation of SQLite's mprintf function which PDO
 787                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 788                         // https://bugs.php.net/bug.php?id=63419
 789                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 790                         // https://bugs.php.net/bug.php?id=62361
 791                         // There is an additional bug regarding sorting this data after insert
 792                         // on older versions of sqlite shipped with ubuntu 12.04
 793                         // https://phabricator.wikimedia.org/T74367
 794                         $this->queryLogger->debug(
 795                                 __FUNCTION__ .
 796                                 ': Quoting value containing null byte. ' .
 797                                 'For consistency all binary data should have been ' .
 798                                 'first processed with self::encodeBlob()'
 799                         );
 800                         return "x'" . bin2hex( $s ) . "'";
 801                 } else {
 802                         return $this->mConn->quote( $s );
 803                 }
 804         }
 805
 806         /**
 807          * @return string
 808          */
 809         function buildLike() {
 810                 $params = func_get_args();
 811                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 812                         $params = $params[0];
 813                 }
 814
 815                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 816         }
 817
 818         /**
 819          * @param string $field Field or column to cast
 820          * @return string
 821          * @since 1.28
 822          */
 823         public function buildStringCast( $field ) {
 824                 return 'CAST ( ' . $field . ' AS TEXT )';
 825         }
 826
 827         /**
 828          * No-op version of deadlockLoop
 829          *
 830          * @return mixed
 831          */
 832         public function deadlockLoop( /*...*/ ) {
 833                 $args = func_get_args();
 834                 $function = array_shift( $args );
 835
 836                 return call_user_func_array( $function, $args );
 837         }
 838
 839         /**
 840          * @param string $s
 841          * @return string
 842          */
 843         protected function replaceVars( $s ) {
 844                 $s = parent::replaceVars( $s );
 845                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 846                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 847
 848                         // binary/varbinary column type -> blob
 849                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 850                         // no such thing as unsigned
 851                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 852                         // INT -> INTEGER
 853                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 854                         // floating point types -> REAL
 855                         $s = preg_replace(
 856                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 857                                 'REAL',
 858                                 $s
 859                         );
 860                         // varchar -> TEXT
 861                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 862                         // TEXT normalization
 863                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 864                         // BLOB normalization
 865                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 866                         // BOOL -> INTEGER
 867                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 868                         // DATETIME -> TEXT
 869                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 870                         // No ENUM type
 871                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 872                         // binary collation type -> nothing
 873                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 874                         // auto_increment -> autoincrement
 875                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 876                         // No explicit options
 877                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 878                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 879                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 880                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 881                         // No truncated indexes
 882                         $s = preg_replace( '/\(\d+\)/', '', $s );
 883                         // No FULLTEXT
 884                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 885                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 886                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 887                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 888                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 889                         // INSERT IGNORE --> INSERT OR IGNORE
 890                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 891                 }
 892
 893                 return $s;
 894         }
 895
 896         public function lock( $lockName, $method, $timeout = 5 ) {
 897                 if ( !is_dir( "{$this->dbDir}/locks" ) ) { // create dir as needed
 898                         if ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) ) {
 899                                 throw new DBError( $this, "Cannot create directory \"{$this->dbDir}/locks\"." );
 900                         }
 901                 }
 902
 903                 return $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout )->isOK();
 904         }
 905
 906         public function unlock( $lockName, $method ) {
 907                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isOK();
 908         }
 909
 910         /**
 911          * Build a concatenation list to feed into a SQL query
 912          *
 913          * @param string[] $stringList
 914          * @return string
 915          */
 916         function buildConcat( $stringList ) {
 917                 return '(' . implode( ') || (', $stringList ) . ')';
 918         }
 919
 920         public function buildGroupConcatField(
 921                 $delim, $table, $field, $conds = '', $join_conds = []
 922         ) {
 923                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 924
 925                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
 926         }
 927
 928         /**
 929          * @param string $oldName
 930          * @param string $newName
 931          * @param bool $temporary
 932          * @param string $fname
 933          * @return bool|ResultWrapper
 934          * @throws RuntimeException
 935          */
 936         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 937                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 938                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 939                 $obj = $this->fetchObject( $res );
 940                 if ( !$obj ) {
 941                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
 942                 }
 943                 $sql = $obj->sql;
 944                 $sql = preg_replace(
 945                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 946                         $this->addIdentifierQuotes( $newName ),
 947                         $sql,
 948                         1
 949                 );
 950                 if ( $temporary ) {
 951                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 952                                 $this->queryLogger->debug(
 953                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 954                         } else {
 955                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 956                         }
 957                 }
 958
 959                 $res = $this->query( $sql, $fname );
 960
 961                 // Take over indexes
 962                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
 963                 foreach ( $indexList as $index ) {
 964                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
 965                                 continue;
 966                         }
 967
 968                         if ( $index->unique ) {
 969                                 $sql = 'CREATE UNIQUE INDEX';
 970                         } else {
 971                                 $sql = 'CREATE INDEX';
 972                         }
 973                         // Try to come up with a new index name, given indexes have database scope in SQLite
 974                         $indexName = $newName . '_' . $index->name;
 975                         $sql .= ' ' . $indexName . ' ON ' . $newName;
 976
 977                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
 978                         $fields = [];
 979                         foreach ( $indexInfo as $indexInfoRow ) {
 980                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
 981                         }
 982
 983                         $sql .= '(' . implode( ',', $fields ) . ')';
 984
 985                         $this->query( $sql );
 986                 }
 987
 988                 return $res;
 989         }
 990
 991         /**
 992          * List all tables on the database
 993          *
 994          * @param string $prefix Only show tables with this prefix, e.g. mw_
 995          * @param string $fname Calling function name
 996          *
 997          * @return array
 998          */
 999         function listTables( $prefix = null, $fname = __METHOD__ ) {
1000                 $result = $this->select(
1001                         'sqlite_master',
1002                         'name',
1003                         "type='table'"
1004                 );
1005
1006                 $endArray = [];
1007
1008                 foreach ( $result as $table ) {
1009                         $vars = get_object_vars( $table );
1010                         $table = array_pop( $vars );
1011
1012                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1013                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1014                                         $endArray[] = $table;
1015                                 }
1016                         }
1017                 }
1018
1019                 return $endArray;
1020         }
1021
1022         /**
1023          * Override due to no CASCADE support
1024          *
1025          * @param string $tableName
1026          * @param string $fName
1027          * @return bool|ResultWrapper
1028          * @throws DBReadOnlyError
1029          */
1030         public function dropTable( $tableName, $fName = __METHOD__ ) {
1031                 if ( !$this->tableExists( $tableName, $fName ) ) {
1032                         return false;
1033                 }
1034                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1035
1036                 return $this->query( $sql, $fName );
1037         }
1038
1039         protected function requiresDatabaseUser() {
1040                 return false; // just a file
1041         }
1042
1043         /**
1044          * @return string
1045          */
1046         public function __toString() {
1047                 return 'SQLite ' . (string)$this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
1048         }
1049 }