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 use Wikimedia\Rdbms\Blob;
  25 use Wikimedia\Rdbms\SQLiteField;
  26 use Wikimedia\Rdbms\ResultWrapper;
  27
  28 /**
  29  * @ingroup Database
  30  */
  31 class DatabaseSqlite extends Database {
  32         /** @var bool Whether full text is enabled */
  33         private static $fulltextEnabled = null;
  34
  35         /** @var string Directory */
  36         protected $dbDir;
  37         /** @var string File name for SQLite database file */
  38         protected $dbPath;
  39         /** @var string Transaction mode */
  40         protected $trxMode;
  41
  42         /** @var int The number of rows affected as an integer */
  43         protected $mAffectedRows;
  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 Database::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 bool
 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( $fileName );
 158
 159                 return (bool)$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 & self::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         public function selectDB( $db ) {
 203                 return false; // doesn't make sense
 204         }
 205
 206         /**
 207          * @return string SQLite DB file path
 208          * @since 1.25
 209          */
 210         public function getDbFilePath() {
 211                 return $this->dbPath;
 212         }
 213
 214         /**
 215          * Does not actually close the connection, just destroys the reference for GC to do its work
 216          * @return bool
 217          */
 218         protected function closeConnection() {
 219                 $this->mConn = null;
 220
 221                 return true;
 222         }
 223
 224         /**
 225          * Generates a database file name. Explicitly public for installer.
 226          * @param string $dir Directory where database resides
 227          * @param string $dbName Database name
 228          * @return string
 229          */
 230         public static function generateFileName( $dir, $dbName ) {
 231                 return "$dir/$dbName.sqlite";
 232         }
 233
 234         /**
 235          * Check if the searchindext table is FTS enabled.
 236          * @return bool False if not enabled.
 237          */
 238         function checkForEnabledSearch() {
 239                 if ( self::$fulltextEnabled === null ) {
 240                         self::$fulltextEnabled = false;
 241                         $table = $this->tableName( 'searchindex' );
 242                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 243                         if ( $res ) {
 244                                 $row = $res->fetchRow();
 245                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 246                         }
 247                 }
 248
 249                 return self::$fulltextEnabled;
 250         }
 251
 252         /**
 253          * Returns version of currently supported SQLite fulltext search module or false if none present.
 254          * @return string
 255          */
 256         static function getFulltextSearchModule() {
 257                 static $cachedResult = null;
 258                 if ( $cachedResult !== null ) {
 259                         return $cachedResult;
 260                 }
 261                 $cachedResult = false;
 262                 $table = 'dummy_search_test';
 263
 264                 $db = self::newStandaloneInstance( ':memory:' );
 265                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 266                         $cachedResult = 'FTS3';
 267                 }
 268                 $db->close();
 269
 270                 return $cachedResult;
 271         }
 272
 273         /**
 274          * Attaches external database to our connection, see https://sqlite.org/lang_attach.html
 275          * for details.
 276          *
 277          * @param string $name Database name to be used in queries like
 278          *   SELECT foo FROM dbname.table
 279          * @param bool|string $file Database file name. If omitted, will be generated
 280          *   using $name and configured data directory
 281          * @param string $fname Calling function name
 282          * @return ResultWrapper
 283          */
 284         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 285                 if ( !$file ) {
 286                         $file = self::generateFileName( $this->dbDir, $name );
 287                 }
 288                 $file = $this->addQuotes( $file );
 289
 290                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 291         }
 292
 293         function isWriteQuery( $sql ) {
 294                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 295         }
 296
 297         /**
 298          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 299          *
 300          * @param string $sql
 301          * @return bool|ResultWrapper
 302          */
 303         protected function doQuery( $sql ) {
 304                 $res = $this->mConn->query( $sql );
 305                 if ( $res === false ) {
 306                         return false;
 307                 }
 308
 309                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 310                 $this->mAffectedRows = $r->rowCount();
 311                 $res = new ResultWrapper( $this, $r->fetchAll() );
 312
 313                 return $res;
 314         }
 315
 316         /**
 317          * @param ResultWrapper|mixed $res
 318          */
 319         function freeResult( $res ) {
 320                 if ( $res instanceof ResultWrapper ) {
 321                         $res->result = null;
 322                 } else {
 323                         $res = null;
 324                 }
 325         }
 326
 327         /**
 328          * @param ResultWrapper|array $res
 329          * @return stdClass|bool
 330          */
 331         function fetchObject( $res ) {
 332                 if ( $res instanceof ResultWrapper ) {
 333                         $r =& $res->result;
 334                 } else {
 335                         $r =& $res;
 336                 }
 337
 338                 $cur = current( $r );
 339                 if ( is_array( $cur ) ) {
 340                         next( $r );
 341                         $obj = new stdClass;
 342                         foreach ( $cur as $k => $v ) {
 343                                 if ( !is_numeric( $k ) ) {
 344                                         $obj->$k = $v;
 345                                 }
 346                         }
 347
 348                         return $obj;
 349                 }
 350
 351                 return false;
 352         }
 353
 354         /**
 355          * @param ResultWrapper|mixed $res
 356          * @return array|bool
 357          */
 358         function fetchRow( $res ) {
 359                 if ( $res instanceof ResultWrapper ) {
 360                         $r =& $res->result;
 361                 } else {
 362                         $r =& $res;
 363                 }
 364                 $cur = current( $r );
 365                 if ( is_array( $cur ) ) {
 366                         next( $r );
 367
 368                         return $cur;
 369                 }
 370
 371                 return false;
 372         }
 373
 374         /**
 375          * The PDO::Statement class implements the array interface so count() will work
 376          *
 377          * @param ResultWrapper|array $res
 378          * @return int
 379          */
 380         function numRows( $res ) {
 381                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 382
 383                 return count( $r );
 384         }
 385
 386         /**
 387          * @param ResultWrapper $res
 388          * @return int
 389          */
 390         function numFields( $res ) {
 391                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 392                 if ( is_array( $r ) && count( $r ) > 0 ) {
 393                         // The size of the result array is twice the number of fields. (Bug: 65578)
 394                         return count( $r[0] ) / 2;
 395                 } else {
 396                         // If the result is empty return 0
 397                         return 0;
 398                 }
 399         }
 400
 401         /**
 402          * @param ResultWrapper $res
 403          * @param int $n
 404          * @return bool
 405          */
 406         function fieldName( $res, $n ) {
 407                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 408                 if ( is_array( $r ) ) {
 409                         $keys = array_keys( $r[0] );
 410
 411                         return $keys[$n];
 412                 }
 413
 414                 return false;
 415         }
 416
 417         /**
 418          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 419          *
 420          * @param string $name
 421          * @param string $format
 422          * @return string
 423          */
 424         function tableName( $name, $format = 'quoted' ) {
 425                 // table names starting with sqlite_ are reserved
 426                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 427                         return $name;
 428                 }
 429
 430                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 431         }
 432
 433         /**
 434          * This must be called after nextSequenceVal
 435          *
 436          * @return int
 437          */
 438         function insertId() {
 439                 // PDO::lastInsertId yields a string :(
 440                 return intval( $this->mConn->lastInsertId() );
 441         }
 442
 443         /**
 444          * @param ResultWrapper|array $res
 445          * @param int $row
 446          */
 447         function dataSeek( $res, $row ) {
 448                 if ( $res instanceof ResultWrapper ) {
 449                         $r =& $res->result;
 450                 } else {
 451                         $r =& $res;
 452                 }
 453                 reset( $r );
 454                 if ( $row > 0 ) {
 455                         for ( $i = 0; $i < $row; $i++ ) {
 456                                 next( $r );
 457                         }
 458                 }
 459         }
 460
 461         /**
 462          * @return string
 463          */
 464         function lastError() {
 465                 if ( !is_object( $this->mConn ) ) {
 466                         return "Cannot return last error, no db connection";
 467                 }
 468                 $e = $this->mConn->errorInfo();
 469
 470                 return isset( $e[2] ) ? $e[2] : '';
 471         }
 472
 473         /**
 474          * @return string
 475          */
 476         function lastErrno() {
 477                 if ( !is_object( $this->mConn ) ) {
 478                         return "Cannot return last error, no db connection";
 479                 } else {
 480                         $info = $this->mConn->errorInfo();
 481
 482                         return $info[1];
 483                 }
 484         }
 485
 486         /**
 487          * @return int
 488          */
 489         function affectedRows() {
 490                 return $this->mAffectedRows;
 491         }
 492
 493         /**
 494          * Returns information about an index
 495          * Returns false if the index does not exist
 496          * - if errors are explicitly ignored, returns NULL on failure
 497          *
 498          * @param string $table
 499          * @param string $index
 500          * @param string $fname
 501          * @return array|false
 502          */
 503         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 504                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 505                 $res = $this->query( $sql, $fname );
 506                 if ( !$res || $res->numRows() == 0 ) {
 507                         return false;
 508                 }
 509                 $info = [];
 510                 foreach ( $res as $row ) {
 511                         $info[] = $row->name;
 512                 }
 513
 514                 return $info;
 515         }
 516
 517         /**
 518          * @param string $table
 519          * @param string $index
 520          * @param string $fname
 521          * @return bool|null
 522          */
 523         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 524                 $row = $this->selectRow( 'sqlite_master', '*',
 525                         [
 526                                 'type' => 'index',
 527                                 'name' => $this->indexName( $index ),
 528                         ], $fname );
 529                 if ( !$row || !isset( $row->sql ) ) {
 530                         return null;
 531                 }
 532
 533                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 534                 $indexPos = strpos( $row->sql, 'INDEX' );
 535                 if ( $indexPos === false ) {
 536                         return null;
 537                 }
 538                 $firstPart = substr( $row->sql, 0, $indexPos );
 539                 $options = explode( ' ', $firstPart );
 540
 541                 return in_array( 'UNIQUE', $options );
 542         }
 543
 544         /**
 545          * Filter the options used in SELECT statements
 546          *
 547          * @param array $options
 548          * @return array
 549          */
 550         function makeSelectOptions( $options ) {
 551                 foreach ( $options as $k => $v ) {
 552                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 553                                 $options[$k] = '';
 554                         }
 555                 }
 556
 557                 return parent::makeSelectOptions( $options );
 558         }
 559
 560         /**
 561          * @param array $options
 562          * @return string
 563          */
 564         protected function makeUpdateOptionsArray( $options ) {
 565                 $options = parent::makeUpdateOptionsArray( $options );
 566                 $options = self::fixIgnore( $options );
 567
 568                 return $options;
 569         }
 570
 571         /**
 572          * @param array $options
 573          * @return array
 574          */
 575         static function fixIgnore( $options ) {
 576                 # SQLite uses OR IGNORE not just IGNORE
 577                 foreach ( $options as $k => $v ) {
 578                         if ( $v == 'IGNORE' ) {
 579                                 $options[$k] = 'OR IGNORE';
 580                         }
 581                 }
 582
 583                 return $options;
 584         }
 585
 586         /**
 587          * @param array $options
 588          * @return string
 589          */
 590         function makeInsertOptions( $options ) {
 591                 $options = self::fixIgnore( $options );
 592
 593                 return parent::makeInsertOptions( $options );
 594         }
 595
 596         /**
 597          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 598          * @param string $table
 599          * @param array $a
 600          * @param string $fname
 601          * @param array $options
 602          * @return bool
 603          */
 604         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 605                 if ( !count( $a ) ) {
 606                         return true;
 607                 }
 608
 609                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 610                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 611                         $ret = true;
 612                         foreach ( $a as $v ) {
 613                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 614                                         $ret = false;
 615                                 }
 616                         }
 617                 } else {
 618                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 619                 }
 620
 621                 return $ret;
 622         }
 623
 624         /**
 625          * @param string $table
 626          * @param array $uniqueIndexes Unused
 627          * @param string|array $rows
 628          * @param string $fname
 629          * @return bool|ResultWrapper
 630          */
 631         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 632                 if ( !count( $rows ) ) {
 633                         return true;
 634                 }
 635
 636                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 637                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 638                         $ret = true;
 639                         foreach ( $rows as $v ) {
 640                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 641                                         $ret = false;
 642                                 }
 643                         }
 644                 } else {
 645                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 646                 }
 647
 648                 return $ret;
 649         }
 650
 651         /**
 652          * Returns the size of a text field, or -1 for "unlimited"
 653          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 654          *
 655          * @param string $table
 656          * @param string $field
 657          * @return int
 658          */
 659         function textFieldSize( $table, $field ) {
 660                 return -1;
 661         }
 662
 663         /**
 664          * @return bool
 665          */
 666         function unionSupportsOrderAndLimit() {
 667                 return false;
 668         }
 669
 670         /**
 671          * @param string[] $sqls
 672          * @param bool $all Whether to "UNION ALL" or not
 673          * @return string
 674          */
 675         function unionQueries( $sqls, $all ) {
 676                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 677
 678                 return implode( $glue, $sqls );
 679         }
 680
 681         /**
 682          * @return bool
 683          */
 684         function wasDeadlock() {
 685                 return $this->lastErrno() == 5; // SQLITE_BUSY
 686         }
 687
 688         /**
 689          * @return bool
 690          */
 691         function wasErrorReissuable() {
 692                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 693         }
 694
 695         /**
 696          * @return bool
 697          */
 698         function wasReadOnlyError() {
 699                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 700         }
 701
 702         /**
 703          * @return string Wikitext of a link to the server software's web site
 704          */
 705         public function getSoftwareLink() {
 706                 return "[{{int:version-db-sqlite-url}} SQLite]";
 707         }
 708
 709         /**
 710          * @return string Version information from the database
 711          */
 712         function getServerVersion() {
 713                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 714
 715                 return $ver;
 716         }
 717
 718         /**
 719          * Get information about a given field
 720          * Returns false if the field does not exist.
 721          *
 722          * @param string $table
 723          * @param string $field
 724          * @return SQLiteField|bool False on failure
 725          */
 726         function fieldInfo( $table, $field ) {
 727                 $tableName = $this->tableName( $table );
 728                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 729                 $res = $this->query( $sql, __METHOD__ );
 730                 foreach ( $res as $row ) {
 731                         if ( $row->name == $field ) {
 732                                 return new SQLiteField( $row, $tableName );
 733                         }
 734                 }
 735
 736                 return false;
 737         }
 738
 739         protected function doBegin( $fname = '' ) {
 740                 if ( $this->trxMode ) {
 741                         $this->query( "BEGIN {$this->trxMode}", $fname );
 742                 } else {
 743                         $this->query( 'BEGIN', $fname );
 744                 }
 745                 $this->mTrxLevel = 1;
 746         }
 747
 748         /**
 749          * @param string $s
 750          * @return string
 751          */
 752         function strencode( $s ) {
 753                 return substr( $this->addQuotes( $s ), 1, -1 );
 754         }
 755
 756         /**
 757          * @param string $b
 758          * @return Blob
 759          */
 760         function encodeBlob( $b ) {
 761                 return new Blob( $b );
 762         }
 763
 764         /**
 765          * @param Blob|string $b
 766          * @return string
 767          */
 768         function decodeBlob( $b ) {
 769                 if ( $b instanceof Blob ) {
 770                         $b = $b->fetch();
 771                 }
 772
 773                 return $b;
 774         }
 775
 776         /**
 777          * @param string|int|null|bool|Blob $s
 778          * @return string|int
 779          */
 780         function addQuotes( $s ) {
 781                 if ( $s instanceof Blob ) {
 782                         return "x'" . bin2hex( $s->fetch() ) . "'";
 783                 } elseif ( is_bool( $s ) ) {
 784                         return (int)$s;
 785                 } elseif ( strpos( $s, "\0" ) !== false ) {
 786                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 787                         // This is a known limitation of SQLite's mprintf function which PDO
 788                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 789                         // https://bugs.php.net/bug.php?id=63419
 790                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 791                         // https://bugs.php.net/bug.php?id=62361
 792                         // There is an additional bug regarding sorting this data after insert
 793                         // on older versions of sqlite shipped with ubuntu 12.04
 794                         // https://phabricator.wikimedia.org/T74367
 795                         $this->queryLogger->debug(
 796                                 __FUNCTION__ .
 797                                 ': Quoting value containing null byte. ' .
 798                                 'For consistency all binary data should have been ' .
 799                                 'first processed with self::encodeBlob()'
 800                         );
 801                         return "x'" . bin2hex( $s ) . "'";
 802                 } else {
 803                         return $this->mConn->quote( $s );
 804                 }
 805         }
 806
 807         /**
 808          * @return string
 809          */
 810         function buildLike() {
 811                 $params = func_get_args();
 812                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 813                         $params = $params[0];
 814                 }
 815
 816                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 817         }
 818
 819         /**
 820          * @param string $field Field or column to cast
 821          * @return string
 822          * @since 1.28
 823          */
 824         public function buildStringCast( $field ) {
 825                 return 'CAST ( ' . $field . ' AS TEXT )';
 826         }
 827
 828         /**
 829          * No-op version of deadlockLoop
 830          *
 831          * @return mixed
 832          */
 833         public function deadlockLoop( /*...*/ ) {
 834                 $args = func_get_args();
 835                 $function = array_shift( $args );
 836
 837                 return call_user_func_array( $function, $args );
 838         }
 839
 840         /**
 841          * @param string $s
 842          * @return string
 843          */
 844         protected function replaceVars( $s ) {
 845                 $s = parent::replaceVars( $s );
 846                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 847                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 848
 849                         // binary/varbinary column type -> blob
 850                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 851                         // no such thing as unsigned
 852                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 853                         // INT -> INTEGER
 854                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 855                         // floating point types -> REAL
 856                         $s = preg_replace(
 857                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 858                                 'REAL',
 859                                 $s
 860                         );
 861                         // varchar -> TEXT
 862                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 863                         // TEXT normalization
 864                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 865                         // BLOB normalization
 866                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 867                         // BOOL -> INTEGER
 868                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 869                         // DATETIME -> TEXT
 870                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 871                         // No ENUM type
 872                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 873                         // binary collation type -> nothing
 874                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 875                         // auto_increment -> autoincrement
 876                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 877                         // No explicit options
 878                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 879                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 880                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 881                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 882                         // No truncated indexes
 883                         $s = preg_replace( '/\(\d+\)/', '', $s );
 884                         // No FULLTEXT
 885                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 886                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 887                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 888                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 889                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 890                         // INSERT IGNORE --> INSERT OR IGNORE
 891                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 892                 }
 893
 894                 return $s;
 895         }
 896
 897         public function lock( $lockName, $method, $timeout = 5 ) {
 898                 if ( !is_dir( "{$this->dbDir}/locks" ) ) { // create dir as needed
 899                         if ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) ) {
 900                                 throw new DBError( $this, "Cannot create directory \"{$this->dbDir}/locks\"." );
 901                         }
 902                 }
 903
 904                 return $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout )->isOK();
 905         }
 906
 907         public function unlock( $lockName, $method ) {
 908                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isOK();
 909         }
 910
 911         /**
 912          * Build a concatenation list to feed into a SQL query
 913          *
 914          * @param string[] $stringList
 915          * @return string
 916          */
 917         function buildConcat( $stringList ) {
 918                 return '(' . implode( ') || (', $stringList ) . ')';
 919         }
 920
 921         public function buildGroupConcatField(
 922                 $delim, $table, $field, $conds = '', $join_conds = []
 923         ) {
 924                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 925
 926                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
 927         }
 928
 929         /**
 930          * @param string $oldName
 931          * @param string $newName
 932          * @param bool $temporary
 933          * @param string $fname
 934          * @return bool|ResultWrapper
 935          * @throws RuntimeException
 936          */
 937         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 938                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 939                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 940                 $obj = $this->fetchObject( $res );
 941                 if ( !$obj ) {
 942                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
 943                 }
 944                 $sql = $obj->sql;
 945                 $sql = preg_replace(
 946                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 947                         $this->addIdentifierQuotes( $newName ),
 948                         $sql,
 949                         1
 950                 );
 951                 if ( $temporary ) {
 952                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 953                                 $this->queryLogger->debug(
 954                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 955                         } else {
 956                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 957                         }
 958                 }
 959
 960                 $res = $this->query( $sql, $fname );
 961
 962                 // Take over indexes
 963                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
 964                 foreach ( $indexList as $index ) {
 965                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
 966                                 continue;
 967                         }
 968
 969                         if ( $index->unique ) {
 970                                 $sql = 'CREATE UNIQUE INDEX';
 971                         } else {
 972                                 $sql = 'CREATE INDEX';
 973                         }
 974                         // Try to come up with a new index name, given indexes have database scope in SQLite
 975                         $indexName = $newName . '_' . $index->name;
 976                         $sql .= ' ' . $indexName . ' ON ' . $newName;
 977
 978                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
 979                         $fields = [];
 980                         foreach ( $indexInfo as $indexInfoRow ) {
 981                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
 982                         }
 983
 984                         $sql .= '(' . implode( ',', $fields ) . ')';
 985
 986                         $this->query( $sql );
 987                 }
 988
 989                 return $res;
 990         }
 991
 992         /**
 993          * List all tables on the database
 994          *
 995          * @param string $prefix Only show tables with this prefix, e.g. mw_
 996          * @param string $fname Calling function name
 997          *
 998          * @return array
 999          */
1000         function listTables( $prefix = null, $fname = __METHOD__ ) {
1001                 $result = $this->select(
1002                         'sqlite_master',
1003                         'name',
1004                         "type='table'"
1005                 );
1006
1007                 $endArray = [];
1008
1009                 foreach ( $result as $table ) {
1010                         $vars = get_object_vars( $table );
1011                         $table = array_pop( $vars );
1012
1013                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1014                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1015                                         $endArray[] = $table;
1016                                 }
1017                         }
1018                 }
1019
1020                 return $endArray;
1021         }
1022
1023         /**
1024          * Override due to no CASCADE support
1025          *
1026          * @param string $tableName
1027          * @param string $fName
1028          * @return bool|ResultWrapper
1029          * @throws DBReadOnlyError
1030          */
1031         public function dropTable( $tableName, $fName = __METHOD__ ) {
1032                 if ( !$this->tableExists( $tableName, $fName ) ) {
1033                         return false;
1034                 }
1035                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1036
1037                 return $this->query( $sql, $fName );
1038         }
1039
1040         protected function requiresDatabaseUser() {
1041                 return false; // just a file
1042         }
1043
1044         /**
1045          * @return string
1046          */
1047         public function __toString() {
1048                 return 'SQLite ' . (string)$this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
1049         }
1050 }