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 namespace Wikimedia\Rdbms;
  25
  26 use PDO;
  27 use PDOException;
  28 use LockManager;
  29 use FSLockManager;
  30 use InvalidArgumentException;
  31 use RuntimeException;
  32 use stdClass;
  33
  34 /**
  35  * @ingroup Database
  36  */
  37 class DatabaseSqlite extends Database {
  38         /** @var bool Whether full text is enabled */
  39         private static $fulltextEnabled = null;
  40
  41         /** @var string Directory */
  42         protected $dbDir;
  43         /** @var string File name for SQLite database file */
  44         protected $dbPath;
  45         /** @var string Transaction mode */
  46         protected $trxMode;
  47
  48         /** @var int The number of rows affected as an integer */
  49         protected $lastAffectedRowCount;
  50         /** @var resource */
  51         protected $lastResultHandle;
  52
  53         /** @var PDO */
  54         protected $conn;
  55
  56         /** @var FSLockManager (hopefully on the same server as the DB) */
  57         protected $lockMgr;
  58
  59         /** @var array List of shared database already attached to this connection */
  60         private $alreadyAttached = [];
  61
  62         /**
  63          * Additional params include:
  64          *   - dbDirectory : directory containing the DB and the lock file directory
  65          *                   [defaults to $wgSQLiteDataDir]
  66          *   - dbFilePath  : use this to force the path of the DB file
  67          *   - trxMode     : one of (deferred, immediate, exclusive)
  68          * @param array $p
  69          */
  70         function __construct( array $p ) {
  71                 if ( isset( $p['dbFilePath'] ) ) {
  72                         parent::__construct( $p );
  73                         // Standalone .sqlite file mode.
  74                         // Super doesn't open when $user is false, but we can work with $dbName,
  75                         // which is derived from the file path in this case.
  76                         $this->openFile( $p['dbFilePath'] );
  77                         $lockDomain = md5( $p['dbFilePath'] );
  78                 } elseif ( !isset( $p['dbDirectory'] ) ) {
  79                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
  80                 } else {
  81                         $this->dbDir = $p['dbDirectory'];
  82                         $this->dbName = $p['dbname'];
  83                         $lockDomain = $this->dbName;
  84                         // Stock wiki mode using standard file names per DB.
  85                         parent::__construct( $p );
  86                         // Super doesn't open when $user is false, but we can work with $dbName
  87                         if ( $p['dbname'] && !$this->isOpen() ) {
  88                                 $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] );
  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                 /** @var DatabaseSqlite $db */
 120                 $db = Database::factory( 'sqlite', $p );
 121
 122                 return $db;
 123         }
 124
 125         /**
 126          * @return string
 127          */
 128         function getType() {
 129                 return 'sqlite';
 130         }
 131
 132         /**
 133          * @todo Check if it should be true like parent class
 134          *
 135          * @return bool
 136          */
 137         function implicitGroupby() {
 138                 return false;
 139         }
 140
 141         /** Open an SQLite database and return a resource handle to it
 142          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
 143          *
 144          * @param string $server
 145          * @param string $user
 146          * @param string $pass
 147          * @param string $dbName
 148          *
 149          * @throws DBConnectionError
 150          * @return bool
 151          */
 152         function open( $server, $user, $pass, $dbName ) {
 153                 $this->close();
 154                 $fileName = self::generateFileName( $this->dbDir, $dbName );
 155                 if ( !is_readable( $fileName ) ) {
 156                         $this->conn = false;
 157                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 158                 }
 159                 $this->openFile( $fileName );
 160
 161                 return (bool)$this->conn;
 162         }
 163
 164         /**
 165          * Opens a database file
 166          *
 167          * @param string $fileName
 168          * @throws DBConnectionError
 169          * @return PDO|bool SQL connection or false if failed
 170          */
 171         protected function openFile( $fileName ) {
 172                 $err = false;
 173
 174                 $this->dbPath = $fileName;
 175                 try {
 176                         if ( $this->flags & self::DBO_PERSISTENT ) {
 177                                 $this->conn = new PDO( "sqlite:$fileName", '', '',
 178                                         [ PDO::ATTR_PERSISTENT => true ] );
 179                         } else {
 180                                 $this->conn = new PDO( "sqlite:$fileName", '', '' );
 181                         }
 182                 } catch ( PDOException $e ) {
 183                         $err = $e->getMessage();
 184                 }
 185
 186                 if ( !$this->conn ) {
 187                         $this->queryLogger->debug( "DB connection error: $err\n" );
 188                         throw new DBConnectionError( $this, $err );
 189                 }
 190
 191                 $this->opened = !!$this->conn;
 192                 if ( $this->opened ) {
 193                         # Set error codes only, don't raise exceptions
 194                         $this->conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 195                         # Enforce LIKE to be case sensitive, just like MySQL
 196                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 197
 198                         return $this->conn;
 199                 }
 200
 201                 return false;
 202         }
 203
 204         public function selectDB( $db ) {
 205                 return false; // doesn't make sense
 206         }
 207
 208         /**
 209          * @return string SQLite DB file path
 210          * @since 1.25
 211          */
 212         public function getDbFilePath() {
 213                 return $this->dbPath;
 214         }
 215
 216         /**
 217          * Does not actually close the connection, just destroys the reference for GC to do its work
 218          * @return bool
 219          */
 220         protected function closeConnection() {
 221                 $this->conn = null;
 222
 223                 return true;
 224         }
 225
 226         /**
 227          * Generates a database file name. Explicitly public for installer.
 228          * @param string $dir Directory where database resides
 229          * @param string $dbName Database name
 230          * @return string
 231          */
 232         public static function generateFileName( $dir, $dbName ) {
 233                 return "$dir/$dbName.sqlite";
 234         }
 235
 236         /**
 237          * Check if the searchindext table is FTS enabled.
 238          * @return bool False if not enabled.
 239          */
 240         function checkForEnabledSearch() {
 241                 if ( self::$fulltextEnabled === null ) {
 242                         self::$fulltextEnabled = false;
 243                         $table = $this->tableName( 'searchindex' );
 244                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 245                         if ( $res ) {
 246                                 $row = $res->fetchRow();
 247                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 248                         }
 249                 }
 250
 251                 return self::$fulltextEnabled;
 252         }
 253
 254         /**
 255          * Returns version of currently supported SQLite fulltext search module or false if none present.
 256          * @return string
 257          */
 258         static function getFulltextSearchModule() {
 259                 static $cachedResult = null;
 260                 if ( $cachedResult !== null ) {
 261                         return $cachedResult;
 262                 }
 263                 $cachedResult = false;
 264                 $table = 'dummy_search_test';
 265
 266                 $db = self::newStandaloneInstance( ':memory:' );
 267                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 268                         $cachedResult = 'FTS3';
 269                 }
 270                 $db->close();
 271
 272                 return $cachedResult;
 273         }
 274
 275         /**
 276          * Attaches external database to our connection, see https://sqlite.org/lang_attach.html
 277          * for details.
 278          *
 279          * @param string $name Database name to be used in queries like
 280          *   SELECT foo FROM dbname.table
 281          * @param bool|string $file Database file name. If omitted, will be generated
 282          *   using $name and configured data directory
 283          * @param string $fname Calling function name
 284          * @return ResultWrapper
 285          */
 286         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 287                 if ( !$file ) {
 288                         $file = self::generateFileName( $this->dbDir, $name );
 289                 }
 290                 $file = $this->addQuotes( $file );
 291
 292                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 293         }
 294
 295         function isWriteQuery( $sql ) {
 296                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 297         }
 298
 299         protected function isTransactableQuery( $sql ) {
 300                 return parent::isTransactableQuery( $sql ) && !in_array(
 301                         $this->getQueryVerb( $sql ),
 302                         [ 'ATTACH', 'PRAGMA' ],
 303                         true
 304                 );
 305         }
 306
 307         /**
 308          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 309          *
 310          * @param string $sql
 311          * @return bool|ResultWrapper
 312          */
 313         protected function doQuery( $sql ) {
 314                 $res = $this->conn->query( $sql );
 315                 if ( $res === false ) {
 316                         return false;
 317                 }
 318
 319                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 320                 $this->lastAffectedRowCount = $r->rowCount();
 321                 $res = new ResultWrapper( $this, $r->fetchAll() );
 322
 323                 return $res;
 324         }
 325
 326         /**
 327          * @param ResultWrapper|mixed $res
 328          */
 329         function freeResult( $res ) {
 330                 if ( $res instanceof ResultWrapper ) {
 331                         $res->result = null;
 332                 } else {
 333                         $res = null;
 334                 }
 335         }
 336
 337         /**
 338          * @param ResultWrapper|array $res
 339          * @return stdClass|bool
 340          */
 341         function fetchObject( $res ) {
 342                 if ( $res instanceof ResultWrapper ) {
 343                         $r =& $res->result;
 344                 } else {
 345                         $r =& $res;
 346                 }
 347
 348                 $cur = current( $r );
 349                 if ( is_array( $cur ) ) {
 350                         next( $r );
 351                         $obj = new stdClass;
 352                         foreach ( $cur as $k => $v ) {
 353                                 if ( !is_numeric( $k ) ) {
 354                                         $obj->$k = $v;
 355                                 }
 356                         }
 357
 358                         return $obj;
 359                 }
 360
 361                 return false;
 362         }
 363
 364         /**
 365          * @param ResultWrapper|mixed $res
 366          * @return array|bool
 367          */
 368         function fetchRow( $res ) {
 369                 if ( $res instanceof ResultWrapper ) {
 370                         $r =& $res->result;
 371                 } else {
 372                         $r =& $res;
 373                 }
 374                 $cur = current( $r );
 375                 if ( is_array( $cur ) ) {
 376                         next( $r );
 377
 378                         return $cur;
 379                 }
 380
 381                 return false;
 382         }
 383
 384         /**
 385          * The PDO::Statement class implements the array interface so count() will work
 386          *
 387          * @param ResultWrapper|array $res
 388          * @return int
 389          */
 390         function numRows( $res ) {
 391                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 392
 393                 return count( $r );
 394         }
 395
 396         /**
 397          * @param ResultWrapper $res
 398          * @return int
 399          */
 400         function numFields( $res ) {
 401                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 402                 if ( is_array( $r ) && count( $r ) > 0 ) {
 403                         // The size of the result array is twice the number of fields. (Bug: 65578)
 404                         return count( $r[0] ) / 2;
 405                 } else {
 406                         // If the result is empty return 0
 407                         return 0;
 408                 }
 409         }
 410
 411         /**
 412          * @param ResultWrapper $res
 413          * @param int $n
 414          * @return bool
 415          */
 416         function fieldName( $res, $n ) {
 417                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 418                 if ( is_array( $r ) ) {
 419                         $keys = array_keys( $r[0] );
 420
 421                         return $keys[$n];
 422                 }
 423
 424                 return false;
 425         }
 426
 427         /**
 428          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 429          *
 430          * @param string $name
 431          * @param string $format
 432          * @return string
 433          */
 434         function tableName( $name, $format = 'quoted' ) {
 435                 // table names starting with sqlite_ are reserved
 436                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 437                         return $name;
 438                 }
 439
 440                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 441         }
 442
 443         /**
 444          * This must be called after nextSequenceVal
 445          *
 446          * @return int
 447          */
 448         function insertId() {
 449                 // PDO::lastInsertId yields a string :(
 450                 return intval( $this->conn->lastInsertId() );
 451         }
 452
 453         /**
 454          * @param ResultWrapper|array $res
 455          * @param int $row
 456          */
 457         function dataSeek( $res, $row ) {
 458                 if ( $res instanceof ResultWrapper ) {
 459                         $r =& $res->result;
 460                 } else {
 461                         $r =& $res;
 462                 }
 463                 reset( $r );
 464                 if ( $row > 0 ) {
 465                         for ( $i = 0; $i < $row; $i++ ) {
 466                                 next( $r );
 467                         }
 468                 }
 469         }
 470
 471         /**
 472          * @return string
 473          */
 474         function lastError() {
 475                 if ( !is_object( $this->conn ) ) {
 476                         return "Cannot return last error, no db connection";
 477                 }
 478                 $e = $this->conn->errorInfo();
 479
 480                 return isset( $e[2] ) ? $e[2] : '';
 481         }
 482
 483         /**
 484          * @return string
 485          */
 486         function lastErrno() {
 487                 if ( !is_object( $this->conn ) ) {
 488                         return "Cannot return last error, no db connection";
 489                 } else {
 490                         $info = $this->conn->errorInfo();
 491
 492                         return $info[1];
 493                 }
 494         }
 495
 496         /**
 497          * @return int
 498          */
 499         protected function fetchAffectedRowCount() {
 500                 return $this->lastAffectedRowCount;
 501         }
 502
 503         /**
 504          * Returns information about an index
 505          * Returns false if the index does not exist
 506          * - if errors are explicitly ignored, returns NULL on failure
 507          *
 508          * @param string $table
 509          * @param string $index
 510          * @param string $fname
 511          * @return array|false
 512          */
 513         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 514                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 515                 $res = $this->query( $sql, $fname );
 516                 if ( !$res || $res->numRows() == 0 ) {
 517                         return false;
 518                 }
 519                 $info = [];
 520                 foreach ( $res as $row ) {
 521                         $info[] = $row->name;
 522                 }
 523
 524                 return $info;
 525         }
 526
 527         /**
 528          * @param string $table
 529          * @param string $index
 530          * @param string $fname
 531          * @return bool|null
 532          */
 533         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 534                 $row = $this->selectRow( 'sqlite_master', '*',
 535                         [
 536                                 'type' => 'index',
 537                                 'name' => $this->indexName( $index ),
 538                         ], $fname );
 539                 if ( !$row || !isset( $row->sql ) ) {
 540                         return null;
 541                 }
 542
 543                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 544                 $indexPos = strpos( $row->sql, 'INDEX' );
 545                 if ( $indexPos === false ) {
 546                         return null;
 547                 }
 548                 $firstPart = substr( $row->sql, 0, $indexPos );
 549                 $options = explode( ' ', $firstPart );
 550
 551                 return in_array( 'UNIQUE', $options );
 552         }
 553
 554         /**
 555          * Filter the options used in SELECT statements
 556          *
 557          * @param array $options
 558          * @return array
 559          */
 560         function makeSelectOptions( $options ) {
 561                 foreach ( $options as $k => $v ) {
 562                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 563                                 $options[$k] = '';
 564                         }
 565                 }
 566
 567                 return parent::makeSelectOptions( $options );
 568         }
 569
 570         /**
 571          * @param array $options
 572          * @return array
 573          */
 574         protected function makeUpdateOptionsArray( $options ) {
 575                 $options = parent::makeUpdateOptionsArray( $options );
 576                 $options = self::fixIgnore( $options );
 577
 578                 return $options;
 579         }
 580
 581         /**
 582          * @param array $options
 583          * @return array
 584          */
 585         static function fixIgnore( $options ) {
 586                 # SQLite uses OR IGNORE not just IGNORE
 587                 foreach ( $options as $k => $v ) {
 588                         if ( $v == 'IGNORE' ) {
 589                                 $options[$k] = 'OR IGNORE';
 590                         }
 591                 }
 592
 593                 return $options;
 594         }
 595
 596         /**
 597          * @param array $options
 598          * @return string
 599          */
 600         function makeInsertOptions( $options ) {
 601                 $options = self::fixIgnore( $options );
 602
 603                 return parent::makeInsertOptions( $options );
 604         }
 605
 606         /**
 607          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 608          * @param string $table
 609          * @param array $a
 610          * @param string $fname
 611          * @param array $options
 612          * @return bool
 613          */
 614         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 615                 if ( !count( $a ) ) {
 616                         return true;
 617                 }
 618
 619                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 620                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 621                         $ret = true;
 622                         foreach ( $a as $v ) {
 623                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 624                                         $ret = false;
 625                                 }
 626                         }
 627                 } else {
 628                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 629                 }
 630
 631                 return $ret;
 632         }
 633
 634         /**
 635          * @param string $table
 636          * @param array $uniqueIndexes Unused
 637          * @param string|array $rows
 638          * @param string $fname
 639          * @return bool|ResultWrapper
 640          */
 641         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 642                 if ( !count( $rows ) ) {
 643                         return true;
 644                 }
 645
 646                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 647                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 648                         $ret = true;
 649                         foreach ( $rows as $v ) {
 650                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 651                                         $ret = false;
 652                                 }
 653                         }
 654                 } else {
 655                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 656                 }
 657
 658                 return $ret;
 659         }
 660
 661         /**
 662          * Returns the size of a text field, or -1 for "unlimited"
 663          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 664          *
 665          * @param string $table
 666          * @param string $field
 667          * @return int
 668          */
 669         function textFieldSize( $table, $field ) {
 670                 return -1;
 671         }
 672
 673         /**
 674          * @return bool
 675          */
 676         function unionSupportsOrderAndLimit() {
 677                 return false;
 678         }
 679
 680         /**
 681          * @param string[] $sqls
 682          * @param bool $all Whether to "UNION ALL" or not
 683          * @return string
 684          */
 685         function unionQueries( $sqls, $all ) {
 686                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 687
 688                 return implode( $glue, $sqls );
 689         }
 690
 691         /**
 692          * @return bool
 693          */
 694         function wasDeadlock() {
 695                 return $this->lastErrno() == 5; // SQLITE_BUSY
 696         }
 697
 698         /**
 699          * @return bool
 700          */
 701         function wasErrorReissuable() {
 702                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 703         }
 704
 705         /**
 706          * @return bool
 707          */
 708         function wasReadOnlyError() {
 709                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 710         }
 711
 712         /**
 713          * @return string Wikitext of a link to the server software's web site
 714          */
 715         public function getSoftwareLink() {
 716                 return "[{{int:version-db-sqlite-url}} SQLite]";
 717         }
 718
 719         /**
 720          * @return string Version information from the database
 721          */
 722         function getServerVersion() {
 723                 $ver = $this->conn->getAttribute( PDO::ATTR_SERVER_VERSION );
 724
 725                 return $ver;
 726         }
 727
 728         /**
 729          * Get information about a given field
 730          * Returns false if the field does not exist.
 731          *
 732          * @param string $table
 733          * @param string $field
 734          * @return SQLiteField|bool False on failure
 735          */
 736         function fieldInfo( $table, $field ) {
 737                 $tableName = $this->tableName( $table );
 738                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 739                 $res = $this->query( $sql, __METHOD__ );
 740                 foreach ( $res as $row ) {
 741                         if ( $row->name == $field ) {
 742                                 return new SQLiteField( $row, $tableName );
 743                         }
 744                 }
 745
 746                 return false;
 747         }
 748
 749         protected function doBegin( $fname = '' ) {
 750                 if ( $this->trxMode ) {
 751                         $this->query( "BEGIN {$this->trxMode}", $fname );
 752                 } else {
 753                         $this->query( 'BEGIN', $fname );
 754                 }
 755                 $this->trxLevel = 1;
 756         }
 757
 758         /**
 759          * @param string $s
 760          * @return string
 761          */
 762         function strencode( $s ) {
 763                 return substr( $this->addQuotes( $s ), 1, -1 );
 764         }
 765
 766         /**
 767          * @param string $b
 768          * @return Blob
 769          */
 770         function encodeBlob( $b ) {
 771                 return new Blob( $b );
 772         }
 773
 774         /**
 775          * @param Blob|string $b
 776          * @return string
 777          */
 778         function decodeBlob( $b ) {
 779                 if ( $b instanceof Blob ) {
 780                         $b = $b->fetch();
 781                 }
 782
 783                 return $b;
 784         }
 785
 786         /**
 787          * @param string|int|null|bool|Blob $s
 788          * @return string|int
 789          */
 790         function addQuotes( $s ) {
 791                 if ( $s instanceof Blob ) {
 792                         return "x'" . bin2hex( $s->fetch() ) . "'";
 793                 } elseif ( is_bool( $s ) ) {
 794                         return (int)$s;
 795                 } elseif ( strpos( (string)$s, "\0" ) !== false ) {
 796                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 797                         // This is a known limitation of SQLite's mprintf function which PDO
 798                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 799                         // https://bugs.php.net/bug.php?id=63419
 800                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 801                         // https://bugs.php.net/bug.php?id=62361
 802                         // There is an additional bug regarding sorting this data after insert
 803                         // on older versions of sqlite shipped with ubuntu 12.04
 804                         // https://phabricator.wikimedia.org/T74367
 805                         $this->queryLogger->debug(
 806                                 __FUNCTION__ .
 807                                 ': Quoting value containing null byte. ' .
 808                                 'For consistency all binary data should have been ' .
 809                                 'first processed with self::encodeBlob()'
 810                         );
 811                         return "x'" . bin2hex( (string)$s ) . "'";
 812                 } else {
 813                         return $this->conn->quote( (string)$s );
 814                 }
 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         public function setTableAliases( array $aliases ) {
1039                 parent::setTableAliases( $aliases );
1040                 foreach ( $this->tableAliases as $params ) {
1041                         if ( isset( $this->alreadyAttached[$params['dbname']] ) ) {
1042                                 continue;
1043                         }
1044                         $this->attachDatabase( $params['dbname'] );
1045                         $this->alreadyAttached[$params['dbname']] = true;
1046                 }
1047         }
1048
1049         protected function requiresDatabaseUser() {
1050                 return false; // just a file
1051         }
1052
1053         /**
1054          * @return string
1055          */
1056         public function __toString() {
1057                 return 'SQLite ' . (string)$this->conn->getAttribute( PDO::ATTR_SERVER_VERSION );
1058         }
1059 }
1060
1061 class_alias( DatabaseSqlite::class, 'DatabaseSqlite' );