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 NullLockManager;
  27 use PDO;
  28 use PDOException;
  29 use Exception;
  30 use LockManager;
  31 use FSLockManager;
  32 use RuntimeException;
  33 use stdClass;
  34
  35 /**
  36  * @ingroup Database
  37  */
  38 class DatabaseSqlite extends Database {
  39         /** @var string|null Directory for SQLite database files listed under their DB name */
  40         protected $dbDir;
  41         /** @var string|null Explicit path for the SQLite database file */
  42         protected $dbPath;
  43         /** @var string Transaction mode */
  44         protected $trxMode;
  45
  46         /** @var int The number of rows affected as an integer */
  47         protected $lastAffectedRowCount;
  48         /** @var resource */
  49         protected $lastResultHandle;
  50
  51         /** @var PDO */
  52         protected $conn;
  53
  54         /** @var FSLockManager (hopefully on the same server as the DB) */
  55         protected $lockMgr;
  56
  57         /** @var array List of shared database already attached to this connection */
  58         private $alreadyAttached = [];
  59
  60         /** @var bool Whether full text is enabled */
  61         private static $fulltextEnabled = null;
  62
  63         /**
  64          * Additional params include:
  65          *   - dbDirectory : directory containing the DB and the lock file directory
  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         public function __construct( array $p ) {
  71                 if ( isset( $p['dbFilePath'] ) ) {
  72                         $this->dbPath = $p['dbFilePath'];
  73                         if ( !strlen( $p['dbname'] ) ) {
  74                                 $p['dbname'] = self::generateDatabaseName( $this->dbPath );
  75                         }
  76                 } elseif ( isset( $p['dbDirectory'] ) ) {
  77                         $this->dbDir = $p['dbDirectory'];
  78                 }
  79
  80                 // Set a dummy user to make initConnection() trigger open()
  81                 parent::__construct( [ 'user' => '@' ] + $p );
  82
  83                 $this->trxMode = strtoupper( $p['trxMode'] ?? '' );
  84
  85                 $lockDirectory = $this->getLockFileDirectory();
  86                 if ( $lockDirectory !== null ) {
  87                         $this->lockMgr = new FSLockManager( [
  88                                 'domain' => $this->getDomainID(),
  89                                 'lockDirectory' => $lockDirectory
  90                         ] );
  91                 } else {
  92                         $this->lockMgr = new NullLockManager( [ 'domain' => $this->getDomainID() ] );
  93                 }
  94         }
  95
  96         protected static function getAttributes() {
  97                 return [ self::ATTR_DB_LEVEL_LOCKING => true ];
  98         }
  99
 100         /**
 101          * @param string $filename
 102          * @param array $p Options map; supports:
 103          *   - flags       : (same as __construct counterpart)
 104          *   - trxMode     : (same as __construct counterpart)
 105          *   - dbDirectory : (same as __construct counterpart)
 106          * @return DatabaseSqlite
 107          * @since 1.25
 108          */
 109         public static function newStandaloneInstance( $filename, array $p = [] ) {
 110                 $p['dbFilePath'] = $filename;
 111                 $p['schema'] = null;
 112                 $p['tablePrefix'] = '';
 113                 /** @var DatabaseSqlite $db */
 114                 $db = Database::factory( 'sqlite', $p );
 115
 116                 return $db;
 117         }
 118
 119         /**
 120          * @return string
 121          */
 122         public function getType() {
 123                 return 'sqlite';
 124         }
 125
 126         /**
 127          * @todo Check if it should be true like parent class
 128          *
 129          * @return bool
 130          */
 131         public function implicitGroupby() {
 132                 return false;
 133         }
 134
 135         protected function open( $server, $user, $pass, $dbName, $schema, $tablePrefix ) {
 136                 $this->close();
 137
 138                 // Note that for SQLite, $server, $user, and $pass are ignored
 139
 140                 if ( $schema !== null ) {
 141                         throw new DBExpectedError( $this, __CLASS__ . ": cannot use schemas ('$schema')" );
 142                 }
 143
 144                 if ( $this->dbPath !== null ) {
 145                         $path = $this->dbPath;
 146                 } elseif ( $this->dbDir !== null ) {
 147                         $path = self::generateFileName( $this->dbDir, $dbName );
 148                 } else {
 149                         throw new DBExpectedError( $this, __CLASS__ . ": DB path or directory required" );
 150                 }
 151
 152                 if ( !in_array( $this->trxMode, [ '', 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ], true ) ) {
 153                         throw new DBExpectedError(
 154                                 $this,
 155                                 __CLASS__ . ": invalid transaction mode '{$this->trxMode}'"
 156                         );
 157                 }
 158
 159                 if ( !self::isProcessMemoryPath( $path ) && !is_readable( $path ) ) {
 160                         $error = "SQLite database file not readable";
 161                         $this->connLogger->error(
 162                                 "Error connecting to {db_server}: {error}",
 163                                 $this->getLogContext( [ 'method' => __METHOD__, 'error' => $error ] )
 164                         );
 165                         throw new DBConnectionError( $this, $error );
 166                 }
 167
 168                 try {
 169                         $conn = new PDO(
 170                                 "sqlite:$path",
 171                                 '',
 172                                 '',
 173                                 [ PDO::ATTR_PERSISTENT => (bool)( $this->flags & self::DBO_PERSISTENT ) ]
 174                         );
 175                         // Set error codes only, don't raise exceptions
 176                         $conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 177                 } catch ( PDOException $e ) {
 178                         $error = $e->getMessage();
 179                         $this->connLogger->error(
 180                                 "Error connecting to {db_server}: {error}",
 181                                 $this->getLogContext( [ 'method' => __METHOD__, 'error' => $error ] )
 182                         );
 183                         throw new DBConnectionError( $this, $error );
 184                 }
 185
 186                 $this->conn = $conn;
 187                 $this->currentDomain = new DatabaseDomain( $dbName, null, $tablePrefix );
 188
 189                 try {
 190                         $flags = self::QUERY_IGNORE_DBO_TRX | self::QUERY_NO_RETRY;
 191                         // Enforce LIKE to be case sensitive, just like MySQL
 192                         $this->query( 'PRAGMA case_sensitive_like = 1', __METHOD__, $flags );
 193                         // Apply an optimizations or requirements regarding fsync() usage
 194                         $sync = $this->connectionVariables['synchronous'] ?? null;
 195                         if ( in_array( $sync, [ 'EXTRA', 'FULL', 'NORMAL', 'OFF' ], true ) ) {
 196                                 $this->query( "PRAGMA synchronous = $sync", __METHOD__, $flags );
 197                         }
 198                 } catch ( Exception $e ) {
 199                         // Connection was not fully initialized and is not safe for use
 200                         $this->conn = false;
 201                         throw $e;
 202                 }
 203         }
 204
 205         /**
 206          * @return string|null SQLite DB file path
 207          * @throws DBUnexpectedError
 208          * @since 1.25
 209          */
 210         public function getDbFilePath() {
 211                 return $this->dbPath ?? self::generateFileName( $this->dbDir, $this->getDBname() );
 212         }
 213
 214         /**
 215          * @return string|null Lock file directory
 216          */
 217         public function getLockFileDirectory() {
 218                 if ( $this->dbPath !== null && !self::isProcessMemoryPath( $this->dbPath ) ) {
 219                         return dirname( $this->dbPath ) . '/locks';
 220                 } elseif ( $this->dbDir !== null && !self::isProcessMemoryPath( $this->dbDir ) ) {
 221                         return $this->dbDir . '/locks';
 222                 }
 223
 224                 return null;
 225         }
 226
 227         /**
 228          * Does not actually close the connection, just destroys the reference for GC to do its work
 229          * @return bool
 230          */
 231         protected function closeConnection() {
 232                 $this->conn = null;
 233
 234                 return true;
 235         }
 236
 237         /**
 238          * Generates a database file name. Explicitly public for installer.
 239          * @param string $dir Directory where database resides
 240          * @param string|bool $dbName Database name (or false from Database::factory, validated here)
 241          * @return string
 242          * @throws DBUnexpectedError
 243          */
 244         public static function generateFileName( $dir, $dbName ) {
 245                 if ( $dir == '' ) {
 246                         throw new DBUnexpectedError( null, __CLASS__ . ": no DB directory specified" );
 247                 } elseif ( self::isProcessMemoryPath( $dir ) ) {
 248                         throw new DBUnexpectedError(
 249                                 null,
 250                                 __CLASS__ . ": cannot use process memory directory '$dir'"
 251                         );
 252                 } elseif ( !strlen( $dbName ) ) {
 253                         throw new DBUnexpectedError( null, __CLASS__ . ": no DB name specified" );
 254                 }
 255
 256                 return "$dir/$dbName.sqlite";
 257         }
 258
 259         /**
 260          * @param string $path
 261          * @return string
 262          */
 263         private static function generateDatabaseName( $path ) {
 264                 if ( preg_match( '/^(:memory:$|file::memory:)/', $path ) ) {
 265                         // E.g. "file::memory:?cache=shared" => ":memory":
 266                         return ':memory:';
 267                 } elseif ( preg_match( '/^file::([^?]+)\?mode=memory(&|$)/', $path, $m ) ) {
 268                         // E.g. "file:memdb1?mode=memory" => ":memdb1:"
 269                         return ":{$m[1]}:";
 270                 } else {
 271                         // E.g. "/home/.../some_db.sqlite3" => "some_db"
 272                         return preg_replace( '/\.sqlite\d?$/', '', basename( $path ) );
 273                 }
 274         }
 275
 276         /**
 277          * @param string $path
 278          * @return bool
 279          */
 280         private static function isProcessMemoryPath( $path ) {
 281                 return preg_match( '/^(:memory:$|file:(:memory:|[^?]+\?mode=memory(&|$)))/', $path );
 282         }
 283
 284         /**
 285          * Check if the searchindext table is FTS enabled.
 286          * @return bool False if not enabled.
 287          */
 288         public function checkForEnabledSearch() {
 289                 if ( self::$fulltextEnabled === null ) {
 290                         self::$fulltextEnabled = false;
 291                         $table = $this->tableName( 'searchindex' );
 292                         $res = $this->query(
 293                                 "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'",
 294                                 __METHOD__,
 295                                 self::QUERY_IGNORE_DBO_TRX
 296                         );
 297                         if ( $res ) {
 298                                 $row = $res->fetchRow();
 299                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 300                         }
 301                 }
 302
 303                 return self::$fulltextEnabled;
 304         }
 305
 306         /**
 307          * Returns version of currently supported SQLite fulltext search module or false if none present.
 308          * @return string
 309          */
 310         static function getFulltextSearchModule() {
 311                 static $cachedResult = null;
 312                 if ( $cachedResult !== null ) {
 313                         return $cachedResult;
 314                 }
 315                 $cachedResult = false;
 316                 $table = 'dummy_search_test';
 317
 318                 $db = self::newStandaloneInstance( ':memory:' );
 319                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 320                         $cachedResult = 'FTS3';
 321                 }
 322                 $db->close();
 323
 324                 return $cachedResult;
 325         }
 326
 327         /**
 328          * Attaches external database to our connection, see https://sqlite.org/lang_attach.html
 329          * for details.
 330          *
 331          * @param string $name Database name to be used in queries like
 332          *   SELECT foo FROM dbname.table
 333          * @param bool|string $file Database file name. If omitted, will be generated
 334          *   using $name and configured data directory
 335          * @param string $fname Calling function name
 336          * @return IResultWrapper
 337          */
 338         public function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 339                 $file = is_string( $file ) ? $file : self::generateFileName( $this->dbDir, $name );
 340                 $encFile = $this->addQuotes( $file );
 341
 342                 return $this->query(
 343                         "ATTACH DATABASE $encFile AS $name",
 344                         $fname,
 345                         self::QUERY_IGNORE_DBO_TRX
 346                 );
 347         }
 348
 349         protected function isWriteQuery( $sql ) {
 350                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 351         }
 352
 353         protected function isTransactableQuery( $sql ) {
 354                 return parent::isTransactableQuery( $sql ) && !in_array(
 355                         $this->getQueryVerb( $sql ),
 356                         [ 'ATTACH', 'PRAGMA' ],
 357                         true
 358                 );
 359         }
 360
 361         /**
 362          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 363          *
 364          * @param string $sql
 365          * @return bool|IResultWrapper
 366          */
 367         protected function doQuery( $sql ) {
 368                 $res = $this->getBindingHandle()->query( $sql );
 369                 if ( $res === false ) {
 370                         return false;
 371                 }
 372
 373                 $resource = ResultWrapper::unwrap( $res );
 374                 $this->lastAffectedRowCount = $resource->rowCount();
 375                 $res = new ResultWrapper( $this, $resource->fetchAll() );
 376
 377                 return $res;
 378         }
 379
 380         /**
 381          * @param IResultWrapper|mixed $res
 382          */
 383         function freeResult( $res ) {
 384                 if ( $res instanceof ResultWrapper ) {
 385                         $res->free();
 386                 }
 387         }
 388
 389         /**
 390          * @param IResultWrapper|array $res
 391          * @return stdClass|bool
 392          */
 393         function fetchObject( $res ) {
 394                 $resource =& ResultWrapper::unwrap( $res );
 395
 396                 $cur = current( $resource );
 397                 if ( is_array( $cur ) ) {
 398                         next( $resource );
 399                         $obj = new stdClass;
 400                         foreach ( $cur as $k => $v ) {
 401                                 if ( !is_numeric( $k ) ) {
 402                                         $obj->$k = $v;
 403                                 }
 404                         }
 405
 406                         return $obj;
 407                 }
 408
 409                 return false;
 410         }
 411
 412         /**
 413          * @param IResultWrapper|mixed $res
 414          * @return array|bool
 415          */
 416         function fetchRow( $res ) {
 417                 $resource =& ResultWrapper::unwrap( $res );
 418                 $cur = current( $resource );
 419                 if ( is_array( $cur ) ) {
 420                         next( $resource );
 421
 422                         return $cur;
 423                 }
 424
 425                 return false;
 426         }
 427
 428         /**
 429          * The PDO::Statement class implements the array interface so count() will work
 430          *
 431          * @param IResultWrapper|array|false $res
 432          * @return int
 433          */
 434         function numRows( $res ) {
 435                 // false does not implement Countable
 436                 $resource = ResultWrapper::unwrap( $res );
 437
 438                 return is_array( $resource ) ? count( $resource ) : 0;
 439         }
 440
 441         /**
 442          * @param IResultWrapper $res
 443          * @return int
 444          */
 445         function numFields( $res ) {
 446                 $resource = ResultWrapper::unwrap( $res );
 447                 if ( is_array( $resource ) && count( $resource ) > 0 ) {
 448                         // The size of the result array is twice the number of fields. (T67578)
 449                         return count( $resource[0] ) / 2;
 450                 } else {
 451                         // If the result is empty return 0
 452                         return 0;
 453                 }
 454         }
 455
 456         /**
 457          * @param IResultWrapper $res
 458          * @param int $n
 459          * @return bool
 460          */
 461         function fieldName( $res, $n ) {
 462                 $resource = ResultWrapper::unwrap( $res );
 463                 if ( is_array( $resource ) ) {
 464                         $keys = array_keys( $resource[0] );
 465
 466                         return $keys[$n];
 467                 }
 468
 469                 return false;
 470         }
 471
 472         /**
 473          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 474          *
 475          * @param string $name
 476          * @param string $format
 477          * @return string
 478          */
 479         function tableName( $name, $format = 'quoted' ) {
 480                 // table names starting with sqlite_ are reserved
 481                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 482                         return $name;
 483                 }
 484
 485                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 486         }
 487
 488         /**
 489          * This must be called after nextSequenceVal
 490          *
 491          * @return int
 492          */
 493         function insertId() {
 494                 // PDO::lastInsertId yields a string :(
 495                 return intval( $this->getBindingHandle()->lastInsertId() );
 496         }
 497
 498         /**
 499          * @param IResultWrapper|array $res
 500          * @param int $row
 501          */
 502         function dataSeek( $res, $row ) {
 503                 $resource =& ResultWrapper::unwrap( $res );
 504                 reset( $resource );
 505                 if ( $row > 0 ) {
 506                         for ( $i = 0; $i < $row; $i++ ) {
 507                                 next( $resource );
 508                         }
 509                 }
 510         }
 511
 512         /**
 513          * @return string
 514          */
 515         function lastError() {
 516                 if ( !is_object( $this->conn ) ) {
 517                         return "Cannot return last error, no db connection";
 518                 }
 519                 $e = $this->conn->errorInfo();
 520
 521                 return $e[2] ?? '';
 522         }
 523
 524         /**
 525          * @return string
 526          */
 527         function lastErrno() {
 528                 if ( !is_object( $this->conn ) ) {
 529                         return "Cannot return last error, no db connection";
 530                 } else {
 531                         $info = $this->conn->errorInfo();
 532
 533                         return $info[1];
 534                 }
 535         }
 536
 537         /**
 538          * @return int
 539          */
 540         protected function fetchAffectedRowCount() {
 541                 return $this->lastAffectedRowCount;
 542         }
 543
 544         function tableExists( $table, $fname = __METHOD__ ) {
 545                 $tableRaw = $this->tableName( $table, 'raw' );
 546                 if ( isset( $this->sessionTempTables[$tableRaw] ) ) {
 547                         return true; // already known to exist
 548                 }
 549
 550                 $encTable = $this->addQuotes( $tableRaw );
 551                 $res = $this->query(
 552                         "SELECT 1 FROM sqlite_master WHERE type='table' AND name=$encTable",
 553                         __METHOD__,
 554                         self::QUERY_IGNORE_DBO_TRX
 555                 );
 556
 557                 return $res->numRows() ? true : false;
 558         }
 559
 560         /**
 561          * Returns information about an index
 562          * Returns false if the index does not exist
 563          * - if errors are explicitly ignored, returns NULL on failure
 564          *
 565          * @param string $table
 566          * @param string $index
 567          * @param string $fname
 568          * @return array|false
 569          */
 570         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 571                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 572                 $res = $this->query( $sql, $fname, self::QUERY_IGNORE_DBO_TRX );
 573                 if ( !$res || $res->numRows() == 0 ) {
 574                         return false;
 575                 }
 576                 $info = [];
 577                 foreach ( $res as $row ) {
 578                         $info[] = $row->name;
 579                 }
 580
 581                 return $info;
 582         }
 583
 584         /**
 585          * @param string $table
 586          * @param string $index
 587          * @param string $fname
 588          * @return bool|null
 589          */
 590         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 591                 $row = $this->selectRow( 'sqlite_master', '*',
 592                         [
 593                                 'type' => 'index',
 594                                 'name' => $this->indexName( $index ),
 595                         ], $fname );
 596                 if ( !$row || !isset( $row->sql ) ) {
 597                         return null;
 598                 }
 599
 600                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 601                 $indexPos = strpos( $row->sql, 'INDEX' );
 602                 if ( $indexPos === false ) {
 603                         return null;
 604                 }
 605                 $firstPart = substr( $row->sql, 0, $indexPos );
 606                 $options = explode( ' ', $firstPart );
 607
 608                 return in_array( 'UNIQUE', $options );
 609         }
 610
 611         /**
 612          * Filter the options used in SELECT statements
 613          *
 614          * @param array $options
 615          * @return array
 616          */
 617         function makeSelectOptions( $options ) {
 618                 foreach ( $options as $k => $v ) {
 619                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 620                                 $options[$k] = '';
 621                         }
 622                 }
 623
 624                 return parent::makeSelectOptions( $options );
 625         }
 626
 627         /**
 628          * @param array $options
 629          * @return array
 630          */
 631         protected function makeUpdateOptionsArray( $options ) {
 632                 $options = parent::makeUpdateOptionsArray( $options );
 633                 $options = self::fixIgnore( $options );
 634
 635                 return $options;
 636         }
 637
 638         /**
 639          * @param array $options
 640          * @return array
 641          */
 642         static function fixIgnore( $options ) {
 643                 # SQLite uses OR IGNORE not just IGNORE
 644                 foreach ( $options as $k => $v ) {
 645                         if ( $v == 'IGNORE' ) {
 646                                 $options[$k] = 'OR IGNORE';
 647                         }
 648                 }
 649
 650                 return $options;
 651         }
 652
 653         /**
 654          * @param array $options
 655          * @return string
 656          */
 657         function makeInsertOptions( $options ) {
 658                 $options = self::fixIgnore( $options );
 659
 660                 return parent::makeInsertOptions( $options );
 661         }
 662
 663         /**
 664          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 665          * @param string $table
 666          * @param array $a
 667          * @param string $fname
 668          * @param array $options
 669          * @return bool
 670          */
 671         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 672                 if ( !count( $a ) ) {
 673                         return true;
 674                 }
 675
 676                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 677                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 678                         $affectedRowCount = 0;
 679                         try {
 680                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 681                                 foreach ( $a as $v ) {
 682                                         parent::insert( $table, $v, "$fname/multi-row", $options );
 683                                         $affectedRowCount += $this->affectedRows();
 684                                 }
 685                                 $this->endAtomic( $fname );
 686                         } catch ( Exception $e ) {
 687                                 $this->cancelAtomic( $fname );
 688                                 throw $e;
 689                         }
 690                         $this->affectedRowCount = $affectedRowCount;
 691                 } else {
 692                         parent::insert( $table, $a, "$fname/single-row", $options );
 693                 }
 694
 695                 return true;
 696         }
 697
 698         /**
 699          * @param string $table
 700          * @param array $uniqueIndexes Unused
 701          * @param string|array $rows
 702          * @param string $fname
 703          */
 704         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 705                 if ( !count( $rows ) ) {
 706                         return;
 707                 }
 708
 709                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 710                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 711                         $affectedRowCount = 0;
 712                         try {
 713                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 714                                 foreach ( $rows as $v ) {
 715                                         $this->nativeReplace( $table, $v, "$fname/multi-row" );
 716                                         $affectedRowCount += $this->affectedRows();
 717                                 }
 718                                 $this->endAtomic( $fname );
 719                         } catch ( Exception $e ) {
 720                                 $this->cancelAtomic( $fname );
 721                                 throw $e;
 722                         }
 723                         $this->affectedRowCount = $affectedRowCount;
 724                 } else {
 725                         $this->nativeReplace( $table, $rows, "$fname/single-row" );
 726                 }
 727         }
 728
 729         /**
 730          * Returns the size of a text field, or -1 for "unlimited"
 731          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 732          *
 733          * @param string $table
 734          * @param string $field
 735          * @return int
 736          */
 737         function textFieldSize( $table, $field ) {
 738                 return -1;
 739         }
 740
 741         /**
 742          * @return bool
 743          */
 744         function unionSupportsOrderAndLimit() {
 745                 return false;
 746         }
 747
 748         /**
 749          * @param string[] $sqls
 750          * @param bool $all Whether to "UNION ALL" or not
 751          * @return string
 752          */
 753         function unionQueries( $sqls, $all ) {
 754                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 755
 756                 return implode( $glue, $sqls );
 757         }
 758
 759         /**
 760          * @return bool
 761          */
 762         function wasDeadlock() {
 763                 return $this->lastErrno() == 5; // SQLITE_BUSY
 764         }
 765
 766         /**
 767          * @return bool
 768          */
 769         function wasReadOnlyError() {
 770                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 771         }
 772
 773         public function wasConnectionError( $errno ) {
 774                 return $errno == 17; // SQLITE_SCHEMA;
 775         }
 776
 777         protected function wasKnownStatementRollbackError() {
 778                 // ON CONFLICT ROLLBACK clauses make it so that SQLITE_CONSTRAINT error is
 779                 // ambiguous with regard to whether it implies a ROLLBACK or an ABORT happened.
 780                 // https://sqlite.org/lang_createtable.html#uniqueconst
 781                 // https://sqlite.org/lang_conflict.html
 782                 return false;
 783         }
 784
 785         public function serverIsReadOnly() {
 786                 $path = $this->getDbFilePath();
 787
 788                 return ( !self::isProcessMemoryPath( $path ) && !is_writable( $path ) );
 789         }
 790
 791         /**
 792          * @return string Wikitext of a link to the server software's web site
 793          */
 794         public function getSoftwareLink() {
 795                 return "[{{int:version-db-sqlite-url}} SQLite]";
 796         }
 797
 798         /**
 799          * @return string Version information from the database
 800          */
 801         function getServerVersion() {
 802                 $ver = $this->getBindingHandle()->getAttribute( PDO::ATTR_SERVER_VERSION );
 803
 804                 return $ver;
 805         }
 806
 807         /**
 808          * Get information about a given field
 809          * Returns false if the field does not exist.
 810          *
 811          * @param string $table
 812          * @param string $field
 813          * @return SQLiteField|bool False on failure
 814          */
 815         function fieldInfo( $table, $field ) {
 816                 $tableName = $this->tableName( $table );
 817                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 818                 $res = $this->query( $sql, __METHOD__, self::QUERY_IGNORE_DBO_TRX );
 819                 foreach ( $res as $row ) {
 820                         if ( $row->name == $field ) {
 821                                 return new SQLiteField( $row, $tableName );
 822                         }
 823                 }
 824
 825                 return false;
 826         }
 827
 828         protected function doBegin( $fname = '' ) {
 829                 if ( $this->trxMode != '' ) {
 830                         $this->query( "BEGIN {$this->trxMode}", $fname );
 831                 } else {
 832                         $this->query( 'BEGIN', $fname );
 833                 }
 834         }
 835
 836         /**
 837          * @param string $s
 838          * @return string
 839          */
 840         function strencode( $s ) {
 841                 return substr( $this->addQuotes( $s ), 1, -1 );
 842         }
 843
 844         /**
 845          * @param string $b
 846          * @return Blob
 847          */
 848         function encodeBlob( $b ) {
 849                 return new Blob( $b );
 850         }
 851
 852         /**
 853          * @param Blob|string $b
 854          * @return string
 855          */
 856         function decodeBlob( $b ) {
 857                 if ( $b instanceof Blob ) {
 858                         $b = $b->fetch();
 859                 }
 860
 861                 return $b;
 862         }
 863
 864         /**
 865          * @param string|int|null|bool|Blob $s
 866          * @return string|int
 867          */
 868         function addQuotes( $s ) {
 869                 if ( $s instanceof Blob ) {
 870                         return "x'" . bin2hex( $s->fetch() ) . "'";
 871                 } elseif ( is_bool( $s ) ) {
 872                         return (int)$s;
 873                 } elseif ( strpos( (string)$s, "\0" ) !== false ) {
 874                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 875                         // This is a known limitation of SQLite's mprintf function which PDO
 876                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 877                         // https://bugs.php.net/bug.php?id=63419
 878                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 879                         // https://bugs.php.net/bug.php?id=62361
 880                         // There is an additional bug regarding sorting this data after insert
 881                         // on older versions of sqlite shipped with ubuntu 12.04
 882                         // https://phabricator.wikimedia.org/T74367
 883                         $this->queryLogger->debug(
 884                                 __FUNCTION__ .
 885                                 ': Quoting value containing null byte. ' .
 886                                 'For consistency all binary data should have been ' .
 887                                 'first processed with self::encodeBlob()'
 888                         );
 889                         return "x'" . bin2hex( (string)$s ) . "'";
 890                 } else {
 891                         return $this->getBindingHandle()->quote( (string)$s );
 892                 }
 893         }
 894
 895         public function buildSubstring( $input, $startPosition, $length = null ) {
 896                 $this->assertBuildSubstringParams( $startPosition, $length );
 897                 $params = [ $input, $startPosition ];
 898                 if ( $length !== null ) {
 899                         $params[] = $length;
 900                 }
 901                 return 'SUBSTR(' . implode( ',', $params ) . ')';
 902         }
 903
 904         /**
 905          * @param string $field Field or column to cast
 906          * @return string
 907          * @since 1.28
 908          */
 909         public function buildStringCast( $field ) {
 910                 return 'CAST ( ' . $field . ' AS TEXT )';
 911         }
 912
 913         /**
 914          * No-op version of deadlockLoop
 915          *
 916          * @return mixed
 917          */
 918         public function deadlockLoop( /*...*/ ) {
 919                 $args = func_get_args();
 920                 $function = array_shift( $args );
 921
 922                 return $function( ...$args );
 923         }
 924
 925         /**
 926          * @param string $s
 927          * @return string
 928          */
 929         protected function replaceVars( $s ) {
 930                 $s = parent::replaceVars( $s );
 931                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 932                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 933
 934                         // binary/varbinary column type -> blob
 935                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 936                         // no such thing as unsigned
 937                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 938                         // INT -> INTEGER
 939                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 940                         // floating point types -> REAL
 941                         $s = preg_replace(
 942                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 943                                 'REAL',
 944                                 $s
 945                         );
 946                         // varchar -> TEXT
 947                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 948                         // TEXT normalization
 949                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 950                         // BLOB normalization
 951                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 952                         // BOOL -> INTEGER
 953                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 954                         // DATETIME -> TEXT
 955                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 956                         // No ENUM type
 957                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 958                         // binary collation type -> nothing
 959                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 960                         // auto_increment -> autoincrement
 961                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 962                         // No explicit options
 963                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 964                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 965                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 966                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 967                         // No truncated indexes
 968                         $s = preg_replace( '/\(\d+\)/', '', $s );
 969                         // No FULLTEXT
 970                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 971                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 972                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 973                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 974                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 975                         // INSERT IGNORE --> INSERT OR IGNORE
 976                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 977                 }
 978
 979                 return $s;
 980         }
 981
 982         public function lock( $lockName, $method, $timeout = 5 ) {
 983                 $status = $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout );
 984                 if (
 985                         $this->lockMgr instanceof FSLockManager &&
 986                         $status->hasMessage( 'lockmanager-fail-openlock' )
 987                 ) {
 988                         throw new DBError( $this, "Cannot create directory \"{$this->getLockFileDirectory()}\"" );
 989                 }
 990
 991                 return $status->isOK();
 992         }
 993
 994         public function unlock( $lockName, $method ) {
 995                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isGood();
 996         }
 997
 998         /**
 999          * Build a concatenation list to feed into a SQL query
1000          *
1001          * @param string[] $stringList
1002          * @return string
1003          */
1004         function buildConcat( $stringList ) {
1005                 return '(' . implode( ') || (', $stringList ) . ')';
1006         }
1007
1008         public function buildGroupConcatField(
1009                 $delim, $table, $field, $conds = '', $join_conds = []
1010         ) {
1011                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
1012
1013                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
1014         }
1015
1016         /**
1017          * @param string $oldName
1018          * @param string $newName
1019          * @param bool $temporary
1020          * @param string $fname
1021          * @return bool|IResultWrapper
1022          * @throws RuntimeException
1023          */
1024         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1025                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
1026                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
1027                 $obj = $this->fetchObject( $res );
1028                 if ( !$obj ) {
1029                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
1030                 }
1031                 $sql = $obj->sql;
1032                 $sql = preg_replace(
1033                         '/(?<=\W)"?' .
1034                                 preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ), '/' ) .
1035                                 '"?(?=\W)/',
1036                         $this->addIdentifierQuotes( $newName ),
1037                         $sql,
1038                         1
1039                 );
1040                 if ( $temporary ) {
1041                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
1042                                 $this->queryLogger->debug(
1043                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
1044                         } else {
1045                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
1046                         }
1047                 }
1048
1049                 $res = $this->query( $sql, $fname, self::QUERY_PSEUDO_PERMANENT );
1050
1051                 // Take over indexes
1052                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
1053                 foreach ( $indexList as $index ) {
1054                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
1055                                 continue;
1056                         }
1057
1058                         if ( $index->unique ) {
1059                                 $sql = 'CREATE UNIQUE INDEX';
1060                         } else {
1061                                 $sql = 'CREATE INDEX';
1062                         }
1063                         // Try to come up with a new index name, given indexes have database scope in SQLite
1064                         $indexName = $newName . '_' . $index->name;
1065                         $sql .= ' ' . $indexName . ' ON ' . $newName;
1066
1067                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
1068                         $fields = [];
1069                         foreach ( $indexInfo as $indexInfoRow ) {
1070                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
1071                         }
1072
1073                         $sql .= '(' . implode( ',', $fields ) . ')';
1074
1075                         $this->query( $sql );
1076                 }
1077
1078                 return $res;
1079         }
1080
1081         /**
1082          * List all tables on the database
1083          *
1084          * @param string|null $prefix Only show tables with this prefix, e.g. mw_
1085          * @param string $fname Calling function name
1086          *
1087          * @return array
1088          */
1089         function listTables( $prefix = null, $fname = __METHOD__ ) {
1090                 $result = $this->select(
1091                         'sqlite_master',
1092                         'name',
1093                         "type='table'"
1094                 );
1095
1096                 $endArray = [];
1097
1098                 foreach ( $result as $table ) {
1099                         $vars = get_object_vars( $table );
1100                         $table = array_pop( $vars );
1101
1102                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1103                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1104                                         $endArray[] = $table;
1105                                 }
1106                         }
1107                 }
1108
1109                 return $endArray;
1110         }
1111
1112         /**
1113          * Override due to no CASCADE support
1114          *
1115          * @param string $tableName
1116          * @param string $fName
1117          * @return bool|IResultWrapper
1118          * @throws DBReadOnlyError
1119          */
1120         public function dropTable( $tableName, $fName = __METHOD__ ) {
1121                 if ( !$this->tableExists( $tableName, $fName ) ) {
1122                         return false;
1123                 }
1124                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1125
1126                 return $this->query( $sql, $fName, self::QUERY_IGNORE_DBO_TRX );
1127         }
1128
1129         public function setTableAliases( array $aliases ) {
1130                 parent::setTableAliases( $aliases );
1131                 foreach ( $this->tableAliases as $params ) {
1132                         if ( isset( $this->alreadyAttached[$params['dbname']] ) ) {
1133                                 continue;
1134                         }
1135                         $this->attachDatabase( $params['dbname'] );
1136                         $this->alreadyAttached[$params['dbname']] = true;
1137                 }
1138         }
1139
1140         public function resetSequenceForTable( $table, $fname = __METHOD__ ) {
1141                 $encTable = $this->addIdentifierQuotes( 'sqlite_sequence' );
1142                 $encName = $this->addQuotes( $this->tableName( $table, 'raw' ) );
1143                 $this->query(
1144                         "DELETE FROM $encTable WHERE name = $encName",
1145                         $fname,
1146                         self::QUERY_IGNORE_DBO_TRX
1147                 );
1148         }
1149
1150         public function databasesAreIndependent() {
1151                 return true;
1152         }
1153
1154         /**
1155          * @return PDO
1156          */
1157         protected function getBindingHandle() {
1158                 return parent::getBindingHandle();
1159         }
1160 }
1161
1162 /**
1163  * @deprecated since 1.29
1164  */
1165 class_alias( DatabaseSqlite::class, 'DatabaseSqlite' );