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         /** @var string[] See https://www.sqlite.org/lang_transaction.html */
  64         private static $VALID_TRX_MODES = [ '', 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ];
  65
  66         /**
  67          * Additional params include:
  68          *   - dbDirectory : directory containing the DB and the lock file directory
  69          *   - dbFilePath  : use this to force the path of the DB file
  70          *   - trxMode     : one of (deferred, immediate, exclusive)
  71          * @param array $params
  72          */
  73         public function __construct( array $params ) {
  74                 if ( isset( $params['dbFilePath'] ) ) {
  75                         $this->dbPath = $params['dbFilePath'];
  76                         if ( !strlen( $params['dbname'] ) ) {
  77                                 $params['dbname'] = self::generateDatabaseName( $this->dbPath );
  78                         }
  79                 } elseif ( isset( $params['dbDirectory'] ) ) {
  80                         $this->dbDir = $params['dbDirectory'];
  81                 }
  82
  83                 parent::__construct( $params );
  84
  85                 $this->trxMode = strtoupper( $params['trxMode'] ?? '' );
  86
  87                 $lockDirectory = $this->getLockFileDirectory();
  88                 if ( $lockDirectory !== null ) {
  89                         $this->lockMgr = new FSLockManager( [
  90                                 'domain' => $this->getDomainID(),
  91                                 'lockDirectory' => $lockDirectory
  92                         ] );
  93                 } else {
  94                         $this->lockMgr = new NullLockManager( [ 'domain' => $this->getDomainID() ] );
  95                 }
  96         }
  97
  98         protected static function getAttributes() {
  99                 return [
 100                         self::ATTR_DB_IS_FILE => true,
 101                         self::ATTR_DB_LEVEL_LOCKING => true
 102                 ];
 103         }
 104
 105         /**
 106          * @param string $filename
 107          * @param array $p Options map; supports:
 108          *   - flags       : (same as __construct counterpart)
 109          *   - trxMode     : (same as __construct counterpart)
 110          *   - dbDirectory : (same as __construct counterpart)
 111          * @return DatabaseSqlite
 112          * @since 1.25
 113          */
 114         public static function newStandaloneInstance( $filename, array $p = [] ) {
 115                 $p['dbFilePath'] = $filename;
 116                 $p['schema'] = null;
 117                 $p['tablePrefix'] = '';
 118                 /** @var DatabaseSqlite $db */
 119                 $db = Database::factory( 'sqlite', $p );
 120
 121                 return $db;
 122         }
 123
 124         /**
 125          * @return string
 126          */
 127         public function getType() {
 128                 return 'sqlite';
 129         }
 130
 131         protected function open( $server, $user, $pass, $dbName, $schema, $tablePrefix ) {
 132                 $this->close();
 133
 134                 // Note that for SQLite, $server, $user, and $pass are ignored
 135
 136                 if ( $schema !== null ) {
 137                         throw $this->newExceptionAfterConnectError( "Got schema '$schema'; not supported." );
 138                 }
 139
 140                 if ( $this->dbPath !== null ) {
 141                         $path = $this->dbPath;
 142                 } elseif ( $this->dbDir !== null ) {
 143                         $path = self::generateFileName( $this->dbDir, $dbName );
 144                 } else {
 145                         throw $this->newExceptionAfterConnectError( "DB path or directory required" );
 146                 }
 147
 148                 // Check if the database file already exists but is non-readable
 149                 if (
 150                         !self::isProcessMemoryPath( $path ) &&
 151                         file_exists( $path ) &&
 152                         !is_readable( $path )
 153                 ) {
 154                         throw $this->newExceptionAfterConnectError( 'SQLite database file is not readable' );
 155                 } elseif ( !in_array( $this->trxMode, self::$VALID_TRX_MODES, true ) ) {
 156                         throw $this->newExceptionAfterConnectError( "Got mode '{$this->trxMode}' for BEGIN" );
 157                 }
 158
 159                 $attributes = [];
 160                 if ( $this->getFlag( self::DBO_PERSISTENT ) ) {
 161                         // Persistent connections can avoid some schema index reading overhead.
 162                         // On the other hand, they can cause horrible contention with DBO_TRX.
 163                         if ( $this->getFlag( self::DBO_TRX ) || $this->getFlag( self::DBO_DEFAULT ) ) {
 164                                 $this->connLogger->warning(
 165                                         __METHOD__ . ": ignoring DBO_PERSISTENT due to DBO_TRX or DBO_DEFAULT",
 166                                         $this->getLogContext()
 167                                 );
 168                         } else {
 169                                 $attributes[PDO::ATTR_PERSISTENT] = true;
 170                         }
 171                 }
 172
 173                 try {
 174                         // Open the database file, creating it if it does not yet exist
 175                         $this->conn = new PDO( "sqlite:$path", null, null, $attributes );
 176                 } catch ( PDOException $e ) {
 177                         throw $this->newExceptionAfterConnectError( $e->getMessage() );
 178                 }
 179
 180                 $this->currentDomain = new DatabaseDomain( $dbName, null, $tablePrefix );
 181
 182                 try {
 183                         $flags = self::QUERY_IGNORE_DBO_TRX | self::QUERY_NO_RETRY;
 184                         // Enforce LIKE to be case sensitive, just like MySQL
 185                         $this->query( 'PRAGMA case_sensitive_like = 1', __METHOD__, $flags );
 186                         // Apply optimizations or requirements regarding fsync() usage
 187                         $sync = $this->connectionVariables['synchronous'] ?? null;
 188                         if ( in_array( $sync, [ 'EXTRA', 'FULL', 'NORMAL', 'OFF' ], true ) ) {
 189                                 $this->query( "PRAGMA synchronous = $sync", __METHOD__, $flags );
 190                         }
 191                 } catch ( Exception $e ) {
 192                         throw $this->newExceptionAfterConnectError( $e->getMessage() );
 193                 }
 194         }
 195
 196         /**
 197          * @return string|null SQLite DB file path
 198          * @throws DBUnexpectedError
 199          * @since 1.25
 200          */
 201         public function getDbFilePath() {
 202                 return $this->dbPath ?? self::generateFileName( $this->dbDir, $this->getDBname() );
 203         }
 204
 205         /**
 206          * @return string|null Lock file directory
 207          */
 208         public function getLockFileDirectory() {
 209                 if ( $this->dbPath !== null && !self::isProcessMemoryPath( $this->dbPath ) ) {
 210                         return dirname( $this->dbPath ) . '/locks';
 211                 } elseif ( $this->dbDir !== null && !self::isProcessMemoryPath( $this->dbDir ) ) {
 212                         return $this->dbDir . '/locks';
 213                 }
 214
 215                 return null;
 216         }
 217
 218         /**
 219          * Does not actually close the connection, just destroys the reference for GC to do its work
 220          * @return bool
 221          */
 222         protected function closeConnection() {
 223                 $this->conn = null;
 224
 225                 return true;
 226         }
 227
 228         /**
 229          * Generates a database file name. Explicitly public for installer.
 230          * @param string $dir Directory where database resides
 231          * @param string|bool $dbName Database name (or false from Database::factory, validated here)
 232          * @return string
 233          * @throws DBUnexpectedError
 234          */
 235         public static function generateFileName( $dir, $dbName ) {
 236                 if ( $dir == '' ) {
 237                         throw new DBUnexpectedError( null, __CLASS__ . ": no DB directory specified" );
 238                 } elseif ( self::isProcessMemoryPath( $dir ) ) {
 239                         throw new DBUnexpectedError(
 240                                 null,
 241                                 __CLASS__ . ": cannot use process memory directory '$dir'"
 242                         );
 243                 } elseif ( !strlen( $dbName ) ) {
 244                         throw new DBUnexpectedError( null, __CLASS__ . ": no DB name specified" );
 245                 }
 246
 247                 return "$dir/$dbName.sqlite";
 248         }
 249
 250         /**
 251          * @param string $path
 252          * @return string
 253          */
 254         private static function generateDatabaseName( $path ) {
 255                 if ( preg_match( '/^(:memory:$|file::memory:)/', $path ) ) {
 256                         // E.g. "file::memory:?cache=shared" => ":memory":
 257                         return ':memory:';
 258                 } elseif ( preg_match( '/^file::([^?]+)\?mode=memory(&|$)/', $path, $m ) ) {
 259                         // E.g. "file:memdb1?mode=memory" => ":memdb1:"
 260                         return ":{$m[1]}:";
 261                 } else {
 262                         // E.g. "/home/.../some_db.sqlite3" => "some_db"
 263                         return preg_replace( '/\.sqlite\d?$/', '', basename( $path ) );
 264                 }
 265         }
 266
 267         /**
 268          * @param string $path
 269          * @return bool
 270          */
 271         private static function isProcessMemoryPath( $path ) {
 272                 return preg_match( '/^(:memory:$|file:(:memory:|[^?]+\?mode=memory(&|$)))/', $path );
 273         }
 274
 275         /**
 276          * Returns version of currently supported SQLite fulltext search module or false if none present.
 277          * @return string
 278          */
 279         static function getFulltextSearchModule() {
 280                 static $cachedResult = null;
 281                 if ( $cachedResult !== null ) {
 282                         return $cachedResult;
 283                 }
 284                 $cachedResult = false;
 285                 $table = 'dummy_search_test';
 286
 287                 $db = self::newStandaloneInstance( ':memory:' );
 288                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 289                         $cachedResult = 'FTS3';
 290                 }
 291                 $db->close();
 292
 293                 return $cachedResult;
 294         }
 295
 296         /**
 297          * Attaches external database to our connection, see https://sqlite.org/lang_attach.html
 298          * for details.
 299          *
 300          * @param string $name Database name to be used in queries like
 301          *   SELECT foo FROM dbname.table
 302          * @param bool|string $file Database file name. If omitted, will be generated
 303          *   using $name and configured data directory
 304          * @param string $fname Calling function name
 305          * @return IResultWrapper
 306          */
 307         public function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 308                 $file = is_string( $file ) ? $file : self::generateFileName( $this->dbDir, $name );
 309                 $encFile = $this->addQuotes( $file );
 310
 311                 return $this->query(
 312                         "ATTACH DATABASE $encFile AS $name",
 313                         $fname,
 314                         self::QUERY_IGNORE_DBO_TRX
 315                 );
 316         }
 317
 318         protected function isWriteQuery( $sql ) {
 319                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 320         }
 321
 322         protected function isTransactableQuery( $sql ) {
 323                 return parent::isTransactableQuery( $sql ) && !in_array(
 324                         $this->getQueryVerb( $sql ),
 325                         [ 'ATTACH', 'PRAGMA' ],
 326                         true
 327                 );
 328         }
 329
 330         /**
 331          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 332          *
 333          * @param string $sql
 334          * @return bool|IResultWrapper
 335          */
 336         protected function doQuery( $sql ) {
 337                 $res = $this->getBindingHandle()->query( $sql );
 338                 if ( $res === false ) {
 339                         return false;
 340                 }
 341
 342                 $resource = ResultWrapper::unwrap( $res );
 343                 $this->lastAffectedRowCount = $resource->rowCount();
 344                 $res = new ResultWrapper( $this, $resource->fetchAll() );
 345
 346                 return $res;
 347         }
 348
 349         /**
 350          * @param IResultWrapper|mixed $res
 351          */
 352         function freeResult( $res ) {
 353                 if ( $res instanceof ResultWrapper ) {
 354                         $res->free();
 355                 }
 356         }
 357
 358         /**
 359          * @param IResultWrapper|array $res
 360          * @return stdClass|bool
 361          */
 362         function fetchObject( $res ) {
 363                 $resource =& ResultWrapper::unwrap( $res );
 364
 365                 $cur = current( $resource );
 366                 if ( is_array( $cur ) ) {
 367                         next( $resource );
 368                         $obj = new stdClass;
 369                         foreach ( $cur as $k => $v ) {
 370                                 if ( !is_numeric( $k ) ) {
 371                                         $obj->$k = $v;
 372                                 }
 373                         }
 374
 375                         return $obj;
 376                 }
 377
 378                 return false;
 379         }
 380
 381         /**
 382          * @param IResultWrapper|mixed $res
 383          * @return array|bool
 384          */
 385         function fetchRow( $res ) {
 386                 $resource =& ResultWrapper::unwrap( $res );
 387                 $cur = current( $resource );
 388                 if ( is_array( $cur ) ) {
 389                         next( $resource );
 390
 391                         return $cur;
 392                 }
 393
 394                 return false;
 395         }
 396
 397         /**
 398          * The PDO::Statement class implements the array interface so count() will work
 399          *
 400          * @param IResultWrapper|array|false $res
 401          * @return int
 402          */
 403         function numRows( $res ) {
 404                 // false does not implement Countable
 405                 $resource = ResultWrapper::unwrap( $res );
 406
 407                 return is_array( $resource ) ? count( $resource ) : 0;
 408         }
 409
 410         /**
 411          * @param IResultWrapper $res
 412          * @return int
 413          */
 414         function numFields( $res ) {
 415                 $resource = ResultWrapper::unwrap( $res );
 416                 if ( is_array( $resource ) && count( $resource ) > 0 ) {
 417                         // The size of the result array is twice the number of fields. (T67578)
 418                         return count( $resource[0] ) / 2;
 419                 } else {
 420                         // If the result is empty return 0
 421                         return 0;
 422                 }
 423         }
 424
 425         /**
 426          * @param IResultWrapper $res
 427          * @param int $n
 428          * @return bool
 429          */
 430         function fieldName( $res, $n ) {
 431                 $resource = ResultWrapper::unwrap( $res );
 432                 if ( is_array( $resource ) ) {
 433                         $keys = array_keys( $resource[0] );
 434
 435                         return $keys[$n];
 436                 }
 437
 438                 return false;
 439         }
 440
 441         protected function doSelectDomain( DatabaseDomain $domain ) {
 442                 if ( $domain->getSchema() !== null ) {
 443                         throw new DBExpectedError(
 444                                 $this,
 445                                 __CLASS__ . ": domain '{$domain->getId()}' has a schema component"
 446                         );
 447                 }
 448
 449                 $database = $domain->getDatabase();
 450                 // A null database means "don't care" so leave it as is and update the table prefix
 451                 if ( $database === null ) {
 452                         $this->currentDomain = new DatabaseDomain(
 453                                 $this->currentDomain->getDatabase(),
 454                                 null,
 455                                 $domain->getTablePrefix()
 456                         );
 457
 458                         return true;
 459                 }
 460
 461                 if ( $database !== $this->getDBname() ) {
 462                         throw new DBExpectedError(
 463                                 $this,
 464                                 __CLASS__ . ": cannot change database (got '$database')"
 465                         );
 466                 }
 467
 468                 return true;
 469         }
 470
 471         /**
 472          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 473          *
 474          * @param string $name
 475          * @param string $format
 476          * @return string
 477          */
 478         function tableName( $name, $format = 'quoted' ) {
 479                 // table names starting with sqlite_ are reserved
 480                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 481                         return $name;
 482                 }
 483
 484                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 485         }
 486
 487         /**
 488          * This must be called after nextSequenceVal
 489          *
 490          * @return int
 491          */
 492         function insertId() {
 493                 // PDO::lastInsertId yields a string :(
 494                 return intval( $this->getBindingHandle()->lastInsertId() );
 495         }
 496
 497         /**
 498          * @param IResultWrapper|array $res
 499          * @param int $row
 500          */
 501         function dataSeek( $res, $row ) {
 502                 $resource =& ResultWrapper::unwrap( $res );
 503                 reset( $resource );
 504                 if ( $row > 0 ) {
 505                         for ( $i = 0; $i < $row; $i++ ) {
 506                                 next( $resource );
 507                         }
 508                 }
 509         }
 510
 511         /**
 512          * @return string
 513          */
 514         function lastError() {
 515                 if ( !is_object( $this->conn ) ) {
 516                         return "Cannot return last error, no db connection";
 517                 }
 518                 $e = $this->conn->errorInfo();
 519
 520                 return $e[2] ?? '';
 521         }
 522
 523         /**
 524          * @return string
 525          */
 526         function lastErrno() {
 527                 if ( !is_object( $this->conn ) ) {
 528                         return "Cannot return last error, no db connection";
 529                 } else {
 530                         $info = $this->conn->errorInfo();
 531
 532                         return $info[1];
 533                 }
 534         }
 535
 536         /**
 537          * @return int
 538          */
 539         protected function fetchAffectedRowCount() {
 540                 return $this->lastAffectedRowCount;
 541         }
 542
 543         function tableExists( $table, $fname = __METHOD__ ) {
 544                 $tableRaw = $this->tableName( $table, 'raw' );
 545                 if ( isset( $this->sessionTempTables[$tableRaw] ) ) {
 546                         return true; // already known to exist
 547                 }
 548
 549                 $encTable = $this->addQuotes( $tableRaw );
 550                 $res = $this->query(
 551                         "SELECT 1 FROM sqlite_master WHERE type='table' AND name=$encTable",
 552                         __METHOD__,
 553                         self::QUERY_IGNORE_DBO_TRX
 554                 );
 555
 556                 return $res->numRows() ? true : false;
 557         }
 558
 559         /**
 560          * Returns information about an index
 561          * Returns false if the index does not exist
 562          * - if errors are explicitly ignored, returns NULL on failure
 563          *
 564          * @param string $table
 565          * @param string $index
 566          * @param string $fname
 567          * @return array|false
 568          */
 569         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 570                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 571                 $res = $this->query( $sql, $fname, self::QUERY_IGNORE_DBO_TRX );
 572                 if ( !$res || $res->numRows() == 0 ) {
 573                         return false;
 574                 }
 575                 $info = [];
 576                 foreach ( $res as $row ) {
 577                         $info[] = $row->name;
 578                 }
 579
 580                 return $info;
 581         }
 582
 583         /**
 584          * @param string $table
 585          * @param string $index
 586          * @param string $fname
 587          * @return bool|null
 588          */
 589         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 590                 $row = $this->selectRow( 'sqlite_master', '*',
 591                         [
 592                                 'type' => 'index',
 593                                 'name' => $this->indexName( $index ),
 594                         ], $fname );
 595                 if ( !$row || !isset( $row->sql ) ) {
 596                         return null;
 597                 }
 598
 599                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 600                 $indexPos = strpos( $row->sql, 'INDEX' );
 601                 if ( $indexPos === false ) {
 602                         return null;
 603                 }
 604                 $firstPart = substr( $row->sql, 0, $indexPos );
 605                 $options = explode( ' ', $firstPart );
 606
 607                 return in_array( 'UNIQUE', $options );
 608         }
 609
 610         /**
 611          * Filter the options used in SELECT statements
 612          *
 613          * @param array $options
 614          * @return array
 615          */
 616         function makeSelectOptions( $options ) {
 617                 foreach ( $options as $k => $v ) {
 618                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 619                                 $options[$k] = '';
 620                         }
 621                 }
 622
 623                 return parent::makeSelectOptions( $options );
 624         }
 625
 626         /**
 627          * @param array $options
 628          * @return array
 629          */
 630         protected function makeUpdateOptionsArray( $options ) {
 631                 $options = parent::makeUpdateOptionsArray( $options );
 632                 $options = self::fixIgnore( $options );
 633
 634                 return $options;
 635         }
 636
 637         /**
 638          * @param array $options
 639          * @return array
 640          */
 641         static function fixIgnore( $options ) {
 642                 # SQLite uses OR IGNORE not just IGNORE
 643                 foreach ( $options as $k => $v ) {
 644                         if ( $v == 'IGNORE' ) {
 645                                 $options[$k] = 'OR IGNORE';
 646                         }
 647                 }
 648
 649                 return $options;
 650         }
 651
 652         /**
 653          * @param array $options
 654          * @return string
 655          */
 656         function makeInsertOptions( $options ) {
 657                 $options = self::fixIgnore( $options );
 658
 659                 return parent::makeInsertOptions( $options );
 660         }
 661
 662         /**
 663          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 664          * @param string $table
 665          * @param array $a
 666          * @param string $fname
 667          * @param array $options
 668          * @return bool
 669          */
 670         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 671                 if ( !count( $a ) ) {
 672                         return true;
 673                 }
 674
 675                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 676                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 677                         $affectedRowCount = 0;
 678                         try {
 679                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 680                                 foreach ( $a as $v ) {
 681                                         parent::insert( $table, $v, "$fname/multi-row", $options );
 682                                         $affectedRowCount += $this->affectedRows();
 683                                 }
 684                                 $this->endAtomic( $fname );
 685                         } catch ( Exception $e ) {
 686                                 $this->cancelAtomic( $fname );
 687                                 throw $e;
 688                         }
 689                         $this->affectedRowCount = $affectedRowCount;
 690                 } else {
 691                         parent::insert( $table, $a, "$fname/single-row", $options );
 692                 }
 693
 694                 return true;
 695         }
 696
 697         /**
 698          * @param string $table
 699          * @param array $uniqueIndexes Unused
 700          * @param string|array $rows
 701          * @param string $fname
 702          */
 703         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 704                 if ( !count( $rows ) ) {
 705                         return;
 706                 }
 707
 708                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 709                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 710                         $affectedRowCount = 0;
 711                         try {
 712                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 713                                 foreach ( $rows as $v ) {
 714                                         $this->nativeReplace( $table, $v, "$fname/multi-row" );
 715                                         $affectedRowCount += $this->affectedRows();
 716                                 }
 717                                 $this->endAtomic( $fname );
 718                         } catch ( Exception $e ) {
 719                                 $this->cancelAtomic( $fname );
 720                                 throw $e;
 721                         }
 722                         $this->affectedRowCount = $affectedRowCount;
 723                 } else {
 724                         $this->nativeReplace( $table, $rows, "$fname/single-row" );
 725                 }
 726         }
 727
 728         /**
 729          * Returns the size of a text field, or -1 for "unlimited"
 730          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 731          *
 732          * @param string $table
 733          * @param string $field
 734          * @return int
 735          */
 736         function textFieldSize( $table, $field ) {
 737                 return -1;
 738         }
 739
 740         /**
 741          * @return bool
 742          */
 743         function unionSupportsOrderAndLimit() {
 744                 return false;
 745         }
 746
 747         /**
 748          * @param string[] $sqls
 749          * @param bool $all Whether to "UNION ALL" or not
 750          * @return string
 751          */
 752         function unionQueries( $sqls, $all ) {
 753                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 754
 755                 return implode( $glue, $sqls );
 756         }
 757
 758         /**
 759          * @return bool
 760          */
 761         function wasDeadlock() {
 762                 return $this->lastErrno() == 5; // SQLITE_BUSY
 763         }
 764
 765         /**
 766          * @return bool
 767          */
 768         function wasReadOnlyError() {
 769                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 770         }
 771
 772         public function wasConnectionError( $errno ) {
 773                 return $errno == 17; // SQLITE_SCHEMA;
 774         }
 775
 776         protected function wasKnownStatementRollbackError() {
 777                 // ON CONFLICT ROLLBACK clauses make it so that SQLITE_CONSTRAINT error is
 778                 // ambiguous with regard to whether it implies a ROLLBACK or an ABORT happened.
 779                 // https://sqlite.org/lang_createtable.html#uniqueconst
 780                 // https://sqlite.org/lang_conflict.html
 781                 return false;
 782         }
 783
 784         public function serverIsReadOnly() {
 785                 $this->assertHasConnectionHandle();
 786
 787                 $path = $this->getDbFilePath();
 788
 789                 return ( !self::isProcessMemoryPath( $path ) && !is_writable( $path ) );
 790         }
 791
 792         /**
 793          * @return string Wikitext of a link to the server software's web site
 794          */
 795         public function getSoftwareLink() {
 796                 return "[{{int:version-db-sqlite-url}} SQLite]";
 797         }
 798
 799         /**
 800          * @return string Version information from the database
 801          */
 802         function getServerVersion() {
 803                 $ver = $this->getBindingHandle()->getAttribute( PDO::ATTR_SERVER_VERSION );
 804
 805                 return $ver;
 806         }
 807
 808         /**
 809          * Get information about a given field
 810          * Returns false if the field does not exist.
 811          *
 812          * @param string $table
 813          * @param string $field
 814          * @return SQLiteField|bool False on failure
 815          */
 816         function fieldInfo( $table, $field ) {
 817                 $tableName = $this->tableName( $table );
 818                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 819                 $res = $this->query( $sql, __METHOD__, self::QUERY_IGNORE_DBO_TRX );
 820                 foreach ( $res as $row ) {
 821                         if ( $row->name == $field ) {
 822                                 return new SQLiteField( $row, $tableName );
 823                         }
 824                 }
 825
 826                 return false;
 827         }
 828
 829         protected function doBegin( $fname = '' ) {
 830                 if ( $this->trxMode != '' ) {
 831                         $this->query( "BEGIN {$this->trxMode}", $fname );
 832                 } else {
 833                         $this->query( 'BEGIN', $fname );
 834                 }
 835         }
 836
 837         /**
 838          * @param string $s
 839          * @return string
 840          */
 841         function strencode( $s ) {
 842                 return substr( $this->addQuotes( $s ), 1, -1 );
 843         }
 844
 845         /**
 846          * @param string $b
 847          * @return Blob
 848          */
 849         function encodeBlob( $b ) {
 850                 return new Blob( $b );
 851         }
 852
 853         /**
 854          * @param Blob|string $b
 855          * @return string
 856          */
 857         function decodeBlob( $b ) {
 858                 if ( $b instanceof Blob ) {
 859                         $b = $b->fetch();
 860                 }
 861
 862                 return $b;
 863         }
 864
 865         /**
 866          * @param string|int|null|bool|Blob $s
 867          * @return string|int
 868          */
 869         function addQuotes( $s ) {
 870                 if ( $s instanceof Blob ) {
 871                         return "x'" . bin2hex( $s->fetch() ) . "'";
 872                 } elseif ( is_bool( $s ) ) {
 873                         return (int)$s;
 874                 } elseif ( strpos( (string)$s, "\0" ) !== false ) {
 875                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 876                         // This is a known limitation of SQLite's mprintf function which PDO
 877                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 878                         // https://bugs.php.net/bug.php?id=63419
 879                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 880                         // https://bugs.php.net/bug.php?id=62361
 881                         // There is an additional bug regarding sorting this data after insert
 882                         // on older versions of sqlite shipped with ubuntu 12.04
 883                         // https://phabricator.wikimedia.org/T74367
 884                         $this->queryLogger->debug(
 885                                 __FUNCTION__ .
 886                                 ': Quoting value containing null byte. ' .
 887                                 'For consistency all binary data should have been ' .
 888                                 'first processed with self::encodeBlob()'
 889                         );
 890                         return "x'" . bin2hex( (string)$s ) . "'";
 891                 } else {
 892                         return $this->getBindingHandle()->quote( (string)$s );
 893                 }
 894         }
 895
 896         public function buildSubstring( $input, $startPosition, $length = null ) {
 897                 $this->assertBuildSubstringParams( $startPosition, $length );
 898                 $params = [ $input, $startPosition ];
 899                 if ( $length !== null ) {
 900                         $params[] = $length;
 901                 }
 902                 return 'SUBSTR(' . implode( ',', $params ) . ')';
 903         }
 904
 905         /**
 906          * @param string $field Field or column to cast
 907          * @return string
 908          * @since 1.28
 909          */
 910         public function buildStringCast( $field ) {
 911                 return 'CAST ( ' . $field . ' AS TEXT )';
 912         }
 913
 914         /**
 915          * No-op version of deadlockLoop
 916          *
 917          * @return mixed
 918          */
 919         public function deadlockLoop( /*...*/ ) {
 920                 $args = func_get_args();
 921                 $function = array_shift( $args );
 922
 923                 return $function( ...$args );
 924         }
 925
 926         /**
 927          * @param string $s
 928          * @return string
 929          */
 930         protected function replaceVars( $s ) {
 931                 $s = parent::replaceVars( $s );
 932                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 933                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 934
 935                         // binary/varbinary column type -> blob
 936                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 937                         // no such thing as unsigned
 938                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 939                         // INT -> INTEGER
 940                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 941                         // floating point types -> REAL
 942                         $s = preg_replace(
 943                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 944                                 'REAL',
 945                                 $s
 946                         );
 947                         // varchar -> TEXT
 948                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 949                         // TEXT normalization
 950                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 951                         // BLOB normalization
 952                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 953                         // BOOL -> INTEGER
 954                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 955                         // DATETIME -> TEXT
 956                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 957                         // No ENUM type
 958                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 959                         // binary collation type -> nothing
 960                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 961                         // auto_increment -> autoincrement
 962                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 963                         // No explicit options
 964                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 965                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 966                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 967                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 968                         // No truncated indexes
 969                         $s = preg_replace( '/\(\d+\)/', '', $s );
 970                         // No FULLTEXT
 971                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 972                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 973                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 974                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 975                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 976                         // INSERT IGNORE --> INSERT OR IGNORE
 977                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 978                 }
 979
 980                 return $s;
 981         }
 982
 983         public function lock( $lockName, $method, $timeout = 5 ) {
 984                 $status = $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout );
 985                 if (
 986                         $this->lockMgr instanceof FSLockManager &&
 987                         $status->hasMessage( 'lockmanager-fail-openlock' )
 988                 ) {
 989                         throw new DBError( $this, "Cannot create directory \"{$this->getLockFileDirectory()}\"" );
 990                 }
 991
 992                 return $status->isOK();
 993         }
 994
 995         public function unlock( $lockName, $method ) {
 996                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isGood();
 997         }
 998
 999         /**
1000          * Build a concatenation list to feed into a SQL query
1001          *
1002          * @param string[] $stringList
1003          * @return string
1004          */
1005         function buildConcat( $stringList ) {
1006                 return '(' . implode( ') || (', $stringList ) . ')';
1007         }
1008
1009         public function buildGroupConcatField(
1010                 $delim, $table, $field, $conds = '', $join_conds = []
1011         ) {
1012                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
1013
1014                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
1015         }
1016
1017         /**
1018          * @param string $oldName
1019          * @param string $newName
1020          * @param bool $temporary
1021          * @param string $fname
1022          * @return bool|IResultWrapper
1023          * @throws RuntimeException
1024          */
1025         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1026                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
1027                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
1028                 $obj = $this->fetchObject( $res );
1029                 if ( !$obj ) {
1030                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
1031                 }
1032                 $sql = $obj->sql;
1033                 $sql = preg_replace(
1034                         '/(?<=\W)"?' .
1035                                 preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ), '/' ) .
1036                                 '"?(?=\W)/',
1037                         $this->addIdentifierQuotes( $newName ),
1038                         $sql,
1039                         1
1040                 );
1041                 if ( $temporary ) {
1042                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
1043                                 $this->queryLogger->debug(
1044                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
1045                         } else {
1046                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
1047                         }
1048                 }
1049
1050                 $res = $this->query( $sql, $fname, self::QUERY_PSEUDO_PERMANENT );
1051
1052                 // Take over indexes
1053                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
1054                 foreach ( $indexList as $index ) {
1055                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
1056                                 continue;
1057                         }
1058
1059                         if ( $index->unique ) {
1060                                 $sql = 'CREATE UNIQUE INDEX';
1061                         } else {
1062                                 $sql = 'CREATE INDEX';
1063                         }
1064                         // Try to come up with a new index name, given indexes have database scope in SQLite
1065                         $indexName = $newName . '_' . $index->name;
1066                         $sql .= ' ' . $indexName . ' ON ' . $newName;
1067
1068                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
1069                         $fields = [];
1070                         foreach ( $indexInfo as $indexInfoRow ) {
1071                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
1072                         }
1073
1074                         $sql .= '(' . implode( ',', $fields ) . ')';
1075
1076                         $this->query( $sql );
1077                 }
1078
1079                 return $res;
1080         }
1081
1082         /**
1083          * List all tables on the database
1084          *
1085          * @param string|null $prefix Only show tables with this prefix, e.g. mw_
1086          * @param string $fname Calling function name
1087          *
1088          * @return array
1089          */
1090         function listTables( $prefix = null, $fname = __METHOD__ ) {
1091                 $result = $this->select(
1092                         'sqlite_master',
1093                         'name',
1094                         "type='table'"
1095                 );
1096
1097                 $endArray = [];
1098
1099                 foreach ( $result as $table ) {
1100                         $vars = get_object_vars( $table );
1101                         $table = array_pop( $vars );
1102
1103                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1104                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1105                                         $endArray[] = $table;
1106                                 }
1107                         }
1108                 }
1109
1110                 return $endArray;
1111         }
1112
1113         /**
1114          * Override due to no CASCADE support
1115          *
1116          * @param string $tableName
1117          * @param string $fName
1118          * @return bool|IResultWrapper
1119          * @throws DBReadOnlyError
1120          */
1121         public function dropTable( $tableName, $fName = __METHOD__ ) {
1122                 if ( !$this->tableExists( $tableName, $fName ) ) {
1123                         return false;
1124                 }
1125                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1126
1127                 return $this->query( $sql, $fName, self::QUERY_IGNORE_DBO_TRX );
1128         }
1129
1130         public function setTableAliases( array $aliases ) {
1131                 parent::setTableAliases( $aliases );
1132                 foreach ( $this->tableAliases as $params ) {
1133                         if ( isset( $this->alreadyAttached[$params['dbname']] ) ) {
1134                                 continue;
1135                         }
1136                         $this->attachDatabase( $params['dbname'] );
1137                         $this->alreadyAttached[$params['dbname']] = true;
1138                 }
1139         }
1140
1141         public function resetSequenceForTable( $table, $fname = __METHOD__ ) {
1142                 $encTable = $this->addIdentifierQuotes( 'sqlite_sequence' );
1143                 $encName = $this->addQuotes( $this->tableName( $table, 'raw' ) );
1144                 $this->query(
1145                         "DELETE FROM $encTable WHERE name = $encName",
1146                         $fname,
1147                         self::QUERY_IGNORE_DBO_TRX
1148                 );
1149         }
1150
1151         public function databasesAreIndependent() {
1152                 return true;
1153         }
1154
1155         /**
1156          * @return PDO
1157          */
1158         protected function getBindingHandle() {
1159                 return parent::getBindingHandle();
1160         }
1161 }
1162
1163 /**
1164  * @deprecated since 1.29
1165  */
1166 class_alias( DatabaseSqlite::class, 'DatabaseSqlite' );