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