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