includes/libs/rdbms/database/DatabaseSqlite.php

   1 <?php
   2 /**
   3  * This is the SQLite database abstraction layer.
   4  * See maintenance/sqlite/README for development notes and other specific information
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  * @ingroup Database
  23  */
  24 namespace Wikimedia\Rdbms;
  25
  26 use NullLockManager;
  27 use PDO;
  28 use PDOException;
  29 use Exception;
  30 use LockManager;
  31 use FSLockManager;
  32 use RuntimeException;
  33 use stdClass;
  34
  35 /**
  36  * @ingroup Database
  37  */
  38 class DatabaseSqlite extends Database {
  39         /** @var string|null Directory for SQLite database files listed under their DB name */
  40         protected $dbDir;
  41         /** @var string|null Explicit path for the SQLite database file */
  42         protected $dbPath;
  43         /** @var string Transaction mode */
  44         protected $trxMode;
  45
  46         /** @var int The number of rows affected as an integer */
  47         protected $lastAffectedRowCount;
  48         /** @var resource */
  49         protected $lastResultHandle;
  50
  51         /** @var PDO */
  52         protected $conn;
  53
  54         /** @var FSLockManager (hopefully on the same server as the DB) */
  55         protected $lockMgr;
  56
  57         /** @var array List of shared database already attached to this connection */
  58         private $alreadyAttached = [];
  59
  60         /** @var bool Whether full text is enabled */
  61         private static $fulltextEnabled = null;
  62
  63         /**
  64          * Additional params include:
  65          *   - dbDirectory : directory containing the DB and the lock file directory
  66          *   - dbFilePath  : use this to force the path of the DB file
  67          *   - trxMode     : one of (deferred, immediate, exclusive)
  68          * @param array $p
  69          */
  70         public function __construct( array $p ) {
  71                 if ( isset( $p['dbFilePath'] ) ) {
  72                         $this->dbPath = $p['dbFilePath'];
  73                         if ( !strlen( $p['dbname'] ) ) {
  74                                 $p['dbname'] = self::generateDatabaseName( $this->dbPath );
  75                         }
  76                 } elseif ( isset( $p['dbDirectory'] ) ) {
  77                         $this->dbDir = $p['dbDirectory'];
  78                 }
  79
  80                 // Set a dummy user to make initConnection() trigger open()
  81                 parent::__construct( [ 'user' => '@' ] + $p );
  82
  83                 $this->trxMode = strtoupper( $p['trxMode'] ?? '' );
  84
  85                 $lockDirectory = $this->getLockFileDirectory();
  86                 if ( $lockDirectory !== null ) {
  87                         $this->lockMgr = new FSLockManager( [
  88                                 'domain' => $this->getDomainID(),
  89                                 'lockDirectory' => $lockDirectory
  90                         ] );
  91                 } else {
  92                         $this->lockMgr = new NullLockManager( [ 'domain' => $this->getDomainID() ] );
  93                 }
  94         }
  95
  96         protected static function getAttributes() {
  97                 return [ self::ATTR_DB_LEVEL_LOCKING => true ];
  98         }
  99
 100         /**
 101          * @param string $filename
 102          * @param array $p Options map; supports:
 103          *   - flags       : (same as __construct counterpart)
 104          *   - trxMode     : (same as __construct counterpart)
 105          *   - dbDirectory : (same as __construct counterpart)
 106          * @return DatabaseSqlite
 107          * @since 1.25
 108          */
 109         public static function newStandaloneInstance( $filename, array $p = [] ) {
 110                 $p['dbFilePath'] = $filename;
 111                 $p['schema'] = null;
 112                 $p['tablePrefix'] = '';
 113                 /** @var DatabaseSqlite $db */
 114                 $db = Database::factory( 'sqlite', $p );
 115
 116                 return $db;
 117         }
 118
 119         /**
 120          * @return string
 121          */
 122         public function getType() {
 123                 return 'sqlite';
 124         }
 125
 126         /**
 127          * @todo Check if it should be true like parent class
 128          *
 129          * @return bool
 130          */
 131         public function implicitGroupby() {
 132                 return false;
 133         }
 134
 135         protected function open( $server, $user, $pass, $dbName, $schema, $tablePrefix ) {
 136                 $this->close();
 137
 138                 // Note that for SQLite, $server, $user, and $pass are ignored
 139
 140                 if ( $schema !== null ) {
 141                         throw new DBExpectedError( $this, __CLASS__ . ": cannot use schemas ('$schema')" );
 142                 }
 143
 144                 if ( $this->dbPath !== null ) {
 145                         $path = $this->dbPath;
 146                 } elseif ( $this->dbDir !== null ) {
 147                         $path = self::generateFileName( $this->dbDir, $dbName );
 148                 } else {
 149                         throw new DBExpectedError( $this, __CLASS__ . ": DB path or directory required" );
 150                 }
 151
 152                 if ( !in_array( $this->trxMode, [ '', 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ], true ) ) {
 153                         throw new DBExpectedError(
 154                                 $this,
 155                                 __CLASS__ . ": invalid transaction mode '{$this->trxMode}'"
 156                         );
 157                 }
 158
 159                 if ( !self::isProcessMemoryPath( $path ) && !is_readable( $path ) ) {
 160                         $error = "SQLite database file not readable";
 161                         $this->connLogger->error(
 162                                 "Error connecting to {db_server}: {error}",
 163                                 $this->getLogContext( [ 'method' => __METHOD__, 'error' => $error ] )
 164                         );
 165                         throw new DBConnectionError( $this, $error );
 166                 }
 167
 168                 try {
 169                         $conn = new PDO(
 170                                 "sqlite:$path",
 171                                 '',
 172                                 '',
 173                                 [ PDO::ATTR_PERSISTENT => (bool)( $this->flags & self::DBO_PERSISTENT ) ]
 174                         );
 175                         // Set error codes only, don't raise exceptions
 176                         $conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 177                 } catch ( PDOException $e ) {
 178                         $error = $e->getMessage();
 179                         $this->connLogger->error(
 180                                 "Error connecting to {db_server}: {error}",
 181                                 $this->getLogContext( [ 'method' => __METHOD__, 'error' => $error ] )
 182                         );
 183                         throw new DBConnectionError( $this, $error );
 184                 }
 185
 186                 $this->conn = $conn;
 187                 $this->currentDomain = new DatabaseDomain( $dbName, null, $tablePrefix );
 188
 189                 try {
 190                         $flags = self::QUERY_IGNORE_DBO_TRX | self::QUERY_NO_RETRY;
 191                         // Enforce LIKE to be case sensitive, just like MySQL
 192                         $this->query( 'PRAGMA case_sensitive_like = 1', __METHOD__, $flags );
 193                         // Apply an optimizations or requirements regarding fsync() usage
 194                         $sync = $this->connectionVariables['synchronous'] ?? null;
 195                         if ( in_array( $sync, [ 'EXTRA', 'FULL', 'NORMAL', 'OFF' ], true ) ) {
 196                                 $this->query( "PRAGMA synchronous = $sync", __METHOD__, $flags );
 197                         }
 198                 } catch ( Exception $e ) {
 199                         // Connection was not fully initialized and is not safe for use
 200                         $this->conn = false;
 201                         throw $e;
 202                 }
 203         }
 204
 205         /**
 206          * @return string|null SQLite DB file path
 207          * @throws DBUnexpectedError
 208          * @since 1.25
 209          */
 210         public function getDbFilePath() {
 211                 return $this->dbPath ?? self::generateFileName( $this->dbDir, $this->getDBname() );
 212         }
 213
 214         /**
 215          * @return string|null Lock file directory
 216          */
 217         public function getLockFileDirectory() {
 218                 if ( $this->dbPath !== null && !self::isProcessMemoryPath( $this->dbPath ) ) {
 219                         return dirname( $this->dbPath ) . '/locks';
 220                 } elseif ( $this->dbDir !== null && !self::isProcessMemoryPath( $this->dbDir ) ) {
 221                         return $this->dbDir . '/locks';
 222                 }
 223
 224                 return null;
 225         }
 226
 227         /**
 228          * Does not actually close the connection, just destroys the reference for GC to do its work
 229          * @return bool
 230          */
 231         protected function closeConnection() {
 232                 $this->conn = null;
 233
 234                 return true;
 235         }
 236
 237         /**
 238          * Generates a database file name. Explicitly public for installer.
 239          * @param string $dir Directory where database resides
 240          * @param string|bool $dbName Database name (or false from Database::factory, validated here)
 241          * @return string
 242          * @throws DBUnexpectedError
 243          */
 244         public static function generateFileName( $dir, $dbName ) {
 245                 if ( $dir == '' ) {
 246                         throw new DBUnexpectedError( null, __CLASS__ . ": no DB directory specified" );
 247                 } elseif ( self::isProcessMemoryPath( $dir ) ) {
 248                         throw new DBUnexpectedError(
 249                                 null,
 250                                 __CLASS__ . ": cannot use process memory directory '$dir'"
 251                         );
 252                 } elseif ( !strlen( $dbName ) ) {
 253                         throw new DBUnexpectedError( null, __CLASS__ . ": no DB name specified" );
 254                 }
 255
 256                 return "$dir/$dbName.sqlite";
 257         }
 258
 259         /**
 260          * @param string $path
 261          * @return string
 262          */
 263         private static function generateDatabaseName( $path ) {
 264                 if ( preg_match( '/^(:memory:$|file::memory:)/', $path ) ) {
 265                         // E.g. "file::memory:?cache=shared" => ":memory":
 266                         return ':memory:';
 267                 } elseif ( preg_match( '/^file::([^?]+)\?mode=memory(&|$)/', $path, $m ) ) {
 268                         // E.g. "file:memdb1?mode=memory" => ":memdb1:"
 269                         return ":{$m[1]}:";
 270                 } else {
 271                         // E.g. "/home/.../some_db.sqlite3" => "some_db"
 272                         return preg_replace( '/\.sqlite\d?$/', '', basename( $path ) );
 273                 }
 274         }
 275
 276         /**
 277          * @param string $path
 278          * @return bool
 279          */
 280         private static function isProcessMemoryPath( $path ) {
 281                 return preg_match( '/^(:memory:$|file:(:memory:|[^?]+\?mode=memory(&|$)))/', $path );
 282         }
 283
 284         /**
 285          * Check if the searchindext table is FTS enabled.
 286          * @return bool False if not enabled.
 287          */
 288         public function checkForEnabledSearch() {
 289                 if ( self::$fulltextEnabled === null ) {
 290                         self::$fulltextEnabled = false;
 291                         $table = $this->tableName( 'searchindex' );
 292                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 293                         if ( $res ) {
 294                                 $row = $res->fetchRow();
 295                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 296                         }
 297                 }
 298
 299                 return self::$fulltextEnabled;
 300         }
 301
 302         /**
 303          * Returns version of currently supported SQLite fulltext search module or false if none present.
 304          * @return string
 305          */
 306         static function getFulltextSearchModule() {
 307                 static $cachedResult = null;
 308                 if ( $cachedResult !== null ) {
 309                         return $cachedResult;
 310                 }
 311                 $cachedResult = false;
 312                 $table = 'dummy_search_test';
 313
 314                 $db = self::newStandaloneInstance( ':memory:' );
 315                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 316                         $cachedResult = 'FTS3';
 317                 }
 318                 $db->close();
 319
 320                 return $cachedResult;
 321         }
 322
 323         /**
 324          * Attaches external database to our connection, see https://sqlite.org/lang_attach.html
 325          * for details.
 326          *
 327          * @param string $name Database name to be used in queries like
 328          *   SELECT foo FROM dbname.table
 329          * @param bool|string $file Database file name. If omitted, will be generated
 330          *   using $name and configured data directory
 331          * @param string $fname Calling function name
 332          * @return IResultWrapper
 333          */
 334         public function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 335                 $file = is_string( $file ) ? $file : self::generateFileName( $this->dbDir, $name );
 336                 $encFile = $this->addQuotes( $file );
 337
 338                 return $this->query( "ATTACH DATABASE $encFile AS $name", $fname );
 339         }
 340
 341         protected function isWriteQuery( $sql ) {
 342                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 343         }
 344
 345         protected function isTransactableQuery( $sql ) {
 346                 return parent::isTransactableQuery( $sql ) && !in_array(
 347                         $this->getQueryVerb( $sql ),
 348                         [ 'ATTACH', 'PRAGMA' ],
 349                         true
 350                 );
 351         }
 352
 353         /**
 354          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 355          *
 356          * @param string $sql
 357          * @return bool|IResultWrapper
 358          */
 359         protected function doQuery( $sql ) {
 360                 $res = $this->getBindingHandle()->query( $sql );
 361                 if ( $res === false ) {
 362                         return false;
 363                 }
 364
 365                 $resource = ResultWrapper::unwrap( $res );
 366                 $this->lastAffectedRowCount = $resource->rowCount();
 367                 $res = new ResultWrapper( $this, $resource->fetchAll() );
 368
 369                 return $res;
 370         }
 371
 372         /**
 373          * @param IResultWrapper|mixed $res
 374          */
 375         function freeResult( $res ) {
 376                 if ( $res instanceof ResultWrapper ) {
 377                         $res->free();
 378                 }
 379         }
 380
 381         /**
 382          * @param IResultWrapper|array $res
 383          * @return stdClass|bool
 384          */
 385         function fetchObject( $res ) {
 386                 $resource =& ResultWrapper::unwrap( $res );
 387
 388                 $cur = current( $resource );
 389                 if ( is_array( $cur ) ) {
 390                         next( $resource );
 391                         $obj = new stdClass;
 392                         foreach ( $cur as $k => $v ) {
 393                                 if ( !is_numeric( $k ) ) {
 394                                         $obj->$k = $v;
 395                                 }
 396                         }
 397
 398                         return $obj;
 399                 }
 400
 401                 return false;
 402         }
 403
 404         /**
 405          * @param IResultWrapper|mixed $res
 406          * @return array|bool
 407          */
 408         function fetchRow( $res ) {
 409                 $resource =& ResultWrapper::unwrap( $res );
 410                 $cur = current( $resource );
 411                 if ( is_array( $cur ) ) {
 412                         next( $resource );
 413
 414                         return $cur;
 415                 }
 416
 417                 return false;
 418         }
 419
 420         /**
 421          * The PDO::Statement class implements the array interface so count() will work
 422          *
 423          * @param IResultWrapper|array|false $res
 424          * @return int
 425          */
 426         function numRows( $res ) {
 427                 // false does not implement Countable
 428                 $resource = ResultWrapper::unwrap( $res );
 429
 430                 return is_array( $resource ) ? count( $resource ) : 0;
 431         }
 432
 433         /**
 434          * @param IResultWrapper $res
 435          * @return int
 436          */
 437         function numFields( $res ) {
 438                 $resource = ResultWrapper::unwrap( $res );
 439                 if ( is_array( $resource ) && count( $resource ) > 0 ) {
 440                         // The size of the result array is twice the number of fields. (T67578)
 441                         return count( $resource[0] ) / 2;
 442                 } else {
 443                         // If the result is empty return 0
 444                         return 0;
 445                 }
 446         }
 447
 448         /**
 449          * @param IResultWrapper $res
 450          * @param int $n
 451          * @return bool
 452          */
 453         function fieldName( $res, $n ) {
 454                 $resource = ResultWrapper::unwrap( $res );
 455                 if ( is_array( $resource ) ) {
 456                         $keys = array_keys( $resource[0] );
 457
 458                         return $keys[$n];
 459                 }
 460
 461                 return false;
 462         }
 463
 464         /**
 465          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 466          *
 467          * @param string $name
 468          * @param string $format
 469          * @return string
 470          */
 471         function tableName( $name, $format = 'quoted' ) {
 472                 // table names starting with sqlite_ are reserved
 473                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 474                         return $name;
 475                 }
 476
 477                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 478         }
 479
 480         /**
 481          * This must be called after nextSequenceVal
 482          *
 483          * @return int
 484          */
 485         function insertId() {
 486                 // PDO::lastInsertId yields a string :(
 487                 return intval( $this->getBindingHandle()->lastInsertId() );
 488         }
 489
 490         /**
 491          * @param IResultWrapper|array $res
 492          * @param int $row
 493          */
 494         function dataSeek( $res, $row ) {
 495                 $resource =& ResultWrapper::unwrap( $res );
 496                 reset( $resource );
 497                 if ( $row > 0 ) {
 498                         for ( $i = 0; $i < $row; $i++ ) {
 499                                 next( $resource );
 500                         }
 501                 }
 502         }
 503
 504         /**
 505          * @return string
 506          */
 507         function lastError() {
 508                 if ( !is_object( $this->conn ) ) {
 509                         return "Cannot return last error, no db connection";
 510                 }
 511                 $e = $this->conn->errorInfo();
 512
 513                 return $e[2] ?? '';
 514         }
 515
 516         /**
 517          * @return string
 518          */
 519         function lastErrno() {
 520                 if ( !is_object( $this->conn ) ) {
 521                         return "Cannot return last error, no db connection";
 522                 } else {
 523                         $info = $this->conn->errorInfo();
 524
 525                         return $info[1];
 526                 }
 527         }
 528
 529         /**
 530          * @return int
 531          */
 532         protected function fetchAffectedRowCount() {
 533                 return $this->lastAffectedRowCount;
 534         }
 535
 536         function tableExists( $table, $fname = __METHOD__ ) {
 537                 $tableRaw = $this->tableName( $table, 'raw' );
 538                 if ( isset( $this->sessionTempTables[$tableRaw] ) ) {
 539                         return true; // already known to exist
 540                 }
 541
 542                 $encTable = $this->addQuotes( $tableRaw );
 543                 $res = $this->query(
 544                         "SELECT 1 FROM sqlite_master WHERE type='table' AND name=$encTable" );
 545
 546                 return $res->numRows() ? true : false;
 547         }
 548
 549         /**
 550          * Returns information about an index
 551          * Returns false if the index does not exist
 552          * - if errors are explicitly ignored, returns NULL on failure
 553          *
 554          * @param string $table
 555          * @param string $index
 556          * @param string $fname
 557          * @return array|false
 558          */
 559         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 560                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 561                 $res = $this->query( $sql, $fname );
 562                 if ( !$res || $res->numRows() == 0 ) {
 563                         return false;
 564                 }
 565                 $info = [];
 566                 foreach ( $res as $row ) {
 567                         $info[] = $row->name;
 568                 }
 569
 570                 return $info;
 571         }
 572
 573         /**
 574          * @param string $table
 575          * @param string $index
 576          * @param string $fname
 577          * @return bool|null
 578          */
 579         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 580                 $row = $this->selectRow( 'sqlite_master', '*',
 581                         [
 582                                 'type' => 'index',
 583                                 'name' => $this->indexName( $index ),
 584                         ], $fname );
 585                 if ( !$row || !isset( $row->sql ) ) {
 586                         return null;
 587                 }
 588
 589                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 590                 $indexPos = strpos( $row->sql, 'INDEX' );
 591                 if ( $indexPos === false ) {
 592                         return null;
 593                 }
 594                 $firstPart = substr( $row->sql, 0, $indexPos );
 595                 $options = explode( ' ', $firstPart );
 596
 597                 return in_array( 'UNIQUE', $options );
 598         }
 599
 600         /**
 601          * Filter the options used in SELECT statements
 602          *
 603          * @param array $options
 604          * @return array
 605          */
 606         function makeSelectOptions( $options ) {
 607                 foreach ( $options as $k => $v ) {
 608                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 609                                 $options[$k] = '';
 610                         }
 611                 }
 612
 613                 return parent::makeSelectOptions( $options );
 614         }
 615
 616         /**
 617          * @param array $options
 618          * @return array
 619          */
 620         protected function makeUpdateOptionsArray( $options ) {
 621                 $options = parent::makeUpdateOptionsArray( $options );
 622                 $options = self::fixIgnore( $options );
 623
 624                 return $options;
 625         }
 626
 627         /**
 628          * @param array $options
 629          * @return array
 630          */
 631         static function fixIgnore( $options ) {
 632                 # SQLite uses OR IGNORE not just IGNORE
 633                 foreach ( $options as $k => $v ) {
 634                         if ( $v == 'IGNORE' ) {
 635                                 $options[$k] = 'OR IGNORE';
 636                         }
 637                 }
 638
 639                 return $options;
 640         }
 641
 642         /**
 643          * @param array $options
 644          * @return string
 645          */
 646         function makeInsertOptions( $options ) {
 647                 $options = self::fixIgnore( $options );
 648
 649                 return parent::makeInsertOptions( $options );
 650         }
 651
 652         /**
 653          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 654          * @param string $table
 655          * @param array $a
 656          * @param string $fname
 657          * @param array $options
 658          * @return bool
 659          */
 660         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 661                 if ( !count( $a ) ) {
 662                         return true;
 663                 }
 664
 665                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 666                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 667                         $affectedRowCount = 0;
 668                         try {
 669                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 670                                 foreach ( $a as $v ) {
 671                                         parent::insert( $table, $v, "$fname/multi-row", $options );
 672                                         $affectedRowCount += $this->affectedRows();
 673                                 }
 674                                 $this->endAtomic( $fname );
 675                         } catch ( Exception $e ) {
 676                                 $this->cancelAtomic( $fname );
 677                                 throw $e;
 678                         }
 679                         $this->affectedRowCount = $affectedRowCount;
 680                 } else {
 681                         parent::insert( $table, $a, "$fname/single-row", $options );
 682                 }
 683
 684                 return true;
 685         }
 686
 687         /**
 688          * @param string $table
 689          * @param array $uniqueIndexes Unused
 690          * @param string|array $rows
 691          * @param string $fname
 692          */
 693         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 694                 if ( !count( $rows ) ) {
 695                         return;
 696                 }
 697
 698                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 699                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 700                         $affectedRowCount = 0;
 701                         try {
 702                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 703                                 foreach ( $rows as $v ) {
 704                                         $this->nativeReplace( $table, $v, "$fname/multi-row" );
 705                                         $affectedRowCount += $this->affectedRows();
 706                                 }
 707                                 $this->endAtomic( $fname );
 708                         } catch ( Exception $e ) {
 709                                 $this->cancelAtomic( $fname );
 710                                 throw $e;
 711                         }
 712                         $this->affectedRowCount = $affectedRowCount;
 713                 } else {
 714                         $this->nativeReplace( $table, $rows, "$fname/single-row" );
 715                 }
 716         }
 717
 718         /**
 719          * Returns the size of a text field, or -1 for "unlimited"
 720          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 721          *
 722          * @param string $table
 723          * @param string $field
 724          * @return int
 725          */
 726         function textFieldSize( $table, $field ) {
 727                 return -1;
 728         }
 729
 730         /**
 731          * @return bool
 732          */
 733         function unionSupportsOrderAndLimit() {
 734                 return false;
 735         }
 736
 737         /**
 738          * @param string[] $sqls
 739          * @param bool $all Whether to "UNION ALL" or not
 740          * @return string
 741          */
 742         function unionQueries( $sqls, $all ) {
 743                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 744
 745                 return implode( $glue, $sqls );
 746         }
 747
 748         /**
 749          * @return bool
 750          */
 751         function wasDeadlock() {
 752                 return $this->lastErrno() == 5; // SQLITE_BUSY
 753         }
 754
 755         /**
 756          * @return bool
 757          */
 758         function wasReadOnlyError() {
 759                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 760         }
 761
 762         public function wasConnectionError( $errno ) {
 763                 return $errno == 17; // SQLITE_SCHEMA;
 764         }
 765
 766         protected function wasKnownStatementRollbackError() {
 767                 // ON CONFLICT ROLLBACK clauses make it so that SQLITE_CONSTRAINT error is
 768                 // ambiguous with regard to whether it implies a ROLLBACK or an ABORT happened.
 769                 // https://sqlite.org/lang_createtable.html#uniqueconst
 770                 // https://sqlite.org/lang_conflict.html
 771                 return false;
 772         }
 773
 774         public function serverIsReadOnly() {
 775                 $path = $this->getDbFilePath();
 776
 777                 return ( !self::isProcessMemoryPath( $path ) && !is_writable( $path ) );
 778         }
 779
 780         /**
 781          * @return string Wikitext of a link to the server software's web site
 782          */
 783         public function getSoftwareLink() {
 784                 return "[{{int:version-db-sqlite-url}} SQLite]";
 785         }
 786
 787         /**
 788          * @return string Version information from the database
 789          */
 790         function getServerVersion() {
 791                 $ver = $this->getBindingHandle()->getAttribute( PDO::ATTR_SERVER_VERSION );
 792
 793                 return $ver;
 794         }
 795
 796         /**
 797          * Get information about a given field
 798          * Returns false if the field does not exist.
 799          *
 800          * @param string $table
 801          * @param string $field
 802          * @return SQLiteField|bool False on failure
 803          */
 804         function fieldInfo( $table, $field ) {
 805                 $tableName = $this->tableName( $table );
 806                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 807                 $res = $this->query( $sql, __METHOD__ );
 808                 foreach ( $res as $row ) {
 809                         if ( $row->name == $field ) {
 810                                 return new SQLiteField( $row, $tableName );
 811                         }
 812                 }
 813
 814                 return false;
 815         }
 816
 817         protected function doBegin( $fname = '' ) {
 818                 if ( $this->trxMode != '' ) {
 819                         $this->query( "BEGIN {$this->trxMode}", $fname );
 820                 } else {
 821                         $this->query( 'BEGIN', $fname );
 822                 }
 823         }
 824
 825         /**
 826          * @param string $s
 827          * @return string
 828          */
 829         function strencode( $s ) {
 830                 return substr( $this->addQuotes( $s ), 1, -1 );
 831         }
 832
 833         /**
 834          * @param string $b
 835          * @return Blob
 836          */
 837         function encodeBlob( $b ) {
 838                 return new Blob( $b );
 839         }
 840
 841         /**
 842          * @param Blob|string $b
 843          * @return string
 844          */
 845         function decodeBlob( $b ) {
 846                 if ( $b instanceof Blob ) {
 847                         $b = $b->fetch();
 848                 }
 849
 850                 return $b;
 851         }
 852
 853         /**
 854          * @param string|int|null|bool|Blob $s
 855          * @return string|int
 856          */
 857         function addQuotes( $s ) {
 858                 if ( $s instanceof Blob ) {
 859                         return "x'" . bin2hex( $s->fetch() ) . "'";
 860                 } elseif ( is_bool( $s ) ) {
 861                         return (int)$s;
 862                 } elseif ( strpos( (string)$s, "\0" ) !== false ) {
 863                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 864                         // This is a known limitation of SQLite's mprintf function which PDO
 865                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 866                         // https://bugs.php.net/bug.php?id=63419
 867                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 868                         // https://bugs.php.net/bug.php?id=62361
 869                         // There is an additional bug regarding sorting this data after insert
 870                         // on older versions of sqlite shipped with ubuntu 12.04
 871                         // https://phabricator.wikimedia.org/T74367
 872                         $this->queryLogger->debug(
 873                                 __FUNCTION__ .
 874                                 ': Quoting value containing null byte. ' .
 875                                 'For consistency all binary data should have been ' .
 876                                 'first processed with self::encodeBlob()'
 877                         );
 878                         return "x'" . bin2hex( (string)$s ) . "'";
 879                 } else {
 880                         return $this->getBindingHandle()->quote( (string)$s );
 881                 }
 882         }
 883
 884         public function buildSubstring( $input, $startPosition, $length = null ) {
 885                 $this->assertBuildSubstringParams( $startPosition, $length );
 886                 $params = [ $input, $startPosition ];
 887                 if ( $length !== null ) {
 888                         $params[] = $length;
 889                 }
 890                 return 'SUBSTR(' . implode( ',', $params ) . ')';
 891         }
 892
 893         /**
 894          * @param string $field Field or column to cast
 895          * @return string
 896          * @since 1.28
 897          */
 898         public function buildStringCast( $field ) {
 899                 return 'CAST ( ' . $field . ' AS TEXT )';
 900         }
 901
 902         /**
 903          * No-op version of deadlockLoop
 904          *
 905          * @return mixed
 906          */
 907         public function deadlockLoop( /*...*/ ) {
 908                 $args = func_get_args();
 909                 $function = array_shift( $args );
 910
 911                 return $function( ...$args );
 912         }
 913
 914         /**
 915          * @param string $s
 916          * @return string
 917          */
 918         protected function replaceVars( $s ) {
 919                 $s = parent::replaceVars( $s );
 920                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 921                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 922
 923                         // binary/varbinary column type -> blob
 924                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 925                         // no such thing as unsigned
 926                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 927                         // INT -> INTEGER
 928                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 929                         // floating point types -> REAL
 930                         $s = preg_replace(
 931                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 932                                 'REAL',
 933                                 $s
 934                         );
 935                         // varchar -> TEXT
 936                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 937                         // TEXT normalization
 938                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 939                         // BLOB normalization
 940                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 941                         // BOOL -> INTEGER
 942                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 943                         // DATETIME -> TEXT
 944                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 945                         // No ENUM type
 946                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 947                         // binary collation type -> nothing
 948                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 949                         // auto_increment -> autoincrement
 950                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 951                         // No explicit options
 952                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 953                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 954                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 955                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 956                         // No truncated indexes
 957                         $s = preg_replace( '/\(\d+\)/', '', $s );
 958                         // No FULLTEXT
 959                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 960                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 961                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 962                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 963                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 964                         // INSERT IGNORE --> INSERT OR IGNORE
 965                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 966                 }
 967
 968                 return $s;
 969         }
 970
 971         public function lock( $lockName, $method, $timeout = 5 ) {
 972                 $status = $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout );
 973                 if (
 974                         $this->lockMgr instanceof FSLockManager &&
 975                         $status->hasMessage( 'lockmanager-fail-openlock' )
 976                 ) {
 977                         throw new DBError( $this, "Cannot create directory \"{$this->getLockFileDirectory()}\"" );
 978                 }
 979
 980                 return $status->isOK();
 981         }
 982
 983         public function unlock( $lockName, $method ) {
 984                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isGood();
 985         }
 986
 987         /**
 988          * Build a concatenation list to feed into a SQL query
 989          *
 990          * @param string[] $stringList
 991          * @return string
 992          */
 993         function buildConcat( $stringList ) {
 994                 return '(' . implode( ') || (', $stringList ) . ')';
 995         }
 996
 997         public function buildGroupConcatField(
 998                 $delim, $table, $field, $conds = '', $join_conds = []
 999         ) {
1000                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
1001
1002                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
1003         }
1004
1005         /**
1006          * @param string $oldName
1007          * @param string $newName
1008          * @param bool $temporary
1009          * @param string $fname
1010          * @return bool|IResultWrapper
1011          * @throws RuntimeException
1012          */
1013         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1014                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
1015                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
1016                 $obj = $this->fetchObject( $res );
1017                 if ( !$obj ) {
1018                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
1019                 }
1020                 $sql = $obj->sql;
1021                 $sql = preg_replace(
1022                         '/(?<=\W)"?' .
1023                                 preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ), '/' ) .
1024                                 '"?(?=\W)/',
1025                         $this->addIdentifierQuotes( $newName ),
1026                         $sql,
1027                         1
1028                 );
1029                 if ( $temporary ) {
1030                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
1031                                 $this->queryLogger->debug(
1032                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
1033                         } else {
1034                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
1035                         }
1036                 }
1037
1038                 $res = $this->query( $sql, $fname, self::QUERY_PSEUDO_PERMANENT );
1039
1040                 // Take over indexes
1041                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
1042                 foreach ( $indexList as $index ) {
1043                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
1044                                 continue;
1045                         }
1046
1047                         if ( $index->unique ) {
1048                                 $sql = 'CREATE UNIQUE INDEX';
1049                         } else {
1050                                 $sql = 'CREATE INDEX';
1051                         }
1052                         // Try to come up with a new index name, given indexes have database scope in SQLite
1053                         $indexName = $newName . '_' . $index->name;
1054                         $sql .= ' ' . $indexName . ' ON ' . $newName;
1055
1056                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
1057                         $fields = [];
1058                         foreach ( $indexInfo as $indexInfoRow ) {
1059                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
1060                         }
1061
1062                         $sql .= '(' . implode( ',', $fields ) . ')';
1063
1064                         $this->query( $sql );
1065                 }
1066
1067                 return $res;
1068         }
1069
1070         /**
1071          * List all tables on the database
1072          *
1073          * @param string|null $prefix Only show tables with this prefix, e.g. mw_
1074          * @param string $fname Calling function name
1075          *
1076          * @return array
1077          */
1078         function listTables( $prefix = null, $fname = __METHOD__ ) {
1079                 $result = $this->select(
1080                         'sqlite_master',
1081                         'name',
1082                         "type='table'"
1083                 );
1084
1085                 $endArray = [];
1086
1087                 foreach ( $result as $table ) {
1088                         $vars = get_object_vars( $table );
1089                         $table = array_pop( $vars );
1090
1091                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1092                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1093                                         $endArray[] = $table;
1094                                 }
1095                         }
1096                 }
1097
1098                 return $endArray;
1099         }
1100
1101         /**
1102          * Override due to no CASCADE support
1103          *
1104          * @param string $tableName
1105          * @param string $fName
1106          * @return bool|IResultWrapper
1107          * @throws DBReadOnlyError
1108          */
1109         public function dropTable( $tableName, $fName = __METHOD__ ) {
1110                 if ( !$this->tableExists( $tableName, $fName ) ) {
1111                         return false;
1112                 }
1113                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1114
1115                 return $this->query( $sql, $fName );
1116         }
1117
1118         public function setTableAliases( array $aliases ) {
1119                 parent::setTableAliases( $aliases );
1120                 foreach ( $this->tableAliases as $params ) {
1121                         if ( isset( $this->alreadyAttached[$params['dbname']] ) ) {
1122                                 continue;
1123                         }
1124                         $this->attachDatabase( $params['dbname'] );
1125                         $this->alreadyAttached[$params['dbname']] = true;
1126                 }
1127         }
1128
1129         public function resetSequenceForTable( $table, $fname = __METHOD__ ) {
1130                 $encTable = $this->addIdentifierQuotes( 'sqlite_sequence' );
1131                 $encName = $this->addQuotes( $this->tableName( $table, 'raw' ) );
1132                 $this->query( "DELETE FROM $encTable WHERE name = $encName", $fname );
1133         }
1134
1135         public function databasesAreIndependent() {
1136                 return true;
1137         }
1138
1139         /**
1140          * @return PDO
1141          */
1142         protected function getBindingHandle() {
1143                 return parent::getBindingHandle();
1144         }
1145 }
1146
1147 /**
1148  * @deprecated since 1.29
1149  */
1150 class_alias( DatabaseSqlite::class, 'DatabaseSqlite' );