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