includes/libs/rdbms/database/DatabaseSqlite.php

   1 <?php
   2 /**
   3  * This is the SQLite database abstraction layer.
   4  * See maintenance/sqlite/README for development notes and other specific information
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  * @ingroup Database
  23  */
  24 namespace Wikimedia\Rdbms;
  25
  26 use NullLockManager;
  27 use PDO;
  28 use PDOException;
  29 use Exception;
  30 use LockManager;
  31 use FSLockManager;
  32 use RuntimeException;
  33 use stdClass;
  34
  35 /**
  36  * @ingroup Database
  37  */
  38 class DatabaseSqlite extends Database {
  39         /** @var string|null Directory for SQLite database files listed under their DB name */
  40         protected $dbDir;
  41         /** @var string|null Explicit path for the SQLite database file */
  42         protected $dbPath;
  43         /** @var string Transaction mode */
  44         protected $trxMode;
  45
  46         /** @var int The number of rows affected as an integer */
  47         protected $lastAffectedRowCount;
  48         /** @var resource */
  49         protected $lastResultHandle;
  50
  51         /** @var PDO */
  52         protected $conn;
  53
  54         /** @var FSLockManager (hopefully on the same server as the DB) */
  55         protected $lockMgr;
  56
  57         /** @var array List of shared database already attached to this connection */
  58         private $alreadyAttached = [];
  59
  60         /** @var bool Whether full text is enabled */
  61         private static $fulltextEnabled = null;
  62
  63         /** @var string[] See https://www.sqlite.org/lang_transaction.html */
  64         private static $VALID_TRX_MODES = [ '', 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ];
  65
  66         /**
  67          * Additional params include:
  68          *   - dbDirectory : directory containing the DB and the lock file directory
  69          *   - dbFilePath  : use this to force the path of the DB file
  70          *   - trxMode     : one of (deferred, immediate, exclusive)
  71          * @param array $p
  72          */
  73         public function __construct( array $p ) {
  74                 if ( isset( $p['dbFilePath'] ) ) {
  75                         $this->dbPath = $p['dbFilePath'];
  76                         if ( !strlen( $p['dbname'] ) ) {
  77                                 $p['dbname'] = self::generateDatabaseName( $this->dbPath );
  78                         }
  79                 } elseif ( isset( $p['dbDirectory'] ) ) {
  80                         $this->dbDir = $p['dbDirectory'];
  81                 }
  82
  83                 parent::__construct( $p );
  84
  85                 $this->trxMode = strtoupper( $p['trxMode'] ?? '' );
  86
  87                 $lockDirectory = $this->getLockFileDirectory();
  88                 if ( $lockDirectory !== null ) {
  89                         $this->lockMgr = new FSLockManager( [
  90                                 'domain' => $this->getDomainID(),
  91                                 'lockDirectory' => $lockDirectory
  92                         ] );
  93                 } else {
  94                         $this->lockMgr = new NullLockManager( [ 'domain' => $this->getDomainID() ] );
  95                 }
  96         }
  97
  98         protected static function getAttributes() {
  99                 return [ self::ATTR_DB_LEVEL_LOCKING => true ];
 100         }
 101
 102         /**
 103          * @param string $filename
 104          * @param array $p Options map; supports:
 105          *   - flags       : (same as __construct counterpart)
 106          *   - trxMode     : (same as __construct counterpart)
 107          *   - dbDirectory : (same as __construct counterpart)
 108          * @return DatabaseSqlite
 109          * @since 1.25
 110          */
 111         public static function newStandaloneInstance( $filename, array $p = [] ) {
 112                 $p['dbFilePath'] = $filename;
 113                 $p['schema'] = null;
 114                 $p['tablePrefix'] = '';
 115                 /** @var DatabaseSqlite $db */
 116                 $db = Database::factory( 'sqlite', $p );
 117
 118                 return $db;
 119         }
 120
 121         /**
 122          * @return string
 123          */
 124         public function getType() {
 125                 return 'sqlite';
 126         }
 127
 128         protected function open( $server, $user, $pass, $dbName, $schema, $tablePrefix ) {
 129                 $this->close();
 130
 131                 // Note that for SQLite, $server, $user, and $pass are ignored
 132
 133                 if ( $schema !== null ) {
 134                         throw $this->newExceptionAfterConnectError( "Got schema '$schema'; not supported." );
 135                 }
 136
 137                 if ( $this->dbPath !== null ) {
 138                         $path = $this->dbPath;
 139                 } elseif ( $this->dbDir !== null ) {
 140                         $path = self::generateFileName( $this->dbDir, $dbName );
 141                 } else {
 142                         throw $this->newExceptionAfterConnectError( "DB path or directory required" );
 143                 }
 144
 145                 // Check if the database file already exists but is non-readable
 146                 if (
 147                         !self::isProcessMemoryPath( $path ) &&
 148                         file_exists( $path ) &&
 149                         !is_readable( $path )
 150                 ) {
 151                         throw $this->newExceptionAfterConnectError( 'SQLite database file is not readable' );
 152                 } elseif ( !in_array( $this->trxMode, self::$VALID_TRX_MODES, true ) ) {
 153                         throw $this->newExceptionAfterConnectError( "Got mode '{$this->trxMode}' for BEGIN" );
 154                 }
 155
 156                 $attributes = [];
 157                 if ( $this->getFlag( self::DBO_PERSISTENT ) ) {
 158                         // Persistent connections can avoid some schema index reading overhead.
 159                         // On the other hand, they can cause horrible contention with DBO_TRX.
 160                         if ( $this->getFlag( self::DBO_TRX ) || $this->getFlag( self::DBO_DEFAULT ) ) {
 161                                 $this->connLogger->warning(
 162                                         __METHOD__ . ": ignoring DBO_PERSISTENT due to DBO_TRX or DBO_DEFAULT",
 163                                         $this->getLogContext()
 164                                 );
 165                         } else {
 166                                 $attributes[PDO::ATTR_PERSISTENT] = true;
 167                         }
 168                 }
 169
 170                 try {
 171                         // Open the database file, creating it if it does not yet exist
 172                         $this->conn = new PDO( "sqlite:$path", null, null, $attributes );
 173                 } catch ( PDOException $e ) {
 174                         throw $this->newExceptionAfterConnectError( $e->getMessage() );
 175                 }
 176
 177                 $this->currentDomain = new DatabaseDomain( $dbName, null, $tablePrefix );
 178
 179                 try {
 180                         $flags = self::QUERY_IGNORE_DBO_TRX | self::QUERY_NO_RETRY;
 181                         // Enforce LIKE to be case sensitive, just like MySQL
 182                         $this->query( 'PRAGMA case_sensitive_like = 1', __METHOD__, $flags );
 183                         // Apply optimizations or requirements regarding fsync() usage
 184                         $sync = $this->connectionVariables['synchronous'] ?? null;
 185                         if ( in_array( $sync, [ 'EXTRA', 'FULL', 'NORMAL', 'OFF' ], true ) ) {
 186                                 $this->query( "PRAGMA synchronous = $sync", __METHOD__, $flags );
 187                         }
 188                 } catch ( Exception $e ) {
 189                         throw $this->newExceptionAfterConnectError( $e->getMessage() );
 190                 }
 191         }
 192
 193         /**
 194          * @return string|null SQLite DB file path
 195          * @throws DBUnexpectedError
 196          * @since 1.25
 197          */
 198         public function getDbFilePath() {
 199                 return $this->dbPath ?? self::generateFileName( $this->dbDir, $this->getDBname() );
 200         }
 201
 202         /**
 203          * @return string|null Lock file directory
 204          */
 205         public function getLockFileDirectory() {
 206                 if ( $this->dbPath !== null && !self::isProcessMemoryPath( $this->dbPath ) ) {
 207                         return dirname( $this->dbPath ) . '/locks';
 208                 } elseif ( $this->dbDir !== null && !self::isProcessMemoryPath( $this->dbDir ) ) {
 209                         return $this->dbDir . '/locks';
 210                 }
 211
 212                 return null;
 213         }
 214
 215         /**
 216          * Does not actually close the connection, just destroys the reference for GC to do its work
 217          * @return bool
 218          */
 219         protected function closeConnection() {
 220                 $this->conn = null;
 221
 222                 return true;
 223         }
 224
 225         /**
 226          * Generates a database file name. Explicitly public for installer.
 227          * @param string $dir Directory where database resides
 228          * @param string|bool $dbName Database name (or false from Database::factory, validated here)
 229          * @return string
 230          * @throws DBUnexpectedError
 231          */
 232         public static function generateFileName( $dir, $dbName ) {
 233                 if ( $dir == '' ) {
 234                         throw new DBUnexpectedError( null, __CLASS__ . ": no DB directory specified" );
 235                 } elseif ( self::isProcessMemoryPath( $dir ) ) {
 236                         throw new DBUnexpectedError(
 237                                 null,
 238                                 __CLASS__ . ": cannot use process memory directory '$dir'"
 239                         );
 240                 } elseif ( !strlen( $dbName ) ) {
 241                         throw new DBUnexpectedError( null, __CLASS__ . ": no DB name specified" );
 242                 }
 243
 244                 return "$dir/$dbName.sqlite";
 245         }
 246
 247         /**
 248          * @param string $path
 249          * @return string
 250          */
 251         private static function generateDatabaseName( $path ) {
 252                 if ( preg_match( '/^(:memory:$|file::memory:)/', $path ) ) {
 253                         // E.g. "file::memory:?cache=shared" => ":memory":
 254                         return ':memory:';
 255                 } elseif ( preg_match( '/^file::([^?]+)\?mode=memory(&|$)/', $path, $m ) ) {
 256                         // E.g. "file:memdb1?mode=memory" => ":memdb1:"
 257                         return ":{$m[1]}:";
 258                 } else {
 259                         // E.g. "/home/.../some_db.sqlite3" => "some_db"
 260                         return preg_replace( '/\.sqlite\d?$/', '', basename( $path ) );
 261                 }
 262         }
 263
 264         /**
 265          * @param string $path
 266          * @return bool
 267          */
 268         private static function isProcessMemoryPath( $path ) {
 269                 return preg_match( '/^(:memory:$|file:(:memory:|[^?]+\?mode=memory(&|$)))/', $path );
 270         }
 271
 272         /**
 273          * Check if the searchindext table is FTS enabled.
 274          * @return bool False if not enabled.
 275          */
 276         public function checkForEnabledSearch() {
 277                 if ( self::$fulltextEnabled === null ) {
 278                         self::$fulltextEnabled = false;
 279                         $table = $this->tableName( 'searchindex' );
 280                         $res = $this->query(
 281                                 "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'",
 282                                 __METHOD__,
 283                                 self::QUERY_IGNORE_DBO_TRX
 284                         );
 285                         if ( $res ) {
 286                                 $row = $res->fetchRow();
 287                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 288                         }
 289                 }
 290
 291                 return self::$fulltextEnabled;
 292         }
 293
 294         /**
 295          * Returns version of currently supported SQLite fulltext search module or false if none present.
 296          * @return string
 297          */
 298         static function getFulltextSearchModule() {
 299                 static $cachedResult = null;
 300                 if ( $cachedResult !== null ) {
 301                         return $cachedResult;
 302                 }
 303                 $cachedResult = false;
 304                 $table = 'dummy_search_test';
 305
 306                 $db = self::newStandaloneInstance( ':memory:' );
 307                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 308                         $cachedResult = 'FTS3';
 309                 }
 310                 $db->close();
 311
 312                 return $cachedResult;
 313         }
 314
 315         /**
 316          * Attaches external database to our connection, see https://sqlite.org/lang_attach.html
 317          * for details.
 318          *
 319          * @param string $name Database name to be used in queries like
 320          *   SELECT foo FROM dbname.table
 321          * @param bool|string $file Database file name. If omitted, will be generated
 322          *   using $name and configured data directory
 323          * @param string $fname Calling function name
 324          * @return IResultWrapper
 325          */
 326         public function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 327                 $file = is_string( $file ) ? $file : self::generateFileName( $this->dbDir, $name );
 328                 $encFile = $this->addQuotes( $file );
 329
 330                 return $this->query(
 331                         "ATTACH DATABASE $encFile AS $name",
 332                         $fname,
 333                         self::QUERY_IGNORE_DBO_TRX
 334                 );
 335         }
 336
 337         protected function isWriteQuery( $sql ) {
 338                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 339         }
 340
 341         protected function isTransactableQuery( $sql ) {
 342                 return parent::isTransactableQuery( $sql ) && !in_array(
 343                         $this->getQueryVerb( $sql ),
 344                         [ 'ATTACH', 'PRAGMA' ],
 345                         true
 346                 );
 347         }
 348
 349         /**
 350          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 351          *
 352          * @param string $sql
 353          * @return bool|IResultWrapper
 354          */
 355         protected function doQuery( $sql ) {
 356                 $res = $this->getBindingHandle()->query( $sql );
 357                 if ( $res === false ) {
 358                         return false;
 359                 }
 360
 361                 $resource = ResultWrapper::unwrap( $res );
 362                 $this->lastAffectedRowCount = $resource->rowCount();
 363                 $res = new ResultWrapper( $this, $resource->fetchAll() );
 364
 365                 return $res;
 366         }
 367
 368         /**
 369          * @param IResultWrapper|mixed $res
 370          */
 371         function freeResult( $res ) {
 372                 if ( $res instanceof ResultWrapper ) {
 373                         $res->free();
 374                 }
 375         }
 376
 377         /**
 378          * @param IResultWrapper|array $res
 379          * @return stdClass|bool
 380          */
 381         function fetchObject( $res ) {
 382                 $resource =& ResultWrapper::unwrap( $res );
 383
 384                 $cur = current( $resource );
 385                 if ( is_array( $cur ) ) {
 386                         next( $resource );
 387                         $obj = new stdClass;
 388                         foreach ( $cur as $k => $v ) {
 389                                 if ( !is_numeric( $k ) ) {
 390                                         $obj->$k = $v;
 391                                 }
 392                         }
 393
 394                         return $obj;
 395                 }
 396
 397                 return false;
 398         }
 399
 400         /**
 401          * @param IResultWrapper|mixed $res
 402          * @return array|bool
 403          */
 404         function fetchRow( $res ) {
 405                 $resource =& ResultWrapper::unwrap( $res );
 406                 $cur = current( $resource );
 407                 if ( is_array( $cur ) ) {
 408                         next( $resource );
 409
 410                         return $cur;
 411                 }
 412
 413                 return false;
 414         }
 415
 416         /**
 417          * The PDO::Statement class implements the array interface so count() will work
 418          *
 419          * @param IResultWrapper|array|false $res
 420          * @return int
 421          */
 422         function numRows( $res ) {
 423                 // false does not implement Countable
 424                 $resource = ResultWrapper::unwrap( $res );
 425
 426                 return is_array( $resource ) ? count( $resource ) : 0;
 427         }
 428
 429         /**
 430          * @param IResultWrapper $res
 431          * @return int
 432          */
 433         function numFields( $res ) {
 434                 $resource = ResultWrapper::unwrap( $res );
 435                 if ( is_array( $resource ) && count( $resource ) > 0 ) {
 436                         // The size of the result array is twice the number of fields. (T67578)
 437                         return count( $resource[0] ) / 2;
 438                 } else {
 439                         // If the result is empty return 0
 440                         return 0;
 441                 }
 442         }
 443
 444         /**
 445          * @param IResultWrapper $res
 446          * @param int $n
 447          * @return bool
 448          */
 449         function fieldName( $res, $n ) {
 450                 $resource = ResultWrapper::unwrap( $res );
 451                 if ( is_array( $resource ) ) {
 452                         $keys = array_keys( $resource[0] );
 453
 454                         return $keys[$n];
 455                 }
 456
 457                 return false;
 458         }
 459
 460         protected function doSelectDomain( DatabaseDomain $domain ) {
 461                 if ( $domain->getSchema() !== null ) {
 462                         throw new DBExpectedError(
 463                                 $this,
 464                                 __CLASS__ . ": domain '{$domain->getId()}' has a schema component"
 465                         );
 466                 }
 467
 468                 $database = $domain->getDatabase();
 469                 // A null database means "don't care" so leave it as is and update the table prefix
 470                 if ( $database === null ) {
 471                         $this->currentDomain = new DatabaseDomain(
 472                                 $this->currentDomain->getDatabase(),
 473                                 null,
 474                                 $domain->getTablePrefix()
 475                         );
 476
 477                         return true;
 478                 }
 479
 480                 if ( $database !== $this->getDBname() ) {
 481                         throw new DBExpectedError(
 482                                 $this,
 483                                 __CLASS__ . ": cannot change database (got '$database')"
 484                         );
 485                 }
 486
 487                 return true;
 488         }
 489
 490         /**
 491          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 492          *
 493          * @param string $name
 494          * @param string $format
 495          * @return string
 496          */
 497         function tableName( $name, $format = 'quoted' ) {
 498                 // table names starting with sqlite_ are reserved
 499                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 500                         return $name;
 501                 }
 502
 503                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 504         }
 505
 506         /**
 507          * This must be called after nextSequenceVal
 508          *
 509          * @return int
 510          */
 511         function insertId() {
 512                 // PDO::lastInsertId yields a string :(
 513                 return intval( $this->getBindingHandle()->lastInsertId() );
 514         }
 515
 516         /**
 517          * @param IResultWrapper|array $res
 518          * @param int $row
 519          */
 520         function dataSeek( $res, $row ) {
 521                 $resource =& ResultWrapper::unwrap( $res );
 522                 reset( $resource );
 523                 if ( $row > 0 ) {
 524                         for ( $i = 0; $i < $row; $i++ ) {
 525                                 next( $resource );
 526                         }
 527                 }
 528         }
 529
 530         /**
 531          * @return string
 532          */
 533         function lastError() {
 534                 if ( !is_object( $this->conn ) ) {
 535                         return "Cannot return last error, no db connection";
 536                 }
 537                 $e = $this->conn->errorInfo();
 538
 539                 return $e[2] ?? '';
 540         }
 541
 542         /**
 543          * @return string
 544          */
 545         function lastErrno() {
 546                 if ( !is_object( $this->conn ) ) {
 547                         return "Cannot return last error, no db connection";
 548                 } else {
 549                         $info = $this->conn->errorInfo();
 550
 551                         return $info[1];
 552                 }
 553         }
 554
 555         /**
 556          * @return int
 557          */
 558         protected function fetchAffectedRowCount() {
 559                 return $this->lastAffectedRowCount;
 560         }
 561
 562         function tableExists( $table, $fname = __METHOD__ ) {
 563                 $tableRaw = $this->tableName( $table, 'raw' );
 564                 if ( isset( $this->sessionTempTables[$tableRaw] ) ) {
 565                         return true; // already known to exist
 566                 }
 567
 568                 $encTable = $this->addQuotes( $tableRaw );
 569                 $res = $this->query(
 570                         "SELECT 1 FROM sqlite_master WHERE type='table' AND name=$encTable",
 571                         __METHOD__,
 572                         self::QUERY_IGNORE_DBO_TRX
 573                 );
 574
 575                 return $res->numRows() ? true : false;
 576         }
 577
 578         /**
 579          * Returns information about an index
 580          * Returns false if the index does not exist
 581          * - if errors are explicitly ignored, returns NULL on failure
 582          *
 583          * @param string $table
 584          * @param string $index
 585          * @param string $fname
 586          * @return array|false
 587          */
 588         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 589                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 590                 $res = $this->query( $sql, $fname, self::QUERY_IGNORE_DBO_TRX );
 591                 if ( !$res || $res->numRows() == 0 ) {
 592                         return false;
 593                 }
 594                 $info = [];
 595                 foreach ( $res as $row ) {
 596                         $info[] = $row->name;
 597                 }
 598
 599                 return $info;
 600         }
 601
 602         /**
 603          * @param string $table
 604          * @param string $index
 605          * @param string $fname
 606          * @return bool|null
 607          */
 608         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 609                 $row = $this->selectRow( 'sqlite_master', '*',
 610                         [
 611                                 'type' => 'index',
 612                                 'name' => $this->indexName( $index ),
 613                         ], $fname );
 614                 if ( !$row || !isset( $row->sql ) ) {
 615                         return null;
 616                 }
 617
 618                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 619                 $indexPos = strpos( $row->sql, 'INDEX' );
 620                 if ( $indexPos === false ) {
 621                         return null;
 622                 }
 623                 $firstPart = substr( $row->sql, 0, $indexPos );
 624                 $options = explode( ' ', $firstPart );
 625
 626                 return in_array( 'UNIQUE', $options );
 627         }
 628
 629         /**
 630          * Filter the options used in SELECT statements
 631          *
 632          * @param array $options
 633          * @return array
 634          */
 635         function makeSelectOptions( $options ) {
 636                 foreach ( $options as $k => $v ) {
 637                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 638                                 $options[$k] = '';
 639                         }
 640                 }
 641
 642                 return parent::makeSelectOptions( $options );
 643         }
 644
 645         /**
 646          * @param array $options
 647          * @return array
 648          */
 649         protected function makeUpdateOptionsArray( $options ) {
 650                 $options = parent::makeUpdateOptionsArray( $options );
 651                 $options = self::fixIgnore( $options );
 652
 653                 return $options;
 654         }
 655
 656         /**
 657          * @param array $options
 658          * @return array
 659          */
 660         static function fixIgnore( $options ) {
 661                 # SQLite uses OR IGNORE not just IGNORE
 662                 foreach ( $options as $k => $v ) {
 663                         if ( $v == 'IGNORE' ) {
 664                                 $options[$k] = 'OR IGNORE';
 665                         }
 666                 }
 667
 668                 return $options;
 669         }
 670
 671         /**
 672          * @param array $options
 673          * @return string
 674          */
 675         function makeInsertOptions( $options ) {
 676                 $options = self::fixIgnore( $options );
 677
 678                 return parent::makeInsertOptions( $options );
 679         }
 680
 681         /**
 682          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 683          * @param string $table
 684          * @param array $a
 685          * @param string $fname
 686          * @param array $options
 687          * @return bool
 688          */
 689         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 690                 if ( !count( $a ) ) {
 691                         return true;
 692                 }
 693
 694                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 695                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 696                         $affectedRowCount = 0;
 697                         try {
 698                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 699                                 foreach ( $a as $v ) {
 700                                         parent::insert( $table, $v, "$fname/multi-row", $options );
 701                                         $affectedRowCount += $this->affectedRows();
 702                                 }
 703                                 $this->endAtomic( $fname );
 704                         } catch ( Exception $e ) {
 705                                 $this->cancelAtomic( $fname );
 706                                 throw $e;
 707                         }
 708                         $this->affectedRowCount = $affectedRowCount;
 709                 } else {
 710                         parent::insert( $table, $a, "$fname/single-row", $options );
 711                 }
 712
 713                 return true;
 714         }
 715
 716         /**
 717          * @param string $table
 718          * @param array $uniqueIndexes Unused
 719          * @param string|array $rows
 720          * @param string $fname
 721          */
 722         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 723                 if ( !count( $rows ) ) {
 724                         return;
 725                 }
 726
 727                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 728                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 729                         $affectedRowCount = 0;
 730                         try {
 731                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 732                                 foreach ( $rows as $v ) {
 733                                         $this->nativeReplace( $table, $v, "$fname/multi-row" );
 734                                         $affectedRowCount += $this->affectedRows();
 735                                 }
 736                                 $this->endAtomic( $fname );
 737                         } catch ( Exception $e ) {
 738                                 $this->cancelAtomic( $fname );
 739                                 throw $e;
 740                         }
 741                         $this->affectedRowCount = $affectedRowCount;
 742                 } else {
 743                         $this->nativeReplace( $table, $rows, "$fname/single-row" );
 744                 }
 745         }
 746
 747         /**
 748          * Returns the size of a text field, or -1 for "unlimited"
 749          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 750          *
 751          * @param string $table
 752          * @param string $field
 753          * @return int
 754          */
 755         function textFieldSize( $table, $field ) {
 756                 return -1;
 757         }
 758
 759         /**
 760          * @return bool
 761          */
 762         function unionSupportsOrderAndLimit() {
 763                 return false;
 764         }
 765
 766         /**
 767          * @param string[] $sqls
 768          * @param bool $all Whether to "UNION ALL" or not
 769          * @return string
 770          */
 771         function unionQueries( $sqls, $all ) {
 772                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 773
 774                 return implode( $glue, $sqls );
 775         }
 776
 777         /**
 778          * @return bool
 779          */
 780         function wasDeadlock() {
 781                 return $this->lastErrno() == 5; // SQLITE_BUSY
 782         }
 783
 784         /**
 785          * @return bool
 786          */
 787         function wasReadOnlyError() {
 788                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 789         }
 790
 791         public function wasConnectionError( $errno ) {
 792                 return $errno == 17; // SQLITE_SCHEMA;
 793         }
 794
 795         protected function wasKnownStatementRollbackError() {
 796                 // ON CONFLICT ROLLBACK clauses make it so that SQLITE_CONSTRAINT error is
 797                 // ambiguous with regard to whether it implies a ROLLBACK or an ABORT happened.
 798                 // https://sqlite.org/lang_createtable.html#uniqueconst
 799                 // https://sqlite.org/lang_conflict.html
 800                 return false;
 801         }
 802
 803         public function serverIsReadOnly() {
 804                 $this->assertHasConnectionHandle();
 805
 806                 $path = $this->getDbFilePath();
 807
 808                 return ( !self::isProcessMemoryPath( $path ) && !is_writable( $path ) );
 809         }
 810
 811         /**
 812          * @return string Wikitext of a link to the server software's web site
 813          */
 814         public function getSoftwareLink() {
 815                 return "[{{int:version-db-sqlite-url}} SQLite]";
 816         }
 817
 818         /**
 819          * @return string Version information from the database
 820          */
 821         function getServerVersion() {
 822                 $ver = $this->getBindingHandle()->getAttribute( PDO::ATTR_SERVER_VERSION );
 823
 824                 return $ver;
 825         }
 826
 827         /**
 828          * Get information about a given field
 829          * Returns false if the field does not exist.
 830          *
 831          * @param string $table
 832          * @param string $field
 833          * @return SQLiteField|bool False on failure
 834          */
 835         function fieldInfo( $table, $field ) {
 836                 $tableName = $this->tableName( $table );
 837                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 838                 $res = $this->query( $sql, __METHOD__, self::QUERY_IGNORE_DBO_TRX );
 839                 foreach ( $res as $row ) {
 840                         if ( $row->name == $field ) {
 841                                 return new SQLiteField( $row, $tableName );
 842                         }
 843                 }
 844
 845                 return false;
 846         }
 847
 848         protected function doBegin( $fname = '' ) {
 849                 if ( $this->trxMode != '' ) {
 850                         $this->query( "BEGIN {$this->trxMode}", $fname );
 851                 } else {
 852                         $this->query( 'BEGIN', $fname );
 853                 }
 854         }
 855
 856         /**
 857          * @param string $s
 858          * @return string
 859          */
 860         function strencode( $s ) {
 861                 return substr( $this->addQuotes( $s ), 1, -1 );
 862         }
 863
 864         /**
 865          * @param string $b
 866          * @return Blob
 867          */
 868         function encodeBlob( $b ) {
 869                 return new Blob( $b );
 870         }
 871
 872         /**
 873          * @param Blob|string $b
 874          * @return string
 875          */
 876         function decodeBlob( $b ) {
 877                 if ( $b instanceof Blob ) {
 878                         $b = $b->fetch();
 879                 }
 880
 881                 return $b;
 882         }
 883
 884         /**
 885          * @param string|int|null|bool|Blob $s
 886          * @return string|int
 887          */
 888         function addQuotes( $s ) {
 889                 if ( $s instanceof Blob ) {
 890                         return "x'" . bin2hex( $s->fetch() ) . "'";
 891                 } elseif ( is_bool( $s ) ) {
 892                         return (int)$s;
 893                 } elseif ( strpos( (string)$s, "\0" ) !== false ) {
 894                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 895                         // This is a known limitation of SQLite's mprintf function which PDO
 896                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 897                         // https://bugs.php.net/bug.php?id=63419
 898                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 899                         // https://bugs.php.net/bug.php?id=62361
 900                         // There is an additional bug regarding sorting this data after insert
 901                         // on older versions of sqlite shipped with ubuntu 12.04
 902                         // https://phabricator.wikimedia.org/T74367
 903                         $this->queryLogger->debug(
 904                                 __FUNCTION__ .
 905                                 ': Quoting value containing null byte. ' .
 906                                 'For consistency all binary data should have been ' .
 907                                 'first processed with self::encodeBlob()'
 908                         );
 909                         return "x'" . bin2hex( (string)$s ) . "'";
 910                 } else {
 911                         return $this->getBindingHandle()->quote( (string)$s );
 912                 }
 913         }
 914
 915         public function buildSubstring( $input, $startPosition, $length = null ) {
 916                 $this->assertBuildSubstringParams( $startPosition, $length );
 917                 $params = [ $input, $startPosition ];
 918                 if ( $length !== null ) {
 919                         $params[] = $length;
 920                 }
 921                 return 'SUBSTR(' . implode( ',', $params ) . ')';
 922         }
 923
 924         /**
 925          * @param string $field Field or column to cast
 926          * @return string
 927          * @since 1.28
 928          */
 929         public function buildStringCast( $field ) {
 930                 return 'CAST ( ' . $field . ' AS TEXT )';
 931         }
 932
 933         /**
 934          * No-op version of deadlockLoop
 935          *
 936          * @return mixed
 937          */
 938         public function deadlockLoop( /*...*/ ) {
 939                 $args = func_get_args();
 940                 $function = array_shift( $args );
 941
 942                 return $function( ...$args );
 943         }
 944
 945         /**
 946          * @param string $s
 947          * @return string
 948          */
 949         protected function replaceVars( $s ) {
 950                 $s = parent::replaceVars( $s );
 951                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 952                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 953
 954                         // binary/varbinary column type -> blob
 955                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 956                         // no such thing as unsigned
 957                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 958                         // INT -> INTEGER
 959                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 960                         // floating point types -> REAL
 961                         $s = preg_replace(
 962                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 963                                 'REAL',
 964                                 $s
 965                         );
 966                         // varchar -> TEXT
 967                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 968                         // TEXT normalization
 969                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 970                         // BLOB normalization
 971                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 972                         // BOOL -> INTEGER
 973                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 974                         // DATETIME -> TEXT
 975                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 976                         // No ENUM type
 977                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 978                         // binary collation type -> nothing
 979                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 980                         // auto_increment -> autoincrement
 981                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 982                         // No explicit options
 983                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 984                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 985                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 986                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 987                         // No truncated indexes
 988                         $s = preg_replace( '/\(\d+\)/', '', $s );
 989                         // No FULLTEXT
 990                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 991                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 992                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 993                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 994                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 995                         // INSERT IGNORE --> INSERT OR IGNORE
 996                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 997                 }
 998
 999                 return $s;
1000         }
1001
1002         public function lock( $lockName, $method, $timeout = 5 ) {
1003                 $status = $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout );
1004                 if (
1005                         $this->lockMgr instanceof FSLockManager &&
1006                         $status->hasMessage( 'lockmanager-fail-openlock' )
1007                 ) {
1008                         throw new DBError( $this, "Cannot create directory \"{$this->getLockFileDirectory()}\"" );
1009                 }
1010
1011                 return $status->isOK();
1012         }
1013
1014         public function unlock( $lockName, $method ) {
1015                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isGood();
1016         }
1017
1018         /**
1019          * Build a concatenation list to feed into a SQL query
1020          *
1021          * @param string[] $stringList
1022          * @return string
1023          */
1024         function buildConcat( $stringList ) {
1025                 return '(' . implode( ') || (', $stringList ) . ')';
1026         }
1027
1028         public function buildGroupConcatField(
1029                 $delim, $table, $field, $conds = '', $join_conds = []
1030         ) {
1031                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
1032
1033                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
1034         }
1035
1036         /**
1037          * @param string $oldName
1038          * @param string $newName
1039          * @param bool $temporary
1040          * @param string $fname
1041          * @return bool|IResultWrapper
1042          * @throws RuntimeException
1043          */
1044         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1045                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
1046                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
1047                 $obj = $this->fetchObject( $res );
1048                 if ( !$obj ) {
1049                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
1050                 }
1051                 $sql = $obj->sql;
1052                 $sql = preg_replace(
1053                         '/(?<=\W)"?' .
1054                                 preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ), '/' ) .
1055                                 '"?(?=\W)/',
1056                         $this->addIdentifierQuotes( $newName ),
1057                         $sql,
1058                         1
1059                 );
1060                 if ( $temporary ) {
1061                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
1062                                 $this->queryLogger->debug(
1063                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
1064                         } else {
1065                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
1066                         }
1067                 }
1068
1069                 $res = $this->query( $sql, $fname, self::QUERY_PSEUDO_PERMANENT );
1070
1071                 // Take over indexes
1072                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
1073                 foreach ( $indexList as $index ) {
1074                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
1075                                 continue;
1076                         }
1077
1078                         if ( $index->unique ) {
1079                                 $sql = 'CREATE UNIQUE INDEX';
1080                         } else {
1081                                 $sql = 'CREATE INDEX';
1082                         }
1083                         // Try to come up with a new index name, given indexes have database scope in SQLite
1084                         $indexName = $newName . '_' . $index->name;
1085                         $sql .= ' ' . $indexName . ' ON ' . $newName;
1086
1087                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
1088                         $fields = [];
1089                         foreach ( $indexInfo as $indexInfoRow ) {
1090                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
1091                         }
1092
1093                         $sql .= '(' . implode( ',', $fields ) . ')';
1094
1095                         $this->query( $sql );
1096                 }
1097
1098                 return $res;
1099         }
1100
1101         /**
1102          * List all tables on the database
1103          *
1104          * @param string|null $prefix Only show tables with this prefix, e.g. mw_
1105          * @param string $fname Calling function name
1106          *
1107          * @return array
1108          */
1109         function listTables( $prefix = null, $fname = __METHOD__ ) {
1110                 $result = $this->select(
1111                         'sqlite_master',
1112                         'name',
1113                         "type='table'"
1114                 );
1115
1116                 $endArray = [];
1117
1118                 foreach ( $result as $table ) {
1119                         $vars = get_object_vars( $table );
1120                         $table = array_pop( $vars );
1121
1122                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1123                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1124                                         $endArray[] = $table;
1125                                 }
1126                         }
1127                 }
1128
1129                 return $endArray;
1130         }
1131
1132         /**
1133          * Override due to no CASCADE support
1134          *
1135          * @param string $tableName
1136          * @param string $fName
1137          * @return bool|IResultWrapper
1138          * @throws DBReadOnlyError
1139          */
1140         public function dropTable( $tableName, $fName = __METHOD__ ) {
1141                 if ( !$this->tableExists( $tableName, $fName ) ) {
1142                         return false;
1143                 }
1144                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1145
1146                 return $this->query( $sql, $fName, self::QUERY_IGNORE_DBO_TRX );
1147         }
1148
1149         public function setTableAliases( array $aliases ) {
1150                 parent::setTableAliases( $aliases );
1151                 foreach ( $this->tableAliases as $params ) {
1152                         if ( isset( $this->alreadyAttached[$params['dbname']] ) ) {
1153                                 continue;
1154                         }
1155                         $this->attachDatabase( $params['dbname'] );
1156                         $this->alreadyAttached[$params['dbname']] = true;
1157                 }
1158         }
1159
1160         public function resetSequenceForTable( $table, $fname = __METHOD__ ) {
1161                 $encTable = $this->addIdentifierQuotes( 'sqlite_sequence' );
1162                 $encName = $this->addQuotes( $this->tableName( $table, 'raw' ) );
1163                 $this->query(
1164                         "DELETE FROM $encTable WHERE name = $encName",
1165                         $fname,
1166                         self::QUERY_IGNORE_DBO_TRX
1167                 );
1168         }
1169
1170         public function databasesAreIndependent() {
1171                 return true;
1172         }
1173
1174         /**
1175          * @return PDO
1176          */
1177         protected function getBindingHandle() {
1178                 return parent::getBindingHandle();
1179         }
1180 }
1181
1182 /**
1183  * @deprecated since 1.29
1184  */
1185 class_alias( DatabaseSqlite::class, 'DatabaseSqlite' );