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 PDO;
  27 use PDOException;
  28 use LockManager;
  29 use FSLockManager;
  30 use InvalidArgumentException;
  31 use RuntimeException;
  32 use stdClass;
  33
  34 /**
  35  * @ingroup Database
  36  */
  37 class DatabaseSqlite extends Database {
  38         /** @var bool Whether full text is enabled */
  39         private static $fulltextEnabled = null;
  40
  41         /** @var string Directory */
  42         protected $dbDir;
  43         /** @var string File name for SQLite database file */
  44         protected $dbPath;
  45         /** @var string Transaction mode */
  46         protected $trxMode;
  47
  48         /** @var int The number of rows affected as an integer */
  49         protected $lastAffectedRowCount;
  50         /** @var resource */
  51         protected $lastResultHandle;
  52
  53         /** @var PDO */
  54         protected $conn;
  55
  56         /** @var FSLockManager (hopefully on the same server as the DB) */
  57         protected $lockMgr;
  58
  59         /** @var array List of shared database already attached to this connection */
  60         private $alreadyAttached = [];
  61
  62         /**
  63          * Additional params include:
  64          *   - dbDirectory : directory containing the DB and the lock file directory
  65          *                   [defaults to $wgSQLiteDataDir]
  66          *   - dbFilePath  : use this to force the path of the DB file
  67          *   - trxMode     : one of (deferred, immediate, exclusive)
  68          * @param array $p
  69          */
  70         function __construct( array $p ) {
  71                 if ( isset( $p['dbFilePath'] ) ) {
  72                         $this->dbPath = $p['dbFilePath'];
  73                         $lockDomain = md5( $this->dbPath );
  74                         // Use "X" for things like X.sqlite and ":memory:" for RAM-only DBs
  75                         if ( !isset( $p['dbname'] ) || !strlen( $p['dbname'] ) ) {
  76                                 $p['dbname'] = preg_replace( '/\.sqlite\d?$/', '', basename( $this->dbPath ) );
  77                         }
  78                 } elseif ( isset( $p['dbDirectory'] ) ) {
  79                         $this->dbDir = $p['dbDirectory'];
  80                         $lockDomain = $p['dbname'];
  81                 } else {
  82                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
  83                 }
  84
  85                 $this->trxMode = isset( $p['trxMode'] ) ? strtoupper( $p['trxMode'] ) : null;
  86                 if ( $this->trxMode &&
  87                         !in_array( $this->trxMode, [ 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ] )
  88                 ) {
  89                         $this->trxMode = null;
  90                         $this->queryLogger->warning( "Invalid SQLite transaction mode provided." );
  91                 }
  92
  93                 $this->lockMgr = new FSLockManager( [
  94                         'domain' => $lockDomain,
  95                         'lockDirectory' => "{$this->dbDir}/locks"
  96                 ] );
  97
  98                 parent::__construct( $p );
  99         }
 100
 101         protected static function getAttributes() {
 102                 return [ self::ATTR_DB_LEVEL_LOCKING => true ];
 103         }
 104
 105         /**
 106          * @param string $filename
 107          * @param array $p Options map; supports:
 108          *   - flags       : (same as __construct counterpart)
 109          *   - trxMode     : (same as __construct counterpart)
 110          *   - dbDirectory : (same as __construct counterpart)
 111          * @return DatabaseSqlite
 112          * @since 1.25
 113          */
 114         public static function newStandaloneInstance( $filename, array $p = [] ) {
 115                 $p['dbFilePath'] = $filename;
 116                 $p['schema'] = null;
 117                 $p['tablePrefix'] = '';
 118                 /** @var DatabaseSqlite $db */
 119                 $db = Database::factory( 'sqlite', $p );
 120
 121                 return $db;
 122         }
 123
 124         protected function doInitConnection() {
 125                 if ( $this->dbPath !== null ) {
 126                         // Standalone .sqlite file mode.
 127                         $this->openFile(
 128                                 $this->dbPath,
 129                                 $this->connectionParams['dbname'],
 130                                 $this->connectionParams['tablePrefix']
 131                         );
 132                 } elseif ( $this->dbDir !== null ) {
 133                         // Stock wiki mode using standard file names per DB
 134                         if ( strlen( $this->connectionParams['dbname'] ) ) {
 135                                 $this->open(
 136                                         $this->connectionParams['host'],
 137                                         $this->connectionParams['user'],
 138                                         $this->connectionParams['password'],
 139                                         $this->connectionParams['dbname'],
 140                                         $this->connectionParams['schema'],
 141                                         $this->connectionParams['tablePrefix']
 142                                 );
 143                         } else {
 144                                 // Caller will manually call open() later?
 145                                 $this->connLogger->debug( __METHOD__ . ': no database opened.' );
 146                         }
 147                 } else {
 148                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
 149                 }
 150         }
 151
 152         /**
 153          * @return string
 154          */
 155         function getType() {
 156                 return 'sqlite';
 157         }
 158
 159         /**
 160          * @todo Check if it should be true like parent class
 161          *
 162          * @return bool
 163          */
 164         function implicitGroupby() {
 165                 return false;
 166         }
 167
 168         protected function open( $server, $user, $pass, $dbName, $schema, $tablePrefix ) {
 169                 $this->close();
 170                 $fileName = self::generateFileName( $this->dbDir, $dbName );
 171                 if ( !is_readable( $fileName ) ) {
 172                         $this->conn = false;
 173                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 174                 }
 175                 // Only $dbName is used, the other parameters are irrelevant for SQLite databases
 176                 $this->openFile( $fileName, $dbName, $tablePrefix );
 177
 178                 return (bool)$this->conn;
 179         }
 180
 181         /**
 182          * Opens a database file
 183          *
 184          * @param string $fileName
 185          * @param string $dbName
 186          * @param string $tablePrefix
 187          * @throws DBConnectionError
 188          * @return PDO|bool SQL connection or false if failed
 189          */
 190         protected function openFile( $fileName, $dbName, $tablePrefix ) {
 191                 $err = false;
 192
 193                 $this->dbPath = $fileName;
 194                 try {
 195                         if ( $this->flags & self::DBO_PERSISTENT ) {
 196                                 $this->conn = new PDO( "sqlite:$fileName", '', '',
 197                                         [ PDO::ATTR_PERSISTENT => true ] );
 198                         } else {
 199                                 $this->conn = new PDO( "sqlite:$fileName", '', '' );
 200                         }
 201                 } catch ( PDOException $e ) {
 202                         $err = $e->getMessage();
 203                 }
 204
 205                 if ( !$this->conn ) {
 206                         $this->queryLogger->debug( "DB connection error: $err\n" );
 207                         throw new DBConnectionError( $this, $err );
 208                 }
 209
 210                 $this->opened = is_object( $this->conn );
 211                 if ( $this->opened ) {
 212                         $this->currentDomain = new DatabaseDomain( $dbName, null, $tablePrefix );
 213                         # Set error codes only, don't raise exceptions
 214                         $this->conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 215                         # Enforce LIKE to be case sensitive, just like MySQL
 216                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 217
 218                         return $this->conn;
 219                 }
 220
 221                 return false;
 222         }
 223
 224         /**
 225          * @return string SQLite DB file path
 226          * @since 1.25
 227          */
 228         public function getDbFilePath() {
 229                 return $this->dbPath;
 230         }
 231
 232         /**
 233          * Does not actually close the connection, just destroys the reference for GC to do its work
 234          * @return bool
 235          */
 236         protected function closeConnection() {
 237                 $this->conn = null;
 238
 239                 return true;
 240         }
 241
 242         /**
 243          * Generates a database file name. Explicitly public for installer.
 244          * @param string $dir Directory where database resides
 245          * @param string $dbName Database name
 246          * @return string
 247          */
 248         public static function generateFileName( $dir, $dbName ) {
 249                 return "$dir/$dbName.sqlite";
 250         }
 251
 252         /**
 253          * Check if the searchindext table is FTS enabled.
 254          * @return bool False if not enabled.
 255          */
 256         function checkForEnabledSearch() {
 257                 if ( self::$fulltextEnabled === null ) {
 258                         self::$fulltextEnabled = false;
 259                         $table = $this->tableName( 'searchindex' );
 260                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 261                         if ( $res ) {
 262                                 $row = $res->fetchRow();
 263                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 264                         }
 265                 }
 266
 267                 return self::$fulltextEnabled;
 268         }
 269
 270         /**
 271          * Returns version of currently supported SQLite fulltext search module or false if none present.
 272          * @return string
 273          */
 274         static function getFulltextSearchModule() {
 275                 static $cachedResult = null;
 276                 if ( $cachedResult !== null ) {
 277                         return $cachedResult;
 278                 }
 279                 $cachedResult = false;
 280                 $table = 'dummy_search_test';
 281
 282                 $db = self::newStandaloneInstance( ':memory:' );
 283                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 284                         $cachedResult = 'FTS3';
 285                 }
 286                 $db->close();
 287
 288                 return $cachedResult;
 289         }
 290
 291         /**
 292          * Attaches external database to our connection, see https://sqlite.org/lang_attach.html
 293          * for details.
 294          *
 295          * @param string $name Database name to be used in queries like
 296          *   SELECT foo FROM dbname.table
 297          * @param bool|string $file Database file name. If omitted, will be generated
 298          *   using $name and configured data directory
 299          * @param string $fname Calling function name
 300          * @return ResultWrapper
 301          */
 302         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 303                 if ( !$file ) {
 304                         $file = self::generateFileName( $this->dbDir, $name );
 305                 }
 306                 $file = $this->addQuotes( $file );
 307
 308                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 309         }
 310
 311         protected function isWriteQuery( $sql ) {
 312                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 313         }
 314
 315         protected function isTransactableQuery( $sql ) {
 316                 return parent::isTransactableQuery( $sql ) && !in_array(
 317                         $this->getQueryVerb( $sql ),
 318                         [ 'ATTACH', 'PRAGMA' ],
 319                         true
 320                 );
 321         }
 322
 323         /**
 324          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 325          *
 326          * @param string $sql
 327          * @return bool|ResultWrapper
 328          */
 329         protected function doQuery( $sql ) {
 330                 $res = $this->getBindingHandle()->query( $sql );
 331                 if ( $res === false ) {
 332                         return false;
 333                 }
 334
 335                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 336                 $this->lastAffectedRowCount = $r->rowCount();
 337                 $res = new ResultWrapper( $this, $r->fetchAll() );
 338
 339                 return $res;
 340         }
 341
 342         /**
 343          * @param ResultWrapper|mixed $res
 344          */
 345         function freeResult( $res ) {
 346                 if ( $res instanceof ResultWrapper ) {
 347                         $res->result = null;
 348                 } else {
 349                         $res = null;
 350                 }
 351         }
 352
 353         /**
 354          * @param ResultWrapper|array $res
 355          * @return stdClass|bool
 356          */
 357         function fetchObject( $res ) {
 358                 if ( $res instanceof ResultWrapper ) {
 359                         $r =& $res->result;
 360                 } else {
 361                         $r =& $res;
 362                 }
 363
 364                 $cur = current( $r );
 365                 if ( is_array( $cur ) ) {
 366                         next( $r );
 367                         $obj = new stdClass;
 368                         foreach ( $cur as $k => $v ) {
 369                                 if ( !is_numeric( $k ) ) {
 370                                         $obj->$k = $v;
 371                                 }
 372                         }
 373
 374                         return $obj;
 375                 }
 376
 377                 return false;
 378         }
 379
 380         /**
 381          * @param ResultWrapper|mixed $res
 382          * @return array|bool
 383          */
 384         function fetchRow( $res ) {
 385                 if ( $res instanceof ResultWrapper ) {
 386                         $r =& $res->result;
 387                 } else {
 388                         $r =& $res;
 389                 }
 390                 $cur = current( $r );
 391                 if ( is_array( $cur ) ) {
 392                         next( $r );
 393
 394                         return $cur;
 395                 }
 396
 397                 return false;
 398         }
 399
 400         /**
 401          * The PDO::Statement class implements the array interface so count() will work
 402          *
 403          * @param ResultWrapper|array|false $res
 404          * @return int
 405          */
 406         function numRows( $res ) {
 407                 // false does not implement Countable
 408                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 409
 410                 return is_array( $r ) ? count( $r ) : 0;
 411         }
 412
 413         /**
 414          * @param ResultWrapper $res
 415          * @return int
 416          */
 417         function numFields( $res ) {
 418                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 419                 if ( is_array( $r ) && count( $r ) > 0 ) {
 420                         // The size of the result array is twice the number of fields. (T67578)
 421                         return count( $r[0] ) / 2;
 422                 } else {
 423                         // If the result is empty return 0
 424                         return 0;
 425                 }
 426         }
 427
 428         /**
 429          * @param ResultWrapper $res
 430          * @param int $n
 431          * @return bool
 432          */
 433         function fieldName( $res, $n ) {
 434                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 435                 if ( is_array( $r ) ) {
 436                         $keys = array_keys( $r[0] );
 437
 438                         return $keys[$n];
 439                 }
 440
 441                 return false;
 442         }
 443
 444         /**
 445          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 446          *
 447          * @param string $name
 448          * @param string $format
 449          * @return string
 450          */
 451         function tableName( $name, $format = 'quoted' ) {
 452                 // table names starting with sqlite_ are reserved
 453                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 454                         return $name;
 455                 }
 456
 457                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 458         }
 459
 460         /**
 461          * This must be called after nextSequenceVal
 462          *
 463          * @return int
 464          */
 465         function insertId() {
 466                 // PDO::lastInsertId yields a string :(
 467                 return intval( $this->getBindingHandle()->lastInsertId() );
 468         }
 469
 470         /**
 471          * @param ResultWrapper|array $res
 472          * @param int $row
 473          */
 474         function dataSeek( $res, $row ) {
 475                 if ( $res instanceof ResultWrapper ) {
 476                         $r =& $res->result;
 477                 } else {
 478                         $r =& $res;
 479                 }
 480                 reset( $r );
 481                 if ( $row > 0 ) {
 482                         for ( $i = 0; $i < $row; $i++ ) {
 483                                 next( $r );
 484                         }
 485                 }
 486         }
 487
 488         /**
 489          * @return string
 490          */
 491         function lastError() {
 492                 if ( !is_object( $this->conn ) ) {
 493                         return "Cannot return last error, no db connection";
 494                 }
 495                 $e = $this->conn->errorInfo();
 496
 497                 return $e[2] ?? '';
 498         }
 499
 500         /**
 501          * @return string
 502          */
 503         function lastErrno() {
 504                 if ( !is_object( $this->conn ) ) {
 505                         return "Cannot return last error, no db connection";
 506                 } else {
 507                         $info = $this->conn->errorInfo();
 508
 509                         return $info[1];
 510                 }
 511         }
 512
 513         /**
 514          * @return int
 515          */
 516         protected function fetchAffectedRowCount() {
 517                 return $this->lastAffectedRowCount;
 518         }
 519
 520         function tableExists( $table, $fname = __METHOD__ ) {
 521                 $tableRaw = $this->tableName( $table, 'raw' );
 522                 if ( isset( $this->sessionTempTables[$tableRaw] ) ) {
 523                         return true; // already known to exist
 524                 }
 525
 526                 $encTable = $this->addQuotes( $tableRaw );
 527                 $res = $this->query(
 528                         "SELECT 1 FROM sqlite_master WHERE type='table' AND name=$encTable" );
 529
 530                 return $res->numRows() ? true : false;
 531         }
 532
 533         /**
 534          * Returns information about an index
 535          * Returns false if the index does not exist
 536          * - if errors are explicitly ignored, returns NULL on failure
 537          *
 538          * @param string $table
 539          * @param string $index
 540          * @param string $fname
 541          * @return array|false
 542          */
 543         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 544                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 545                 $res = $this->query( $sql, $fname );
 546                 if ( !$res || $res->numRows() == 0 ) {
 547                         return false;
 548                 }
 549                 $info = [];
 550                 foreach ( $res as $row ) {
 551                         $info[] = $row->name;
 552                 }
 553
 554                 return $info;
 555         }
 556
 557         /**
 558          * @param string $table
 559          * @param string $index
 560          * @param string $fname
 561          * @return bool|null
 562          */
 563         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 564                 $row = $this->selectRow( 'sqlite_master', '*',
 565                         [
 566                                 'type' => 'index',
 567                                 'name' => $this->indexName( $index ),
 568                         ], $fname );
 569                 if ( !$row || !isset( $row->sql ) ) {
 570                         return null;
 571                 }
 572
 573                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 574                 $indexPos = strpos( $row->sql, 'INDEX' );
 575                 if ( $indexPos === false ) {
 576                         return null;
 577                 }
 578                 $firstPart = substr( $row->sql, 0, $indexPos );
 579                 $options = explode( ' ', $firstPart );
 580
 581                 return in_array( 'UNIQUE', $options );
 582         }
 583
 584         /**
 585          * Filter the options used in SELECT statements
 586          *
 587          * @param array $options
 588          * @return array
 589          */
 590         function makeSelectOptions( $options ) {
 591                 foreach ( $options as $k => $v ) {
 592                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 593                                 $options[$k] = '';
 594                         }
 595                 }
 596
 597                 return parent::makeSelectOptions( $options );
 598         }
 599
 600         /**
 601          * @param array $options
 602          * @return array
 603          */
 604         protected function makeUpdateOptionsArray( $options ) {
 605                 $options = parent::makeUpdateOptionsArray( $options );
 606                 $options = self::fixIgnore( $options );
 607
 608                 return $options;
 609         }
 610
 611         /**
 612          * @param array $options
 613          * @return array
 614          */
 615         static function fixIgnore( $options ) {
 616                 # SQLite uses OR IGNORE not just IGNORE
 617                 foreach ( $options as $k => $v ) {
 618                         if ( $v == 'IGNORE' ) {
 619                                 $options[$k] = 'OR IGNORE';
 620                         }
 621                 }
 622
 623                 return $options;
 624         }
 625
 626         /**
 627          * @param array $options
 628          * @return string
 629          */
 630         function makeInsertOptions( $options ) {
 631                 $options = self::fixIgnore( $options );
 632
 633                 return parent::makeInsertOptions( $options );
 634         }
 635
 636         /**
 637          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 638          * @param string $table
 639          * @param array $a
 640          * @param string $fname
 641          * @param array $options
 642          * @return bool
 643          */
 644         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 645                 if ( !count( $a ) ) {
 646                         return true;
 647                 }
 648
 649                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 650                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 651                         $ret = true;
 652                         foreach ( $a as $v ) {
 653                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 654                                         $ret = false;
 655                                 }
 656                         }
 657                 } else {
 658                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 659                 }
 660
 661                 return $ret;
 662         }
 663
 664         /**
 665          * @param string $table
 666          * @param array $uniqueIndexes Unused
 667          * @param string|array $rows
 668          * @param string $fname
 669          * @return bool|ResultWrapper
 670          */
 671         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 672                 if ( !count( $rows ) ) {
 673                         return true;
 674                 }
 675
 676                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 677                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 678                         $ret = true;
 679                         foreach ( $rows as $v ) {
 680                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 681                                         $ret = false;
 682                                 }
 683                         }
 684                 } else {
 685                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 686                 }
 687
 688                 return $ret;
 689         }
 690
 691         /**
 692          * Returns the size of a text field, or -1 for "unlimited"
 693          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 694          *
 695          * @param string $table
 696          * @param string $field
 697          * @return int
 698          */
 699         function textFieldSize( $table, $field ) {
 700                 return -1;
 701         }
 702
 703         /**
 704          * @return bool
 705          */
 706         function unionSupportsOrderAndLimit() {
 707                 return false;
 708         }
 709
 710         /**
 711          * @param string[] $sqls
 712          * @param bool $all Whether to "UNION ALL" or not
 713          * @return string
 714          */
 715         function unionQueries( $sqls, $all ) {
 716                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 717
 718                 return implode( $glue, $sqls );
 719         }
 720
 721         /**
 722          * @return bool
 723          */
 724         function wasDeadlock() {
 725                 return $this->lastErrno() == 5; // SQLITE_BUSY
 726         }
 727
 728         /**
 729          * @return bool
 730          */
 731         function wasReadOnlyError() {
 732                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 733         }
 734
 735         public function wasConnectionError( $errno ) {
 736                 return $errno == 17; // SQLITE_SCHEMA;
 737         }
 738
 739         protected function wasKnownStatementRollbackError() {
 740                 // ON CONFLICT ROLLBACK clauses make it so that SQLITE_CONSTRAINT error is
 741                 // ambiguous with regard to whether it implies a ROLLBACK or an ABORT happened.
 742                 // https://sqlite.org/lang_createtable.html#uniqueconst
 743                 // https://sqlite.org/lang_conflict.html
 744                 return false;
 745         }
 746
 747         /**
 748          * @return string Wikitext of a link to the server software's web site
 749          */
 750         public function getSoftwareLink() {
 751                 return "[{{int:version-db-sqlite-url}} SQLite]";
 752         }
 753
 754         /**
 755          * @return string Version information from the database
 756          */
 757         function getServerVersion() {
 758                 $ver = $this->getBindingHandle()->getAttribute( PDO::ATTR_SERVER_VERSION );
 759
 760                 return $ver;
 761         }
 762
 763         /**
 764          * Get information about a given field
 765          * Returns false if the field does not exist.
 766          *
 767          * @param string $table
 768          * @param string $field
 769          * @return SQLiteField|bool False on failure
 770          */
 771         function fieldInfo( $table, $field ) {
 772                 $tableName = $this->tableName( $table );
 773                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 774                 $res = $this->query( $sql, __METHOD__ );
 775                 foreach ( $res as $row ) {
 776                         if ( $row->name == $field ) {
 777                                 return new SQLiteField( $row, $tableName );
 778                         }
 779                 }
 780
 781                 return false;
 782         }
 783
 784         protected function doBegin( $fname = '' ) {
 785                 if ( $this->trxMode ) {
 786                         $this->query( "BEGIN {$this->trxMode}", $fname );
 787                 } else {
 788                         $this->query( 'BEGIN', $fname );
 789                 }
 790                 $this->trxLevel = 1;
 791         }
 792
 793         /**
 794          * @param string $s
 795          * @return string
 796          */
 797         function strencode( $s ) {
 798                 return substr( $this->addQuotes( $s ), 1, -1 );
 799         }
 800
 801         /**
 802          * @param string $b
 803          * @return Blob
 804          */
 805         function encodeBlob( $b ) {
 806                 return new Blob( $b );
 807         }
 808
 809         /**
 810          * @param Blob|string $b
 811          * @return string
 812          */
 813         function decodeBlob( $b ) {
 814                 if ( $b instanceof Blob ) {
 815                         $b = $b->fetch();
 816                 }
 817
 818                 return $b;
 819         }
 820
 821         /**
 822          * @param string|int|null|bool|Blob $s
 823          * @return string|int
 824          */
 825         function addQuotes( $s ) {
 826                 if ( $s instanceof Blob ) {
 827                         return "x'" . bin2hex( $s->fetch() ) . "'";
 828                 } elseif ( is_bool( $s ) ) {
 829                         return (int)$s;
 830                 } elseif ( strpos( (string)$s, "\0" ) !== false ) {
 831                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 832                         // This is a known limitation of SQLite's mprintf function which PDO
 833                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 834                         // https://bugs.php.net/bug.php?id=63419
 835                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 836                         // https://bugs.php.net/bug.php?id=62361
 837                         // There is an additional bug regarding sorting this data after insert
 838                         // on older versions of sqlite shipped with ubuntu 12.04
 839                         // https://phabricator.wikimedia.org/T74367
 840                         $this->queryLogger->debug(
 841                                 __FUNCTION__ .
 842                                 ': Quoting value containing null byte. ' .
 843                                 'For consistency all binary data should have been ' .
 844                                 'first processed with self::encodeBlob()'
 845                         );
 846                         return "x'" . bin2hex( (string)$s ) . "'";
 847                 } else {
 848                         return $this->getBindingHandle()->quote( (string)$s );
 849                 }
 850         }
 851
 852         public function buildSubstring( $input, $startPosition, $length = null ) {
 853                 $this->assertBuildSubstringParams( $startPosition, $length );
 854                 $params = [ $input, $startPosition ];
 855                 if ( $length !== null ) {
 856                         $params[] = $length;
 857                 }
 858                 return 'SUBSTR(' . implode( ',', $params ) . ')';
 859         }
 860
 861         /**
 862          * @param string $field Field or column to cast
 863          * @return string
 864          * @since 1.28
 865          */
 866         public function buildStringCast( $field ) {
 867                 return 'CAST ( ' . $field . ' AS TEXT )';
 868         }
 869
 870         /**
 871          * No-op version of deadlockLoop
 872          *
 873          * @return mixed
 874          */
 875         public function deadlockLoop( /*...*/ ) {
 876                 $args = func_get_args();
 877                 $function = array_shift( $args );
 878
 879                 return $function( ...$args );
 880         }
 881
 882         /**
 883          * @param string $s
 884          * @return string
 885          */
 886         protected function replaceVars( $s ) {
 887                 $s = parent::replaceVars( $s );
 888                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 889                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 890
 891                         // binary/varbinary column type -> blob
 892                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 893                         // no such thing as unsigned
 894                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 895                         // INT -> INTEGER
 896                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 897                         // floating point types -> REAL
 898                         $s = preg_replace(
 899                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 900                                 'REAL',
 901                                 $s
 902                         );
 903                         // varchar -> TEXT
 904                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 905                         // TEXT normalization
 906                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 907                         // BLOB normalization
 908                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 909                         // BOOL -> INTEGER
 910                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 911                         // DATETIME -> TEXT
 912                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 913                         // No ENUM type
 914                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 915                         // binary collation type -> nothing
 916                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 917                         // auto_increment -> autoincrement
 918                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 919                         // No explicit options
 920                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 921                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 922                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 923                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 924                         // No truncated indexes
 925                         $s = preg_replace( '/\(\d+\)/', '', $s );
 926                         // No FULLTEXT
 927                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 928                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 929                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 930                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 931                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 932                         // INSERT IGNORE --> INSERT OR IGNORE
 933                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 934                 }
 935
 936                 return $s;
 937         }
 938
 939         public function lock( $lockName, $method, $timeout = 5 ) {
 940                 if ( !is_dir( "{$this->dbDir}/locks" ) ) { // create dir as needed
 941                         if ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) ) {
 942                                 throw new DBError( $this, "Cannot create directory \"{$this->dbDir}/locks\"." );
 943                         }
 944                 }
 945
 946                 return $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout )->isOK();
 947         }
 948
 949         public function unlock( $lockName, $method ) {
 950                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isOK();
 951         }
 952
 953         /**
 954          * Build a concatenation list to feed into a SQL query
 955          *
 956          * @param string[] $stringList
 957          * @return string
 958          */
 959         function buildConcat( $stringList ) {
 960                 return '(' . implode( ') || (', $stringList ) . ')';
 961         }
 962
 963         public function buildGroupConcatField(
 964                 $delim, $table, $field, $conds = '', $join_conds = []
 965         ) {
 966                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 967
 968                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
 969         }
 970
 971         /**
 972          * @param string $oldName
 973          * @param string $newName
 974          * @param bool $temporary
 975          * @param string $fname
 976          * @return bool|ResultWrapper
 977          * @throws RuntimeException
 978          */
 979         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 980                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 981                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 982                 $obj = $this->fetchObject( $res );
 983                 if ( !$obj ) {
 984                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
 985                 }
 986                 $sql = $obj->sql;
 987                 $sql = preg_replace(
 988                         '/(?<=\W)"?' .
 989                                 preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ), '/' ) .
 990                                 '"?(?=\W)/',
 991                         $this->addIdentifierQuotes( $newName ),
 992                         $sql,
 993                         1
 994                 );
 995                 if ( $temporary ) {
 996                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 997                                 $this->queryLogger->debug(
 998                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 999                         } else {
1000                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
1001                         }
1002                 }
1003
1004                 $res = $this->query( $sql, $fname );
1005
1006                 // Take over indexes
1007                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
1008                 foreach ( $indexList as $index ) {
1009                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
1010                                 continue;
1011                         }
1012
1013                         if ( $index->unique ) {
1014                                 $sql = 'CREATE UNIQUE INDEX';
1015                         } else {
1016                                 $sql = 'CREATE INDEX';
1017                         }
1018                         // Try to come up with a new index name, given indexes have database scope in SQLite
1019                         $indexName = $newName . '_' . $index->name;
1020                         $sql .= ' ' . $indexName . ' ON ' . $newName;
1021
1022                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
1023                         $fields = [];
1024                         foreach ( $indexInfo as $indexInfoRow ) {
1025                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
1026                         }
1027
1028                         $sql .= '(' . implode( ',', $fields ) . ')';
1029
1030                         $this->query( $sql );
1031                 }
1032
1033                 return $res;
1034         }
1035
1036         /**
1037          * List all tables on the database
1038          *
1039          * @param string|null $prefix Only show tables with this prefix, e.g. mw_
1040          * @param string $fname Calling function name
1041          *
1042          * @return array
1043          */
1044         function listTables( $prefix = null, $fname = __METHOD__ ) {
1045                 $result = $this->select(
1046                         'sqlite_master',
1047                         'name',
1048                         "type='table'"
1049                 );
1050
1051                 $endArray = [];
1052
1053                 foreach ( $result as $table ) {
1054                         $vars = get_object_vars( $table );
1055                         $table = array_pop( $vars );
1056
1057                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1058                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1059                                         $endArray[] = $table;
1060                                 }
1061                         }
1062                 }
1063
1064                 return $endArray;
1065         }
1066
1067         /**
1068          * Override due to no CASCADE support
1069          *
1070          * @param string $tableName
1071          * @param string $fName
1072          * @return bool|ResultWrapper
1073          * @throws DBReadOnlyError
1074          */
1075         public function dropTable( $tableName, $fName = __METHOD__ ) {
1076                 if ( !$this->tableExists( $tableName, $fName ) ) {
1077                         return false;
1078                 }
1079                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1080
1081                 return $this->query( $sql, $fName );
1082         }
1083
1084         public function setTableAliases( array $aliases ) {
1085                 parent::setTableAliases( $aliases );
1086                 foreach ( $this->tableAliases as $params ) {
1087                         if ( isset( $this->alreadyAttached[$params['dbname']] ) ) {
1088                                 continue;
1089                         }
1090                         $this->attachDatabase( $params['dbname'] );
1091                         $this->alreadyAttached[$params['dbname']] = true;
1092                 }
1093         }
1094
1095         public function resetSequenceForTable( $table, $fname = __METHOD__ ) {
1096                 $encTable = $this->addIdentifierQuotes( 'sqlite_sequence' );
1097                 $encName = $this->addQuotes( $this->tableName( $table, 'raw' ) );
1098                 $this->query( "DELETE FROM $encTable WHERE name = $encName", $fname );
1099         }
1100
1101         public function databasesAreIndependent() {
1102                 return true;
1103         }
1104
1105         /**
1106          * @return string
1107          */
1108         public function __toString() {
1109                 return is_object( $this->conn )
1110                         ? 'SQLite ' . (string)$this->conn->getAttribute( PDO::ATTR_SERVER_VERSION )
1111                         : '(not connected)';
1112         }
1113
1114         /**
1115          * @return PDO
1116          */
1117         protected function getBindingHandle() {
1118                 return parent::getBindingHandle();
1119         }
1120 }
1121
1122 /**
1123  * @deprecated since 1.29
1124  */
1125 class_alias( DatabaseSqlite::class, 'DatabaseSqlite' );