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 Exception;
  29 use LockManager;
  30 use FSLockManager;
  31 use InvalidArgumentException;
  32 use RuntimeException;
  33 use stdClass;
  34
  35 /**
  36  * @ingroup Database
  37  */
  38 class DatabaseSqlite extends Database {
  39         /** @var bool Whether full text is enabled */
  40         private static $fulltextEnabled = null;
  41
  42         /** @var string Directory */
  43         protected $dbDir;
  44         /** @var string File name for SQLite database file */
  45         protected $dbPath;
  46         /** @var string Transaction mode */
  47         protected $trxMode;
  48
  49         /** @var int The number of rows affected as an integer */
  50         protected $lastAffectedRowCount;
  51         /** @var resource */
  52         protected $lastResultHandle;
  53
  54         /** @var PDO */
  55         protected $conn;
  56
  57         /** @var FSLockManager (hopefully on the same server as the DB) */
  58         protected $lockMgr;
  59
  60         /** @var array List of shared database already attached to this connection */
  61         private $alreadyAttached = [];
  62
  63         /**
  64          * Additional params include:
  65          *   - dbDirectory : directory containing the DB and the lock file directory
  66          *                   [defaults to $wgSQLiteDataDir]
  67          *   - dbFilePath  : use this to force the path of the DB file
  68          *   - trxMode     : one of (deferred, immediate, exclusive)
  69          * @param array $p
  70          */
  71         function __construct( array $p ) {
  72                 if ( isset( $p['dbFilePath'] ) ) {
  73                         $this->dbPath = $p['dbFilePath'];
  74                         $lockDomain = md5( $this->dbPath );
  75                         // Use "X" for things like X.sqlite and ":memory:" for RAM-only DBs
  76                         if ( !isset( $p['dbname'] ) || !strlen( $p['dbname'] ) ) {
  77                                 $p['dbname'] = preg_replace( '/\.sqlite\d?$/', '', basename( $this->dbPath ) );
  78                         }
  79                 } elseif ( isset( $p['dbDirectory'] ) ) {
  80                         $this->dbDir = $p['dbDirectory'];
  81                         $lockDomain = $p['dbname'];
  82                 } else {
  83                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
  84                 }
  85
  86                 $this->trxMode = isset( $p['trxMode'] ) ? strtoupper( $p['trxMode'] ) : null;
  87                 if ( $this->trxMode &&
  88                         !in_array( $this->trxMode, [ 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ] )
  89                 ) {
  90                         $this->trxMode = null;
  91                         $this->queryLogger->warning( "Invalid SQLite transaction mode provided." );
  92                 }
  93
  94                 $this->lockMgr = new FSLockManager( [
  95                         'domain' => $lockDomain,
  96                         'lockDirectory' => "{$this->dbDir}/locks"
  97                 ] );
  98
  99                 parent::__construct( $p );
 100         }
 101
 102         protected static function getAttributes() {
 103                 return [ self::ATTR_DB_LEVEL_LOCKING => true ];
 104         }
 105
 106         /**
 107          * @param string $filename
 108          * @param array $p Options map; supports:
 109          *   - flags       : (same as __construct counterpart)
 110          *   - trxMode     : (same as __construct counterpart)
 111          *   - dbDirectory : (same as __construct counterpart)
 112          * @return DatabaseSqlite
 113          * @since 1.25
 114          */
 115         public static function newStandaloneInstance( $filename, array $p = [] ) {
 116                 $p['dbFilePath'] = $filename;
 117                 $p['schema'] = null;
 118                 $p['tablePrefix'] = '';
 119                 /** @var DatabaseSqlite $db */
 120                 $db = Database::factory( 'sqlite', $p );
 121
 122                 return $db;
 123         }
 124
 125         protected function doInitConnection() {
 126                 if ( $this->dbPath !== null ) {
 127                         // Standalone .sqlite file mode.
 128                         $this->openFile(
 129                                 $this->dbPath,
 130                                 $this->connectionParams['dbname'],
 131                                 $this->connectionParams['tablePrefix']
 132                         );
 133                 } elseif ( $this->dbDir !== null ) {
 134                         // Stock wiki mode using standard file names per DB
 135                         if ( strlen( $this->connectionParams['dbname'] ) ) {
 136                                 $this->open(
 137                                         $this->connectionParams['host'],
 138                                         $this->connectionParams['user'],
 139                                         $this->connectionParams['password'],
 140                                         $this->connectionParams['dbname'],
 141                                         $this->connectionParams['schema'],
 142                                         $this->connectionParams['tablePrefix']
 143                                 );
 144                         } else {
 145                                 // Caller will manually call open() later?
 146                                 $this->connLogger->debug( __METHOD__ . ': no database opened.' );
 147                         }
 148                 } else {
 149                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
 150                 }
 151         }
 152
 153         /**
 154          * @return string
 155          */
 156         function getType() {
 157                 return 'sqlite';
 158         }
 159
 160         /**
 161          * @todo Check if it should be true like parent class
 162          *
 163          * @return bool
 164          */
 165         function implicitGroupby() {
 166                 return false;
 167         }
 168
 169         protected function open( $server, $user, $pass, $dbName, $schema, $tablePrefix ) {
 170                 $this->close();
 171
 172                 if ( $schema !== null ) {
 173                         throw new DBExpectedError( $this, __CLASS__ . ": domain schemas are not supported." );
 174                 }
 175
 176                 // Only $dbName is used, the other parameters are irrelevant for SQLite databases
 177                 $this->openFile( self::generateFileName( $this->dbDir, $dbName ), $dbName, $tablePrefix );
 178         }
 179
 180         /**
 181          * Opens a database file
 182          *
 183          * @param string $fileName
 184          * @param string $dbName
 185          * @param string $tablePrefix
 186          * @throws DBConnectionError
 187          */
 188         protected function openFile( $fileName, $dbName, $tablePrefix ) {
 189                 if ( !$this->hasMemoryPath() && !is_readable( $fileName ) ) {
 190                         $error = "SQLite database file not readable";
 191                         $this->connLogger->error(
 192                                 "Error connecting to {db_server}: {error}",
 193                                 $this->getLogContext( [ 'method' => __METHOD__, 'error' => $error ] )
 194                         );
 195                         throw new DBConnectionError( $this, $error );
 196                 }
 197
 198                 $this->dbPath = $fileName;
 199                 try {
 200                         $this->conn = new PDO(
 201                                 "sqlite:$fileName",
 202                                 '',
 203                                 '',
 204                                 [ PDO::ATTR_PERSISTENT => (bool)( $this->flags & self::DBO_PERSISTENT ) ]
 205                         );
 206                         $error = 'unknown error';
 207                 } catch ( PDOException $e ) {
 208                         $error = $e->getMessage();
 209                 }
 210
 211                 if ( !$this->conn ) {
 212                         $this->connLogger->error(
 213                                 "Error connecting to {db_server}: {error}",
 214                                 $this->getLogContext( [ 'method' => __METHOD__, 'error' => $error ] )
 215                         );
 216                         throw new DBConnectionError( $this, $error );
 217                 }
 218
 219                 try {
 220                         // Set error codes only, don't raise exceptions
 221                         $this->conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 222
 223                         $this->currentDomain = new DatabaseDomain( $dbName, null, $tablePrefix );
 224
 225                         $flags = self::QUERY_IGNORE_DBO_TRX | self::QUERY_NO_RETRY;
 226                         // Enforce LIKE to be case sensitive, just like MySQL
 227                         $this->query( 'PRAGMA case_sensitive_like = 1', __METHOD__, $flags );
 228                         // Apply an optimizations or requirements regarding fsync() usage
 229                         $sync = $this->connectionVariables['synchronous'] ?? null;
 230                         if ( in_array( $sync, [ 'EXTRA', 'FULL', 'NORMAL', 'OFF' ], true ) ) {
 231                                 $this->query( "PRAGMA synchronous = $sync", __METHOD__ );
 232                         }
 233                 } catch ( Exception $e ) {
 234                         // Connection was not fully initialized and is not safe for use
 235                         $this->conn = false;
 236                         throw $e;
 237                 }
 238         }
 239
 240         /**
 241          * @return string SQLite DB file path
 242          * @since 1.25
 243          */
 244         public function getDbFilePath() {
 245                 return $this->dbPath;
 246         }
 247
 248         /**
 249          * Does not actually close the connection, just destroys the reference for GC to do its work
 250          * @return bool
 251          */
 252         protected function closeConnection() {
 253                 $this->conn = null;
 254
 255                 return true;
 256         }
 257
 258         /**
 259          * Generates a database file name. Explicitly public for installer.
 260          * @param string $dir Directory where database resides
 261          * @param string $dbName Database name
 262          * @return string
 263          */
 264         public static function generateFileName( $dir, $dbName ) {
 265                 return "$dir/$dbName.sqlite";
 266         }
 267
 268         /**
 269          * Check if the searchindext table is FTS enabled.
 270          * @return bool False if not enabled.
 271          */
 272         public function checkForEnabledSearch() {
 273                 if ( self::$fulltextEnabled === null ) {
 274                         self::$fulltextEnabled = false;
 275                         $table = $this->tableName( 'searchindex' );
 276                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 277                         if ( $res ) {
 278                                 $row = $res->fetchRow();
 279                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 280                         }
 281                 }
 282
 283                 return self::$fulltextEnabled;
 284         }
 285
 286         /**
 287          * Returns version of currently supported SQLite fulltext search module or false if none present.
 288          * @return string
 289          */
 290         static function getFulltextSearchModule() {
 291                 static $cachedResult = null;
 292                 if ( $cachedResult !== null ) {
 293                         return $cachedResult;
 294                 }
 295                 $cachedResult = false;
 296                 $table = 'dummy_search_test';
 297
 298                 $db = self::newStandaloneInstance( ':memory:' );
 299                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 300                         $cachedResult = 'FTS3';
 301                 }
 302                 $db->close();
 303
 304                 return $cachedResult;
 305         }
 306
 307         /**
 308          * Attaches external database to our connection, see https://sqlite.org/lang_attach.html
 309          * for details.
 310          *
 311          * @param string $name Database name to be used in queries like
 312          *   SELECT foo FROM dbname.table
 313          * @param bool|string $file Database file name. If omitted, will be generated
 314          *   using $name and configured data directory
 315          * @param string $fname Calling function name
 316          * @return IResultWrapper
 317          */
 318         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 319                 if ( !$file ) {
 320                         $file = self::generateFileName( $this->dbDir, $name );
 321                 }
 322                 $file = $this->addQuotes( $file );
 323
 324                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 325         }
 326
 327         protected function isWriteQuery( $sql ) {
 328                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 329         }
 330
 331         protected function isTransactableQuery( $sql ) {
 332                 return parent::isTransactableQuery( $sql ) && !in_array(
 333                         $this->getQueryVerb( $sql ),
 334                         [ 'ATTACH', 'PRAGMA' ],
 335                         true
 336                 );
 337         }
 338
 339         /**
 340          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 341          *
 342          * @param string $sql
 343          * @return bool|IResultWrapper
 344          */
 345         protected function doQuery( $sql ) {
 346                 $res = $this->getBindingHandle()->query( $sql );
 347                 if ( $res === false ) {
 348                         return false;
 349                 }
 350
 351                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 352                 $this->lastAffectedRowCount = $r->rowCount();
 353                 $res = new ResultWrapper( $this, $r->fetchAll() );
 354
 355                 return $res;
 356         }
 357
 358         /**
 359          * @param IResultWrapper|mixed $res
 360          */
 361         function freeResult( $res ) {
 362                 if ( $res instanceof ResultWrapper ) {
 363                         $res->result = null;
 364                 } else {
 365                         $res = null;
 366                 }
 367         }
 368
 369         /**
 370          * @param IResultWrapper|array $res
 371          * @return stdClass|bool
 372          */
 373         function fetchObject( $res ) {
 374                 if ( $res instanceof ResultWrapper ) {
 375                         $r =& $res->result;
 376                 } else {
 377                         $r =& $res;
 378                 }
 379
 380                 $cur = current( $r );
 381                 if ( is_array( $cur ) ) {
 382                         next( $r );
 383                         $obj = new stdClass;
 384                         foreach ( $cur as $k => $v ) {
 385                                 if ( !is_numeric( $k ) ) {
 386                                         $obj->$k = $v;
 387                                 }
 388                         }
 389
 390                         return $obj;
 391                 }
 392
 393                 return false;
 394         }
 395
 396         /**
 397          * @param IResultWrapper|mixed $res
 398          * @return array|bool
 399          */
 400         function fetchRow( $res ) {
 401                 if ( $res instanceof ResultWrapper ) {
 402                         $r =& $res->result;
 403                 } else {
 404                         $r =& $res;
 405                 }
 406                 $cur = current( $r );
 407                 if ( is_array( $cur ) ) {
 408                         next( $r );
 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                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 425
 426                 return is_array( $r ) ? count( $r ) : 0;
 427         }
 428
 429         /**
 430          * @param IResultWrapper $res
 431          * @return int
 432          */
 433         function numFields( $res ) {
 434                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 435                 if ( is_array( $r ) && count( $r ) > 0 ) {
 436                         // The size of the result array is twice the number of fields. (T67578)
 437                         return count( $r[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                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 451                 if ( is_array( $r ) ) {
 452                         $keys = array_keys( $r[0] );
 453
 454                         return $keys[$n];
 455                 }
 456
 457                 return false;
 458         }
 459
 460         /**
 461          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 462          *
 463          * @param string $name
 464          * @param string $format
 465          * @return string
 466          */
 467         function tableName( $name, $format = 'quoted' ) {
 468                 // table names starting with sqlite_ are reserved
 469                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 470                         return $name;
 471                 }
 472
 473                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 474         }
 475
 476         /**
 477          * This must be called after nextSequenceVal
 478          *
 479          * @return int
 480          */
 481         function insertId() {
 482                 // PDO::lastInsertId yields a string :(
 483                 return intval( $this->getBindingHandle()->lastInsertId() );
 484         }
 485
 486         /**
 487          * @param IResultWrapper|array $res
 488          * @param int $row
 489          */
 490         function dataSeek( $res, $row ) {
 491                 if ( $res instanceof ResultWrapper ) {
 492                         $r =& $res->result;
 493                 } else {
 494                         $r =& $res;
 495                 }
 496                 reset( $r );
 497                 if ( $row > 0 ) {
 498                         for ( $i = 0; $i < $row; $i++ ) {
 499                                 next( $r );
 500                         }
 501                 }
 502         }
 503
 504         /**
 505          * @return string
 506          */
 507         function lastError() {
 508                 if ( !is_object( $this->conn ) ) {
 509                         return "Cannot return last error, no db connection";
 510                 }
 511                 $e = $this->conn->errorInfo();
 512
 513                 return $e[2] ?? '';
 514         }
 515
 516         /**
 517          * @return string
 518          */
 519         function lastErrno() {
 520                 if ( !is_object( $this->conn ) ) {
 521                         return "Cannot return last error, no db connection";
 522                 } else {
 523                         $info = $this->conn->errorInfo();
 524
 525                         return $info[1];
 526                 }
 527         }
 528
 529         /**
 530          * @return int
 531          */
 532         protected function fetchAffectedRowCount() {
 533                 return $this->lastAffectedRowCount;
 534         }
 535
 536         function tableExists( $table, $fname = __METHOD__ ) {
 537                 $tableRaw = $this->tableName( $table, 'raw' );
 538                 if ( isset( $this->sessionTempTables[$tableRaw] ) ) {
 539                         return true; // already known to exist
 540                 }
 541
 542                 $encTable = $this->addQuotes( $tableRaw );
 543                 $res = $this->query(
 544                         "SELECT 1 FROM sqlite_master WHERE type='table' AND name=$encTable" );
 545
 546                 return $res->numRows() ? true : false;
 547         }
 548
 549         /**
 550          * Returns information about an index
 551          * Returns false if the index does not exist
 552          * - if errors are explicitly ignored, returns NULL on failure
 553          *
 554          * @param string $table
 555          * @param string $index
 556          * @param string $fname
 557          * @return array|false
 558          */
 559         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 560                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 561                 $res = $this->query( $sql, $fname );
 562                 if ( !$res || $res->numRows() == 0 ) {
 563                         return false;
 564                 }
 565                 $info = [];
 566                 foreach ( $res as $row ) {
 567                         $info[] = $row->name;
 568                 }
 569
 570                 return $info;
 571         }
 572
 573         /**
 574          * @param string $table
 575          * @param string $index
 576          * @param string $fname
 577          * @return bool|null
 578          */
 579         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 580                 $row = $this->selectRow( 'sqlite_master', '*',
 581                         [
 582                                 'type' => 'index',
 583                                 'name' => $this->indexName( $index ),
 584                         ], $fname );
 585                 if ( !$row || !isset( $row->sql ) ) {
 586                         return null;
 587                 }
 588
 589                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 590                 $indexPos = strpos( $row->sql, 'INDEX' );
 591                 if ( $indexPos === false ) {
 592                         return null;
 593                 }
 594                 $firstPart = substr( $row->sql, 0, $indexPos );
 595                 $options = explode( ' ', $firstPart );
 596
 597                 return in_array( 'UNIQUE', $options );
 598         }
 599
 600         /**
 601          * Filter the options used in SELECT statements
 602          *
 603          * @param array $options
 604          * @return array
 605          */
 606         function makeSelectOptions( $options ) {
 607                 foreach ( $options as $k => $v ) {
 608                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 609                                 $options[$k] = '';
 610                         }
 611                 }
 612
 613                 return parent::makeSelectOptions( $options );
 614         }
 615
 616         /**
 617          * @param array $options
 618          * @return array
 619          */
 620         protected function makeUpdateOptionsArray( $options ) {
 621                 $options = parent::makeUpdateOptionsArray( $options );
 622                 $options = self::fixIgnore( $options );
 623
 624                 return $options;
 625         }
 626
 627         /**
 628          * @param array $options
 629          * @return array
 630          */
 631         static function fixIgnore( $options ) {
 632                 # SQLite uses OR IGNORE not just IGNORE
 633                 foreach ( $options as $k => $v ) {
 634                         if ( $v == 'IGNORE' ) {
 635                                 $options[$k] = 'OR IGNORE';
 636                         }
 637                 }
 638
 639                 return $options;
 640         }
 641
 642         /**
 643          * @param array $options
 644          * @return string
 645          */
 646         function makeInsertOptions( $options ) {
 647                 $options = self::fixIgnore( $options );
 648
 649                 return parent::makeInsertOptions( $options );
 650         }
 651
 652         /**
 653          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 654          * @param string $table
 655          * @param array $a
 656          * @param string $fname
 657          * @param array $options
 658          * @return bool
 659          */
 660         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 661                 if ( !count( $a ) ) {
 662                         return true;
 663                 }
 664
 665                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 666                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 667                         $affectedRowCount = 0;
 668                         try {
 669                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 670                                 foreach ( $a as $v ) {
 671                                         parent::insert( $table, $v, "$fname/multi-row", $options );
 672                                         $affectedRowCount += $this->affectedRows();
 673                                 }
 674                                 $this->endAtomic( $fname );
 675                         } catch ( Exception $e ) {
 676                                 $this->cancelAtomic( $fname );
 677                                 throw $e;
 678                         }
 679                         $this->affectedRowCount = $affectedRowCount;
 680                 } else {
 681                         parent::insert( $table, $a, "$fname/single-row", $options );
 682                 }
 683
 684                 return true;
 685         }
 686
 687         /**
 688          * @param string $table
 689          * @param array $uniqueIndexes Unused
 690          * @param string|array $rows
 691          * @param string $fname
 692          */
 693         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 694                 if ( !count( $rows ) ) {
 695                         return;
 696                 }
 697
 698                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 699                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 700                         $affectedRowCount = 0;
 701                         try {
 702                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 703                                 foreach ( $rows as $v ) {
 704                                         $this->nativeReplace( $table, $v, "$fname/multi-row" );
 705                                         $affectedRowCount += $this->affectedRows();
 706                                 }
 707                                 $this->endAtomic( $fname );
 708                         } catch ( Exception $e ) {
 709                                 $this->cancelAtomic( $fname );
 710                                 throw $e;
 711                         }
 712                         $this->affectedRowCount = $affectedRowCount;
 713                 } else {
 714                         $this->nativeReplace( $table, $rows, "$fname/single-row" );
 715                 }
 716         }
 717
 718         /**
 719          * Returns the size of a text field, or -1 for "unlimited"
 720          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 721          *
 722          * @param string $table
 723          * @param string $field
 724          * @return int
 725          */
 726         function textFieldSize( $table, $field ) {
 727                 return -1;
 728         }
 729
 730         /**
 731          * @return bool
 732          */
 733         function unionSupportsOrderAndLimit() {
 734                 return false;
 735         }
 736
 737         /**
 738          * @param string[] $sqls
 739          * @param bool $all Whether to "UNION ALL" or not
 740          * @return string
 741          */
 742         function unionQueries( $sqls, $all ) {
 743                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 744
 745                 return implode( $glue, $sqls );
 746         }
 747
 748         /**
 749          * @return bool
 750          */
 751         function wasDeadlock() {
 752                 return $this->lastErrno() == 5; // SQLITE_BUSY
 753         }
 754
 755         /**
 756          * @return bool
 757          */
 758         function wasReadOnlyError() {
 759                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 760         }
 761
 762         public function wasConnectionError( $errno ) {
 763                 return $errno == 17; // SQLITE_SCHEMA;
 764         }
 765
 766         protected function wasKnownStatementRollbackError() {
 767                 // ON CONFLICT ROLLBACK clauses make it so that SQLITE_CONSTRAINT error is
 768                 // ambiguous with regard to whether it implies a ROLLBACK or an ABORT happened.
 769                 // https://sqlite.org/lang_createtable.html#uniqueconst
 770                 // https://sqlite.org/lang_conflict.html
 771                 return false;
 772         }
 773
 774         public function serverIsReadOnly() {
 775                 return ( !$this->hasMemoryPath() && !is_writable( $this->dbPath ) );
 776         }
 777
 778         /**
 779          * @return bool
 780          */
 781         private function hasMemoryPath() {
 782                 return ( strpos( $this->dbPath, ':memory:' ) === 0 );
 783         }
 784
 785         /**
 786          * @return string Wikitext of a link to the server software's web site
 787          */
 788         public function getSoftwareLink() {
 789                 return "[{{int:version-db-sqlite-url}} SQLite]";
 790         }
 791
 792         /**
 793          * @return string Version information from the database
 794          */
 795         function getServerVersion() {
 796                 $ver = $this->getBindingHandle()->getAttribute( PDO::ATTR_SERVER_VERSION );
 797
 798                 return $ver;
 799         }
 800
 801         /**
 802          * Get information about a given field
 803          * Returns false if the field does not exist.
 804          *
 805          * @param string $table
 806          * @param string $field
 807          * @return SQLiteField|bool False on failure
 808          */
 809         function fieldInfo( $table, $field ) {
 810                 $tableName = $this->tableName( $table );
 811                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 812                 $res = $this->query( $sql, __METHOD__ );
 813                 foreach ( $res as $row ) {
 814                         if ( $row->name == $field ) {
 815                                 return new SQLiteField( $row, $tableName );
 816                         }
 817                 }
 818
 819                 return false;
 820         }
 821
 822         protected function doBegin( $fname = '' ) {
 823                 if ( $this->trxMode ) {
 824                         $this->query( "BEGIN {$this->trxMode}", $fname );
 825                 } else {
 826                         $this->query( 'BEGIN', $fname );
 827                 }
 828         }
 829
 830         /**
 831          * @param string $s
 832          * @return string
 833          */
 834         function strencode( $s ) {
 835                 return substr( $this->addQuotes( $s ), 1, -1 );
 836         }
 837
 838         /**
 839          * @param string $b
 840          * @return Blob
 841          */
 842         function encodeBlob( $b ) {
 843                 return new Blob( $b );
 844         }
 845
 846         /**
 847          * @param Blob|string $b
 848          * @return string
 849          */
 850         function decodeBlob( $b ) {
 851                 if ( $b instanceof Blob ) {
 852                         $b = $b->fetch();
 853                 }
 854
 855                 return $b;
 856         }
 857
 858         /**
 859          * @param string|int|null|bool|Blob $s
 860          * @return string|int
 861          */
 862         function addQuotes( $s ) {
 863                 if ( $s instanceof Blob ) {
 864                         return "x'" . bin2hex( $s->fetch() ) . "'";
 865                 } elseif ( is_bool( $s ) ) {
 866                         return (int)$s;
 867                 } elseif ( strpos( (string)$s, "\0" ) !== false ) {
 868                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 869                         // This is a known limitation of SQLite's mprintf function which PDO
 870                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 871                         // https://bugs.php.net/bug.php?id=63419
 872                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 873                         // https://bugs.php.net/bug.php?id=62361
 874                         // There is an additional bug regarding sorting this data after insert
 875                         // on older versions of sqlite shipped with ubuntu 12.04
 876                         // https://phabricator.wikimedia.org/T74367
 877                         $this->queryLogger->debug(
 878                                 __FUNCTION__ .
 879                                 ': Quoting value containing null byte. ' .
 880                                 'For consistency all binary data should have been ' .
 881                                 'first processed with self::encodeBlob()'
 882                         );
 883                         return "x'" . bin2hex( (string)$s ) . "'";
 884                 } else {
 885                         return $this->getBindingHandle()->quote( (string)$s );
 886                 }
 887         }
 888
 889         public function buildSubstring( $input, $startPosition, $length = null ) {
 890                 $this->assertBuildSubstringParams( $startPosition, $length );
 891                 $params = [ $input, $startPosition ];
 892                 if ( $length !== null ) {
 893                         $params[] = $length;
 894                 }
 895                 return 'SUBSTR(' . implode( ',', $params ) . ')';
 896         }
 897
 898         /**
 899          * @param string $field Field or column to cast
 900          * @return string
 901          * @since 1.28
 902          */
 903         public function buildStringCast( $field ) {
 904                 return 'CAST ( ' . $field . ' AS TEXT )';
 905         }
 906
 907         /**
 908          * No-op version of deadlockLoop
 909          *
 910          * @return mixed
 911          */
 912         public function deadlockLoop( /*...*/ ) {
 913                 $args = func_get_args();
 914                 $function = array_shift( $args );
 915
 916                 return $function( ...$args );
 917         }
 918
 919         /**
 920          * @param string $s
 921          * @return string
 922          */
 923         protected function replaceVars( $s ) {
 924                 $s = parent::replaceVars( $s );
 925                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 926                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 927
 928                         // binary/varbinary column type -> blob
 929                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 930                         // no such thing as unsigned
 931                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 932                         // INT -> INTEGER
 933                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 934                         // floating point types -> REAL
 935                         $s = preg_replace(
 936                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 937                                 'REAL',
 938                                 $s
 939                         );
 940                         // varchar -> TEXT
 941                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 942                         // TEXT normalization
 943                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 944                         // BLOB normalization
 945                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 946                         // BOOL -> INTEGER
 947                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 948                         // DATETIME -> TEXT
 949                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 950                         // No ENUM type
 951                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 952                         // binary collation type -> nothing
 953                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 954                         // auto_increment -> autoincrement
 955                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 956                         // No explicit options
 957                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 958                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 959                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 960                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 961                         // No truncated indexes
 962                         $s = preg_replace( '/\(\d+\)/', '', $s );
 963                         // No FULLTEXT
 964                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 965                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 966                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 967                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 968                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 969                         // INSERT IGNORE --> INSERT OR IGNORE
 970                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 971                 }
 972
 973                 return $s;
 974         }
 975
 976         public function lock( $lockName, $method, $timeout = 5 ) {
 977                 if ( !is_dir( "{$this->dbDir}/locks" ) ) { // create dir as needed
 978                         if ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) ) {
 979                                 throw new DBError( $this, "Cannot create directory \"{$this->dbDir}/locks\"." );
 980                         }
 981                 }
 982
 983                 return $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout )->isOK();
 984         }
 985
 986         public function unlock( $lockName, $method ) {
 987                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isOK();
 988         }
 989
 990         /**
 991          * Build a concatenation list to feed into a SQL query
 992          *
 993          * @param string[] $stringList
 994          * @return string
 995          */
 996         function buildConcat( $stringList ) {
 997                 return '(' . implode( ') || (', $stringList ) . ')';
 998         }
 999
1000         public function buildGroupConcatField(
1001                 $delim, $table, $field, $conds = '', $join_conds = []
1002         ) {
1003                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
1004
1005                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
1006         }
1007
1008         /**
1009          * @param string $oldName
1010          * @param string $newName
1011          * @param bool $temporary
1012          * @param string $fname
1013          * @return bool|IResultWrapper
1014          * @throws RuntimeException
1015          */
1016         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1017                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
1018                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
1019                 $obj = $this->fetchObject( $res );
1020                 if ( !$obj ) {
1021                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
1022                 }
1023                 $sql = $obj->sql;
1024                 $sql = preg_replace(
1025                         '/(?<=\W)"?' .
1026                                 preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ), '/' ) .
1027                                 '"?(?=\W)/',
1028                         $this->addIdentifierQuotes( $newName ),
1029                         $sql,
1030                         1
1031                 );
1032                 if ( $temporary ) {
1033                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
1034                                 $this->queryLogger->debug(
1035                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
1036                         } else {
1037                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
1038                         }
1039                 }
1040
1041                 $res = $this->query( $sql, $fname, self::QUERY_PSEUDO_PERMANENT );
1042
1043                 // Take over indexes
1044                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
1045                 foreach ( $indexList as $index ) {
1046                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
1047                                 continue;
1048                         }
1049
1050                         if ( $index->unique ) {
1051                                 $sql = 'CREATE UNIQUE INDEX';
1052                         } else {
1053                                 $sql = 'CREATE INDEX';
1054                         }
1055                         // Try to come up with a new index name, given indexes have database scope in SQLite
1056                         $indexName = $newName . '_' . $index->name;
1057                         $sql .= ' ' . $indexName . ' ON ' . $newName;
1058
1059                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
1060                         $fields = [];
1061                         foreach ( $indexInfo as $indexInfoRow ) {
1062                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
1063                         }
1064
1065                         $sql .= '(' . implode( ',', $fields ) . ')';
1066
1067                         $this->query( $sql );
1068                 }
1069
1070                 return $res;
1071         }
1072
1073         /**
1074          * List all tables on the database
1075          *
1076          * @param string|null $prefix Only show tables with this prefix, e.g. mw_
1077          * @param string $fname Calling function name
1078          *
1079          * @return array
1080          */
1081         function listTables( $prefix = null, $fname = __METHOD__ ) {
1082                 $result = $this->select(
1083                         'sqlite_master',
1084                         'name',
1085                         "type='table'"
1086                 );
1087
1088                 $endArray = [];
1089
1090                 foreach ( $result as $table ) {
1091                         $vars = get_object_vars( $table );
1092                         $table = array_pop( $vars );
1093
1094                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1095                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1096                                         $endArray[] = $table;
1097                                 }
1098                         }
1099                 }
1100
1101                 return $endArray;
1102         }
1103
1104         /**
1105          * Override due to no CASCADE support
1106          *
1107          * @param string $tableName
1108          * @param string $fName
1109          * @return bool|IResultWrapper
1110          * @throws DBReadOnlyError
1111          */
1112         public function dropTable( $tableName, $fName = __METHOD__ ) {
1113                 if ( !$this->tableExists( $tableName, $fName ) ) {
1114                         return false;
1115                 }
1116                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1117
1118                 return $this->query( $sql, $fName );
1119         }
1120
1121         public function setTableAliases( array $aliases ) {
1122                 parent::setTableAliases( $aliases );
1123                 foreach ( $this->tableAliases as $params ) {
1124                         if ( isset( $this->alreadyAttached[$params['dbname']] ) ) {
1125                                 continue;
1126                         }
1127                         $this->attachDatabase( $params['dbname'] );
1128                         $this->alreadyAttached[$params['dbname']] = true;
1129                 }
1130         }
1131
1132         public function resetSequenceForTable( $table, $fname = __METHOD__ ) {
1133                 $encTable = $this->addIdentifierQuotes( 'sqlite_sequence' );
1134                 $encName = $this->addQuotes( $this->tableName( $table, 'raw' ) );
1135                 $this->query( "DELETE FROM $encTable WHERE name = $encName", $fname );
1136         }
1137
1138         public function databasesAreIndependent() {
1139                 return true;
1140         }
1141
1142         /**
1143          * @return PDO
1144          */
1145         protected function getBindingHandle() {
1146                 return parent::getBindingHandle();
1147         }
1148 }
1149
1150 /**
1151  * @deprecated since 1.29
1152  */
1153 class_alias( DatabaseSqlite::class, 'DatabaseSqlite' );