includes/libs/rdbms/database/DatabaseSqlite.php

   1 <?php
   2 /**
   3  * This is the SQLite database abstraction layer.
   4  * See maintenance/sqlite/README for development notes and other specific information
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  * @ingroup Database
  23  */
  24 namespace Wikimedia\Rdbms;
  25
  26 use NullLockManager;
  27 use PDO;
  28 use PDOException;
  29 use Exception;
  30 use LockManager;
  31 use FSLockManager;
  32 use InvalidArgumentException;
  33 use RuntimeException;
  34 use stdClass;
  35
  36 /**
  37  * @ingroup Database
  38  */
  39 class DatabaseSqlite extends Database {
  40         /** @var bool Whether full text is enabled */
  41         private static $fulltextEnabled = null;
  42
  43         /** @var string|null Directory */
  44         protected $dbDir;
  45         /** @var string File name for SQLite database file */
  46         protected $dbPath;
  47         /** @var string Transaction mode */
  48         protected $trxMode;
  49
  50         /** @var int The number of rows affected as an integer */
  51         protected $lastAffectedRowCount;
  52         /** @var resource */
  53         protected $lastResultHandle;
  54
  55         /** @var PDO */
  56         protected $conn;
  57
  58         /** @var FSLockManager (hopefully on the same server as the DB) */
  59         protected $lockMgr;
  60
  61         /** @var array List of shared database already attached to this connection */
  62         private $alreadyAttached = [];
  63
  64         /**
  65          * Additional params include:
  66          *   - dbDirectory : directory containing the DB and the lock file directory
  67          *                   [defaults to $wgSQLiteDataDir]
  68          *   - dbFilePath  : use this to force the path of the DB file
  69          *   - trxMode     : one of (deferred, immediate, exclusive)
  70          * @param array $p
  71          */
  72         function __construct( array $p ) {
  73                 if ( isset( $p['dbFilePath'] ) ) {
  74                         $this->dbPath = $p['dbFilePath'];
  75                         $lockDomain = md5( $this->dbPath );
  76                         // Use "X" for things like X.sqlite and ":memory:" for RAM-only DBs
  77                         if ( !isset( $p['dbname'] ) || !strlen( $p['dbname'] ) ) {
  78                                 $p['dbname'] = preg_replace( '/\.sqlite\d?$/', '', basename( $this->dbPath ) );
  79                         }
  80                 } elseif ( isset( $p['dbDirectory'] ) ) {
  81                         $this->dbDir = $p['dbDirectory'];
  82                         $lockDomain = $p['dbname'];
  83                 } else {
  84                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
  85                 }
  86
  87                 $this->trxMode = isset( $p['trxMode'] ) ? strtoupper( $p['trxMode'] ) : null;
  88                 if ( $this->trxMode &&
  89                         !in_array( $this->trxMode, [ 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ] )
  90                 ) {
  91                         $this->trxMode = null;
  92                         $this->queryLogger->warning( "Invalid SQLite transaction mode provided." );
  93                 }
  94
  95                 if ( $this->hasProcessMemoryPath() ) {
  96                         $this->lockMgr = new NullLockManager( [ 'domain' => $lockDomain ] );
  97                 } else {
  98                         $this->lockMgr = new FSLockManager( [
  99                                 'domain' => $lockDomain,
 100                                 'lockDirectory' => is_string( $this->dbDir )
 101                                         ? "{$this->dbDir}/locks"
 102                                         : dirname( $this->dbPath ) . "/locks"
 103                         ] );
 104                 }
 105
 106                 parent::__construct( $p );
 107         }
 108
 109         protected static function getAttributes() {
 110                 return [ self::ATTR_DB_LEVEL_LOCKING => true ];
 111         }
 112
 113         /**
 114          * @param string $filename
 115          * @param array $p Options map; supports:
 116          *   - flags       : (same as __construct counterpart)
 117          *   - trxMode     : (same as __construct counterpart)
 118          *   - dbDirectory : (same as __construct counterpart)
 119          * @return DatabaseSqlite
 120          * @since 1.25
 121          */
 122         public static function newStandaloneInstance( $filename, array $p = [] ) {
 123                 $p['dbFilePath'] = $filename;
 124                 $p['schema'] = null;
 125                 $p['tablePrefix'] = '';
 126                 /** @var DatabaseSqlite $db */
 127                 $db = Database::factory( 'sqlite', $p );
 128
 129                 return $db;
 130         }
 131
 132         protected function doInitConnection() {
 133                 if ( $this->dbPath !== null ) {
 134                         // Standalone .sqlite file mode.
 135                         $this->openFile(
 136                                 $this->dbPath,
 137                                 $this->connectionParams['dbname'],
 138                                 $this->connectionParams['tablePrefix']
 139                         );
 140                 } elseif ( $this->dbDir !== null ) {
 141                         // Stock wiki mode using standard file names per DB
 142                         if ( strlen( $this->connectionParams['dbname'] ) ) {
 143                                 $this->open(
 144                                         $this->connectionParams['host'],
 145                                         $this->connectionParams['user'],
 146                                         $this->connectionParams['password'],
 147                                         $this->connectionParams['dbname'],
 148                                         $this->connectionParams['schema'],
 149                                         $this->connectionParams['tablePrefix']
 150                                 );
 151                         } else {
 152                                 // Caller will manually call open() later?
 153                                 $this->connLogger->debug( __METHOD__ . ': no database opened.' );
 154                         }
 155                 } else {
 156                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
 157                 }
 158         }
 159
 160         /**
 161          * @return string
 162          */
 163         function getType() {
 164                 return 'sqlite';
 165         }
 166
 167         /**
 168          * @todo Check if it should be true like parent class
 169          *
 170          * @return bool
 171          */
 172         function implicitGroupby() {
 173                 return false;
 174         }
 175
 176         protected function open( $server, $user, $pass, $dbName, $schema, $tablePrefix ) {
 177                 $this->close();
 178
 179                 if ( $schema !== null ) {
 180                         throw new DBExpectedError( $this, __CLASS__ . ": domain schemas are not supported." );
 181                 }
 182
 183                 // Only $dbName is used, the other parameters are irrelevant for SQLite databases
 184                 $this->openFile( self::generateFileName( $this->dbDir, $dbName ), $dbName, $tablePrefix );
 185         }
 186
 187         /**
 188          * Opens a database file
 189          *
 190          * @param string $fileName
 191          * @param string $dbName
 192          * @param string $tablePrefix
 193          * @throws DBConnectionError
 194          */
 195         protected function openFile( $fileName, $dbName, $tablePrefix ) {
 196                 if ( !$this->hasProcessMemoryPath() && !is_readable( $fileName ) ) {
 197                         $error = "SQLite database file not readable";
 198                         $this->connLogger->error(
 199                                 "Error connecting to {db_server}: {error}",
 200                                 $this->getLogContext( [ 'method' => __METHOD__, 'error' => $error ] )
 201                         );
 202                         throw new DBConnectionError( $this, $error );
 203                 }
 204
 205                 $this->dbPath = $fileName;
 206                 try {
 207                         $this->conn = new PDO(
 208                                 "sqlite:$fileName",
 209                                 '',
 210                                 '',
 211                                 [ PDO::ATTR_PERSISTENT => (bool)( $this->flags & self::DBO_PERSISTENT ) ]
 212                         );
 213                         $error = 'unknown error';
 214                 } catch ( PDOException $e ) {
 215                         $error = $e->getMessage();
 216                 }
 217
 218                 if ( !$this->conn ) {
 219                         $this->connLogger->error(
 220                                 "Error connecting to {db_server}: {error}",
 221                                 $this->getLogContext( [ 'method' => __METHOD__, 'error' => $error ] )
 222                         );
 223                         throw new DBConnectionError( $this, $error );
 224                 }
 225
 226                 try {
 227                         // Set error codes only, don't raise exceptions
 228                         $this->conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 229
 230                         $this->currentDomain = new DatabaseDomain( $dbName, null, $tablePrefix );
 231
 232                         $flags = self::QUERY_IGNORE_DBO_TRX | self::QUERY_NO_RETRY;
 233                         // Enforce LIKE to be case sensitive, just like MySQL
 234                         $this->query( 'PRAGMA case_sensitive_like = 1', __METHOD__, $flags );
 235                         // Apply an optimizations or requirements regarding fsync() usage
 236                         $sync = $this->connectionVariables['synchronous'] ?? null;
 237                         if ( in_array( $sync, [ 'EXTRA', 'FULL', 'NORMAL', 'OFF' ], true ) ) {
 238                                 $this->query( "PRAGMA synchronous = $sync", __METHOD__ );
 239                         }
 240                 } catch ( Exception $e ) {
 241                         // Connection was not fully initialized and is not safe for use
 242                         $this->conn = false;
 243                         throw $e;
 244                 }
 245         }
 246
 247         /**
 248          * @return string SQLite DB file path
 249          * @since 1.25
 250          */
 251         public function getDbFilePath() {
 252                 return $this->dbPath;
 253         }
 254
 255         /**
 256          * Does not actually close the connection, just destroys the reference for GC to do its work
 257          * @return bool
 258          */
 259         protected function closeConnection() {
 260                 $this->conn = null;
 261
 262                 return true;
 263         }
 264
 265         /**
 266          * Generates a database file name. Explicitly public for installer.
 267          * @param string $dir Directory where database resides
 268          * @param string $dbName Database name
 269          * @return string
 270          */
 271         public static function generateFileName( $dir, $dbName ) {
 272                 return "$dir/$dbName.sqlite";
 273         }
 274
 275         /**
 276          * Check if the searchindext table is FTS enabled.
 277          * @return bool False if not enabled.
 278          */
 279         public function checkForEnabledSearch() {
 280                 if ( self::$fulltextEnabled === null ) {
 281                         self::$fulltextEnabled = false;
 282                         $table = $this->tableName( 'searchindex' );
 283                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 284                         if ( $res ) {
 285                                 $row = $res->fetchRow();
 286                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 287                         }
 288                 }
 289
 290                 return self::$fulltextEnabled;
 291         }
 292
 293         /**
 294          * Returns version of currently supported SQLite fulltext search module or false if none present.
 295          * @return string
 296          */
 297         static function getFulltextSearchModule() {
 298                 static $cachedResult = null;
 299                 if ( $cachedResult !== null ) {
 300                         return $cachedResult;
 301                 }
 302                 $cachedResult = false;
 303                 $table = 'dummy_search_test';
 304
 305                 $db = self::newStandaloneInstance( ':memory:' );
 306                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 307                         $cachedResult = 'FTS3';
 308                 }
 309                 $db->close();
 310
 311                 return $cachedResult;
 312         }
 313
 314         /**
 315          * Attaches external database to our connection, see https://sqlite.org/lang_attach.html
 316          * for details.
 317          *
 318          * @param string $name Database name to be used in queries like
 319          *   SELECT foo FROM dbname.table
 320          * @param bool|string $file Database file name. If omitted, will be generated
 321          *   using $name and configured data directory
 322          * @param string $fname Calling function name
 323          * @return IResultWrapper
 324          */
 325         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 326                 if ( !$file ) {
 327                         $file = self::generateFileName( $this->dbDir, $name );
 328                 }
 329                 $file = $this->addQuotes( $file );
 330
 331                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 332         }
 333
 334         protected function isWriteQuery( $sql ) {
 335                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 336         }
 337
 338         protected function isTransactableQuery( $sql ) {
 339                 return parent::isTransactableQuery( $sql ) && !in_array(
 340                         $this->getQueryVerb( $sql ),
 341                         [ 'ATTACH', 'PRAGMA' ],
 342                         true
 343                 );
 344         }
 345
 346         /**
 347          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 348          *
 349          * @param string $sql
 350          * @return bool|IResultWrapper
 351          */
 352         protected function doQuery( $sql ) {
 353                 $res = $this->getBindingHandle()->query( $sql );
 354                 if ( $res === false ) {
 355                         return false;
 356                 }
 357
 358                 $resource = ResultWrapper::unwrap( $res );
 359                 $this->lastAffectedRowCount = $resource->rowCount();
 360                 $res = new ResultWrapper( $this, $resource->fetchAll() );
 361
 362                 return $res;
 363         }
 364
 365         /**
 366          * @param IResultWrapper|mixed $res
 367          */
 368         function freeResult( $res ) {
 369                 if ( $res instanceof ResultWrapper ) {
 370                         $res->free();
 371                 }
 372         }
 373
 374         /**
 375          * @param IResultWrapper|array $res
 376          * @return stdClass|bool
 377          */
 378         function fetchObject( $res ) {
 379                 $resource =& ResultWrapper::unwrap( $res );
 380
 381                 $cur = current( $resource );
 382                 if ( is_array( $cur ) ) {
 383                         next( $resource );
 384                         $obj = new stdClass;
 385                         foreach ( $cur as $k => $v ) {
 386                                 if ( !is_numeric( $k ) ) {
 387                                         $obj->$k = $v;
 388                                 }
 389                         }
 390
 391                         return $obj;
 392                 }
 393
 394                 return false;
 395         }
 396
 397         /**
 398          * @param IResultWrapper|mixed $res
 399          * @return array|bool
 400          */
 401         function fetchRow( $res ) {
 402                 $resource =& ResultWrapper::unwrap( $res );
 403                 $cur = current( $resource );
 404                 if ( is_array( $cur ) ) {
 405                         next( $resource );
 406
 407                         return $cur;
 408                 }
 409
 410                 return false;
 411         }
 412
 413         /**
 414          * The PDO::Statement class implements the array interface so count() will work
 415          *
 416          * @param IResultWrapper|array|false $res
 417          * @return int
 418          */
 419         function numRows( $res ) {
 420                 // false does not implement Countable
 421                 $resource = ResultWrapper::unwrap( $res );
 422
 423                 return is_array( $resource ) ? count( $resource ) : 0;
 424         }
 425
 426         /**
 427          * @param IResultWrapper $res
 428          * @return int
 429          */
 430         function numFields( $res ) {
 431                 $resource = ResultWrapper::unwrap( $res );
 432                 if ( is_array( $resource ) && count( $resource ) > 0 ) {
 433                         // The size of the result array is twice the number of fields. (T67578)
 434                         return count( $resource[0] ) / 2;
 435                 } else {
 436                         // If the result is empty return 0
 437                         return 0;
 438                 }
 439         }
 440
 441         /**
 442          * @param IResultWrapper $res
 443          * @param int $n
 444          * @return bool
 445          */
 446         function fieldName( $res, $n ) {
 447                 $resource = ResultWrapper::unwrap( $res );
 448                 if ( is_array( $resource ) ) {
 449                         $keys = array_keys( $resource[0] );
 450
 451                         return $keys[$n];
 452                 }
 453
 454                 return false;
 455         }
 456
 457         /**
 458          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 459          *
 460          * @param string $name
 461          * @param string $format
 462          * @return string
 463          */
 464         function tableName( $name, $format = 'quoted' ) {
 465                 // table names starting with sqlite_ are reserved
 466                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 467                         return $name;
 468                 }
 469
 470                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 471         }
 472
 473         /**
 474          * This must be called after nextSequenceVal
 475          *
 476          * @return int
 477          */
 478         function insertId() {
 479                 // PDO::lastInsertId yields a string :(
 480                 return intval( $this->getBindingHandle()->lastInsertId() );
 481         }
 482
 483         /**
 484          * @param IResultWrapper|array $res
 485          * @param int $row
 486          */
 487         function dataSeek( $res, $row ) {
 488                 $resource =& ResultWrapper::unwrap( $res );
 489                 reset( $resource );
 490                 if ( $row > 0 ) {
 491                         for ( $i = 0; $i < $row; $i++ ) {
 492                                 next( $resource );
 493                         }
 494                 }
 495         }
 496
 497         /**
 498          * @return string
 499          */
 500         function lastError() {
 501                 if ( !is_object( $this->conn ) ) {
 502                         return "Cannot return last error, no db connection";
 503                 }
 504                 $e = $this->conn->errorInfo();
 505
 506                 return $e[2] ?? '';
 507         }
 508
 509         /**
 510          * @return string
 511          */
 512         function lastErrno() {
 513                 if ( !is_object( $this->conn ) ) {
 514                         return "Cannot return last error, no db connection";
 515                 } else {
 516                         $info = $this->conn->errorInfo();
 517
 518                         return $info[1];
 519                 }
 520         }
 521
 522         /**
 523          * @return int
 524          */
 525         protected function fetchAffectedRowCount() {
 526                 return $this->lastAffectedRowCount;
 527         }
 528
 529         function tableExists( $table, $fname = __METHOD__ ) {
 530                 $tableRaw = $this->tableName( $table, 'raw' );
 531                 if ( isset( $this->sessionTempTables[$tableRaw] ) ) {
 532                         return true; // already known to exist
 533                 }
 534
 535                 $encTable = $this->addQuotes( $tableRaw );
 536                 $res = $this->query(
 537                         "SELECT 1 FROM sqlite_master WHERE type='table' AND name=$encTable" );
 538
 539                 return $res->numRows() ? true : false;
 540         }
 541
 542         /**
 543          * Returns information about an index
 544          * Returns false if the index does not exist
 545          * - if errors are explicitly ignored, returns NULL on failure
 546          *
 547          * @param string $table
 548          * @param string $index
 549          * @param string $fname
 550          * @return array|false
 551          */
 552         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 553                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 554                 $res = $this->query( $sql, $fname );
 555                 if ( !$res || $res->numRows() == 0 ) {
 556                         return false;
 557                 }
 558                 $info = [];
 559                 foreach ( $res as $row ) {
 560                         $info[] = $row->name;
 561                 }
 562
 563                 return $info;
 564         }
 565
 566         /**
 567          * @param string $table
 568          * @param string $index
 569          * @param string $fname
 570          * @return bool|null
 571          */
 572         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 573                 $row = $this->selectRow( 'sqlite_master', '*',
 574                         [
 575                                 'type' => 'index',
 576                                 'name' => $this->indexName( $index ),
 577                         ], $fname );
 578                 if ( !$row || !isset( $row->sql ) ) {
 579                         return null;
 580                 }
 581
 582                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 583                 $indexPos = strpos( $row->sql, 'INDEX' );
 584                 if ( $indexPos === false ) {
 585                         return null;
 586                 }
 587                 $firstPart = substr( $row->sql, 0, $indexPos );
 588                 $options = explode( ' ', $firstPart );
 589
 590                 return in_array( 'UNIQUE', $options );
 591         }
 592
 593         /**
 594          * Filter the options used in SELECT statements
 595          *
 596          * @param array $options
 597          * @return array
 598          */
 599         function makeSelectOptions( $options ) {
 600                 foreach ( $options as $k => $v ) {
 601                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 602                                 $options[$k] = '';
 603                         }
 604                 }
 605
 606                 return parent::makeSelectOptions( $options );
 607         }
 608
 609         /**
 610          * @param array $options
 611          * @return array
 612          */
 613         protected function makeUpdateOptionsArray( $options ) {
 614                 $options = parent::makeUpdateOptionsArray( $options );
 615                 $options = self::fixIgnore( $options );
 616
 617                 return $options;
 618         }
 619
 620         /**
 621          * @param array $options
 622          * @return array
 623          */
 624         static function fixIgnore( $options ) {
 625                 # SQLite uses OR IGNORE not just IGNORE
 626                 foreach ( $options as $k => $v ) {
 627                         if ( $v == 'IGNORE' ) {
 628                                 $options[$k] = 'OR IGNORE';
 629                         }
 630                 }
 631
 632                 return $options;
 633         }
 634
 635         /**
 636          * @param array $options
 637          * @return string
 638          */
 639         function makeInsertOptions( $options ) {
 640                 $options = self::fixIgnore( $options );
 641
 642                 return parent::makeInsertOptions( $options );
 643         }
 644
 645         /**
 646          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 647          * @param string $table
 648          * @param array $a
 649          * @param string $fname
 650          * @param array $options
 651          * @return bool
 652          */
 653         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 654                 if ( !count( $a ) ) {
 655                         return true;
 656                 }
 657
 658                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 659                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 660                         $affectedRowCount = 0;
 661                         try {
 662                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 663                                 foreach ( $a as $v ) {
 664                                         parent::insert( $table, $v, "$fname/multi-row", $options );
 665                                         $affectedRowCount += $this->affectedRows();
 666                                 }
 667                                 $this->endAtomic( $fname );
 668                         } catch ( Exception $e ) {
 669                                 $this->cancelAtomic( $fname );
 670                                 throw $e;
 671                         }
 672                         $this->affectedRowCount = $affectedRowCount;
 673                 } else {
 674                         parent::insert( $table, $a, "$fname/single-row", $options );
 675                 }
 676
 677                 return true;
 678         }
 679
 680         /**
 681          * @param string $table
 682          * @param array $uniqueIndexes Unused
 683          * @param string|array $rows
 684          * @param string $fname
 685          */
 686         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 687                 if ( !count( $rows ) ) {
 688                         return;
 689                 }
 690
 691                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 692                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 693                         $affectedRowCount = 0;
 694                         try {
 695                                 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
 696                                 foreach ( $rows as $v ) {
 697                                         $this->nativeReplace( $table, $v, "$fname/multi-row" );
 698                                         $affectedRowCount += $this->affectedRows();
 699                                 }
 700                                 $this->endAtomic( $fname );
 701                         } catch ( Exception $e ) {
 702                                 $this->cancelAtomic( $fname );
 703                                 throw $e;
 704                         }
 705                         $this->affectedRowCount = $affectedRowCount;
 706                 } else {
 707                         $this->nativeReplace( $table, $rows, "$fname/single-row" );
 708                 }
 709         }
 710
 711         /**
 712          * Returns the size of a text field, or -1 for "unlimited"
 713          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 714          *
 715          * @param string $table
 716          * @param string $field
 717          * @return int
 718          */
 719         function textFieldSize( $table, $field ) {
 720                 return -1;
 721         }
 722
 723         /**
 724          * @return bool
 725          */
 726         function unionSupportsOrderAndLimit() {
 727                 return false;
 728         }
 729
 730         /**
 731          * @param string[] $sqls
 732          * @param bool $all Whether to "UNION ALL" or not
 733          * @return string
 734          */
 735         function unionQueries( $sqls, $all ) {
 736                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 737
 738                 return implode( $glue, $sqls );
 739         }
 740
 741         /**
 742          * @return bool
 743          */
 744         function wasDeadlock() {
 745                 return $this->lastErrno() == 5; // SQLITE_BUSY
 746         }
 747
 748         /**
 749          * @return bool
 750          */
 751         function wasReadOnlyError() {
 752                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 753         }
 754
 755         public function wasConnectionError( $errno ) {
 756                 return $errno == 17; // SQLITE_SCHEMA;
 757         }
 758
 759         protected function wasKnownStatementRollbackError() {
 760                 // ON CONFLICT ROLLBACK clauses make it so that SQLITE_CONSTRAINT error is
 761                 // ambiguous with regard to whether it implies a ROLLBACK or an ABORT happened.
 762                 // https://sqlite.org/lang_createtable.html#uniqueconst
 763                 // https://sqlite.org/lang_conflict.html
 764                 return false;
 765         }
 766
 767         public function serverIsReadOnly() {
 768                 return ( !$this->hasProcessMemoryPath() && !is_writable( $this->dbPath ) );
 769         }
 770
 771         /**
 772          * @return bool
 773          */
 774         private function hasProcessMemoryPath() {
 775                 return ( strpos( $this->dbPath, ':memory:' ) === 0 );
 776         }
 777
 778         /**
 779          * @return string Wikitext of a link to the server software's web site
 780          */
 781         public function getSoftwareLink() {
 782                 return "[{{int:version-db-sqlite-url}} SQLite]";
 783         }
 784
 785         /**
 786          * @return string Version information from the database
 787          */
 788         function getServerVersion() {
 789                 $ver = $this->getBindingHandle()->getAttribute( PDO::ATTR_SERVER_VERSION );
 790
 791                 return $ver;
 792         }
 793
 794         /**
 795          * Get information about a given field
 796          * Returns false if the field does not exist.
 797          *
 798          * @param string $table
 799          * @param string $field
 800          * @return SQLiteField|bool False on failure
 801          */
 802         function fieldInfo( $table, $field ) {
 803                 $tableName = $this->tableName( $table );
 804                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 805                 $res = $this->query( $sql, __METHOD__ );
 806                 foreach ( $res as $row ) {
 807                         if ( $row->name == $field ) {
 808                                 return new SQLiteField( $row, $tableName );
 809                         }
 810                 }
 811
 812                 return false;
 813         }
 814
 815         protected function doBegin( $fname = '' ) {
 816                 if ( $this->trxMode ) {
 817                         $this->query( "BEGIN {$this->trxMode}", $fname );
 818                 } else {
 819                         $this->query( 'BEGIN', $fname );
 820                 }
 821         }
 822
 823         /**
 824          * @param string $s
 825          * @return string
 826          */
 827         function strencode( $s ) {
 828                 return substr( $this->addQuotes( $s ), 1, -1 );
 829         }
 830
 831         /**
 832          * @param string $b
 833          * @return Blob
 834          */
 835         function encodeBlob( $b ) {
 836                 return new Blob( $b );
 837         }
 838
 839         /**
 840          * @param Blob|string $b
 841          * @return string
 842          */
 843         function decodeBlob( $b ) {
 844                 if ( $b instanceof Blob ) {
 845                         $b = $b->fetch();
 846                 }
 847
 848                 return $b;
 849         }
 850
 851         /**
 852          * @param string|int|null|bool|Blob $s
 853          * @return string|int
 854          */
 855         function addQuotes( $s ) {
 856                 if ( $s instanceof Blob ) {
 857                         return "x'" . bin2hex( $s->fetch() ) . "'";
 858                 } elseif ( is_bool( $s ) ) {
 859                         return (int)$s;
 860                 } elseif ( strpos( (string)$s, "\0" ) !== false ) {
 861                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 862                         // This is a known limitation of SQLite's mprintf function which PDO
 863                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 864                         // https://bugs.php.net/bug.php?id=63419
 865                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 866                         // https://bugs.php.net/bug.php?id=62361
 867                         // There is an additional bug regarding sorting this data after insert
 868                         // on older versions of sqlite shipped with ubuntu 12.04
 869                         // https://phabricator.wikimedia.org/T74367
 870                         $this->queryLogger->debug(
 871                                 __FUNCTION__ .
 872                                 ': Quoting value containing null byte. ' .
 873                                 'For consistency all binary data should have been ' .
 874                                 'first processed with self::encodeBlob()'
 875                         );
 876                         return "x'" . bin2hex( (string)$s ) . "'";
 877                 } else {
 878                         return $this->getBindingHandle()->quote( (string)$s );
 879                 }
 880         }
 881
 882         public function buildSubstring( $input, $startPosition, $length = null ) {
 883                 $this->assertBuildSubstringParams( $startPosition, $length );
 884                 $params = [ $input, $startPosition ];
 885                 if ( $length !== null ) {
 886                         $params[] = $length;
 887                 }
 888                 return 'SUBSTR(' . implode( ',', $params ) . ')';
 889         }
 890
 891         /**
 892          * @param string $field Field or column to cast
 893          * @return string
 894          * @since 1.28
 895          */
 896         public function buildStringCast( $field ) {
 897                 return 'CAST ( ' . $field . ' AS TEXT )';
 898         }
 899
 900         /**
 901          * No-op version of deadlockLoop
 902          *
 903          * @return mixed
 904          */
 905         public function deadlockLoop( /*...*/ ) {
 906                 $args = func_get_args();
 907                 $function = array_shift( $args );
 908
 909                 return $function( ...$args );
 910         }
 911
 912         /**
 913          * @param string $s
 914          * @return string
 915          */
 916         protected function replaceVars( $s ) {
 917                 $s = parent::replaceVars( $s );
 918                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 919                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 920
 921                         // binary/varbinary column type -> blob
 922                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 923                         // no such thing as unsigned
 924                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 925                         // INT -> INTEGER
 926                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 927                         // floating point types -> REAL
 928                         $s = preg_replace(
 929                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 930                                 'REAL',
 931                                 $s
 932                         );
 933                         // varchar -> TEXT
 934                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 935                         // TEXT normalization
 936                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 937                         // BLOB normalization
 938                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 939                         // BOOL -> INTEGER
 940                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 941                         // DATETIME -> TEXT
 942                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 943                         // No ENUM type
 944                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 945                         // binary collation type -> nothing
 946                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 947                         // auto_increment -> autoincrement
 948                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 949                         // No explicit options
 950                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 951                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 952                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 953                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 954                         // No truncated indexes
 955                         $s = preg_replace( '/\(\d+\)/', '', $s );
 956                         // No FULLTEXT
 957                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 958                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 959                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 960                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 961                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 962                         // INSERT IGNORE --> INSERT OR IGNORE
 963                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 964                 }
 965
 966                 return $s;
 967         }
 968
 969         public function lock( $lockName, $method, $timeout = 5 ) {
 970                 // Give better error message for permission problems than just returning false
 971                 if (
 972                         !is_dir( "{$this->dbDir}/locks" ) &&
 973                         ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) )
 974                 ) {
 975                         throw new DBError( $this, "Cannot create directory \"{$this->dbDir}/locks\"." );
 976                 }
 977
 978                 return $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout )->isOK();
 979         }
 980
 981         public function unlock( $lockName, $method ) {
 982                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isGood();
 983         }
 984
 985         /**
 986          * Build a concatenation list to feed into a SQL query
 987          *
 988          * @param string[] $stringList
 989          * @return string
 990          */
 991         function buildConcat( $stringList ) {
 992                 return '(' . implode( ') || (', $stringList ) . ')';
 993         }
 994
 995         public function buildGroupConcatField(
 996                 $delim, $table, $field, $conds = '', $join_conds = []
 997         ) {
 998                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 999
1000                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
1001         }
1002
1003         /**
1004          * @param string $oldName
1005          * @param string $newName
1006          * @param bool $temporary
1007          * @param string $fname
1008          * @return bool|IResultWrapper
1009          * @throws RuntimeException
1010          */
1011         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1012                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
1013                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
1014                 $obj = $this->fetchObject( $res );
1015                 if ( !$obj ) {
1016                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
1017                 }
1018                 $sql = $obj->sql;
1019                 $sql = preg_replace(
1020                         '/(?<=\W)"?' .
1021                                 preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ), '/' ) .
1022                                 '"?(?=\W)/',
1023                         $this->addIdentifierQuotes( $newName ),
1024                         $sql,
1025                         1
1026                 );
1027                 if ( $temporary ) {
1028                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
1029                                 $this->queryLogger->debug(
1030                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
1031                         } else {
1032                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
1033                         }
1034                 }
1035
1036                 $res = $this->query( $sql, $fname, self::QUERY_PSEUDO_PERMANENT );
1037
1038                 // Take over indexes
1039                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
1040                 foreach ( $indexList as $index ) {
1041                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
1042                                 continue;
1043                         }
1044
1045                         if ( $index->unique ) {
1046                                 $sql = 'CREATE UNIQUE INDEX';
1047                         } else {
1048                                 $sql = 'CREATE INDEX';
1049                         }
1050                         // Try to come up with a new index name, given indexes have database scope in SQLite
1051                         $indexName = $newName . '_' . $index->name;
1052                         $sql .= ' ' . $indexName . ' ON ' . $newName;
1053
1054                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
1055                         $fields = [];
1056                         foreach ( $indexInfo as $indexInfoRow ) {
1057                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
1058                         }
1059
1060                         $sql .= '(' . implode( ',', $fields ) . ')';
1061
1062                         $this->query( $sql );
1063                 }
1064
1065                 return $res;
1066         }
1067
1068         /**
1069          * List all tables on the database
1070          *
1071          * @param string|null $prefix Only show tables with this prefix, e.g. mw_
1072          * @param string $fname Calling function name
1073          *
1074          * @return array
1075          */
1076         function listTables( $prefix = null, $fname = __METHOD__ ) {
1077                 $result = $this->select(
1078                         'sqlite_master',
1079                         'name',
1080                         "type='table'"
1081                 );
1082
1083                 $endArray = [];
1084
1085                 foreach ( $result as $table ) {
1086                         $vars = get_object_vars( $table );
1087                         $table = array_pop( $vars );
1088
1089                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1090                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1091                                         $endArray[] = $table;
1092                                 }
1093                         }
1094                 }
1095
1096                 return $endArray;
1097         }
1098
1099         /**
1100          * Override due to no CASCADE support
1101          *
1102          * @param string $tableName
1103          * @param string $fName
1104          * @return bool|IResultWrapper
1105          * @throws DBReadOnlyError
1106          */
1107         public function dropTable( $tableName, $fName = __METHOD__ ) {
1108                 if ( !$this->tableExists( $tableName, $fName ) ) {
1109                         return false;
1110                 }
1111                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1112
1113                 return $this->query( $sql, $fName );
1114         }
1115
1116         public function setTableAliases( array $aliases ) {
1117                 parent::setTableAliases( $aliases );
1118                 foreach ( $this->tableAliases as $params ) {
1119                         if ( isset( $this->alreadyAttached[$params['dbname']] ) ) {
1120                                 continue;
1121                         }
1122                         $this->attachDatabase( $params['dbname'] );
1123                         $this->alreadyAttached[$params['dbname']] = true;
1124                 }
1125         }
1126
1127         public function resetSequenceForTable( $table, $fname = __METHOD__ ) {
1128                 $encTable = $this->addIdentifierQuotes( 'sqlite_sequence' );
1129                 $encName = $this->addQuotes( $this->tableName( $table, 'raw' ) );
1130                 $this->query( "DELETE FROM $encTable WHERE name = $encName", $fname );
1131         }
1132
1133         public function databasesAreIndependent() {
1134                 return true;
1135         }
1136
1137         /**
1138          * @return PDO
1139          */
1140         protected function getBindingHandle() {
1141                 return parent::getBindingHandle();
1142         }
1143 }
1144
1145 /**
1146  * @deprecated since 1.29
1147  */
1148 class_alias( DatabaseSqlite::class, 'DatabaseSqlite' );