includes/libs/rdbms/database/DatabaseSqlite.php

   1 <?php
   2 /**
   3  * This is the SQLite database abstraction layer.
   4  * See maintenance/sqlite/README for development notes and other specific information
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  * @ingroup Database
  23  */
  24 namespace Wikimedia\Rdbms;
  25
  26 use PDO;
  27 use PDOException;
  28 use LockManager;
  29 use FSLockManager;
  30 use InvalidArgumentException;
  31 use RuntimeException;
  32 use stdClass;
  33
  34 /**
  35  * @ingroup Database
  36  */
  37 class DatabaseSqlite extends Database {
  38         /** @var bool Whether full text is enabled */
  39         private static $fulltextEnabled = null;
  40
  41         /** @var string Directory */
  42         protected $dbDir;
  43         /** @var string File name for SQLite database file */
  44         protected $dbPath;
  45         /** @var string Transaction mode */
  46         protected $trxMode;
  47
  48         /** @var int The number of rows affected as an integer */
  49         protected $mAffectedRows;
  50         /** @var resource */
  51         protected $mLastResult;
  52
  53         /** @var PDO */
  54         protected $mConn;
  55
  56         /** @var FSLockManager (hopefully on the same server as the DB) */
  57         protected $lockMgr;
  58
  59         /**
  60          * Additional params include:
  61          *   - dbDirectory : directory containing the DB and the lock file directory
  62          *                   [defaults to $wgSQLiteDataDir]
  63          *   - dbFilePath  : use this to force the path of the DB file
  64          *   - trxMode     : one of (deferred, immediate, exclusive)
  65          * @param array $p
  66          */
  67         function __construct( array $p ) {
  68                 if ( isset( $p['dbFilePath'] ) ) {
  69                         parent::__construct( $p );
  70                         // Standalone .sqlite file mode.
  71                         // Super doesn't open when $user is false, but we can work with $dbName,
  72                         // which is derived from the file path in this case.
  73                         $this->openFile( $p['dbFilePath'] );
  74                         $lockDomain = md5( $p['dbFilePath'] );
  75                 } elseif ( !isset( $p['dbDirectory'] ) ) {
  76                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
  77                 } else {
  78                         $this->dbDir = $p['dbDirectory'];
  79                         $this->mDBname = $p['dbname'];
  80                         $lockDomain = $this->mDBname;
  81                         // Stock wiki mode using standard file names per DB.
  82                         parent::__construct( $p );
  83                         // Super doesn't open when $user is false, but we can work with $dbName
  84                         if ( $p['dbname'] && !$this->isOpen() ) {
  85                                 if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  86                                         $done = [];
  87                                         foreach ( $this->tableAliases as $params ) {
  88                                                 if ( isset( $done[$params['dbname']] ) ) {
  89                                                         continue;
  90                                                 }
  91                                                 $this->attachDatabase( $params['dbname'] );
  92                                                 $done[$params['dbname']] = 1;
  93                                         }
  94                                 }
  95                         }
  96                 }
  97
  98                 $this->trxMode = isset( $p['trxMode'] ) ? strtoupper( $p['trxMode'] ) : null;
  99                 if ( $this->trxMode &&
 100                         !in_array( $this->trxMode, [ 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ] )
 101                 ) {
 102                         $this->trxMode = null;
 103                         $this->queryLogger->warning( "Invalid SQLite transaction mode provided." );
 104                 }
 105
 106                 $this->lockMgr = new FSLockManager( [
 107                         'domain' => $lockDomain,
 108                         'lockDirectory' => "{$this->dbDir}/locks"
 109                 ] );
 110         }
 111
 112         /**
 113          * @param string $filename
 114          * @param array $p Options map; supports:
 115          *   - flags       : (same as __construct counterpart)
 116          *   - trxMode     : (same as __construct counterpart)
 117          *   - dbDirectory : (same as __construct counterpart)
 118          * @return DatabaseSqlite
 119          * @since 1.25
 120          */
 121         public static function newStandaloneInstance( $filename, array $p = [] ) {
 122                 $p['dbFilePath'] = $filename;
 123                 $p['schema'] = false;
 124                 $p['tablePrefix'] = '';
 125                 /** @var DatabaseSqlite $db */
 126                 $db = Database::factory( 'sqlite', $p );
 127
 128                 return $db;
 129         }
 130
 131         /**
 132          * @return string
 133          */
 134         function getType() {
 135                 return 'sqlite';
 136         }
 137
 138         /**
 139          * @todo Check if it should be true like parent class
 140          *
 141          * @return bool
 142          */
 143         function implicitGroupby() {
 144                 return false;
 145         }
 146
 147         /** Open an SQLite database and return a resource handle to it
 148          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
 149          *
 150          * @param string $server
 151          * @param string $user
 152          * @param string $pass
 153          * @param string $dbName
 154          *
 155          * @throws DBConnectionError
 156          * @return bool
 157          */
 158         function open( $server, $user, $pass, $dbName ) {
 159                 $this->close();
 160                 $fileName = self::generateFileName( $this->dbDir, $dbName );
 161                 if ( !is_readable( $fileName ) ) {
 162                         $this->mConn = false;
 163                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 164                 }
 165                 $this->openFile( $fileName );
 166
 167                 return (bool)$this->mConn;
 168         }
 169
 170         /**
 171          * Opens a database file
 172          *
 173          * @param string $fileName
 174          * @throws DBConnectionError
 175          * @return PDO|bool SQL connection or false if failed
 176          */
 177         protected function openFile( $fileName ) {
 178                 $err = false;
 179
 180                 $this->dbPath = $fileName;
 181                 try {
 182                         if ( $this->mFlags & self::DBO_PERSISTENT ) {
 183                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 184                                         [ PDO::ATTR_PERSISTENT => true ] );
 185                         } else {
 186                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 187                         }
 188                 } catch ( PDOException $e ) {
 189                         $err = $e->getMessage();
 190                 }
 191
 192                 if ( !$this->mConn ) {
 193                         $this->queryLogger->debug( "DB connection error: $err\n" );
 194                         throw new DBConnectionError( $this, $err );
 195                 }
 196
 197                 $this->mOpened = !!$this->mConn;
 198                 if ( $this->mOpened ) {
 199                         # Set error codes only, don't raise exceptions
 200                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 201                         # Enforce LIKE to be case sensitive, just like MySQL
 202                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 203
 204                         return $this->mConn;
 205                 }
 206
 207                 return false;
 208         }
 209
 210         public function selectDB( $db ) {
 211                 return false; // doesn't make sense
 212         }
 213
 214         /**
 215          * @return string SQLite DB file path
 216          * @since 1.25
 217          */
 218         public function getDbFilePath() {
 219                 return $this->dbPath;
 220         }
 221
 222         /**
 223          * Does not actually close the connection, just destroys the reference for GC to do its work
 224          * @return bool
 225          */
 226         protected function closeConnection() {
 227                 $this->mConn = null;
 228
 229                 return true;
 230         }
 231
 232         /**
 233          * Generates a database file name. Explicitly public for installer.
 234          * @param string $dir Directory where database resides
 235          * @param string $dbName Database name
 236          * @return string
 237          */
 238         public static function generateFileName( $dir, $dbName ) {
 239                 return "$dir/$dbName.sqlite";
 240         }
 241
 242         /**
 243          * Check if the searchindext table is FTS enabled.
 244          * @return bool False if not enabled.
 245          */
 246         function checkForEnabledSearch() {
 247                 if ( self::$fulltextEnabled === null ) {
 248                         self::$fulltextEnabled = false;
 249                         $table = $this->tableName( 'searchindex' );
 250                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 251                         if ( $res ) {
 252                                 $row = $res->fetchRow();
 253                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 254                         }
 255                 }
 256
 257                 return self::$fulltextEnabled;
 258         }
 259
 260         /**
 261          * Returns version of currently supported SQLite fulltext search module or false if none present.
 262          * @return string
 263          */
 264         static function getFulltextSearchModule() {
 265                 static $cachedResult = null;
 266                 if ( $cachedResult !== null ) {
 267                         return $cachedResult;
 268                 }
 269                 $cachedResult = false;
 270                 $table = 'dummy_search_test';
 271
 272                 $db = self::newStandaloneInstance( ':memory:' );
 273                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 274                         $cachedResult = 'FTS3';
 275                 }
 276                 $db->close();
 277
 278                 return $cachedResult;
 279         }
 280
 281         /**
 282          * Attaches external database to our connection, see https://sqlite.org/lang_attach.html
 283          * for details.
 284          *
 285          * @param string $name Database name to be used in queries like
 286          *   SELECT foo FROM dbname.table
 287          * @param bool|string $file Database file name. If omitted, will be generated
 288          *   using $name and configured data directory
 289          * @param string $fname Calling function name
 290          * @return ResultWrapper
 291          */
 292         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 293                 if ( !$file ) {
 294                         $file = self::generateFileName( $this->dbDir, $name );
 295                 }
 296                 $file = $this->addQuotes( $file );
 297
 298                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 299         }
 300
 301         function isWriteQuery( $sql ) {
 302                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 303         }
 304
 305         /**
 306          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 307          *
 308          * @param string $sql
 309          * @return bool|ResultWrapper
 310          */
 311         protected function doQuery( $sql ) {
 312                 $res = $this->mConn->query( $sql );
 313                 if ( $res === false ) {
 314                         return false;
 315                 }
 316
 317                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 318                 $this->mAffectedRows = $r->rowCount();
 319                 $res = new ResultWrapper( $this, $r->fetchAll() );
 320
 321                 return $res;
 322         }
 323
 324         /**
 325          * @param ResultWrapper|mixed $res
 326          */
 327         function freeResult( $res ) {
 328                 if ( $res instanceof ResultWrapper ) {
 329                         $res->result = null;
 330                 } else {
 331                         $res = null;
 332                 }
 333         }
 334
 335         /**
 336          * @param ResultWrapper|array $res
 337          * @return stdClass|bool
 338          */
 339         function fetchObject( $res ) {
 340                 if ( $res instanceof ResultWrapper ) {
 341                         $r =& $res->result;
 342                 } else {
 343                         $r =& $res;
 344                 }
 345
 346                 $cur = current( $r );
 347                 if ( is_array( $cur ) ) {
 348                         next( $r );
 349                         $obj = new stdClass;
 350                         foreach ( $cur as $k => $v ) {
 351                                 if ( !is_numeric( $k ) ) {
 352                                         $obj->$k = $v;
 353                                 }
 354                         }
 355
 356                         return $obj;
 357                 }
 358
 359                 return false;
 360         }
 361
 362         /**
 363          * @param ResultWrapper|mixed $res
 364          * @return array|bool
 365          */
 366         function fetchRow( $res ) {
 367                 if ( $res instanceof ResultWrapper ) {
 368                         $r =& $res->result;
 369                 } else {
 370                         $r =& $res;
 371                 }
 372                 $cur = current( $r );
 373                 if ( is_array( $cur ) ) {
 374                         next( $r );
 375
 376                         return $cur;
 377                 }
 378
 379                 return false;
 380         }
 381
 382         /**
 383          * The PDO::Statement class implements the array interface so count() will work
 384          *
 385          * @param ResultWrapper|array $res
 386          * @return int
 387          */
 388         function numRows( $res ) {
 389                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 390
 391                 return count( $r );
 392         }
 393
 394         /**
 395          * @param ResultWrapper $res
 396          * @return int
 397          */
 398         function numFields( $res ) {
 399                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 400                 if ( is_array( $r ) && count( $r ) > 0 ) {
 401                         // The size of the result array is twice the number of fields. (Bug: 65578)
 402                         return count( $r[0] ) / 2;
 403                 } else {
 404                         // If the result is empty return 0
 405                         return 0;
 406                 }
 407         }
 408
 409         /**
 410          * @param ResultWrapper $res
 411          * @param int $n
 412          * @return bool
 413          */
 414         function fieldName( $res, $n ) {
 415                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 416                 if ( is_array( $r ) ) {
 417                         $keys = array_keys( $r[0] );
 418
 419                         return $keys[$n];
 420                 }
 421
 422                 return false;
 423         }
 424
 425         /**
 426          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 427          *
 428          * @param string $name
 429          * @param string $format
 430          * @return string
 431          */
 432         function tableName( $name, $format = 'quoted' ) {
 433                 // table names starting with sqlite_ are reserved
 434                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 435                         return $name;
 436                 }
 437
 438                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 439         }
 440
 441         /**
 442          * This must be called after nextSequenceVal
 443          *
 444          * @return int
 445          */
 446         function insertId() {
 447                 // PDO::lastInsertId yields a string :(
 448                 return intval( $this->mConn->lastInsertId() );
 449         }
 450
 451         /**
 452          * @param ResultWrapper|array $res
 453          * @param int $row
 454          */
 455         function dataSeek( $res, $row ) {
 456                 if ( $res instanceof ResultWrapper ) {
 457                         $r =& $res->result;
 458                 } else {
 459                         $r =& $res;
 460                 }
 461                 reset( $r );
 462                 if ( $row > 0 ) {
 463                         for ( $i = 0; $i < $row; $i++ ) {
 464                                 next( $r );
 465                         }
 466                 }
 467         }
 468
 469         /**
 470          * @return string
 471          */
 472         function lastError() {
 473                 if ( !is_object( $this->mConn ) ) {
 474                         return "Cannot return last error, no db connection";
 475                 }
 476                 $e = $this->mConn->errorInfo();
 477
 478                 return isset( $e[2] ) ? $e[2] : '';
 479         }
 480
 481         /**
 482          * @return string
 483          */
 484         function lastErrno() {
 485                 if ( !is_object( $this->mConn ) ) {
 486                         return "Cannot return last error, no db connection";
 487                 } else {
 488                         $info = $this->mConn->errorInfo();
 489
 490                         return $info[1];
 491                 }
 492         }
 493
 494         /**
 495          * @return int
 496          */
 497         function affectedRows() {
 498                 return $this->mAffectedRows;
 499         }
 500
 501         /**
 502          * Returns information about an index
 503          * Returns false if the index does not exist
 504          * - if errors are explicitly ignored, returns NULL on failure
 505          *
 506          * @param string $table
 507          * @param string $index
 508          * @param string $fname
 509          * @return array|false
 510          */
 511         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 512                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 513                 $res = $this->query( $sql, $fname );
 514                 if ( !$res || $res->numRows() == 0 ) {
 515                         return false;
 516                 }
 517                 $info = [];
 518                 foreach ( $res as $row ) {
 519                         $info[] = $row->name;
 520                 }
 521
 522                 return $info;
 523         }
 524
 525         /**
 526          * @param string $table
 527          * @param string $index
 528          * @param string $fname
 529          * @return bool|null
 530          */
 531         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 532                 $row = $this->selectRow( 'sqlite_master', '*',
 533                         [
 534                                 'type' => 'index',
 535                                 'name' => $this->indexName( $index ),
 536                         ], $fname );
 537                 if ( !$row || !isset( $row->sql ) ) {
 538                         return null;
 539                 }
 540
 541                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 542                 $indexPos = strpos( $row->sql, 'INDEX' );
 543                 if ( $indexPos === false ) {
 544                         return null;
 545                 }
 546                 $firstPart = substr( $row->sql, 0, $indexPos );
 547                 $options = explode( ' ', $firstPart );
 548
 549                 return in_array( 'UNIQUE', $options );
 550         }
 551
 552         /**
 553          * Filter the options used in SELECT statements
 554          *
 555          * @param array $options
 556          * @return array
 557          */
 558         function makeSelectOptions( $options ) {
 559                 foreach ( $options as $k => $v ) {
 560                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 561                                 $options[$k] = '';
 562                         }
 563                 }
 564
 565                 return parent::makeSelectOptions( $options );
 566         }
 567
 568         /**
 569          * @param array $options
 570          * @return array
 571          */
 572         protected function makeUpdateOptionsArray( $options ) {
 573                 $options = parent::makeUpdateOptionsArray( $options );
 574                 $options = self::fixIgnore( $options );
 575
 576                 return $options;
 577         }
 578
 579         /**
 580          * @param array $options
 581          * @return array
 582          */
 583         static function fixIgnore( $options ) {
 584                 # SQLite uses OR IGNORE not just IGNORE
 585                 foreach ( $options as $k => $v ) {
 586                         if ( $v == 'IGNORE' ) {
 587                                 $options[$k] = 'OR IGNORE';
 588                         }
 589                 }
 590
 591                 return $options;
 592         }
 593
 594         /**
 595          * @param array $options
 596          * @return string
 597          */
 598         function makeInsertOptions( $options ) {
 599                 $options = self::fixIgnore( $options );
 600
 601                 return parent::makeInsertOptions( $options );
 602         }
 603
 604         /**
 605          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 606          * @param string $table
 607          * @param array $a
 608          * @param string $fname
 609          * @param array $options
 610          * @return bool
 611          */
 612         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 613                 if ( !count( $a ) ) {
 614                         return true;
 615                 }
 616
 617                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 618                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 619                         $ret = true;
 620                         foreach ( $a as $v ) {
 621                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 622                                         $ret = false;
 623                                 }
 624                         }
 625                 } else {
 626                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 627                 }
 628
 629                 return $ret;
 630         }
 631
 632         /**
 633          * @param string $table
 634          * @param array $uniqueIndexes Unused
 635          * @param string|array $rows
 636          * @param string $fname
 637          * @return bool|ResultWrapper
 638          */
 639         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 640                 if ( !count( $rows ) ) {
 641                         return true;
 642                 }
 643
 644                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 645                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 646                         $ret = true;
 647                         foreach ( $rows as $v ) {
 648                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 649                                         $ret = false;
 650                                 }
 651                         }
 652                 } else {
 653                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 654                 }
 655
 656                 return $ret;
 657         }
 658
 659         /**
 660          * Returns the size of a text field, or -1 for "unlimited"
 661          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 662          *
 663          * @param string $table
 664          * @param string $field
 665          * @return int
 666          */
 667         function textFieldSize( $table, $field ) {
 668                 return -1;
 669         }
 670
 671         /**
 672          * @return bool
 673          */
 674         function unionSupportsOrderAndLimit() {
 675                 return false;
 676         }
 677
 678         /**
 679          * @param string[] $sqls
 680          * @param bool $all Whether to "UNION ALL" or not
 681          * @return string
 682          */
 683         function unionQueries( $sqls, $all ) {
 684                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 685
 686                 return implode( $glue, $sqls );
 687         }
 688
 689         /**
 690          * @return bool
 691          */
 692         function wasDeadlock() {
 693                 return $this->lastErrno() == 5; // SQLITE_BUSY
 694         }
 695
 696         /**
 697          * @return bool
 698          */
 699         function wasErrorReissuable() {
 700                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 701         }
 702
 703         /**
 704          * @return bool
 705          */
 706         function wasReadOnlyError() {
 707                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 708         }
 709
 710         /**
 711          * @return string Wikitext of a link to the server software's web site
 712          */
 713         public function getSoftwareLink() {
 714                 return "[{{int:version-db-sqlite-url}} SQLite]";
 715         }
 716
 717         /**
 718          * @return string Version information from the database
 719          */
 720         function getServerVersion() {
 721                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 722
 723                 return $ver;
 724         }
 725
 726         /**
 727          * Get information about a given field
 728          * Returns false if the field does not exist.
 729          *
 730          * @param string $table
 731          * @param string $field
 732          * @return SQLiteField|bool False on failure
 733          */
 734         function fieldInfo( $table, $field ) {
 735                 $tableName = $this->tableName( $table );
 736                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 737                 $res = $this->query( $sql, __METHOD__ );
 738                 foreach ( $res as $row ) {
 739                         if ( $row->name == $field ) {
 740                                 return new SQLiteField( $row, $tableName );
 741                         }
 742                 }
 743
 744                 return false;
 745         }
 746
 747         protected function doBegin( $fname = '' ) {
 748                 if ( $this->trxMode ) {
 749                         $this->query( "BEGIN {$this->trxMode}", $fname );
 750                 } else {
 751                         $this->query( 'BEGIN', $fname );
 752                 }
 753                 $this->mTrxLevel = 1;
 754         }
 755
 756         /**
 757          * @param string $s
 758          * @return string
 759          */
 760         function strencode( $s ) {
 761                 return substr( $this->addQuotes( $s ), 1, -1 );
 762         }
 763
 764         /**
 765          * @param string $b
 766          * @return Blob
 767          */
 768         function encodeBlob( $b ) {
 769                 return new Blob( $b );
 770         }
 771
 772         /**
 773          * @param Blob|string $b
 774          * @return string
 775          */
 776         function decodeBlob( $b ) {
 777                 if ( $b instanceof Blob ) {
 778                         $b = $b->fetch();
 779                 }
 780
 781                 return $b;
 782         }
 783
 784         /**
 785          * @param string|int|null|bool|Blob $s
 786          * @return string|int
 787          */
 788         function addQuotes( $s ) {
 789                 if ( $s instanceof Blob ) {
 790                         return "x'" . bin2hex( $s->fetch() ) . "'";
 791                 } elseif ( is_bool( $s ) ) {
 792                         return (int)$s;
 793                 } elseif ( strpos( (string)$s, "\0" ) !== false ) {
 794                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 795                         // This is a known limitation of SQLite's mprintf function which PDO
 796                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 797                         // https://bugs.php.net/bug.php?id=63419
 798                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 799                         // https://bugs.php.net/bug.php?id=62361
 800                         // There is an additional bug regarding sorting this data after insert
 801                         // on older versions of sqlite shipped with ubuntu 12.04
 802                         // https://phabricator.wikimedia.org/T74367
 803                         $this->queryLogger->debug(
 804                                 __FUNCTION__ .
 805                                 ': Quoting value containing null byte. ' .
 806                                 'For consistency all binary data should have been ' .
 807                                 'first processed with self::encodeBlob()'
 808                         );
 809                         return "x'" . bin2hex( (string)$s ) . "'";
 810                 } else {
 811                         return $this->mConn->quote( (string)$s );
 812                 }
 813         }
 814
 815         /**
 816          * @param string $field Field or column to cast
 817          * @return string
 818          * @since 1.28
 819          */
 820         public function buildStringCast( $field ) {
 821                 return 'CAST ( ' . $field . ' AS TEXT )';
 822         }
 823
 824         /**
 825          * No-op version of deadlockLoop
 826          *
 827          * @return mixed
 828          */
 829         public function deadlockLoop( /*...*/ ) {
 830                 $args = func_get_args();
 831                 $function = array_shift( $args );
 832
 833                 return call_user_func_array( $function, $args );
 834         }
 835
 836         /**
 837          * @param string $s
 838          * @return string
 839          */
 840         protected function replaceVars( $s ) {
 841                 $s = parent::replaceVars( $s );
 842                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 843                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 844
 845                         // binary/varbinary column type -> blob
 846                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 847                         // no such thing as unsigned
 848                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 849                         // INT -> INTEGER
 850                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 851                         // floating point types -> REAL
 852                         $s = preg_replace(
 853                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 854                                 'REAL',
 855                                 $s
 856                         );
 857                         // varchar -> TEXT
 858                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 859                         // TEXT normalization
 860                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 861                         // BLOB normalization
 862                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 863                         // BOOL -> INTEGER
 864                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 865                         // DATETIME -> TEXT
 866                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 867                         // No ENUM type
 868                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 869                         // binary collation type -> nothing
 870                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 871                         // auto_increment -> autoincrement
 872                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 873                         // No explicit options
 874                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 875                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 876                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 877                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 878                         // No truncated indexes
 879                         $s = preg_replace( '/\(\d+\)/', '', $s );
 880                         // No FULLTEXT
 881                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 882                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 883                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 884                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 885                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 886                         // INSERT IGNORE --> INSERT OR IGNORE
 887                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 888                 }
 889
 890                 return $s;
 891         }
 892
 893         public function lock( $lockName, $method, $timeout = 5 ) {
 894                 if ( !is_dir( "{$this->dbDir}/locks" ) ) { // create dir as needed
 895                         if ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) ) {
 896                                 throw new DBError( $this, "Cannot create directory \"{$this->dbDir}/locks\"." );
 897                         }
 898                 }
 899
 900                 return $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout )->isOK();
 901         }
 902
 903         public function unlock( $lockName, $method ) {
 904                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isOK();
 905         }
 906
 907         /**
 908          * Build a concatenation list to feed into a SQL query
 909          *
 910          * @param string[] $stringList
 911          * @return string
 912          */
 913         function buildConcat( $stringList ) {
 914                 return '(' . implode( ') || (', $stringList ) . ')';
 915         }
 916
 917         public function buildGroupConcatField(
 918                 $delim, $table, $field, $conds = '', $join_conds = []
 919         ) {
 920                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 921
 922                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
 923         }
 924
 925         /**
 926          * @param string $oldName
 927          * @param string $newName
 928          * @param bool $temporary
 929          * @param string $fname
 930          * @return bool|ResultWrapper
 931          * @throws RuntimeException
 932          */
 933         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 934                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 935                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 936                 $obj = $this->fetchObject( $res );
 937                 if ( !$obj ) {
 938                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
 939                 }
 940                 $sql = $obj->sql;
 941                 $sql = preg_replace(
 942                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 943                         $this->addIdentifierQuotes( $newName ),
 944                         $sql,
 945                         1
 946                 );
 947                 if ( $temporary ) {
 948                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 949                                 $this->queryLogger->debug(
 950                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 951                         } else {
 952                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 953                         }
 954                 }
 955
 956                 $res = $this->query( $sql, $fname );
 957
 958                 // Take over indexes
 959                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
 960                 foreach ( $indexList as $index ) {
 961                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
 962                                 continue;
 963                         }
 964
 965                         if ( $index->unique ) {
 966                                 $sql = 'CREATE UNIQUE INDEX';
 967                         } else {
 968                                 $sql = 'CREATE INDEX';
 969                         }
 970                         // Try to come up with a new index name, given indexes have database scope in SQLite
 971                         $indexName = $newName . '_' . $index->name;
 972                         $sql .= ' ' . $indexName . ' ON ' . $newName;
 973
 974                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
 975                         $fields = [];
 976                         foreach ( $indexInfo as $indexInfoRow ) {
 977                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
 978                         }
 979
 980                         $sql .= '(' . implode( ',', $fields ) . ')';
 981
 982                         $this->query( $sql );
 983                 }
 984
 985                 return $res;
 986         }
 987
 988         /**
 989          * List all tables on the database
 990          *
 991          * @param string $prefix Only show tables with this prefix, e.g. mw_
 992          * @param string $fname Calling function name
 993          *
 994          * @return array
 995          */
 996         function listTables( $prefix = null, $fname = __METHOD__ ) {
 997                 $result = $this->select(
 998                         'sqlite_master',
 999                         'name',
1000                         "type='table'"
1001                 );
1002
1003                 $endArray = [];
1004
1005                 foreach ( $result as $table ) {
1006                         $vars = get_object_vars( $table );
1007                         $table = array_pop( $vars );
1008
1009                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1010                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1011                                         $endArray[] = $table;
1012                                 }
1013                         }
1014                 }
1015
1016                 return $endArray;
1017         }
1018
1019         /**
1020          * Override due to no CASCADE support
1021          *
1022          * @param string $tableName
1023          * @param string $fName
1024          * @return bool|ResultWrapper
1025          * @throws DBReadOnlyError
1026          */
1027         public function dropTable( $tableName, $fName = __METHOD__ ) {
1028                 if ( !$this->tableExists( $tableName, $fName ) ) {
1029                         return false;
1030                 }
1031                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1032
1033                 return $this->query( $sql, $fName );
1034         }
1035
1036         protected function requiresDatabaseUser() {
1037                 return false; // just a file
1038         }
1039
1040         /**
1041          * @return string
1042          */
1043         public function __toString() {
1044                 return 'SQLite ' . (string)$this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
1045         }
1046 }
1047
1048 class_alias( DatabaseSqlite::class, 'DatabaseSqlite' );