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 DBConnectionError;
  31 use DBReadOnlyError;
  32 use InvalidArgumentException;
  33 use RuntimeException;
  34 use DBError;
  35 use stdClass;
  36
  37 /**
  38  * @ingroup Database
  39  */
  40 class DatabaseSqlite extends Database {
  41         /** @var bool Whether full text is enabled */
  42         private static $fulltextEnabled = null;
  43
  44         /** @var string Directory */
  45         protected $dbDir;
  46         /** @var string File name for SQLite database file */
  47         protected $dbPath;
  48         /** @var string Transaction mode */
  49         protected $trxMode;
  50
  51         /** @var int The number of rows affected as an integer */
  52         protected $mAffectedRows;
  53         /** @var resource */
  54         protected $mLastResult;
  55
  56         /** @var PDO */
  57         protected $mConn;
  58
  59         /** @var FSLockManager (hopefully on the same server as the DB) */
  60         protected $lockMgr;
  61
  62         /**
  63          * Additional params include:
  64          *   - dbDirectory : directory containing the DB and the lock file directory
  65          *                   [defaults to $wgSQLiteDataDir]
  66          *   - dbFilePath  : use this to force the path of the DB file
  67          *   - trxMode     : one of (deferred, immediate, exclusive)
  68          * @param array $p
  69          */
  70         function __construct( array $p ) {
  71                 if ( isset( $p['dbFilePath'] ) ) {
  72                         parent::__construct( $p );
  73                         // Standalone .sqlite file mode.
  74                         // Super doesn't open when $user is false, but we can work with $dbName,
  75                         // which is derived from the file path in this case.
  76                         $this->openFile( $p['dbFilePath'] );
  77                         $lockDomain = md5( $p['dbFilePath'] );
  78                 } elseif ( !isset( $p['dbDirectory'] ) ) {
  79                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
  80                 } else {
  81                         $this->dbDir = $p['dbDirectory'];
  82                         $this->mDBname = $p['dbname'];
  83                         $lockDomain = $this->mDBname;
  84                         // Stock wiki mode using standard file names per DB.
  85                         parent::__construct( $p );
  86                         // Super doesn't open when $user is false, but we can work with $dbName
  87                         if ( $p['dbname'] && !$this->isOpen() ) {
  88                                 if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  89                                         $done = [];
  90                                         foreach ( $this->tableAliases as $params ) {
  91                                                 if ( isset( $done[$params['dbname']] ) ) {
  92                                                         continue;
  93                                                 }
  94                                                 $this->attachDatabase( $params['dbname'] );
  95                                                 $done[$params['dbname']] = 1;
  96                                         }
  97                                 }
  98                         }
  99                 }
 100
 101                 $this->trxMode = isset( $p['trxMode'] ) ? strtoupper( $p['trxMode'] ) : null;
 102                 if ( $this->trxMode &&
 103                         !in_array( $this->trxMode, [ 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ] )
 104                 ) {
 105                         $this->trxMode = null;
 106                         $this->queryLogger->warning( "Invalid SQLite transaction mode provided." );
 107                 }
 108
 109                 $this->lockMgr = new FSLockManager( [
 110                         'domain' => $lockDomain,
 111                         'lockDirectory' => "{$this->dbDir}/locks"
 112                 ] );
 113         }
 114
 115         /**
 116          * @param string $filename
 117          * @param array $p Options map; supports:
 118          *   - flags       : (same as __construct counterpart)
 119          *   - trxMode     : (same as __construct counterpart)
 120          *   - dbDirectory : (same as __construct counterpart)
 121          * @return DatabaseSqlite
 122          * @since 1.25
 123          */
 124         public static function newStandaloneInstance( $filename, array $p = [] ) {
 125                 $p['dbFilePath'] = $filename;
 126                 $p['schema'] = false;
 127                 $p['tablePrefix'] = '';
 128                 /** @var DatabaseSqlite $db */
 129                 $db = Database::factory( 'sqlite', $p );
 130
 131                 return $db;
 132         }
 133
 134         /**
 135          * @return string
 136          */
 137         function getType() {
 138                 return 'sqlite';
 139         }
 140
 141         /**
 142          * @todo Check if it should be true like parent class
 143          *
 144          * @return bool
 145          */
 146         function implicitGroupby() {
 147                 return false;
 148         }
 149
 150         /** Open an SQLite database and return a resource handle to it
 151          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
 152          *
 153          * @param string $server
 154          * @param string $user
 155          * @param string $pass
 156          * @param string $dbName
 157          *
 158          * @throws DBConnectionError
 159          * @return bool
 160          */
 161         function open( $server, $user, $pass, $dbName ) {
 162                 $this->close();
 163                 $fileName = self::generateFileName( $this->dbDir, $dbName );
 164                 if ( !is_readable( $fileName ) ) {
 165                         $this->mConn = false;
 166                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 167                 }
 168                 $this->openFile( $fileName );
 169
 170                 return (bool)$this->mConn;
 171         }
 172
 173         /**
 174          * Opens a database file
 175          *
 176          * @param string $fileName
 177          * @throws DBConnectionError
 178          * @return PDO|bool SQL connection or false if failed
 179          */
 180         protected function openFile( $fileName ) {
 181                 $err = false;
 182
 183                 $this->dbPath = $fileName;
 184                 try {
 185                         if ( $this->mFlags & self::DBO_PERSISTENT ) {
 186                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 187                                         [ PDO::ATTR_PERSISTENT => true ] );
 188                         } else {
 189                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 190                         }
 191                 } catch ( PDOException $e ) {
 192                         $err = $e->getMessage();
 193                 }
 194
 195                 if ( !$this->mConn ) {
 196                         $this->queryLogger->debug( "DB connection error: $err\n" );
 197                         throw new DBConnectionError( $this, $err );
 198                 }
 199
 200                 $this->mOpened = !!$this->mConn;
 201                 if ( $this->mOpened ) {
 202                         # Set error codes only, don't raise exceptions
 203                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 204                         # Enforce LIKE to be case sensitive, just like MySQL
 205                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 206
 207                         return $this->mConn;
 208                 }
 209
 210                 return false;
 211         }
 212
 213         public function selectDB( $db ) {
 214                 return false; // doesn't make sense
 215         }
 216
 217         /**
 218          * @return string SQLite DB file path
 219          * @since 1.25
 220          */
 221         public function getDbFilePath() {
 222                 return $this->dbPath;
 223         }
 224
 225         /**
 226          * Does not actually close the connection, just destroys the reference for GC to do its work
 227          * @return bool
 228          */
 229         protected function closeConnection() {
 230                 $this->mConn = null;
 231
 232                 return true;
 233         }
 234
 235         /**
 236          * Generates a database file name. Explicitly public for installer.
 237          * @param string $dir Directory where database resides
 238          * @param string $dbName Database name
 239          * @return string
 240          */
 241         public static function generateFileName( $dir, $dbName ) {
 242                 return "$dir/$dbName.sqlite";
 243         }
 244
 245         /**
 246          * Check if the searchindext table is FTS enabled.
 247          * @return bool False if not enabled.
 248          */
 249         function checkForEnabledSearch() {
 250                 if ( self::$fulltextEnabled === null ) {
 251                         self::$fulltextEnabled = false;
 252                         $table = $this->tableName( 'searchindex' );
 253                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 254                         if ( $res ) {
 255                                 $row = $res->fetchRow();
 256                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 257                         }
 258                 }
 259
 260                 return self::$fulltextEnabled;
 261         }
 262
 263         /**
 264          * Returns version of currently supported SQLite fulltext search module or false if none present.
 265          * @return string
 266          */
 267         static function getFulltextSearchModule() {
 268                 static $cachedResult = null;
 269                 if ( $cachedResult !== null ) {
 270                         return $cachedResult;
 271                 }
 272                 $cachedResult = false;
 273                 $table = 'dummy_search_test';
 274
 275                 $db = self::newStandaloneInstance( ':memory:' );
 276                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 277                         $cachedResult = 'FTS3';
 278                 }
 279                 $db->close();
 280
 281                 return $cachedResult;
 282         }
 283
 284         /**
 285          * Attaches external database to our connection, see https://sqlite.org/lang_attach.html
 286          * for details.
 287          *
 288          * @param string $name Database name to be used in queries like
 289          *   SELECT foo FROM dbname.table
 290          * @param bool|string $file Database file name. If omitted, will be generated
 291          *   using $name and configured data directory
 292          * @param string $fname Calling function name
 293          * @return ResultWrapper
 294          */
 295         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 296                 if ( !$file ) {
 297                         $file = self::generateFileName( $this->dbDir, $name );
 298                 }
 299                 $file = $this->addQuotes( $file );
 300
 301                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 302         }
 303
 304         function isWriteQuery( $sql ) {
 305                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 306         }
 307
 308         /**
 309          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 310          *
 311          * @param string $sql
 312          * @return bool|ResultWrapper
 313          */
 314         protected function doQuery( $sql ) {
 315                 $res = $this->mConn->query( $sql );
 316                 if ( $res === false ) {
 317                         return false;
 318                 }
 319
 320                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 321                 $this->mAffectedRows = $r->rowCount();
 322                 $res = new ResultWrapper( $this, $r->fetchAll() );
 323
 324                 return $res;
 325         }
 326
 327         /**
 328          * @param ResultWrapper|mixed $res
 329          */
 330         function freeResult( $res ) {
 331                 if ( $res instanceof ResultWrapper ) {
 332                         $res->result = null;
 333                 } else {
 334                         $res = null;
 335                 }
 336         }
 337
 338         /**
 339          * @param ResultWrapper|array $res
 340          * @return stdClass|bool
 341          */
 342         function fetchObject( $res ) {
 343                 if ( $res instanceof ResultWrapper ) {
 344                         $r =& $res->result;
 345                 } else {
 346                         $r =& $res;
 347                 }
 348
 349                 $cur = current( $r );
 350                 if ( is_array( $cur ) ) {
 351                         next( $r );
 352                         $obj = new stdClass;
 353                         foreach ( $cur as $k => $v ) {
 354                                 if ( !is_numeric( $k ) ) {
 355                                         $obj->$k = $v;
 356                                 }
 357                         }
 358
 359                         return $obj;
 360                 }
 361
 362                 return false;
 363         }
 364
 365         /**
 366          * @param ResultWrapper|mixed $res
 367          * @return array|bool
 368          */
 369         function fetchRow( $res ) {
 370                 if ( $res instanceof ResultWrapper ) {
 371                         $r =& $res->result;
 372                 } else {
 373                         $r =& $res;
 374                 }
 375                 $cur = current( $r );
 376                 if ( is_array( $cur ) ) {
 377                         next( $r );
 378
 379                         return $cur;
 380                 }
 381
 382                 return false;
 383         }
 384
 385         /**
 386          * The PDO::Statement class implements the array interface so count() will work
 387          *
 388          * @param ResultWrapper|array $res
 389          * @return int
 390          */
 391         function numRows( $res ) {
 392                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 393
 394                 return count( $r );
 395         }
 396
 397         /**
 398          * @param ResultWrapper $res
 399          * @return int
 400          */
 401         function numFields( $res ) {
 402                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 403                 if ( is_array( $r ) && count( $r ) > 0 ) {
 404                         // The size of the result array is twice the number of fields. (Bug: 65578)
 405                         return count( $r[0] ) / 2;
 406                 } else {
 407                         // If the result is empty return 0
 408                         return 0;
 409                 }
 410         }
 411
 412         /**
 413          * @param ResultWrapper $res
 414          * @param int $n
 415          * @return bool
 416          */
 417         function fieldName( $res, $n ) {
 418                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 419                 if ( is_array( $r ) ) {
 420                         $keys = array_keys( $r[0] );
 421
 422                         return $keys[$n];
 423                 }
 424
 425                 return false;
 426         }
 427
 428         /**
 429          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 430          *
 431          * @param string $name
 432          * @param string $format
 433          * @return string
 434          */
 435         function tableName( $name, $format = 'quoted' ) {
 436                 // table names starting with sqlite_ are reserved
 437                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 438                         return $name;
 439                 }
 440
 441                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 442         }
 443
 444         /**
 445          * This must be called after nextSequenceVal
 446          *
 447          * @return int
 448          */
 449         function insertId() {
 450                 // PDO::lastInsertId yields a string :(
 451                 return intval( $this->mConn->lastInsertId() );
 452         }
 453
 454         /**
 455          * @param ResultWrapper|array $res
 456          * @param int $row
 457          */
 458         function dataSeek( $res, $row ) {
 459                 if ( $res instanceof ResultWrapper ) {
 460                         $r =& $res->result;
 461                 } else {
 462                         $r =& $res;
 463                 }
 464                 reset( $r );
 465                 if ( $row > 0 ) {
 466                         for ( $i = 0; $i < $row; $i++ ) {
 467                                 next( $r );
 468                         }
 469                 }
 470         }
 471
 472         /**
 473          * @return string
 474          */
 475         function lastError() {
 476                 if ( !is_object( $this->mConn ) ) {
 477                         return "Cannot return last error, no db connection";
 478                 }
 479                 $e = $this->mConn->errorInfo();
 480
 481                 return isset( $e[2] ) ? $e[2] : '';
 482         }
 483
 484         /**
 485          * @return string
 486          */
 487         function lastErrno() {
 488                 if ( !is_object( $this->mConn ) ) {
 489                         return "Cannot return last error, no db connection";
 490                 } else {
 491                         $info = $this->mConn->errorInfo();
 492
 493                         return $info[1];
 494                 }
 495         }
 496
 497         /**
 498          * @return int
 499          */
 500         function affectedRows() {
 501                 return $this->mAffectedRows;
 502         }
 503
 504         /**
 505          * Returns information about an index
 506          * Returns false if the index does not exist
 507          * - if errors are explicitly ignored, returns NULL on failure
 508          *
 509          * @param string $table
 510          * @param string $index
 511          * @param string $fname
 512          * @return array|false
 513          */
 514         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 515                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 516                 $res = $this->query( $sql, $fname );
 517                 if ( !$res || $res->numRows() == 0 ) {
 518                         return false;
 519                 }
 520                 $info = [];
 521                 foreach ( $res as $row ) {
 522                         $info[] = $row->name;
 523                 }
 524
 525                 return $info;
 526         }
 527
 528         /**
 529          * @param string $table
 530          * @param string $index
 531          * @param string $fname
 532          * @return bool|null
 533          */
 534         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 535                 $row = $this->selectRow( 'sqlite_master', '*',
 536                         [
 537                                 'type' => 'index',
 538                                 'name' => $this->indexName( $index ),
 539                         ], $fname );
 540                 if ( !$row || !isset( $row->sql ) ) {
 541                         return null;
 542                 }
 543
 544                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 545                 $indexPos = strpos( $row->sql, 'INDEX' );
 546                 if ( $indexPos === false ) {
 547                         return null;
 548                 }
 549                 $firstPart = substr( $row->sql, 0, $indexPos );
 550                 $options = explode( ' ', $firstPart );
 551
 552                 return in_array( 'UNIQUE', $options );
 553         }
 554
 555         /**
 556          * Filter the options used in SELECT statements
 557          *
 558          * @param array $options
 559          * @return array
 560          */
 561         function makeSelectOptions( $options ) {
 562                 foreach ( $options as $k => $v ) {
 563                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 564                                 $options[$k] = '';
 565                         }
 566                 }
 567
 568                 return parent::makeSelectOptions( $options );
 569         }
 570
 571         /**
 572          * @param array $options
 573          * @return string
 574          */
 575         protected function makeUpdateOptionsArray( $options ) {
 576                 $options = parent::makeUpdateOptionsArray( $options );
 577                 $options = self::fixIgnore( $options );
 578
 579                 return $options;
 580         }
 581
 582         /**
 583          * @param array $options
 584          * @return array
 585          */
 586         static function fixIgnore( $options ) {
 587                 # SQLite uses OR IGNORE not just IGNORE
 588                 foreach ( $options as $k => $v ) {
 589                         if ( $v == 'IGNORE' ) {
 590                                 $options[$k] = 'OR IGNORE';
 591                         }
 592                 }
 593
 594                 return $options;
 595         }
 596
 597         /**
 598          * @param array $options
 599          * @return string
 600          */
 601         function makeInsertOptions( $options ) {
 602                 $options = self::fixIgnore( $options );
 603
 604                 return parent::makeInsertOptions( $options );
 605         }
 606
 607         /**
 608          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 609          * @param string $table
 610          * @param array $a
 611          * @param string $fname
 612          * @param array $options
 613          * @return bool
 614          */
 615         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 616                 if ( !count( $a ) ) {
 617                         return true;
 618                 }
 619
 620                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 621                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 622                         $ret = true;
 623                         foreach ( $a as $v ) {
 624                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 625                                         $ret = false;
 626                                 }
 627                         }
 628                 } else {
 629                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 630                 }
 631
 632                 return $ret;
 633         }
 634
 635         /**
 636          * @param string $table
 637          * @param array $uniqueIndexes Unused
 638          * @param string|array $rows
 639          * @param string $fname
 640          * @return bool|ResultWrapper
 641          */
 642         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 643                 if ( !count( $rows ) ) {
 644                         return true;
 645                 }
 646
 647                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 648                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 649                         $ret = true;
 650                         foreach ( $rows as $v ) {
 651                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 652                                         $ret = false;
 653                                 }
 654                         }
 655                 } else {
 656                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 657                 }
 658
 659                 return $ret;
 660         }
 661
 662         /**
 663          * Returns the size of a text field, or -1 for "unlimited"
 664          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 665          *
 666          * @param string $table
 667          * @param string $field
 668          * @return int
 669          */
 670         function textFieldSize( $table, $field ) {
 671                 return -1;
 672         }
 673
 674         /**
 675          * @return bool
 676          */
 677         function unionSupportsOrderAndLimit() {
 678                 return false;
 679         }
 680
 681         /**
 682          * @param string[] $sqls
 683          * @param bool $all Whether to "UNION ALL" or not
 684          * @return string
 685          */
 686         function unionQueries( $sqls, $all ) {
 687                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 688
 689                 return implode( $glue, $sqls );
 690         }
 691
 692         /**
 693          * @return bool
 694          */
 695         function wasDeadlock() {
 696                 return $this->lastErrno() == 5; // SQLITE_BUSY
 697         }
 698
 699         /**
 700          * @return bool
 701          */
 702         function wasErrorReissuable() {
 703                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 704         }
 705
 706         /**
 707          * @return bool
 708          */
 709         function wasReadOnlyError() {
 710                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 711         }
 712
 713         /**
 714          * @return string Wikitext of a link to the server software's web site
 715          */
 716         public function getSoftwareLink() {
 717                 return "[{{int:version-db-sqlite-url}} SQLite]";
 718         }
 719
 720         /**
 721          * @return string Version information from the database
 722          */
 723         function getServerVersion() {
 724                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 725
 726                 return $ver;
 727         }
 728
 729         /**
 730          * Get information about a given field
 731          * Returns false if the field does not exist.
 732          *
 733          * @param string $table
 734          * @param string $field
 735          * @return SQLiteField|bool False on failure
 736          */
 737         function fieldInfo( $table, $field ) {
 738                 $tableName = $this->tableName( $table );
 739                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 740                 $res = $this->query( $sql, __METHOD__ );
 741                 foreach ( $res as $row ) {
 742                         if ( $row->name == $field ) {
 743                                 return new SQLiteField( $row, $tableName );
 744                         }
 745                 }
 746
 747                 return false;
 748         }
 749
 750         protected function doBegin( $fname = '' ) {
 751                 if ( $this->trxMode ) {
 752                         $this->query( "BEGIN {$this->trxMode}", $fname );
 753                 } else {
 754                         $this->query( 'BEGIN', $fname );
 755                 }
 756                 $this->mTrxLevel = 1;
 757         }
 758
 759         /**
 760          * @param string $s
 761          * @return string
 762          */
 763         function strencode( $s ) {
 764                 return substr( $this->addQuotes( $s ), 1, -1 );
 765         }
 766
 767         /**
 768          * @param string $b
 769          * @return Blob
 770          */
 771         function encodeBlob( $b ) {
 772                 return new Blob( $b );
 773         }
 774
 775         /**
 776          * @param Blob|string $b
 777          * @return string
 778          */
 779         function decodeBlob( $b ) {
 780                 if ( $b instanceof Blob ) {
 781                         $b = $b->fetch();
 782                 }
 783
 784                 return $b;
 785         }
 786
 787         /**
 788          * @param string|int|null|bool|Blob $s
 789          * @return string|int
 790          */
 791         function addQuotes( $s ) {
 792                 if ( $s instanceof Blob ) {
 793                         return "x'" . bin2hex( $s->fetch() ) . "'";
 794                 } elseif ( is_bool( $s ) ) {
 795                         return (int)$s;
 796                 } elseif ( strpos( $s, "\0" ) !== false ) {
 797                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 798                         // This is a known limitation of SQLite's mprintf function which PDO
 799                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 800                         // https://bugs.php.net/bug.php?id=63419
 801                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 802                         // https://bugs.php.net/bug.php?id=62361
 803                         // There is an additional bug regarding sorting this data after insert
 804                         // on older versions of sqlite shipped with ubuntu 12.04
 805                         // https://phabricator.wikimedia.org/T74367
 806                         $this->queryLogger->debug(
 807                                 __FUNCTION__ .
 808                                 ': Quoting value containing null byte. ' .
 809                                 'For consistency all binary data should have been ' .
 810                                 'first processed with self::encodeBlob()'
 811                         );
 812                         return "x'" . bin2hex( $s ) . "'";
 813                 } else {
 814                         return $this->mConn->quote( $s );
 815                 }
 816         }
 817
 818         /**
 819          * @return string
 820          */
 821         function buildLike() {
 822                 $params = func_get_args();
 823                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 824                         $params = $params[0];
 825                 }
 826
 827                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 828         }
 829
 830         /**
 831          * @param string $field Field or column to cast
 832          * @return string
 833          * @since 1.28
 834          */
 835         public function buildStringCast( $field ) {
 836                 return 'CAST ( ' . $field . ' AS TEXT )';
 837         }
 838
 839         /**
 840          * No-op version of deadlockLoop
 841          *
 842          * @return mixed
 843          */
 844         public function deadlockLoop( /*...*/ ) {
 845                 $args = func_get_args();
 846                 $function = array_shift( $args );
 847
 848                 return call_user_func_array( $function, $args );
 849         }
 850
 851         /**
 852          * @param string $s
 853          * @return string
 854          */
 855         protected function replaceVars( $s ) {
 856                 $s = parent::replaceVars( $s );
 857                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 858                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 859
 860                         // binary/varbinary column type -> blob
 861                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 862                         // no such thing as unsigned
 863                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 864                         // INT -> INTEGER
 865                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 866                         // floating point types -> REAL
 867                         $s = preg_replace(
 868                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 869                                 'REAL',
 870                                 $s
 871                         );
 872                         // varchar -> TEXT
 873                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 874                         // TEXT normalization
 875                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 876                         // BLOB normalization
 877                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 878                         // BOOL -> INTEGER
 879                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 880                         // DATETIME -> TEXT
 881                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 882                         // No ENUM type
 883                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 884                         // binary collation type -> nothing
 885                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 886                         // auto_increment -> autoincrement
 887                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 888                         // No explicit options
 889                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 890                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 891                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 892                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 893                         // No truncated indexes
 894                         $s = preg_replace( '/\(\d+\)/', '', $s );
 895                         // No FULLTEXT
 896                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 897                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 898                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 899                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 900                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 901                         // INSERT IGNORE --> INSERT OR IGNORE
 902                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 903                 }
 904
 905                 return $s;
 906         }
 907
 908         public function lock( $lockName, $method, $timeout = 5 ) {
 909                 if ( !is_dir( "{$this->dbDir}/locks" ) ) { // create dir as needed
 910                         if ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) ) {
 911                                 throw new DBError( $this, "Cannot create directory \"{$this->dbDir}/locks\"." );
 912                         }
 913                 }
 914
 915                 return $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout )->isOK();
 916         }
 917
 918         public function unlock( $lockName, $method ) {
 919                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isOK();
 920         }
 921
 922         /**
 923          * Build a concatenation list to feed into a SQL query
 924          *
 925          * @param string[] $stringList
 926          * @return string
 927          */
 928         function buildConcat( $stringList ) {
 929                 return '(' . implode( ') || (', $stringList ) . ')';
 930         }
 931
 932         public function buildGroupConcatField(
 933                 $delim, $table, $field, $conds = '', $join_conds = []
 934         ) {
 935                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 936
 937                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
 938         }
 939
 940         /**
 941          * @param string $oldName
 942          * @param string $newName
 943          * @param bool $temporary
 944          * @param string $fname
 945          * @return bool|ResultWrapper
 946          * @throws RuntimeException
 947          */
 948         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 949                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 950                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 951                 $obj = $this->fetchObject( $res );
 952                 if ( !$obj ) {
 953                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
 954                 }
 955                 $sql = $obj->sql;
 956                 $sql = preg_replace(
 957                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 958                         $this->addIdentifierQuotes( $newName ),
 959                         $sql,
 960                         1
 961                 );
 962                 if ( $temporary ) {
 963                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 964                                 $this->queryLogger->debug(
 965                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 966                         } else {
 967                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 968                         }
 969                 }
 970
 971                 $res = $this->query( $sql, $fname );
 972
 973                 // Take over indexes
 974                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
 975                 foreach ( $indexList as $index ) {
 976                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
 977                                 continue;
 978                         }
 979
 980                         if ( $index->unique ) {
 981                                 $sql = 'CREATE UNIQUE INDEX';
 982                         } else {
 983                                 $sql = 'CREATE INDEX';
 984                         }
 985                         // Try to come up with a new index name, given indexes have database scope in SQLite
 986                         $indexName = $newName . '_' . $index->name;
 987                         $sql .= ' ' . $indexName . ' ON ' . $newName;
 988
 989                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
 990                         $fields = [];
 991                         foreach ( $indexInfo as $indexInfoRow ) {
 992                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
 993                         }
 994
 995                         $sql .= '(' . implode( ',', $fields ) . ')';
 996
 997                         $this->query( $sql );
 998                 }
 999
1000                 return $res;
1001         }
1002
1003         /**
1004          * List all tables on the database
1005          *
1006          * @param string $prefix Only show tables with this prefix, e.g. mw_
1007          * @param string $fname Calling function name
1008          *
1009          * @return array
1010          */
1011         function listTables( $prefix = null, $fname = __METHOD__ ) {
1012                 $result = $this->select(
1013                         'sqlite_master',
1014                         'name',
1015                         "type='table'"
1016                 );
1017
1018                 $endArray = [];
1019
1020                 foreach ( $result as $table ) {
1021                         $vars = get_object_vars( $table );
1022                         $table = array_pop( $vars );
1023
1024                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1025                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1026                                         $endArray[] = $table;
1027                                 }
1028                         }
1029                 }
1030
1031                 return $endArray;
1032         }
1033
1034         /**
1035          * Override due to no CASCADE support
1036          *
1037          * @param string $tableName
1038          * @param string $fName
1039          * @return bool|ResultWrapper
1040          * @throws DBReadOnlyError
1041          */
1042         public function dropTable( $tableName, $fName = __METHOD__ ) {
1043                 if ( !$this->tableExists( $tableName, $fName ) ) {
1044                         return false;
1045                 }
1046                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1047
1048                 return $this->query( $sql, $fName );
1049         }
1050
1051         protected function requiresDatabaseUser() {
1052                 return false; // just a file
1053         }
1054
1055         /**
1056          * @return string
1057          */
1058         public function __toString() {
1059                 return 'SQLite ' . (string)$this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
1060         }
1061 }
1062
1063 class_alias( DatabaseSqlite::class, 'DatabaseSqlite' );
1064