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
  25 /**
  26  * @ingroup Database
  27  */
  28 class DatabaseSqlite extends DatabaseBase {
  29         /** @var bool Whether full text is enabled */
  30         private static $fulltextEnabled = null;
  31
  32         /** @var string Directory */
  33         protected $dbDir;
  34
  35         /** @var string File name for SQLite database file */
  36         protected $dbPath;
  37
  38         /** @var string Transaction mode */
  39         protected $trxMode;
  40
  41         /** @var int The number of rows affected as an integer */
  42         protected $mAffectedRows;
  43
  44         /** @var resource */
  45         protected $mLastResult;
  46
  47         /** @var PDO */
  48         protected $mConn;
  49
  50         /** @var FSLockManager (hopefully on the same server as the DB) */
  51         protected $lockMgr;
  52
  53         /**
  54          * Additional params include:
  55          *   - dbDirectory : directory containing the DB and the lock file directory
  56          *                   [defaults to $wgSQLiteDataDir]
  57          *   - dbFilePath  : use this to force the path of the DB file
  58          *   - trxMode     : one of (deferred, immediate, exclusive)
  59          * @param array $p
  60          */
  61         function __construct( array $p ) {
  62                 if ( isset( $p['dbFilePath'] ) ) {
  63                         parent::__construct( $p );
  64                         // Standalone .sqlite file mode.
  65                         // Super doesn't open when $user is false, but we can work with $dbName,
  66                         // which is derived from the file path in this case.
  67                         $this->openFile( $p['dbFilePath'] );
  68                         $lockDomain = md5( $p['dbFilePath'] );
  69                 } elseif ( !isset( $p['dbDirectory'] ) ) {
  70                         throw new InvalidArgumentException( "Need 'dbDirectory' or 'dbFilePath' parameter." );
  71                 } else {
  72                         $this->dbDir = $p['dbDirectory'];
  73                         $this->mDBname = $p['dbname'];
  74                         $lockDomain = $this->mDBname;
  75                         // Stock wiki mode using standard file names per DB.
  76                         parent::__construct( $p );
  77                         // Super doesn't open when $user is false, but we can work with $dbName
  78                         if ( $p['dbname'] && !$this->isOpen() ) {
  79                                 if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  80                                         $done = [];
  81                                         foreach ( $this->tableAliases as $params ) {
  82                                                 if ( isset( $done[$params['dbname']] ) ) {
  83                                                         continue;
  84                                                 }
  85                                                 $this->attachDatabase( $params['dbname'] );
  86                                                 $done[$params['dbname']] = 1;
  87                                         }
  88                                 }
  89                         }
  90                 }
  91
  92                 $this->trxMode = isset( $p['trxMode'] ) ? strtoupper( $p['trxMode'] ) : null;
  93                 if ( $this->trxMode &&
  94                         !in_array( $this->trxMode, [ 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ] )
  95                 ) {
  96                         $this->trxMode = null;
  97                         $this->queryLogger->warning( "Invalid SQLite transaction mode provided." );
  98                 }
  99
 100                 $this->lockMgr = new FSLockManager( [
 101                         'domain' => $lockDomain,
 102                         'lockDirectory' => "{$this->dbDir}/locks"
 103                 ] );
 104         }
 105
 106         /**
 107          * @param string $filename
 108          * @param array $p Options map; supports:
 109          *   - flags       : (same as __construct counterpart)
 110          *   - trxMode     : (same as __construct counterpart)
 111          *   - dbDirectory : (same as __construct counterpart)
 112          * @return DatabaseSqlite
 113          * @since 1.25
 114          */
 115         public static function newStandaloneInstance( $filename, array $p = [] ) {
 116                 $p['dbFilePath'] = $filename;
 117                 $p['schema'] = false;
 118                 $p['tablePrefix'] = '';
 119
 120                 return DatabaseBase::factory( 'sqlite', $p );
 121         }
 122
 123         /**
 124          * @return string
 125          */
 126         function getType() {
 127                 return 'sqlite';
 128         }
 129
 130         /**
 131          * @todo Check if it should be true like parent class
 132          *
 133          * @return bool
 134          */
 135         function implicitGroupby() {
 136                 return false;
 137         }
 138
 139         /** Open an SQLite database and return a resource handle to it
 140          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
 141          *
 142          * @param string $server
 143          * @param string $user
 144          * @param string $pass
 145          * @param string $dbName
 146          *
 147          * @throws DBConnectionError
 148          * @return PDO
 149          */
 150         function open( $server, $user, $pass, $dbName ) {
 151                 $this->close();
 152                 $fileName = self::generateFileName( $this->dbDir, $dbName );
 153                 if ( !is_readable( $fileName ) ) {
 154                         $this->mConn = false;
 155                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 156                 }
 157                 $this->openFile( $fileName );
 158
 159                 return $this->mConn;
 160         }
 161
 162         /**
 163          * Opens a database file
 164          *
 165          * @param string $fileName
 166          * @throws DBConnectionError
 167          * @return PDO|bool SQL connection or false if failed
 168          */
 169         protected function openFile( $fileName ) {
 170                 $err = false;
 171
 172                 $this->dbPath = $fileName;
 173                 try {
 174                         if ( $this->mFlags & DBO_PERSISTENT ) {
 175                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 176                                         [ PDO::ATTR_PERSISTENT => true ] );
 177                         } else {
 178                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 179                         }
 180                 } catch ( PDOException $e ) {
 181                         $err = $e->getMessage();
 182                 }
 183
 184                 if ( !$this->mConn ) {
 185                         $this->queryLogger->debug( "DB connection error: $err\n" );
 186                         throw new DBConnectionError( $this, $err );
 187                 }
 188
 189                 $this->mOpened = !!$this->mConn;
 190                 if ( $this->mOpened ) {
 191                         # Set error codes only, don't raise exceptions
 192                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 193                         # Enforce LIKE to be case sensitive, just like MySQL
 194                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 195
 196                         return $this->mConn;
 197                 }
 198
 199                 return false;
 200         }
 201
 202         /**
 203          * @return string SQLite DB file path
 204          * @since 1.25
 205          */
 206         public function getDbFilePath() {
 207                 return $this->dbPath;
 208         }
 209
 210         /**
 211          * Does not actually close the connection, just destroys the reference for GC to do its work
 212          * @return bool
 213          */
 214         protected function closeConnection() {
 215                 $this->mConn = null;
 216
 217                 return true;
 218         }
 219
 220         /**
 221          * Generates a database file name. Explicitly public for installer.
 222          * @param string $dir Directory where database resides
 223          * @param string $dbName Database name
 224          * @return string
 225          */
 226         public static function generateFileName( $dir, $dbName ) {
 227                 return "$dir/$dbName.sqlite";
 228         }
 229
 230         /**
 231          * Check if the searchindext table is FTS enabled.
 232          * @return bool False if not enabled.
 233          */
 234         function checkForEnabledSearch() {
 235                 if ( self::$fulltextEnabled === null ) {
 236                         self::$fulltextEnabled = false;
 237                         $table = $this->tableName( 'searchindex' );
 238                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 239                         if ( $res ) {
 240                                 $row = $res->fetchRow();
 241                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 242                         }
 243                 }
 244
 245                 return self::$fulltextEnabled;
 246         }
 247
 248         /**
 249          * Returns version of currently supported SQLite fulltext search module or false if none present.
 250          * @return string
 251          */
 252         static function getFulltextSearchModule() {
 253                 static $cachedResult = null;
 254                 if ( $cachedResult !== null ) {
 255                         return $cachedResult;
 256                 }
 257                 $cachedResult = false;
 258                 $table = 'dummy_search_test';
 259
 260                 $db = self::newStandaloneInstance( ':memory:' );
 261                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 262                         $cachedResult = 'FTS3';
 263                 }
 264                 $db->close();
 265
 266                 return $cachedResult;
 267         }
 268
 269         /**
 270          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 271          * for details.
 272          *
 273          * @param string $name Database name to be used in queries like
 274          *   SELECT foo FROM dbname.table
 275          * @param bool|string $file Database file name. If omitted, will be generated
 276          *   using $name and configured data directory
 277          * @param string $fname Calling function name
 278          * @return ResultWrapper
 279          */
 280         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 281                 if ( !$file ) {
 282                         $file = self::generateFileName( $this->dbDir, $name );
 283                 }
 284                 $file = $this->addQuotes( $file );
 285
 286                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 287         }
 288
 289         function isWriteQuery( $sql ) {
 290                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 291         }
 292
 293         /**
 294          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 295          *
 296          * @param string $sql
 297          * @return bool|ResultWrapper
 298          */
 299         protected function doQuery( $sql ) {
 300                 $res = $this->mConn->query( $sql );
 301                 if ( $res === false ) {
 302                         return false;
 303                 }
 304
 305                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 306                 $this->mAffectedRows = $r->rowCount();
 307                 $res = new ResultWrapper( $this, $r->fetchAll() );
 308
 309                 return $res;
 310         }
 311
 312         /**
 313          * @param ResultWrapper|mixed $res
 314          */
 315         function freeResult( $res ) {
 316                 if ( $res instanceof ResultWrapper ) {
 317                         $res->result = null;
 318                 } else {
 319                         $res = null;
 320                 }
 321         }
 322
 323         /**
 324          * @param ResultWrapper|array $res
 325          * @return stdClass|bool
 326          */
 327         function fetchObject( $res ) {
 328                 if ( $res instanceof ResultWrapper ) {
 329                         $r =& $res->result;
 330                 } else {
 331                         $r =& $res;
 332                 }
 333
 334                 $cur = current( $r );
 335                 if ( is_array( $cur ) ) {
 336                         next( $r );
 337                         $obj = new stdClass;
 338                         foreach ( $cur as $k => $v ) {
 339                                 if ( !is_numeric( $k ) ) {
 340                                         $obj->$k = $v;
 341                                 }
 342                         }
 343
 344                         return $obj;
 345                 }
 346
 347                 return false;
 348         }
 349
 350         /**
 351          * @param ResultWrapper|mixed $res
 352          * @return array|bool
 353          */
 354         function fetchRow( $res ) {
 355                 if ( $res instanceof ResultWrapper ) {
 356                         $r =& $res->result;
 357                 } else {
 358                         $r =& $res;
 359                 }
 360                 $cur = current( $r );
 361                 if ( is_array( $cur ) ) {
 362                         next( $r );
 363
 364                         return $cur;
 365                 }
 366
 367                 return false;
 368         }
 369
 370         /**
 371          * The PDO::Statement class implements the array interface so count() will work
 372          *
 373          * @param ResultWrapper|array $res
 374          * @return int
 375          */
 376         function numRows( $res ) {
 377                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 378
 379                 return count( $r );
 380         }
 381
 382         /**
 383          * @param ResultWrapper $res
 384          * @return int
 385          */
 386         function numFields( $res ) {
 387                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 388                 if ( is_array( $r ) && count( $r ) > 0 ) {
 389                         // The size of the result array is twice the number of fields. (Bug: 65578)
 390                         return count( $r[0] ) / 2;
 391                 } else {
 392                         // If the result is empty return 0
 393                         return 0;
 394                 }
 395         }
 396
 397         /**
 398          * @param ResultWrapper $res
 399          * @param int $n
 400          * @return bool
 401          */
 402         function fieldName( $res, $n ) {
 403                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 404                 if ( is_array( $r ) ) {
 405                         $keys = array_keys( $r[0] );
 406
 407                         return $keys[$n];
 408                 }
 409
 410                 return false;
 411         }
 412
 413         /**
 414          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 415          *
 416          * @param string $name
 417          * @param string $format
 418          * @return string
 419          */
 420         function tableName( $name, $format = 'quoted' ) {
 421                 // table names starting with sqlite_ are reserved
 422                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 423                         return $name;
 424                 }
 425
 426                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 427         }
 428
 429         /**
 430          * Index names have DB scope
 431          *
 432          * @param string $index
 433          * @return string
 434          */
 435         protected function indexName( $index ) {
 436                 return $index;
 437         }
 438
 439         /**
 440          * This must be called after nextSequenceVal
 441          *
 442          * @return int
 443          */
 444         function insertId() {
 445                 // PDO::lastInsertId yields a string :(
 446                 return intval( $this->mConn->lastInsertId() );
 447         }
 448
 449         /**
 450          * @param ResultWrapper|array $res
 451          * @param int $row
 452          */
 453         function dataSeek( $res, $row ) {
 454                 if ( $res instanceof ResultWrapper ) {
 455                         $r =& $res->result;
 456                 } else {
 457                         $r =& $res;
 458                 }
 459                 reset( $r );
 460                 if ( $row > 0 ) {
 461                         for ( $i = 0; $i < $row; $i++ ) {
 462                                 next( $r );
 463                         }
 464                 }
 465         }
 466
 467         /**
 468          * @return string
 469          */
 470         function lastError() {
 471                 if ( !is_object( $this->mConn ) ) {
 472                         return "Cannot return last error, no db connection";
 473                 }
 474                 $e = $this->mConn->errorInfo();
 475
 476                 return isset( $e[2] ) ? $e[2] : '';
 477         }
 478
 479         /**
 480          * @return string
 481          */
 482         function lastErrno() {
 483                 if ( !is_object( $this->mConn ) ) {
 484                         return "Cannot return last error, no db connection";
 485                 } else {
 486                         $info = $this->mConn->errorInfo();
 487
 488                         return $info[1];
 489                 }
 490         }
 491
 492         /**
 493          * @return int
 494          */
 495         function affectedRows() {
 496                 return $this->mAffectedRows;
 497         }
 498
 499         /**
 500          * Returns information about an index
 501          * Returns false if the index does not exist
 502          * - if errors are explicitly ignored, returns NULL on failure
 503          *
 504          * @param string $table
 505          * @param string $index
 506          * @param string $fname
 507          * @return array
 508          */
 509         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 510                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 511                 $res = $this->query( $sql, $fname );
 512                 if ( !$res ) {
 513                         return null;
 514                 }
 515                 if ( $res->numRows() == 0 ) {
 516                         return false;
 517                 }
 518                 $info = [];
 519                 foreach ( $res as $row ) {
 520                         $info[] = $row->name;
 521                 }
 522
 523                 return $info;
 524         }
 525
 526         /**
 527          * @param string $table
 528          * @param string $index
 529          * @param string $fname
 530          * @return bool|null
 531          */
 532         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 533                 $row = $this->selectRow( 'sqlite_master', '*',
 534                         [
 535                                 'type' => 'index',
 536                                 'name' => $this->indexName( $index ),
 537                         ], $fname );
 538                 if ( !$row || !isset( $row->sql ) ) {
 539                         return null;
 540                 }
 541
 542                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 543                 $indexPos = strpos( $row->sql, 'INDEX' );
 544                 if ( $indexPos === false ) {
 545                         return null;
 546                 }
 547                 $firstPart = substr( $row->sql, 0, $indexPos );
 548                 $options = explode( ' ', $firstPart );
 549
 550                 return in_array( 'UNIQUE', $options );
 551         }
 552
 553         /**
 554          * Filter the options used in SELECT statements
 555          *
 556          * @param array $options
 557          * @return array
 558          */
 559         function makeSelectOptions( $options ) {
 560                 foreach ( $options as $k => $v ) {
 561                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 562                                 $options[$k] = '';
 563                         }
 564                 }
 565
 566                 return parent::makeSelectOptions( $options );
 567         }
 568
 569         /**
 570          * @param array $options
 571          * @return string
 572          */
 573         protected function makeUpdateOptionsArray( $options ) {
 574                 $options = parent::makeUpdateOptionsArray( $options );
 575                 $options = self::fixIgnore( $options );
 576
 577                 return $options;
 578         }
 579
 580         /**
 581          * @param array $options
 582          * @return array
 583          */
 584         static function fixIgnore( $options ) {
 585                 # SQLite uses OR IGNORE not just IGNORE
 586                 foreach ( $options as $k => $v ) {
 587                         if ( $v == 'IGNORE' ) {
 588                                 $options[$k] = 'OR IGNORE';
 589                         }
 590                 }
 591
 592                 return $options;
 593         }
 594
 595         /**
 596          * @param array $options
 597          * @return string
 598          */
 599         function makeInsertOptions( $options ) {
 600                 $options = self::fixIgnore( $options );
 601
 602                 return parent::makeInsertOptions( $options );
 603         }
 604
 605         /**
 606          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 607          * @param string $table
 608          * @param array $a
 609          * @param string $fname
 610          * @param array $options
 611          * @return bool
 612          */
 613         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 614                 if ( !count( $a ) ) {
 615                         return true;
 616                 }
 617
 618                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 619                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 620                         $ret = true;
 621                         foreach ( $a as $v ) {
 622                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 623                                         $ret = false;
 624                                 }
 625                         }
 626                 } else {
 627                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 628                 }
 629
 630                 return $ret;
 631         }
 632
 633         /**
 634          * @param string $table
 635          * @param array $uniqueIndexes Unused
 636          * @param string|array $rows
 637          * @param string $fname
 638          * @return bool|ResultWrapper
 639          */
 640         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 641                 if ( !count( $rows ) ) {
 642                         return true;
 643                 }
 644
 645                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 646                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 647                         $ret = true;
 648                         foreach ( $rows as $v ) {
 649                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 650                                         $ret = false;
 651                                 }
 652                         }
 653                 } else {
 654                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 655                 }
 656
 657                 return $ret;
 658         }
 659
 660         /**
 661          * Returns the size of a text field, or -1 for "unlimited"
 662          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 663          *
 664          * @param string $table
 665          * @param string $field
 666          * @return int
 667          */
 668         function textFieldSize( $table, $field ) {
 669                 return -1;
 670         }
 671
 672         /**
 673          * @return bool
 674          */
 675         function unionSupportsOrderAndLimit() {
 676                 return false;
 677         }
 678
 679         /**
 680          * @param string $sqls
 681          * @param bool $all Whether to "UNION ALL" or not
 682          * @return string
 683          */
 684         function unionQueries( $sqls, $all ) {
 685                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 686
 687                 return implode( $glue, $sqls );
 688         }
 689
 690         /**
 691          * @return bool
 692          */
 693         function wasDeadlock() {
 694                 return $this->lastErrno() == 5; // SQLITE_BUSY
 695         }
 696
 697         /**
 698          * @return bool
 699          */
 700         function wasErrorReissuable() {
 701                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 702         }
 703
 704         /**
 705          * @return bool
 706          */
 707         function wasReadOnlyError() {
 708                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 709         }
 710
 711         /**
 712          * @return string Wikitext of a link to the server software's web site
 713          */
 714         public function getSoftwareLink() {
 715                 return "[{{int:version-db-sqlite-url}} SQLite]";
 716         }
 717
 718         /**
 719          * @return string Version information from the database
 720          */
 721         function getServerVersion() {
 722                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 723
 724                 return $ver;
 725         }
 726
 727         /**
 728          * Get information about a given field
 729          * Returns false if the field does not exist.
 730          *
 731          * @param string $table
 732          * @param string $field
 733          * @return SQLiteField|bool False on failure
 734          */
 735         function fieldInfo( $table, $field ) {
 736                 $tableName = $this->tableName( $table );
 737                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 738                 $res = $this->query( $sql, __METHOD__ );
 739                 foreach ( $res as $row ) {
 740                         if ( $row->name == $field ) {
 741                                 return new SQLiteField( $row, $tableName );
 742                         }
 743                 }
 744
 745                 return false;
 746         }
 747
 748         protected function doBegin( $fname = '' ) {
 749                 if ( $this->trxMode ) {
 750                         $this->query( "BEGIN {$this->trxMode}", $fname );
 751                 } else {
 752                         $this->query( 'BEGIN', $fname );
 753                 }
 754                 $this->mTrxLevel = 1;
 755         }
 756
 757         /**
 758          * @param string $s
 759          * @return string
 760          */
 761         function strencode( $s ) {
 762                 return substr( $this->addQuotes( $s ), 1, -1 );
 763         }
 764
 765         /**
 766          * @param string $b
 767          * @return Blob
 768          */
 769         function encodeBlob( $b ) {
 770                 return new Blob( $b );
 771         }
 772
 773         /**
 774          * @param Blob|string $b
 775          * @return string
 776          */
 777         function decodeBlob( $b ) {
 778                 if ( $b instanceof Blob ) {
 779                         $b = $b->fetch();
 780                 }
 781
 782                 return $b;
 783         }
 784
 785         /**
 786          * @param string|int|null|bool|Blob $s
 787          * @return string|int
 788          */
 789         function addQuotes( $s ) {
 790                 if ( $s instanceof Blob ) {
 791                         return "x'" . bin2hex( $s->fetch() ) . "'";
 792                 } elseif ( is_bool( $s ) ) {
 793                         return (int)$s;
 794                 } elseif ( strpos( $s, "\0" ) !== false ) {
 795                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 796                         // This is a known limitation of SQLite's mprintf function which PDO
 797                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 798                         // https://bugs.php.net/bug.php?id=63419
 799                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 800                         // https://bugs.php.net/bug.php?id=62361
 801                         // There is an additional bug regarding sorting this data after insert
 802                         // on older versions of sqlite shipped with ubuntu 12.04
 803                         // https://phabricator.wikimedia.org/T74367
 804                         $this->queryLogger->debug(
 805                                 __FUNCTION__ .
 806                                 ': Quoting value containing null byte. ' .
 807                                 'For consistency all binary data should have been ' .
 808                                 'first processed with self::encodeBlob()'
 809                         );
 810                         return "x'" . bin2hex( $s ) . "'";
 811                 } else {
 812                         return $this->mConn->quote( $s );
 813                 }
 814         }
 815
 816         /**
 817          * @return string
 818          */
 819         function buildLike() {
 820                 $params = func_get_args();
 821                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 822                         $params = $params[0];
 823                 }
 824
 825                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 826         }
 827
 828         /**
 829          * @param string $field Field or column to cast
 830          * @return string
 831          * @since 1.28
 832          */
 833         public function buildStringCast( $field ) {
 834                 return 'CAST ( ' . $field . ' AS TEXT )';
 835         }
 836
 837         /**
 838          * No-op version of deadlockLoop
 839          *
 840          * @return mixed
 841          */
 842         public function deadlockLoop( /*...*/ ) {
 843                 $args = func_get_args();
 844                 $function = array_shift( $args );
 845
 846                 return call_user_func_array( $function, $args );
 847         }
 848
 849         /**
 850          * @param string $s
 851          * @return string
 852          */
 853         protected function replaceVars( $s ) {
 854                 $s = parent::replaceVars( $s );
 855                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 856                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 857
 858                         // binary/varbinary column type -> blob
 859                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 860                         // no such thing as unsigned
 861                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 862                         // INT -> INTEGER
 863                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 864                         // floating point types -> REAL
 865                         $s = preg_replace(
 866                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 867                                 'REAL',
 868                                 $s
 869                         );
 870                         // varchar -> TEXT
 871                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 872                         // TEXT normalization
 873                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 874                         // BLOB normalization
 875                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 876                         // BOOL -> INTEGER
 877                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 878                         // DATETIME -> TEXT
 879                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 880                         // No ENUM type
 881                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 882                         // binary collation type -> nothing
 883                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 884                         // auto_increment -> autoincrement
 885                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 886                         // No explicit options
 887                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 888                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 889                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 890                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 891                         // No truncated indexes
 892                         $s = preg_replace( '/\(\d+\)/', '', $s );
 893                         // No FULLTEXT
 894                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 895                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 896                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 897                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 898                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 899                         // INSERT IGNORE --> INSERT OR IGNORE
 900                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 901                 }
 902
 903                 return $s;
 904         }
 905
 906         public function lock( $lockName, $method, $timeout = 5 ) {
 907                 if ( !is_dir( "{$this->dbDir}/locks" ) ) { // create dir as needed
 908                         if ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) ) {
 909                                 throw new DBError( $this, "Cannot create directory \"{$this->dbDir}/locks\"." );
 910                         }
 911                 }
 912
 913                 return $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout )->isOK();
 914         }
 915
 916         public function unlock( $lockName, $method ) {
 917                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isOK();
 918         }
 919
 920         /**
 921          * Build a concatenation list to feed into a SQL query
 922          *
 923          * @param string[] $stringList
 924          * @return string
 925          */
 926         function buildConcat( $stringList ) {
 927                 return '(' . implode( ') || (', $stringList ) . ')';
 928         }
 929
 930         public function buildGroupConcatField(
 931                 $delim, $table, $field, $conds = '', $join_conds = []
 932         ) {
 933                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 934
 935                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
 936         }
 937
 938         /**
 939          * @param string $oldName
 940          * @param string $newName
 941          * @param bool $temporary
 942          * @param string $fname
 943          * @return bool|ResultWrapper
 944          * @throws RuntimeException
 945          */
 946         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 947                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 948                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 949                 $obj = $this->fetchObject( $res );
 950                 if ( !$obj ) {
 951                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
 952                 }
 953                 $sql = $obj->sql;
 954                 $sql = preg_replace(
 955                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 956                         $this->addIdentifierQuotes( $newName ),
 957                         $sql,
 958                         1
 959                 );
 960                 if ( $temporary ) {
 961                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 962                                 $this->queryLogger->debug(
 963                                         "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 964                         } else {
 965                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 966                         }
 967                 }
 968
 969                 $res = $this->query( $sql, $fname );
 970
 971                 // Take over indexes
 972                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
 973                 foreach ( $indexList as $index ) {
 974                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
 975                                 continue;
 976                         }
 977
 978                         if ( $index->unique ) {
 979                                 $sql = 'CREATE UNIQUE INDEX';
 980                         } else {
 981                                 $sql = 'CREATE INDEX';
 982                         }
 983                         // Try to come up with a new index name, given indexes have database scope in SQLite
 984                         $indexName = $newName . '_' . $index->name;
 985                         $sql .= ' ' . $indexName . ' ON ' . $newName;
 986
 987                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
 988                         $fields = [];
 989                         foreach ( $indexInfo as $indexInfoRow ) {
 990                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
 991                         }
 992
 993                         $sql .= '(' . implode( ',', $fields ) . ')';
 994
 995                         $this->query( $sql );
 996                 }
 997
 998                 return $res;
 999         }
1000
1001         /**
1002          * List all tables on the database
1003          *
1004          * @param string $prefix Only show tables with this prefix, e.g. mw_
1005          * @param string $fname Calling function name
1006          *
1007          * @return array
1008          */
1009         function listTables( $prefix = null, $fname = __METHOD__ ) {
1010                 $result = $this->select(
1011                         'sqlite_master',
1012                         'name',
1013                         "type='table'"
1014                 );
1015
1016                 $endArray = [];
1017
1018                 foreach ( $result as $table ) {
1019                         $vars = get_object_vars( $table );
1020                         $table = array_pop( $vars );
1021
1022                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1023                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1024                                         $endArray[] = $table;
1025                                 }
1026                         }
1027                 }
1028
1029                 return $endArray;
1030         }
1031
1032         /**
1033          * Override due to no CASCADE support
1034          *
1035          * @param string $tableName
1036          * @param string $fName
1037          * @return bool|ResultWrapper
1038          * @throws DBReadOnlyError
1039          */
1040         public function dropTable( $tableName, $fName = __METHOD__ ) {
1041                 if ( !$this->tableExists( $tableName, $fName ) ) {
1042                         return false;
1043                 }
1044                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1045
1046                 return $this->query( $sql, $fName );
1047         }
1048
1049         protected function requiresDatabaseUser() {
1050                 return false; // just a file
1051         }
1052
1053         /**
1054          * @return string
1055          */
1056         public function __toString() {
1057                 return 'SQLite ' . (string)$this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
1058         }
1059 }