includes/db/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                 global $wgSharedDB, $wgSQLiteDataDir;
  63
  64                 $this->dbDir = isset( $p['dbDirectory'] ) ? $p['dbDirectory'] : $wgSQLiteDataDir;
  65
  66                 if ( isset( $p['dbFilePath'] ) ) {
  67                         $this->mFlags = isset( $p['flags'] ) ? $p['flags'] : 0;
  68                         // Standalone .sqlite file mode
  69                         $this->openFile( $p['dbFilePath'] );
  70                         // @FIXME: clean up base constructor so this can call super instead
  71                         $this->mTrxAtomicLevels = new SplStack;
  72                 } else {
  73                         $this->mDBname = $p['dbname'];
  74                         // Stock wiki mode using standard file names per DB
  75                         parent::__construct( $p );
  76                         // parent doesn't open when $user is false, but we can work with $dbName
  77                         if ( $p['dbname'] && !$this->isOpen() ) {
  78                                 if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  79                                         if ( $wgSharedDB ) {
  80                                                 $this->attachDatabase( $wgSharedDB );
  81                                         }
  82                                 }
  83                         }
  84                 }
  85
  86                 $this->trxMode = isset( $p['trxMode'] ) ? strtoupper( $p['trxMode'] ) : null;
  87                 if ( $this->trxMode &&
  88                         !in_array( $this->trxMode, array( 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ) )
  89                 ) {
  90                         $this->trxMode = null;
  91                         wfWarn( "Invalid SQLite transaction mode provided." );
  92                 }
  93
  94                 $this->lockMgr = new FSLockManager( array( 'lockDirectory' => "{$this->dbDir}/locks" ) );
  95         }
  96
  97         /**
  98          * @param string $filename
  99          * @param array $p Options map; supports:
 100          *   - flags       : (same as __construct counterpart)
 101          *   - trxMode     : (same as __construct counterpart)
 102          *   - dbDirectory : (same as __construct counterpart)
 103          * @return DatabaseSqlite
 104          * @since 1.25
 105          */
 106         public static function newStandaloneInstance( $filename, array $p = array() ) {
 107                 $p['dbFilePath'] = $filename;
 108
 109                 return new self( $p );
 110         }
 111
 112         /**
 113          * @return string
 114          */
 115         function getType() {
 116                 return 'sqlite';
 117         }
 118
 119         /**
 120          * @todo Check if it should be true like parent class
 121          *
 122          * @return bool
 123          */
 124         function implicitGroupby() {
 125                 return false;
 126         }
 127
 128         /** Open an SQLite database and return a resource handle to it
 129          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
 130          *
 131          * @param string $server
 132          * @param string $user
 133          * @param string $pass
 134          * @param string $dbName
 135          *
 136          * @throws DBConnectionError
 137          * @return PDO
 138          */
 139         function open( $server, $user, $pass, $dbName ) {
 140                 $this->close();
 141                 $fileName = self::generateFileName( $this->dbDir, $dbName );
 142                 if ( !is_readable( $fileName ) ) {
 143                         $this->mConn = false;
 144                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 145                 }
 146                 $this->openFile( $fileName );
 147
 148                 return $this->mConn;
 149         }
 150
 151         /**
 152          * Opens a database file
 153          *
 154          * @param string $fileName
 155          * @throws DBConnectionError
 156          * @return PDO|bool SQL connection or false if failed
 157          */
 158         protected function openFile( $fileName ) {
 159                 $err = false;
 160
 161                 $this->dbPath = $fileName;
 162                 try {
 163                         if ( $this->mFlags & DBO_PERSISTENT ) {
 164                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 165                                         array( PDO::ATTR_PERSISTENT => true ) );
 166                         } else {
 167                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 168                         }
 169                 } catch ( PDOException $e ) {
 170                         $err = $e->getMessage();
 171                 }
 172
 173                 if ( !$this->mConn ) {
 174                         wfDebug( "DB connection error: $err\n" );
 175                         throw new DBConnectionError( $this, $err );
 176                 }
 177
 178                 $this->mOpened = !!$this->mConn;
 179                 if ( $this->mOpened ) {
 180                         # Set error codes only, don't raise exceptions
 181                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 182                         # Enforce LIKE to be case sensitive, just like MySQL
 183                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 184
 185                         return $this->mConn;
 186                 }
 187
 188                 return false;
 189         }
 190
 191         /**
 192          * @return string SQLite DB file path
 193          * @since 1.25
 194          */
 195         public function getDbFilePath() {
 196                 return $this->dbPath;
 197         }
 198
 199         /**
 200          * Does not actually close the connection, just destroys the reference for GC to do its work
 201          * @return bool
 202          */
 203         protected function closeConnection() {
 204                 $this->mConn = null;
 205
 206                 return true;
 207         }
 208
 209         /**
 210          * Generates a database file name. Explicitly public for installer.
 211          * @param string $dir Directory where database resides
 212          * @param string $dbName Database name
 213          * @return string
 214          */
 215         public static function generateFileName( $dir, $dbName ) {
 216                 return "$dir/$dbName.sqlite";
 217         }
 218
 219         /**
 220          * Check if the searchindext table is FTS enabled.
 221          * @return bool False if not enabled.
 222          */
 223         function checkForEnabledSearch() {
 224                 if ( self::$fulltextEnabled === null ) {
 225                         self::$fulltextEnabled = false;
 226                         $table = $this->tableName( 'searchindex' );
 227                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 228                         if ( $res ) {
 229                                 $row = $res->fetchRow();
 230                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 231                         }
 232                 }
 233
 234                 return self::$fulltextEnabled;
 235         }
 236
 237         /**
 238          * Returns version of currently supported SQLite fulltext search module or false if none present.
 239          * @return string
 240          */
 241         static function getFulltextSearchModule() {
 242                 static $cachedResult = null;
 243                 if ( $cachedResult !== null ) {
 244                         return $cachedResult;
 245                 }
 246                 $cachedResult = false;
 247                 $table = 'dummy_search_test';
 248
 249                 $db = self::newStandaloneInstance( ':memory:' );
 250                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 251                         $cachedResult = 'FTS3';
 252                 }
 253                 $db->close();
 254
 255                 return $cachedResult;
 256         }
 257
 258         /**
 259          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 260          * for details.
 261          *
 262          * @param string $name Database name to be used in queries like
 263          *   SELECT foo FROM dbname.table
 264          * @param bool|string $file Database file name. If omitted, will be generated
 265          *   using $name and configured data directory
 266          * @param string $fname Calling function name
 267          * @return ResultWrapper
 268          */
 269         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 270                 if ( !$file ) {
 271                         $file = self::generateFileName( $this->dbDir, $name );
 272                 }
 273                 $file = $this->addQuotes( $file );
 274
 275                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 276         }
 277
 278         /**
 279          * @see DatabaseBase::isWriteQuery()
 280          *
 281          * @param string $sql
 282          * @return bool
 283          */
 284         function isWriteQuery( $sql ) {
 285                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 286         }
 287
 288         /**
 289          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 290          *
 291          * @param string $sql
 292          * @return bool|ResultWrapper
 293          */
 294         protected function doQuery( $sql ) {
 295                 $res = $this->mConn->query( $sql );
 296                 if ( $res === false ) {
 297                         return false;
 298                 } else {
 299                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 300                         $this->mAffectedRows = $r->rowCount();
 301                         $res = new ResultWrapper( $this, $r->fetchAll() );
 302                 }
 303
 304                 return $res;
 305         }
 306
 307         /**
 308          * @param ResultWrapper|mixed $res
 309          */
 310         function freeResult( $res ) {
 311                 if ( $res instanceof ResultWrapper ) {
 312                         $res->result = null;
 313                 } else {
 314                         $res = null;
 315                 }
 316         }
 317
 318         /**
 319          * @param ResultWrapper|array $res
 320          * @return stdClass|bool
 321          */
 322         function fetchObject( $res ) {
 323                 if ( $res instanceof ResultWrapper ) {
 324                         $r =& $res->result;
 325                 } else {
 326                         $r =& $res;
 327                 }
 328
 329                 $cur = current( $r );
 330                 if ( is_array( $cur ) ) {
 331                         next( $r );
 332                         $obj = new stdClass;
 333                         foreach ( $cur as $k => $v ) {
 334                                 if ( !is_numeric( $k ) ) {
 335                                         $obj->$k = $v;
 336                                 }
 337                         }
 338
 339                         return $obj;
 340                 }
 341
 342                 return false;
 343         }
 344
 345         /**
 346          * @param ResultWrapper|mixed $res
 347          * @return array|bool
 348          */
 349         function fetchRow( $res ) {
 350                 if ( $res instanceof ResultWrapper ) {
 351                         $r =& $res->result;
 352                 } else {
 353                         $r =& $res;
 354                 }
 355                 $cur = current( $r );
 356                 if ( is_array( $cur ) ) {
 357                         next( $r );
 358
 359                         return $cur;
 360                 }
 361
 362                 return false;
 363         }
 364
 365         /**
 366          * The PDO::Statement class implements the array interface so count() will work
 367          *
 368          * @param ResultWrapper|array $res
 369          * @return int
 370          */
 371         function numRows( $res ) {
 372                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 373
 374                 return count( $r );
 375         }
 376
 377         /**
 378          * @param ResultWrapper $res
 379          * @return int
 380          */
 381         function numFields( $res ) {
 382                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 383                 if ( is_array( $r ) && count( $r ) > 0 ) {
 384                         // The size of the result array is twice the number of fields. (Bug: 65578)
 385                         return count( $r[0] ) / 2;
 386                 } else {
 387                         // If the result is empty return 0
 388                         return 0;
 389                 }
 390         }
 391
 392         /**
 393          * @param ResultWrapper $res
 394          * @param int $n
 395          * @return bool
 396          */
 397         function fieldName( $res, $n ) {
 398                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 399                 if ( is_array( $r ) ) {
 400                         $keys = array_keys( $r[0] );
 401
 402                         return $keys[$n];
 403                 }
 404
 405                 return false;
 406         }
 407
 408         /**
 409          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 410          *
 411          * @param string $name
 412          * @param string $format
 413          * @return string
 414          */
 415         function tableName( $name, $format = 'quoted' ) {
 416                 // table names starting with sqlite_ are reserved
 417                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 418                         return $name;
 419                 }
 420
 421                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 422         }
 423
 424         /**
 425          * Index names have DB scope
 426          *
 427          * @param string $index
 428          * @return string
 429          */
 430         function indexName( $index ) {
 431                 return $index;
 432         }
 433
 434         /**
 435          * This must be called after nextSequenceVal
 436          *
 437          * @return int
 438          */
 439         function insertId() {
 440                 // PDO::lastInsertId yields a string :(
 441                 return intval( $this->mConn->lastInsertId() );
 442         }
 443
 444         /**
 445          * @param ResultWrapper|array $res
 446          * @param int $row
 447          */
 448         function dataSeek( $res, $row ) {
 449                 if ( $res instanceof ResultWrapper ) {
 450                         $r =& $res->result;
 451                 } else {
 452                         $r =& $res;
 453                 }
 454                 reset( $r );
 455                 if ( $row > 0 ) {
 456                         for ( $i = 0; $i < $row; $i++ ) {
 457                                 next( $r );
 458                         }
 459                 }
 460         }
 461
 462         /**
 463          * @return string
 464          */
 465         function lastError() {
 466                 if ( !is_object( $this->mConn ) ) {
 467                         return "Cannot return last error, no db connection";
 468                 }
 469                 $e = $this->mConn->errorInfo();
 470
 471                 return isset( $e[2] ) ? $e[2] : '';
 472         }
 473
 474         /**
 475          * @return string
 476          */
 477         function lastErrno() {
 478                 if ( !is_object( $this->mConn ) ) {
 479                         return "Cannot return last error, no db connection";
 480                 } else {
 481                         $info = $this->mConn->errorInfo();
 482
 483                         return $info[1];
 484                 }
 485         }
 486
 487         /**
 488          * @return int
 489          */
 490         function affectedRows() {
 491                 return $this->mAffectedRows;
 492         }
 493
 494         /**
 495          * Returns information about an index
 496          * Returns false if the index does not exist
 497          * - if errors are explicitly ignored, returns NULL on failure
 498          *
 499          * @param string $table
 500          * @param string $index
 501          * @param string $fname
 502          * @return array
 503          */
 504         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 505                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 506                 $res = $this->query( $sql, $fname );
 507                 if ( !$res ) {
 508                         return null;
 509                 }
 510                 if ( $res->numRows() == 0 ) {
 511                         return false;
 512                 }
 513                 $info = array();
 514                 foreach ( $res as $row ) {
 515                         $info[] = $row->name;
 516                 }
 517
 518                 return $info;
 519         }
 520
 521         /**
 522          * @param string $table
 523          * @param string $index
 524          * @param string $fname
 525          * @return bool|null
 526          */
 527         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 528                 $row = $this->selectRow( 'sqlite_master', '*',
 529                         array(
 530                                 'type' => 'index',
 531                                 'name' => $this->indexName( $index ),
 532                         ), $fname );
 533                 if ( !$row || !isset( $row->sql ) ) {
 534                         return null;
 535                 }
 536
 537                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 538                 $indexPos = strpos( $row->sql, 'INDEX' );
 539                 if ( $indexPos === false ) {
 540                         return null;
 541                 }
 542                 $firstPart = substr( $row->sql, 0, $indexPos );
 543                 $options = explode( ' ', $firstPart );
 544
 545                 return in_array( 'UNIQUE', $options );
 546         }
 547
 548         /**
 549          * Filter the options used in SELECT statements
 550          *
 551          * @param array $options
 552          * @return array
 553          */
 554         function makeSelectOptions( $options ) {
 555                 foreach ( $options as $k => $v ) {
 556                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 557                                 $options[$k] = '';
 558                         }
 559                 }
 560
 561                 return parent::makeSelectOptions( $options );
 562         }
 563
 564         /**
 565          * @param array $options
 566          * @return string
 567          */
 568         protected function makeUpdateOptionsArray( $options ) {
 569                 $options = parent::makeUpdateOptionsArray( $options );
 570                 $options = self::fixIgnore( $options );
 571
 572                 return $options;
 573         }
 574
 575         /**
 576          * @param array $options
 577          * @return array
 578          */
 579         static function fixIgnore( $options ) {
 580                 # SQLite uses OR IGNORE not just IGNORE
 581                 foreach ( $options as $k => $v ) {
 582                         if ( $v == 'IGNORE' ) {
 583                                 $options[$k] = 'OR IGNORE';
 584                         }
 585                 }
 586
 587                 return $options;
 588         }
 589
 590         /**
 591          * @param array $options
 592          * @return string
 593          */
 594         function makeInsertOptions( $options ) {
 595                 $options = self::fixIgnore( $options );
 596
 597                 return parent::makeInsertOptions( $options );
 598         }
 599
 600         /**
 601          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 602          * @param string $table
 603          * @param array $a
 604          * @param string $fname
 605          * @param array $options
 606          * @return bool
 607          */
 608         function insert( $table, $a, $fname = __METHOD__, $options = array() ) {
 609                 if ( !count( $a ) ) {
 610                         return true;
 611                 }
 612
 613                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 614                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 615                         $ret = true;
 616                         foreach ( $a as $v ) {
 617                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 618                                         $ret = false;
 619                                 }
 620                         }
 621                 } else {
 622                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 623                 }
 624
 625                 return $ret;
 626         }
 627
 628         /**
 629          * @param string $table
 630          * @param array $uniqueIndexes Unused
 631          * @param string|array $rows
 632          * @param string $fname
 633          * @return bool|ResultWrapper
 634          */
 635         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 636                 if ( !count( $rows ) ) {
 637                         return true;
 638                 }
 639
 640                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 641                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 642                         $ret = true;
 643                         foreach ( $rows as $v ) {
 644                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 645                                         $ret = false;
 646                                 }
 647                         }
 648                 } else {
 649                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 650                 }
 651
 652                 return $ret;
 653         }
 654
 655         /**
 656          * Returns the size of a text field, or -1 for "unlimited"
 657          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 658          *
 659          * @param string $table
 660          * @param string $field
 661          * @return int
 662          */
 663         function textFieldSize( $table, $field ) {
 664                 return -1;
 665         }
 666
 667         /**
 668          * @return bool
 669          */
 670         function unionSupportsOrderAndLimit() {
 671                 return false;
 672         }
 673
 674         /**
 675          * @param string $sqls
 676          * @param bool $all Whether to "UNION ALL" or not
 677          * @return string
 678          */
 679         function unionQueries( $sqls, $all ) {
 680                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 681
 682                 return implode( $glue, $sqls );
 683         }
 684
 685         /**
 686          * @return bool
 687          */
 688         function wasDeadlock() {
 689                 return $this->lastErrno() == 5; // SQLITE_BUSY
 690         }
 691
 692         /**
 693          * @return bool
 694          */
 695         function wasErrorReissuable() {
 696                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 697         }
 698
 699         /**
 700          * @return bool
 701          */
 702         function wasReadOnlyError() {
 703                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 704         }
 705
 706         /**
 707          * @return string Wikitext of a link to the server software's web site
 708          */
 709         public function getSoftwareLink() {
 710                 return "[{{int:version-db-sqlite-url}} SQLite]";
 711         }
 712
 713         /**
 714          * @return string Version information from the database
 715          */
 716         function getServerVersion() {
 717                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 718
 719                 return $ver;
 720         }
 721
 722         /**
 723          * @return string User-friendly database information
 724          */
 725         public function getServerInfo() {
 726                 return wfMessage( self::getFulltextSearchModule()
 727                         ? 'sqlite-has-fts'
 728                         : 'sqlite-no-fts', $this->getServerVersion() )->text();
 729         }
 730
 731         /**
 732          * Get information about a given field
 733          * Returns false if the field does not exist.
 734          *
 735          * @param string $table
 736          * @param string $field
 737          * @return SQLiteField|bool False on failure
 738          */
 739         function fieldInfo( $table, $field ) {
 740                 $tableName = $this->tableName( $table );
 741                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 742                 $res = $this->query( $sql, __METHOD__ );
 743                 foreach ( $res as $row ) {
 744                         if ( $row->name == $field ) {
 745                                 return new SQLiteField( $row, $tableName );
 746                         }
 747                 }
 748
 749                 return false;
 750         }
 751
 752         protected function doBegin( $fname = '' ) {
 753                 if ( $this->trxMode ) {
 754                         $this->query( "BEGIN {$this->trxMode}", $fname );
 755                 } else {
 756                         $this->query( 'BEGIN', $fname );
 757                 }
 758                 $this->mTrxLevel = 1;
 759         }
 760
 761         /**
 762          * @param string $s
 763          * @return string
 764          */
 765         function strencode( $s ) {
 766                 return substr( $this->addQuotes( $s ), 1, -1 );
 767         }
 768
 769         /**
 770          * @param string $b
 771          * @return Blob
 772          */
 773         function encodeBlob( $b ) {
 774                 return new Blob( $b );
 775         }
 776
 777         /**
 778          * @param Blob|string $b
 779          * @return string
 780          */
 781         function decodeBlob( $b ) {
 782                 if ( $b instanceof Blob ) {
 783                         $b = $b->fetch();
 784                 }
 785
 786                 return $b;
 787         }
 788
 789         /**
 790          * @param Blob|string $s
 791          * @return string
 792          */
 793         function addQuotes( $s ) {
 794                 if ( $s instanceof Blob ) {
 795                         return "x'" . bin2hex( $s->fetch() ) . "'";
 796                 } elseif ( is_bool( $s ) ) {
 797                         return (int)$s;
 798                 } elseif ( strpos( $s, "\0" ) !== false ) {
 799                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 800                         // This is a known limitation of SQLite's mprintf function which PDO should work around,
 801                         // but doesn't. I have reported this to php.net as bug #63419:
 802                         // https://bugs.php.net/bug.php?id=63419
 803                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 804                         // https://bugs.php.net/bug.php?id=62361
 805                         // There is an additional bug regarding sorting this data after insert
 806                         // on older versions of sqlite shipped with ubuntu 12.04
 807                         // https://bugzilla.wikimedia.org/show_bug.cgi?id=72367
 808                         wfDebugLog( __CLASS__, __FUNCTION__ . ': Quoting value containing null byte. For consistency all binary data should have been first processed with self::encodeBlob()' );
 809                         return "x'" . bin2hex( $s ) . "'";
 810                 } else {
 811                         return $this->mConn->quote( $s );
 812                 }
 813         }
 814
 815         /**
 816          * @return string
 817          */
 818         function buildLike() {
 819                 $params = func_get_args();
 820                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 821                         $params = $params[0];
 822                 }
 823
 824                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 825         }
 826
 827         /**
 828          * @return string
 829          */
 830         public function getSearchEngine() {
 831                 return "SearchSqlite";
 832         }
 833
 834         /**
 835          * No-op version of deadlockLoop
 836          *
 837          * @return mixed
 838          */
 839         public function deadlockLoop( /*...*/ ) {
 840                 $args = func_get_args();
 841                 $function = array_shift( $args );
 842
 843                 return call_user_func_array( $function, $args );
 844         }
 845
 846         /**
 847          * @param string $s
 848          * @return string
 849          */
 850         protected function replaceVars( $s ) {
 851                 $s = parent::replaceVars( $s );
 852                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 853                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 854
 855                         // binary/varbinary column type -> blob
 856                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 857                         // no such thing as unsigned
 858                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 859                         // INT -> INTEGER
 860                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 861                         // floating point types -> REAL
 862                         $s = preg_replace(
 863                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 864                                 'REAL',
 865                                 $s
 866                         );
 867                         // varchar -> TEXT
 868                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 869                         // TEXT normalization
 870                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 871                         // BLOB normalization
 872                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 873                         // BOOL -> INTEGER
 874                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 875                         // DATETIME -> TEXT
 876                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 877                         // No ENUM type
 878                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 879                         // binary collation type -> nothing
 880                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 881                         // auto_increment -> autoincrement
 882                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 883                         // No explicit options
 884                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 885                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 886                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 887                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 888                         // No truncated indexes
 889                         $s = preg_replace( '/\(\d+\)/', '', $s );
 890                         // No FULLTEXT
 891                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 892                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 893                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 894                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 895                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 896                         // INSERT IGNORE --> INSERT OR IGNORE
 897                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 898                 }
 899
 900                 return $s;
 901         }
 902
 903         public function lock( $lockName, $method, $timeout = 5 ) {
 904                 if ( !is_dir( "{$this->dbDir}/locks" ) ) { // create dir as needed
 905                         if ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) ) {
 906                                 throw new DBError( "Cannot create directory \"{$this->dbDir}/locks\"." );
 907                         }
 908                 }
 909
 910                 return $this->lockMgr->lock( array( $lockName ), LockManager::LOCK_EX, $timeout )->isOK();
 911         }
 912
 913         public function unlock( $lockName, $method ) {
 914                 return $this->lockMgr->unlock( array( $lockName ), LockManager::LOCK_EX )->isOK();
 915         }
 916
 917         /**
 918          * Build a concatenation list to feed into a SQL query
 919          *
 920          * @param string[] $stringList
 921          * @return string
 922          */
 923         function buildConcat( $stringList ) {
 924                 return '(' . implode( ') || (', $stringList ) . ')';
 925         }
 926
 927         public function buildGroupConcatField(
 928                 $delim, $table, $field, $conds = '', $join_conds = array()
 929         ) {
 930                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 931
 932                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, array(), $join_conds ) . ')';
 933         }
 934
 935         /**
 936          * @throws MWException
 937          * @param string $oldName
 938          * @param string $newName
 939          * @param bool $temporary
 940          * @param string $fname
 941          * @return bool|ResultWrapper
 942          */
 943         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 944                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 945                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 946                 $obj = $this->fetchObject( $res );
 947                 if ( !$obj ) {
 948                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 949                 }
 950                 $sql = $obj->sql;
 951                 $sql = preg_replace(
 952                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 953                         $this->addIdentifierQuotes( $newName ),
 954                         $sql,
 955                         1
 956                 );
 957                 if ( $temporary ) {
 958                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 959                                 wfDebug( "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 960                         } else {
 961                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 962                         }
 963                 }
 964
 965                 return $this->query( $sql, $fname );
 966         }
 967
 968         /**
 969          * List all tables on the database
 970          *
 971          * @param string $prefix Only show tables with this prefix, e.g. mw_
 972          * @param string $fname Calling function name
 973          *
 974          * @return array
 975          */
 976         function listTables( $prefix = null, $fname = __METHOD__ ) {
 977                 $result = $this->select(
 978                         'sqlite_master',
 979                         'name',
 980                         "type='table'"
 981                 );
 982
 983                 $endArray = array();
 984
 985                 foreach ( $result as $table ) {
 986                         $vars = get_object_vars( $table );
 987                         $table = array_pop( $vars );
 988
 989                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
 990                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
 991                                         $endArray[] = $table;
 992                                 }
 993                         }
 994                 }
 995
 996                 return $endArray;
 997         }
 998 } // end DatabaseSqlite class
 999
1000 /**
1001  * @ingroup Database
1002  */
1003 class SQLiteField implements Field {
1004         private $info, $tableName;
1005
1006         function __construct( $info, $tableName ) {
1007                 $this->info = $info;
1008                 $this->tableName = $tableName;
1009         }
1010
1011         function name() {
1012                 return $this->info->name;
1013         }
1014
1015         function tableName() {
1016                 return $this->tableName;
1017         }
1018
1019         function defaultValue() {
1020                 if ( is_string( $this->info->dflt_value ) ) {
1021                         // Typically quoted
1022                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
1023                                 return str_replace( "''", "'", $this->info->dflt_value );
1024                         }
1025                 }
1026
1027                 return $this->info->dflt_value;
1028         }
1029
1030         /**
1031          * @return bool
1032          */
1033         function isNullable() {
1034                 return !$this->info->notnull;
1035         }
1036
1037         function type() {
1038                 return $this->info->type;
1039         }
1040 } // end SQLiteField