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 File name for SQLite database file */
  33         public $mDatabaseFile;
  34
  35         /** @var int The number of rows affected as an integer */
  36         protected $mAffectedRows;
  37
  38         /** @var resource */
  39         protected $mLastResult;
  40
  41         /**
  42          * @var string
  43          * @todo Seems to serve no purpose. Remove?
  44          */
  45         private $mName;
  46
  47         /** @var PDO */
  48         protected $mConn;
  49
  50         function __construct( $p = null ) {
  51                 global $wgSharedDB;
  52
  53                 if ( !is_array( $p ) ) { // legacy calling pattern
  54                         wfDeprecated( __METHOD__ . " method called without parameter array.", "1.22" );
  55                         $args = func_get_args();
  56                         $p = array(
  57                                 'host' => isset( $args[0] ) ? $args[0] : false,
  58                                 'user' => isset( $args[1] ) ? $args[1] : false,
  59                                 'password' => isset( $args[2] ) ? $args[2] : false,
  60                                 'dbname' => isset( $args[3] ) ? $args[3] : false,
  61                                 'flags' => isset( $args[4] ) ? $args[4] : 0,
  62                                 'tablePrefix' => isset( $args[5] ) ? $args[5] : 'get from global',
  63                                 'foreign' => isset( $args[6] ) ? $args[6] : false
  64                         );
  65                 }
  66                 $this->mName = $p['dbname'];
  67                 parent::__construct( $p );
  68                 // parent doesn't open when $user is false, but we can work with $dbName
  69                 if ( $p['dbname'] && !$this->isOpen() ) {
  70                         if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  71                                 if ( $wgSharedDB ) {
  72                                         $this->attachDatabase( $wgSharedDB );
  73                                 }
  74                         }
  75                 }
  76         }
  77
  78         /**
  79          * @return string
  80          */
  81         function getType() {
  82                 return 'sqlite';
  83         }
  84
  85         /**
  86          * @todo Check if it should be true like parent class
  87          *
  88          * @return bool
  89          */
  90         function implicitGroupby() {
  91                 return false;
  92         }
  93
  94         /** Open an SQLite database and return a resource handle to it
  95          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  96          *
  97          * @param string $server
  98          * @param string $user
  99          * @param string $pass
 100          * @param string $dbName
 101          *
 102          * @throws DBConnectionError
 103          * @return PDO
 104          */
 105         function open( $server, $user, $pass, $dbName ) {
 106                 global $wgSQLiteDataDir;
 107
 108                 $this->close();
 109                 $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
 110                 if ( !is_readable( $fileName ) ) {
 111                         $this->mConn = false;
 112                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 113                 }
 114                 $this->openFile( $fileName );
 115
 116                 return $this->mConn;
 117         }
 118
 119         /**
 120          * Opens a database file
 121          *
 122          * @param string $fileName
 123          * @throws DBConnectionError
 124          * @return PDO|bool SQL connection or false if failed
 125          */
 126         function openFile( $fileName ) {
 127                 $err = false;
 128
 129                 $this->mDatabaseFile = $fileName;
 130                 try {
 131                         if ( $this->mFlags & DBO_PERSISTENT ) {
 132                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 133                                         array( PDO::ATTR_PERSISTENT => true ) );
 134                         } else {
 135                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 136                         }
 137                 } catch ( PDOException $e ) {
 138                         $err = $e->getMessage();
 139                 }
 140
 141                 if ( !$this->mConn ) {
 142                         wfDebug( "DB connection error: $err\n" );
 143                         throw new DBConnectionError( $this, $err );
 144                 }
 145
 146                 $this->mOpened = !!$this->mConn;
 147                 # set error codes only, don't raise exceptions
 148                 if ( $this->mOpened ) {
 149                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 150                         # Enforce LIKE to be case sensitive, just like MySQL
 151                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 152
 153                         return true;
 154                 }
 155         }
 156
 157         /**
 158          * Does not actually close the connection, just destroys the reference for GC to do its work
 159          * @return bool
 160          */
 161         protected function closeConnection() {
 162                 $this->mConn = null;
 163
 164                 return true;
 165         }
 166
 167         /**
 168          * Generates a database file name. Explicitly public for installer.
 169          * @param string $dir Directory where database resides
 170          * @param string $dbName Database name
 171          * @return string
 172          */
 173         public static function generateFileName( $dir, $dbName ) {
 174                 return "$dir/$dbName.sqlite";
 175         }
 176
 177         /**
 178          * Check if the searchindext table is FTS enabled.
 179          * @return bool False if not enabled.
 180          */
 181         function checkForEnabledSearch() {
 182                 if ( self::$fulltextEnabled === null ) {
 183                         self::$fulltextEnabled = false;
 184                         $table = $this->tableName( 'searchindex' );
 185                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 186                         if ( $res ) {
 187                                 $row = $res->fetchRow();
 188                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 189                         }
 190                 }
 191
 192                 return self::$fulltextEnabled;
 193         }
 194
 195         /**
 196          * Returns version of currently supported SQLite fulltext search module or false if none present.
 197          * @return string
 198          */
 199         static function getFulltextSearchModule() {
 200                 static $cachedResult = null;
 201                 if ( $cachedResult !== null ) {
 202                         return $cachedResult;
 203                 }
 204                 $cachedResult = false;
 205                 $table = 'dummy_search_test';
 206
 207                 $db = new DatabaseSqliteStandalone( ':memory:' );
 208
 209                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 210                         $cachedResult = 'FTS3';
 211                 }
 212                 $db->close();
 213
 214                 return $cachedResult;
 215         }
 216
 217         /**
 218          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 219          * for details.
 220          *
 221          * @param string $name Database name to be used in queries like
 222          *   SELECT foo FROM dbname.table
 223          * @param bool|string $file Database file name. If omitted, will be generated
 224          *   using $name and $wgSQLiteDataDir
 225          * @param string $fname Calling function name
 226          * @return ResultWrapper
 227          */
 228         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 229                 global $wgSQLiteDataDir;
 230                 if ( !$file ) {
 231                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 232                 }
 233                 $file = $this->addQuotes( $file );
 234
 235                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 236         }
 237
 238         /**
 239          * @see DatabaseBase::isWriteQuery()
 240          *
 241          * @param $sql string
 242          * @return bool
 243          */
 244         function isWriteQuery( $sql ) {
 245                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 246         }
 247
 248         /**
 249          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 250          *
 251          * @param string $sql
 252          * @return bool|ResultWrapper
 253          */
 254         protected function doQuery( $sql ) {
 255                 $res = $this->mConn->query( $sql );
 256                 if ( $res === false ) {
 257                         return false;
 258                 } else {
 259                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 260                         $this->mAffectedRows = $r->rowCount();
 261                         $res = new ResultWrapper( $this, $r->fetchAll() );
 262                 }
 263
 264                 return $res;
 265         }
 266
 267         /**
 268          * @param ResultWrapper|mixed $res
 269          */
 270         function freeResult( $res ) {
 271                 if ( $res instanceof ResultWrapper ) {
 272                         $res->result = null;
 273                 } else {
 274                         $res = null;
 275                 }
 276         }
 277
 278         /**
 279          * @param ResultWrapper|array $res
 280          * @return stdClass|bool
 281          */
 282         function fetchObject( $res ) {
 283                 if ( $res instanceof ResultWrapper ) {
 284                         $r =& $res->result;
 285                 } else {
 286                         $r =& $res;
 287                 }
 288
 289                 $cur = current( $r );
 290                 if ( is_array( $cur ) ) {
 291                         next( $r );
 292                         $obj = new stdClass;
 293                         foreach ( $cur as $k => $v ) {
 294                                 if ( !is_numeric( $k ) ) {
 295                                         $obj->$k = $v;
 296                                 }
 297                         }
 298
 299                         return $obj;
 300                 }
 301
 302                 return false;
 303         }
 304
 305         /**
 306          * @param ResultWrapper|mixed $res
 307          * @return array|bool
 308          */
 309         function fetchRow( $res ) {
 310                 if ( $res instanceof ResultWrapper ) {
 311                         $r =& $res->result;
 312                 } else {
 313                         $r =& $res;
 314                 }
 315                 $cur = current( $r );
 316                 if ( is_array( $cur ) ) {
 317                         next( $r );
 318
 319                         return $cur;
 320                 }
 321
 322                 return false;
 323         }
 324
 325         /**
 326          * The PDO::Statement class implements the array interface so count() will work
 327          *
 328          * @param ResultWrapper|array $res
 329          * @return int
 330          */
 331         function numRows( $res ) {
 332                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 333
 334                 return count( $r );
 335         }
 336
 337         /**
 338          * @param ResultWrapper $res
 339          * @return int
 340          */
 341         function numFields( $res ) {
 342                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 343
 344                 return is_array( $r ) ? count( $r[0] ) : 0;
 345         }
 346
 347         /**
 348          * @param ResultWrapper $res
 349          * @param $n
 350          * @return bool
 351          */
 352         function fieldName( $res, $n ) {
 353                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 354                 if ( is_array( $r ) ) {
 355                         $keys = array_keys( $r[0] );
 356
 357                         return $keys[$n];
 358                 }
 359
 360                 return false;
 361         }
 362
 363         /**
 364          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 365          *
 366          * @param string $name
 367          * @param string $format
 368          * @return string
 369          */
 370         function tableName( $name, $format = 'quoted' ) {
 371                 // table names starting with sqlite_ are reserved
 372                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 373                         return $name;
 374                 }
 375
 376                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 377         }
 378
 379         /**
 380          * Index names have DB scope
 381          *
 382          * @param string $index
 383          * @return string
 384          */
 385         function indexName( $index ) {
 386                 return $index;
 387         }
 388
 389         /**
 390          * This must be called after nextSequenceVal
 391          *
 392          * @return int
 393          */
 394         function insertId() {
 395                 // PDO::lastInsertId yields a string :(
 396                 return intval( $this->mConn->lastInsertId() );
 397         }
 398
 399         /**
 400          * @param ResultWrapper|array $res
 401          * @param int $row
 402          */
 403         function dataSeek( $res, $row ) {
 404                 if ( $res instanceof ResultWrapper ) {
 405                         $r =& $res->result;
 406                 } else {
 407                         $r =& $res;
 408                 }
 409                 reset( $r );
 410                 if ( $row > 0 ) {
 411                         for ( $i = 0; $i < $row; $i++ ) {
 412                                 next( $r );
 413                         }
 414                 }
 415         }
 416
 417         /**
 418          * @return string
 419          */
 420         function lastError() {
 421                 if ( !is_object( $this->mConn ) ) {
 422                         return "Cannot return last error, no db connection";
 423                 }
 424                 $e = $this->mConn->errorInfo();
 425
 426                 return isset( $e[2] ) ? $e[2] : '';
 427         }
 428
 429         /**
 430          * @return string
 431          */
 432         function lastErrno() {
 433                 if ( !is_object( $this->mConn ) ) {
 434                         return "Cannot return last error, no db connection";
 435                 } else {
 436                         $info = $this->mConn->errorInfo();
 437
 438                         return $info[1];
 439                 }
 440         }
 441
 442         /**
 443          * @return int
 444          */
 445         function affectedRows() {
 446                 return $this->mAffectedRows;
 447         }
 448
 449         /**
 450          * Returns information about an index
 451          * Returns false if the index does not exist
 452          * - if errors are explicitly ignored, returns NULL on failure
 453          *
 454          * @param string $table
 455          * @param string $index
 456          * @param string $fname
 457          * @return array
 458          */
 459         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 460                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 461                 $res = $this->query( $sql, $fname );
 462                 if ( !$res ) {
 463                         return null;
 464                 }
 465                 if ( $res->numRows() == 0 ) {
 466                         return false;
 467                 }
 468                 $info = array();
 469                 foreach ( $res as $row ) {
 470                         $info[] = $row->name;
 471                 }
 472
 473                 return $info;
 474         }
 475
 476         /**
 477          * @param string $table
 478          * @param string $index
 479          * @param string $fname
 480          * @return bool|null
 481          */
 482         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 483                 $row = $this->selectRow( 'sqlite_master', '*',
 484                         array(
 485                                 'type' => 'index',
 486                                 'name' => $this->indexName( $index ),
 487                         ), $fname );
 488                 if ( !$row || !isset( $row->sql ) ) {
 489                         return null;
 490                 }
 491
 492                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 493                 $indexPos = strpos( $row->sql, 'INDEX' );
 494                 if ( $indexPos === false ) {
 495                         return null;
 496                 }
 497                 $firstPart = substr( $row->sql, 0, $indexPos );
 498                 $options = explode( ' ', $firstPart );
 499
 500                 return in_array( 'UNIQUE', $options );
 501         }
 502
 503         /**
 504          * Filter the options used in SELECT statements
 505          *
 506          * @param array $options
 507          * @return array
 508          */
 509         function makeSelectOptions( $options ) {
 510                 foreach ( $options as $k => $v ) {
 511                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 512                                 $options[$k] = '';
 513                         }
 514                 }
 515
 516                 return parent::makeSelectOptions( $options );
 517         }
 518
 519         /**
 520          * @param array $options
 521          * @return string
 522          */
 523         protected function makeUpdateOptions( $options ) {
 524                 $options = self::fixIgnore( $options );
 525
 526                 return parent::makeUpdateOptions( $options );
 527         }
 528
 529         /**
 530          * @param array $options
 531          * @return array
 532          */
 533         static function fixIgnore( $options ) {
 534                 # SQLite uses OR IGNORE not just IGNORE
 535                 foreach ( $options as $k => $v ) {
 536                         if ( $v == 'IGNORE' ) {
 537                                 $options[$k] = 'OR IGNORE';
 538                         }
 539                 }
 540
 541                 return $options;
 542         }
 543
 544         /**
 545          * @param array $options
 546          * @return string
 547          */
 548         function makeInsertOptions( $options ) {
 549                 $options = self::fixIgnore( $options );
 550
 551                 return parent::makeInsertOptions( $options );
 552         }
 553
 554         /**
 555          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 556          * @param string $table
 557          * @param array $a
 558          * @param string $fname
 559          * @param array $options
 560          * @return bool
 561          */
 562         function insert( $table, $a, $fname = __METHOD__, $options = array() ) {
 563                 if ( !count( $a ) ) {
 564                         return true;
 565                 }
 566
 567                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 568                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 569                         $ret = true;
 570                         foreach ( $a as $v ) {
 571                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 572                                         $ret = false;
 573                                 }
 574                         }
 575                 } else {
 576                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 577                 }
 578
 579                 return $ret;
 580         }
 581
 582         /**
 583          * @param string $table
 584          * @param array $uniqueIndexes Unused
 585          * @param string|array $rows
 586          * @param string $fname
 587          * @return bool|ResultWrapper
 588          */
 589         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 590                 if ( !count( $rows ) ) {
 591                         return true;
 592                 }
 593
 594                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 595                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 596                         $ret = true;
 597                         foreach ( $rows as $v ) {
 598                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 599                                         $ret = false;
 600                                 }
 601                         }
 602                 } else {
 603                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 604                 }
 605
 606                 return $ret;
 607         }
 608
 609         /**
 610          * Returns the size of a text field, or -1 for "unlimited"
 611          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 612          *
 613          * @param string $table
 614          * @param string $field
 615          * @return int
 616          */
 617         function textFieldSize( $table, $field ) {
 618                 return -1;
 619         }
 620
 621         /**
 622          * @return bool
 623          */
 624         function unionSupportsOrderAndLimit() {
 625                 return false;
 626         }
 627
 628         /**
 629          * @param string $sqls
 630          * @param bool $all Whether to "UNION ALL" or not
 631          * @return string
 632          */
 633         function unionQueries( $sqls, $all ) {
 634                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 635
 636                 return implode( $glue, $sqls );
 637         }
 638
 639         /**
 640          * @return bool
 641          */
 642         function wasDeadlock() {
 643                 return $this->lastErrno() == 5; // SQLITE_BUSY
 644         }
 645
 646         /**
 647          * @return bool
 648          */
 649         function wasErrorReissuable() {
 650                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 651         }
 652
 653         /**
 654          * @return bool
 655          */
 656         function wasReadOnlyError() {
 657                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 658         }
 659
 660         /**
 661          * @return string wikitext of a link to the server software's web site
 662          */
 663         public function getSoftwareLink() {
 664                 return "[http://sqlite.org/ SQLite]";
 665         }
 666
 667         /**
 668          * @return string Version information from the database
 669          */
 670         function getServerVersion() {
 671                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 672
 673                 return $ver;
 674         }
 675
 676         /**
 677          * @return string User-friendly database information
 678          */
 679         public function getServerInfo() {
 680                 return wfMessage( self::getFulltextSearchModule()
 681                         ? 'sqlite-has-fts'
 682                         : 'sqlite-no-fts', $this->getServerVersion() )->text();
 683         }
 684
 685         /**
 686          * Get information about a given field
 687          * Returns false if the field does not exist.
 688          *
 689          * @param string $table
 690          * @param string $field
 691          * @return SQLiteField|bool False on failure
 692          */
 693         function fieldInfo( $table, $field ) {
 694                 $tableName = $this->tableName( $table );
 695                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 696                 $res = $this->query( $sql, __METHOD__ );
 697                 foreach ( $res as $row ) {
 698                         if ( $row->name == $field ) {
 699                                 return new SQLiteField( $row, $tableName );
 700                         }
 701                 }
 702
 703                 return false;
 704         }
 705
 706         protected function doBegin( $fname = '' ) {
 707                 if ( $this->mTrxLevel == 1 ) {
 708                         $this->commit( __METHOD__ );
 709                 }
 710                 try {
 711                         $this->mConn->beginTransaction();
 712                 } catch ( PDOException $e ) {
 713                         throw new DBUnexpectedError( $this, 'Error in BEGIN query: ' . $e->getMessage() );
 714                 }
 715                 $this->mTrxLevel = 1;
 716         }
 717
 718         protected function doCommit( $fname = '' ) {
 719                 if ( $this->mTrxLevel == 0 ) {
 720                         return;
 721                 }
 722                 try {
 723                         $this->mConn->commit();
 724                 } catch ( PDOException $e ) {
 725                         throw new DBUnexpectedError( $this, 'Error in COMMIT query: ' . $e->getMessage() );
 726                 }
 727                 $this->mTrxLevel = 0;
 728         }
 729
 730         protected function doRollback( $fname = '' ) {
 731                 if ( $this->mTrxLevel == 0 ) {
 732                         return;
 733                 }
 734                 $this->mConn->rollBack();
 735                 $this->mTrxLevel = 0;
 736         }
 737
 738         /**
 739          * @param string $s
 740          * @return string
 741          */
 742         function strencode( $s ) {
 743                 return substr( $this->addQuotes( $s ), 1, -1 );
 744         }
 745
 746         /**
 747          * @param $b
 748          * @return Blob
 749          */
 750         function encodeBlob( $b ) {
 751                 return new Blob( $b );
 752         }
 753
 754         /**
 755          * @param $b Blob|string
 756          * @return string
 757          */
 758         function decodeBlob( $b ) {
 759                 if ( $b instanceof Blob ) {
 760                         $b = $b->fetch();
 761                 }
 762
 763                 return $b;
 764         }
 765
 766         /**
 767          * @param Blob|string $s
 768          * @return string
 769          */
 770         function addQuotes( $s ) {
 771                 if ( $s instanceof Blob ) {
 772                         return "x'" . bin2hex( $s->fetch() ) . "'";
 773                 } elseif ( is_bool( $s ) ) {
 774                         return (int)$s;
 775                 } elseif ( strpos( $s, "\0" ) !== false ) {
 776                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 777                         // This is a known limitation of SQLite's mprintf function which PDO should work around,
 778                         // but doesn't. I have reported this to php.net as bug #63419:
 779                         // https://bugs.php.net/bug.php?id=63419
 780                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 781                         // https://bugs.php.net/bug.php?id=62361
 782                         return "x'" . bin2hex( $s ) . "'";
 783                 } else {
 784                         return $this->mConn->quote( $s );
 785                 }
 786         }
 787
 788         /**
 789          * @return string
 790          */
 791         function buildLike() {
 792                 $params = func_get_args();
 793                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 794                         $params = $params[0];
 795                 }
 796
 797                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 798         }
 799
 800         /**
 801          * @return string
 802          */
 803         public function getSearchEngine() {
 804                 return "SearchSqlite";
 805         }
 806
 807         /**
 808          * No-op version of deadlockLoop
 809          *
 810          * @return mixed
 811          */
 812         public function deadlockLoop( /*...*/ ) {
 813                 $args = func_get_args();
 814                 $function = array_shift( $args );
 815
 816                 return call_user_func_array( $function, $args );
 817         }
 818
 819         /**
 820          * @param string $s
 821          * @return string
 822          */
 823         protected function replaceVars( $s ) {
 824                 $s = parent::replaceVars( $s );
 825                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 826                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 827
 828                         // binary/varbinary column type -> blob
 829                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 830                         // no such thing as unsigned
 831                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 832                         // INT -> INTEGER
 833                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 834                         // floating point types -> REAL
 835                         $s = preg_replace(
 836                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 837                                 'REAL',
 838                                 $s
 839                         );
 840                         // varchar -> TEXT
 841                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 842                         // TEXT normalization
 843                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 844                         // BLOB normalization
 845                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 846                         // BOOL -> INTEGER
 847                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 848                         // DATETIME -> TEXT
 849                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 850                         // No ENUM type
 851                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 852                         // binary collation type -> nothing
 853                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 854                         // auto_increment -> autoincrement
 855                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 856                         // No explicit options
 857                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 858                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 859                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 860                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 861                         // No truncated indexes
 862                         $s = preg_replace( '/\(\d+\)/', '', $s );
 863                         // No FULLTEXT
 864                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 865                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 866                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 867                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 868                 }
 869
 870                 return $s;
 871         }
 872
 873         /**
 874          * Build a concatenation list to feed into a SQL query
 875          *
 876          * @param string[] $stringList
 877          * @return string
 878          */
 879         function buildConcat( $stringList ) {
 880                 return '(' . implode( ') || (', $stringList ) . ')';
 881         }
 882
 883         public function buildGroupConcatField(
 884                 $delim, $table, $field, $conds = '', $join_conds = array()
 885         ) {
 886                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 887
 888                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, array(), $join_conds ) . ')';
 889         }
 890
 891         /**
 892          * @throws MWException
 893          * @param string $oldName
 894          * @param string $newName
 895          * @param bool $temporary
 896          * @param string $fname
 897          * @return bool|ResultWrapper
 898          */
 899         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 900                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 901                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 902                 $obj = $this->fetchObject( $res );
 903                 if ( !$obj ) {
 904                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 905                 }
 906                 $sql = $obj->sql;
 907                 $sql = preg_replace(
 908                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 909                         $this->addIdentifierQuotes( $newName ),
 910                         $sql,
 911                         1
 912                 );
 913                 if ( $temporary ) {
 914                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 915                                 wfDebug( "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 916                         } else {
 917                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 918                         }
 919                 }
 920
 921                 return $this->query( $sql, $fname );
 922         }
 923
 924         /**
 925          * List all tables on the database
 926          *
 927          * @param string $prefix Only show tables with this prefix, e.g. mw_
 928          * @param string $fname Calling function name
 929          *
 930          * @return array
 931          */
 932         function listTables( $prefix = null, $fname = __METHOD__ ) {
 933                 $result = $this->select(
 934                         'sqlite_master',
 935                         'name',
 936                         "type='table'"
 937                 );
 938
 939                 $endArray = array();
 940
 941                 foreach ( $result as $table ) {
 942                         $vars = get_object_vars( $table );
 943                         $table = array_pop( $vars );
 944
 945                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
 946                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
 947                                         $endArray[] = $table;
 948                                 }
 949                         }
 950                 }
 951
 952                 return $endArray;
 953         }
 954 } // end DatabaseSqlite class
 955
 956 /**
 957  * This class allows simple acccess to a SQLite database independently from main database settings
 958  * @ingroup Database
 959  */
 960 class DatabaseSqliteStandalone extends DatabaseSqlite {
 961         public function __construct( $fileName, $flags = 0 ) {
 962                 $this->mFlags = $flags;
 963                 $this->tablePrefix( null );
 964                 $this->openFile( $fileName );
 965         }
 966 }
 967
 968 /**
 969  * @ingroup Database
 970  */
 971 class SQLiteField implements Field {
 972         private $info, $tableName;
 973
 974         function __construct( $info, $tableName ) {
 975                 $this->info = $info;
 976                 $this->tableName = $tableName;
 977         }
 978
 979         function name() {
 980                 return $this->info->name;
 981         }
 982
 983         function tableName() {
 984                 return $this->tableName;
 985         }
 986
 987         function defaultValue() {
 988                 if ( is_string( $this->info->dflt_value ) ) {
 989                         // Typically quoted
 990                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 991                                 return str_replace( "''", "'", $this->info->dflt_value );
 992                         }
 993                 }
 994
 995                 return $this->info->dflt_value;
 996         }
 997
 998         /**
 999          * @return bool
1000          */
1001         function isNullable() {
1002                 return !$this->info->notnull;
1003         }
1004
1005         function type() {
1006                 return $this->info->type;
1007         }
1008 } // end SQLiteField