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 $wgSQLiteDataDir;
  63
  64                 $this->dbDir = isset( $p['dbDirectory'] ) ? $p['dbDirectory'] : $wgSQLiteDataDir;
  65
  66                 if ( isset( $p['dbFilePath'] ) ) {
  67                         parent::__construct( $p );
  68                         // Standalone .sqlite file mode.
  69                         // Super doesn't open when $user is false, but we can work with $dbName,
  70                         // which is derived from the file path in this case.
  71                         $this->openFile( $p['dbFilePath'] );
  72                         $lockDomain = md5( $p['dbFilePath'] );
  73                 } else {
  74                         $this->mDBname = $p['dbname'];
  75                         $lockDomain = $this->mDBname;
  76                         // Stock wiki mode using standard file names per DB.
  77                         parent::__construct( $p );
  78                         // Super doesn't open when $user is false, but we can work with $dbName
  79                         if ( $p['dbname'] && !$this->isOpen() ) {
  80                                 if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  81                                         $done = [];
  82                                         foreach ( $this->tableAliases as $params ) {
  83                                                 if ( isset( $done[$params['dbname']] ) ) {
  84                                                         continue;
  85                                                 }
  86                                                 $this->attachDatabase( $params['dbname'] );
  87                                                 $done[$params['dbname']] = 1;
  88                                         }
  89                                 }
  90                         }
  91                 }
  92
  93                 $this->trxMode = isset( $p['trxMode'] ) ? strtoupper( $p['trxMode'] ) : null;
  94                 if ( $this->trxMode &&
  95                         !in_array( $this->trxMode, [ 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE' ] )
  96                 ) {
  97                         $this->trxMode = null;
  98                         wfWarn( "Invalid SQLite transaction mode provided." );
  99                 }
 100
 101                 $this->lockMgr = new FSLockManager( [
 102                         'domain' => $lockDomain,
 103                         'lockDirectory' => "{$this->dbDir}/locks"
 104                 ] );
 105         }
 106
 107         /**
 108          * @param string $filename
 109          * @param array $p Options map; supports:
 110          *   - flags       : (same as __construct counterpart)
 111          *   - trxMode     : (same as __construct counterpart)
 112          *   - dbDirectory : (same as __construct counterpart)
 113          * @return DatabaseSqlite
 114          * @since 1.25
 115          */
 116         public static function newStandaloneInstance( $filename, array $p = [] ) {
 117                 $p['dbFilePath'] = $filename;
 118                 $p['schema'] = false;
 119                 $p['tablePrefix'] = '';
 120
 121                 return DatabaseBase::factory( 'sqlite', $p );
 122         }
 123
 124         /**
 125          * @return string
 126          */
 127         function getType() {
 128                 return 'sqlite';
 129         }
 130
 131         /**
 132          * @todo Check if it should be true like parent class
 133          *
 134          * @return bool
 135          */
 136         function implicitGroupby() {
 137                 return false;
 138         }
 139
 140         /** Open an SQLite database and return a resource handle to it
 141          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
 142          *
 143          * @param string $server
 144          * @param string $user
 145          * @param string $pass
 146          * @param string $dbName
 147          *
 148          * @throws DBConnectionError
 149          * @return PDO
 150          */
 151         function open( $server, $user, $pass, $dbName ) {
 152                 $this->close();
 153                 $fileName = self::generateFileName( $this->dbDir, $dbName );
 154                 if ( !is_readable( $fileName ) ) {
 155                         $this->mConn = false;
 156                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 157                 }
 158                 $this->openFile( $fileName );
 159
 160                 return $this->mConn;
 161         }
 162
 163         /**
 164          * Opens a database file
 165          *
 166          * @param string $fileName
 167          * @throws DBConnectionError
 168          * @return PDO|bool SQL connection or false if failed
 169          */
 170         protected function openFile( $fileName ) {
 171                 $err = false;
 172
 173                 $this->dbPath = $fileName;
 174                 try {
 175                         if ( $this->mFlags & DBO_PERSISTENT ) {
 176                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 177                                         [ PDO::ATTR_PERSISTENT => true ] );
 178                         } else {
 179                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 180                         }
 181                 } catch ( PDOException $e ) {
 182                         $err = $e->getMessage();
 183                 }
 184
 185                 if ( !$this->mConn ) {
 186                         wfDebug( "DB connection error: $err\n" );
 187                         throw new DBConnectionError( $this, $err );
 188                 }
 189
 190                 $this->mOpened = !!$this->mConn;
 191                 if ( $this->mOpened ) {
 192                         # Set error codes only, don't raise exceptions
 193                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 194                         # Enforce LIKE to be case sensitive, just like MySQL
 195                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 196
 197                         return $this->mConn;
 198                 }
 199
 200                 return false;
 201         }
 202
 203         /**
 204          * @return string SQLite DB file path
 205          * @since 1.25
 206          */
 207         public function getDbFilePath() {
 208                 return $this->dbPath;
 209         }
 210
 211         /**
 212          * Does not actually close the connection, just destroys the reference for GC to do its work
 213          * @return bool
 214          */
 215         protected function closeConnection() {
 216                 $this->mConn = null;
 217
 218                 return true;
 219         }
 220
 221         /**
 222          * Generates a database file name. Explicitly public for installer.
 223          * @param string $dir Directory where database resides
 224          * @param string $dbName Database name
 225          * @return string
 226          */
 227         public static function generateFileName( $dir, $dbName ) {
 228                 return "$dir/$dbName.sqlite";
 229         }
 230
 231         /**
 232          * Check if the searchindext table is FTS enabled.
 233          * @return bool False if not enabled.
 234          */
 235         function checkForEnabledSearch() {
 236                 if ( self::$fulltextEnabled === null ) {
 237                         self::$fulltextEnabled = false;
 238                         $table = $this->tableName( 'searchindex' );
 239                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 240                         if ( $res ) {
 241                                 $row = $res->fetchRow();
 242                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 243                         }
 244                 }
 245
 246                 return self::$fulltextEnabled;
 247         }
 248
 249         /**
 250          * Returns version of currently supported SQLite fulltext search module or false if none present.
 251          * @return string
 252          */
 253         static function getFulltextSearchModule() {
 254                 static $cachedResult = null;
 255                 if ( $cachedResult !== null ) {
 256                         return $cachedResult;
 257                 }
 258                 $cachedResult = false;
 259                 $table = 'dummy_search_test';
 260
 261                 $db = self::newStandaloneInstance( ':memory:' );
 262                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 263                         $cachedResult = 'FTS3';
 264                 }
 265                 $db->close();
 266
 267                 return $cachedResult;
 268         }
 269
 270         /**
 271          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 272          * for details.
 273          *
 274          * @param string $name Database name to be used in queries like
 275          *   SELECT foo FROM dbname.table
 276          * @param bool|string $file Database file name. If omitted, will be generated
 277          *   using $name and configured data directory
 278          * @param string $fname Calling function name
 279          * @return ResultWrapper
 280          */
 281         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 282                 if ( !$file ) {
 283                         $file = self::generateFileName( $this->dbDir, $name );
 284                 }
 285                 $file = $this->addQuotes( $file );
 286
 287                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 288         }
 289
 290         function isWriteQuery( $sql ) {
 291                 return parent::isWriteQuery( $sql ) && !preg_match( '/^(ATTACH|PRAGMA)\b/i', $sql );
 292         }
 293
 294         /**
 295          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 296          *
 297          * @param string $sql
 298          * @return bool|ResultWrapper
 299          */
 300         protected function doQuery( $sql ) {
 301                 $res = $this->mConn->query( $sql );
 302                 if ( $res === false ) {
 303                         return false;
 304                 } else {
 305                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 306                         $this->mAffectedRows = $r->rowCount();
 307                         $res = new ResultWrapper( $this, $r->fetchAll() );
 308                 }
 309
 310                 return $res;
 311         }
 312
 313         /**
 314          * @param ResultWrapper|mixed $res
 315          */
 316         function freeResult( $res ) {
 317                 if ( $res instanceof ResultWrapper ) {
 318                         $res->result = null;
 319                 } else {
 320                         $res = null;
 321                 }
 322         }
 323
 324         /**
 325          * @param ResultWrapper|array $res
 326          * @return stdClass|bool
 327          */
 328         function fetchObject( $res ) {
 329                 if ( $res instanceof ResultWrapper ) {
 330                         $r =& $res->result;
 331                 } else {
 332                         $r =& $res;
 333                 }
 334
 335                 $cur = current( $r );
 336                 if ( is_array( $cur ) ) {
 337                         next( $r );
 338                         $obj = new stdClass;
 339                         foreach ( $cur as $k => $v ) {
 340                                 if ( !is_numeric( $k ) ) {
 341                                         $obj->$k = $v;
 342                                 }
 343                         }
 344
 345                         return $obj;
 346                 }
 347
 348                 return false;
 349         }
 350
 351         /**
 352          * @param ResultWrapper|mixed $res
 353          * @return array|bool
 354          */
 355         function fetchRow( $res ) {
 356                 if ( $res instanceof ResultWrapper ) {
 357                         $r =& $res->result;
 358                 } else {
 359                         $r =& $res;
 360                 }
 361                 $cur = current( $r );
 362                 if ( is_array( $cur ) ) {
 363                         next( $r );
 364
 365                         return $cur;
 366                 }
 367
 368                 return false;
 369         }
 370
 371         /**
 372          * The PDO::Statement class implements the array interface so count() will work
 373          *
 374          * @param ResultWrapper|array $res
 375          * @return int
 376          */
 377         function numRows( $res ) {
 378                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 379
 380                 return count( $r );
 381         }
 382
 383         /**
 384          * @param ResultWrapper $res
 385          * @return int
 386          */
 387         function numFields( $res ) {
 388                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 389                 if ( is_array( $r ) && count( $r ) > 0 ) {
 390                         // The size of the result array is twice the number of fields. (Bug: 65578)
 391                         return count( $r[0] ) / 2;
 392                 } else {
 393                         // If the result is empty return 0
 394                         return 0;
 395                 }
 396         }
 397
 398         /**
 399          * @param ResultWrapper $res
 400          * @param int $n
 401          * @return bool
 402          */
 403         function fieldName( $res, $n ) {
 404                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 405                 if ( is_array( $r ) ) {
 406                         $keys = array_keys( $r[0] );
 407
 408                         return $keys[$n];
 409                 }
 410
 411                 return false;
 412         }
 413
 414         /**
 415          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 416          *
 417          * @param string $name
 418          * @param string $format
 419          * @return string
 420          */
 421         function tableName( $name, $format = 'quoted' ) {
 422                 // table names starting with sqlite_ are reserved
 423                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 424                         return $name;
 425                 }
 426
 427                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 428         }
 429
 430         /**
 431          * Index names have DB scope
 432          *
 433          * @param string $index
 434          * @return string
 435          */
 436         protected function indexName( $index ) {
 437                 return $index;
 438         }
 439
 440         /**
 441          * This must be called after nextSequenceVal
 442          *
 443          * @return int
 444          */
 445         function insertId() {
 446                 // PDO::lastInsertId yields a string :(
 447                 return intval( $this->mConn->lastInsertId() );
 448         }
 449
 450         /**
 451          * @param ResultWrapper|array $res
 452          * @param int $row
 453          */
 454         function dataSeek( $res, $row ) {
 455                 if ( $res instanceof ResultWrapper ) {
 456                         $r =& $res->result;
 457                 } else {
 458                         $r =& $res;
 459                 }
 460                 reset( $r );
 461                 if ( $row > 0 ) {
 462                         for ( $i = 0; $i < $row; $i++ ) {
 463                                 next( $r );
 464                         }
 465                 }
 466         }
 467
 468         /**
 469          * @return string
 470          */
 471         function lastError() {
 472                 if ( !is_object( $this->mConn ) ) {
 473                         return "Cannot return last error, no db connection";
 474                 }
 475                 $e = $this->mConn->errorInfo();
 476
 477                 return isset( $e[2] ) ? $e[2] : '';
 478         }
 479
 480         /**
 481          * @return string
 482          */
 483         function lastErrno() {
 484                 if ( !is_object( $this->mConn ) ) {
 485                         return "Cannot return last error, no db connection";
 486                 } else {
 487                         $info = $this->mConn->errorInfo();
 488
 489                         return $info[1];
 490                 }
 491         }
 492
 493         /**
 494          * @return int
 495          */
 496         function affectedRows() {
 497                 return $this->mAffectedRows;
 498         }
 499
 500         /**
 501          * Returns information about an index
 502          * Returns false if the index does not exist
 503          * - if errors are explicitly ignored, returns NULL on failure
 504          *
 505          * @param string $table
 506          * @param string $index
 507          * @param string $fname
 508          * @return array
 509          */
 510         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 511                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 512                 $res = $this->query( $sql, $fname );
 513                 if ( !$res ) {
 514                         return null;
 515                 }
 516                 if ( $res->numRows() == 0 ) {
 517                         return false;
 518                 }
 519                 $info = [];
 520                 foreach ( $res as $row ) {
 521                         $info[] = $row->name;
 522                 }
 523
 524                 return $info;
 525         }
 526
 527         /**
 528          * @param string $table
 529          * @param string $index
 530          * @param string $fname
 531          * @return bool|null
 532          */
 533         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 534                 $row = $this->selectRow( 'sqlite_master', '*',
 535                         [
 536                                 'type' => 'index',
 537                                 'name' => $this->indexName( $index ),
 538                         ], $fname );
 539                 if ( !$row || !isset( $row->sql ) ) {
 540                         return null;
 541                 }
 542
 543                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 544                 $indexPos = strpos( $row->sql, 'INDEX' );
 545                 if ( $indexPos === false ) {
 546                         return null;
 547                 }
 548                 $firstPart = substr( $row->sql, 0, $indexPos );
 549                 $options = explode( ' ', $firstPart );
 550
 551                 return in_array( 'UNIQUE', $options );
 552         }
 553
 554         /**
 555          * Filter the options used in SELECT statements
 556          *
 557          * @param array $options
 558          * @return array
 559          */
 560         function makeSelectOptions( $options ) {
 561                 foreach ( $options as $k => $v ) {
 562                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 563                                 $options[$k] = '';
 564                         }
 565                 }
 566
 567                 return parent::makeSelectOptions( $options );
 568         }
 569
 570         /**
 571          * @param array $options
 572          * @return string
 573          */
 574         protected function makeUpdateOptionsArray( $options ) {
 575                 $options = parent::makeUpdateOptionsArray( $options );
 576                 $options = self::fixIgnore( $options );
 577
 578                 return $options;
 579         }
 580
 581         /**
 582          * @param array $options
 583          * @return array
 584          */
 585         static function fixIgnore( $options ) {
 586                 # SQLite uses OR IGNORE not just IGNORE
 587                 foreach ( $options as $k => $v ) {
 588                         if ( $v == 'IGNORE' ) {
 589                                 $options[$k] = 'OR IGNORE';
 590                         }
 591                 }
 592
 593                 return $options;
 594         }
 595
 596         /**
 597          * @param array $options
 598          * @return string
 599          */
 600         function makeInsertOptions( $options ) {
 601                 $options = self::fixIgnore( $options );
 602
 603                 return parent::makeInsertOptions( $options );
 604         }
 605
 606         /**
 607          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 608          * @param string $table
 609          * @param array $a
 610          * @param string $fname
 611          * @param array $options
 612          * @return bool
 613          */
 614         function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
 615                 if ( !count( $a ) ) {
 616                         return true;
 617                 }
 618
 619                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 620                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 621                         $ret = true;
 622                         foreach ( $a as $v ) {
 623                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 624                                         $ret = false;
 625                                 }
 626                         }
 627                 } else {
 628                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 629                 }
 630
 631                 return $ret;
 632         }
 633
 634         /**
 635          * @param string $table
 636          * @param array $uniqueIndexes Unused
 637          * @param string|array $rows
 638          * @param string $fname
 639          * @return bool|ResultWrapper
 640          */
 641         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 642                 if ( !count( $rows ) ) {
 643                         return true;
 644                 }
 645
 646                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 647                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 648                         $ret = true;
 649                         foreach ( $rows as $v ) {
 650                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 651                                         $ret = false;
 652                                 }
 653                         }
 654                 } else {
 655                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 656                 }
 657
 658                 return $ret;
 659         }
 660
 661         /**
 662          * Returns the size of a text field, or -1 for "unlimited"
 663          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 664          *
 665          * @param string $table
 666          * @param string $field
 667          * @return int
 668          */
 669         function textFieldSize( $table, $field ) {
 670                 return -1;
 671         }
 672
 673         /**
 674          * @return bool
 675          */
 676         function unionSupportsOrderAndLimit() {
 677                 return false;
 678         }
 679
 680         /**
 681          * @param string $sqls
 682          * @param bool $all Whether to "UNION ALL" or not
 683          * @return string
 684          */
 685         function unionQueries( $sqls, $all ) {
 686                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 687
 688                 return implode( $glue, $sqls );
 689         }
 690
 691         /**
 692          * @return bool
 693          */
 694         function wasDeadlock() {
 695                 return $this->lastErrno() == 5; // SQLITE_BUSY
 696         }
 697
 698         /**
 699          * @return bool
 700          */
 701         function wasErrorReissuable() {
 702                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 703         }
 704
 705         /**
 706          * @return bool
 707          */
 708         function wasReadOnlyError() {
 709                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 710         }
 711
 712         /**
 713          * @return string Wikitext of a link to the server software's web site
 714          */
 715         public function getSoftwareLink() {
 716                 return "[{{int:version-db-sqlite-url}} SQLite]";
 717         }
 718
 719         /**
 720          * @return string Version information from the database
 721          */
 722         function getServerVersion() {
 723                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 724
 725                 return $ver;
 726         }
 727
 728         /**
 729          * @return string User-friendly database information
 730          */
 731         public function getServerInfo() {
 732                 return wfMessage( self::getFulltextSearchModule()
 733                         ? 'sqlite-has-fts'
 734                         : 'sqlite-no-fts', $this->getServerVersion() )->text();
 735         }
 736
 737         /**
 738          * Get information about a given field
 739          * Returns false if the field does not exist.
 740          *
 741          * @param string $table
 742          * @param string $field
 743          * @return SQLiteField|bool False on failure
 744          */
 745         function fieldInfo( $table, $field ) {
 746                 $tableName = $this->tableName( $table );
 747                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 748                 $res = $this->query( $sql, __METHOD__ );
 749                 foreach ( $res as $row ) {
 750                         if ( $row->name == $field ) {
 751                                 return new SQLiteField( $row, $tableName );
 752                         }
 753                 }
 754
 755                 return false;
 756         }
 757
 758         protected function doBegin( $fname = '' ) {
 759                 if ( $this->trxMode ) {
 760                         $this->query( "BEGIN {$this->trxMode}", $fname );
 761                 } else {
 762                         $this->query( 'BEGIN', $fname );
 763                 }
 764                 $this->mTrxLevel = 1;
 765         }
 766
 767         /**
 768          * @param string $s
 769          * @return string
 770          */
 771         function strencode( $s ) {
 772                 return substr( $this->addQuotes( $s ), 1, -1 );
 773         }
 774
 775         /**
 776          * @param string $b
 777          * @return Blob
 778          */
 779         function encodeBlob( $b ) {
 780                 return new Blob( $b );
 781         }
 782
 783         /**
 784          * @param Blob|string $b
 785          * @return string
 786          */
 787         function decodeBlob( $b ) {
 788                 if ( $b instanceof Blob ) {
 789                         $b = $b->fetch();
 790                 }
 791
 792                 return $b;
 793         }
 794
 795         /**
 796          * @param Blob|string $s
 797          * @return string
 798          */
 799         function addQuotes( $s ) {
 800                 if ( $s instanceof Blob ) {
 801                         return "x'" . bin2hex( $s->fetch() ) . "'";
 802                 } elseif ( is_bool( $s ) ) {
 803                         return (int)$s;
 804                 } elseif ( strpos( $s, "\0" ) !== false ) {
 805                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 806                         // This is a known limitation of SQLite's mprintf function which PDO
 807                         // should work around, but doesn't. I have reported this to php.net as bug #63419:
 808                         // https://bugs.php.net/bug.php?id=63419
 809                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 810                         // https://bugs.php.net/bug.php?id=62361
 811                         // There is an additional bug regarding sorting this data after insert
 812                         // on older versions of sqlite shipped with ubuntu 12.04
 813                         // https://phabricator.wikimedia.org/T74367
 814                         wfDebugLog(
 815                                 __CLASS__,
 816                                 __FUNCTION__ .
 817                                         ': Quoting value containing null byte. ' .
 818                                         'For consistency all binary data should have been ' .
 819                                         'first processed with self::encodeBlob()'
 820                         );
 821                         return "x'" . bin2hex( $s ) . "'";
 822                 } else {
 823                         return $this->mConn->quote( $s );
 824                 }
 825         }
 826
 827         /**
 828          * @return string
 829          */
 830         function buildLike() {
 831                 $params = func_get_args();
 832                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 833                         $params = $params[0];
 834                 }
 835
 836                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 837         }
 838
 839         /**
 840          * @param string $field Field or column to cast
 841          * @return string
 842          * @since 1.28
 843          */
 844         public function buildStringCast( $field ) {
 845                 return 'CAST ( ' . $field . ' AS TEXT )';
 846         }
 847
 848         /**
 849          * @return string
 850          */
 851         public function getSearchEngine() {
 852                 return "SearchSqlite";
 853         }
 854
 855         /**
 856          * No-op version of deadlockLoop
 857          *
 858          * @return mixed
 859          */
 860         public function deadlockLoop( /*...*/ ) {
 861                 $args = func_get_args();
 862                 $function = array_shift( $args );
 863
 864                 return call_user_func_array( $function, $args );
 865         }
 866
 867         /**
 868          * @param string $s
 869          * @return string
 870          */
 871         protected function replaceVars( $s ) {
 872                 $s = parent::replaceVars( $s );
 873                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 874                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 875
 876                         // binary/varbinary column type -> blob
 877                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 878                         // no such thing as unsigned
 879                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 880                         // INT -> INTEGER
 881                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 882                         // floating point types -> REAL
 883                         $s = preg_replace(
 884                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 885                                 'REAL',
 886                                 $s
 887                         );
 888                         // varchar -> TEXT
 889                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 890                         // TEXT normalization
 891                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 892                         // BLOB normalization
 893                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 894                         // BOOL -> INTEGER
 895                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 896                         // DATETIME -> TEXT
 897                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 898                         // No ENUM type
 899                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 900                         // binary collation type -> nothing
 901                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 902                         // auto_increment -> autoincrement
 903                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 904                         // No explicit options
 905                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 906                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 907                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 908                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 909                         // No truncated indexes
 910                         $s = preg_replace( '/\(\d+\)/', '', $s );
 911                         // No FULLTEXT
 912                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 913                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 914                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 915                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 916                 } elseif ( preg_match( '/^\s*INSERT IGNORE\b/i', $s ) ) {
 917                         // INSERT IGNORE --> INSERT OR IGNORE
 918                         $s = preg_replace( '/^\s*INSERT IGNORE\b/i', 'INSERT OR IGNORE', $s );
 919                 }
 920
 921                 return $s;
 922         }
 923
 924         public function lock( $lockName, $method, $timeout = 5 ) {
 925                 if ( !is_dir( "{$this->dbDir}/locks" ) ) { // create dir as needed
 926                         if ( !is_writable( $this->dbDir ) || !mkdir( "{$this->dbDir}/locks" ) ) {
 927                                 throw new DBError( $this, "Cannot create directory \"{$this->dbDir}/locks\"." );
 928                         }
 929                 }
 930
 931                 return $this->lockMgr->lock( [ $lockName ], LockManager::LOCK_EX, $timeout )->isOK();
 932         }
 933
 934         public function unlock( $lockName, $method ) {
 935                 return $this->lockMgr->unlock( [ $lockName ], LockManager::LOCK_EX )->isOK();
 936         }
 937
 938         /**
 939          * Build a concatenation list to feed into a SQL query
 940          *
 941          * @param string[] $stringList
 942          * @return string
 943          */
 944         function buildConcat( $stringList ) {
 945                 return '(' . implode( ') || (', $stringList ) . ')';
 946         }
 947
 948         public function buildGroupConcatField(
 949                 $delim, $table, $field, $conds = '', $join_conds = []
 950         ) {
 951                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 952
 953                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
 954         }
 955
 956         /**
 957          * @param string $oldName
 958          * @param string $newName
 959          * @param bool $temporary
 960          * @param string $fname
 961          * @return bool|ResultWrapper
 962          * @throws RuntimeException
 963          */
 964         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 965                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 966                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 967                 $obj = $this->fetchObject( $res );
 968                 if ( !$obj ) {
 969                         throw new RuntimeException( "Couldn't retrieve structure for table $oldName" );
 970                 }
 971                 $sql = $obj->sql;
 972                 $sql = preg_replace(
 973                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 974                         $this->addIdentifierQuotes( $newName ),
 975                         $sql,
 976                         1
 977                 );
 978                 if ( $temporary ) {
 979                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 980                                 wfDebug( "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 981                         } else {
 982                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 983                         }
 984                 }
 985
 986                 $res = $this->query( $sql, $fname );
 987
 988                 // Take over indexes
 989                 $indexList = $this->query( 'PRAGMA INDEX_LIST(' . $this->addQuotes( $oldName ) . ')' );
 990                 foreach ( $indexList as $index ) {
 991                         if ( strpos( $index->name, 'sqlite_autoindex' ) === 0 ) {
 992                                 continue;
 993                         }
 994
 995                         if ( $index->unique ) {
 996                                 $sql = 'CREATE UNIQUE INDEX';
 997                         } else {
 998                                 $sql = 'CREATE INDEX';
 999                         }
1000                         // Try to come up with a new index name, given indexes have database scope in SQLite
1001                         $indexName = $newName . '_' . $index->name;
1002                         $sql .= ' ' . $indexName . ' ON ' . $newName;
1003
1004                         $indexInfo = $this->query( 'PRAGMA INDEX_INFO(' . $this->addQuotes( $index->name ) . ')' );
1005                         $fields = [];
1006                         foreach ( $indexInfo as $indexInfoRow ) {
1007                                 $fields[$indexInfoRow->seqno] = $indexInfoRow->name;
1008                         }
1009
1010                         $sql .= '(' . implode( ',', $fields ) . ')';
1011
1012                         $this->query( $sql );
1013                 }
1014
1015                 return $res;
1016         }
1017
1018         /**
1019          * List all tables on the database
1020          *
1021          * @param string $prefix Only show tables with this prefix, e.g. mw_
1022          * @param string $fname Calling function name
1023          *
1024          * @return array
1025          */
1026         function listTables( $prefix = null, $fname = __METHOD__ ) {
1027                 $result = $this->select(
1028                         'sqlite_master',
1029                         'name',
1030                         "type='table'"
1031                 );
1032
1033                 $endArray = [];
1034
1035                 foreach ( $result as $table ) {
1036                         $vars = get_object_vars( $table );
1037                         $table = array_pop( $vars );
1038
1039                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1040                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
1041                                         $endArray[] = $table;
1042                                 }
1043                         }
1044                 }
1045
1046                 return $endArray;
1047         }
1048
1049         /**
1050          * Override due to no CASCADE support
1051          *
1052          * @param string $tableName
1053          * @param string $fName
1054          * @return bool|ResultWrapper
1055          * @throws DBReadOnlyError
1056          */
1057         public function dropTable( $tableName, $fName = __METHOD__ ) {
1058                 if ( !$this->tableExists( $tableName, $fName ) ) {
1059                         return false;
1060                 }
1061                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1062
1063                 return $this->query( $sql, $fName );
1064         }
1065
1066         /**
1067          * @return string
1068          */
1069         public function __toString() {
1070                 return 'SQLite ' . (string)$this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
1071         }
1072
1073 } // end DatabaseSqlite class