includes/db/DatabaseSqlite.php

   1 <?php
   2 /**
   3  * This script is the SQLite database abstraction layer
   4  *
   5  * See maintenance/sqlite/README for development notes and other specific information
   6  * @ingroup Database
   7  * @file
   8  */
   9
  10 /**
  11  * @ingroup Database
  12  */
  13 class DatabaseSqlite extends DatabaseBase {
  14
  15         private static $fulltextEnabled = null;
  16
  17         var $mAffectedRows;
  18         var $mLastResult;
  19         var $mDatabaseFile;
  20         var $mName;
  21
  22         /**
  23          * Constructor.
  24          * Parameters $server, $user and $password are not used.
  25          */
  26         function __construct( $server = false, $user = false, $password = false, $dbName = false, $failFunction = false, $flags = 0 ) {
  27                 global $wgSharedDB;
  28                 $this->mFailFunction = $failFunction;
  29                 $this->mFlags = $flags;
  30                 $this->mName = $dbName;
  31
  32                 if ( $this->open( $server, $user, $password, $dbName ) && $wgSharedDB ) {
  33                         $this->attachDatabase( $wgSharedDB );
  34                 }
  35         }
  36
  37         function getType() {
  38                 return 'sqlite';
  39         }
  40
  41         /**
  42          * @todo: check if it should be true like parent class
  43          */
  44         function implicitGroupby()   { return false; }
  45
  46         static function newFromParams( $server, $user, $password, $dbName, $failFunction = false, $flags = 0 ) {
  47                 return new DatabaseSqlite( $server, $user, $password, $dbName, $failFunction, $flags );
  48         }
  49
  50         /** Open an SQLite database and return a resource handle to it
  51          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  52          */
  53         function open( $server, $user, $pass, $dbName ) {
  54                 global $wgSQLiteDataDir;
  55
  56                 $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
  57                 if ( !is_readable( $fileName ) ) {
  58                         throw new DBConnectionError( $this, "SQLite database not accessible" );
  59                         $this->mConn = false;
  60                 }
  61                 $this->openFile( $fileName );
  62                 return $this->mConn;
  63         }
  64
  65         /**
  66          * Opens a database file
  67          * @return SQL connection or false if failed
  68          */
  69         function openFile( $fileName ) {
  70                 $this->mDatabaseFile = $fileName;
  71                 try {
  72                         if ( $this->mFlags & DBO_PERSISTENT ) {
  73                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
  74                                         array( PDO::ATTR_PERSISTENT => true ) );
  75                         } else {
  76                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
  77                         }
  78                 } catch ( PDOException $e ) {
  79                         $err = $e->getMessage();
  80                 }
  81                 if ( $this->mConn === false ) {
  82                         wfDebug( "DB connection error: $err\n" );
  83                         if ( !$this->mFailFunction ) {
  84                                 throw new DBConnectionError( $this, $err );
  85                         } else {
  86                                 return false;
  87                         }
  88
  89                 }
  90                 $this->mOpened = !!$this->mConn;
  91                 # set error codes only, don't raise exceptions
  92                 if ( $this->mOpened ) {
  93                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
  94                         return true;
  95                 }
  96         }
  97
  98         /**
  99          * Close an SQLite database
 100          */
 101         function close() {
 102                 $this->mOpened = false;
 103                 if ( is_object( $this->mConn ) ) {
 104                         if ( $this->trxLevel() ) $this->commit();
 105                         $this->mConn = null;
 106                 }
 107                 return true;
 108         }
 109
 110         /**
 111          * Generates a database file name. Explicitly public for installer.
 112          * @param $dir String: Directory where database resides
 113          * @param $dbName String: Database name
 114          * @return String
 115          */
 116         public static function generateFileName( $dir, $dbName ) {
 117                 return "$dir/$dbName.sqlite";
 118         }
 119
 120         /**
 121          * Check if the searchindext table is FTS enabled.
 122          * @returns false if not enabled.
 123          */
 124         function checkForEnabledSearch() {
 125                 if ( self::$fulltextEnabled === null ) {
 126                         self::$fulltextEnabled = false;
 127                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = 'searchindex'", __METHOD__ );
 128                         if ( $res ) {
 129                                 $row = $res->fetchRow();
 130                                 self::$fulltextEnabled = stristr($row['sql'], 'fts' ) !== false;
 131                         }
 132                 }
 133                 return self::$fulltextEnabled;
 134         }
 135
 136         /**
 137          * Returns version of currently supported SQLite fulltext search module or false if none present.
 138          * @return String
 139          */
 140         function getFulltextSearchModule() {
 141                 $table = 'dummy_search_test';
 142                 $this->query( "DROP TABLE IF EXISTS $table", __METHOD__ );
 143
 144                 if ( $this->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 145                         $this->query( "DROP TABLE IF EXISTS $table", __METHOD__ );
 146                         return 'FTS3';
 147                 }
 148                 return false;
 149         }
 150
 151         /**
 152          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 153          * for details.
 154          * @param $name: Database name to be used in queries like SELECT foo FROM dbname.table
 155          * @param $file: Database file name. If omitted, will be generated using $name and $wgSQLiteDataDir
 156          */
 157         function attachDatabase( $name, $file = false, $fname = 'DatabaseSqlite::attachDatabase' ) {
 158                 global $wgSQLiteDataDir;
 159                 if ( !$file ) {
 160                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 161                 }
 162                 $file = $this->addQuotes( $file );
 163                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 164         }
 165
 166         /**
 167          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 168          */
 169         function doQuery( $sql ) {
 170                 $res = $this->mConn->query( $sql );
 171                 if ( $res === false ) {
 172                         return false;
 173                 } else {
 174                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 175                         $this->mAffectedRows = $r->rowCount();
 176                         $res = new ResultWrapper( $this, $r->fetchAll() );
 177                 }
 178                 return $res;
 179         }
 180
 181         function freeResult( $res ) {
 182                 if ( $res instanceof ResultWrapper )
 183                         $res->result = null;
 184                 else
 185                         $res = null;
 186         }
 187
 188         function fetchObject( $res ) {
 189                 if ( $res instanceof ResultWrapper )
 190                         $r =& $res->result;
 191                 else
 192                         $r =& $res;
 193
 194                 $cur = current( $r );
 195                 if ( is_array( $cur ) ) {
 196                         next( $r );
 197                         $obj = new stdClass;
 198                         foreach ( $cur as $k => $v )
 199                                 if ( !is_numeric( $k ) )
 200                                         $obj->$k = $v;
 201
 202                         return $obj;
 203                 }
 204                 return false;
 205         }
 206
 207         function fetchRow( $res ) {
 208                 if ( $res instanceof ResultWrapper )
 209                         $r =& $res->result;
 210                 else
 211                         $r =& $res;
 212
 213                 $cur = current( $r );
 214                 if ( is_array( $cur ) ) {
 215                         next( $r );
 216                         return $cur;
 217                 }
 218                 return false;
 219         }
 220
 221         /**
 222          * The PDO::Statement class implements the array interface so count() will work
 223          */
 224         function numRows( $res ) {
 225                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 226                 return count( $r );
 227         }
 228
 229         function numFields( $res ) {
 230                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 231                 return is_array( $r ) ? count( $r[0] ) : 0;
 232         }
 233
 234         function fieldName( $res, $n ) {
 235                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 236                 if ( is_array( $r ) ) {
 237                         $keys = array_keys( $r[0] );
 238                         return $keys[$n];
 239                 }
 240                 return  false;
 241         }
 242
 243         /**
 244          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 245          */
 246         function tableName( $name ) {
 247                 return str_replace( '`', '', parent::tableName( $name ) );
 248         }
 249
 250         /**
 251          * Index names have DB scope
 252          */
 253         function indexName( $index ) {
 254                 return $index;
 255         }
 256
 257         /**
 258          * This must be called after nextSequenceVal
 259          */
 260         function insertId() {
 261                 return $this->mConn->lastInsertId();
 262         }
 263
 264         function dataSeek( $res, $row ) {
 265                 if ( $res instanceof ResultWrapper )
 266                         $r =& $res->result;
 267                 else
 268                         $r =& $res;
 269                 reset( $r );
 270                 if ( $row > 0 )
 271                         for ( $i = 0; $i < $row; $i++ )
 272                                 next( $r );
 273         }
 274
 275         function lastError() {
 276                 if ( !is_object( $this->mConn ) )
 277                         return "Cannot return last error, no db connection";
 278                 $e = $this->mConn->errorInfo();
 279                 return isset( $e[2] ) ? $e[2] : '';
 280         }
 281
 282         function lastErrno() {
 283                 if ( !is_object( $this->mConn ) ) {
 284                         return "Cannot return last error, no db connection";
 285                 } else {
 286                         $info = $this->mConn->errorInfo();
 287                         return $info[1];
 288                 }
 289         }
 290
 291         function affectedRows() {
 292                 return $this->mAffectedRows;
 293         }
 294
 295         /**
 296          * Returns information about an index
 297          * Returns false if the index does not exist
 298          * - if errors are explicitly ignored, returns NULL on failure
 299          */
 300         function indexInfo( $table, $index, $fname = 'DatabaseSqlite::indexExists' ) {
 301                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 302                 $res = $this->query( $sql, $fname );
 303                 if ( !$res ) {
 304                         return null;
 305                 }
 306                 if ( $res->numRows() == 0 ) {
 307                         return false;
 308                 }
 309                 $info = array();
 310                 foreach ( $res as $row ) {
 311                         $info[] = $row->name;
 312                 }
 313                 return $info;
 314         }
 315
 316         function indexUnique( $table, $index, $fname = 'DatabaseSqlite::indexUnique' ) {
 317                 $row = $this->selectRow( 'sqlite_master', '*',
 318                         array(
 319                                 'type' => 'index',
 320                                 'name' => $this->indexName( $index ),
 321                         ), $fname );
 322                 if ( !$row || !isset( $row->sql ) ) {
 323                         return null;
 324                 }
 325
 326                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 327                 $indexPos = strpos( $row->sql, 'INDEX' );
 328                 if ( $indexPos === false ) {
 329                         return null;
 330                 }
 331                 $firstPart = substr( $row->sql, 0, $indexPos );
 332                 $options = explode( ' ', $firstPart );
 333                 return in_array( 'UNIQUE', $options );
 334         }
 335
 336         /**
 337          * Filter the options used in SELECT statements
 338          */
 339         function makeSelectOptions( $options ) {
 340                 foreach ( $options as $k => $v )
 341                         if ( is_numeric( $k ) && $v == 'FOR UPDATE' )
 342                                 $options[$k] = '';
 343                 return parent::makeSelectOptions( $options );
 344         }
 345
 346         /**
 347          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 348          */
 349         function insert( $table, $a, $fname = 'DatabaseSqlite::insert', $options = array() ) {
 350                 if ( !count( $a ) ) return true;
 351                 if ( !is_array( $options ) ) $options = array( $options );
 352
 353                 # SQLite uses OR IGNORE not just IGNORE
 354                 foreach ( $options as $k => $v )
 355                         if ( $v == 'IGNORE' )
 356                                 $options[$k] = 'OR IGNORE';
 357
 358                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 359                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 360                         $ret = true;
 361                         foreach ( $a as $k => $v )
 362                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) )
 363                                         $ret = false;
 364                 } else {
 365                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 366                 }
 367
 368                 return $ret;
 369         }
 370
 371         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseSqlite::replace' ) {
 372                 if ( !count( $rows ) ) return true;
 373
 374                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 375                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 376                         $ret = true;
 377                         foreach ( $rows as $k => $v )
 378                                 if ( !parent::replace( $table, $uniqueIndexes, $v, "$fname/multi-row" ) )
 379                                         $ret = false;
 380                 } else {
 381                         $ret = parent::replace( $table, $uniqueIndexes, $rows, "$fname/single-row" );
 382                 }
 383
 384                 return $ret;
 385         }
 386
 387         /**
 388          * Returns the size of a text field, or -1 for "unlimited"
 389          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 390          */
 391         function textFieldSize( $table, $field ) {
 392                 return - 1;
 393         }
 394
 395         function unionSupportsOrderAndLimit() {
 396                 return false;
 397         }
 398
 399         function unionQueries( $sqls, $all ) {
 400                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 401                 return implode( $glue, $sqls );
 402         }
 403
 404         function wasDeadlock() {
 405                 return $this->lastErrno() == 5; // SQLITE_BUSY
 406         }
 407
 408         function wasErrorReissuable() {
 409                 return $this->lastErrno() ==  17; // SQLITE_SCHEMA;
 410         }
 411
 412         function wasReadOnlyError() {
 413                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 414         }
 415
 416         /**
 417          * @return string wikitext of a link to the server software's web site
 418          */
 419         function getSoftwareLink() {
 420                 return "[http://sqlite.org/ SQLite]";
 421         }
 422
 423         /**
 424          * @return string Version information from the database
 425          */
 426         function getServerVersion() {
 427                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 428                 return $ver;
 429         }
 430
 431         /**
 432          * Query whether a given column exists in the mediawiki schema
 433          */
 434         function fieldExists( $table, $field, $fname = '' ) {
 435                 $info = $this->fieldInfo( $table, $field );
 436                 return (bool)$info;
 437         }
 438
 439         /**
 440          * Get information about a given field
 441          * Returns false if the field does not exist.
 442          */
 443         function fieldInfo( $table, $field ) {
 444                 $tableName = $this->tableName( $table );
 445                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 446                 $res = $this->query( $sql, __METHOD__ );
 447                 foreach ( $res as $row ) {
 448                         if ( $row->name == $field ) {
 449                                 return new SQLiteField( $row, $tableName );
 450                         }
 451                 }
 452                 return false;
 453         }
 454
 455         function begin( $fname = '' ) {
 456                 if ( $this->mTrxLevel == 1 ) $this->commit();
 457                 $this->mConn->beginTransaction();
 458                 $this->mTrxLevel = 1;
 459         }
 460
 461         function commit( $fname = '' ) {
 462                 if ( $this->mTrxLevel == 0 ) return;
 463                 $this->mConn->commit();
 464                 $this->mTrxLevel = 0;
 465         }
 466
 467         function rollback( $fname = '' ) {
 468                 if ( $this->mTrxLevel == 0 ) return;
 469                 $this->mConn->rollBack();
 470                 $this->mTrxLevel = 0;
 471         }
 472
 473         function limitResultForUpdate( $sql, $num ) {
 474                 return $this->limitResult( $sql, $num );
 475         }
 476
 477         function strencode( $s ) {
 478                 return substr( $this->addQuotes( $s ), 1, - 1 );
 479         }
 480
 481         function encodeBlob( $b ) {
 482                 return new Blob( $b );
 483         }
 484
 485         function decodeBlob( $b ) {
 486                 if ( $b instanceof Blob ) {
 487                         $b = $b->fetch();
 488                 }
 489                 return $b;
 490         }
 491
 492         function addQuotes( $s ) {
 493                 if ( $s instanceof Blob ) {
 494                         return "x'" . bin2hex( $s->fetch() ) . "'";
 495                 } else {
 496                         return $this->mConn->quote( $s );
 497                 }
 498         }
 499
 500         function quote_ident( $s ) {
 501                 return $s;
 502         }
 503
 504         function buildLike() {
 505                 $params = func_get_args();
 506                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 507                         $params = $params[0];
 508                 }
 509                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 510         }
 511
 512         /**
 513          * How lagged is this slave?
 514          */
 515         public function getLag() {
 516                 return 0;
 517         }
 518
 519         /**
 520          * Called by the installer script (when modified according to the MediaWikiLite installation instructions)
 521          * - this is the same way PostgreSQL works, MySQL reads in tables.sql and interwiki.sql using dbsource (which calls db->sourceFile)
 522          */
 523         public function setup_database() {
 524                 global $IP;
 525
 526                 # Process common MySQL/SQLite table definitions
 527                 $err = $this->sourceFile( "$IP/maintenance/tables.sql" );
 528                 if ( $err !== true ) {
 529                         echo " <b>FAILED</b></li>";
 530                         dieout( htmlspecialchars( $err ) );
 531                 }
 532                 echo " done.</li>";
 533
 534                 # Use DatabasePostgres's code to populate interwiki from MySQL template
 535                 $f = fopen( "$IP/maintenance/interwiki.sql", 'r' );
 536                 if ( !$f ) {
 537                         dieout( "Could not find the interwiki.sql file." );
 538                 }
 539
 540                 $sql = "INSERT INTO interwiki(iw_prefix,iw_url,iw_local) VALUES ";
 541                 while ( !feof( $f ) ) {
 542                         $line = fgets( $f, 1024 );
 543                         $matches = array();
 544                         if ( !preg_match( '/^\s*(\(.+?),(\d)\)/', $line, $matches ) ) continue;
 545                         $this->query( "$sql $matches[1],$matches[2])" );
 546                 }
 547         }
 548
 549         public function getSearchEngine() {
 550                 return "SearchSqlite";
 551         }
 552
 553         /**
 554          * No-op version of deadlockLoop
 555          */
 556         public function deadlockLoop( /*...*/ ) {
 557                 $args = func_get_args();
 558                 $function = array_shift( $args );
 559                 return call_user_func_array( $function, $args );
 560         }
 561
 562         protected function replaceVars( $s ) {
 563                 $s = parent::replaceVars( $s );
 564                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 565                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 566
 567                         // binary/varbinary column type -> blob
 568                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 569                         // no such thing as unsigned
 570                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 571                         // INT -> INTEGER
 572                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\([\s\d]*\)|\b)/i', 'INTEGER', $s );
 573                         // varchar -> TEXT
 574                         $s = preg_replace( '/\bvarchar\(\d+\)/i', 'TEXT', $s );
 575                         // TEXT normalization
 576                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 577                         // BLOB normalization
 578                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 579                         // BOOL -> INTEGER
 580                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 581                         // DATETIME -> TEXT
 582                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 583                         // No ENUM type
 584                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 585                         // binary collation type -> nothing
 586                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 587                         // auto_increment -> autoincrement
 588                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 589                         // No explicit options
 590                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 591                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 592                         // No truncated indexes
 593                         $s = preg_replace( '/\(\d+\)/', '', $s );
 594                         // No FULLTEXT
 595                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 596                 }
 597                 return $s;
 598         }
 599
 600         /*
 601          * Build a concatenation list to feed into a SQL query
 602          */
 603         function buildConcat( $stringList ) {
 604                 return '(' . implode( ') || (', $stringList ) . ')';
 605         }
 606
 607         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseSqlite::duplicateTableStructure' ) {
 608                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name='$oldName' AND type='table'", $fname );
 609                 $obj = $this->fetchObject( $res );
 610                 if ( !$obj ) {
 611                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 612                 }
 613                 $sql = $obj->sql;
 614                 $sql = preg_replace( '/\b' . preg_quote( $oldName ) . '\b/', $newName, $sql, 1 );
 615                 return $this->query( $sql, $fname );
 616         }
 617
 618 } // end DatabaseSqlite class
 619
 620 /**
 621  * This class allows simple acccess to a SQLite database independently from main database settings
 622  * @ingroup Database
 623  */
 624 class DatabaseSqliteStandalone extends DatabaseSqlite {
 625         public function __construct( $fileName, $flags = 0 ) {
 626                 $this->mFlags = $flags;
 627                 $this->openFile( $fileName );
 628         }
 629 }
 630
 631 /**
 632  * @ingroup Database
 633  */
 634 class SQLiteField {
 635         private $info, $tableName;
 636         function __construct( $info, $tableName ) {
 637                 $this->info = $info;
 638                 $this->tableName = $tableName;
 639         }
 640
 641         function name() {
 642                 return $this->info->name;
 643         }
 644
 645         function tableName() {
 646                 return $this->tableName;
 647         }
 648
 649         function defaultValue() {
 650                 if ( is_string( $this->info->dflt_value ) ) {
 651                         // Typically quoted
 652                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 653                                 return str_replace( "''", "'", $this->info->dflt_value );
 654                         }
 655                 }
 656                 return $this->info->dflt_value;
 657         }
 658
 659         function maxLength() {
 660                 return -1;
 661         }
 662
 663         function nullable() {
 664                 // SQLite dynamic types are always nullable
 665                 return true;
 666         }
 667
 668         # isKey(),  isMultipleKey() not implemented, MySQL-specific concept.
 669         # Suggest removal from base class [TS]
 670
 671         function type() {
 672                 return $this->info->type;
 673         }
 674
 675 } // end SQLiteField