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  * @file
   7  * @ingroup Database
   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, $flags = 0 ) {
  27                 global $wgSharedDB;
  28                 $this->mFlags = $flags;
  29                 $this->mName = $dbName;
  30
  31                 if ( $this->open( $server, $user, $password, $dbName ) && $wgSharedDB ) {
  32                         $this->attachDatabase( $wgSharedDB );
  33                 }
  34         }
  35
  36         /**
  37          * Serialization handler, see http://php.net/manual/en/language.oop5.magic.php#language.oop5.magic.sleep
  38          * for details. Instances of this class sometimes get serialized, e.g. with Title and its BacklinkCache
  39          * Because attempts to serialize mConn end in "can't serialize PDO objects" exceptions, we simply disallow
  40          * to serialize anything in this class.
  41          */
  42         function __sleep() {
  43                 return array();
  44         }
  45
  46         function getType() {
  47                 return 'sqlite';
  48         }
  49
  50         /**
  51          * @todo: check if it should be true like parent class
  52          */
  53         function implicitGroupby()   { return false; }
  54
  55         static function newFromParams( $server, $user, $password, $dbName, $flags = 0 ) {
  56                 return new DatabaseSqlite( $server, $user, $password, $dbName, $flags );
  57         }
  58
  59         /** Open an SQLite database and return a resource handle to it
  60          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  61          */
  62         function open( $server, $user, $pass, $dbName ) {
  63                 global $wgSQLiteDataDir;
  64
  65                 $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
  66                 if ( !is_readable( $fileName ) ) {
  67                         throw new DBConnectionError( $this, "SQLite database not accessible" );
  68                         $this->mConn = false;
  69                 }
  70                 $this->openFile( $fileName );
  71                 return $this->mConn;
  72         }
  73
  74         /**
  75          * Opens a database file
  76          * @return SQL connection or false if failed
  77          */
  78         function openFile( $fileName ) {
  79                 $this->mDatabaseFile = $fileName;
  80                 try {
  81                         if ( $this->mFlags & DBO_PERSISTENT ) {
  82                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
  83                                         array( PDO::ATTR_PERSISTENT => true ) );
  84                         } else {
  85                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
  86                         }
  87                 } catch ( PDOException $e ) {
  88                         $err = $e->getMessage();
  89                 }
  90                 if ( $this->mConn === false ) {
  91                         wfDebug( "DB connection error: $err\n" );
  92                         return false;
  93                 }
  94                 $this->mOpened = !!$this->mConn;
  95                 # set error codes only, don't raise exceptions
  96                 if ( $this->mOpened ) {
  97                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
  98                         return true;
  99                 }
 100         }
 101
 102         /**
 103          * Close an SQLite database
 104          */
 105         function close() {
 106                 $this->mOpened = false;
 107                 if ( is_object( $this->mConn ) ) {
 108                         if ( $this->trxLevel() ) $this->commit();
 109                         $this->mConn = null;
 110                 }
 111                 return true;
 112         }
 113
 114         /**
 115          * Generates a database file name. Explicitly public for installer.
 116          * @param $dir String: Directory where database resides
 117          * @param $dbName String: Database name
 118          * @return String
 119          */
 120         public static function generateFileName( $dir, $dbName ) {
 121                 return "$dir/$dbName.sqlite";
 122         }
 123
 124         /**
 125          * Check if the searchindext table is FTS enabled.
 126          * @returns false if not enabled.
 127          */
 128         function checkForEnabledSearch() {
 129                 if ( self::$fulltextEnabled === null ) {
 130                         self::$fulltextEnabled = false;
 131                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = 'searchindex'", __METHOD__ );
 132                         if ( $res ) {
 133                                 $row = $res->fetchRow();
 134                                 self::$fulltextEnabled = stristr($row['sql'], 'fts' ) !== false;
 135                         }
 136                 }
 137                 return self::$fulltextEnabled;
 138         }
 139
 140         /**
 141          * Returns version of currently supported SQLite fulltext search module or false if none present.
 142          * @return String
 143          */
 144         function getFulltextSearchModule() {
 145                 $table = 'dummy_search_test';
 146                 $this->query( "DROP TABLE IF EXISTS $table", __METHOD__ );
 147
 148                 if ( $this->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 149                         $this->query( "DROP TABLE IF EXISTS $table", __METHOD__ );
 150                         return 'FTS3';
 151                 }
 152                 return false;
 153         }
 154
 155         /**
 156          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 157          * for details.
 158          * @param $name String: database name to be used in queries like SELECT foo FROM dbname.table
 159          * @param $file String: database file name. If omitted, will be generated using $name and $wgSQLiteDataDir
 160          * @param $fname String: calling function name
 161          */
 162         function attachDatabase( $name, $file = false, $fname = 'DatabaseSqlite::attachDatabase' ) {
 163                 global $wgSQLiteDataDir;
 164                 if ( !$file ) {
 165                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 166                 }
 167                 $file = $this->addQuotes( $file );
 168                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 169         }
 170
 171         /**
 172          * @see DatabaseBase::isWriteQuery()
 173          */
 174         function isWriteQuery( $sql ) {
 175                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 176         }
 177
 178         /**
 179          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 180          */
 181         function doQuery( $sql ) {
 182                 $res = $this->mConn->query( $sql );
 183                 if ( $res === false ) {
 184                         return false;
 185                 } else {
 186                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 187                         $this->mAffectedRows = $r->rowCount();
 188                         $res = new ResultWrapper( $this, $r->fetchAll() );
 189                 }
 190                 return $res;
 191         }
 192
 193         function freeResult( $res ) {
 194                 if ( $res instanceof ResultWrapper )
 195                         $res->result = null;
 196                 else
 197                         $res = null;
 198         }
 199
 200         function fetchObject( $res ) {
 201                 if ( $res instanceof ResultWrapper )
 202                         $r =& $res->result;
 203                 else
 204                         $r =& $res;
 205
 206                 $cur = current( $r );
 207                 if ( is_array( $cur ) ) {
 208                         next( $r );
 209                         $obj = new stdClass;
 210                         foreach ( $cur as $k => $v )
 211                                 if ( !is_numeric( $k ) )
 212                                         $obj->$k = $v;
 213
 214                         return $obj;
 215                 }
 216                 return false;
 217         }
 218
 219         function fetchRow( $res ) {
 220                 if ( $res instanceof ResultWrapper )
 221                         $r =& $res->result;
 222                 else
 223                         $r =& $res;
 224
 225                 $cur = current( $r );
 226                 if ( is_array( $cur ) ) {
 227                         next( $r );
 228                         return $cur;
 229                 }
 230                 return false;
 231         }
 232
 233         /**
 234          * The PDO::Statement class implements the array interface so count() will work
 235          */
 236         function numRows( $res ) {
 237                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 238                 return count( $r );
 239         }
 240
 241         function numFields( $res ) {
 242                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 243                 return is_array( $r ) ? count( $r[0] ) : 0;
 244         }
 245
 246         function fieldName( $res, $n ) {
 247                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 248                 if ( is_array( $r ) ) {
 249                         $keys = array_keys( $r[0] );
 250                         return $keys[$n];
 251                 }
 252                 return  false;
 253         }
 254
 255         /**
 256          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 257          */
 258         function tableName( $name ) {
 259                 return str_replace( '`', '', parent::tableName( $name ) );
 260         }
 261
 262         /**
 263          * Index names have DB scope
 264          */
 265         function indexName( $index ) {
 266                 return $index;
 267         }
 268
 269         /**
 270          * This must be called after nextSequenceVal
 271          */
 272         function insertId() {
 273                 return $this->mConn->lastInsertId();
 274         }
 275
 276         function dataSeek( $res, $row ) {
 277                 if ( $res instanceof ResultWrapper )
 278                         $r =& $res->result;
 279                 else
 280                         $r =& $res;
 281                 reset( $r );
 282                 if ( $row > 0 )
 283                         for ( $i = 0; $i < $row; $i++ )
 284                                 next( $r );
 285         }
 286
 287         function lastError() {
 288                 if ( !is_object( $this->mConn ) )
 289                         return "Cannot return last error, no db connection";
 290                 $e = $this->mConn->errorInfo();
 291                 return isset( $e[2] ) ? $e[2] : '';
 292         }
 293
 294         function lastErrno() {
 295                 if ( !is_object( $this->mConn ) ) {
 296                         return "Cannot return last error, no db connection";
 297                 } else {
 298                         $info = $this->mConn->errorInfo();
 299                         return $info[1];
 300                 }
 301         }
 302
 303         function affectedRows() {
 304                 return $this->mAffectedRows;
 305         }
 306
 307         /**
 308          * Returns information about an index
 309          * Returns false if the index does not exist
 310          * - if errors are explicitly ignored, returns NULL on failure
 311          */
 312         function indexInfo( $table, $index, $fname = 'DatabaseSqlite::indexExists' ) {
 313                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 314                 $res = $this->query( $sql, $fname );
 315                 if ( !$res ) {
 316                         return null;
 317                 }
 318                 if ( $res->numRows() == 0 ) {
 319                         return false;
 320                 }
 321                 $info = array();
 322                 foreach ( $res as $row ) {
 323                         $info[] = $row->name;
 324                 }
 325                 return $info;
 326         }
 327
 328         function indexUnique( $table, $index, $fname = 'DatabaseSqlite::indexUnique' ) {
 329                 $row = $this->selectRow( 'sqlite_master', '*',
 330                         array(
 331                                 'type' => 'index',
 332                                 'name' => $this->indexName( $index ),
 333                         ), $fname );
 334                 if ( !$row || !isset( $row->sql ) ) {
 335                         return null;
 336                 }
 337
 338                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 339                 $indexPos = strpos( $row->sql, 'INDEX' );
 340                 if ( $indexPos === false ) {
 341                         return null;
 342                 }
 343                 $firstPart = substr( $row->sql, 0, $indexPos );
 344                 $options = explode( ' ', $firstPart );
 345                 return in_array( 'UNIQUE', $options );
 346         }
 347
 348         /**
 349          * Filter the options used in SELECT statements
 350          */
 351         function makeSelectOptions( $options ) {
 352                 foreach ( $options as $k => $v )
 353                         if ( is_numeric( $k ) && $v == 'FOR UPDATE' )
 354                                 $options[$k] = '';
 355                 return parent::makeSelectOptions( $options );
 356         }
 357
 358         /**
 359          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 360          */
 361         function insert( $table, $a, $fname = 'DatabaseSqlite::insert', $options = array() ) {
 362                 if ( !count( $a ) ) return true;
 363                 if ( !is_array( $options ) ) $options = array( $options );
 364
 365                 # SQLite uses OR IGNORE not just IGNORE
 366                 foreach ( $options as $k => $v )
 367                         if ( $v == 'IGNORE' )
 368                                 $options[$k] = 'OR IGNORE';
 369
 370                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 371                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 372                         $ret = true;
 373                         foreach ( $a as $k => $v )
 374                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) )
 375                                         $ret = false;
 376                 } else {
 377                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 378                 }
 379
 380                 return $ret;
 381         }
 382
 383         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseSqlite::replace' ) {
 384                 if ( !count( $rows ) ) return true;
 385
 386                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 387                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 388                         $ret = true;
 389                         foreach ( $rows as $k => $v )
 390                                 if ( !parent::replace( $table, $uniqueIndexes, $v, "$fname/multi-row" ) )
 391                                         $ret = false;
 392                 } else {
 393                         $ret = parent::replace( $table, $uniqueIndexes, $rows, "$fname/single-row" );
 394                 }
 395
 396                 return $ret;
 397         }
 398
 399         /**
 400          * Returns the size of a text field, or -1 for "unlimited"
 401          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 402          */
 403         function textFieldSize( $table, $field ) {
 404                 return - 1;
 405         }
 406
 407         function unionSupportsOrderAndLimit() {
 408                 return false;
 409         }
 410
 411         function unionQueries( $sqls, $all ) {
 412                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 413                 return implode( $glue, $sqls );
 414         }
 415
 416         function wasDeadlock() {
 417                 return $this->lastErrno() == 5; // SQLITE_BUSY
 418         }
 419
 420         function wasErrorReissuable() {
 421                 return $this->lastErrno() ==  17; // SQLITE_SCHEMA;
 422         }
 423
 424         function wasReadOnlyError() {
 425                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 426         }
 427
 428         /**
 429          * @return string wikitext of a link to the server software's web site
 430          */
 431         function getSoftwareLink() {
 432                 return "[http://sqlite.org/ SQLite]";
 433         }
 434
 435         /**
 436          * @return string Version information from the database
 437          */
 438         function getServerVersion() {
 439                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 440                 return $ver;
 441         }
 442
 443         /**
 444          * Get information about a given field
 445          * Returns false if the field does not exist.
 446          */
 447         function fieldInfo( $table, $field ) {
 448                 $tableName = $this->tableName( $table );
 449                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 450                 $res = $this->query( $sql, __METHOD__ );
 451                 foreach ( $res as $row ) {
 452                         if ( $row->name == $field ) {
 453                                 return new SQLiteField( $row, $tableName );
 454                         }
 455                 }
 456                 return false;
 457         }
 458
 459         function begin( $fname = '' ) {
 460                 if ( $this->mTrxLevel == 1 ) $this->commit();
 461                 $this->mConn->beginTransaction();
 462                 $this->mTrxLevel = 1;
 463         }
 464
 465         function commit( $fname = '' ) {
 466                 if ( $this->mTrxLevel == 0 ) return;
 467                 $this->mConn->commit();
 468                 $this->mTrxLevel = 0;
 469         }
 470
 471         function rollback( $fname = '' ) {
 472                 if ( $this->mTrxLevel == 0 ) return;
 473                 $this->mConn->rollBack();
 474                 $this->mTrxLevel = 0;
 475         }
 476
 477         function limitResultForUpdate( $sql, $num ) {
 478                 return $this->limitResult( $sql, $num );
 479         }
 480
 481         function strencode( $s ) {
 482                 return substr( $this->addQuotes( $s ), 1, - 1 );
 483         }
 484
 485         function encodeBlob( $b ) {
 486                 return new Blob( $b );
 487         }
 488
 489         function decodeBlob( $b ) {
 490                 if ( $b instanceof Blob ) {
 491                         $b = $b->fetch();
 492                 }
 493                 return $b;
 494         }
 495
 496         function addQuotes( $s ) {
 497                 if ( $s instanceof Blob ) {
 498                         return "x'" . bin2hex( $s->fetch() ) . "'";
 499                 } else {
 500                         return $this->mConn->quote( $s );
 501                 }
 502         }
 503
 504         function quote_ident( $s ) {
 505                 return $s;
 506         }
 507
 508         function buildLike() {
 509                 $params = func_get_args();
 510                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 511                         $params = $params[0];
 512                 }
 513                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 514         }
 515
 516         /**
 517          * Called by the installer script (when modified according to the MediaWikiLite installation instructions)
 518          * - this is the same way PostgreSQL works, MySQL reads in tables.sql and interwiki.sql using dbsource (which calls db->sourceFile)
 519          */
 520         public function setup_database() {
 521                 global $IP;
 522
 523                 # Process common MySQL/SQLite table definitions
 524                 $err = $this->sourceFile( "$IP/maintenance/tables.sql" );
 525                 if ( $err !== true ) {
 526                         echo " <b>FAILED</b></li>";
 527                         dieout( htmlspecialchars( $err ) );
 528                 }
 529                 echo " done.</li>";
 530
 531                 # Use DatabasePostgres's code to populate interwiki from MySQL template
 532                 $f = fopen( "$IP/maintenance/interwiki.sql", 'r' );
 533                 if ( !$f ) {
 534                         dieout( "Could not find the interwiki.sql file." );
 535                 }
 536
 537                 $sql = "INSERT INTO interwiki(iw_prefix,iw_url,iw_local) VALUES ";
 538                 while ( !feof( $f ) ) {
 539                         $line = fgets( $f, 1024 );
 540                         $matches = array();
 541                         if ( !preg_match( '/^\s*(\(.+?),(\d)\)/', $line, $matches ) ) continue;
 542                         $this->query( "$sql $matches[1],$matches[2])" );
 543                 }
 544         }
 545
 546         public function getSearchEngine() {
 547                 return "SearchSqlite";
 548         }
 549
 550         /**
 551          * No-op version of deadlockLoop
 552          */
 553         public function deadlockLoop( /*...*/ ) {
 554                 $args = func_get_args();
 555                 $function = array_shift( $args );
 556                 return call_user_func_array( $function, $args );
 557         }
 558
 559         protected function replaceVars( $s ) {
 560                 $s = parent::replaceVars( $s );
 561                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 562                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 563
 564                         // binary/varbinary column type -> blob
 565                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 566                         // no such thing as unsigned
 567                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 568                         // INT -> INTEGER
 569                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\([\s\d]*\)|\b)/i', 'INTEGER', $s );
 570                         // varchar -> TEXT
 571                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 572                         // TEXT normalization
 573                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 574                         // BLOB normalization
 575                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 576                         // BOOL -> INTEGER
 577                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 578                         // DATETIME -> TEXT
 579                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 580                         // No ENUM type
 581                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 582                         // binary collation type -> nothing
 583                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 584                         // auto_increment -> autoincrement
 585                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 586                         // No explicit options
 587                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 588                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 589                         // No truncated indexes
 590                         $s = preg_replace( '/\(\d+\)/', '', $s );
 591                         // No FULLTEXT
 592                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 593                 }
 594                 return $s;
 595         }
 596
 597         /*
 598          * Build a concatenation list to feed into a SQL query
 599          */
 600         function buildConcat( $stringList ) {
 601                 return '(' . implode( ') || (', $stringList ) . ')';
 602         }
 603
 604         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseSqlite::duplicateTableStructure' ) {
 605                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name='$oldName' AND type='table'", $fname );
 606                 $obj = $this->fetchObject( $res );
 607                 if ( !$obj ) {
 608                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 609                 }
 610                 $sql = $obj->sql;
 611                 $sql = preg_replace( '/\b' . preg_quote( $oldName ) . '\b/', $newName, $sql, 1 );
 612                 return $this->query( $sql, $fname );
 613         }
 614
 615 } // end DatabaseSqlite class
 616
 617 /**
 618  * This class allows simple acccess to a SQLite database independently from main database settings
 619  * @ingroup Database
 620  */
 621 class DatabaseSqliteStandalone extends DatabaseSqlite {
 622         public function __construct( $fileName, $flags = 0 ) {
 623                 $this->mFlags = $flags;
 624                 $this->openFile( $fileName );
 625         }
 626 }
 627
 628 /**
 629  * @ingroup Database
 630  */
 631 class SQLiteField {
 632         private $info, $tableName;
 633         function __construct( $info, $tableName ) {
 634                 $this->info = $info;
 635                 $this->tableName = $tableName;
 636         }
 637
 638         function name() {
 639                 return $this->info->name;
 640         }
 641
 642         function tableName() {
 643                 return $this->tableName;
 644         }
 645
 646         function defaultValue() {
 647                 if ( is_string( $this->info->dflt_value ) ) {
 648                         // Typically quoted
 649                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 650                                 return str_replace( "''", "'", $this->info->dflt_value );
 651                         }
 652                 }
 653                 return $this->info->dflt_value;
 654         }
 655
 656         function maxLength() {
 657                 return -1;
 658         }
 659
 660         function nullable() {
 661                 // SQLite dynamic types are always nullable
 662                 return true;
 663         }
 664
 665         # isKey(),  isMultipleKey() not implemented, MySQL-specific concept.
 666         # Suggest removal from base class [TS]
 667
 668         function type() {
 669                 return $this->info->type;
 670         }
 671
 672 } // end SQLiteField