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