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( $server ) {
  32                         if ( $this->open( $server, $user, $password, $dbName ) && $wgSharedDB ) {
  33                                 $this->attachDatabase( $wgSharedDB );
  34                         }
  35                 }
  36         }
  37
  38         function getType() {
  39                 return 'sqlite';
  40         }
  41
  42         /**
  43          * @todo: check if it should be true like parent class
  44          */
  45         function implicitGroupby()   { return false; }
  46
  47         /** Open an SQLite database and return a resource handle to it
  48          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  49          */
  50         function open( $server, $user, $pass, $dbName ) {
  51                 global $wgSQLiteDataDir;
  52
  53                 $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
  54                 if ( !is_readable( $fileName ) ) {
  55                         $this->mConn = false;
  56                         throw new DBConnectionError( $this, "SQLite database not accessible" );
  57                 }
  58                 $this->openFile( $fileName );
  59                 return $this->mConn;
  60         }
  61
  62         /**
  63          * Opens a database file
  64          * @return SQL connection or false if failed
  65          */
  66         function openFile( $fileName ) {
  67                 $this->mDatabaseFile = $fileName;
  68                 try {
  69                         if ( $this->mFlags & DBO_PERSISTENT ) {
  70                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
  71                                         array( PDO::ATTR_PERSISTENT => true ) );
  72                         } else {
  73                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
  74                         }
  75                 } catch ( PDOException $e ) {
  76                         $err = $e->getMessage();
  77                 }
  78                 if ( !$this->mConn ) {
  79                         wfDebug( "DB connection error: $err\n" );
  80                         throw new DBConnectionError( $this, $err );
  81                 }
  82                 $this->mOpened = !!$this->mConn;
  83                 # set error codes only, don't raise exceptions
  84                 if ( $this->mOpened ) {
  85                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
  86                         return true;
  87                 }
  88         }
  89
  90         /**
  91          * Close an SQLite database
  92          */
  93         function close() {
  94                 $this->mOpened = false;
  95                 if ( is_object( $this->mConn ) ) {
  96                         if ( $this->trxLevel() ) $this->commit();
  97                         $this->mConn = null;
  98                 }
  99                 return true;
 100         }
 101
 102         /**
 103          * Generates a database file name. Explicitly public for installer.
 104          * @param $dir String: Directory where database resides
 105          * @param $dbName String: Database name
 106          * @return String
 107          */
 108         public static function generateFileName( $dir, $dbName ) {
 109                 return "$dir/$dbName.sqlite";
 110         }
 111
 112         /**
 113          * Check if the searchindext table is FTS enabled.
 114          * @returns false if not enabled.
 115          */
 116         function checkForEnabledSearch() {
 117                 if ( self::$fulltextEnabled === null ) {
 118                         self::$fulltextEnabled = false;
 119                         $table = $this->tableName( 'searchindex' );
 120                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 121                         if ( $res ) {
 122                                 $row = $res->fetchRow();
 123                                 self::$fulltextEnabled = stristr($row['sql'], 'fts' ) !== false;
 124                         }
 125                 }
 126                 return self::$fulltextEnabled;
 127         }
 128
 129         /**
 130          * Returns version of currently supported SQLite fulltext search module or false if none present.
 131          * @return String
 132          */
 133         function getFulltextSearchModule() {
 134                 static $cachedResult = null;
 135                 if ( $cachedResult !== null ) {
 136                         return $cachedResult;
 137                 }
 138                 $cachedResult = false;
 139                 $table = 'dummy_search_test';
 140                 $this->query( "DROP TABLE IF EXISTS $table", __METHOD__ );
 141
 142                 if ( $this->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 143                         $this->query( "DROP TABLE IF EXISTS $table", __METHOD__ );
 144                         $cachedResult = 'FTS3';
 145                 }
 146                 return $cachedResult;
 147         }
 148
 149         /**
 150          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 151          * for details.
 152          * @param $name String: database name to be used in queries like SELECT foo FROM dbname.table
 153          * @param $file String: database file name. If omitted, will be generated using $name and $wgSQLiteDataDir
 154          * @param $fname String: calling function name
 155          */
 156         function attachDatabase( $name, $file = false, $fname = 'DatabaseSqlite::attachDatabase' ) {
 157                 global $wgSQLiteDataDir;
 158                 if ( !$file ) {
 159                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 160                 }
 161                 $file = $this->addQuotes( $file );
 162                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 163         }
 164
 165         /**
 166          * @see DatabaseBase::isWriteQuery()
 167          */
 168         function isWriteQuery( $sql ) {
 169                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 170         }
 171
 172         /**
 173          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 174          */
 175         function doQuery( $sql ) {
 176                 $res = $this->mConn->query( $sql );
 177                 if ( $res === false ) {
 178                         return false;
 179                 } else {
 180                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 181                         $this->mAffectedRows = $r->rowCount();
 182                         $res = new ResultWrapper( $this, $r->fetchAll() );
 183                 }
 184                 return $res;
 185         }
 186
 187         function freeResult( $res ) {
 188                 if ( $res instanceof ResultWrapper ) {
 189                         $res->result = null;
 190                 } else {
 191                         $res = null;
 192                 }
 193         }
 194
 195         function fetchObject( $res ) {
 196                 if ( $res instanceof ResultWrapper ) {
 197                         $r =& $res->result;
 198                 } else {
 199                         $r =& $res;
 200                 }
 201
 202                 $cur = current( $r );
 203                 if ( is_array( $cur ) ) {
 204                         next( $r );
 205                         $obj = new stdClass;
 206                         foreach ( $cur as $k => $v ) {
 207                                 if ( !is_numeric( $k ) ) {
 208                                         $obj->$k = $v;
 209                                 }
 210                         }
 211
 212                         return $obj;
 213                 }
 214                 return false;
 215         }
 216
 217         function fetchRow( $res ) {
 218                 if ( $res instanceof ResultWrapper ) {
 219                         $r =& $res->result;
 220                 } else {
 221                         $r =& $res;
 222                 }
 223                 $cur = current( $r );
 224                 if ( is_array( $cur ) ) {
 225                         next( $r );
 226                         return $cur;
 227                 }
 228                 return false;
 229         }
 230
 231         /**
 232          * The PDO::Statement class implements the array interface so count() will work
 233          */
 234         function numRows( $res ) {
 235                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 236                 return count( $r );
 237         }
 238
 239         function numFields( $res ) {
 240                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 241                 return is_array( $r ) ? count( $r[0] ) : 0;
 242         }
 243
 244         function fieldName( $res, $n ) {
 245                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 246                 if ( is_array( $r ) ) {
 247                         $keys = array_keys( $r[0] );
 248                         return $keys[$n];
 249                 }
 250                 return  false;
 251         }
 252
 253         /**
 254          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 255          */
 256         function tableName( $name ) {
 257                 // table names starting with sqlite_ are reserved
 258                 if ( strpos( $name, 'sqlite_' ) === 0 ) return $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                 }
 282                 reset( $r );
 283                 if ( $row > 0 ) {
 284                         for ( $i = 0; $i < $row; $i++ ) {
 285                                 next( $r );
 286                         }
 287                 }
 288         }
 289
 290         function lastError() {
 291                 if ( !is_object( $this->mConn ) ) {
 292                         return "Cannot return last error, no db connection";
 293                 }
 294                 $e = $this->mConn->errorInfo();
 295                 return isset( $e[2] ) ? $e[2] : '';
 296         }
 297
 298         function lastErrno() {
 299                 if ( !is_object( $this->mConn ) ) {
 300                         return "Cannot return last error, no db connection";
 301                 } else {
 302                         $info = $this->mConn->errorInfo();
 303                         return $info[1];
 304                 }
 305         }
 306
 307         function affectedRows() {
 308                 return $this->mAffectedRows;
 309         }
 310
 311         /**
 312          * Returns information about an index
 313          * Returns false if the index does not exist
 314          * - if errors are explicitly ignored, returns NULL on failure
 315          */
 316         function indexInfo( $table, $index, $fname = 'DatabaseSqlite::indexExists' ) {
 317                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 318                 $res = $this->query( $sql, $fname );
 319                 if ( !$res ) {
 320                         return null;
 321                 }
 322                 if ( $res->numRows() == 0 ) {
 323                         return false;
 324                 }
 325                 $info = array();
 326                 foreach ( $res as $row ) {
 327                         $info[] = $row->name;
 328                 }
 329                 return $info;
 330         }
 331
 332         function indexUnique( $table, $index, $fname = 'DatabaseSqlite::indexUnique' ) {
 333                 $row = $this->selectRow( 'sqlite_master', '*',
 334                         array(
 335                                 'type' => 'index',
 336                                 'name' => $this->indexName( $index ),
 337                         ), $fname );
 338                 if ( !$row || !isset( $row->sql ) ) {
 339                         return null;
 340                 }
 341
 342                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 343                 $indexPos = strpos( $row->sql, 'INDEX' );
 344                 if ( $indexPos === false ) {
 345                         return null;
 346                 }
 347                 $firstPart = substr( $row->sql, 0, $indexPos );
 348                 $options = explode( ' ', $firstPart );
 349                 return in_array( 'UNIQUE', $options );
 350         }
 351
 352         /**
 353          * Filter the options used in SELECT statements
 354          */
 355         function makeSelectOptions( $options ) {
 356                 foreach ( $options as $k => $v ) {
 357                         if ( is_numeric( $k ) && $v == 'FOR UPDATE' ) {
 358                                 $options[$k] = '';
 359                         }
 360                 }
 361                 return parent::makeSelectOptions( $options );
 362         }
 363
 364         /**
 365          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 366          */
 367         function insert( $table, $a, $fname = 'DatabaseSqlite::insert', $options = array() ) {
 368                 if ( !count( $a ) ) {
 369                         return true;
 370                 }
 371                 if ( !is_array( $options ) ) {
 372                         $options = array( $options );
 373                 }
 374
 375                 # SQLite uses OR IGNORE not just IGNORE
 376                 foreach ( $options as $k => $v ) {
 377                         if ( $v == 'IGNORE' ) {
 378                                 $options[$k] = 'OR IGNORE';
 379                         }
 380                 }
 381
 382                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 383                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 384                         $ret = true;
 385                         foreach ( $a as $v ) {
 386                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 387                                         $ret = false;
 388                                 }
 389                         }
 390                 } else {
 391                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 392                 }
 393
 394                 return $ret;
 395         }
 396
 397         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseSqlite::replace' ) {
 398                 if ( !count( $rows ) ) return true;
 399
 400                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 401                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 402                         $ret = true;
 403                         foreach ( $rows as $v ) {
 404                                 if ( !parent::replace( $table, $uniqueIndexes, $v, "$fname/multi-row" ) ) {
 405                                         $ret = false;
 406                                 }
 407                         }
 408                 } else {
 409                         $ret = parent::replace( $table, $uniqueIndexes, $rows, "$fname/single-row" );
 410                 }
 411
 412                 return $ret;
 413         }
 414
 415         /**
 416          * Returns the size of a text field, or -1 for "unlimited"
 417          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 418          */
 419         function textFieldSize( $table, $field ) {
 420                 return -1;
 421         }
 422
 423         function unionSupportsOrderAndLimit() {
 424                 return false;
 425         }
 426
 427         function unionQueries( $sqls, $all ) {
 428                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 429                 return implode( $glue, $sqls );
 430         }
 431
 432         function wasDeadlock() {
 433                 return $this->lastErrno() == 5; // SQLITE_BUSY
 434         }
 435
 436         function wasErrorReissuable() {
 437                 return $this->lastErrno() ==  17; // SQLITE_SCHEMA;
 438         }
 439
 440         function wasReadOnlyError() {
 441                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 442         }
 443
 444         /**
 445          * @return string wikitext of a link to the server software's web site
 446          */
 447         public static function getSoftwareLink() {
 448                 return "[http://sqlite.org/ SQLite]";
 449         }
 450
 451         /**
 452          * @return string Version information from the database
 453          */
 454         function getServerVersion() {
 455                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 456                 return $ver;
 457         }
 458
 459         /**
 460          * @return string User-friendly database information
 461          */
 462         public function getServerInfo() {
 463                 return wfMsg( $this->getFulltextSearchModule() ? 'sqlite-has-fts' : 'sqlite-no-fts', $this->getServerVersion() );
 464         }
 465
 466         /**
 467          * Get information about a given field
 468          * Returns false if the field does not exist.
 469          */
 470         function fieldInfo( $table, $field ) {
 471                 $tableName = $this->tableName( $table );
 472                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 473                 $res = $this->query( $sql, __METHOD__ );
 474                 foreach ( $res as $row ) {
 475                         if ( $row->name == $field ) {
 476                                 return new SQLiteField( $row, $tableName );
 477                         }
 478                 }
 479                 return false;
 480         }
 481
 482         function begin( $fname = '' ) {
 483                 if ( $this->mTrxLevel == 1 ) $this->commit();
 484                 $this->mConn->beginTransaction();
 485                 $this->mTrxLevel = 1;
 486         }
 487
 488         function commit( $fname = '' ) {
 489                 if ( $this->mTrxLevel == 0 ) return;
 490                 $this->mConn->commit();
 491                 $this->mTrxLevel = 0;
 492         }
 493
 494         function rollback( $fname = '' ) {
 495                 if ( $this->mTrxLevel == 0 ) return;
 496                 $this->mConn->rollBack();
 497                 $this->mTrxLevel = 0;
 498         }
 499
 500         function limitResultForUpdate( $sql, $num ) {
 501                 return $this->limitResult( $sql, $num );
 502         }
 503
 504         function strencode( $s ) {
 505                 return substr( $this->addQuotes( $s ), 1, - 1 );
 506         }
 507
 508         function encodeBlob( $b ) {
 509                 return new Blob( $b );
 510         }
 511
 512         function decodeBlob( $b ) {
 513                 if ( $b instanceof Blob ) {
 514                         $b = $b->fetch();
 515                 }
 516                 return $b;
 517         }
 518
 519         function addQuotes( $s ) {
 520                 if ( $s instanceof Blob ) {
 521                         return "x'" . bin2hex( $s->fetch() ) . "'";
 522                 } else {
 523                         return $this->mConn->quote( $s );
 524                 }
 525         }
 526
 527         function buildLike() {
 528                 $params = func_get_args();
 529                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 530                         $params = $params[0];
 531                 }
 532                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 533         }
 534
 535         public function getSearchEngine() {
 536                 return "SearchSqlite";
 537         }
 538
 539         /**
 540          * No-op version of deadlockLoop
 541          */
 542         public function deadlockLoop( /*...*/ ) {
 543                 $args = func_get_args();
 544                 $function = array_shift( $args );
 545                 return call_user_func_array( $function, $args );
 546         }
 547
 548         protected function replaceVars( $s ) {
 549                 $s = parent::replaceVars( $s );
 550                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 551                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 552
 553                         // binary/varbinary column type -> blob
 554                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 555                         // no such thing as unsigned
 556                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 557                         // INT -> INTEGER
 558                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 559                         // floating point types -> REAL
 560                         $s = preg_replace( '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i', 'REAL', $s );
 561                         // varchar -> TEXT
 562                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 563                         // TEXT normalization
 564                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 565                         // BLOB normalization
 566                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 567                         // BOOL -> INTEGER
 568                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 569                         // DATETIME -> TEXT
 570                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 571                         // No ENUM type
 572                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 573                         // binary collation type -> nothing
 574                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 575                         // auto_increment -> autoincrement
 576                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 577                         // No explicit options
 578                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 579                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 580                         // No truncated indexes
 581                         $s = preg_replace( '/\(\d+\)/', '', $s );
 582                         // No FULLTEXT
 583                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 584                 }
 585                 return $s;
 586         }
 587
 588         /*
 589          * Build a concatenation list to feed into a SQL query
 590          */
 591         function buildConcat( $stringList ) {
 592                 return '(' . implode( ') || (', $stringList ) . ')';
 593         }
 594
 595         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseSqlite::duplicateTableStructure' ) {
 596
 597                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name='$oldName' AND type='table'", $fname );
 598                 $obj = $this->fetchObject( $res );
 599                 if ( !$obj ) {
 600                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 601                 }
 602                 $sql = $obj->sql;
 603                 $sql = preg_replace( '/\b' . preg_quote( $oldName ) . '\b/', $newName, $sql, 1 );
 604                 return $this->query( $sql, $fname );
 605         }
 606
 607
 608         /**
 609          * List all tables on the database
 610          *
 611          * @param $prefix Only show tables with this prefix, e.g. mw_
 612          * @param $fname String: calling function name
 613          */
 614         function listTables( $prefix = null, $fname = 'DatabaseSqlite::listTables' ) {
 615                 $result = $this->select(
 616                         'sqlite_master',
 617                         'name',
 618                         "type='table'"
 619                 );
 620
 621                 $endArray = array();
 622
 623                 foreach( $result as $table ) {
 624                         $vars = get_object_vars($table);
 625                         $table = array_pop( $vars );
 626
 627                         if( !$prefix || strpos( $table, $prefix ) === 0 ) {
 628                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
 629                                         $endArray[] = $table;
 630                                 }
 631
 632                         }
 633                 }
 634
 635                 return $endArray;
 636         }
 637
 638 } // end DatabaseSqlite class
 639
 640 /**
 641  * This class allows simple acccess to a SQLite database independently from main database settings
 642  * @ingroup Database
 643  */
 644 class DatabaseSqliteStandalone extends DatabaseSqlite {
 645         public function __construct( $fileName, $flags = 0 ) {
 646                 $this->mFlags = $flags;
 647                 $this->tablePrefix( null );
 648                 $this->openFile( $fileName );
 649         }
 650 }
 651
 652 /**
 653  * @ingroup Database
 654  */
 655 class SQLiteField implements Field {
 656         private $info, $tableName;
 657         function __construct( $info, $tableName ) {
 658                 $this->info = $info;
 659                 $this->tableName = $tableName;
 660         }
 661
 662         function name() {
 663                 return $this->info->name;
 664         }
 665
 666         function tableName() {
 667                 return $this->tableName;
 668         }
 669
 670         function defaultValue() {
 671                 if ( is_string( $this->info->dflt_value ) ) {
 672                         // Typically quoted
 673                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 674                                 return str_replace( "''", "'", $this->info->dflt_value );
 675                         }
 676                 }
 677                 return $this->info->dflt_value;
 678         }
 679
 680         function isNullable() {
 681                 return !$this->info->notnull;
 682         }
 683
 684         function type() {
 685                 return $this->info->type;
 686         }
 687
 688 } // end SQLiteField