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 String: database name to be used in queries like SELECT foo FROM dbname.table
 155          * @param $file String: database file name. If omitted, will be generated using $name and $wgSQLiteDataDir
 156          * @param $fname String: calling function name
 157          */
 158         function attachDatabase( $name, $file = false, $fname = 'DatabaseSqlite::attachDatabase' ) {
 159                 global $wgSQLiteDataDir;
 160                 if ( !$file ) {
 161                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 162                 }
 163                 $file = $this->addQuotes( $file );
 164                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 165         }
 166
 167         /**
 168          * @see DatabaseBase::isWriteQuery()
 169          */
 170         function isWriteQuery( $sql ) {
 171                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 172         }
 173
 174         /**
 175          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 176          */
 177         function doQuery( $sql ) {
 178                 $res = $this->mConn->query( $sql );
 179                 if ( $res === false ) {
 180                         return false;
 181                 } else {
 182                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 183                         $this->mAffectedRows = $r->rowCount();
 184                         $res = new ResultWrapper( $this, $r->fetchAll() );
 185                 }
 186                 return $res;
 187         }
 188
 189         function freeResult( $res ) {
 190                 if ( $res instanceof ResultWrapper )
 191                         $res->result = null;
 192                 else
 193                         $res = null;
 194         }
 195
 196         function fetchObject( $res ) {
 197                 if ( $res instanceof ResultWrapper )
 198                         $r =& $res->result;
 199                 else
 200                         $r =& $res;
 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                         return $obj;
 211                 }
 212                 return false;
 213         }
 214
 215         function fetchRow( $res ) {
 216                 if ( $res instanceof ResultWrapper )
 217                         $r =& $res->result;
 218                 else
 219                         $r =& $res;
 220
 221                 $cur = current( $r );
 222                 if ( is_array( $cur ) ) {
 223                         next( $r );
 224                         return $cur;
 225                 }
 226                 return false;
 227         }
 228
 229         /**
 230          * The PDO::Statement class implements the array interface so count() will work
 231          */
 232         function numRows( $res ) {
 233                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 234                 return count( $r );
 235         }
 236
 237         function numFields( $res ) {
 238                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 239                 return is_array( $r ) ? count( $r[0] ) : 0;
 240         }
 241
 242         function fieldName( $res, $n ) {
 243                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 244                 if ( is_array( $r ) ) {
 245                         $keys = array_keys( $r[0] );
 246                         return $keys[$n];
 247                 }
 248                 return  false;
 249         }
 250
 251         /**
 252          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 253          */
 254         function tableName( $name ) {
 255                 return str_replace( '`', '', parent::tableName( $name ) );
 256         }
 257
 258         /**
 259          * Index names have DB scope
 260          */
 261         function indexName( $index ) {
 262                 return $index;
 263         }
 264
 265         /**
 266          * This must be called after nextSequenceVal
 267          */
 268         function insertId() {
 269                 return $this->mConn->lastInsertId();
 270         }
 271
 272         function dataSeek( $res, $row ) {
 273                 if ( $res instanceof ResultWrapper )
 274                         $r =& $res->result;
 275                 else
 276                         $r =& $res;
 277                 reset( $r );
 278                 if ( $row > 0 )
 279                         for ( $i = 0; $i < $row; $i++ )
 280                                 next( $r );
 281         }
 282
 283         function lastError() {
 284                 if ( !is_object( $this->mConn ) )
 285                         return "Cannot return last error, no db connection";
 286                 $e = $this->mConn->errorInfo();
 287                 return isset( $e[2] ) ? $e[2] : '';
 288         }
 289
 290         function lastErrno() {
 291                 if ( !is_object( $this->mConn ) ) {
 292                         return "Cannot return last error, no db connection";
 293                 } else {
 294                         $info = $this->mConn->errorInfo();
 295                         return $info[1];
 296                 }
 297         }
 298
 299         function affectedRows() {
 300                 return $this->mAffectedRows;
 301         }
 302
 303         /**
 304          * Returns information about an index
 305          * Returns false if the index does not exist
 306          * - if errors are explicitly ignored, returns NULL on failure
 307          */
 308         function indexInfo( $table, $index, $fname = 'DatabaseSqlite::indexExists' ) {
 309                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 310                 $res = $this->query( $sql, $fname );
 311                 if ( !$res ) {
 312                         return null;
 313                 }
 314                 if ( $res->numRows() == 0 ) {
 315                         return false;
 316                 }
 317                 $info = array();
 318                 foreach ( $res as $row ) {
 319                         $info[] = $row->name;
 320                 }
 321                 return $info;
 322         }
 323
 324         function indexUnique( $table, $index, $fname = 'DatabaseSqlite::indexUnique' ) {
 325                 $row = $this->selectRow( 'sqlite_master', '*',
 326                         array(
 327                                 'type' => 'index',
 328                                 'name' => $this->indexName( $index ),
 329                         ), $fname );
 330                 if ( !$row || !isset( $row->sql ) ) {
 331                         return null;
 332                 }
 333
 334                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 335                 $indexPos = strpos( $row->sql, 'INDEX' );
 336                 if ( $indexPos === false ) {
 337                         return null;
 338                 }
 339                 $firstPart = substr( $row->sql, 0, $indexPos );
 340                 $options = explode( ' ', $firstPart );
 341                 return in_array( 'UNIQUE', $options );
 342         }
 343
 344         /**
 345          * Filter the options used in SELECT statements
 346          */
 347         function makeSelectOptions( $options ) {
 348                 foreach ( $options as $k => $v )
 349                         if ( is_numeric( $k ) && $v == 'FOR UPDATE' )
 350                                 $options[$k] = '';
 351                 return parent::makeSelectOptions( $options );
 352         }
 353
 354         /**
 355          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 356          */
 357         function insert( $table, $a, $fname = 'DatabaseSqlite::insert', $options = array() ) {
 358                 if ( !count( $a ) ) return true;
 359                 if ( !is_array( $options ) ) $options = array( $options );
 360
 361                 # SQLite uses OR IGNORE not just IGNORE
 362                 foreach ( $options as $k => $v )
 363                         if ( $v == 'IGNORE' )
 364                                 $options[$k] = 'OR IGNORE';
 365
 366                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 367                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 368                         $ret = true;
 369                         foreach ( $a as $k => $v )
 370                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) )
 371                                         $ret = false;
 372                 } else {
 373                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 374                 }
 375
 376                 return $ret;
 377         }
 378
 379         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseSqlite::replace' ) {
 380                 if ( !count( $rows ) ) return true;
 381
 382                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 383                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 384                         $ret = true;
 385                         foreach ( $rows as $k => $v )
 386                                 if ( !parent::replace( $table, $uniqueIndexes, $v, "$fname/multi-row" ) )
 387                                         $ret = false;
 388                 } else {
 389                         $ret = parent::replace( $table, $uniqueIndexes, $rows, "$fname/single-row" );
 390                 }
 391
 392                 return $ret;
 393         }
 394
 395         /**
 396          * Returns the size of a text field, or -1 for "unlimited"
 397          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 398          */
 399         function textFieldSize( $table, $field ) {
 400                 return - 1;
 401         }
 402
 403         function unionSupportsOrderAndLimit() {
 404                 return false;
 405         }
 406
 407         function unionQueries( $sqls, $all ) {
 408                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 409                 return implode( $glue, $sqls );
 410         }
 411
 412         function wasDeadlock() {
 413                 return $this->lastErrno() == 5; // SQLITE_BUSY
 414         }
 415
 416         function wasErrorReissuable() {
 417                 return $this->lastErrno() ==  17; // SQLITE_SCHEMA;
 418         }
 419
 420         function wasReadOnlyError() {
 421                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 422         }
 423
 424         /**
 425          * @return string wikitext of a link to the server software's web site
 426          */
 427         function getSoftwareLink() {
 428                 return "[http://sqlite.org/ SQLite]";
 429         }
 430
 431         /**
 432          * @return string Version information from the database
 433          */
 434         function getServerVersion() {
 435                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 436                 return $ver;
 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          * Called by the installer script (when modified according to the MediaWikiLite installation instructions)
 514          * - this is the same way PostgreSQL works, MySQL reads in tables.sql and interwiki.sql using dbsource (which calls db->sourceFile)
 515          */
 516         public function setup_database() {
 517                 global $IP;
 518
 519                 # Process common MySQL/SQLite table definitions
 520                 $err = $this->sourceFile( "$IP/maintenance/tables.sql" );
 521                 if ( $err !== true ) {
 522                         echo " <b>FAILED</b></li>";
 523                         dieout( htmlspecialchars( $err ) );
 524                 }
 525                 echo " done.</li>";
 526
 527                 # Use DatabasePostgres's code to populate interwiki from MySQL template
 528                 $f = fopen( "$IP/maintenance/interwiki.sql", 'r' );
 529                 if ( !$f ) {
 530                         dieout( "Could not find the interwiki.sql file." );
 531                 }
 532
 533                 $sql = "INSERT INTO interwiki(iw_prefix,iw_url,iw_local) VALUES ";
 534                 while ( !feof( $f ) ) {
 535                         $line = fgets( $f, 1024 );
 536                         $matches = array();
 537                         if ( !preg_match( '/^\s*(\(.+?),(\d)\)/', $line, $matches ) ) continue;
 538                         $this->query( "$sql $matches[1],$matches[2])" );
 539                 }
 540         }
 541
 542         public function getSearchEngine() {
 543                 return "SearchSqlite";
 544         }
 545
 546         /**
 547          * No-op version of deadlockLoop
 548          */
 549         public function deadlockLoop( /*...*/ ) {
 550                 $args = func_get_args();
 551                 $function = array_shift( $args );
 552                 return call_user_func_array( $function, $args );
 553         }
 554
 555         protected function replaceVars( $s ) {
 556                 $s = parent::replaceVars( $s );
 557                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 558                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 559
 560                         // binary/varbinary column type -> blob
 561                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 562                         // no such thing as unsigned
 563                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 564                         // INT -> INTEGER
 565                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\([\s\d]*\)|\b)/i', 'INTEGER', $s );
 566                         // varchar -> TEXT
 567                         $s = preg_replace( '/\bvarchar\(\d+\)/i', 'TEXT', $s );
 568                         // TEXT normalization
 569                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 570                         // BLOB normalization
 571                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 572                         // BOOL -> INTEGER
 573                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 574                         // DATETIME -> TEXT
 575                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 576                         // No ENUM type
 577                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 578                         // binary collation type -> nothing
 579                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 580                         // auto_increment -> autoincrement
 581                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 582                         // No explicit options
 583                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 584                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 585                         // No truncated indexes
 586                         $s = preg_replace( '/\(\d+\)/', '', $s );
 587                         // No FULLTEXT
 588                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 589                 }
 590                 return $s;
 591         }
 592
 593         /*
 594          * Build a concatenation list to feed into a SQL query
 595          */
 596         function buildConcat( $stringList ) {
 597                 return '(' . implode( ') || (', $stringList ) . ')';
 598         }
 599
 600         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseSqlite::duplicateTableStructure' ) {
 601                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name='$oldName' AND type='table'", $fname );
 602                 $obj = $this->fetchObject( $res );
 603                 if ( !$obj ) {
 604                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 605                 }
 606                 $sql = $obj->sql;
 607                 $sql = preg_replace( '/\b' . preg_quote( $oldName ) . '\b/', $newName, $sql, 1 );
 608                 return $this->query( $sql, $fname );
 609         }
 610
 611 } // end DatabaseSqlite class
 612
 613 /**
 614  * This class allows simple acccess to a SQLite database independently from main database settings
 615  * @ingroup Database
 616  */
 617 class DatabaseSqliteStandalone extends DatabaseSqlite {
 618         public function __construct( $fileName, $flags = 0 ) {
 619                 $this->mFlags = $flags;
 620                 $this->openFile( $fileName );
 621         }
 622 }
 623
 624 /**
 625  * @ingroup Database
 626  */
 627 class SQLiteField {
 628         private $info, $tableName;
 629         function __construct( $info, $tableName ) {
 630                 $this->info = $info;
 631                 $this->tableName = $tableName;
 632         }
 633
 634         function name() {
 635                 return $this->info->name;
 636         }
 637
 638         function tableName() {
 639                 return $this->tableName;
 640         }
 641
 642         function defaultValue() {
 643                 if ( is_string( $this->info->dflt_value ) ) {
 644                         // Typically quoted
 645                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 646                                 return str_replace( "''", "'", $this->info->dflt_value );
 647                         }
 648                 }
 649                 return $this->info->dflt_value;
 650         }
 651
 652         function maxLength() {
 653                 return -1;
 654         }
 655
 656         function nullable() {
 657                 // SQLite dynamic types are always nullable
 658                 return true;
 659         }
 660
 661         # isKey(),  isMultipleKey() not implemented, MySQL-specific concept.
 662         # Suggest removal from base class [TS]
 663
 664         function type() {
 665                 return $this->info->type;
 666         }
 667
 668 } // end SQLiteField