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         function getType() {
  37                 return 'sqlite';
  38         }
  39
  40         /**
  41          * @todo: check if it should be true like parent class
  42          */
  43         function implicitGroupby()   { return false; }
  44
  45         static function newFromParams( $server, $user, $password, $dbName, $flags = 0 ) {
  46                 return new DatabaseSqlite( $server, $user, $password, $dbName, $flags );
  47         }
  48
  49         /** Open an SQLite database and return a resource handle to it
  50          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  51          */
  52         function open( $server, $user, $pass, $dbName ) {
  53                 global $wgSQLiteDataDir;
  54
  55                 $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
  56                 if ( !is_readable( $fileName ) ) {
  57                         $this->mConn = false;
  58                         throw new DBConnectionError( $this, "SQLite database not accessible" );
  59                 }
  60                 $this->openFile( $fileName );
  61                 return $this->mConn;
  62         }
  63
  64         /**
  65          * Opens a database file
  66          * @return SQL connection or false if failed
  67          */
  68         function openFile( $fileName ) {
  69                 $this->mDatabaseFile = $fileName;
  70                 try {
  71                         if ( $this->mFlags & DBO_PERSISTENT ) {
  72                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
  73                                         array( PDO::ATTR_PERSISTENT => true ) );
  74                         } else {
  75                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
  76                         }
  77                 } catch ( PDOException $e ) {
  78                         $err = $e->getMessage();
  79                 }
  80                 if ( !$this->mConn ) {
  81                         wfDebug( "DB connection error: $err\n" );
  82                         throw new DBConnectionError( $this, $err );
  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/$dbName.sqlite";
 112         }
 113
 114         /**
 115          * Check if the searchindext table is FTS enabled.
 116          * @returns false if not enabled.
 117          */
 118         function checkForEnabledSearch() {
 119                 if ( self::$fulltextEnabled === null ) {
 120                         self::$fulltextEnabled = false;
 121                         $table = $this->tableName( 'searchindex' );
 122                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 123                         if ( $res ) {
 124                                 $row = $res->fetchRow();
 125                                 self::$fulltextEnabled = stristr($row['sql'], 'fts' ) !== false;
 126                         }
 127                 }
 128                 return self::$fulltextEnabled;
 129         }
 130
 131         /**
 132          * Returns version of currently supported SQLite fulltext search module or false if none present.
 133          * @return String
 134          */
 135         function getFulltextSearchModule() {
 136                 static $cachedResult = null;
 137                 if ( $cachedResult !== null ) {
 138                         return $cachedResult;
 139                 }
 140                 $cachedResult = false;
 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                         $cachedResult = 'FTS3';
 147                 }
 148                 return $cachedResult;
 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
 197         function fetchObject( $res ) {
 198                 if ( $res instanceof ResultWrapper ) {
 199                         $r =& $res->result;
 200                 } else {
 201                         $r =& $res;
 202                 }
 203
 204                 $cur = current( $r );
 205                 if ( is_array( $cur ) ) {
 206                         next( $r );
 207                         $obj = new stdClass;
 208                         foreach ( $cur as $k => $v ) {
 209                                 if ( !is_numeric( $k ) ) {
 210                                         $obj->$k = $v;
 211                                 }
 212                         }
 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                 // table names starting with sqlite_ are reserved
 260                 if ( strpos( $name, 'sqlite_' ) === 0 ) return $name;
 261                 return str_replace( '`', '', parent::tableName( $name ) );
 262         }
 263
 264         /**
 265          * Index names have DB scope
 266          */
 267         function indexName( $index ) {
 268                 return $index;
 269         }
 270
 271         /**
 272          * This must be called after nextSequenceVal
 273          */
 274         function insertId() {
 275                 return $this->mConn->lastInsertId();
 276         }
 277
 278         function dataSeek( $res, $row ) {
 279                 if ( $res instanceof ResultWrapper ) {
 280                         $r =& $res->result;
 281                 } else {
 282                         $r =& $res;
 283                 }
 284                 reset( $r );
 285                 if ( $row > 0 ) {
 286                         for ( $i = 0; $i < $row; $i++ ) {
 287                                 next( $r );
 288                         }
 289                 }
 290         }
 291
 292         function lastError() {
 293                 if ( !is_object( $this->mConn ) ) {
 294                         return "Cannot return last error, no db connection";
 295                 }
 296                 $e = $this->mConn->errorInfo();
 297                 return isset( $e[2] ) ? $e[2] : '';
 298         }
 299
 300         function lastErrno() {
 301                 if ( !is_object( $this->mConn ) ) {
 302                         return "Cannot return last error, no db connection";
 303                 } else {
 304                         $info = $this->mConn->errorInfo();
 305                         return $info[1];
 306                 }
 307         }
 308
 309         function affectedRows() {
 310                 return $this->mAffectedRows;
 311         }
 312
 313         /**
 314          * Returns information about an index
 315          * Returns false if the index does not exist
 316          * - if errors are explicitly ignored, returns NULL on failure
 317          */
 318         function indexInfo( $table, $index, $fname = 'DatabaseSqlite::indexExists' ) {
 319                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 320                 $res = $this->query( $sql, $fname );
 321                 if ( !$res ) {
 322                         return null;
 323                 }
 324                 if ( $res->numRows() == 0 ) {
 325                         return false;
 326                 }
 327                 $info = array();
 328                 foreach ( $res as $row ) {
 329                         $info[] = $row->name;
 330                 }
 331                 return $info;
 332         }
 333
 334         function indexUnique( $table, $index, $fname = 'DatabaseSqlite::indexUnique' ) {
 335                 $row = $this->selectRow( 'sqlite_master', '*',
 336                         array(
 337                                 'type' => 'index',
 338                                 'name' => $this->indexName( $index ),
 339                         ), $fname );
 340                 if ( !$row || !isset( $row->sql ) ) {
 341                         return null;
 342                 }
 343
 344                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 345                 $indexPos = strpos( $row->sql, 'INDEX' );
 346                 if ( $indexPos === false ) {
 347                         return null;
 348                 }
 349                 $firstPart = substr( $row->sql, 0, $indexPos );
 350                 $options = explode( ' ', $firstPart );
 351                 return in_array( 'UNIQUE', $options );
 352         }
 353
 354         /**
 355          * Filter the options used in SELECT statements
 356          */
 357         function makeSelectOptions( $options ) {
 358                 foreach ( $options as $k => $v ) {
 359                         if ( is_numeric( $k ) && $v == 'FOR UPDATE' ) {
 360                                 $options[$k] = '';
 361                         }
 362                 }
 363                 return parent::makeSelectOptions( $options );
 364         }
 365
 366         /**
 367          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 368          */
 369         function insert( $table, $a, $fname = 'DatabaseSqlite::insert', $options = array() ) {
 370                 if ( !count( $a ) ) {
 371                         return true;
 372                 }
 373                 if ( !is_array( $options ) ) {
 374                         $options = array( $options );
 375                 }
 376
 377                 # SQLite uses OR IGNORE not just IGNORE
 378                 foreach ( $options as $k => $v ) {
 379                         if ( $v == 'IGNORE' ) {
 380                                 $options[$k] = 'OR IGNORE';
 381                         }
 382                 }
 383
 384                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 385                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 386                         $ret = true;
 387                         foreach ( $a as $v ) {
 388                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 389                                         $ret = false;
 390                                 }
 391                         }
 392                 } else {
 393                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 394                 }
 395
 396                 return $ret;
 397         }
 398
 399         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseSqlite::replace' ) {
 400                 if ( !count( $rows ) ) return true;
 401
 402                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 403                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 404                         $ret = true;
 405                         foreach ( $rows as $v ) {
 406                                 if ( !parent::replace( $table, $uniqueIndexes, $v, "$fname/multi-row" ) ) {
 407                                         $ret = false;
 408                                 }
 409                         }
 410                 } else {
 411                         $ret = parent::replace( $table, $uniqueIndexes, $rows, "$fname/single-row" );
 412                 }
 413
 414                 return $ret;
 415         }
 416
 417         /**
 418          * Returns the size of a text field, or -1 for "unlimited"
 419          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 420          */
 421         function textFieldSize( $table, $field ) {
 422                 return - 1;
 423         }
 424
 425         function unionSupportsOrderAndLimit() {
 426                 return false;
 427         }
 428
 429         function unionQueries( $sqls, $all ) {
 430                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 431                 return implode( $glue, $sqls );
 432         }
 433
 434         function wasDeadlock() {
 435                 return $this->lastErrno() == 5; // SQLITE_BUSY
 436         }
 437
 438         function wasErrorReissuable() {
 439                 return $this->lastErrno() ==  17; // SQLITE_SCHEMA;
 440         }
 441
 442         function wasReadOnlyError() {
 443                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 444         }
 445
 446         /**
 447          * @return string wikitext of a link to the server software's web site
 448          */
 449         public static function getSoftwareLink() {
 450                 return "[http://sqlite.org/ SQLite]";
 451         }
 452
 453         /**
 454          * @return string Version information from the database
 455          */
 456         function getServerVersion() {
 457                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 458                 return $ver;
 459         }
 460
 461         /**
 462          * @return string User-friendly database information
 463          */
 464         public function getServerInfo() {
 465                 return wfMsg( $this->getFulltextSearchModule() ? 'sqlite-has-fts' : 'sqlite-no-fts', $this->getServerVersion() );
 466         }
 467
 468         /**
 469          * Get information about a given field
 470          * Returns false if the field does not exist.
 471          */
 472         function fieldInfo( $table, $field ) {
 473                 $tableName = $this->tableName( $table );
 474                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 475                 $res = $this->query( $sql, __METHOD__ );
 476                 foreach ( $res as $row ) {
 477                         if ( $row->name == $field ) {
 478                                 return new SQLiteField( $row, $tableName );
 479                         }
 480                 }
 481                 return false;
 482         }
 483
 484         function begin( $fname = '' ) {
 485                 if ( $this->mTrxLevel == 1 ) $this->commit();
 486                 $this->mConn->beginTransaction();
 487                 $this->mTrxLevel = 1;
 488         }
 489
 490         function commit( $fname = '' ) {
 491                 if ( $this->mTrxLevel == 0 ) return;
 492                 $this->mConn->commit();
 493                 $this->mTrxLevel = 0;
 494         }
 495
 496         function rollback( $fname = '' ) {
 497                 if ( $this->mTrxLevel == 0 ) return;
 498                 $this->mConn->rollBack();
 499                 $this->mTrxLevel = 0;
 500         }
 501
 502         function limitResultForUpdate( $sql, $num ) {
 503                 return $this->limitResult( $sql, $num );
 504         }
 505
 506         function strencode( $s ) {
 507                 return substr( $this->addQuotes( $s ), 1, - 1 );
 508         }
 509
 510         function encodeBlob( $b ) {
 511                 return new Blob( $b );
 512         }
 513
 514         function decodeBlob( $b ) {
 515                 if ( $b instanceof Blob ) {
 516                         $b = $b->fetch();
 517                 }
 518                 return $b;
 519         }
 520
 521         function addQuotes( $s ) {
 522                 if ( $s instanceof Blob ) {
 523                         return "x'" . bin2hex( $s->fetch() ) . "'";
 524                 } else {
 525                         return $this->mConn->quote( $s );
 526                 }
 527         }
 528
 529         function quote_ident( $s ) {
 530                 return $s;
 531         }
 532
 533         function buildLike() {
 534                 $params = func_get_args();
 535                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 536                         $params = $params[0];
 537                 }
 538                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 539         }
 540
 541         public function getSearchEngine() {
 542                 return "SearchSqlite";
 543         }
 544
 545         /**
 546          * No-op version of deadlockLoop
 547          */
 548         public function deadlockLoop( /*...*/ ) {
 549                 $args = func_get_args();
 550                 $function = array_shift( $args );
 551                 return call_user_func_array( $function, $args );
 552         }
 553
 554         protected function replaceVars( $s ) {
 555                 $s = parent::replaceVars( $s );
 556                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 557                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 558
 559                         // binary/varbinary column type -> blob
 560                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 561                         // no such thing as unsigned
 562                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 563                         // INT -> INTEGER
 564                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 565                         // floating point types -> REAL
 566                         $s = preg_replace( '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i', 'REAL', $s );
 567                         // varchar -> TEXT
 568                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 569                         // TEXT normalization
 570                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 571                         // BLOB normalization
 572                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 573                         // BOOL -> INTEGER
 574                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 575                         // DATETIME -> TEXT
 576                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 577                         // No ENUM type
 578                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 579                         // binary collation type -> nothing
 580                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 581                         // auto_increment -> autoincrement
 582                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 583                         // No explicit options
 584                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 585                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 586                         // No truncated indexes
 587                         $s = preg_replace( '/\(\d+\)/', '', $s );
 588                         // No FULLTEXT
 589                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 590                 }
 591                 return $s;
 592         }
 593
 594         /*
 595          * Build a concatenation list to feed into a SQL query
 596          */
 597         function buildConcat( $stringList ) {
 598                 return '(' . implode( ') || (', $stringList ) . ')';
 599         }
 600
 601         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseSqlite::duplicateTableStructure' ) {
 602                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name='$oldName' AND type='table'", $fname );
 603                 $obj = $this->fetchObject( $res );
 604                 if ( !$obj ) {
 605                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 606                 }
 607                 $sql = $obj->sql;
 608                 $sql = preg_replace( '/\b' . preg_quote( $oldName ) . '\b/', $newName, $sql, 1 );
 609                 return $this->query( $sql, $fname );
 610         }
 611
 612 } // end DatabaseSqlite class
 613
 614 /**
 615  * This class allows simple acccess to a SQLite database independently from main database settings
 616  * @ingroup Database
 617  */
 618 class DatabaseSqliteStandalone extends DatabaseSqlite {
 619         public function __construct( $fileName, $flags = 0 ) {
 620                 $this->mFlags = $flags;
 621                 $this->tablePrefix( null );
 622                 $this->openFile( $fileName );
 623         }
 624 }
 625
 626 /**
 627  * @ingroup Database
 628  */
 629 class SQLiteField {
 630         private $info, $tableName;
 631         function __construct( $info, $tableName ) {
 632                 $this->info = $info;
 633                 $this->tableName = $tableName;
 634         }
 635
 636         function name() {
 637                 return $this->info->name;
 638         }
 639
 640         function tableName() {
 641                 return $this->tableName;
 642         }
 643
 644         function defaultValue() {
 645                 if ( is_string( $this->info->dflt_value ) ) {
 646                         // Typically quoted
 647                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 648                                 return str_replace( "''", "'", $this->info->dflt_value );
 649                         }
 650                 }
 651                 return $this->info->dflt_value;
 652         }
 653
 654         function maxLength() {
 655                 return -1;
 656         }
 657
 658         function nullable() {
 659                 // SQLite dynamic types are always nullable
 660                 return true;
 661         }
 662
 663         # isKey(),  isMultipleKey() not implemented, MySQL-specific concept.
 664         # Suggest removal from base class [TS]
 665
 666         function type() {
 667                 return $this->info->type;
 668         }
 669
 670 } // end SQLiteField