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