includes/db/DatabaseSqlite.php

   1 <?php
   2 /**
   3  * This script is the SQLite database abstraction layer
   4  *
   5  * See maintenance/sqlite/README for development notes and other specific information
   6  * @ingroup Database
   7  * @file
   8  */
   9
  10 /**
  11  * @ingroup Database
  12  */
  13 class DatabaseSqlite extends DatabaseBase {
  14
  15         var $mAffectedRows;
  16         var $mLastResult;
  17         var $mDatabaseFile;
  18         var $mName;
  19
  20         /**
  21          * Constructor.
  22          * Parameters $server, $user and $password are not used.
  23          */
  24         function __construct( $server = false, $user = false, $password = false, $dbName = false, $failFunction = false, $flags = 0, $fileame = false ) {
  25                 global $wgSQLiteDataDir;
  26                 $this->mFailFunction = $failFunction;
  27                 $this->mFlags = $flags;
  28                 $this->mDatabaseFile = self::generateFileName( $wgSQLiteDataDir, $dbName );
  29                 if ( !is_readable( $this->mDatabaseFile ) )
  30                         throw new DBConnectionError( $this, "SQLite database not accessible" );
  31                 $this->mName = $dbName;
  32                 $this->open( $server, $user, $password, $dbName );
  33         }
  34
  35         function getType() {
  36                 return 'sqlite';
  37         }
  38
  39         /**
  40          * @todo: check if it should be true like parent class
  41          */
  42         function implicitGroupby()   { return false; }
  43
  44         static function newFromParams( $server, $user, $password, $dbName, $failFunction = false, $flags = 0 ) {
  45                 return new DatabaseSqlite( $server, $user, $password, $dbName, $failFunction, $flags );
  46         }
  47
  48         /** Open an SQLite database and return a resource handle to it
  49          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  50          */
  51         function open( $server, $user, $pass, $dbName ) {
  52                 $this->mConn = false;
  53                 if ( $dbName ) {
  54                         $file = $this->mDatabaseFile;
  55                         try {
  56                                 if ( $this->mFlags & DBO_PERSISTENT ) {
  57                                         $this->mConn = new PDO( "sqlite:$file", $user, $pass,
  58                                                 array( PDO::ATTR_PERSISTENT => true ) );
  59                                 } else {
  60                                         $this->mConn = new PDO( "sqlite:$file", $user, $pass );
  61                                 }
  62                         } catch ( PDOException $e ) {
  63                                 $err = $e->getMessage();
  64                         }
  65                         if ( $this->mConn === false ) {
  66                                 wfDebug( "DB connection error: $err\n" );
  67                                 if ( !$this->mFailFunction ) {
  68                                         throw new DBConnectionError( $this, $err );
  69                                 } else {
  70                                         return false;
  71                                 }
  72
  73                         }
  74                         $this->mOpened = $this->mConn;
  75                         # set error codes only, don't raise exceptions
  76                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
  77                 }
  78                 return $this->mConn;
  79         }
  80
  81         /**
  82          * Close an SQLite database
  83          */
  84         function close() {
  85                 $this->mOpened = false;
  86                 if ( is_object( $this->mConn ) ) {
  87                         if ( $this->trxLevel() ) $this->commit();
  88                         $this->mConn = null;
  89                 }
  90                 return true;
  91         }
  92
  93         /**
  94          * Generates a database file name. Explicitly public for installer.
  95          * @param $dir String: Directory where database resides
  96          * @param $dbName String: Database name
  97          * @return String
  98          */
  99         public static function generateFileName( $dir, $dbName ) {
 100                 return "$dir/$dbName.sqlite";
 101         }
 102
 103         /**
 104          * Returns version of currently supported SQLite fulltext search module or false if none present.
 105          * @return String
 106          */
 107         function getFulltextSearchModule() {
 108                 $table = 'dummy_search_test';
 109                 $this->query( "DROP TABLE IF EXISTS $table", __METHOD__ );
 110                 if ( $this->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 111                         $this->query( "DROP TABLE IF EXISTS $table", __METHOD__ );
 112                         return 'FTS3';
 113                 }
 114                 return false;
 115         }
 116
 117         /**
 118          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 119          */
 120         function doQuery( $sql ) {
 121                 $res = $this->mConn->query( $sql );
 122                 if ( $res === false ) {
 123                         return false;
 124                 } else {
 125                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 126                         $this->mAffectedRows = $r->rowCount();
 127                         $res = new ResultWrapper( $this, $r->fetchAll() );
 128                 }
 129                 return $res;
 130         }
 131
 132         function freeResult( $res ) {
 133                 if ( $res instanceof ResultWrapper )
 134                         $res->result = null;
 135                 else
 136                         $res = null;
 137         }
 138
 139         function fetchObject( $res ) {
 140                 if ( $res instanceof ResultWrapper )
 141                         $r =& $res->result;
 142                 else
 143                         $r =& $res;
 144
 145                 $cur = current( $r );
 146                 if ( is_array( $cur ) ) {
 147                         next( $r );
 148                         $obj = new stdClass;
 149                         foreach ( $cur as $k => $v )
 150                                 if ( !is_numeric( $k ) )
 151                                         $obj->$k = $v;
 152
 153                         return $obj;
 154                 }
 155                 return false;
 156         }
 157
 158         function fetchRow( $res ) {
 159                 if ( $res instanceof ResultWrapper )
 160                         $r =& $res->result;
 161                 else
 162                         $r =& $res;
 163
 164                 $cur = current( $r );
 165                 if ( is_array( $cur ) ) {
 166                         next( $r );
 167                         return $cur;
 168                 }
 169                 return false;
 170         }
 171
 172         /**
 173          * The PDO::Statement class implements the array interface so count() will work
 174          */
 175         function numRows( $res ) {
 176                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 177                 return count( $r );
 178         }
 179
 180         function numFields( $res ) {
 181                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 182                 return is_array( $r ) ? count( $r[0] ) : 0;
 183         }
 184
 185         function fieldName( $res, $n ) {
 186                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 187                 if ( is_array( $r ) ) {
 188                         $keys = array_keys( $r[0] );
 189                         return $keys[$n];
 190                 }
 191                 return  false;
 192         }
 193
 194         /**
 195          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 196          */
 197         function tableName( $name ) {
 198                 return str_replace( '`', '', parent::tableName( $name ) );
 199         }
 200
 201         /**
 202          * Index names have DB scope
 203          */
 204         function indexName( $index ) {
 205                 return $index;
 206         }
 207
 208         /**
 209          * This must be called after nextSequenceVal
 210          */
 211         function insertId() {
 212                 return $this->mConn->lastInsertId();
 213         }
 214
 215         function dataSeek( $res, $row ) {
 216                 if ( $res instanceof ResultWrapper )
 217                         $r =& $res->result;
 218                 else
 219                         $r =& $res;
 220                 reset( $r );
 221                 if ( $row > 0 )
 222                         for ( $i = 0; $i < $row; $i++ )
 223                                 next( $r );
 224         }
 225
 226         function lastError() {
 227                 if ( !is_object( $this->mConn ) )
 228                         return "Cannot return last error, no db connection";
 229                 $e = $this->mConn->errorInfo();
 230                 return isset( $e[2] ) ? $e[2] : '';
 231         }
 232
 233         function lastErrno() {
 234                 if ( !is_object( $this->mConn ) ) {
 235                         return "Cannot return last error, no db connection";
 236                 } else {
 237                         $info = $this->mConn->errorInfo();
 238                         return $info[1];
 239                 }
 240         }
 241
 242         function affectedRows() {
 243                 return $this->mAffectedRows;
 244         }
 245
 246         /**
 247          * Returns information about an index
 248          * Returns false if the index does not exist
 249          * - if errors are explicitly ignored, returns NULL on failure
 250          */
 251         function indexInfo( $table, $index, $fname = 'DatabaseSqlite::indexExists' ) {
 252                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 253                 $res = $this->query( $sql, $fname );
 254                 if ( !$res ) {
 255                         return null;
 256                 }
 257                 if ( $res->numRows() == 0 ) {
 258                         return false;
 259                 }
 260                 $info = array();
 261                 foreach ( $res as $row ) {
 262                         $info[] = $row->name;
 263                 }
 264                 return $info;
 265         }
 266
 267         function indexUnique( $table, $index, $fname = 'DatabaseSqlite::indexUnique' ) {
 268                 $row = $this->selectRow( 'sqlite_master', '*',
 269                         array(
 270                                 'type' => 'index',
 271                                 'name' => $this->indexName( $index ),
 272                         ), $fname );
 273                 if ( !$row || !isset( $row->sql ) ) {
 274                         return null;
 275                 }
 276
 277                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 278                 $indexPos = strpos( $row->sql, 'INDEX' );
 279                 if ( $indexPos === false ) {
 280                         return null;
 281                 }
 282                 $firstPart = substr( $row->sql, 0, $indexPos );
 283                 $options = explode( ' ', $firstPart );
 284                 return in_array( 'UNIQUE', $options );
 285         }
 286
 287         /**
 288          * Filter the options used in SELECT statements
 289          */
 290         function makeSelectOptions( $options ) {
 291                 foreach ( $options as $k => $v )
 292                         if ( is_numeric( $k ) && $v == 'FOR UPDATE' )
 293                                 $options[$k] = '';
 294                 return parent::makeSelectOptions( $options );
 295         }
 296
 297         /**
 298          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 299          */
 300         function insert( $table, $a, $fname = 'DatabaseSqlite::insert', $options = array() ) {
 301                 if ( !count( $a ) ) return true;
 302                 if ( !is_array( $options ) ) $options = array( $options );
 303
 304                 # SQLite uses OR IGNORE not just IGNORE
 305                 foreach ( $options as $k => $v )
 306                         if ( $v == 'IGNORE' )
 307                                 $options[$k] = 'OR IGNORE';
 308
 309                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 310                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 311                         $ret = true;
 312                         foreach ( $a as $k => $v )
 313                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) )
 314                                         $ret = false;
 315                 } else {
 316                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 317                 }
 318
 319                 return $ret;
 320         }
 321
 322         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseSqlite::replace' ) {
 323                 if ( !count( $rows ) ) return true;
 324
 325                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 326                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 327                         $ret = true;
 328                         foreach ( $rows as $k => $v )
 329                                 if ( !parent::replace( $table, $uniqueIndexes, $v, "$fname/multi-row" ) )
 330                                         $ret = false;
 331                 } else {
 332                         $ret = parent::replace( $table, $uniqueIndexes, $rows, "$fname/single-row" );
 333                 }
 334
 335                 return $ret;
 336         }
 337
 338         /**
 339          * Returns the size of a text field, or -1 for "unlimited"
 340          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 341          */
 342         function textFieldSize( $table, $field ) {
 343                 return - 1;
 344         }
 345
 346         function unionSupportsOrderAndLimit() {
 347                 return false;
 348         }
 349
 350         function unionQueries( $sqls, $all ) {
 351                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 352                 return implode( $glue, $sqls );
 353         }
 354
 355         function wasDeadlock() {
 356                 return $this->lastErrno() == 5; // SQLITE_BUSY
 357         }
 358
 359         function wasErrorReissuable() {
 360                 return $this->lastErrno() ==  17; // SQLITE_SCHEMA;
 361         }
 362
 363         function wasReadOnlyError() {
 364                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 365         }
 366
 367         /**
 368          * @return string wikitext of a link to the server software's web site
 369          */
 370         function getSoftwareLink() {
 371                 return "[http://sqlite.org/ SQLite]";
 372         }
 373
 374         /**
 375          * @return string Version information from the database
 376          */
 377         function getServerVersion() {
 378                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 379                 return $ver;
 380         }
 381
 382         /**
 383          * Query whether a given column exists in the mediawiki schema
 384          */
 385         function fieldExists( $table, $field, $fname = '' ) {
 386                 $info = $this->fieldInfo( $table, $field );
 387                 return (bool)$info;
 388         }
 389
 390         /**
 391          * Get information about a given field
 392          * Returns false if the field does not exist.
 393          */
 394         function fieldInfo( $table, $field ) {
 395                 $tableName = $this->tableName( $table );
 396                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 397                 $res = $this->query( $sql, __METHOD__ );
 398                 foreach ( $res as $row ) {
 399                         if ( $row->name == $field ) {
 400                                 return new SQLiteField( $row, $tableName );
 401                         }
 402                 }
 403                 return false;
 404         }
 405
 406         function begin( $fname = '' ) {
 407                 if ( $this->mTrxLevel == 1 ) $this->commit();
 408                 $this->mConn->beginTransaction();
 409                 $this->mTrxLevel = 1;
 410         }
 411
 412         function commit( $fname = '' ) {
 413                 if ( $this->mTrxLevel == 0 ) return;
 414                 $this->mConn->commit();
 415                 $this->mTrxLevel = 0;
 416         }
 417
 418         function rollback( $fname = '' ) {
 419                 if ( $this->mTrxLevel == 0 ) return;
 420                 $this->mConn->rollBack();
 421                 $this->mTrxLevel = 0;
 422         }
 423
 424         function limitResultForUpdate( $sql, $num ) {
 425                 return $this->limitResult( $sql, $num );
 426         }
 427
 428         function strencode( $s ) {
 429                 return substr( $this->addQuotes( $s ), 1, - 1 );
 430         }
 431
 432         function encodeBlob( $b ) {
 433                 return new Blob( $b );
 434         }
 435
 436         function decodeBlob( $b ) {
 437                 if ( $b instanceof Blob ) {
 438                         $b = $b->fetch();
 439                 }
 440                 return $b;
 441         }
 442
 443         function addQuotes( $s ) {
 444                 if ( $s instanceof Blob ) {
 445                         return "x'" . bin2hex( $s->fetch() ) . "'";
 446                 } else {
 447                         return $this->mConn->quote( $s );
 448                 }
 449         }
 450
 451         function quote_ident( $s ) {
 452                 return $s;
 453         }
 454
 455         function buildLike() {
 456                 $params = func_get_args();
 457                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 458                         $params = $params[0];
 459                 }
 460                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 461         }
 462
 463         /**
 464          * How lagged is this slave?
 465          */
 466         public function getLag() {
 467                 return 0;
 468         }
 469
 470         /**
 471          * Called by the installer script (when modified according to the MediaWikiLite installation instructions)
 472          * - this is the same way PostgreSQL works, MySQL reads in tables.sql and interwiki.sql using dbsource (which calls db->sourceFile)
 473          */
 474         public function setup_database() {
 475                 global $IP;
 476
 477                 # Process common MySQL/SQLite table definitions
 478                 $err = $this->sourceFile( "$IP/maintenance/tables.sql" );
 479                 if ( $err !== true ) {
 480                         $this->reportQueryError( $err, 0, $sql, __FUNCTION__ );
 481                         exit( 1 );
 482                 }
 483
 484                 # Use DatabasePostgres's code to populate interwiki from MySQL template
 485                 $f = fopen( "$IP/maintenance/interwiki.sql", 'r' );
 486                 if ( $f == false ) dieout( "<li>Could not find the interwiki.sql file" );
 487                 $sql = "INSERT INTO interwiki(iw_prefix,iw_url,iw_local) VALUES ";
 488                 while ( !feof( $f ) ) {
 489                         $line = fgets( $f, 1024 );
 490                         $matches = array();
 491                         if ( !preg_match( '/^\s*(\(.+?),(\d)\)/', $line, $matches ) ) continue;
 492                         $this->query( "$sql $matches[1],$matches[2])" );
 493                 }
 494         }
 495
 496         public function getSearchEngine() {
 497                 return "SearchSqlite";
 498         }
 499
 500         /**
 501          * No-op version of deadlockLoop
 502          */
 503         public function deadlockLoop( /*...*/ ) {
 504                 $args = func_get_args();
 505                 $function = array_shift( $args );
 506                 return call_user_func_array( $function, $args );
 507         }
 508
 509         protected function replaceVars( $s ) {
 510                 $s = parent::replaceVars( $s );
 511                 if ( preg_match( '/^\s*CREATE TABLE/i', $s ) ) {
 512                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 513
 514                         // binary/varbinary column type -> blob
 515                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'blob\1', $s );
 516                         // no such thing as unsigned
 517                         $s = preg_replace( '/\bunsigned\b/i', '', $s );
 518                         // INT -> INTEGER for primary keys
 519                         $s = preg_replacE( '/\bint\b/i', 'integer', $s );
 520                         // No ENUM type
 521                         $s = preg_replace( '/enum\([^)]*\)/i', 'blob', $s );
 522                         // binary collation type -> nothing
 523                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 524                         // auto_increment -> autoincrement
 525                         $s = preg_replace( '/\bauto_increment\b/i', 'autoincrement', $s );
 526                         // No explicit options
 527                         $s = preg_replace( '/\)[^)]*$/', ')', $s );
 528                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 529                         // No truncated indexes
 530                         $s = preg_replace( '/\(\d+\)/', '', $s );
 531                         // No FULLTEXT
 532                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 533                 }
 534                 return $s;
 535         }
 536
 537         /*
 538          * Build a concatenation list to feed into a SQL query
 539          */
 540         function buildConcat( $stringList ) {
 541                 return '(' . implode( ') || (', $stringList ) . ')';
 542         }
 543
 544         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseSqlite::duplicateTableStructure' ) {
 545                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name='$oldName' AND type='table'", $fname );
 546                 $sql = $this->fetchObject( $res )->sql;
 547                 $sql = preg_replace( '/\b' . preg_quote( $oldName ) . '\b/', $newName, $sql, 1 );
 548                 return $this->query( $sql, $fname );
 549         }
 550
 551 } // end DatabaseSqlite class
 552
 553 /**
 554  * @ingroup Database
 555  */
 556 class SQLiteField {
 557         private $info, $tableName;
 558         function __construct( $info, $tableName ) {
 559                 $this->info = $info;
 560                 $this->tableName = $tableName;
 561         }
 562
 563         function name() {
 564                 return $this->info->name;
 565         }
 566
 567         function tableName() {
 568                 return $this->tableName;
 569         }
 570
 571         function defaultValue() {
 572                 if ( is_string( $this->info->dflt_value ) ) {
 573                         // Typically quoted
 574                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 575                                 return str_replace( "''", "'", $this->info->dflt_value );
 576                         }
 577                 }
 578                 return $this->info->dflt_value;
 579         }
 580
 581         function maxLength() {
 582                 return -1;
 583         }
 584
 585         function nullable() {
 586                 // SQLite dynamic types are always nullable
 587                 return true;
 588         }
 589
 590         # isKey(),  isMultipleKey() not implemented, MySQL-specific concept.
 591         # Suggest removal from base class [TS]
 592
 593         function type() {
 594                 return $this->info->type;
 595         }
 596
 597 } // end SQLiteField