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