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