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