%PDF- %PDF-
| Direktori : /www/varak.net/wiki.varak.net/includes/libs/rdbms/database/resultwrapper/ |
| Current File : /www/varak.net/wiki.varak.net/includes/libs/rdbms/database/resultwrapper/ResultWrapper.php |
<?php
namespace Wikimedia\Rdbms;
use stdClass;
use RuntimeException;
/**
* Result wrapper for grabbing data queried from an IDatabase object
*
* Note that using the Iterator methods in combination with the non-Iterator
* DB result iteration functions may cause rows to be skipped or repeated.
*
* By default, this will use the iteration methods of the IDatabase handle if provided.
* Subclasses can override methods to make it solely work on the result resource instead.
* If no database is provided, and the subclass does not override the DB iteration methods,
* then a RuntimeException will be thrown when iteration is attempted.
*
* The result resource field should not be accessed from non-Database related classes.
* It is database class specific and is stored here to associate iterators with queries.
*
* @ingroup Database
*/
class ResultWrapper implements IResultWrapper {
/** @var resource|array|null Optional underlying result handle for subclass usage */
public $result;
/** @var IDatabase|null */
protected $db;
/** @var int */
protected $pos = 0;
/** @var stdClass|null */
protected $currentRow = null;
/**
* Create a row iterator from a result resource and an optional Database object
*
* Only Database-related classes should construct ResultWrapper. Other code may
* use the FakeResultWrapper subclass for convenience or compatibility shims, however.
*
* @param IDatabase|null $db Optional database handle
* @param ResultWrapper|array|resource $result Optional underlying result handle
*/
public function __construct( IDatabase $db = null, $result ) {
$this->db = $db;
if ( $result instanceof ResultWrapper ) {
$this->result = $result->result;
} else {
$this->result = $result;
}
}
public function numRows() {
return $this->getDB()->numRows( $this );
}
public function fetchObject() {
return $this->getDB()->fetchObject( $this );
}
public function fetchRow() {
return $this->getDB()->fetchRow( $this );
}
public function seek( $row ) {
$this->getDB()->dataSeek( $this, $row );
}
public function free() {
if ( $this->db ) {
$this->db->freeResult( $this );
$this->db = null;
}
$this->result = null;
}
/**
* @return IDatabase
* @throws RuntimeException
*/
private function getDB() {
if ( !$this->db ) {
throw new RuntimeException( static::class . ' needs a DB handle for iteration.' );
}
return $this->db;
}
function rewind() {
if ( $this->numRows() ) {
$this->getDB()->dataSeek( $this, 0 );
}
$this->pos = 0;
$this->currentRow = null;
}
function current() {
if ( is_null( $this->currentRow ) ) {
$this->next();
}
return $this->currentRow;
}
function key() {
return $this->pos;
}
function next() {
$this->pos++;
$this->currentRow = $this->fetchObject();
return $this->currentRow;
}
function valid() {
return $this->current() !== false;
}
}
/**
* @deprecated since 1.29
*/
class_alias( ResultWrapper::class, 'ResultWrapper' );