wiki.techinc.nl/includes/libs/rdbms/database/resultwrapper/ResultWrapper.php
Aaron Schulz a830c14d0b rdbms: make implement IResultWrapper directly instead of via inheritence
Change-Id: If1b15c0c21d0ee336025fb99f47fc19ddf1d5435
2019-07-04 13:42:53 +00:00

140 lines
3.1 KiB
PHP

<?php
namespace Wikimedia\Rdbms;
use stdClass;
use RuntimeException;
use InvalidArgumentException;
/**
* Result wrapper for grabbing data queried from an IDatabase object
*
* Only IDatabase-related classes should construct these. Other code may
* use the FakeResultWrapper class for convenience or compatibility shims.
*
* Note that using the Iterator methods in combination with the non-Iterator
* IDatabase 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.
*
* @ingroup Database
*/
class ResultWrapper implements IResultWrapper {
/** @var IDatabase */
protected $db;
/** @var mixed|null RDBMS driver-specific result resource */
protected $result;
/** @var int */
protected $pos = 0;
/** @var stdClass|bool|null */
protected $currentRow;
/**
* @param IDatabase $db Database handle that the result comes from
* @param self|mixed $result RDBMS driver-specific result resource
*/
public function __construct( IDatabase $db, $result ) {
$this->db = $db;
if ( $result instanceof self ) {
$this->result = $result->result;
} elseif ( $result !== null ) {
$this->result = $result;
} else {
throw new InvalidArgumentException( "Null result resource provided" );
}
}
/**
* Get the underlying RDBMS driver-specific result resource
*
* The result resource field should not be accessed from non-Database related classes.
* It is database class specific and is stored here to associate iterators with queries.
*
* @param self|mixed &$res
* @return mixed
* @since 1.34
*/
public static function &unwrap( &$res ) {
if ( $res instanceof self ) {
if ( $res->result === null ) {
throw new RuntimeException( "The result resource was already freed" );
}
return $res->result;
} else {
return $res;
}
}
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( $pos ) {
$this->getDB()->dataSeek( $this, $pos );
$this->pos = $pos;
}
public function free() {
$this->db = null;
$this->result = null;
}
function rewind() {
if ( $this->numRows() ) {
$this->getDB()->dataSeek( $this, 0 );
}
$this->pos = 0;
$this->currentRow = null;
}
function current() {
if ( $this->currentRow === null ) {
$this->currentRow = $this->fetchObject();
}
return $this->currentRow;
}
function key() {
return $this->pos;
}
function next() {
$this->pos++;
$this->currentRow = $this->fetchObject();
return $this->currentRow;
}
function valid() {
return $this->current() !== false;
}
/**
* @return IDatabase
* @throws RuntimeException
*/
private function getDB() {
if ( !$this->db ) {
throw new RuntimeException( "Database handle was already freed" );
}
return $this->db;
}
}
/**
* @deprecated since 1.29
*/
class_alias( ResultWrapper::class, 'ResultWrapper' );