Chris@0: <?php
Chris@0: /**
Chris@12:  * @see       https://github.com/zendframework/zend-diactoros for the canonical source repository
Chris@12:  * @copyright Copyright (c) 2015-2017 Zend Technologies USA Inc. (http://www.zend.com)
Chris@0:  * @license   https://github.com/zendframework/zend-diactoros/blob/master/LICENSE.md New BSD License
Chris@0:  */
Chris@0: 
Chris@0: namespace Zend\Diactoros;
Chris@0: 
Chris@0: use Psr\Http\Message\StreamInterface;
Chris@0: use RuntimeException;
Chris@0: 
Chris@16: use const SEEK_SET;
Chris@16: 
Chris@0: /**
Chris@0:  * Class RelativeStream
Chris@0:  *
Chris@0:  * Wrapper for default Stream class, representing subpart (starting from given offset) of initial stream.
Chris@0:  * It can be used to avoid copying full stream, conserving memory.
Chris@0:  * @example see Zend\Diactoros\AbstractSerializer::splitStream()
Chris@0:  */
Chris@0: final class RelativeStream implements StreamInterface
Chris@0: {
Chris@0:     /**
Chris@0:      * @var StreamInterface
Chris@0:      */
Chris@0:     private $decoratedStream;
Chris@0: 
Chris@0:     /**
Chris@0:      * @var int
Chris@0:      */
Chris@0:     private $offset;
Chris@0: 
Chris@0:     /**
Chris@0:      * Class constructor
Chris@0:      *
Chris@0:      * @param StreamInterface $decoratedStream
Chris@0:      * @param int $offset
Chris@0:      */
Chris@0:     public function __construct(StreamInterface $decoratedStream, $offset)
Chris@0:     {
Chris@0:         $this->decoratedStream = $decoratedStream;
Chris@0:         $this->offset = (int)$offset;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function __toString()
Chris@0:     {
Chris@0:         if ($this->isSeekable()) {
Chris@0:             $this->seek(0);
Chris@0:         }
Chris@0:         return $this->getContents();
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function close()
Chris@0:     {
Chris@0:         $this->decoratedStream->close();
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function detach()
Chris@0:     {
Chris@0:         return $this->decoratedStream->detach();
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function getSize()
Chris@0:     {
Chris@0:         return $this->decoratedStream->getSize() - $this->offset;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function tell()
Chris@0:     {
Chris@0:         return $this->decoratedStream->tell() - $this->offset;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function eof()
Chris@0:     {
Chris@0:         return $this->decoratedStream->eof();
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function isSeekable()
Chris@0:     {
Chris@0:         return $this->decoratedStream->isSeekable();
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function seek($offset, $whence = SEEK_SET)
Chris@0:     {
Chris@0:         if ($whence == SEEK_SET) {
Chris@0:             return $this->decoratedStream->seek($offset + $this->offset, $whence);
Chris@0:         }
Chris@0:         return $this->decoratedStream->seek($offset, $whence);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function rewind()
Chris@0:     {
Chris@0:         return $this->seek(0);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function isWritable()
Chris@0:     {
Chris@0:         return $this->decoratedStream->isWritable();
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function write($string)
Chris@0:     {
Chris@0:         if ($this->tell() < 0) {
Chris@0:             throw new RuntimeException('Invalid pointer position');
Chris@0:         }
Chris@0:         return $this->decoratedStream->write($string);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function isReadable()
Chris@0:     {
Chris@0:         return $this->decoratedStream->isReadable();
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function read($length)
Chris@0:     {
Chris@0:         if ($this->tell() < 0) {
Chris@0:             throw new RuntimeException('Invalid pointer position');
Chris@0:         }
Chris@0:         return $this->decoratedStream->read($length);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function getContents()
Chris@0:     {
Chris@0:         if ($this->tell() < 0) {
Chris@0:             throw new RuntimeException('Invalid pointer position');
Chris@0:         }
Chris@0:         return $this->decoratedStream->getContents();
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function getMetadata($key = null)
Chris@0:     {
Chris@0:         return $this->decoratedStream->getMetadata($key);
Chris@0:     }
Chris@0: }