aleph1.co.uk Git - yaffs-website/blob - src/RelativeStream.php

   1 <?php
   2 /**
   3  * @see       https://github.com/zendframework/zend-diactoros for the canonical source repository
   4  * @copyright Copyright (c) 2015-2017 Zend Technologies USA Inc. (http://www.zend.com)
   5  * @license   https://github.com/zendframework/zend-diactoros/blob/master/LICENSE.md New BSD License
   6  */
   7
   8 namespace Zend\Diactoros;
   9
  10 use Psr\Http\Message\StreamInterface;
  11 use RuntimeException;
  12
  13 /**
  14  * Class RelativeStream
  15  *
  16  * Wrapper for default Stream class, representing subpart (starting from given offset) of initial stream.
  17  * It can be used to avoid copying full stream, conserving memory.
  18  * @example see Zend\Diactoros\AbstractSerializer::splitStream()
  19  */
  20 final class RelativeStream implements StreamInterface
  21 {
  22     /**
  23      * @var StreamInterface
  24      */
  25     private $decoratedStream;
  26
  27     /**
  28      * @var int
  29      */
  30     private $offset;
  31
  32     /**
  33      * Class constructor
  34      *
  35      * @param StreamInterface $decoratedStream
  36      * @param int $offset
  37      */
  38     public function __construct(StreamInterface $decoratedStream, $offset)
  39     {
  40         $this->decoratedStream = $decoratedStream;
  41         $this->offset = (int)$offset;
  42     }
  43
  44     /**
  45      * {@inheritdoc}
  46      */
  47     public function __toString()
  48     {
  49         if ($this->isSeekable()) {
  50             $this->seek(0);
  51         }
  52         return $this->getContents();
  53     }
  54
  55     /**
  56      * {@inheritdoc}
  57      */
  58     public function close()
  59     {
  60         $this->decoratedStream->close();
  61     }
  62
  63     /**
  64      * {@inheritdoc}
  65      */
  66     public function detach()
  67     {
  68         return $this->decoratedStream->detach();
  69     }
  70
  71     /**
  72      * {@inheritdoc}
  73      */
  74     public function getSize()
  75     {
  76         return $this->decoratedStream->getSize() - $this->offset;
  77     }
  78
  79     /**
  80      * {@inheritdoc}
  81      */
  82     public function tell()
  83     {
  84         return $this->decoratedStream->tell() - $this->offset;
  85     }
  86
  87     /**
  88      * {@inheritdoc}
  89      */
  90     public function eof()
  91     {
  92         return $this->decoratedStream->eof();
  93     }
  94
  95     /**
  96      * {@inheritdoc}
  97      */
  98     public function isSeekable()
  99     {
 100         return $this->decoratedStream->isSeekable();
 101     }
 102
 103     /**
 104      * {@inheritdoc}
 105      */
 106     public function seek($offset, $whence = SEEK_SET)
 107     {
 108         if ($whence == SEEK_SET) {
 109             return $this->decoratedStream->seek($offset + $this->offset, $whence);
 110         }
 111         return $this->decoratedStream->seek($offset, $whence);
 112     }
 113
 114     /**
 115      * {@inheritdoc}
 116      */
 117     public function rewind()
 118     {
 119         return $this->seek(0);
 120     }
 121
 122     /**
 123      * {@inheritdoc}
 124      */
 125     public function isWritable()
 126     {
 127         return $this->decoratedStream->isWritable();
 128     }
 129
 130     /**
 131      * {@inheritdoc}
 132      */
 133     public function write($string)
 134     {
 135         if ($this->tell() < 0) {
 136             throw new RuntimeException('Invalid pointer position');
 137         }
 138         return $this->decoratedStream->write($string);
 139     }
 140
 141     /**
 142      * {@inheritdoc}
 143      */
 144     public function isReadable()
 145     {
 146         return $this->decoratedStream->isReadable();
 147     }
 148
 149     /**
 150      * {@inheritdoc}
 151      */
 152     public function read($length)
 153     {
 154         if ($this->tell() < 0) {
 155             throw new RuntimeException('Invalid pointer position');
 156         }
 157         return $this->decoratedStream->read($length);
 158     }
 159
 160     /**
 161      * {@inheritdoc}
 162      */
 163     public function getContents()
 164     {
 165         if ($this->tell() < 0) {
 166             throw new RuntimeException('Invalid pointer position');
 167         }
 168         return $this->decoratedStream->getContents();
 169     }
 170
 171     /**
 172      * {@inheritdoc}
 173      */
 174     public function getMetadata($key = null)
 175     {
 176         return $this->decoratedStream->getMetadata($key);
 177     }
 178 }