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 use const SEEK_SET;
  14
  15 /**
  16  * Class RelativeStream
  17  *
  18  * Wrapper for default Stream class, representing subpart (starting from given offset) of initial stream.
  19  * It can be used to avoid copying full stream, conserving memory.
  20  * @example see Zend\Diactoros\AbstractSerializer::splitStream()
  21  */
  22 final class RelativeStream implements StreamInterface
  23 {
  24     /**
  25      * @var StreamInterface
  26      */
  27     private $decoratedStream;
  28
  29     /**
  30      * @var int
  31      */
  32     private $offset;
  33
  34     /**
  35      * Class constructor
  36      *
  37      * @param StreamInterface $decoratedStream
  38      * @param int $offset
  39      */
  40     public function __construct(StreamInterface $decoratedStream, $offset)
  41     {
  42         $this->decoratedStream = $decoratedStream;
  43         $this->offset = (int)$offset;
  44     }
  45
  46     /**
  47      * {@inheritdoc}
  48      */
  49     public function __toString()
  50     {
  51         if ($this->isSeekable()) {
  52             $this->seek(0);
  53         }
  54         return $this->getContents();
  55     }
  56
  57     /**
  58      * {@inheritdoc}
  59      */
  60     public function close()
  61     {
  62         $this->decoratedStream->close();
  63     }
  64
  65     /**
  66      * {@inheritdoc}
  67      */
  68     public function detach()
  69     {
  70         return $this->decoratedStream->detach();
  71     }
  72
  73     /**
  74      * {@inheritdoc}
  75      */
  76     public function getSize()
  77     {
  78         return $this->decoratedStream->getSize() - $this->offset;
  79     }
  80
  81     /**
  82      * {@inheritdoc}
  83      */
  84     public function tell()
  85     {
  86         return $this->decoratedStream->tell() - $this->offset;
  87     }
  88
  89     /**
  90      * {@inheritdoc}
  91      */
  92     public function eof()
  93     {
  94         return $this->decoratedStream->eof();
  95     }
  96
  97     /**
  98      * {@inheritdoc}
  99      */
 100     public function isSeekable()
 101     {
 102         return $this->decoratedStream->isSeekable();
 103     }
 104
 105     /**
 106      * {@inheritdoc}
 107      */
 108     public function seek($offset, $whence = SEEK_SET)
 109     {
 110         if ($whence == SEEK_SET) {
 111             return $this->decoratedStream->seek($offset + $this->offset, $whence);
 112         }
 113         return $this->decoratedStream->seek($offset, $whence);
 114     }
 115
 116     /**
 117      * {@inheritdoc}
 118      */
 119     public function rewind()
 120     {
 121         return $this->seek(0);
 122     }
 123
 124     /**
 125      * {@inheritdoc}
 126      */
 127     public function isWritable()
 128     {
 129         return $this->decoratedStream->isWritable();
 130     }
 131
 132     /**
 133      * {@inheritdoc}
 134      */
 135     public function write($string)
 136     {
 137         if ($this->tell() < 0) {
 138             throw new RuntimeException('Invalid pointer position');
 139         }
 140         return $this->decoratedStream->write($string);
 141     }
 142
 143     /**
 144      * {@inheritdoc}
 145      */
 146     public function isReadable()
 147     {
 148         return $this->decoratedStream->isReadable();
 149     }
 150
 151     /**
 152      * {@inheritdoc}
 153      */
 154     public function read($length)
 155     {
 156         if ($this->tell() < 0) {
 157             throw new RuntimeException('Invalid pointer position');
 158         }
 159         return $this->decoratedStream->read($length);
 160     }
 161
 162     /**
 163      * {@inheritdoc}
 164      */
 165     public function getContents()
 166     {
 167         if ($this->tell() < 0) {
 168             throw new RuntimeException('Invalid pointer position');
 169         }
 170         return $this->decoratedStream->getContents();
 171     }
 172
 173     /**
 174      * {@inheritdoc}
 175      */
 176     public function getMetadata($key = null)
 177     {
 178         return $this->decoratedStream->getMetadata($key);
 179     }
 180 }