1: <?php
  2: 
  3: namespace Guzzle\Http;
  4: 
  5: /**
  6:  * EntityBody decorator used to return only a subset of an entity body
  7:  */
  8: class ReadLimitEntityBody extends AbstractEntityBodyDecorator
  9: {
 10:     /**
 11:      * @var int Limit the number of bytes that can be read
 12:      */
 13:     protected $limit;
 14: 
 15:     /**
 16:      * @var int Offset to start reading from
 17:      */
 18:     protected $offset;
 19: 
 20:     /**
 21:      * @param EntityBodyInterface $body   Body to wrap
 22:      * @param int                 $limit  Total number of bytes to allow to be read from the stream
 23:      * @param int                 $offset Position to seek to before reading (only works on seekable streams)
 24:      */
 25:     public function __construct(EntityBodyInterface $body, $limit, $offset = 0)
 26:     {
 27:         parent::__construct($body);
 28:         $this->setLimit($limit)->setOffset($offset);
 29:         $this->body->seek($offset);
 30:     }
 31: 
 32:     /**
 33:      * Returns only a subset of the decorated entity body when cast as a string
 34:      * {@inheritdoc}
 35:      */
 36:     public function __toString()
 37:     {
 38:         return substr((string) $this->body, $this->offset, $this->limit) ?: '';
 39:     }
 40: 
 41:     /**
 42:      * {@inheritdoc}
 43:      */
 44:     public function isConsumed()
 45:     {
 46:         return (($this->offset + $this->limit) - $this->body->ftell()) <= 0;
 47:     }
 48: 
 49:     /**
 50:      * Returns the Content-Length of the limited subset of data
 51:      * {@inheritdoc}
 52:      */
 53:     public function getContentLength()
 54:     {
 55:         $length = $this->body->getContentLength();
 56: 
 57:         return $length === false
 58:             ? $this->limit
 59:             : min($this->limit, min($length, $this->offset + $this->limit) - $this->offset);
 60:     }
 61: 
 62:     /**
 63:      * Allow for a bounded seek on the read limited entity body
 64:      * {@inheritdoc}
 65:      */
 66:     public function seek($offset, $whence = SEEK_SET)
 67:     {
 68:         return $whence === SEEK_SET
 69:             ? $this->body->seek(max($this->offset, min($this->offset + $this->limit, $offset)))
 70:             : false;
 71:     }
 72: 
 73:     /**
 74:      * Set the offset to start limiting from
 75:      *
 76:      * @param int $offset Offset to seek to and begin byte limiting from
 77:      *
 78:      * @return self
 79:      */
 80:     public function setOffset($offset)
 81:     {
 82:         $this->body->seek($offset);
 83:         $this->offset = $offset;
 84: 
 85:         return $this;
 86:     }
 87: 
 88:     /**
 89:      * Set the limit of bytes that the decorator allows to be read from the stream
 90:      *
 91:      * @param int $limit Total number of bytes to allow to be read from the stream
 92:      *
 93:      * @return self
 94:      */
 95:     public function setLimit($limit)
 96:     {
 97:         $this->limit = $limit;
 98: 
 99:         return $this;
100:     }
101: 
102:     /**
103:      * {@inheritdoc}
104:      */
105:     public function read($length)
106:     {
107:         // Check if the current position is less than the total allowed bytes + original offset
108:         $remaining = ($this->offset + $this->limit) - $this->body->ftell();
109:         if ($remaining > 0) {
110:             // Only return the amount of requested data, ensuring that the byte limit is not exceeded
111:             return $this->body->read(min($remaining, $length));
112:         } else {
113:             return false;
114:         }
115:     }
116: }
117: