File indexing completed on 2024-12-29 05:27:23

 <?php
 namespace GuzzleHttp\Psr7;
 
 use Psr\Http\Message\StreamInterface;
 
 
 /**
  * Decorator used to return only a subset of a stream
  */
 class LimitStream implements StreamInterface
 {
     use StreamDecoratorTrait;
 
     /** @var int Offset to start reading from */
     private $offset;
 
     /** @var int Limit the number of bytes that can be read */
     private $limit;
 
     /**
      * @param StreamInterface $stream Stream to wrap
      * @param int             $limit  Total number of bytes to allow to be read
      *                                from the stream. Pass -1 for no limit.
      * @param int             $offset Position to seek to before reading (only
      *                                works on seekable streams).
      */
     public function __construct(
         StreamInterface $stream,
         $limit = -1,
         $offset = 0
     ) {
         $this->stream = $stream;
         $this->setLimit($limit);
         $this->setOffset($offset);
     }
 
     public function eof()
     {
         // Always return true if the underlying stream is EOF
         if ($this->stream->eof()) {
             return true;
         }
 
         // No limit and the underlying stream is not at EOF
         if ($this->limit == -1) {
             return false;
         }
 
         return $this->stream->tell() >= $this->offset + $this->limit;
     }
 
     /**
      * Returns the size of the limited subset of data
      * {@inheritdoc}
      */
     public function getSize()
     {
         if (null === ($length = $this->stream->getSize())) {
             return null;
         } elseif ($this->limit == -1) {
             return $length - $this->offset;
         } else {
             return min($this->limit, $length - $this->offset);
         }
     }
 
     /**
      * Allow for a bounded seek on the read limited stream
      * {@inheritdoc}
      */
     public function seek($offset, $whence = SEEK_SET)
     {
         if ($whence !== SEEK_SET || $offset < 0) {
             throw new \RuntimeException(sprintf(
                 'Cannot seek to offset % with whence %s',
                 $offset,
                 $whence
             ));
         }
 
         $offset += $this->offset;
 
         if ($this->limit !== -1) {
             if ($offset > $this->offset + $this->limit) {
                 $offset = $this->offset + $this->limit;
             }
         }
 
         $this->stream->seek($offset);
     }
 
     /**
      * Give a relative tell()
      * {@inheritdoc}
      */
     public function tell()
     {
         return $this->stream->tell() - $this->offset;
     }
 
     /**
      * Set the offset to start limiting from
      *
      * @param int $offset Offset to seek to and begin byte limiting from
      *
      * @throws \RuntimeException if the stream cannot be seeked.
      */
     public function setOffset($offset)
     {
         $current = $this->stream->tell();
 
         if ($current !== $offset) {
             // If the stream cannot seek to the offset position, then read to it
             if ($this->stream->isSeekable()) {
                 $this->stream->seek($offset);
             } elseif ($current > $offset) {
                 throw new \RuntimeException("Could not seek to stream offset $offset");
             } else {
                 $this->stream->read($offset - $current);
             }
         }
 
         $this->offset = $offset;
     }
 
     /**
      * Set the limit of bytes that the decorator allows to be read from the
      * stream.
      *
      * @param int $limit Number of bytes to allow to be read from the stream.
      *                   Use -1 for no limit.
      */
     public function setLimit($limit)
     {
         $this->limit = $limit;
     }
 
     public function read($length)
     {
         if ($this->limit == -1) {
             return $this->stream->read($length);
         }
 
         // Check if the current position is less than the total allowed
         // bytes + original offset
         $remaining = ($this->offset + $this->limit) - $this->stream->tell();
         if ($remaining > 0) {
             // Only return the amount of requested data, ensuring that the byte
             // limit is not exceeded
             return $this->stream->read(min($remaining, $length));
         }
 
         return '';
     }
 }