Chris@0: <?php
Chris@0: namespace GuzzleHttp\Psr7;
Chris@0: 
Chris@0: use Psr\Http\Message\StreamInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Provides a buffer stream that can be written to to fill a buffer, and read
Chris@0:  * from to remove bytes from the buffer.
Chris@0:  *
Chris@0:  * This stream returns a "hwm" metadata value that tells upstream consumers
Chris@0:  * what the configured high water mark of the stream is, or the maximum
Chris@0:  * preferred size of the buffer.
Chris@0:  */
Chris@0: class BufferStream implements StreamInterface
Chris@0: {
Chris@0:     private $hwm;
Chris@0:     private $buffer = '';
Chris@0: 
Chris@0:     /**
Chris@0:      * @param int $hwm High water mark, representing the preferred maximum
Chris@0:      *                 buffer size. If the size of the buffer exceeds the high
Chris@0:      *                 water mark, then calls to write will continue to succeed
Chris@0:      *                 but will return false to inform writers to slow down
Chris@0:      *                 until the buffer has been drained by reading from it.
Chris@0:      */
Chris@0:     public function __construct($hwm = 16384)
Chris@0:     {
Chris@0:         $this->hwm = $hwm;
Chris@0:     }
Chris@0: 
Chris@0:     public function __toString()
Chris@0:     {
Chris@0:         return $this->getContents();
Chris@0:     }
Chris@0: 
Chris@0:     public function getContents()
Chris@0:     {
Chris@0:         $buffer = $this->buffer;
Chris@0:         $this->buffer = '';
Chris@0: 
Chris@0:         return $buffer;
Chris@0:     }
Chris@0: 
Chris@0:     public function close()
Chris@0:     {
Chris@0:         $this->buffer = '';
Chris@0:     }
Chris@0: 
Chris@0:     public function detach()
Chris@0:     {
Chris@0:         $this->close();
Chris@0:     }
Chris@0: 
Chris@0:     public function getSize()
Chris@0:     {
Chris@0:         return strlen($this->buffer);
Chris@0:     }
Chris@0: 
Chris@0:     public function isReadable()
Chris@0:     {
Chris@0:         return true;
Chris@0:     }
Chris@0: 
Chris@0:     public function isWritable()
Chris@0:     {
Chris@0:         return true;
Chris@0:     }
Chris@0: 
Chris@0:     public function isSeekable()
Chris@0:     {
Chris@0:         return false;
Chris@0:     }
Chris@0: 
Chris@0:     public function rewind()
Chris@0:     {
Chris@0:         $this->seek(0);
Chris@0:     }
Chris@0: 
Chris@0:     public function seek($offset, $whence = SEEK_SET)
Chris@0:     {
Chris@0:         throw new \RuntimeException('Cannot seek a BufferStream');
Chris@0:     }
Chris@0: 
Chris@0:     public function eof()
Chris@0:     {
Chris@0:         return strlen($this->buffer) === 0;
Chris@0:     }
Chris@0: 
Chris@0:     public function tell()
Chris@0:     {
Chris@0:         throw new \RuntimeException('Cannot determine the position of a BufferStream');
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Reads data from the buffer.
Chris@0:      */
Chris@0:     public function read($length)
Chris@0:     {
Chris@0:         $currentLength = strlen($this->buffer);
Chris@0: 
Chris@0:         if ($length >= $currentLength) {
Chris@0:             // No need to slice the buffer because we don't have enough data.
Chris@0:             $result = $this->buffer;
Chris@0:             $this->buffer = '';
Chris@0:         } else {
Chris@0:             // Slice up the result to provide a subset of the buffer.
Chris@0:             $result = substr($this->buffer, 0, $length);
Chris@0:             $this->buffer = substr($this->buffer, $length);
Chris@0:         }
Chris@0: 
Chris@0:         return $result;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Writes data to the buffer.
Chris@0:      */
Chris@0:     public function write($string)
Chris@0:     {
Chris@0:         $this->buffer .= $string;
Chris@0: 
Chris@0:         // TODO: What should happen here?
Chris@0:         if (strlen($this->buffer) >= $this->hwm) {
Chris@0:             return false;
Chris@0:         }
Chris@0: 
Chris@0:         return strlen($string);
Chris@0:     }
Chris@0: 
Chris@0:     public function getMetadata($key = null)
Chris@0:     {
Chris@0:         if ($key == 'hwm') {
Chris@0:             return $this->hwm;
Chris@0:         }
Chris@0: 
Chris@0:         return $key ? null : [];
Chris@0:     }
Chris@0: }