Chris@0: <?php
Chris@0: namespace GuzzleHttp\Psr7;
Chris@0: 
Chris@0: use Psr\Http\Message\StreamInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Compose stream implementations based on a hash of functions.
Chris@0:  *
Chris@0:  * Allows for easy testing and extension of a provided stream without needing
Chris@0:  * to create a concrete class for a simple extension point.
Chris@0:  */
Chris@0: class FnStream implements StreamInterface
Chris@0: {
Chris@0:     /** @var array */
Chris@0:     private $methods;
Chris@0: 
Chris@0:     /** @var array Methods that must be implemented in the given array */
Chris@0:     private static $slots = ['__toString', 'close', 'detach', 'rewind',
Chris@0:         'getSize', 'tell', 'eof', 'isSeekable', 'seek', 'isWritable', 'write',
Chris@0:         'isReadable', 'read', 'getContents', 'getMetadata'];
Chris@0: 
Chris@0:     /**
Chris@0:      * @param array $methods Hash of method name to a callable.
Chris@0:      */
Chris@0:     public function __construct(array $methods)
Chris@0:     {
Chris@0:         $this->methods = $methods;
Chris@0: 
Chris@0:         // Create the functions on the class
Chris@0:         foreach ($methods as $name => $fn) {
Chris@0:             $this->{'_fn_' . $name} = $fn;
Chris@0:         }
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Lazily determine which methods are not implemented.
Chris@0:      * @throws \BadMethodCallException
Chris@0:      */
Chris@0:     public function __get($name)
Chris@0:     {
Chris@0:         throw new \BadMethodCallException(str_replace('_fn_', '', $name)
Chris@0:             . '() is not implemented in the FnStream');
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * The close method is called on the underlying stream only if possible.
Chris@0:      */
Chris@0:     public function __destruct()
Chris@0:     {
Chris@0:         if (isset($this->_fn_close)) {
Chris@0:             call_user_func($this->_fn_close);
Chris@0:         }
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@17:      * An unserialize would allow the __destruct to run when the unserialized value goes out of scope.
Chris@17:      * @throws \LogicException
Chris@17:      */
Chris@17:     public function __wakeup()
Chris@17:     {
Chris@17:         throw new \LogicException('FnStream should never be unserialized');
Chris@17:     }
Chris@17: 
Chris@17:     /**
Chris@0:      * Adds custom functionality to an underlying stream by intercepting
Chris@0:      * specific method calls.
Chris@0:      *
Chris@0:      * @param StreamInterface $stream  Stream to decorate
Chris@0:      * @param array           $methods Hash of method name to a closure
Chris@0:      *
Chris@0:      * @return FnStream
Chris@0:      */
Chris@0:     public static function decorate(StreamInterface $stream, array $methods)
Chris@0:     {
Chris@0:         // If any of the required methods were not provided, then simply
Chris@0:         // proxy to the decorated stream.
Chris@0:         foreach (array_diff(self::$slots, array_keys($methods)) as $diff) {
Chris@0:             $methods[$diff] = [$stream, $diff];
Chris@0:         }
Chris@0: 
Chris@0:         return new self($methods);
Chris@0:     }
Chris@0: 
Chris@0:     public function __toString()
Chris@0:     {
Chris@0:         return call_user_func($this->_fn___toString);
Chris@0:     }
Chris@0: 
Chris@0:     public function close()
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_close);
Chris@0:     }
Chris@0: 
Chris@0:     public function detach()
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_detach);
Chris@0:     }
Chris@0: 
Chris@0:     public function getSize()
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_getSize);
Chris@0:     }
Chris@0: 
Chris@0:     public function tell()
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_tell);
Chris@0:     }
Chris@0: 
Chris@0:     public function eof()
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_eof);
Chris@0:     }
Chris@0: 
Chris@0:     public function isSeekable()
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_isSeekable);
Chris@0:     }
Chris@0: 
Chris@0:     public function rewind()
Chris@0:     {
Chris@0:         call_user_func($this->_fn_rewind);
Chris@0:     }
Chris@0: 
Chris@0:     public function seek($offset, $whence = SEEK_SET)
Chris@0:     {
Chris@0:         call_user_func($this->_fn_seek, $offset, $whence);
Chris@0:     }
Chris@0: 
Chris@0:     public function isWritable()
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_isWritable);
Chris@0:     }
Chris@0: 
Chris@0:     public function write($string)
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_write, $string);
Chris@0:     }
Chris@0: 
Chris@0:     public function isReadable()
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_isReadable);
Chris@0:     }
Chris@0: 
Chris@0:     public function read($length)
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_read, $length);
Chris@0:     }
Chris@0: 
Chris@0:     public function getContents()
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_getContents);
Chris@0:     }
Chris@0: 
Chris@0:     public function getMetadata($key = null)
Chris@0:     {
Chris@0:         return call_user_func($this->_fn_getMetadata, $key);
Chris@0:     }
Chris@0: }