274 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
			
		
		
	
	
			274 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
| <?php
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| namespace GuzzleHttp;
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| 
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| use Psr\Http\Message\RequestInterface;
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| 
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| /**
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|  * Creates a composed Guzzle handler function by stacking middlewares on top of
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|  * an HTTP handler function.
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|  */
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| class HandlerStack
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| {
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|     /** @var callable */
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|     private $handler;
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| 
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|     /** @var array */
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|     private $stack = [];
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| 
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|     /** @var callable|null */
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|     private $cached;
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| 
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|     /**
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|      * Creates a default handler stack that can be used by clients.
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|      *
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|      * The returned handler will wrap the provided handler or use the most
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|      * appropriate default handler for you system. The returned HandlerStack has
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|      * support for cookies, redirects, HTTP error exceptions, and preparing a body
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|      * before sending.
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|      *
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|      * The returned handler stack can be passed to a client in the "handler"
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|      * option.
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|      *
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|      * @param callable $handler HTTP handler function to use with the stack. If no
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|      *                          handler is provided, the best handler for your
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|      *                          system will be utilized.
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|      *
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|      * @return HandlerStack
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|      */
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|     public static function create(callable $handler = null)
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|     {
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|         $stack = new self($handler ?: choose_handler());
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|         $stack->push(Middleware::httpErrors(), 'http_errors');
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|         $stack->push(Middleware::redirect(), 'allow_redirects');
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|         $stack->push(Middleware::cookies(), 'cookies');
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|         $stack->push(Middleware::prepareBody(), 'prepare_body');
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| 
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|         return $stack;
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|     }
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| 
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|     /**
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|      * @param callable $handler Underlying HTTP handler.
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|      */
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|     public function __construct(callable $handler = null)
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|     {
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|         $this->handler = $handler;
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|     }
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| 
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|     /**
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|      * Invokes the handler stack as a composed handler
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|      *
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|      * @param RequestInterface $request
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|      * @param array            $options
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|      */
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|     public function __invoke(RequestInterface $request, array $options)
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|     {
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|         $handler = $this->resolve();
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| 
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|         return $handler($request, $options);
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|     }
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| 
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|     /**
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|      * Dumps a string representation of the stack.
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|      *
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|      * @return string
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|      */
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|     public function __toString()
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|     {
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|         $depth = 0;
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|         $stack = [];
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|         if ($this->handler) {
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|             $stack[] = "0) Handler: " . $this->debugCallable($this->handler);
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|         }
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| 
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|         $result = '';
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|         foreach (array_reverse($this->stack) as $tuple) {
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|             $depth++;
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|             $str = "{$depth}) Name: '{$tuple[1]}', ";
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|             $str .= "Function: " . $this->debugCallable($tuple[0]);
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|             $result = "> {$str}\n{$result}";
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|             $stack[] = $str;
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|         }
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| 
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|         foreach (array_keys($stack) as $k) {
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|             $result .= "< {$stack[$k]}\n";
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|         }
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| 
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|         return $result;
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|     }
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| 
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|     /**
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|      * Set the HTTP handler that actually returns a promise.
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|      *
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|      * @param callable $handler Accepts a request and array of options and
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|      *                          returns a Promise.
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|      */
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|     public function setHandler(callable $handler)
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|     {
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|         $this->handler = $handler;
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|         $this->cached = null;
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|     }
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| 
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|     /**
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|      * Returns true if the builder has a handler.
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|      *
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|      * @return bool
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|      */
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|     public function hasHandler()
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|     {
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|         return (bool) $this->handler;
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|     }
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| 
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|     /**
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|      * Unshift a middleware to the bottom of the stack.
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|      *
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|      * @param callable $middleware Middleware function
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|      * @param string   $name       Name to register for this middleware.
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|      */
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|     public function unshift(callable $middleware, $name = null)
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|     {
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|         array_unshift($this->stack, [$middleware, $name]);
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|         $this->cached = null;
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|     }
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| 
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|     /**
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|      * Push a middleware to the top of the stack.
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|      *
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|      * @param callable $middleware Middleware function
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|      * @param string   $name       Name to register for this middleware.
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|      */
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|     public function push(callable $middleware, $name = '')
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|     {
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|         $this->stack[] = [$middleware, $name];
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|         $this->cached = null;
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|     }
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| 
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|     /**
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|      * Add a middleware before another middleware by name.
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|      *
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|      * @param string   $findName   Middleware to find
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|      * @param callable $middleware Middleware function
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|      * @param string   $withName   Name to register for this middleware.
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|      */
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|     public function before($findName, callable $middleware, $withName = '')
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|     {
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|         $this->splice($findName, $withName, $middleware, true);
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|     }
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| 
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|     /**
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|      * Add a middleware after another middleware by name.
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|      *
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|      * @param string   $findName   Middleware to find
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|      * @param callable $middleware Middleware function
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|      * @param string   $withName   Name to register for this middleware.
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|      */
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|     public function after($findName, callable $middleware, $withName = '')
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|     {
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|         $this->splice($findName, $withName, $middleware, false);
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|     }
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| 
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|     /**
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|      * Remove a middleware by instance or name from the stack.
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|      *
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|      * @param callable|string $remove Middleware to remove by instance or name.
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|      */
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|     public function remove($remove)
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|     {
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|         $this->cached = null;
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|         $idx = is_callable($remove) ? 0 : 1;
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|         $this->stack = array_values(array_filter(
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|             $this->stack,
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|             function ($tuple) use ($idx, $remove) {
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|                 return $tuple[$idx] !== $remove;
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|             }
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|         ));
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|     }
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| 
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|     /**
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|      * Compose the middleware and handler into a single callable function.
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|      *
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|      * @return callable
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|      */
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|     public function resolve()
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|     {
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|         if (!$this->cached) {
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|             if (!($prev = $this->handler)) {
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|                 throw new \LogicException('No handler has been specified');
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|             }
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| 
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|             foreach (array_reverse($this->stack) as $fn) {
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|                 $prev = $fn[0]($prev);
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|             }
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| 
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|             $this->cached = $prev;
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|         }
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| 
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|         return $this->cached;
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|     }
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| 
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|     /**
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|      * @param $name
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|      * @return int
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|      */
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|     private function findByName($name)
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|     {
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|         foreach ($this->stack as $k => $v) {
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|             if ($v[1] === $name) {
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|                 return $k;
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|             }
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|         }
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| 
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|         throw new \InvalidArgumentException("Middleware not found: $name");
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|     }
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| 
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|     /**
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|      * Splices a function into the middleware list at a specific position.
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|      *
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|      * @param          $findName
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|      * @param          $withName
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|      * @param callable $middleware
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|      * @param          $before
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|      */
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|     private function splice($findName, $withName, callable $middleware, $before)
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|     {
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|         $this->cached = null;
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|         $idx = $this->findByName($findName);
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|         $tuple = [$middleware, $withName];
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| 
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|         if ($before) {
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|             if ($idx === 0) {
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|                 array_unshift($this->stack, $tuple);
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|             } else {
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|                 $replacement = [$tuple, $this->stack[$idx]];
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|                 array_splice($this->stack, $idx, 1, $replacement);
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|             }
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|         } elseif ($idx === count($this->stack) - 1) {
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|             $this->stack[] = $tuple;
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|         } else {
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|             $replacement = [$this->stack[$idx], $tuple];
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|             array_splice($this->stack, $idx, 1, $replacement);
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|         }
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|     }
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| 
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|     /**
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|      * Provides a debug string for a given callable.
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|      *
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|      * @param array|callable $fn Function to write as a string.
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|      *
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|      * @return string
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|      */
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|     private function debugCallable($fn)
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|     {
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|         if (is_string($fn)) {
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|             return "callable({$fn})";
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|         }
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| 
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|         if (is_array($fn)) {
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|             return is_string($fn[0])
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|                 ? "callable({$fn[0]}::{$fn[1]})"
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|                 : "callable(['" . get_class($fn[0]) . "', '{$fn[1]}'])";
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|         }
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| 
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|         return 'callable(' . spl_object_hash($fn) . ')';
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|     }
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| }
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