comparison vendor/symfony/http-foundation/Response.php @ 0:4c8ae668cc8c

Initial import (non-working)

+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[e-mail]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpFoundation;
+
+/**
+ * Response represents an HTTP response.
+ *
+ * @author Fabien Potencier <[e-mail]>
+ */
+class Response
+{
+    const HTTP_CONTINUE = 100;
+    const HTTP_SWITCHING_PROTOCOLS = 101;
+    const HTTP_PROCESSING = 102;            // RFC2518
+    const HTTP_OK = 200;
+    const HTTP_CREATED = 201;
+    const HTTP_ACCEPTED = 202;
+    const HTTP_NON_AUTHORITATIVE_INFORMATION = 203;
+    const HTTP_NO_CONTENT = 204;
+    const HTTP_RESET_CONTENT = 205;
+    const HTTP_PARTIAL_CONTENT = 206;
+    const HTTP_MULTI_STATUS = 207;          // RFC4918
+    const HTTP_ALREADY_REPORTED = 208;      // RFC5842
+    const HTTP_IM_USED = 226;               // RFC3229
+    const HTTP_MULTIPLE_CHOICES = 300;
+    const HTTP_MOVED_PERMANENTLY = 301;
+    const HTTP_FOUND = 302;
+    const HTTP_SEE_OTHER = 303;
+    const HTTP_NOT_MODIFIED = 304;
+    const HTTP_USE_PROXY = 305;
+    const HTTP_RESERVED = 306;
+    const HTTP_TEMPORARY_REDIRECT = 307;
+    const HTTP_PERMANENTLY_REDIRECT = 308;  // RFC7238
+    const HTTP_BAD_REQUEST = 400;
+    const HTTP_UNAUTHORIZED = 401;
+    const HTTP_PAYMENT_REQUIRED = 402;
+    const HTTP_FORBIDDEN = 403;
+    const HTTP_NOT_FOUND = 404;
+    const HTTP_METHOD_NOT_ALLOWED = 405;
+    const HTTP_NOT_ACCEPTABLE = 406;
+    const HTTP_PROXY_AUTHENTICATION_REQUIRED = 407;
+    const HTTP_REQUEST_TIMEOUT = 408;
+    const HTTP_CONFLICT = 409;
+    const HTTP_GONE = 410;
+    const HTTP_LENGTH_REQUIRED = 411;
+    const HTTP_PRECONDITION_FAILED = 412;
+    const HTTP_REQUEST_ENTITY_TOO_LARGE = 413;
+    const HTTP_REQUEST_URI_TOO_LONG = 414;
+    const HTTP_UNSUPPORTED_MEDIA_TYPE = 415;
+    const HTTP_REQUESTED_RANGE_NOT_SATISFIABLE = 416;
+    const HTTP_EXPECTATION_FAILED = 417;
+    const HTTP_I_AM_A_TEAPOT = 418;                                               // RFC2324
+    const HTTP_MISDIRECTED_REQUEST = 421;                                         // RFC7540
+    const HTTP_UNPROCESSABLE_ENTITY = 422;                                        // RFC4918
+    const HTTP_LOCKED = 423;                                                      // RFC4918
+    const HTTP_FAILED_DEPENDENCY = 424;                                           // RFC4918
+    const HTTP_RESERVED_FOR_WEBDAV_ADVANCED_COLLECTIONS_EXPIRED_PROPOSAL = 425;   // RFC2817
+    const HTTP_UPGRADE_REQUIRED = 426;                                            // RFC2817
+    const HTTP_PRECONDITION_REQUIRED = 428;                                       // RFC6585
+    const HTTP_TOO_MANY_REQUESTS = 429;                                           // RFC6585
+    const HTTP_REQUEST_HEADER_FIELDS_TOO_LARGE = 431;                             // RFC6585
+    const HTTP_UNAVAILABLE_FOR_LEGAL_REASONS = 451;
+    const HTTP_INTERNAL_SERVER_ERROR = 500;
+    const HTTP_NOT_IMPLEMENTED = 501;
+    const HTTP_BAD_GATEWAY = 502;
+    const HTTP_SERVICE_UNAVAILABLE = 503;
+    const HTTP_GATEWAY_TIMEOUT = 504;
+    const HTTP_VERSION_NOT_SUPPORTED = 505;
+    const HTTP_VARIANT_ALSO_NEGOTIATES_EXPERIMENTAL = 506;                        // RFC2295
+    const HTTP_INSUFFICIENT_STORAGE = 507;                                        // RFC4918
+    const HTTP_LOOP_DETECTED = 508;                                               // RFC5842
+    const HTTP_NOT_EXTENDED = 510;                                                // RFC2774
+    const HTTP_NETWORK_AUTHENTICATION_REQUIRED = 511;                             // RFC6585
+
+    /**
+     * @var \Symfony\Component\HttpFoundation\ResponseHeaderBag
+     */
+    public $headers;
+
+    /**
+     * @var string
+     */
+    protected $content;
+
+    /**
+     * @var string
+     */
+    protected $version;
+
+    /**
+     * @var int
+     */
+    protected $statusCode;
+
+    /**
+     * @var string
+     */
+    protected $statusText;
+
+    /**
+     * @var string
+     */
+    protected $charset;
+
+    /**
+     * Status codes translation table.
+     *
+     * The list of codes is complete according to the
+     * {@link http://www.iana.org/assignments/http-status-codes/ Hypertext Transfer Protocol (HTTP) Status Code Registry}
+     * (last updated 2016-03-01).
+     *
+     * Unless otherwise noted, the status code is defined in RFC2616.
+     *
+     * @var array
+     */
+    public static $statusTexts = array(
+        100 => 'Continue',
+        101 => 'Switching Protocols',
+        102 => 'Processing',            // RFC2518
+        200 => 'OK',
+        201 => 'Created',
+        202 => 'Accepted',
+        203 => 'Non-Authoritative Information',
+        204 => 'No Content',
+        205 => 'Reset Content',
+        206 => 'Partial Content',
+        207 => 'Multi-Status',          // RFC4918
+        208 => 'Already Reported',      // RFC5842
+        226 => 'IM Used',               // RFC3229
+        300 => 'Multiple Choices',
+        301 => 'Moved Permanently',
+        302 => 'Found',
+        303 => 'See Other',
+        304 => 'Not Modified',
+        305 => 'Use Proxy',
+        307 => 'Temporary Redirect',
+        308 => 'Permanent Redirect',    // RFC7238
+        400 => 'Bad Request',
+        401 => 'Unauthorized',
+        402 => 'Payment Required',
+        403 => 'Forbidden',
+        404 => 'Not Found',
+        405 => 'Method Not Allowed',
+        406 => 'Not Acceptable',
+        407 => 'Proxy Authentication Required',
+        408 => 'Request Timeout',
+        409 => 'Conflict',
+        410 => 'Gone',
+        411 => 'Length Required',
+        412 => 'Precondition Failed',
+        413 => 'Payload Too Large',
+        414 => 'URI Too Long',
+        415 => 'Unsupported Media Type',
+        416 => 'Range Not Satisfiable',
+        417 => 'Expectation Failed',
+        418 => 'I\'m a teapot',                                               // RFC2324
+        421 => 'Misdirected Request',                                         // RFC7540
+        422 => 'Unprocessable Entity',                                        // RFC4918
+        423 => 'Locked',                                                      // RFC4918
+        424 => 'Failed Dependency',                                           // RFC4918
+        425 => 'Reserved for WebDAV advanced collections expired proposal',   // RFC2817
+        426 => 'Upgrade Required',                                            // RFC2817
+        428 => 'Precondition Required',                                       // RFC6585
+        429 => 'Too Many Requests',                                           // RFC6585
+        431 => 'Request Header Fields Too Large',                             // RFC6585
+        451 => 'Unavailable For Legal Reasons',                               // RFC7725
+        500 => 'Internal Server Error',
+        501 => 'Not Implemented',
+        502 => 'Bad Gateway',
+        503 => 'Service Unavailable',
+        504 => 'Gateway Timeout',
+        505 => 'HTTP Version Not Supported',
+        506 => 'Variant Also Negotiates',                                     // RFC2295
+        507 => 'Insufficient Storage',                                        // RFC4918
+        508 => 'Loop Detected',                                               // RFC5842
+        510 => 'Not Extended',                                                // RFC2774
+        511 => 'Network Authentication Required',                             // RFC6585
+    );
+
+    private static $deprecatedMethods = array(
+        'setDate', 'getDate',
+        'setExpires', 'getExpires',
+        'setLastModified', 'getLastModified',
+        'setProtocolVersion', 'getProtocolVersion',
+        'setStatusCode', 'getStatusCode',
+        'setCharset', 'getCharset',
+        'setPrivate', 'setPublic',
+        'getAge', 'getMaxAge', 'setMaxAge', 'setSharedMaxAge',
+        'getTtl', 'setTtl', 'setClientTtl',
+        'getEtag', 'setEtag',
+        'hasVary', 'getVary', 'setVary',
+        'isInvalid', 'isSuccessful', 'isRedirection',
+        'isClientError', 'isOk', 'isForbidden',
+        'isNotFound', 'isRedirect', 'isEmpty',
+    );
+    private static $deprecationsTriggered = array(
+        __CLASS__ => true,
+        BinaryFileResponse::class => true,
+        JsonResponse::class => true,
+        RedirectResponse::class => true,
+        StreamedResponse::class => true,
+    );
+
+    /**
+     * Constructor.
+     *
+     * @param mixed $content The response content, see setContent()
+     * @param int   $status  The response status code
+     * @param array $headers An array of response headers
+     *
+     * @throws \InvalidArgumentException When the HTTP status code is not valid
+     */
+    public function __construct($content = '', $status = 200, $headers = array())
+    {
+        $this->headers = new ResponseHeaderBag($headers);
+        $this->setContent($content);
+        $this->setStatusCode($status);
+        $this->setProtocolVersion('1.0');
+
+        /* RFC2616 - 14.18 says all Responses need to have a Date */
+        if (!$this->headers->has('Date')) {
+            $this->setDate(\DateTime::createFromFormat('U', time()));
+        }
+
+        // Deprecations
+        $class = get_class($this);
+        if ($this instanceof \PHPUnit_Framework_MockObject_MockObject || $this instanceof \Prophecy\Doubler\DoubleInterface) {
+            $class = get_parent_class($class);
+        }
+        if (isset(self::$deprecationsTriggered[$class])) {
+            return;
+        }
+
+        self::$deprecationsTriggered[$class] = true;
+        foreach (self::$deprecatedMethods as $method) {
+            $r = new \ReflectionMethod($class, $method);
+            if (__CLASS__ !== $r->getDeclaringClass()->getName()) {
+                @trigger_error(sprintf('Extending %s::%s() in %s is deprecated since version 3.2 and won\'t be supported anymore in 4.0 as it will be final.', __CLASS__, $method, $class), E_USER_DEPRECATED);
+            }
+        }
+    }
+
+    /**
+     * Factory method for chainability.
+     *
+     * Example:
+     *
+     *     return Response::create($body, 200)
+     *         ->setSharedMaxAge(300);
+     *
+     * @param mixed $content The response content, see setContent()
+     * @param int   $status  The response status code
+     * @param array $headers An array of response headers
+     *
+     * @return static
+     */
+    public static function create($content = '', $status = 200, $headers = array())
+    {
+        return new static($content, $status, $headers);
+    }
+
+    /**
+     * Returns the Response as an HTTP string.
+     *
+     * The string representation of the Response is the same as the
+     * one that will be sent to the client only if the prepare() method
+     * has been called before.
+     *
+     * @return string The Response as an HTTP string
+     *
+     * @see prepare()
+     */
+    public function __toString()
+    {
+        return
+            sprintf('HTTP/%s %s %s', $this->version, $this->statusCode, $this->statusText)."\r\n".
+            $this->headers."\r\n".
+            $this->getContent();
+    }
+
+    /**
+     * Clones the current Response instance.
+     */
+    public function __clone()
+    {
+        $this->headers = clone $this->headers;
+    }
+
+    /**
+     * Prepares the Response before it is sent to the client.
+     *
+     * This method tweaks the Response to ensure that it is
+     * compliant with RFC 2616. Most of the changes are based on
+     * the Request that is "associated" with this Response.
+     *
+     * @param Request $request A Request instance
+     *
+     * @return $this
+     */
+    public function prepare(Request $request)
+    {
+        $headers = $this->headers;
+
+        if ($this->isInformational() || $this->isEmpty()) {
+            $this->setContent(null);
+            $headers->remove('Content-Type');
+            $headers->remove('Content-Length');
+        } else {
+            // Content-type based on the Request
+            if (!$headers->has('Content-Type')) {
+                $format = $request->getRequestFormat();
+                if (null !== $format && $mimeType = $request->getMimeType($format)) {
+                    $headers->set('Content-Type', $mimeType);
+                }
+            }
+
+            // Fix Content-Type
+            $charset = $this->charset ?: 'UTF-8';
+            if (!$headers->has('Content-Type')) {
+                $headers->set('Content-Type', 'text/html; charset='.$charset);
+            } elseif (0 === stripos($headers->get('Content-Type'), 'text/') && false === stripos($headers->get('Content-Type'), 'charset')) {
+                // add the charset
+                $headers->set('Content-Type', $headers->get('Content-Type').'; charset='.$charset);
+            }
+
+            // Fix Content-Length
+            if ($headers->has('Transfer-Encoding')) {
+                $headers->remove('Content-Length');
+            }
+
+            if ($request->isMethod('HEAD')) {
+                // cf. RFC2616 14.13
+                $length = $headers->get('Content-Length');
+                $this->setContent(null);
+                if ($length) {
+                    $headers->set('Content-Length', $length);
+                }
+            }
+        }
+
+        // Fix protocol
+        if ('HTTP/1.0' != $request->server->get('SERVER_PROTOCOL')) {
+            $this->setProtocolVersion('1.1');
+        }
+
+        // Check if we need to send extra expire info headers
+        if ('1.0' == $this->getProtocolVersion() && false !== strpos($this->headers->get('Cache-Control'), 'no-cache')) {
+            $this->headers->set('pragma', 'no-cache');
+            $this->headers->set('expires', -1);
+        }
+
+        $this->ensureIEOverSSLCompatibility($request);
+
+        return $this;
+    }
+
+    /**
+     * Sends HTTP headers.
+     *
+     * @return $this
+     */
+    public function sendHeaders()
+    {
+        // headers have already been sent by the developer
+        if (headers_sent()) {
+            return $this;
+        }
+
+        /* RFC2616 - 14.18 says all Responses need to have a Date */
+        if (!$this->headers->has('Date')) {
+            $this->setDate(\DateTime::createFromFormat('U', time()));
+        }
+
+        // headers
+        foreach ($this->headers->allPreserveCase() as $name => $values) {
+            foreach ($values as $value) {
+                header($name.': '.$value, false, $this->statusCode);
+            }
+        }
+
+        // status
+        header(sprintf('HTTP/%s %s %s', $this->version, $this->statusCode, $this->statusText), true, $this->statusCode);
+
+        // cookies
+        foreach ($this->headers->getCookies() as $cookie) {
+            if ($cookie->isRaw()) {
+                setrawcookie($cookie->getName(), $cookie->getValue(), $cookie->getExpiresTime(), $cookie->getPath(), $cookie->getDomain(), $cookie->isSecure(), $cookie->isHttpOnly());
+            } else {
+                setcookie($cookie->getName(), $cookie->getValue(), $cookie->getExpiresTime(), $cookie->getPath(), $cookie->getDomain(), $cookie->isSecure(), $cookie->isHttpOnly());
+            }
+        }
+
+        return $this;
+    }
+
+    /**
+     * Sends content for the current web response.
+     *
+     * @return $this
+     */
+    public function sendContent()
+    {
+        echo $this->content;
+
+        return $this;
+    }
+
+    /**
+     * Sends HTTP headers and content.
+     *
+     * @return $this
+     */
+    public function send()
+    {
+        $this->sendHeaders();
+        $this->sendContent();
+
+        if (function_exists('fastcgi_finish_request')) {
+            fastcgi_finish_request();
+        } elseif ('cli' !== PHP_SAPI) {
+            static::closeOutputBuffers(0, true);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Sets the response content.
+     *
+     * Valid types are strings, numbers, null, and objects that implement a __toString() method.
+     *
+     * @param mixed $content Content that can be cast to string
+     *
+     * @return $this
+     *
+     * @throws \UnexpectedValueException
+     */
+    public function setContent($content)
+    {
+        if (null !== $content && !is_string($content) && !is_numeric($content) && !is_callable(array($content, '__toString'))) {
+            throw new \UnexpectedValueException(sprintf('The Response content must be a string or object implementing __toString(), "%s" given.', gettype($content)));
+        }
+
+        $this->content = (string) $content;
+
+        return $this;
+    }
+
+    /**
+     * Gets the current response content.
+     *
+     * @return string Content
+     */
+    public function getContent()
+    {
+        return $this->content;
+    }
+
+    /**
+     * Sets the HTTP protocol version (1.0 or 1.1).
+     *
+     * @param string $version The HTTP protocol version
+     *
+     * @return $this
+     */
+    public function setProtocolVersion($version)
+    {
+        $this->version = $version;
+
+        return $this;
+    }
+
+    /**
+     * Gets the HTTP protocol version.
+     *
+     * @return string The HTTP protocol version
+     */
+    public function getProtocolVersion()
+    {
+        return $this->version;
+    }
+
+    /**
+     * Sets the response status code.
+     *
+     * @param int   $code HTTP status code
+     * @param mixed $text HTTP status text
+     *
+     * If the status text is null it will be automatically populated for the known
+     * status codes and left empty otherwise.
+     *
+     * @return $this
+     *
+     * @throws \InvalidArgumentException When the HTTP status code is not valid
+     */
+    public function setStatusCode($code, $text = null)
+    {
+        $this->statusCode = $code = (int) $code;
+        if ($this->isInvalid()) {
+            throw new \InvalidArgumentException(sprintf('The HTTP status code "%s" is not valid.', $code));
+        }
+
+        if (null === $text) {
+            $this->statusText = isset(self::$statusTexts[$code]) ? self::$statusTexts[$code] : 'unknown status';
+
+            return $this;
+        }
+
+        if (false === $text) {
+            $this->statusText = '';
+
+            return $this;
+        }
+
+        $this->statusText = $text;
+
+        return $this;
+    }
+
+    /**
+     * Retrieves the status code for the current web response.
+     *
+     * @return int Status code
+     */
+    public function getStatusCode()
+    {
+        return $this->statusCode;
+    }
+
+    /**
+     * Sets the response charset.
+     *
+     * @param string $charset Character set
+     *
+     * @return $this
+     */
+    public function setCharset($charset)
+    {
+        $this->charset = $charset;
+
+        return $this;
+    }
+
+    /**
+     * Retrieves the response charset.
+     *
+     * @return string Character set
+     */
+    public function getCharset()
+    {
+        return $this->charset;
+    }
+
+    /**
+     * Returns true if the response is worth caching under any circumstance.
+     *
+     * Responses marked "private" with an explicit Cache-Control directive are
+     * considered uncacheable.
+     *
+     * Responses with neither a freshness lifetime (Expires, max-age) nor cache
+     * validator (Last-Modified, ETag) are considered uncacheable.
+     *
+     * @return bool true if the response is worth caching, false otherwise
+     */
+    public function isCacheable()
+    {
+        if (!in_array($this->statusCode, array(200, 203, 300, 301, 302, 404, 410))) {
+            return false;
+        }
+
+        if ($this->headers->hasCacheControlDirective('no-store') || $this->headers->getCacheControlDirective('private')) {
+            return false;
+        }
+
+        return $this->isValidateable() || $this->isFresh();
+    }
+
+    /**
+     * Returns true if the response is "fresh".
+     *
+     * Fresh responses may be served from cache without any interaction with the
+     * origin. A response is considered fresh when it includes a Cache-Control/max-age
+     * indicator or Expires header and the calculated age is less than the freshness lifetime.
+     *
+     * @return bool true if the response is fresh, false otherwise
+     */
+    public function isFresh()
+    {
+        return $this->getTtl() > 0;
+    }
+
+    /**
+     * Returns true if the response includes headers that can be used to validate
+     * the response with the origin server using a conditional GET request.
+     *
+     * @return bool true if the response is validateable, false otherwise
+     */
+    public function isValidateable()
+    {
+        return $this->headers->has('Last-Modified') || $this->headers->has('ETag');
+    }
+
+    /**
+     * Marks the response as "private".
+     *
+     * It makes the response ineligible for serving other clients.
+     *
+     * @return $this
+     */
+    public function setPrivate()
+    {
+        $this->headers->removeCacheControlDirective('public');
+        $this->headers->addCacheControlDirective('private');
+
+        return $this;
+    }
+
+    /**
+     * Marks the response as "public".
+     *
+     * It makes the response eligible for serving other clients.
+     *
+     * @return $this
+     */
+    public function setPublic()
+    {
+        $this->headers->addCacheControlDirective('public');
+        $this->headers->removeCacheControlDirective('private');
+
+        return $this;
+    }
+
+    /**
+     * Returns true if the response must be revalidated by caches.
+     *
+     * This method indicates that the response must not be served stale by a
+     * cache in any circumstance without first revalidating with the origin.
+     * When present, the TTL of the response should not be overridden to be
+     * greater than the value provided by the origin.
+     *
+     * @return bool true if the response must be revalidated by a cache, false otherwise
+     */
+    public function mustRevalidate()
+    {
+        return $this->headers->hasCacheControlDirective('must-revalidate') || $this->headers->hasCacheControlDirective('proxy-revalidate');
+    }
+
+    /**
+     * Returns the Date header as a DateTime instance.
+     *
+     * @return \DateTime A \DateTime instance
+     *
+     * @throws \RuntimeException When the header is not parseable
+     */
+    public function getDate()
+    {
+        /*
+            RFC2616 - 14.18 says all Responses need to have a Date.
+            Make sure we provide one even if it the header
+            has been removed in the meantime.
+         */
+        if (!$this->headers->has('Date')) {
+            $this->setDate(\DateTime::createFromFormat('U', time()));
+        }
+
+        return $this->headers->getDate('Date');
+    }
+
+    /**
+     * Sets the Date header.
+     *
+     * @param \DateTime $date A \DateTime instance
+     *
+     * @return $this
+     */
+    public function setDate(\DateTime $date)
+    {
+        $date->setTimezone(new \DateTimeZone('UTC'));
+        $this->headers->set('Date', $date->format('D, d M Y H:i:s').' GMT');
+
+        return $this;
+    }
+
+    /**
+     * Returns the age of the response.
+     *
+     * @return int The age of the response in seconds
+     */
+    public function getAge()
+    {
+        if (null !== $age = $this->headers->get('Age')) {
+            return (int) $age;
+        }
+
+        return max(time() - $this->getDate()->format('U'), 0);
+    }
+
+    /**
+     * Marks the response stale by setting the Age header to be equal to the maximum age of the response.
+     *
+     * @return $this
+     */
+    public function expire()
+    {
+        if ($this->isFresh()) {
+            $this->headers->set('Age', $this->getMaxAge());
+        }
+
+        return $this;
+    }
+
+    /**
+     * Returns the value of the Expires header as a DateTime instance.
+     *
+     * @return \DateTime|null A DateTime instance or null if the header does not exist
+     */
+    public function getExpires()
+    {
+        try {
+            return $this->headers->getDate('Expires');
+        } catch (\RuntimeException $e) {
+            // according to RFC 2616 invalid date formats (e.g. "0" and "-1") must be treated as in the past
+            return \DateTime::createFromFormat(DATE_RFC2822, 'Sat, 01 Jan 00 00:00:00 +0000');
+        }
+    }
+
+    /**
+     * Sets the Expires HTTP header with a DateTime instance.
+     *
+     * Passing null as value will remove the header.
+     *
+     * @param \DateTime|null $date A \DateTime instance or null to remove the header
+     *
+     * @return $this
+     */
+    public function setExpires(\DateTime $date = null)
+    {
+        if (null === $date) {
+            $this->headers->remove('Expires');
+        } else {
+            $date = clone $date;
+            $date->setTimezone(new \DateTimeZone('UTC'));
+            $this->headers->set('Expires', $date->format('D, d M Y H:i:s').' GMT');
+        }
+
+        return $this;
+    }
+
+    /**
+     * Returns the number of seconds after the time specified in the response's Date
+     * header when the response should no longer be considered fresh.
+     *
+     * First, it checks for a s-maxage directive, then a max-age directive, and then it falls
+     * back on an expires header. It returns null when no maximum age can be established.
+     *
+     * @return int|null Number of seconds
+     */
+    public function getMaxAge()
+    {
+        if ($this->headers->hasCacheControlDirective('s-maxage')) {
+            return (int) $this->headers->getCacheControlDirective('s-maxage');
+        }
+
+        if ($this->headers->hasCacheControlDirective('max-age')) {
+            return (int) $this->headers->getCacheControlDirective('max-age');
+        }
+
+        if (null !== $this->getExpires()) {
+            return $this->getExpires()->format('U') - $this->getDate()->format('U');
+        }
+    }
+
+    /**
+     * Sets the number of seconds after which the response should no longer be considered fresh.
+     *
+     * This methods sets the Cache-Control max-age directive.
+     *
+     * @param int $value Number of seconds
+     *
+     * @return $this
+     */
+    public function setMaxAge($value)
+    {
+        $this->headers->addCacheControlDirective('max-age', $value);
+
+        return $this;
+    }
+
+    /**
+     * Sets the number of seconds after which the response should no longer be considered fresh by shared caches.
+     *
+     * This methods sets the Cache-Control s-maxage directive.
+     *
+     * @param int $value Number of seconds
+     *
+     * @return $this
+     */
+    public function setSharedMaxAge($value)
+    {
+        $this->setPublic();
+        $this->headers->addCacheControlDirective('s-maxage', $value);
+
+        return $this;
+    }
+
+    /**
+     * Returns the response's time-to-live in seconds.
+     *
+     * It returns null when no freshness information is present in the response.
+     *
+     * When the responses TTL is <= 0, the response may not be served from cache without first
+     * revalidating with the origin.
+     *
+     * @return int|null The TTL in seconds
+     */
+    public function getTtl()
+    {
+        if (null !== $maxAge = $this->getMaxAge()) {
+            return $maxAge - $this->getAge();
+        }
+    }
+
+    /**
+     * Sets the response's time-to-live for shared caches.
+     *
+     * This method adjusts the Cache-Control/s-maxage directive.
+     *
+     * @param int $seconds Number of seconds
+     *
+     * @return $this
+     */
+    public function setTtl($seconds)
+    {
+        $this->setSharedMaxAge($this->getAge() + $seconds);
+
+        return $this;
+    }
+
+    /**
+     * Sets the response's time-to-live for private/client caches.
+     *
+     * This method adjusts the Cache-Control/max-age directive.
+     *
+     * @param int $seconds Number of seconds
+     *
+     * @return $this
+     */
+    public function setClientTtl($seconds)
+    {
+        $this->setMaxAge($this->getAge() + $seconds);
+
+        return $this;
+    }
+
+    /**
+     * Returns the Last-Modified HTTP header as a DateTime instance.
+     *
+     * @return \DateTime|null A DateTime instance or null if the header does not exist
+     *
+     * @throws \RuntimeException When the HTTP header is not parseable
+     */
+    public function getLastModified()
+    {
+        return $this->headers->getDate('Last-Modified');
+    }
+
+    /**
+     * Sets the Last-Modified HTTP header with a DateTime instance.
+     *
+     * Passing null as value will remove the header.
+     *
+     * @param \DateTime|null $date A \DateTime instance or null to remove the header
+     *
+     * @return $this
+     */
+    public function setLastModified(\DateTime $date = null)
+    {
+        if (null === $date) {
+            $this->headers->remove('Last-Modified');
+        } else {
+            $date = clone $date;
+            $date->setTimezone(new \DateTimeZone('UTC'));
+            $this->headers->set('Last-Modified', $date->format('D, d M Y H:i:s').' GMT');
+        }
+
+        return $this;
+    }
+
+    /**
+     * Returns the literal value of the ETag HTTP header.
+     *
+     * @return string|null The ETag HTTP header or null if it does not exist
+     */
+    public function getEtag()
+    {
+        return $this->headers->get('ETag');
+    }
+
+    /**
+     * Sets the ETag value.
+     *
+     * @param string|null $etag The ETag unique identifier or null to remove the header
+     * @param bool        $weak Whether you want a weak ETag or not
+     *
+     * @return $this
+     */
+    public function setEtag($etag = null, $weak = false)
+    {
+        if (null === $etag) {
+            $this->headers->remove('Etag');
+        } else {
+            if (0 !== strpos($etag, '"')) {
+                $etag = '"'.$etag.'"';
+            }
+
+            $this->headers->set('ETag', (true === $weak ? 'W/' : '').$etag);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Sets the response's cache headers (validation and/or expiration).
+     *
+     * Available options are: etag, last_modified, max_age, s_maxage, private, and public.
+     *
+     * @param array $options An array of cache options
+     *
+     * @return $this
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function setCache(array $options)
+    {
+        if ($diff = array_diff(array_keys($options), array('etag', 'last_modified', 'max_age', 's_maxage', 'private', 'public'))) {
+            throw new \InvalidArgumentException(sprintf('Response does not support the following options: "%s".', implode('", "', array_values($diff))));
+        }
+
+        if (isset($options['etag'])) {
+            $this->setEtag($options['etag']);
+        }
+
+        if (isset($options['last_modified'])) {
+            $this->setLastModified($options['last_modified']);
+        }
+
+        if (isset($options['max_age'])) {
+            $this->setMaxAge($options['max_age']);
+        }
+
+        if (isset($options['s_maxage'])) {
+            $this->setSharedMaxAge($options['s_maxage']);
+        }
+
+        if (isset($options['public'])) {
+            if ($options['public']) {
+                $this->setPublic();
+            } else {
+                $this->setPrivate();
+            }
+        }
+
+        if (isset($options['private'])) {
+            if ($options['private']) {
+                $this->setPrivate();
+            } else {
+                $this->setPublic();
+            }
+        }
+
+        return $this;
+    }
+
+    /**
+     * Modifies the response so that it conforms to the rules defined for a 304 status code.
+     *
+     * This sets the status, removes the body, and discards any headers
+     * that MUST NOT be included in 304 responses.
+     *
+     * @return $this
+     *
+     * @see http://tools.ietf.org/html/rfc2616#section-10.3.5
+     */
+    public function setNotModified()
+    {
+        $this->setStatusCode(304);
+        $this->setContent(null);
+
+        // remove headers that MUST NOT be included with 304 Not Modified responses
+        foreach (array('Allow', 'Content-Encoding', 'Content-Language', 'Content-Length', 'Content-MD5', 'Content-Type', 'Last-Modified') as $header) {
+            $this->headers->remove($header);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Returns true if the response includes a Vary header.
+     *
+     * @return bool true if the response includes a Vary header, false otherwise
+     */
+    public function hasVary()
+    {
+        return null !== $this->headers->get('Vary');
+    }
+
+    /**
+     * Returns an array of header names given in the Vary header.
+     *
+     * @return array An array of Vary names
+     */
+    public function getVary()
+    {
+        if (!$vary = $this->headers->get('Vary', null, false)) {
+            return array();
+        }
+
+        $ret = array();
+        foreach ($vary as $item) {
+            $ret = array_merge($ret, preg_split('/[\s,]+/', $item));
+        }
+
+        return $ret;
+    }
+
+    /**
+     * Sets the Vary header.
+     *
+     * @param string|array $headers
+     * @param bool         $replace Whether to replace the actual value or not (true by default)
+     *
+     * @return $this
+     */
+    public function setVary($headers, $replace = true)
+    {
+        $this->headers->set('Vary', $headers, $replace);
+
+        return $this;
+    }
+
+    /**
+     * Determines if the Response validators (ETag, Last-Modified) match
+     * a conditional value specified in the Request.
+     *
+     * If the Response is not modified, it sets the status code to 304 and
+     * removes the actual content by calling the setNotModified() method.
+     *
+     * @param Request $request A Request instance
+     *
+     * @return bool true if the Response validators match the Request, false otherwise
+     */
+    public function isNotModified(Request $request)
+    {
+        if (!$request->isMethodCacheable()) {
+            return false;
+        }
+
+        $notModified = false;
+        $lastModified = $this->headers->get('Last-Modified');
+        $modifiedSince = $request->headers->get('If-Modified-Since');
+
+        if ($etags = $request->getETags()) {
+            $notModified = in_array($this->getEtag(), $etags) || in_array('*', $etags);
+        }
+
+        if ($modifiedSince && $lastModified) {
+            $notModified = strtotime($modifiedSince) >= strtotime($lastModified) && (!$etags || $notModified);
+        }
+
+        if ($notModified) {
+            $this->setNotModified();
+        }
+
+        return $notModified;
+    }
+
+    /**
+     * Is response invalid?
+     *
+     * @return bool
+     *
+     * @see http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
+     */
+    public function isInvalid()
+    {
+        return $this->statusCode < 100 || $this->statusCode >= 600;
+    }
+
+    /**
+     * Is response informative?
+     *
+     * @return bool
+     */
+    public function isInformational()
+    {
+        return $this->statusCode >= 100 && $this->statusCode < 200;
+    }
+
+    /**
+     * Is response successful?
+     *
+     * @return bool
+     */
+    public function isSuccessful()
+    {
+        return $this->statusCode >= 200 && $this->statusCode < 300;
+    }
+
+    /**
+     * Is the response a redirect?
+     *
+     * @return bool
+     */
+    public function isRedirection()
+    {
+        return $this->statusCode >= 300 && $this->statusCode < 400;
+    }
+
+    /**
+     * Is there a client error?
+     *
+     * @return bool
+     */
+    public function isClientError()
+    {
+        return $this->statusCode >= 400 && $this->statusCode < 500;
+    }
+
+    /**
+     * Was there a server side error?
+     *
+     * @return bool
+     */
+    public function isServerError()
+    {
+        return $this->statusCode >= 500 && $this->statusCode < 600;
+    }
+
+    /**
+     * Is the response OK?
+     *
+     * @return bool
+     */
+    public function isOk()
+    {
+        return 200 === $this->statusCode;
+    }
+
+    /**
+     * Is the response forbidden?
+     *
+     * @return bool
+     */
+    public function isForbidden()
+    {
+        return 403 === $this->statusCode;
+    }
+
+    /**
+     * Is the response a not found error?
+     *
+     * @return bool
+     */
+    public function isNotFound()
+    {
+        return 404 === $this->statusCode;
+    }
+
+    /**
+     * Is the response a redirect of some form?
+     *
+     * @param string $location
+     *
+     * @return bool
+     */
+    public function isRedirect($location = null)
+    {
+        return in_array($this->statusCode, array(201, 301, 302, 303, 307, 308)) && (null === $location ?: $location == $this->headers->get('Location'));
+    }
+
+    /**
+     * Is the response empty?
+     *
+     * @return bool
+     */
+    public function isEmpty()
+    {
+        return in_array($this->statusCode, array(204, 304));
+    }
+
+    /**
+     * Cleans or flushes output buffers up to target level.
+     *
+     * Resulting level can be greater than target level if a non-removable buffer has been encountered.
+     *
+     * @param int  $targetLevel The target output buffering level
+     * @param bool $flush       Whether to flush or clean the buffers
+     */
+    public static function closeOutputBuffers($targetLevel, $flush)
+    {
+        $status = ob_get_status(true);
+        $level = count($status);
+        // PHP_OUTPUT_HANDLER_* are not defined on HHVM 3.3
+        $flags = defined('PHP_OUTPUT_HANDLER_REMOVABLE') ? PHP_OUTPUT_HANDLER_REMOVABLE | ($flush ? PHP_OUTPUT_HANDLER_FLUSHABLE : PHP_OUTPUT_HANDLER_CLEANABLE) : -1;
+
+        while ($level-- > $targetLevel && ($s = $status[$level]) && (!isset($s['del']) ? !isset($s['flags']) || $flags === ($s['flags'] & $flags) : $s['del'])) {
+            if ($flush) {
+                ob_end_flush();
+            } else {
+                ob_end_clean();
+            }
+        }
+    }
+
+    /**
+     * Checks if we need to remove Cache-Control for SSL encrypted downloads when using IE < 9.
+     *
+     * @see http://support.microsoft.com/kb/323308
+     */
+    protected function ensureIEOverSSLCompatibility(Request $request)
+    {
+        if (false !== stripos($this->headers->get('Content-Disposition'), 'attachment') && preg_match('/MSIE (.*?);/i', $request->server->get('HTTP_USER_AGENT'), $match) == 1 && true === $request->isSecure()) {
+            if ((int) preg_replace('/(MSIE )(.*?);/', '$2', $match[0]) < 9) {
+                $this->headers->remove('Cache-Control');
+            }
+        }
+    }
+}