Subversion Repositories php-qbpwcf

<?php

/*

 * This file is part of the Symfony package.

 *

 * (c) Fabien Potencier <fabien@symfony.com>

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

namespace Symfony\Component\HttpFoundation;

// Help opcache.preload discover always-needed symbols

class_exists(ResponseHeaderBag::class);

/**

 * Response represents an HTTP response.

 *

 * @author Fabien Potencier <fabien@symfony.com>

 */

class Response

{

    const HTTP_CONTINUE = 100;

    const HTTP_SWITCHING_PROTOCOLS = 101;

    const HTTP_PROCESSING = 102;            // RFC2518

    const HTTP_EARLY_HINTS = 103;           // RFC8297

    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_TOO_EARLY = 425;                                                   // RFC-ietf-httpbis-replay-04

    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

    /**

     * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control

     */

    private const HTTP_RESPONSE_CACHE_CONTROL_DIRECTIVES = [

        'must_revalidate' => false,

        'no_cache' => false,

        'no_store' => false,

        'no_transform' => false,

        'public' => false,

        'private' => false,

        'proxy_revalidate' => false,

        'max_age' => true,

        's_maxage' => true,

        'immutable' => false,

        'last_modified' => true,

        'etag' => true,

    ];

    /**

     * @var 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 https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml 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 = [

        100 => 'Continue',

        101 => 'Switching Protocols',

        102 => 'Processing',            // RFC2518

        103 => 'Early Hints',

        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 => 'Too Early',                                                   // RFC-ietf-httpbis-replay-04

        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

    ];

    /**

     * @throws \InvalidArgumentException When the HTTP status code is not valid

     */

    public function __construct(?string $content = '', int $status = 200, array $headers = [])

    {

        $this->headers = new ResponseHeaderBag($headers);

        $this->setContent($content);

        $this->setStatusCode($status);

        $this->setProtocolVersion('1.0');

    }

    /**

     * Factory method for chainability.

     *

     * Example:

     *

     *     return Response::create($body, 200)

     *         ->setSharedMaxAge(300);

     *

     * @return static

     *

     * @deprecated since Symfony 5.1, use __construct() instead.

     */

    public static function create(?string $content = '', int $status = 200, array $headers = [])

    {

        trigger_deprecation('symfony/http-foundation', '5.1', 'The "%s()" method is deprecated, use "new %s()" instead.', __METHOD__, \get_called_class());

        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.

     *

     * @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');

            // prevent PHP from sending the Content-Type header based on default_mimetype

            ini_set('default_mimetype', '');

        } else {

            // Content-type based on the Request

            if (!$headers->has('Content-Type')) {

                $format = $request->getRequestFormat(null);

                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' == $this->getProtocolVersion() && false !== strpos($headers->get('Cache-Control'), 'no-cache')) {

            $headers->set('pragma', 'no-cache');

            $headers->set('expires', -1);

        }

        $this->ensureIEOverSSLCompatibility($request);

        if ($request->isSecure()) {

            foreach ($headers->getCookies() as $cookie) {

                $cookie->setSecureDefault(true);

            }

        }

        return $this;

    }

    /**

     * Sends HTTP headers.

     *

     * @return $this

     */

    public function sendHeaders()

    {

        // headers have already been sent by the developer

        if (headers_sent()) {

            return $this;

        }

        // headers

        foreach ($this->headers->allPreserveCaseWithoutCookies() as $name => $values) {

            $replace = 0 === strcasecmp($name, 'Content-Type');

            foreach ($values as $value) {

                header($name.': '.$value, $replace, $this->statusCode);

            }

        }

        // cookies

        foreach ($this->headers->getCookies() as $cookie) {

            header('Set-Cookie: '.$cookie, false, $this->statusCode);

        }

        // status

        header(sprintf('HTTP/%s %s %s', $this->version, $this->statusCode, $this->statusText), true, $this->statusCode);

        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 (!\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true)) {

            static::closeOutputBuffers(0, true);

        }

        return $this;

    }

    /**

     * Sets the response content.

     *

     * @return $this

     *

     * @throws \UnexpectedValueException

     */

    public function setContent(?string $content)

    {

        $this->content = $content ?? '';

        return $this;

    }

    /**

     * Gets the current response content.

     *

     * @return string|false

     */

    public function getContent()

    {

        return $this->content;

    }

    /**

     * Sets the HTTP protocol version (1.0 or 1.1).

     *

     * @return $this

     *

     * @final

     */

    public function setProtocolVersion(string $version): object

    {

        $this->version = $version;

        return $this;

    }

    /**

     * Gets the HTTP protocol version.

     *

     * @final

     */

    public function getProtocolVersion(): string

    {

        return $this->version;

    }

    /**

     * Sets the response status code.

     *

     * 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

     *

     * @final

     */

    public function setStatusCode(int $code, $text = null): object

    {

        $this->statusCode = $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.

     *

     * @final

     */

    public function getStatusCode(): int

    {

        return $this->statusCode;

    }

    /**

     * Sets the response charset.

     *

     * @return $this

     *

     * @final

     */

    public function setCharset(string $charset): object

    {

        $this->charset = $charset;

        return $this;

    }

    /**

     * Retrieves the response charset.

     *

     * @final

     */

    public function getCharset(): ?string

    {

        return $this->charset;

    }

    /**

     * Returns true if the response may safely be kept in a shared (surrogate) cache.

     *

     * 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 because there is

     * no way to tell when or how to remove them from the cache.

     *

     * Note that RFC 7231 and RFC 7234 possibly allow for a more permissive implementation,

     * for example "status codes that are defined as cacheable by default [...]

     * can be reused by a cache with heuristic expiration unless otherwise indicated"

     * (https://tools.ietf.org/html/rfc7231#section-6.1)

     *

     * @final

     */

    public function isCacheable(): bool

    {

        if (!\in_array($this->statusCode, [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.

     *

     * @final

     */

    public function isFresh(): bool

    {

        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.

     *

     * @final

     */

    public function isValidateable(): bool

    {

        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

     *

     * @final

     */

    public function setPrivate(): object

    {

        $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

     *

     * @final

     */

    public function setPublic(): object

    {

        $this->headers->addCacheControlDirective('public');

        $this->headers->removeCacheControlDirective('private');

        return $this;

    }

    /**

     * Marks the response as "immutable".

     *

     * @return $this

     *

     * @final

     */

    public function setImmutable(bool $immutable = true): object

    {

        if ($immutable) {

            $this->headers->addCacheControlDirective('immutable');

        } else {

            $this->headers->removeCacheControlDirective('immutable');

        }

        return $this;

    }

    /**

     * Returns true if the response is marked as "immutable".

     *

     * @final

     */

    public function isImmutable(): bool

    {

        return $this->headers->hasCacheControlDirective('immutable');

    }

    /**

     * Returns true if the response must be revalidated by shared caches once it has become stale.

     *

     * 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.

     *

     * @final

     */

    public function mustRevalidate(): bool

    {

        return $this->headers->hasCacheControlDirective('must-revalidate') || $this->headers->hasCacheControlDirective('proxy-revalidate');

    }

    /**

     * Returns the Date header as a DateTime instance.

     *

     * @throws \RuntimeException When the header is not parseable

     *

     * @final

     */

    public function getDate(): ?\DateTimeInterface

    {

        return $this->headers->getDate('Date');

    }

    /**

     * Sets the Date header.

     *

     * @return $this

     *

     * @final

     */

    public function setDate(\DateTimeInterface $date): object

    {

        if ($date instanceof \DateTime) {

            $date = \DateTimeImmutable::createFromMutable($date);

        }

        $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 in seconds.

     *

     * @final

     */

    public function getAge(): int

    {

        if (null !== $age = $this->headers->get('Age')) {

            return (int) $age;

        }

        return max(time() - (int) $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());

            $this->headers->remove('Expires');

        }

        return $this;

    }

    /**

     * Returns the value of the Expires header as a DateTime instance.

     *

     * @final

     */

    public function getExpires(): ?\DateTimeInterface

    {

        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('U', time() - 172800);

        }

    }

    /**

     * Sets the Expires HTTP header with a DateTime instance.

     *

     * Passing null as value will remove the header.

     *

     * @return $this

     *

     * @final

     */

    public function setExpires(\DateTimeInterface $date = null): object

    {

        if (null === $date) {

            $this->headers->remove('Expires');

            return $this;

        }

        if ($date instanceof \DateTime) {

            $date = \DateTimeImmutable::createFromMutable($date);

        }

        $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.

     *

     * @final

     */

    public function getMaxAge(): ?int

    {

        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 (int) $this->getExpires()->format('U') - (int) $this->getDate()->format('U');

        }

        return null;

    }

    /**

     * Sets the number of seconds after which the response should no longer be considered fresh.

     *

     * This methods sets the Cache-Control max-age directive.

     *

     * @return $this

     *

     * @final

     */

    public function setMaxAge(int $value): object

    {

        $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.

     *

     * @return $this

     *

     * @final

     */

    public function setSharedMaxAge(int $value): object

    {

        $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.

     *

     * @final

     */

    public function getTtl(): ?int

    {

        $maxAge = $this->getMaxAge();

        return null !== $maxAge ? $maxAge - $this->getAge() : null;

    }

    /**

     * Sets the response's time-to-live for shared caches in seconds.

     *

     * This method adjusts the Cache-Control/s-maxage directive.

     *

     * @return $this

     *

     * @final

     */

    public function setTtl(int $seconds): object

    {

        $this->setSharedMaxAge($this->getAge() + $seconds);

        return $this;

    }

    /**

     * Sets the response's time-to-live for private/client caches in seconds.

     *

     * This method adjusts the Cache-Control/max-age directive.

     *

     * @return $this

     *

     * @final

     */

    public function setClientTtl(int $seconds): object

    {

        $this->setMaxAge($this->getAge() + $seconds);

        return $this;

    }

    /**

     * Returns the Last-Modified HTTP header as a DateTime instance.

     *

     * @throws \RuntimeException When the HTTP header is not parseable

     *

     * @final

     */

    public function getLastModified(): ?\DateTimeInterface

    {

        return $this->headers->getDate('Last-Modified');

    }

    /**

     * Sets the Last-Modified HTTP header with a DateTime instance.

     *

     * Passing null as value will remove the header.

     *

     * @return $this

     *

     * @final

     */

    public function setLastModified(\DateTimeInterface $date = null): object

    {

        if (null === $date) {

            $this->headers->remove('Last-Modified');

            return $this;

        }

        if ($date instanceof \DateTime) {

            $date = \DateTimeImmutable::createFromMutable($date);

        }

        $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.

     *

     * @final

     */

    public function getEtag(): ?string

    {

        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

     *

     * @final

     */

    public function setEtag(string $etag = null, bool $weak = false): object

    {

        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: must_revalidate, no_cache, no_store, no_transform, public, private, proxy_revalidate, max_age, s_maxage, immutable, last_modified and etag.

     *

     * @return $this

     *

     * @throws \InvalidArgumentException

     *

     * @final

     */

    public function setCache(array $options): object

    {

        if ($diff = array_diff(array_keys($options), array_keys(self::HTTP_RESPONSE_CACHE_CONTROL_DIRECTIVES))) {

            throw new \InvalidArgumentException(sprintf('Response does not support the following options: "%s".', implode('", "', $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']);

        }

        foreach (self::HTTP_RESPONSE_CACHE_CONTROL_DIRECTIVES as $directive => $hasValue) {

            if (!$hasValue && isset($options[$directive])) {

                if ($options[$directive]) {

                    $this->headers->addCacheControlDirective(str_replace('_', '-', $directive));

                } else {

                    $this->headers->removeCacheControlDirective(str_replace('_', '-', $directive));

                }

            }

        }

        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.