vendor/symfony/http-foundation/Response.php line 905
<?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 symbolsclass_exists(ResponseHeaderBag::class);/*** Response represents an HTTP response.** @author Fabien Potencier <fabien@symfony.com>*/class Response{public const HTTP_CONTINUE = 100;public const HTTP_SWITCHING_PROTOCOLS = 101;public const HTTP_PROCESSING = 102; // RFC2518public const HTTP_EARLY_HINTS = 103; // RFC8297public const HTTP_OK = 200;public const HTTP_CREATED = 201;public const HTTP_ACCEPTED = 202;public const HTTP_NON_AUTHORITATIVE_INFORMATION = 203;public const HTTP_NO_CONTENT = 204;public const HTTP_RESET_CONTENT = 205;public const HTTP_PARTIAL_CONTENT = 206;public const HTTP_MULTI_STATUS = 207; // RFC4918public const HTTP_ALREADY_REPORTED = 208; // RFC5842public const HTTP_IM_USED = 226; // RFC3229public const HTTP_MULTIPLE_CHOICES = 300;public const HTTP_MOVED_PERMANENTLY = 301;public const HTTP_FOUND = 302;public const HTTP_SEE_OTHER = 303;public const HTTP_NOT_MODIFIED = 304;public const HTTP_USE_PROXY = 305;public const HTTP_RESERVED = 306;public const HTTP_TEMPORARY_REDIRECT = 307;public const HTTP_PERMANENTLY_REDIRECT = 308; // RFC7238public const HTTP_BAD_REQUEST = 400;public const HTTP_UNAUTHORIZED = 401;public const HTTP_PAYMENT_REQUIRED = 402;public const HTTP_FORBIDDEN = 403;public const HTTP_NOT_FOUND = 404;public const HTTP_METHOD_NOT_ALLOWED = 405;public const HTTP_NOT_ACCEPTABLE = 406;public const HTTP_PROXY_AUTHENTICATION_REQUIRED = 407;public const HTTP_REQUEST_TIMEOUT = 408;public const HTTP_CONFLICT = 409;public const HTTP_GONE = 410;public const HTTP_LENGTH_REQUIRED = 411;public const HTTP_PRECONDITION_FAILED = 412;public const HTTP_REQUEST_ENTITY_TOO_LARGE = 413;public const HTTP_REQUEST_URI_TOO_LONG = 414;public const HTTP_UNSUPPORTED_MEDIA_TYPE = 415;public const HTTP_REQUESTED_RANGE_NOT_SATISFIABLE = 416;public const HTTP_EXPECTATION_FAILED = 417;public const HTTP_I_AM_A_TEAPOT = 418; // RFC2324public const HTTP_MISDIRECTED_REQUEST = 421; // RFC7540public const HTTP_UNPROCESSABLE_ENTITY = 422; // RFC4918public const HTTP_LOCKED = 423; // RFC4918public const HTTP_FAILED_DEPENDENCY = 424; // RFC4918public const HTTP_TOO_EARLY = 425; // RFC-ietf-httpbis-replay-04public const HTTP_UPGRADE_REQUIRED = 426; // RFC2817public const HTTP_PRECONDITION_REQUIRED = 428; // RFC6585public const HTTP_TOO_MANY_REQUESTS = 429; // RFC6585public const HTTP_REQUEST_HEADER_FIELDS_TOO_LARGE = 431; // RFC6585public const HTTP_UNAVAILABLE_FOR_LEGAL_REASONS = 451; // RFC7725public const HTTP_INTERNAL_SERVER_ERROR = 500;public const HTTP_NOT_IMPLEMENTED = 501;public const HTTP_BAD_GATEWAY = 502;public const HTTP_SERVICE_UNAVAILABLE = 503;public const HTTP_GATEWAY_TIMEOUT = 504;public const HTTP_VERSION_NOT_SUPPORTED = 505;public const HTTP_VARIANT_ALSO_NEGOTIATES_EXPERIMENTAL = 506; // RFC2295public const HTTP_INSUFFICIENT_STORAGE = 507; // RFC4918public const HTTP_LOOP_DETECTED = 508; // RFC5842public const HTTP_NOT_EXTENDED = 510; // RFC2774public 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,'stale_if_error' => true, // RFC5861'stale_while_revalidate' => true, // RFC5861'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 2021-10-01).** Unless otherwise noted, the status code is defined in RFC2616.** @var array*/public static $statusTexts = [100 => 'Continue',101 => 'Switching Protocols',102 => 'Processing', // RFC2518103 => 'Early Hints',200 => 'OK',201 => 'Created',202 => 'Accepted',203 => 'Non-Authoritative Information',204 => 'No Content',205 => 'Reset Content',206 => 'Partial Content',207 => 'Multi-Status', // RFC4918208 => 'Already Reported', // RFC5842226 => 'IM Used', // RFC3229300 => 'Multiple Choices',301 => 'Moved Permanently',302 => 'Found',303 => 'See Other',304 => 'Not Modified',305 => 'Use Proxy',307 => 'Temporary Redirect',308 => 'Permanent Redirect', // RFC7238400 => '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 => 'Content Too Large', // RFC-ietf-httpbis-semantics414 => 'URI Too Long',415 => 'Unsupported Media Type',416 => 'Range Not Satisfiable',417 => 'Expectation Failed',418 => 'I\'m a teapot', // RFC2324421 => 'Misdirected Request', // RFC7540422 => 'Unprocessable Content', // RFC-ietf-httpbis-semantics423 => 'Locked', // RFC4918424 => 'Failed Dependency', // RFC4918425 => 'Too Early', // RFC-ietf-httpbis-replay-04426 => 'Upgrade Required', // RFC2817428 => 'Precondition Required', // RFC6585429 => 'Too Many Requests', // RFC6585431 => 'Request Header Fields Too Large', // RFC6585451 => 'Unavailable For Legal Reasons', // RFC7725500 => 'Internal Server Error',501 => 'Not Implemented',502 => 'Bad Gateway',503 => 'Service Unavailable',504 => 'Gateway Timeout',505 => 'HTTP Version Not Supported',506 => 'Variant Also Negotiates', // RFC2295507 => 'Insufficient Storage', // RFC4918508 => 'Loop Detected', // RFC5842510 => 'Not Extended', // RFC2774511 => 'Network Authentication Required', // RFC6585];/*** @param int $status The HTTP status code (200 "OK" by default)** @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');}/*** 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.** @see prepare()*/public function __toString(): string{returnsprintf('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 $request): static{$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_mimetypeini_set('default_mimetype', '');} else {// Content-type based on the Requestif (!$headers->has('Content-Type')) {$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-Lengthif ($headers->has('Transfer-Encoding')) {$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 protocolif ('HTTP/1.0' != $request->server->get('SERVER_PROTOCOL')) {$this->setProtocolVersion('1.1');}// Check if we need to send extra expire info headersif ('1.0' == $this->getProtocolVersion() && str_contains($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(): static{// headers have already been sent by the developerif (headers_sent()) {return $this;}// headersforeach ($this->headers->allPreserveCaseWithoutCookies() as $name => $values) {$replace = 0 === strcasecmp($name, 'Content-Type');foreach ($values as $value) {header($name.': '.$value, $replace, $this->statusCode);}}// cookiesforeach ($this->headers->getCookies() as $cookie) {header('Set-Cookie: '.$cookie, false, $this->statusCode);}// statusheader(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(): static{echo $this->content;return $this;}/*** Sends HTTP headers and content.** @return $this*/public function send(): static{$this->sendHeaders();$this->sendContent();if (\function_exists('fastcgi_finish_request')) {fastcgi_finish_request();} elseif (\function_exists('litespeed_finish_request')) {litespeed_finish_request();} elseif (!\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true)) {static::closeOutputBuffers(0, true);flush();}return $this;}/*** Sets the response content.** @return $this*/public function setContent(?string $content): static{$this->content = $content ?? '';return $this;}/*** Gets the current response content.*/public function getContent(): string|false{return $this->content;}/*** Sets the HTTP protocol version (1.0 or 1.1).** @return $this** @final*/public function setProtocolVersion(string $version): static{$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, string $text = null): static{$this->statusCode = $code;if ($this->isInvalid()) {throw new \InvalidArgumentException(sprintf('The HTTP status code "%s" is not valid.', $code));}if (null === $text) {$this->statusText = 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 $charset): static{$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 $this** @final*/public function setPrivate(): static{$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 $this** @final*/public function setPublic(): static{$this->headers->addCacheControlDirective('public');$this->headers->removeCacheControlDirective('private');return $this;}/*** Marks the response as "immutable".** @return $this** @final*/public function setImmutable(bool $immutable = true): static{if ($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 $date): static{if ($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 $this*/public function expire(): static{if ($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) {// according to RFC 2616 invalid date formats (e.g. "0" and "-1") must be treated as in the pastreturn \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): static{if (1 > \func_num_args()) {trigger_deprecation('symfony/http-foundation', '6.2', 'Calling "%s()" without any arguments is deprecated, pass null explicitly instead.', __METHOD__);}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 !== $expires = $this->getExpires()) {$maxAge = (int) $expires->format('U') - (int) $this->getDate()->format('U');return max($maxAge, 0);}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 $value): static{$this->headers->addCacheControlDirective('max-age', $value);return $this;}/*** Sets the number of seconds after which the response should no longer be returned by shared caches when backend is down.** This method sets the Cache-Control stale-if-error directive.** @return $this** @final*/public function setStaleIfError(int $value): static{$this->headers->addCacheControlDirective('stale-if-error', $value);return $this;}/*** Sets the number of seconds after which the response should no longer return stale content by shared caches.** This method sets the Cache-Control stale-while-revalidate directive.** @return $this** @final*/public function setStaleWhileRevalidate(int $value): static{$this->headers->addCacheControlDirective('stale-while-revalidate', $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 $value): static{$this->setPublic();$this->headers->addCacheControlDirective('s-maxage', $value);return $this;}/*** Returns the response's time-to-live in seconds.** It returns null when no freshness information is present in the response.** When the response's TTL is 0, the response may not be served from cache without first* revalidating with the origin.** @final*/public function getTtl(): ?int{$maxAge = $this->getMaxAge();return null !== $maxAge ? max($maxAge - $this->getAge(), 0) : 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 $seconds): static{$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 $seconds): static{$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): static{if (1 > \func_num_args()) {trigger_deprecation('symfony/http-foundation', '6.2', 'Calling "%s()" without any arguments is deprecated, pass null explicitly instead.', __METHOD__);}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): static{if (1 > \func_num_args()) {trigger_deprecation('symfony/http-foundation', '6.2', 'Calling "%s()" without any arguments is deprecated, pass null explicitly instead.', __METHOD__);}if (null === $etag) {$this->headers->remove('Etag');} else {if (!str_starts_with($etag, '"')) {$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 $options): static{if ($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($options['s_maxage']);}if (isset($options['stale_while_revalidate'])) {$this->setStaleWhileRevalidate($options['stale_while_revalidate']);}if (isset($options['stale_if_error'])) {$this->setStaleIfError($options['stale_if_error']);}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.** This sets the status, removes the body, and discards any headers* that MUST NOT be included in 304 responses.** @return $this** @see https://tools.ietf.org/html/rfc2616#section-10.3.5** @final*/public function setNotModified(): static{$this->setStatusCode(304);$this->setContent(null);// remove headers that MUST NOT be included with 304 Not Modified responsesforeach (['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.** @final*/public function hasVary(): bool{return null !== $this->headers->get('Vary');}/*** Returns an array of header names given in the Vary header.** @final*/public function getVary(): array{if (!$vary = $this->headers->all('Vary')) {return [];}$ret = [];foreach ($vary as $item) {$ret[] = preg_split('/[\s,]+/', $item);}return array_merge([], ...$ret);}/*** Sets the Vary header.** @param bool $replace Whether to replace the actual value or not (true by default)** @return $this** @final*/public function setVary(string|array $headers, bool $replace = true): static{$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.** @final*/public function isNotModified(Request $request): bool{if (!$request->isMethodCacheable()) {return false;}$notModified = false;$lastModified = $this->headers->get('Last-Modified');$modifiedSince = $request->headers->get('If-Modified-Since');if (($ifNoneMatchEtags = $request->getETags()) && (null !== $etag = $this->getEtag())) {if (0 == strncmp($etag, 'W/', 2)) {$etag = substr($etag, 2);}// Use weak comparison as per https://tools.ietf.org/html/rfc7232#section-3.2.foreach ($ifNoneMatchEtags as $ifNoneMatchEtag) {if (0 == strncmp($ifNoneMatchEtag, 'W/', 2)) {$ifNoneMatchEtag = substr($ifNoneMatchEtag, 2);}if ($ifNoneMatchEtag === $etag || '*' === $ifNoneMatchEtag) {$notModified = true;break;}}}// Only do If-Modified-Since date comparison when If-None-Match is not present as per https://tools.ietf.org/html/rfc7232#section-3.3.elseif ($modifiedSince && $lastModified) {$notModified = strtotime($modifiedSince) >= strtotime($lastModified);}if ($notModified) {$this->setNotModified();}return $notModified;}/*** Is response invalid?** @see https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html** @final*/public function isInvalid(): bool{return $this->statusCode < 100 || $this->statusCode >= 600;}/*** Is response informative?** @final*/public function isInformational(): bool{return $this->statusCode >= 100 && $this->statusCode < 200;}/*** Is response successful?** @final*/public function isSuccessful(): bool{return $this->statusCode >= 200 && $this->statusCode < 300;}/*** Is the response a redirect?** @final*/public function isRedirection(): bool{return $this->statusCode >= 300 && $this->statusCode < 400;}/*** Is there a client error?** @final*/public function isClientError(): bool{return $this->statusCode >= 400 && $this->statusCode < 500;}/*** Was there a server side error?** @final*/public function isServerError(): bool{return $this->statusCode >= 500 && $this->statusCode < 600;}/*** Is the response OK?** @final*/public function isOk(): bool{return 200 === $this->statusCode;}/*** Is the response forbidden?** @final*/public function isForbidden(): bool{return 403 === $this->statusCode;}/*** Is the response a not found error?** @final*/public function isNotFound(): bool{return 404 === $this->statusCode;}/*** Is the response a redirect of some form?** @final*/public function isRedirect(string $location = null): bool{return \in_array($this->statusCode, [201, 301, 302, 303, 307, 308]) && (null === $location ?: $location == $this->headers->get('Location'));}/*** Is the response empty?** @final*/public function isEmpty(): bool{return \in_array($this->statusCode, [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.** @final*/public static function closeOutputBuffers(int $targetLevel, bool $flush): void{$status = ob_get_status(true);$level = \count($status);$flags = \PHP_OUTPUT_HANDLER_REMOVABLE | ($flush ? \PHP_OUTPUT_HANDLER_FLUSHABLE : \PHP_OUTPUT_HANDLER_CLEANABLE);while ($level-- > $targetLevel && ($s = $status[$level]) && (!isset($s['del']) ? !isset($s['flags']) || ($s['flags'] & $flags) === $flags : $s['del'])) {if ($flush) {ob_end_flush();} else {ob_end_clean();}}}/*** Marks a response as safe according to RFC8674.** @see https://tools.ietf.org/html/rfc8674*/public function setContentSafe(bool $safe = true): void{if ($safe) {$this->headers->set('Preference-Applied', 'safe');} elseif ('safe' === $this->headers->get('Preference-Applied')) {$this->headers->remove('Preference-Applied');}$this->setVary('Prefer', false);}/*** Checks if we need to remove Cache-Control for SSL encrypted downloads when using IE < 9.** @see http://support.microsoft.com/kb/323308** @final*/protected function ensureIEOverSSLCompatibility(Request $request): void{if (false !== stripos($this->headers->get('Content-Disposition') ?? '', 'attachment') && 1 == preg_match('/MSIE (.*?);/i', $request->server->get('HTTP_USER_AGENT') ?? '', $match) && true === $request->isSecure()) {if ((int) preg_replace('/(MSIE )(.*?);/', '$2', $match[0]) < 9) {$this->headers->remove('Cache-Control');}}}}