public static function createCheckoutRequest(Credentials $credentials, PaymentRequest $paymentRequest)
 {
     LogPagSeguro::info("PaymentService.Register(" . $paymentRequest->toString() . ") - begin");
     $connectionData = new PagSeguroConnectionData($credentials, self::serviceName);
     try {
         $connection = new HttpConnection();
         $connection->post(self::buildCheckoutRequestUrl($connectionData), PaymentParser::getData($paymentRequest), $connectionData->getServiceTimeout(), $connectionData->getCharset());
         $httpStatus = new HttpStatus($connection->getStatus());
         switch ($httpStatus->getType()) {
             case 'OK':
                 $PaymentParserData = PaymentParser::readSuccessXml($connection->getResponse());
                 $paymentUrl = self::buildCheckoutUrl($connectionData, $PaymentParserData->getCode());
                 LogPagSeguro::info("PaymentService.Register(" . $paymentRequest->toString() . ") - end {1}" . $PaymentParserData->getCode());
                 break;
             case 'BAD_REQUEST':
                 $errors = PaymentParser::readErrors($connection->getResponse());
                 $e = new PagSeguroServiceException($httpStatus, $errors);
                 LogPagSeguro::error("PaymentService.Register(" . $paymentRequest->toString() . ") - error " . $e->getOneLineMessage());
                 throw $e;
                 break;
             default:
                 $e = new PagSeguroServiceException($httpStatus);
                 LogPagSeguro::error("PaymentService.Register(" . $paymentRequest->toString() . ") - error " . $e->getOneLineMessage());
                 throw $e;
                 break;
         }
         return isset($paymentUrl) ? $paymentUrl : false;
     } catch (PagSeguroServiceException $e) {
         throw $e;
     } catch (Exception $e) {
         LogPagSeguro::error("Exception: " . $e->getMessage());
         throw $e;
     }
 }

 /**
  * Returns a transaction from a notification code
  * 
  * @param Credentials $credentials
  * @param String $notificationCode
  * @throws PagSeguroServiceException
  * @throws Exception
  * @return a transaction
  * @see Transaction
  */
 public static function checkTransaction(Credentials $credentials, $notificationCode)
 {
     LogPagSeguro::info("NotificationService.CheckTransaction(notificationCode={$notificationCode}) - begin");
     $connectionData = new PagSeguroConnectionData($credentials, self::serviceName);
     try {
         $connection = new HttpConnection();
         $connection->get(self::buildTransactionNotificationUrl($connectionData, $notificationCode), $connectionData->getServiceTimeout(), $connectionData->getCharset());
         $httpStatus = new HttpStatus($connection->getStatus());
         switch ($httpStatus->getType()) {
             case 'OK':
                 // parses the transaction
                 $transaction = TransactionParser::readTransaction($connection->getResponse());
                 LogPagSeguro::info("NotificationService.CheckTransaction(notificationCode={$notificationCode}) - end " . $transaction->toString() . ")");
                 break;
             case 'BAD_REQUEST':
                 $errors = TransactionParser::readErrors($connection->getResponse());
                 $e = new PagSeguroServiceException($httpStatus, $errors);
                 LogPagSeguro::info("NotificationService.CheckTransaction(notificationCode={$notificationCode}) - error " . $e->getOneLineMessage());
                 throw $e;
                 break;
             default:
                 $e = new PagSeguroServiceException($httpStatus);
                 LogPagSeguro::info("NotificationService.CheckTransaction(notificationCode={$notificationCode}) - error " . $e->getOneLineMessage());
                 throw $e;
                 break;
         }
         return isset($transaction) ? $transaction : null;
     } catch (PagSeguroServiceException $e) {
         throw $e;
     } catch (Exception $e) {
         LogPagSeguro::error("Exception: " . $e->getMessage());
         throw $e;
     }
 }

/**
 * Displays an error message if the page has been blacklisted and the action implies parsing and rendering.
 */
function efSlowPagesBlacklist($oTitle, $unused, $oOutputPage, $oUser, $oWebRequest, $oMediaWiki)
{
    global $wgSlowPagesBlacklist;
    $sFullUrl = $oTitle->getFullURL();
    if (in_array($sFullUrl, $wgSlowPagesBlacklist)) {
        switch ($oMediaWiki->getAction()) {
            case 'delete':
            case 'history':
            case 'raw':
            case 'rollback':
            case 'submit':
                // Let through.
                break;
            case 'edit':
                // Force text editor since the visual editor implies parsing.
                if ('source' != $oWebRequest->getVal('useeditor', '')) {
                    $oResponse = $oWebRequest->response();
                    $iCode = 303;
                    $sMessage = HttpStatus::getMessage($iCode);
                    $oResponse->header("HTTP/1.1 {$iCode} {$sMessage}");
                    $oResponse->header("Location: {$sFullUrl}?action=edit&useeditor=source");
                }
                break;
            default:
                // If a staff user requested forceview, let through.
                if (!$oUser->isAllowed('forceview') || !$oWebRequest->getInt('forceview')) {
                    throw new ErrorPageError('slowpagesblacklist-title', 'slowpagesblacklist-content');
                }
                break;
        }
    }
    return true;
}

 /**
  * Borrowed from \Wikibase\Test\SpecialPageTestBase
  *
  * @param string      $sub The subpage parameter to call the page with
  * @param WebRequest $request Web request that may contain URL parameters, etc
  */
 protected function execute($sub = '', WebRequest $request = null, $user = null)
 {
     $request = $request === null ? new FauxRequest() : $request;
     $response = $request->response();
     $page = $this->getInstance();
     if ($this->store !== null) {
         $page->setStore($this->store);
     }
     $page->setContext($this->makeRequestContext($request, $user, $this->getTitle($page)));
     $out = $page->getOutput();
     ob_start();
     $page->execute($sub);
     if ($out->getRedirect() !== '') {
         $out->output();
         $text = ob_get_contents();
     } elseif ($out->isDisabled()) {
         $text = ob_get_contents();
     } else {
         $text = $out->getHTML();
     }
     ob_end_clean();
     $code = $response->getStatusCode();
     if ($code > 0) {
         $response->header("Status: " . $code . ' ' . \HttpStatus::getMessage($code));
     }
     $this->text = $text;
     $this->response = $response;
 }

 public function ServiceException($code, $message = NULL)
 {
     if ($message === NULL) {
         $message = HttpStatus::getMessage($code);
     }
     parent::__construct($message, $code);
 }

 public function execute($par = '')
 {
     $this->getOutput()->disable();
     if (wfReadOnly()) {
         // HTTP 423 Locked
         HttpStatus::header(423);
         print 'Wiki is in read-only mode';
         return;
     } elseif (!$this->getRequest()->wasPosted()) {
         HttpStatus::header(400);
         print 'Request must be POSTed';
         return;
     }
     $optional = array('maxjobs' => 0, 'maxtime' => 30, 'type' => false, 'async' => true);
     $required = array_flip(array('title', 'tasks', 'signature', 'sigexpiry'));
     $params = array_intersect_key($this->getRequest()->getValues(), $required + $optional);
     $missing = array_diff_key($required, $params);
     if (count($missing)) {
         HttpStatus::header(400);
         print 'Missing parameters: ' . implode(', ', array_keys($missing));
         return;
     }
     $squery = $params;
     unset($squery['signature']);
     $correctSignature = self::getQuerySignature($squery, $this->getConfig()->get('SecretKey'));
     $providedSignature = $params['signature'];
     $verified = is_string($providedSignature) && hash_equals($correctSignature, $providedSignature);
     if (!$verified || $params['sigexpiry'] < time()) {
         HttpStatus::header(400);
         print 'Invalid or stale signature provided';
         return;
     }
     // Apply any default parameter values
     $params += $optional;
     if ($params['async']) {
         // Client will usually disconnect before checking the response,
         // but it needs to know when it is safe to disconnect. Until this
         // reaches ignore_user_abort(), it is not safe as the jobs won't run.
         ignore_user_abort(true);
         // jobs may take a bit of time
         // HTTP 202 Accepted
         HttpStatus::header(202);
         ob_flush();
         flush();
         // Once the client receives this response, it can disconnect
     }
     // Do all of the specified tasks...
     if (in_array('jobs', explode('|', $params['tasks']))) {
         $runner = new JobRunner(LoggerFactory::getInstance('runJobs'));
         $response = $runner->run(array('type' => $params['type'], 'maxJobs' => $params['maxjobs'] ? $params['maxjobs'] : 1, 'maxTime' => $params['maxtime'] ? $params['maxjobs'] : 30));
         if (!$params['async']) {
             print FormatJson::encode($response, true);
         }
     }
 }

 public function sendError()
 {
     $message = $this->getMessage();
     $code = $this->getStatusCode();
     header("HTTP/1.0 " . HttpStatus::getMessage($code));
     foreach ($this->getAdditionalHeaders() as $k => $v) {
         header($k . ': ' . $v, false);
     }
     echo '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">';
     echo '<html>';
     echo '<head><title>Error</title></head>';
     echo '<body><p>Error ' . httpStatus::getMessage($code) . '</p>';
     echo '<p>' . $this->getMessage() . '</p></body>';
     echo '</html>';
 }

 /**
  * Returns HTML for reporting the HTTP error.
  * This will be a minimal but complete HTML document.
  *
  * @return string HTML
  */
 public function getHTML()
 {
     if ($this->header === null) {
         $header = HttpStatus::getMessage($this->httpCode);
     } elseif ($this->header instanceof Message) {
         $header = $this->header->escaped();
     } else {
         $header = htmlspecialchars($this->header);
     }
     if ($this->content instanceof Message) {
         $content = $this->content->escaped();
     } else {
         $content = htmlspecialchars($this->content);
     }
     return "<!DOCTYPE html>\n" . "<html><head><title>{$header}</title></head>\n" . "<body><h1>{$header}</h1><p>{$content}</p></body></html>\n";
 }

 /**
  * @param SpecialPage $page The special page to execute
  * @param string $subPage The subpage parameter to call the page with
  * @param WebRequest|null $request Web request that may contain URL parameters, etc
  * @param Language|string|null $language The language which should be used in the context
  * @param User|null $user The user which should be used in the context of this special page
  *
  * @throws Exception
  * @return array( string, WebResponse ) A two-elements array containing the HTML output
  * generated by the special page as well as the response object.
  */
 public function executeSpecialPage(SpecialPage $page, $subPage = '', WebRequest $request = null, $language = null, User $user = null)
 {
     $context = $this->newContext($request, $language, $user);
     $output = new OutputPage($context);
     $context->setOutput($output);
     $page->setContext($context);
     $output->setTitle($page->getPageTitle());
     $html = $this->getHTMLFromSpecialPage($page, $subPage);
     $response = $context->getRequest()->response();
     if ($response instanceof FauxResponse) {
         $code = $response->getStatusCode();
         if ($code > 0) {
             $response->header('Status: ' . $code . ' ' . HttpStatus::getMessage($code));
         }
     }
     return [$html, $response];
 }

 private function getTextForRequestBy($page, $request, $queryParameters)
 {
     $response = $request->response();
     $page->setContext($this->makeRequestContext($request, new MockSuperUser(), $this->getTitle($page)));
     $out = $page->getOutput();
     ob_start();
     $page->execute($queryParameters);
     if ($out->getRedirect() !== '') {
         $out->output();
         $text = ob_get_contents();
     } elseif ($out->isDisabled()) {
         $text = ob_get_contents();
     } else {
         $text = $out->getHTML();
     }
     ob_end_clean();
     $code = $response->getStatusCode();
     if ($code > 0) {
         $response->header("Status: " . $code . ' ' . \HttpStatus::getMessage($code));
     }
     return $text;
 }

/**
 * Output a thumbnail generation error message
 *
 * @param int $status
 * @param string $msgHtml HTML
 * @return void
 */
function wfThumbError($status, $msgHtml)
{
    global $wgShowHostnames;
    header('Cache-Control: no-cache');
    header('Content-Type: text/html; charset=utf-8');
    if ($status == 400 || $status == 404 || $status == 429) {
        HttpStatus::header($status);
    } elseif ($status == 403) {
        HttpStatus::header(403);
        header('Vary: Cookie');
    } else {
        HttpStatus::header(500);
    }
    if ($wgShowHostnames) {
        header('X-MW-Thumbnail-Renderer: ' . wfHostname());
        $url = htmlspecialchars(isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : '');
        $hostname = htmlspecialchars(wfHostname());
        $debug = "<!-- {$url} -->\n<!-- {$hostname} -->\n";
    } else {
        $debug = '';
    }
    $content = <<<EOT
<!DOCTYPE html>
<html><head>
<meta charset="UTF-8" />
<title>Error generating thumbnail</title>
</head>
<body>
<h1>Error generating thumbnail</h1>
<p>
{$msgHtml}
</p>
{$debug}
</body>
</html>

EOT;
    header('Content-Length: ' . strlen($content));
    echo $content;
}

//.........这里部分代码省略.........
        return;
    }
    // Check IMS against the source file
    // This means that clients can keep a cached copy even after it has been deleted on the server
    if (!empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
        // Fix IE brokenness
        $imsString = preg_replace('/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"]);
        // Calculate time
        wfSuppressWarnings();
        $imsUnix = strtotime($imsString);
        wfRestoreWarnings();
        if (wfTimestamp(TS_UNIX, $img->getTimestamp()) <= $imsUnix) {
            header('HTTP/1.1 304 Not Modified');
            wfProfileOut(__METHOD__);
            return;
        }
    }
    // Get the normalized thumbnail name from the parameters...
    try {
        $thumbName = $img->thumbName($params);
        if (!strlen($thumbName)) {
            // invalid params?
            wfThumbError(400, 'The specified thumbnail parameters are not valid.');
            wfProfileOut(__METHOD__);
            return;
        }
        $thumbName2 = $img->thumbName($params, File::THUMB_FULL_NAME);
        // b/c; "long" style
    } catch (MWException $e) {
        wfThumbError(500, $e->getHTML());
        wfProfileOut(__METHOD__);
        return;
    }
    // For 404 handled thumbnails, we only use the the base name of the URI
    // for the thumb params and the parent directory for the source file name.
    // Check that the zone relative path matches up so squid caches won't pick
    // up thumbs that would not be purged on source file deletion (bug 34231).
    if (isset($params['rel404'])) {
        // thumbnail was handled via 404
        if (rawurldecode($params['rel404']) === $img->getThumbRel($thumbName)) {
            // Request for the canonical thumbnail name
        } elseif (rawurldecode($params['rel404']) === $img->getThumbRel($thumbName2)) {
            // Request for the "long" thumbnail name; redirect to canonical name
            $response = RequestContext::getMain()->getRequest()->response();
            $response->header("HTTP/1.1 301 " . HttpStatus::getMessage(301));
            $response->header('Location: ' . wfExpandUrl($img->getThumbUrl($thumbName), PROTO_CURRENT));
            $response->header('Expires: ' . gmdate('D, d M Y H:i:s', time() + 7 * 86400) . ' GMT');
            if ($wgVaryOnXFP) {
                $varyHeader[] = 'X-Forwarded-Proto';
            }
            if (count($varyHeader)) {
                $response->header('Vary: ' . implode(', ', $varyHeader));
            }
            wfProfileOut(__METHOD__);
            return;
        } else {
            wfThumbError(404, "The given path of the specified thumbnail is incorrect;\n\t\t\t\texpected '" . $img->getThumbRel($thumbName) . "' but got '" . rawurldecode($params['rel404']) . "'.");
            wfProfileOut(__METHOD__);
            return;
        }
    }
    // Suggest a good name for users downloading this thumbnail
    $headers[] = "Content-Disposition: {$img->getThumbDisposition($thumbName)}";
    if (count($varyHeader)) {
        $headers[] = 'Vary: ' . implode(', ', $varyHeader);
    }
    // Stream the file if it exists already...
    $thumbPath = $img->getThumbPath($thumbName);
    if ($img->getRepo()->fileExists($thumbPath)) {
        $img->getRepo()->streamFile($thumbPath, $headers);
        wfProfileOut(__METHOD__);
        return;
    }
    // Thumbnail isn't already there, so create the new thumbnail...
    try {
        $thumb = $img->transform($params, File::RENDER_NOW);
    } catch (Exception $ex) {
        // Tried to select a page on a non-paged file?
        $thumb = false;
    }
    // Check for thumbnail generation errors...
    $errorMsg = false;
    $msg = wfMessage('thumbnail_error');
    if (!$thumb) {
        $errorMsg = $msg->rawParams('File::transform() returned false')->escaped();
    } elseif ($thumb->isError()) {
        $errorMsg = $thumb->getHtmlMsg();
    } elseif (!$thumb->hasFile()) {
        $errorMsg = $msg->rawParams('No path supplied in thumbnail object')->escaped();
    } elseif ($thumb->fileIsSource()) {
        $errorMsg = $msg->rawParams('Image was not scaled, is the requested width bigger than the source?')->escaped();
    }
    if ($errorMsg !== false) {
        wfThumbError(500, $errorMsg);
    } else {
        // Stream the file if there were no errors
        $thumb->streamFile($headers);
    }
    wfProfileOut(__METHOD__);
}

/**
 * Provide a simple HTTP error.
 *
 * @param int|string $code
 * @param string $label
 * @param string $desc
 */
function wfHttpError($code, $label, $desc)
{
    global $wgOut;
    HttpStatus::header($code);
    if ($wgOut) {
        $wgOut->disable();
        $wgOut->sendCacheControl();
    }
    header('Content-type: text/html; charset=utf-8');
    print '<!DOCTYPE html>' . '<html><head><title>' . htmlspecialchars($label) . '</title></head><body><h1>' . htmlspecialchars($label) . '</h1><p>' . nl2br(htmlspecialchars($desc)) . "</p></body></html>\n";
}

 /**
  * Finally, all the text has been munged and accumulated into
  * the object, let's actually output it:
  */
 public function output()
 {
     global $wgLanguageCode, $wgDebugRedirects, $wgMimeType, $wgVaryOnXFP;
     if ($this->mDoNothing) {
         return;
     }
     wfProfileIn(__METHOD__);
     $response = $this->getRequest()->response();
     if ($this->mRedirect != '') {
         # Standards require redirect URLs to be absolute
         $this->mRedirect = wfExpandUrl($this->mRedirect, PROTO_CURRENT);
         $redirect = $this->mRedirect;
         $code = $this->mRedirectCode;
         if (wfRunHooks("BeforePageRedirect", array($this, &$redirect, &$code))) {
             if ($code == '301' || $code == '303') {
                 if (!$wgDebugRedirects) {
                     $message = HttpStatus::getMessage($code);
                     $response->header("HTTP/1.1 {$code} {$message}");
                 }
                 $this->mLastModified = wfTimestamp(TS_RFC2822);
             }
             if ($wgVaryOnXFP) {
                 $this->addVaryHeader('X-Forwarded-Proto');
             }
             $this->sendCacheControl();
             $response->header("Content-Type: text/html; charset=utf-8");
             if ($wgDebugRedirects) {
                 $url = htmlspecialchars($redirect);
                 print "<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
                 print "<p>Location: <a href=\"{$url}\">{$url}</a></p>\n";
                 print "</body>\n</html>\n";
             } else {
                 $response->header('Location: ' . $redirect);
             }
         }
         wfProfileOut(__METHOD__);
         return;
     } elseif ($this->mStatusCode) {
         $message = HttpStatus::getMessage($this->mStatusCode);
         if ($message) {
             $response->header('HTTP/1.1 ' . $this->mStatusCode . ' ' . $message);
         }
     }
     # Buffer output; final headers may depend on later processing
     ob_start();
     $response->header("Content-type: {$wgMimeType}; charset=UTF-8");
     $response->header('Content-language: ' . $wgLanguageCode);
     // Prevent framing, if requested
     $frameOptions = $this->getFrameOptions();
     if ($frameOptions) {
         $response->header("X-Frame-Options: {$frameOptions}");
     }
     if ($this->mArticleBodyOnly) {
         $this->out($this->mBodytext);
     } else {
         $this->addDefaultModules();
         $sk = $this->getSkin();
         // Hook that allows last minute changes to the output page, e.g.
         // adding of CSS or Javascript by extensions.
         wfRunHooks('BeforePageDisplay', array(&$this, &$sk));
         wfProfileIn('Output-skin');
         $sk->outputPage($this);
         wfProfileOut('Output-skin');
     }
     $this->sendCacheControl();
     ob_end_flush();
     wfProfileOut(__METHOD__);
 }

 /**
  * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
  *
  * If no origin parameter is present, nothing happens.
  * If an origin parameter is present but doesn't match the Origin header, a 403 status code
  * is set and false is returned.
  * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
  * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
  * headers are set.
  *
  * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
  */
 protected function handleCORS()
 {
     global $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions;
     $originParam = $this->getParameter('origin');
     // defaults to null
     if ($originParam === null) {
         // No origin parameter, nothing to do
         return true;
     }
     $request = $this->getRequest();
     $response = $request->response();
     // Origin: header is a space-separated list of origins, check all of them
     $originHeader = $request->getHeader('Origin');
     if ($originHeader === false) {
         $origins = array();
     } else {
         $origins = explode(' ', $originHeader);
     }
     if (!in_array($originParam, $origins)) {
         // origin parameter set but incorrect
         // Send a 403 response
         $message = HttpStatus::getMessage(403);
         $response->header("HTTP/1.1 403 {$message}", true, 403);
         $response->header('Cache-Control: no-cache');
         echo "'origin' parameter does not match Origin header\n";
         return false;
     }
     if (self::matchOrigin($originParam, $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions)) {
         $response->header("Access-Control-Allow-Origin: {$originParam}");
         $response->header('Access-Control-Allow-Credentials: true');
         $this->getOutput()->addVaryHeader('Origin');
     }
     return true;
 }

/**
 * Issue a standard HTTP 403 Forbidden header ($msg1-a message index, not a message) and an
 * error message ($msg2, also a message index), (both required) then end the script
 * subsequent arguments to $msg2 will be passed as parameters only for replacing in $msg2
 * @param string $msg1
 * @param string $msg2
 */
function wfForbidden($msg1, $msg2)
{
    global $wgImgAuthDetails;
    $args = func_get_args();
    array_shift($args);
    array_shift($args);
    $args = isset($args[0]) && is_array($args[0]) ? $args[0] : $args;
    $msgHdr = wfMessage($msg1)->escaped();
    $detailMsgKey = $wgImgAuthDetails ? $msg2 : 'badaccess-group0';
    $detailMsg = wfMessage($detailMsgKey, $args)->escaped();
    wfDebugLog('img_auth', "wfForbidden Hdr: " . wfMessage($msg1)->inLanguage('en')->text() . " Msg: " . wfMessage($msg2, $args)->inLanguage('en')->text());
    HttpStatus::header(403);
    header('Cache-Control: no-cache');
    header('Content-Type: text/html; charset=utf-8');
    echo <<<ENDS
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>{$msgHdr}</title>
</head>
<body>
<h1>{$msgHdr}</h1>
<p>{$detailMsg}</p>
</body>
</html>
ENDS;
}

 /**
  * Construct the header and output it
  */
 function sendHeaders()
 {
     if ($this->mResponseCode) {
         // For back-compat, it is supported that mResponseCode be a string like " 200 OK"
         // (with leading space and the status message after). Cast response code to an integer
         // to take advantage of PHP's conversion rules which will turn "  200 OK" into 200.
         // http://php.net/string#language.types.string.conversion
         $n = intval(trim($this->mResponseCode));
         HttpStatus::header($n);
     }
     header("Content-Type: " . $this->mContentType);
     if ($this->mLastModified) {
         header("Last-Modified: " . $this->mLastModified);
     } else {
         header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
     }
     if ($this->mCacheDuration) {
         # If CDN caches are configured, tell them to cache the response,
         # and tell the client to always check with the CDN. Otherwise,
         # tell the client to use a cached copy, without a way to purge it.
         if ($this->mConfig->get('UseSquid')) {
             # Expect explicit purge of the proxy cache, but require end user agents
             # to revalidate against the proxy on each visit.
             # Surrogate-Control controls our CDN, Cache-Control downstream caches
             if ($this->mConfig->get('UseESI')) {
                 header('Surrogate-Control: max-age=' . $this->mCacheDuration . ', content="ESI/1.0"');
                 header('Cache-Control: s-maxage=0, must-revalidate, max-age=0');
             } else {
                 header('Cache-Control: s-maxage=' . $this->mCacheDuration . ', must-revalidate, max-age=0');
             }
         } else {
             # Let the client do the caching. Cache is not purged.
             header("Expires: " . gmdate("D, d M Y H:i:s", time() + $this->mCacheDuration) . " GMT");
             header("Cache-Control: s-maxage={$this->mCacheDuration}," . "public,max-age={$this->mCacheDuration}");
         }
     } else {
         # always expired, always modified
         header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
         // Date in the past
         header("Cache-Control: no-cache, must-revalidate");
         // HTTP/1.1
         header("Pragma: no-cache");
         // HTTP/1.0
     }
     if ($this->mVary) {
         header("Vary: " . $this->mVary);
     }
 }

# big mess.
if (ob_get_level() == 0) {
    require_once "{$IP}/includes/OutputHandler.php";
    ob_start('wfOutputHandler');
}
if (!defined('MW_NO_SETUP')) {
    require_once "{$IP}/includes/Setup.php";
}
# Multiple DBs or commits might be used; keep the request as transactional as possible
if (isset($_SERVER['REQUEST_METHOD']) && $_SERVER['REQUEST_METHOD'] === 'POST') {
    ignore_user_abort(true);
}
if (!defined('MW_API') && RequestContext::getMain()->getRequest()->getHeader('Promise-Non-Write-API-Action')) {
    header('Cache-Control: no-cache');
    header('Content-Type: text/html; charset=utf-8');
    HttpStatus::header(400);
    $error = wfMessage('nonwrite-api-promise-error')->escaped();
    $content = <<<EOT
<!DOCTYPE html>
<html>
<head><meta charset="UTF-8" /></head>
<body>
{$error}
</body>
</html>

EOT;
    header('Content-Length: ' . strlen($content));
    echo $content;
    die;
}

 public function reportHTML()
 {
     $httpMessage = HttpStatus::getMessage($this->httpCode);
     header("Status: {$this->httpCode} {$httpMessage}");
     header('Content-type: text/html; charset=utf-8');
     if ($this->header === null) {
         $header = $httpMessage;
     } elseif ($this->header instanceof Message) {
         $header = $this->header->escaped();
     } else {
         $header = htmlspecialchars($this->header);
     }
     if ($this->content instanceof Message) {
         $content = $this->content->escaped();
     } else {
         $content = htmlspecialchars($this->content);
     }
     print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\n" . "<html><head><title>{$header}</title></head>\n" . "<body><h1>{$header}</h1><p>{$content}</p></body></html>\n";
 }

 /**
  * If file available in stash, cats it out to the client as a simple HTTP response.
  * n.b. Most sanity checking done in UploadStashLocalFile, so this is straightforward.
  *
  * @param $key String: the key of a particular requested file
  */
 public function showUpload($key)
 {
     global $wgOut;
     // prevent callers from doing standard HTML output -- we'll take it from here
     $wgOut->disable();
     try {
         $params = $this->parseKey($key);
         if ($params['type'] === 'thumb') {
             return $this->outputThumbFromStash($params['file'], $params['params']);
         } else {
             return $this->outputLocalFile($params['file']);
         }
     } catch (UploadStashFileNotFoundException $e) {
         $code = 404;
         $message = $e->getMessage();
     } catch (UploadStashZeroLengthFileException $e) {
         $code = 500;
         $message = $e->getMessage();
     } catch (UploadStashBadPathException $e) {
         $code = 500;
         $message = $e->getMessage();
     } catch (SpecialUploadStashTooLargeException $e) {
         $code = 500;
         $message = 'Cannot serve a file larger than ' . self::MAX_SERVE_BYTES . ' bytes. ' . $e->getMessage();
     } catch (Exception $e) {
         $code = 500;
         $message = $e->getMessage();
     }
     wfHttpError($code, HttpStatus::getMessage($code), $message);
     return false;
 }