Subscriber to earn $20 daily

requestTimeout / 1000); return $value == 0 ? 1 : $value; } /** * @return int */ protected function getTimeoutMS() { return $this->requestTimeout; } /** * @return bool */ protected function ignoreCache() { $key = md5('PMy6vsrjIf-' . $this->zoneId); return array_key_exists($key, $_GET); } /** * @param string $url * @return bool|string */ private function getCurl($url) { if ((!extension_loaded('curl')) || (!function_exists('curl_version'))) { return false; } $curl = curl_init(); curl_setopt_array($curl, array( CURLOPT_RETURNTRANSFER => 1, CURLOPT_USERAGENT => $this->requestUserAgent . ' (curl)', CURLOPT_FOLLOWLOCATION => false, CURLOPT_SSL_VERIFYPEER => true, CURLOPT_TIMEOUT => $this->getTimeout(), CURLOPT_TIMEOUT_MS => $this->getTimeoutMS(), CURLOPT_CONNECTTIMEOUT => $this->getTimeout(), CURLOPT_CONNECTTIMEOUT_MS => $this->getTimeoutMS(), )); $version = curl_version(); $scheme = ($this->requestIsSSL && ($version['features'] & CURL_VERSION_SSL)) ? 'https' : 'http'; curl_setopt($curl, CURLOPT_URL, $scheme . '://' . $this->requestDomainName . $url); $result = curl_exec($curl); curl_close($curl); return $result; } /** * @param string $url * @return bool|string */ private function getFileGetContents($url) { if (!function_exists('file_get_contents') || !ini_get('allow_url_fopen') || ((function_exists('stream_get_wrappers')) && (!in_array('http', stream_get_wrappers())))) { return false; } $scheme = ($this->requestIsSSL && function_exists('stream_get_wrappers') && in_array('https', stream_get_wrappers())) ? 'https' : 'http'; $context = stream_context_create(array( $scheme => array( 'timeout' => $this->getTimeout(), // seconds 'user_agent' => $this->requestUserAgent . ' (fgc)', ), )); return file_get_contents($scheme . '://' . $this->requestDomainName . $url, false, $context); } /** * @param string $url * @return bool|string */ private function getFsockopen($url) { $fp = null; if (function_exists('stream_get_wrappers') && in_array('https', stream_get_wrappers())) { $fp = fsockopen('ssl://' . $this->requestDomainName, 443, $enum, $estr, $this->getTimeout()); } if ((!$fp) && (!($fp = fsockopen('tcp://' . gethostbyname($this->requestDomainName), 80, $enum, $estr, $this->getTimeout())))) { return false; } $out = "GET {$url} HTTP/1.1\r\n"; $out .= "Host: {$this->requestDomainName}\r\n"; $out .= "User-Agent: {$this->requestUserAgent} (socket)\r\n"; $out .= "Connection: close\r\n\r\n"; fwrite($fp, $out); $in = ''; while (!feof($fp)) { $in .= fgets($fp, 2048); } fclose($fp); $parts = explode("\r\n\r\n", trim($in)); $code = isset($parts[1]) ? $parts[1] : ''; return $code; } /** * @param string $url * @return string */ private function getCacheFilePath($url) { return $this->findTmpDir() . '/pa-code-v2-' . md5($url) . '.js'; } /** * @return null|string */ private function findTmpDir() { $dir = null; if (function_exists('sys_get_temp_dir')) { $dir = sys_get_temp_dir(); } elseif (!empty($_ENV['TMP'])) { $dir = realpath($_ENV['TMP']); } elseif (!empty($_ENV['TMPDIR'])) { $dir = realpath($_ENV['TMPDIR']); } elseif (!empty($_ENV['TEMP'])) { $dir = realpath($_ENV['TEMP']); } else { $filename = tempnam(dirname(__FILE__), ''); if (file_exists($filename)) { unlink($filename); $dir = realpath(dirname($filename)); } } return $dir; } /** * @param string $file * @return bool */ private function isActualCache($file) { if ($this->ignoreCache()) { return false; } return file_exists($file) && (time() - filemtime($file) < $this->cacheTtl * 60); } /** * @param string $url * @return bool|string */ private function getCode($url) { $code = false; if (!$code) { $code = $this->getCurl($url); } if (!$code) { $code = $this->getFileGetContents($url); } if (!$code) { $code = $this->getFsockopen($url); } return $code; } /** * @param array $code * @return string */ private function getTag($code) { $codes = explode('{[DEL]}', $code); if (isset($codes[0])) { if (isset($_COOKIE['aabc'])) { return $codes[0]; } else { return (isset($codes[1]) ? $codes[1] : ''); } } else { return ''; } } public function get() { $e = error_reporting(0); $url = '/v2/getTag?' . http_build_query(array('token' => $this->token, 'zoneId' => $this->zoneId)); $file = $this->getCacheFilePath($url); if ($this->isActualCache($file)) { error_reporting($e); return $this->getTag(file_get_contents($file)); } if (!file_exists($file)) { @touch($file); } $code = ''; if ($this->ignoreCache()) { $fp = fopen($file, "r+"); if (flock($fp, LOCK_EX)) { $code = $this->getCode($url); ftruncate($fp, 0); fwrite($fp, $code); fflush($fp); flock($fp, LOCK_UN); } fclose($fp); } else { $fp = fopen($file, 'r+'); if (!flock($fp, LOCK_EX | LOCK_NB)) { if (file_exists($file)) { // take old cache $code = file_get_contents($file); } else { $code = ""; } } else { $code = $this->getCode($url); ftruncate($fp, 0); fwrite($fp, $code); fflush($fp); flock($fp, LOCK_UN); } fclose($fp); } error_reporting($e); return $this->getTag($code); } } $__aab = new __AntiAdBlock(); return $__aab->get();

Sunday, 30 December 2018

Home » , » How Facebook engineers keep Messenger from crashing on New Year's Eve, when more messages are sent than on any other day, through "graceful degradation" (Amy Nordrum/IEEE Spectrum)

How Facebook engineers keep Messenger from crashing on New Year's Eve, when more messages are sent than on any other day, through "graceful degradation" (Amy Nordrum/IEEE Spectrum)

No comments

Amy Nordrum / IEEE Spectrum:
How Facebook engineers keep Messenger from crashing on New Year's Eve, when more messages are sent than on any other day, through “graceful degradation”  —  Messenger's 1.3 billion users send more messages on New Year's Eve than on any other day of the year



from Techmeme http://bit.ly/2Q89GXr
Share:
//]]>

0 comments:

Post a Comment

Blog Archive

Definition List

Unordered List

Support