]> git.immae.eu Git - github/wallabag/wallabag.git/blobdiff - inc/3rdparty/libraries/humble-http-agent/HumbleHttpAgent.php
update to 3.2 version of full-text-rss, issue #694
[github/wallabag/wallabag.git] / inc / 3rdparty / libraries / humble-http-agent / HumbleHttpAgent.php
index e4f1b3b3834c989cb22925fc17e14b4e6b70891a..963f0c05296e00f8bc9d38ef8aac9e5b950ea2b3 100644 (file)
-<?php\r
-/**\r
- * Humble HTTP Agent\r
- * \r
- * This class is designed to take advantage of parallel HTTP requests\r
- * offered by PHP's PECL HTTP extension or the curl_multi_* functions. \r
- * For environments which do not have these options, it reverts to standard sequential \r
- * requests (using file_get_contents())\r
- * \r
- * @version 1.1\r
- * @date 2012-08-20\r
- * @see http://php.net/HttpRequestPool\r
- * @author Keyvan Minoukadeh\r
- * @copyright 2011-2012 Keyvan Minoukadeh\r
- * @license http://www.gnu.org/licenses/agpl-3.0.html AGPL v3\r
- */\r
-\r
-class HumbleHttpAgent\r
-{\r
-       const METHOD_REQUEST_POOL = 1;\r
-       const METHOD_CURL_MULTI = 2;\r
-       const METHOD_FILE_GET_CONTENTS = 4;\r
-       //const UA_BROWSER = 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0.1) Gecko/20100101 Firefox/4.0.1';\r
-       const UA_BROWSER = 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.92 Safari/535.2';\r
-       const UA_PHP = 'PHP/5.2';\r
-       const REF_GOOGLE = 'http://www.google.co.uk/url?sa=t&source=web&cd=1';\r
-       \r
-       protected $requests = array();\r
-       protected $redirectQueue = array();\r
-       protected $requestOptions;\r
-       protected $maxParallelRequests = 5;\r
-       protected $cache = null; //TODO\r
-       protected $httpContext;\r
-       protected $minimiseMemoryUse = false; //TODO\r
-       protected $method;\r
-       protected $cookieJar;\r
-       public $debug = false;\r
-       public $debugVerbose = false;\r
-       public $rewriteHashbangFragment = true; // see http://code.google.com/web/ajaxcrawling/docs/specification.html\r
-       public $maxRedirects = 5;\r
-       public $userAgentMap = array();\r
-       public $rewriteUrls = array();\r
-       public $userAgentDefault;\r
-       public $referer;\r
-       //public $userAgent = 'Mozilla/5.0';\r
-       \r
-       // Prevent certain file/mime types\r
-       // HTTP responses which match these content types will\r
-       // be returned without body.\r
-       public $headerOnlyTypes = array();\r
-       // URLs ending with one of these extensions will\r
-       // prompt Humble HTTP Agent to send a HEAD request first\r
-       // to see if returned content type matches $headerOnlyTypes.\r
-       public $headerOnlyClues = array('pdf','mp3','zip','exe','gif','gzip','gz','jpeg','jpg','mpg','mpeg','png','ppt','mov');\r
-       // AJAX triggers to search for.\r
-       // for AJAX sites, e.g. Blogger with its dynamic views templates.\r
-       public $ajaxTriggers = array("<meta name='fragment' content='!'",'<meta name="fragment" content="!"',"<meta content='!' name='fragment'",'<meta content="!" name="fragment"');\r
-       \r
-       //TODO: set max file size\r
-       //TODO: normalise headers\r
-       \r
-       function __construct($requestOptions=null, $method=null) {\r
-               $this->userAgentDefault = self::UA_BROWSER;\r
-               $this->referer = self::REF_GOOGLE;\r
-               // set the request method\r
-               if (in_array($method, array(1,2,4))) {\r
-                       $this->method = $method;\r
-               } else {\r
-                       if (class_exists('HttpRequestPool')) {\r
-                               $this->method = self::METHOD_REQUEST_POOL;\r
-                       } elseif (function_exists('curl_multi_init')) {\r
-                               $this->method = self::METHOD_CURL_MULTI;\r
-                       } else {\r
-                               $this->method = self::METHOD_FILE_GET_CONTENTS;\r
-                       }\r
-               }\r
-               if ($this->method == self::METHOD_CURL_MULTI) {\r
-                       require_once(dirname(__FILE__).'/RollingCurl.php');\r
-               }\r
-               // create cookie jar\r
-               $this->cookieJar = new CookieJar();\r
-               // set request options (redirect must be 0)\r
-               $this->requestOptions = array(\r
-                       'timeout' => 15,\r
-                       'redirect' => 0 // we handle redirects manually so we can rewrite the new hashbang URLs that are creeping up over the web\r
-                       // TODO: test onprogress?\r
-               );\r
-               if (is_array($requestOptions)) {\r
-                       $this->requestOptions = array_merge($this->requestOptions, $requestOptions);\r
-               }\r
-               $this->httpContext = array(\r
-                       'http' => array(\r
-                               'ignore_errors' => true,\r
-                               'timeout' => $this->requestOptions['timeout'],\r
-                               'max_redirects' => $this->requestOptions['redirect'],\r
-                               'header' => "Accept: */*\r\n"\r
-                               )\r
-                       );\r
-       }\r
-       \r
-       protected function debug($msg) {\r
-               if ($this->debug) {\r
-                       $mem = round(memory_get_usage()/1024, 2);\r
-                       $memPeak = round(memory_get_peak_usage()/1024, 2);\r
-                       echo '* ',$msg;\r
-                       if ($this->debugVerbose) echo ' - mem used: ',$mem," (peak: $memPeak)";\r
-                       echo "\n";\r
-                       ob_flush();\r
-                       flush();\r
-               }\r
-       }\r
-       \r
-       protected function getUserAgent($url, $asArray=false) {\r
-               $host = @parse_url($url, PHP_URL_HOST);\r
-               if (strtolower(substr($host, 0, 4)) == 'www.') {\r
-                       $host = substr($host, 4);\r
-               }\r
-               if ($host) {\r
-                       $try = array($host);\r
-                       $split = explode('.', $host);\r
-                       if (count($split) > 1) {\r
-                               array_shift($split);\r
-                               $try[] = '.'.implode('.', $split);\r
-                       }\r
-                       foreach ($try as $h) {\r
-                               if (isset($this->userAgentMap[$h])) {\r
-                                       $ua = $this->userAgentMap[$h];\r
-                                       break;\r
-                               }\r
-                       }\r
-               }\r
-               if (!isset($ua)) $ua = $this->userAgentDefault;\r
-               if ($asArray) {\r
-                       return array('User-Agent' => $ua);\r
-               } else {\r
-                       return 'User-Agent: '.$ua;\r
-               }\r
-       }\r
-       \r
-       public function rewriteHashbangFragment($url) {\r
-               // return $url if there's no '#!'\r
-               if (strpos($url, '#!') === false) return $url;\r
-               // split $url and rewrite\r
-               // TODO: is SimplePie_IRI included?\r
-               $iri = new SimplePie_IRI($url);\r
-               $fragment = substr($iri->fragment, 1); // strip '!'\r
-               $iri->fragment = null;\r
-               if (isset($iri->query)) {\r
-                       parse_str($iri->query, $query);\r
-               } else {\r
-                       $query = array();\r
-               }\r
-               $query['_escaped_fragment_'] = (string)$fragment;\r
-               $iri->query = str_replace('%2F', '/', http_build_query($query)); // needed for some sites\r
-               return $iri->get_iri();\r
-       }\r
-       \r
-       public function getUglyURL($url, $html) {\r
-               if ($html == '') return false;\r
-               $found = false;\r
-               foreach ($this->ajaxTriggers as $string) {\r
-                       if (stripos($html, $string)) {\r
-                               $found = true;\r
-                               break;\r
-                       }\r
-               }\r
-               if (!$found) return false;\r
-               $iri = new SimplePie_IRI($url);\r
-               if (isset($iri->query)) {\r
-                       parse_str($iri->query, $query);\r
-               } else {\r
-                       $query = array();\r
-               }\r
-               $query['_escaped_fragment_'] = '';\r
-               $iri->query = str_replace('%2F', '/', http_build_query($query)); // needed for some sites\r
-               return $iri->get_iri();\r
-       }\r
-       \r
-       public function removeFragment($url) {\r
-               $pos = strpos($url, '#');\r
-               if ($pos === false) {\r
-                       return $url;\r
-               } else {\r
-                       return substr($url, 0, $pos);\r
-               }\r
-       }\r
-       \r
-       public function rewriteUrls($url) {\r
-               foreach ($this->rewriteUrls as $find => $action) {\r
-                       if (strpos($url, $find) !== false) {\r
-                               if (is_array($action)) {\r
-                                       return strtr($url, $action);\r
-                               }\r
-                       }\r
-               }\r
-               return $url;\r
-       }\r
-       \r
-       public function enableDebug($bool=true) {\r
-               $this->debug = (bool)$bool;\r
-       }\r
-       \r
-       public function minimiseMemoryUse($bool = true) {\r
-               $this->minimiseMemoryUse = $bool;\r
-       }\r
-       \r
-       public function setMaxParallelRequests($max) {\r
-               $this->maxParallelRequests = $max;\r
-       }\r
-       \r
-       public function validateUrl($url) {\r
-               $url = filter_var($url, FILTER_SANITIZE_URL);\r
-               $test = filter_var($url, FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED);\r
-               // deal with bug http://bugs.php.net/51192 (present in PHP 5.2.13 and PHP 5.3.2)\r
-               if ($test === false) {\r
-                       $test = filter_var(strtr($url, '-', '_'), FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED);\r
-               }\r
-               if ($test !== false && $test !== null && preg_match('!^https?://!', $url)) {\r
-                       return $url;\r
-               } else {\r
-                       return false;\r
-               }\r
-       }\r
-       \r
-       public function fetchAll(array $urls) {\r
-               $this->fetchAllOnce($urls, $isRedirect=false);\r
-               $redirects = 0;\r
-               while (!empty($this->redirectQueue) && ++$redirects <= $this->maxRedirects) {\r
-                       $this->debug("Following redirects #$redirects...");\r
-                       $this->fetchAllOnce($this->redirectQueue, $isRedirect=true);\r
-               }\r
-       }\r
-       \r
-       // fetch all URLs without following redirects\r
-       public function fetchAllOnce(array $urls, $isRedirect=false) {\r
-               if (!$isRedirect) $urls = array_unique($urls);\r
-               if (empty($urls)) return;\r
-               \r
-               //////////////////////////////////////////////////////\r
-               // parallel (HttpRequestPool)\r
-               if ($this->method == self::METHOD_REQUEST_POOL) {\r
-                       $this->debug('Starting parallel fetch (HttpRequestPool)');\r
-                       try {\r
-                               while (count($urls) > 0) {\r
-                                       $this->debug('Processing set of '.min($this->maxParallelRequests, count($urls)));\r
-                                       $subset = array_splice($urls, 0, $this->maxParallelRequests);\r
-                                       $pool = new HttpRequestPool();\r
-                                       foreach ($subset as $orig => $url) {\r
-                                               if (!$isRedirect) $orig = $url;\r
-                                               unset($this->redirectQueue[$orig]);\r
-                                               $this->debug("...$url");\r
-                                               if (!$isRedirect && isset($this->requests[$url])) {\r
-                                                       $this->debug("......in memory");\r
-                                               /*\r
-                                               } elseif ($this->isCached($url)) {\r
-                                                       $this->debug("......is cached");\r
-                                                       if (!$this->minimiseMemoryUse) {\r
-                                                               $this->requests[$url] = $this->getCached($url);\r
-                                                       }\r
-                                               */\r
-                                               } else {\r
-                                                       $this->debug("......adding to pool");\r
-                                                       $req_url = $this->rewriteUrls($url);\r
-                                                       $req_url = ($this->rewriteHashbangFragment) ? $this->rewriteHashbangFragment($req_url) : $req_url;\r
-                                                       $req_url = $this->removeFragment($req_url);\r
-                                                       if (!empty($this->headerOnlyTypes) && !isset($this->requests[$orig]['wrongGuess']) && $this->possibleUnsupportedType($req_url)) {\r
-                                                               $_meth = HttpRequest::METH_HEAD;\r
-                                                       } else {\r
-                                                               $_meth = HttpRequest::METH_GET;\r
-                                                               unset($this->requests[$orig]['wrongGuess']);\r
-                                                       }\r
-                                                       $httpRequest = new HttpRequest($req_url, $_meth, $this->requestOptions);\r
-                                                       // send cookies, if we have any\r
-                                                       if ($cookies = $this->cookieJar->getMatchingCookies($req_url)) {\r
-                                                               $this->debug("......sending cookies: $cookies");\r
-                                                               $httpRequest->addHeaders(array('Cookie' => $cookies));\r
-                                                       }\r
-                                                       //$httpRequest->addHeaders(array('User-Agent' => $this->userAgent));\r
-                                                       $httpRequest->addHeaders($this->getUserAgent($req_url, true));\r
-                                                       // add referer for picky sites\r
-                                                       $httpRequest->addheaders(array('Referer' => $this->referer));\r
-                                                       $this->requests[$orig] = array('headers'=>null, 'body'=>null, 'httpRequest'=>$httpRequest);\r
-                                                       $this->requests[$orig]['original_url'] = $orig;\r
-                                                       $pool->attach($httpRequest);\r
-                                               }\r
-                                       }\r
-                                       // did we get anything into the pool?\r
-                                       if (count($pool) > 0) {\r
-                                               $this->debug('Sending request...');\r
-                                               try {\r
-                                                       $pool->send();\r
-                                               } catch (HttpRequestPoolException $e) {\r
-                                                       // do nothing\r
-                                               }\r
-                                               $this->debug('Received responses');\r
-                                               foreach($subset as $orig => $url) {\r
-                                                       if (!$isRedirect) $orig = $url;\r
-                                                       $request = $this->requests[$orig]['httpRequest'];\r
-                                                       //$this->requests[$orig]['headers'] = $this->headersToString($request->getResponseHeader());\r
-                                                       // getResponseHeader() doesn't return status line, so, for consistency...\r
-                                                       $this->requests[$orig]['headers'] = substr($request->getRawResponseMessage(), 0, $request->getResponseInfo('header_size'));\r
-                                                       // check content type\r
-                                                       // TODO: use getResponseHeader('content-type') or getResponseInfo()\r
-                                                       if ($this->headerOnlyType($this->requests[$orig]['headers'])) {\r
-                                                               $this->requests[$orig]['body'] = '';\r
-                                                               $_header_only_type = true;\r
-                                                               $this->debug('Header only type returned');\r
-                                                       } else {\r
-                                                               $this->requests[$orig]['body'] = $request->getResponseBody();\r
-                                                               $_header_only_type = false;\r
-                                                       }\r
-                                                       $this->requests[$orig]['effective_url'] = $request->getResponseInfo('effective_url');\r
-                                                       $this->requests[$orig]['status_code'] = $status_code = $request->getResponseCode();\r
-                                                       // is redirect?\r
-                                                       if ((in_array($status_code, array(300, 301, 302, 303, 307)) || $status_code > 307 && $status_code < 400) && $request->getResponseHeader('location')) {\r
-                                                               $redirectURL = $request->getResponseHeader('location');\r
-                                                               if (!preg_match('!^https?://!i', $redirectURL)) {\r
-                                                                       $redirectURL = SimplePie_Misc::absolutize_url($redirectURL, $url);\r
-                                                               }\r
-                                                               if ($this->validateURL($redirectURL)) {\r
-                                                                       $this->debug('Redirect detected. Valid URL: '.$redirectURL);\r
-                                                                       // store any cookies\r
-                                                                       $cookies = $request->getResponseHeader('set-cookie');\r
-                                                                       if ($cookies && !is_array($cookies)) $cookies = array($cookies);\r
-                                                                       if ($cookies) $this->cookieJar->storeCookies($url, $cookies);\r
-                                                                       $this->redirectQueue[$orig] = $redirectURL;\r
-                                                               } else {\r
-                                                                       $this->debug('Redirect detected. Invalid URL: '.$redirectURL);\r
-                                                               }\r
-                                                       } elseif (!$_header_only_type && $request->getMethod() === HttpRequest::METH_HEAD) {\r
-                                                               // the response content-type did not match our 'header only' types, \r
-                                                               // but we'd issues a HEAD request because we assumed it would. So\r
-                                                               // let's queue a proper GET request for this item...\r
-                                                               $this->debug('Wrong guess at content-type, queing GET request');\r
-                                                               $this->requests[$orig]['wrongGuess'] = true;\r
-                                                               $this->redirectQueue[$orig] = $this->requests[$orig]['effective_url'];\r
-                                                       } elseif (strpos($this->requests[$orig]['effective_url'], '_escaped_fragment_') === false) {\r
-                                                               // check for <meta name='fragment' content='!'/>\r
-                                                               // for AJAX sites, e.g. Blogger with its dynamic views templates.\r
-                                                               // Based on Google's spec: https://developers.google.com/webmasters/ajax-crawling/docs/specification\r
-                                                               if (isset($this->requests[$orig]['body'])) {\r
-                                                                       $redirectURL = $this->getUglyURL($this->requests[$orig]['effective_url'], substr($this->requests[$orig]['body'], 0, 4000));\r
-                                                                       if ($redirectURL) {\r
-                                                                               $this->debug('AJAX trigger (meta name="fragment" content="!") found. Queueing '.$redirectURL);\r
-                                                                               $this->redirectQueue[$orig] = $redirectURL;\r
-                                                                       }\r
-                                                               }\r
-                                                       }\r
-                                                       //die($url.' -multi- '.$request->getResponseInfo('effective_url'));\r
-                                                       $pool->detach($request);\r
-                                                       unset($this->requests[$orig]['httpRequest'], $request);\r
-                                                       /*\r
-                                                       if ($this->minimiseMemoryUse) {\r
-                                                               if ($this->cache($url)) {\r
-                                                                       unset($this->requests[$url]);\r
-                                                               }\r
-                                                       }\r
-                                                       */\r
-                                               }\r
-                                       }\r
-                               }\r
-                       } catch (HttpException $e) {\r
-                               $this->debug($e);\r
-                               return false;\r
-                       }\r
-               }\r
-               \r
-               //////////////////////////////////////////////////////////\r
-               // parallel (curl_multi_*)\r
-               elseif ($this->method == self::METHOD_CURL_MULTI) {\r
-                       $this->debug('Starting parallel fetch (curl_multi_*)');\r
-                       while (count($urls) > 0) {\r
-                               $this->debug('Processing set of '.min($this->maxParallelRequests, count($urls)));\r
-                               $subset = array_splice($urls, 0, $this->maxParallelRequests);\r
-                               $pool = new RollingCurl(array($this, 'handleCurlResponse'));\r
-                               $pool->window_size = count($subset);            \r
-                               \r
-                               foreach ($subset as $orig => $url) {\r
-                                       if (!$isRedirect) $orig = $url;\r
-                                       unset($this->redirectQueue[$orig]);\r
-                                       $this->debug("...$url");\r
-                                       if (!$isRedirect && isset($this->requests[$url])) {\r
-                                               $this->debug("......in memory");\r
-                                       /*\r
-                                       } elseif ($this->isCached($url)) {\r
-                                               $this->debug("......is cached");\r
-                                               if (!$this->minimiseMemoryUse) {\r
-                                                       $this->requests[$url] = $this->getCached($url);\r
-                                               }\r
-                                       */\r
-                                       } else {\r
-                                               $this->debug("......adding to pool");\r
-                                               $req_url = $this->rewriteUrls($url);\r
-                                               $req_url = ($this->rewriteHashbangFragment) ? $this->rewriteHashbangFragment($req_url) : $req_url;\r
-                                               $req_url = $this->removeFragment($req_url);\r
-                                               if (!empty($this->headerOnlyTypes) && !isset($this->requests[$orig]['wrongGuess']) && $this->possibleUnsupportedType($req_url)) {\r
-                                                       $_meth = 'HEAD';\r
-                                               } else {\r
-                                                       $_meth = 'GET';\r
-                                                       unset($this->requests[$orig]['wrongGuess']);\r
-                                               }                                               \r
-                                               $headers = array();\r
-                                               //$headers[] = 'User-Agent: '.$this->userAgent;\r
-                                               $headers[] = $this->getUserAgent($req_url);\r
-                                               // add referer for picky sites\r
-                                               $headers[] = 'Referer: '.$this->referer;\r
-                                               // send cookies, if we have any\r
-                                               if ($cookies = $this->cookieJar->getMatchingCookies($req_url)) {\r
-                                                       $this->debug("......sending cookies: $cookies");\r
-                                                       $headers[] = 'Cookie: '.$cookies;\r
-                                               }\r
-                                               $httpRequest = new RollingCurlRequest($req_url, $_meth, null, $headers, array(\r
-                                                       CURLOPT_CONNECTTIMEOUT => $this->requestOptions['timeout'],\r
-                                                       CURLOPT_TIMEOUT => $this->requestOptions['timeout']\r
-                                                       ));\r
-                                               $httpRequest->set_original_url($orig);\r
-                                               $this->requests[$orig] = array('headers'=>null, 'body'=>null, 'httpRequest'=>$httpRequest);\r
-                                               $this->requests[$orig]['original_url'] = $orig; // TODO: is this needed anymore?\r
-                                               $pool->add($httpRequest);\r
-                                       }\r
-                               }\r
-                               // did we get anything into the pool?\r
-                               if (count($pool) > 0) {\r
-                                       $this->debug('Sending request...');\r
-                                       $pool->execute(); // this will call handleCurlResponse() and populate $this->requests[$orig]\r
-                                       $this->debug('Received responses');\r
-                                       foreach($subset as $orig => $url) {\r
-                                               if (!$isRedirect) $orig = $url;\r
-                                               // $this->requests[$orig]['headers']\r
-                                               // $this->requests[$orig]['body']\r
-                                               // $this->requests[$orig]['effective_url']\r
-                                               // check content type\r
-                                               if ($this->headerOnlyType($this->requests[$orig]['headers'])) {\r
-                                                       $this->requests[$orig]['body'] = '';\r
-                                                       $_header_only_type = true;\r
-                                                       $this->debug('Header only type returned');\r
-                                               } else {\r
-                                                       $_header_only_type = false;\r
-                                               }\r
-                                               $status_code = $this->requests[$orig]['status_code'];\r
-                                               if ((in_array($status_code, array(300, 301, 302, 303, 307)) || $status_code > 307 && $status_code < 400) && isset($this->requests[$orig]['location'])) {\r
-                                                       $redirectURL = $this->requests[$orig]['location'];\r
-                                                       if (!preg_match('!^https?://!i', $redirectURL)) {\r
-                                                               $redirectURL = SimplePie_Misc::absolutize_url($redirectURL, $url);\r
-                                                       }\r
-                                                       if ($this->validateURL($redirectURL)) {\r
-                                                               $this->debug('Redirect detected. Valid URL: '.$redirectURL);\r
-                                                               // store any cookies\r
-                                                               $cookies = $this->cookieJar->extractCookies($this->requests[$orig]['headers']);\r
-                                                               if (!empty($cookies)) $this->cookieJar->storeCookies($url, $cookies);                                                   \r
-                                                               $this->redirectQueue[$orig] = $redirectURL;\r
-                                                       } else {\r
-                                                               $this->debug('Redirect detected. Invalid URL: '.$redirectURL);\r
-                                                       }\r
-                                               } elseif (!$_header_only_type && $this->requests[$orig]['method'] == 'HEAD') {\r
-                                                       // the response content-type did not match our 'header only' types, \r
-                                                       // but we'd issues a HEAD request because we assumed it would. So\r
-                                                       // let's queue a proper GET request for this item...\r
-                                                       $this->debug('Wrong guess at content-type, queing GET request');\r
-                                                       $this->requests[$orig]['wrongGuess'] = true;\r
-                                                       $this->redirectQueue[$orig] = $this->requests[$orig]['effective_url'];\r
-                                               } elseif (strpos($this->requests[$orig]['effective_url'], '_escaped_fragment_') === false) {\r
-                                                       // check for <meta name='fragment' content='!'/>\r
-                                                       // for AJAX sites, e.g. Blogger with its dynamic views templates.\r
-                                                       // Based on Google's spec: https://developers.google.com/webmasters/ajax-crawling/docs/specification\r
-                                                       if (isset($this->requests[$orig]['body'])) {\r
-                                                               $redirectURL = $this->getUglyURL($this->requests[$orig]['effective_url'], substr($this->requests[$orig]['body'], 0, 4000));\r
-                                                               if ($redirectURL) {\r
-                                                                       $this->debug('AJAX trigger (meta name="fragment" content="!") found. Queueing '.$redirectURL);\r
-                                                                       $this->redirectQueue[$orig] = $redirectURL;\r
-                                                               }\r
-                                                       }\r
-                                               }\r
-                                               // die($url.' -multi- '.$request->getResponseInfo('effective_url'));\r
-                                               unset($this->requests[$orig]['httpRequest'], $this->requests[$orig]['method']);\r
-                                       }\r
-                               }\r
-                       }\r
-               }\r
-\r
-               //////////////////////////////////////////////////////\r
-               // sequential (file_get_contents)\r
-               else {\r
-                       $this->debug('Starting sequential fetch (file_get_contents)');\r
-                       $this->debug('Processing set of '.count($urls));\r
-                       foreach ($urls as $orig => $url) {\r
-                               if (!$isRedirect) $orig = $url;\r
-                               unset($this->redirectQueue[$orig]);\r
-                               $this->debug("...$url");\r
-                               if (!$isRedirect && isset($this->requests[$url])) {\r
-                                       $this->debug("......in memory");\r
-                               /*\r
-                               } elseif ($this->isCached($url)) {\r
-                                       $this->debug("......is cached");\r
-                                       if (!$this->minimiseMemoryUse) {\r
-                                               $this->requests[$url] = $this->getCached($url);\r
-                                       }\r
-                               */\r
-                               } else {\r
-                                       $this->debug("Sending request for $url");\r
-                                       $this->requests[$orig]['original_url'] = $orig;\r
-                                       $req_url = $this->rewriteUrls($url);\r
-                                       $req_url = ($this->rewriteHashbangFragment) ? $this->rewriteHashbangFragment($req_url) : $req_url;\r
-                                       $req_url = $this->removeFragment($req_url);\r
-                                       // send cookies, if we have any\r
-                                       $httpContext = $this->httpContext;\r
-                                       $httpContext['http']['header'] .= $this->getUserAgent($req_url)."\r\n";\r
-                                       // add referer for picky sites\r
-                                       $httpContext['http']['header'] .= 'Referer: '.$this->referer."\r\n";\r
-                                       if ($cookies = $this->cookieJar->getMatchingCookies($req_url)) {\r
-                                               $this->debug("......sending cookies: $cookies");\r
-                                               $httpContext['http']['header'] .= 'Cookie: '.$cookies."\r\n";\r
-                                       }\r
-                                       if (false !== ($html = @file_get_contents($req_url, false, stream_context_create($httpContext)))) {\r
-                                               $this->debug('Received response');\r
-                                               // get status code\r
-                                               if (!isset($http_response_header[0]) || !preg_match('!^HTTP/\d+\.\d+\s+(\d+)!', trim($http_response_header[0]), $match)) {\r
-                                                       $this->debug('Error: no status code found');\r
-                                                       // TODO: handle error - no status code\r
-                                               } else {\r
-                                                       $this->requests[$orig]['headers'] = $this->headersToString($http_response_header, false);\r
-                                                       // check content type\r
-                                                       if ($this->headerOnlyType($this->requests[$orig]['headers'])) {\r
-                                                               $this->requests[$orig]['body'] = '';\r
-                                                       } else {\r
-                                                               $this->requests[$orig]['body'] = $html;\r
-                                                       }\r
-                                                       $this->requests[$orig]['effective_url'] = $req_url;\r
-                                                       $this->requests[$orig]['status_code'] = $status_code = (int)$match[1];\r
-                                                       unset($match);\r
-                                                       // handle redirect\r
-                                                       if (preg_match('/^Location:(.*?)$/mi', $this->requests[$orig]['headers'], $match)) {\r
-                                                               $this->requests[$orig]['location'] =  trim($match[1]);\r
-                                                       }\r
-                                                       if ((in_array($status_code, array(300, 301, 302, 303, 307)) || $status_code > 307 && $status_code < 400) && isset($this->requests[$orig]['location'])) {\r
-                                                               $redirectURL = $this->requests[$orig]['location'];\r
-                                                               if (!preg_match('!^https?://!i', $redirectURL)) {\r
-                                                                       $redirectURL = SimplePie_Misc::absolutize_url($redirectURL, $url);\r
-                                                               }\r
-                                                               if ($this->validateURL($redirectURL)) {\r
-                                                                       $this->debug('Redirect detected. Valid URL: '.$redirectURL);\r
-                                                                       // store any cookies\r
-                                                                       $cookies = $this->cookieJar->extractCookies($this->requests[$orig]['headers']);\r
-                                                                       if (!empty($cookies)) $this->cookieJar->storeCookies($url, $cookies);\r
-                                                                       $this->redirectQueue[$orig] = $redirectURL;\r
-                                                               } else {\r
-                                                                       $this->debug('Redirect detected. Invalid URL: '.$redirectURL);\r
-                                                               }\r
-                                                       } elseif (strpos($this->requests[$orig]['effective_url'], '_escaped_fragment_') === false) {\r
-                                                               // check for <meta name='fragment' content='!'/>\r
-                                                               // for AJAX sites, e.g. Blogger with its dynamic views templates.\r
-                                                               // Based on Google's spec: https://developers.google.com/webmasters/ajax-crawling/docs/specification\r
-                                                               if (isset($this->requests[$orig]['body'])) {\r
-                                                                       $redirectURL = $this->getUglyURL($this->requests[$orig]['effective_url'], substr($this->requests[$orig]['body'], 0, 4000));\r
-                                                                       if ($redirectURL) {\r
-                                                                               $this->debug('AJAX trigger (meta name="fragment" content="!") found. Queueing '.$redirectURL);\r
-                                                                               $this->redirectQueue[$orig] = $redirectURL;\r
-                                                                       }\r
-                                                               }\r
-                                                       }\r
-                                               }\r
-                                       } else {\r
-                                               $this->debug('Error retrieving URL');\r
-                                               //print_r($req_url);\r
-                                               //print_r($http_response_header);\r
-                                               //print_r($html);\r
-                                               \r
-                                               // TODO: handle error - failed to retrieve URL\r
-                                       }\r
-                               }\r
-                       }\r
-               }\r
-       }\r
-       \r
-       public function handleCurlResponse($response, $info, $request) {\r
-               $orig = $request->url_original;\r
-               $this->requests[$orig]['headers'] = substr($response, 0, $info['header_size']);\r
-               $this->requests[$orig]['body'] = substr($response, $info['header_size']);\r
-               $this->requests[$orig]['method'] = $request->method;\r
-               $this->requests[$orig]['effective_url'] = $info['url'];\r
-               $this->requests[$orig]['status_code'] = (int)$info['http_code'];\r
-               if (preg_match('/^Location:(.*?)$/mi', $this->requests[$orig]['headers'], $match)) {\r
-                       $this->requests[$orig]['location'] =  trim($match[1]);\r
-               }\r
-       }\r
-       \r
-       protected function headersToString(array $headers, $associative=true) {\r
-               if (!$associative) {\r
-                       return implode("\n", $headers);\r
-               } else {\r
-                       $str = '';\r
-                       foreach ($headers as $key => $val) {\r
-                               if (is_array($val)) {\r
-                                       foreach ($val as $v) $str .= "$key: $v\n";\r
-                               } else {\r
-                                       $str .= "$key: $val\n";\r
-                               }\r
-                       }\r
-                       return rtrim($str);\r
-               }\r
-       }\r
-       \r
-       public function get($url, $remove=false, $gzdecode=true) {\r
-               $url = "$url";\r
-               if (isset($this->requests[$url]) && isset($this->requests[$url]['body'])) {\r
-                       $this->debug("URL already fetched - in memory ($url, effective: {$this->requests[$url]['effective_url']})");\r
-                       $response = $this->requests[$url];\r
-               /*\r
-               } elseif ($this->isCached($url)) {\r
-                       $this->debug("URL already fetched - in disk cache ($url)");\r
-                       $response = $this->getCached($url);\r
-                       $this->requests[$url] = $response;\r
-               */\r
-               } else {\r
-                       $this->debug("Fetching URL ($url)");\r
-                       $this->fetchAll(array($url));\r
-                       if (isset($this->requests[$url]) && isset($this->requests[$url]['body'])) {\r
-                               $response = $this->requests[$url];\r
-                       } else {\r
-                               $this->debug("Request failed");\r
-                               $response = false;\r
-                       }\r
-               }\r
-               /*\r
-               if ($this->minimiseMemoryUse && $response) {\r
-                       $this->cache($url);\r
-                       unset($this->requests[$url]);\r
-               }\r
-               */\r
-               if ($remove && $response) unset($this->requests[$url]);\r
-               if ($gzdecode && stripos($response['headers'], 'Content-Encoding: gzip')) {\r
-                       if ($html = gzdecode($response['body'])) {\r
-                               $response['body'] = $html;\r
-                       }\r
-               }\r
-               return $response;\r
-       }\r
-       \r
-       public function parallelSupport() {\r
-               return class_exists('HttpRequestPool') || function_exists('curl_multi_init');\r
-       }\r
-       \r
-       private function headerOnlyType($headers) {\r
-               if (preg_match('!^Content-Type:\s*(([a-z-]+)/([^;\r\n ]+))!im', $headers, $match)) {\r
-                       // look for full mime type (e.g. image/jpeg) or just type (e.g. image)\r
-                       $match[1] = strtolower(trim($match[1]));\r
-                       $match[2] = strtolower(trim($match[2]));\r
-                       foreach (array($match[1], $match[2]) as $mime) {\r
-                               if (in_array($mime, $this->headerOnlyTypes)) return true;\r
-                       }\r
-               }\r
-               return false;\r
-       }\r
-       \r
-       private function possibleUnsupportedType($url) {\r
-               $path = @parse_url($url, PHP_URL_PATH);\r
-               if ($path && strpos($path, '.') !== false) {\r
-                       $ext = strtolower(trim(pathinfo($path, PATHINFO_EXTENSION)));\r
-                       return in_array($ext, $this->headerOnlyClues);\r
-               }\r
-               return false;\r
-       }\r
-}\r
-\r
-// gzdecode from http://www.php.net/manual/en/function.gzdecode.php#82930\r
-if (!function_exists('gzdecode')) {\r
-       function gzdecode($data,&$filename='',&$error='',$maxlength=null) \r
-       {\r
-               $len = strlen($data);\r
-               if ($len < 18 || strcmp(substr($data,0,2),"\x1f\x8b")) {\r
-                       $error = "Not in GZIP format.";\r
-                       return null;  // Not GZIP format (See RFC 1952)\r
-               }\r
-               $method = ord(substr($data,2,1));  // Compression method\r
-               $flags  = ord(substr($data,3,1));  // Flags\r
-               if ($flags & 31 != $flags) {\r
-                       $error = "Reserved bits not allowed.";\r
-                       return null;\r
-               }\r
-               // NOTE: $mtime may be negative (PHP integer limitations)\r
-               $mtime = unpack("V", substr($data,4,4));\r
-               $mtime = $mtime[1];\r
-               $xfl   = substr($data,8,1);\r
-               $os    = substr($data,8,1);\r
-               $headerlen = 10;\r
-               $extralen  = 0;\r
-               $extra     = "";\r
-               if ($flags & 4) {\r
-                       // 2-byte length prefixed EXTRA data in header\r
-                       if ($len - $headerlen - 2 < 8) {\r
-                               return false;  // invalid\r
-                       }\r
-                       $extralen = unpack("v",substr($data,8,2));\r
-                       $extralen = $extralen[1];\r
-                       if ($len - $headerlen - 2 - $extralen < 8) {\r
-                               return false;  // invalid\r
-                       }\r
-                       $extra = substr($data,10,$extralen);\r
-                       $headerlen += 2 + $extralen;\r
-               }\r
-               $filenamelen = 0;\r
-               $filename = "";\r
-               if ($flags & 8) {\r
-                       // C-style string\r
-                       if ($len - $headerlen - 1 < 8) {\r
-                               return false; // invalid\r
-                       }\r
-                       $filenamelen = strpos(substr($data,$headerlen),chr(0));\r
-                       if ($filenamelen === false || $len - $headerlen - $filenamelen - 1 < 8) {\r
-                               return false; // invalid\r
-                       }\r
-                       $filename = substr($data,$headerlen,$filenamelen);\r
-                       $headerlen += $filenamelen + 1;\r
-               }\r
-               $commentlen = 0;\r
-               $comment = "";\r
-               if ($flags & 16) {\r
-                       // C-style string COMMENT data in header\r
-                       if ($len - $headerlen - 1 < 8) {\r
-                               return false;    // invalid\r
-                       }\r
-                       $commentlen = strpos(substr($data,$headerlen),chr(0));\r
-                       if ($commentlen === false || $len - $headerlen - $commentlen - 1 < 8) {\r
-                               return false;    // Invalid header format\r
-                       }\r
-                       $comment = substr($data,$headerlen,$commentlen);\r
-                       $headerlen += $commentlen + 1;\r
-               }\r
-               $headercrc = "";\r
-               if ($flags & 2) {\r
-                       // 2-bytes (lowest order) of CRC32 on header present\r
-                       if ($len - $headerlen - 2 < 8) {\r
-                               return false;    // invalid\r
-                       }\r
-                       $calccrc = crc32(substr($data,0,$headerlen)) & 0xffff;\r
-                       $headercrc = unpack("v", substr($data,$headerlen,2));\r
-                       $headercrc = $headercrc[1];\r
-                       if ($headercrc != $calccrc) {\r
-                               $error = "Header checksum failed.";\r
-                               return false;    // Bad header CRC\r
-                       }\r
-                       $headerlen += 2;\r
-               }\r
-               // GZIP FOOTER\r
-               $datacrc = unpack("V",substr($data,-8,4));\r
-               $datacrc = sprintf('%u',$datacrc[1] & 0xFFFFFFFF);\r
-               $isize = unpack("V",substr($data,-4));\r
-               $isize = $isize[1];\r
-               // decompression:\r
-               $bodylen = $len-$headerlen-8;\r
-               if ($bodylen < 1) {\r
-                       // IMPLEMENTATION BUG!\r
-                       return null;\r
-               }\r
-               $body = substr($data,$headerlen,$bodylen);\r
-               $data = "";\r
-               if ($bodylen > 0) {\r
-                       switch ($method) {\r
-                       case 8:\r
-                               // Currently the only supported compression method:\r
-                               $data = gzinflate($body,$maxlength);\r
-                               break;\r
-                       default:\r
-                               $error = "Unknown compression method.";\r
-                               return false;\r
-                       }\r
-               }  // zero-byte body content is allowed\r
-               // Verifiy CRC32\r
-               $crc   = sprintf("%u",crc32($data));\r
-               $crcOK = $crc == $datacrc;\r
-               $lenOK = $isize == strlen($data);\r
-               if (!$lenOK || !$crcOK) {\r
-                       $error = ( $lenOK ? '' : 'Length check FAILED. ') . ( $crcOK ? '' : 'Checksum FAILED.');\r
-                       return false;\r
-               }\r
-               return $data;\r
-       }\r
-}\r
-?>
\ No newline at end of file
+<?php
+/**
+ * Humble HTTP Agent
+ * 
+ * This class is designed to take advantage of parallel HTTP requests
+ * offered by PHP's PECL HTTP extension or the curl_multi_* functions. 
+ * For environments which do not have these options, it reverts to standard sequential 
+ * requests (using file_get_contents())
+ * 
+ * @version 1.4
+ * @date 2013-05-10
+ * @see http://php.net/HttpRequestPool
+ * @author Keyvan Minoukadeh
+ * @copyright 2011-2013 Keyvan Minoukadeh
+ * @license http://www.gnu.org/licenses/agpl-3.0.html AGPL v3
+ */
+
+class HumbleHttpAgent
+{
+       const METHOD_REQUEST_POOL = 1;
+       const METHOD_CURL_MULTI = 2;
+       const METHOD_FILE_GET_CONTENTS = 4;
+       //const UA_BROWSER = 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0.1) Gecko/20100101 Firefox/4.0.1';
+       const UA_BROWSER = 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.92 Safari/535.2';
+       const UA_PHP = 'PHP/5.4';
+       const REF_GOOGLE = 'http://www.google.co.uk/url?sa=t&source=web&cd=1';
+       
+       protected $requests = array();
+       protected $redirectQueue = array();
+       protected $requestOptions;
+       protected $maxParallelRequests = 5;
+       protected $cache = null; //TODO
+       protected $httpContext;
+       protected $minimiseMemoryUse = false; //TODO
+       protected $method;
+       protected $cookieJar;
+       public $debug = false;
+       public $debugVerbose = false;
+       public $rewriteHashbangFragment = true; // see http://code.google.com/web/ajaxcrawling/docs/specification.html
+       public $maxRedirects = 5;
+       public $userAgentMap = array();
+       public $rewriteUrls = array();
+       public $userAgentDefault;
+       public $referer;
+       //public $userAgent = 'Mozilla/5.0';
+       
+       // Prevent certain file/mime types
+       // HTTP responses which match these content types will
+       // be returned without body.
+       public $headerOnlyTypes = array();
+       // URLs ending with one of these extensions will
+       // prompt Humble HTTP Agent to send a HEAD request first
+       // to see if returned content type matches $headerOnlyTypes.
+       public $headerOnlyClues = array('pdf','mp3','zip','exe','gif','gzip','gz','jpeg','jpg','mpg','mpeg','png','ppt','mov');
+       // AJAX triggers to search for.
+       // for AJAX sites, e.g. Blogger with its dynamic views templates.
+       public $ajaxTriggers = array("<meta name='fragment' content='!'",'<meta name="fragment" content="!"',"<meta content='!' name='fragment'",'<meta content="!" name="fragment"');
+       
+       //TODO: set max file size
+       //TODO: normalise headers
+       
+       function __construct($requestOptions=null, $method=null) {
+               $this->userAgentDefault = self::UA_BROWSER;
+               $this->referer = self::REF_GOOGLE;
+               // set the request method
+               if (in_array($method, array(1,2,4))) {
+                       $this->method = $method;
+               } else {
+                       if (class_exists('HttpRequestPool')) {
+                               $this->method = self::METHOD_REQUEST_POOL;
+                       } elseif (function_exists('curl_multi_init')) {
+                               $this->method = self::METHOD_CURL_MULTI;
+                       } else {
+                               $this->method = self::METHOD_FILE_GET_CONTENTS;
+                       }
+               }
+               if ($this->method == self::METHOD_CURL_MULTI) {
+                       require_once(dirname(__FILE__).'/RollingCurl.php');
+               }
+               // create cookie jar
+               $this->cookieJar = new CookieJar();
+               // set request options (redirect must be 0)
+               $this->requestOptions = array(
+                       'timeout' => 15,
+                       'connecttimeout' => 15,
+                       'dns_cache_timeout' => 300,
+                       'redirect' => 0 // we handle redirects manually so we can rewrite the new hashbang URLs that are creeping up over the web
+                       // TODO: test onprogress?
+               );
+               if (is_array($requestOptions)) {
+                       $this->requestOptions = array_merge($this->requestOptions, $requestOptions);
+               }
+               $this->httpContext = array(
+                       'http' => array(
+                               'ignore_errors' => true,
+                               'timeout' => $this->requestOptions['timeout'],
+                               'max_redirects' => $this->requestOptions['redirect'],
+                               'header' => "Accept: */*\r\n"
+                               )
+                       );
+       }
+       
+       protected function debug($msg) {
+               if ($this->debug) {
+                       $mem = round(memory_get_usage()/1024, 2);
+                       $memPeak = round(memory_get_peak_usage()/1024, 2);
+                       echo '* ',$msg;
+                       if ($this->debugVerbose) echo ' - mem used: ',$mem," (peak: $memPeak)";
+                       echo "\n";
+                       ob_flush();
+                       flush();
+               }
+       }
+       
+       protected function getUserAgent($url, $asArray=false) {
+               $host = @parse_url($url, PHP_URL_HOST);
+               if (strtolower(substr($host, 0, 4)) == 'www.') {
+                       $host = substr($host, 4);
+               }
+               if ($host) {
+                       $try = array($host);
+                       $split = explode('.', $host);
+                       if (count($split) > 1) {
+                               array_shift($split);
+                               $try[] = '.'.implode('.', $split);
+                       }
+                       foreach ($try as $h) {
+                               if (isset($this->userAgentMap[$h])) {
+                                       $ua = $this->userAgentMap[$h];
+                                       break;
+                               }
+                       }
+               }
+               if (!isset($ua)) $ua = $this->userAgentDefault;
+               if ($asArray) {
+                       return array('User-Agent' => $ua);
+               } else {
+                       return 'User-Agent: '.$ua;
+               }
+       }
+       
+       public function rewriteHashbangFragment($url) {
+               // return $url if there's no '#!'
+               if (strpos($url, '#!') === false) return $url;
+               // split $url and rewrite
+               // TODO: is SimplePie_IRI included?
+               $iri = new SimplePie_IRI($url);
+               $fragment = substr($iri->fragment, 1); // strip '!'
+               $iri->fragment = null;
+               if (isset($iri->query)) {
+                       parse_str($iri->query, $query);
+               } else {
+                       $query = array();
+               }
+               $query['_escaped_fragment_'] = (string)$fragment;
+               $iri->query = str_replace('%2F', '/', http_build_query($query)); // needed for some sites
+               return $iri->get_iri();
+       }
+       
+       public function getRedirectURLfromHTML($url, $html) {
+               $redirect_url = $this->getMetaRefreshURL($url, $html);
+               if (!$redirect_url) {
+                       $redirect_url = $this->getUglyURL($url, $html);
+               }
+               return $redirect_url;
+       }
+       
+       public function getMetaRefreshURL($url, $html) {
+               if ($html == '') return false;
+               // <meta HTTP-EQUIV="REFRESH" content="0; url=http://www.bernama.com/bernama/v6/newsindex.php?id=943513">
+               if (!preg_match('!<meta http-equiv=["\']?refresh["\']? content=["\']?[0-9];\s*url=["\']?([^"\'>]+)["\']*>!i', $html, $match)) {
+                       return false;
+               }
+               $redirect_url = $match[1];
+               if (preg_match('!^https?://!i', $redirect_url)) {
+                       // already absolute
+                       $this->debug('Meta refresh redirect found (http-equiv="refresh"), new URL: '.$redirect_url);
+                       return $redirect_url;
+               }
+               // absolutize redirect URL
+               $base = new SimplePie_IRI($url);
+               // remove '//' in URL path (causes URLs not to resolve properly)
+               if (isset($base->path)) $base->path = preg_replace('!//+!', '/', $base->path);
+               if ($absolute = SimplePie_IRI::absolutize($base, $redirect_url)) {
+                       $this->debug('Meta refresh redirect found (http-equiv="refresh"), new URL: '.$absolute);
+                       return $absolute;
+               }
+               return false;
+       }       
+       
+       public function getUglyURL($url, $html) {
+               if ($html == '') return false;
+               $found = false;
+               foreach ($this->ajaxTriggers as $string) {
+                       if (stripos($html, $string)) {
+                               $found = true;
+                               break;
+                       }
+               }
+               if (!$found) return false;
+               $iri = new SimplePie_IRI($url);
+               if (isset($iri->query)) {
+                       parse_str($iri->query, $query);
+               } else {
+                       $query = array();
+               }
+               $query['_escaped_fragment_'] = '';
+               $iri->query = str_replace('%2F', '/', http_build_query($query)); // needed for some sites
+               $ugly_url = $iri->get_iri();
+               $this->debug('AJAX trigger (meta name="fragment" content="!") found, new URL: '.$ugly_url);
+               return $ugly_url;
+       }
+       
+       public function removeFragment($url) {
+               $pos = strpos($url, '#');
+               if ($pos === false) {
+                       return $url;
+               } else {
+                       return substr($url, 0, $pos);
+               }
+       }
+       
+       public function rewriteUrls($url) {
+               foreach ($this->rewriteUrls as $find => $action) {
+                       if (strpos($url, $find) !== false) {
+                               if (is_array($action)) {
+                                       return strtr($url, $action);
+                               }
+                       }
+               }
+               return $url;
+       }
+       
+       public function enableDebug($bool=true) {
+               $this->debug = (bool)$bool;
+       }
+       
+       public function minimiseMemoryUse($bool = true) {
+               $this->minimiseMemoryUse = $bool;
+       }
+       
+       public function setMaxParallelRequests($max) {
+               $this->maxParallelRequests = $max;
+       }
+       
+       public function validateUrl($url) {
+               $url = filter_var($url, FILTER_SANITIZE_URL);
+               $test = filter_var($url, FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED);
+               // deal with bug http://bugs.php.net/51192 (present in PHP 5.2.13 and PHP 5.3.2)
+               if ($test === false) {
+                       $test = filter_var(strtr($url, '-', '_'), FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED);
+               }
+               if ($test !== false && $test !== null && preg_match('!^https?://!', $url)) {
+                       return $url;
+               } else {
+                       return false;
+               }
+       }
+       
+       public function fetchAll(array $urls) {
+               $this->fetchAllOnce($urls, $isRedirect=false);
+               $redirects = 0;
+               while (!empty($this->redirectQueue) && ++$redirects <= $this->maxRedirects) {
+                       $this->debug("Following redirects #$redirects...");
+                       $this->fetchAllOnce($this->redirectQueue, $isRedirect=true);
+               }
+       }
+       
+       // fetch all URLs without following redirects
+       public function fetchAllOnce(array $urls, $isRedirect=false) {
+               if (!$isRedirect) $urls = array_unique($urls);
+               if (empty($urls)) return;
+               
+               //////////////////////////////////////////////////////
+               // parallel (HttpRequestPool)
+               if ($this->method == self::METHOD_REQUEST_POOL) {
+                       $this->debug('Starting parallel fetch (HttpRequestPool)');
+                       try {
+                               while (count($urls) > 0) {
+                                       $this->debug('Processing set of '.min($this->maxParallelRequests, count($urls)));
+                                       $subset = array_splice($urls, 0, $this->maxParallelRequests);
+                                       $pool = new HttpRequestPool();
+                                       foreach ($subset as $orig => $url) {
+                                               if (!$isRedirect) $orig = $url;
+                                               unset($this->redirectQueue[$orig]);
+                                               $this->debug("...$url");
+                                               if (!$isRedirect && isset($this->requests[$url])) {
+                                                       $this->debug("......in memory");
+                                               /*
+                                               } elseif ($this->isCached($url)) {
+                                                       $this->debug("......is cached");
+                                                       if (!$this->minimiseMemoryUse) {
+                                                               $this->requests[$url] = $this->getCached($url);
+                                                       }
+                                               */
+                                               } else {
+                                                       $this->debug("......adding to pool");
+                                                       $req_url = $this->rewriteUrls($url);
+                                                       $req_url = ($this->rewriteHashbangFragment) ? $this->rewriteHashbangFragment($req_url) : $req_url;
+                                                       $req_url = $this->removeFragment($req_url);
+                                                       if (!empty($this->headerOnlyTypes) && !isset($this->requests[$orig]['wrongGuess']) && $this->possibleUnsupportedType($req_url)) {
+                                                               $_meth = HttpRequest::METH_HEAD;
+                                                       } else {
+                                                               $_meth = HttpRequest::METH_GET;
+                                                               unset($this->requests[$orig]['wrongGuess']);
+                                                       }
+                                                       $httpRequest = new HttpRequest($req_url, $_meth, $this->requestOptions);
+                                                       // send cookies, if we have any
+                                                       if ($cookies = $this->cookieJar->getMatchingCookies($req_url)) {
+                                                               $this->debug("......sending cookies: $cookies");
+                                                               $httpRequest->addHeaders(array('Cookie' => $cookies));
+                                                       }
+                                                       //$httpRequest->addHeaders(array('User-Agent' => $this->userAgent));
+                                                       $httpRequest->addHeaders($this->getUserAgent($req_url, true));
+                                                       // add referer for picky sites
+                                                       $httpRequest->addheaders(array('Referer' => $this->referer));
+                                                       $this->requests[$orig] = array('headers'=>null, 'body'=>null, 'httpRequest'=>$httpRequest);
+                                                       $this->requests[$orig]['original_url'] = $orig;
+                                                       $pool->attach($httpRequest);
+                                               }
+                                       }
+                                       // did we get anything into the pool?
+                                       if (count($pool) > 0) {
+                                               $this->debug('Sending request...');
+                                               try {
+                                                       $pool->send();
+                                               } catch (HttpRequestPoolException $e) {
+                                                       // do nothing
+                                               }
+                                               $this->debug('Received responses');
+                                               foreach($subset as $orig => $url) {
+                                                       if (!$isRedirect) $orig = $url;
+                                                       $request = $this->requests[$orig]['httpRequest'];
+                                                       //$this->requests[$orig]['headers'] = $this->headersToString($request->getResponseHeader());
+                                                       // getResponseHeader() doesn't return status line, so, for consistency...
+                                                       $this->requests[$orig]['headers'] = substr($request->getRawResponseMessage(), 0, $request->getResponseInfo('header_size'));
+                                                       // check content type
+                                                       // TODO: use getResponseHeader('content-type') or getResponseInfo()
+                                                       if ($this->headerOnlyType($this->requests[$orig]['headers'])) {
+                                                               $this->requests[$orig]['body'] = '';
+                                                               $_header_only_type = true;
+                                                               $this->debug('Header only type returned');
+                                                       } else {
+                                                               $this->requests[$orig]['body'] = $request->getResponseBody();
+                                                               $_header_only_type = false;
+                                                       }
+                                                       $this->requests[$orig]['effective_url'] = $request->getResponseInfo('effective_url');
+                                                       $this->requests[$orig]['status_code'] = $status_code = $request->getResponseCode();
+                                                       // is redirect?
+                                                       if ((in_array($status_code, array(300, 301, 302, 303, 307)) || $status_code > 307 && $status_code < 400) && $request->getResponseHeader('location')) {
+                                                               $redirectURL = $request->getResponseHeader('location');
+                                                               if (!preg_match('!^https?://!i', $redirectURL)) {
+                                                                       $redirectURL = SimplePie_Misc::absolutize_url($redirectURL, $url);
+                                                               }
+                                                               if ($this->validateURL($redirectURL)) {
+                                                                       $this->debug('Redirect detected. Valid URL: '.$redirectURL);
+                                                                       // store any cookies
+                                                                       $cookies = $request->getResponseHeader('set-cookie');
+                                                                       if ($cookies && !is_array($cookies)) $cookies = array($cookies);
+                                                                       if ($cookies) $this->cookieJar->storeCookies($url, $cookies);
+                                                                       $this->redirectQueue[$orig] = $redirectURL;
+                                                               } else {
+                                                                       $this->debug('Redirect detected. Invalid URL: '.$redirectURL);
+                                                               }
+                                                       } elseif (!$_header_only_type && $request->getMethod() === HttpRequest::METH_HEAD) {
+                                                               // the response content-type did not match our 'header only' types, 
+                                                               // but we'd issues a HEAD request because we assumed it would. So
+                                                               // let's queue a proper GET request for this item...
+                                                               $this->debug('Wrong guess at content-type, queing GET request');
+                                                               $this->requests[$orig]['wrongGuess'] = true;
+                                                               $this->redirectQueue[$orig] = $this->requests[$orig]['effective_url'];
+                                                       } elseif (strpos($this->requests[$orig]['effective_url'], '_escaped_fragment_') === false) {
+                                                               // check for <meta name='fragment' content='!'/>
+                                                               // for AJAX sites, e.g. Blogger with its dynamic views templates.
+                                                               // Based on Google's spec: https://developers.google.com/webmasters/ajax-crawling/docs/specification
+                                                               if (isset($this->requests[$orig]['body'])) {
+                                                                       $redirectURL = $this->getRedirectURLfromHTML($this->requests[$orig]['effective_url'], substr($this->requests[$orig]['body'], 0, 4000));
+                                                                       if ($redirectURL) {
+                                                                               $this->redirectQueue[$orig] = $redirectURL;
+                                                                       }
+                                                               }
+                                                       }
+                                                       //die($url.' -multi- '.$request->getResponseInfo('effective_url'));
+                                                       $pool->detach($request);
+                                                       unset($this->requests[$orig]['httpRequest'], $request);
+                                                       /*
+                                                       if ($this->minimiseMemoryUse) {
+                                                               if ($this->cache($url)) {
+                                                                       unset($this->requests[$url]);
+                                                               }
+                                                       }
+                                                       */
+                                               }
+                                       }
+                               }
+                       } catch (HttpException $e) {
+                               $this->debug($e);
+                               return false;
+                       }
+               }
+               
+               //////////////////////////////////////////////////////////
+               // parallel (curl_multi_*)
+               elseif ($this->method == self::METHOD_CURL_MULTI) {
+                       $this->debug('Starting parallel fetch (curl_multi_*)');
+                       while (count($urls) > 0) {
+                               $this->debug('Processing set of '.min($this->maxParallelRequests, count($urls)));
+                               $subset = array_splice($urls, 0, $this->maxParallelRequests);
+                               $pool = new RollingCurl(array($this, 'handleCurlResponse'));
+                               $pool->window_size = count($subset);            
+                               
+                               foreach ($subset as $orig => $url) {
+                                       if (!$isRedirect) $orig = $url;
+                                       unset($this->redirectQueue[$orig]);
+                                       $this->debug("...$url");
+                                       if (!$isRedirect && isset($this->requests[$url])) {
+                                               $this->debug("......in memory");
+                                       /*
+                                       } elseif ($this->isCached($url)) {
+                                               $this->debug("......is cached");
+                                               if (!$this->minimiseMemoryUse) {
+                                                       $this->requests[$url] = $this->getCached($url);
+                                               }
+                                       */
+                                       } else {
+                                               $this->debug("......adding to pool");
+                                               $req_url = $this->rewriteUrls($url);
+                                               $req_url = ($this->rewriteHashbangFragment) ? $this->rewriteHashbangFragment($req_url) : $req_url;
+                                               $req_url = $this->removeFragment($req_url);
+                                               if (!empty($this->headerOnlyTypes) && !isset($this->requests[$orig]['wrongGuess']) && $this->possibleUnsupportedType($req_url)) {
+                                                       $_meth = 'HEAD';
+                                               } else {
+                                                       $_meth = 'GET';
+                                                       unset($this->requests[$orig]['wrongGuess']);
+                                               }                                               
+                                               $headers = array();
+                                               //$headers[] = 'User-Agent: '.$this->userAgent;
+                                               $headers[] = $this->getUserAgent($req_url);
+                                               // add referer for picky sites
+                                               $headers[] = 'Referer: '.$this->referer;
+                                               // send cookies, if we have any
+                                               if ($cookies = $this->cookieJar->getMatchingCookies($req_url)) {
+                                                       $this->debug("......sending cookies: $cookies");
+                                                       $headers[] = 'Cookie: '.$cookies;
+                                               }
+                                               $httpRequest = new RollingCurlRequest($req_url, $_meth, null, $headers, array(
+                                                       CURLOPT_CONNECTTIMEOUT => $this->requestOptions['timeout'],
+                                                       CURLOPT_TIMEOUT => $this->requestOptions['timeout']
+                                                       ));
+                                               $httpRequest->set_original_url($orig);
+                                               $this->requests[$orig] = array('headers'=>null, 'body'=>null, 'httpRequest'=>$httpRequest);
+                                               $this->requests[$orig]['original_url'] = $orig; // TODO: is this needed anymore?
+                                               $pool->add($httpRequest);
+                                       }
+                               }
+                               // did we get anything into the pool?
+                               if (count($pool) > 0) {
+                                       $this->debug('Sending request...');
+                                       $pool->execute(); // this will call handleCurlResponse() and populate $this->requests[$orig]
+                                       $this->debug('Received responses');
+                                       foreach($subset as $orig => $url) {
+                                               if (!$isRedirect) $orig = $url;
+                                               // $this->requests[$orig]['headers']
+                                               // $this->requests[$orig]['body']
+                                               // $this->requests[$orig]['effective_url']
+                                               // check content type
+                                               if ($this->headerOnlyType($this->requests[$orig]['headers'])) {
+                                                       $this->requests[$orig]['body'] = '';
+                                                       $_header_only_type = true;
+                                                       $this->debug('Header only type returned');
+                                               } else {
+                                                       $_header_only_type = false;
+                                               }
+                                               $status_code = $this->requests[$orig]['status_code'];
+                                               if ((in_array($status_code, array(300, 301, 302, 303, 307)) || $status_code > 307 && $status_code < 400) && isset($this->requests[$orig]['location'])) {
+                                                       $redirectURL = $this->requests[$orig]['location'];
+                                                       if (!preg_match('!^https?://!i', $redirectURL)) {
+                                                               $redirectURL = SimplePie_Misc::absolutize_url($redirectURL, $url);
+                                                       }
+                                                       if ($this->validateURL($redirectURL)) {
+                                                               $this->debug('Redirect detected. Valid URL: '.$redirectURL);
+                                                               // store any cookies
+                                                               $cookies = $this->cookieJar->extractCookies($this->requests[$orig]['headers']);
+                                                               if (!empty($cookies)) $this->cookieJar->storeCookies($url, $cookies);                                                   
+                                                               $this->redirectQueue[$orig] = $redirectURL;
+                                                       } else {
+                                                               $this->debug('Redirect detected. Invalid URL: '.$redirectURL);
+                                                       }
+                                               } elseif (!$_header_only_type && $this->requests[$orig]['method'] == 'HEAD') {
+                                                       // the response content-type did not match our 'header only' types, 
+                                                       // but we'd issues a HEAD request because we assumed it would. So
+                                                       // let's queue a proper GET request for this item...
+                                                       $this->debug('Wrong guess at content-type, queing GET request');
+                                                       $this->requests[$orig]['wrongGuess'] = true;
+                                                       $this->redirectQueue[$orig] = $this->requests[$orig]['effective_url'];
+                                               } elseif (strpos($this->requests[$orig]['effective_url'], '_escaped_fragment_') === false) {
+                                                       // check for <meta name='fragment' content='!'/>
+                                                       // for AJAX sites, e.g. Blogger with its dynamic views templates.
+                                                       // Based on Google's spec: https://developers.google.com/webmasters/ajax-crawling/docs/specification
+                                                       if (isset($this->requests[$orig]['body'])) {
+                                                               $redirectURL = $this->getRedirectURLfromHTML($this->requests[$orig]['effective_url'], substr($this->requests[$orig]['body'], 0, 4000));
+                                                               if ($redirectURL) {
+                                                                       $this->redirectQueue[$orig] = $redirectURL;
+                                                               }
+                                                       }
+                                               }
+                                               // die($url.' -multi- '.$request->getResponseInfo('effective_url'));
+                                               unset($this->requests[$orig]['httpRequest'], $this->requests[$orig]['method']);
+                                       }
+                               }
+                       }
+               }
+
+               //////////////////////////////////////////////////////
+               // sequential (file_get_contents)
+               else {
+                       $this->debug('Starting sequential fetch (file_get_contents)');
+                       $this->debug('Processing set of '.count($urls));
+                       foreach ($urls as $orig => $url) {
+                               if (!$isRedirect) $orig = $url;
+                               unset($this->redirectQueue[$orig]);
+                               $this->debug("...$url");
+                               if (!$isRedirect && isset($this->requests[$url])) {
+                                       $this->debug("......in memory");
+                               /*
+                               } elseif ($this->isCached($url)) {
+                                       $this->debug("......is cached");
+                                       if (!$this->minimiseMemoryUse) {
+                                               $this->requests[$url] = $this->getCached($url);
+                                       }
+                               */
+                               } else {
+                                       $this->debug("Sending request for $url");
+                                       $this->requests[$orig]['original_url'] = $orig;
+                                       $req_url = $this->rewriteUrls($url);
+                                       $req_url = ($this->rewriteHashbangFragment) ? $this->rewriteHashbangFragment($req_url) : $req_url;
+                                       $req_url = $this->removeFragment($req_url);
+                                       // send cookies, if we have any
+                                       $httpContext = $this->httpContext;
+                                       $httpContext['http']['header'] .= $this->getUserAgent($req_url)."\r\n";
+                                       // add referer for picky sites
+                                       $httpContext['http']['header'] .= 'Referer: '.$this->referer."\r\n";
+                                       if ($cookies = $this->cookieJar->getMatchingCookies($req_url)) {
+                                               $this->debug("......sending cookies: $cookies");
+                                               $httpContext['http']['header'] .= 'Cookie: '.$cookies."\r\n";
+                                       }
+                                       if (false !== ($html = @file_get_contents($req_url, false, stream_context_create($httpContext)))) {
+                                               $this->debug('Received response');
+                                               // get status code
+                                               if (!isset($http_response_header[0]) || !preg_match('!^HTTP/\d+\.\d+\s+(\d+)!', trim($http_response_header[0]), $match)) {
+                                                       $this->debug('Error: no status code found');
+                                                       // TODO: handle error - no status code
+                                               } else {
+                                                       $this->requests[$orig]['headers'] = $this->headersToString($http_response_header, false);
+                                                       // check content type
+                                                       if ($this->headerOnlyType($this->requests[$orig]['headers'])) {
+                                                               $this->requests[$orig]['body'] = '';
+                                                       } else {
+                                                               $this->requests[$orig]['body'] = $html;
+                                                       }
+                                                       $this->requests[$orig]['effective_url'] = $req_url;
+                                                       $this->requests[$orig]['status_code'] = $status_code = (int)$match[1];
+                                                       unset($match);
+                                                       // handle redirect
+                                                       if (preg_match('/^Location:(.*?)$/mi', $this->requests[$orig]['headers'], $match)) {
+                                                               $this->requests[$orig]['location'] =  trim($match[1]);
+                                                       }
+                                                       if ((in_array($status_code, array(300, 301, 302, 303, 307)) || $status_code > 307 && $status_code < 400) && isset($this->requests[$orig]['location'])) {
+                                                               $redirectURL = $this->requests[$orig]['location'];
+                                                               if (!preg_match('!^https?://!i', $redirectURL)) {
+                                                                       $redirectURL = SimplePie_Misc::absolutize_url($redirectURL, $url);
+                                                               }
+                                                               if ($this->validateURL($redirectURL)) {
+                                                                       $this->debug('Redirect detected. Valid URL: '.$redirectURL);
+                                                                       // store any cookies
+                                                                       $cookies = $this->cookieJar->extractCookies($this->requests[$orig]['headers']);
+                                                                       if (!empty($cookies)) $this->cookieJar->storeCookies($url, $cookies);
+                                                                       $this->redirectQueue[$orig] = $redirectURL;
+                                                               } else {
+                                                                       $this->debug('Redirect detected. Invalid URL: '.$redirectURL);
+                                                               }
+                                                       } elseif (strpos($this->requests[$orig]['effective_url'], '_escaped_fragment_') === false) {
+                                                               // check for <meta name='fragment' content='!'/>
+                                                               // for AJAX sites, e.g. Blogger with its dynamic views templates.
+                                                               // Based on Google's spec: https://developers.google.com/webmasters/ajax-crawling/docs/specification
+                                                               if (isset($this->requests[$orig]['body'])) {
+                                                                       $redirectURL = $this->getRedirectURLfromHTML($this->requests[$orig]['effective_url'], substr($this->requests[$orig]['body'], 0, 4000));
+                                                                       if ($redirectURL) {
+                                                                               $this->redirectQueue[$orig] = $redirectURL;
+                                                                       }
+                                                               }
+                                                       }
+                                               }
+                                       } else {
+                                               $this->debug('Error retrieving URL');
+                                               //print_r($req_url);
+                                               //print_r($http_response_header);
+                                               //print_r($html);
+                                               
+                                               // TODO: handle error - failed to retrieve URL
+                                       }
+                               }
+                       }
+               }
+       }
+       
+       public function handleCurlResponse($response, $info, $request) {
+               $orig = $request->url_original;
+               $this->requests[$orig]['headers'] = substr($response, 0, $info['header_size']);
+               $this->requests[$orig]['body'] = substr($response, $info['header_size']);
+               $this->requests[$orig]['method'] = $request->method;
+               $this->requests[$orig]['effective_url'] = $info['url'];
+               $this->requests[$orig]['status_code'] = (int)$info['http_code'];
+               if (preg_match('/^Location:(.*?)$/mi', $this->requests[$orig]['headers'], $match)) {
+                       $this->requests[$orig]['location'] =  trim($match[1]);
+               }
+       }
+       
+       protected function headersToString(array $headers, $associative=true) {
+               if (!$associative) {
+                       return implode("\n", $headers);
+               } else {
+                       $str = '';
+                       foreach ($headers as $key => $val) {
+                               if (is_array($val)) {
+                                       foreach ($val as $v) $str .= "$key: $v\n";
+                               } else {
+                                       $str .= "$key: $val\n";
+                               }
+                       }
+                       return rtrim($str);
+               }
+       }
+       
+       public function get($url, $remove=false, $gzdecode=true) {
+               $url = "$url";
+               if (isset($this->requests[$url]) && isset($this->requests[$url]['body'])) {
+                       $this->debug("URL already fetched - in memory ($url, effective: {$this->requests[$url]['effective_url']})");
+                       $response = $this->requests[$url];
+               /*
+               } elseif ($this->isCached($url)) {
+                       $this->debug("URL already fetched - in disk cache ($url)");
+                       $response = $this->getCached($url);
+                       $this->requests[$url] = $response;
+               */
+               } else {
+                       $this->debug("Fetching URL ($url)");
+                       $this->fetchAll(array($url));
+                       if (isset($this->requests[$url]) && isset($this->requests[$url]['body'])) {
+                               $response = $this->requests[$url];
+                       } else {
+                               $this->debug("Request failed");
+                               $response = false;
+                       }
+               }
+               /*
+               if ($this->minimiseMemoryUse && $response) {
+                       $this->cache($url);
+                       unset($this->requests[$url]);
+               }
+               */
+               if ($remove && $response) unset($this->requests[$url]);
+               if ($gzdecode && stripos($response['headers'], 'Content-Encoding: gzip')) {
+                       if ($html = gzdecode($response['body'])) {
+                               $response['body'] = $html;
+                       }
+               }
+               return $response;
+       }
+       
+       public function parallelSupport() {
+               return class_exists('HttpRequestPool') || function_exists('curl_multi_init');
+       }
+       
+       private function headerOnlyType($headers) {
+               if (preg_match('!^Content-Type:\s*(([a-z-]+)/([^;\r\n ]+))!im', $headers, $match)) {
+                       // look for full mime type (e.g. image/jpeg) or just type (e.g. image)
+                       $match[1] = strtolower(trim($match[1]));
+                       $match[2] = strtolower(trim($match[2]));
+                       foreach (array($match[1], $match[2]) as $mime) {
+                               if (in_array($mime, $this->headerOnlyTypes)) return true;
+                       }
+               }
+               return false;
+       }
+       
+       private function possibleUnsupportedType($url) {
+               $path = @parse_url($url, PHP_URL_PATH);
+               if ($path && strpos($path, '.') !== false) {
+                       $ext = strtolower(trim(pathinfo($path, PATHINFO_EXTENSION)));
+                       return in_array($ext, $this->headerOnlyClues);
+               }
+               return false;
+       }
+}
+
+// gzdecode from http://www.php.net/manual/en/function.gzdecode.php#82930
+if (!function_exists('gzdecode')) {
+       function gzdecode($data,&$filename='',&$error='',$maxlength=null) 
+       {
+               $len = strlen($data);
+               if ($len < 18 || strcmp(substr($data,0,2),"\x1f\x8b")) {
+                       $error = "Not in GZIP format.";
+                       return null;  // Not GZIP format (See RFC 1952)
+               }
+               $method = ord(substr($data,2,1));  // Compression method
+               $flags  = ord(substr($data,3,1));  // Flags
+               if ($flags & 31 != $flags) {
+                       $error = "Reserved bits not allowed.";
+                       return null;
+               }
+               // NOTE: $mtime may be negative (PHP integer limitations)
+               $mtime = unpack("V", substr($data,4,4));
+               $mtime = $mtime[1];
+               $xfl   = substr($data,8,1);
+               $os    = substr($data,8,1);
+               $headerlen = 10;
+               $extralen  = 0;
+               $extra     = "";
+               if ($flags & 4) {
+                       // 2-byte length prefixed EXTRA data in header
+                       if ($len - $headerlen - 2 < 8) {
+                               return false;  // invalid
+                       }
+                       $extralen = unpack("v",substr($data,8,2));
+                       $extralen = $extralen[1];
+                       if ($len - $headerlen - 2 - $extralen < 8) {
+                               return false;  // invalid
+                       }
+                       $extra = substr($data,10,$extralen);
+                       $headerlen += 2 + $extralen;
+               }
+               $filenamelen = 0;
+               $filename = "";
+               if ($flags & 8) {
+                       // C-style string
+                       if ($len - $headerlen - 1 < 8) {
+                               return false; // invalid
+                       }
+                       $filenamelen = strpos(substr($data,$headerlen),chr(0));
+                       if ($filenamelen === false || $len - $headerlen - $filenamelen - 1 < 8) {
+                               return false; // invalid
+                       }
+                       $filename = substr($data,$headerlen,$filenamelen);
+                       $headerlen += $filenamelen + 1;
+               }
+               $commentlen = 0;
+               $comment = "";
+               if ($flags & 16) {
+                       // C-style string COMMENT data in header
+                       if ($len - $headerlen - 1 < 8) {
+                               return false;    // invalid
+                       }
+                       $commentlen = strpos(substr($data,$headerlen),chr(0));
+                       if ($commentlen === false || $len - $headerlen - $commentlen - 1 < 8) {
+                               return false;    // Invalid header format
+                       }
+                       $comment = substr($data,$headerlen,$commentlen);
+                       $headerlen += $commentlen + 1;
+               }
+               $headercrc = "";
+               if ($flags & 2) {
+                       // 2-bytes (lowest order) of CRC32 on header present
+                       if ($len - $headerlen - 2 < 8) {
+                               return false;    // invalid
+                       }
+                       $calccrc = crc32(substr($data,0,$headerlen)) & 0xffff;
+                       $headercrc = unpack("v", substr($data,$headerlen,2));
+                       $headercrc = $headercrc[1];
+                       if ($headercrc != $calccrc) {
+                               $error = "Header checksum failed.";
+                               return false;    // Bad header CRC
+                       }
+                       $headerlen += 2;
+               }
+               // GZIP FOOTER
+               $datacrc = unpack("V",substr($data,-8,4));
+               $datacrc = sprintf('%u',$datacrc[1] & 0xFFFFFFFF);
+               $isize = unpack("V",substr($data,-4));
+               $isize = $isize[1];
+               // decompression:
+               $bodylen = $len-$headerlen-8;
+               if ($bodylen < 1) {
+                       // IMPLEMENTATION BUG!
+                       return null;
+               }
+               $body = substr($data,$headerlen,$bodylen);
+               $data = "";
+               if ($bodylen > 0) {
+                       switch ($method) {
+                       case 8:
+                               // Currently the only supported compression method:
+                               $data = gzinflate($body,$maxlength);
+                               break;
+                       default:
+                               $error = "Unknown compression method.";
+                               return false;
+                       }
+               }  // zero-byte body content is allowed
+               // Verifiy CRC32
+               $crc   = sprintf("%u",crc32($data));
+               $crcOK = $crc == $datacrc;
+               $lenOK = $isize == strlen($data);
+               if (!$lenOK || !$crcOK) {
+                       $error = ( $lenOK ? '' : 'Length check FAILED. ') . ( $crcOK ? '' : 'Checksum FAILED.');
+                       return false;
+               }
+               return $data;
+       }
+}
\ No newline at end of file