class Tweeper {
private static $userAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Firefox/60.0";
+ private static $maxConnectionTimeout = 5;
+ private static $maxConnectionRetries = 5;
/**
* Create a new Tweeper object controlling optional settings.
}
/**
+ * Perform a cURL session multiple times when it fails with a timeout.
+ *
+ * @param resource $ch
+ * a cURL session handle.
+ */
+ private static function curlExec($ch) {
+ $ret = FALSE;
+ $attempt = 0;
+ do {
+ $ret = curl_exec($ch);
+ if (FALSE === $ret) {
+ trigger_error(curl_error($ch), E_USER_WARNING);
+ }
+ } while (curl_errno($ch) == CURLE_OPERATION_TIMEDOUT && ++$attempt < Tweeper::$maxConnectionRetries);
+
+ return $ret;
+ }
+
+ /**
* Get the contents from a URL.
*/
private static function getUrlContents($url) {
$ch = curl_init($url);
curl_setopt_array($ch, array(
CURLOPT_HEADER => FALSE,
+ CURLOPT_CONNECTTIMEOUT => Tweeper::$maxConnectionTimeout,
// Follow http redirects to get the real URL.
CURLOPT_FOLLOWLOCATION => TRUE,
CURLOPT_RETURNTRANSFER => TRUE,
CURLOPT_HTTPHEADER => array('Accept-language: en'),
CURLOPT_USERAGENT => Tweeper::$userAgent,
));
- $contents = curl_exec($ch);
- if (FALSE === $contents) {
- trigger_error(curl_error($ch));
- }
+ $contents = Tweeper::curlExec($ch);
curl_close($ch);
return $contents;
curl_setopt_array($ch, array(
CURLOPT_HEADER => TRUE,
CURLOPT_NOBODY => TRUE,
+ CURLOPT_CONNECTTIMEOUT => Tweeper::$maxConnectionTimeout,
// Follow http redirects to get the real URL.
CURLOPT_FOLLOWLOCATION => TRUE,
CURLOPT_RETURNTRANSFER => TRUE,
CURLOPT_SSL_VERIFYPEER => FALSE,
CURLOPT_USERAGENT => Tweeper::$userAgent,
));
- curl_exec($ch);
+
+ $ret = Tweeper::curlExec($ch);
+ if (FALSE === $ret) {
+ curl_close($ch);
+ return FALSE;
+ }
+
$url_info = curl_getinfo($ch);
if (FALSE === $url_info) {
- trigger_error(curl_error($ch));
+ trigger_error(curl_error($ch), E_USER_WARNING);
}
curl_close($ch);
);
$url_info = Tweeper::getUrlInfo($url);
+ if (FALSE === $url_info) {
+ trigger_error("Failed to retrieve info for URL: " . $url, E_USER_WARNING);
+ return '';
+ }
$supported = in_array($url_info['content_type'], $supported_content_types);
if (!$supported) {
- error_log("Unsupported enclosure content type \"" . $url_info['content_type'] . "\" for URL: " . $url_info['url']);
+ trigger_error("Unsupported enclosure content type \"" . $url_info['content_type'] . "\" for URL: " . $url_info['url'], E_USER_WARNING);
return '';
}
$output .= " line $error->line";
- error_log($output);
+ trigger_error($output, E_USER_WARNING);
}
/**
$xml_data = $serializer->serialize($data, 'xml', $serializer_options);
if (!$xml_data) {
- trigger_error("Cannot serialize data", E_USER_ERROR);
+ trigger_error("Cannot serialize data", E_USER_WARNING);
return NULL;
}
$json_match_expr = '/window._sharedData = (.*);/';
$ret = preg_match($json_match_expr, $html, $matches);
if ($ret !== 1) {
- trigger_error("Cannot match expression: $json_match_expr\n", E_USER_ERROR);
+ trigger_error("Cannot match expression: $json_match_expr\n", E_USER_WARNING);
return NULL;
}
private function loadStylesheet($host) {
$stylesheet = "file://" . __DIR__ . "/rss_converter_" . $host . ".xsl";
if (FALSE === file_exists($stylesheet)) {
- trigger_error("Conversion to RSS not supported for $host ($stylesheet not found)", E_USER_ERROR);
+ trigger_error("Conversion to RSS not supported for $host ($stylesheet not found)", E_USER_WARNING);
return NULL;
}
$stylesheet_contents = Tweeper::getUrlContents($stylesheet);
+ if (FALSE === $stylesheet_contents) {
+ trigger_error("Cannot open $stylesheet", E_USER_WARNING);
+ return NULL;
+ }
$xslDoc = new DOMDocument();
$xslDoc->loadXML($stylesheet_contents);
/**
* Convert the site content to RSS.
*/
- public function tweep($src_url, $host=NULL, $validate_scheme=TRUE) {
+ public function tweep($src_url, $host = NULL, $validate_scheme = TRUE) {
$url = parse_url($src_url);
if (FALSE === $url) {
- trigger_error("Invalid URL: $src_url", E_USER_ERROR);
+ trigger_error("Invalid URL: $src_url", E_USER_WARNING);
return NULL;
}
if (TRUE === $validate_scheme) {
$scheme = $url["scheme"];
if (!in_array($scheme, array("http", "https"))) {
- trigger_error("unsupported scheme: $scheme", E_USER_ERROR);
+ trigger_error("unsupported scheme: $scheme", E_USER_WARNING);
return NULL;
}
}
- // if the host is not given derive it from the URL
+ // If the host is not given derive it from the URL.
if (NULL === $host) {
if (empty($url["host"])) {
- trigger_error("Invalid host in URL: $src_url", E_USER_ERROR);
+ trigger_error("Invalid host in URL: $src_url", E_USER_WARNING);
return NULL;
}
// Strip the leading www. to be more forgiving on input URLs.
$html = Tweeper::getUrlContents($src_url);
if (FALSE === $html) {
+ trigger_error("Failed to retrieve $src_url", E_USER_WARNING);
return NULL;
}
$output = $xsltProcessor->transformToXML($xmlDoc);
if (FALSE === $output) {
- trigger_error('XSL transformation failed.', E_USER_ERROR);
+ trigger_error('XSL transformation failed.', E_USER_WARNING);
return NULL;
}