rss-bridge/lib/contents.php
logmanoriginal 2460b67886 cache: Refactor cache factory to non-static class
The cache factory can be based on the abstract factory class if it
wasn't static. This allows for higher abstraction and makes future
extensions possible. Also, not all parts of RSS-Bridge need to work
on the same instance of the factory.

References #1001
2019-06-18 19:04:19 +02:00

402 lines
12 KiB
PHP

<?php
/**
* This file is part of RSS-Bridge, a PHP project capable of generating RSS and
* Atom feeds for websites that don't have one.
*
* For the full license information, please view the UNLICENSE file distributed
* with this source code.
*
* @package Core
* @license http://unlicense.org/ UNLICENSE
* @link https://github.com/rss-bridge/rss-bridge
*/
/**
* Gets contents from the Internet.
*
* **Content caching** (disabled in debug mode)
*
* A copy of the received content is stored in a local cache folder `server/` at
* {@see PATH_CACHE}. The `If-Modified-Since` header is added to the request, if
* the provided URL has been cached before.
*
* When the server responds with `304 Not Modified`, the cached data is returned.
* This will improve response times and reduce bandwidth for servers that support
* the `If-Modified-Since` header.
*
* Cached files are forcefully removed after 24 hours.
*
* @link https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-Modified-Since
* If-Modified-Since
*
* @param string $url The URL.
* @param array $header (optional) A list of cURL header.
* For more information follow the links below.
* * https://php.net/manual/en/function.curl-setopt.php
* * https://curl.haxx.se/libcurl/c/CURLOPT_HTTPHEADER.html
* @param array $opts (optional) A list of cURL options as associative array in
* the format `$opts[$option] = $value;`, where `$option` is any `CURLOPT_XXX`
* option and `$value` the corresponding value.
*
* For more information see http://php.net/manual/en/function.curl-setopt.php
* @return string The contents.
*/
function getContents($url, $header = array(), $opts = array()){
Debug::log('Reading contents from "' . $url . '"');
// Initialize cache
$cacheFac = new CacheFactory();
$cacheFac->setWorkingDir(PATH_LIB_CACHES);
$cache = $cacheFac->create(Configuration::getConfig('cache', 'type'));
$cache->setScope('server');
$cache->purgeCache(86400); // 24 hours (forced)
$params = [$url];
$cache->setKey($params);
// Use file_get_contents if in CLI mode with no root certificates defined
if(php_sapi_name() === 'cli' && empty(ini_get('curl.cainfo'))) {
$data = @file_get_contents($url);
if($data === false) {
$errorCode = 500;
} else {
$errorCode = 200;
}
$curlError = '';
$curlErrno = '';
$headerSize = 0;
$finalHeader = array();
} else {
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
if(is_array($header) && count($header) !== 0) {
Debug::log('Setting headers: ' . json_encode($header));
curl_setopt($ch, CURLOPT_HTTPHEADER, $header);
}
curl_setopt($ch, CURLOPT_USERAGENT, ini_get('user_agent'));
curl_setopt($ch, CURLOPT_ENCODING, '');
curl_setopt($ch, CURLOPT_PROTOCOLS, CURLPROTO_HTTP | CURLPROTO_HTTPS);
if(is_array($opts) && count($opts) !== 0) {
Debug::log('Setting options: ' . json_encode($opts));
foreach($opts as $key => $value) {
curl_setopt($ch, $key, $value);
}
}
if(defined('PROXY_URL') && !defined('NOPROXY')) {
Debug::log('Setting proxy url: ' . PROXY_URL);
curl_setopt($ch, CURLOPT_PROXY, PROXY_URL);
}
// We always want the response header as part of the data!
curl_setopt($ch, CURLOPT_HEADER, true);
// Build "If-Modified-Since" header
if(!Debug::isEnabled() && $time = $cache->getTime()) { // Skip if cache file doesn't exist
Debug::log('Adding If-Modified-Since');
curl_setopt($ch, CURLOPT_TIMEVALUE, $time);
curl_setopt($ch, CURLOPT_TIMECONDITION, CURL_TIMECOND_IFMODSINCE);
}
// Enables logging for the outgoing header
curl_setopt($ch, CURLINFO_HEADER_OUT, true);
$data = curl_exec($ch);
$errorCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
$curlError = curl_error($ch);
$curlErrno = curl_errno($ch);
$curlInfo = curl_getinfo($ch);
Debug::log('Outgoing header: ' . json_encode($curlInfo));
if($data === false)
Debug::log('Cant\'t download ' . $url . ' cUrl error: ' . $curlError . ' (' . $curlErrno . ')');
$headerSize = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
$header = substr($data, 0, $headerSize);
Debug::log('Response header: ' . $header);
$headers = parseResponseHeader($header);
$finalHeader = end($headers);
curl_close($ch);
}
switch($errorCode) {
case 200: // Contents received
Debug::log('New contents received');
$data = substr($data, $headerSize);
// Disable caching if the server responds with "Cache-Control: no-cache"
// or "Cache-Control: no-store"
$finalHeader = array_change_key_case($finalHeader, CASE_LOWER);
if(array_key_exists('cache-control', $finalHeader)) {
Debug::log('Server responded with "Cache-Control" header');
$directives = explode(',', $finalHeader['cache-control']);
$directives = array_map('trim', $directives);
if(in_array('no-cache', $directives)
|| in_array('no-store', $directives)) { // Skip caching
Debug::log('Skip server side caching');
return $data;
}
}
Debug::log('Store response to cache');
$cache->saveData($data);
return $data;
case 304: // Not modified, use cached data
Debug::log('Contents not modified on host, returning cached data');
return $cache->loadData();
default:
if(array_key_exists('Server', $finalHeader) && strpos($finalHeader['Server'], 'cloudflare') !== false) {
returnServerError(<<< EOD
The server responded with a Cloudflare challenge, which is not supported by RSS-Bridge!
If this error persists longer than a week, please consider opening an issue on GitHub!
EOD
);
}
$lastError = error_get_last();
if($lastError !== null)
$lastError = $lastError['message'];
returnError(<<<EOD
The requested resource cannot be found!
Please make sure your input parameters are correct!
cUrl error: $curlError ($curlErrno)
PHP error: $lastError
EOD
, $errorCode);
}
}
/**
* Gets contents from the Internet as simplhtmldom object.
*
* @param string $url The URL.
* @param array $header (optional) A list of cURL header.
* For more information follow the links below.
* * https://php.net/manual/en/function.curl-setopt.php
* * https://curl.haxx.se/libcurl/c/CURLOPT_HTTPHEADER.html
* @param array $opts (optional) A list of cURL options as associative array in
* the format `$opts[$option] = $value;`, where `$option` is any `CURLOPT_XXX`
* option and `$value` the corresponding value.
*
* For more information see http://php.net/manual/en/function.curl-setopt.php
* @param bool $lowercase Force all selectors to lowercase.
* @param bool $forceTagsClosed Forcefully close tags in malformed HTML.
*
* _Remarks_: Forcefully closing tags is great for malformed HTML, but it can
* lead to parsing errors.
* @param string $target_charset Defines the target charset.
* @param bool $stripRN Replace all occurrences of `"\r"` and `"\n"` by `" "`.
* @param string $defaultBRText Specifies the replacement text for `<br>` tags
* when returning plaintext.
* @param string $defaultSpanText Specifies the replacement text for `<span />`
* tags when returning plaintext.
* @return string Contents as simplehtmldom object.
*/
function getSimpleHTMLDOM($url,
$header = array(),
$opts = array(),
$lowercase = true,
$forceTagsClosed = true,
$target_charset = DEFAULT_TARGET_CHARSET,
$stripRN = true,
$defaultBRText = DEFAULT_BR_TEXT,
$defaultSpanText = DEFAULT_SPAN_TEXT){
$content = getContents($url, $header, $opts);
return str_get_html($content,
$lowercase,
$forceTagsClosed,
$target_charset,
$stripRN,
$defaultBRText,
$defaultSpanText);
}
/**
* Gets contents from the Internet as simplhtmldom object. Contents are cached
* and re-used for subsequent calls until the cache duration elapsed.
*
* _Notice_: Cached contents are forcefully removed after 24 hours (86400 seconds).
*
* @param string $url The URL.
* @param int $duration Cache duration in seconds.
* @param array $header (optional) A list of cURL header.
* For more information follow the links below.
* * https://php.net/manual/en/function.curl-setopt.php
* * https://curl.haxx.se/libcurl/c/CURLOPT_HTTPHEADER.html
* @param array $opts (optional) A list of cURL options as associative array in
* the format `$opts[$option] = $value;`, where `$option` is any `CURLOPT_XXX`
* option and `$value` the corresponding value.
*
* For more information see http://php.net/manual/en/function.curl-setopt.php
* @param bool $lowercase Force all selectors to lowercase.
* @param bool $forceTagsClosed Forcefully close tags in malformed HTML.
*
* _Remarks_: Forcefully closing tags is great for malformed HTML, but it can
* lead to parsing errors.
* @param string $target_charset Defines the target charset.
* @param bool $stripRN Replace all occurrences of `"\r"` and `"\n"` by `" "`.
* @param string $defaultBRText Specifies the replacement text for `<br>` tags
* when returning plaintext.
* @param string $defaultSpanText Specifies the replacement text for `<span />`
* tags when returning plaintext.
* @return string Contents as simplehtmldom object.
*/
function getSimpleHTMLDOMCached($url,
$duration = 86400,
$header = array(),
$opts = array(),
$lowercase = true,
$forceTagsClosed = true,
$target_charset = DEFAULT_TARGET_CHARSET,
$stripRN = true,
$defaultBRText = DEFAULT_BR_TEXT,
$defaultSpanText = DEFAULT_SPAN_TEXT){
Debug::log('Caching url ' . $url . ', duration ' . $duration);
// Initialize cache
$cacheFac = new CacheFactory();
$cacheFac->setWorkingDir(PATH_LIB_CACHES);
$cache = $cacheFac->create(Configuration::getConfig('cache', 'type'));
$cache->setScope('pages');
$cache->purgeCache(86400); // 24 hours (forced)
$params = [$url];
$cache->setKey($params);
// Determine if cached file is within duration
$time = $cache->getTime();
if($time !== false
&& (time() - $duration < $time)
&& Debug::isEnabled()) { // Contents within duration
$content = $cache->loadData();
} else { // Content not within duration
$content = getContents($url, $header, $opts);
if($content !== false) {
$cache->saveData($content);
}
}
return str_get_html($content,
$lowercase,
$forceTagsClosed,
$target_charset,
$stripRN,
$defaultBRText,
$defaultSpanText);
}
/**
* Parses the cURL response header into an associative array
*
* Based on https://stackoverflow.com/a/18682872
*
* @param string $header The cURL response header.
* @return array An associative array of response headers.
*/
function parseResponseHeader($header) {
$headers = array();
$requests = explode("\r\n\r\n", trim($header));
foreach ($requests as $request) {
$header = array();
foreach (explode("\r\n", $request) as $i => $line) {
if($i === 0) {
$header['http_code'] = $line;
} else {
list ($key, $value) = explode(':', $line);
$header[$key] = trim($value);
}
}
$headers[] = $header;
}
return $headers;
}
/**
* Determines the MIME type from a URL/Path file extension.
*
* _Remarks_:
*
* * The built-in functions `mime_content_type` and `fileinfo` require fetching
* remote contents.
* * A caller can hint for a MIME type by appending `#.ext` to the URL (i.e. `#.image`).
*
* Based on https://stackoverflow.com/a/1147952
*
* @param string $url The URL or path to the file.
* @return string The MIME type of the file.
*/
function getMimeType($url) {
static $mime = null;
if (is_null($mime)) {
// Default values, overriden by /etc/mime.types when present
$mime = array(
'jpg' => 'image/jpeg',
'gif' => 'image/gif',
'png' => 'image/png',
'image' => 'image/*'
);
// '@' is used to mute open_basedir warning, see issue #818
if (@is_readable('/etc/mime.types')) {
$file = fopen('/etc/mime.types', 'r');
while(($line = fgets($file)) !== false) {
$line = trim(preg_replace('/#.*/', '', $line));
if(!$line)
continue;
$parts = preg_split('/\s+/', $line);
if(count($parts) == 1)
continue;
$type = array_shift($parts);
foreach($parts as $part)
$mime[$part] = $type;
}
fclose($file);
}
}
if (strpos($url, '?') !== false) {
$url_temp = substr($url, 0, strpos($url, '?'));
if (strpos($url, '#') !== false) {
$anchor = substr($url, strpos($url, '#'));
$url_temp .= $anchor;
}
$url = $url_temp;
}
$ext = strtolower(pathinfo($url, PATHINFO_EXTENSION));
if (!empty($mime[$ext])) {
return $mime[$ext];
}
return 'application/octet-stream';
}