/**
* Check selected RFC 7232 precondition headers
*
* RFC 7232 envisions a particular model where you send your request to "a
* resource", and for write requests that you can read "the resource" by
* changing the method to GET. When the API receives a GET request, it
* works out even though "the resource" from RFC 7232's perspective might
* be many resources from MediaWiki's perspective. But it totally fails for
* a POST, since what HTTP sees as "the resource" is probably just
* "/api.php" with all the interesting bits in the body.
*
* Therefore, we only support RFC 7232 precondition headers for GET (and
* HEAD). That means we don't need to bother with If-Match and
* If-Unmodified-Since since they only apply to modification requests.
*
* And since we don't support Range, If-Range is ignored too.
*
* @since 1.26
* @param ApiBase $module Api module being used
* @return bool True on success, false should exit immediately
*/
protected function checkConditionalRequestHeaders($module)
{
if ($this->mInternalMode) {
// No headers to check in internal mode
return true;
}
if ($this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD') {
// Don't check POSTs
return true;
}
$return304 = false;
$ifNoneMatch = array_diff($this->getRequest()->getHeader('If-None-Match', WebRequest::GETHEADER_LIST) ?: array(), array(''));
if ($ifNoneMatch) {
if ($ifNoneMatch === array('*')) {
// API responses always "exist"
$etag = '*';
} else {
$etag = $module->getConditionalRequestData('etag');
}
}
if ($ifNoneMatch && $etag !== null) {
$test = substr($etag, 0, 2) === 'W/' ? substr($etag, 2) : $etag;
$match = array_map(function ($s) {
return substr($s, 0, 2) === 'W/' ? substr($s, 2) : $s;
}, $ifNoneMatch);
$return304 = in_array($test, $match, true);
} else {
$value = trim($this->getRequest()->getHeader('If-Modified-Since'));
// Some old browsers sends sizes after the date, like this:
// Wed, 20 Aug 2003 06:51:19 GMT; length=5202
// Ignore that.
$i = strpos($value, ';');
if ($i !== false) {
$value = trim(substr($value, 0, $i));
}
if ($value !== '') {
try {
$ts = new MWTimestamp($value);
if ($ts->getTimestamp(TS_RFC2822) === $value || $ts->format('l, d-M-y H:i:s') . ' GMT' === $value || $ts->format('D M j H:i:s Y') === $value || $ts->format('D M j H:i:s Y') === $value) {
$lastMod = $module->getConditionalRequestData('last-modified');
if ($lastMod !== null) {
// Mix in some MediaWiki modification times
$modifiedTimes = array('page' => $lastMod, 'user' => $this->getUser()->getTouched(), 'epoch' => $this->getConfig()->get('CacheEpoch'));
if ($this->getConfig()->get('UseSquid')) {
// T46570: the core page itself may not change, but resources might
$modifiedTimes['sepoch'] = wfTimestamp(TS_MW, time() - $this->getConfig()->get('SquidMaxage'));
}
Hooks::run('OutputPageCheckLastModified', array(&$modifiedTimes));
$lastMod = max($modifiedTimes);
$return304 = wfTimestamp(TS_MW, $lastMod) <= $ts->getTimestamp(TS_MW);
}
}
} catch (TimestampException $e) {
// Invalid timestamp, ignore it
}
}
}
if ($return304) {
$this->getRequest()->response()->statusHeader(304);
// Avoid outputting the compressed representation of a zero-length body
MediaWiki\suppressWarnings();
ini_set('zlib.output_compression', 0);
MediaWiki\restoreWarnings();
wfClearOutputBuffers();
return false;
}
return true;
}