private function isUpdatingLatestVersion(Tracker_Artifact $artifact) { $valid_unmodified = true; $valid_match = true; if (isset($_SERVER['HTTP_IF_UNMODIFIED_SINCE'])) { $client_version = strtotime($_SERVER['HTTP_IF_UNMODIFIED_SINCE']); $last_version = $artifact->getLastUpdateDate(); $valid_unmodified = $last_version == $client_version; } if (isset($_SERVER['HTTP_IF_MATCH'])) { $client_version = $_SERVER['HTTP_IF_MATCH']; $last_version = $artifact->getVersionIdentifier(); $valid_match = $last_version == $client_version; } return $valid_unmodified && $valid_match; }