/* * call-seq: * easy.on_progress { |dl_total, dl_now, ul_total, ul_now| ... } => <old handler> * * Assign or remove the +on_progress+ handler for this Curl::Easy instance. * To remove a previously-supplied handler, call this method with no * attached block. * * The +on_progress+ handler is called regularly by libcurl (approximately once * per second) during transfers to allow the application to receive progress * information. There is no guarantee that the reported progress will change * between calls. * * The result of the block call determines whether libcurl continues the transfer. * Returning a non-true value (i.e. nil or false) will cause the transfer to abort, * throwing a Curl::Err::AbortedByCallbackError. */ static VALUE ruby_curl_easy_on_progress_set(int argc, VALUE *argv, VALUE self) {