HI Dmitry, > Am 05.03.2024 um 02:04 schrieb Dmitry Karpov via curl-library > <curl-library@lists.haxx.se>: > > Hi All, > After running some speed throttling tests on the latest libcurl, I noticed > that the speed throttling precision got lost again. > > I reported this issue for 8.5.0, and it was fixed for 8.6.0 as part of > https://github.com/curl/curl/commit/1da640abb6886aab822ff0c0da71b1df0ca89d0f, > which avoided read looping when speed throttling was enabled > by setting curl_off_t max_recv to zero ( curl_off_t max_recv = > data->set.max_recv_speed ? 0 : CURL_OFF_T_MAX; ) in readwrite_data() in > lib\transfer.c. > > But it looks like that part was lost during some recent readwrite_data() > refactoring, and this function got back to read looping when the speed limit > is set, which depending on network speed and download size can create speed > deviations more than 10%. > > In order to have more or less precise speed limits (<1% on average), we need > to avoid read looping for cases of the speed limit, so the following change > should be probably applied: > > --- > lib/transfer.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > diff --git a/lib/transfer.c b/lib/transfer.c > index 3ae4b61c0..3ad7904de 100644 > --- a/lib/transfer.c > +++ b/lib/transfer.c > @@ -495,7 +495,7 @@ static CURLcode readwrite_data(struct Curl_easy *data, > /* Observe any imposed speed limit */ > if(bytestoread && data->set.max_recv_speed) { > curl_off_t net_limit = data->set.max_recv_speed - total_received; > - if(net_limit <= 0) > + if(net_limit <= 0 || total_received) > break; > if((size_t)net_limit < bytestoread) > bytestoread = (size_t)net_limit;
Thanks for the suggestion. I made the change into https://github.com/curl/curl/pull/13050. Would be happy to head if this works for you as well. Cheers, Stefan > -- > > which will break the reading loop after the first read. > > Thanks, > Dmitry Karpov > -- > Unsubscribe: https://lists.haxx.se/mailman/listinfo/curl-library > Etiquette: https://curl.se/mail/etiquette.html -- Unsubscribe: https://lists.haxx.se/mailman/listinfo/curl-library Etiquette: https://curl.se/mail/etiquette.html
