Rate limit

Lets an application set a speed cap. Do not transfer data faster than a set number of bytes per second. libcurl then attempts to keep the average speed below the given threshold over a period of multiple seconds.
There are separate options for receiving (CURLOPT_MAX_RECV_SPEED_LARGE) and sending (CURLOPT_MAX_SEND_SPEED_LARGE).
Here is an example source code showing it in use:
#include <stdio.h>
#include <curl/curl.h>
int main(void)
CURL *curl;
CURLcode res = CURLE_OK;
curl = curl_easy_init();
if(curl) {
curl_off_t maxrecv = 31415;
curl_off_t maxsend = 67954;
curl_easy_setopt(curl, CURLOPT_MAX_RECV_SPEED_LARGE, maxrecv);
curl_easy_setopt(curl, CURLOPT_MAX_SEND_SPEED_LARGE, maxsend);
curl_easy_setopt(curl, CURLOPT_URL, "");
res = curl_easy_perform(curl);
return (int)res;