CURLOPT_MAX_RECV_SPEED_LARGE/CURLOPT_MAX_SEND_SPEED_LARGE not work when reusing CURL easy_handle.

[Ymir1711]

I did this

Download two part of file using the same CURL easy_hanle with maxspeed.

I expected the following

The speed limit is also effective for the second download.

curl/libcurl version

curl-7_76_1

Issue

data->progress.ul_limit_size / data->progress.dl_limit_size was not reset to zero at the beginning.

Diff

diff --git a/lib/progress.c b/lib/progress.c
index cc040a8..c9ff706 100644
--- a/lib/progress.c
+++ b/lib/progress.c
@@ -241,6 +241,8 @@ void Curl_pgrsStartNow(struct Curl_easy *data)
   data->progress.is_t_startransfer_set = false;
   data->progress.ul_limit_start = data->progress.start;
   data->progress.dl_limit_start = data->progress.start;
+  data->progress.ul_limit_size = 0;
+  data->progress.dl_limit_size = 0;
   data->progress.downloaded = 0;
   data->progress.uploaded = 0;
   /* clear all bits except HIDE and HEADERS_OUT */

Demo

#include <stdio.h>
#include <string.h>
#include <curl/curl.h>

static int progress_callback(void *clientp,   double dltotal,   double dlnow,   double ultotal,   double ulnow)
{
    static time_t time_last = 0;
    static double dlnow_last = 0;

    time_t now = time(NULL);
    if (time_last == 0) {
        time_last = now;
        dlnow_last = dlnow;
    }

    if (now > time_last + 1) {
        printf("Speed: %.2f KB/S, Progress: %.2f %%\n", (dlnow - dlnow_last) / (now - time_last) / 1024, dlnow / dltotal * 100);
        time_last = now;
        dlnow_last = dlnow;
    }

    return 0;
}

static size_t write_callback(char *ptr, size_t size, size_t nmemb, void *userdata)
{
    return size * nmemb;
}

void perform(CURLM *multi_handle, CURL *easy_handle)
{
    CURLMcode mcode = curl_multi_add_handle(multi_handle, easy_handle);

    CURLcode result = CURLE_OK;
    while (!mcode) {
        int still_running = 0;
        int numfds = 0;

        mcode = curl_multi_perform(multi_handle, &still_running);

        if (!mcode && !still_running) {
            int rc;
            CURLMsg *msg = curl_multi_info_read(multi_handle, &rc);
            if (msg) {
                result = msg->data.result;
                printf("Curl result: %d\n", result);
                break;
            }
        }else {
            long timeout;
            curl_multi_timeout(multi_handle, &timeout);
            if (timeout < 0) {
                timeout = 100;
            }

            curl_multi_wait(multi_handle, NULL, 0, timeout, &numfds);
        }
    }

    curl_multi_remove_handle(multi_handle, easy_handle);
}

int main()
{
    curl_version_info_data *data = curl_version_info(CURLVERSION_NOW);
    printf("Curl version: %s\n", data->version);

    CURLM *multi_handle = curl_multi_init();
    if (!multi_handle) {
        return -1;
    }

    CURL *easy_handle = curl_easy_init();
    if (!easy_handle) {
        return -1;
    }

    const char *url = "https://xxx.com/file/bin/10MB.bin";
    curl_easy_setopt(easy_handle, CURLOPT_URL, url);
    curl_easy_setopt(easy_handle, CURLOPT_PROGRESSFUNCTION, progress_callback);
    curl_easy_setopt(easy_handle, CURLOPT_NOPROGRESS, 0L);
    curl_easy_setopt(easy_handle, CURLOPT_WRITEFUNCTION, write_callback);
    curl_easy_setopt(easy_handle, CURLOPT_VERBOSE, 1L);
    curl_easy_setopt(easy_handle, CURLOPT_SSL_VERIFYPEER, 0L);
    curl_easy_setopt(easy_handle, CURLOPT_MAX_RECV_SPEED_LARGE, (curl_off_t)65535);

    char range[32] = {'\0'};
    strcpy(range, "0-1000000");
    curl_easy_setopt(easy_handle, CURLOPT_RANGE, range);

    perform(multi_handle, easy_handle);

    strcpy(range, "1000001-2000000");
    curl_easy_setopt(easy_handle, CURLOPT_RANGE, range);

    perform(multi_handle, easy_handle);

    curl_easy_cleanup(easy_handle);
    curl_multi_cleanup(multi_handle);

    return 0;
}

[bagder]

Seems accurate! Can you make a "real" pull request out of this change or would you like me to do it?

[Ymir1711]

It's better for you to do it.