#include <curl/curl.h>

size_t read_callback(char *ptr, size_t size, size_t nmemb, void *userdata) {
	/* Just ensure that it works:
	 * static int i = 0;
	 * printf("read_callback %d\n", i++);
	*/

	/*
	 *  You could uncomment the line to ensure that a data transfer helps to perform
	 *  a request after a connection lost.
	 */
	/* if (0) */
	{
		return CURL_READFUNC_PAUSE;
	}
	ptr[0] = '\n';
	return 1;
}

int progress_callback(void *clientp,
                      double dltotal,
                      double dlnow,
                      double ultotal,
                      double ulnow) {
	/*
	 * Ensure that the continue does not actually help without a
	 * data transfer.
	 */
	CURL *curl = (CURL*) clientp;
	curl_easy_pause(curl, CURLPAUSE_CONT);
	return 0;
}

int main() {
	CURL *curl = curl_easy_init();
	if(curl) {
  		/* We want to use our own read function. */
  		curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_callback);

		/* It will help us to continue the read function. */
		curl_easy_setopt(curl, CURLOPT_XFERINFOFUNCTION, progress_callback);
		curl_easy_setopt(curl, CURLOPT_XFERINFODATA, curl);
		curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0L);

		/* It will help us to ensure that keepalive does not help. */
		curl_easy_setopt(curl, CURLOPT_TCP_KEEPALIVE, 1L);
		curl_easy_setopt(curl, CURLOPT_TCP_KEEPIDLE, 1L);
		curl_easy_setopt(curl, CURLOPT_TCP_KEEPINTVL, 1L);

  		/* Enable uploading. */
		curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "POST");
  		curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
 
  		curl_easy_setopt(curl, CURLOPT_URL, "http://localhost:2379/v3/watch");
		curl_easy_perform(curl);
	}
}