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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
/* <DESC>
* multi_socket API using libuv
* </DESC>
*/
/* Example application using the multi socket interface to download multiple
files in parallel, powered by libuv.
Requires libuv and (of course) libcurl.
See https://nikhilm.github.io/uvbook/ for more information on libuv.
*/
#include <stdio.h>
#include <stdlib.h>
#include <uv.h>
#include <curl/curl.h>
uv_loop_t *loop;
CURLM *curl_handle;
uv_timer_t timeout;
typedef struct curl_context_s {
uv_poll_t poll_handle;
curl_socket_t sockfd;
} curl_context_t;
static curl_context_t *create_curl_context(curl_socket_t sockfd)
{
curl_context_t *context;
context = (curl_context_t *) malloc(sizeof(*context));
context->sockfd = sockfd;
uv_poll_init_socket(loop, &context->poll_handle, sockfd);
context->poll_handle.data = context;
return context;
}
static void curl_close_cb(uv_handle_t *handle)
{
curl_context_t *context = (curl_context_t *) handle->data;
free(context);
}
static void destroy_curl_context(curl_context_t *context)
{
uv_close((uv_handle_t *) &context->poll_handle, curl_close_cb);
}
static void add_download(const char *url, int num)
{
char filename[50];
FILE *file;
CURL *handle;
snprintf(filename, 50, "%d.download", num);
file = fopen(filename, "wb");
if(!file) {
fprintf(stderr, "Error opening %s\n", filename);
return;
}
handle = curl_easy_init();
curl_easy_setopt(handle, CURLOPT_WRITEDATA, file);
curl_easy_setopt(handle, CURLOPT_PRIVATE, file);
curl_easy_setopt(handle, CURLOPT_URL, url);
curl_multi_add_handle(curl_handle, handle);
fprintf(stderr, "Added download %s -> %s\n", url, filename);
}
static void check_multi_info(void)
{
char *done_url;
CURLMsg *message;
int pending;
CURL *easy_handle;
FILE *file;
while((message = curl_multi_info_read(curl_handle, &pending))) {
switch(message->msg) {
case CURLMSG_DONE:
/* Do not use message data after calling curl_multi_remove_handle() and
curl_easy_cleanup(). As per curl_multi_info_read() docs:
"WARNING: The data the returned pointer points to will not survive
calling curl_multi_cleanup, curl_multi_remove_handle or
curl_easy_cleanup." */
easy_handle = message->easy_handle;
curl_easy_getinfo(easy_handle, CURLINFO_EFFECTIVE_URL, &done_url);
curl_easy_getinfo(easy_handle, CURLINFO_PRIVATE, &file);
printf("%s DONE\n", done_url);
curl_multi_remove_handle(curl_handle, easy_handle);
curl_easy_cleanup(easy_handle);
if(file) {
fclose(file);
}
break;
default:
fprintf(stderr, "CURLMSG default\n");
break;
}
}
}
static void curl_perform(uv_poll_t *req, int status, int events)
{
int running_handles;
int flags = 0;
curl_context_t *context;
if(events & UV_READABLE)
flags |= CURL_CSELECT_IN;
if(events & UV_WRITABLE)
flags |= CURL_CSELECT_OUT;
context = (curl_context_t *) req->data;
curl_multi_socket_action(curl_handle, context->sockfd, flags,
&running_handles);
check_multi_info();
}
static void on_timeout(uv_timer_t *req)
{
int running_handles;
curl_multi_socket_action(curl_handle, CURL_SOCKET_TIMEOUT, 0,
&running_handles);
check_multi_info();
}
static int start_timeout(CURLM *multi, long timeout_ms, void *userp)
{
if(timeout_ms < 0) {
uv_timer_stop(&timeout);
}
else {
if(timeout_ms == 0)
timeout_ms = 1; /* 0 means directly call socket_action, but we'll do it
in a bit */
uv_timer_start(&timeout, on_timeout, timeout_ms, 0);
}
return 0;
}
static int handle_socket(CURL *easy, curl_socket_t s, int action, void *userp,
void *socketp)
{
curl_context_t *curl_context;
int events = 0;
switch(action) {
case CURL_POLL_IN:
case CURL_POLL_OUT:
case CURL_POLL_INOUT:
curl_context = socketp ?
(curl_context_t *) socketp : create_curl_context(s);
curl_multi_assign(curl_handle, s, (void *) curl_context);
if(action != CURL_POLL_IN)
events |= UV_WRITABLE;
if(action != CURL_POLL_OUT)
events |= UV_READABLE;
uv_poll_start(&curl_context->poll_handle, events, curl_perform);
break;
case CURL_POLL_REMOVE:
if(socketp) {
uv_poll_stop(&((curl_context_t*)socketp)->poll_handle);
destroy_curl_context((curl_context_t*) socketp);
curl_multi_assign(curl_handle, s, NULL);
}
break;
default:
abort();
}
return 0;
}
int main(int argc, char **argv)
{
loop = uv_default_loop();
if(argc <= 1)
return 0;
if(curl_global_init(CURL_GLOBAL_ALL)) {
fprintf(stderr, "Could not init curl\n");
return 1;
}
uv_timer_init(loop, &timeout);
curl_handle = curl_multi_init();
curl_multi_setopt(curl_handle, CURLMOPT_SOCKETFUNCTION, handle_socket);
curl_multi_setopt(curl_handle, CURLMOPT_TIMERFUNCTION, start_timeout);
while(argc-- > 1) {
add_download(argv[argc], argc);
}
uv_run(loop, UV_RUN_DEFAULT);
curl_multi_cleanup(curl_handle);
return 0;
}
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