1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23 /* <DESC>
24 * multi_socket API using libevent
25 * </DESC>
26 */
27
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <event2/event.h>
31 #include <curl/curl.h>
32
33 struct event_base *base;
34 CURLM *curl_handle;
35 struct event *timeout;
36
37 typedef struct curl_context_s {
38 struct event *event;
39 curl_socket_t sockfd;
40 } curl_context_t;
41
42 static void curl_perform(int fd, short event, void *arg);
43
create_curl_context(curl_socket_t sockfd)44 static curl_context_t *create_curl_context(curl_socket_t sockfd)
45 {
46 curl_context_t *context;
47
48 context = (curl_context_t *) malloc(sizeof(*context));
49
50 context->sockfd = sockfd;
51
52 context->event = event_new(base, sockfd, 0, curl_perform, context);
53
54 return context;
55 }
56
destroy_curl_context(curl_context_t * context)57 static void destroy_curl_context(curl_context_t *context)
58 {
59 event_del(context->event);
60 event_free(context->event);
61 free(context);
62 }
63
add_download(const char * url,int num)64 static void add_download(const char *url, int num)
65 {
66 char filename[50];
67 FILE *file;
68 CURL *handle;
69
70 snprintf(filename, 50, "%d.download", num);
71
72 file = fopen(filename, "wb");
73 if(!file) {
74 fprintf(stderr, "Error opening %s\n", filename);
75 return;
76 }
77
78 handle = curl_easy_init();
79 curl_easy_setopt(handle, CURLOPT_WRITEDATA, file);
80 curl_easy_setopt(handle, CURLOPT_PRIVATE, file);
81 curl_easy_setopt(handle, CURLOPT_URL, url);
82 curl_multi_add_handle(curl_handle, handle);
83 fprintf(stderr, "Added download %s -> %s\n", url, filename);
84 }
85
check_multi_info(void)86 static void check_multi_info(void)
87 {
88 char *done_url;
89 CURLMsg *message;
90 int pending;
91 CURL *easy_handle;
92 FILE *file;
93
94 while((message = curl_multi_info_read(curl_handle, &pending))) {
95 switch(message->msg) {
96 case CURLMSG_DONE:
97 /* Do not use message data after calling curl_multi_remove_handle() and
98 curl_easy_cleanup(). As per curl_multi_info_read() docs:
99 "WARNING: The data the returned pointer points to will not survive
100 calling curl_multi_cleanup, curl_multi_remove_handle or
101 curl_easy_cleanup." */
102 easy_handle = message->easy_handle;
103
104 curl_easy_getinfo(easy_handle, CURLINFO_EFFECTIVE_URL, &done_url);
105 curl_easy_getinfo(easy_handle, CURLINFO_PRIVATE, &file);
106 printf("%s DONE\n", done_url);
107
108 curl_multi_remove_handle(curl_handle, easy_handle);
109 curl_easy_cleanup(easy_handle);
110 if(file) {
111 fclose(file);
112 }
113 break;
114
115 default:
116 fprintf(stderr, "CURLMSG default\n");
117 break;
118 }
119 }
120 }
121
curl_perform(int fd,short event,void * arg)122 static void curl_perform(int fd, short event, void *arg)
123 {
124 int running_handles;
125 int flags = 0;
126 curl_context_t *context;
127
128 if(event & EV_READ)
129 flags |= CURL_CSELECT_IN;
130 if(event & EV_WRITE)
131 flags |= CURL_CSELECT_OUT;
132
133 context = (curl_context_t *) arg;
134
135 curl_multi_socket_action(curl_handle, context->sockfd, flags,
136 &running_handles);
137
138 check_multi_info();
139 }
140
on_timeout(evutil_socket_t fd,short events,void * arg)141 static void on_timeout(evutil_socket_t fd, short events, void *arg)
142 {
143 int running_handles;
144 curl_multi_socket_action(curl_handle, CURL_SOCKET_TIMEOUT, 0,
145 &running_handles);
146 check_multi_info();
147 }
148
start_timeout(CURLM * multi,long timeout_ms,void * userp)149 static int start_timeout(CURLM *multi, long timeout_ms, void *userp)
150 {
151 if(timeout_ms < 0) {
152 evtimer_del(timeout);
153 }
154 else {
155 if(timeout_ms == 0)
156 timeout_ms = 1; /* 0 means directly call socket_action, but we will do it
157 in a bit */
158 struct timeval tv;
159 tv.tv_sec = timeout_ms / 1000;
160 tv.tv_usec = (timeout_ms % 1000) * 1000;
161 evtimer_del(timeout);
162 evtimer_add(timeout, &tv);
163 }
164 return 0;
165 }
166
handle_socket(CURL * easy,curl_socket_t s,int action,void * userp,void * socketp)167 static int handle_socket(CURL *easy, curl_socket_t s, int action, void *userp,
168 void *socketp)
169 {
170 curl_context_t *curl_context;
171 int events = 0;
172
173 switch(action) {
174 case CURL_POLL_IN:
175 case CURL_POLL_OUT:
176 case CURL_POLL_INOUT:
177 curl_context = socketp ?
178 (curl_context_t *) socketp : create_curl_context(s);
179
180 curl_multi_assign(curl_handle, s, (void *) curl_context);
181
182 if(action != CURL_POLL_IN)
183 events |= EV_WRITE;
184 if(action != CURL_POLL_OUT)
185 events |= EV_READ;
186
187 events |= EV_PERSIST;
188
189 event_del(curl_context->event);
190 event_assign(curl_context->event, base, curl_context->sockfd, events,
191 curl_perform, curl_context);
192 event_add(curl_context->event, NULL);
193
194 break;
195 case CURL_POLL_REMOVE:
196 if(socketp) {
197 event_del(((curl_context_t*) socketp)->event);
198 destroy_curl_context((curl_context_t*) socketp);
199 curl_multi_assign(curl_handle, s, NULL);
200 }
201 break;
202 default:
203 abort();
204 }
205
206 return 0;
207 }
208
main(int argc,char ** argv)209 int main(int argc, char **argv)
210 {
211 if(argc <= 1)
212 return 0;
213
214 if(curl_global_init(CURL_GLOBAL_ALL)) {
215 fprintf(stderr, "Could not init curl\n");
216 return 1;
217 }
218
219 base = event_base_new();
220 timeout = evtimer_new(base, on_timeout, NULL);
221
222 curl_handle = curl_multi_init();
223 curl_multi_setopt(curl_handle, CURLMOPT_SOCKETFUNCTION, handle_socket);
224 curl_multi_setopt(curl_handle, CURLMOPT_TIMERFUNCTION, start_timeout);
225
226 while(argc-- > 1) {
227 add_download(argv[argc], argc);
228 }
229
230 event_base_dispatch(base);
231
232 curl_multi_cleanup(curl_handle);
233 event_free(timeout);
234 event_base_free(base);
235
236 libevent_global_shutdown();
237 curl_global_cleanup();
238
239 return 0;
240 }
241