1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 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 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24
25 /* <DESC>
26 * multi_socket API using libevent
27 * </DESC>
28 */
29
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <event2/event.h>
33 #include <curl/curl.h>
34
35 static struct event_base *base;
36 static CURLM *curl_handle;
37 static struct event *timeout;
38
39 typedef struct curl_context_s {
40 struct event *event;
41 curl_socket_t sockfd;
42 } curl_context_t;
43
44 static void curl_perform(int fd, short event, void *arg);
45
create_curl_context(curl_socket_t sockfd)46 static curl_context_t *create_curl_context(curl_socket_t sockfd)
47 {
48 curl_context_t *context;
49
50 context = (curl_context_t *) malloc(sizeof(*context));
51
52 context->sockfd = sockfd;
53
54 context->event = event_new(base, sockfd, 0, curl_perform, context);
55
56 return context;
57 }
58
destroy_curl_context(curl_context_t * context)59 static void destroy_curl_context(curl_context_t *context)
60 {
61 event_del(context->event);
62 event_free(context->event);
63 free(context);
64 }
65
add_download(const char * url,int num)66 static void add_download(const char *url, int num)
67 {
68 char filename[50];
69 FILE *file;
70 CURL *handle;
71
72 snprintf(filename, 50, "%d.download", num);
73
74 file = fopen(filename, "wb");
75 if(!file) {
76 fprintf(stderr, "Error opening %s\n", filename);
77 return;
78 }
79
80 handle = curl_easy_init();
81 curl_easy_setopt(handle, CURLOPT_WRITEDATA, file);
82 curl_easy_setopt(handle, CURLOPT_PRIVATE, file);
83 curl_easy_setopt(handle, CURLOPT_URL, url);
84 curl_multi_add_handle(curl_handle, handle);
85 fprintf(stderr, "Added download %s -> %s\n", url, filename);
86 }
87
check_multi_info(void)88 static void check_multi_info(void)
89 {
90 char *done_url;
91 CURLMsg *message;
92 int pending;
93 CURL *easy_handle;
94 FILE *file;
95
96 while((message = curl_multi_info_read(curl_handle, &pending))) {
97 switch(message->msg) {
98 case CURLMSG_DONE:
99 /* Do not use message data after calling curl_multi_remove_handle() and
100 curl_easy_cleanup(). As per curl_multi_info_read() docs:
101 "WARNING: The data the returned pointer points to does not survive
102 calling curl_multi_cleanup, curl_multi_remove_handle or
103 curl_easy_cleanup." */
104 easy_handle = message->easy_handle;
105
106 curl_easy_getinfo(easy_handle, CURLINFO_EFFECTIVE_URL, &done_url);
107 curl_easy_getinfo(easy_handle, CURLINFO_PRIVATE, &file);
108 printf("%s DONE\n", done_url);
109
110 curl_multi_remove_handle(curl_handle, easy_handle);
111 curl_easy_cleanup(easy_handle);
112 if(file) {
113 fclose(file);
114 }
115 break;
116
117 default:
118 fprintf(stderr, "CURLMSG default\n");
119 break;
120 }
121 }
122 }
123
curl_perform(int fd,short event,void * arg)124 static void curl_perform(int fd, short event, void *arg)
125 {
126 int running_handles;
127 int flags = 0;
128 curl_context_t *context;
129
130 (void)fd;
131
132 if(event & EV_READ)
133 flags |= CURL_CSELECT_IN;
134 if(event & EV_WRITE)
135 flags |= CURL_CSELECT_OUT;
136
137 context = (curl_context_t *) arg;
138
139 curl_multi_socket_action(curl_handle, context->sockfd, flags,
140 &running_handles);
141
142 check_multi_info();
143 }
144
on_timeout(evutil_socket_t fd,short events,void * arg)145 static void on_timeout(evutil_socket_t fd, short events, void *arg)
146 {
147 int running_handles;
148 (void)fd;
149 (void)events;
150 (void)arg;
151 curl_multi_socket_action(curl_handle, CURL_SOCKET_TIMEOUT, 0,
152 &running_handles);
153 check_multi_info();
154 }
155
start_timeout(CURLM * multi,long timeout_ms,void * userp)156 static int start_timeout(CURLM *multi, long timeout_ms, void *userp)
157 {
158 (void)multi;
159 (void)userp;
160 if(timeout_ms < 0) {
161 evtimer_del(timeout);
162 }
163 else {
164 struct timeval tv;
165 if(timeout_ms == 0)
166 timeout_ms = 1; /* 0 means call socket_action asap */
167 tv.tv_sec = timeout_ms / 1000;
168 tv.tv_usec = (timeout_ms % 1000) * 1000;
169 evtimer_del(timeout);
170 evtimer_add(timeout, &tv);
171 }
172 return 0;
173 }
174
handle_socket(CURL * easy,curl_socket_t s,int action,void * userp,void * socketp)175 static int handle_socket(CURL *easy, curl_socket_t s, int action, void *userp,
176 void *socketp)
177 {
178 curl_context_t *curl_context;
179 int events = 0;
180
181 (void)easy;
182 (void)userp;
183
184 switch(action) {
185 case CURL_POLL_IN:
186 case CURL_POLL_OUT:
187 case CURL_POLL_INOUT:
188 curl_context = socketp ?
189 (curl_context_t *) socketp : create_curl_context(s);
190
191 curl_multi_assign(curl_handle, s, (void *) curl_context);
192
193 if(action != CURL_POLL_IN)
194 events |= EV_WRITE;
195 if(action != CURL_POLL_OUT)
196 events |= EV_READ;
197
198 events |= EV_PERSIST;
199
200 event_del(curl_context->event);
201 event_assign(curl_context->event, base, curl_context->sockfd,
202 (short)events, curl_perform, curl_context);
203 event_add(curl_context->event, NULL);
204
205 break;
206 case CURL_POLL_REMOVE:
207 if(socketp) {
208 event_del(((curl_context_t*) socketp)->event);
209 destroy_curl_context((curl_context_t*) socketp);
210 curl_multi_assign(curl_handle, s, NULL);
211 }
212 break;
213 default:
214 abort();
215 }
216
217 return 0;
218 }
219
main(int argc,char ** argv)220 int main(int argc, char **argv)
221 {
222 if(argc <= 1)
223 return 0;
224
225 if(curl_global_init(CURL_GLOBAL_ALL)) {
226 fprintf(stderr, "Could not init curl\n");
227 return 1;
228 }
229
230 base = event_base_new();
231 timeout = evtimer_new(base, on_timeout, NULL);
232
233 curl_handle = curl_multi_init();
234 curl_multi_setopt(curl_handle, CURLMOPT_SOCKETFUNCTION, handle_socket);
235 curl_multi_setopt(curl_handle, CURLMOPT_TIMERFUNCTION, start_timeout);
236
237 while(argc-- > 1) {
238 add_download(argv[argc], argc);
239 }
240
241 event_base_dispatch(base);
242
243 curl_multi_cleanup(curl_handle);
244 event_free(timeout);
245 event_base_free(base);
246
247 libevent_global_shutdown();
248 curl_global_cleanup();
249
250 return 0;
251 }
252