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 struct event_base *base;
36 CURLM *curl_handle;
37 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 if(event & EV_READ)
131 flags |= CURL_CSELECT_IN;
132 if(event & EV_WRITE)
133 flags |= CURL_CSELECT_OUT;
134
135 context = (curl_context_t *) arg;
136
137 curl_multi_socket_action(curl_handle, context->sockfd, flags,
138 &running_handles);
139
140 check_multi_info();
141 }
142
on_timeout(evutil_socket_t fd,short events,void * arg)143 static void on_timeout(evutil_socket_t fd, short events, void *arg)
144 {
145 int running_handles;
146 curl_multi_socket_action(curl_handle, CURL_SOCKET_TIMEOUT, 0,
147 &running_handles);
148 check_multi_info();
149 }
150
start_timeout(CURLM * multi,long timeout_ms,void * userp)151 static int start_timeout(CURLM *multi, long timeout_ms, void *userp)
152 {
153 if(timeout_ms < 0) {
154 evtimer_del(timeout);
155 }
156 else {
157 if(timeout_ms == 0)
158 timeout_ms = 1; /* 0 means call socket_action asap */
159 struct timeval tv;
160 tv.tv_sec = timeout_ms / 1000;
161 tv.tv_usec = (timeout_ms % 1000) * 1000;
162 evtimer_del(timeout);
163 evtimer_add(timeout, &tv);
164 }
165 return 0;
166 }
167
handle_socket(CURL * easy,curl_socket_t s,int action,void * userp,void * socketp)168 static int handle_socket(CURL *easy, curl_socket_t s, int action, void *userp,
169 void *socketp)
170 {
171 curl_context_t *curl_context;
172 int events = 0;
173
174 switch(action) {
175 case CURL_POLL_IN:
176 case CURL_POLL_OUT:
177 case CURL_POLL_INOUT:
178 curl_context = socketp ?
179 (curl_context_t *) socketp : create_curl_context(s);
180
181 curl_multi_assign(curl_handle, s, (void *) curl_context);
182
183 if(action != CURL_POLL_IN)
184 events |= EV_WRITE;
185 if(action != CURL_POLL_OUT)
186 events |= EV_READ;
187
188 events |= EV_PERSIST;
189
190 event_del(curl_context->event);
191 event_assign(curl_context->event, base, curl_context->sockfd, events,
192 curl_perform, curl_context);
193 event_add(curl_context->event, NULL);
194
195 break;
196 case CURL_POLL_REMOVE:
197 if(socketp) {
198 event_del(((curl_context_t*) socketp)->event);
199 destroy_curl_context((curl_context_t*) socketp);
200 curl_multi_assign(curl_handle, s, NULL);
201 }
202 break;
203 default:
204 abort();
205 }
206
207 return 0;
208 }
209
main(int argc,char ** argv)210 int main(int argc, char **argv)
211 {
212 if(argc <= 1)
213 return 0;
214
215 if(curl_global_init(CURL_GLOBAL_ALL)) {
216 fprintf(stderr, "Could not init curl\n");
217 return 1;
218 }
219
220 base = event_base_new();
221 timeout = evtimer_new(base, on_timeout, NULL);
222
223 curl_handle = curl_multi_init();
224 curl_multi_setopt(curl_handle, CURLMOPT_SOCKETFUNCTION, handle_socket);
225 curl_multi_setopt(curl_handle, CURLMOPT_TIMERFUNCTION, start_timeout);
226
227 while(argc-- > 1) {
228 add_download(argv[argc], argc);
229 }
230
231 event_base_dispatch(base);
232
233 curl_multi_cleanup(curl_handle);
234 event_free(timeout);
235 event_base_free(base);
236
237 libevent_global_shutdown();
238 curl_global_cleanup();
239
240 return 0;
241 }
242
