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comparison mupdf-source/thirdparty/curl/docs/examples/hiperfifo.c @ 2:b50eed0cc0ef upstream

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ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4. The directory name has changed: no version number in the expanded directory now.
author Franz Glasner <fzglas.hg@dom66.de>
date Mon, 15 Sep 2025 11:43:07 +0200
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1:1d09e1dec1d9 2:b50eed0cc0ef
1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2019, 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.haxx.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 /* <DESC>
23 * multi socket API usage with libevent 2
24 * </DESC>
25 */
26 /* Example application source code using the multi socket interface to
27 download many files at once.
28
29 Written by Jeff Pohlmeyer
30
31 Requires libevent version 2 and a (POSIX?) system that has mkfifo().
32
33 This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c"
34 sample programs.
35
36 When running, the program creates the named pipe "hiper.fifo"
37
38 Whenever there is input into the fifo, the program reads the input as a list
39 of URL's and creates some new easy handles to fetch each URL via the
40 curl_multi "hiper" API.
41
42
43 Thus, you can try a single URL:
44 % echo http://www.yahoo.com > hiper.fifo
45
46 Or a whole bunch of them:
47 % cat my-url-list > hiper.fifo
48
49 The fifo buffer is handled almost instantly, so you can even add more URL's
50 while the previous requests are still being downloaded.
51
52 Note:
53 For the sake of simplicity, URL length is limited to 1023 char's !
54
55 This is purely a demo app, all retrieved data is simply discarded by the write
56 callback.
57
58 */
59
60 #include <stdio.h>
61 #include <string.h>
62 #include <stdlib.h>
63 #include <sys/time.h>
64 #include <time.h>
65 #include <unistd.h>
66 #include <sys/poll.h>
67 #include <curl/curl.h>
68 #include <event2/event.h>
69 #include <event2/event_struct.h>
70 #include <fcntl.h>
71 #include <sys/stat.h>
72 #include <errno.h>
73 #include <sys/cdefs.h>
74
75 #define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */
76
77
78 /* Global information, common to all connections */
79 typedef struct _GlobalInfo
80 {
81 struct event_base *evbase;
82 struct event fifo_event;
83 struct event timer_event;
84 CURLM *multi;
85 int still_running;
86 FILE *input;
87 int stopped;
88 } GlobalInfo;
89
90
91 /* Information associated with a specific easy handle */
92 typedef struct _ConnInfo
93 {
94 CURL *easy;
95 char *url;
96 GlobalInfo *global;
97 char error[CURL_ERROR_SIZE];
98 } ConnInfo;
99
100
101 /* Information associated with a specific socket */
102 typedef struct _SockInfo
103 {
104 curl_socket_t sockfd;
105 CURL *easy;
106 int action;
107 long timeout;
108 struct event ev;
109 GlobalInfo *global;
110 } SockInfo;
111
112 #define mycase(code) \
113 case code: s = __STRING(code)
114
115 /* Die if we get a bad CURLMcode somewhere */
116 static void mcode_or_die(const char *where, CURLMcode code)
117 {
118 if(CURLM_OK != code) {
119 const char *s;
120 switch(code) {
121 mycase(CURLM_BAD_HANDLE); break;
122 mycase(CURLM_BAD_EASY_HANDLE); break;
123 mycase(CURLM_OUT_OF_MEMORY); break;
124 mycase(CURLM_INTERNAL_ERROR); break;
125 mycase(CURLM_UNKNOWN_OPTION); break;
126 mycase(CURLM_LAST); break;
127 default: s = "CURLM_unknown"; break;
128 mycase(CURLM_BAD_SOCKET);
129 fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
130 /* ignore this error */
131 return;
132 }
133 fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
134 exit(code);
135 }
136 }
137
138
139 /* Update the event timer after curl_multi library calls */
140 static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
141 {
142 struct timeval timeout;
143 (void)multi;
144
145 timeout.tv_sec = timeout_ms/1000;
146 timeout.tv_usec = (timeout_ms%1000)*1000;
147 fprintf(MSG_OUT, "multi_timer_cb: Setting timeout to %ld ms\n", timeout_ms);
148
149 /*
150 * if timeout_ms is -1, just delete the timer
151 *
152 * For all other values of timeout_ms, this should set or *update* the timer
153 * to the new value
154 */
155 if(timeout_ms == -1)
156 evtimer_del(&g->timer_event);
157 else /* includes timeout zero */
158 evtimer_add(&g->timer_event, &timeout);
159 return 0;
160 }
161
162
163 /* Check for completed transfers, and remove their easy handles */
164 static void check_multi_info(GlobalInfo *g)
165 {
166 char *eff_url;
167 CURLMsg *msg;
168 int msgs_left;
169 ConnInfo *conn;
170 CURL *easy;
171 CURLcode res;
172
173 fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running);
174 while((msg = curl_multi_info_read(g->multi, &msgs_left))) {
175 if(msg->msg == CURLMSG_DONE) {
176 easy = msg->easy_handle;
177 res = msg->data.result;
178 curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
179 curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
180 fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error);
181 curl_multi_remove_handle(g->multi, easy);
182 free(conn->url);
183 curl_easy_cleanup(easy);
184 free(conn);
185 }
186 }
187 if(g->still_running == 0 && g->stopped)
188 event_base_loopbreak(g->evbase);
189 }
190
191
192
193 /* Called by libevent when we get action on a multi socket */
194 static void event_cb(int fd, short kind, void *userp)
195 {
196 GlobalInfo *g = (GlobalInfo*) userp;
197 CURLMcode rc;
198
199 int action =
200 ((kind & EV_READ) ? CURL_CSELECT_IN : 0) |
201 ((kind & EV_WRITE) ? CURL_CSELECT_OUT : 0);
202
203 rc = curl_multi_socket_action(g->multi, fd, action, &g->still_running);
204 mcode_or_die("event_cb: curl_multi_socket_action", rc);
205
206 check_multi_info(g);
207 if(g->still_running <= 0) {
208 fprintf(MSG_OUT, "last transfer done, kill timeout\n");
209 if(evtimer_pending(&g->timer_event, NULL)) {
210 evtimer_del(&g->timer_event);
211 }
212 }
213 }
214
215
216
217 /* Called by libevent when our timeout expires */
218 static void timer_cb(int fd, short kind, void *userp)
219 {
220 GlobalInfo *g = (GlobalInfo *)userp;
221 CURLMcode rc;
222 (void)fd;
223 (void)kind;
224
225 rc = curl_multi_socket_action(g->multi,
226 CURL_SOCKET_TIMEOUT, 0, &g->still_running);
227 mcode_or_die("timer_cb: curl_multi_socket_action", rc);
228 check_multi_info(g);
229 }
230
231
232
233 /* Clean up the SockInfo structure */
234 static void remsock(SockInfo *f)
235 {
236 if(f) {
237 event_del(&f->ev);
238 free(f);
239 }
240 }
241
242
243
244 /* Assign information to a SockInfo structure */
245 static void setsock(SockInfo *f, curl_socket_t s, CURL *e, int act,
246 GlobalInfo *g)
247 {
248 int kind =
249 ((act & CURL_POLL_IN) ? EV_READ : 0) |
250 ((act & CURL_POLL_OUT) ? EV_WRITE : 0) | EV_PERSIST;
251
252 f->sockfd = s;
253 f->action = act;
254 f->easy = e;
255 event_del(&f->ev);
256 event_assign(&f->ev, g->evbase, f->sockfd, kind, event_cb, g);
257 event_add(&f->ev, NULL);
258 }
259
260
261
262 /* Initialize a new SockInfo structure */
263 static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
264 {
265 SockInfo *fdp = calloc(sizeof(SockInfo), 1);
266
267 fdp->global = g;
268 setsock(fdp, s, easy, action, g);
269 curl_multi_assign(g->multi, s, fdp);
270 }
271
272 /* CURLMOPT_SOCKETFUNCTION */
273 static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
274 {
275 GlobalInfo *g = (GlobalInfo*) cbp;
276 SockInfo *fdp = (SockInfo*) sockp;
277 const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE" };
278
279 fprintf(MSG_OUT,
280 "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
281 if(what == CURL_POLL_REMOVE) {
282 fprintf(MSG_OUT, "\n");
283 remsock(fdp);
284 }
285 else {
286 if(!fdp) {
287 fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]);
288 addsock(s, e, what, g);
289 }
290 else {
291 fprintf(MSG_OUT,
292 "Changing action from %s to %s\n",
293 whatstr[fdp->action], whatstr[what]);
294 setsock(fdp, s, e, what, g);
295 }
296 }
297 return 0;
298 }
299
300
301
302 /* CURLOPT_WRITEFUNCTION */
303 static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data)
304 {
305 (void)ptr;
306 (void)data;
307 return size * nmemb;
308 }
309
310
311 /* CURLOPT_PROGRESSFUNCTION */
312 static int prog_cb(void *p, double dltotal, double dlnow, double ult,
313 double uln)
314 {
315 ConnInfo *conn = (ConnInfo *)p;
316 (void)ult;
317 (void)uln;
318
319 fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal);
320 return 0;
321 }
322
323
324 /* Create a new easy handle, and add it to the global curl_multi */
325 static void new_conn(char *url, GlobalInfo *g)
326 {
327 ConnInfo *conn;
328 CURLMcode rc;
329
330 conn = calloc(1, sizeof(ConnInfo));
331 conn->error[0]='\0';
332
333 conn->easy = curl_easy_init();
334 if(!conn->easy) {
335 fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
336 exit(2);
337 }
338 conn->global = g;
339 conn->url = strdup(url);
340 curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
341 curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
342 curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, conn);
343 curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L);
344 curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
345 curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
346 curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 0L);
347 curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
348 curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
349 curl_easy_setopt(conn->easy, CURLOPT_FOLLOWLOCATION, 1L);
350 fprintf(MSG_OUT,
351 "Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url);
352 rc = curl_multi_add_handle(g->multi, conn->easy);
353 mcode_or_die("new_conn: curl_multi_add_handle", rc);
354
355 /* note that the add_handle() will set a time-out to trigger very soon so
356 that the necessary socket_action() call will be called by this app */
357 }
358
359 /* This gets called whenever data is received from the fifo */
360 static void fifo_cb(int fd, short event, void *arg)
361 {
362 char s[1024];
363 long int rv = 0;
364 int n = 0;
365 GlobalInfo *g = (GlobalInfo *)arg;
366 (void)fd;
367 (void)event;
368
369 do {
370 s[0]='\0';
371 rv = fscanf(g->input, "%1023s%n", s, &n);
372 s[n]='\0';
373 if(n && s[0]) {
374 if(!strcmp(s, "stop")) {
375 g->stopped = 1;
376 if(g->still_running == 0)
377 event_base_loopbreak(g->evbase);
378 }
379 else
380 new_conn(s, arg); /* if we read a URL, go get it! */
381 }
382 else
383 break;
384 } while(rv != EOF);
385 }
386
387 /* Create a named pipe and tell libevent to monitor it */
388 static const char *fifo = "hiper.fifo";
389 static int init_fifo(GlobalInfo *g)
390 {
391 struct stat st;
392 curl_socket_t sockfd;
393
394 fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
395 if(lstat (fifo, &st) == 0) {
396 if((st.st_mode & S_IFMT) == S_IFREG) {
397 errno = EEXIST;
398 perror("lstat");
399 exit(1);
400 }
401 }
402 unlink(fifo);
403 if(mkfifo (fifo, 0600) == -1) {
404 perror("mkfifo");
405 exit(1);
406 }
407 sockfd = open(fifo, O_RDWR | O_NONBLOCK, 0);
408 if(sockfd == -1) {
409 perror("open");
410 exit(1);
411 }
412 g->input = fdopen(sockfd, "r");
413
414 fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo);
415 event_assign(&g->fifo_event, g->evbase, sockfd, EV_READ|EV_PERSIST,
416 fifo_cb, g);
417 event_add(&g->fifo_event, NULL);
418 return (0);
419 }
420
421 static void clean_fifo(GlobalInfo *g)
422 {
423 event_del(&g->fifo_event);
424 fclose(g->input);
425 unlink(fifo);
426 }
427
428 int main(int argc, char **argv)
429 {
430 GlobalInfo g;
431 (void)argc;
432 (void)argv;
433
434 memset(&g, 0, sizeof(GlobalInfo));
435 g.evbase = event_base_new();
436 init_fifo(&g);
437 g.multi = curl_multi_init();
438 evtimer_assign(&g.timer_event, g.evbase, timer_cb, &g);
439
440 /* setup the generic multi interface options we want */
441 curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
442 curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
443 curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
444 curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g);
445
446 /* we don't call any curl_multi_socket*() function yet as we have no handles
447 added! */
448
449 event_base_dispatch(g.evbase);
450
451 /* this, of course, won't get called since only way to stop this program is
452 via ctrl-C, but it is here to show how cleanup /would/ be done. */
453 clean_fifo(&g);
454 event_del(&g.timer_event);
455 event_base_free(g.evbase);
456 curl_multi_cleanup(g.multi);
457 return 0;
458 }