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comparison mupdf-source/thirdparty/curl/docs/examples/ephiperfifo.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 epoll and timerfd
24 * </DESC>
25 */
26 /* Example application source code using the multi socket interface to
27 * download many files at once.
28 *
29 * This example features the same basic functionality as hiperfifo.c does,
30 * but this uses epoll and timerfd instead of libevent.
31 *
32 * Written by Jeff Pohlmeyer, converted to use epoll by Josh Bialkowski
33
34 Requires a linux system with epoll
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 <errno.h>
61 #include <fcntl.h>
62 #include <signal.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <sys/epoll.h>
67 #include <sys/stat.h>
68 #include <sys/time.h>
69 #include <sys/timerfd.h>
70 #include <sys/types.h>
71 #include <time.h>
72 #include <unistd.h>
73
74 #include <curl/curl.h>
75
76 #define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */
77
78
79 /* Global information, common to all connections */
80 typedef struct _GlobalInfo
81 {
82 int epfd; /* epoll filedescriptor */
83 int tfd; /* timer filedescriptor */
84 int fifofd; /* fifo filedescriptor */
85 CURLM *multi;
86 int still_running;
87 FILE *input;
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 GlobalInfo *global;
109 } SockInfo;
110
111 #define mycase(code) \
112 case code: s = __STRING(code)
113
114 /* Die if we get a bad CURLMcode somewhere */
115 static void mcode_or_die(const char *where, CURLMcode code)
116 {
117 if(CURLM_OK != code) {
118 const char *s;
119 switch(code) {
120 mycase(CURLM_BAD_HANDLE); break;
121 mycase(CURLM_BAD_EASY_HANDLE); break;
122 mycase(CURLM_OUT_OF_MEMORY); break;
123 mycase(CURLM_INTERNAL_ERROR); break;
124 mycase(CURLM_UNKNOWN_OPTION); break;
125 mycase(CURLM_LAST); break;
126 default: s = "CURLM_unknown"; break;
127 mycase(CURLM_BAD_SOCKET);
128 fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
129 /* ignore this error */
130 return;
131 }
132 fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
133 exit(code);
134 }
135 }
136
137 static void timer_cb(GlobalInfo* g, int revents);
138
139 /* Update the timer after curl_multi library does it's thing. Curl will
140 * inform us through this callback what it wants the new timeout to be,
141 * after it does some work. */
142 static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
143 {
144 struct itimerspec its;
145
146 fprintf(MSG_OUT, "multi_timer_cb: Setting timeout to %ld ms\n", timeout_ms);
147
148 if(timeout_ms > 0) {
149 its.it_interval.tv_sec = 1;
150 its.it_interval.tv_nsec = 0;
151 its.it_value.tv_sec = timeout_ms / 1000;
152 its.it_value.tv_nsec = (timeout_ms % 1000) * 1000 * 1000;
153 }
154 else if(timeout_ms == 0) {
155 /* libcurl wants us to timeout now, however setting both fields of
156 * new_value.it_value to zero disarms the timer. The closest we can
157 * do is to schedule the timer to fire in 1 ns. */
158 its.it_interval.tv_sec = 1;
159 its.it_interval.tv_nsec = 0;
160 its.it_value.tv_sec = 0;
161 its.it_value.tv_nsec = 1;
162 }
163 else {
164 memset(&its, 0, sizeof(struct itimerspec));
165 }
166
167 timerfd_settime(g->tfd, /*flags=*/0, &its, NULL);
168 return 0;
169 }
170
171
172 /* Check for completed transfers, and remove their easy handles */
173 static void check_multi_info(GlobalInfo *g)
174 {
175 char *eff_url;
176 CURLMsg *msg;
177 int msgs_left;
178 ConnInfo *conn;
179 CURL *easy;
180 CURLcode res;
181
182 fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running);
183 while((msg = curl_multi_info_read(g->multi, &msgs_left))) {
184 if(msg->msg == CURLMSG_DONE) {
185 easy = msg->easy_handle;
186 res = msg->data.result;
187 curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
188 curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
189 fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error);
190 curl_multi_remove_handle(g->multi, easy);
191 free(conn->url);
192 curl_easy_cleanup(easy);
193 free(conn);
194 }
195 }
196 }
197
198 /* Called by libevent when we get action on a multi socket filedescriptor*/
199 static void event_cb(GlobalInfo *g, int fd, int revents)
200 {
201 CURLMcode rc;
202 struct itimerspec its;
203
204 int action = ((revents & EPOLLIN) ? CURL_CSELECT_IN : 0) |
205 ((revents & EPOLLOUT) ? CURL_CSELECT_OUT : 0);
206
207 rc = curl_multi_socket_action(g->multi, fd, action, &g->still_running);
208 mcode_or_die("event_cb: curl_multi_socket_action", rc);
209
210 check_multi_info(g);
211 if(g->still_running <= 0) {
212 fprintf(MSG_OUT, "last transfer done, kill timeout\n");
213 memset(&its, 0, sizeof(struct itimerspec));
214 timerfd_settime(g->tfd, 0, &its, NULL);
215 }
216 }
217
218 /* Called by main loop when our timeout expires */
219 static void timer_cb(GlobalInfo* g, int revents)
220 {
221 CURLMcode rc;
222 uint64_t count = 0;
223 ssize_t err = 0;
224
225 err = read(g->tfd, &count, sizeof(uint64_t));
226 if(err == -1) {
227 /* Note that we may call the timer callback even if the timerfd isn't
228 * readable. It's possible that there are multiple events stored in the
229 * epoll buffer (i.e. the timer may have fired multiple times). The
230 * event count is cleared after the first call so future events in the
231 * epoll buffer will fail to read from the timer. */
232 if(errno == EAGAIN) {
233 fprintf(MSG_OUT, "EAGAIN on tfd %d\n", g->tfd);
234 return;
235 }
236 }
237 if(err != sizeof(uint64_t)) {
238 fprintf(stderr, "read(tfd) == %ld", err);
239 perror("read(tfd)");
240 }
241
242 rc = curl_multi_socket_action(g->multi,
243 CURL_SOCKET_TIMEOUT, 0, &g->still_running);
244 mcode_or_die("timer_cb: curl_multi_socket_action", rc);
245 check_multi_info(g);
246 }
247
248
249
250 /* Clean up the SockInfo structure */
251 static void remsock(SockInfo *f, GlobalInfo* g)
252 {
253 if(f) {
254 if(f->sockfd) {
255 if(epoll_ctl(g->epfd, EPOLL_CTL_DEL, f->sockfd, NULL))
256 fprintf(stderr, "EPOLL_CTL_DEL failed for fd: %d : %s\n",
257 f->sockfd, strerror(errno));
258 }
259 free(f);
260 }
261 }
262
263
264
265 /* Assign information to a SockInfo structure */
266 static void setsock(SockInfo *f, curl_socket_t s, CURL *e, int act,
267 GlobalInfo *g)
268 {
269 struct epoll_event ev;
270 int kind = ((act & CURL_POLL_IN) ? EPOLLIN : 0) |
271 ((act & CURL_POLL_OUT) ? EPOLLOUT : 0);
272
273 if(f->sockfd) {
274 if(epoll_ctl(g->epfd, EPOLL_CTL_DEL, f->sockfd, NULL))
275 fprintf(stderr, "EPOLL_CTL_DEL failed for fd: %d : %s\n",
276 f->sockfd, strerror(errno));
277 }
278
279 f->sockfd = s;
280 f->action = act;
281 f->easy = e;
282
283 ev.events = kind;
284 ev.data.fd = s;
285 if(epoll_ctl(g->epfd, EPOLL_CTL_ADD, s, &ev))
286 fprintf(stderr, "EPOLL_CTL_ADD failed for fd: %d : %s\n",
287 s, strerror(errno));
288 }
289
290
291
292 /* Initialize a new SockInfo structure */
293 static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
294 {
295 SockInfo *fdp = (SockInfo*)calloc(sizeof(SockInfo), 1);
296
297 fdp->global = g;
298 setsock(fdp, s, easy, action, g);
299 curl_multi_assign(g->multi, s, fdp);
300 }
301
302 /* CURLMOPT_SOCKETFUNCTION */
303 static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
304 {
305 GlobalInfo *g = (GlobalInfo*) cbp;
306 SockInfo *fdp = (SockInfo*) sockp;
307 const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE" };
308
309 fprintf(MSG_OUT,
310 "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
311 if(what == CURL_POLL_REMOVE) {
312 fprintf(MSG_OUT, "\n");
313 remsock(fdp, g);
314 }
315 else {
316 if(!fdp) {
317 fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]);
318 addsock(s, e, what, g);
319 }
320 else {
321 fprintf(MSG_OUT,
322 "Changing action from %s to %s\n",
323 whatstr[fdp->action], whatstr[what]);
324 setsock(fdp, s, e, what, g);
325 }
326 }
327 return 0;
328 }
329
330
331
332 /* CURLOPT_WRITEFUNCTION */
333 static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data)
334 {
335 (void)ptr;
336 (void)data;
337 return size * nmemb;
338 }
339
340
341 /* CURLOPT_PROGRESSFUNCTION */
342 static int prog_cb(void *p, double dltotal, double dlnow, double ult,
343 double uln)
344 {
345 ConnInfo *conn = (ConnInfo *)p;
346 (void)ult;
347 (void)uln;
348
349 fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal);
350 return 0;
351 }
352
353
354 /* Create a new easy handle, and add it to the global curl_multi */
355 static void new_conn(char *url, GlobalInfo *g)
356 {
357 ConnInfo *conn;
358 CURLMcode rc;
359
360 conn = (ConnInfo*)calloc(1, sizeof(ConnInfo));
361 conn->error[0]='\0';
362
363 conn->easy = curl_easy_init();
364 if(!conn->easy) {
365 fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
366 exit(2);
367 }
368 conn->global = g;
369 conn->url = strdup(url);
370 curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
371 curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
372 curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, conn);
373 curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L);
374 curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
375 curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
376 curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 0L);
377 curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
378 curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
379 curl_easy_setopt(conn->easy, CURLOPT_FOLLOWLOCATION, 1L);
380 curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 3L);
381 curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 10L);
382 fprintf(MSG_OUT,
383 "Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url);
384 rc = curl_multi_add_handle(g->multi, conn->easy);
385 mcode_or_die("new_conn: curl_multi_add_handle", rc);
386
387 /* note that the add_handle() will set a time-out to trigger very soon so
388 that the necessary socket_action() call will be called by this app */
389 }
390
391 /* This gets called whenever data is received from the fifo */
392 static void fifo_cb(GlobalInfo* g, int revents)
393 {
394 char s[1024];
395 long int rv = 0;
396 int n = 0;
397
398 do {
399 s[0]='\0';
400 rv = fscanf(g->input, "%1023s%n", s, &n);
401 s[n]='\0';
402 if(n && s[0]) {
403 new_conn(s, g); /* if we read a URL, go get it! */
404 }
405 else
406 break;
407 } while(rv != EOF);
408 }
409
410 /* Create a named pipe and tell libevent to monitor it */
411 static const char *fifo = "hiper.fifo";
412 static int init_fifo(GlobalInfo *g)
413 {
414 struct stat st;
415 curl_socket_t sockfd;
416 struct epoll_event epev;
417
418 fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
419 if(lstat (fifo, &st) == 0) {
420 if((st.st_mode & S_IFMT) == S_IFREG) {
421 errno = EEXIST;
422 perror("lstat");
423 exit(1);
424 }
425 }
426 unlink(fifo);
427 if(mkfifo (fifo, 0600) == -1) {
428 perror("mkfifo");
429 exit(1);
430 }
431 sockfd = open(fifo, O_RDWR | O_NONBLOCK, 0);
432 if(sockfd == -1) {
433 perror("open");
434 exit(1);
435 }
436
437 g->fifofd = sockfd;
438 g->input = fdopen(sockfd, "r");
439
440 epev.events = EPOLLIN;
441 epev.data.fd = sockfd;
442 epoll_ctl(g->epfd, EPOLL_CTL_ADD, sockfd, &epev);
443
444 fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo);
445 return 0;
446 }
447
448 static void clean_fifo(GlobalInfo *g)
449 {
450 epoll_ctl(g->epfd, EPOLL_CTL_DEL, g->fifofd, NULL);
451 fclose(g->input);
452 unlink(fifo);
453 }
454
455
456 int g_should_exit_ = 0;
457
458 void SignalHandler(int signo)
459 {
460 if(signo == SIGINT) {
461 g_should_exit_ = 1;
462 }
463 }
464
465 int main(int argc, char **argv)
466 {
467 GlobalInfo g;
468 struct itimerspec its;
469 struct epoll_event ev;
470 struct epoll_event events[10];
471 (void)argc;
472 (void)argv;
473
474 g_should_exit_ = 0;
475 signal(SIGINT, SignalHandler);
476
477 memset(&g, 0, sizeof(GlobalInfo));
478 g.epfd = epoll_create1(EPOLL_CLOEXEC);
479 if(g.epfd == -1) {
480 perror("epoll_create1 failed");
481 exit(1);
482 }
483
484 g.tfd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
485 if(g.tfd == -1) {
486 perror("timerfd_create failed");
487 exit(1);
488 }
489
490 memset(&its, 0, sizeof(struct itimerspec));
491 its.it_interval.tv_sec = 1;
492 its.it_value.tv_sec = 1;
493 timerfd_settime(g.tfd, 0, &its, NULL);
494
495 ev.events = EPOLLIN;
496 ev.data.fd = g.tfd;
497 epoll_ctl(g.epfd, EPOLL_CTL_ADD, g.tfd, &ev);
498
499 init_fifo(&g);
500 g.multi = curl_multi_init();
501
502 /* setup the generic multi interface options we want */
503 curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
504 curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
505 curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
506 curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g);
507
508 /* we don't call any curl_multi_socket*() function yet as we have no handles
509 added! */
510
511 fprintf(MSG_OUT, "Entering wait loop\n");
512 fflush(MSG_OUT);
513 while(!g_should_exit_) {
514 int idx;
515 int err = epoll_wait(g.epfd, events,
516 sizeof(events)/sizeof(struct epoll_event), 10000);
517 if(err == -1) {
518 if(errno == EINTR) {
519 fprintf(MSG_OUT, "note: wait interrupted\n");
520 continue;
521 }
522 else {
523 perror("epoll_wait");
524 exit(1);
525 }
526 }
527
528 for(idx = 0; idx < err; ++idx) {
529 if(events[idx].data.fd == g.fifofd) {
530 fifo_cb(&g, events[idx].events);
531 }
532 else if(events[idx].data.fd == g.tfd) {
533 timer_cb(&g, events[idx].events);
534 }
535 else {
536 event_cb(&g, events[idx].data.fd, events[idx].events);
537 }
538 }
539 }
540
541 fprintf(MSG_OUT, "Exiting normally.\n");
542 fflush(MSG_OUT);
543
544 curl_multi_cleanup(g.multi);
545 clean_fifo(&g);
546 return 0;
547 }