hiperfifo.c 12 KB

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  1. /***************************************************************************
  2. * _ _ ____ _
  3. * Project ___| | | | _ \| |
  4. * / __| | | | |_) | |
  5. * | (__| |_| | _ <| |___
  6. * \___|\___/|_| \_\_____|
  7. *
  8. * Copyright (C) 1998 - 2020, 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. /* <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. Written by Jeff Pohlmeyer
  29. Requires libevent version 2 and a (POSIX?) system that has mkfifo().
  30. This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c"
  31. sample programs.
  32. When running, the program creates the named pipe "hiper.fifo"
  33. Whenever there is input into the fifo, the program reads the input as a list
  34. of URL's and creates some new easy handles to fetch each URL via the
  35. curl_multi "hiper" API.
  36. Thus, you can try a single URL:
  37. % echo http://www.yahoo.com > hiper.fifo
  38. Or a whole bunch of them:
  39. % cat my-url-list > hiper.fifo
  40. The fifo buffer is handled almost instantly, so you can even add more URL's
  41. while the previous requests are still being downloaded.
  42. Note:
  43. For the sake of simplicity, URL length is limited to 1023 char's !
  44. This is purely a demo app, all retrieved data is simply discarded by the write
  45. callback.
  46. */
  47. #include <stdio.h>
  48. #include <string.h>
  49. #include <stdlib.h>
  50. #include <sys/time.h>
  51. #include <time.h>
  52. #include <unistd.h>
  53. #include <sys/poll.h>
  54. #include <curl/curl.h>
  55. #include <event2/event.h>
  56. #include <event2/event_struct.h>
  57. #include <fcntl.h>
  58. #include <sys/stat.h>
  59. #include <errno.h>
  60. #include <sys/cdefs.h>
  61. #define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */
  62. /* Global information, common to all connections */
  63. typedef struct _GlobalInfo
  64. {
  65. struct event_base *evbase;
  66. struct event fifo_event;
  67. struct event timer_event;
  68. CURLM *multi;
  69. int still_running;
  70. FILE *input;
  71. int stopped;
  72. } GlobalInfo;
  73. /* Information associated with a specific easy handle */
  74. typedef struct _ConnInfo
  75. {
  76. CURL *easy;
  77. char *url;
  78. GlobalInfo *global;
  79. char error[CURL_ERROR_SIZE];
  80. } ConnInfo;
  81. /* Information associated with a specific socket */
  82. typedef struct _SockInfo
  83. {
  84. curl_socket_t sockfd;
  85. CURL *easy;
  86. int action;
  87. long timeout;
  88. struct event ev;
  89. GlobalInfo *global;
  90. } SockInfo;
  91. #define mycase(code) \
  92. case code: s = __STRING(code)
  93. /* Die if we get a bad CURLMcode somewhere */
  94. static void mcode_or_die(const char *where, CURLMcode code)
  95. {
  96. if(CURLM_OK != code) {
  97. const char *s;
  98. switch(code) {
  99. mycase(CURLM_BAD_HANDLE); break;
  100. mycase(CURLM_BAD_EASY_HANDLE); break;
  101. mycase(CURLM_OUT_OF_MEMORY); break;
  102. mycase(CURLM_INTERNAL_ERROR); break;
  103. mycase(CURLM_UNKNOWN_OPTION); break;
  104. mycase(CURLM_LAST); break;
  105. default: s = "CURLM_unknown"; break;
  106. mycase(CURLM_BAD_SOCKET);
  107. fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
  108. /* ignore this error */
  109. return;
  110. }
  111. fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
  112. exit(code);
  113. }
  114. }
  115. /* Update the event timer after curl_multi library calls */
  116. static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
  117. {
  118. struct timeval timeout;
  119. (void)multi;
  120. timeout.tv_sec = timeout_ms/1000;
  121. timeout.tv_usec = (timeout_ms%1000)*1000;
  122. fprintf(MSG_OUT, "multi_timer_cb: Setting timeout to %ld ms\n", timeout_ms);
  123. /*
  124. * if timeout_ms is -1, just delete the timer
  125. *
  126. * For all other values of timeout_ms, this should set or *update* the timer
  127. * to the new value
  128. */
  129. if(timeout_ms == -1)
  130. evtimer_del(&g->timer_event);
  131. else /* includes timeout zero */
  132. evtimer_add(&g->timer_event, &timeout);
  133. return 0;
  134. }
  135. /* Check for completed transfers, and remove their easy handles */
  136. static void check_multi_info(GlobalInfo *g)
  137. {
  138. char *eff_url;
  139. CURLMsg *msg;
  140. int msgs_left;
  141. ConnInfo *conn;
  142. CURL *easy;
  143. CURLcode res;
  144. fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running);
  145. while((msg = curl_multi_info_read(g->multi, &msgs_left))) {
  146. if(msg->msg == CURLMSG_DONE) {
  147. easy = msg->easy_handle;
  148. res = msg->data.result;
  149. curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
  150. curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
  151. fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error);
  152. curl_multi_remove_handle(g->multi, easy);
  153. free(conn->url);
  154. curl_easy_cleanup(easy);
  155. free(conn);
  156. }
  157. }
  158. if(g->still_running == 0 && g->stopped)
  159. event_base_loopbreak(g->evbase);
  160. }
  161. /* Called by libevent when we get action on a multi socket */
  162. static void event_cb(int fd, short kind, void *userp)
  163. {
  164. GlobalInfo *g = (GlobalInfo*) userp;
  165. CURLMcode rc;
  166. int action =
  167. ((kind & EV_READ) ? CURL_CSELECT_IN : 0) |
  168. ((kind & EV_WRITE) ? CURL_CSELECT_OUT : 0);
  169. rc = curl_multi_socket_action(g->multi, fd, action, &g->still_running);
  170. mcode_or_die("event_cb: curl_multi_socket_action", rc);
  171. check_multi_info(g);
  172. if(g->still_running <= 0) {
  173. fprintf(MSG_OUT, "last transfer done, kill timeout\n");
  174. if(evtimer_pending(&g->timer_event, NULL)) {
  175. evtimer_del(&g->timer_event);
  176. }
  177. }
  178. }
  179. /* Called by libevent when our timeout expires */
  180. static void timer_cb(int fd, short kind, void *userp)
  181. {
  182. GlobalInfo *g = (GlobalInfo *)userp;
  183. CURLMcode rc;
  184. (void)fd;
  185. (void)kind;
  186. rc = curl_multi_socket_action(g->multi,
  187. CURL_SOCKET_TIMEOUT, 0, &g->still_running);
  188. mcode_or_die("timer_cb: curl_multi_socket_action", rc);
  189. check_multi_info(g);
  190. }
  191. /* Clean up the SockInfo structure */
  192. static void remsock(SockInfo *f)
  193. {
  194. if(f) {
  195. event_del(&f->ev);
  196. free(f);
  197. }
  198. }
  199. /* Assign information to a SockInfo structure */
  200. static void setsock(SockInfo *f, curl_socket_t s, CURL *e, int act,
  201. GlobalInfo *g)
  202. {
  203. int kind =
  204. ((act & CURL_POLL_IN) ? EV_READ : 0) |
  205. ((act & CURL_POLL_OUT) ? EV_WRITE : 0) | EV_PERSIST;
  206. f->sockfd = s;
  207. f->action = act;
  208. f->easy = e;
  209. event_del(&f->ev);
  210. event_assign(&f->ev, g->evbase, f->sockfd, kind, event_cb, g);
  211. event_add(&f->ev, NULL);
  212. }
  213. /* Initialize a new SockInfo structure */
  214. static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
  215. {
  216. SockInfo *fdp = calloc(sizeof(SockInfo), 1);
  217. fdp->global = g;
  218. setsock(fdp, s, easy, action, g);
  219. curl_multi_assign(g->multi, s, fdp);
  220. }
  221. /* CURLMOPT_SOCKETFUNCTION */
  222. static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
  223. {
  224. GlobalInfo *g = (GlobalInfo*) cbp;
  225. SockInfo *fdp = (SockInfo*) sockp;
  226. const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE" };
  227. fprintf(MSG_OUT,
  228. "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
  229. if(what == CURL_POLL_REMOVE) {
  230. fprintf(MSG_OUT, "\n");
  231. remsock(fdp);
  232. }
  233. else {
  234. if(!fdp) {
  235. fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]);
  236. addsock(s, e, what, g);
  237. }
  238. else {
  239. fprintf(MSG_OUT,
  240. "Changing action from %s to %s\n",
  241. whatstr[fdp->action], whatstr[what]);
  242. setsock(fdp, s, e, what, g);
  243. }
  244. }
  245. return 0;
  246. }
  247. /* CURLOPT_WRITEFUNCTION */
  248. static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data)
  249. {
  250. (void)ptr;
  251. (void)data;
  252. return size * nmemb;
  253. }
  254. /* CURLOPT_PROGRESSFUNCTION */
  255. static int prog_cb(void *p, double dltotal, double dlnow, double ult,
  256. double uln)
  257. {
  258. ConnInfo *conn = (ConnInfo *)p;
  259. (void)ult;
  260. (void)uln;
  261. fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal);
  262. return 0;
  263. }
  264. /* Create a new easy handle, and add it to the global curl_multi */
  265. static void new_conn(char *url, GlobalInfo *g)
  266. {
  267. ConnInfo *conn;
  268. CURLMcode rc;
  269. conn = calloc(1, sizeof(ConnInfo));
  270. conn->error[0]='\0';
  271. conn->easy = curl_easy_init();
  272. if(!conn->easy) {
  273. fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
  274. exit(2);
  275. }
  276. conn->global = g;
  277. conn->url = strdup(url);
  278. curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
  279. curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
  280. curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, conn);
  281. curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L);
  282. curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
  283. curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
  284. curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 0L);
  285. curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
  286. curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
  287. curl_easy_setopt(conn->easy, CURLOPT_FOLLOWLOCATION, 1L);
  288. fprintf(MSG_OUT,
  289. "Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url);
  290. rc = curl_multi_add_handle(g->multi, conn->easy);
  291. mcode_or_die("new_conn: curl_multi_add_handle", rc);
  292. /* note that the add_handle() will set a time-out to trigger very soon so
  293. that the necessary socket_action() call will be called by this app */
  294. }
  295. /* This gets called whenever data is received from the fifo */
  296. static void fifo_cb(int fd, short event, void *arg)
  297. {
  298. char s[1024];
  299. long int rv = 0;
  300. int n = 0;
  301. GlobalInfo *g = (GlobalInfo *)arg;
  302. (void)fd;
  303. (void)event;
  304. do {
  305. s[0]='\0';
  306. rv = fscanf(g->input, "%1023s%n", s, &n);
  307. s[n]='\0';
  308. if(n && s[0]) {
  309. if(!strcmp(s, "stop")) {
  310. g->stopped = 1;
  311. if(g->still_running == 0)
  312. event_base_loopbreak(g->evbase);
  313. }
  314. else
  315. new_conn(s, arg); /* if we read a URL, go get it! */
  316. }
  317. else
  318. break;
  319. } while(rv != EOF);
  320. }
  321. /* Create a named pipe and tell libevent to monitor it */
  322. static const char *fifo = "hiper.fifo";
  323. static int init_fifo(GlobalInfo *g)
  324. {
  325. struct stat st;
  326. curl_socket_t sockfd;
  327. fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
  328. if(lstat (fifo, &st) == 0) {
  329. if((st.st_mode & S_IFMT) == S_IFREG) {
  330. errno = EEXIST;
  331. perror("lstat");
  332. exit(1);
  333. }
  334. }
  335. unlink(fifo);
  336. if(mkfifo (fifo, 0600) == -1) {
  337. perror("mkfifo");
  338. exit(1);
  339. }
  340. sockfd = open(fifo, O_RDWR | O_NONBLOCK, 0);
  341. if(sockfd == -1) {
  342. perror("open");
  343. exit(1);
  344. }
  345. g->input = fdopen(sockfd, "r");
  346. fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo);
  347. event_assign(&g->fifo_event, g->evbase, sockfd, EV_READ|EV_PERSIST,
  348. fifo_cb, g);
  349. event_add(&g->fifo_event, NULL);
  350. return (0);
  351. }
  352. static void clean_fifo(GlobalInfo *g)
  353. {
  354. event_del(&g->fifo_event);
  355. fclose(g->input);
  356. unlink(fifo);
  357. }
  358. int main(int argc, char **argv)
  359. {
  360. GlobalInfo g;
  361. (void)argc;
  362. (void)argv;
  363. memset(&g, 0, sizeof(GlobalInfo));
  364. g.evbase = event_base_new();
  365. init_fifo(&g);
  366. g.multi = curl_multi_init();
  367. evtimer_assign(&g.timer_event, g.evbase, timer_cb, &g);
  368. /* setup the generic multi interface options we want */
  369. curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
  370. curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
  371. curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
  372. curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g);
  373. /* we don't call any curl_multi_socket*() function yet as we have no handles
  374. added! */
  375. event_base_dispatch(g.evbase);
  376. /* this, of course, won't get called since only way to stop this program is
  377. via ctrl-C, but it is here to show how cleanup /would/ be done. */
  378. clean_fifo(&g);
  379. event_del(&g.timer_event);
  380. event_base_free(g.evbase);
  381. curl_multi_cleanup(g.multi);
  382. return 0;
  383. }