Home | History | Annotate | Download | only in examples 
      1 /***************************************************************************
      2  *                                  _   _ ____  _
      3  *  Project                     ___| | | |  _ \| |
      4  *                             / __| | | | |_) | |
      5  *                            | (__| |_| |  _ <| |___
      6  *                             \___|\___/|_| \_\_____|
      7  *
      8  * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel (at) 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 interface together with libev
     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 libev instead of libevent.
     31  *
     32  * Written by Jeff Pohlmeyer, converted to use libev by Markus Koetter
     33 
     34 Requires libev and a (POSIX?) system that has mkfifo().
     35 
     36 This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c"
     37 sample programs.
     38 
     39 When running, the program creates the named pipe "hiper.fifo"
     40 
     41 Whenever there is input into the fifo, the program reads the input as a list
     42 of URL's and creates some new easy handles to fetch each URL via the
     43 curl_multi "hiper" API.
     44 
     45 
     46 Thus, you can try a single URL:
     47   % echo http://www.yahoo.com > hiper.fifo
     48 
     49 Or a whole bunch of them:
     50   % cat my-url-list > hiper.fifo
     51 
     52 The fifo buffer is handled almost instantly, so you can even add more URL's
     53 while the previous requests are still being downloaded.
     54 
     55 Note:
     56   For the sake of simplicity, URL length is limited to 1023 char's !
     57 
     58 This is purely a demo app, all retrieved data is simply discarded by the write
     59 callback.
     60 
     61 */
     62 
     63 #include <stdio.h>
     64 #include <string.h>
     65 #include <stdlib.h>
     66 #include <sys/time.h>
     67 #include <time.h>
     68 #include <unistd.h>
     69 #include <sys/poll.h>
     70 #include <curl/curl.h>
     71 #include <ev.h>
     72 #include <fcntl.h>
     73 #include <sys/stat.h>
     74 #include <errno.h>
     75 
     76 #define DPRINT(x...) printf(x)
     77 
     78 #define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */
     79 
     80 
     81 /* Global information, common to all connections */
     82 typedef struct _GlobalInfo
     83 {
     84   struct ev_loop *loop;
     85   struct ev_io fifo_event;
     86   struct ev_timer timer_event;
     87   CURLM *multi;
     88   int still_running;
     89   FILE *input;
     90 } GlobalInfo;
     91 
     92 
     93 /* Information associated with a specific easy handle */
     94 typedef struct _ConnInfo
     95 {
     96   CURL *easy;
     97   char *url;
     98   GlobalInfo *global;
     99   char error[CURL_ERROR_SIZE];
    100 } ConnInfo;
    101 
    102 
    103 /* Information associated with a specific socket */
    104 typedef struct _SockInfo
    105 {
    106   curl_socket_t sockfd;
    107   CURL *easy;
    108   int action;
    109   long timeout;
    110   struct ev_io ev;
    111   int evset;
    112   GlobalInfo *global;
    113 } SockInfo;
    114 
    115 static void timer_cb(EV_P_ struct ev_timer *w, int revents);
    116 
    117 /* Update the event timer after curl_multi library calls */
    118 static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
    119 {
    120   DPRINT("%s %li\n", __PRETTY_FUNCTION__,  timeout_ms);
    121   ev_timer_stop(g->loop, &g->timer_event);
    122   if(timeout_ms >= 0) {
    123     /* -1 means delete, other values are timeout times in milliseconds */
    124     double  t = timeout_ms / 1000;
    125     ev_timer_init(&g->timer_event, timer_cb, t, 0.);
    126     ev_timer_start(g->loop, &g->timer_event);
    127   }
    128   return 0;
    129 }
    130 
    131 /* Die if we get a bad CURLMcode somewhere */
    132 static void mcode_or_die(const char *where, CURLMcode code)
    133 {
    134   if(CURLM_OK != code) {
    135     const char *s;
    136     switch(code) {
    137     case CURLM_BAD_HANDLE:
    138       s = "CURLM_BAD_HANDLE";
    139       break;
    140     case CURLM_BAD_EASY_HANDLE:
    141       s = "CURLM_BAD_EASY_HANDLE";
    142       break;
    143     case CURLM_OUT_OF_MEMORY:
    144       s = "CURLM_OUT_OF_MEMORY";
    145       break;
    146     case CURLM_INTERNAL_ERROR:
    147       s = "CURLM_INTERNAL_ERROR";
    148       break;
    149     case CURLM_UNKNOWN_OPTION:
    150       s = "CURLM_UNKNOWN_OPTION";
    151       break;
    152     case CURLM_LAST:
    153       s = "CURLM_LAST";
    154       break;
    155     default:
    156       s = "CURLM_unknown";
    157       break;
    158     case CURLM_BAD_SOCKET:
    159       s = "CURLM_BAD_SOCKET";
    160       fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
    161       /* ignore this error */
    162       return;
    163     }
    164     fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
    165     exit(code);
    166   }
    167 }
    168 
    169 
    170 
    171 /* Check for completed transfers, and remove their easy handles */
    172 static void check_multi_info(GlobalInfo *g)
    173 {
    174   char *eff_url;
    175   CURLMsg *msg;
    176   int msgs_left;
    177   ConnInfo *conn;
    178   CURL *easy;
    179   CURLcode res;
    180 
    181   fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running);
    182   while((msg = curl_multi_info_read(g->multi, &msgs_left))) {
    183     if(msg->msg == CURLMSG_DONE) {
    184       easy = msg->easy_handle;
    185       res = msg->data.result;
    186       curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
    187       curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
    188       fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error);
    189       curl_multi_remove_handle(g->multi, easy);
    190       free(conn->url);
    191       curl_easy_cleanup(easy);
    192       free(conn);
    193     }
    194   }
    195 }
    196 
    197 
    198 
    199 /* Called by libevent when we get action on a multi socket */
    200 static void event_cb(EV_P_ struct ev_io *w, int revents)
    201 {
    202   DPRINT("%s  w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);
    203   GlobalInfo *g = (GlobalInfo*) w->data;
    204   CURLMcode rc;
    205 
    206   int action = (revents&EV_READ?CURL_POLL_IN:0)|
    207     (revents&EV_WRITE?CURL_POLL_OUT:0);
    208   rc = curl_multi_socket_action(g->multi, w->fd, action, &g->still_running);
    209   mcode_or_die("event_cb: curl_multi_socket_action", rc);
    210   check_multi_info(g);
    211   if(g->still_running <= 0) {
    212     fprintf(MSG_OUT, "last transfer done, kill timeout\n");
    213     ev_timer_stop(g->loop, &g->timer_event);
    214   }
    215 }
    216 
    217 /* Called by libevent when our timeout expires */
    218 static void timer_cb(EV_P_ struct ev_timer *w, int revents)
    219 {
    220   DPRINT("%s  w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);
    221 
    222   GlobalInfo *g = (GlobalInfo *)w->data;
    223   CURLMcode rc;
    224 
    225   rc = curl_multi_socket_action(g->multi, CURL_SOCKET_TIMEOUT, 0,
    226                                 &g->still_running);
    227   mcode_or_die("timer_cb: curl_multi_socket_action", rc);
    228   check_multi_info(g);
    229 }
    230 
    231 /* Clean up the SockInfo structure */
    232 static void remsock(SockInfo *f, GlobalInfo *g)
    233 {
    234   printf("%s  \n", __PRETTY_FUNCTION__);
    235   if(f) {
    236     if(f->evset)
    237       ev_io_stop(g->loop, &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   printf("%s  \n", __PRETTY_FUNCTION__);
    249 
    250   int kind = (act&CURL_POLL_IN?EV_READ:0)|(act&CURL_POLL_OUT?EV_WRITE:0);
    251 
    252   f->sockfd = s;
    253   f->action = act;
    254   f->easy = e;
    255   if(f->evset)
    256     ev_io_stop(g->loop, &f->ev);
    257   ev_io_init(&f->ev, event_cb, f->sockfd, kind);
    258   f->ev.data = g;
    259   f->evset = 1;
    260   ev_io_start(g->loop, &f->ev);
    261 }
    262 
    263 
    264 
    265 /* Initialize a new SockInfo structure */
    266 static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
    267 {
    268   SockInfo *fdp = calloc(sizeof(SockInfo), 1);
    269 
    270   fdp->global = g;
    271   setsock(fdp, s, easy, action, g);
    272   curl_multi_assign(g->multi, s, fdp);
    273 }
    274 
    275 /* CURLMOPT_SOCKETFUNCTION */
    276 static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
    277 {
    278   DPRINT("%s e %p s %i what %i cbp %p sockp %p\n",
    279          __PRETTY_FUNCTION__, e, s, what, cbp, sockp);
    280 
    281   GlobalInfo *g = (GlobalInfo*) cbp;
    282   SockInfo *fdp = (SockInfo*) sockp;
    283   const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE"};
    284 
    285   fprintf(MSG_OUT,
    286           "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
    287   if(what == CURL_POLL_REMOVE) {
    288     fprintf(MSG_OUT, "\n");
    289     remsock(fdp, g);
    290   }
    291   else {
    292     if(!fdp) {
    293       fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]);
    294       addsock(s, e, what, g);
    295     }
    296     else {
    297       fprintf(MSG_OUT,
    298               "Changing action from %s to %s\n",
    299               whatstr[fdp->action], whatstr[what]);
    300       setsock(fdp, s, e, what, g);
    301     }
    302   }
    303   return 0;
    304 }
    305 
    306 
    307 /* CURLOPT_WRITEFUNCTION */
    308 static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data)
    309 {
    310   size_t realsize = size * nmemb;
    311   ConnInfo *conn = (ConnInfo*) data;
    312   (void)ptr;
    313   (void)conn;
    314   return realsize;
    315 }
    316 
    317 
    318 /* CURLOPT_PROGRESSFUNCTION */
    319 static int prog_cb(void *p, double dltotal, double dlnow, double ult,
    320                    double uln)
    321 {
    322   ConnInfo *conn = (ConnInfo *)p;
    323   (void)ult;
    324   (void)uln;
    325 
    326   fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal);
    327   return 0;
    328 }
    329 
    330 
    331 /* Create a new easy handle, and add it to the global curl_multi */
    332 static void new_conn(char *url, GlobalInfo *g)
    333 {
    334   ConnInfo *conn;
    335   CURLMcode rc;
    336 
    337   conn = calloc(1, sizeof(ConnInfo));
    338   conn->error[0]='\0';
    339 
    340   conn->easy = curl_easy_init();
    341   if(!conn->easy) {
    342     fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
    343     exit(2);
    344   }
    345   conn->global = g;
    346   conn->url = strdup(url);
    347   curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
    348   curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
    349   curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, conn);
    350   curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L);
    351   curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
    352   curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
    353   curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 0L);
    354   curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
    355   curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
    356   curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 3L);
    357   curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 10L);
    358 
    359   fprintf(MSG_OUT,
    360           "Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url);
    361   rc = curl_multi_add_handle(g->multi, conn->easy);
    362   mcode_or_die("new_conn: curl_multi_add_handle", rc);
    363 
    364   /* note that the add_handle() will set a time-out to trigger very soon so
    365      that the necessary socket_action() call will be called by this app */
    366 }
    367 
    368 /* This gets called whenever data is received from the fifo */
    369 static void fifo_cb(EV_P_ struct ev_io *w, int revents)
    370 {
    371   char s[1024];
    372   long int rv = 0;
    373   int n = 0;
    374   GlobalInfo *g = (GlobalInfo *)w->data;
    375 
    376   do {
    377     s[0]='\0';
    378     rv = fscanf(g->input, "%1023s%n", s, &n);
    379     s[n]='\0';
    380     if(n && s[0]) {
    381       new_conn(s, g);  /* if we read a URL, go get it! */
    382     }
    383     else
    384       break;
    385   } while(rv != EOF);
    386 }
    387 
    388 /* Create a named pipe and tell libevent to monitor it */
    389 static int init_fifo(GlobalInfo *g)
    390 {
    391   struct stat st;
    392   static const char *fifo = "hiper.fifo";
    393   curl_socket_t sockfd;
    394 
    395   fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
    396   if(lstat (fifo, &st) == 0) {
    397     if((st.st_mode & S_IFMT) == S_IFREG) {
    398       errno = EEXIST;
    399       perror("lstat");
    400       exit(1);
    401     }
    402   }
    403   unlink(fifo);
    404   if(mkfifo (fifo, 0600) == -1) {
    405     perror("mkfifo");
    406     exit(1);
    407   }
    408   sockfd = open(fifo, O_RDWR | O_NONBLOCK, 0);
    409   if(sockfd == -1) {
    410     perror("open");
    411     exit(1);
    412   }
    413   g->input = fdopen(sockfd, "r");
    414 
    415   fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo);
    416   ev_io_init(&g->fifo_event, fifo_cb, sockfd, EV_READ);
    417   ev_io_start(g->loop, &g->fifo_event);
    418   return (0);
    419 }
    420 
    421 int main(int argc, char **argv)
    422 {
    423   GlobalInfo g;
    424   CURLMcode rc;
    425   (void)argc;
    426   (void)argv;
    427 
    428   memset(&g, 0, sizeof(GlobalInfo));
    429   g.loop = ev_default_loop(0);
    430 
    431   init_fifo(&g);
    432   g.multi = curl_multi_init();
    433 
    434   ev_timer_init(&g.timer_event, timer_cb, 0., 0.);
    435   g.timer_event.data = &g;
    436   g.fifo_event.data = &g;
    437   curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
    438   curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
    439   curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
    440   curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g);
    441 
    442   /* we don't call any curl_multi_socket*() function yet as we have no handles
    443      added! */
    444 
    445   ev_loop(g.loop, 0);
    446   curl_multi_cleanup(g.multi);
    447   return 0;
    448 }
    449