Annotation of embedaddon/curl/docs/examples/evhiperfifo.c, revision 1.1

1.1     ! misho       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 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) |
        !           251:              ((act & CURL_POLL_OUT) ? EV_WRITE : 0);
        !           252: 
        !           253:   f->sockfd = s;
        !           254:   f->action = act;
        !           255:   f->easy = e;
        !           256:   if(f->evset)
        !           257:     ev_io_stop(g->loop, &f->ev);
        !           258:   ev_io_init(&f->ev, event_cb, f->sockfd, kind);
        !           259:   f->ev.data = g;
        !           260:   f->evset = 1;
        !           261:   ev_io_start(g->loop, &f->ev);
        !           262: }
        !           263: 
        !           264: 
        !           265: 
        !           266: /* Initialize a new SockInfo structure */
        !           267: static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
        !           268: {
        !           269:   SockInfo *fdp = calloc(sizeof(SockInfo), 1);
        !           270: 
        !           271:   fdp->global = g;
        !           272:   setsock(fdp, s, easy, action, g);
        !           273:   curl_multi_assign(g->multi, s, fdp);
        !           274: }
        !           275: 
        !           276: /* CURLMOPT_SOCKETFUNCTION */
        !           277: static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
        !           278: {
        !           279:   DPRINT("%s e %p s %i what %i cbp %p sockp %p\n",
        !           280:          __PRETTY_FUNCTION__, e, s, what, cbp, sockp);
        !           281: 
        !           282:   GlobalInfo *g = (GlobalInfo*) cbp;
        !           283:   SockInfo *fdp = (SockInfo*) sockp;
        !           284:   const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE"};
        !           285: 
        !           286:   fprintf(MSG_OUT,
        !           287:           "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
        !           288:   if(what == CURL_POLL_REMOVE) {
        !           289:     fprintf(MSG_OUT, "\n");
        !           290:     remsock(fdp, g);
        !           291:   }
        !           292:   else {
        !           293:     if(!fdp) {
        !           294:       fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]);
        !           295:       addsock(s, e, what, g);
        !           296:     }
        !           297:     else {
        !           298:       fprintf(MSG_OUT,
        !           299:               "Changing action from %s to %s\n",
        !           300:               whatstr[fdp->action], whatstr[what]);
        !           301:       setsock(fdp, s, e, what, g);
        !           302:     }
        !           303:   }
        !           304:   return 0;
        !           305: }
        !           306: 
        !           307: 
        !           308: /* CURLOPT_WRITEFUNCTION */
        !           309: static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data)
        !           310: {
        !           311:   size_t realsize = size * nmemb;
        !           312:   ConnInfo *conn = (ConnInfo*) data;
        !           313:   (void)ptr;
        !           314:   (void)conn;
        !           315:   return realsize;
        !           316: }
        !           317: 
        !           318: 
        !           319: /* CURLOPT_PROGRESSFUNCTION */
        !           320: static int prog_cb(void *p, double dltotal, double dlnow, double ult,
        !           321:                    double uln)
        !           322: {
        !           323:   ConnInfo *conn = (ConnInfo *)p;
        !           324:   (void)ult;
        !           325:   (void)uln;
        !           326: 
        !           327:   fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal);
        !           328:   return 0;
        !           329: }
        !           330: 
        !           331: 
        !           332: /* Create a new easy handle, and add it to the global curl_multi */
        !           333: static void new_conn(char *url, GlobalInfo *g)
        !           334: {
        !           335:   ConnInfo *conn;
        !           336:   CURLMcode rc;
        !           337: 
        !           338:   conn = calloc(1, sizeof(ConnInfo));
        !           339:   conn->error[0]='\0';
        !           340: 
        !           341:   conn->easy = curl_easy_init();
        !           342:   if(!conn->easy) {
        !           343:     fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
        !           344:     exit(2);
        !           345:   }
        !           346:   conn->global = g;
        !           347:   conn->url = strdup(url);
        !           348:   curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
        !           349:   curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
        !           350:   curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, conn);
        !           351:   curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L);
        !           352:   curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
        !           353:   curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
        !           354:   curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 0L);
        !           355:   curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
        !           356:   curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
        !           357:   curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 3L);
        !           358:   curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 10L);
        !           359: 
        !           360:   fprintf(MSG_OUT,
        !           361:           "Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url);
        !           362:   rc = curl_multi_add_handle(g->multi, conn->easy);
        !           363:   mcode_or_die("new_conn: curl_multi_add_handle", rc);
        !           364: 
        !           365:   /* note that the add_handle() will set a time-out to trigger very soon so
        !           366:      that the necessary socket_action() call will be called by this app */
        !           367: }
        !           368: 
        !           369: /* This gets called whenever data is received from the fifo */
        !           370: static void fifo_cb(EV_P_ struct ev_io *w, int revents)
        !           371: {
        !           372:   char s[1024];
        !           373:   long int rv = 0;
        !           374:   int n = 0;
        !           375:   GlobalInfo *g = (GlobalInfo *)w->data;
        !           376: 
        !           377:   do {
        !           378:     s[0]='\0';
        !           379:     rv = fscanf(g->input, "%1023s%n", s, &n);
        !           380:     s[n]='\0';
        !           381:     if(n && s[0]) {
        !           382:       new_conn(s, g);  /* if we read a URL, go get it! */
        !           383:     }
        !           384:     else
        !           385:       break;
        !           386:   } while(rv != EOF);
        !           387: }
        !           388: 
        !           389: /* Create a named pipe and tell libevent to monitor it */
        !           390: static int init_fifo(GlobalInfo *g)
        !           391: {
        !           392:   struct stat st;
        !           393:   static const char *fifo = "hiper.fifo";
        !           394:   curl_socket_t sockfd;
        !           395: 
        !           396:   fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
        !           397:   if(lstat (fifo, &st) == 0) {
        !           398:     if((st.st_mode & S_IFMT) == S_IFREG) {
        !           399:       errno = EEXIST;
        !           400:       perror("lstat");
        !           401:       exit(1);
        !           402:     }
        !           403:   }
        !           404:   unlink(fifo);
        !           405:   if(mkfifo (fifo, 0600) == -1) {
        !           406:     perror("mkfifo");
        !           407:     exit(1);
        !           408:   }
        !           409:   sockfd = open(fifo, O_RDWR | O_NONBLOCK, 0);
        !           410:   if(sockfd == -1) {
        !           411:     perror("open");
        !           412:     exit(1);
        !           413:   }
        !           414:   g->input = fdopen(sockfd, "r");
        !           415: 
        !           416:   fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo);
        !           417:   ev_io_init(&g->fifo_event, fifo_cb, sockfd, EV_READ);
        !           418:   ev_io_start(g->loop, &g->fifo_event);
        !           419:   return (0);
        !           420: }
        !           421: 
        !           422: int main(int argc, char **argv)
        !           423: {
        !           424:   GlobalInfo g;
        !           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: }

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