Annotation of embedaddon/curl/docs/examples/asiohiper.cpp, revision 1.1

1.1     ! misho       1: /***************************************************************************
        !             2:  *                                  _   _ ____  _
        !             3:  *  Project                     ___| | | |  _ \| |
        !             4:  *                             / __| | | | |_) | |
        !             5:  *                            | (__| |_| |  _ <| |___
        !             6:  *                             \___|\___/|_| \_\_____|
        !             7:  *
        !             8:  * Copyright (C) 2012 - 2018, 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: 
        !            23: /* <DESC>
        !            24:  * demonstrate the use of multi socket interface with boost::asio
        !            25:  * </DESC>
        !            26:  */
        !            27: /*
        !            28:  * This program is in c++ and uses boost::asio instead of libevent/libev.
        !            29:  * Requires boost::asio, boost::bind and boost::system
        !            30:  *
        !            31:  * This is an adaptation of libcurl's "hiperfifo.c" and "evhiperfifo.c"
        !            32:  * sample programs. This example implements a subset of the functionality from
        !            33:  * hiperfifo.c, for full functionality refer hiperfifo.c or evhiperfifo.c
        !            34:  *
        !            35:  * Written by Lijo Antony based on hiperfifo.c by Jeff Pohlmeyer
        !            36:  *
        !            37:  * When running, the program creates an easy handle for a URL and
        !            38:  * uses the curl_multi API to fetch it.
        !            39:  *
        !            40:  * Note:
        !            41:  *  For the sake of simplicity, URL is hard coded to "www.google.com"
        !            42:  *
        !            43:  * This is purely a demo app, all retrieved data is simply discarded by the
        !            44:  * write callback.
        !            45:  *
        !            46:  * ===========================================================================
        !            47:  * WARNING: This example program is known to have flaws:
        !            48:  * https://github.com/curl/curl/issues/2407
        !            49:  *
        !            50:  * It still kept in the example repository with the hope that it might be
        !            51:  * useful, and maybe some day someone who knows enough about boost::asio will
        !            52:  * read this text, accept the challenge and make the example code work
        !            53:  * correctly. Until then: expect this example program to fail occasionally.
        !            54:  * ===========================================================================
        !            55:  */
        !            56: 
        !            57: 
        !            58: #include <curl/curl.h>
        !            59: #include <boost/asio.hpp>
        !            60: #include <boost/bind.hpp>
        !            61: #include <iostream>
        !            62: 
        !            63: #define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */
        !            64: 
        !            65: /* boost::asio related objects
        !            66:  * using global variables for simplicity
        !            67:  */
        !            68: boost::asio::io_service io_service;
        !            69: boost::asio::deadline_timer timer(io_service);
        !            70: std::map<curl_socket_t, boost::asio::ip::tcp::socket *> socket_map;
        !            71: 
        !            72: /* Global information, common to all connections */
        !            73: typedef struct _GlobalInfo
        !            74: {
        !            75:   CURLM *multi;
        !            76:   int still_running;
        !            77: } GlobalInfo;
        !            78: 
        !            79: /* Information associated with a specific easy handle */
        !            80: typedef struct _ConnInfo
        !            81: {
        !            82:   CURL *easy;
        !            83:   char *url;
        !            84:   GlobalInfo *global;
        !            85:   char error[CURL_ERROR_SIZE];
        !            86: } ConnInfo;
        !            87: 
        !            88: static void timer_cb(const boost::system::error_code & error, GlobalInfo *g);
        !            89: 
        !            90: /* Update the event timer after curl_multi library calls */
        !            91: static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
        !            92: {
        !            93:   fprintf(MSG_OUT, "\nmulti_timer_cb: timeout_ms %ld", timeout_ms);
        !            94: 
        !            95:   /* cancel running timer */
        !            96:   timer.cancel();
        !            97: 
        !            98:   if(timeout_ms > 0) {
        !            99:     /* update timer */
        !           100:     timer.expires_from_now(boost::posix_time::millisec(timeout_ms));
        !           101:     timer.async_wait(boost::bind(&timer_cb, _1, g));
        !           102:   }
        !           103:   else if(timeout_ms == 0) {
        !           104:     /* call timeout function immediately */
        !           105:     boost::system::error_code error; /*success*/
        !           106:     timer_cb(error, g);
        !           107:   }
        !           108: 
        !           109:   return 0;
        !           110: }
        !           111: 
        !           112: /* Die if we get a bad CURLMcode somewhere */
        !           113: static void mcode_or_die(const char *where, CURLMcode code)
        !           114: {
        !           115:   if(CURLM_OK != code) {
        !           116:     const char *s;
        !           117:     switch(code) {
        !           118:     case CURLM_CALL_MULTI_PERFORM:
        !           119:       s = "CURLM_CALL_MULTI_PERFORM";
        !           120:       break;
        !           121:     case CURLM_BAD_HANDLE:
        !           122:       s = "CURLM_BAD_HANDLE";
        !           123:       break;
        !           124:     case CURLM_BAD_EASY_HANDLE:
        !           125:       s = "CURLM_BAD_EASY_HANDLE";
        !           126:       break;
        !           127:     case CURLM_OUT_OF_MEMORY:
        !           128:       s = "CURLM_OUT_OF_MEMORY";
        !           129:       break;
        !           130:     case CURLM_INTERNAL_ERROR:
        !           131:       s = "CURLM_INTERNAL_ERROR";
        !           132:       break;
        !           133:     case CURLM_UNKNOWN_OPTION:
        !           134:       s = "CURLM_UNKNOWN_OPTION";
        !           135:       break;
        !           136:     case CURLM_LAST:
        !           137:       s = "CURLM_LAST";
        !           138:       break;
        !           139:     default:
        !           140:       s = "CURLM_unknown";
        !           141:       break;
        !           142:     case CURLM_BAD_SOCKET:
        !           143:       s = "CURLM_BAD_SOCKET";
        !           144:       fprintf(MSG_OUT, "\nERROR: %s returns %s", where, s);
        !           145:       /* ignore this error */
        !           146:       return;
        !           147:     }
        !           148: 
        !           149:     fprintf(MSG_OUT, "\nERROR: %s returns %s", where, s);
        !           150: 
        !           151:     exit(code);
        !           152:   }
        !           153: }
        !           154: 
        !           155: /* Check for completed transfers, and remove their easy handles */
        !           156: static void check_multi_info(GlobalInfo *g)
        !           157: {
        !           158:   char *eff_url;
        !           159:   CURLMsg *msg;
        !           160:   int msgs_left;
        !           161:   ConnInfo *conn;
        !           162:   CURL *easy;
        !           163:   CURLcode res;
        !           164: 
        !           165:   fprintf(MSG_OUT, "\nREMAINING: %d", g->still_running);
        !           166: 
        !           167:   while((msg = curl_multi_info_read(g->multi, &msgs_left))) {
        !           168:     if(msg->msg == CURLMSG_DONE) {
        !           169:       easy = msg->easy_handle;
        !           170:       res = msg->data.result;
        !           171:       curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
        !           172:       curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
        !           173:       fprintf(MSG_OUT, "\nDONE: %s => (%d) %s", eff_url, res, conn->error);
        !           174:       curl_multi_remove_handle(g->multi, easy);
        !           175:       free(conn->url);
        !           176:       curl_easy_cleanup(easy);
        !           177:       free(conn);
        !           178:     }
        !           179:   }
        !           180: }
        !           181: 
        !           182: /* Called by asio when there is an action on a socket */
        !           183: static void event_cb(GlobalInfo *g, curl_socket_t s,
        !           184:                      int action, const boost::system::error_code & error,
        !           185:                      int *fdp)
        !           186: {
        !           187:   fprintf(MSG_OUT, "\nevent_cb: action=%d", action);
        !           188: 
        !           189:   if(socket_map.find(s) == socket_map.end()) {
        !           190:     fprintf(MSG_OUT, "\nevent_cb: socket already closed");
        !           191:     return;
        !           192:   }
        !           193: 
        !           194:   /* make sure the event matches what are wanted */
        !           195:   if(*fdp == action || *fdp == CURL_POLL_INOUT) {
        !           196:     CURLMcode rc;
        !           197:     if(error)
        !           198:       action = CURL_CSELECT_ERR;
        !           199:     rc = curl_multi_socket_action(g->multi, s, action, &g->still_running);
        !           200: 
        !           201:     mcode_or_die("event_cb: curl_multi_socket_action", rc);
        !           202:     check_multi_info(g);
        !           203: 
        !           204:     if(g->still_running <= 0) {
        !           205:       fprintf(MSG_OUT, "\nlast transfer done, kill timeout");
        !           206:       timer.cancel();
        !           207:     }
        !           208: 
        !           209:     /* keep on watching.
        !           210:      * the socket may have been closed and/or fdp may have been changed
        !           211:      * in curl_multi_socket_action(), so check them both */
        !           212:     if(!error && socket_map.find(s) != socket_map.end() &&
        !           213:        (*fdp == action || *fdp == CURL_POLL_INOUT)) {
        !           214:       boost::asio::ip::tcp::socket *tcp_socket = socket_map.find(s)->second;
        !           215: 
        !           216:       if(action == CURL_POLL_IN) {
        !           217:         tcp_socket->async_read_some(boost::asio::null_buffers(),
        !           218:                                     boost::bind(&event_cb, g, s,
        !           219:                                                 action, _1, fdp));
        !           220:       }
        !           221:       if(action == CURL_POLL_OUT) {
        !           222:         tcp_socket->async_write_some(boost::asio::null_buffers(),
        !           223:                                      boost::bind(&event_cb, g, s,
        !           224:                                                  action, _1, fdp));
        !           225:       }
        !           226:     }
        !           227:   }
        !           228: }
        !           229: 
        !           230: /* Called by asio when our timeout expires */
        !           231: static void timer_cb(const boost::system::error_code & error, GlobalInfo *g)
        !           232: {
        !           233:   if(!error) {
        !           234:     fprintf(MSG_OUT, "\ntimer_cb: ");
        !           235: 
        !           236:     CURLMcode rc;
        !           237:     rc = curl_multi_socket_action(g->multi, CURL_SOCKET_TIMEOUT, 0,
        !           238:                                   &g->still_running);
        !           239: 
        !           240:     mcode_or_die("timer_cb: curl_multi_socket_action", rc);
        !           241:     check_multi_info(g);
        !           242:   }
        !           243: }
        !           244: 
        !           245: /* Clean up any data */
        !           246: static void remsock(int *f, GlobalInfo *g)
        !           247: {
        !           248:   fprintf(MSG_OUT, "\nremsock: ");
        !           249: 
        !           250:   if(f) {
        !           251:     free(f);
        !           252:   }
        !           253: }
        !           254: 
        !           255: static void setsock(int *fdp, curl_socket_t s, CURL *e, int act, int oldact,
        !           256:                     GlobalInfo *g)
        !           257: {
        !           258:   fprintf(MSG_OUT, "\nsetsock: socket=%d, act=%d, fdp=%p", s, act, fdp);
        !           259: 
        !           260:   std::map<curl_socket_t, boost::asio::ip::tcp::socket *>::iterator it =
        !           261:     socket_map.find(s);
        !           262: 
        !           263:   if(it == socket_map.end()) {
        !           264:     fprintf(MSG_OUT, "\nsocket %d is a c-ares socket, ignoring", s);
        !           265:     return;
        !           266:   }
        !           267: 
        !           268:   boost::asio::ip::tcp::socket * tcp_socket = it->second;
        !           269: 
        !           270:   *fdp = act;
        !           271: 
        !           272:   if(act == CURL_POLL_IN) {
        !           273:     fprintf(MSG_OUT, "\nwatching for socket to become readable");
        !           274:     if(oldact != CURL_POLL_IN && oldact != CURL_POLL_INOUT) {
        !           275:       tcp_socket->async_read_some(boost::asio::null_buffers(),
        !           276:                                   boost::bind(&event_cb, g, s,
        !           277:                                               CURL_POLL_IN, _1, fdp));
        !           278:     }
        !           279:   }
        !           280:   else if(act == CURL_POLL_OUT) {
        !           281:     fprintf(MSG_OUT, "\nwatching for socket to become writable");
        !           282:     if(oldact != CURL_POLL_OUT && oldact != CURL_POLL_INOUT) {
        !           283:       tcp_socket->async_write_some(boost::asio::null_buffers(),
        !           284:                                    boost::bind(&event_cb, g, s,
        !           285:                                                CURL_POLL_OUT, _1, fdp));
        !           286:     }
        !           287:   }
        !           288:   else if(act == CURL_POLL_INOUT) {
        !           289:     fprintf(MSG_OUT, "\nwatching for socket to become readable & writable");
        !           290:     if(oldact != CURL_POLL_IN && oldact != CURL_POLL_INOUT) {
        !           291:       tcp_socket->async_read_some(boost::asio::null_buffers(),
        !           292:                                   boost::bind(&event_cb, g, s,
        !           293:                                               CURL_POLL_IN, _1, fdp));
        !           294:     }
        !           295:     if(oldact != CURL_POLL_OUT && oldact != CURL_POLL_INOUT) {
        !           296:       tcp_socket->async_write_some(boost::asio::null_buffers(),
        !           297:                                    boost::bind(&event_cb, g, s,
        !           298:                                                CURL_POLL_OUT, _1, fdp));
        !           299:     }
        !           300:   }
        !           301: }
        !           302: 
        !           303: static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
        !           304: {
        !           305:   /* fdp is used to store current action */
        !           306:   int *fdp = (int *) calloc(sizeof(int), 1);
        !           307: 
        !           308:   setsock(fdp, s, easy, action, 0, g);
        !           309:   curl_multi_assign(g->multi, s, fdp);
        !           310: }
        !           311: 
        !           312: /* CURLMOPT_SOCKETFUNCTION */
        !           313: static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
        !           314: {
        !           315:   fprintf(MSG_OUT, "\nsock_cb: socket=%d, what=%d, sockp=%p", s, what, sockp);
        !           316: 
        !           317:   GlobalInfo *g = (GlobalInfo*) cbp;
        !           318:   int *actionp = (int *) sockp;
        !           319:   const char *whatstr[] = { "none", "IN", "OUT", "INOUT", "REMOVE"};
        !           320: 
        !           321:   fprintf(MSG_OUT,
        !           322:           "\nsocket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
        !           323: 
        !           324:   if(what == CURL_POLL_REMOVE) {
        !           325:     fprintf(MSG_OUT, "\n");
        !           326:     remsock(actionp, g);
        !           327:   }
        !           328:   else {
        !           329:     if(!actionp) {
        !           330:       fprintf(MSG_OUT, "\nAdding data: %s", whatstr[what]);
        !           331:       addsock(s, e, what, g);
        !           332:     }
        !           333:     else {
        !           334:       fprintf(MSG_OUT,
        !           335:               "\nChanging action from %s to %s",
        !           336:               whatstr[*actionp], whatstr[what]);
        !           337:       setsock(actionp, s, e, what, *actionp, g);
        !           338:     }
        !           339:   }
        !           340: 
        !           341:   return 0;
        !           342: }
        !           343: 
        !           344: /* CURLOPT_WRITEFUNCTION */
        !           345: static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data)
        !           346: {
        !           347:   size_t written = size * nmemb;
        !           348:   char *pBuffer = (char *)malloc(written + 1);
        !           349: 
        !           350:   strncpy(pBuffer, (const char *)ptr, written);
        !           351:   pBuffer[written] = '\0';
        !           352: 
        !           353:   fprintf(MSG_OUT, "%s", pBuffer);
        !           354: 
        !           355:   free(pBuffer);
        !           356: 
        !           357:   return written;
        !           358: }
        !           359: 
        !           360: /* CURLOPT_PROGRESSFUNCTION */
        !           361: static int prog_cb(void *p, double dltotal, double dlnow, double ult,
        !           362:                    double uln)
        !           363: {
        !           364:   ConnInfo *conn = (ConnInfo *)p;
        !           365: 
        !           366:   (void)ult;
        !           367:   (void)uln;
        !           368: 
        !           369:   fprintf(MSG_OUT, "\nProgress: %s (%g/%g)", conn->url, dlnow, dltotal);
        !           370:   fprintf(MSG_OUT, "\nProgress: %s (%g)", conn->url, ult);
        !           371: 
        !           372:   return 0;
        !           373: }
        !           374: 
        !           375: /* CURLOPT_OPENSOCKETFUNCTION */
        !           376: static curl_socket_t opensocket(void *clientp, curlsocktype purpose,
        !           377:                                 struct curl_sockaddr *address)
        !           378: {
        !           379:   fprintf(MSG_OUT, "\nopensocket :");
        !           380: 
        !           381:   curl_socket_t sockfd = CURL_SOCKET_BAD;
        !           382: 
        !           383:   /* restrict to IPv4 */
        !           384:   if(purpose == CURLSOCKTYPE_IPCXN && address->family == AF_INET) {
        !           385:     /* create a tcp socket object */
        !           386:     boost::asio::ip::tcp::socket *tcp_socket =
        !           387:       new boost::asio::ip::tcp::socket(io_service);
        !           388: 
        !           389:     /* open it and get the native handle*/
        !           390:     boost::system::error_code ec;
        !           391:     tcp_socket->open(boost::asio::ip::tcp::v4(), ec);
        !           392: 
        !           393:     if(ec) {
        !           394:       /* An error occurred */
        !           395:       std::cout << std::endl << "Couldn't open socket [" << ec << "][" <<
        !           396:         ec.message() << "]";
        !           397:       fprintf(MSG_OUT, "\nERROR: Returning CURL_SOCKET_BAD to signal error");
        !           398:     }
        !           399:     else {
        !           400:       sockfd = tcp_socket->native_handle();
        !           401:       fprintf(MSG_OUT, "\nOpened socket %d", sockfd);
        !           402: 
        !           403:       /* save it for monitoring */
        !           404:       socket_map.insert(std::pair<curl_socket_t,
        !           405:                         boost::asio::ip::tcp::socket *>(sockfd, tcp_socket));
        !           406:     }
        !           407:   }
        !           408: 
        !           409:   return sockfd;
        !           410: }
        !           411: 
        !           412: /* CURLOPT_CLOSESOCKETFUNCTION */
        !           413: static int close_socket(void *clientp, curl_socket_t item)
        !           414: {
        !           415:   fprintf(MSG_OUT, "\nclose_socket : %d", item);
        !           416: 
        !           417:   std::map<curl_socket_t, boost::asio::ip::tcp::socket *>::iterator it =
        !           418:     socket_map.find(item);
        !           419: 
        !           420:   if(it != socket_map.end()) {
        !           421:     delete it->second;
        !           422:     socket_map.erase(it);
        !           423:   }
        !           424: 
        !           425:   return 0;
        !           426: }
        !           427: 
        !           428: /* Create a new easy handle, and add it to the global curl_multi */
        !           429: static void new_conn(char *url, GlobalInfo *g)
        !           430: {
        !           431:   ConnInfo *conn;
        !           432:   CURLMcode rc;
        !           433: 
        !           434:   conn = (ConnInfo *) calloc(1, sizeof(ConnInfo));
        !           435: 
        !           436:   conn->easy = curl_easy_init();
        !           437:   if(!conn->easy) {
        !           438:     fprintf(MSG_OUT, "\ncurl_easy_init() failed, exiting!");
        !           439:     exit(2);
        !           440:   }
        !           441: 
        !           442:   conn->global = g;
        !           443:   conn->url = strdup(url);
        !           444:   curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
        !           445:   curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
        !           446:   curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, &conn);
        !           447:   curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L);
        !           448:   curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
        !           449:   curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
        !           450:   curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 1L);
        !           451:   curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
        !           452:   curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
        !           453:   curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 3L);
        !           454:   curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 10L);
        !           455: 
        !           456:   /* call this function to get a socket */
        !           457:   curl_easy_setopt(conn->easy, CURLOPT_OPENSOCKETFUNCTION, opensocket);
        !           458: 
        !           459:   /* call this function to close a socket */
        !           460:   curl_easy_setopt(conn->easy, CURLOPT_CLOSESOCKETFUNCTION, close_socket);
        !           461: 
        !           462:   fprintf(MSG_OUT,
        !           463:           "\nAdding easy %p to multi %p (%s)", conn->easy, g->multi, url);
        !           464:   rc = curl_multi_add_handle(g->multi, conn->easy);
        !           465:   mcode_or_die("new_conn: curl_multi_add_handle", rc);
        !           466: 
        !           467:   /* note that the add_handle() will set a time-out to trigger very soon so
        !           468:      that the necessary socket_action() call will be called by this app */
        !           469: }
        !           470: 
        !           471: int main(int argc, char **argv)
        !           472: {
        !           473:   GlobalInfo g;
        !           474: 
        !           475:   (void)argc;
        !           476:   (void)argv;
        !           477: 
        !           478:   memset(&g, 0, sizeof(GlobalInfo));
        !           479:   g.multi = curl_multi_init();
        !           480: 
        !           481:   curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
        !           482:   curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
        !           483:   curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
        !           484:   curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g);
        !           485: 
        !           486:   new_conn((char *)"www.google.com", &g);  /* add a URL */
        !           487: 
        !           488:   /* enter io_service run loop */
        !           489:   io_service.run();
        !           490: 
        !           491:   curl_multi_cleanup(g.multi);
        !           492: 
        !           493:   fprintf(MSG_OUT, "\ndone.\n");
        !           494: 
        !           495:   return 0;
        !           496: }

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