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authorLijo Antony <lta@one.com>2012-11-21 14:19:45 +0400
committerDaniel Stenberg <daniel@haxx.se>2012-11-21 18:21:31 +0100
commitba33665d1ffc27ccbb9a65c6af058c7c977c9614 (patch)
tree8921a34efbb533a034e11256c26025d522687b44
parent67f053b6724499185b947fbfa11d7a01061129a8 (diff)
examples: Added a c++ example of using multi with boost::asio
Added an example for demonstrating the usage of curl multi interface with boost::asio in c++
-rw-r--r--docs/examples/Makefile.inc2
-rw-r--r--docs/examples/asiohiper.cpp467
2 files changed, 468 insertions, 1 deletions
diff --git a/docs/examples/Makefile.inc b/docs/examples/Makefile.inc
index 2b31f86fb..e1f24cb7c 100644
--- a/docs/examples/Makefile.inc
+++ b/docs/examples/Makefile.inc
@@ -12,4 +12,4 @@ check_PROGRAMS = 10-at-a-time anyauthput cookie_interface debug fileupload \
COMPLICATED_EXAMPLES = curlgtk.c curlx.c htmltitle.cc cacertinmem.c \
ftpuploadresume.c ghiper.c hiperfifo.c htmltidy.c multithread.c \
opensslthreadlock.c sampleconv.c synctime.c threaded-ssl.c evhiperfifo.c \
- smooth-gtk-thread.c version-check.pl href_extractor.c
+ smooth-gtk-thread.c version-check.pl href_extractor.c asiohiper.cpp
diff --git a/docs/examples/asiohiper.cpp b/docs/examples/asiohiper.cpp
new file mode 100644
index 000000000..1ea350253
--- /dev/null
+++ b/docs/examples/asiohiper.cpp
@@ -0,0 +1,467 @@
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+/*
+ * file: asiohiper.cpp
+ * Example program to demonstrate the use of multi socket interface
+ * with boost::asio
+ *
+ * This program is in c++ and uses boost::asio instead of libevent/libev.
+ * Requires boost::asio, boost::bind and boost::system
+ *
+ * This is an adaptation of libcurl's "hiperfifo.c" and "evhiperfifo.c"
+ * sample programs. This example implements a subset of the functionality from
+ * hiperfifo.c, for full functionality refer hiperfifo.c or evhiperfifo.c
+ *
+ * Written by Lijo Antony based on hiperfifo.c by Jeff Pohlmeyer
+ *
+ * When running, the program creates an easy handle for a URL and
+ * uses the curl_multi API to fetch it.
+ *
+ * Note:
+ * For the sake of simplicity, URL is hard coded to "www.google.com"
+ *
+ * This is purely a demo app, all retrieved data is simply discarded by the write
+ * callback.
+ */
+
+
+#include <curl/curl.h>
+#include <boost/asio.hpp>
+#include <boost/bind.hpp>
+
+#define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */
+
+/* boost::asio related objects
+ * using global variables for simplicity
+ */
+boost::asio::io_service io_service;
+boost::asio::deadline_timer timer(io_service);
+std::map<curl_socket_t, boost::asio::ip::tcp::socket *> socket_map;
+
+/* Global information, common to all connections */
+typedef struct _GlobalInfo
+{
+ CURLM *multi;
+ int still_running;
+} GlobalInfo;
+
+/* Information associated with a specific easy handle */
+typedef struct _ConnInfo
+{
+ CURL *easy;
+ char *url;
+ GlobalInfo *global;
+ char error[CURL_ERROR_SIZE];
+} ConnInfo;
+
+static void timer_cb(const boost::system::error_code & error, GlobalInfo *g);
+
+/* Update the event timer after curl_multi library calls */
+static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
+{
+ fprintf(MSG_OUT, "\nmulti_timer_cb: timeout_ms %ld", timeout_ms);
+
+ /* cancel running timer */
+ timer.cancel();
+
+ if ( timeout_ms > 0 )
+ {
+ /* update timer */
+ timer.expires_from_now(boost::posix_time::millisec(timeout_ms));
+ timer.async_wait(boost::bind(&timer_cb, _1, g));
+ }
+ else
+ {
+ /* call timeout function immediately */
+ boost::system::error_code error; /*success*/
+ timer_cb(error, g);
+ }
+
+ return 0;
+}
+
+/* Die if we get a bad CURLMcode somewhere */
+static void mcode_or_die(const char *where, CURLMcode code)
+{
+ if ( CURLM_OK != code )
+ {
+ const char *s;
+ switch ( code )
+ {
+ case CURLM_CALL_MULTI_PERFORM: s="CURLM_CALL_MULTI_PERFORM"; break;
+ case CURLM_BAD_HANDLE: s="CURLM_BAD_HANDLE"; break;
+ case CURLM_BAD_EASY_HANDLE: s="CURLM_BAD_EASY_HANDLE"; break;
+ case CURLM_OUT_OF_MEMORY: s="CURLM_OUT_OF_MEMORY"; break;
+ case CURLM_INTERNAL_ERROR: s="CURLM_INTERNAL_ERROR"; break;
+ case CURLM_UNKNOWN_OPTION: s="CURLM_UNKNOWN_OPTION"; break;
+ case CURLM_LAST: s="CURLM_LAST"; break;
+ default: s="CURLM_unknown";
+ break;
+ case CURLM_BAD_SOCKET: s="CURLM_BAD_SOCKET";
+ fprintf(MSG_OUT, "\nERROR: %s returns %s", where, s);
+ /* ignore this error */
+ return;
+ }
+ fprintf(MSG_OUT, "\nERROR: %s returns %s", where, s);
+ exit(code);
+ }
+}
+
+/* Check for completed transfers, and remove their easy handles */
+static void check_multi_info(GlobalInfo *g)
+{
+ char *eff_url;
+ CURLMsg *msg;
+ int msgs_left;
+ ConnInfo *conn;
+ CURL *easy;
+ CURLcode res;
+
+ fprintf(MSG_OUT, "\nREMAINING: %d", g->still_running);
+
+ while ((msg = curl_multi_info_read(g->multi, &msgs_left)))
+ {
+ if (msg->msg == CURLMSG_DONE)
+ {
+ easy = msg->easy_handle;
+ res = msg->data.result;
+ curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
+ curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
+ fprintf(MSG_OUT, "\nDONE: %s => (%d) %s", eff_url, res, conn->error);
+ curl_multi_remove_handle(g->multi, easy);
+ free(conn->url);
+ curl_easy_cleanup(easy);
+ free(conn);
+ }
+ }
+}
+
+/* Called by asio when there is an action on a socket */
+static void event_cb(GlobalInfo * g, boost::asio::ip::tcp::socket * tcp_socket, int action)
+{
+ fprintf(MSG_OUT, "\nevent_cb: action=%d", action);
+
+ CURLMcode rc;
+ rc = curl_multi_socket_action(g->multi, tcp_socket->native_handle(), action, &g->still_running);
+
+ mcode_or_die("event_cb: curl_multi_socket_action", rc);
+ check_multi_info(g);
+
+ if ( g->still_running <= 0 )
+ {
+ fprintf(MSG_OUT, "\nlast transfer done, kill timeout");
+ timer.cancel();
+ }
+}
+
+/* Called by asio when our timeout expires */
+static void timer_cb(const boost::system::error_code & error, GlobalInfo *g)
+{
+ if ( !error)
+ {
+ fprintf(MSG_OUT, "\ntimer_cb: ");
+
+ CURLMcode rc;
+ rc = curl_multi_socket_action(g->multi, CURL_SOCKET_TIMEOUT, 0, &g->still_running);
+
+ mcode_or_die("timer_cb: curl_multi_socket_action", rc);
+ check_multi_info(g);
+ }
+}
+
+/* Clean up any data */
+static void remsock(int *f, GlobalInfo *g)
+{
+ fprintf(MSG_OUT, "\nremsock: ");
+
+ if ( f )
+ {
+ free(f);
+ }
+}
+
+static void setsock(int *fdp, curl_socket_t s, CURL*e, int act, GlobalInfo*g)
+{
+ fprintf(MSG_OUT, "\nsetsock: socket=%d, act=%d, fdp=%p", s, act, fdp);
+
+ std::map<curl_socket_t, boost::asio::ip::tcp::socket *>::iterator it = socket_map.find(s);
+
+ if ( it == socket_map.end() )
+ {
+ fprintf(MSG_OUT, "\nsocket %d is a c-ares socket, ignoring", s);
+ return;
+ }
+
+ boost::asio::ip::tcp::socket * tcp_socket = it->second;
+
+ *fdp = act;
+
+ if ( act == CURL_POLL_IN )
+ {
+ fprintf(MSG_OUT, "\nwatching for socket to become readable");
+
+ tcp_socket->async_read_some(boost::asio::null_buffers(),
+ boost::bind(&event_cb, g,
+ tcp_socket,
+ act));
+ }
+ else if ( act == CURL_POLL_OUT )
+ {
+ fprintf(MSG_OUT, "\nwatching for socket to become writable");
+
+ tcp_socket->async_write_some(boost::asio::null_buffers(),
+ boost::bind(&event_cb, g,
+ tcp_socket,
+ act));
+ }
+ else if ( act == CURL_POLL_INOUT )
+ {
+ fprintf(MSG_OUT, "\nwatching for socket to become readable & writable");
+
+ tcp_socket->async_read_some(boost::asio::null_buffers(),
+ boost::bind(&event_cb, g,
+ tcp_socket,
+ act));
+
+ tcp_socket->async_write_some(boost::asio::null_buffers(),
+ boost::bind(&event_cb, g,
+ tcp_socket,
+ act));
+ }
+}
+
+
+static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
+{
+ int *fdp = (int *)calloc(sizeof(int), 1); /* fdp is used to store current action */
+
+ setsock(fdp, s, easy, action, g);
+ curl_multi_assign(g->multi, s, fdp);
+}
+
+/* CURLMOPT_SOCKETFUNCTION */
+static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
+{
+ fprintf(MSG_OUT, "\nsock_cb: socket=%d, what=%d, sockp=%p", s, what, sockp);
+
+ GlobalInfo *g = (GlobalInfo*) cbp;
+ int *actionp = (int*) sockp;
+ const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE"};
+
+ fprintf(MSG_OUT,
+ "\nsocket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
+
+ if ( what == CURL_POLL_REMOVE )
+ {
+ fprintf(MSG_OUT, "\n");
+ remsock(actionp, g);
+ }
+ else
+ {
+ if ( !actionp )
+ {
+ fprintf(MSG_OUT, "\nAdding data: %s", whatstr[what]);
+ addsock(s, e, what, g);
+ }
+ else
+ {
+ fprintf(MSG_OUT,
+ "\nChanging action from %s to %s",
+ whatstr[*actionp], whatstr[what]);
+ setsock(actionp, s, e, what, g);
+ }
+ }
+ return 0;
+}
+
+
+/* CURLOPT_WRITEFUNCTION */
+static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data)
+{
+
+ size_t written = size * nmemb;
+ char* pBuffer = (char*)malloc(written + 1);
+
+ strncpy(pBuffer, (const char *)ptr, written);
+ pBuffer [written] = '\0';
+
+ fprintf(MSG_OUT, "%s", pBuffer);
+
+ free(pBuffer);
+
+ return written;
+}
+
+
+/* CURLOPT_PROGRESSFUNCTION */
+static int prog_cb (void *p, double dltotal, double dlnow, double ult,
+ double uln)
+{
+ ConnInfo *conn = (ConnInfo *)p;
+ (void)ult;
+ (void)uln;
+
+ fprintf(MSG_OUT, "\nProgress: %s (%g/%g)", conn->url, dlnow, dltotal);
+ fprintf(MSG_OUT, "\nProgress: %s (%g)", conn->url, ult);
+
+ return 0;
+}
+
+/* CURLOPT_OPENSOCKETFUNCTION */
+static curl_socket_t opensocket(void *clientp,
+ curlsocktype purpose,
+ struct curl_sockaddr *address)
+{
+ fprintf(MSG_OUT, "\nopensocket :");
+
+ curl_socket_t sockfd = CURL_SOCKET_BAD;
+
+ struct sockaddr_in * addr = (struct sockaddr_in *)&(address->addr);
+ char * ip_addr_str = inet_ntoa(addr->sin_addr);
+ unsigned short port = ntohs(addr->sin_port);
+
+ /* create a tcp socket object */
+ boost::asio::ip::address ip_addr = boost::asio::ip::address::from_string(ip_addr_str);
+ boost::asio::ip::tcp::endpoint endpoint(ip_addr, port);
+ boost::asio::ip::tcp::socket * tcp_socket = new boost::asio::ip::tcp::socket(io_service);
+
+ /* connect */
+ boost::system::error_code ec;
+ tcp_socket->connect(endpoint, ec);
+
+ if (ec)
+ {
+ //An error occurred
+ std::cout << std::endl << "Couldn't connect to remote endpoint '" << endpoint << "' [" << ec << "][" << ec.message() << "]";
+ fprintf(MSG_OUT, "\nERROR: Returning CURL_SOCKET_BAD to signal error");
+ }
+ else
+ {
+ sockfd = tcp_socket->native_handle();
+ std::cout << std::endl << "Connected to remote endpoint '" << endpoint << "', with socket : " << sockfd;
+
+ /* save it for monitoring */
+ socket_map.insert(std::pair<curl_socket_t, boost::asio::ip::tcp::socket *>(sockfd, tcp_socket));
+ }
+
+ return sockfd;
+}
+
+/* CURLOPT_SOCKOPTFUNCTION */
+static int sockopt_callback(void *clientp, curl_socket_t curlfd,
+ curlsocktype purpose)
+{
+ fprintf(MSG_OUT, "\nsockopt_callback :");
+
+ /* This return code was added in libcurl 7.21.5 */
+ return CURL_SOCKOPT_ALREADY_CONNECTED;
+}
+
+/* CURLOPT_CLOSESOCKETFUNCTION */
+static int closesocket(void *clientp, curl_socket_t item)
+{
+ fprintf(MSG_OUT, "\nclosesocket :");
+
+ std::map<curl_socket_t, boost::asio::ip::tcp::socket *>::iterator it = socket_map.find(item);
+
+ if ( it != socket_map.end() )
+ {
+ delete it->second;
+ socket_map.erase(it);
+ }
+
+ return 0;
+}
+
+/* Create a new easy handle, and add it to the global curl_multi */
+static void new_conn(char *url, GlobalInfo *g )
+{
+ ConnInfo *conn;
+ CURLMcode rc;
+
+ conn = (ConnInfo *)calloc(1, sizeof(ConnInfo));
+ memset(conn, 0, sizeof(ConnInfo));
+ conn->error[0]='\0';
+
+ conn->easy = curl_easy_init();
+
+ if ( !conn->easy )
+ {
+ fprintf(MSG_OUT, "\ncurl_easy_init() failed, exiting!");
+ exit(2);
+ }
+ conn->global = g;
+ conn->url = strdup(url);
+ curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
+ curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
+ curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, &conn);
+ curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L);
+ curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
+ curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
+ curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 1L);
+ curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
+ curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
+ curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 3L);
+ curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 10L);
+
+ /* call this function to get a socket */
+ curl_easy_setopt(conn->easy, CURLOPT_OPENSOCKETFUNCTION, opensocket);
+
+ /* call this function to set options for the socket */
+ curl_easy_setopt(conn->easy, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
+ curl_easy_setopt(conn->easy, CURLOPT_CLOSESOCKETFUNCTION, closesocket);
+
+ fprintf(MSG_OUT,
+ "\nAdding easy %p to multi %p (%s)", conn->easy, g->multi, url);
+ rc = curl_multi_add_handle(g->multi, conn->easy);
+ mcode_or_die("new_conn: curl_multi_add_handle", rc);
+
+ /* note that the add_handle() will set a time-out to trigger very soon so
+ that the necessary socket_action() call will be called by this app */
+}
+
+int main(int argc, char **argv)
+{
+ GlobalInfo g;
+ CURLMcode rc;
+ (void)argc;
+ (void)argv;
+
+ memset(&g, 0, sizeof(GlobalInfo));
+ g.multi = curl_multi_init();
+
+ curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
+ curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
+ curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
+ curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g);
+
+ new_conn((char *)"www.google.com", &g); /* add a URL */
+
+ /* enter io_service run loop */
+ io_service.run();
+
+ curl_multi_cleanup(g.multi);
+
+ fprintf(MSG_OUT, "\ndone.\n");
+ return 0;
+}