/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2020, 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 https://curl.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. * ***************************************************************************/ /* <DESC> * multi_socket API using libevent * </DESC> */ #include <stdio.h> #include <stdlib.h> #include <event2/event.h> #include <curl/curl.h> struct event_base *base; CURLM *curl_handle; struct event *timeout; typedef struct curl_context_s { struct event *event; curl_socket_t sockfd; } curl_context_t; static void curl_perform(int fd, short event, void *arg); static curl_context_t *create_curl_context(curl_socket_t sockfd) { curl_context_t *context; context = (curl_context_t *) malloc(sizeof(*context)); context->sockfd = sockfd; context->event = event_new(base, sockfd, 0, curl_perform, context); return context; } static void destroy_curl_context(curl_context_t *context) { event_del(context->event); event_free(context->event); free(context); } static void add_download(const char *url, int num) { char filename[50]; FILE *file; CURL *handle; snprintf(filename, 50, "%d.download", num); file = fopen(filename, "wb"); if(!file) { fprintf(stderr, "Error opening %s\n", filename); return; } handle = curl_easy_init(); curl_easy_setopt(handle, CURLOPT_WRITEDATA, file); curl_easy_setopt(handle, CURLOPT_PRIVATE, file); curl_easy_setopt(handle, CURLOPT_URL, url); curl_multi_add_handle(curl_handle, handle); fprintf(stderr, "Added download %s -> %s\n", url, filename); } static void check_multi_info(void) { char *done_url; CURLMsg *message; int pending; CURL *easy_handle; FILE *file; while((message = curl_multi_info_read(curl_handle, &pending))) { switch(message->msg) { case CURLMSG_DONE: /* Do not use message data after calling curl_multi_remove_handle() and curl_easy_cleanup(). As per curl_multi_info_read() docs: "WARNING: The data the returned pointer points to will not survive calling curl_multi_cleanup, curl_multi_remove_handle or curl_easy_cleanup." */ easy_handle = message->easy_handle; curl_easy_getinfo(easy_handle, CURLINFO_EFFECTIVE_URL, &done_url); curl_easy_getinfo(easy_handle, CURLINFO_PRIVATE, &file); printf("%s DONE\n", done_url); curl_multi_remove_handle(curl_handle, easy_handle); curl_easy_cleanup(easy_handle); if(file) { fclose(file); } break; default: fprintf(stderr, "CURLMSG default\n"); break; } } } static void curl_perform(int fd, short event, void *arg) { int running_handles; int flags = 0; curl_context_t *context; if(event & EV_READ) flags |= CURL_CSELECT_IN; if(event & EV_WRITE) flags |= CURL_CSELECT_OUT; context = (curl_context_t *) arg; curl_multi_socket_action(curl_handle, context->sockfd, flags, &running_handles); check_multi_info(); } static void on_timeout(evutil_socket_t fd, short events, void *arg) { int running_handles; curl_multi_socket_action(curl_handle, CURL_SOCKET_TIMEOUT, 0, &running_handles); check_multi_info(); } static int start_timeout(CURLM *multi, long timeout_ms, void *userp) { if(timeout_ms < 0) { evtimer_del(timeout); } else { if(timeout_ms == 0) timeout_ms = 1; /* 0 means directly call socket_action, but we'll do it in a bit */ struct timeval tv; tv.tv_sec = timeout_ms / 1000; tv.tv_usec = (timeout_ms % 1000) * 1000; evtimer_del(timeout); evtimer_add(timeout, &tv); } return 0; } static int handle_socket(CURL *easy, curl_socket_t s, int action, void *userp, void *socketp) { curl_context_t *curl_context; int events = 0; switch(action) { case CURL_POLL_IN: case CURL_POLL_OUT: case CURL_POLL_INOUT: curl_context = socketp ? (curl_context_t *) socketp : create_curl_context(s); curl_multi_assign(curl_handle, s, (void *) curl_context); if(action != CURL_POLL_IN) events |= EV_WRITE; if(action != CURL_POLL_OUT) events |= EV_READ; events |= EV_PERSIST; event_del(curl_context->event); event_assign(curl_context->event, base, curl_context->sockfd, events, curl_perform, curl_context); event_add(curl_context->event, NULL); break; case CURL_POLL_REMOVE: if(socketp) { event_del(((curl_context_t*) socketp)->event); destroy_curl_context((curl_context_t*) socketp); curl_multi_assign(curl_handle, s, NULL); } break; default: abort(); } return 0; } int main(int argc, char **argv) { if(argc <= 1) return 0; if(curl_global_init(CURL_GLOBAL_ALL)) { fprintf(stderr, "Could not init curl\n"); return 1; } base = event_base_new(); timeout = evtimer_new(base, on_timeout, NULL); curl_handle = curl_multi_init(); curl_multi_setopt(curl_handle, CURLMOPT_SOCKETFUNCTION, handle_socket); curl_multi_setopt(curl_handle, CURLMOPT_TIMERFUNCTION, start_timeout); while(argc-- > 1) { add_download(argv[argc], argc); } event_base_dispatch(base); curl_multi_cleanup(curl_handle); event_free(timeout); event_base_free(base); libevent_global_shutdown(); curl_global_cleanup(); return 0; }