diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/examples/Makefile.inc | 2 | ||||
| -rw-r--r-- | docs/examples/multi-event.c | 240 |
2 files changed, 241 insertions, 1 deletions
diff --git a/docs/examples/Makefile.inc b/docs/examples/Makefile.inc index 6fd8ecd76..f03fcf2f0 100644 --- a/docs/examples/Makefile.inc +++ b/docs/examples/Makefile.inc @@ -45,4 +45,4 @@ COMPLICATED_EXAMPLES = curlgtk.c curlx.c htmltitle.cpp cacertinmem.c \ sampleconv.c synctime.c threaded-ssl.c evhiperfifo.c \ smooth-gtk-thread.c version-check.pl href_extractor.c asiohiper.cpp \ multi-uv.c xmlstream.c usercertinmem.c sessioninfo.c \ - threaded-shared-conn.c crawler.c ephiperfifo.c + threaded-shared-conn.c crawler.c ephiperfifo.c multi-event.c diff --git a/docs/examples/multi-event.c b/docs/examples/multi-event.c new file mode 100644 index 000000000..ce2791974 --- /dev/null +++ b/docs/examples/multi-event.c @@ -0,0 +1,240 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 1998 - 2018, 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.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. + * + ***************************************************************************/ + +/* <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; +} |