/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) Daniel Stenberg, , 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. * * SPDX-License-Identifier: curl * ***************************************************************************/ /* * multi_socket API using libuv * */ /* Use the socket_action interface to download multiple files in parallel, powered by libuv. Requires libuv and (of course) libcurl. See https://docs.libuv.org/en/v1.x/index.html libuv API documentation */ #include #include #include #include /* object to pass to the callbacks */ struct datauv { uv_timer_t timeout; uv_loop_t *loop; CURLM *multi; }; typedef struct curl_context_s { uv_poll_t poll_handle; curl_socket_t sockfd; struct datauv *uv; } curl_context_t; static curl_context_t *create_curl_context(curl_socket_t sockfd, struct datauv *uv) { curl_context_t *context; context = (curl_context_t *) malloc(sizeof(*context)); context->sockfd = sockfd; context->uv = uv; uv_poll_init_socket(uv->loop, &context->poll_handle, sockfd); context->poll_handle.data = context; return context; } static void curl_close_cb(uv_handle_t *handle) { curl_context_t *context = (curl_context_t *) handle->data; free(context); } static void destroy_curl_context(curl_context_t *context) { uv_close((uv_handle_t *) &context->poll_handle, curl_close_cb); } static void add_download(const char *url, int num, CURLM *multi) { 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(multi, handle); fprintf(stderr, "Added download %s -> %s\n", url, filename); } static void check_multi_info(curl_context_t *context) { char *done_url; CURLMsg *message; int pending; CURL *easy_handle; FILE *file; while((message = curl_multi_info_read(context->uv->multi, &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 does 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(context->uv->multi, easy_handle); curl_easy_cleanup(easy_handle); if(file) { fclose(file); } break; default: fprintf(stderr, "CURLMSG default\n"); break; } } } /* callback from libuv on socket activity */ static void on_uv_socket(uv_poll_t *req, int status, int events) { int running_handles; int flags = 0; curl_context_t *context = (curl_context_t *) req->data; (void)status; if(events & UV_READABLE) flags |= CURL_CSELECT_IN; if(events & UV_WRITABLE) flags |= CURL_CSELECT_OUT; curl_multi_socket_action(context->uv->multi, context->sockfd, flags, &running_handles); check_multi_info(context); } /* callback from libuv when timeout expires */ static void on_uv_timeout(uv_timer_t *req) { curl_context_t *context = (curl_context_t *) req->data; if(context) { int running_handles; curl_multi_socket_action(context->uv->multi, CURL_SOCKET_TIMEOUT, 0, &running_handles); check_multi_info(context); } } /* callback from libcurl to update the timeout expiry */ static int cb_timeout(CURLM *multi, long timeout_ms, struct datauv *uv) { (void)multi; if(timeout_ms < 0) uv_timer_stop(&uv->timeout); else { if(timeout_ms == 0) timeout_ms = 1; /* 0 means call curl_multi_socket_action asap but NOT within the callback itself */ uv_timer_start(&uv->timeout, on_uv_timeout, timeout_ms, 0); /* do not repeat */ } return 0; } /* callback from libcurl to update socket activity to wait for */ static int cb_socket(CURL *easy, curl_socket_t s, int action, struct datauv *uv, void *socketp) { curl_context_t *curl_context; int events = 0; (void)easy; 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, uv); curl_multi_assign(uv->multi, s, (void *) curl_context); if(action != CURL_POLL_IN) events |= UV_WRITABLE; if(action != CURL_POLL_OUT) events |= UV_READABLE; uv_poll_start(&curl_context->poll_handle, events, on_uv_socket); break; case CURL_POLL_REMOVE: if(socketp) { uv_poll_stop(&((curl_context_t*)socketp)->poll_handle); destroy_curl_context((curl_context_t*) socketp); curl_multi_assign(uv->multi, s, NULL); } break; default: abort(); } return 0; } int main(int argc, char **argv) { struct datauv uv = { 0 }; int running_handles; if(argc <= 1) return 0; curl_global_init(CURL_GLOBAL_ALL); uv.loop = uv_default_loop(); uv_timer_init(uv.loop, &uv.timeout); uv.multi = curl_multi_init(); curl_multi_setopt(uv.multi, CURLMOPT_SOCKETFUNCTION, cb_socket); curl_multi_setopt(uv.multi, CURLMOPT_SOCKETDATA, &uv); curl_multi_setopt(uv.multi, CURLMOPT_TIMERFUNCTION, cb_timeout); curl_multi_setopt(uv.multi, CURLMOPT_TIMERDATA, &uv); while(argc-- > 1) { add_download(argv[argc], argc, uv.multi); } /* kickstart the thing */ curl_multi_socket_action(uv.multi, CURL_SOCKET_TIMEOUT, 0, &running_handles); uv_run(uv.loop, UV_RUN_DEFAULT); curl_multi_cleanup(uv.multi); return 0; }