/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 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.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
/* <DESC>
* HTTP/2 server push
* </DESC>
*/
/* curl stuff */
#include <curl/curl.h>
#include <curl/mprintf.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* somewhat unix-specific */
#include <sys/time.h>
#include <unistd.h>
#ifndef CURLPIPE_MULTIPLEX
#error "too old libcurl, cannot do HTTP/2 server push!"
#endif
static int verbose = 1;
static
int my_trace(CURL *handle, curl_infotype type,
char *data, size_t size,
void *userp)
{
const char *text;
(void)handle; /* prevent compiler warning */
(void)userp;
switch(type) {
case CURLINFO_TEXT:
fprintf(stderr, "== Info: %s", data);
/* FALLTHROUGH */
default: /* in case a new one is introduced to shock us */
return 0;
case CURLINFO_HEADER_OUT:
text = "=> Send header";
break;
case CURLINFO_DATA_OUT:
if(verbose <= 1)
return 0;
text = "=> Send data";
break;
case CURLINFO_HEADER_IN:
text = "<= Recv header";
break;
case CURLINFO_DATA_IN:
if(verbose <= 1)
return 0;
text = "<= Recv data";
break;
}
fprintf(stderr, "%s, %lu bytes (0x%lx)\n",
text, (unsigned long)size, (unsigned long)size);
return 0;
}
struct transfer {
int idx;
CURL *easy;
char filename[128];
FILE *out;
curl_off_t recv_size;
curl_off_t pause_at;
int started;
int paused;
int resumed;
int done;
};
static size_t transfer_count = 1;
static struct transfer *transfers;
static struct transfer *get_transfer_for_easy(CURL *easy)
{
size_t i;
for(i = 0; i < transfer_count; ++i) {
if(easy == transfers[i].easy)
return &transfers[i];
}
return NULL;
}
static size_t my_write_cb(char *buf, size_t nitems, size_t buflen,
void *userdata)
{
struct transfer *t = userdata;
ssize_t nwritten;
if(!t->resumed &&
t->recv_size < t->pause_at &&
((curl_off_t)(t->recv_size + (nitems * buflen)) >= t->pause_at)) {
fprintf(stderr, "[t-%d] PAUSE\n", t->idx);
t->paused = 1;
return CURL_WRITEFUNC_PAUSE;
}
if(!t->out) {
curl_msnprintf(t->filename, sizeof(t->filename)-1, "download_%u.data",
t->idx);
t->out = fopen(t->filename, "wb");
if(!t->out)
return 0;
}
nwritten = fwrite(buf, nitems, buflen, t->out);
if(nwritten < 0) {
fprintf(stderr, "[t-%d] write failure\n", t->idx);
return 0;
}
t->recv_size += nwritten;
return (size_t)nwritten;
}
static int setup(CURL *hnd, const char *url, struct transfer *t)
{
curl_easy_setopt(hnd, CURLOPT_URL, url);
curl_easy_setopt(hnd, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYPEER, 0L);
curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYHOST, 0L);
curl_easy_setopt(hnd, CURLOPT_WRITEFUNCTION, my_write_cb);
curl_easy_setopt(hnd, CURLOPT_WRITEDATA, t);
/* please be verbose */
if(verbose) {
curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
curl_easy_setopt(hnd, CURLOPT_DEBUGFUNCTION, my_trace);
}
#if (CURLPIPE_MULTIPLEX > 0)
/* wait for pipe connection to confirm */
curl_easy_setopt(hnd, CURLOPT_PIPEWAIT, 1L);
#endif
return 0; /* all is good */
}
static void usage(const char *msg)
{
if(msg)
fprintf(stderr, "%s\n", msg);
fprintf(stderr,
"usage: [options] url\n"
" download a url with following options:\n"
" -m number max parallel downloads\n"
" -n number total downloads\n"
" -p number pause transfer after `number` response bytes\n"
);
}
/*
* Download a file over HTTP/2, take care of server push.
*/
int main(int argc, char *argv[])
{
CURLM *multi_handle;
struct CURLMsg *m;
const char *url;
size_t i, n, max_parallel = 1;
size_t active_transfers;
long pause_offset = 0;
int abort_paused = 0;
struct transfer *t;
int ch;
while((ch = getopt(argc, argv, "ahm:n:P:")) != -1) {
switch(ch) {
case 'h':
usage(NULL);
return 2;
case 'a':
abort_paused = 1;
break;
case 'm':
max_parallel = (size_t)strtol(optarg, NULL, 10);
break;
case 'n':
transfer_count = (size_t)strtol(optarg, NULL, 10);
break;
case 'P':
pause_offset = strtol(optarg, NULL, 10);
break;
default:
usage("invalid option");
return 1;
}
}
argc -= optind;
argv += optind;
if(argc != 1) {
usage("not enough arguments");
return 2;
}
url = argv[0];
transfers = calloc(transfer_count, sizeof(*transfers));
if(!transfers) {
fprintf(stderr, "error allocating transfer structs\n");
return 1;
}
multi_handle = curl_multi_init();
curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
active_transfers = 0;
for(i = 0; i < transfer_count; ++i) {
t = &transfers[i];
t->idx = (int)i;
t->pause_at = (curl_off_t)pause_offset * i;
}
n = (max_parallel < transfer_count)? max_parallel : transfer_count;
for(i = 0; i < n; ++i) {
t = &transfers[i];
t->easy = curl_easy_init();
if(!t->easy || setup(t->easy, url, t)) {
fprintf(stderr, "[t-%d] FAILED setup\n", (int)i);
return 1;
}
curl_multi_add_handle(multi_handle, t->easy);
t->started = 1;
++active_transfers;
fprintf(stderr, "[t-%d] STARTED\n", t->idx);
}
do {
int still_running; /* keep number of running handles */
CURLMcode mc = curl_multi_perform(multi_handle, &still_running);
if(still_running) {
/* wait for activity, timeout or "nothing" */
mc = curl_multi_poll(multi_handle, NULL, 0, 1000, NULL);
fprintf(stderr, "curl_multi_poll() -> %d\n", mc);
}
if(mc)
break;
do {
int msgq = 0;
m = curl_multi_info_read(multi_handle, &msgq);
if(m && (m->msg == CURLMSG_DONE)) {
CURL *e = m->easy_handle;
active_transfers--;
curl_multi_remove_handle(multi_handle, e);
t = get_transfer_for_easy(e);
if(t) {
t->done = 1;
}
else
curl_easy_cleanup(e);
}
else {
/* nothing happening, maintenance */
if(abort_paused) {
/* abort paused transfers */
for(i = 0; i < transfer_count; ++i) {
t = &transfers[i];
if(!t->done && t->paused && t->easy) {
curl_multi_remove_handle(multi_handle, t->easy);
t->done = 1;
active_transfers--;
fprintf(stderr, "[t-%d] ABORTED\n", t->idx);
}
}
}
else {
/* resume one paused transfer */
for(i = 0; i < transfer_count; ++i) {
t = &transfers[i];
if(!t->done && t->paused) {
t->resumed = 1;
t->paused = 0;
curl_easy_pause(t->easy, CURLPAUSE_CONT);
fprintf(stderr, "[t-%d] RESUMED\n", t->idx);
break;
}
}
}
while(active_transfers < max_parallel) {
for(i = 0; i < transfer_count; ++i) {
t = &transfers[i];
if(!t->started) {
t->easy = curl_easy_init();
if(!t->easy || setup(t->easy, url, t)) {
fprintf(stderr, "[t-%d] FAILEED setup\n", (int)i);
return 1;
}
curl_multi_add_handle(multi_handle, t->easy);
t->started = 1;
++active_transfers;
fprintf(stderr, "[t-%d] STARTED\n", t->idx);
break;
}
}
/* all started */
if(i == transfer_count)
break;
}
}
} while(m);
} while(active_transfers); /* as long as we have transfers going */
for(i = 0; i < transfer_count; ++i) {
t = &transfers[i];
if(t->out) {
fclose(t->out);
t->out = NULL;
}
if(t->easy) {
curl_easy_cleanup(t->easy);
t->easy = NULL;
}
}
free(transfers);
curl_multi_cleanup(multi_handle);
return 0;
}