CMake/Utilities/cmcurl-7.19.0/docs/examples/hiperfifo.c

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2008-09-23 20:32:06 +04:00
/*****************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* $Id$
*
* Example application source code using the multi socket interface to
* download many files at once.
*
* Written by Jeff Pohlmeyer
Requires libevent and a (POSIX?) system that has mkfifo().
This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c"
sample programs.
When running, the program creates the named pipe "hiper.fifo"
Whenever there is input into the fifo, the program reads the input as a list
of URL's and creates some new easy handles to fetch each URL via the
curl_multi "hiper" API.
Thus, you can try a single URL:
% echo http://www.yahoo.com > hiper.fifo
Or a whole bunch of them:
% cat my-url-list > hiper.fifo
The fifo buffer is handled almost instantly, so you can even add more URL's
while the previous requests are still being downloaded.
Note:
For the sake of simplicity, URL length is limited to 1023 char's !
This is purely a demo app, all retrieved data is simply discarded by the write
callback.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include <sys/poll.h>
#include <curl/curl.h>
#include <event.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <errno.h>
#define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */
/* Global information, common to all connections */
typedef struct _GlobalInfo {
struct event fifo_event;
struct event timer_event;
CURLM *multi;
int prev_running;
int still_running;
FILE* input;
} GlobalInfo;
/* Information associated with a specific easy handle */
typedef struct _ConnInfo {
CURL *easy;
char *url;
GlobalInfo *global;
char error[CURL_ERROR_SIZE];
} ConnInfo;
/* Information associated with a specific socket */
typedef struct _SockInfo {
curl_socket_t sockfd;
CURL *easy;
int action;
long timeout;
struct event ev;
int evset;
GlobalInfo *global;
} SockInfo;
/* Update the event timer after curl_multi library calls */
static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
{
struct timeval timeout;
(void)multi; /* unused */
timeout.tv_sec = timeout_ms/1000;
timeout.tv_usec = (timeout_ms%1000)*1000;
fprintf(MSG_OUT, "multi_timer_cb: Setting timeout to %ld ms\n", timeout_ms);
evtimer_add(&g->timer_event, &timeout);
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_OK: s="CURLM_OK"; 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, "ERROR: %s returns %s\n", where, s);
/* ignore this error */
return;
}
fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
exit(code);
}
}
/* Check for completed transfers, and remove their easy handles */
static void check_run_count(GlobalInfo *g)
{
if (g->prev_running > g->still_running) {
char *eff_url=NULL;
CURLMsg *msg;
int msgs_left;
ConnInfo *conn=NULL;
CURL*easy;
CURLcode res;
fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running);
/*
I am still uncertain whether it is safe to remove an easy handle
from inside the curl_multi_info_read loop, so here I will search
for completed transfers in the inner "while" loop, and then remove
them in the outer "do-while" loop...
*/
do {
easy=NULL;
while ((msg = curl_multi_info_read(g->multi, &msgs_left))) {
if (msg->msg == CURLMSG_DONE) {
easy=msg->easy_handle;
res=msg->data.result;
break;
}
}
if (easy) {
curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error);
curl_multi_remove_handle(g->multi, easy);
free(conn->url);
curl_easy_cleanup(easy);
free(conn);
}
} while ( easy );
}
g->prev_running = g->still_running;
}
/* Called by libevent when we get action on a multi socket */
static void event_cb(int fd, short kind, void *userp)
{
GlobalInfo *g = (GlobalInfo*) userp;
CURLMcode rc;
(void)kind; /* unused */
do {
rc = curl_multi_socket(g->multi, fd, &g->still_running);
} while (rc == CURLM_CALL_MULTI_PERFORM);
mcode_or_die("event_cb: curl_multi_socket", rc);
check_run_count(g);
if ( g->still_running <= 0 ) {
fprintf(MSG_OUT, "last transfer done, kill timeout\n");
if (evtimer_pending(&g->timer_event, NULL)) {
evtimer_del(&g->timer_event);
}
}
}
/* Called by libevent when our timeout expires */
static void timer_cb(int fd, short kind, void *userp)
{
GlobalInfo *g = (GlobalInfo *)userp;
CURLMcode rc;
(void)fd;
(void)kind;
do {
rc = curl_multi_socket(g->multi, CURL_SOCKET_TIMEOUT, &g->still_running);
} while (rc == CURLM_CALL_MULTI_PERFORM);
mcode_or_die("timer_cb: curl_multi_socket", rc);
check_run_count(g);
}
/* Clean up the SockInfo structure */
static void remsock(SockInfo *f)
{
if (f) {
if (f->evset)
event_del(&f->ev);
free(f);
}
}
/* Assign information to a SockInfo structure */
static void setsock(SockInfo*f, curl_socket_t s, CURL*e, int act, GlobalInfo*g)
{
int kind =
(act&CURL_POLL_IN?EV_READ:0)|(act&CURL_POLL_OUT?EV_WRITE:0)|EV_PERSIST;
f->sockfd = s;
f->action = act;
f->easy = e;
if (f->evset)
event_del(&f->ev);
event_set(&f->ev, f->sockfd, kind, event_cb, g);
f->evset=1;
event_add(&f->ev, NULL);
}
/* Initialize a new SockInfo structure */
static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g) {
SockInfo *fdp = calloc(sizeof(SockInfo), 1);
fdp->global = g;
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)
{
GlobalInfo *g = (GlobalInfo*) cbp;
SockInfo *fdp = (SockInfo*) sockp;
const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE" };
fprintf(MSG_OUT,
"socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
if (what == CURL_POLL_REMOVE) {
fprintf(MSG_OUT, "\n");
remsock(fdp);
}
else {
if (!fdp) {
fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]);
addsock(s, e, what, g);
}
else {
fprintf(MSG_OUT,
"Changing action from %s to %s\n",
whatstr[fdp->action], whatstr[what]);
setsock(fdp, 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 realsize = size * nmemb;
ConnInfo *conn = (ConnInfo*) data;
(void)ptr;
(void)conn;
return realsize;
}
/* 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, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal);
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 = calloc(1, sizeof(ConnInfo));
memset(conn, 0, sizeof(ConnInfo));
conn->error[0]='\0';
conn->easy = curl_easy_init();
if (!conn->easy) {
fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
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, 0L);
curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
fprintf(MSG_OUT,
"Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url);
rc =curl_multi_add_handle(g->multi, conn->easy);
mcode_or_die("new_conn: curl_multi_add_handle", rc);
do {
rc = curl_multi_socket_all(g->multi, &g->still_running);
} while (CURLM_CALL_MULTI_PERFORM == rc);
mcode_or_die("new_conn: curl_multi_socket_all", rc);
check_run_count(g);
}
/* This gets called whenever data is received from the fifo */
static void fifo_cb(int fd, short event, void *arg)
{
char s[1024];
long int rv=0;
int n=0;
GlobalInfo *g = (GlobalInfo *)arg;
(void)fd; /* unused */
(void)event; /* unused */
do {
s[0]='\0';
rv=fscanf(g->input, "%1023s%n", s, &n);
s[n]='\0';
if ( n && s[0] ) {
new_conn(s,arg); /* if we read a URL, go get it! */
} else break;
} while ( rv != EOF);
}
/* Create a named pipe and tell libevent to monitor it */
static int init_fifo (GlobalInfo *g)
{
struct stat st;
static const char *fifo = "hiper.fifo";
int sockfd;
fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
if (lstat (fifo, &st) == 0) {
if ((st.st_mode & S_IFMT) == S_IFREG) {
errno = EEXIST;
perror("lstat");
exit (1);
}
}
unlink(fifo);
if (mkfifo (fifo, 0600) == -1) {
perror("mkfifo");
exit (1);
}
sockfd = open(fifo, O_RDWR | O_NONBLOCK, 0);
if (sockfd == -1) {
perror("open");
exit (1);
}
g->input = fdopen(sockfd, "r");
fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo);
event_set(&g->fifo_event, sockfd, EV_READ | EV_PERSIST, fifo_cb, g);
event_add(&g->fifo_event, NULL);
return (0);
}
int main(int argc, char **argv)
{
GlobalInfo g;
CURLMcode rc;
(void)argc;
(void)argv;
memset(&g, 0, sizeof(GlobalInfo));
event_init();
init_fifo(&g);
g.multi = curl_multi_init();
evtimer_set(&g.timer_event, timer_cb, &g);
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);
do {
rc = curl_multi_socket_all(g.multi, &g.still_running);
} while (CURLM_CALL_MULTI_PERFORM == rc);
event_dispatch();
curl_multi_cleanup(g.multi);
return 0;
}