summaryrefslogtreecommitdiff
path: root/docs/examples/evhiperfifo.c
blob: efe42475a9b5bc49a83c5553c8cae754caf8b693 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2016, 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 interface together with libev
 * </DESC>
 */
/* Example application source code using the multi socket interface to
 * download many files at once.
 *
 * This example features the same basic functionality as hiperfifo.c does,
 * but this uses libev instead of libevent.
 *
 * Written by Jeff Pohlmeyer, converted to use libev by Markus Koetter

Requires libev 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 <ev.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <errno.h>

#define DPRINT(x...) printf(x)

#define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */


/* Global information, common to all connections */
typedef struct _GlobalInfo
{
  struct ev_loop *loop;
  struct ev_io fifo_event;
  struct ev_timer timer_event;
  CURLM *multi;
  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 ev_io ev;
  int evset;
  GlobalInfo *global;
} SockInfo;

static void timer_cb(EV_P_ struct ev_timer *w, int revents);

/* Update the event timer after curl_multi library calls */
static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
{
  DPRINT("%s %li\n", __PRETTY_FUNCTION__,  timeout_ms);
  ev_timer_stop(g->loop, &g->timer_event);
  if(timeout_ms > 0) {
    double  t = timeout_ms / 1000;
    ev_timer_init(&g->timer_event, timer_cb, t, 0.);
    ev_timer_start(g->loop, &g->timer_event);
  }
  else
    timer_cb(g->loop, &g->timer_event, 0);
  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_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_multi_info(GlobalInfo *g)
{
  char *eff_url;
  CURLMsg *msg;
  int msgs_left;
  ConnInfo *conn;
  CURL *easy;
  CURLcode res;

  fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running);
  while((msg = curl_multi_info_read(g->multi, &msgs_left))) {
    if(msg->msg == CURLMSG_DONE) {
      easy = msg->easy_handle;
      res = msg->data.result;
      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);
    }
  }
}



/* Called by libevent when we get action on a multi socket */
static void event_cb(EV_P_ struct ev_io *w, int revents)
{
  DPRINT("%s  w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);
  GlobalInfo *g = (GlobalInfo*) w->data;
  CURLMcode rc;

  int action = (revents&EV_READ?CURL_POLL_IN:0)|
    (revents&EV_WRITE?CURL_POLL_OUT:0);
  rc = curl_multi_socket_action(g->multi, w->fd, action, &g->still_running);
  mcode_or_die("event_cb: curl_multi_socket_action", rc);
  check_multi_info(g);
  if(g->still_running <= 0) {
    fprintf(MSG_OUT, "last transfer done, kill timeout\n");
    ev_timer_stop(g->loop, &g->timer_event);
  }
}

/* Called by libevent when our timeout expires */
static void timer_cb(EV_P_ struct ev_timer *w, int revents)
{
  DPRINT("%s  w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);

  GlobalInfo *g = (GlobalInfo *)w->data;
  CURLMcode rc;

  rc = curl_multi_socket_action(g->multi, CURL_SOCKET_TIMEOUT, 0,
                                &g->still_running);
  mcode_or_die("timer_cb: curl_multi_socket_action", rc);
  check_multi_info(g);
}

/* Clean up the SockInfo structure */
static void remsock(SockInfo *f, GlobalInfo *g)
{
  printf("%s  \n", __PRETTY_FUNCTION__);
  if(f) {
    if(f->evset)
      ev_io_stop(g->loop, &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)
{
  printf("%s  \n", __PRETTY_FUNCTION__);

  int kind = (act&CURL_POLL_IN?EV_READ:0)|(act&CURL_POLL_OUT?EV_WRITE:0);

  f->sockfd = s;
  f->action = act;
  f->easy = e;
  if(f->evset)
    ev_io_stop(g->loop, &f->ev);
  ev_io_init(&f->ev, event_cb, f->sockfd, kind);
  f->ev.data = g;
  f->evset=1;
  ev_io_start(g->loop, &f->ev);
}



/* 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)
{
  DPRINT("%s e %p s %i what %i cbp %p sockp %p\n",
         __PRETTY_FUNCTION__, e, s, what, cbp, 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, g);
  }
  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);
  curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 3L);
  curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 10L);

  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);

  /* note that the add_handle() will set a time-out to trigger very soon so
     that the necessary socket_action() call will be called by this app */
}

/* This gets called whenever data is received from the fifo */
static void fifo_cb(EV_P_ struct ev_io *w, int revents)
{
  char s[1024];
  long int rv=0;
  int n=0;
  GlobalInfo *g = (GlobalInfo *)w->data;

  do {
    s[0]='\0';
    rv=fscanf(g->input, "%1023s%n", s, &n);
    s[n]='\0';
    if(n && s[0]) {
      new_conn(s, g);  /* 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";
  curl_socket_t 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);
  ev_io_init(&g->fifo_event, fifo_cb, sockfd, EV_READ);
  ev_io_start(g->loop, &g->fifo_event);
  return (0);
}

int main(int argc, char **argv)
{
  GlobalInfo g;
  CURLMcode rc;
  (void)argc;
  (void)argv;

  memset(&g, 0, sizeof(GlobalInfo));
  g.loop = ev_default_loop(0);

  init_fifo(&g);
  g.multi = curl_multi_init();

  ev_timer_init(&g.timer_event, timer_cb, 0., 0.);
  g.timer_event.data = &g;
  g.fifo_event.data = &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);

  /* we don't call any curl_multi_socket*() function yet as we have no handles
     added! */

  ev_loop(g.loop, 0);
  curl_multi_cleanup(g.multi);
  return 0;
}