src/examples/minimal_example_comet.c

/*
     This file is part of libmicrohttpd
     Copyright (C) 2007, 2008 Christian Grothoff (and other contributing authors)
     Copyright (C) 2016-2022 Evgeny Grin (Karlson2k)

     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
     License as published by the Free Software Foundation; either
     version 2.1 of the License, or (at your option) any later version.

     This library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Lesser General Public License for more details.

     You should have received a copy of the GNU Lesser General Public
     License along with this library; if not, write to the Free Software
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/
/**
 * @file minimal_example.c
 * @brief minimal example for how to generate an infinite stream with libmicrohttpd
 * @author Christian Grothoff
 * @author Karlson2k (Evgeny Grin)
 */

#include "platform.h"
#include <microhttpd.h>

static ssize_t
data_generator (void *cls, uint64_t pos, char *buf, size_t max)
{
  (void) cls; /* Unused. Silent compiler warning. */
  (void) pos; /* Unused. Silent compiler warning. */
  if (max < 80)
    return 0;
  memset (buf, 'A', max - 1);
  buf[79] = '\n';
  return 80;
}


static enum MHD_Result
ahc_echo (void *cls,
          struct MHD_Connection *connection,
          const char *url,
          const char *method,
          const char *version,
          const char *upload_data, size_t *upload_data_size, void **req_cls)
{
  static int aptr;
  struct MHD_Response *response;
  enum MHD_Result ret;
  (void) cls;               /* Unused. Silent compiler warning. */
  (void) url;               /* Unused. Silent compiler warning. */
  (void) version;           /* Unused. Silent compiler warning. */
  (void) upload_data;       /* Unused. Silent compiler warning. */
  (void) upload_data_size;  /* Unused. Silent compiler warning. */

  if (0 != strcmp (method, "GET"))
    return MHD_NO;              /* unexpected method */
  if (&aptr != *req_cls)
  {
    /* do never respond on first call */
    *req_cls = &aptr;
    return MHD_YES;
  }
  *req_cls = NULL;                  /* reset when done */
  response = MHD_create_response_from_callback (MHD_SIZE_UNKNOWN,
                                                80,
                                                &data_generator, NULL, NULL);
  ret = MHD_queue_response (connection, MHD_HTTP_OK, response);
  MHD_destroy_response (response);
  return ret;
}


int
main (int argc, char *const *argv)
{
  struct MHD_Daemon *d;
  int port;

  if (argc != 2)
  {
    printf ("%s PORT\n", argv[0]);
    return 1;
  }
  port = atoi (argv[1]);
  if ( (1 > port) || (port > 65535) )
  {
    fprintf (stderr,
             "Port must be a number between 1 and 65535.\n");
    return 1;
  }
  d = MHD_start_daemon (MHD_USE_AUTO | MHD_USE_THREAD_PER_CONNECTION
                        | MHD_USE_INTERNAL_POLLING_THREAD | MHD_USE_ERROR_LOG,
                        (uint16_t) port,
                        NULL, NULL, &ahc_echo, NULL, MHD_OPTION_END);
  if (d == NULL)
    return 1;
  (void) getc (stdin);
  MHD_stop_daemon (d);
  return 0;
}