text: /***************************************************************************
   *                                  _   _ ____  _
   *  Project                     ___| | | |  _ \| |
   *                             / __| | | | |_) | |
   *                            | (__| |_| |  _ <| |___
   *                             \___|\___/|_| \_\_____|
   *
   * Copyright (C) 1998 - 2015, 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 http://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 API usage together with with glib2
   * </DESC>
   */
  /* Example application source code using the multi socket interface to
   * download many files at once.
   *
   * Written by Jeff Pohlmeyer
  
  Requires glib-2.x and a (POSIX?) system that has mkfifo().
  
  This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c"
  sample programs, adapted to use glib's g_io_channel in place of libevent.
  
  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.
  
  This is purely a demo app, all retrieved data is simply discarded by the write
  callback.
  
  */
  
  
  #include <glib.h>
  #include <sys/stat.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <stdlib.h>
  #include <stdio.h>
  #include <errno.h>
  #include <curl/curl.h>
  
  
  #define MSG_OUT g_print   /* Change to "g_error" to write to stderr */
  #define SHOW_VERBOSE 0    /* Set to non-zero for libcurl messages */
  #define SHOW_PROGRESS 0   /* Set to non-zero to enable progress callback */
  
  
  
  /* Global information, common to all connections */
  typedef struct _GlobalInfo {
    CURLM *multi;
    guint timer_event;
    int still_running;
  } 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;
    GIOChannel *ch;
    guint ev;
    GlobalInfo *global;
  } SockInfo;
  
  
  
  
  /* 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_BAD_SOCKET:         s="CURLM_BAD_SOCKET";         break;
        case     CURLM_UNKNOWN_OPTION:     s="CURLM_UNKNOWN_OPTION";     break;
        case     CURLM_LAST:               s="CURLM_LAST";               break;
        default: s="CURLM_unknown";
      }
      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;
  
    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);
        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 glib when our timeout expires */
  static gboolean timer_cb(gpointer data)
  {
    GlobalInfo *g = (GlobalInfo *)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);
    return FALSE;
  }
  
  
  
  /* Update the event timer after curl_multi library calls */
  static int update_timeout_cb(CURLM *multi, long timeout_ms, void *userp)
  {
    struct timeval timeout;
    GlobalInfo *g=(GlobalInfo *)userp;
    timeout.tv_sec = timeout_ms/1000;
    timeout.tv_usec = (timeout_ms%1000)*1000;
  
    MSG_OUT("*** update_timeout_cb %ld => %ld:%ld ***\n",
                timeout_ms, timeout.tv_sec, timeout.tv_usec);
  
    g->timer_event = g_timeout_add(timeout_ms, timer_cb, g);
    return 0;
  }
  
  
  
  
  /* Called by glib when we get action on a multi socket */
  static gboolean event_cb(GIOChannel *ch, GIOCondition condition, gpointer data)
  {
    GlobalInfo *g = (GlobalInfo*) data;
    CURLMcode rc;
    int fd=g_io_channel_unix_get_fd(ch);
  
    int action =
      (condition & G_IO_IN ? CURL_CSELECT_IN : 0) |
      (condition & G_IO_OUT ? CURL_CSELECT_OUT : 0);
  
    rc = curl_multi_socket_action(g->multi, fd, action, &g->still_running);
    mcode_or_die("event_cb: curl_multi_socket_action", rc);
  
    check_multi_info(g);
    if(g->still_running) {
      return TRUE;
    } else {
      MSG_OUT("last transfer done, kill timeout\n");
      if (g->timer_event) { g_source_remove(g->timer_event); }
      return FALSE;
    }
  }
  
  
  
  /* Clean up the SockInfo structure */
  static void remsock(SockInfo *f)
  {
    if (!f) { return; }
    if (f->ev) { g_source_remove(f->ev); }
    g_free(f);
  }
  
  
  
  /* Assign information to a SockInfo structure */
  static void setsock(SockInfo*f, curl_socket_t s, CURL*e, int act, GlobalInfo*g)
  {
    GIOCondition kind =
       (act&CURL_POLL_IN?G_IO_IN:0)|(act&CURL_POLL_OUT?G_IO_OUT:0);
  
    f->sockfd = s;
    f->action = act;
    f->easy = e;
    if (f->ev) { g_source_remove(f->ev); }
    f->ev=g_io_add_watch(f->ch, kind, event_cb,g);
  
  }
  
  
  
  /* Initialize a new SockInfo structure */
  static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
  {
    SockInfo *fdp = g_malloc0(sizeof(SockInfo));
  
    fdp->global = g;
    fdp->ch=g_io_channel_unix_new(s);
    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;
    static const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE" };
  
    MSG_OUT("socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
    if (what == CURL_POLL_REMOVE) {
      MSG_OUT("\n");
      remsock(fdp);
    } else {
      if (!fdp) {
        MSG_OUT("Adding data: %s%s\n",
               what&CURL_POLL_IN?"READ":"",
               what&CURL_POLL_OUT?"WRITE":"" );
        addsock(s, e, what, g);
      }
      else {
        MSG_OUT(
          "Changing action from %d to %d\n", fdp->action, 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;
    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 = g_malloc0(sizeof(ConnInfo));
  
    conn->error[0]='\0';
  
    conn->easy = curl_easy_init();
    if (!conn->easy) {
      MSG_OUT("curl_easy_init() failed, exiting!\n");
      exit(2);
    }
    conn->global = g;
    conn->url = g_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, (long)SHOW_VERBOSE);
    curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
    curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
    curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, SHOW_PROGRESS?0L:1L);
    curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
    curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
    curl_easy_setopt(conn->easy, CURLOPT_FOLLOWLOCATION, 1L);
    curl_easy_setopt(conn->easy, CURLOPT_CONNECTTIMEOUT, 30L);
    curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 1L);
    curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 30L);
  
    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 by glib whenever data is received from the fifo */
  static gboolean fifo_cb (GIOChannel *ch, GIOCondition condition, gpointer data)
  {
    #define BUF_SIZE 1024
    gsize len, tp;
    gchar *buf, *tmp, *all=NULL;
    GIOStatus rv;
  
    do {
      GError *err=NULL;
      rv = g_io_channel_read_line (ch,&buf,&len,&tp,&err);
      if ( buf ) {
        if (tp) { buf[tp]='\0'; }
        new_conn(buf,(GlobalInfo*)data);
        g_free(buf);
      } else {
        buf = g_malloc(BUF_SIZE+1);
        while (TRUE) {
          buf[BUF_SIZE]='\0';
          g_io_channel_read_chars(ch,buf,BUF_SIZE,&len,&err);
          if (len) {
            buf[len]='\0';
            if (all) {
              tmp=all;
              all=g_strdup_printf("%s%s", tmp, buf);
              g_free(tmp);
            } else {
              all = g_strdup(buf);
            }
          } else {
             break;
          }
        }
        if (all) {
          new_conn(all,(GlobalInfo*)data);
          g_free(all);
        }
        g_free(buf);
      }
      if ( err ) {
        g_error("fifo_cb: %s", err->message);
        g_free(err);
        break;
      }
    } while ( (len) && (rv == G_IO_STATUS_NORMAL) );
    return TRUE;
  }
  
  
  
  
  int init_fifo(void)
  {
   struct stat st;
   const char *fifo = "hiper.fifo";
   int socket;
  
   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);
   }
  
   socket = open (fifo, O_RDWR | O_NONBLOCK, 0);
  
   if (socket == -1) {
    perror("open");
    exit (1);
   }
   MSG_OUT("Now, pipe some URL's into > %s\n", fifo);
  
   return socket;
  
  }
  
  
  
  
  int main(int argc, char **argv)
  {
    GlobalInfo *g;
    CURLMcode rc;
    GMainLoop*gmain;
    int fd;
    GIOChannel* ch;
    g=g_malloc0(sizeof(GlobalInfo));
  
    fd=init_fifo();
    ch=g_io_channel_unix_new(fd);
    g_io_add_watch(ch,G_IO_IN,fifo_cb,g);
    gmain=g_main_loop_new(NULL,FALSE);
    g->multi = curl_multi_init();
    curl_multi_setopt(g->multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
    curl_multi_setopt(g->multi, CURLMOPT_SOCKETDATA, g);
    curl_multi_setopt(g->multi, CURLMOPT_TIMERFUNCTION, update_timeout_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! */
  
    g_main_loop_run(gmain);
    curl_multi_cleanup(g->multi);
    return 0;
  }
  