/*****************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * $Id$
 *
 * Connect N connections. Z are idle, and X are active. Transfer as fast as
 * possible.
 *
 * Run for a specific amount of time (10 secs for now). Output detailed timing
 * information.
 *
 * Uses libevent.
 *
 */

/* The maximum number of simultanoues connections/transfers we support */
#define NCONNECTIONS 50000

#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> /* for libevent */

#ifndef FALSE
#define FALSE 0
#endif

#ifndef TRUE
#define TRUE 1
#endif

#define MICROSEC 1000000 /* number of microseconds in one second */

/* The maximum time (in microseconds) we run the test */
#define RUN_FOR_THIS_LONG (5*MICROSEC)

/* Number of loops (seconds) we allow the total download amount and alive
   connections to remain the same until we bail out. Set this slightly higher
   when using asynch supported libcurl. */
#define IDLE_TIME 10

struct ourfdset {
  /* __fds_bits is what the Linux glibc headers use when they declare the
     fd_set struct so by using this we can actually avoid the typecase for the
     FD_SET() macro usage but it would hardly be portable */
  char __fds_bits[NCONNECTIONS/8];
};
#define FD2_ZERO(x) memset(x, 0, sizeof(struct ourfdset))

typedef struct ourfdset fd2_set;

struct globalinfo {
  size_t dlcounter;
};

struct connection {
  CURL *e;
  int id; /* just a counter for easy browsing */
  char *url;
  size_t dlcounter;
  struct globalinfo *global;
  char error[CURL_ERROR_SIZE];
};

struct fdinfo {
  /* create a link list of fdinfo structs */
  struct fdinfo *next;
  struct fdinfo *prev;
  curl_socket_t sockfd;
  CURL *easy;
  int action; /* as set by libcurl */
  long timeout; /* as set by libcurl */
  struct event ev; /* */
  int evset; /* true if the 'ev' struct has been used in a event_set() call */
  CURLMcode *multi; /* pointer to the multi handle */
  int *running_handles; /* pointer to the running_handles counter */
};

static struct fdinfo *allsocks;

static int running_handles;

/* called from libevent on action on a particular socket ("event") */
static void eventcallback(int fd, short type, void *userp)
{
  struct fdinfo *fdp = (struct fdinfo *)userp;

  fprintf(stderr, "EVENT callback\n");

  /* tell libcurl to deal with the transfer associated with this socket */
  curl_multi_socket(fdp->multi, fd, fdp->running_handles);
}

static void remsock(struct fdinfo *f)
{
  if(!f)
    /* did not find socket to remove! */
    return;

  if(f->prev)
    f->prev->next = f->next;
  if(f->next)
    f->next->prev = f->prev;
  else
    /* this was the last entry */
    allsocks = NULL;
}

static void setsock(struct fdinfo *fdp, curl_socket_t s, CURL *easy,
                    int action)
{
  fdp->sockfd = s;
  fdp->action = action;
  fdp->easy = easy;

  if(fdp->evset)
    /* first remove the existing event if the old setup was used */
    event_del(&fdp->ev);

  /* now use and add the current socket setup */
  event_set(&fdp->ev, fdp->sockfd,
            (action&CURL_POLL_IN?EV_READ:0)|
            (action&CURL_POLL_OUT?EV_WRITE:0),
            eventcallback, fdp);

  fdp->evset=1;

  fprintf(stderr, "event_add() for fd %d\n", s);
  event_add(&fdp->ev, NULL); /* no timeout */
}

static void addsock(curl_socket_t s, CURL *easy, int action, CURLM *multi)
{
  struct fdinfo *fdp = calloc(sizeof(struct fdinfo), 1);

  fdp->multi = multi;
  fdp->running_handles = &running_handles;
  setsock(fdp, s, easy, action);

  if(allsocks) {
    fdp->next = allsocks;
    allsocks->prev = fdp;

    /* now set allsocks to point to the new struct */
    allsocks = fdp;
  }
  else
    allsocks = fdp;

  /* Set this association in libcurl */
  curl_multi_assign(multi, s, fdp);
}

static void fdinfo2fdset(fd2_set *fdread, fd2_set *fdwrite, int *maxfd)
{
  struct fdinfo *fdp = allsocks;
  int writable=0;

  FD2_ZERO(fdread);
  FD2_ZERO(fdwrite);

  *maxfd = 0;

#if 0
  printf("Wait for: ");
#endif

  while(fdp) {
    if(fdp->action & CURL_POLL_IN) {
      FD_SET(fdp->sockfd, (fd_set *)fdread);
    }
    if(fdp->action & CURL_POLL_OUT) {
      FD_SET(fdp->sockfd, (fd_set *)fdwrite);
      writable++;
    }

#if 0
    printf("%d (%s%s) ",
           fdp->sockfd,
           (fdp->action & CURL_POLL_IN)?"r":"",
           (fdp->action & CURL_POLL_OUT)?"w":"");
#endif

    if(fdp->sockfd > *maxfd)
      *maxfd = fdp->sockfd;

    fdp = fdp->next;
  }
#if 0
  if(writable)
    printf("Check for %d writable sockets\n", writable);
#endif
}

/* on port 8999 we run a fork enabled sws that supports 'idle' and 'stream' */
#define PORT "8999"

#define HOST "192.168.1.13"

#define URL_IDLE   "http://" HOST ":" PORT "/1000"
#define URL_ACTIVE "http://" HOST ":" PORT "/1001"


static int socket_callback(CURL *easy,      /* easy handle */
                           curl_socket_t s, /* socket */
                           int what,        /* see above */
                           void *cbp,       /* callback pointer */
                           void *socketp)   /* socket pointer */
{
  struct fdinfo *fdp = (struct fdinfo *)socketp;

  fprintf(stderr, "socket %d easy %p what %d\n", s, easy, what);

  if(what == CURL_POLL_REMOVE)
    remsock(fdp);
  else {
    if(!fdp) {
      /* not previously known, add it and set association */
      printf("Add info for socket %d (%d)\n", s, what);
      addsock(s, easy, what, cbp);
    }
    else {
      /* we already know about it, just change action/timeout */
      printf("Changing info for socket %d from %d to %d\n",
             s, fdp->action, what);
      setsock(fdp, s, easy, what);
    }
  }
  return 0; /* return code meaning? */
}


static size_t
writecallback(void *ptr, size_t size, size_t nmemb, void *data)
{
  size_t realsize = size * nmemb;
  struct connection *c = (struct connection *)data;

  c->dlcounter += realsize;
  c->global->dlcounter += realsize;

#if 1
  printf("%02d: %d, total %d\n",
         c->id, c->dlcounter, c->global->dlcounter);
#endif
  return realsize;
}

/* return the diff between two timevals, in us */
static long tvdiff(struct timeval *newer, struct timeval *older)
{
  return (newer->tv_sec-older->tv_sec)*1000000+
    (newer->tv_usec-older->tv_usec);
}


/* store the start time of the program in this variable */
static struct timeval timer;

static void timer_start(void)
{
  /* capture the time of the start moment */
  gettimeofday(&timer, NULL);
}

static struct timeval cont; /* at this moment we continued */

int still_running; /* keep number of running handles */

struct conncount {
  long time_us;
  long laps;
  long maxtime;
};

static struct timeval timerpause;
static void timer_pause(void)
{
  /* capture the time of the pause moment */
  gettimeofday(&timerpause, NULL);

  /* If we have a previous continue (all times except the first), we can now
     store the time for a whole "lap" */
  if(cont.tv_sec) {
    long lap;

    lap = tvdiff(&timerpause, &cont);
  }
}

static long paused; /* amount of us we have been pausing */

static void timer_continue(void)
{
  /* Capture the time of the restored operation moment, now calculate how long
     time we were paused and added that to the 'paused' variable.
   */
  gettimeofday(&cont, NULL);

  paused += tvdiff(&cont, &timerpause);
}

static long total; /* amount of us from start to stop */
static void timer_total(void)
{
  struct timeval stop;
  /* Capture the time of the operation stopped moment, now calculate how long
     time we were running and how much of that pausing.
   */
  gettimeofday(&stop, NULL);

  total = tvdiff(&stop, &timer);
}

struct globalinfo info;
struct connection *conns;

long selects;
long timeouts;

long multi_socket;
long performalive;
long performselect;
long topselect;

int num_total;
int num_idle;
int num_active;

static void report(void)
{
  int i;
  long active = total - paused;
  long numdl = 0;

  for(i=0; i < num_total; i++) {
    if(conns[i].dlcounter)
      numdl++;
  }

  printf("Summary from %d simultanoues transfers (%d active)\n",
         num_total, num_active);
  printf("%d out of %d connections provided data\n", numdl, num_total);

  printf("Total time: %ldus paused: %ldus curl_multi_socket(): %ldus\n",
         total, paused, active);

  printf("%d calls to select() "
         "Average time: %dus\n",
         selects, paused/selects);
  printf(" Average number of readable connections per select() return: %d\n",
         performselect/selects);

  printf(" Max number of readable connections for a single select() "
         "return: %d\n",
         topselect);

  printf("%ld calls to multi_socket(), "
         "Average time: %ldus\n",
         multi_socket, active/multi_socket);

  printf("%ld select() timeouts\n", timeouts);

  printf("Downloaded %ld bytes in %ld bytes/sec, %ld usec/byte\n",
         info.dlcounter,
         info.dlcounter/(total/1000000),
         total/info.dlcounter);

}

int main(int argc, char **argv)
{
  CURLM *multi_handle;
  CURLMsg *msg;
  CURLcode code = CURLE_OK;
  CURLMcode mcode = CURLM_OK;
  int rc;
  int i;
  fd2_set fdsizecheck;
  int selectmaxamount;
  struct fdinfo *fdp;
  char act;
  long timeout_ms;

  memset(&info, 0, sizeof(struct globalinfo));

  if(argc < 3) {
    printf("Usage: hiper-event [num idle] [num active]\n");
    return 1;
  }

  num_idle = atoi(argv[1]);
  num_active = atoi(argv[2]);

  num_total = num_idle + num_active;

  conns = calloc(num_total, sizeof(struct connection));
  if(!conns) {
    printf("Out of memory\n");
    return 3;
  }

  if(num_total >= NCONNECTIONS) {
    printf("Too many connections requested, increase NCONNECTIONS!\n");
    return 2;
  }

  event_init(); /* Initalize the event library */

  printf("About to do %d connections\n", num_total);

  /* init the multi stack */
  multi_handle = curl_multi_init();

  for(i=0; i< num_total; i++) {
    CURL *e;
    char *nl;

    memset(&conns[i], 0, sizeof(struct connection));

    if(i < num_idle)
      conns[i].url = URL_IDLE;
    else
      conns[i].url = URL_ACTIVE;

    e  = curl_easy_init();

    if(!e) {
      printf("curl_easy_init() for handle %d failed, exiting!\n", i);
      return 2;
    }

    conns[i].e = e;
    conns[i].id = i;
    conns[i].global = &info;

    curl_easy_setopt(e, CURLOPT_URL, conns[i].url);
    curl_easy_setopt(e, CURLOPT_WRITEFUNCTION, writecallback);
    curl_easy_setopt(e, CURLOPT_WRITEDATA, &conns[i]);
    curl_easy_setopt(e, CURLOPT_VERBOSE, 0);
    curl_easy_setopt(e, CURLOPT_ERRORBUFFER, conns[i].error);
    curl_easy_setopt(e, CURLOPT_PRIVATE, &conns[i]);

    /* add the easy to the multi */
    if(CURLM_OK != curl_multi_add_handle(multi_handle, e)) {
      printf("curl_multi_add_handle() returned error for %d\n", i);
      return 3;
    }
  }

  curl_multi_setopt(multi_handle, CURLMOPT_SOCKETFUNCTION, socket_callback);
  curl_multi_setopt(multi_handle, CURLMOPT_SOCKETDATA, multi_handle);

  /* we start the action by calling *socket() right away */
  while(CURLM_CALL_MULTI_PERFORM == curl_multi_socket_all(multi_handle,
                                                          &running_handles));

  /* event_dispatch() isn't good enough for us, since we need a global timeout
     to occur after a given time of inactivity
   */

  /* get the timeout value from libcurl */
  curl_multi_timeout(multi_handle, &timeout_ms);

  while(running_handles) {
    struct timeval timeout;

    /* convert ms to timeval */
    timeout.tv_sec = timeout_ms/1000;
    timeout.tv_usec = (timeout_ms%1000)*1000;

    event_loopexit(&timeout);

    /* The event_loopexit() function may have taken a while and it may or may
       not have invoked libcurl calls during that time. During those calls,
       the timeout situation might very well have changed, so we check the
       timeout time again to see if we really need to call curl_multi_socket()
       at this point! */

    /* get the timeout value from libcurl */
    curl_multi_timeout(multi_handle, &timeout_ms);

    if(timeout_ms <= 0) {
      /* no time left */
      curl_multi_socket(multi_handle, CURL_SOCKET_TIMEOUT, &running_handles);

      /* and get the new timeout value again */
      curl_multi_timeout(multi_handle, &timeout_ms);
    }
  }

  if(still_running != num_total) {
    /* something made connections fail, extract the reason and tell */
    int msgs_left;
    struct connection *cptr;
    while ((msg = curl_multi_info_read(multi_handle, &msgs_left))) {
      if (msg->msg == CURLMSG_DONE) {
        curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, &cptr);

        printf("%d => (%d) %s", cptr->id, msg->data.result, cptr->error);
      }
    }

  }

  curl_multi_cleanup(multi_handle);

  /* cleanup all the easy handles */
  for(i=0; i< num_total; i++)
    curl_easy_cleanup(conns[i].e);

  report();

  return code;
}