hlist.c

/*
   Copyright (C) 2016 Xfennec, CQFD Corp.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include "hlist.h"

static int max_hlist_size = 2;

void set_hlist_size(double throughput_wait_secs) {
   int new_size;
   new_size = ceil(10.0 / throughput_wait_secs);
   max_hlist_size = (new_size > 1) ? new_size : max_hlist_size;
}

int add_to_hlist(hlist **begin, hlist **end, int size, int value) {
   int ret;

   if (*begin == NULL) {
       if ((*begin = malloc(sizeof(hlist))) == NULL)
           return 0;
       *end = *begin;
       (*begin)->next = NULL;
       (*begin)->prev = NULL;
       ret = 1;
   }
   else if (size == max_hlist_size) {
       hlist *tmp = (*end)->prev;
       tmp->next = NULL;
       (*end)->next = *begin;
       (*end)->prev = NULL;
       *begin = *end;
       *end = tmp;
       (*begin)->next->prev = *begin;
       ret = 0;
   }
   else {
       hlist *new = malloc(sizeof(hlist));
       if (!new)
           return 0;
       new->next = *begin;
       new->prev = NULL;
       *begin = new;
       (*begin)->next->prev = *begin;
       ret = 1;
   }
   (*begin)->value = value;
   return ret;
}

void free_hlist(hlist *begin) {
   hlist *tmp = begin;

   while (begin) {
      tmp = begin->next;
      free(begin);
      begin = tmp;
   }
}

int get_hlist_average(hlist *begin, int size) {
   unsigned long long avg = 0;

   while (begin) {
      avg += begin->value;
      begin = begin->next;
   }
   return avg / size;
}