/*
   Unix SMB/CIFS implementation.

   Copyright (C) Andrew Tridgell 2005
   Copyright (C) Jelmer Vernooij 2005

   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 "replace.h"
#include "talloc.h"

/**
  return the number of elements in a string list
*/
static size_t str_list_length(const char **list)
{
	size_t ret;
	for (ret=0;list && list[ret];ret++) /* noop */ ;
	return ret;
}

/**
  add an entry to a string list
*/
const char **str_list_add(const char **list, const char *s)
{
	size_t len = str_list_length(list);
	const char **ret;

	ret = talloc_realloc(NULL, list, const char *, len+2);
	if (ret == NULL) return NULL;

	ret[len] = talloc_strdup(ret, s);
	if (ret[len] == NULL) return NULL;

	ret[len+1] = NULL;

	return ret;
}

/**
  compare two timeval structures. 
  Return -1 if tv1 < tv2
  Return 0 if tv1 == tv2
  Return 1 if tv1 > tv2
*/
static int timeval_compare(const struct timeval *tv1, const struct timeval *tv2)
{
	if (tv1->tv_sec  > tv2->tv_sec)  return 1;
	if (tv1->tv_sec  < tv2->tv_sec)  return -1;
	if (tv1->tv_usec > tv2->tv_usec) return 1;
	if (tv1->tv_usec < tv2->tv_usec) return -1;
	return 0;
}

/**
  return a zero timeval
*/
struct timeval timeval_zero(void)
{
	struct timeval tv;
	tv.tv_sec = 0;
	tv.tv_usec = 0;
	return tv;
}

/**
  return true if a timeval is zero
*/
bool timeval_is_zero(const struct timeval *tv)
{
	return tv->tv_sec == 0 && tv->tv_usec == 0;
}

/**
  return a timeval for the current time
*/
struct timeval timeval_current(void)
{
	struct timeval tv;
	GetTimeOfDay(&tv);
	return tv;
}

/**
  return a timeval struct with the given elements
*/
struct timeval timeval_set(uint32_t secs, uint32_t usecs)
{
	struct timeval tv;
	tv.tv_sec = secs;
	tv.tv_usec = usecs;
	return tv;
}

/**
  return the difference between two timevals as a timeval
  if tv1 comes after tv2, then return a zero timeval
  (this is *tv2 - *tv1)
*/
struct timeval timeval_until(const struct timeval *tv1,
			     const struct timeval *tv2)
{
	struct timeval t;
	if (timeval_compare(tv1, tv2) >= 0) {
		return timeval_zero();
	}
	t.tv_sec = tv2->tv_sec - tv1->tv_sec;
	if (tv1->tv_usec > tv2->tv_usec) {
		t.tv_sec--;
		t.tv_usec = 1000000 - (tv1->tv_usec - tv2->tv_usec);
	} else {
		t.tv_usec = tv2->tv_usec - tv1->tv_usec;
	}
	return t;
}