/*
  *  OpenVPN -- An application to securely tunnel IP networks
  *             over a single UDP port, with support for SSL/TLS-based
  *             session authentication and key exchange,
  *             packet encryption, packet authentication, and
  *             packet compression.
  *

  *  Copyright (C) 2002-2009 OpenVPN Technologies, Inc. <sales@openvpn.net>

  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2
  *  as published by the Free Software Foundation.
  *
  *  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 (see the file COPYING included with this
  *  distribution); if not, write to the Free Software Foundation, Inc.,
  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #ifndef INTEGER_H
 #define INTEGER_H
 
 #include "error.h"
 
 /*
  * min/max functions
  */
 
 static inline int
 max_int (int x, int y)
 {
   if (x > y)
     return x;
   else
     return y;
 }
 
 static inline int
 min_int (int x, int y)
 {
   if (x < y)
     return x;
   else
     return y;
 }
 
 static inline int
 constrain_int (int x, int min, int max)
 {
   if (min > max)
     return min;
   if (x < min)
     return min;
   else if (x > max)
     return max;
   else
     return x;
 }
 
 /*
  * Functions used for circular buffer index arithmetic.
  */
 
 /*
  * Return x - y on a circle of circumference mod by shortest path.
  *
  * 0 <= x < mod
  * 0 <= y < mod
  */
 static inline int
 modulo_subtract(int x, int y, int mod)
 {
   const int d1 = x - y;
   const int d2 = (x > y ? -mod : mod) + d1;
   ASSERT (0 <= x && x < mod && 0 <= y && y < mod);
   return abs(d1) > abs(d2) ? d2 : d1;
 }
 
 /*
  * Return x + y on a circle of circumference mod.
  *
  * 0 <= x < mod
  * -mod <= y <= mod
  */
 static inline int
 modulo_add(int x, int y, int mod)
 {
   int sum = x + y;
   ASSERT (0 <= x && x < mod && -mod <= y && y <= mod);
   if (sum >= mod)
     sum -= mod;
   if (sum < 0)
     sum += mod;
   return sum;
 }
 
 static inline int
 index_verify (int index, int size, const char *file, int line)
 {
   if (index < 0 || index >= size)
     msg (M_FATAL, "Assertion Failed: Array index=%d out of bounds for array size=%d in %s:%d",
 	 index,
 	 size,
 	 file,
 	 line);
   return index;
 }
 
 #endif