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/**************************************************************/
/* ********************************************************** */
/* * * */
/* * RANDOM ACCESS STACK * */
/* * * */
/* * $Module: RAS * */
/* * * */
/* * Copyright (C) 1999, 2000, 2001 MPI fuer Informatik * */
/* * * */
/* * This program is free software; you can redistribute * */
/* * it and/or modify it under the terms of the FreeBSD * */
/* * Licence. * */
/* * * */
/* * 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 LICENCE file * */
/* * for more details. * */
/* * * */
/* * * */
/* $Revision: 1.2 $ * */
/* $State: Exp $ * */
/* $Date: 2010-02-22 14:09:58 $ * */
/* $Author: weidenb $ * */
/* * * */
/* * Contact: * */
/* * Christoph Weidenbach * */
/* * MPI fuer Informatik * */
/* * Stuhlsatzenhausweg 85 * */
/* * 66123 Saarbruecken * */
/* * Email: spass@mpi-inf.mpg.de * */
/* * Germany * */
/* * * */
/* ********************************************************** */
/**************************************************************/
#ifndef _RAS_
#define _RAS_
/**************************************************************/
/* Includes */
/**************************************************************/
#include "misc.h"
#include "memory.h"
/**************************************************************/
/* Constants and types */
/**************************************************************/
#define ras_alloc -1 /* index of size of allocated space */
#define ras_top -2 /* index of next free element */
#define ras_head 2 /* size of stack head for management purposes */
#define ras_stdsize 16 /* standard stack size */
typedef POINTER *RAS;
/* A RAS (Random Access Stack) is a pointer to an array of elements */
/* where the actual size of the stack and its current top pointer */
/* are stored one and two cells before the array pointer. */
/**************************************************************/
/* Functions */
/**************************************************************/
RAS ras_InitWithSize(RAS ras, int size);
/**************************************************************/
/* Inline Functions */
/**************************************************************/
static __inline__ RAS ras_CreateWithSize(int size)
/****************************************************************
INPUT: The maximal expected size of the stack to create.
RETURNS: A new empty stack.
*****************************************************************/
{
RAS result;
#ifdef CHECK
if (size <= 0) {
misc_StartErrorReport();
misc_ErrorReport("\n In ras_CreateWithSize: size not positive.");
misc_FinishErrorReport();
}
#endif
result = (RAS) memory_Malloc((size + ras_head) * sizeof(POINTER));
result = result + ras_head; /* leave space for head */
result[ras_alloc] = (POINTER) size;
result[ras_top] = (POINTER) 0;
return result;
}
static __inline__ RAS ras_Create(void)
{
return ras_CreateWithSize(ras_stdsize);
}
static __inline__ void ras_Free(RAS ras)
{
if (ras != NULL) {
memory_Free (
ras - ras_head,
(ras_head + (int) ras[ras_alloc]) * sizeof(POINTER)
);
}
}
static __inline__ RAS ras_Init(RAS ras)
/****************************************************************
INPUT: A random access stack.
RETURNS: The initialized and potentially new stack.
CAUTION: Because it potentially frees the old stack this
function must be called inside an assignment like:
stack = ras_InitWithSize(stack, ...)
*****************************************************************/
{
return ras_InitWithSize(ras, ras_stdsize);
}
static __inline__ int ras_Size(RAS ras)
{
return (int) ras[ras_top];
}
static __inline__ RAS ras_FastPush(RAS ras, POINTER entry)
/*********************************************************
INPUT: A random access stack and an element to push.
RETURNS: The modified stack.
CAUTION: The function does not care about stack overflow!
**********************************************************/
{
int top;
#ifdef CHECK
if (ras_Size(ras) == (int) ras[ras_alloc]) {
misc_StartErrorReport();
misc_ErrorReport("\n In ras_FastPush: stack overflow.");
misc_FinishErrorReport();
}
#endif
top = ras_Size(ras);
ras[top++] = entry;
ras[ras_top] = (POINTER) top;
return ras;
}
static __inline__ RAS ras_Push(RAS ras, POINTER entry)
/*********************************************************
INPUT: A random access stack and an element to push.
RETURNS: The modified and potentially new stack.
SUMMARY: Before the push the stack is checked for overflow
and in case of overflow its size is doubled while
elements are copied to the (new) stack.
CAUTION: Must be called inside an assignment:
stack = ras_Push(stack, ...)
**********************************************************/
{
RAS old;
int oldsize;
POINTER *oldscan, *scan;
/* if not enough space allocated, double it: */
if (ras_Size(ras) == (int) ras[ras_alloc]) {
old = ras;
oldsize = (int) old[ras_alloc];
ras = ras_CreateWithSize(oldsize * 2);
ras[ras_top] = (POINTER) oldsize;
/* copy entries: */
for (oldscan = old + oldsize - 1,scan = ras + oldsize - 1; oldscan >= old;
oldscan--, scan--)
*scan = *oldscan;
ras_Free(old);
}
return ras_FastPush(ras, entry);
}
static __inline__ BOOL ras_LegalIndex(RAS ras, int stack_index)
{
return 0 <= stack_index && stack_index < ras_Size(ras);
}
static __inline__ POINTER ras_Get(RAS ras, int stack_index)
{
#ifdef CHECK
if (!ras_LegalIndex(ras, stack_index)) {
misc_StartErrorReport();
misc_ErrorReport("\n In ras_Get: illegal stack index.");
misc_FinishErrorReport();
}
#endif
return ras[stack_index];
}
static __inline__ RAS ras_Set(RAS ras, int stack_index, POINTER entry)
{
#ifdef CHECK
if (!ras_LegalIndex(ras, stack_index)) {
misc_StartErrorReport();
misc_ErrorReport("\n In ras_Set: illegal stack index.");
misc_FinishErrorReport();
}
#endif
ras[stack_index] = entry;
return ras;
}
static __inline__ BOOL ras_Empty(RAS ras)
{
return ras_Size(ras) == 0;
}
static __inline__ POINTER ras_Pop(RAS ras)
{
int top;
#ifdef CHECK
if (ras_Empty(ras)) {
misc_StartErrorReport();
misc_ErrorReport("\n In ras_Pop: empty stack.");
misc_FinishErrorReport();
}
#endif
top = ras_Size(ras) - 1;
ras[ras_top] = (POINTER) top;
return ras[top];
}
static __inline__ POINTER ras_Top(RAS ras)
{
#ifdef CHECK
if (ras_Empty(ras)) {
misc_StartErrorReport();
misc_ErrorReport("\n In ras_Top: empty stack.");
misc_FinishErrorReport();
}
#endif
return ras[ras_Size(ras) - 1];
}
#endif
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