cdesktopenv/cde/programs/dthelp/parser.ccdf/volumegen/Pstack.c

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/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/* $XConsortium: Pstack.c /main/4 1995/11/08 11:47:39 rswiston $ */
/************************************<+>*************************************
****************************************************************************
*
* File: PStack.c
*
* Project: Cache Creek (Rivers) Project
* Description: Utility functions for volumegen program
* Author: Brian Cripe
* Modifications by (Mike Wilson)
* Language: C
*
* (C) Copyright 1992, Hewlett-Packard, all rights reserved.
*
****************************************************************************
************************************<+>*************************************/
#include <stdio.h>
#include "PstackI.h"
#define REALLOC_INCR 10
/*****************************************************************************
* Function: PStack PStackCreate();
*
* Parameters: NONE.
*
* Return Value: PStack.
*
* Purpose: Generates a PStack structure and returns it to the
* caller.
*
*****************************************************************************/
PStack PStackCreate()
{
PStack stack;
stack = (PStack) malloc (sizeof (struct PStackRec));
stack->count = 0;
stack->size = REALLOC_INCR;
stack->items = (void **) malloc (stack->size * sizeof (void **));
return (stack);
}
/*****************************************************************************
* Function: PStack PStackDestroy();
*
* Parameters: stack:
*
* Return Value: void.
*
* Purpose: Destroys a PStack structure.
*
*****************************************************************************/
void PStackDestroy(
PStack stack)
{
free (stack->items);
free (stack);
}
/*****************************************************************************
* Function: PStack PStackPush();
*
* Parameters: stack:
* ptr:
*
* Return Value: void
*
* Purpose: Pushes a PStack structure on the current stack.
*
*****************************************************************************/
void PStackPush(
PStack stack,
void *ptr)
{
if (stack->count == stack->size) {
stack->size += REALLOC_INCR;
stack->items = (void **) realloc (stack->items,
stack->size * sizeof (void **));
}
*(stack->items + stack->count) = ptr;
stack->count++;
}
/*****************************************************************************
* Function: PStack *PStackPeek();
*
* Parameters: stack:
*
* Return Value: void.
*
* Purpose: Gets a PStack.
*
*****************************************************************************/
void *PStackPeek(
PStack stack)
{
if (stack->count == 0)
return (NULL);
else
return (*(stack->items + stack->count - 1));
}
/*****************************************************************************
* Function: PStack *PStackPop();
*
* Parameters: stack:
*
* Return Value: void.
*
* Purpose: Pops the top element off the stack
*
*****************************************************************************/
void *PStackPop(
PStack stack)
{
if (stack->count == 0)
return (NULL);
else {
stack->count--;
return (*(stack->items + stack->count));
}
}