/*
 *  M_APM  -  mapmstck.c
 *
 *  Copyright (C) 1999 - 2007   Michael C. Ring
 *
 *  Permission to use, copy, and distribute this software and its
 *  documentation for any purpose with or without fee is hereby granted,
 *  provided that the above copyright notice appear in all copies and
 *  that both that copyright notice and this permission notice appear
 *  in supporting documentation.
 *
 *  Permission to modify the software is granted. Permission to distribute
 *  the modified code is granted. Modifications are to be distributed by
 *  using the file 'license.txt' as a template to modify the file header.
 *  'license.txt' is available in the official MAPM distribution.
 *
 *  This software is provided "as is" without express or implied warranty.
 */

/*
 *
 *      This file contains the stack implementation for using
 *	local M_APM variables.
 *
 */

#include "pgAdmin3.h"
#include "pgscript/utilities/mapm-lib/m_apm_lc.h"

static	int	M_stack_ptr  = -1;
static	int	M_last_init  = -1;
static	int	M_stack_size = 0;

static  const char    *M_stack_err_msg = "\'M_get_stack_var\', Out of memory";

static	M_APM	*M_stack_array;

/****************************************************************************/
void	M_free_all_stck()
{
	int	k;

	if (M_last_init >= 0)
	{
		for (k = 0; k <= M_last_init; k++)
			m_apm_free(M_stack_array[k]);

		M_stack_ptr  = -1;
		M_last_init  = -1;
		M_stack_size = 0;

		MAPM_FREE(M_stack_array);
	}
}
/****************************************************************************/
M_APM	M_get_stack_var()
{
	void    *vp;

	if (++M_stack_ptr > M_last_init)
	{
		if (M_stack_size == 0)
		{
			M_stack_size = 18;
			if ((vp = MAPM_MALLOC(M_stack_size * sizeof(M_APM))) == NULL)
			{
				/* fatal, this does not return */

				M_apm_log_error_msg(M_APM_FATAL, M_stack_err_msg);
			}

			M_stack_array = (M_APM *)vp;
		}

		if ((M_last_init + 4) >= M_stack_size)
		{
			M_stack_size += 12;
			if ((vp = MAPM_REALLOC(M_stack_array,
			                       (M_stack_size * sizeof(M_APM)))) == NULL)
			{
				/* fatal, this does not return */

				M_apm_log_error_msg(M_APM_FATAL, M_stack_err_msg);
			}

			M_stack_array = (M_APM *)vp;
		}

		M_stack_array[M_stack_ptr]     = m_apm_init();
		M_stack_array[M_stack_ptr + 1] = m_apm_init();
		M_stack_array[M_stack_ptr + 2] = m_apm_init();
		M_stack_array[M_stack_ptr + 3] = m_apm_init();

		M_last_init = M_stack_ptr + 3;

		/* printf("M_last_init = %d \n",M_last_init); */
	}

	return(M_stack_array[M_stack_ptr]);
}
/****************************************************************************/
void	M_restore_stack(int count)
{
	M_stack_ptr -= count;
}
/****************************************************************************/