/*
* Copyright (c) 2020 Tama Communications Corporation
*
* This file is part of GNU GLOBAL.
*
* 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 .
*/
#ifdef HAVE_CONFIG_H
#include
#endif
#ifdef STDC_HEADERS
#include
#endif
#include
#include
#include "checkalloc.h"
#include "die.h"
#include "vstack.h"
/*
Stack: usage and memory status
Function call Memory status
----------------------------------------------------------
not exist
struct X *curp;
vs = vstack_open(sizeof(struct X)); ||
curp = vstack_top(vs); || curp == NULL
curp = vstack_push(vs); |struct X|<- curp
curp = vstack_push(vs); |struct X|struct X|<- curp
curp = vstack_top(vs); |struct X|struct X|<- curp
curp = vstack_pop(vs); |struct X|<- curp
curp = vstack_pop(vs); || curp == NULL
vstack_close(vs); not exist
*/
/**
* vstack_open: make a stack
*
* @param[in] size size of entry
* @param[in] expand expand size of array
* @return vs VSTACK structure
*/
VSTACK *
vstack_open(int size, int expand)
{
VSTACK *vs = (VSTACK *)check_calloc(sizeof(VSTACK), 1);
vs->varray = varray_open(size, expand);
vs->stack_top = -1; /* empty */
return vs;
}
/**
* vstack_push: push a new entry to the stack.
*
* @param[in] vs VSTACK structure
* @return pointer of the entry
*/
void *
vstack_push(VSTACK *vs)
{
void *entry = varray_assign(vs->varray, ++vs->stack_top, 1);
memset(entry, 0, vs->varray->size);
return entry;
}
/**
* vstack_pop: pop the top entry of the stack.
*
* @param[in] vs VSTACK structure
* @return pointer of the entry
*/
void *
vstack_pop(VSTACK *vs)
{
if (--vs->stack_top < 0) {
vs->stack_top = -1;
return NULL;
}
return varray_assign(vs->varray, vs->stack_top, 0);
}
/**
* vstack_top: return the top entry of the stack.
*
* @param[in] vs VSTACK structure
* @return pointer of the entry
*/
void *
vstack_top(VSTACK *vs)
{
if (vs->stack_top < 0)
return NULL;
return varray_assign(vs->varray, vs->stack_top, 0);
}
/**
* vstack_close: close the stack.
*
* @param[in] vs VSTACK structure
*/
void
vstack_close(VSTACK *vs)
{
if (vs) {
varray_close(vs->varray);
(void)free(vs);
}
}