root/third_party/bintrees/bintrees/stack.c

DEFINITIONS

1. stack_init
2. stack_delete
3. stack_push
4. stack_pop
5. stack_is_empty
6. stack_reset

/*
 * stack.c
 *
 *  Author: mozman
 *  Copyright (c) 2010-2013 by Manfred Moitzi
 *  License: MIT-License
 */

#include "ctrees.h"
#include "stack.h"

extern node_stack_t *
stack_init(int size)
{
        node_stack_t *stack;

        stack = PyMem_Malloc(sizeof(node_stack_t));
        stack->stack = PyMem_Malloc(sizeof(node_t *) * size);
        stack->size = size;
        stack->stackptr = 0;
        return stack;
}

extern void
stack_delete(node_stack_t *stack)
{
        PyMem_Free(stack->stack);
        PyMem_Free(stack);
}

extern void
stack_push(node_stack_t *stack, node_t *node)
{
        stack->stack[stack->stackptr++] = node;
        if (stack->stackptr >= stack->size) {
                stack->size *= 2;
                stack->stack = PyMem_Realloc(stack->stack,
                                sizeof(node_t *) * stack->size);
        }
}

extern node_t *
stack_pop(node_stack_t *stack)
{
        return (stack->stackptr > 0) ? stack->stack[--stack->stackptr] : NULL;
}

extern int
stack_is_empty(node_stack_t *stack)
{
        return (stack->stackptr == 0);
}

extern void
stack_reset(node_stack_t *stack)
{
        stack->stackptr = 0;
}