aos/lib/collections/stack.c
Daniel Schwyn 6d444bf552 Main handout
Signed-off-by: Daniel Schwyn <daniel.schwyn@inf.ethz.ch>
2022-03-03 14:57:51 +01:00

83 lines
1.9 KiB
C

/**
* \file
* \brief Barrelfish collections library stack
*/
/*
* Copyright (c) 2012, ETH Zurich.
* All rights reserved.
*
* This file is distributed under the terms in the attached LICENSE file.
* If you do not find this file, copies can be found by writing to:
* ETH Zurich D-INFK, Universitaetstrasse 6, CH-8092 Zurich. Attn: Systems Group.
*/
#include <collections/list.h>
#include <collections/stack.h>
#include <assert.h>
/**
* \brief Initialize the stack data structure.
*
* \param stack Pointer to a pointer to a stack. Filled-in by function.
*
* Example usage:
* \code
* struct collections_stack *stack;
* collections_stack_create(&stack);
* \endcode
*/
void collections_stack_create(struct collections_stack **stack)
{
*stack = (struct collections_stack *)
malloc(sizeof(struct collections_stack));
assert(*stack != NULL);
(*stack)->num_elements = 0;
// create a linked list to hold the elements of the stack
collections_list_create(&(*stack)->elements, NULL);
return;
}
/**
* \brief Returns the top element of the stack and removes it.
*/
void *collections_stack_pop(struct collections_stack *stack)
{
return collections_list_remove_ith_item(stack->elements, 0);
}
/**
* \brief Push an element to the top of the stack.
*/
void collections_stack_push(struct collections_stack *stack, void *element)
{
collections_list_insert(stack->elements, element);
return;
}
/**
* \brief Returns the top element of the stack, does not remove it.
*/
void *collections_stack_top(struct collections_stack *stack)
{
return collections_list_get_ith_item(stack->elements, 0);
}
/**
* \brief Free all memory associated with the stack.
*/
void collections_stack_release(struct collections_stack *stack)
{
if (stack == NULL) {
return;
}
collections_list_release(stack->elements);
free(stack);
}