/Users/maurits/Documents/studie/afstuderen/biosphere/common/stack.c

Go to the documentation of this file.

/*
 * Author: MA Hartman
 * Date: mar 5, 2007
 * 
 * Function:
 * General purpose stack implementation.
 * 
 * License information:
 * 
 * Copyright (c) 2006 Maurits Hartman
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 * 
 */
 
#include "stack.h"
#include "alloc.h"

#include <assert.h>

#define INITIAL_STACK_SIZE 16


bs_stack *new_stack(apr_pool_t *mp)
{
        apr_status_t rv;
        apr_pool_t *pool;
        bs_stack *stack = NULL;
        
        /* Create a subpool for this stack and its data: */
        rv = apr_pool_create(&pool, mp);
        assert(rv == APR_SUCCESS);
        
        /* Initialize data members: */
    stack                               = apr_pcalloc(pool, sizeof(bs_stack));
    stack->size         = 0;
    stack->allocated    = INITIAL_STACK_SIZE;
    stack->pool                 = pool;
    stack->data         = apr_pcalloc(pool, sizeof(void * [INITIAL_STACK_SIZE]));
        
        return stack;   
}


void delete_stack(bs_stack *stack)
{
        if (stack != NULL) {
                /* The stack is allocated from its own subpool, so this will delete
                 * it completely: */
        apr_pool_destroy(stack->pool);
    }   
}


void stack_push(bs_stack *stack, void *data)
{
        assert(stack != NULL);
        
        /* Double the allocated space if it is full: */
    if (stack->size == stack->allocated) {
        stack->allocated *= 2;
        stack->data = pool_realloc(stack->data,
                        stack->size,
                        sizeof(void *) * stack->allocated,
                        stack->pool);
    }

    stack->data[stack->size++] = data;
}


void *stack_pop(bs_stack *stack)
{
        void *ret;
        
        assert(stack != NULL);
        ret = stack_top(stack);
        
        /* This stack implementation will only release memory when it is deleted: */
        if (stack->size != 0) stack->size--;
        
        return ret;
}


void *stack_top(const bs_stack *stack)
{
        assert(stack != NULL);
        if (stack->size == 0) return NULL;
        return stack->data[stack->size - 1];
}


int stack_empty(const bs_stack *stack)
{
        assert(stack != NULL);
        return stack->size;
}


void *stack_index(const bs_stack *stack, unsigned index)
{
        assert(stack != NULL && index < stack->size);
        return stack->data[index];
}


inline unsigned stack_size(const bs_stack *stack)
{
        assert(stack != NULL);
        return stack->size;     
}

---