zend_stack.c

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/*
   +----------------------------------------------------------------------+
   | Zend Engine                                                          |
   +----------------------------------------------------------------------+
   | Copyright (c) Zend Technologies Ltd. (http://www.zend.com)           |
   +----------------------------------------------------------------------+
   | This source file is subject to version 2.00 of the Zend license,     |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.zend.com/license/2_00.txt.                                |
   | If you did not receive a copy of the Zend license and are unable to  |
   | obtain it through the world-wide-web, please send a note to          |
   | license@zend.com so we can mail you a copy immediately.              |
   +----------------------------------------------------------------------+
   | Authors: Andi Gutmans <andi@php.net>                                 |
   |          Zeev Suraski <zeev@php.net>                                 |
   +----------------------------------------------------------------------+
*/
 
#include "zend.h"
#include "zend_stack.h"
 
#define ZEND_STACK_ELEMENT(stack, n) ((void *)((char *) (stack)->elements + (stack)->size * (n)))
 
ZEND_API void zend_stack_init(zend_stack *stack, int size)
{
    stack->size = size;
    stack->top = 0;
    stack->max = 0;
    stack->elements = NULL;
}
 
ZEND_API int zend_stack_push(zend_stack *stack, const void *element)
{
    /* We need to allocate more memory */
    if (stack->top >= stack->max) {
        stack->max += STACK_BLOCK_SIZE;
        stack->elements = safe_erealloc(stack->elements, stack->size, stack->max, 0);
    }
    memcpy(ZEND_STACK_ELEMENT(stack, stack->top), element, stack->size);
    return stack->top++;
}
 
 
ZEND_API void *zend_stack_top(const zend_stack *stack)
{
    if (stack->top > 0) {
        return ZEND_STACK_ELEMENT(stack, stack->top - 1);
    } else {
        return NULL;
    }
}
 
 
ZEND_API void zend_stack_del_top(zend_stack *stack)
{
    --stack->top;
}
 
 
ZEND_API int zend_stack_int_top(const zend_stack *stack)
{
    int *e = zend_stack_top(stack);
    if (e) {
        return *e;
    } else {
        return FAILURE;
    }
}
 
 
ZEND_API bool zend_stack_is_empty(const zend_stack *stack)
{
    return stack->top == 0;
}
 
 
ZEND_API void zend_stack_destroy(zend_stack *stack)
{
    if (stack->elements) {
        efree(stack->elements);
        stack->elements = NULL;
    }
}
 
 
ZEND_API void *zend_stack_base(const zend_stack *stack)
{
    return stack->elements;
}
 
 
ZEND_API int zend_stack_count(const zend_stack *stack)
{
    return stack->top;
}
 
 
ZEND_API void zend_stack_apply(zend_stack *stack, int type, int (*apply_function)(void *element))
{
    int i;
 
    switch (type) {
        case ZEND_STACK_APPLY_TOPDOWN:
            for (i=stack->top-1; i>=0; i--) {
                if (apply_function(ZEND_STACK_ELEMENT(stack, i))) {
                    break;
                }
            }
            break;
        case ZEND_STACK_APPLY_BOTTOMUP:
            for (i=0; i<stack->top; i++) {
                if (apply_function(ZEND_STACK_ELEMENT(stack, i))) {
                    break;
                }
            }
            break;
    }
}
 
 
ZEND_API void zend_stack_apply_with_argument(zend_stack *stack, zend_stack_apply_direction type, int (*apply_function)(void *element, void *arg), void *arg)
{
    int i;
 
    switch (type) {
        case ZEND_STACK_APPLY_TOPDOWN:
            for (i=stack->top-1; i>=0; i--) {
                if (apply_function(ZEND_STACK_ELEMENT(stack, i), arg)) {
                    break;
                }
            }
            break;
        case ZEND_STACK_APPLY_BOTTOMUP:
            for (i=0; i<stack->top; i++) {
                if (apply_function(ZEND_STACK_ELEMENT(stack, i), arg)) {
                    break;
                }
            }
            break;
    }
}
 
ZEND_API void zend_stack_clean(zend_stack *stack, void (*func)(void *), bool free_elements)
{
    int i;
 
    if (func) {
        for (i = 0; i < stack->top; i++) {
            func(ZEND_STACK_ELEMENT(stack, i));
        }
    }
    if (free_elements) {
        if (stack->elements) {
            efree(stack->elements);
            stack->elements = NULL;
        }
        stack->top = stack->max = 0;
    }
}