zend_ptr_stack.h

Go to the documentation of this file.

/*
   +----------------------------------------------------------------------+
   | 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>                                 |
   +----------------------------------------------------------------------+
*/
 
#ifndef ZEND_PTR_STACK_H
#define ZEND_PTR_STACK_H
 
#include "zend_alloc.h"
 
typedef struct _zend_ptr_stack {
    int top, max;
    void **elements;
    void **top_element;
    bool persistent;
} zend_ptr_stack;
 
 
#define PTR_STACK_BLOCK_SIZE 64
 
BEGIN_EXTERN_C()
ZEND_API void zend_ptr_stack_init(zend_ptr_stack *stack);
ZEND_API void zend_ptr_stack_init_ex(zend_ptr_stack *stack, bool persistent);
ZEND_API void zend_ptr_stack_n_push(zend_ptr_stack *stack, int count, ...);
ZEND_API void zend_ptr_stack_n_pop(zend_ptr_stack *stack, int count, ...);
ZEND_API void zend_ptr_stack_destroy(zend_ptr_stack *stack);
ZEND_API void zend_ptr_stack_apply(zend_ptr_stack *stack, void (*func)(void *));
ZEND_API void zend_ptr_stack_reverse_apply(zend_ptr_stack *stack, void (*func)(void *));
ZEND_API void zend_ptr_stack_clean(zend_ptr_stack *stack, void (*func)(void *), bool free_elements);
ZEND_API int zend_ptr_stack_num_elements(zend_ptr_stack *stack);
END_EXTERN_C()
 
#define ZEND_PTR_STACK_RESIZE_IF_NEEDED(stack, count)       \
    if (stack->top+count > stack->max) {                    \
        /* we need to allocate more memory */               \
        do {                                                \
            stack->max += PTR_STACK_BLOCK_SIZE;             \
        } while (stack->top+count > stack->max);            \
        stack->elements = (void **) safe_perealloc(stack->elements, sizeof(void *), (stack->max), 0, stack->persistent);    \
        stack->top_element = stack->elements+stack->top;    \
    }
 
/*  Not doing this with a macro because of the loop unrolling in the element assignment.
    Just using a macro for 3 in the body for readability sake. */
static zend_always_inline void zend_ptr_stack_3_push(zend_ptr_stack *stack, void *a, void *b, void *c)
{
#define ZEND_PTR_STACK_NUM_ARGS 3
 
    ZEND_PTR_STACK_RESIZE_IF_NEEDED(stack, ZEND_PTR_STACK_NUM_ARGS)
 
    stack->top += ZEND_PTR_STACK_NUM_ARGS;
    *(stack->top_element++) = a;
    *(stack->top_element++) = b;
    *(stack->top_element++) = c;
 
#undef ZEND_PTR_STACK_NUM_ARGS
}
 
static zend_always_inline void zend_ptr_stack_2_push(zend_ptr_stack *stack, void *a, void *b)
{
#define ZEND_PTR_STACK_NUM_ARGS 2
 
    ZEND_PTR_STACK_RESIZE_IF_NEEDED(stack, ZEND_PTR_STACK_NUM_ARGS)
 
    stack->top += ZEND_PTR_STACK_NUM_ARGS;
    *(stack->top_element++) = a;
    *(stack->top_element++) = b;
 
#undef ZEND_PTR_STACK_NUM_ARGS
}
 
static zend_always_inline void zend_ptr_stack_3_pop(zend_ptr_stack *stack, void **a, void **b, void **c)
{
    *a = *(--stack->top_element);
    *b = *(--stack->top_element);
    *c = *(--stack->top_element);
    stack->top -= 3;
}
 
static zend_always_inline void zend_ptr_stack_2_pop(zend_ptr_stack *stack, void **a, void **b)
{
    *a = *(--stack->top_element);
    *b = *(--stack->top_element);
    stack->top -= 2;
}
 
static zend_always_inline void zend_ptr_stack_push(zend_ptr_stack *stack, void *ptr)
{
    ZEND_PTR_STACK_RESIZE_IF_NEEDED(stack, 1)
 
    stack->top++;
    *(stack->top_element++) = ptr;
}
 
static zend_always_inline void *zend_ptr_stack_pop(zend_ptr_stack *stack)
{
    stack->top--;
    return *(--stack->top_element);
}
 
static zend_always_inline void *zend_ptr_stack_top(zend_ptr_stack *stack)
{
    return stack->elements[stack->top - 1];
}
 
#endif /* ZEND_PTR_STACK_H */