博客水木

PHP开发之链表简介：节点元素只含有前面提到的3个元素，第三个字段data和哈希表的实现一样， 是一个柔性结构体。

typedef struct _zend_llist_element {
    struct _zend_llist_element *next;
    struct _zend_llist_element *prev;
    char data[1]; /* Needs to always be last in the struct */
} zend_llist_element;

typedef struct _zend_llist {
    zend_llist_element *head;
    zend_llist_element *tail;
    size_t count;
    size_t size;
    llist_dtor_func_t dtor;
    unsigned char persistent;
    zend_llist_element *traverse_ptr;
} zend_llist;

ZEND_API void zend_llist_add_element(zend_llist *l, void *element)
{
    zend_llist_element *tmp = pemalloc(sizeof(zend_llist_element)+l->size-1, l->persistent);

    tmp->prev = l->tail;
    tmp->next = NULL;
    if (l->tail) {
        l->tail->next = tmp;
    } else {
        l->head = tmp;
    }
    l->tail = tmp;
    memcpy(tmp->data, element, l->size);

    ++l->count;
}

/* traversal */
ZEND_API void *zend_llist_get_first_ex(zend_llist *l, zend_llist_position *pos);
ZEND_API void *zend_llist_get_last_ex(zend_llist *l, zend_llist_position *pos);
ZEND_API void *zend_llist_get_next_ex(zend_llist *l, zend_llist_position *pos);
ZEND_API void *zend_llist_get_prev_ex(zend_llist *l, zend_llist_position *pos);

#define zend_llist_get_first(l) zend_llist_get_first_ex(l, NULL)
#define zend_llist_get_last(l) zend_llist_get_last_ex(l, NULL)
#define zend_llist_get_next(l) zend_llist_get_next_ex(l, NULL)
#define zend_llist_get_prev(l) zend_llist_get_prev_ex(l, NULL)