mango/obj/link.c

#include <mango/object.h>

#define LINK_CAST(p) OBJECT_C_CAST(struct link, l_base, &link_type, p)

struct link {
	struct object l_base;
	char l_name[OBJECT_NAME_MAX];
	struct object *l_dest;
};

static struct object_type link_type;

static kern_status_t link_query_name(struct object *obj, char out[OBJECT_NAME_MAX])
{
	struct link *link = LINK_CAST(obj);
	strncpy(out, link->l_name, OBJECT_NAME_MAX - 1);
	out[OBJECT_NAME_MAX - 1] = 0;

	return KERN_OK;
}

static struct object_type link_type = {
	.ob_name = "link",
	.ob_size = sizeof(struct link),
	.ob_header_offset = offsetof(struct link, l_base),
	.ob_ops = {
		.query_name = link_query_name,
	},
};

void init_link_objects(void)
{
	object_type_register(&link_type);
}

struct object *link_create(const char *name, struct object *dest)
{
	struct object *link_obj = object_create(&link_type);
	if (!link_obj) {
		return NULL;
	}

	struct link *link = LINK_CAST(link_obj);

	strncpy(link->l_name, name, sizeof link->l_name - 1);
	link->l_name[sizeof link->l_name - 1] = 0;

	link->l_dest = object_ref(dest);

	return link_obj;
}

struct object *link_read_ptr(struct object *link_obj)
{
	struct link *link = LINK_CAST(link_obj);
	return link->l_dest;
}

bool object_is_link(struct object *obj)
{
	return obj->ob_type == &link_type;
}