/*
 * This file implements the File object and associated functions.  A file
 * represents an opened file, and holds a reference the the underlying inode.
 * Most of the functions here are just wrappers around the file operations.
 * They perform the necessary validation to ensure the operation can be called
 * on the particular file.  If no operation is found, they may implement a
 * generic version.
 */

#include <errno.h>
#include <nucleus/object.h>
#include <nucleus/vfs.h>

static void file_delete(Object *);

/* File object type */
ObjectType fileType = {
	.name = "FILE",
	.size = sizeof(File),
	.delete = file_delete,
};

/* Destroy a file */
static void
file_delete(Object *obj)
{
	File *file = (void *) obj;
	if (file->inode)
		put(file->inode);
	if (file->path)
		destroy_list(file->path);
}

/* Open a file */
int
file_open(File *file)
{
	if (!file->ops || !file->ops->open)
		return -EINVAL;
	return file->ops->open(file);
}

/* Read a file */
size_t
file_read(File *file, char *buf, size_t size)
{
	size_t count = 0;
	if (!file->ops || !file->ops->read)
		return count;
	count = file->ops->read(file, buf, size, file->pos);
	file->pos += count;
	return count;
}

/* Write a file */
size_t
file_write(File *file, char *buf, size_t size)
{
	size_t count = 0;
	if (!file->ops || !file->ops->write)
		return count;
	count = file->ops->write(file, buf, size, file->pos);
	file->pos += count;
	return count;
}