1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32

use axfs_vfs::{VfsNodeAttr, VfsNodeOps, VfsNodePerm, VfsNodeType, VfsResult};

/// A zero device behaves like `/dev/zero`.
///
/// It always returns a chunk of `\0` bytes when read, and all writes are discarded.
pub struct ZeroDev;

impl VfsNodeOps for ZeroDev {
    fn get_attr(&self) -> VfsResult<VfsNodeAttr> {
        Ok(VfsNodeAttr::new(
            VfsNodePerm::default_file(),
            VfsNodeType::CharDevice,
            0,
            0,
        ))
    }

    fn read_at(&self, _offset: u64, buf: &mut [u8]) -> VfsResult<usize> {
        buf.fill(0);
        Ok(buf.len())
    }

    fn write_at(&self, _offset: u64, buf: &[u8]) -> VfsResult<usize> {
        Ok(buf.len())
    }

    fn truncate(&self, _size: u64) -> VfsResult {
        Ok(())
    }

    axfs_vfs::impl_vfs_non_dir_default! {}
}