axfs_ng_vfs/node/
file.rs

1use alloc::sync::Arc;
2use core::ops::Deref;
3
4use axpoll::Pollable;
5
6use super::NodeOps;
7use crate::{VfsError, VfsResult};
8
9pub trait FileNodeOps: NodeOps + Pollable {
10    /// Reads a number of bytes starting from a given offset.
11    fn read_at(&self, buf: &mut [u8], offset: u64) -> VfsResult<usize>;
12
13    /// Writes a number of bytes starting from a given offset.
14    fn write_at(&self, buf: &[u8], offset: u64) -> VfsResult<usize>;
15
16    /// Appends data to the file.
17    ///
18    /// Returns `(written, offset)` where `written` is the number of bytes
19    /// written and `offset` is the new file size.
20    fn append(&self, buf: &[u8]) -> VfsResult<(usize, u64)>;
21
22    /// Sets the size of the file.
23    fn set_len(&self, len: u64) -> VfsResult<()>;
24
25    /// Sets the file's symlink target.
26    fn set_symlink(&self, target: &str) -> VfsResult<()>;
27
28    /// Manipulates the underlying device parameters of special files.
29    fn ioctl(&self, _cmd: u32, _arg: usize) -> VfsResult<usize> {
30        Err(VfsError::NotATty)
31    }
32}
33
34#[repr(transparent)]
35pub struct FileNode(Arc<dyn FileNodeOps>);
36
37impl Deref for FileNode {
38    type Target = dyn FileNodeOps;
39
40    fn deref(&self) -> &Self::Target {
41        &*self.0
42    }
43}
44
45impl From<FileNode> for Arc<dyn NodeOps> {
46    fn from(node: FileNode) -> Self {
47        node.0.clone()
48    }
49}
50
51impl FileNode {
52    pub fn new(ops: Arc<dyn FileNodeOps>) -> Self {
53        Self(ops)
54    }
55
56    pub fn inner(&self) -> &Arc<dyn FileNodeOps> {
57        &self.0
58    }
59
60    pub fn downcast<T: FileNodeOps>(self: &Arc<Self>) -> VfsResult<Arc<T>> {
61        self.0
62            .clone()
63            .into_any()
64            .downcast()
65            .map_err(|_| VfsError::InvalidInput)
66    }
67}
axfs_ng_vfs/node/file.rs

axfs_ng_vfs/node/
file.rs
