tokio_uring/buf/
io_buf.rs

1/// An `io-uring` compatible buffer.
2///
3/// The `IoBuf` trait is implemented by buffer types that can be used with
4/// io-uring operations. Users will not need to use this trait directly.
5/// The [`BoundedBuf`] trait provides some useful methods including `slice`.
6///
7/// # Safety
8///
9/// Buffers passed to `io-uring` operations must reference a stable memory
10/// region. While the runtime holds ownership to a buffer, the pointer returned
11/// by `stable_ptr` must remain valid even if the `IoBuf` value is moved.
12///
13/// [`BoundedBuf`]: crate::buf::BoundedBuf
14pub unsafe trait IoBuf: Unpin + 'static {
15    /// Returns a raw pointer to the vector’s buffer.
16    ///
17    /// This method is to be used by the `tokio-uring` runtime and it is not
18    /// expected for users to call it directly.
19    ///
20    /// The implementation must ensure that, while the `tokio-uring` runtime
21    /// owns the value, the pointer returned by `stable_ptr` **does not**
22    /// change.
23    fn stable_ptr(&self) -> *const u8;
24
25    /// Number of initialized bytes.
26    ///
27    /// This method is to be used by the `tokio-uring` runtime and it is not
28    /// expected for users to call it directly.
29    ///
30    /// For `Vec`, this is identical to `len()`.
31    fn bytes_init(&self) -> usize;
32
33    /// Total size of the buffer, including uninitialized memory, if any.
34    ///
35    /// This method is to be used by the `tokio-uring` runtime and it is not
36    /// expected for users to call it directly.
37    ///
38    /// For `Vec`, this is identical to `capacity()`.
39    fn bytes_total(&self) -> usize;
40}
41
42unsafe impl IoBuf for Vec<u8> {
43    fn stable_ptr(&self) -> *const u8 {
44        self.as_ptr()
45    }
46
47    fn bytes_init(&self) -> usize {
48        self.len()
49    }
50
51    fn bytes_total(&self) -> usize {
52        self.capacity()
53    }
54}
55
56unsafe impl IoBuf for &'static [u8] {
57    fn stable_ptr(&self) -> *const u8 {
58        self.as_ptr()
59    }
60
61    fn bytes_init(&self) -> usize {
62        <[u8]>::len(self)
63    }
64
65    fn bytes_total(&self) -> usize {
66        self.bytes_init()
67    }
68}
69
70unsafe impl IoBuf for &'static str {
71    fn stable_ptr(&self) -> *const u8 {
72        self.as_ptr()
73    }
74
75    fn bytes_init(&self) -> usize {
76        <str>::len(self)
77    }
78
79    fn bytes_total(&self) -> usize {
80        self.bytes_init()
81    }
82}
83
84#[cfg(feature = "bytes")]
85unsafe impl IoBuf for bytes::Bytes {
86    fn stable_ptr(&self) -> *const u8 {
87        self.as_ptr()
88    }
89
90    fn bytes_init(&self) -> usize {
91        self.len()
92    }
93
94    fn bytes_total(&self) -> usize {
95        self.len()
96    }
97}
98
99#[cfg(feature = "bytes")]
100unsafe impl IoBuf for bytes::BytesMut {
101    fn stable_ptr(&self) -> *const u8 {
102        self.as_ptr()
103    }
104
105    fn bytes_init(&self) -> usize {
106        self.len()
107    }
108
109    fn bytes_total(&self) -> usize {
110        self.capacity()
111    }
112}
tokio_uring/buf/io_buf.rs

tokio_uring/buf/
io_buf.rs
