quiche/
buffers.rs

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26
27use std::fmt::Debug;
28use std::sync::Arc;
29
30/// A trait for providing internal storage buffers for streams,
31/// enabling zero-copy operations.
32/// The associated type `Buf` can be any type that dereferences to
33/// a slice, but should be fast to clone, eg. by wrapping it with an
34/// [`Arc`].
35pub trait BufFactory: Clone + Default + Debug {
36    /// The type of the generated buffer. The clone operation should be cheap,
37    /// e.g., by using an [`Arc`].
38    type Buf: Clone + Debug + AsRef<[u8]>;
39
40    /// Generate a new buffer from a given slice, the buffer must contain the
41    /// same data as the original slice.
42    fn buf_from_slice(buf: &[u8]) -> Self::Buf;
43}
44
45/// A trait that enables zero-copy sends to quiche. When buffers produced
46/// by the `BufFactory` implement this trait, quiche and h3 can supply the
47/// raw buffers to be sent, instead of slices that must be copied first.
48pub trait BufSplit {
49    /// Split the buffer at a given point, after the split the old buffer
50    /// must only contain the first `at` bytes, while the newly produced
51    /// buffer must containt the remaining bytes.
52    fn split_at(&mut self, at: usize) -> Self;
53
54    /// Try to prepend a prefix to the buffer, return true if succeeded.
55    fn try_add_prefix(&mut self, _prefix: &[u8]) -> bool {
56        false
57    }
58}
59
60/// The default [`BufFactory`] allocates buffers on the heap on demand.
61#[derive(Debug, Clone, Default)]
62pub struct DefaultBufFactory;
63
64/// The default [`BufFactory::Buf`] is a boxed slice wrapped in an [`Arc`].
65#[derive(Debug, Clone, Default)]
66pub struct DefaultBuf(Arc<Box<[u8]>>);
67
68impl BufFactory for DefaultBufFactory {
69    type Buf = DefaultBuf;
70
71    fn buf_from_slice(buf: &[u8]) -> Self::Buf {
72        DefaultBuf(Arc::new(buf.into()))
73    }
74}
75
76impl AsRef<[u8]> for DefaultBuf {
77    fn as_ref(&self) -> &[u8] {
78        &self.0[..]
79    }
80}
quiche/buffers.rs

quiche/
buffers.rs
