asynchronous_codec/
encoder.rs

1use super::fuse::Fuse;
2use bytes::BytesMut;
3use std::io::Error;
4
5/// Encoding of messages as bytes, for use with `FramedWrite`.
6pub trait Encoder {
7    /// The type of items consumed by `encode`
8    type Item<'a>;
9    /// The type of encoding errors.
10    type Error: From<Error>;
11
12    /// Encodes an item into the `BytesMut` provided by dst.
13    fn encode(&mut self, item: Self::Item<'_>, dst: &mut BytesMut) -> Result<(), Self::Error>;
14}
15
16impl<T, U: Encoder> Encoder for Fuse<T, U> {
17    type Item<'a> = U::Item<'a>;
18    type Error = U::Error;
19
20    fn encode(&mut self, item: Self::Item<'_>, dst: &mut BytesMut) -> Result<(), Self::Error> {
21        self.u.encode(item, dst)
22    }
23}
24
25#[cfg(test)]
26mod tests {
27    use super::*;
28    use crate::FramedWrite;
29    use futures::executor::block_on;
30    use futures_util::SinkExt;
31
32    #[test]
33    fn can_use_borrowed_data() {
34        let mut buf = Vec::new();
35
36        let mut write = FramedWrite::new(&mut buf, BorrowedCodec);
37        block_on(write.send(&[1, 2, 3, 4])).unwrap();
38
39        assert_eq!(buf, vec![1, 2, 3, 4])
40    }
41
42    struct BorrowedCodec;
43
44    impl Encoder for BorrowedCodec {
45        type Item<'a> = &'a [u8];
46        type Error = Error;
47
48        fn encode(&mut self, item: Self::Item<'_>, dst: &mut BytesMut) -> Result<(), Self::Error> {
49            dst.extend_from_slice(item);
50
51            Ok(())
52        }
53    }
54}
asynchronous_codec/encoder.rs

asynchronous_codec/
encoder.rs
