mirror of
https://github.com/tokio-rs/tokio.git
synced 2025-09-28 12:10:37 +00:00
8a7e57786a
In an effort to reach API stability, the `tokio` crate is shedding its
_public_ dependencies on crates that are either a) do not provide a
stable (1.0+) release with longevity guarantees or b) match the `tokio`
release cadence. Of course, implementing `std` traits fits the
requirements.
The on exception, for now, is the `Stream` trait found in `futures_core`.
It is expected that this trait will not change much and be moved into `std.
Since Tokio is not yet going reaching 1.0, I feel that it is acceptable to maintain
a dependency on this trait given how foundational it is.
Since the `Stream` implementation is optional, types that are logically
streams provide `async fn next_*` functions to obtain the next value.
Avoiding the `next()` name prevents fn conflicts with `StreamExt::next()`.
Additionally, some misc cleanup is also done:
- `tokio::io::io` -> `tokio::io::util`.
- `delay` -> `delay_until`.
- `Timeout::new` -> `timeout(...)`.
- `signal::ctrl_c()` returns a future instead of a stream.
- `{tcp,unix}::Incoming` is removed (due to lack of `Stream` trait).
- `time::Throttle` is removed (due to lack of `Stream` trait).
- Fix: `mpsc::UnboundedSender::send(&self)` (no more conflict with `Sink` fns).
98 lines
2.4 KiB
Rust
98 lines
2.4 KiB
Rust
#![warn(rust_2018_idioms)]
|
|
|
|
use tokio::prelude::*;
|
|
use tokio_test::assert_ok;
|
|
use tokio_util::codec::{Decoder, Encoder, Framed, FramedParts};
|
|
|
|
use bytes::{Buf, BufMut, BytesMut, IntoBuf};
|
|
use futures::StreamExt;
|
|
use std::io::{self, Read};
|
|
use std::pin::Pin;
|
|
use std::task::{Context, Poll};
|
|
|
|
const INITIAL_CAPACITY: usize = 8 * 1024;
|
|
|
|
/// Encode and decode u32 values.
|
|
struct U32Codec;
|
|
|
|
impl Decoder for U32Codec {
|
|
type Item = u32;
|
|
type Error = io::Error;
|
|
|
|
fn decode(&mut self, buf: &mut BytesMut) -> io::Result<Option<u32>> {
|
|
if buf.len() < 4 {
|
|
return Ok(None);
|
|
}
|
|
|
|
let n = buf.split_to(4).into_buf().get_u32_be();
|
|
Ok(Some(n))
|
|
}
|
|
}
|
|
|
|
impl Encoder for U32Codec {
|
|
type Item = u32;
|
|
type Error = io::Error;
|
|
|
|
fn encode(&mut self, item: u32, dst: &mut BytesMut) -> io::Result<()> {
|
|
// Reserve space
|
|
dst.reserve(4);
|
|
dst.put_u32_be(item);
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
/// This value should never be used
|
|
struct DontReadIntoThis;
|
|
|
|
impl Read for DontReadIntoThis {
|
|
fn read(&mut self, _: &mut [u8]) -> io::Result<usize> {
|
|
Err(io::Error::new(
|
|
io::ErrorKind::Other,
|
|
"Read into something you weren't supposed to.",
|
|
))
|
|
}
|
|
}
|
|
|
|
impl AsyncRead for DontReadIntoThis {
|
|
fn poll_read(
|
|
self: Pin<&mut Self>,
|
|
_cx: &mut Context<'_>,
|
|
_buf: &mut [u8],
|
|
) -> Poll<io::Result<usize>> {
|
|
unreachable!()
|
|
}
|
|
}
|
|
|
|
#[tokio::test]
|
|
async fn can_read_from_existing_buf() {
|
|
let mut parts = FramedParts::new(DontReadIntoThis, U32Codec);
|
|
parts.read_buf = vec![0, 0, 0, 42].into();
|
|
|
|
let mut framed = Framed::from_parts(parts);
|
|
let num = assert_ok!(framed.next().await.unwrap());
|
|
|
|
assert_eq!(num, 42);
|
|
}
|
|
|
|
#[test]
|
|
fn external_buf_grows_to_init() {
|
|
let mut parts = FramedParts::new(DontReadIntoThis, U32Codec);
|
|
parts.read_buf = vec![0, 0, 0, 42].into();
|
|
|
|
let framed = Framed::from_parts(parts);
|
|
let FramedParts { read_buf, .. } = framed.into_parts();
|
|
|
|
assert_eq!(read_buf.capacity(), INITIAL_CAPACITY);
|
|
}
|
|
|
|
#[test]
|
|
fn external_buf_does_not_shrink() {
|
|
let mut parts = FramedParts::new(DontReadIntoThis, U32Codec);
|
|
parts.read_buf = vec![0; INITIAL_CAPACITY * 2].into();
|
|
|
|
let framed = Framed::from_parts(parts);
|
|
let FramedParts { read_buf, .. } = framed.into_parts();
|
|
|
|
assert_eq!(read_buf.capacity(), INITIAL_CAPACITY * 2);
|
|
}
|