vox_core/
memory_link.rs

1use moire::sync::mpsc;
2use vox_types::{Backing, Link, LinkRx, LinkTx};
3
4/// In-process [`Link`] backed by tokio mpsc channels.
5///
6/// Each direction is an unbounded channel carrying `Vec<u8>` — raw bytes,
7/// no serialization, no IO. Useful for testing Conduits, Session, and
8/// anything above the transport layer without real networking.
9// r[impl transport.memory]
10// r[impl zerocopy.framing.link.memory]
11pub struct MemoryLink {
12    tx: mpsc::Sender<Vec<u8>>,
13    rx: mpsc::Receiver<Vec<u8>>,
14}
15
16/// Create a pair of connected [`MemoryLink`]s.
17///
18/// Returns `(a, b)` where sending on `a` delivers to `b` and vice versa.
19pub fn memory_link_pair(buffer: usize) -> (MemoryLink, MemoryLink) {
20    let (tx_a, rx_b) = mpsc::channel("memory_link.a→b", buffer);
21    let (tx_b, rx_a) = mpsc::channel("memory_link.b→a", buffer);
22
23    let a = MemoryLink { tx: tx_a, rx: rx_a };
24    let b = MemoryLink { tx: tx_b, rx: rx_b };
25
26    (a, b)
27}
28
29impl Link for MemoryLink {
30    type Tx = MemoryLinkTx;
31    type Rx = MemoryLinkRx;
32
33    fn split(self) -> (Self::Tx, Self::Rx) {
34        (MemoryLinkTx { tx: self.tx }, MemoryLinkRx { rx: self.rx })
35    }
36}
37
38// ---------------------------------------------------------------------------
39// Tx
40// ---------------------------------------------------------------------------
41
42/// Sending half of a [`MemoryLink`].
43#[derive(Clone)]
44pub struct MemoryLinkTx {
45    tx: mpsc::Sender<Vec<u8>>,
46}
47
48impl LinkTx for MemoryLinkTx {
49    async fn send(&self, bytes: Vec<u8>) -> std::io::Result<()> {
50        let permit = self.tx.clone().reserve_owned().await.map_err(|_| {
51            std::io::Error::new(std::io::ErrorKind::ConnectionReset, "receiver dropped")
52        })?;
53        drop(permit.send(bytes));
54        Ok(())
55    }
56
57    async fn close(self) -> std::io::Result<()> {
58        drop(self.tx);
59        Ok(())
60    }
61}
62
63// ---------------------------------------------------------------------------
64// Rx
65// ---------------------------------------------------------------------------
66
67/// Receiving half of a [`MemoryLink`].
68pub struct MemoryLinkRx {
69    rx: mpsc::Receiver<Vec<u8>>,
70}
71
72/// MemoryLink never fails on recv — the only "error" is channel closed (returns None).
73#[derive(Debug)]
74pub struct MemoryLinkRxError;
75
76impl std::fmt::Display for MemoryLinkRxError {
77    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
78        write!(f, "memory link rx error (unreachable)")
79    }
80}
81
82impl std::error::Error for MemoryLinkRxError {}
83
84impl LinkRx for MemoryLinkRx {
85    type Error = MemoryLinkRxError;
86
87    async fn recv(&mut self) -> Result<Option<Backing>, Self::Error> {
88        match self.rx.recv().await {
89            Some(bytes) => Ok(Some(Backing::Boxed(bytes.into_boxed_slice()))),
90            None => Ok(None),
91        }
92    }
93}
vox_core/memory_link.rs

vox_core/
memory_link.rs
