async_flow/io/
port.rs

1// This is free and unencumbered software released into the public domain.
2
3use super::{PortDirection, PortState};
4use dogma::{MaybeLabeled, MaybeNamed};
5
6/// The common interface for ports, whether for input or output.
7pub trait Port<T: Send>: MaybeNamed + MaybeLabeled {
8    /// Closes this port without dropping it, returning immediately.
9    ///
10    /// If the port had an open connection, it will be disconnected.
11    /// If the port was already closed, no further action is taken.
12    /// There is no facility to reopen a port once it has been closed.
13    fn close(&mut self);
14
15    /// The dataflow direction of this port.
16    fn direction(&self) -> PortDirection;
17
18    /// The current state of this port.
19    fn state(&self) -> PortState;
20
21    /// Checks whether this port is an input port.
22    fn is_input(&self) -> bool {
23        self.direction().is_input()
24    }
25
26    /// Checks whether this port is an output port.
27    fn is_output(&self) -> bool {
28        self.direction().is_output()
29    }
30
31    /// Checks whether this port is currently unconnected.
32    fn is_unconnected(&self) -> bool {
33        self.state().is_unconnected()
34    }
35
36    /// Checks whether this port is currently connected.
37    fn is_connected(&self) -> bool {
38        self.state().is_connected()
39    }
40
41    /// Checks whether this port is currently disconnected.
42    fn is_disconnected(&self) -> bool {
43        self.state().is_disconnected()
44    }
45
46    /// Checks whether this port is currently closed.
47    fn is_closed(&self) -> bool {
48        self.state().is_closed()
49    }
50
51    /// Returns the remaining buffer capacity of the connection.
52    fn capacity(&self) -> Option<usize> {
53        None // unknown
54    }
55
56    /// Returns the maximum buffer capacity of the connection.
57    fn max_capacity(&self) -> Option<usize> {
58        None // unknown
59    }
60}
61
62impl<T: Send> core::fmt::Debug for &dyn Port<T> {
63    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
64        f.debug_struct("Port")
65            .field("name", &self.name())
66            .field("state", &self.state())
67            .finish()
68    }
69}
async_flow/io/port.rs

async_flow/io/
port.rs
