nix_compat/wire/ser/
mod.rs

1use std::error::Error as StdError;
2use std::future::Future;
3use std::{fmt, io};
4
5use super::ProtocolVersion;
6
7mod bytes;
8mod collections;
9mod int;
10mod writer;
11
12pub use writer::{NixWriter, NixWriterBuilder};
13
14pub trait Error: Sized + StdError {
15    fn custom<T: fmt::Display>(msg: T) -> Self;
16
17    fn io_error(err: std::io::Error) -> Self {
18        Self::custom(format_args!("There was an I/O error {err}"))
19    }
20
21    fn unsupported_data<T: fmt::Display>(msg: T) -> Self {
22        Self::custom(msg)
23    }
24
25    fn invalid_enum<T: fmt::Display>(msg: T) -> Self {
26        Self::custom(msg)
27    }
28}
29
30impl Error for io::Error {
31    fn custom<T: fmt::Display>(msg: T) -> Self {
32        io::Error::other(msg.to_string())
33    }
34
35    fn io_error(err: std::io::Error) -> Self {
36        err
37    }
38
39    fn unsupported_data<T: fmt::Display>(msg: T) -> Self {
40        io::Error::new(io::ErrorKind::InvalidData, msg.to_string())
41    }
42}
43
44pub trait NixWrite: Send {
45    type Error: Error;
46
47    /// Some types are serialized differently depending on the version
48    /// of the protocol and so this can be used for implementing that.
49    fn version(&self) -> ProtocolVersion;
50
51    /// Write a single u64 to the protocol.
52    fn write_number(&mut self, value: u64) -> impl Future<Output = Result<(), Self::Error>> + Send;
53
54    /// Write a slice of bytes to the protocol.
55    fn write_slice(&mut self, buf: &[u8]) -> impl Future<Output = Result<(), Self::Error>> + Send;
56
57    /// Write a value that implements `std::fmt::Display` to the protocol.
58    /// The protocol uses many small string formats and instead of allocating
59    /// a `String` each time we want to write one an implementation of `NixWrite`
60    /// can instead use `Display` to dump these formats to a reusable buffer.
61    fn write_display<D>(&mut self, msg: D) -> impl Future<Output = Result<(), Self::Error>> + Send
62    where
63        D: fmt::Display + Send,
64        Self: Sized,
65    {
66        async move {
67            let s = msg.to_string();
68            self.write_slice(s.as_bytes()).await
69        }
70    }
71
72    /// Write a value to the protocol.
73    /// Uses `NixSerialize::serialize` to write the value.
74    fn write_value<V>(&mut self, value: &V) -> impl Future<Output = Result<(), Self::Error>> + Send
75    where
76        V: NixSerialize + Send + ?Sized,
77        Self: Sized,
78    {
79        value.serialize(self)
80    }
81}
82
83impl<T: NixWrite> NixWrite for &mut T {
84    type Error = T::Error;
85
86    fn version(&self) -> ProtocolVersion {
87        (**self).version()
88    }
89
90    fn write_number(&mut self, value: u64) -> impl Future<Output = Result<(), Self::Error>> + Send {
91        (**self).write_number(value)
92    }
93
94    fn write_slice(&mut self, buf: &[u8]) -> impl Future<Output = Result<(), Self::Error>> + Send {
95        (**self).write_slice(buf)
96    }
97
98    fn write_display<D>(&mut self, msg: D) -> impl Future<Output = Result<(), Self::Error>> + Send
99    where
100        D: fmt::Display + Send,
101        Self: Sized,
102    {
103        (**self).write_display(msg)
104    }
105
106    fn write_value<V>(&mut self, value: &V) -> impl Future<Output = Result<(), Self::Error>> + Send
107    where
108        V: NixSerialize + Send + ?Sized,
109        Self: Sized,
110    {
111        (**self).write_value(value)
112    }
113}
114
115pub trait NixSerialize {
116    /// Write a value to the writer.
117    fn serialize<W>(&self, writer: &mut W) -> impl Future<Output = Result<(), W::Error>> + Send
118    where
119        W: NixWrite;
120}
121
122// Noop
123impl NixSerialize for () {
124    async fn serialize<W>(&self, _writer: &mut W) -> Result<(), W::Error>
125    where
126        W: NixWrite,
127    {
128        Ok(())
129    }
130}
nix_compat/wire/ser/mod.rs

nix_compat/wire/ser/
mod.rs
