std_shims/
io.rs

1#[cfg(feature = "std")]
2pub use std::io::*;
3
4#[cfg(not(feature = "std"))]
5mod shims {
6  use core::fmt::{Debug, Formatter};
7  use alloc::{boxed::Box, vec::Vec};
8
9  #[derive(Clone, Copy, PartialEq, Eq, Debug)]
10  pub enum ErrorKind {
11    UnexpectedEof,
12    Other,
13  }
14
15  pub struct Error {
16    kind: ErrorKind,
17    error: Box<dyn Send + Sync>,
18  }
19
20  impl Debug for Error {
21    fn fmt(&self, fmt: &mut Formatter<'_>) -> core::result::Result<(), core::fmt::Error> {
22      fmt.debug_struct("Error").field("kind", &self.kind).finish_non_exhaustive()
23    }
24  }
25
26  impl Error {
27    pub fn new<E: 'static + Send + Sync>(kind: ErrorKind, error: E) -> Error {
28      Error { kind, error: Box::new(error) }
29    }
30
31    pub fn other<E: 'static + Send + Sync>(error: E) -> Error {
32      Error { kind: ErrorKind::Other, error: Box::new(error) }
33    }
34
35    pub fn kind(&self) -> ErrorKind {
36      self.kind
37    }
38
39    pub fn into_inner(self) -> Option<Box<dyn Send + Sync>> {
40      Some(self.error)
41    }
42  }
43
44  pub type Result<T> = core::result::Result<T, Error>;
45
46  pub trait Read {
47    fn read(&mut self, buf: &mut [u8]) -> Result<usize>;
48
49    fn read_exact(&mut self, buf: &mut [u8]) -> Result<()> {
50      let read = self.read(buf)?;
51      if read != buf.len() {
52        Err(Error::new(ErrorKind::UnexpectedEof, "reader ran out of bytes"))?;
53      }
54      Ok(())
55    }
56  }
57
58  impl Read for &[u8] {
59    fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
60      let read = buf.len().min(self.len());
61      buf[.. read].copy_from_slice(&self[.. read]);
62      *self = &self[read ..];
63      Ok(read)
64    }
65  }
66
67  pub trait BufRead: Read {
68    fn fill_buf(&mut self) -> Result<&[u8]>;
69    fn consume(&mut self, amt: usize);
70  }
71
72  impl BufRead for &[u8] {
73    fn fill_buf(&mut self) -> Result<&[u8]> {
74      Ok(*self)
75    }
76    fn consume(&mut self, amt: usize) {
77      *self = &self[amt ..];
78    }
79  }
80
81  pub trait Write {
82    fn write(&mut self, buf: &[u8]) -> Result<usize>;
83    fn write_all(&mut self, buf: &[u8]) -> Result<()> {
84      if self.write(buf)? != buf.len() {
85        Err(Error::new(ErrorKind::UnexpectedEof, "writer ran out of bytes"))?;
86      }
87      Ok(())
88    }
89  }
90
91  impl Write for Vec<u8> {
92    fn write(&mut self, buf: &[u8]) -> Result<usize> {
93      self.extend(buf);
94      Ok(buf.len())
95    }
96  }
97}
98
99#[cfg(not(feature = "std"))]
100pub use shims::*;
std_shims/io.rs

std_shims/
io.rs
