embedrs_bytes/buf/
reader.rs

1use {Buf};
2
3#[cfg(feature = "std")]
4use std::{cmp, io};
5
6/// A `Buf` adapter which implements `io::Read` for the inner value.
7///
8/// This struct is generally created by calling `reader()` on `Buf`. See
9/// documentation of [`reader()`](trait.Buf.html#method.reader) for more
10/// details.
11#[derive(Debug)]
12pub struct Reader<B> {
13    buf: B,
14}
15
16pub fn new<B>(buf: B) -> Reader<B> {
17    Reader { buf: buf }
18}
19
20impl<B: Buf> Reader<B> {
21    /// Gets a reference to the underlying `Buf`.
22    ///
23    /// It is inadvisable to directly read from the underlying `Buf`.
24    ///
25    /// # Examples
26    ///
27    /// ```rust
28    /// use embedrs_bytes::Buf;
29    /// use std::io::{self, Cursor};
30    ///
31    /// let mut buf = Cursor::new(b"hello world").reader();
32    ///
33    /// assert_eq!(0, buf.get_ref().position());
34    /// ```
35    pub fn get_ref(&self) -> &B {
36        &self.buf
37    }
38
39    /// Gets a mutable reference to the underlying `Buf`.
40    ///
41    /// It is inadvisable to directly read from the underlying `Buf`.
42    ///
43    /// # Examples
44    ///
45    /// ```rust
46    /// use embedrs_bytes::Buf;
47    /// use std::io::{self, Cursor};
48    ///
49    /// let mut buf = Cursor::new(b"hello world").reader();
50    /// let mut dst = vec![];
51    ///
52    /// buf.get_mut().set_position(2);
53    /// io::copy(&mut buf, &mut dst).unwrap();
54    ///
55    /// assert_eq!(*dst, b"llo world"[..]);
56    /// ```
57    pub fn get_mut(&mut self) -> &mut B {
58        &mut self.buf
59    }
60
61    /// Consumes this `Reader`, returning the underlying value.
62    ///
63    /// # Examples
64    ///
65    /// ```rust
66    /// use embedrs_bytes::Buf;
67    /// use std::io::{self, Cursor};
68    ///
69    /// let mut buf = Cursor::new(b"hello world").reader();
70    /// let mut dst = vec![];
71    ///
72    /// io::copy(&mut buf, &mut dst).unwrap();
73    ///
74    /// let buf = buf.into_inner();
75    /// assert_eq!(0, buf.remaining());
76    /// ```
77    pub fn into_inner(self) -> B {
78        self.buf
79    }
80}
81
82#[cfg(feature = "std")]
83impl<B: Buf + Sized> io::Read for Reader<B> {
84    fn read(&mut self, dst: &mut [u8]) -> io::Result<usize> {
85        let len = cmp::min(self.buf.remaining(), dst.len());
86
87        Buf::copy_to_slice(&mut self.buf, &mut dst[0..len]);
88        Ok(len)
89    }
90}
embedrs_bytes/buf/reader.rs

embedrs_bytes/buf/
reader.rs
