     1
     2
     3
     4
     5
     6
     7
     8
     9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81

    use crate::Buf;

    use std::{cmp, io};

    /// A `Buf` adapter which implements `io::Read` for the inner value.
    ///
    /// This struct is generally created by calling `reader()` on `Buf`. See
    /// documentation of [`reader()`](trait.Buf.html#method.reader) for more
    /// details.
    #[derive(Debug)]
    pub struct Reader<B> {
        buf: B,
    }

    pub fn new<B>(buf: B) -> Reader<B> {
        Reader { buf }
    }

    impl<B: Buf> Reader<B> {
        /// Gets a reference to the underlying `Buf`.
        ///
        /// It is inadvisable to directly read from the underlying `Buf`.
        ///
        /// # Examples
        ///
        /// ```rust
        /// use bytes::Buf;
        ///
        /// let buf = b"hello world".reader();
        ///
        /// assert_eq!(b"hello world", buf.get_ref());
        /// ```
        pub fn get_ref(&self) -> &B {
            &self.buf
        }

        /// Gets a mutable reference to the underlying `Buf`.
        ///
        /// It is inadvisable to directly read from the underlying `Buf`.
        pub fn get_mut(&mut self) -> &mut B {
            &mut self.buf
        }

        /// Consumes this `Reader`, returning the underlying value.
        ///
        /// # Examples
        ///
        /// ```rust
        /// use bytes::Buf;
        /// use std::io;
        ///
        /// let mut buf = b"hello world".reader();
        /// let mut dst = vec![];
        ///
        /// io::copy(&mut buf, &mut dst).unwrap();
        ///
        /// let buf = buf.into_inner();
        /// assert_eq!(0, buf.remaining());
        /// ```
        pub fn into_inner(self) -> B {
            self.buf
        }
    }

    impl<B: Buf + Sized> io::Read for Reader<B> {
        fn read(&mut self, dst: &mut [u8]) -> io::Result<usize> {
            let len = cmp::min(self.buf.remaining(), dst.len());

            Buf::copy_to_slice(&mut self.buf, &mut dst[0..len]);
            Ok(len)
        }
    }

    impl<B: Buf + Sized> io::BufRead for Reader<B> {
        fn fill_buf(&mut self) -> io::Result<&[u8]> {
            Ok(self.buf.chunk())
        }
        fn consume(&mut self, amt: usize) {
            self.buf.advance(amt)
        }
    }