blob: f1154dacebb71790254b5249af949037e2d860ae [file] [log] [blame]
use {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: 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;
/// use std::io::{self, Cursor};
///
/// let mut buf = Cursor::new(b"hello world").reader();
///
/// assert_eq!(0, buf.get_ref().position());
/// ```
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`.
///
/// # Examples
///
/// ```rust
/// use bytes::Buf;
/// use std::io::{self, Cursor};
///
/// let mut buf = Cursor::new(b"hello world").reader();
/// let mut dst = vec![];
///
/// buf.get_mut().set_position(2);
/// io::copy(&mut buf, &mut dst).unwrap();
///
/// assert_eq!(*dst, b"llo world"[..]);
/// ```
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::{self, Cursor};
///
/// let mut buf = Cursor::new(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.bytes())
}
fn consume(&mut self, amt: usize) {
self.buf.advance(amt)
}
}