1 files changed, 81 insertions, 0 deletions
diff --git a/src/buf/reader.rs b/src/buf/reader.rs
new file mode 100644
index 0000000..f2b4d98
--- /dev/null
+++ b/src/buf/reader.rs
@@ -0,0 +1,81 @@
+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)
+    }
+}