Split buf.rs into separate files

src/buf/take.rs

@@ -0,0 +1,153 @@
+use {Buf};
+
+use std::cmp;
+
+/// A `Buf` adapter which limits the bytes read from an underlying buffer.
+///
+/// This struct is generally created by calling `take()` on `Buf`. See
+/// documentation of [`take()`](trait.Buf.html#method.take) for more details.
+pub struct Take<T> {
+    inner: T,
+    limit: usize,
+}
+
+pub fn new<T>(inner: T, limit: usize) -> Take<T> {
+    Take {
+        inner: inner,
+        limit: limit,
+    }
+}
+
+impl<T> Take<T> {
+    /// Consumes this `Take`, returning the underlying value.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use bytes::{Buf, BufMut};
+    /// use std::io::Cursor;
+    ///
+    /// let mut buf = Cursor::new(b"hello world").take(2);
+    /// let mut dst = vec![];
+    ///
+    /// dst.put(&mut buf);
+    /// assert_eq!(*dst, b"he"[..]);
+    ///
+    /// let mut buf = buf.into_inner();
+    ///
+    /// dst.clear();
+    /// dst.put(&mut buf);
+    /// assert_eq!(*dst, b"llo world"[..]);
+    /// ```
+    pub fn into_inner(self) -> T {
+        self.inner
+    }
+
+    /// Gets a reference to the underlying `Buf`.
+    ///
+    /// It is inadvisable to directly read from the underlying `Buf`.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use bytes::{Buf, BufMut};
+    /// use std::io::Cursor;
+    ///
+    /// let mut buf = Cursor::new(b"hello world").take(2);
+    ///
+    /// assert_eq!(0, buf.get_ref().position());
+    /// ```
+    pub fn get_ref(&self) -> &T {
+        &self.inner
+    }
+
+    /// Gets a mutable reference to the underlying `Buf`.
+    ///
+    /// It is inadvisable to directly read from the underlying `Buf`.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use bytes::{Buf, BufMut};
+    /// use std::io::Cursor;
+    ///
+    /// let mut buf = Cursor::new(b"hello world").take(2);
+    /// let mut dst = vec![];
+    ///
+    /// buf.get_mut().set_position(2);
+    ///
+    /// dst.put(&mut buf);
+    /// assert_eq!(*dst, b"ll"[..]);
+    /// ```
+    pub fn get_mut(&mut self) -> &mut T {
+        &mut self.inner
+    }
+
+    /// Returns the maximum number of bytes that can be read.
+    ///
+    /// # Note
+    ///
+    /// If the inner `Buf` has fewer bytes than indicated by this method then
+    /// that is the actual number of available bytes.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use bytes::Buf;
+    /// use std::io::Cursor;
+    ///
+    /// let mut buf = Cursor::new(b"hello world").take(2);
+    ///
+    /// assert_eq!(2, buf.limit());
+    /// assert_eq!(b'h', buf.get_u8());
+    /// assert_eq!(1, buf.limit());
+    /// ```
+    pub fn limit(&self) -> usize {
+        self.limit
+    }
+
+    /// Sets the maximum number of bytes that can be read.
+    ///
+    /// # Note
+    ///
+    /// If the inner `Buf` has fewer bytes than `lim` then that is the actual
+    /// number of available bytes.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use bytes::{Buf, BufMut};
+    /// use std::io::Cursor;
+    ///
+    /// let mut buf = Cursor::new(b"hello world").take(2);
+    /// let mut dst = vec![];
+    ///
+    /// dst.put(&mut buf);
+    /// assert_eq!(*dst, b"he"[..]);
+    ///
+    /// dst.clear();
+    ///
+    /// buf.set_limit(3);
+    /// dst.put(&mut buf);
+    /// assert_eq!(*dst, b"llo"[..]);
+    /// ```
+    pub fn set_limit(&mut self, lim: usize) {
+        self.limit = lim
+    }
+}
+
+impl<T: Buf> Buf for Take<T> {
+    fn remaining(&self) -> usize {
+        cmp::min(self.inner.remaining(), self.limit)
+    }
+
+    fn bytes(&self) -> &[u8] {
+        &self.inner.bytes()[..self.limit]
+    }
+
+    fn advance(&mut self, cnt: usize) {
+        let cnt = cmp::min(cnt, self.limit);
+        self.limit -= cnt;
+        self.inner.advance(cnt);
+    }
+}