Bump version to v0.4.8 (#206)

* Recycle space when reserving from Vec-backed Bytes

BytesMut::reserve, when called on a BytesMut instance which is backed by
a non-shared Vec<u8>, would previously just delegate to Vec::reserve
regardless of the current location in the buffer. If the Bytes is
actually the trailing component of a larger Vec, then the unused space
won't be recycled. In applications which continually move the pointer
forward to consume data as it comes in, this can cause the underlying
buffer to get extremely large.

This commit checks whether there's extra space at the start of the
backing Vec in this case, and reuses the unused space if possible
instead of allocating.

* Avoid excessive copying when reusing Vec space

Only reuse space in a Vec-backed Bytes when doing so would gain back
more than half of the current capacity. This avoids excessive copy
operations when a large buffer is almost (but not completely) full.

.travis.yml

@@ -19,7 +19,7 @@ matrix:
     #
     # This job will also build and deploy the docs to gh-pages.
     - env: TARGET=x86_64-unknown-linux-gnu
-      rust: 1.10.0
+      rust: 1.15.0
       after_success:
         - |
             pip install 'travis-cargo<0.2' --user &&
@@ -30,8 +30,36 @@ matrix:
     # Run tests on some extra platforms
     - env: TARGET=i686-unknown-linux-gnu
     - env: TARGET=armv7-unknown-linux-gnueabihf
-    - env: TARGET=powerpc-unknown-linux-gnu
-    - env: TARGET=powerpc64-unknown-linux-gnu
+    - env: RUST_TEST_THREADS=1 TARGET=powerpc-unknown-linux-gnu
+    - env: RUST_TEST_THREADS=1 TARGET=powerpc64-unknown-linux-gnu
+
+    # Serde implementation
+    - env: EXTRA_ARGS="--features serde"
+
+    # WASM support
+    - rust: beta
+      script:
+        - rustup target add wasm32-unknown-unknown
+        - cargo build --target=wasm32-unknown-unknown
+
+    # Sanitizers
+    - rust: nightly
+      os: linux
+      script:
+        - |
+          set -e
+
+          export RUST_TEST_THREADS=1
+          export ASAN_OPTIONS="detect_odr_violation=0 detect_leaks=0"
+          export TSAN_OPTIONS="suppressions=`pwd`/ci/tsan"
+
+          # Run address sanitizer
+          RUSTFLAGS="-Z sanitizer=address" \
+          cargo test --tests --target x86_64-unknown-linux-gnu
+
+          # Run thread sanitizer
+          RUSTFLAGS="-Z sanitizer=thread" \
+          cargo test --tests --target x86_64-unknown-linux-gnu
 
 before_install: set -e
 

CHANGELOG.md

@@ -0,0 +1,64 @@
+# 0.4.8 (May 25, 2018)
+
+* Fix panic in `BytesMut` `FromIterator` implementation.
+* Bytes: Recycle space when reserving space in vec mode (#197).
+* Bytes: Add resize fn (#203).
+
+# 0.4.7 (April 27, 2018)
+
+* Make `Buf` and `BufMut` usable as trait objects (#186).
+* impl BorrowMut for BytesMut (#185).
+* Improve accessor performance (#195).
+
+# 0.4.6 (Janary 8, 2018)
+
+* Implement FromIterator for Bytes/BytesMut (#148).
+* Add `advance` fn to Bytes/BytesMut (#166).
+* Add `unsplit` fn to `BytesMut` (#162, #173).
+* Improvements to Bytes split fns (#92).
+
+# 0.4.5 (August 12, 2017)
+
+* Fix range bug in `Take::bytes`
+* Misc performance improvements
+* Add extra `PartialEq` implementations.
+* Add `Bytes::with_capacity`
+* Implement `AsMut[u8]` for `BytesMut`
+
+# 0.4.4 (May 26, 2017)
+
+* Add serde support behind feature flag
+* Add `extend_from_slice` on `Bytes` and `BytesMut`
+* Add `truncate` and `clear` on `Bytes`
+* Misc additional std trait implementations
+* Misc performance improvements
+
+# 0.4.3 (April 30, 2017)
+
+* Fix Vec::advance_mut bug
+* Bump minimum Rust version to 1.15
+* Misc performance tweaks
+
+# 0.4.2 (April 5, 2017)
+
+* Misc performance tweaks
+* Improved `Debug` implementation for `Bytes`
+* Avoid some incorrect assert panics
+
+# 0.4.1 (March 15, 2017)
+
+* Expose `buf` module and have most types available from there vs. root.
+* Implement `IntoBuf` for `T: Buf`.
+* Add `FromBuf` and `Buf::collect`.
+* Add iterator adapter for `Buf`.
+* Add scatter/gather support to `Buf` and `BufMut`.
+* Add `Buf::chain`.
+* Reduce allocations on repeated calls to `BytesMut::reserve`.
+* Implement `Debug` for more types.
+* Remove `Source` in favor of `IntoBuf`.
+* Implement `Extend` for `BytesMut`.
+
+
+# 0.4.0 (February 24, 2017)
+
+* Initial release

Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 
 name          = "bytes"
-version       = "0.4.0"
-license       = "MIT"
+version       = "0.4.8" # don't forget to update html_root_url
+license       = "MIT/Apache-2.0"
 authors       = ["Carl Lerche <[email protected]>"]
 description   = "Types and traits for working with bytes"
 documentation = "https://carllerche.github.io/bytes/bytes"
@@ -21,6 +21,8 @@ categories = ["network-programming", "data-structures"]
 
 [dependencies]
 byteorder = "1.0.0"
+iovec = "0.1"
+serde = { version = "1.0", optional = true }
 
 [dev-dependencies]
-tokio-core = "0.1.0"
+serde_test = "1.0"

README.md

@@ -24,6 +24,15 @@ extern crate bytes;
 use bytes::{Bytes, BytesMut, Buf, BufMut};
 ```
 
+## Serde support
+
+Serde support is optional and disabled by default. To enable use the feature `serde`.
+
+```toml
+[dependencies]
+bytes = { version = "0.4", features = ["serde"] }
+```
+
 # License
 
 `bytes` is primarily distributed under the terms of both the MIT license and the

benches/bytes.rs

@@ -0,0 +1,217 @@
+#![feature(test)]
+
+extern crate bytes;
+extern crate test;
+
+use test::Bencher;
+use bytes::{Bytes, BytesMut, BufMut};
+
+#[bench]
+fn alloc_small(b: &mut Bencher) {
+    b.iter(|| {
+        for _ in 0..1024 {
+            test::black_box(BytesMut::with_capacity(12));
+        }
+    })
+}
+
+#[bench]
+fn alloc_mid(b: &mut Bencher) {
+    b.iter(|| {
+        test::black_box(BytesMut::with_capacity(128));
+    })
+}
+
+#[bench]
+fn alloc_big(b: &mut Bencher) {
+    b.iter(|| {
+        test::black_box(BytesMut::with_capacity(4096));
+    })
+}
+
+#[bench]
+fn split_off_and_drop(b: &mut Bencher) {
+    b.iter(|| {
+        for _ in 0..1024 {
+            let v = vec![10; 200];
+            let mut b = Bytes::from(v);
+            test::black_box(b.split_off(100));
+            test::black_box(b);
+        }
+    })
+}
+
+#[bench]
+fn deref_unique(b: &mut Bencher) {
+    let mut buf = BytesMut::with_capacity(4096);
+    buf.put(&[0u8; 1024][..]);
+
+    b.iter(|| {
+        for _ in 0..1024 {
+            test::black_box(&buf[..]);
+        }
+    })
+}
+
+#[bench]
+fn deref_unique_unroll(b: &mut Bencher) {
+    let mut buf = BytesMut::with_capacity(4096);
+    buf.put(&[0u8; 1024][..]);
+
+    b.iter(|| {
+        for _ in 0..128 {
+            test::black_box(&buf[..]);
+            test::black_box(&buf[..]);
+            test::black_box(&buf[..]);
+            test::black_box(&buf[..]);
+            test::black_box(&buf[..]);
+            test::black_box(&buf[..]);
+            test::black_box(&buf[..]);
+            test::black_box(&buf[..]);
+        }
+    })
+}
+
+#[bench]
+fn deref_shared(b: &mut Bencher) {
+    let mut buf = BytesMut::with_capacity(4096);
+    buf.put(&[0u8; 1024][..]);
+    let _b2 = buf.split_off(1024);
+
+    b.iter(|| {
+        for _ in 0..1024 {
+            test::black_box(&buf[..]);
+        }
+    })
+}
+
+#[bench]
+fn deref_inline(b: &mut Bencher) {
+    let mut buf = BytesMut::with_capacity(8);
+    buf.put(&[0u8; 8][..]);
+
+    b.iter(|| {
+        for _ in 0..1024 {
+            test::black_box(&buf[..]);
+        }
+    })
+}
+
+#[bench]
+fn deref_two(b: &mut Bencher) {
+    let mut buf1 = BytesMut::with_capacity(8);
+    buf1.put(&[0u8; 8][..]);
+
+    let mut buf2 = BytesMut::with_capacity(4096);
+    buf2.put(&[0u8; 1024][..]);
+
+    b.iter(|| {
+        for _ in 0..512 {
+            test::black_box(&buf1[..]);
+            test::black_box(&buf2[..]);
+        }
+    })
+}
+
+#[bench]
+fn alloc_write_split_to_mid(b: &mut Bencher) {
+    b.iter(|| {
+        let mut buf = BytesMut::with_capacity(128);
+        buf.put_slice(&[0u8; 64]);
+        test::black_box(buf.split_to(64));
+    })
+}
+
+#[bench]
+fn drain_write_drain(b: &mut Bencher) {
+    let data = [0u8; 128];
+
+    b.iter(|| {
+        let mut buf = BytesMut::with_capacity(1024);
+        let mut parts = Vec::with_capacity(8);
+
+        for _ in 0..8 {
+            buf.put(&data[..]);
+            parts.push(buf.split_to(128));
+        }
+
+        test::black_box(parts);
+    })
+}
+
+#[bench]
+fn fmt_write(b: &mut Bencher) {
+    use std::fmt::Write;
+    let mut buf = BytesMut::with_capacity(128);
+    let s = "foo bar baz quux lorem ipsum dolor et";
+
+    b.bytes = s.len() as u64;
+    b.iter(|| {
+        let _ = write!(buf, "{}", s);
+        test::black_box(&buf);
+        unsafe { buf.set_len(0); }
+    })
+}
+
+#[bench]
+fn from_long_slice(b: &mut Bencher) {
+    let data = [0u8; 128];
+    b.bytes = data.len() as u64;
+    b.iter(|| {
+        let buf = BytesMut::from(&data[..]);
+        test::black_box(buf);
+    })
+}
+
+#[bench]
+fn slice_empty(b: &mut Bencher) {
+    b.iter(|| {
+        let b = Bytes::from(vec![17; 1024]).clone();
+        for i in 0..1000 {
+            test::black_box(b.slice(i % 100, i % 100));
+        }
+    })
+}
+
+#[bench]
+fn slice_short_from_arc(b: &mut Bencher) {
+    b.iter(|| {
+        // `clone` is to convert to ARC
+        let b = Bytes::from(vec![17; 1024]).clone();
+        for i in 0..1000 {
+            test::black_box(b.slice(1, 2 + i % 10));
+        }
+    })
+}
+
+// Keep in sync with bytes.rs
+#[cfg(target_pointer_width = "64")]
+const INLINE_CAP: usize = 4 * 8 - 1;
+#[cfg(target_pointer_width = "32")]
+const INLINE_CAP: usize = 4 * 4 - 1;
+
+#[bench]
+fn slice_avg_le_inline_from_arc(b: &mut Bencher) {
+    b.iter(|| {
+        // `clone` is to convert to ARC
+        let b = Bytes::from(vec![17; 1024]).clone();
+        for i in 0..1000 {
+            // [1, INLINE_CAP]
+            let len = 1 + i % (INLINE_CAP - 1);
+            test::black_box(b.slice(i % 10, i % 10 + len));
+        }
+    })
+}
+
+#[bench]
+fn slice_large_le_inline_from_arc(b: &mut Bencher) {
+    b.iter(|| {
+        // `clone` is to convert to ARC
+        let b = Bytes::from(vec![17; 1024]).clone();
+        for i in 0..1000 {
+            // [INLINE_CAP - 10, INLINE_CAP]
+            let len = INLINE_CAP - 9 + i % 10;
+            test::black_box(b.slice(i % 10, i % 10 + len));
+        }
+    })
+}

benches/vs_easy_buf.rs

@@ -1,210 +0,0 @@
-#![feature(test)]
-
-extern crate tokio_core;
-extern crate bytes;
-extern crate test;
-
-mod bench_easy_buf {
-    use test::{self, Bencher};
-    use tokio_core::io::EasyBuf;
-
-    #[bench]
-    fn alloc_small(b: &mut Bencher) {
-        b.iter(|| {
-            for _ in 0..1024 {
-                test::black_box(EasyBuf::with_capacity(12));
-            }
-        })
-    }
-
-    #[bench]
-    fn alloc_mid(b: &mut Bencher) {
-        b.iter(|| {
-            test::black_box(EasyBuf::with_capacity(128));
-        })
-    }
-
-    #[bench]
-    fn alloc_big(b: &mut Bencher) {
-        b.iter(|| {
-            test::black_box(EasyBuf::with_capacity(4096));
-        })
-    }
-
-    #[bench]
-    fn deref_front(b: &mut Bencher) {
-        let mut buf = EasyBuf::with_capacity(4096);
-        buf.get_mut().extend_from_slice(&[0; 1024][..]);
-
-        b.iter(|| {
-            for _ in 0..1024 {
-                test::black_box(buf.as_slice());
-            }
-        })
-    }
-
-    #[bench]
-    fn deref_mid(b: &mut Bencher) {
-        let mut buf = EasyBuf::with_capacity(4096);
-        buf.get_mut().extend_from_slice(&[0; 1024][..]);
-        let _a = buf.drain_to(512);
-
-        b.iter(|| {
-            for _ in 0..1024 {
-                test::black_box(buf.as_slice());
-            }
-        })
-    }
-
-    #[bench]
-    fn alloc_write_drain_to_mid(b: &mut Bencher) {
-        b.iter(|| {
-            let mut buf = EasyBuf::with_capacity(128);
-            buf.get_mut().extend_from_slice(&[0u8; 64]);
-            test::black_box(buf.drain_to(64));
-        })
-    }
-
-    #[bench]
-    fn drain_write_drain(b: &mut Bencher) {
-        let data = [0u8; 128];
-
-        b.iter(|| {
-            let mut buf = EasyBuf::with_capacity(1024);
-            let mut parts = Vec::with_capacity(8);
-
-            for _ in 0..8 {
-                buf.get_mut().extend_from_slice(&data[..]);
-                parts.push(buf.drain_to(128));
-            }
-
-            test::black_box(parts);
-        })
-    }
-}
-
-mod bench_bytes {
-    use test::{self, Bencher};
-    use bytes::{BytesMut, BufMut};
-
-    #[bench]
-    fn alloc_small(b: &mut Bencher) {
-        b.iter(|| {
-            for _ in 0..1024 {
-                test::black_box(BytesMut::with_capacity(12));
-            }
-        })
-    }
-
-    #[bench]
-    fn alloc_mid(b: &mut Bencher) {
-        b.iter(|| {
-            test::black_box(BytesMut::with_capacity(128));
-        })
-    }
-
-    #[bench]
-    fn alloc_big(b: &mut Bencher) {
-        b.iter(|| {
-            test::black_box(BytesMut::with_capacity(4096));
-        })
-    }
-
-    #[bench]
-    fn deref_unique(b: &mut Bencher) {
-        let mut buf = BytesMut::with_capacity(4096);
-        buf.put(&[0u8; 1024][..]);
-
-        b.iter(|| {
-            for _ in 0..1024 {
-                test::black_box(&buf[..]);
-            }
-        })
-    }
-
-    #[bench]
-    fn deref_unique_unroll(b: &mut Bencher) {
-        let mut buf = BytesMut::with_capacity(4096);
-        buf.put(&[0u8; 1024][..]);
-
-        b.iter(|| {
-            for _ in 0..128 {
-                test::black_box(&buf[..]);
-                test::black_box(&buf[..]);
-                test::black_box(&buf[..]);
-                test::black_box(&buf[..]);
-                test::black_box(&buf[..]);
-                test::black_box(&buf[..]);
-                test::black_box(&buf[..]);
-                test::black_box(&buf[..]);
-            }
-        })
-    }
-
-    #[bench]
-    fn deref_shared(b: &mut Bencher) {
-        let mut buf = BytesMut::with_capacity(4096);
-        buf.put(&[0u8; 1024][..]);
-        let _b2 = buf.split_off(1024);
-
-        b.iter(|| {
-            for _ in 0..1024 {
-                test::black_box(&buf[..]);
-            }
-        })
-    }
-
-    #[bench]
-    fn deref_inline(b: &mut Bencher) {
-        let mut buf = BytesMut::with_capacity(8);
-        buf.put(&[0u8; 8][..]);
-
-        b.iter(|| {
-            for _ in 0..1024 {
-                test::black_box(&buf[..]);
-            }
-        })
-    }
-
-    #[bench]
-    fn deref_two(b: &mut Bencher) {
-        let mut buf1 = BytesMut::with_capacity(8);
-        buf1.put(&[0u8; 8][..]);
-
-        let mut buf2 = BytesMut::with_capacity(4096);
-        buf2.put(&[0u8; 1024][..]);
-
-        b.iter(|| {
-            for _ in 0..512 {
-                test::black_box(&buf1[..]);
-                test::black_box(&buf2[..]);
-            }
-        })
-    }
-
-    #[bench]
-    fn alloc_write_drain_to_mid(b: &mut Bencher) {
-        b.iter(|| {
-            let mut buf = BytesMut::with_capacity(128);
-            buf.put_slice(&[0u8; 64]);
-            test::black_box(buf.drain_to(64));
-        })
-    }
-
-    #[bench]
-    fn drain_write_drain(b: &mut Bencher) {
-        let data = [0u8; 128];
-
-        b.iter(|| {
-            let mut buf = BytesMut::with_capacity(1024);
-            let mut parts = Vec::with_capacity(8);
-
-            for _ in 0..8 {
-                buf.put(&data[..]);
-                parts.push(buf.drain_to(128));
-            }
-
-            test::black_box(parts);
-        })
-    }
-}

ci/script.sh

@@ -3,13 +3,13 @@
 set -ex
 
 main() {
-    cross build --target $TARGET
+    cross build --target $TARGET $EXTRA_ARGS
 
     if [ ! -z $DISABLE_TESTS ]; then
         return
     fi
 
-    cross test --target $TARGET
+    cross test --target $TARGET $EXTRA_ARGS
 }
 
 # we don't run the "test phase" when doing deploys

ci/tsan

@@ -0,0 +1,21 @@
+# TSAN suppressions file for `bytes`
+
+# TSAN does not understand fences and `Arc::drop` is implemented using a fence.
+# This causes many false positives.
+race:Arc*drop
+race:arc*Weak*drop
+
+# `std` mpsc is not used in any Bytes code base. This race is triggered by some
+# rust runtime logic.
+race:std*mpsc_queue
+
+# Not sure why this is warning, but it is in the test harness and not the library.
+race:TestEvent*clone
+race:test::run_tests_console::*closure
+
+# Probably more fences in std.
+race:__call_tls_dtors
+
+# `is_inline` is explicitly called concurrently without synchronization. The
+# safety explanation can be found in a comment.
+race:Inner::is_inline

src/buf/chain.rs

@@ -0,0 +1,226 @@
+use {Buf, BufMut};
+use iovec::IoVec;
+
+/// A `Chain` sequences two buffers.
+///
+/// `Chain` is an adapter that links two underlying buffers and provides a
+/// continous view across both buffers. It is able to sequence either immutable
+/// buffers ([`Buf`] values) or mutable buffers ([`BufMut`] values).
+///
+/// This struct is generally created by calling [`Buf::chain`]. Please see that
+/// function's documentation for more detail.
+///
+/// # Examples
+///
+/// ```
+/// use bytes::{Bytes, Buf, IntoBuf};
+/// use bytes::buf::Chain;
+///
+/// let buf = Bytes::from(&b"hello "[..]).into_buf()
+///             .chain(Bytes::from(&b"world"[..]));
+///
+/// let full: Bytes = buf.collect();
+/// assert_eq!(full[..], b"hello world"[..]);
+/// ```
+///
+/// [`Buf::chain`]: trait.Buf.html#method.chain
+/// [`Buf`]: trait.Buf.html
+/// [`BufMut`]: trait.BufMut.html
+#[derive(Debug)]
+pub struct Chain<T, U> {
+    a: T,
+    b: U,
+}
+
+impl<T, U> Chain<T, U> {
+    /// Creates a new `Chain` sequencing the provided values.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use bytes::BytesMut;
+    /// use bytes::buf::Chain;
+    ///
+    /// let buf = Chain::new(
+    ///     BytesMut::with_capacity(1024),
+    ///     BytesMut::with_capacity(1024));
+    ///
+    /// // Use the chained buffer
+    /// ```
+    pub fn new(a: T, b: U) -> Chain<T, U> {
+        Chain {
+            a: a,
+            b: b,
+        }
+    }
+
+    /// Gets a reference to the first underlying `Buf`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use bytes::{Bytes, Buf, IntoBuf};
+    ///
+    /// let buf = Bytes::from(&b"hello"[..]).into_buf()
+    ///             .chain(Bytes::from(&b"world"[..]));
+    ///
+    /// assert_eq!(buf.first_ref().get_ref()[..], b"hello"[..]);
+    /// ```
+    pub fn first_ref(&self) -> &T {
+        &self.a
+    }
+
+    /// Gets a mutable reference to the first underlying `Buf`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use bytes::{Bytes, Buf, IntoBuf};
+    ///
+    /// let mut buf = Bytes::from(&b"hello "[..]).into_buf()
+    ///                 .chain(Bytes::from(&b"world"[..]));
+    ///
+    /// buf.first_mut().set_position(1);
+    ///
+    /// let full: Bytes = buf.collect();
+    /// assert_eq!(full[..], b"ello world"[..]);
+    /// ```
+    pub fn first_mut(&mut self) -> &mut T {
+        &mut self.a
+    }
+
+    /// Gets a reference to the last underlying `Buf`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use bytes::{Bytes, Buf, IntoBuf};
+    ///
+    /// let buf = Bytes::from(&b"hello"[..]).into_buf()
+    ///             .chain(Bytes::from(&b"world"[..]));
+    ///
+    /// assert_eq!(buf.last_ref().get_ref()[..], b"world"[..]);
+    /// ```
+    pub fn last_ref(&self) -> &U {
+        &self.b
+    }
+
+    /// Gets a mutable reference to the last underlying `Buf`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use bytes::{Bytes, Buf, IntoBuf};
+    ///
+    /// let mut buf = Bytes::from(&b"hello "[..]).into_buf()
+    ///                 .chain(Bytes::from(&b"world"[..]));
+    ///
+    /// buf.last_mut().set_position(1);
+    ///
+    /// let full: Bytes = buf.collect();
+    /// assert_eq!(full[..], b"hello orld"[..]);
+    /// ```
+    pub fn last_mut(&mut self) -> &mut U {
+        &mut self.b
+    }
+
+    /// Consumes this `Chain`, returning the underlying values.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use bytes::{Bytes, Buf, IntoBuf};
+    ///
+    /// let buf = Bytes::from(&b"hello"[..]).into_buf()
+    ///             .chain(Bytes::from(&b"world"[..]));
+    ///
+    /// let (first, last) = buf.into_inner();
+    /// assert_eq!(first.get_ref()[..], b"hello"[..]);
+    /// assert_eq!(last.get_ref()[..], b"world"[..]);
+    /// ```
+    pub fn into_inner(self) -> (T, U) {
+        (self.a, self.b)
+    }
+}
+
+impl<T, U> Buf for Chain<T, U>
+    where T: Buf,
+          U: Buf,
+{
+    fn remaining(&self) -> usize {
+        self.a.remaining() + self.b.remaining()
+    }
+
+    fn bytes(&self) -> &[u8] {
+        if self.a.has_remaining() {
+            self.a.bytes()
+        } else {
+            self.b.bytes()
+        }
+    }
+
+    fn advance(&mut self, mut cnt: usize) {
+        let a_rem = self.a.remaining();
+
+        if a_rem != 0 {
+            if a_rem >= cnt {
+                self.a.advance(cnt);
+                return;
+            }
+
+            // Consume what is left of a
+            self.a.advance(a_rem);
+
+            cnt -= a_rem;
+        }
+
+        self.b.advance(cnt);
+    }
+
+    fn bytes_vec<'a>(&'a self, dst: &mut [&'a IoVec]) -> usize {
+        let mut n = self.a.bytes_vec(dst);
+        n += self.b.bytes_vec(&mut dst[n..]);
+        n
+    }
+}
+
+impl<T, U> BufMut for Chain<T, U>
+    where T: BufMut,
+          U: BufMut,
+{
+    fn remaining_mut(&self) -> usize {
+        self.a.remaining_mut() + self.b.remaining_mut()
+    }
+
+    unsafe fn bytes_mut(&mut self) -> &mut [u8] {
+        if self.a.has_remaining_mut() {
+            self.a.bytes_mut()
+        } else {
+            self.b.bytes_mut()
+        }
+    }
+
+    unsafe fn advance_mut(&mut self, mut cnt: usize) {
+        let a_rem = self.a.remaining_mut();
+
+        if a_rem != 0 {
+            if a_rem >= cnt {
+                self.a.advance_mut(cnt);
+                return;
+            }
+
+            // Consume what is left of a
+            self.a.advance_mut(a_rem);
+
+            cnt -= a_rem;
+        }
+
+        self.b.advance_mut(cnt);
+    }
+
+    unsafe fn bytes_vec_mut<'a>(&'a mut self, dst: &mut [&'a mut IoVec]) -> usize {
+        let mut n = self.a.bytes_vec_mut(dst);
+        n += self.b.bytes_vec_mut(&mut dst[n..]);
+        n
+    }
+}

src/buf/from_buf.rs

@@ -0,0 +1,117 @@
+use {Buf, BufMut, IntoBuf, Bytes, BytesMut};
+
+/// Conversion from a [`Buf`]
+///
+/// Implementing `FromBuf` for a type defines how it is created from a buffer.
+/// This is common for types which represent byte storage of some kind.
+///
+/// [`FromBuf::from_buf`] is rarely called explicitly, and it is instead used
+/// through [`Buf::collect`]. See [`Buf::collect`] documentation for more examples.
+///
+/// See also [`IntoBuf`].
+///
+/// # Examples
+///
+/// Basic  usage:
+///
+/// ```
+/// use bytes::{Bytes, IntoBuf};
+/// use bytes::buf::FromBuf;
+///
+/// let buf = Bytes::from(&b"hello world"[..]).into_buf();
+/// let vec = Vec::from_buf(buf);
+///
+/// assert_eq!(vec, &b"hello world"[..]);
+/// ```
+///
+/// Using [`Buf::collect`] to implicitly use `FromBuf`:
+///
+/// ```
+/// use bytes::{Buf, Bytes, IntoBuf};
+///
+/// let buf = Bytes::from(&b"hello world"[..]).into_buf();
+/// let vec: Vec<u8> = buf.collect();
+///
+/// assert_eq!(vec, &b"hello world"[..]);
+/// ```
+///
+/// Implementing `FromBuf` for your type:
+///
+/// ```
+/// use bytes::{BufMut, Bytes};
+/// use bytes::buf::{IntoBuf, FromBuf};
+///
+/// // A sample buffer, that's just a wrapper over Vec<u8>
+/// struct MyBuffer(Vec<u8>);
+///
+/// impl FromBuf for MyBuffer {
+///     fn from_buf<B>(buf: B) -> Self where B: IntoBuf {
+///         let mut v = Vec::new();
+///         v.put(buf.into_buf());
+///         MyBuffer(v)
+///     }
+/// }
+///
+/// // Now we can make a new buf
+/// let buf = Bytes::from(&b"hello world"[..]);
+///
+/// // And make a MyBuffer out of it
+/// let my_buf = MyBuffer::from_buf(buf);
+///
+/// assert_eq!(my_buf.0, &b"hello world"[..]);
+/// ```
+///
+/// [`Buf`]: trait.Buf.html
+/// [`FromBuf::from_buf`]: #method.from_buf
+/// [`Buf::collect`]: trait.Buf.html#method.collect
+/// [`IntoBuf`]: trait.IntoBuf.html
+pub trait FromBuf {
+    /// Creates a value from a buffer.
+    ///
+    /// See the [type-level documentation](#) for more details.
+    ///
+    /// # Examples
+    ///
+    /// Basic  usage:
+    ///
+    /// ```
+    /// use bytes::{Bytes, IntoBuf};
+    /// use bytes::buf::FromBuf;
+    ///
+    /// let buf = Bytes::from(&b"hello world"[..]).into_buf();
+    /// let vec = Vec::from_buf(buf);
+    ///
+    /// assert_eq!(vec, &b"hello world"[..]);
+    /// ```
+    fn from_buf<T>(buf: T) -> Self where T: IntoBuf;
+}
+
+impl FromBuf for Vec<u8> {
+    fn from_buf<T>(buf: T) -> Self
+        where T: IntoBuf
+    {
+        let buf = buf.into_buf();
+        let mut ret = Vec::with_capacity(buf.remaining());
+        ret.put(buf);
+        ret
+    }
+}
+
+impl FromBuf for Bytes {
+    fn from_buf<T>(buf: T) -> Self
+        where T: IntoBuf
+    {
+        BytesMut::from_buf(buf).freeze()
+    }
+}
+
+impl FromBuf for BytesMut {
+    fn from_buf<T>(buf: T) -> Self
+        where T: IntoBuf
+    {
+        let buf = buf.into_buf();
+        let mut ret = BytesMut::with_capacity(buf.remaining());
+        ret.put(buf);
+        ret
+    }
+}

src/buf/into_buf.rs

@@ -0,0 +1,138 @@
+use super::{Buf};
+
+use std::io;
+
+/// Conversion into a `Buf`
+///
+/// An `IntoBuf` implementation defines how to convert a value into a `Buf`.
+/// This is common for types that represent byte storage of some kind. `IntoBuf`
+/// may be implemented directly for types or on references for those types.
+///
+/// # Examples
+///
+/// ```
+/// use bytes::{Buf, IntoBuf, BigEndian};
+///
+/// let bytes = b"\x00\x01hello world";
+/// let mut buf = bytes.into_buf();
+///
+/// assert_eq!(1, buf.get_u16::<BigEndian>());
+///
+/// let mut rest = [0; 11];
+/// buf.copy_to_slice(&mut rest);
+///
+/// assert_eq!(b"hello world", &rest);
+/// ```
+pub trait IntoBuf {
+    /// The `Buf` type that `self` is being converted into
+    type Buf: Buf;
+
+    /// Creates a `Buf` from a value.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use bytes::{Buf, IntoBuf, BigEndian};
+    ///
+    /// let bytes = b"\x00\x01hello world";
+    /// let mut buf = bytes.into_buf();
+    ///
+    /// assert_eq!(1, buf.get_u16::<BigEndian>());
+    ///
+    /// let mut rest = [0; 11];
+    /// buf.copy_to_slice(&mut rest);
+    ///
+    /// assert_eq!(b"hello world", &rest);
+    /// ```
+    fn into_buf(self) -> Self::Buf;
+}
+
+impl<T: Buf> IntoBuf for T {
+    type Buf = Self;
+
+    fn into_buf(self) -> Self {
+        self
+    }
+}
+
+impl<'a> IntoBuf for &'a [u8] {
+    type Buf = io::Cursor<&'a [u8]>;
+
+    fn into_buf(self) -> Self::Buf {
+        io::Cursor::new(self)
+    }
+}
+
+impl<'a> IntoBuf for &'a str {
+    type Buf = io::Cursor<&'a [u8]>;
+
+    fn into_buf(self) -> Self::Buf {
+        self.as_bytes().into_buf()
+    }
+}
+
+impl IntoBuf for Vec<u8> {
+    type Buf = io::Cursor<Vec<u8>>;
+
+    fn into_buf(self) -> Self::Buf {
+        io::Cursor::new(self)
+    }
+}
+
+impl<'a> IntoBuf for &'a Vec<u8> {
+    type Buf = io::Cursor<&'a [u8]>;
+
+    fn into_buf(self) -> Self::Buf {
+        io::Cursor::new(&self[..])
+    }
+}
+
+// Kind of annoying... but this impl is required to allow passing `&'static
+// [u8]` where for<'a> &'a T: IntoBuf is required.
+impl<'a> IntoBuf for &'a &'static [u8] {
+    type Buf = io::Cursor<&'static [u8]>;
+
+    fn into_buf(self) -> Self::Buf {
+        io::Cursor::new(self)
+    }
+}
+
+impl<'a> IntoBuf for &'a &'static str {
+    type Buf = io::Cursor<&'static [u8]>;
+
+    fn into_buf(self) -> Self::Buf {
+        self.as_bytes().into_buf()
+    }
+}
+
+impl IntoBuf for String {
+    type Buf = io::Cursor<Vec<u8>>;
+
+    fn into_buf(self) -> Self::Buf {
+        self.into_bytes().into_buf()
+    }
+}
+
+impl<'a> IntoBuf for &'a String {
+    type Buf = io::Cursor<&'a [u8]>;
+
+    fn into_buf(self) -> Self::Buf {
+        self.as_bytes().into_buf()
+    }
+}
+
+impl IntoBuf for u8 {
+    type Buf = Option<[u8; 1]>;
+
+    fn into_buf(self) -> Self::Buf {
+        Some([self])
+    }
+}
+
+impl IntoBuf for i8 {
+    type Buf = Option<[u8; 1]>;
+
+    fn into_buf(self) -> Self::Buf {
+        Some([self as u8; 1])
+    }
+}

src/buf/iter.rs

@@ -0,0 +1,116 @@
+use Buf;
+
+/// Iterator over the bytes contained by the buffer.
+///
+/// This struct is created by the [`iter`] method on [`Buf`].
+///
+/// # Examples
+///
+/// Basic usage:
+///
+/// ```
+/// use bytes::{Buf, IntoBuf, Bytes};
+///
+/// let buf = Bytes::from(&b"abc"[..]).into_buf();
+/// let mut iter = buf.iter();
+///
+/// assert_eq!(iter.next(), Some(b'a'));
+/// assert_eq!(iter.next(), Some(b'b'));
+/// assert_eq!(iter.next(), Some(b'c'));
+/// assert_eq!(iter.next(), None);
+/// ```
+///
+/// [`iter`]: trait.Buf.html#method.iter
+/// [`Buf`]: trait.Buf.html
+#[derive(Debug)]
+pub struct Iter<T> {
+    inner: T,
+}
+
+impl<T> Iter<T> {
+    /// Consumes this `Iter`, returning the underlying value.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use bytes::{Buf, IntoBuf, Bytes};
+    ///
+    /// let buf = Bytes::from(&b"abc"[..]).into_buf();
+    /// let mut iter = buf.iter();
+    ///
+    /// assert_eq!(iter.next(), Some(b'a'));
+    ///
+    /// let buf = iter.into_inner();
+    /// assert_eq!(2, buf.remaining());
+    /// ```
+    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, IntoBuf, Bytes};
+    ///
+    /// let buf = Bytes::from(&b"abc"[..]).into_buf();
+    /// let mut iter = buf.iter();
+    ///
+    /// assert_eq!(iter.next(), Some(b'a'));
+    ///
+    /// assert_eq!(2, iter.get_ref().remaining());
+    /// ```
+    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, IntoBuf, BytesMut};
+    ///
+    /// let buf = BytesMut::from(&b"abc"[..]).into_buf();
+    /// let mut iter = buf.iter();
+    ///
+    /// assert_eq!(iter.next(), Some(b'a'));
+    ///
+    /// iter.get_mut().set_position(0);
+    ///
+    /// assert_eq!(iter.next(), Some(b'a'));
+    /// ```
+    pub fn get_mut(&mut self) -> &mut T {
+        &mut self.inner
+    }
+}
+
+pub fn new<T>(inner: T) -> Iter<T> {
+    Iter { inner: inner }
+}
+
+impl<T: Buf> Iterator for Iter<T> {
+    type Item = u8;
+
+    fn next(&mut self) -> Option<u8> {
+        if !self.inner.has_remaining() {
+            return None;
+        }
+
+        let b = self.inner.bytes()[0];
+        self.inner.advance(1);
+        Some(b)
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let rem = self.inner.remaining();
+        (rem, Some(rem))
+    }
+}
+
+impl<T: Buf> ExactSizeIterator for Iter<T> { }

src/buf/mod.rs

@@ -0,0 +1,37 @@
+//! Utilities for working with buffers.
+//!
+//! A buffer is any structure that contains a sequence of bytes. The bytes may
+//! or may not be stored in contiguous memory. This module contains traits used
+//! to abstract over buffers as well as utilities for working with buffer types.
+//!
+//! # `Buf`, `BufMut`
+//!
+//! These are the two foundational traits for abstractly working with buffers.
+//! They can be thought as iterators for byte structures. They offer additional
+//! performance over `Iterator` by providing an API optimized for byte slices.
+//!
+//! See [`Buf`] and [`BufMut`] for more details.
+//!
+//! [rope]: https://en.wikipedia.org/wiki/Rope_(data_structure)
+//! [`Buf`]: trait.Buf.html
+//! [`BufMut`]: trait.BufMut.html
+
+mod buf;
+mod buf_mut;
+mod from_buf;
+mod chain;
+mod into_buf;
+mod iter;
+mod reader;
+mod take;
+mod writer;
+
+pub use self::buf::Buf;
+pub use self::buf_mut::BufMut;
+pub use self::from_buf::FromBuf;
+pub use self::chain::Chain;
+pub use self::into_buf::IntoBuf;
+pub use self::iter::Iter;
+pub use self::reader::Reader;
+pub use self::take::Take;
+pub use self::writer::Writer;

src/buf/reader.rs

@@ -0,0 +1,88 @@
+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)
+    }
+}

src/buf/take.rs

@@ -0,0 +1,155 @@
+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.
+#[derive(Debug)]
+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] {
+        let bytes = self.inner.bytes();
+        &bytes[..cmp::min(bytes.len(), self.limit)]
+    }
+
+    fn advance(&mut self, cnt: usize) {
+        assert!(cnt <= self.limit);
+        self.inner.advance(cnt);
+        self.limit -= cnt;
+    }
+}

src/buf/writer.rs

@@ -0,0 +1,88 @@
+use BufMut;
+
+use std::{cmp, io};
+
+/// A `BufMut` adapter which implements `io::Write` for the inner value.
+///
+/// This struct is generally created by calling `writer()` on `BufMut`. See
+/// documentation of [`writer()`](trait.BufMut.html#method.writer) for more
+/// details.
+#[derive(Debug)]
+pub struct Writer<B> {
+    buf: B,
+}
+
+pub fn new<B>(buf: B) -> Writer<B> {
+    Writer { buf: buf }
+}
+
+impl<B: BufMut> Writer<B> {
+    /// Gets a reference to the underlying `BufMut`.
+    ///
+    /// It is inadvisable to directly write to the underlying `BufMut`.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use bytes::BufMut;
+    ///
+    /// let mut buf = Vec::with_capacity(1024).writer();
+    ///
+    /// assert_eq!(1024, buf.get_ref().capacity());
+    /// ```
+    pub fn get_ref(&self) -> &B {
+        &self.buf
+    }
+
+    /// Gets a mutable reference to the underlying `BufMut`.
+    ///
+    /// It is inadvisable to directly write to the underlying `BufMut`.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use bytes::BufMut;
+    ///
+    /// let mut buf = vec![].writer();
+    ///
+    /// buf.get_mut().reserve(1024);
+    ///
+    /// assert_eq!(1024, buf.get_ref().capacity());
+    /// ```
+    pub fn get_mut(&mut self) -> &mut B {
+        &mut self.buf
+    }
+
+    /// Consumes this `Writer`, returning the underlying value.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// use bytes::BufMut;
+    /// use std::io::{self, Cursor};
+    ///
+    /// let mut buf = vec![].writer();
+    /// let mut src = Cursor::new(b"hello world");
+    ///
+    /// io::copy(&mut src, &mut buf).unwrap();
+    ///
+    /// let buf = buf.into_inner();
+    /// assert_eq!(*buf, b"hello world"[..]);
+    /// ```
+    pub fn into_inner(self) -> B {
+        self.buf
+    }
+}
+
+impl<B: BufMut + Sized> io::Write for Writer<B> {
+    fn write(&mut self, src: &[u8]) -> io::Result<usize> {
+        let n = cmp::min(self.buf.remaining_mut(), src.len());
+
+        self.buf.put(&src[0..n]);
+        Ok(n)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}

src/debug.rs

@@ -0,0 +1,40 @@
+use std::fmt;
+
+/// Alternative implementation of `fmt::Debug` for byte slice.
+///
+/// Standard `Debug` implementation for `[u8]` is comma separated
+/// list of numbers. Since large amount of byte strings are in fact
+/// ASCII strings or contain a lot of ASCII strings (e. g. HTTP),
+/// it is convenient to print strings as ASCII when possible.
+///
+/// This struct wraps `&[u8]` just to override `fmt::Debug`.
+///
+/// `BsDebug` is not a part of public API of bytes crate.
+pub struct BsDebug<'a>(pub &'a [u8]);
+
+impl<'a> fmt::Debug for BsDebug<'a> {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        try!(write!(fmt, "b\""));
+        for &c in self.0 {
+            // https://doc.rust-lang.org/reference.html#byte-escapes
+            if c == b'\n' {
+                try!(write!(fmt, "\\n"));
+            } else if c == b'\r' {
+                try!(write!(fmt, "\\r"));
+            } else if c == b'\t' {
+                try!(write!(fmt, "\\t"));
+            } else if c == b'\\' || c == b'"' {
+                try!(write!(fmt, "\\{}", c as char));
+            } else if c == b'\0' {
+                try!(write!(fmt, "\\0"));
+            // ASCII printable
+            } else if c >= 0x20 && c < 0x7f {
+                try!(write!(fmt, "{}", c as char));
+            } else {
+                try!(write!(fmt, "\\x{:02x}", c));
+            }
+        }
+        try!(write!(fmt, "\""));
+        Ok(())
+    }
+}

src/lib.rs

@@ -29,12 +29,12 @@
 //! buf.put(&b"hello world"[..]);
 //! buf.put_u16::<BigEndian>(1234);
 //!
-//! let a = buf.drain();
+//! let a = buf.take();
 //! assert_eq!(a, b"hello world\x04\xD2"[..]);
 //!
 //! buf.put(&b"goodbye world"[..]);
 //!
-//! let b = buf.drain();
+//! let b = buf.take();
 //! assert_eq!(b, b"goodbye world"[..]);
 //!
 //! assert_eq!(buf.capacity(), 998);
@@ -62,27 +62,40 @@
 //! ## Relation with `Read` and `Write`
 //!
 //! At first glance, it may seem that `Buf` and `BufMut` overlap in
-//! functionality with `std::io::Ready` and `std::io::Write`. However, they
+//! functionality with `std::io::Read` and `std::io::Write`. However, they
 //! serve different purposes. A buffer is the value that is provided as an
 //! argument to `Read::read` and `Write::write`. `Read` and `Write` may then
 //! perform a syscall, which has the potential of failing. Operations on `Buf`
 //! and `BufMut` are infallible.
 
-#![deny(warnings, missing_docs)]
+#![deny(warnings, missing_docs, missing_debug_implementations)]
+#![doc(html_root_url = "https://docs.rs/bytes/0.4.8")]
 
 extern crate byteorder;
+extern crate iovec;
 
-mod buf;
-mod bytes;
-
+pub mod buf;
 pub use buf::{
     Buf,
     BufMut,
     IntoBuf,
-    Source,
+};
+#[deprecated(since = "0.4.1", note = "moved to `buf` module")]
+#[doc(hidden)]
+pub use buf::{
     Reader,
     Writer,
     Take,
 };
+
+mod bytes;
+mod debug;
 pub use bytes::{Bytes, BytesMut};
+
+#[deprecated]
 pub use byteorder::{ByteOrder, BigEndian, LittleEndian};
+
+// Optional Serde support
+#[cfg(feature = "serde")]
+#[doc(hidden)]
+pub mod serde;

src/serde.rs

@@ -0,0 +1,82 @@
+extern crate serde;
+
+use std::{cmp, fmt};
+use self::serde::{Serialize, Serializer, Deserialize, Deserializer, de};
+use super::{Bytes, BytesMut};
+
+macro_rules! serde_impl {
+    ($ty:ident, $visitor_ty:ident) => (
+        impl Serialize for $ty {
+            #[inline]
+            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+                where S: Serializer
+            {
+                serializer.serialize_bytes(&self)
+            }
+        }
+
+        struct $visitor_ty;
+
+        impl<'de> de::Visitor<'de> for $visitor_ty {
+            type Value = $ty;
+
+            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter.write_str("byte array")
+            }
+
+            #[inline]
+            fn visit_seq<V>(self, mut seq: V) -> Result<Self::Value, V::Error>
+                where V: de::SeqAccess<'de>
+            {
+                let len = cmp::min(seq.size_hint().unwrap_or(0), 4096);
+                let mut values = Vec::with_capacity(len);
+
+                while let Some(value) = try!(seq.next_element()) {
+                    values.push(value);
+                }
+
+                Ok(values.into())
+            }
+
+            #[inline]
+            fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
+                where E: de::Error
+            {
+                Ok($ty::from(v))
+            }
+
+            #[inline]
+            fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
+                where E: de::Error
+            {
+                Ok($ty::from(v))
+            }
+
+            #[inline]
+            fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+                where E: de::Error
+            {
+                Ok($ty::from(v))
+            }
+
+            #[inline]
+            fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
+                where E: de::Error
+            {
+                Ok($ty::from(v))
+            }
+        }
+
+        impl<'de> Deserialize<'de> for $ty {
+            #[inline]
+            fn deserialize<D>(deserializer: D) -> Result<$ty, D::Error>
+                where D: Deserializer<'de>
+            {
+                deserializer.deserialize_byte_buf($visitor_ty)
+            }
+        }
+    );
+}
+
+serde_impl!(Bytes, BytesVisitor);
+serde_impl!(BytesMut, BytesMutVisitor);

tests/test_buf.rs

@@ -1,7 +1,9 @@
 extern crate bytes;
 extern crate byteorder;
+extern crate iovec;
 
 use bytes::Buf;
+use iovec::IoVec;
 use std::io::Cursor;
 
 #[test]
@@ -20,11 +22,6 @@ fn test_fresh_cursor_vec() {
 
     assert_eq!(buf.remaining(), 0);
     assert_eq!(buf.bytes(), b"");
-
-    buf.advance(1);
-
-    assert_eq!(buf.remaining(), 0);
-    assert_eq!(buf.bytes(), b"");
 }
 
 #[test]
@@ -36,13 +33,26 @@ fn test_get_u8() {
 #[test]
 fn test_get_u16() {
     let buf = b"\x21\x54zomg";
-    assert_eq!(0x2154, Cursor::new(buf).get_u16::<byteorder::BigEndian>());
-    assert_eq!(0x5421, Cursor::new(buf).get_u16::<byteorder::LittleEndian>());
+    assert_eq!(0x2154, Cursor::new(buf).get_u16_be());
+    assert_eq!(0x5421, Cursor::new(buf).get_u16_le());
 }
 
 #[test]
 #[should_panic]
 fn test_get_u16_buffer_underflow() {
     let mut buf = Cursor::new(b"\x21");
-    buf.get_u16::<byteorder::BigEndian>();
+    buf.get_u16_be();
+}
+
+#[test]
+fn test_bufs_vec() {
+    let buf = Cursor::new(b"hello world");
+
+    let b1: &[u8] = &mut [0];
+    let b2: &[u8] = &mut [0];
+
+    let mut dst: [&IoVec; 2] =
+        [b1.into(), b2.into()];
+
+    assert_eq!(1, buf.bytes_vec(&mut dst[..]));
 }

tests/test_buf_mut.rs

@@ -1,7 +1,9 @@
 extern crate bytes;
 extern crate byteorder;
+extern crate iovec;
 
 use bytes::{BufMut, BytesMut};
+use iovec::IoVec;
 use std::usize;
 use std::fmt::Write;
 
@@ -39,14 +41,25 @@ fn test_put_u8() {
 #[test]
 fn test_put_u16() {
     let mut buf = Vec::with_capacity(8);
-    buf.put_u16::<byteorder::BigEndian>(8532);
+    buf.put_u16_be(8532);
     assert_eq!(b"\x21\x54", &buf[..]);
 
     buf.clear();
-    buf.put_u16::<byteorder::LittleEndian>(8532);
+    buf.put_u16_le(8532);
     assert_eq!(b"\x54\x21", &buf[..]);
 }
 
+#[test]
+fn test_vec_advance_mut() {
+    // Regression test for carllerche/bytes#108.
+    let mut buf = Vec::with_capacity(8);
+    unsafe {
+        buf.advance_mut(12);
+        assert_eq!(buf.len(), 12);
+        assert!(buf.capacity() >= 12, "capacity: {}", buf.capacity());
+    }
+}
+
 #[test]
 fn test_clone() {
     let mut buf = BytesMut::with_capacity(100);
@@ -56,3 +69,15 @@ fn test_clone() {
     buf.write_str(" of our emergecy broadcast system").unwrap();
     assert!(buf != buf2);
 }
+
+#[test]
+fn test_bufs_vec_mut() {
+    use std::mem;
+
+    let mut buf = BytesMut::from(&b"hello world"[..]);
+
+    unsafe {
+        let mut dst: [&mut IoVec; 2] = mem::zeroed();
+        assert_eq!(1, buf.bytes_vec_mut(&mut dst[..]));
+    }
+}

tests/test_bytes.rs

@@ -43,7 +43,7 @@ fn from_slice() {
 #[test]
 fn fmt() {
     let a = format!("{:?}", Bytes::from(&b"abcdefg"[..]));
-    let b = format!("{:?}", b"abcdefg");
+    let b = "b\"abcdefg\"";
 
     assert_eq!(a, b);
 
@@ -51,6 +51,28 @@ fn fmt() {
     assert_eq!(a, b);
 }
 
+#[test]
+fn fmt_write() {
+    use std::fmt::Write;
+    use std::iter::FromIterator;
+    let s = String::from_iter((0..10).map(|_| "abcdefg"));
+
+    let mut a = BytesMut::with_capacity(64);
+    write!(a, "{}", &s[..64]).unwrap();
+    assert_eq!(a, s[..64].as_bytes());
+
+
+    let mut b = BytesMut::with_capacity(64);
+    write!(b, "{}", &s[..32]).unwrap();
+    write!(b, "{}", &s[32..64]).unwrap();
+    assert_eq!(b, s[..64].as_bytes());
+
+
+    let mut c = BytesMut::with_capacity(64);
+    write!(c, "{}", s).unwrap_err();
+    assert!(c.is_empty());
+}
+
 #[test]
 fn len() {
     let a = Bytes::from(&b"abcdefg"[..]);
@@ -79,6 +101,15 @@ fn slice() {
     let b = a.slice(3, 5);
     assert_eq!(b, b"lo"[..]);
 
+    let b = a.slice(0, 0);
+    assert_eq!(b, b""[..]);
+
+    let b = a.slice(3, 3);
+    assert_eq!(b, b""[..]);
+
+    let b = a.slice(a.len(), a.len());
+    assert_eq!(b, b""[..]);
+
     let b = a.slice_to(5);
     assert_eq!(b, b"hello"[..]);
 
@@ -135,34 +166,78 @@ fn split_off_uninitialized() {
 }
 
 #[test]
-fn drain_to_1() {
+fn split_off_to_loop() {
+    let s = b"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
+    for i in 0..(s.len() + 1) {
+        {
+            let mut bytes = Bytes::from(&s[..]);
+            let off = bytes.split_off(i);
+            assert_eq!(i, bytes.len());
+            let mut sum = Vec::new();
+            sum.extend(&bytes);
+            sum.extend(&off);
+            assert_eq!(&s[..], &sum[..]);
+        }
+        {
+            let mut bytes = BytesMut::from(&s[..]);
+            let off = bytes.split_off(i);
+            assert_eq!(i, bytes.len());
+            let mut sum = Vec::new();
+            sum.extend(&bytes);
+            sum.extend(&off);
+            assert_eq!(&s[..], &sum[..]);
+        }
+        {
+            let mut bytes = Bytes::from(&s[..]);
+            let off = bytes.split_to(i);
+            assert_eq!(i, off.len());
+            let mut sum = Vec::new();
+            sum.extend(&off);
+            sum.extend(&bytes);
+            assert_eq!(&s[..], &sum[..]);
+        }
+        {
+            let mut bytes = BytesMut::from(&s[..]);
+            let off = bytes.split_to(i);
+            assert_eq!(i, off.len());
+            let mut sum = Vec::new();
+            sum.extend(&off);
+            sum.extend(&bytes);
+            assert_eq!(&s[..], &sum[..]);
+        }
+    }
+}
+
+#[test]
+fn split_to_1() {
     // Inline
     let mut a = Bytes::from(SHORT);
-    let b = a.drain_to(4);
+    let b = a.split_to(4);
 
     assert_eq!(SHORT[4..], a);
     assert_eq!(SHORT[..4], b);
 
     // Allocated
     let mut a = Bytes::from(LONG);
-    let b = a.drain_to(4);
+    let b = a.split_to(4);
 
     assert_eq!(LONG[4..], a);
     assert_eq!(LONG[..4], b);
 
     let mut a = Bytes::from(LONG);
-    let b = a.drain_to(30);
+    let b = a.split_to(30);
 
     assert_eq!(LONG[30..], a);
     assert_eq!(LONG[..30], b);
 }
 
 #[test]
-fn drain_to_2() {
+fn split_to_2() {
     let mut a = Bytes::from(LONG);
     assert_eq!(LONG, a);
 
-    let b = a.drain_to(1);
+    let b = a.split_to(1);
 
     assert_eq!(LONG[1..], a);
     drop(b);
@@ -170,22 +245,22 @@ fn drain_to_2() {
 
 #[test]
 #[should_panic]
-fn drain_to_oob() {
+fn split_to_oob() {
     let mut hello = Bytes::from(&b"helloworld"[..]);
-    hello.drain_to(inline_cap() + 1);
+    hello.split_to(inline_cap() + 1);
 }
 
 #[test]
 #[should_panic]
-fn drain_to_oob_mut() {
+fn split_to_oob_mut() {
     let mut hello = BytesMut::from(&b"helloworld"[..]);
-    hello.drain_to(inline_cap() + 1);
+    hello.split_to(inline_cap() + 1);
 }
 
 #[test]
-fn drain_to_uninitialized() {
+fn split_to_uninitialized() {
     let mut bytes = BytesMut::with_capacity(1024);
-    let other = bytes.drain_to(128);
+    let other = bytes.split_to(128);
 
     assert_eq!(bytes.len(), 0);
     assert_eq!(bytes.capacity(), 896);
@@ -194,6 +269,28 @@ fn drain_to_uninitialized() {
     assert_eq!(other.capacity(), 128);
 }
 
+#[test]
+fn split_off_to_at_gt_len() {
+    fn make_bytes() -> Bytes {
+        let mut bytes = BytesMut::with_capacity(100);
+        bytes.put_slice(&[10, 20, 30, 40]);
+        bytes.freeze()
+    }
+
+    use std::panic;
+
+    make_bytes().split_to(4);
+    make_bytes().split_off(4);
+
+    assert!(panic::catch_unwind(move || {
+        make_bytes().split_to(5);
+    }).is_err());
+
+    assert!(panic::catch_unwind(move || {
+        make_bytes().split_off(5);
+    }).is_err());
+}
+
 #[test]
 fn fns_defined_for_bytes_mut() {
     let mut bytes = BytesMut::from(&b"hello world"[..]);
@@ -219,7 +316,7 @@ fn reserve_convert() {
     let mut bytes = BytesMut::with_capacity(inline_cap());
     bytes.put("abcdefghijkl");
 
-    let a = bytes.drain_to(10);
+    let a = bytes.split_to(10);
     bytes.reserve(inline_cap() - 3);
     assert_eq!(inline_cap(), bytes.capacity());
 
@@ -233,10 +330,10 @@ fn reserve_convert() {
 
     // Arc -> Vec
     let mut bytes = BytesMut::from(LONG);
-    let a = bytes.drain_to(30);
+    let a = bytes.split_to(30);
 
     bytes.reserve(128);
-    assert_eq!(bytes.capacity(), (bytes.len() + 128).next_power_of_two());
+    assert!(bytes.capacity() >= bytes.len() + 128);
 
     drop(a);
 }
@@ -245,12 +342,93 @@ fn reserve_convert() {
 fn reserve_growth() {
     let mut bytes = BytesMut::with_capacity(64);
     bytes.put("hello world");
-    let _ = bytes.drain();
+    let _ = bytes.take();
 
     bytes.reserve(65);
     assert_eq!(bytes.capacity(), 128);
 }
 
+#[test]
+fn reserve_allocates_at_least_original_capacity() {
+    let mut bytes = BytesMut::with_capacity(1024);
+
+    for i in 0..1020 {
+        bytes.put(i as u8);
+    }
+
+    let _other = bytes.take();
+
+    bytes.reserve(16);
+    assert_eq!(bytes.capacity(), 1024);
+}
+
+#[test]
+fn reserve_max_original_capacity_value() {
+    const SIZE: usize = 128 * 1024;
+
+    let mut bytes = BytesMut::with_capacity(SIZE);
+
+    for _ in 0..SIZE {
+        bytes.put(0u8);
+    }
+
+    let _other = bytes.take();
+
+    bytes.reserve(16);
+    assert_eq!(bytes.capacity(), 64 * 1024);
+}
+
+// Without either looking at the internals of the BytesMut or doing weird stuff
+// with the memory allocator, there's no good way to automatically verify from
+// within the program that this actually recycles memory. Instead, just exercise
+// the code path to ensure that the results are correct.
+#[test]
+fn reserve_vec_recycling() {
+    let mut bytes = BytesMut::from(Vec::with_capacity(16));
+    assert_eq!(bytes.capacity(), 16);
+    bytes.put("0123456789012345");
+    bytes.advance(10);
+    assert_eq!(bytes.capacity(), 6);
+    bytes.reserve(8);
+    assert_eq!(bytes.capacity(), 16);
+}
+
+#[test]
+fn reserve_in_arc_unique_does_not_overallocate() {
+    let mut bytes = BytesMut::with_capacity(1000);
+    bytes.take();
+
+    // now bytes is Arc and refcount == 1
+
+    assert_eq!(1000, bytes.capacity());
+    bytes.reserve(2001);
+    assert_eq!(2001, bytes.capacity());
+}
+
+#[test]
+fn reserve_in_arc_unique_doubles() {
+    let mut bytes = BytesMut::with_capacity(1000);
+    bytes.take();
+
+    // now bytes is Arc and refcount == 1
+
+    assert_eq!(1000, bytes.capacity());
+    bytes.reserve(1001);
+    assert_eq!(2000, bytes.capacity());
+}
+
+#[test]
+fn reserve_in_arc_nonunique_does_not_overallocate() {
+    let mut bytes = BytesMut::with_capacity(1000);
+    let _copy = bytes.take();
+
+    // now bytes is Arc and refcount == 2
+
+    assert_eq!(1000, bytes.capacity());
+    bytes.reserve(2001);
+    assert_eq!(2001, bytes.capacity());
+}
+
 #[test]
 fn inline_storage() {
     let mut bytes = BytesMut::with_capacity(inline_cap());
@@ -261,6 +439,90 @@ fn inline_storage() {
 }
 
 #[test]
+fn extend_mut() {
+    let mut bytes = BytesMut::with_capacity(0);
+    bytes.extend(LONG);
+    assert_eq!(*bytes, LONG[..]);
+}
+
+#[test]
+fn extend_shr() {
+    let mut bytes = Bytes::new();
+    bytes.extend(LONG);
+    assert_eq!(*bytes, LONG[..]);
+}
+
+#[test]
+fn extend_from_slice_mut() {
+    for &i in &[3, 34] {
+        let mut bytes = BytesMut::new();
+        bytes.extend_from_slice(&LONG[..i]);
+        bytes.extend_from_slice(&LONG[i..]);
+        assert_eq!(LONG[..], *bytes);
+    }
+}
+
+#[test]
+fn extend_from_slice_shr() {
+    for &i in &[3, 34] {
+        let mut bytes = Bytes::new();
+        bytes.extend_from_slice(&LONG[..i]);
+        bytes.extend_from_slice(&LONG[i..]);
+        assert_eq!(LONG[..], *bytes);
+    }
+}
+
+#[test]
+fn from_static() {
+    let mut a = Bytes::from_static(b"ab");
+    let b = a.split_off(1);
+
+    assert_eq!(a, b"a"[..]);
+    assert_eq!(b, b"b"[..]);
+}
+
+#[test]
+fn advance_inline() {
+    let mut a = Bytes::from(&b"hello world"[..]);
+    a.advance(6);
+    assert_eq!(a, &b"world"[..]);
+}
+
+#[test]
+fn advance_static() {
+    let mut a = Bytes::from_static(b"hello world");
+    a.advance(6);
+    assert_eq!(a, &b"world"[..]);
+}
+
+#[test]
+fn advance_vec() {
+    let mut a = BytesMut::from(b"hello world boooo yah world zomg wat wat".to_vec());
+    a.advance(16);
+    assert_eq!(a, b"o yah world zomg wat wat"[..]);
+
+    a.advance(4);
+    assert_eq!(a, b"h world zomg wat wat"[..]);
+
+    // Reserve some space.
+    a.reserve(1024);
+    assert_eq!(a, b"h world zomg wat wat"[..]);
+
+    a.advance(6);
+    assert_eq!(a, b"d zomg wat wat"[..]);
+}
+
+#[test]
+#[should_panic]
+fn advance_past_len() {
+    let mut a = BytesMut::from(b"hello world".to_vec());
+    a.advance(20);
+}
+
+#[test]
+// Only run these tests on little endian systems. CI uses qemu for testing
+// little endian... and qemu doesn't really support threading all that well.
+#[cfg(target_endian = "little")]
 fn stress() {
     // Tests promoting a buffer from a vec -> shared in a concurrent situation
     use std::sync::{Arc, Barrier};
@@ -271,7 +533,7 @@ fn stress() {
 
     for i in 0..ITERS {
         let data = [i as u8; 256];
-        let buf = Arc::new(BytesMut::from(&data[..]));
+        let buf = Arc::new(Bytes::from(&data[..]));
 
         let barrier = Arc::new(Barrier::new(THREADS));
         let mut joins = Vec::with_capacity(THREADS);
@@ -282,7 +544,8 @@ fn stress() {
 
             joins.push(thread::spawn(move || {
                 c.wait();
-                let _buf = buf.clone();
+                let buf: Bytes = (*buf).clone();
+                drop(buf);
             }));
         }
 
@@ -293,3 +556,157 @@ fn stress() {
         assert_eq!(*buf, data[..]);
     }
 }
+
+#[test]
+fn partial_eq_bytesmut() {
+    let bytes = Bytes::from(&b"The quick red fox"[..]);
+    let bytesmut = BytesMut::from(&b"The quick red fox"[..]);
+    assert!(bytes == bytesmut);
+    assert!(bytesmut == bytes);
+    let bytes2 = Bytes::from(&b"Jumped over the lazy brown dog"[..]);
+    assert!(bytes2 != bytesmut);
+    assert!(bytesmut != bytes2);
+}
+
+#[test]
+fn unsplit_basic() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aaabbbcccddd");
+
+    let splitted = buf.split_off(6);
+    assert_eq!(b"aaabbb", &buf[..]);
+    assert_eq!(b"cccddd", &splitted[..]);
+
+    buf.unsplit(splitted);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn unsplit_empty_other() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aaabbbcccddd");
+
+    // empty other
+    let other = BytesMut::new();
+
+    buf.unsplit(other);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn unsplit_empty_self() {
+    // empty self
+    let mut buf = BytesMut::new();
+
+    let mut other = BytesMut::with_capacity(64);
+    other.extend_from_slice(b"aaabbbcccddd");
+
+    buf.unsplit(other);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn unsplit_inline_arc() {
+    let mut buf = BytesMut::with_capacity(8); //inline
+    buf.extend_from_slice(b"aaaabbbb");
+
+    let mut buf2 = BytesMut::with_capacity(64);
+    buf2.extend_from_slice(b"ccccddddeeee");
+
+    buf2.split_off(8); //arc
+
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn unsplit_arc_inline() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbeeee");
+
+    buf.split_off(8); //arc
+
+    let mut buf2 = BytesMut::with_capacity(8); //inline
+    buf2.extend_from_slice(b"ccccdddd");
+
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+
+}
+
+#[test]
+fn unsplit_both_inline() {
+    let mut buf = BytesMut::with_capacity(16); //inline
+    buf.extend_from_slice(b"aaaabbbbccccdddd");
+
+    let splitted = buf.split_off(8); // both inline
+    assert_eq!(b"aaaabbbb", &buf[..]);
+    assert_eq!(b"ccccdddd", &splitted[..]);
+
+    buf.unsplit(splitted);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+
+#[test]
+fn unsplit_arc_different() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbeeee");
+
+    buf.split_off(8); //arc
+
+    let mut buf2 = BytesMut::with_capacity(64);
+    buf2.extend_from_slice(b"ccccddddeeee");
+
+    buf2.split_off(8); //arc
+
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn unsplit_arc_non_contiguous() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbeeeeccccdddd");
+
+    let mut buf2 = buf.split_off(8); //arc
+
+    let buf3 = buf2.split_off(4); //arc
+
+    buf.unsplit(buf3);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn unsplit_two_split_offs() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbccccdddd");
+
+    let mut buf2 = buf.split_off(8); //arc
+    let buf3 = buf2.split_off(4); //arc
+
+    buf2.unsplit(buf3);
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn from_iter_no_size_hint() {
+    use std::iter;
+
+    let mut expect = vec![];
+
+    let actual: Bytes = iter::repeat(b'x')
+        .scan(100, |cnt, item| {
+            if *cnt >= 1 {
+                *cnt -= 1;
+                expect.push(item);
+                Some(item)
+            } else {
+                None
+            }
+        })
+        .collect();
+
+    assert_eq!(&actual[..], &expect[..]);
+}

tests/test_chain.rs

@@ -0,0 +1,122 @@
+extern crate bytes;
+extern crate iovec;
+
+use bytes::{Buf, BufMut, Bytes, BytesMut};
+use bytes::buf::Chain;
+use iovec::IoVec;
+use std::io::Cursor;
+
+#[test]
+fn collect_two_bufs() {
+    let a = Cursor::new(Bytes::from(&b"hello"[..]));
+    let b = Cursor::new(Bytes::from(&b"world"[..]));
+
+    let res: Vec<u8> = a.chain(b).collect();
+    assert_eq!(res, &b"helloworld"[..]);
+}
+
+#[test]
+fn writing_chained() {
+    let mut a = BytesMut::with_capacity(64);
+    let mut b = BytesMut::with_capacity(64);
+
+    {
+        let mut buf = Chain::new(&mut a, &mut b);
+
+        for i in 0..128 {
+            buf.put(i as u8);
+        }
+    }
+
+    assert_eq!(64, a.len());
+    assert_eq!(64, b.len());
+
+    for i in 0..64 {
+        let expect = i as u8;
+        assert_eq!(expect, a[i]);
+        assert_eq!(expect + 64, b[i]);
+    }
+}
+
+#[test]
+fn iterating_two_bufs() {
+    let a = Cursor::new(Bytes::from(&b"hello"[..]));
+    let b = Cursor::new(Bytes::from(&b"world"[..]));
+
+    let res: Vec<u8> = a.chain(b).iter().collect();
+    assert_eq!(res, &b"helloworld"[..]);
+}
+
+#[test]
+fn vectored_read() {
+    let a = Cursor::new(Bytes::from(&b"hello"[..]));
+    let b = Cursor::new(Bytes::from(&b"world"[..]));
+
+    let mut buf = a.chain(b);
+
+    {
+        let b1: &[u8] = &mut [0];
+        let b2: &[u8] = &mut [0];
+        let b3: &[u8] = &mut [0];
+        let b4: &[u8] = &mut [0];
+        let mut iovecs: [&IoVec; 4] =
+            [b1.into(), b2.into(), b3.into(), b4.into()];
+
+        assert_eq!(2, buf.bytes_vec(&mut iovecs));
+        assert_eq!(iovecs[0][..], b"hello"[..]);
+        assert_eq!(iovecs[1][..], b"world"[..]);
+        assert_eq!(iovecs[2][..], b"\0"[..]);
+        assert_eq!(iovecs[3][..], b"\0"[..]);
+    }
+
+    buf.advance(2);
+
+    {
+        let b1: &[u8] = &mut [0];
+        let b2: &[u8] = &mut [0];
+        let b3: &[u8] = &mut [0];
+        let b4: &[u8] = &mut [0];
+        let mut iovecs: [&IoVec; 4] =
+            [b1.into(), b2.into(), b3.into(), b4.into()];
+
+        assert_eq!(2, buf.bytes_vec(&mut iovecs));
+        assert_eq!(iovecs[0][..], b"llo"[..]);
+        assert_eq!(iovecs[1][..], b"world"[..]);
+        assert_eq!(iovecs[2][..], b"\0"[..]);
+        assert_eq!(iovecs[3][..], b"\0"[..]);
+    }
+
+    buf.advance(3);
+
+    {
+        let b1: &[u8] = &mut [0];
+        let b2: &[u8] = &mut [0];
+        let b3: &[u8] = &mut [0];
+        let b4: &[u8] = &mut [0];
+        let mut iovecs: [&IoVec; 4] =
+            [b1.into(), b2.into(), b3.into(), b4.into()];
+
+        assert_eq!(1, buf.bytes_vec(&mut iovecs));
+        assert_eq!(iovecs[0][..], b"world"[..]);
+        assert_eq!(iovecs[1][..], b"\0"[..]);
+        assert_eq!(iovecs[2][..], b"\0"[..]);
+        assert_eq!(iovecs[3][..], b"\0"[..]);
+    }
+
+    buf.advance(3);
+
+    {
+        let b1: &[u8] = &mut [0];
+        let b2: &[u8] = &mut [0];
+        let b3: &[u8] = &mut [0];
+        let b4: &[u8] = &mut [0];
+        let mut iovecs: [&IoVec; 4] =
+            [b1.into(), b2.into(), b3.into(), b4.into()];
+
+        assert_eq!(1, buf.bytes_vec(&mut iovecs));
+        assert_eq!(iovecs[0][..], b"ld"[..]);
+        assert_eq!(iovecs[1][..], b"\0"[..]);
+        assert_eq!(iovecs[2][..], b"\0"[..]);
+        assert_eq!(iovecs[3][..], b"\0"[..]);
+    }
+}

tests/test_debug.rs

@@ -0,0 +1,35 @@
+extern crate bytes;
+
+use bytes::Bytes;
+
+#[test]
+fn fmt() {
+    let vec: Vec<_> = (0..0x100).map(|b| b as u8).collect();
+
+    let expected = "b\"\
+        \\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\
+        \\x08\\t\\n\\x0b\\x0c\\r\\x0e\\x0f\
+        \\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\
+        \\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f\
+        \x20!\\\"#$%&'()*+,-./0123456789:;<=>?\
+        @ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\\\]^_\
+        `abcdefghijklmnopqrstuvwxyz{|}~\\x7f\
+        \\x80\\x81\\x82\\x83\\x84\\x85\\x86\\x87\
+        \\x88\\x89\\x8a\\x8b\\x8c\\x8d\\x8e\\x8f\
+        \\x90\\x91\\x92\\x93\\x94\\x95\\x96\\x97\
+        \\x98\\x99\\x9a\\x9b\\x9c\\x9d\\x9e\\x9f\
+        \\xa0\\xa1\\xa2\\xa3\\xa4\\xa5\\xa6\\xa7\
+        \\xa8\\xa9\\xaa\\xab\\xac\\xad\\xae\\xaf\
+        \\xb0\\xb1\\xb2\\xb3\\xb4\\xb5\\xb6\\xb7\
+        \\xb8\\xb9\\xba\\xbb\\xbc\\xbd\\xbe\\xbf\
+        \\xc0\\xc1\\xc2\\xc3\\xc4\\xc5\\xc6\\xc7\
+        \\xc8\\xc9\\xca\\xcb\\xcc\\xcd\\xce\\xcf\
+        \\xd0\\xd1\\xd2\\xd3\\xd4\\xd5\\xd6\\xd7\
+        \\xd8\\xd9\\xda\\xdb\\xdc\\xdd\\xde\\xdf\
+        \\xe0\\xe1\\xe2\\xe3\\xe4\\xe5\\xe6\\xe7\
+        \\xe8\\xe9\\xea\\xeb\\xec\\xed\\xee\\xef\
+        \\xf0\\xf1\\xf2\\xf3\\xf4\\xf5\\xf6\\xf7\
+        \\xf8\\xf9\\xfa\\xfb\\xfc\\xfd\\xfe\\xff\"";
+
+    assert_eq!(expected, format!("{:?}", Bytes::from(vec)));
+}

tests/test_from_buf.rs

@@ -0,0 +1,34 @@
+extern crate bytes;
+
+use bytes::{Buf, Bytes, BytesMut};
+use std::io::Cursor;
+
+const LONG: &'static [u8] = b"mary had a little lamb, little lamb, little lamb";
+const SHORT: &'static [u8] = b"hello world";
+
+#[test]
+fn collect_to_vec() {
+    let buf: Vec<u8> = Cursor::new(SHORT).collect();
+    assert_eq!(buf, SHORT);
+
+    let buf: Vec<u8> = Cursor::new(LONG).collect();
+    assert_eq!(buf, LONG);
+}
+
+#[test]
+fn collect_to_bytes() {
+    let buf: Bytes = Cursor::new(SHORT).collect();
+    assert_eq!(buf, SHORT);
+
+    let buf: Bytes = Cursor::new(LONG).collect();
+    assert_eq!(buf, LONG);
+}
+
+#[test]
+fn collect_to_bytes_mut() {
+    let buf: BytesMut = Cursor::new(SHORT).collect();
+    assert_eq!(buf, SHORT);
+
+    let buf: BytesMut = Cursor::new(LONG).collect();
+    assert_eq!(buf, LONG);
+}

tests/test_iter.rs

@@ -0,0 +1,22 @@
+extern crate bytes;
+
+use bytes::{Buf, IntoBuf, Bytes};
+
+#[test]
+fn iter_len() {
+    let buf = Bytes::from(&b"hello world"[..]).into_buf();
+    let iter = buf.iter();
+
+    assert_eq!(iter.size_hint(), (11, Some(11)));
+    assert_eq!(iter.len(), 11);
+}
+
+
+#[test]
+fn empty_iter_len() {
+    let buf = Bytes::from(&b""[..]).into_buf();
+    let iter = buf.iter();
+
+    assert_eq!(iter.size_hint(), (0, Some(0)));
+    assert_eq!(iter.len(), 0);
+}

tests/test_serde.rs

@@ -0,0 +1,21 @@
+#![cfg(feature = "serde")]
+
+extern crate bytes;
+extern crate serde_test;
+use serde_test::{Token, assert_tokens};
+
+#[test]
+fn test_ser_de_empty() {
+    let b = bytes::Bytes::new();
+    assert_tokens(&b, &[Token::Bytes(b"")]);
+    let b = bytes::BytesMut::with_capacity(0);
+    assert_tokens(&b, &[Token::Bytes(b"")]);
+}
+
+#[test]
+fn test_ser_de() {
+    let b = bytes::Bytes::from(&b"bytes"[..]);
+    assert_tokens(&b, &[Token::Bytes(b"bytes")]);
+    let b = bytes::BytesMut::from(&b"bytes"[..]);
+    assert_tokens(&b, &[Token::Bytes(b"bytes")]);
+}

tests/test_take.rs

@@ -0,0 +1,13 @@
+extern crate bytes;
+
+use bytes::Buf;
+use std::io::Cursor;
+
+#[test]
+fn long_take() {
+    // Tests that take with a size greater than the buffer length will not
+    // overrun the buffer. Regression test for #138.
+    let buf = Cursor::new(b"hello world").take(100);
+    assert_eq!(11, buf.remaining());
+    assert_eq!(b"hello world", buf.bytes());
+}