diff --git a/src/header/common/content_length.rs b/src/header/common/content_length.rs
index dd2536b1..bc023b50 100644
--- a/src/header/common/content_length.rs
+++ b/src/header/common/content_length.rs
@@ -40,6 +40,7 @@ impl Header for ContentLength {
         static NAME: &'static str = "Content-Length";
         NAME
     }
+
     fn parse_header(raw: &Raw) -> ::Result<ContentLength> {
         // If multiple Content-Length headers were sent, everything can still
         // be alright if they all contain the same value, and all parse
@@ -49,9 +50,9 @@ impl Header for ContentLength {
             .fold(None, |prev, x| {
                 match (prev, x) {
                     (None, x) => Some(x),
-                    (e@Some(Err(_)), _ ) => e,
+                    (e @ Some(Err(_)), _ ) => e,
                     (Some(Ok(prev)), Ok(x)) if prev == x => Some(Ok(prev)),
-                    _ => Some(Err(::Error::Header))
+                    _ => Some(Err(::Error::Header)),
                 }
             })
             .unwrap_or(Err(::Error::Header))
diff --git a/src/header/common/retry_after.rs b/src/header/common/retry_after.rs
index 2722d680..23c4bf6c 100644
--- a/src/header/common/retry_after.rs
+++ b/src/header/common/retry_after.rs
@@ -141,9 +141,7 @@ impl Header for RetryAfter {
 
 #[cfg(test)]
 mod tests {
-    extern crate httparse;
-
-    use header::{Header, Headers};
+    use header::Header;
     use header::shared::HttpDate;
     use time::{Duration};
 
@@ -179,17 +177,15 @@ mod tests {
 
     #[test]
     fn hyper_headers_from_raw_delay() {
-        let headers = Headers::from_raw(&[httparse::Header { name: "Retry-After", value: b"300" }]).unwrap();
-        let retry_after = headers.get::<RetryAfter>().unwrap();
-        assert_eq!(retry_after, &RetryAfter::Delay(Duration::seconds(300)));
+        let retry_after = RetryAfter::parse_header(&b"300".to_vec().into()).unwrap();
+        assert_eq!(retry_after, RetryAfter::Delay(Duration::seconds(300)));
     }
 
     #[test]
     fn hyper_headers_from_raw_datetime() {
-        let headers = Headers::from_raw(&[httparse::Header { name: "Retry-After", value: b"Sun, 06 Nov 1994 08:49:37 GMT" }]).unwrap();
-        let retry_after = headers.get::<RetryAfter>().unwrap();
+        let retry_after = RetryAfter::parse_header(&b"Sun, 06 Nov 1994 08:49:37 GMT".to_vec().into()).unwrap();
         let expected = "Sun, 06 Nov 1994 08:49:37 GMT".parse::<HttpDate>().unwrap();
 
-        assert_eq!(retry_after, &RetryAfter::DateTime(expected.0));
+        assert_eq!(retry_after, RetryAfter::DateTime(expected.0));
     }
 }
diff --git a/src/header/internals/vec_map.rs b/src/header/internals/vec_map.rs
index 70b30d17..ecdaa17b 100644
--- a/src/header/internals/vec_map.rs
+++ b/src/header/internals/vec_map.rs
@@ -4,9 +4,9 @@ pub struct VecMap<K, V> {
 }
 
 impl<K: PartialEq, V> VecMap<K, V> {
-    pub fn new() -> VecMap<K, V> {
+    pub fn with_capacity(cap: usize) -> VecMap<K, V> {
         VecMap {
-            vec: Vec::new()
+            vec: Vec::with_capacity(cap)
         }
     }
 
@@ -43,6 +43,7 @@ impl<K: PartialEq, V> VecMap<K, V> {
     }
 
     pub fn len(&self) -> usize { self.vec.len() }
+
     pub fn iter(&self) -> ::std::slice::Iter<(K, V)> {
         self.vec.iter()
     }
diff --git a/src/header/mod.rs b/src/header/mod.rs
index 1238e87b..d56716f1 100644
--- a/src/header/mod.rs
+++ b/src/header/mod.rs
@@ -80,7 +80,6 @@ use std::borrow::{Cow, ToOwned};
 use std::iter::{FromIterator, IntoIterator};
 use std::{mem, fmt};
 
-use httparse;
 use unicase::UniCase;
 
 use self::internals::{Item, VecMap, Entry};
@@ -88,6 +87,7 @@ use self::internals::{Item, VecMap, Entry};
 pub use self::shared::*;
 pub use self::common::*;
 pub use self::raw::Raw;
+use http::buf::MemSlice;
 
 mod common;
 mod internals;
@@ -346,31 +346,17 @@ literals! {
 impl Headers {
 
     /// Creates a new, empty headers map.
+    #[inline]
     pub fn new() -> Headers {
-        Headers {
-            data: VecMap::new()
-        }
+        Headers::with_capacity(0)
     }
 
-    #[doc(hidden)]
-    pub fn from_raw(raw: &[httparse::Header]) -> ::Result<Headers> {
-        let mut headers = Headers::new();
-        for header in raw {
-            trace!("raw header: {:?}={:?}", header.name, &header.value[..]);
-            let name = HeaderName(UniCase(maybe_literal(header.name)));
-            let trim = header.value.iter().rev().take_while(|&&x| x == b' ').count();
-            let value = &header.value[.. header.value.len() - trim];
-
-            match headers.data.entry(name) {
-                Entry::Vacant(entry) => {
-                    entry.insert(Item::new_raw(self::raw::parsed(value)));
-                }
-                Entry::Occupied(entry) => {
-                    entry.into_mut().mut_raw().push(value);
-                }
-            };
+    /// Creates a new `Headers` struct with space reserved for `len` headers.
+    #[inline]
+    pub fn with_capacity(len: usize) -> Headers {
+        Headers {
+            data: VecMap::with_capacity(len)
         }
-        Ok(headers)
     }
 
     /// Set a header field to the corresponding value.
@@ -586,6 +572,24 @@ impl<'a> Extend<HeaderView<'a>> for Headers {
     }
 }
 
+impl<'a> Extend<(&'a str, MemSlice)> for Headers {
+    fn extend<I: IntoIterator<Item=(&'a str, MemSlice)>>(&mut self, iter: I) {
+        for (name, value) in iter {
+            let name = HeaderName(UniCase(maybe_literal(name)));
+            //let trim = header.value.iter().rev().take_while(|&&x| x == b' ').count();
+
+            match self.data.entry(name) {
+                Entry::Vacant(entry) => {
+                    entry.insert(Item::new_raw(self::raw::parsed(value)));
+                }
+                Entry::Occupied(entry) => {
+                    self::raw::push(entry.into_mut().mut_raw(), value);
+                }
+            };
+        }
+    }
+}
+
 impl<'a> FromIterator<HeaderView<'a>> for Headers {
     fn from_iter<I: IntoIterator<Item=HeaderView<'a>>>(iter: I) -> Headers {
         let mut headers = Headers::new();
@@ -658,37 +662,25 @@ mod tests {
     use mime::SubLevel::Plain;
     use super::{Headers, Header, Raw, ContentLength, ContentType,
                 Accept, Host, qitem};
-    use httparse;
 
     #[cfg(feature = "nightly")]
     use test::Bencher;
 
-    // Slice.position_elem was unstable
-    fn index_of(slice: &[u8], byte: u8) -> Option<usize> {
-        for (index, &b) in slice.iter().enumerate() {
-            if b == byte {
-                return Some(index);
-            }
-        }
-        None
-    }
-
-    macro_rules! raw {
-        ($($line:expr),*) => ({
-            [$({
-                let line = $line;
-                let pos = index_of(line, b':').expect("raw splits on ':', not found");
-                httparse::Header {
-                    name: ::std::str::from_utf8(&line[..pos]).unwrap(),
-                    value: &line[pos + 2..]
-                }
-            }),*]
+    macro_rules! make_header {
+        ($name:expr, $value:expr) => ({
+            let mut headers = Headers::new();
+            headers.set_raw(String::from_utf8($name.to_vec()).unwrap(), $value.to_vec());
+            headers
+        });
+        ($text:expr) => ({
+            let bytes = $text;
+            let colon = bytes.iter().position(|&x| x == b':').unwrap();
+            make_header!(&bytes[..colon], &bytes[colon + 2..])
         })
     }
-
     #[test]
     fn test_from_raw() {
-        let headers = Headers::from_raw(&raw!(b"Content-Length: 10")).unwrap();
+        let headers = make_header!(b"Content-Length", b"10");
         assert_eq!(headers.get(), Some(&ContentLength(10)));
     }
 
@@ -738,20 +730,20 @@ mod tests {
 
     #[test]
     fn test_different_structs_for_same_header() {
-        let headers = Headers::from_raw(&raw!(b"Content-Length: 10")).unwrap();
+        let headers = make_header!(b"Content-Length: 10");
         assert_eq!(headers.get::<ContentLength>(), Some(&ContentLength(10)));
         assert_eq!(headers.get::<CrazyLength>(), Some(&CrazyLength(Some(false), 10)));
     }
 
     #[test]
     fn test_trailing_whitespace() {
-        let headers = Headers::from_raw(&raw!(b"Content-Length: 10   ")).unwrap();
+        let headers = make_header!(b"Content-Length: 10   ");
         assert_eq!(headers.get::<ContentLength>(), Some(&ContentLength(10)));
     }
 
     #[test]
     fn test_multiple_reads() {
-        let headers = Headers::from_raw(&raw!(b"Content-Length: 10")).unwrap();
+        let headers = make_header!(b"Content-Length: 10");
         let ContentLength(one) = *headers.get::<ContentLength>().unwrap();
         let ContentLength(two) = *headers.get::<ContentLength>().unwrap();
         assert_eq!(one, two);
@@ -759,15 +751,16 @@ mod tests {
 
     #[test]
     fn test_different_reads() {
-        let headers = Headers::from_raw(
-            &raw!(b"Content-Length: 10", b"Content-Type: text/plain")).unwrap();
+        let mut headers = Headers::new();
+        headers.set_raw("Content-Length", "10");
+        headers.set_raw("Content-Type", "text/plain");
         let ContentLength(_) = *headers.get::<ContentLength>().unwrap();
         let ContentType(_) = *headers.get::<ContentType>().unwrap();
     }
 
     #[test]
     fn test_get_mutable() {
-        let mut headers = Headers::from_raw(&raw!(b"Content-Length: 10")).unwrap();
+        let mut headers = make_header!(b"Content-Length: 10");
         *headers.get_mut::<ContentLength>().unwrap() = ContentLength(20);
         assert_eq!(headers.get_raw("content-length").unwrap(), &[b"20".to_vec()][..]);
         assert_eq!(*headers.get::<ContentLength>().unwrap(), ContentLength(20));
@@ -786,7 +779,7 @@ mod tests {
 
     #[test]
     fn test_headers_to_string_raw() {
-        let mut headers = Headers::from_raw(&raw!(b"Content-Length: 10")).unwrap();
+        let mut headers = make_header!(b"Content-Length: 10");
         headers.set_raw("x-foo", vec![b"foo".to_vec(), b"bar".to_vec()]);
         let s = headers.to_string();
         assert_eq!(s, "Content-Length: 10\r\nx-foo: foo\r\nx-foo: bar\r\n");
@@ -900,13 +893,6 @@ mod tests {
         })
     }
 
-    #[cfg(feature = "nightly")]
-    #[bench]
-    fn bench_headers_from_raw(b: &mut Bencher) {
-        let raw = raw!(b"Content-Length: 10");
-        b.iter(|| Headers::from_raw(&raw).unwrap())
-    }
-
     #[cfg(feature = "nightly")]
     #[bench]
     fn bench_headers_get(b: &mut Bencher) {
diff --git a/src/header/parsing.rs b/src/header/parsing.rs
index e3c4c070..8caecf78 100644
--- a/src/header/parsing.rs
+++ b/src/header/parsing.rs
@@ -21,7 +21,7 @@ pub fn from_one_raw_str<T: str::FromStr>(raw: &Raw) -> ::Result<T> {
 
 /// Reads a raw string into a value.
 pub fn from_raw_str<T: str::FromStr>(raw: &[u8]) -> ::Result<T> {
-    let s = try!(str::from_utf8(raw));
+    let s = try!(str::from_utf8(raw)).trim();
     T::from_str(s).or(Err(::Error::Header))
 }
 
@@ -36,7 +36,7 @@ pub fn from_comma_delimited<T: str::FromStr>(raw: &Raw) -> ::Result<Vec<T>> {
                           "" => None,
                           y => Some(y)
                       })
-                      .filter_map(|x| x.parse().ok()))
+                      .filter_map(|x| x.trim().parse().ok()))
     }
     Ok(result)
 }
diff --git a/src/header/raw.rs b/src/header/raw.rs
index 39735a2f..5e93d677 100644
--- a/src/header/raw.rs
+++ b/src/header/raw.rs
@@ -1,5 +1,6 @@
 use std::borrow::Cow;
 use std::fmt;
+use http::buf::MemSlice;
 
 /// A raw header value.
 #[derive(Clone, PartialEq, Eq)]
@@ -19,8 +20,8 @@ impl Raw {
     #[inline]
     pub fn one(&self) -> Option<&[u8]> {
         match self.0 {
-            Lines::One(ref line) => Some(line),
-            Lines::Many(ref lines) if lines.len() == 1 => Some(&lines[0]),
+            Lines::One(ref line) => Some(line.as_ref()),
+            Lines::Many(ref lines) if lines.len() == 1 => Some(lines[0].as_ref()),
             _ => None
         }
     }
@@ -29,37 +30,42 @@ impl Raw {
     #[inline]
     pub fn iter(&self) -> RawLines {
         RawLines {
-            inner: match self.0 {
-                Lines::One(ref line) => unsafe {
-                    ::std::slice::from_raw_parts(line, 1)
-                }.iter(),
-                Lines::Many(ref lines) => lines.iter()
-            }
+            inner: &self.0,
+            pos: 0,
         }
     }
 
     /// Append a line to this `Raw` header value.
     pub fn push(&mut self, val: &[u8]) {
+        self.push_line(maybe_literal(val.into()));
+    }
+
+    fn push_line(&mut self, line: Line) {
         let lines = ::std::mem::replace(&mut self.0, Lines::Many(Vec::new()));
         match lines {
-            Lines::One(line) => {
-                self.0 = Lines::Many(vec![line, maybe_literal(val.into())]);
+            Lines::One(one) => {
+                self.0 = Lines::Many(vec![one, line]);
             }
             Lines::Many(mut lines) => {
-                lines.push(maybe_literal(val.into()));
+                lines.push(line);
                 self.0 = Lines::Many(lines);
             }
         }
     }
 }
 
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 enum Lines {
     One(Line),
-    Many(Vec<Line>)
+    Many(Vec<Line>),
 }
 
-type Line = Cow<'static, [u8]>;
+#[derive(Debug, Clone, PartialEq, Eq)]
+enum Line {
+    Static(&'static [u8]),
+    Owned(Vec<u8>),
+    Shared(MemSlice),
+}
 
 fn eq<A: AsRef<[u8]>, B: AsRef<[u8]>>(a: &[A], b: &[B]) -> bool {
     if a.len() != b.len() {
@@ -123,24 +129,59 @@ impl From<String> for Raw {
 impl From<Vec<u8>> for Raw {
     #[inline]
     fn from(val: Vec<u8>) -> Raw {
-        Raw(Lines::One(Cow::Owned(val)))
+        Raw(Lines::One(Line::from(val)))
     }
 }
 
 impl From<&'static str> for Raw {
     fn from(val: &'static str) -> Raw {
-        Raw(Lines::One(Cow::Borrowed(val.as_bytes())))
+        Raw(Lines::One(Line::Static(val.as_bytes())))
     }
 }
 
 impl From<&'static [u8]> for Raw {
     fn from(val: &'static [u8]) -> Raw {
-        Raw(Lines::One(Cow::Borrowed(val)))
+        Raw(Lines::One(Line::Static(val)))
     }
 }
 
-pub fn parsed(val: &[u8]) -> Raw {
-    Raw(Lines::One(maybe_literal(val.into())))
+impl From<MemSlice> for Raw {
+    #[inline]
+    fn from(val: MemSlice) -> Raw {
+        Raw(Lines::One(Line::Shared(val)))
+    }
+}
+
+impl From<Vec<u8>> for Line {
+    #[inline]
+    fn from(val: Vec<u8>) -> Line {
+        Line::Owned(val)
+    }
+}
+
+impl From<MemSlice> for Line {
+    #[inline]
+    fn from(val: MemSlice) -> Line {
+        Line::Shared(val)
+    }
+}
+
+impl AsRef<[u8]> for Line {
+    fn as_ref(&self) -> &[u8] {
+        match *self {
+            Line::Static(ref s) => s,
+            Line::Owned(ref v) => v.as_ref(),
+            Line::Shared(ref m) => m.as_ref(),
+        }
+    }
+}
+
+pub fn parsed(val: MemSlice) -> Raw {
+    Raw(Lines::One(From::from(val)))
+}
+
+pub fn push(raw: &mut Raw, val: MemSlice) {
+    raw.push_line(Line::from(val));
 }
 
 impl fmt::Debug for Raw {
@@ -154,6 +195,7 @@ impl fmt::Debug for Raw {
 
 impl ::std::ops::Index<usize> for Raw {
     type Output = [u8];
+
     fn index(&self, idx: usize) -> &[u8] {
         match self.0 {
             Lines::One(ref line) => if idx == 0 {
@@ -168,12 +210,12 @@ impl ::std::ops::Index<usize> for Raw {
 
 macro_rules! literals {
     ($($len:expr => $($value:expr),+;)+) => (
-        fn maybe_literal<'a>(s: Cow<'a, [u8]>) -> Cow<'static, [u8]> {
+        fn maybe_literal<'a>(s: Cow<'a, [u8]>) -> Line {
             match s.len() {
                 $($len => {
                     $(
                     if s.as_ref() == $value {
-                        return Cow::Borrowed($value);
+                        return Line::Static($value);
                     }
                     )+
                 })+
@@ -181,7 +223,7 @@ macro_rules! literals {
                 _ => ()
             }
 
-            Cow::Owned(s.into_owned())
+            Line::from(s.into_owned())
         }
 
         #[test]
@@ -216,7 +258,8 @@ impl<'a> IntoIterator for &'a Raw {
 
 #[derive(Debug)]
 pub struct RawLines<'a> {
-    inner: ::std::slice::Iter<'a, Cow<'static, [u8]>>
+    inner: &'a Lines,
+    pos: usize,
 }
 
 impl<'a> Iterator for RawLines<'a> {
@@ -224,6 +267,17 @@ impl<'a> Iterator for RawLines<'a> {
 
     #[inline]
     fn next(&mut self) -> Option<&'a [u8]> {
-        self.inner.next().map(AsRef::as_ref)
+        let current_pos = self.pos;
+        self.pos += 1;
+        match *self.inner {
+            Lines::One(ref line) => {
+                if current_pos == 0 {
+                    Some(line.as_ref())
+                } else {
+                    None
+                }
+            }
+            Lines::Many(ref lines) => lines.get(current_pos).map(|l| l.as_ref()),
+        }
     }
 }
diff --git a/src/http/buf.rs b/src/http/buf.rs
index 295f7a5f..f31a4680 100644
--- a/src/http/buf.rs
+++ b/src/http/buf.rs
@@ -1,13 +1,14 @@
-use std::cell::UnsafeCell;
+use std::borrow::Cow;
+use std::cell::{Cell, UnsafeCell};
 use std::fmt;
 use std::io::{self, Read};
-use std::ops::{Deref, Range, RangeFrom, RangeTo, RangeFull};
+use std::ops::{Index, Range, RangeFrom, RangeTo, RangeFull};
 use std::ptr;
 use std::sync::Arc;
 
 pub struct MemBuf {
     buf: Arc<UnsafeCell<Vec<u8>>>,
-    start: usize,
+    start: Cell<usize>,
     end: usize,
 }
 
@@ -19,13 +20,13 @@ impl MemBuf {
     pub fn with_capacity(cap: usize) -> MemBuf {
         MemBuf {
             buf: Arc::new(UnsafeCell::new(vec![0; cap])),
-            start: 0,
+            start: Cell::new(0),
             end: 0,
         }
     }
 
     pub fn bytes(&self) -> &[u8] {
-        &self.buf()[self.start..self.end]
+        &self.buf()[self.start.get()..self.end]
     }
 
     pub fn is_empty(&self) -> bool {
@@ -33,7 +34,7 @@ impl MemBuf {
     }
 
     pub fn len(&self) -> usize {
-        self.end - self.start
+        self.end - self.start.get()
     }
 
     pub fn capacity(&self) -> usize {
@@ -41,20 +42,21 @@ impl MemBuf {
     }
 
     pub fn read_from<R: Read>(&mut self, io: &mut R) -> io::Result<usize> {
-        let start = self.end - self.start;
+        let start = self.end - self.start.get();
         let n = try!(io.read(&mut self.buf_mut()[start..]));
         self.end += n;
         Ok(n)
     }
 
-    pub fn slice(&mut self, len: usize) -> MemSlice {
-        assert!(self.end - self.start >= len);
-        let start = self.start;
-        self.start += len;
+    pub fn slice(&self, len: usize) -> MemSlice {
+        assert!(self.end - self.start.get() >= len);
+        let start = self.start.get();
+        let end = start + len;
+        self.start.set(end);
         MemSlice {
             buf: self.buf.clone(),
             start: start,
-            end: self.start,
+            end: end,
         }
     }
 
@@ -67,18 +69,18 @@ impl MemBuf {
         }
         let is_unique = Arc::get_mut(&mut self.buf).is_some();
         trace!("MemBuf::reserve {} access", if is_unique { "unique" } else { "shared" });
-        if is_unique && remaining + self.start >= needed {
+        if is_unique && remaining + self.start.get() >= needed {
             // we have unique access, we can mutate this vector
             trace!("MemBuf::reserve unique access, shifting");
             unsafe {
                 let mut buf = &mut *self.buf.get();
                 let len = self.len();
                 ptr::copy(
-                    buf.as_ptr().offset(self.start as isize),
+                    buf.as_ptr().offset(self.start.get() as isize),
                     buf.as_mut_ptr(),
                     len
                 );
-                self.start = 0;
+                self.start.set(0);
                 self.end = len;
             }
         } else if is_unique {
@@ -109,7 +111,7 @@ impl MemBuf {
         match Arc::get_mut(&mut self.buf) {
             Some(_) => {
                 trace!("MemBuf::reset was unique, re-using");
-                self.start = 0;
+                self.start.set(0);
                 self.end = 0;
             },
             None => {
@@ -119,13 +121,19 @@ impl MemBuf {
         }
     }
 
+    #[cfg(all(feature = "nightly", test))]
+    pub fn restart(&mut self) {
+        Arc::get_mut(&mut self.buf).unwrap();
+        self.start.set(0);
+    }
+
     fn buf_mut(&mut self) -> &mut [u8] {
         // The contract here is that we NEVER have a MemSlice that exists
         // with slice.end > self.start.
         // In other words, we should *ALWAYS* be the only instance that can
         // look at the bytes on the right side of self.start.
         unsafe {
-            &mut (*self.buf.get())[self.start..]
+            &mut (*self.buf.get())[self.start.get()..]
         }
     }
 
@@ -169,9 +177,9 @@ fn test_grow_zerofill() {
 impl fmt::Debug for MemBuf {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_struct("MemBuf")
-            .field("start", &self.start)
+            .field("start", &self.start.get())
             .field("end", &self.end)
-            .field("buf", &&self.buf()[self.start..self.end])
+            .field("buf", &&self.buf()[self.start.get()..self.end])
             .finish()
     }
 }
@@ -182,7 +190,7 @@ impl From<Vec<u8>> for MemBuf {
         vec.shrink_to_fit();
         MemBuf {
             buf: Arc::new(UnsafeCell::new(vec)),
-            start: 0,
+            start: Cell::new(0),
             end: end,
         }
     }
@@ -203,23 +211,118 @@ impl MemSlice {
         }
     }
 
+    pub fn len(&self) -> usize {
+        self.get().len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.get().is_empty()
+    }
+
     pub fn slice<S: Slice>(&self, range: S) -> MemSlice {
         range.slice(self)
     }
-}
 
-
-impl fmt::Debug for MemSlice {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Debug::fmt(&**self, f)
+    fn get(&self) -> &[u8] {
+        unsafe { &(*self.buf.get())[self.start..self.end] }
     }
 }
 
-impl Deref for  MemSlice {
-    type Target = [u8];
-    fn deref(&self) -> &[u8] {
-        unsafe {
-            &(*self.buf.get())[self.start..self.end]
+impl AsRef<[u8]> for MemSlice {
+    fn as_ref(&self) -> &[u8] {
+        self.get()
+    }
+}
+
+impl fmt::Debug for MemSlice {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Debug::fmt(&self.get(), f)
+    }
+}
+
+impl Index<usize> for MemSlice {
+    type Output = u8;
+    fn index(&self, i: usize) -> &u8 {
+        &self.get()[i]
+    }
+}
+
+impl<'a> From<&'a [u8]> for MemSlice {
+    fn from(v: &'a [u8]) -> MemSlice {
+        MemSlice {
+            buf: Arc::new(UnsafeCell::new(v.to_vec())),
+            start: 0,
+            end: v.len(),
+        }
+    }
+}
+
+impl From<Vec<u8>> for MemSlice {
+    fn from(v: Vec<u8>) -> MemSlice {
+        let len = v.len();
+        MemSlice {
+            buf: Arc::new(UnsafeCell::new(v)),
+            start: 0,
+            end: len,
+        }
+    }
+}
+
+impl<'a> From<&'a str> for MemSlice {
+    fn from(v: &'a str) -> MemSlice {
+        let v = v.as_bytes();
+        MemSlice {
+            buf: Arc::new(UnsafeCell::new(v.to_vec())),
+            start: 0,
+            end: v.len(),
+        }
+    }
+}
+
+impl<'a> From<Cow<'a, [u8]>> for MemSlice {
+    fn from(v: Cow<'a, [u8]>) -> MemSlice {
+        let v = v.into_owned();
+        let len = v.len();
+        MemSlice {
+            buf: Arc::new(UnsafeCell::new(v)),
+            start: 0,
+            end: len,
+        }
+    }
+}
+
+impl PartialEq for MemSlice {
+    fn eq(&self, other: &MemSlice) -> bool {
+        self.get() == other.get()
+    }
+}
+
+impl PartialEq<[u8]> for MemSlice {
+    fn eq(&self, other: &[u8]) -> bool {
+        self.get() == other
+    }
+}
+
+impl PartialEq<str> for MemSlice {
+    fn eq(&self, other: &str) -> bool {
+        self.get() == other.as_bytes()
+    }
+}
+
+impl PartialEq<Vec<u8>> for MemSlice {
+    fn eq(&self, other: &Vec<u8>) -> bool {
+        self.get() == other.as_slice()
+    }
+}
+
+impl Eq for MemSlice {}
+
+impl Clone for MemSlice {
+    fn clone(&self) -> MemSlice {
+        MemSlice {
+            buf: self.buf.clone(),
+            start: self.start,
+            end: self.end,
         }
     }
 }
@@ -296,18 +399,18 @@ mod tests {
 
     #[test]
     fn test_mem_slice_slice() {
-        let mut buf = MemBuf::from(b"Hello World".to_vec());
+        let buf = MemBuf::from(b"Hello World".to_vec());
 
         let len = buf.len();
         let full = buf.slice(len);
 
-        assert_eq!(&*full, b"Hello World");
-        assert_eq!(&*full.slice(6..), b"World");
-        assert_eq!(&*full.slice(..5), b"Hello");
-        assert_eq!(&*full.slice(..), b"Hello World");
+        assert_eq!(full.as_ref(), b"Hello World");
+        assert_eq!(full.slice(6..).as_ref(), b"World");
+        assert_eq!(full.slice(..5).as_ref(), b"Hello");
+        assert_eq!(full.slice(..).as_ref(), b"Hello World");
         for a in 0..len {
             for b in a..len {
-                assert_eq!(&*full.slice(a..b), &b"Hello World"[a..b], "{}..{}", a, b);
+                assert_eq!(full.slice(a..b).as_ref(), &b"Hello World"[a..b], "{}..{}", a, b);
             }
         }
     }
diff --git a/src/http/chunk.rs b/src/http/chunk.rs
index 04e598fe..a8d6f408 100644
--- a/src/http/chunk.rs
+++ b/src/http/chunk.rs
@@ -69,7 +69,7 @@ impl AsRef<[u8]> for Chunk {
         match self.0 {
             Inner::Owned(ref vec) => vec,
             Inner::Referenced(ref vec) => vec,
-            Inner::Mem(ref slice) => slice,
+            Inner::Mem(ref slice) => slice.as_ref(),
             Inner::Static(slice) => slice,
         }
     }
diff --git a/src/http/conn.rs b/src/http/conn.rs
index 758b961a..7954fadb 100644
--- a/src/http/conn.rs
+++ b/src/http/conn.rs
@@ -595,6 +595,21 @@ mod tests {
         }
     }
 
+    #[test]
+    fn test_conn_parse_partial() {
+        let good_message = b"GET / HTTP/1.1\r\nHost: foo.bar\r\n\r\n".to_vec();
+        let io = AsyncIo::new_buf(good_message, 10);
+        let mut conn = Conn::<_, ServerTransaction>::new(io, Default::default());
+        assert!(conn.poll().unwrap().is_not_ready());
+        conn.io.io_mut().block_in(50);
+        let async = conn.poll().unwrap();
+        assert!(async.is_ready());
+        match async {
+            Async::Ready(Some(Frame::Message { .. })) => (),
+            f => panic!("frame is not Message: {:?}", f),
+        }
+    }
+
     #[test]
     fn test_conn_closed_read() {
         let io = AsyncIo::new_buf(vec![], 0);
diff --git a/src/http/h1/decode.rs b/src/http/h1/decode.rs
index aaef02ea..1c226cce 100644
--- a/src/http/h1/decode.rs
+++ b/src/http/h1/decode.rs
@@ -88,7 +88,7 @@ impl Decoder {
                 } else {
                     let to_read = *remaining as usize;
                     let buf = try!(body.read_mem(to_read));
-                    let num = buf.len() as u64;
+                    let num = buf.as_ref().len() as u64;
                     trace!("Length read: {}", num);
                     if num > *remaining {
                         *remaining = 0;
@@ -399,7 +399,7 @@ mod tests {
         let mut mock_buf = &b"10\r\n1234567890abcdef\r\n0\r\n"[..];
         let buf = Decoder::chunked().decode(&mut mock_buf).expect("decode");
         assert_eq!(16, buf.len());
-        let result = String::from_utf8(buf.to_vec()).expect("decode String");
+        let result = String::from_utf8(buf.as_ref().to_vec()).expect("decode String");
         assert_eq!("1234567890abcdef", &result);
     }
 
@@ -411,7 +411,7 @@ mod tests {
         // normal read
         let buf = decoder.decode(&mut mock_buf).expect("decode");
         assert_eq!(16, buf.len());
-        let result = String::from_utf8(buf.to_vec()).expect("decode String");
+        let result = String::from_utf8(buf.as_ref().to_vec()).expect("decode String");
         assert_eq!("1234567890abcdef", &result);
 
         // eof read
@@ -438,7 +438,7 @@ mod tests {
                     if buf.is_empty() {
                         break; // eof
                     }
-                    outs.write(&buf).expect("write buffer");
+                    outs.write(buf.as_ref()).expect("write buffer");
                 }
                 Err(e) => match e.kind() {
                     io::ErrorKind::WouldBlock => {
diff --git a/src/http/h1/parse.rs b/src/http/h1/parse.rs
index 559bd006..814eab67 100644
--- a/src/http/h1/parse.rs
+++ b/src/http/h1/parse.rs
@@ -6,6 +6,7 @@ use httparse;
 use header::{self, Headers, ContentLength, TransferEncoding};
 use http::{MessageHead, RawStatus, Http1Transaction, ParseResult, ServerTransaction, ClientTransaction, RequestLine};
 use http::h1::{Encoder, Decoder};
+use http::buf::{MemBuf, MemSlice};
 use method::Method;
 use status::StatusCode;
 use version::HttpVersion::{Http10, Http11};
@@ -13,7 +14,7 @@ use version::HttpVersion::{Http10, Http11};
 const MAX_HEADERS: usize = 100;
 const AVERAGE_HEADER_SIZE: usize = 30; // totally scientific
 
-pub fn parse<T: Http1Transaction<Incoming=I>, I>(buf: &[u8]) -> ParseResult<I> {
+pub fn parse<T: Http1Transaction<Incoming=I>, I>(buf: &MemBuf) -> ParseResult<I> {
     if buf.len() == 0 {
         return Ok(None);
     }
@@ -25,23 +26,29 @@ impl Http1Transaction for ServerTransaction {
     type Incoming = RequestLine;
     type Outgoing = StatusCode;
 
-    fn parse(buf: &[u8]) -> ParseResult<RequestLine> {
+    fn parse(buf: &MemBuf) -> ParseResult<RequestLine> {
         let mut headers = [httparse::EMPTY_HEADER; MAX_HEADERS];
         trace!("Request.parse([Header; {}], [u8; {}])", headers.len(), buf.len());
         let mut req = httparse::Request::new(&mut headers);
-        Ok(match try!(req.parse(buf)) {
+        Ok(match try!(req.parse(buf.bytes())) {
             httparse::Status::Complete(len) => {
                 trace!("Request.parse Complete({})", len);
+                let mut headers = Headers::with_capacity(req.headers.len());
+                let slice = buf.slice(len);
+                headers.extend(HeadersAsMemSliceIter {
+                    headers: req.headers.iter(),
+                    slice: slice,
+                });
                 Some((MessageHead {
                     version: if req.version.unwrap() == 1 { Http11 } else { Http10 },
                     subject: RequestLine(
                         try!(req.method.unwrap().parse()),
                         try!(req.path.unwrap().parse())
                     ),
-                    headers: try!(Headers::from_raw(req.headers))
+                    headers: headers,
                 }, len))
-            },
-            httparse::Status::Partial => None
+            }
+            httparse::Status::Partial => None,
         })
     }
 
@@ -112,11 +119,11 @@ impl Http1Transaction for ClientTransaction {
     type Incoming = RawStatus;
     type Outgoing = RequestLine;
 
-    fn parse(buf: &[u8]) -> ParseResult<RawStatus> {
+    fn parse(buf: &MemBuf) -> ParseResult<RawStatus> {
         let mut headers = [httparse::EMPTY_HEADER; MAX_HEADERS];
         trace!("Response.parse([Header; {}], [u8; {}])", headers.len(), buf.len());
         let mut res = httparse::Response::new(&mut headers);
-        Ok(match try!(res.parse(buf)) {
+        Ok(match try!(res.parse(buf.bytes())) {
             httparse::Status::Complete(len) => {
                 trace!("Response.try_parse Complete({})", len);
                 let code = res.code.unwrap();
@@ -124,10 +131,16 @@ impl Http1Transaction for ClientTransaction {
                     Some(reason) if reason == res.reason.unwrap() => Cow::Borrowed(reason),
                     _ => Cow::Owned(res.reason.unwrap().to_owned())
                 };
+                let mut headers = Headers::with_capacity(res.headers.len());
+                let slice = buf.slice(len);
+                headers.extend(HeadersAsMemSliceIter {
+                    headers: res.headers.iter(),
+                    slice: slice,
+                });
                 Some((MessageHead {
                     version: if res.version.unwrap() == 1 { Http11 } else { Http10 },
                     subject: RawStatus(code, reason),
-                    headers: try!(Headers::from_raw(res.headers))
+                    headers: headers,
                 }, len))
             },
             httparse::Status::Partial => None
@@ -216,6 +229,22 @@ impl Http1Transaction for ClientTransaction {
     }
 }
 
+struct HeadersAsMemSliceIter<'a> {
+    headers: ::std::slice::Iter<'a, httparse::Header<'a>>,
+    slice: MemSlice,
+}
+
+impl<'a> Iterator for HeadersAsMemSliceIter<'a> {
+    type Item = (&'a str, MemSlice);
+    fn next(&mut self) -> Option<Self::Item> {
+        self.headers.next().map(|header| {
+            let value_start = header.value.as_ptr() as usize - self.slice.as_ref().as_ptr() as usize;
+            let value_end = value_start + header.value.len();
+            (header.name, self.slice.slice(value_start..value_end))
+        })
+    }
+}
+
 struct FastWrite<'a>(&'a mut Vec<u8>);
 
 impl<'a> fmt::Write for FastWrite<'a> {
@@ -244,22 +273,23 @@ fn extend(dst: &mut Vec<u8>, data: &[u8]) {
 #[cfg(test)]
 mod tests {
     use http;
+    use http::buf::MemBuf;
     use super::{parse};
 
     #[test]
     fn test_parse_request() {
-        let raw = b"GET /echo HTTP/1.1\r\nHost: hyper.rs\r\n\r\n";
-        parse::<http::ServerTransaction, _>(raw).unwrap();
+        let raw = MemBuf::from(b"GET /echo HTTP/1.1\r\nHost: hyper.rs\r\n\r\n".to_vec());
+        parse::<http::ServerTransaction, _>(&raw).unwrap();
     }
 
     #[test]
     fn test_parse_raw_status() {
-        let raw = b"HTTP/1.1 200 OK\r\n\r\n";
-        let (res, _) = parse::<http::ClientTransaction, _>(raw).unwrap().unwrap();
+        let raw = MemBuf::from(b"HTTP/1.1 200 OK\r\n\r\n".to_vec());
+        let (res, _) = parse::<http::ClientTransaction, _>(&raw).unwrap().unwrap();
         assert_eq!(res.subject.1, "OK");
 
-        let raw = b"HTTP/1.1 200 Howdy\r\n\r\n";
-        let (res, _) = parse::<http::ClientTransaction, _>(raw).unwrap().unwrap();
+        let raw = MemBuf::from(b"HTTP/1.1 200 Howdy\r\n\r\n".to_vec());
+        let (res, _) = parse::<http::ClientTransaction, _>(&raw).unwrap().unwrap();
         assert_eq!(res.subject.1, "Howdy");
     }
 
@@ -269,9 +299,26 @@ mod tests {
     #[cfg(feature = "nightly")]
     #[bench]
     fn bench_parse_incoming(b: &mut Bencher) {
-        let raw = b"GET /echo HTTP/1.1\r\nHost: hyper.rs\r\n\r\n";
+        let mut raw = MemBuf::from(b"GET /super_long_uri/and_whatever?what_should_we_talk_about/\
+                                  I_wonder/Hard_to_write_in_an_uri_after_all/you_have_to_make\
+                                  _up_the_punctuation_yourself/how_fun_is_that?test=foo&test1=\
+                                  foo1&test2=foo2&test3=foo3&test4=foo4 HTTP/1.1\r\nHost: \
+                                  hyper.rs\r\nAccept: a lot of things\r\nAccept-Charset: \
+                                  utf8\r\nAccept-Encoding: *\r\nAccess-Control-Allow-\
+                                  Credentials: None\r\nAccess-Control-Allow-Origin: None\r\n\
+                                  Access-Control-Allow-Methods: None\r\nAccess-Control-Allow-\
+                                  Headers: None\r\nContent-Encoding: utf8\r\nContent-Security-\
+                                  Policy: None\r\nContent-Type: text/html\r\nOrigin: hyper\
+                                  \r\nSec-Websocket-Extensions: It looks super important!\r\n\
+                                  Sec-Websocket-Origin: hyper\r\nSec-Websocket-Version: 4.3\r\
+                                  \nStrict-Transport-Security: None\r\nUser-Agent: hyper\r\n\
+                                  X-Content-Duration: None\r\nX-Content-Security-Policy: None\
+                                  \r\nX-DNSPrefetch-Control: None\r\nX-Frame-Options: \
+                                  Something important obviously\r\nX-Requested-With: Nothing\
+                                  \r\n\r\n".to_vec());
         b.iter(|| {
-            parse::<http::ServerTransaction, _>(raw).unwrap()
+            parse::<http::ServerTransaction, _>(&raw).unwrap();
+            raw.restart();
         });
     }
 
diff --git a/src/http/io.rs b/src/http/io.rs
index 95853ca6..643b5cfb 100644
--- a/src/http/io.rs
+++ b/src/http/io.rs
@@ -70,11 +70,11 @@ impl<T: Io> Buffered<T> {
                 _ => return Err(e.into())
             }
         }
-        match try!(parse::<S, _>(self.read_buf.bytes())) {
-            Some((head, len)) => {
-                trace!("parsed {} bytes out of {}", len, self.read_buf.len());
-                self.read_buf.slice(len);
-                Ok(Some(head))
+        match try!(parse::<S, _>(&self.read_buf)) {
+            Some(head) => {
+                //trace!("parsed {} bytes out of {}", len, self.read_buf.len());
+                //self.read_buf.slice(len);
+                Ok(Some(head.0))
             },
             None => {
                 if self.read_buf.capacity() >= MAX_BUFFER_SIZE {
@@ -140,7 +140,7 @@ impl<T: Write> Write for Buffered<T> {
     }
 }
 
-fn parse<T: Http1Transaction<Incoming=I>, I>(rdr: &[u8]) -> ParseResult<I> {
+fn parse<T: Http1Transaction<Incoming=I>, I>(rdr: &MemBuf) -> ParseResult<I> {
     h1::parse::<T, I>(rdr)
 }
 
diff --git a/src/http/mod.rs b/src/http/mod.rs
index cdad710e..13c50119 100644
--- a/src/http/mod.rs
+++ b/src/http/mod.rs
@@ -13,9 +13,11 @@ use version::HttpVersion::{Http10, Http11};
 pub use self::conn::{Conn, KeepAlive, KA};
 pub use self::body::{Body, TokioBody};
 pub use self::chunk::Chunk;
+use self::buf::MemBuf;
 
 mod body;
-mod buf;
+#[doc(hidden)]
+pub mod buf;
 mod chunk;
 mod conn;
 mod io;
@@ -123,7 +125,7 @@ pub trait Http1Transaction {
     type Incoming;
     type Outgoing: Default;
     //type KeepAlive: KeepAlive;
-    fn parse(bytes: &[u8]) -> ParseResult<Self::Incoming>;
+    fn parse(bytes: &MemBuf) -> ParseResult<Self::Incoming>;
     fn decoder(head: &MessageHead<Self::Incoming>) -> ::Result<h1::Decoder>;
     fn encode(head: &mut MessageHead<Self::Outgoing>, dst: &mut Vec<u8>) -> h1::Encoder;
     fn should_set_length(head: &MessageHead<Self::Outgoing>) -> bool;
diff --git a/src/mock.rs b/src/mock.rs
index db969032..934732ad 100644
--- a/src/mock.rs
+++ b/src/mock.rs
@@ -6,7 +6,8 @@ use tokio::io::Io;
 
 #[derive(Debug)]
 pub struct Buf {
-    vec: Vec<u8>
+    vec: Vec<u8>,
+    pos: usize,
 }
 
 impl Buf {
@@ -17,6 +18,7 @@ impl Buf {
     pub fn wrap(vec: Vec<u8>) -> Buf {
         Buf {
             vec: vec,
+            pos: 0,
         }
     }
 }
@@ -48,7 +50,10 @@ impl Write for Buf {
 
 impl Read for Buf {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        (&*self.vec).read(buf)
+        (&self.vec[self.pos..]).read(buf).map(|n| {
+            self.pos += n;
+            n
+        })
     }
 }