perf(header): optimize when inserting a new type header

src/header/internals/cell.rs

@@ -58,6 +58,11 @@ impl<V: ?Sized + Any + 'static> PtrMapCell<V> {
         PtrMapCell(UnsafeCell::new(PtrMap::Empty))
     }
 
+    #[inline]
+    pub fn with_one(key: TypeId, val: Box<V>)  -> PtrMapCell<V> {
+        PtrMapCell(UnsafeCell::new(PtrMap::One(key, val)))
+    }
+
     #[inline]
     pub fn get(&self, key: TypeId) -> Option<&V> {
         let map = unsafe { &*self.0.get() };

src/header/internals/item.rs

@@ -23,12 +23,11 @@ impl Item {
     }
 
     #[inline]
-    pub fn new_typed(ty: Box<Header + Send + Sync>) -> Item {
-        let map = PtrMapCell::new();
-        unsafe { map.insert((*ty).get_type(), ty); }
+
+    pub fn new_typed<H: Header>(val: H) -> Item {
         Item {
             raw: OptCell::new(None),
-            typed: map,
+            typed: PtrMapCell::with_one(TypeId::of::<H>(), Box::new(val)),
         }
     }
 

src/header/mod.rs

@@ -344,6 +344,7 @@ macro_rules! literals {
                 _ => ()
             }
 
+            trace!("maybe_literal not found, copying {:?}", s);
             Cow::Owned(s.to_owned())
         }
 
@@ -397,7 +398,7 @@ impl Headers {
     pub fn set<H: Header>(&mut self, value: H) {
         trace!("Headers.set( {:?}, {:?} )", header_name::<H>(), HeaderValueString(&value));
         self.data.insert(HeaderName(Ascii::new(Cow::Borrowed(header_name::<H>()))),
-                         Item::new_typed(Box::new(value)));
+                         Item::new_typed(value));
     }
 
     /// Get a reference to the header field's value, if it exists.
@@ -682,10 +683,11 @@ impl AsRef<str> for HeaderName {
 }
 
 impl PartialEq for HeaderName {
+    #[inline]
     fn eq(&self, other: &HeaderName) -> bool {
         let s = self.as_ref();
         let k = other.as_ref();
-        if s.len() == k.len() && s.as_ptr() == k.as_ptr() {
+        if s.as_ptr() == k.as_ptr() && s.len() == k.len() {
             true
         } else {
             self.0 == other.0
@@ -696,7 +698,7 @@ impl PartialEq for HeaderName {
 impl PartialEq<HeaderName> for str {
     fn eq(&self, other: &HeaderName) -> bool {
         let k = other.as_ref();
-        if self.len() == k.len() && self.as_ptr() == k.as_ptr() {
+        if self.as_ptr() == k.as_ptr() && self.len() == k.len() {
             true
         } else {
             other.0 == self
@@ -975,6 +977,16 @@ mod tests {
         b.iter(|| assert!(headers.get::<ContentLength>().is_none()))
     }
 
+    #[cfg(feature = "nightly")]
+    #[bench]
+    fn bench_headers_get_miss_previous_10(b: &mut Bencher) {
+        let mut headers = Headers::new();
+        for i in 0..10 {
+            headers.set_raw(format!("non-standard-{}", i), "hi");
+        }
+        b.iter(|| assert!(headers.get::<ContentLength>().is_none()))
+    }
+
     #[cfg(feature = "nightly")]
     #[bench]
     fn bench_headers_set(b: &mut Bencher) {
@@ -982,6 +994,33 @@ mod tests {
         b.iter(|| headers.set(ContentLength(12)))
     }
 
+    #[cfg(feature = "nightly")]
+    #[bench]
+    fn bench_headers_set_previous_10(b: &mut Bencher) {
+        let mut headers = Headers::new();
+        for i in 0..10 {
+            headers.set_raw(format!("non-standard-{}", i), "hi");
+        }
+        b.iter(|| headers.set(ContentLength(12)))
+    }
+
+    #[cfg(feature = "nightly")]
+    #[bench]
+    fn bench_headers_set_raw(b: &mut Bencher) {
+        let mut headers = Headers::new();
+        b.iter(|| headers.set_raw("non-standard", "hello"))
+    }
+
+    #[cfg(feature = "nightly")]
+    #[bench]
+    fn bench_headers_set_raw_previous_10(b: &mut Bencher) {
+        let mut headers = Headers::new();
+        for i in 0..10 {
+            headers.set_raw(format!("non-standard-{}", i), "hi");
+        }
+        b.iter(|| headers.set_raw("non-standard", "hello"))
+    }
+
     #[cfg(feature = "nightly")]
     #[bench]
     fn bench_headers_has(b: &mut Bencher) {
@@ -1003,8 +1042,16 @@ mod tests {
     #[cfg(feature = "nightly")]
     #[bench]
     fn bench_headers_fmt(b: &mut Bencher) {
+        use std::fmt::Write;
+        let mut buf = String::with_capacity(64);
         let mut headers = Headers::new();
         headers.set(ContentLength(11));
-        b.iter(|| headers.to_string())
+        headers.set(ContentType::json());
+        b.bytes = headers.to_string().len() as u64;
+        b.iter(|| {
+            let _ = write!(buf, "{}", headers);
+            ::test::black_box(&buf);
+            unsafe { buf.as_mut_vec().set_len(0); }
+        })
     }
 }