Merge branch 'master' into master

actix-http/CHANGES.md

@@ -5,7 +5,11 @@
 - Implement `MessageBody` for `&mut B` where `B: MessageBody + Unpin`. [#2868]
 - Implement `MessageBody` for `Pin<B>` where `B::Target: MessageBody`. [#2868]
 
+### Performance
+- Improve overall performance of operations on `Extensions`. [#2890]
+
 [#2868]: https://github.com/actix/actix-web/pull/2868
+[#2890]: https://github.com/actix/actix-web/pull/2890
 
 
 ## 3.2.2 - 2022-09-11

actix-http/src/extensions.rs

@@ -1,9 +1,30 @@
 use std::{
     any::{Any, TypeId},
+    collections::HashMap,
     fmt,
+    hash::{BuildHasherDefault, Hasher},
 };
 
-use ahash::AHashMap;
+/// A hasher for `TypeId`s that takes advantage of its known characteristics.
+///
+/// Author of `anymap` crate has done research on the topic:
+/// https://github.com/chris-morgan/anymap/blob/2e9a5704/src/lib.rs#L599
+#[derive(Debug, Default)]
+struct NoOpHasher(u64);
+
+impl Hasher for NoOpHasher {
+    fn write(&mut self, _bytes: &[u8]) {
+        unimplemented!("This NoOpHasher can only handle u64s")
+    }
+
+    fn write_u64(&mut self, i: u64) {
+        self.0 = i;
+    }
+
+    fn finish(&self) -> u64 {
+        self.0
+    }
+}
 
 /// A type map for request extensions.
 ///
@@ -11,7 +32,7 @@ use ahash::AHashMap;
 #[derive(Default)]
 pub struct Extensions {
     /// Use AHasher with a std HashMap with for faster lookups on the small `TypeId` keys.
-    map: AHashMap<TypeId, Box<dyn Any>>,
+    map: HashMap<TypeId, Box<dyn Any>, BuildHasherDefault<NoOpHasher>>,
 }
 
 impl Extensions {
@@ -19,7 +40,7 @@ impl Extensions {
     #[inline]
     pub fn new() -> Extensions {
         Extensions {
-            map: AHashMap::new(),
+            map: HashMap::default(),
         }
     }