consistent case s/web/Web

prepare beta 2 release set (#1975 )
ensure poll_flush on h1 connection disconnect (#1974 )
2025-07-04 18:06:23 +02:00 · 2021-02-10 12:12:03 +00:00 · 2021-02-10 12:10:03 +00:00 · 2021-02-10 10:11:53 +00:00 · 2021-02-09 22:59:17 +00:00 · 2021-02-09 22:32:46 +00:00
165 changed files with 5796 additions and 5022 deletions
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@ -1,21 +1,21 @@
 <!-- Thanks for considering contributing actix! -->
-<!-- Please fill out the following to make our reviews easy. -->
+<!-- Please fill out the following to get your PR reviewed quicker. -->

 ## PR Type
 <!-- What kind of change does this PR make? -->
 <!-- Bug Fix / Feature / Refactor / Code Style / Other -->
-INSERT_PR_TYPE
+PR_TYPE


 ## PR Checklist
-Check your PR fulfills the following:
-
+<!-- Check your PR fulfills the following items. ->>
 <!-- For draft PRs check the boxes as you complete them. -->

 - [ ] Tests for the changes have been added / updated.
 - [ ] Documentation comments have been added / updated.
 - [ ] A changelog entry has been made for the appropriate packages.
- [ ] Format code with the latest stable rustfmt
+- [ ] Format code with the latest stable rustfmt.
+- [ ] (Team) Label with affected crates and semver status.


 ## Overview
--- a/.github/workflows/bench.yml
+++ b/.github/workflows/bench.yml
@ -1,4 +1,4 @@
-name: Benchmark (Linux)
+name: Benchmark

 on:
  pull_request:
--- a/.github/workflows/clippy-fmt.yml
+++ b/.github/workflows/clippy-fmt.yml
@ -1,32 +1,39 @@
+name: Lint
+
 on:
  pull_request:
    types: [opened, synchronize, reopened]

-name: Clippy and rustfmt Check
 jobs:
-  clippy_check:
+  fmt:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2

-      - uses: actions-rs/toolchain@v1
+      - name: Install Rust
+        uses: actions-rs/toolchain@v1
        with:
          toolchain: stable
          components: rustfmt
-          override: true
      - name: Check with rustfmt
        uses: actions-rs/cargo@v1
        with:
          command: fmt
          args: --all -- --check

-      - uses: actions-rs/toolchain@v1
+  clippy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install Rust
+        uses: actions-rs/toolchain@v1
        with:
-          toolchain: nightly
+          toolchain: stable
          components: clippy
          override: true
      - name: Check with Clippy
        uses: actions-rs/clippy-check@v1
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
-          args: --all-features --all --tests
+          args: --workspace --tests --all-features
--- a/.github/workflows/upload-doc.yml
+++ b/.github/workflows/upload-doc.yml
@ -24,7 +24,7 @@ jobs:
        uses: actions-rs/cargo@v1
        with:
          command: doc
-          args: --no-deps --workspace --all-features
+          args: --workspace --all-features --no-deps

      - name: Tweak HTML
        run: echo "<meta http-equiv=refresh content=0;url=os_balloon/index.html>" > target/doc/index.html
--- a/CHANGES.md
+++ b/CHANGES.md
@ -3,6 +3,46 @@
 ## Unreleased - 2021-xx-xx


+## 4.0.0-beta.2 - 2021-xx-xx
+### Added
+* The method `Either<web::Json<T>, web::Form<T>>::into_inner()` which returns the inner type for
+  whichever variant was created. Also works for `Either<web::Form<T>, web::Json<T>>`. [#1894]
+* Add `services!` macro for helping register multiple services to `App`. [#1933]
+* Enable registering a vec of services of the same type to `App` [#1933]
+
+### Changed
+* Rework `Responder` trait to be sync and returns `Response`/`HttpResponse` directly.
+  Making it simpler and more performant. [#1891]
+* `ServiceRequest::into_parts` and `ServiceRequest::from_parts` can no longer fail. [#1893]
+* `ServiceRequest::from_request` can no longer fail. [#1893]
+* Our `Either` type now uses `Left`/`Right` variants (instead of `A`/`B`) [#1894]
+* `test::{call_service, read_response, read_response_json, send_request}` take `&Service`
+  in argument [#1905]
+* `App::wrap_fn`, `Resource::wrap_fn` and `Scope::wrap_fn` provide `&Service` in closure
+  argument. [#1905]
+* `web::block` no longer requires the output is a Result. [#1957]
+
+### Fixed
+* Multiple calls to `App::data` with the same type now keeps the latest call's data. [#1906]
+
+### Removed
+* Public field of `web::Path` has been made private. [#1894]
+* Public field of `web::Query` has been made private. [#1894]
+* `TestRequest::with_header`; use `TestRequest::default().insert_header()`. [#1869]
+* `AppService::set_service_data`; for custom HTTP service factories adding application data, use the
+  layered data model by calling `ServiceRequest::add_data_container` when handling
+  requests instead. [#1906]
+
+[#1891]: https://github.com/actix/actix-web/pull/1891
+[#1893]: https://github.com/actix/actix-web/pull/1893
+[#1894]: https://github.com/actix/actix-web/pull/1894
+[#1869]: https://github.com/actix/actix-web/pull/1869
+[#1905]: https://github.com/actix/actix-web/pull/1905
+[#1906]: https://github.com/actix/actix-web/pull/1906
+[#1933]: https://github.com/actix/actix-web/pull/1933
+[#1957]: https://github.com/actix/actix-web/pull/1957
+
+
 ## 4.0.0-beta.1 - 2021-01-07
 ### Added
 * `Compat` middleware enabling generic response body/error type of middlewares like `Logger` and
@ -24,13 +64,15 @@
 ### Removed
 * Public modules `middleware::{normalize, err_handlers}`. All necessary middleware structs are now
  exposed directly by the `middleware` module.
+* Remove `actix-threadpool` as dependency. `actix_threadpool::BlockingError` error type can be imported 
+  from `actix_web::error` module. [#1878]

 [#1812]: https://github.com/actix/actix-web/pull/1812
 [#1813]: https://github.com/actix/actix-web/pull/1813
 [#1852]: https://github.com/actix/actix-web/pull/1852
 [#1865]: https://github.com/actix/actix-web/pull/1865
 [#1875]: https://github.com/actix/actix-web/pull/1875
-
+[#1878]: https://github.com/actix/actix-web/pull/1878

 ## 3.3.2 - 2020-12-01
 ### Fixed
--- a/Cargo.toml
+++ b/Cargo.toml
@ -1,6 +1,6 @@
 [package]
 name = "actix-web"
-version = "4.0.0-beta.1"
+version = "4.0.0-beta.2"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
 description = "Actix Web is a powerful, pragmatic, and extremely fast web framework for Rust"
 readme = "README.md"
@ -47,10 +47,10 @@ compress = ["actix-http/compress", "awc/compress"]
 secure-cookies = ["actix-http/secure-cookies"]

 # openssl
-openssl = ["actix-tls/accept", "actix-tls/openssl", "awc/openssl", "open-ssl"]
+openssl = ["tls_openssl", "actix-tls/accept", "actix-tls/openssl", "awc/openssl"]

 # rustls
-rustls = ["actix-tls/accept", "actix-tls/rustls", "awc/rustls", "rust-tls"]
+rustls = ["tls_rustls", "actix-tls/accept", "actix-tls/rustls", "awc/rustls"]

 [[example]]
 name = "basic"
@ -74,22 +74,22 @@ required-features = ["rustls"]

 [dependencies]
 actix-codec = "0.4.0-beta.1"
-actix-macros = "0.1.0"
-actix-router = "0.2.4"
-actix-rt = "2.0.0-beta.1"
-actix-server = "2.0.0-beta.2"
-actix-service = "2.0.0-beta.2"
-actix-utils = "3.0.0-beta.1"
-actix-threadpool = "0.3.1"
-actix-tls = { version = "3.0.0-beta.2", default-features = false, optional = true }
+actix-macros = "0.2.0"
+actix-router = "0.2.7"
+actix-rt = "2"
+actix-server = "2.0.0-beta.3"
+actix-service = "2.0.0-beta.4"
+actix-utils = "3.0.0-beta.2"
+actix-tls = { version = "3.0.0-beta.3", default-features = false, optional = true }

 actix-web-codegen = "0.4.0"
-actix-http = "3.0.0-beta.1"
-awc = { version = "3.0.0-beta.1", default-features = false }
+actix-http = "3.0.0-beta.2"
+awc = { version = "3.0.0-beta.2", default-features = false }

-ahash = "0.6"
+ahash = "0.7"
 bytes = "1"
 derive_more = "0.99.5"
+either = "1.5.3"
 encoding_rs = "0.8"
 futures-core = { version = "0.3.7", default-features = false }
 futures-util = { version = "0.3.7", default-features = false }
@ -101,15 +101,14 @@ regex = "1.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 serde_urlencoded = "0.7"
-time = { version = "0.2.7", default-features = false, features = ["std"] }
+time = { version = "0.2.23", default-features = false, features = ["std"] }
 url = "2.1"
-open-ssl = { package = "openssl", version = "0.10", optional = true }
-rust-tls = { package = "rustls", version = "0.19.0", optional = true }
+tls_openssl = { package = "openssl", version = "0.10.9", optional = true }
+tls_rustls = { package = "rustls", version = "0.19.0", optional = true }
 smallvec = "1.6"

 [dev-dependencies]
-actix = "0.11.0-beta.1"
-actix-http = { version = "3.0.0-beta.1", features = ["actors"] }
+actix = { version = "0.11.0-beta.2", default-features = false }
 rand = "0.8"
 env_logger = "0.8"
 serde_derive = "1.0"
@ -139,3 +138,7 @@ harness = false
 [[bench]]
 name = "service"
 harness = false
+
+[[bench]]
+name = "responder"
+harness = false
--- a/README.md
+++ b/README.md
@ -1,20 +1,19 @@
 <div align="center">
-  <h1>Actix web</h1>
+  <h1>Actix Web</h1>
  <p>
    <strong>Actix Web is a powerful, pragmatic, and extremely fast web framework for Rust</strong>
  </p>
  <p>

 [![crates.io](https://img.shields.io/crates/v/actix-web?label=latest)](https://crates.io/crates/actix-web)
-[![Documentation](https://docs.rs/actix-web/badge.svg?version=3.3.2)](https://docs.rs/actix-web/3.3.2)
+[![Documentation](https://docs.rs/actix-web/badge.svg?version=4.0.0-beta.2)](https://docs.rs/actix-web/4.0.0-beta.2)
 [![Version](https://img.shields.io/badge/rustc-1.46+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.46.html)
-![License](https://img.shields.io/crates/l/actix-web.svg)
-[![Dependency Status](https://deps.rs/crate/actix-web/3.3.2/status.svg)](https://deps.rs/crate/actix-web/3.3.2)
+![MIT or Apache 2.0 licensed](https://img.shields.io/crates/l/actix-web.svg)
+[![Dependency Status](https://deps.rs/crate/actix-web/4.0.0-beta.2/status.svg)](https://deps.rs/crate/actix-web/4.0.0-beta.2)
 <br />
-[![Build Status](https://travis-ci.org/actix/actix-web.svg?branch=master)](https://travis-ci.org/actix/actix-web) 
+[![build status](https://github.com/actix/actix-web/workflows/CI%20%28Linux%29/badge.svg?branch=master&event=push)](https://github.com/actix/actix-web/actions)
 [![codecov](https://codecov.io/gh/actix/actix-web/branch/master/graph/badge.svg)](https://codecov.io/gh/actix/actix-web) 
-[![Download](https://img.shields.io/crates/d/actix-web.svg)](https://crates.io/crates/actix-web)
-[![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+![downloads](https://img.shields.io/crates/d/actix-web.svg)
 [![Chat on Discord](https://img.shields.io/discord/771444961383153695?label=chat&logo=discord)](https://discord.gg/NWpN5mmg3x)

  </p>
@ -99,9 +98,9 @@ One of the fastest web frameworks available according to the
 This project is licensed under either of

 * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
-  [http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0))
+  [http://www.apache.org/licenses/LICENSE-2.0])
 * MIT license ([LICENSE-MIT](LICENSE-MIT) or
-  [http://opensource.org/licenses/MIT](http://opensource.org/licenses/MIT))
+  [http://opensource.org/licenses/MIT])

 at your option.

--- a/actix-files/CHANGES.md
+++ b/actix-files/CHANGES.md
@ -3,6 +3,14 @@
 ## Unreleased - 2021-xx-xx


+## 0.6.0-beta.2 - 2021-02-10
+* Fix If-Modified-Since and If-Unmodified-Since to not compare using sub-second timestamps. [#1887]
+* Replace `v_htmlescape` with `askama_escape`. [#1953]
+
+[#1887]: https://github.com/actix/actix-web/pull/1887
+[#1953]: https://github.com/actix/actix-web/pull/1953
+
+
 ## 0.6.0-beta.1 - 2021-01-07
 * `HttpRange::parse` now has its own error type.
 * Update `bytes` to `1.0`. [#1813]
--- a/actix-files/Cargo.toml
+++ b/actix-files/Cargo.toml
@ -1,6 +1,6 @@
 [package]
 name = "actix-files"
-version = "0.6.0-beta.1"
+version = "0.6.0-beta.2"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
 description = "Static file serving for Actix Web"
 readme = "README.md"
@ -17,8 +17,10 @@ name = "actix_files"
 path = "src/lib.rs"

 [dependencies]
-actix-web = { version = "4.0.0-beta.1", default-features = false }
-actix-service = "2.0.0-beta.2"
+actix-web = { version = "4.0.0-beta.2", default-features = false }
+actix-service = "2.0.0-beta.4"
+
+askama_escape = "0.10"
 bitflags = "1"
 bytes = "1"
 futures-core = { version = "0.3.7", default-features = false }
@ -28,8 +30,7 @@ log = "0.4"
 mime = "0.3"
 mime_guess = "2.0.1"
 percent-encoding = "2.1"
-v_htmlescape = "0.12"

 [dev-dependencies]
-actix-rt = "2.0.0-beta.1"
-actix-web = "4.0.0-beta.1"
+actix-rt = "2"
+actix-web = "4.0.0-beta.2"
--- a/actix-files/src/chunked.rs
+++ b/actix-files/src/chunked.rs
@ -9,26 +9,35 @@ use std::{

 use actix_web::{
    error::{BlockingError, Error},
-    web,
+    rt::task::{spawn_blocking, JoinHandle},
 };
 use bytes::Bytes;
 use futures_core::{ready, Stream};
-use futures_util::future::{FutureExt, LocalBoxFuture};
-
-use crate::handle_error;
-
-type ChunkedBoxFuture =
-    LocalBoxFuture<'static, Result<(File, Bytes), BlockingError<io::Error>>>;

 #[doc(hidden)]
 /// A helper created from a `std::fs::File` which reads the file
 /// chunk-by-chunk on a `ThreadPool`.
 pub struct ChunkedReadFile {
-    pub(crate) size: u64,
-    pub(crate) offset: u64,
-    pub(crate) file: Option<File>,
-    pub(crate) fut: Option<ChunkedBoxFuture>,
-    pub(crate) counter: u64,
+    size: u64,
+    offset: u64,
+    state: ChunkedReadFileState,
+    counter: u64,
+}
+
+enum ChunkedReadFileState {
+    File(Option<File>),
+    Future(JoinHandle<Result<(File, Bytes), io::Error>>),
+}
+
+impl ChunkedReadFile {
+    pub(crate) fn new(size: u64, offset: u64, file: File) -> Self {
+        Self {
+            size,
+            offset,
+            state: ChunkedReadFileState::File(Some(file)),
+            counter: 0,
+        }
+    }
 }

 impl fmt::Debug for ChunkedReadFile {
@ -44,51 +53,52 @@ impl Stream for ChunkedReadFile {
        mut self: Pin<&mut Self>,
        cx: &mut Context<'_>,
    ) -> Poll<Option<Self::Item>> {
-        if let Some(ref mut fut) = self.fut {
-            return match ready!(Pin::new(fut).poll(cx)) {
-                Ok((file, bytes)) => {
-                    self.fut.take();
-                    self.file = Some(file);
-
-                    self.offset += bytes.len() as u64;
-                    self.counter += bytes.len() as u64;
-
-                    Poll::Ready(Some(Ok(bytes)))
-                }
-                Err(e) => Poll::Ready(Some(Err(handle_error(e)))),
-            };
-        }
-
-        let size = self.size;
-        let offset = self.offset;
-        let counter = self.counter;
+        let this = self.as_mut().get_mut();
+        match this.state {
+            ChunkedReadFileState::File(ref mut file) => {
+                let size = this.size;
+                let offset = this.offset;
+                let counter = this.counter;

                if size == counter {
                    Poll::Ready(None)
                } else {
-            let mut file = self.file.take().expect("Use after completion");
+                    let mut file = file
+                        .take()
+                        .expect("ChunkedReadFile polled after completion");

-            self.fut = Some(
-                web::block(move || {
+                    let fut = spawn_blocking(move || {
                        let max_bytes =
                            cmp::min(size.saturating_sub(counter), 65_536) as usize;

                        let mut buf = Vec::with_capacity(max_bytes);
                        file.seek(io::SeekFrom::Start(offset))?;

-                    let n_bytes =
-                        file.by_ref().take(max_bytes as u64).read_to_end(&mut buf)?;
+                        let n_bytes = file
+                            .by_ref()
+                            .take(max_bytes as u64)
+                            .read_to_end(&mut buf)?;

                        if n_bytes == 0 {
                            return Err(io::ErrorKind::UnexpectedEof.into());
                        }

                        Ok((file, Bytes::from(buf)))
-                })
-                .boxed_local(),
-            );
-
+                    });
+                    this.state = ChunkedReadFileState::Future(fut);
                    self.poll_next(cx)
                }
            }
+            ChunkedReadFileState::Future(ref mut fut) => {
+                let (file, bytes) =
+                    ready!(Pin::new(fut).poll(cx)).map_err(|_| BlockingError)??;
+                this.state = ChunkedReadFileState::File(Some(file));
+
+                this.offset += bytes.len() as u64;
+                this.counter += bytes.len() as u64;
+
+                Poll::Ready(Some(Ok(bytes)))
+            }
+        }
+    }
 }
--- a/actix-files/src/directory.rs
+++ b/actix-files/src/directory.rs
@ -1,8 +1,8 @@
 use std::{fmt::Write, fs::DirEntry, io, path::Path, path::PathBuf};

 use actix_web::{dev::ServiceResponse, HttpRequest, HttpResponse};
+use askama_escape::{escape as escape_html_entity, Html};
 use percent_encoding::{utf8_percent_encode, CONTROLS};
-use v_htmlescape::escape as escape_html_entity;

 /// A directory; responds with the generated directory listing.
 #[derive(Debug)]
@ -50,7 +50,7 @@ macro_rules! encode_file_url {
 // " -- &quot;  & -- &amp;  ' -- &#x27;  < -- &lt;  > -- &gt;  / -- &#x2f;
 macro_rules! encode_file_name {
    ($entry:ident) => {
-        escape_html_entity(&$entry.file_name().to_string_lossy())
+        escape_html_entity(&$entry.file_name().to_string_lossy(), Html)
    };
 }

--- a/actix-files/src/files.rs
+++ b/actix-files/src/files.rs
@ -82,8 +82,9 @@ impl Files {
    /// be inaccessible. Register more specific handlers and services first.
    ///
    /// `Files` uses a threadpool for blocking filesystem operations. By default, the pool uses a
-    /// number of threads equal to 5x the number of available logical CPUs. Pool size can be changed
-    /// by setting ACTIX_THREADPOOL environment variable.
+    /// max number of threads equal to `512 * HttpServer::worker`. Real time thread count are
+    /// adjusted with work load. More threads would spawn when need and threads goes idle for a
+    /// period of time would be de-spawned.
    pub fn new<T: Into<PathBuf>>(mount_path: &str, serve_from: T) -> Files {
        let orig_dir = serve_from.into();
        let dir = match orig_dir.canonicalize() {
--- a/actix-files/src/lib.rs
+++ b/actix-files/src/lib.rs
@ -14,12 +14,10 @@
 #![deny(rust_2018_idioms)]
 #![warn(missing_docs, missing_debug_implementations)]

-use std::io;
-
 use actix_service::boxed::{BoxService, BoxServiceFactory};
 use actix_web::{
    dev::{ServiceRequest, ServiceResponse},
-    error::{BlockingError, Error, ErrorInternalServerError},
+    error::Error,
    http::header::DispositionType,
 };
 use mime_guess::from_ext;
@ -56,13 +54,6 @@ pub fn file_extension_to_mime(ext: &str) -> mime::Mime {
    from_ext(ext).first_or_octet_stream()
 }

-pub(crate) fn handle_error(err: BlockingError<io::Error>) -> Error {
-    match err {
-        BlockingError::Error(err) => err.into(),
-        BlockingError::Canceled => ErrorInternalServerError("Unexpected error"),
-    }
-}
-
 type MimeOverride = dyn Fn(&mime::Name<'_>) -> DispositionType;

 #[cfg(test)]
@ -82,7 +73,8 @@ mod tests {
        },
        middleware::Compress,
        test::{self, TestRequest},
-        web, App, HttpResponse, Responder,
+        web::{self, Bytes},
+        App, HttpResponse, Responder,
    };
    use futures_util::future::ok;

@ -110,7 +102,19 @@ mod tests {
            header::HttpDate::from(SystemTime::now().add(Duration::from_secs(60)));

        let req = TestRequest::default()
-            .header(header::IF_MODIFIED_SINCE, since)
+            .insert_header((header::IF_MODIFIED_SINCE, since))
+            .to_http_request();
+        let resp = file.respond_to(&req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::NOT_MODIFIED);
+    }
+
+    #[actix_rt::test]
+    async fn test_if_modified_since_without_if_none_match_same() {
+        let file = NamedFile::open("Cargo.toml").unwrap();
+        let since = file.last_modified().unwrap();
+
+        let req = TestRequest::default()
+            .insert_header((header::IF_MODIFIED_SINCE, since))
            .to_http_request();
        let resp = file.respond_to(&req).await.unwrap();
        assert_eq!(resp.status(), StatusCode::NOT_MODIFIED);
@ -123,13 +127,37 @@ mod tests {
            header::HttpDate::from(SystemTime::now().add(Duration::from_secs(60)));

        let req = TestRequest::default()
-            .header(header::IF_NONE_MATCH, "miss_etag")
-            .header(header::IF_MODIFIED_SINCE, since)
+            .insert_header((header::IF_NONE_MATCH, "miss_etag"))
+            .insert_header((header::IF_MODIFIED_SINCE, since))
            .to_http_request();
        let resp = file.respond_to(&req).await.unwrap();
        assert_ne!(resp.status(), StatusCode::NOT_MODIFIED);
    }

+    #[actix_rt::test]
+    async fn test_if_unmodified_since() {
+        let file = NamedFile::open("Cargo.toml").unwrap();
+        let since = file.last_modified().unwrap();
+
+        let req = TestRequest::default()
+            .insert_header((header::IF_UNMODIFIED_SINCE, since))
+            .to_http_request();
+        let resp = file.respond_to(&req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::OK);
+    }
+
+    #[actix_rt::test]
+    async fn test_if_unmodified_since_failed() {
+        let file = NamedFile::open("Cargo.toml").unwrap();
+        let since = header::HttpDate::from(SystemTime::UNIX_EPOCH);
+
+        let req = TestRequest::default()
+            .insert_header((header::IF_UNMODIFIED_SINCE, since))
+            .to_http_request();
+        let resp = file.respond_to(&req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::PRECONDITION_FAILED);
+    }
+
    #[actix_rt::test]
    async fn test_named_file_text() {
        assert!(NamedFile::open("test--").is_err());
@ -338,7 +366,7 @@ mod tests {
            DispositionType::Attachment
        }

-        let mut srv = test::init_service(
+        let srv = test::init_service(
            App::new().service(
                Files::new("/", ".")
                    .mime_override(all_attachment)
@ -348,7 +376,7 @@ mod tests {
        .await;

        let request = TestRequest::get().uri("/").to_request();
-        let response = test::call_service(&mut srv, request).await;
+        let response = test::call_service(&srv, request).await;
        assert_eq!(response.status(), StatusCode::OK);

        let content_disposition = response
@ -363,7 +391,7 @@ mod tests {

    #[actix_rt::test]
    async fn test_named_file_ranges_status_code() {
-        let mut srv = test::init_service(
+        let srv = test::init_service(
            App::new().service(Files::new("/test", ".").index_file("Cargo.toml")),
        )
        .await;
@ -371,17 +399,17 @@ mod tests {
        // Valid range header
        let request = TestRequest::get()
            .uri("/t%65st/Cargo.toml")
-            .header(header::RANGE, "bytes=10-20")
+            .insert_header((header::RANGE, "bytes=10-20"))
            .to_request();
-        let response = test::call_service(&mut srv, request).await;
+        let response = test::call_service(&srv, request).await;
        assert_eq!(response.status(), StatusCode::PARTIAL_CONTENT);

        // Invalid range header
        let request = TestRequest::get()
            .uri("/t%65st/Cargo.toml")
-            .header(header::RANGE, "bytes=1-0")
+            .insert_header((header::RANGE, "bytes=1-0"))
            .to_request();
-        let response = test::call_service(&mut srv, request).await;
+        let response = test::call_service(&srv, request).await;

        assert_eq!(response.status(), StatusCode::RANGE_NOT_SATISFIABLE);
    }
@ -393,7 +421,7 @@ mod tests {
        // Valid range header
        let response = srv
            .get("/tests/test.binary")
-            .header(header::RANGE, "bytes=10-20")
+            .insert_header((header::RANGE, "bytes=10-20"))
            .send()
            .await
            .unwrap();
@ -403,7 +431,7 @@ mod tests {
        // Invalid range header
        let response = srv
            .get("/tests/test.binary")
-            .header(header::RANGE, "bytes=10-5")
+            .insert_header((header::RANGE, "bytes=10-5"))
            .send()
            .await
            .unwrap();
@ -418,7 +446,7 @@ mod tests {
        // Valid range header
        let response = srv
            .get("/tests/test.binary")
-            .header(header::RANGE, "bytes=10-20")
+            .insert_header((header::RANGE, "bytes=10-20"))
            .send()
            .await
            .unwrap();
@ -428,7 +456,7 @@ mod tests {
        // Valid range header, starting from 0
        let response = srv
            .get("/tests/test.binary")
-            .header(header::RANGE, "bytes=0-20")
+            .insert_header((header::RANGE, "bytes=0-20"))
            .send()
            .await
            .unwrap();
@ -468,14 +496,14 @@ mod tests {

    #[actix_rt::test]
    async fn test_static_files_with_spaces() {
-        let mut srv = test::init_service(
+        let srv = test::init_service(
            App::new().service(Files::new("/", ".").index_file("Cargo.toml")),
        )
        .await;
        let request = TestRequest::get()
            .uri("/tests/test%20space.binary")
            .to_request();
-        let response = test::call_service(&mut srv, request).await;
+        let response = test::call_service(&srv, request).await;
        assert_eq!(response.status(), StatusCode::OK);

        let bytes = test::read_body(response).await;
@ -485,28 +513,28 @@ mod tests {

    #[actix_rt::test]
    async fn test_files_not_allowed() {
-        let mut srv = test::init_service(App::new().service(Files::new("/", "."))).await;
+        let srv = test::init_service(App::new().service(Files::new("/", "."))).await;

        let req = TestRequest::default()
            .uri("/Cargo.toml")
            .method(Method::POST)
            .to_request();

-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
        assert_eq!(resp.status(), StatusCode::METHOD_NOT_ALLOWED);

-        let mut srv = test::init_service(App::new().service(Files::new("/", "."))).await;
+        let srv = test::init_service(App::new().service(Files::new("/", "."))).await;
        let req = TestRequest::default()
            .method(Method::PUT)
            .uri("/Cargo.toml")
            .to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
        assert_eq!(resp.status(), StatusCode::METHOD_NOT_ALLOWED);
    }

    #[actix_rt::test]
    async fn test_files_guards() {
-        let mut srv = test::init_service(
+        let srv = test::init_service(
            App::new().service(Files::new("/", ".").use_guards(guard::Post())),
        )
        .await;
@ -516,13 +544,13 @@ mod tests {
            .method(Method::POST)
            .to_request();

-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
        assert_eq!(resp.status(), StatusCode::OK);
    }

    #[actix_rt::test]
    async fn test_named_file_content_encoding() {
-        let mut srv = test::init_service(App::new().wrap(Compress::default()).service(
+        let srv = test::init_service(App::new().wrap(Compress::default()).service(
            web::resource("/").to(|| async {
                NamedFile::open("Cargo.toml")
                    .unwrap()
@ -533,16 +561,16 @@ mod tests {

        let request = TestRequest::get()
            .uri("/")
-            .header(header::ACCEPT_ENCODING, "gzip")
+            .insert_header((header::ACCEPT_ENCODING, "gzip"))
            .to_request();
-        let res = test::call_service(&mut srv, request).await;
+        let res = test::call_service(&srv, request).await;
        assert_eq!(res.status(), StatusCode::OK);
        assert!(!res.headers().contains_key(header::CONTENT_ENCODING));
    }

    #[actix_rt::test]
    async fn test_named_file_content_encoding_gzip() {
-        let mut srv = test::init_service(App::new().wrap(Compress::default()).service(
+        let srv = test::init_service(App::new().wrap(Compress::default()).service(
            web::resource("/").to(|| async {
                NamedFile::open("Cargo.toml")
                    .unwrap()
@ -553,9 +581,9 @@ mod tests {

        let request = TestRequest::get()
            .uri("/")
-            .header(header::ACCEPT_ENCODING, "gzip")
+            .insert_header((header::ACCEPT_ENCODING, "gzip"))
            .to_request();
-        let res = test::call_service(&mut srv, request).await;
+        let res = test::call_service(&srv, request).await;
        assert_eq!(res.status(), StatusCode::OK);
        assert_eq!(
            res.headers()
@ -577,27 +605,27 @@ mod tests {

    #[actix_rt::test]
    async fn test_static_files() {
-        let mut srv = test::init_service(
+        let srv = test::init_service(
            App::new().service(Files::new("/", ".").show_files_listing()),
        )
        .await;
        let req = TestRequest::with_uri("/missing").to_request();

-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
        assert_eq!(resp.status(), StatusCode::NOT_FOUND);

-        let mut srv = test::init_service(App::new().service(Files::new("/", "."))).await;
+        let srv = test::init_service(App::new().service(Files::new("/", "."))).await;

        let req = TestRequest::default().to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
        assert_eq!(resp.status(), StatusCode::NOT_FOUND);

-        let mut srv = test::init_service(
+        let srv = test::init_service(
            App::new().service(Files::new("/", ".").show_files_listing()),
        )
        .await;
        let req = TestRequest::with_uri("/tests").to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
        assert_eq!(
            resp.headers().get(header::CONTENT_TYPE).unwrap(),
            "text/html; charset=utf-8"
@ -610,16 +638,16 @@ mod tests {
    #[actix_rt::test]
    async fn test_redirect_to_slash_directory() {
        // should not redirect if no index
-        let mut srv = test::init_service(
+        let srv = test::init_service(
            App::new().service(Files::new("/", ".").redirect_to_slash_directory()),
        )
        .await;
        let req = TestRequest::with_uri("/tests").to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
        assert_eq!(resp.status(), StatusCode::NOT_FOUND);

        // should redirect if index present
-        let mut srv = test::init_service(
+        let srv = test::init_service(
            App::new().service(
                Files::new("/", ".")
                    .index_file("test.png")
@ -628,12 +656,12 @@ mod tests {
        )
        .await;
        let req = TestRequest::with_uri("/tests").to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
        assert_eq!(resp.status(), StatusCode::FOUND);

        // should not redirect if the path is wrong
        let req = TestRequest::with_uri("/not_existing").to_request();
-        let resp = test::call_service(&mut srv, req).await;
+        let resp = test::call_service(&srv, req).await;
        assert_eq!(resp.status(), StatusCode::NOT_FOUND);
    }

@ -645,7 +673,7 @@ mod tests {

    #[actix_rt::test]
    async fn test_default_handler_file_missing() {
-        let mut st = Files::new("/", ".")
+        let st = Files::new("/", ".")
            .default_handler(|req: ServiceRequest| {
                ok(req.into_response(HttpResponse::Ok().body("default content")))
            })
@ -654,7 +682,7 @@ mod tests {
            .unwrap();
        let req = TestRequest::with_uri("/missing").to_srv_request();

-        let resp = test::call_service(&mut st, req).await;
+        let resp = test::call_service(&st, req).await;
        assert_eq!(resp.status(), StatusCode::OK);
        let bytes = test::read_body(resp).await;
        assert_eq!(bytes, web::Bytes::from_static(b"default content"));
@ -723,54 +751,49 @@ mod tests {
    //         );
    //     }

-    //     #[actix_rt::test]
-    //     fn integration_serve_index() {
-    //         let mut srv = test::TestServer::with_factory(|| {
-    //             App::new().handler(
-    //                 "test",
-    //                 Files::new(".").index_file("Cargo.toml"),
-    //             )
-    //         });
+    #[actix_rt::test]
+    async fn integration_serve_index() {
+        let srv = test::init_service(
+            App::new().service(Files::new("test", ".").index_file("Cargo.toml")),
+        )
+        .await;

-    //         let request = srv.get().uri(srv.url("/test")).finish().unwrap();
-    //         let response = srv.execute(request.send()).unwrap();
-    //         assert_eq!(response.status(), StatusCode::OK);
-    //         let bytes = srv.execute(response.body()).unwrap();
-    //         let data = Bytes::from(fs::read("Cargo.toml").unwrap());
-    //         assert_eq!(bytes, data);
+        let req = TestRequest::get().uri("/test").to_request();
+        let res = test::call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::OK);

-    //         let request = srv.get().uri(srv.url("/test/")).finish().unwrap();
-    //         let response = srv.execute(request.send()).unwrap();
-    //         assert_eq!(response.status(), StatusCode::OK);
-    //         let bytes = srv.execute(response.body()).unwrap();
-    //         let data = Bytes::from(fs::read("Cargo.toml").unwrap());
-    //         assert_eq!(bytes, data);
+        let bytes = test::read_body(res).await;

-    //         // nonexistent index file
-    //         let request = srv.get().uri(srv.url("/test/unknown")).finish().unwrap();
-    //         let response = srv.execute(request.send()).unwrap();
-    //         assert_eq!(response.status(), StatusCode::NOT_FOUND);
+        let data = Bytes::from(fs::read("Cargo.toml").unwrap());
+        assert_eq!(bytes, data);

-    //         let request = srv.get().uri(srv.url("/test/unknown/")).finish().unwrap();
-    //         let response = srv.execute(request.send()).unwrap();
-    //         assert_eq!(response.status(), StatusCode::NOT_FOUND);
-    //     }
+        let req = TestRequest::get().uri("/test/").to_request();
+        let res = test::call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::OK);

-    //     #[actix_rt::test]
-    //     fn integration_percent_encoded() {
-    //         let mut srv = test::TestServer::with_factory(|| {
-    //             App::new().handler(
-    //                 "test",
-    //                 Files::new(".").index_file("Cargo.toml"),
-    //             )
-    //         });
+        let bytes = test::read_body(res).await;
+        let data = Bytes::from(fs::read("Cargo.toml").unwrap());
+        assert_eq!(bytes, data);

-    //         let request = srv
-    //             .get()
-    //             .uri(srv.url("/test/%43argo.toml"))
-    //             .finish()
-    //             .unwrap();
-    //         let response = srv.execute(request.send()).unwrap();
-    //         assert_eq!(response.status(), StatusCode::OK);
-    //     }
+        // nonexistent index file
+        let req = TestRequest::get().uri("/test/unknown").to_request();
+        let res = test::call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::NOT_FOUND);
+
+        let req = TestRequest::get().uri("/test/unknown/").to_request();
+        let res = test::call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::NOT_FOUND);
+    }
+
+    #[actix_rt::test]
+    async fn integration_percent_encoded() {
+        let srv = test::init_service(
+            App::new().service(Files::new("test", ".").index_file("Cargo.toml")),
+        )
+        .await;
+
+        let req = TestRequest::get().uri("/test/%43argo.toml").to_request();
+        let res = test::call_service(&srv, req).await;
+        assert_eq!(res.status(), StatusCode::OK);
+    }
 }
--- a/actix-files/src/named.rs
+++ b/actix-files/src/named.rs
@ -16,10 +16,9 @@ use actix_web::{
        },
        ContentEncoding, StatusCode,
    },
-    Error, HttpMessage, HttpRequest, HttpResponse, Responder,
+    HttpMessage, HttpRequest, HttpResponse, Responder,
 };
 use bitflags::bitflags;
-use futures_util::future::{ready, Ready};
 use mime_guess::from_path;

 use crate::ChunkedReadFile;
@ -277,37 +276,31 @@ impl NamedFile {
    }

    /// Creates an `HttpResponse` with file as a streaming body.
-    pub fn into_response(self, req: &HttpRequest) -> Result<HttpResponse, Error> {
+    pub fn into_response(self, req: &HttpRequest) -> HttpResponse {
        if self.status_code != StatusCode::OK {
            let mut res = HttpResponse::build(self.status_code);

            if self.flags.contains(Flags::PREFER_UTF8) {
                let ct = equiv_utf8_text(self.content_type.clone());
-                res.header(header::CONTENT_TYPE, ct.to_string());
+                res.insert_header((header::CONTENT_TYPE, ct.to_string()));
            } else {
-                res.header(header::CONTENT_TYPE, self.content_type.to_string());
+                res.insert_header((header::CONTENT_TYPE, self.content_type.to_string()));
            }

            if self.flags.contains(Flags::CONTENT_DISPOSITION) {
-                res.header(
+                res.insert_header((
                    header::CONTENT_DISPOSITION,
                    self.content_disposition.to_string(),
-                );
+                ));
            }

            if let Some(current_encoding) = self.encoding {
                res.encoding(current_encoding);
            }

-            let reader = ChunkedReadFile {
-                size: self.md.len(),
-                offset: 0,
-                file: Some(self.file),
-                fut: None,
-                counter: 0,
-            };
+            let reader = ChunkedReadFile::new(self.md.len(), 0, self.file);

-            return Ok(res.streaming(reader));
+            return res.streaming(reader);
        }

        let etag = if self.flags.contains(Flags::ETAG) {
@ -332,7 +325,7 @@ impl NamedFile {
            let t2: SystemTime = since.clone().into();

            match (t1.duration_since(UNIX_EPOCH), t2.duration_since(UNIX_EPOCH)) {
-                (Ok(t1), Ok(t2)) => t1 > t2,
+                (Ok(t1), Ok(t2)) => t1.as_secs() > t2.as_secs(),
                _ => false,
            }
        } else {
@ -351,7 +344,7 @@ impl NamedFile {
            let t2: SystemTime = since.clone().into();

            match (t1.duration_since(UNIX_EPOCH), t2.duration_since(UNIX_EPOCH)) {
-                (Ok(t1), Ok(t2)) => t1 <= t2,
+                (Ok(t1), Ok(t2)) => t1.as_secs() <= t2.as_secs(),
                _ => false,
            }
        } else {
@ -362,16 +355,16 @@ impl NamedFile {

        if self.flags.contains(Flags::PREFER_UTF8) {
            let ct = equiv_utf8_text(self.content_type.clone());
-            resp.header(header::CONTENT_TYPE, ct.to_string());
+            resp.insert_header((header::CONTENT_TYPE, ct.to_string()));
        } else {
-            resp.header(header::CONTENT_TYPE, self.content_type.to_string());
+            resp.insert_header((header::CONTENT_TYPE, self.content_type.to_string()));
        }

        if self.flags.contains(Flags::CONTENT_DISPOSITION) {
-            resp.header(
+            resp.insert_header((
                header::CONTENT_DISPOSITION,
                self.content_disposition.to_string(),
-            );
+            ));
        }

        // default compressing
@ -380,14 +373,14 @@ impl NamedFile {
        }

        if let Some(lm) = last_modified {
-            resp.header(header::LAST_MODIFIED, lm.to_string());
+            resp.insert_header((header::LAST_MODIFIED, lm.to_string()));
        }

        if let Some(etag) = etag {
-            resp.header(header::ETAG, etag.to_string());
+            resp.insert_header((header::ETAG, etag.to_string()));
        }

-        resp.header(header::ACCEPT_RANGES, "bytes");
+        resp.insert_header((header::ACCEPT_RANGES, "bytes"));

        let mut length = self.md.len();
        let mut offset = 0;
@ -400,7 +393,7 @@ impl NamedFile {
                    offset = ranges[0].start;

                    resp.encoding(ContentEncoding::Identity);
-                    resp.header(
+                    resp.insert_header((
                        header::CONTENT_RANGE,
                        format!(
                            "bytes {}-{}/{}",
@ -408,35 +401,32 @@ impl NamedFile {
                            offset + length - 1,
                            self.md.len()
                        ),
-                    );
+                    ));
                } else {
-                    resp.header(header::CONTENT_RANGE, format!("bytes */{}", length));
-                    return Ok(resp.status(StatusCode::RANGE_NOT_SATISFIABLE).finish());
+                    resp.insert_header((
+                        header::CONTENT_RANGE,
+                        format!("bytes */{}", length),
+                    ));
+                    return resp.status(StatusCode::RANGE_NOT_SATISFIABLE).finish();
                };
            } else {
-                return Ok(resp.status(StatusCode::BAD_REQUEST).finish());
+                return resp.status(StatusCode::BAD_REQUEST).finish();
            };
        };

        if precondition_failed {
-            return Ok(resp.status(StatusCode::PRECONDITION_FAILED).finish());
+            return resp.status(StatusCode::PRECONDITION_FAILED).finish();
        } else if not_modified {
-            return Ok(resp.status(StatusCode::NOT_MODIFIED).finish());
+            return resp.status(StatusCode::NOT_MODIFIED).finish();
        }

-        let reader = ChunkedReadFile {
-            offset,
-            size: length,
-            file: Some(self.file),
-            fut: None,
-            counter: 0,
-        };
+        let reader = ChunkedReadFile::new(length, offset, self.file);

        if offset != 0 || length != self.md.len() {
            resp.status(StatusCode::PARTIAL_CONTENT);
        }

-        Ok(resp.body(SizedStream::new(length, reader)))
+        resp.body(SizedStream::new(length, reader))
    }
 }

@ -495,10 +485,7 @@ fn none_match(etag: Option<&header::EntityTag>, req: &HttpRequest) -> bool {
 }

 impl Responder for NamedFile {
-    type Error = Error;
-    type Future = Ready<Result<HttpResponse, Error>>;
-
-    fn respond_to(self, req: &HttpRequest) -> Self::Future {
-        ready(self.into_response(req))
+    fn respond_to(self, req: &HttpRequest) -> HttpResponse {
+        self.into_response(req)
    }
 }
--- a/actix-files/src/service.rs
+++ b/actix-files/src/service.rs
@ -1,9 +1,4 @@
-use std::{
-    fmt, io,
-    path::PathBuf,
-    rc::Rc,
-    task::{Context, Poll},
-};
+use std::{fmt, io, path::PathBuf, rc::Rc, task::Poll};

 use actix_service::Service;
 use actix_web::{
@ -40,10 +35,10 @@ type FilesServiceFuture = Either<
 >;

 impl FilesService {
-    fn handle_err(&mut self, e: io::Error, req: ServiceRequest) -> FilesServiceFuture {
+    fn handle_err(&self, e: io::Error, req: ServiceRequest) -> FilesServiceFuture {
        log::debug!("Failed to handle {}: {}", req.path(), e);

-        if let Some(ref mut default) = self.default {
+        if let Some(ref default) = self.default {
            Either::Right(default.call(req))
        } else {
            Either::Left(ok(req.error_response(e)))
@ -62,11 +57,9 @@ impl Service<ServiceRequest> for FilesService {
    type Error = Error;
    type Future = FilesServiceFuture;

-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
-    }
+    actix_service::always_ready!();

-    fn call(&mut self, req: ServiceRequest) -> Self::Future {
+    fn call(&self, req: ServiceRequest) -> Self::Future {
        let is_method_valid = if let Some(guard) = &self.guards {
            // execute user defined guards
            (**guard).check(req.head())
@ -78,7 +71,7 @@ impl Service<ServiceRequest> for FilesService {
        if !is_method_valid {
            return Either::Left(ok(req.into_response(
                actix_web::HttpResponse::MethodNotAllowed()
-                    .header(header::CONTENT_TYPE, "text/plain")
+                    .insert_header(header::ContentType(mime::TEXT_PLAIN_UTF_8))
                    .body("Request did not meet this resource's requirements."),
            )));
        }
@ -102,7 +95,7 @@ impl Service<ServiceRequest> for FilesService {

                    return Either::Left(ok(req.into_response(
                        HttpResponse::Found()
-                            .header(header::LOCATION, redirect_to)
+                            .insert_header((header::LOCATION, redirect_to))
                            .body("")
                            .into_body(),
                    )));
@ -120,10 +113,8 @@ impl Service<ServiceRequest> for FilesService {
                        named_file.flags = self.file_flags;

                        let (req, _) = req.into_parts();
-                        Either::Left(ok(match named_file.into_response(&req) {
-                            Ok(item) => ServiceResponse::new(req, item),
-                            Err(e) => ServiceResponse::from_err(e, req),
-                        }))
+                        let res = named_file.into_response(&req);
+                        Either::Left(ok(ServiceResponse::new(req, res)))
                    }
                    Err(e) => self.handle_err(e, req),
                }
@ -154,12 +145,8 @@ impl Service<ServiceRequest> for FilesService {
                    named_file.flags = self.file_flags;

                    let (req, _) = req.into_parts();
-                    match named_file.into_response(&req) {
-                        Ok(item) => {
-                            Either::Left(ok(ServiceResponse::new(req.clone(), item)))
-                        }
-                        Err(e) => Either::Left(ok(ServiceResponse::from_err(e, req))),
-                    }
+                    let res = named_file.into_response(&req);
+                    Either::Left(ok(ServiceResponse::new(req, res)))
                }
                Err(e) => self.handle_err(e, req),
            }
--- a/actix-files/tests/encoding.rs
+++ b/actix-files/tests/encoding.rs
@ -11,11 +11,10 @@ use actix_web::{
 #[actix_rt::test]
 async fn test_utf8_file_contents() {
    // use default ISO-8859-1 encoding
-    let mut srv =
-        test::init_service(App::new().service(Files::new("/", "./tests"))).await;
+    let srv = test::init_service(App::new().service(Files::new("/", "./tests"))).await;

    let req = TestRequest::with_uri("/utf8.txt").to_request();
-    let res = test::call_service(&mut srv, req).await;
+    let res = test::call_service(&srv, req).await;

    assert_eq!(res.status(), StatusCode::OK);
    assert_eq!(
@ -24,13 +23,13 @@ async fn test_utf8_file_contents() {
    );

    // prefer UTF-8 encoding
-    let mut srv = test::init_service(
+    let srv = test::init_service(
        App::new().service(Files::new("/", "./tests").prefer_utf8(true)),
    )
    .await;

    let req = TestRequest::with_uri("/utf8.txt").to_request();
-    let res = test::call_service(&mut srv, req).await;
+    let res = test::call_service(&srv, req).await;

    assert_eq!(res.status(), StatusCode::OK);
    assert_eq!(
--- a/actix-http-test/CHANGES.md
+++ b/actix-http-test/CHANGES.md
@ -3,6 +3,10 @@
 ## Unreleased - 2021-xx-xx


+## 3.0.0-beta.2 - 2021-02-10
+* No notable changes.
+
+
 ## 3.0.0-beta.1 - 2021-01-07
 * Update `bytes` to `1.0`. [#1813]

--- a/actix-http-test/Cargo.toml
+++ b/actix-http-test/Cargo.toml
@ -1,6 +1,6 @@
 [package]
 name = "actix-http-test"
-version = "3.0.0-beta.1"
+version = "3.0.0-beta.2"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
 description = "Various helpers for Actix applications to use during testing"
 readme = "README.md"
@ -26,16 +26,16 @@ path = "src/lib.rs"
 default = []

 # openssl
-openssl = ["open-ssl", "awc/openssl"]
+openssl = ["tls-openssl", "awc/openssl"]

 [dependencies]
-actix-service = "2.0.0-beta.2"
+actix-service = "2.0.0-beta.4"
 actix-codec = "0.4.0-beta.1"
-actix-tls = "3.0.0-beta.2"
-actix-utils = "3.0.0-beta.1"
-actix-rt = "2.0.0-beta.1"
-actix-server = "2.0.0-beta.2"
-awc = "3.0.0-beta.1"
+actix-tls = "3.0.0-beta.3"
+actix-utils = "3.0.0-beta.2"
+actix-rt = "2"
+actix-server = "2.0.0-beta.3"
+awc = "3.0.0-beta.2"

 base64 = "0.13"
 bytes = "1"
@ -47,9 +47,9 @@ serde = "1.0"
 serde_json = "1.0"
 slab = "0.4"
 serde_urlencoded = "0.7"
-time = { version = "0.2.7", default-features = false, features = ["std"] }
-open-ssl = { version = "0.10", package = "openssl", optional = true }
+time = { version = "0.2.23", default-features = false, features = ["std"] }
+tls-openssl = { version = "0.10.9", package = "openssl", optional = true }

 [dev-dependencies]
-actix-web = "4.0.0-beta.1"
-actix-http = "3.0.0-beta.1"
+actix-web = "4.0.0-beta.2"
+actix-http = "3.0.0-beta.2"
--- a/actix-http-test/README.md
+++ b/actix-http-test/README.md
@ -4,7 +4,7 @@

 [![crates.io](https://img.shields.io/crates/v/actix-http-test?label=latest)](https://crates.io/crates/actix-http-test)
 [![Documentation](https://docs.rs/actix-http-test/badge.svg?version=2.1.0)](https://docs.rs/actix-http-test/2.1.0)
-![Apache 2.0 or MIT licensed](https://img.shields.io/crates/l/actix-http-test)
+![MIT or Apache 2.0 licensed](https://img.shields.io/crates/l/actix-http-test)
 [![Dependency Status](https://deps.rs/crate/actix-http-test/2.1.0/status.svg)](https://deps.rs/crate/actix-http-test/2.1.0)
 [![Join the chat at https://gitter.im/actix/actix-web](https://badges.gitter.im/actix/actix-web.svg)](https://gitter.im/actix/actix-web?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)

--- a/actix-http-test/src/lib.rs
+++ b/actix-http-test/src/lib.rs
@ -4,6 +4,9 @@
 #![doc(html_logo_url = "https://actix.rs/img/logo.png")]
 #![doc(html_favicon_url = "https://actix.rs/favicon.ico")]

+#[cfg(feature = "openssl")]
+extern crate tls_openssl as openssl;
+
 use std::sync::mpsc;
 use std::{net, thread, time};

@ -60,7 +63,7 @@ pub async fn test_server_with_addr<F: ServiceFactory<TcpStream>>(

    // run server in separate thread
    thread::spawn(move || {
-        let sys = System::new("actix-test-server");
+        let sys = System::new();
        let local_addr = tcp.local_addr().unwrap();

        let srv = Server::build()
@ -69,7 +72,7 @@ pub async fn test_server_with_addr<F: ServiceFactory<TcpStream>>(
            .disable_signals();

        sys.block_on(async {
-            srv.start();
+            srv.run();
            tx.send((System::current(), local_addr)).unwrap();
        });

@ -82,7 +85,7 @@ pub async fn test_server_with_addr<F: ServiceFactory<TcpStream>>(
        let connector = {
            #[cfg(feature = "openssl")]
            {
-                use open_ssl::ssl::{SslConnector, SslMethod, SslVerifyMode};
+                use openssl::ssl::{SslConnector, SslMethod, SslVerifyMode};

                let mut builder = SslConnector::builder(SslMethod::tls()).unwrap();
                builder.set_verify(SslVerifyMode::NONE);
@ -106,7 +109,6 @@ pub async fn test_server_with_addr<F: ServiceFactory<TcpStream>>(

        Client::builder().connector(connector).finish()
    };
-    actix_tls::connect::start_default_resolver().await.unwrap();

    TestServer {
        addr,
--- a/actix-http/CHANGES.md
+++ b/actix-http/CHANGES.md
@ -3,6 +3,57 @@
 ## Unreleased - 2021-xx-xx


+## 3.0.0-beta.2 - 2021-02-19
+### Added
+* `IntoHeaderPair` trait that allows using typed and untyped headers in the same methods. [#1869]
+* `ResponseBuilder::insert_header` method which allows using typed headers. [#1869]
+* `ResponseBuilder::append_header` method which allows using typed headers. [#1869]
+* `TestRequest::insert_header` method which allows using typed headers. [#1869]
+* `ContentEncoding` implements all necessary header traits. [#1912]
+* `HeaderMap::len_keys` has the behavior of the old `len` method. [#1964]
+* `HeaderMap::drain` as an efficient draining iterator. [#1964]
+* Implement `IntoIterator` for owned `HeaderMap`. [#1964]
+* `trust-dns` optional feature to enable `trust-dns-resolver` as client dns resolver. [#1969]
+
+### Changed
+* `ResponseBuilder::content_type` now takes an `impl IntoHeaderValue` to support using typed
+  `mime` types. [#1894]
+* Renamed `IntoHeaderValue::{try_into => try_into_value}` to avoid ambiguity with std
+  `TryInto` trait. [#1894]
+* `Extensions::insert` returns Option of replaced item. [#1904]
+* Remove `HttpResponseBuilder::json2()`. [#1903]
+* Enable `HttpResponseBuilder::json()` to receive data by value and reference. [#1903]
+* `client::error::ConnectError` Resolver variant contains `Box<dyn std::error::Error>` type. [#1905]
+* `client::ConnectorConfig` default timeout changed to 5 seconds. [#1905]
+* Simplify `BlockingError` type to a unit struct. It's now only triggered when blocking thread pool
+  is dead. [#1957]
+* `HeaderMap::len` now returns number of values instead of number of keys. [#1964]
+* `HeaderMap::insert` now returns iterator of removed values. [#1964]
+* `HeaderMap::remove` now returns iterator of removed values. [#1964]
+
+### Removed
+* `ResponseBuilder::set`; use `ResponseBuilder::insert_header`. [#1869]
+* `ResponseBuilder::set_header`; use `ResponseBuilder::insert_header`. [#1869]
+* `ResponseBuilder::header`; use `ResponseBuilder::append_header`. [#1869]
+* `TestRequest::with_hdr`; use `TestRequest::default().insert_header()`. [#1869]
+* `TestRequest::with_header`; use `TestRequest::default().insert_header()`. [#1869]
+* `actors` optional feature. [#1969]
+* `ResponseError` impl for `actix::MailboxError`. [#1969]
+
+### Documentation
+* Vastly improve docs and add examples for `HeaderMap`. [#1964]
+
+[#1869]: https://github.com/actix/actix-web/pull/1869
+[#1894]: https://github.com/actix/actix-web/pull/1894
+[#1903]: https://github.com/actix/actix-web/pull/1903
+[#1904]: https://github.com/actix/actix-web/pull/1904
+[#1905]: https://github.com/actix/actix-web/pull/1905
+[#1912]: https://github.com/actix/actix-web/pull/1912
+[#1957]: https://github.com/actix/actix-web/pull/1957
+[#1964]: https://github.com/actix/actix-web/pull/1964
+[#1969]: https://github.com/actix/actix-web/pull/1969
+
+
 ## 3.0.0-beta.1 - 2021-01-07
 ### Added
 * Add `Http3` to `Protocol` enum for future compatibility and also mark `#[non_exhaustive]`.
@ -22,10 +73,14 @@
 * Remove `ConnectError::SslHandshakeError` and re-export of `HandshakeError`.
  due to the removal of this type from `tokio-openssl` crate. openssl handshake 
  error would return as `ConnectError::SslError`. [#1813]
+* Remove `actix-threadpool` dependency. Use `actix_rt::task::spawn_blocking`.
+  Due to this change `actix_threadpool::BlockingError` type is moved into 
+  `actix_http::error` module. [#1878]

 [#1813]: https://github.com/actix/actix-web/pull/1813
 [#1857]: https://github.com/actix/actix-web/pull/1857
 [#1864]: https://github.com/actix/actix-web/pull/1864
+[#1878]: https://github.com/actix/actix-web/pull/1878


 ## 2.2.0 - 2020-11-25
@ -72,15 +127,14 @@
 * Update actix-connect and actix-tls dependencies.


-## [2.0.0-beta.3] - 2020-08-14
-
+## 2.0.0-beta.3 - 2020-08-14
 ### Fixed
 * Memory leak of `client::pool::ConnectorPoolSupport`. [#1626]

 [#1626]: https://github.com/actix/actix-web/pull/1626


-## [2.0.0-beta.2] - 2020-07-21
+## 2.0.0-beta.2 - 2020-07-21
 ### Fixed
 * Potential UB in h1 decoder using uninitialized memory. [#1614]

@ -91,10 +145,8 @@
 [#1615]: https://github.com/actix/actix-web/pull/1615


-## [2.0.0-beta.1] - 2020-07-11
-
+## 2.0.0-beta.1 - 2020-07-11
 ### Changed
-
 * Migrate cookie handling to `cookie` crate. [#1558]
 * Update `sha-1` to 0.9. [#1586]
 * Fix leak in client pool. [#1580]
@ -104,33 +156,30 @@
 [#1586]: https://github.com/actix/actix-web/pull/1586
 [#1580]: https://github.com/actix/actix-web/pull/1580

-## [2.0.0-alpha.4] - 2020-05-21

+## 2.0.0-alpha.4 - 2020-05-21
 ### Changed
-
 * Bump minimum supported Rust version to 1.40
-* content_length function is removed, and you can set Content-Length by calling no_chunking function [#1439]
+* content_length function is removed, and you can set Content-Length by calling
+  no_chunking function [#1439]
 * `BodySize::Sized64` variant has been removed. `BodySize::Sized` now receives a
  `u64` instead of a `usize`.
 * Update `base64` dependency to 0.12

 ### Fixed
-
 * Support parsing of `SameSite=None` [#1503]

 [#1439]: https://github.com/actix/actix-web/pull/1439
 [#1503]: https://github.com/actix/actix-web/pull/1503

-## [2.0.0-alpha.3] - 2020-05-08

+## 2.0.0-alpha.3 - 2020-05-08
 ### Fixed
-
 * Correct spelling of ConnectError::Unresolved [#1487]
 * Fix a mistake in the encoding of websocket continuation messages wherein
  Item::FirstText and Item::FirstBinary are each encoded as the other.

 ### Changed
-
 * Implement `std::error::Error` for our custom errors [#1422]
 * Remove `failure` support for `ResponseError` since that crate
  will be deprecated in the near future.
@ -138,338 +187,247 @@
 [#1422]: https://github.com/actix/actix-web/pull/1422
 [#1487]: https://github.com/actix/actix-web/pull/1487

-## [2.0.0-alpha.2] - 2020-03-07

+## 2.0.0-alpha.2 - 2020-03-07
 ### Changed
-
 * Update `actix-connect` and `actix-tls` dependency to 2.0.0-alpha.1. [#1395]
-
-* Change default initial window size and connection window size for HTTP2 to 2MB and 1MB respectively
-  to improve download speed for awc when downloading large objects. [#1394]
-
-* client::Connector accepts initial_window_size and initial_connection_window_size HTTP2 configuration. [#1394]
-
+* Change default initial window size and connection window size for HTTP2 to 2MB and 1MB
+  respectively to improve download speed for awc when downloading large objects. [#1394]
+* client::Connector accepts initial_window_size and initial_connection_window_size
+  HTTP2 configuration. [#1394]
 * client::Connector allowing to set max_http_version to limit HTTP version to be used. [#1394]

 [#1394]: https://github.com/actix/actix-web/pull/1394
 [#1395]: https://github.com/actix/actix-web/pull/1395

-## [2.0.0-alpha.1] - 2020-02-27

+## 2.0.0-alpha.1 - 2020-02-27
 ### Changed
-
 * Update the `time` dependency to 0.2.7.
 * Moved actors messages support from actix crate, enabled with feature `actors`.
-* Breaking change: trait MessageBody requires Unpin and accepting Pin<&mut Self> instead of &mut self in the poll_next().
+* Breaking change: trait MessageBody requires Unpin and accepting `Pin<&mut Self>` instead of
+  `&mut self` in the poll_next().
 * MessageBody is not implemented for &'static [u8] anymore.

 ### Fixed
-
 * Allow `SameSite=None` cookies to be sent in a response.

-## [1.0.1] - 2019-12-20

+## 1.0.1 - 2019-12-20
 ### Fixed
-
 * Poll upgrade service's readiness from HTTP service handlers
-
 * Replace brotli with brotli2 #1224

-## [1.0.0] - 2019-12-13

+## 1.0.0 - 2019-12-13
 ### Added
-
 * Add websockets continuation frame support

 ### Changed
-
 * Replace `flate2-xxx` features with `compress`

-## [1.0.0-alpha.5] - 2019-12-09

+## 1.0.0-alpha.5 - 2019-12-09
 ### Fixed
-
 * Check `Upgrade` service readiness before calling it
-
-* Fix buffer remaining capacity calcualtion
+* Fix buffer remaining capacity calculation

 ### Changed
-
 * Websockets: Ping and Pong should have binary data #1049

-## [1.0.0-alpha.4] - 2019-12-08

+## 1.0.0-alpha.4 - 2019-12-08
 ### Added
-
 * Add impl ResponseBuilder for Error

 ### Changed
-
 * Use rust based brotli compression library

-## [1.0.0-alpha.3] - 2019-12-07
-
+## 1.0.0-alpha.3 - 2019-12-07
 ### Changed
-
 * Migrate to tokio 0.2
-
 * Migrate to `std::future`


-## [0.2.11] - 2019-11-06
-
+## 0.2.11 - 2019-11-06
 ### Added
-
 * Add support for serde_json::Value to be passed as argument to ResponseBuilder.body()
-
-* Add an additional `filename*` param in the `Content-Disposition` header of `actix_files::NamedFile` to be more compatible. (#1151)
-
+* Add an additional `filename*` param in the `Content-Disposition` header of
+  `actix_files::NamedFile` to be more compatible. (#1151)
 * Allow to use `std::convert::Infallible` as `actix_http::error::Error`

 ### Fixed
+* To be compatible with non-English error responses, `ResponseError` rendered with `text/plain;
+  charset=utf-8` header [#1118]

-* To be compatible with non-English error responses, `ResponseError` rendered with `text/plain; charset=utf-8` header #1118
+[#1878]: https://github.com/actix/actix-web/pull/1878


-## [0.2.10] - 2019-09-11
-
+## 0.2.10 - 2019-09-11
 ### Added
-
-* Add support for sending HTTP requests with `Rc<RequestHead>` in addition to sending HTTP requests with `RequestHead`
+* Add support for sending HTTP requests with `Rc<RequestHead>` in addition to sending HTTP requests
+  with `RequestHead`

 ### Fixed
-
 * h2 will use error response #1080
-
 * on_connect result isn't added to request extensions for http2 requests #1009


-## [0.2.9] - 2019-08-13
-
+## 0.2.9 - 2019-08-13
 ### Changed
-
 * Dropped the `byteorder`-dependency in favor of `stdlib`-implementation
-
 * Update percent-encoding to 2.1
-
 * Update serde_urlencoded to 0.6.1

 ### Fixed
-
 * Fixed a panic in the HTTP2 handshake in client HTTP requests (#1031)


-## [0.2.8] - 2019-08-01
-
+## 0.2.8 - 2019-08-01
 ### Added
-
 * Add `rustls` support
-
 * Add `Clone` impl for `HeaderMap`

 ### Fixed
-
 * awc client panic #1016
-
-* Invalid response with compression middleware enabled, but compression-related features disabled #997
+* Invalid response with compression middleware enabled, but compression-related features
+  disabled #997


-## [0.2.7] - 2019-07-18
-
+## 0.2.7 - 2019-07-18
 ### Added
-
 * Add support for downcasting response errors #986


-## [0.2.6] - 2019-07-17
-
+## 0.2.6 - 2019-07-17
 ### Changed
-
 * Replace `ClonableService` with local copy
-
 * Upgrade `rand` dependency version to 0.7


-## [0.2.5] - 2019-06-28
-
+## 0.2.5 - 2019-06-28
 ### Added
-
 * Add `on-connect` callback, `HttpServiceBuilder::on_connect()` #946

 ### Changed
-
 * Use `encoding_rs` crate instead of unmaintained `encoding` crate
-
 * Add `Copy` and `Clone` impls for `ws::Codec`


-## [0.2.4] - 2019-06-16
-
+## 0.2.4 - 2019-06-16
 ### Fixed
-
 * Do not compress NoContent (204) responses #918


-## [0.2.3] - 2019-06-02
-
+## 0.2.3 - 2019-06-02
 ### Added
-
 * Debug impl for ResponseBuilder
-
 * From SizedStream and BodyStream for Body

 ### Changed
-
 * SizedStream uses u64


-## [0.2.2] - 2019-05-29
-
+## 0.2.2 - 2019-05-29
 ### Fixed
-
 * Parse incoming stream before closing stream on disconnect #868


-## [0.2.1] - 2019-05-25
-
+## 0.2.1 - 2019-05-25
 ### Fixed
-
 * Handle socket read disconnect


-## [0.2.0] - 2019-05-12
-
+## 0.2.0 - 2019-05-12
 ### Changed
-
 * Update actix-service to 0.4
-
 * Expect and upgrade services accept `ServerConfig` config.

 ### Deleted
-
 * `OneRequest` service


-## [0.1.5] - 2019-05-04
-
+## 0.1.5 - 2019-05-04
 ### Fixed
-
 * Clean up response extensions in response pool #817


-## [0.1.4] - 2019-04-24
-
+## 0.1.4 - 2019-04-24
 ### Added
-
 * Allow to render h1 request headers in `Camel-Case`

 ### Fixed
-
 * Read until eof for http/1.0 responses #771


-## [0.1.3] - 2019-04-23
-
+## 0.1.3 - 2019-04-23
 ### Fixed
-
 * Fix http client pool management
-
 * Fix http client wait queue management #794


-## [0.1.2] - 2019-04-23
-
+## 0.1.2 - 2019-04-23
 ### Fixed
-
 * Fix BorrowMutError panic in client connector #793


-## [0.1.1] - 2019-04-19
-
+## 0.1.1 - 2019-04-19
 ### Changed
-
 * Cookie::max_age() accepts value in seconds
-
 * Cookie::max_age_time() accepts value in time::Duration
-
 * Allow to specify server address for client connector


-## [0.1.0] - 2019-04-16
-
+## 0.1.0 - 2019-04-16
 ### Added
-
 * Expose peer addr via `Request::peer_addr()` and `RequestHead::peer_addr`

 ### Changed
-
 * `actix_http::encoding` always available
-
 * use trust-dns-resolver 0.11.0


-## [0.1.0-alpha.5] - 2019-04-12
-
+## 0.1.0-alpha.5 - 2019-04-12
 ### Added
-
 * Allow to use custom service for upgrade requests
-
 * Added `h1::SendResponse` future.

 ### Changed
-
 * MessageBody::length() renamed to MessageBody::size() for consistency
-
 * ws handshake verification functions take RequestHead instead of Request


-## [0.1.0-alpha.4] - 2019-04-08
-
+## 0.1.0-alpha.4 - 2019-04-08
 ### Added
-
 * Allow to use custom `Expect` handler
-
 * Add minimal `std::error::Error` impl for `Error`

 ### Changed
-
 * Export IntoHeaderValue
-
 * Render error and return as response body
-
-* Use thread pool for response body comression
+* Use thread pool for response body compression

 ### Deleted
-
 * Removed PayloadBuffer


-## [0.1.0-alpha.3] - 2019-04-02
-
+## 0.1.0-alpha.3 - 2019-04-02
 ### Added
-
 * Warn when an unsealed private cookie isn't valid UTF-8

 ### Fixed
-
 * Rust 1.31.0 compatibility
-
 * Preallocate read buffer for h1 codec
-
 * Detect socket disconnection during protocol selection


-## [0.1.0-alpha.2] - 2019-03-29
-
+## 0.1.0-alpha.2 - 2019-03-29
 ### Added
-
 * Added ws::Message::Nop, no-op websockets message

 ### Changed
-
-* Do not use thread pool for decomression if chunk size is smaller than 2048.
+* Do not use thread pool for decompression if chunk size is smaller than 2048.


-## [0.1.0-alpha.1] - 2019-03-28
-
+## 0.1.0-alpha.1 - 2019-03-28
 * Initial impl
--- a/actix-http/Cargo.toml
+++ b/actix-http/Cargo.toml
@ -1,6 +1,6 @@
 [package]
 name = "actix-http"
-version = "3.0.0-beta.1"
+version = "3.0.0-beta.2"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
 description = "HTTP primitives for the Actix ecosystem"
 readme = "README.md"
@ -36,31 +36,27 @@ compress = ["flate2", "brotli2"]
 # support for secure cookies
 secure-cookies = ["cookie/secure"]

-# support for actix Actor messages
-actors = ["actix"]
+# trust-dns as client dns resolver
+trust-dns = ["trust-dns-resolver"]

 [dependencies]
-actix-service = "2.0.0-beta.2"
+actix-service = "2.0.0-beta.4"
 actix-codec = "0.4.0-beta.1"
-actix-utils = "3.0.0-beta.1"
-actix-rt = "2.0.0-beta.1"
-actix-threadpool = "0.3.1"
+actix-utils = "3.0.0-beta.2"
+actix-rt = "2"
 actix-tls = "3.0.0-beta.2"
-actix = { version = "0.11.0-beta.1", optional = true }

 base64 = "0.13"
 bitflags = "1.2"
 bytes = "1"
 bytestring = "1"
 cookie = { version = "0.14.1", features = ["percent-encode"] }
-copyless = "0.1.4"
 derive_more = "0.99.5"
-either = "1.5.3"
 encoding_rs = "0.8"
-futures-channel = { version = "0.3.7", default-features = false }
-futures-core = { version = "0.3.7", default-features = false }
-futures-util = { version = "0.3.7", default-features = false, features = ["sink"] }
-fxhash = "0.2.1"
+futures-channel = { version = "0.3.7", default-features = false, features = ["alloc"] }
+futures-core = { version = "0.3.7", default-features = false, features = ["alloc"] }
+futures-util = { version = "0.3.7", default-features = false, features = ["alloc", "sink"] }
+ahash = "0.7"
 h2 = "0.3.0"
 http = "0.2.2"
 httparse = "1.3"
@ -77,23 +73,26 @@ regex = "1.3"
 serde = "1.0"
 serde_json = "1.0"
 sha-1 = "0.9"
+smallvec = "1.6"
 slab = "0.4"
 serde_urlencoded = "0.7"
-time = { version = "0.2.7", default-features = false, features = ["std"] }
+time = { version = "0.2.23", default-features = false, features = ["std"] }

 # compression
 brotli2 = { version="0.3.2", optional = true }
 flate2 = { version = "1.0.13", optional = true }

+trust-dns-resolver = { version = "0.20.0", optional = true }
+
 [dev-dependencies]
-actix-server = "2.0.0-beta.2"
-actix-http-test = { version = "3.0.0-beta.1", features = ["openssl"] }
+actix-server = "2.0.0-beta.3"
+actix-http-test = { version = "3.0.0-beta.2", features = ["openssl"] }
 actix-tls = { version = "3.0.0-beta.2", features = ["openssl"] }
 criterion = "0.3"
-env_logger = "0.7"
+env_logger = "0.8"
 serde_derive = "1.0"
-open-ssl = { version="0.10", package = "openssl" }
-rust-tls = { version="0.19", package = "rustls" }
+tls-openssl = { version = "0.10", package = "openssl" }
+tls-rustls = { version = "0.19", package = "rustls" }

 [[bench]]
 name = "write-camel-case"
--- a/actix-http/README.md
+++ b/actix-http/README.md
@ -3,10 +3,13 @@
 > HTTP primitives for the Actix ecosystem.

 [![crates.io](https://img.shields.io/crates/v/actix-http?label=latest)](https://crates.io/crates/actix-http)
-[![Documentation](https://docs.rs/actix-http/badge.svg?version=2.2.0)](https://docs.rs/actix-http/2.2.0)
-![Apache 2.0 or MIT licensed](https://img.shields.io/crates/l/actix-http)
-[![Dependency Status](https://deps.rs/crate/actix-http/2.2.0/status.svg)](https://deps.rs/crate/actix-http/2.2.0)
-[![Join the chat at https://gitter.im/actix/actix-web](https://badges.gitter.im/actix/actix-web.svg)](https://gitter.im/actix/actix-web?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![Documentation](https://docs.rs/actix-http/badge.svg?version=3.0.0-beta.2)](https://docs.rs/actix-http/3.0.0-beta.2)
+[![Version](https://img.shields.io/badge/rustc-1.46+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.46.html)
+![MIT or Apache 2.0 licensed](https://img.shields.io/crates/l/actix-http.svg)
+<br />
+[![dependency status](https://deps.rs/crate/actix-http/3.0.0-beta.2/status.svg)](https://deps.rs/crate/actix-http/3.0.0-beta.2)
+[![Download](https://img.shields.io/crates/d/actix-http.svg)](https://crates.io/crates/actix-http)
+[![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)

 ## Documentation & Resources

--- a/actix-http/examples/echo.rs
+++ b/actix-http/examples/echo.rs
@ -26,7 +26,10 @@ async fn main() -> io::Result<()> {
                    info!("request body: {:?}", body);
                    Ok::<_, Error>(
                        Response::Ok()
-                            .header("x-head", HeaderValue::from_static("dummy value!"))
+                            .insert_header((
+                                "x-head",
+                                HeaderValue::from_static("dummy value!"),
+                            ))
                            .body(body),
                    )
                })
--- a/actix-http/examples/echo2.rs
+++ b/actix-http/examples/echo2.rs
@ -15,7 +15,7 @@ async fn handle_request(mut req: Request) -> Result<Response, Error> {

    info!("request body: {:?}", body);
    Ok(Response::Ok()
-        .header("x-head", HeaderValue::from_static("dummy value!"))
+        .insert_header(("x-head", HeaderValue::from_static("dummy value!")))
        .body(body))
 }

--- a/actix-http/examples/hello-world.rs
+++ b/actix-http/examples/hello-world.rs
@ -19,7 +19,10 @@ async fn main() -> io::Result<()> {
                .finish(|_req| {
                    info!("{:?}", _req);
                    let mut res = Response::Ok();
-                    res.header("x-head", HeaderValue::from_static("dummy value!"));
+                    res.insert_header((
+                        "x-head",
+                        HeaderValue::from_static("dummy value!"),
+                    ));
                    future::ok::<_, ()>(res.body("Hello world!"))
                })
                .tcp()
--- a/actix-http/src/client/config.rs
+++ b/actix-http/src/client/config.rs
@ -1,8 +1,7 @@
 use std::time::Duration;

-// These values are taken from hyper/src/proto/h2/client.rs
-const DEFAULT_H2_CONN_WINDOW: u32 = 1024 * 1024 * 2; // 2mb
-const DEFAULT_H2_STREAM_WINDOW: u32 = 1024 * 1024; // 1mb
+const DEFAULT_H2_CONN_WINDOW: u32 = 1024 * 1024 * 2; // 2MB
+const DEFAULT_H2_STREAM_WINDOW: u32 = 1024 * 1024; // 1MB

 /// Connector configuration
 #[derive(Clone)]
@ -19,7 +18,7 @@ pub(crate) struct ConnectorConfig {
 impl Default for ConnectorConfig {
    fn default() -> Self {
        Self {
-            timeout: Duration::from_secs(1),
+            timeout: Duration::from_secs(5),
            conn_lifetime: Duration::from_secs(75),
            conn_keep_alive: Duration::from_secs(15),
            disconnect_timeout: Some(Duration::from_millis(3000)),
--- a/actix-http/src/client/connection.rs
+++ b/actix-http/src/client/connection.rs
@ -1,11 +1,14 @@
 use std::future::Future;
+use std::ops::{Deref, DerefMut};
 use std::pin::Pin;
 use std::task::{Context, Poll};
 use std::{fmt, io, time};

 use actix_codec::{AsyncRead, AsyncWrite, Framed, ReadBuf};
+use actix_rt::task::JoinHandle;
 use bytes::Bytes;
-use futures_util::future::{err, Either, FutureExt, LocalBoxFuture, Ready};
+use futures_core::future::LocalBoxFuture;
+use futures_util::future::{err, Either, FutureExt, Ready};
 use h2::client::SendRequest;
 use pin_project::pin_project;

@ -20,7 +23,53 @@ use super::{h1proto, h2proto};

 pub(crate) enum ConnectionType<Io> {
    H1(Io),
-    H2(SendRequest<Bytes>),
+    H2(H2Connection),
+}
+
+// h2 connection has two parts: SendRequest and Connection.
+// Connection is spawned as async task on runtime and H2Connection would hold a handle for
+// this task. So it can wake up and quit the task when SendRequest is dropped.
+pub(crate) struct H2Connection {
+    handle: JoinHandle<()>,
+    sender: SendRequest<Bytes>,
+}
+
+impl H2Connection {
+    pub(crate) fn new<Io>(
+        sender: SendRequest<Bytes>,
+        connection: h2::client::Connection<Io>,
+    ) -> Self
+    where
+        Io: AsyncRead + AsyncWrite + Unpin + 'static,
+    {
+        let handle = actix_rt::spawn(async move {
+            let _ = connection.await;
+        });
+
+        Self { handle, sender }
+    }
+}
+
+// wake up waker when drop
+impl Drop for H2Connection {
+    fn drop(&mut self) {
+        self.handle.abort();
+    }
+}
+
+// only expose sender type to public.
+impl Deref for H2Connection {
+    type Target = SendRequest<Bytes>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.sender
+    }
+}
+
+impl DerefMut for H2Connection {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.sender
+    }
 }

 pub trait Connection {
@ -265,3 +314,35 @@ where
        }
    }
 }
+
+#[cfg(test)]
+mod test {
+    use std::net;
+
+    use actix_rt::net::TcpStream;
+
+    use super::*;
+
+    #[actix_rt::test]
+    async fn test_h2_connection_drop() {
+        let addr = "127.0.0.1:0".parse::<net::SocketAddr>().unwrap();
+        let listener = net::TcpListener::bind(addr).unwrap();
+        let local = listener.local_addr().unwrap();
+
+        std::thread::spawn(move || while listener.accept().is_ok() {});
+
+        let tcp = TcpStream::connect(local).await.unwrap();
+        let (sender, connection) = h2::client::handshake(tcp).await.unwrap();
+        let conn = H2Connection::new(sender.clone(), connection);
+
+        assert!(sender.clone().ready().await.is_ok());
+        assert!(h2::client::SendRequest::clone(&*conn).ready().await.is_ok());
+
+        drop(conn);
+
+        match sender.ready().await {
+            Ok(_) => panic!("connection should be gone and can not be ready"),
+            Err(e) => assert!(e.is_io()),
+        };
+    }
+}
--- a/actix-http/src/client/connector.rs
+++ b/actix-http/src/client/connector.rs
@ -6,7 +6,7 @@ use actix_codec::{AsyncRead, AsyncWrite};
 use actix_rt::net::TcpStream;
 use actix_service::{apply_fn, Service, ServiceExt};
 use actix_tls::connect::{
-    default_connector, Connect as TcpConnect, Connection as TcpConnection,
+    new_connector, Connect as TcpConnect, Connection as TcpConnection, Resolver,
 };
 use actix_utils::timeout::{TimeoutError, TimeoutService};
 use http::Uri;
@ -19,7 +19,6 @@ use super::Connect;

 #[cfg(feature = "openssl")]
 use actix_tls::connect::ssl::openssl::SslConnector as OpensslConnector;
-
 #[cfg(feature = "rustls")]
 use actix_tls::connect::ssl::rustls::ClientConfig;
 #[cfg(feature = "rustls")]
@ -70,7 +69,7 @@ impl Connector<(), ()> {
    > {
        Connector {
            ssl: Self::build_ssl(vec![b"h2".to_vec(), b"http/1.1".to_vec()]),
-            connector: default_connector(),
+            connector: new_connector(resolver::resolver()),
            config: ConnectorConfig::default(),
            _phantom: PhantomData,
        }
@ -100,9 +99,9 @@ impl Connector<(), ()> {
    fn build_ssl(protocols: Vec<Vec<u8>>) -> SslConnector {
        let mut config = ClientConfig::new();
        config.set_protocols(&protocols);
-        config
-            .root_store
-            .add_server_trust_anchors(&actix_tls::accept::rustls::TLS_SERVER_ROOTS);
+        config.root_store.add_server_trust_anchors(
+            &actix_tls::connect::ssl::rustls::TLS_SERVER_ROOTS,
+        );
        SslConnector::Rustls(Arc::new(config))
    }

@ -392,11 +391,11 @@ mod connect_impl {
            Ready<Result<IoConnection<Io>, ConnectError>>,
        >;

-        fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
            self.tcp_pool.poll_ready(cx)
        }

-        fn call(&mut self, req: Connect) -> Self::Future {
+        fn call(&self, req: Connect) -> Self::Future {
            match req.uri.scheme_str() {
                Some("https") | Some("wss") => {
                    Either::Right(err(ConnectError::SslIsNotSupported))
@ -460,11 +459,11 @@ mod connect_impl {
            InnerConnectorResponseB<T2, Io1, Io2>,
        >;

-        fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
            self.tcp_pool.poll_ready(cx)
        }

-        fn call(&mut self, req: Connect) -> Self::Future {
+        fn call(&self, req: Connect) -> Self::Future {
            match req.uri.scheme_str() {
                Some("https") | Some("wss") => Either::Right(InnerConnectorResponseB {
                    fut: self.ssl_pool.call(req),
@ -532,3 +531,82 @@ mod connect_impl {
        }
    }
 }
+
+#[cfg(not(feature = "trust-dns"))]
+mod resolver {
+    use super::*;
+
+    pub(super) fn resolver() -> Resolver {
+        Resolver::Default
+    }
+}
+
+#[cfg(feature = "trust-dns")]
+mod resolver {
+    use std::{cell::RefCell, net::SocketAddr};
+
+    use actix_tls::connect::Resolve;
+    use futures_core::future::LocalBoxFuture;
+    use trust_dns_resolver::{
+        config::{ResolverConfig, ResolverOpts},
+        system_conf::read_system_conf,
+        TokioAsyncResolver,
+    };
+
+    use super::*;
+
+    pub(super) fn resolver() -> Resolver {
+        // new type for impl Resolve trait for TokioAsyncResolver.
+        struct TrustDnsResolver(TokioAsyncResolver);
+
+        impl Resolve for TrustDnsResolver {
+            fn lookup<'a>(
+                &'a self,
+                host: &'a str,
+                port: u16,
+            ) -> LocalBoxFuture<'a, Result<Vec<SocketAddr>, Box<dyn std::error::Error>>>
+            {
+                Box::pin(async move {
+                    let res = self
+                        .0
+                        .lookup_ip(host)
+                        .await?
+                        .iter()
+                        .map(|ip| SocketAddr::new(ip, port))
+                        .collect();
+                    Ok(res)
+                })
+            }
+        }
+
+        // dns struct is cached in thread local.
+        // so new client constructor can reuse the existing dns resolver.
+        thread_local! {
+            static TRUST_DNS_RESOLVER: RefCell<Option<Resolver>> = RefCell::new(None);
+        }
+
+        // get from thread local or construct a new trust-dns resolver.
+        TRUST_DNS_RESOLVER.with(|local| {
+            let resolver = local.borrow().as_ref().map(Clone::clone);
+            match resolver {
+                Some(resolver) => resolver,
+                None => {
+                    let (cfg, opts) = match read_system_conf() {
+                        Ok((cfg, opts)) => (cfg, opts),
+                        Err(e) => {
+                            log::error!("TRust-DNS can not load system config: {}", e);
+                            (ResolverConfig::default(), ResolverOpts::default())
+                        }
+                    };
+
+                    let resolver = TokioAsyncResolver::tokio(cfg, opts).unwrap();
+
+                    // box trust dns resolver and put it in thread local.
+                    let resolver = Resolver::new_custom(TrustDnsResolver(resolver));
+                    *local.borrow_mut() = Some(resolver.clone());
+                    resolver
+                }
+            }
+        })
+    }
+}
--- a/actix-http/src/client/error.rs
+++ b/actix-http/src/client/error.rs
@ -1,6 +1,5 @@
 use std::io;

-use actix_tls::connect::resolver::ResolveError;
 use derive_more::{Display, From};

 #[cfg(feature = "openssl")]
@ -23,7 +22,7 @@ pub enum ConnectError {

    /// Failed to resolve the hostname
    #[display(fmt = "Failed resolving hostname: {}", _0)]
-    Resolver(ResolveError),
+    Resolver(Box<dyn std::error::Error>),

    /// No dns records
    #[display(fmt = "No dns records found for the input")]
--- a/actix-http/src/client/h1proto.rs
+++ b/actix-http/src/client/h1proto.rs
@ -45,14 +45,14 @@ where
                Some(port) => write!(wrt, "{}:{}", host, port),
            };

-            match wrt.get_mut().split().freeze().try_into() {
+            match wrt.get_mut().split().freeze().try_into_value() {
                Ok(value) => match head {
                    RequestHeadType::Owned(ref mut head) => {
-                        head.headers.insert(HOST, value)
+                        head.headers.insert(HOST, value);
                    }
                    RequestHeadType::Rc(_, ref mut extra_headers) => {
                        let headers = extra_headers.get_or_insert(HeaderMap::new());
-                        headers.insert(HOST, value)
+                        headers.insert(HOST, value);
                    }
                },
                Err(e) => log::error!("Can not set HOST header {}", e),
--- a/actix-http/src/client/h2proto.rs
+++ b/actix-http/src/client/h2proto.rs
@ -22,9 +22,10 @@ use super::config::ConnectorConfig;
 use super::connection::{ConnectionType, IoConnection};
 use super::error::SendRequestError;
 use super::pool::Acquired;
+use crate::client::connection::H2Connection;

 pub(crate) async fn send_request<T, B>(
-    mut io: SendRequest<Bytes>,
+    mut io: H2Connection,
    head: RequestHeadType,
    body: B,
    created: time::Instant,
@ -171,9 +172,9 @@ async fn send_body<B: MessageBody>(
    }
 }

-// release SendRequest object
+/// release SendRequest object
 fn release<T: AsyncRead + AsyncWrite + Unpin + 'static>(
-    io: SendRequest<Bytes>,
+    io: H2Connection,
    pool: Option<Acquired<T>>,
    created: time::Instant,
    close: bool,
--- a/actix-http/src/client/pool.rs
+++ b/actix-http/src/client/pool.rs
@ -10,10 +10,11 @@ use actix_codec::{AsyncRead, AsyncWrite, ReadBuf};
 use actix_rt::time::{sleep, Sleep};
 use actix_service::Service;
 use actix_utils::task::LocalWaker;
+use ahash::AHashMap;
 use bytes::Bytes;
 use futures_channel::oneshot;
-use futures_util::future::{poll_fn, FutureExt, LocalBoxFuture};
-use fxhash::FxHashMap;
+use futures_core::future::LocalBoxFuture;
+use futures_util::future::{poll_fn, FutureExt};
 use h2::client::{Connection, SendRequest};
 use http::uri::Authority;
 use indexmap::IndexSet;
@ -25,6 +26,7 @@ use super::connection::{ConnectionType, IoConnection};
 use super::error::ConnectError;
 use super::h2proto::handshake;
 use super::Connect;
+use crate::client::connection::H2Connection;

 #[derive(Clone, Copy, PartialEq)]
 /// Protocol version
@ -45,7 +47,7 @@ impl From<Authority> for Key {
 }

 /// Connections pool
-pub(crate) struct ConnectionPool<T, Io: 'static>(Rc<RefCell<T>>, Rc<RefCell<Inner<Io>>>);
+pub(crate) struct ConnectionPool<T, Io: 'static>(Rc<T>, Rc<RefCell<Inner<Io>>>);

 impl<T, Io> ConnectionPool<T, Io>
 where
@ -53,13 +55,13 @@ where
    T: Service<Connect, Response = (Io, Protocol), Error = ConnectError> + 'static,
 {
    pub(crate) fn new(connector: T, config: ConnectorConfig) -> Self {
-        let connector_rc = Rc::new(RefCell::new(connector));
+        let connector_rc = Rc::new(connector);
        let inner_rc = Rc::new(RefCell::new(Inner {
            config,
            acquired: 0,
            waiters: Slab::new(),
            waiters_queue: IndexSet::new(),
-            available: FxHashMap::default(),
+            available: AHashMap::default(),
            waker: LocalWaker::new(),
        }));

@ -98,12 +100,12 @@ where
    type Error = ConnectError;
    type Future = LocalBoxFuture<'static, Result<IoConnection<Io>, ConnectError>>;

-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        self.0.poll_ready(cx)
    }

-    fn call(&mut self, req: Connect) -> Self::Future {
-        let mut connector = self.0.clone();
+    fn call(&self, req: Connect) -> Self::Future {
+        let connector = self.0.clone();
        let inner = self.1.clone();

        let fut = async move {
@ -138,10 +140,9 @@ where
                            Some(guard.consume()),
                        ))
                    } else {
-                        let (snd, connection) = handshake(io, &config).await?;
-                        actix_rt::spawn(connection.map(|_| ()));
+                        let (sender, connection) = handshake(io, &config).await?;
                        Ok(IoConnection::new(
-                            ConnectionType::H2(snd),
+                            ConnectionType::H2(H2Connection::new(sender, connection)),
                            Instant::now(),
                            Some(guard.consume()),
                        ))
@ -257,7 +258,7 @@ struct AvailableConnection<Io> {
 pub(crate) struct Inner<Io> {
    config: ConnectorConfig,
    acquired: usize,
-    available: FxHashMap<Key, VecDeque<AvailableConnection<Io>>>,
+    available: AHashMap<Key, VecDeque<AvailableConnection<Io>>>,
    waiters: Slab<
        Option<(
            Connect,
@ -325,7 +326,7 @@ where
                {
                    if let Some(timeout) = self.config.disconnect_timeout {
                        if let ConnectionType::H1(io) = conn.io {
-                            actix_rt::spawn(CloseConnection::new(io, timeout))
+                            actix_rt::spawn(CloseConnection::new(io, timeout));
                        }
                    }
                } else {
@ -340,7 +341,7 @@ where
                                    if let ConnectionType::H1(io) = io {
                                        actix_rt::spawn(CloseConnection::new(
                                            io, timeout,
-                                        ))
+                                        ));
                                    }
                                }
                                continue;
@ -372,7 +373,7 @@ where
        self.acquired -= 1;
        if let Some(timeout) = self.config.disconnect_timeout {
            if let ConnectionType::H1(io) = io {
-                actix_rt::spawn(CloseConnection::new(io, timeout))
+                actix_rt::spawn(CloseConnection::new(io, timeout));
            }
        }
        self.check_availability();
@ -428,7 +429,7 @@ struct ConnectorPoolSupport<T, Io>
 where
    Io: AsyncRead + AsyncWrite + Unpin + 'static,
 {
-    connector: T,
+    connector: Rc<T>,
    inner: Rc<RefCell<Inner<Io>>>,
 }

@ -535,7 +536,7 @@ where
            rx: Some(rx),
            inner: Some(inner),
            config,
-        })
+        });
    }
 }

@ -565,11 +566,10 @@ where

        if let Some(ref mut h2) = this.h2 {
            return match Pin::new(h2).poll(cx) {
-                Poll::Ready(Ok((snd, connection))) => {
-                    actix_rt::spawn(connection.map(|_| ()));
+                Poll::Ready(Ok((sender, connection))) => {
                    let rx = this.rx.take().unwrap();
                    let _ = rx.send(Ok(IoConnection::new(
-                        ConnectionType::H2(snd),
+                        ConnectionType::H2(H2Connection::new(sender, connection)),
                        Instant::now(),
                        Some(Acquired(this.key.clone(), this.inner.take())),
                    )));
--- a/actix-http/src/config.rs
+++ b/actix-http/src/config.rs
@ -9,7 +9,7 @@ use bytes::BytesMut;
 use futures_util::{future, FutureExt};
 use time::OffsetDateTime;

-// "Sun, 06 Nov 1994 08:49:37 GMT".len()
+/// "Sun, 06 Nov 1994 08:49:37 GMT".len()
 const DATE_VALUE_LENGTH: usize = 29;

 #[derive(Debug, PartialEq, Clone, Copy)]
--- a/actix-http/src/encoding/decoder.rs
+++ b/actix-http/src/encoding/decoder.rs
@ -3,14 +3,14 @@ use std::io::{self, Write};
 use std::pin::Pin;
 use std::task::{Context, Poll};

-use actix_threadpool::{run, CpuFuture};
+use actix_rt::task::{spawn_blocking, JoinHandle};
 use brotli2::write::BrotliDecoder;
 use bytes::Bytes;
 use flate2::write::{GzDecoder, ZlibDecoder};
 use futures_core::{ready, Stream};

 use super::Writer;
-use crate::error::PayloadError;
+use crate::error::{BlockingError, PayloadError};
 use crate::http::header::{ContentEncoding, HeaderMap, CONTENT_ENCODING};

 const INPLACE: usize = 2049;
@ -19,7 +19,7 @@ pub struct Decoder<S> {
    decoder: Option<ContentDecoder>,
    stream: S,
    eof: bool,
-    fut: Option<CpuFuture<(Option<Bytes>, ContentDecoder), io::Error>>,
+    fut: Option<JoinHandle<Result<(Option<Bytes>, ContentDecoder), io::Error>>>,
 }

 impl<S> Decoder<S>
@ -79,10 +79,8 @@ where
    ) -> Poll<Option<Self::Item>> {
        loop {
            if let Some(ref mut fut) = self.fut {
-                let (chunk, decoder) = match ready!(Pin::new(fut).poll(cx)) {
-                    Ok(item) => item,
-                    Err(e) => return Poll::Ready(Some(Err(e.into()))),
-                };
+                let (chunk, decoder) =
+                    ready!(Pin::new(fut).poll(cx)).map_err(|_| BlockingError)??;
                self.decoder = Some(decoder);
                self.fut.take();
                if let Some(chunk) = chunk {
@ -105,7 +103,7 @@ where
                                return Poll::Ready(Some(Ok(chunk)));
                            }
                        } else {
-                            self.fut = Some(run(move || {
+                            self.fut = Some(spawn_blocking(move || {
                                let chunk = decoder.feed_data(chunk)?;
                                Ok((chunk, decoder))
                            }));
--- a/actix-http/src/encoding/encoder.rs
+++ b/actix-http/src/encoding/encoder.rs
@ -4,7 +4,7 @@ use std::io::{self, Write};
 use std::pin::Pin;
 use std::task::{Context, Poll};

-use actix_threadpool::{run, CpuFuture};
+use actix_rt::task::{spawn_blocking, JoinHandle};
 use brotli2::write::BrotliEncoder;
 use bytes::Bytes;
 use flate2::write::{GzEncoder, ZlibEncoder};
@ -17,6 +17,7 @@ use crate::http::{HeaderValue, StatusCode};
 use crate::{Error, ResponseHead};

 use super::Writer;
+use crate::error::BlockingError;

 const INPLACE: usize = 1024;

@ -26,7 +27,7 @@ pub struct Encoder<B> {
    #[pin]
    body: EncoderBody<B>,
    encoder: Option<ContentEncoder>,
-    fut: Option<CpuFuture<ContentEncoder, io::Error>>,
+    fut: Option<JoinHandle<Result<ContentEncoder, io::Error>>>,
 }

 impl<B: MessageBody> Encoder<B> {
@ -135,10 +136,8 @@ impl<B: MessageBody> MessageBody for Encoder<B> {
            }

            if let Some(ref mut fut) = this.fut {
-                let mut encoder = match ready!(Pin::new(fut).poll(cx)) {
-                    Ok(item) => item,
-                    Err(e) => return Poll::Ready(Some(Err(e.into()))),
-                };
+                let mut encoder =
+                    ready!(Pin::new(fut).poll(cx)).map_err(|_| BlockingError)??;
                let chunk = encoder.take();
                *this.encoder = Some(encoder);
                this.fut.take();
@ -160,7 +159,7 @@ impl<B: MessageBody> MessageBody for Encoder<B> {
                                return Poll::Ready(Some(Ok(chunk)));
                            }
                        } else {
-                            *this.fut = Some(run(move || {
+                            *this.fut = Some(spawn_blocking(move || {
                                encoder.write(&chunk)?;
                                Ok(encoder)
                            }));
--- a/actix-http/src/error.rs
+++ b/actix-http/src/error.rs
@ -7,7 +7,6 @@ use std::string::FromUtf8Error;
 use std::{fmt, io, result};

 use actix_codec::{Decoder, Encoder};
-pub use actix_threadpool::BlockingError;
 use actix_utils::dispatcher::DispatcherError as FramedDispatcherError;
 use actix_utils::timeout::TimeoutError;
 use bytes::BytesMut;
@ -19,7 +18,6 @@ use serde::de::value::Error as DeError;
 use serde_json::error::Error as JsonError;
 use serde_urlencoded::ser::Error as FormError;

-// re-export for convenience
 use crate::body::Body;
 pub use crate::cookie::ParseError as CookieParseError;
 use crate::helpers::Writer;
@ -100,10 +98,6 @@ impl fmt::Debug for Error {
 }

 impl std::error::Error for Error {
-    fn cause(&self) -> Option<&dyn std::error::Error> {
-        None
-    }
-
    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
        None
    }
@ -153,7 +147,10 @@ impl From<ResponseBuilder> for Error {
    }
 }

-/// Return `GATEWAY_TIMEOUT` for `TimeoutError`
+/// Inspects the underlying enum and returns an appropriate status code.
+///
+/// If the variant is [`TimeoutError::Service`], the error code of the service is returned.
+/// Otherwise, [`StatusCode::GATEWAY_TIMEOUT`] is returned.
 impl<E: ResponseError> ResponseError for TimeoutError<E> {
    fn status_code(&self) -> StatusCode {
        match self {
@ -167,44 +164,44 @@ impl<E: ResponseError> ResponseError for TimeoutError<E> {
 #[display(fmt = "UnknownError")]
 struct UnitError;

-/// `InternalServerError` for `UnitError`
+/// Returns [`StatusCode::INTERNAL_SERVER_ERROR`] for [`UnitError`].
 impl ResponseError for UnitError {}

-/// `InternalServerError` for `JsonError`
+/// Returns [`StatusCode::INTERNAL_SERVER_ERROR`] for [`JsonError`].
 impl ResponseError for JsonError {}

-/// `InternalServerError` for `FormError`
+/// Returns [`StatusCode::INTERNAL_SERVER_ERROR`] for [`FormError`].
 impl ResponseError for FormError {}

 #[cfg(feature = "openssl")]
-/// `InternalServerError` for `openssl::ssl::Error`
+/// Returns [`StatusCode::INTERNAL_SERVER_ERROR`] for [`actix_tls::accept::openssl::SslError`].
 impl ResponseError for actix_tls::accept::openssl::SslError {}

-/// Return `BAD_REQUEST` for `de::value::Error`
+/// Returns [`StatusCode::BAD_REQUEST`] for [`DeError`].
 impl ResponseError for DeError {
    fn status_code(&self) -> StatusCode {
        StatusCode::BAD_REQUEST
    }
 }

-/// `InternalServerError` for `Canceled`
+/// Returns [`StatusCode::INTERNAL_SERVER_ERROR`] for [`Canceled`].
 impl ResponseError for Canceled {}

-/// `InternalServerError` for `BlockingError`
-impl<E: fmt::Debug> ResponseError for BlockingError<E> {}
-
-/// Return `BAD_REQUEST` for `Utf8Error`
+/// Returns [`StatusCode::BAD_REQUEST`] for [`Utf8Error`].
 impl ResponseError for Utf8Error {
    fn status_code(&self) -> StatusCode {
        StatusCode::BAD_REQUEST
    }
 }

-/// Return `InternalServerError` for `HttpError`,
-/// Response generation can return `HttpError`, so it is internal error
+/// Returns [`StatusCode::INTERNAL_SERVER_ERROR`] for [`HttpError`].
 impl ResponseError for HttpError {}

-/// Return `InternalServerError` for `io::Error`
+/// Inspects the underlying [`io::ErrorKind`] and returns an appropriate status code.
+///
+/// If the error is [`io::ErrorKind::NotFound`], [`StatusCode::NOT_FOUND`] is returned. If the
+/// error is [`io::ErrorKind::PermissionDenied`], [`StatusCode::FORBIDDEN`] is returned. Otherwise,
+/// [`StatusCode::INTERNAL_SERVER_ERROR`] is returned.
 impl ResponseError for io::Error {
    fn status_code(&self) -> StatusCode {
        match self.kind() {
@ -215,7 +212,7 @@ impl ResponseError for io::Error {
    }
 }

-/// `BadRequest` for `InvalidHeaderValue`
+/// Returns [`StatusCode::BAD_REQUEST`] for [`header::InvalidHeaderValue`].
 impl ResponseError for header::InvalidHeaderValue {
    fn status_code(&self) -> StatusCode {
        StatusCode::BAD_REQUEST
@ -304,33 +301,60 @@ impl From<httparse::Error> for ParseError {
    }
 }

+/// A set of errors that can occur running blocking tasks in thread pool.
+#[derive(Debug, Display)]
+#[display(fmt = "Blocking thread pool is gone")]
+pub struct BlockingError;
+
+impl std::error::Error for BlockingError {}
+
+/// `InternalServerError` for `BlockingError`
+impl ResponseError for BlockingError {}
+
 #[derive(Display, Debug)]
 /// A set of errors that can occur during payload parsing
 pub enum PayloadError {
    /// A payload reached EOF, but is not complete.
    #[display(
-        fmt = "A payload reached EOF, but is not complete. With error: {:?}",
+        fmt = "A payload reached EOF, but is not complete. Inner error: {:?}",
        _0
    )]
    Incomplete(Option<io::Error>),
-    /// Content encoding stream corruption
+
+    /// Content encoding stream corruption.
    #[display(fmt = "Can not decode content-encoding.")]
    EncodingCorrupted,
-    /// A payload reached size limit.
-    #[display(fmt = "A payload reached size limit.")]
+
+    /// Payload reached size limit.
+    #[display(fmt = "Payload reached size limit.")]
    Overflow,
-    /// A payload length is unknown.
-    #[display(fmt = "A payload length is unknown.")]
+
+    /// Payload length is unknown.
+    #[display(fmt = "Payload length is unknown.")]
    UnknownLength,
-    /// Http2 payload error
+
+    /// HTTP/2 payload error.
    #[display(fmt = "{}", _0)]
    Http2Payload(h2::Error),
-    /// Io error
+
+    /// Generic I/O error.
    #[display(fmt = "{}", _0)]
    Io(io::Error),
 }

-impl std::error::Error for PayloadError {}
+impl std::error::Error for PayloadError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        match self {
+            PayloadError::Incomplete(None) => None,
+            PayloadError::Incomplete(Some(err)) => Some(err as &dyn std::error::Error),
+            PayloadError::EncodingCorrupted => None,
+            PayloadError::Overflow => None,
+            PayloadError::UnknownLength => None,
+            PayloadError::Http2Payload(err) => Some(err as &dyn std::error::Error),
+            PayloadError::Io(err) => Some(err as &dyn std::error::Error),
+        }
+    }
+}

 impl From<h2::Error> for PayloadError {
    fn from(err: h2::Error) -> Self {
@ -350,15 +374,12 @@ impl From<io::Error> for PayloadError {
    }
 }

-impl From<BlockingError<io::Error>> for PayloadError {
-    fn from(err: BlockingError<io::Error>) -> Self {
-        match err {
-            BlockingError::Error(e) => PayloadError::Io(e),
-            BlockingError::Canceled => PayloadError::Io(io::Error::new(
+impl From<BlockingError> for PayloadError {
+    fn from(_: BlockingError) -> Self {
+        PayloadError::Io(io::Error::new(
            io::ErrorKind::Other,
            "Operation is canceled",
-            )),
-        }
+        ))
    }
 }

@ -947,11 +968,6 @@ where
    InternalError::new(err, StatusCode::NETWORK_AUTHENTICATION_REQUIRED).into()
 }

-#[cfg(feature = "actors")]
-/// `InternalServerError` for `actix::MailboxError`
-/// This is supported on feature=`actors` only
-impl ResponseError for actix::MailboxError {}
-
 #[cfg(test)]
 mod tests {
    use super::*;
@ -1009,22 +1025,22 @@ mod tests {
    fn test_payload_error() {
        let err: PayloadError =
            io::Error::new(io::ErrorKind::Other, "ParseError").into();
-        assert!(format!("{}", err).contains("ParseError"));
+        assert!(err.to_string().contains("ParseError"));

        let err = PayloadError::Incomplete(None);
        assert_eq!(
-            format!("{}", err),
-            "A payload reached EOF, but is not complete. With error: None"
+            err.to_string(),
+            "A payload reached EOF, but is not complete. Inner error: None"
        );
    }

    macro_rules! from {
        ($from:expr => $error:pat) => {
            match ParseError::from($from) {
-                e @ $error => {
-                    assert!(format!("{}", e).len() >= 5);
+                err @ $error => {
+                    assert!(err.to_string().len() >= 5);
                }
-                e => unreachable!("{:?}", e),
+                err => unreachable!("{:?}", err),
            }
        };
    }
@ -1067,7 +1083,7 @@ mod tests {
        let err = PayloadError::Overflow;
        let resp_err: &dyn ResponseError = &err;
        let err = resp_err.downcast_ref::<PayloadError>().unwrap();
-        assert_eq!(err.to_string(), "A payload reached size limit.");
+        assert_eq!(err.to_string(), "Payload reached size limit.");
        let not_err = resp_err.downcast_ref::<ContentTypeError>();
        assert!(not_err.is_none());
    }
--- a/actix-http/src/extensions.rs
+++ b/actix-http/src/extensions.rs
@ -1,62 +1,119 @@
-use std::any::{Any, TypeId};
-use std::{fmt, mem};
+use std::{
+    any::{Any, TypeId},
+    fmt, mem,
+};

-use fxhash::FxHashMap;
+use ahash::AHashMap;

-/// A type map of request extensions.
+/// A type map for request extensions.
+///
+/// All entries into this map must be owned types (or static references).
 #[derive(Default)]
 pub struct Extensions {
    /// Use FxHasher with a std HashMap with for faster
    /// lookups on the small `TypeId` (u64 equivalent) keys.
-    map: FxHashMap<TypeId, Box<dyn Any>>,
+    map: AHashMap<TypeId, Box<dyn Any>>,
 }

 impl Extensions {
-    /// Create an empty `Extensions`.
+    /// Creates an empty `Extensions`.
    #[inline]
    pub fn new() -> Extensions {
        Extensions {
-            map: FxHashMap::default(),
+            map: AHashMap::default(),
        }
    }

-    /// Insert a type into this `Extensions`.
+    /// Insert an item into the map.
    ///
-    /// If a extension of this type already existed, it will
-    /// be returned.
-    pub fn insert<T: 'static>(&mut self, val: T) {
-        self.map.insert(TypeId::of::<T>(), Box::new(val));
+    /// If an item of this type was already stored, it will be replaced and returned.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    /// assert_eq!(map.insert(""), None);
+    /// assert_eq!(map.insert(1u32), None);
+    /// assert_eq!(map.insert(2u32), Some(1u32));
+    /// assert_eq!(*map.get::<u32>().unwrap(), 2u32);
+    /// ```
+    pub fn insert<T: 'static>(&mut self, val: T) -> Option<T> {
+        self.map
+            .insert(TypeId::of::<T>(), Box::new(val))
+            .and_then(downcast_owned)
    }

-    /// Check if container contains entry
+    /// Check if map contains an item of a given type.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    /// assert!(!map.contains::<u32>());
+    ///
+    /// assert_eq!(map.insert(1u32), None);
+    /// assert!(map.contains::<u32>());
+    /// ```
    pub fn contains<T: 'static>(&self) -> bool {
        self.map.contains_key(&TypeId::of::<T>())
    }

-    /// Get a reference to a type previously inserted on this `Extensions`.
+    /// Get a reference to an item of a given type.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    /// map.insert(1u32);
+    /// assert_eq!(map.get::<u32>(), Some(&1u32));
+    /// ```
    pub fn get<T: 'static>(&self) -> Option<&T> {
        self.map
            .get(&TypeId::of::<T>())
            .and_then(|boxed| boxed.downcast_ref())
    }

-    /// Get a mutable reference to a type previously inserted on this `Extensions`.
+    /// Get a mutable reference to an item of a given type.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    /// map.insert(1u32);
+    /// assert_eq!(map.get_mut::<u32>(), Some(&mut 1u32));
+    /// ```
    pub fn get_mut<T: 'static>(&mut self) -> Option<&mut T> {
        self.map
            .get_mut(&TypeId::of::<T>())
            .and_then(|boxed| boxed.downcast_mut())
    }

-    /// Remove a type from this `Extensions`.
+    /// Remove an item from the map of a given type.
    ///
-    /// If a extension of this type existed, it will be returned.
+    /// If an item of this type was already stored, it will be returned.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    ///
+    /// map.insert(1u32);
+    /// assert_eq!(map.get::<u32>(), Some(&1u32));
+    ///
+    /// assert_eq!(map.remove::<u32>(), Some(1u32));
+    /// assert!(!map.contains::<u32>());
+    /// ```
    pub fn remove<T: 'static>(&mut self) -> Option<T> {
-        self.map
-            .remove(&TypeId::of::<T>())
-            .and_then(|boxed| boxed.downcast().ok().map(|boxed| *boxed))
+        self.map.remove(&TypeId::of::<T>()).and_then(downcast_owned)
    }

    /// Clear the `Extensions` of all inserted extensions.
+    ///
+    /// ```
+    /// # use actix_http::Extensions;
+    /// let mut map = Extensions::new();
+    ///
+    /// map.insert(1u32);
+    /// assert!(map.contains::<u32>());
+    ///
+    /// map.clear();
+    /// assert!(!map.contains::<u32>());
+    /// ```
    #[inline]
    pub fn clear(&mut self) {
        self.map.clear();
@ -79,6 +136,10 @@ impl fmt::Debug for Extensions {
    }
 }

+fn downcast_owned<T: 'static>(boxed: Box<dyn Any>) -> Option<T> {
+    boxed.downcast().ok().map(|boxed| *boxed)
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;
--- a/actix-http/src/h1/client.rs
+++ b/actix-http/src/h1/client.rs
@ -223,15 +223,3 @@ impl Encoder<Message<(RequestHeadType, BodySize)>> for ClientCodec {
        Ok(())
    }
 }
-
-pub struct Writer<'a>(pub &'a mut BytesMut);
-
-impl<'a> io::Write for Writer<'a> {
-    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        self.0.extend_from_slice(buf);
-        Ok(buf.len())
-    }
-    fn flush(&mut self) -> io::Result<()> {
-        Ok(())
-    }
-}
--- a/actix-http/src/h1/decoder.rs
+++ b/actix-http/src/h1/decoder.rs
@ -14,7 +14,7 @@ use crate::header::HeaderMap;
 use crate::message::{ConnectionType, ResponseHead};
 use crate::request::Request;

-const MAX_BUFFER_SIZE: usize = 131_072;
+pub(crate) const MAX_BUFFER_SIZE: usize = 131_072;
 const MAX_HEADERS: usize = 96;

 /// Incoming message decoder
@ -203,7 +203,15 @@ impl MessageType for Request {

                    (len, method, uri, version, req.headers.len())
                }
-                httparse::Status::Partial => return Ok(None),
+                httparse::Status::Partial => {
+                    return if src.len() >= MAX_BUFFER_SIZE {
+                        trace!("MAX_BUFFER_SIZE unprocessed data reached, closing");
+                        Err(ParseError::TooLarge)
+                    } else {
+                        // Return None to notify more read are needed for parsing request
+                        Ok(None)
+                    };
+                }
            }
        };

@ -222,9 +230,6 @@ impl MessageType for Request {
            PayloadLength::None => {
                if method == Method::CONNECT {
                    PayloadType::Stream(PayloadDecoder::eof())
-                } else if src.len() >= MAX_BUFFER_SIZE {
-                    trace!("MAX_BUFFER_SIZE unprocessed data reached, closing");
-                    return Err(ParseError::TooLarge);
                } else {
                    PayloadType::None
                }
@ -273,7 +278,14 @@ impl MessageType for ResponseHead {

                    (len, version, status, res.headers.len())
                }
-                httparse::Status::Partial => return Ok(None),
+                httparse::Status::Partial => {
+                    return if src.len() >= MAX_BUFFER_SIZE {
+                        error!("MAX_BUFFER_SIZE unprocessed data reached, closing");
+                        Err(ParseError::TooLarge)
+                    } else {
+                        Ok(None)
+                    }
+                }
            }
        };

@ -289,9 +301,6 @@ impl MessageType for ResponseHead {
        } else if status == StatusCode::SWITCHING_PROTOCOLS {
            // switching protocol or connect
            PayloadType::Stream(PayloadDecoder::eof())
-        } else if src.len() >= MAX_BUFFER_SIZE {
-            error!("MAX_BUFFER_SIZE unprocessed data reached, closing");
-            return Err(ParseError::TooLarge);
        } else {
            // for HTTP/1.0 read to eof and close connection
            if msg.version == Version::HTTP_10 {
@ -821,8 +830,8 @@ mod tests {
            .get_all(SET_COOKIE)
            .map(|v| v.to_str().unwrap().to_owned())
            .collect();
-        assert_eq!(val[1], "c1=cookie1");
-        assert_eq!(val[0], "c2=cookie2");
+        assert_eq!(val[0], "c1=cookie1");
+        assert_eq!(val[1], "c2=cookie2");
    }

    #[test]
--- a/actix-http/src/h1/dispatcher.rs
+++ b/actix-http/src/h1/dispatcher.rs
@ -1,5 +1,4 @@
 use std::{
-    cell::RefCell,
    collections::VecDeque,
    fmt,
    future::Future,
@ -30,8 +29,8 @@ use super::codec::Codec;
 use super::payload::{Payload, PayloadSender, PayloadStatus};
 use super::{Message, MessageType};

-const LW_BUFFER_SIZE: usize = 4096;
-const HW_BUFFER_SIZE: usize = 32_768;
+const LW_BUFFER_SIZE: usize = 1024;
+const HW_BUFFER_SIZE: usize = 1024 * 8;
 const MAX_PIPELINED_MESSAGES: usize = 16;

 bitflags! {
@ -91,7 +90,7 @@ where
    U: Service<(Request, Framed<T, Codec>), Response = ()>,
    U::Error: fmt::Display,
 {
-    flow: Rc<RefCell<HttpFlow<S, X, U>>>,
+    flow: Rc<HttpFlow<S, X, U>>,
    on_connect_data: OnConnectData,
    flags: Flags,
    peer_addr: Option<net::SocketAddr>,
@ -177,7 +176,7 @@ where
    pub(crate) fn new(
        stream: T,
        config: ServiceConfig,
-        services: Rc<RefCell<HttpFlow<S, X, U>>>,
+        services: Rc<HttpFlow<S, X, U>>,
        on_connect_data: OnConnectData,
        peer_addr: Option<net::SocketAddr>,
    ) -> Self {
@ -200,7 +199,7 @@ where
        config: ServiceConfig,
        read_buf: BytesMut,
        timeout: Option<Sleep>,
-        services: Rc<RefCell<HttpFlow<S, X, U>>>,
+        services: Rc<HttpFlow<S, X, U>>,
        on_connect_data: OnConnectData,
        peer_addr: Option<net::SocketAddr>,
    ) -> Self {
@ -287,44 +286,39 @@ where
        self: Pin<&mut Self>,
        cx: &mut Context<'_>,
    ) -> Result<bool, DispatchError> {
-        if self.write_buf.is_empty() {
-            return Ok(false);
-        }
-
-        let len = self.write_buf.len();
-        let mut written = 0;
        let InnerDispatcherProj { io, write_buf, .. } = self.project();
        let mut io = Pin::new(io.as_mut().unwrap());
+
+        let len = write_buf.len();
+        let mut written = 0;
+
        while written < len {
            match io.as_mut().poll_write(cx, &write_buf[written..]) {
                Poll::Ready(Ok(0)) => {
                    return Err(DispatchError::Io(io::Error::new(
                        io::ErrorKind::WriteZero,
                        "",
-                    )));
-                }
-                Poll::Ready(Ok(n)) => {
-                    written += n;
+                    )))
                }
+                Poll::Ready(Ok(n)) => written += n,
                Poll::Pending => {
-                    if written > 0 {
                    write_buf.advance(written);
-                    }
                    return Ok(true);
                }
                Poll::Ready(Err(err)) => return Err(DispatchError::Io(err)),
            }
        }

-        if written == write_buf.len() {
        // SAFETY: setting length to 0 is safe
        // skips one length check vs truncate
-            unsafe { write_buf.set_len(0) }
-        } else {
-            write_buf.advance(written);
+        unsafe {
+            write_buf.set_len(0);
        }

-        Ok(false)
+        // flush the io and check if get blocked.
+        let blocked = io.poll_flush(cx)?.is_pending();
+
+        Ok(blocked)
    }

    fn send_response(
@ -384,7 +378,7 @@ where
                    Poll::Ready(Ok(req)) => {
                        self.as_mut().send_continue();
                        this = self.as_mut().project();
-                        let fut = this.flow.borrow_mut().service.call(req);
+                        let fut = this.flow.service.call(req);
                        this.state.set(State::ServiceCall(fut));
                        continue;
                    }
@ -412,7 +406,7 @@ where
                },
                StateProj::SendPayload(mut stream) => {
                    loop {
-                        if this.write_buf.len() < HW_BUFFER_SIZE {
+                        if this.write_buf.len() < super::payload::MAX_BUFFER_SIZE {
                            match stream.as_mut().poll_next(cx) {
                                Poll::Ready(Some(Ok(item))) => {
                                    this.codec.encode(
@ -474,12 +468,12 @@ where
        if req.head().expect() {
            // set dispatcher state so the future is pinned.
            let mut this = self.as_mut().project();
-            let task = this.flow.borrow_mut().expect.call(req);
+            let task = this.flow.expect.call(req);
            this.state.set(State::ExpectCall(task));
        } else {
            // the same as above.
            let mut this = self.as_mut().project();
-            let task = this.flow.borrow_mut().service.call(req);
+            let task = this.flow.service.call(req);
            this.state.set(State::ServiceCall(task));
        };

@ -492,7 +486,7 @@ where
                        Poll::Ready(Ok(req)) => {
                            self.as_mut().send_continue();
                            let mut this = self.as_mut().project();
-                            let task = this.flow.borrow_mut().service.call(req);
+                            let task = this.flow.service.call(req);
                            this.state.set(State::ServiceCall(task));
                            continue;
                        }
@ -563,9 +557,7 @@ where
                            // merge on_connect_ext data into request extensions
                            this.on_connect_data.merge_into(&mut req);

-                            if pl == MessageType::Stream
-                                && this.flow.borrow().upgrade.is_some()
-                            {
+                            if pl == MessageType::Stream && this.flow.upgrade.is_some() {
                                this.messages.push_back(DispatcherMessage::Upgrade(req));
                                break;
                            }
@ -615,6 +607,8 @@ where
                        }
                    }
                }
+                // decode is partial and buffer is not full yet.
+                // break and wait for more read.
                Ok(None) => break,
                Err(ParseError::Io(e)) => {
                    self.as_mut().client_disconnected();
@ -622,6 +616,18 @@ where
                    *this.error = Some(DispatchError::Io(e));
                    break;
                }
+                Err(ParseError::TooLarge) => {
+                    if let Some(mut payload) = this.payload.take() {
+                        payload.set_error(PayloadError::Overflow);
+                    }
+                    // Requests overflow buffer size should be responded with 413
+                    this.messages.push_back(DispatcherMessage::Error(
+                        Response::PayloadTooLarge().finish().drop_body(),
+                    ));
+                    this.flags.insert(Flags::READ_DISCONNECT);
+                    *this.error = Some(ParseError::TooLarge.into());
+                    break;
+                }
                Err(e) => {
                    if let Some(mut payload) = this.payload.take() {
                        payload.set_error(PayloadError::EncodingCorrupted);
@ -652,55 +658,50 @@ where
        cx: &mut Context<'_>,
    ) -> Result<(), DispatchError> {
        let mut this = self.as_mut().project();
-        if this.ka_timer.is_none() {
-            // shutdown timeout
+
+        // when a branch is not explicit return early it's meant to fall through
+        // and return as Ok(())
+        match this.ka_timer.as_mut().as_pin_mut() {
+            None => {
+                // conditionally go into shutdown timeout
                if this.flags.contains(Flags::SHUTDOWN) {
-                if let Some(interval) = this.codec.config().client_disconnect_timer() {
-                    this.ka_timer.set(Some(sleep_until(interval)));
+                    if let Some(deadline) = this.codec.config().client_disconnect_timer()
+                    {
+                        // write client disconnect time out and poll again to
+                        // go into Some<Pin<&mut Sleep>> branch
+                        this.ka_timer.set(Some(sleep_until(deadline)));
+                        return self.poll_keepalive(cx);
                    } else {
                        this.flags.insert(Flags::READ_DISCONNECT);
                        if let Some(mut payload) = this.payload.take() {
                            payload.set_error(PayloadError::Incomplete(None));
                        }
-                    return Ok(());
-                }
-            } else {
-                return Ok(());
                    }
                }
-
-        match this.ka_timer.as_mut().as_pin_mut().unwrap().poll(cx) {
-            Poll::Ready(()) => {
-                // if we get timeout during shutdown, drop connection
+            }
+            Some(mut timer) => {
+                // only operate when keep-alive timer is resolved.
+                if timer.as_mut().poll(cx).is_ready() {
+                    // got timeout during shutdown, drop connection
                    if this.flags.contains(Flags::SHUTDOWN) {
                        return Err(DispatchError::DisconnectTimeout);
-                } else if this.ka_timer.as_mut().as_pin_mut().unwrap().deadline()
-                    >= *this.ka_expire
-                {
-                    // check for any outstanding tasks
+                    // exceed deadline. check for any outstanding tasks
+                    } else if timer.deadline() >= *this.ka_expire {
+                        // have no task at hand.
                        if this.state.is_empty() && this.write_buf.is_empty() {
                            if this.flags.contains(Flags::STARTED) {
                                trace!("Keep-alive timeout, close connection");
                                this.flags.insert(Flags::SHUTDOWN);

-                            // start shutdown timer
+                                // start shutdown timeout
                                if let Some(deadline) =
                                    this.codec.config().client_disconnect_timer()
                                {
-                                if let Some(timer) = this.ka_timer.as_mut().as_pin_mut()
-                                {
-                                    timer.reset(deadline);
-                                    let _ = this
-                                        .ka_timer
-                                        .as_mut()
-                                        .as_pin_mut()
-                                        .unwrap()
-                                        .poll(cx);
-                                }
+                                    timer.as_mut().reset(deadline);
+                                    let _ = timer.poll(cx);
                                } else {
                                    // no shutdown timeout, drop socket
                                    this.flags.insert(Flags::WRITE_DISCONNECT);
-                                return Ok(());
                                }
                            } else {
                                // timeout on first request (slow request) return 408
@ -710,31 +711,102 @@ where
                                        Response::RequestTimeout().finish().drop_body(),
                                        ResponseBody::Other(Body::Empty),
                                    );
-                                this = self.as_mut().project();
+                                    this = self.project();
                                } else {
                                    trace!("Keep-alive connection timeout");
                                }
                                this.flags.insert(Flags::STARTED | Flags::SHUTDOWN);
                                this.state.set(State::None);
                            }
+                        // still have unfinished task. try to reset and register keep-alive.
                        } else if let Some(deadline) =
                            this.codec.config().keep_alive_expire()
                        {
-                        if let Some(timer) = this.ka_timer.as_mut().as_pin_mut() {
-                            timer.reset(deadline);
-                            let _ =
-                                this.ka_timer.as_mut().as_pin_mut().unwrap().poll(cx);
+                            timer.as_mut().reset(deadline);
+                            let _ = timer.poll(cx);
+                        }
+                    // timer resolved but still have not met the keep-alive expire deadline.
+                    // reset and register for later wakeup.
+                    } else {
+                        timer.as_mut().reset(*this.ka_expire);
+                        let _ = timer.poll(cx);
                    }
                }
-                } else if let Some(timer) = this.ka_timer.as_mut().as_pin_mut() {
-                    timer.reset(*this.ka_expire);
-                    let _ = this.ka_timer.as_mut().as_pin_mut().unwrap().poll(cx);
            }
        }
-            Poll::Pending => {}
+        Ok(())
    }

-        Ok(())
+    /// Returns true when io stream can be disconnected after write to it.
+    ///
+    /// It covers these conditions:
+    ///
+    /// - `std::io::ErrorKind::ConnectionReset` after partial read.
+    /// - all data read done.
+    #[inline(always)]
+    fn read_available(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Result<bool, DispatchError> {
+        let this = self.project();
+
+        if this.flags.contains(Flags::READ_DISCONNECT) {
+            return Ok(false);
+        };
+
+        let mut io = Pin::new(this.io.as_mut().unwrap());
+
+        let mut read_some = false;
+
+        loop {
+            // grow buffer if necessary.
+            let remaining = this.read_buf.capacity() - this.read_buf.len();
+            if remaining < LW_BUFFER_SIZE {
+                this.read_buf.reserve(HW_BUFFER_SIZE - remaining);
+            }
+
+            match actix_codec::poll_read_buf(io.as_mut(), cx, this.read_buf) {
+                Poll::Pending => return Ok(false),
+                Poll::Ready(Ok(n)) => {
+                    if n == 0 {
+                        return Ok(true);
+                    } else {
+                        // Return early when read buf exceed decoder's max buffer size.
+                        if this.read_buf.len() >= super::decoder::MAX_BUFFER_SIZE {
+                            // at this point it's not known io is still scheduled to
+                            // be waked up. so force wake up dispatcher just in case.
+                            // TODO: figure out the overhead.
+                            cx.waker().wake_by_ref();
+                            return Ok(false);
+                        }
+
+                        read_some = true;
+                    }
+                }
+                Poll::Ready(Err(err)) => {
+                    return if err.kind() == io::ErrorKind::WouldBlock {
+                        Ok(false)
+                    } else if err.kind() == io::ErrorKind::ConnectionReset && read_some {
+                        Ok(true)
+                    } else {
+                        Err(DispatchError::Io(err))
+                    }
+                }
+            }
+        }
+    }
+
+    /// call upgrade service with request.
+    fn upgrade(self: Pin<&mut Self>, req: Request) -> U::Future {
+        let this = self.project();
+        let mut parts = FramedParts::with_read_buf(
+            this.io.take().unwrap(),
+            mem::take(this.codec),
+            mem::take(this.read_buf),
+        );
+        parts.write_buf = mem::take(this.write_buf);
+        let framed = Framed::from_parts(parts);
+        this.flow.upgrade.as_ref().unwrap().call((req, framed))
    }
 }

@ -769,79 +841,46 @@ where
                    if inner.flags.contains(Flags::WRITE_DISCONNECT) {
                        Poll::Ready(Ok(()))
                    } else {
-                        // flush buffer
-                        inner.as_mut().poll_flush(cx)?;
-                        if !inner.write_buf.is_empty() || inner.io.is_none() {
+                        // flush buffer and wait on block.
+                        if inner.as_mut().poll_flush(cx)? {
                            Poll::Pending
                        } else {
-                            match Pin::new(inner.project().io)
-                                .as_pin_mut()
-                                .unwrap()
+                            Pin::new(inner.project().io.as_mut().unwrap())
                                .poll_shutdown(cx)
-                            {
-                                Poll::Ready(res) => {
-                                    Poll::Ready(res.map_err(DispatchError::from))
-                                }
-                                Poll::Pending => Poll::Pending,
-                            }
+                                .map_err(DispatchError::from)
                        }
                    }
                } else {
-                    // read socket into a buf
-                    let should_disconnect =
-                        if !inner.flags.contains(Flags::READ_DISCONNECT) {
-                            let mut inner_p = inner.as_mut().project();
-                            read_available(
-                                cx,
-                                inner_p.io.as_mut().unwrap(),
-                                &mut inner_p.read_buf,
-                            )?
-                        } else {
-                            None
-                        };
+                    // read from io stream and fill read buffer.
+                    let should_disconnect = inner.as_mut().read_available(cx)?;

                    inner.as_mut().poll_request(cx)?;
-                    if let Some(true) = should_disconnect {
-                        let inner_p = inner.as_mut().project();
-                        inner_p.flags.insert(Flags::READ_DISCONNECT);
-                        if let Some(mut payload) = inner_p.payload.take() {
+
+                    // io stream should to be closed.
+                    if should_disconnect {
+                        let inner = inner.as_mut().project();
+                        inner.flags.insert(Flags::READ_DISCONNECT);
+                        if let Some(mut payload) = inner.payload.take() {
                            payload.feed_eof();
                        }
                    };

                    loop {
-                        let inner_p = inner.as_mut().project();
-                        let remaining =
-                            inner_p.write_buf.capacity() - inner_p.write_buf.len();
-                        if remaining < LW_BUFFER_SIZE {
-                            inner_p.write_buf.reserve(HW_BUFFER_SIZE - remaining);
-                        }
-                        let result = inner.as_mut().poll_response(cx)?;
-                        let drain = result == PollResponse::DrainWriteBuf;
-
-                        // switch to upgrade handler
-                        if let PollResponse::Upgrade(req) = result {
-                            let inner_p = inner.as_mut().project();
-                            let mut parts = FramedParts::with_read_buf(
-                                inner_p.io.take().unwrap(),
-                                mem::take(inner_p.codec),
-                                mem::take(inner_p.read_buf),
-                            );
-                            parts.write_buf = mem::take(inner_p.write_buf);
-                            let framed = Framed::from_parts(parts);
-                            let upgrade = inner_p
-                                .flow
-                                .borrow_mut()
-                                .upgrade
-                                .take()
-                                .unwrap()
-                                .call((req, framed));
+                        // poll_response and populate write buffer.
+                        // drain indicate if write buffer should be emptied before next run.
+                        let drain = match inner.as_mut().poll_response(cx)? {
+                            PollResponse::DrainWriteBuf => true,
+                            PollResponse::DoNothing => false,
+                            // upgrade request and goes Upgrade variant of DispatcherState.
+                            PollResponse::Upgrade(req) => {
+                                let upgrade = inner.upgrade(req);
                                self.as_mut()
                                    .project()
                                    .inner
                                    .set(DispatcherState::Upgrade(upgrade));
                                return self.poll(cx);
                            }
+                        };

                        // we didn't get WouldBlock from write operation,
                        // so data get written to kernel completely (macOS)
@ -898,72 +937,6 @@ where
    }
 }

-/// Returns either:
-/// - `Ok(Some(true))` - data was read and done reading all data.
-/// - `Ok(Some(false))` - data was read but there should be more to read.
-/// - `Ok(None)` - no data was read but there should be more to read later.
-/// - Unhandled Errors
-fn read_available<T>(
-    cx: &mut Context<'_>,
-    io: &mut T,
-    buf: &mut BytesMut,
-) -> Result<Option<bool>, io::Error>
-where
-    T: AsyncRead + Unpin,
-{
-    let mut read_some = false;
-
-    loop {
-        // If buf is full return but do not disconnect since
-        // there is more reading to be done
-        if buf.len() >= HW_BUFFER_SIZE {
-            return Ok(Some(false));
-        }
-
-        let remaining = buf.capacity() - buf.len();
-        if remaining < LW_BUFFER_SIZE {
-            buf.reserve(HW_BUFFER_SIZE - remaining);
-        }
-
-        match read(cx, io, buf) {
-            Poll::Pending => {
-                return if read_some { Ok(Some(false)) } else { Ok(None) };
-            }
-            Poll::Ready(Ok(n)) => {
-                if n == 0 {
-                    return Ok(Some(true));
-                } else {
-                    read_some = true;
-                }
-            }
-            Poll::Ready(Err(err)) => {
-                return if err.kind() == io::ErrorKind::WouldBlock {
-                    if read_some {
-                        Ok(Some(false))
-                    } else {
-                        Ok(None)
-                    }
-                } else if err.kind() == io::ErrorKind::ConnectionReset && read_some {
-                    Ok(Some(true))
-                } else {
-                    Err(err)
-                }
-            }
-        }
-    }
-}
-
-fn read<T>(
-    cx: &mut Context<'_>,
-    io: &mut T,
-    buf: &mut BytesMut,
-) -> Poll<Result<usize, io::Error>>
-where
-    T: AsyncRead + Unpin,
-{
-    actix_codec::poll_read_buf(Pin::new(io), cx, buf)
-}
-
 #[cfg(test)]
 mod tests {
    use std::str;
--- a/actix-http/src/h1/encoder.rs
+++ b/actix-http/src/h1/encoder.rs
@ -8,7 +8,7 @@ use bytes::{BufMut, BytesMut};

 use crate::body::BodySize;
 use crate::config::ServiceConfig;
-use crate::header::map;
+use crate::header::{map::Value, HeaderName};
 use crate::helpers;
 use crate::http::header::{CONNECTION, CONTENT_LENGTH, DATE, TRANSFER_ENCODING};
 use crate::http::{HeaderMap, StatusCode, Version};
@ -121,21 +121,11 @@ pub(crate) trait MessageType: Sized {
            _ => {}
        }

-        // merging headers from head and extra headers. HeaderMap::new() does not allocate.
-        let empty_headers = HeaderMap::new();
-        let extra_headers = self.extra_headers().unwrap_or(&empty_headers);
-        let headers = self
-            .headers()
-            .inner
-            .iter()
-            .filter(|(name, _)| !extra_headers.contains_key(*name))
-            .chain(extra_headers.inner.iter());
-
        // write headers

        let mut has_date = false;

-        let mut buf = dst.chunk_mut().as_mut_ptr() as *mut u8;
+        let mut buf = dst.chunk_mut().as_mut_ptr();
        let mut remaining = dst.capacity() - dst.len();

        // tracks bytes written since last buffer resize
@ -143,10 +133,10 @@ pub(crate) trait MessageType: Sized {
        // container's knowledge, this is used to sync the containers cursor after data is written
        let mut pos = 0;

-        for (key, value) in headers {
+        self.write_headers(|key, value| {
            match *key {
-                CONNECTION => continue,
-                TRANSFER_ENCODING | CONTENT_LENGTH if skip_len => continue,
+                CONNECTION => return,
+                TRANSFER_ENCODING | CONTENT_LENGTH if skip_len => return,
                DATE => has_date = true,
                _ => {}
            }
@ -154,8 +144,8 @@ pub(crate) trait MessageType: Sized {
            let k = key.as_str().as_bytes();
            let k_len = k.len();

-            match value {
-                map::Value::One(ref val) => {
+            // TODO: drain?
+            for val in value.iter() {
                let v = val.as_ref();
                let v_len = v.len();

@ -163,8 +153,6 @@ pub(crate) trait MessageType: Sized {
                let len = k_len + v_len + 4;

                if len > remaining {
-                        // not enough room in buffer for this header; reserve more space
-
                    // SAFETY: all the bytes written up to position "pos" are initialized
                    // the written byte count and pointer advancement are kept in sync
                    unsafe {
@ -177,60 +165,14 @@ pub(crate) trait MessageType: Sized {

                    // re-assign buf raw pointer since it's possible that the buffer was
                    // reallocated and/or resized
-                        buf = dst.chunk_mut().as_mut_ptr() as *mut u8;
-                    }
-
-                    // SAFETY: on each write, it is enough to ensure that the advancement of the
-                    // cursor matches the number of bytes written
-                    unsafe {
-                        // use upper Camel-Case
-                        if camel_case {
-                            write_camel_case(k, from_raw_parts_mut(buf, k_len))
-                        } else {
-                            write_data(k, buf, k_len)
-                        }
-
-                        buf = buf.add(k_len);
-
-                        write_data(b": ", buf, 2);
-                        buf = buf.add(2);
-
-                        write_data(v, buf, v_len);
-                        buf = buf.add(v_len);
-
-                        write_data(b"\r\n", buf, 2);
-                        buf = buf.add(2);
-                    }
-
-                    pos += len;
-                    remaining -= len;
-                }
-
-                map::Value::Multi(ref vec) => {
-                    for val in vec {
-                        let v = val.as_ref();
-                        let v_len = v.len();
-                        let len = k_len + v_len + 4;
-
-                        if len > remaining {
-                            // SAFETY: all the bytes written up to position "pos" are initialized
-                            // the written byte count and pointer advancement are kept in sync
-                            unsafe {
-                                dst.advance_mut(pos);
-                            }
-                            pos = 0;
-                            dst.reserve(len * 2);
-                            remaining = dst.capacity() - dst.len();
-
-                            // re-assign buf raw pointer since it's possible that the buffer was
-                            // reallocated and/or resized
-                            buf = dst.chunk_mut().as_mut_ptr() as *mut u8;
+                    buf = dst.chunk_mut().as_mut_ptr();
                }

                // SAFETY: on each write, it is enough to ensure that the advancement of
                // the cursor matches the number of bytes written
                unsafe {
                    if camel_case {
+                        // use Camel-Case headers
                        write_camel_case(k, from_raw_parts_mut(buf, k_len));
                    } else {
                        write_data(k, buf, k_len);
@ -251,9 +193,7 @@ pub(crate) trait MessageType: Sized {
                pos += len;
                remaining -= len;
            }
-                }
-            }
-        }
+        });

        // final cursor synchronization with the bytes container
        //
@ -273,6 +213,24 @@ pub(crate) trait MessageType: Sized {

        Ok(())
    }
+
+    fn write_headers<F>(&mut self, mut f: F)
+    where
+        F: FnMut(&HeaderName, &Value),
+    {
+        match self.extra_headers() {
+            Some(headers) => {
+                // merging headers from head and extra headers.
+                self.headers()
+                    .inner
+                    .iter()
+                    .filter(|(name, _)| !headers.contains_key(*name))
+                    .chain(headers.inner.iter())
+                    .for_each(|(k, v)| f(k, v))
+            }
+            None => self.headers().inner.iter().for_each(|(k, v)| f(k, v)),
+        }
+    }
 }

 impl MessageType for Response<()> {
@ -329,7 +287,7 @@ impl MessageType for RequestHeadType {
        let head = self.as_ref();
        dst.reserve(256 + head.headers.len() * AVERAGE_HEADER_SIZE);
        write!(
-            Writer(dst),
+            helpers::Writer(dst),
            "{} {} {}",
            head.method,
            head.uri.path_and_query().map(|u| u.as_str()).unwrap_or("/"),
@ -462,7 +420,7 @@ impl TransferEncoding {
                    *eof = true;
                    buf.extend_from_slice(b"0\r\n\r\n");
                } else {
-                    writeln!(Writer(buf), "{:X}\r", msg.len())
+                    writeln!(helpers::Writer(buf), "{:X}\r", msg.len())
                        .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;

                    buf.reserve(msg.len() + 2);
@ -512,18 +470,6 @@ impl TransferEncoding {
    }
 }

-struct Writer<'a>(pub &'a mut BytesMut);
-
-impl<'a> io::Write for Writer<'a> {
-    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        self.0.extend_from_slice(buf);
-        Ok(buf.len())
-    }
-    fn flush(&mut self) -> io::Result<()> {
-        Ok(())
-    }
-}
-
 /// # Safety
 /// Callers must ensure that the given length matches given value length.
 unsafe fn write_data(value: &[u8], buf: *mut u8, len: usize) {
--- a/actix-http/src/h1/expect.rs
+++ b/actix-http/src/h1/expect.rs
@ -1,4 +1,4 @@
-use std::task::{Context, Poll};
+use std::task::Poll;

 use actix_service::{Service, ServiceFactory};
 use futures_util::future::{ready, Ready};
@ -26,11 +26,9 @@ impl Service<Request> for ExpectHandler {
    type Error = Error;
    type Future = Ready<Result<Self::Response, Self::Error>>;

-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
-    }
+    actix_service::always_ready!();

-    fn call(&mut self, req: Request) -> Self::Future {
+    fn call(&self, req: Request) -> Self::Future {
        ready(Ok(req))
        // TODO: add some way to trigger error
        // Err(error::ErrorExpectationFailed("test"))
--- a/actix-http/src/h1/service.rs
+++ b/actix-http/src/h1/service.rs
@ -1,4 +1,3 @@
-use std::cell::RefCell;
 use std::future::Future;
 use std::marker::PhantomData;
 use std::pin::Pin;
@ -367,7 +366,7 @@ where
    X: Service<Request>,
    U: Service<(Request, Framed<T, Codec>)>,
 {
-    flow: Rc<RefCell<HttpFlow<S, X, U>>>,
+    flow: Rc<HttpFlow<S, X, U>>,
    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
    cfg: ServiceConfig,
    _phantom: PhantomData<B>,
@ -417,9 +416,9 @@ where
    type Error = DispatchError;
    type Future = Dispatcher<T, S, B, X, U>;

-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        let mut flow = self.flow.borrow_mut();
-        let ready = flow
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        let ready = self
+            .flow
            .expect
            .poll_ready(cx)
            .map_err(|e| {
@ -429,7 +428,8 @@ where
            })?
            .is_ready();

-        let ready = flow
+        let ready = self
+            .flow
            .service
            .poll_ready(cx)
            .map_err(|e| {
@ -440,7 +440,7 @@ where
            .is_ready()
            && ready;

-        let ready = if let Some(ref mut upg) = flow.upgrade {
+        let ready = if let Some(ref upg) = self.flow.upgrade {
            upg.poll_ready(cx)
                .map_err(|e| {
                    let e = e.into();
@ -460,7 +460,7 @@ where
        }
    }

-    fn call(&mut self, (io, addr): (T, Option<net::SocketAddr>)) -> Self::Future {
+    fn call(&self, (io, addr): (T, Option<net::SocketAddr>)) -> Self::Future {
        let on_connect_data =
            OnConnectData::from_io(&io, self.on_connect_ext.as_deref());

--- a/actix-http/src/h1/upgrade.rs
+++ b/actix-http/src/h1/upgrade.rs
@ -1,4 +1,4 @@
-use std::task::{Context, Poll};
+use std::task::Poll;

 use actix_codec::Framed;
 use actix_service::{Service, ServiceFactory};
@ -28,11 +28,9 @@ impl<T> Service<(Request, Framed<T, Codec>)> for UpgradeHandler {
    type Error = Error;
    type Future = Ready<Result<Self::Response, Self::Error>>;

-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
-    }
+    actix_service::always_ready!();

-    fn call(&mut self, _: (Request, Framed<T, Codec>)) -> Self::Future {
+    fn call(&self, _: (Request, Framed<T, Codec>)) -> Self::Future {
        ready(Ok(()))
    }
 }
--- a/actix-http/src/h2/dispatcher.rs
+++ b/actix-http/src/h2/dispatcher.rs
@ -1,4 +1,3 @@
-use std::cell::RefCell;
 use std::future::Future;
 use std::marker::PhantomData;
 use std::net;
@ -37,7 +36,7 @@ where
    S: Service<Request>,
    B: MessageBody,
 {
-    flow: Rc<RefCell<HttpFlow<S, X, U>>>,
+    flow: Rc<HttpFlow<S, X, U>>,
    connection: Connection<T, Bytes>,
    on_connect_data: OnConnectData,
    config: ServiceConfig,
@ -56,7 +55,7 @@ where
    B: MessageBody,
 {
    pub(crate) fn new(
-        services: Rc<RefCell<HttpFlow<S, X, U>>>,
+        flow: Rc<HttpFlow<S, X, U>>,
        connection: Connection<T, Bytes>,
        on_connect_data: OnConnectData,
        config: ServiceConfig,
@ -80,7 +79,7 @@ where
        };

        Dispatcher {
-            flow: services,
+            flow,
            config,
            peer_addr,
            connection,
@ -138,7 +137,7 @@ where

                    let svc = ServiceResponse::<S::Future, S::Response, S::Error, B> {
                        state: ServiceResponseState::ServiceCall(
-                            this.flow.borrow_mut().service.call(req),
+                            this.flow.service.call(req),
                            Some(res),
                        ),
                        config: this.config.clone(),
--- a/actix-http/src/h2/service.rs
+++ b/actix-http/src/h2/service.rs
@ -1,4 +1,3 @@
-use std::cell::RefCell;
 use std::future::Future;
 use std::marker::PhantomData;
 use std::pin::Pin;
@ -249,7 +248,7 @@ pub struct H2ServiceHandler<T, S, B>
 where
    S: Service<Request>,
 {
-    flow: Rc<RefCell<HttpFlow<S, (), ()>>>,
+    flow: Rc<HttpFlow<S, (), ()>>,
    cfg: ServiceConfig,
    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
    _phantom: PhantomData<B>,
@ -290,15 +289,15 @@ where
    type Error = DispatchError;
    type Future = H2ServiceHandlerResponse<T, S, B>;

-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        self.flow.borrow_mut().service.poll_ready(cx).map_err(|e| {
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        self.flow.service.poll_ready(cx).map_err(|e| {
            let e = e.into();
            error!("Service readiness error: {:?}", e);
            DispatchError::Service(e)
        })
    }

-    fn call(&mut self, (io, addr): (T, Option<net::SocketAddr>)) -> Self::Future {
+    fn call(&self, (io, addr): (T, Option<net::SocketAddr>)) -> Self::Future {
        let on_connect_data =
            OnConnectData::from_io(&io, self.on_connect_ext.as_deref());

@ -321,7 +320,7 @@ where
 {
    Incoming(Dispatcher<T, S, B, (), ()>),
    Handshake(
-        Option<Rc<RefCell<HttpFlow<S, (), ()>>>>,
+        Option<Rc<HttpFlow<S, (), ()>>>,
        Option<ServiceConfig>,
        Option<net::SocketAddr>,
        OnConnectData,
--- a/actix-http/src/header/as_name.rs
+++ b/actix-http/src/header/as_name.rs
@ -0,0 +1,46 @@
+//! Helper trait for types that can be effectively borrowed as a [HeaderValue].
+
+use std::{borrow::Cow, str::FromStr};
+
+use http::header::{HeaderName, InvalidHeaderName};
+
+pub trait AsHeaderName: Sealed {}
+
+pub trait Sealed {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName>;
+}
+
+impl Sealed for HeaderName {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName> {
+        Ok(Cow::Borrowed(self))
+    }
+}
+impl AsHeaderName for HeaderName {}
+
+impl Sealed for &HeaderName {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName> {
+        Ok(Cow::Borrowed(*self))
+    }
+}
+impl AsHeaderName for &HeaderName {}
+
+impl Sealed for &str {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName> {
+        HeaderName::from_str(self).map(Cow::Owned)
+    }
+}
+impl AsHeaderName for &str {}
+
+impl Sealed for String {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName> {
+        HeaderName::from_str(self).map(Cow::Owned)
+    }
+}
+impl AsHeaderName for String {}
+
+impl Sealed for &String {
+    fn try_as_name(&self) -> Result<Cow<'_, HeaderName>, InvalidHeaderName> {
+        HeaderName::from_str(self).map(Cow::Owned)
+    }
+}
+impl AsHeaderName for &String {}
--- a/actix-http/src/header/common/accept.rs
+++ b/actix-http/src/header/common/accept.rs
@ -32,50 +32,36 @@ header! {
    /// * `text/plain; q=0.5, text/html, text/x-dvi; q=0.8, text/x-c`
    ///
    /// # Examples
-    /// ```rust
-    /// # extern crate actix_http;
-    /// extern crate mime;
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::{Accept, qitem};
    ///
-    /// # fn main() {
    /// let mut builder = Response::Ok();
-    ///
-    /// builder.set(
+    /// builder.insert_header(
    ///     Accept(vec![
    ///         qitem(mime::TEXT_HTML),
    ///     ])
    /// );
-    /// # }
    /// ```
    ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// extern crate mime;
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::{Accept, qitem};
    ///
-    /// # fn main() {
    /// let mut builder = Response::Ok();
-    ///
-    /// builder.set(
+    /// builder.insert_header(
    ///     Accept(vec![
    ///         qitem(mime::APPLICATION_JSON),
    ///     ])
    /// );
-    /// # }
    /// ```
    ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// extern crate mime;
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::{Accept, QualityItem, q, qitem};
    ///
-    /// # fn main() {
    /// let mut builder = Response::Ok();
-    ///
-    /// builder.set(
+    /// builder.insert_header(
    ///     Accept(vec![
    ///         qitem(mime::TEXT_HTML),
    ///         qitem("application/xhtml+xml".parse().unwrap()),
@ -90,7 +76,6 @@ header! {
    ///         ),
    ///     ])
    /// );
-    /// # }
    /// ```
    (Accept, header::ACCEPT) => (QualityItem<Mime>)+

@ -132,7 +117,7 @@ header! {
        #[test]
        fn test_fuzzing1() {
            use crate::test::TestRequest;
-            let req = TestRequest::with_header(crate::header::ACCEPT, "chunk#;e").finish();
+            let req = TestRequest::default().insert_header((crate::header::ACCEPT, "chunk#;e")).finish();
            let header = Accept::parse(&req);
            assert!(header.is_ok());
        }
--- a/actix-http/src/header/common/accept_charset.rs
+++ b/actix-http/src/header/common/accept_charset.rs
@ -21,44 +21,37 @@ header! {
    /// * `iso-8859-5, unicode-1-1;q=0.8`
    ///
    /// # Examples
-    /// ```rust
-    /// # extern crate actix_http;
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::{AcceptCharset, Charset, qitem};
    ///
-    /// # fn main() {
    /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
    ///     AcceptCharset(vec![qitem(Charset::Us_Ascii)])
    /// );
-    /// # }
    /// ```
-    /// ```rust
-    /// # extern crate actix_http;
+    ///
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::{AcceptCharset, Charset, q, QualityItem};
    ///
-    /// # fn main() {
    /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
    ///     AcceptCharset(vec![
    ///         QualityItem::new(Charset::Us_Ascii, q(900)),
    ///         QualityItem::new(Charset::Iso_8859_10, q(200)),
    ///     ])
    /// );
-    /// # }
    /// ```
-    /// ```rust
-    /// # extern crate actix_http;
+    ///
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::{AcceptCharset, Charset, qitem};
    ///
-    /// # fn main() {
    /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
    ///     AcceptCharset(vec![qitem(Charset::Ext("utf-8".to_owned()))])
    /// );
-    /// # }
    /// ```
    (AcceptCharset, ACCEPT_CHARSET) => (QualityItem<Charset>)+

--- a/actix-http/src/header/common/accept_language.rs
+++ b/actix-http/src/header/common/accept_language.rs
@ -22,41 +22,35 @@ header! {
    ///
    /// # Examples
    ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// # extern crate language_tags;
+    /// ```
+    /// use language_tags::langtag;
    /// use actix_http::Response;
    /// use actix_http::http::header::{AcceptLanguage, LanguageTag, qitem};
    ///
-    /// # fn main() {
    /// let mut builder = Response::Ok();
    /// let mut langtag: LanguageTag = Default::default();
    /// langtag.language = Some("en".to_owned());
    /// langtag.region = Some("US".to_owned());
-    /// builder.set(
+    /// builder.insert_header(
    ///     AcceptLanguage(vec![
    ///         qitem(langtag),
    ///     ])
    /// );
-    /// # }
    /// ```
    ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// # #[macro_use] extern crate language_tags;
+    /// ```
+    /// use language_tags::langtag;
    /// use actix_http::Response;
    /// use actix_http::http::header::{AcceptLanguage, QualityItem, q, qitem};
-    /// #
-    /// # fn main() {
+    ///
    /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
    ///     AcceptLanguage(vec![
    ///         qitem(langtag!(da)),
    ///         QualityItem::new(langtag!(en;;;GB), q(800)),
    ///         QualityItem::new(langtag!(en), q(700)),
    ///     ])
    /// );
-    /// # }
    /// ```
    (AcceptLanguage, ACCEPT_LANGUAGE) => (QualityItem<LanguageTag>)+

--- a/actix-http/src/header/common/allow.rs
+++ b/actix-http/src/header/common/allow.rs
@ -22,38 +22,28 @@ header! {
    ///
    /// # Examples
    ///
-    /// ```rust
-    /// # extern crate http;
-    /// # extern crate actix_http;
+    /// ```
    /// use actix_http::Response;
-    /// use actix_http::http::header::Allow;
-    /// use http::Method;
+    /// use actix_http::http::{header::Allow, Method};
    ///
-    /// # fn main() {
    /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
    ///     Allow(vec![Method::GET])
    /// );
-    /// # }
    /// ```
    ///
-    /// ```rust
-    /// # extern crate http;
-    /// # extern crate actix_http;
+    /// ```
    /// use actix_http::Response;
-    /// use actix_http::http::header::Allow;
-    /// use http::Method;
+    /// use actix_http::http::{header::Allow, Method};
    ///
-    /// # fn main() {
    /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
    ///     Allow(vec![
    ///         Method::GET,
    ///         Method::POST,
    ///         Method::PATCH,
    ///     ])
    /// );
-    /// # }
    /// ```
    (Allow, header::ALLOW) => (Method)*

--- a/actix-http/src/header/common/cache_control.rs
+++ b/actix-http/src/header/common/cache_control.rs
@ -28,12 +28,12 @@ use crate::header::{
 /// * `max-age=30`
 ///
 /// # Examples
-/// ```rust
+/// ```
 /// use actix_http::Response;
 /// use actix_http::http::header::{CacheControl, CacheDirective};
 ///
 /// let mut builder = Response::Ok();
-/// builder.set(CacheControl(vec![CacheDirective::MaxAge(86400u32)]));
+/// builder.insert_header(CacheControl(vec![CacheDirective::MaxAge(86400u32)]));
 /// ```
 ///
 /// ```rust
@ -41,7 +41,7 @@ use crate::header::{
 /// use actix_http::http::header::{CacheControl, CacheDirective};
 ///
 /// let mut builder = Response::Ok();
-/// builder.set(CacheControl(vec![
+/// builder.insert_header(CacheControl(vec![
 ///     CacheDirective::NoCache,
 ///     CacheDirective::Private,
 ///     CacheDirective::MaxAge(360u32),
@ -82,7 +82,7 @@ impl fmt::Display for CacheControl {
 impl IntoHeaderValue for CacheControl {
    type Error = header::InvalidHeaderValue;

-    fn try_into(self) -> Result<header::HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<header::HeaderValue, Self::Error> {
        let mut writer = Writer::new();
        let _ = write!(&mut writer, "{}", self);
        header::HeaderValue::from_maybe_shared(writer.take())
@ -196,7 +196,8 @@ mod tests {

    #[test]
    fn test_parse_multiple_headers() {
-        let req = TestRequest::with_header(header::CACHE_CONTROL, "no-cache, private")
+        let req = TestRequest::default()
+            .insert_header((header::CACHE_CONTROL, "no-cache, private"))
            .finish();
        let cache = Header::parse(&req);
        assert_eq!(
@ -210,8 +211,8 @@ mod tests {

    #[test]
    fn test_parse_argument() {
-        let req =
-            TestRequest::with_header(header::CACHE_CONTROL, "max-age=100, private")
+        let req = TestRequest::default()
+            .insert_header((header::CACHE_CONTROL, "max-age=100, private"))
            .finish();
        let cache = Header::parse(&req);
        assert_eq!(
@ -225,8 +226,9 @@ mod tests {

    #[test]
    fn test_parse_quote_form() {
-        let req =
-            TestRequest::with_header(header::CACHE_CONTROL, "max-age=\"200\"").finish();
+        let req = TestRequest::default()
+            .insert_header((header::CACHE_CONTROL, "max-age=\"200\""))
+            .finish();
        let cache = Header::parse(&req);
        assert_eq!(
            cache.ok(),
@ -236,8 +238,9 @@ mod tests {

    #[test]
    fn test_parse_extension() {
-        let req =
-            TestRequest::with_header(header::CACHE_CONTROL, "foo, bar=baz").finish();
+        let req = TestRequest::default()
+            .insert_header((header::CACHE_CONTROL, "foo, bar=baz"))
+            .finish();
        let cache = Header::parse(&req);
        assert_eq!(
            cache.ok(),
@ -250,7 +253,9 @@ mod tests {

    #[test]
    fn test_parse_bad_syntax() {
-        let req = TestRequest::with_header(header::CACHE_CONTROL, "foo=").finish();
+        let req = TestRequest::default()
+            .insert_header((header::CACHE_CONTROL, "foo="))
+            .finish();
        let cache: Result<CacheControl, _> = Header::parse(&req);
        assert_eq!(cache.ok(), None)
    }
--- a/actix-http/src/header/common/content_disposition.rs
+++ b/actix-http/src/header/common/content_disposition.rs
@ -1,10 +1,10 @@
-// # References
-//
-// "The Content-Disposition Header Field" https://www.ietf.org/rfc/rfc2183.txt
-// "The Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP)" https://www.ietf.org/rfc/rfc6266.txt
-// "Returning Values from Forms: multipart/form-data" https://www.ietf.org/rfc/rfc7578.txt
-// Browser conformance tests at: http://greenbytes.de/tech/tc2231/
-// IANA assignment: http://www.iana.org/assignments/cont-disp/cont-disp.xhtml
+//! # References
+//!
+//! "The Content-Disposition Header Field" https://www.ietf.org/rfc/rfc2183.txt
+//! "The Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP)" https://www.ietf.org/rfc/rfc6266.txt
+//! "Returning Values from Forms: multipart/form-data" https://www.ietf.org/rfc/rfc7578.txt
+//! Browser conformance tests at: http://greenbytes.de/tech/tc2231/
+//! IANA assignment: http://www.iana.org/assignments/cont-disp/cont-disp.xhtml

 use lazy_static::lazy_static;
 use regex::Regex;
@ -454,7 +454,7 @@ impl ContentDisposition {
 impl IntoHeaderValue for ContentDisposition {
    type Error = header::InvalidHeaderValue;

-    fn try_into(self) -> Result<header::HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<header::HeaderValue, Self::Error> {
        let mut writer = Writer::new();
        let _ = write!(&mut writer, "{}", self);
        header::HeaderValue::from_maybe_shared(writer.take())
--- a/actix-http/src/header/common/content_encoding.rs
+++ b/actix-http/src/header/common/content_encoding.rs
@ -0,0 +1,106 @@
+use std::{convert::Infallible, str::FromStr};
+
+use http::header::InvalidHeaderValue;
+
+use crate::{
+    error::ParseError,
+    header::{self, from_one_raw_str, Header, HeaderName, HeaderValue, IntoHeaderValue},
+    HttpMessage,
+};
+
+/// Represents a supported content encoding.
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum ContentEncoding {
+    /// Automatically select encoding based on encoding negotiation.
+    Auto,
+
+    /// A format using the Brotli algorithm.
+    Br,
+
+    /// A format using the zlib structure with deflate algorithm.
+    Deflate,
+
+    /// Gzip algorithm.
+    Gzip,
+
+    /// Indicates the identity function (i.e. no compression, nor modification).
+    Identity,
+}
+
+impl ContentEncoding {
+    /// Is the content compressed?
+    #[inline]
+    pub fn is_compression(self) -> bool {
+        matches!(self, ContentEncoding::Identity | ContentEncoding::Auto)
+    }
+
+    /// Convert content encoding to string
+    #[inline]
+    pub fn as_str(self) -> &'static str {
+        match self {
+            ContentEncoding::Br => "br",
+            ContentEncoding::Gzip => "gzip",
+            ContentEncoding::Deflate => "deflate",
+            ContentEncoding::Identity | ContentEncoding::Auto => "identity",
+        }
+    }
+
+    /// Default Q-factor (quality) value.
+    #[inline]
+    pub fn quality(self) -> f64 {
+        match self {
+            ContentEncoding::Br => 1.1,
+            ContentEncoding::Gzip => 1.0,
+            ContentEncoding::Deflate => 0.9,
+            ContentEncoding::Identity | ContentEncoding::Auto => 0.1,
+        }
+    }
+}
+
+impl Default for ContentEncoding {
+    fn default() -> Self {
+        Self::Identity
+    }
+}
+
+impl FromStr for ContentEncoding {
+    type Err = Infallible;
+
+    fn from_str(val: &str) -> Result<Self, Self::Err> {
+        Ok(Self::from(val))
+    }
+}
+
+impl From<&str> for ContentEncoding {
+    fn from(val: &str) -> ContentEncoding {
+        let val = val.trim();
+
+        if val.eq_ignore_ascii_case("br") {
+            ContentEncoding::Br
+        } else if val.eq_ignore_ascii_case("gzip") {
+            ContentEncoding::Gzip
+        } else if val.eq_ignore_ascii_case("deflate") {
+            ContentEncoding::Deflate
+        } else {
+            ContentEncoding::default()
+        }
+    }
+}
+
+impl IntoHeaderValue for ContentEncoding {
+    type Error = InvalidHeaderValue;
+
+    fn try_into_value(self) -> Result<http::HeaderValue, Self::Error> {
+        Ok(HeaderValue::from_static(self.as_str()))
+    }
+}
+
+impl Header for ContentEncoding {
+    fn name() -> HeaderName {
+        header::CONTENT_ENCODING
+    }
+
+    fn parse<T: HttpMessage>(msg: &T) -> Result<Self, ParseError> {
+        from_one_raw_str(msg.headers().get(Self::name()))
+    }
+}
--- a/actix-http/src/header/common/content_language.rs
+++ b/actix-http/src/header/common/content_language.rs
@ -23,38 +23,31 @@ header! {
    ///
    /// # Examples
    ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// # #[macro_use] extern crate language_tags;
+    /// ```
+    /// use language_tags::langtag;
    /// use actix_http::Response;
-    /// # use actix_http::http::header::{ContentLanguage, qitem};
-    /// #
-    /// # fn main() {
+    /// use actix_http::http::header::{ContentLanguage, qitem};
+    ///
    /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
    ///     ContentLanguage(vec![
    ///         qitem(langtag!(en)),
    ///     ])
    /// );
-    /// # }
    /// ```
    ///
-    /// ```rust
-    /// # extern crate actix_http;
-    /// # #[macro_use] extern crate language_tags;
+    /// ```
+    /// use language_tags::langtag;
    /// use actix_http::Response;
-    /// # use actix_http::http::header::{ContentLanguage, qitem};
-    /// #
-    /// # fn main() {
+    /// use actix_http::http::header::{ContentLanguage, qitem};
    ///
    /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
    ///     ContentLanguage(vec![
    ///         qitem(langtag!(da)),
    ///         qitem(langtag!(en;;;GB)),
    ///     ])
    /// );
-    /// # }
    /// ```
    (ContentLanguage, CONTENT_LANGUAGE) => (QualityItem<LanguageTag>)+

--- a/actix-http/src/header/common/content_range.rs
+++ b/actix-http/src/header/common/content_range.rs
@ -200,7 +200,7 @@ impl Display for ContentRangeSpec {
 impl IntoHeaderValue for ContentRangeSpec {
    type Error = InvalidHeaderValue;

-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
        let mut writer = Writer::new();
        let _ = write!(&mut writer, "{}", self);
        HeaderValue::from_maybe_shared(writer.take())
--- a/actix-http/src/header/common/content_type.rs
+++ b/actix-http/src/header/common/content_type.rs
@ -30,31 +30,24 @@ header! {
    ///
    /// # Examples
    ///
-    /// ```rust
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::ContentType;
    ///
-    /// # fn main() {
    /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
    ///     ContentType::json()
    /// );
-    /// # }
    /// ```
    ///
-    /// ```rust
-    /// # extern crate mime;
-    /// # extern crate actix_http;
-    /// use mime::TEXT_HTML;
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::ContentType;
    ///
-    /// # fn main() {
    /// let mut builder = Response::Ok();
-    /// builder.set(
-    ///     ContentType(TEXT_HTML)
+    /// builder.insert_header(
+    ///     ContentType(mime::TEXT_HTML)
    /// );
-    /// # }
    /// ```
    (ContentType, CONTENT_TYPE) => [Mime]

@ -99,6 +92,7 @@ impl ContentType {
    pub fn form_url_encoded() -> ContentType {
        ContentType(mime::APPLICATION_WWW_FORM_URLENCODED)
    }
+
    /// A constructor  to easily create a `Content-Type: image/jpeg` header.
    #[inline]
    pub fn jpeg() -> ContentType {
--- a/actix-http/src/header/common/date.rs
+++ b/actix-http/src/header/common/date.rs
@ -19,13 +19,15 @@ header! {
    ///
    /// # Example
    ///
-    /// ```rust
+    /// ```
+    /// use std::time::SystemTime;
    /// use actix_http::Response;
    /// use actix_http::http::header::Date;
-    /// use std::time::SystemTime;
    ///
    /// let mut builder = Response::Ok();
-    /// builder.set(Date(SystemTime::now().into()));
+    /// builder.insert_header(
+    ///     Date(SystemTime::now().into())
+    /// );
    /// ```
    (Date, DATE) => [HttpDate]

--- a/actix-http/src/header/common/etag.rs
+++ b/actix-http/src/header/common/etag.rs
@ -27,20 +27,24 @@ header! {
    ///
    /// # Examples
    ///
-    /// ```rust
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::{ETag, EntityTag};
    ///
    /// let mut builder = Response::Ok();
-    /// builder.set(ETag(EntityTag::new(false, "xyzzy".to_owned())));
+    /// builder.insert_header(
+    ///     ETag(EntityTag::new(false, "xyzzy".to_owned()))
+    /// );
    /// ```
    ///
-    /// ```rust
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::{ETag, EntityTag};
    ///
    /// let mut builder = Response::Ok();
-    /// builder.set(ETag(EntityTag::new(true, "xyzzy".to_owned())));
+    /// builder.insert_header(
+    ///     ETag(EntityTag::new(true, "xyzzy".to_owned()))
+    /// );
    /// ```
    (ETag, ETAG) => [EntityTag]

--- a/actix-http/src/header/common/expires.rs
+++ b/actix-http/src/header/common/expires.rs
@ -21,14 +21,16 @@ header! {
    ///
    /// # Example
    ///
-    /// ```rust
+    /// ```
+    /// use std::time::{SystemTime, Duration};
    /// use actix_http::Response;
    /// use actix_http::http::header::Expires;
-    /// use std::time::{SystemTime, Duration};
    ///
    /// let mut builder = Response::Ok();
    /// let expiration = SystemTime::now() + Duration::from_secs(60 * 60 * 24);
-    /// builder.set(Expires(expiration.into()));
+    /// builder.insert_header(
+    ///     Expires(expiration.into())
+    /// );
    /// ```
    (Expires, EXPIRES) => [HttpDate]

--- a/actix-http/src/header/common/if_match.rs
+++ b/actix-http/src/header/common/if_match.rs
@ -29,20 +29,20 @@ header! {
    ///
    /// # Examples
    ///
-    /// ```rust
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::IfMatch;
    ///
    /// let mut builder = Response::Ok();
-    /// builder.set(IfMatch::Any);
+    /// builder.insert_header(IfMatch::Any);
    /// ```
    ///
-    /// ```rust
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::{IfMatch, EntityTag};
    ///
    /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
    ///     IfMatch::Items(vec![
    ///         EntityTag::new(false, "xyzzy".to_owned()),
    ///         EntityTag::new(false, "foobar".to_owned()),
--- a/actix-http/src/header/common/if_modified_since.rs
+++ b/actix-http/src/header/common/if_modified_since.rs
@ -21,14 +21,16 @@ header! {
    ///
    /// # Example
    ///
-    /// ```rust
+    /// ```
+    /// use std::time::{SystemTime, Duration};
    /// use actix_http::Response;
    /// use actix_http::http::header::IfModifiedSince;
-    /// use std::time::{SystemTime, Duration};
    ///
    /// let mut builder = Response::Ok();
    /// let modified = SystemTime::now() - Duration::from_secs(60 * 60 * 24);
-    /// builder.set(IfModifiedSince(modified.into()));
+    /// builder.insert_header(
+    ///     IfModifiedSince(modified.into())
+    /// );
    /// ```
    (IfModifiedSince, IF_MODIFIED_SINCE) => [HttpDate]

--- a/actix-http/src/header/common/if_none_match.rs
+++ b/actix-http/src/header/common/if_none_match.rs
@ -31,20 +31,20 @@ header! {
    ///
    /// # Examples
    ///
-    /// ```rust
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::IfNoneMatch;
    ///
    /// let mut builder = Response::Ok();
-    /// builder.set(IfNoneMatch::Any);
+    /// builder.insert_header(IfNoneMatch::Any);
    /// ```
    ///
-    /// ```rust
+    /// ```
    /// use actix_http::Response;
    /// use actix_http::http::header::{IfNoneMatch, EntityTag};
    ///
    /// let mut builder = Response::Ok();
-    /// builder.set(
+    /// builder.insert_header(
    ///     IfNoneMatch::Items(vec![
    ///         EntityTag::new(false, "xyzzy".to_owned()),
    ///         EntityTag::new(false, "foobar".to_owned()),
@ -73,12 +73,14 @@ mod tests {
    fn test_if_none_match() {
        let mut if_none_match: Result<IfNoneMatch, _>;

-        let req = TestRequest::with_header(IF_NONE_MATCH, "*").finish();
+        let req = TestRequest::default()
+            .insert_header((IF_NONE_MATCH, "*"))
+            .finish();
        if_none_match = Header::parse(&req);
        assert_eq!(if_none_match.ok(), Some(IfNoneMatch::Any));

-        let req =
-            TestRequest::with_header(IF_NONE_MATCH, &b"\"foobar\", W/\"weak-etag\""[..])
+        let req = TestRequest::default()
+            .insert_header((IF_NONE_MATCH, &b"\"foobar\", W/\"weak-etag\""[..]))
            .finish();

        if_none_match = Header::parse(&req);
--- a/actix-http/src/header/common/if_range.rs
+++ b/actix-http/src/header/common/if_range.rs
@ -35,31 +35,34 @@ use crate::httpmessage::HttpMessage;
 ///
 /// # Examples
 ///
-/// ```rust
+/// ```
 /// use actix_http::Response;
 /// use actix_http::http::header::{EntityTag, IfRange};
 ///
 /// let mut builder = Response::Ok();
-/// builder.set(IfRange::EntityTag(EntityTag::new(
-///     false,
-///     "xyzzy".to_owned(),
-/// )));
+/// builder.insert_header(
+///     IfRange::EntityTag(
+///         EntityTag::new(false, "abc".to_owned())
+///     )
+/// );
 /// ```
 ///
-/// ```rust
-/// use actix_http::Response;
-/// use actix_http::http::header::IfRange;
+/// ```
 /// use std::time::{Duration, SystemTime};
+/// use actix_http::{http::header::IfRange, Response};
 ///
 /// let mut builder = Response::Ok();
 /// let fetched = SystemTime::now() - Duration::from_secs(60 * 60 * 24);
-/// builder.set(IfRange::Date(fetched.into()));
+/// builder.insert_header(
+///     IfRange::Date(fetched.into())
+/// );
 /// ```
 #[derive(Clone, Debug, PartialEq)]
 pub enum IfRange {
-    /// The entity-tag the client has of the resource
+    /// The entity-tag the client has of the resource.
    EntityTag(EntityTag),
-    /// The date when the client retrieved the resource
+
+    /// The date when the client retrieved the resource.
    Date(HttpDate),
 }

@ -98,7 +101,7 @@ impl Display for IfRange {
 impl IntoHeaderValue for IfRange {
    type Error = InvalidHeaderValue;

-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
        let mut writer = Writer::new();
        let _ = write!(&mut writer, "{}", self);
        HeaderValue::from_maybe_shared(writer.take())
@ -110,7 +113,8 @@ mod test_if_range {
    use super::IfRange as HeaderField;
    use crate::header::*;
    use std::str;
+
    test_header!(test1, vec![b"Sat, 29 Oct 1994 19:43:31 GMT"]);
-    test_header!(test2, vec![b"\"xyzzy\""]);
+    test_header!(test2, vec![b"\"abc\""]);
    test_header!(test3, vec![b"this-is-invalid"], None::<IfRange>);
 }
--- a/actix-http/src/header/common/if_unmodified_since.rs
+++ b/actix-http/src/header/common/if_unmodified_since.rs
@ -22,14 +22,16 @@ header! {
    ///
    /// # Example
    ///
-    /// ```rust
+    /// ```
+    /// use std::time::{SystemTime, Duration};
    /// use actix_http::Response;
    /// use actix_http::http::header::IfUnmodifiedSince;
-    /// use std::time::{SystemTime, Duration};
    ///
    /// let mut builder = Response::Ok();
    /// let modified = SystemTime::now() - Duration::from_secs(60 * 60 * 24);
-    /// builder.set(IfUnmodifiedSince(modified.into()));
+    /// builder.insert_header(
+    ///     IfUnmodifiedSince(modified.into())
+    /// );
    /// ```
    (IfUnmodifiedSince, IF_UNMODIFIED_SINCE) => [HttpDate]

--- a/actix-http/src/header/common/last_modified.rs
+++ b/actix-http/src/header/common/last_modified.rs
@ -21,14 +21,16 @@ header! {
    ///
    /// # Example
    ///
-    /// ```rust
+    /// ```
+    /// use std::time::{SystemTime, Duration};
    /// use actix_http::Response;
    /// use actix_http::http::header::LastModified;
-    /// use std::time::{SystemTime, Duration};
    ///
    /// let mut builder = Response::Ok();
    /// let modified = SystemTime::now() - Duration::from_secs(60 * 60 * 24);
-    /// builder.set(LastModified(modified.into()));
+    /// builder.insert_header(
+    ///     LastModified(modified.into())
+    /// );
    /// ```
    (LastModified, LAST_MODIFIED) => [HttpDate]

--- a/actix-http/src/header/common/mod.rs
+++ b/actix-http/src/header/common/mod.rs
@ -18,6 +18,7 @@ pub use self::content_disposition::{
 };
 pub use self::content_language::ContentLanguage;
 pub use self::content_range::{ContentRange, ContentRangeSpec};
+pub use self::content_encoding::{ContentEncoding};
 pub use self::content_type::ContentType;
 pub use self::date::Date;
 pub use self::etag::ETag;
@ -83,7 +84,7 @@ macro_rules! test_header {
            let a: Vec<Vec<u8>> = raw.iter().map(|x| x.to_vec()).collect();
            let mut req = test::TestRequest::default();
            for item in a {
-                req = req.header(HeaderField::name(), item).take();
+                req = req.insert_header((HeaderField::name(), item)).take();
            }
            let req = req.finish();
            let value = HeaderField::parse(&req);
@ -110,7 +111,7 @@ macro_rules! test_header {
            let a: Vec<Vec<u8>> = $raw.iter().map(|x| x.to_vec()).collect();
            let mut req = test::TestRequest::default();
            for item in a {
-                req.header(HeaderField::name(), item);
+                req.insert_header((HeaderField::name(), item));
            }
            let req = req.finish();
            let val = HeaderField::parse(&req);
@ -168,7 +169,7 @@ macro_rules! header {
        impl $crate::http::header::IntoHeaderValue for $id {
            type Error = $crate::http::header::InvalidHeaderValue;

-            fn try_into(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
+            fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
                use std::fmt::Write;
                let mut writer = $crate::http::header::Writer::new();
                let _ = write!(&mut writer, "{}", self);
@ -204,7 +205,7 @@ macro_rules! header {
        impl $crate::http::header::IntoHeaderValue for $id {
            type Error = $crate::http::header::InvalidHeaderValue;

-            fn try_into(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
+            fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
                use std::fmt::Write;
                let mut writer = $crate::http::header::Writer::new();
                let _ = write!(&mut writer, "{}", self);
@ -240,8 +241,8 @@ macro_rules! header {
        impl $crate::http::header::IntoHeaderValue for $id {
            type Error = $crate::http::header::InvalidHeaderValue;

-            fn try_into(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
-                self.0.try_into()
+            fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
+                self.0.try_into_value()
            }
        }
    };
@ -289,7 +290,7 @@ macro_rules! header {
        impl $crate::http::header::IntoHeaderValue for $id {
            type Error = $crate::http::header::InvalidHeaderValue;

-            fn try_into(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
+            fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
                use std::fmt::Write;
                let mut writer = $crate::http::header::Writer::new();
                let _ = write!(&mut writer, "{}", self);
@ -340,6 +341,7 @@ mod allow;
 mod cache_control;
 mod content_disposition;
 mod content_language;
+mod content_encoding;
 mod content_range;
 mod content_type;
 mod date;
--- a/actix-http/src/header/into_pair.rs
+++ b/actix-http/src/header/into_pair.rs
@ -0,0 +1,117 @@
+use std::convert::TryFrom;
+
+use http::{
+    header::{HeaderName, InvalidHeaderName, InvalidHeaderValue},
+    Error as HttpError, HeaderValue,
+};
+
+use super::{Header, IntoHeaderValue};
+
+/// Transforms structures into header K/V pairs for inserting into `HeaderMap`s.
+pub trait IntoHeaderPair: Sized {
+    type Error: Into<HttpError>;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error>;
+}
+
+#[derive(Debug)]
+pub enum InvalidHeaderPart {
+    Name(InvalidHeaderName),
+    Value(InvalidHeaderValue),
+}
+
+impl From<InvalidHeaderPart> for HttpError {
+    fn from(part_err: InvalidHeaderPart) -> Self {
+        match part_err {
+            InvalidHeaderPart::Name(err) => err.into(),
+            InvalidHeaderPart::Value(err) => err.into(),
+        }
+    }
+}
+
+impl<V> IntoHeaderPair for (HeaderName, V)
+where
+    V: IntoHeaderValue,
+    V::Error: Into<InvalidHeaderValue>,
+{
+    type Error = InvalidHeaderPart;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        let (name, value) = self;
+        let value = value
+            .try_into_value()
+            .map_err(|err| InvalidHeaderPart::Value(err.into()))?;
+        Ok((name, value))
+    }
+}
+
+impl<V> IntoHeaderPair for (&HeaderName, V)
+where
+    V: IntoHeaderValue,
+    V::Error: Into<InvalidHeaderValue>,
+{
+    type Error = InvalidHeaderPart;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        let (name, value) = self;
+        let value = value
+            .try_into_value()
+            .map_err(|err| InvalidHeaderPart::Value(err.into()))?;
+        Ok((name.clone(), value))
+    }
+}
+
+impl<V> IntoHeaderPair for (&[u8], V)
+where
+    V: IntoHeaderValue,
+    V::Error: Into<InvalidHeaderValue>,
+{
+    type Error = InvalidHeaderPart;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        let (name, value) = self;
+        let name = HeaderName::try_from(name).map_err(InvalidHeaderPart::Name)?;
+        let value = value
+            .try_into_value()
+            .map_err(|err| InvalidHeaderPart::Value(err.into()))?;
+        Ok((name, value))
+    }
+}
+
+impl<V> IntoHeaderPair for (&str, V)
+where
+    V: IntoHeaderValue,
+    V::Error: Into<InvalidHeaderValue>,
+{
+    type Error = InvalidHeaderPart;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        let (name, value) = self;
+        let name = HeaderName::try_from(name).map_err(InvalidHeaderPart::Name)?;
+        let value = value
+            .try_into_value()
+            .map_err(|err| InvalidHeaderPart::Value(err.into()))?;
+        Ok((name, value))
+    }
+}
+
+impl<V> IntoHeaderPair for (String, V)
+where
+    V: IntoHeaderValue,
+    V::Error: Into<InvalidHeaderValue>,
+{
+    type Error = InvalidHeaderPart;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        let (name, value) = self;
+        (name.as_str(), value).try_into_header_pair()
+    }
+}
+
+impl<T: Header> IntoHeaderPair for T {
+    type Error = <T as IntoHeaderValue>::Error;
+
+    fn try_into_header_pair(self) -> Result<(HeaderName, HeaderValue), Self::Error> {
+        Ok((T::name(), self.try_into_value()?))
+    }
+}
--- a/actix-http/src/header/into_value.rs
+++ b/actix-http/src/header/into_value.rs
@ -0,0 +1,131 @@
+use std::convert::TryFrom;
+
+use bytes::Bytes;
+use http::{header::InvalidHeaderValue, Error as HttpError, HeaderValue};
+use mime::Mime;
+
+/// A trait for any object that can be Converted to a `HeaderValue`
+pub trait IntoHeaderValue: Sized {
+    /// The type returned in the event of a conversion error.
+    type Error: Into<HttpError>;
+
+    /// Try to convert value to a HeaderValue.
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error>;
+}
+
+impl IntoHeaderValue for HeaderValue {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        Ok(self)
+    }
+}
+
+impl IntoHeaderValue for &HeaderValue {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        Ok(self.clone())
+    }
+}
+
+impl IntoHeaderValue for &str {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        self.parse()
+    }
+}
+
+impl IntoHeaderValue for &[u8] {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::from_bytes(self)
+    }
+}
+
+impl IntoHeaderValue for Bytes {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::from_maybe_shared(self)
+    }
+}
+
+impl IntoHeaderValue for Vec<u8> {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self)
+    }
+}
+
+impl IntoHeaderValue for String {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self)
+    }
+}
+
+impl IntoHeaderValue for usize {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self.to_string())
+    }
+}
+
+impl IntoHeaderValue for i64 {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self.to_string())
+    }
+}
+
+impl IntoHeaderValue for u64 {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self.to_string())
+    }
+}
+
+impl IntoHeaderValue for i32 {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self.to_string())
+    }
+}
+
+impl IntoHeaderValue for u32 {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::try_from(self.to_string())
+    }
+}
+
+impl IntoHeaderValue for Mime {
+    type Error = InvalidHeaderValue;
+
+    #[inline]
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
+        HeaderValue::from_str(self.as_ref())
+    }
+}
--- a/actix-http/src/header/map.rs
+++ b/actix-http/src/header/map.rs
--- a/actix-http/src/header/mod.rs
+++ b/actix-http/src/header/mod.rs
@ -1,12 +1,9 @@
-//! Various http headers
-// This is mostly copy of [hyper](https://github.com/hyperium/hyper/tree/master/src/header)
+//! Typed HTTP headers, pre-defined `HeaderName`s, traits for parsing and conversion, and other
+//! header utility methods.

-use std::convert::TryFrom;
-use std::{fmt, str::FromStr};
+use std::fmt;

 use bytes::{Bytes, BytesMut};
-use http::Error as HttpError;
-use mime::Mime;
 use percent_encoding::{AsciiSet, CONTROLS};

 pub use http::header::*;
@ -14,22 +11,29 @@ pub use http::header::*;
 use crate::error::ParseError;
 use crate::httpmessage::HttpMessage;

+mod as_name;
+mod into_pair;
+mod into_value;
+mod utils;
+
 mod common;
 pub(crate) mod map;
 mod shared;
+
 pub use self::common::*;
 #[doc(hidden)]
 pub use self::shared::*;

+pub use self::as_name::AsHeaderName;
+pub use self::into_pair::IntoHeaderPair;
+pub use self::into_value::IntoHeaderValue;
 #[doc(hidden)]
 pub use self::map::GetAll;
 pub use self::map::HeaderMap;
+pub use self::utils::*;

-/// A trait for any object that will represent a header field and value.
-pub trait Header
-where
-    Self: IntoHeaderValue,
-{
+/// A trait for any object that already represents a valid header field and value.
+pub trait Header: IntoHeaderValue {
    /// Returns the name of the header field
    fn name() -> HeaderName;

@ -37,170 +41,16 @@ where
    fn parse<T: HttpMessage>(msg: &T) -> Result<Self, ParseError>;
 }

-/// A trait for any object that can be Converted to a `HeaderValue`
-pub trait IntoHeaderValue: Sized {
-    /// The type returned in the event of a conversion error.
-    type Error: Into<HttpError>;
-
-    /// Try to convert value to a Header value.
-    fn try_into(self) -> Result<HeaderValue, Self::Error>;
-}
-
-impl IntoHeaderValue for HeaderValue {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        Ok(self)
-    }
-}
-
-impl<'a> IntoHeaderValue for &'a str {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        self.parse()
-    }
-}
-
-impl<'a> IntoHeaderValue for &'a [u8] {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        HeaderValue::from_bytes(self)
-    }
-}
-
-impl IntoHeaderValue for Bytes {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        HeaderValue::from_maybe_shared(self)
-    }
-}
-
-impl IntoHeaderValue for Vec<u8> {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        HeaderValue::try_from(self)
-    }
-}
-
-impl IntoHeaderValue for String {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        HeaderValue::try_from(self)
-    }
-}
-
-impl IntoHeaderValue for usize {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        let s = format!("{}", self);
-        HeaderValue::try_from(s)
-    }
-}
-
-impl IntoHeaderValue for u64 {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        let s = format!("{}", self);
-        HeaderValue::try_from(s)
-    }
-}
-
-impl IntoHeaderValue for Mime {
-    type Error = InvalidHeaderValue;
-
-    #[inline]
-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
-        HeaderValue::try_from(format!("{}", self))
-    }
-}
-
-/// Represents supported types of content encodings
-#[derive(Copy, Clone, PartialEq, Debug)]
-pub enum ContentEncoding {
-    /// Automatically select encoding based on encoding negotiation
-    Auto,
-    /// A format using the Brotli algorithm
-    Br,
-    /// A format using the zlib structure with deflate algorithm
-    Deflate,
-    /// Gzip algorithm
-    Gzip,
-    /// Indicates the identity function (i.e. no compression, nor modification)
-    Identity,
-}
-
-impl ContentEncoding {
-    #[inline]
-    /// Is the content compressed?
-    pub fn is_compression(self) -> bool {
-        matches!(self, ContentEncoding::Identity | ContentEncoding::Auto)
-    }
-
-    #[inline]
-    /// Convert content encoding to string
-    pub fn as_str(self) -> &'static str {
-        match self {
-            ContentEncoding::Br => "br",
-            ContentEncoding::Gzip => "gzip",
-            ContentEncoding::Deflate => "deflate",
-            ContentEncoding::Identity | ContentEncoding::Auto => "identity",
-        }
-    }
-
-    #[inline]
-    /// default quality value
-    pub fn quality(self) -> f64 {
-        match self {
-            ContentEncoding::Br => 1.1,
-            ContentEncoding::Gzip => 1.0,
-            ContentEncoding::Deflate => 0.9,
-            ContentEncoding::Identity | ContentEncoding::Auto => 0.1,
-        }
-    }
-}
-
-impl<'a> From<&'a str> for ContentEncoding {
-    fn from(s: &'a str) -> ContentEncoding {
-        let s = s.trim();
-
-        if s.eq_ignore_ascii_case("br") {
-            ContentEncoding::Br
-        } else if s.eq_ignore_ascii_case("gzip") {
-            ContentEncoding::Gzip
-        } else if s.eq_ignore_ascii_case("deflate") {
-            ContentEncoding::Deflate
-        } else {
-            ContentEncoding::Identity
-        }
-    }
-}
-
-#[doc(hidden)]
+#[derive(Debug, Default)]
 pub(crate) struct Writer {
    buf: BytesMut,
 }

 impl Writer {
    fn new() -> Writer {
-        Writer {
-            buf: BytesMut::new(),
-        }
+        Writer::default()
    }
+
    fn take(&mut self) -> Bytes {
        self.buf.split().freeze()
    }
@ -219,176 +69,15 @@ impl fmt::Write for Writer {
    }
 }

-#[inline]
-#[doc(hidden)]
-/// Reads a comma-delimited raw header into a Vec.
-pub fn from_comma_delimited<'a, I: Iterator<Item = &'a HeaderValue> + 'a, T: FromStr>(
-    all: I,
-) -> Result<Vec<T>, ParseError> {
-    let mut result = Vec::new();
-    for h in all {
-        let s = h.to_str().map_err(|_| ParseError::Header)?;
-        result.extend(
-            s.split(',')
-                .filter_map(|x| match x.trim() {
-                    "" => None,
-                    y => Some(y),
-                })
-                .filter_map(|x| x.trim().parse().ok()),
-        )
-    }
-    Ok(result)
-}
-
-#[inline]
-#[doc(hidden)]
-/// Reads a single string when parsing a header.
-pub fn from_one_raw_str<T: FromStr>(val: Option<&HeaderValue>) -> Result<T, ParseError> {
-    if let Some(line) = val {
-        let line = line.to_str().map_err(|_| ParseError::Header)?;
-        if !line.is_empty() {
-            return T::from_str(line).or(Err(ParseError::Header));
-        }
-    }
-    Err(ParseError::Header)
-}
-
-#[inline]
-#[doc(hidden)]
-/// Format an array into a comma-delimited string.
-pub fn fmt_comma_delimited<T>(f: &mut fmt::Formatter<'_>, parts: &[T]) -> fmt::Result
-where
-    T: fmt::Display,
-{
-    let mut iter = parts.iter();
-    if let Some(part) = iter.next() {
-        fmt::Display::fmt(part, f)?;
-    }
-    for part in iter {
-        f.write_str(", ")?;
-        fmt::Display::fmt(part, f)?;
-    }
-    Ok(())
-}
-
-// From hyper v0.11.27 src/header/parsing.rs
-
-/// The value part of an extended parameter consisting of three parts:
-/// the REQUIRED character set name (`charset`), the OPTIONAL language information (`language_tag`),
-/// and a character sequence representing the actual value (`value`), separated by single quote
-/// characters. It is defined in [RFC 5987](https://tools.ietf.org/html/rfc5987#section-3.2).
-#[derive(Clone, Debug, PartialEq)]
-pub struct ExtendedValue {
-    /// The character set that is used to encode the `value` to a string.
-    pub charset: Charset,
-    /// The human language details of the `value`, if available.
-    pub language_tag: Option<LanguageTag>,
-    /// The parameter value, as expressed in octets.
-    pub value: Vec<u8>,
-}
-
-/// Parses extended header parameter values (`ext-value`), as defined in
-/// [RFC 5987](https://tools.ietf.org/html/rfc5987#section-3.2).
-///
-/// Extended values are denoted by parameter names that end with `*`.
-///
-/// ## ABNF
-///
-/// ```text
-/// ext-value     = charset  "'" [ language ] "'" value-chars
-///               ; like RFC 2231's <extended-initial-value>
-///               ; (see [RFC2231], Section 7)
-///
-/// charset       = "UTF-8" / "ISO-8859-1" / mime-charset
-///
-/// mime-charset  = 1*mime-charsetc
-/// mime-charsetc = ALPHA / DIGIT
-///               / "!" / "#" / "$" / "%" / "&"
-///               / "+" / "-" / "^" / "_" / "`"
-///               / "{" / "}" / "~"
-///               ; as <mime-charset> in Section 2.3 of [RFC2978]
-///               ; except that the single quote is not included
-///               ; SHOULD be registered in the IANA charset registry
-///
-/// language      = <Language-Tag, defined in [RFC5646], Section 2.1>
-///
-/// value-chars   = *( pct-encoded / attr-char )
-///
-/// pct-encoded   = "%" HEXDIG HEXDIG
-///               ; see [RFC3986], Section 2.1
-///
-/// attr-char     = ALPHA / DIGIT
-///               / "!" / "#" / "$" / "&" / "+" / "-" / "."
-///               / "^" / "_" / "`" / "|" / "~"
-///               ; token except ( "*" / "'" / "%" )
-/// ```
-pub fn parse_extended_value(
-    val: &str,
-) -> Result<ExtendedValue, crate::error::ParseError> {
-    // Break into three pieces separated by the single-quote character
-    let mut parts = val.splitn(3, '\'');
-
-    // Interpret the first piece as a Charset
-    let charset: Charset = match parts.next() {
-        None => return Err(crate::error::ParseError::Header),
-        Some(n) => FromStr::from_str(n).map_err(|_| crate::error::ParseError::Header)?,
-    };
-
-    // Interpret the second piece as a language tag
-    let language_tag: Option<LanguageTag> = match parts.next() {
-        None => return Err(crate::error::ParseError::Header),
-        Some("") => None,
-        Some(s) => match s.parse() {
-            Ok(lt) => Some(lt),
-            Err(_) => return Err(crate::error::ParseError::Header),
-        },
-    };
-
-    // Interpret the third piece as a sequence of value characters
-    let value: Vec<u8> = match parts.next() {
-        None => return Err(crate::error::ParseError::Header),
-        Some(v) => percent_encoding::percent_decode(v.as_bytes()).collect(),
-    };
-
-    Ok(ExtendedValue {
-        value,
-        charset,
-        language_tag,
-    })
-}
-
-impl fmt::Display for ExtendedValue {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let encoded_value =
-            percent_encoding::percent_encode(&self.value[..], HTTP_VALUE);
-        if let Some(ref lang) = self.language_tag {
-            write!(f, "{}'{}'{}", self.charset, lang, encoded_value)
-        } else {
-            write!(f, "{}''{}", self.charset, encoded_value)
-        }
-    }
-}
-
-/// Percent encode a sequence of bytes with a character set defined in
-/// <https://tools.ietf.org/html/rfc5987#section-3.2>
-pub fn http_percent_encode(f: &mut fmt::Formatter<'_>, bytes: &[u8]) -> fmt::Result {
-    let encoded = percent_encoding::percent_encode(bytes, HTTP_VALUE);
-    fmt::Display::fmt(&encoded, f)
-}
-
-/// Convert http::HeaderMap to a HeaderMap
+/// Convert `http::HeaderMap` to our `HeaderMap`.
 impl From<http::HeaderMap> for HeaderMap {
-    fn from(map: http::HeaderMap) -> HeaderMap {
-        let mut new_map = HeaderMap::with_capacity(map.capacity());
-        for (h, v) in map.iter() {
-            new_map.append(h.clone(), v.clone());
-        }
-        new_map
+    fn from(mut map: http::HeaderMap) -> HeaderMap {
+        HeaderMap::from_drain(map.drain())
    }
 }

-// This encode set is used for HTTP header values and is defined at
-// https://tools.ietf.org/html/rfc5987#section-3.2
+/// This encode set is used for HTTP header values and is defined at
+/// https://tools.ietf.org/html/rfc5987#section-3.2.
 pub(crate) const HTTP_VALUE: &AsciiSet = &CONTROLS
    .add(b' ')
    .add(b'"')
@ -410,91 +99,3 @@ pub(crate) const HTTP_VALUE: &AsciiSet = &CONTROLS
    .add(b']')
    .add(b'{')
    .add(b'}');
-
-#[cfg(test)]
-mod tests {
-    use super::shared::Charset;
-    use super::{parse_extended_value, ExtendedValue};
-    use language_tags::LanguageTag;
-
-    #[test]
-    fn test_parse_extended_value_with_encoding_and_language_tag() {
-        let expected_language_tag = "en".parse::<LanguageTag>().unwrap();
-        // RFC 5987, Section 3.2.2
-        // Extended notation, using the Unicode character U+00A3 (POUND SIGN)
-        let result = parse_extended_value("iso-8859-1'en'%A3%20rates");
-        assert!(result.is_ok());
-        let extended_value = result.unwrap();
-        assert_eq!(Charset::Iso_8859_1, extended_value.charset);
-        assert!(extended_value.language_tag.is_some());
-        assert_eq!(expected_language_tag, extended_value.language_tag.unwrap());
-        assert_eq!(
-            vec![163, b' ', b'r', b'a', b't', b'e', b's'],
-            extended_value.value
-        );
-    }
-
-    #[test]
-    fn test_parse_extended_value_with_encoding() {
-        // RFC 5987, Section 3.2.2
-        // Extended notation, using the Unicode characters U+00A3 (POUND SIGN)
-        // and U+20AC (EURO SIGN)
-        let result = parse_extended_value("UTF-8''%c2%a3%20and%20%e2%82%ac%20rates");
-        assert!(result.is_ok());
-        let extended_value = result.unwrap();
-        assert_eq!(Charset::Ext("UTF-8".to_string()), extended_value.charset);
-        assert!(extended_value.language_tag.is_none());
-        assert_eq!(
-            vec![
-                194, 163, b' ', b'a', b'n', b'd', b' ', 226, 130, 172, b' ', b'r', b'a',
-                b't', b'e', b's',
-            ],
-            extended_value.value
-        );
-    }
-
-    #[test]
-    fn test_parse_extended_value_missing_language_tag_and_encoding() {
-        // From: https://greenbytes.de/tech/tc2231/#attwithfn2231quot2
-        let result = parse_extended_value("foo%20bar.html");
-        assert!(result.is_err());
-    }
-
-    #[test]
-    fn test_parse_extended_value_partially_formatted() {
-        let result = parse_extended_value("UTF-8'missing third part");
-        assert!(result.is_err());
-    }
-
-    #[test]
-    fn test_parse_extended_value_partially_formatted_blank() {
-        let result = parse_extended_value("blank second part'");
-        assert!(result.is_err());
-    }
-
-    #[test]
-    fn test_fmt_extended_value_with_encoding_and_language_tag() {
-        let extended_value = ExtendedValue {
-            charset: Charset::Iso_8859_1,
-            language_tag: Some("en".parse().expect("Could not parse language tag")),
-            value: vec![163, b' ', b'r', b'a', b't', b'e', b's'],
-        };
-        assert_eq!("ISO-8859-1'en'%A3%20rates", format!("{}", extended_value));
-    }
-
-    #[test]
-    fn test_fmt_extended_value_with_encoding() {
-        let extended_value = ExtendedValue {
-            charset: Charset::Ext("UTF-8".to_string()),
-            language_tag: None,
-            value: vec![
-                194, 163, b' ', b'a', b'n', b'd', b' ', 226, 130, 172, b' ', b'r', b'a',
-                b't', b'e', b's',
-            ],
-        };
-        assert_eq!(
-            "UTF-8''%C2%A3%20and%20%E2%82%AC%20rates",
-            format!("{}", extended_value)
-        );
-    }
-}
--- a/actix-http/src/header/shared/entity.rs
+++ b/actix-http/src/header/shared/entity.rs
@ -161,7 +161,7 @@ impl FromStr for EntityTag {
 impl IntoHeaderValue for EntityTag {
    type Error = InvalidHeaderValue;

-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
        let mut wrt = Writer::new();
        write!(wrt, "{}", self).unwrap();
        HeaderValue::from_maybe_shared(wrt.take())
--- a/actix-http/src/header/shared/extended.rs
+++ b/actix-http/src/header/shared/extended.rs
@ -0,0 +1,193 @@
+use std::{fmt, str::FromStr};
+
+use language_tags::LanguageTag;
+
+use crate::header::{Charset, HTTP_VALUE};
+
+// From hyper v0.11.27 src/header/parsing.rs
+
+/// The value part of an extended parameter consisting of three parts:
+/// - The REQUIRED character set name (`charset`).
+/// - The OPTIONAL language information (`language_tag`).
+/// - A character sequence representing the actual value (`value`), separated by single quotes.
+///
+/// It is defined in [RFC 5987](https://tools.ietf.org/html/rfc5987#section-3.2).
+#[derive(Clone, Debug, PartialEq)]
+pub struct ExtendedValue {
+    /// The character set that is used to encode the `value` to a string.
+    pub charset: Charset,
+
+    /// The human language details of the `value`, if available.
+    pub language_tag: Option<LanguageTag>,
+
+    /// The parameter value, as expressed in octets.
+    pub value: Vec<u8>,
+}
+
+/// Parses extended header parameter values (`ext-value`), as defined in
+/// [RFC 5987](https://tools.ietf.org/html/rfc5987#section-3.2).
+///
+/// Extended values are denoted by parameter names that end with `*`.
+///
+/// ## ABNF
+///
+/// ```text
+/// ext-value     = charset  "'" [ language ] "'" value-chars
+///               ; like RFC 2231's <extended-initial-value>
+///               ; (see [RFC2231], Section 7)
+///
+/// charset       = "UTF-8" / "ISO-8859-1" / mime-charset
+///
+/// mime-charset  = 1*mime-charsetc
+/// mime-charsetc = ALPHA / DIGIT
+///               / "!" / "#" / "$" / "%" / "&"
+///               / "+" / "-" / "^" / "_" / "`"
+///               / "{" / "}" / "~"
+///               ; as <mime-charset> in Section 2.3 of [RFC2978]
+///               ; except that the single quote is not included
+///               ; SHOULD be registered in the IANA charset registry
+///
+/// language      = <Language-Tag, defined in [RFC5646], Section 2.1>
+///
+/// value-chars   = *( pct-encoded / attr-char )
+///
+/// pct-encoded   = "%" HEXDIG HEXDIG
+///               ; see [RFC3986], Section 2.1
+///
+/// attr-char     = ALPHA / DIGIT
+///               / "!" / "#" / "$" / "&" / "+" / "-" / "."
+///               / "^" / "_" / "`" / "|" / "~"
+///               ; token except ( "*" / "'" / "%" )
+/// ```
+pub fn parse_extended_value(
+    val: &str,
+) -> Result<ExtendedValue, crate::error::ParseError> {
+    // Break into three pieces separated by the single-quote character
+    let mut parts = val.splitn(3, '\'');
+
+    // Interpret the first piece as a Charset
+    let charset: Charset = match parts.next() {
+        None => return Err(crate::error::ParseError::Header),
+        Some(n) => FromStr::from_str(n).map_err(|_| crate::error::ParseError::Header)?,
+    };
+
+    // Interpret the second piece as a language tag
+    let language_tag: Option<LanguageTag> = match parts.next() {
+        None => return Err(crate::error::ParseError::Header),
+        Some("") => None,
+        Some(s) => match s.parse() {
+            Ok(lt) => Some(lt),
+            Err(_) => return Err(crate::error::ParseError::Header),
+        },
+    };
+
+    // Interpret the third piece as a sequence of value characters
+    let value: Vec<u8> = match parts.next() {
+        None => return Err(crate::error::ParseError::Header),
+        Some(v) => percent_encoding::percent_decode(v.as_bytes()).collect(),
+    };
+
+    Ok(ExtendedValue {
+        value,
+        charset,
+        language_tag,
+    })
+}
+
+impl fmt::Display for ExtendedValue {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let encoded_value =
+            percent_encoding::percent_encode(&self.value[..], HTTP_VALUE);
+        if let Some(ref lang) = self.language_tag {
+            write!(f, "{}'{}'{}", self.charset, lang, encoded_value)
+        } else {
+            write!(f, "{}''{}", self.charset, encoded_value)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_extended_value_with_encoding_and_language_tag() {
+        let expected_language_tag = "en".parse::<LanguageTag>().unwrap();
+        // RFC 5987, Section 3.2.2
+        // Extended notation, using the Unicode character U+00A3 (POUND SIGN)
+        let result = parse_extended_value("iso-8859-1'en'%A3%20rates");
+        assert!(result.is_ok());
+        let extended_value = result.unwrap();
+        assert_eq!(Charset::Iso_8859_1, extended_value.charset);
+        assert!(extended_value.language_tag.is_some());
+        assert_eq!(expected_language_tag, extended_value.language_tag.unwrap());
+        assert_eq!(
+            vec![163, b' ', b'r', b'a', b't', b'e', b's'],
+            extended_value.value
+        );
+    }
+
+    #[test]
+    fn test_parse_extended_value_with_encoding() {
+        // RFC 5987, Section 3.2.2
+        // Extended notation, using the Unicode characters U+00A3 (POUND SIGN)
+        // and U+20AC (EURO SIGN)
+        let result = parse_extended_value("UTF-8''%c2%a3%20and%20%e2%82%ac%20rates");
+        assert!(result.is_ok());
+        let extended_value = result.unwrap();
+        assert_eq!(Charset::Ext("UTF-8".to_string()), extended_value.charset);
+        assert!(extended_value.language_tag.is_none());
+        assert_eq!(
+            vec![
+                194, 163, b' ', b'a', b'n', b'd', b' ', 226, 130, 172, b' ', b'r', b'a',
+                b't', b'e', b's',
+            ],
+            extended_value.value
+        );
+    }
+
+    #[test]
+    fn test_parse_extended_value_missing_language_tag_and_encoding() {
+        // From: https://greenbytes.de/tech/tc2231/#attwithfn2231quot2
+        let result = parse_extended_value("foo%20bar.html");
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_parse_extended_value_partially_formatted() {
+        let result = parse_extended_value("UTF-8'missing third part");
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_parse_extended_value_partially_formatted_blank() {
+        let result = parse_extended_value("blank second part'");
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_fmt_extended_value_with_encoding_and_language_tag() {
+        let extended_value = ExtendedValue {
+            charset: Charset::Iso_8859_1,
+            language_tag: Some("en".parse().expect("Could not parse language tag")),
+            value: vec![163, b' ', b'r', b'a', b't', b'e', b's'],
+        };
+        assert_eq!("ISO-8859-1'en'%A3%20rates", format!("{}", extended_value));
+    }
+
+    #[test]
+    fn test_fmt_extended_value_with_encoding() {
+        let extended_value = ExtendedValue {
+            charset: Charset::Ext("UTF-8".to_string()),
+            language_tag: None,
+            value: vec![
+                194, 163, b' ', b'a', b'n', b'd', b' ', 226, 130, 172, b' ', b'r', b'a',
+                b't', b'e', b's',
+            ],
+        };
+        assert_eq!(
+            "UTF-8''%C2%A3%20and%20%E2%82%AC%20rates",
+            format!("{}", extended_value)
+        );
+    }
+}
--- a/actix-http/src/header/shared/httpdate.rs
+++ b/actix-http/src/header/shared/httpdate.rs
@ -48,7 +48,7 @@ impl From<SystemTime> for HttpDate {
 impl IntoHeaderValue for HttpDate {
    type Error = InvalidHeaderValue;

-    fn try_into(self) -> Result<HeaderValue, Self::Error> {
+    fn try_into_value(self) -> Result<HeaderValue, Self::Error> {
        let mut wrt = BytesMut::with_capacity(29).writer();
        write!(
            wrt,
--- a/actix-http/src/header/shared/mod.rs
+++ b/actix-http/src/header/shared/mod.rs
@ -1,14 +1,16 @@
-//! Copied for `hyper::header::shared`;
-
-pub use self::charset::Charset;
-pub use self::encoding::Encoding;
-pub use self::entity::EntityTag;
-pub use self::httpdate::HttpDate;
-pub use self::quality_item::{q, qitem, Quality, QualityItem};
-pub use language_tags::LanguageTag;
+//! Originally taken from `hyper::header::shared`.

 mod charset;
 mod encoding;
 mod entity;
+mod extended;
 mod httpdate;
 mod quality_item;
+
+pub use self::charset::Charset;
+pub use self::encoding::Encoding;
+pub use self::entity::EntityTag;
+pub use self::extended::{parse_extended_value, ExtendedValue};
+pub use self::httpdate::HttpDate;
+pub use self::quality_item::{q, qitem, Quality, QualityItem};
+pub use language_tags::LanguageTag;
--- a/actix-http/src/header/utils.rs
+++ b/actix-http/src/header/utils.rs
@ -0,0 +1,63 @@
+use std::{fmt, str::FromStr};
+
+use http::HeaderValue;
+
+use crate::{error::ParseError, header::HTTP_VALUE};
+
+/// Reads a comma-delimited raw header into a Vec.
+#[inline]
+pub fn from_comma_delimited<'a, I, T>(all: I) -> Result<Vec<T>, ParseError>
+where
+    I: Iterator<Item = &'a HeaderValue> + 'a,
+    T: FromStr,
+{
+    let mut result = Vec::new();
+    for h in all {
+        let s = h.to_str().map_err(|_| ParseError::Header)?;
+        result.extend(
+            s.split(',')
+                .filter_map(|x| match x.trim() {
+                    "" => None,
+                    y => Some(y),
+                })
+                .filter_map(|x| x.trim().parse().ok()),
+        )
+    }
+    Ok(result)
+}
+
+/// Reads a single string when parsing a header.
+#[inline]
+pub fn from_one_raw_str<T: FromStr>(val: Option<&HeaderValue>) -> Result<T, ParseError> {
+    if let Some(line) = val {
+        let line = line.to_str().map_err(|_| ParseError::Header)?;
+        if !line.is_empty() {
+            return T::from_str(line).or(Err(ParseError::Header));
+        }
+    }
+    Err(ParseError::Header)
+}
+
+/// Format an array into a comma-delimited string.
+#[inline]
+pub fn fmt_comma_delimited<T>(f: &mut fmt::Formatter<'_>, parts: &[T]) -> fmt::Result
+where
+    T: fmt::Display,
+{
+    let mut iter = parts.iter();
+    if let Some(part) = iter.next() {
+        fmt::Display::fmt(part, f)?;
+    }
+    for part in iter {
+        f.write_str(", ")?;
+        fmt::Display::fmt(part, f)?;
+    }
+    Ok(())
+}
+
+/// Percent encode a sequence of bytes with a character set defined in
+/// <https://tools.ietf.org/html/rfc5987#section-3.2>
+pub fn http_percent_encode(f: &mut fmt::Formatter<'_>, bytes: &[u8]) -> fmt::Result {
+    let encoded = percent_encoding::percent_encode(bytes, HTTP_VALUE);
+    fmt::Display::fmt(&encoded, f)
+}
--- a/actix-http/src/httpmessage.rs
+++ b/actix-http/src/httpmessage.rs
@ -13,7 +13,7 @@ use crate::payload::Payload;

 struct Cookies(Vec<Cookie<'static>>);

-/// Trait that implements general purpose operations on http messages
+/// Trait that implements general purpose operations on HTTP messages.
 pub trait HttpMessage: Sized {
    /// Type of message payload stream
    type Stream;
@ -30,8 +30,8 @@ pub trait HttpMessage: Sized {
    /// Mutable reference to a the request's extensions container
    fn extensions_mut(&self) -> RefMut<'_, Extensions>;

+    /// Get a header.
    #[doc(hidden)]
-    /// Get a header
    fn get_header<H: Header>(&self) -> Option<H>
    where
        Self: Sized,
@ -43,8 +43,8 @@ pub trait HttpMessage: Sized {
        }
    }

-    /// Read the request content type. If request does not contain
-    /// *Content-Type* header, empty str get returned.
+    /// Read the request content type. If request did not contain a *Content-Type* header, an empty
+    /// string is returned.
    fn content_type(&self) -> &str {
        if let Some(content_type) = self.headers().get(header::CONTENT_TYPE) {
            if let Ok(content_type) = content_type.to_str() {
@ -90,7 +90,7 @@ pub trait HttpMessage: Sized {
        Ok(None)
    }

-    /// Check if request has chunked transfer encoding
+    /// Check if request has chunked transfer encoding.
    fn chunked(&self) -> Result<bool, ParseError> {
        if let Some(encodings) = self.headers().get(header::TRANSFER_ENCODING) {
            if let Ok(s) = encodings.to_str() {
@ -173,10 +173,12 @@ mod tests {

    #[test]
    fn test_content_type() {
-        let req = TestRequest::with_header("content-type", "text/plain").finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "text/plain"))
+            .finish();
        assert_eq!(req.content_type(), "text/plain");
-        let req =
-            TestRequest::with_header("content-type", "application/json; charset=utf=8")
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json; charset=utf=8"))
            .finish();
        assert_eq!(req.content_type(), "application/json");
        let req = TestRequest::default().finish();
@ -185,12 +187,14 @@ mod tests {

    #[test]
    fn test_mime_type() {
-        let req = TestRequest::with_header("content-type", "application/json").finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json"))
+            .finish();
        assert_eq!(req.mime_type().unwrap(), Some(mime::APPLICATION_JSON));
        let req = TestRequest::default().finish();
        assert_eq!(req.mime_type().unwrap(), None);
-        let req =
-            TestRequest::with_header("content-type", "application/json; charset=utf-8")
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json; charset=utf-8"))
            .finish();
        let mt = req.mime_type().unwrap().unwrap();
        assert_eq!(mt.get_param(mime::CHARSET), Some(mime::UTF_8));
@ -200,10 +204,8 @@ mod tests {

    #[test]
    fn test_mime_type_error() {
-        let req = TestRequest::with_header(
-            "content-type",
-            "applicationadfadsfasdflknadsfklnadsfjson",
-        )
+        let req = TestRequest::default()
+            .insert_header(("content-type", "applicationadfadsfasdflknadsfklnadsfjson"))
            .finish();
        assert_eq!(Err(ContentTypeError::ParseError), req.mime_type());
    }
@ -213,26 +215,26 @@ mod tests {
        let req = TestRequest::default().finish();
        assert_eq!(UTF_8.name(), req.encoding().unwrap().name());

-        let req = TestRequest::with_header("content-type", "application/json").finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json"))
+            .finish();
        assert_eq!(UTF_8.name(), req.encoding().unwrap().name());

-        let req = TestRequest::with_header(
-            "content-type",
-            "application/json; charset=ISO-8859-2",
-        )
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json; charset=ISO-8859-2"))
            .finish();
        assert_eq!(ISO_8859_2, req.encoding().unwrap());
    }

    #[test]
    fn test_encoding_error() {
-        let req = TestRequest::with_header("content-type", "applicatjson").finish();
+        let req = TestRequest::default()
+            .insert_header(("content-type", "applicatjson"))
+            .finish();
        assert_eq!(Some(ContentTypeError::ParseError), req.encoding().err());

-        let req = TestRequest::with_header(
-            "content-type",
-            "application/json; charset=kkkttktk",
-        )
+        let req = TestRequest::default()
+            .insert_header(("content-type", "application/json; charset=kkkttktk"))
            .finish();
        assert_eq!(
            Some(ContentTypeError::UnknownEncoding),
@ -245,15 +247,16 @@ mod tests {
        let req = TestRequest::default().finish();
        assert!(!req.chunked().unwrap());

-        let req =
-            TestRequest::with_header(header::TRANSFER_ENCODING, "chunked").finish();
+        let req = TestRequest::default()
+            .insert_header((header::TRANSFER_ENCODING, "chunked"))
+            .finish();
        assert!(req.chunked().unwrap());

        let req = TestRequest::default()
-            .header(
+            .insert_header((
                header::TRANSFER_ENCODING,
                Bytes::from_static(b"some va\xadscc\xacas0xsdasdlue"),
-            )
+            ))
            .finish();
        assert!(req.chunked().is_err());
    }
--- a/actix-http/src/lib.rs
+++ b/actix-http/src/lib.rs
@ -53,7 +53,7 @@ pub use self::response::{Response, ResponseBuilder};
 pub use self::service::HttpService;

 pub mod http {
-    //! Various HTTP related types
+    //! Various HTTP related types.

    // re-exports
    pub use http::header::{HeaderName, HeaderValue};
@ -64,7 +64,7 @@ pub mod http {
    pub use crate::cookie::{Cookie, CookieBuilder};
    pub use crate::header::HeaderMap;

-    /// Various http headers
+    /// A collection of HTTP headers and helpers.
    pub mod header {
        pub use crate::header::*;
    }
--- a/actix-http/src/message.rs
+++ b/actix-http/src/message.rs
@ -3,7 +3,6 @@ use std::net;
 use std::rc::Rc;

 use bitflags::bitflags;
-use copyless::BoxHelper;

 use crate::extensions::Extensions;
 use crate::header::HeaderMap;
@ -35,7 +34,9 @@ bitflags! {
 pub trait Head: Default + 'static {
    fn clear(&mut self);

-    fn pool() -> &'static MessagePool<Self>;
+    fn with_pool<F, R>(f: F) -> R
+    where
+        F: FnOnce(&MessagePool<Self>) -> R;
 }

 #[derive(Debug)]
@ -70,8 +71,11 @@ impl Head for RequestHead {
        self.extensions.get_mut().clear();
    }

-    fn pool() -> &'static MessagePool<Self> {
-        REQUEST_POOL.with(|p| *p)
+    fn with_pool<F, R>(f: F) -> R
+    where
+        F: FnOnce(&MessagePool<Self>) -> R,
+    {
+        REQUEST_POOL.with(|p| f(p))
    }
 }

@ -339,21 +343,15 @@ impl ResponseHead {
 }

 pub struct Message<T: Head> {
+    // Rc here should not be cloned by anyone.
+    // It's used to reuse allocation of T and no shared ownership is allowed.
    head: Rc<T>,
 }

 impl<T: Head> Message<T> {
    /// Get new message from the pool of objects
    pub fn new() -> Self {
-        T::pool().get_message()
-    }
-}
-
-impl<T: Head> Clone for Message<T> {
-    fn clone(&self) -> Self {
-        Message {
-            head: self.head.clone(),
-        }
+        T::with_pool(|p| p.get_message())
    }
 }

@ -373,9 +371,7 @@ impl<T: Head> std::ops::DerefMut for Message<T> {

 impl<T: Head> Drop for Message<T> {
    fn drop(&mut self) {
-        if Rc::strong_count(&self.head) == 1 {
-            T::pool().release(self.head.clone());
-        }
+        T::with_pool(|p| p.release(self.head.clone()))
    }
 }

@ -427,18 +423,17 @@ pub struct MessagePool<T: Head>(RefCell<Vec<Rc<T>>>);
 /// Request's objects pool
 pub struct BoxedResponsePool(RefCell<Vec<Box<ResponseHead>>>);

-thread_local!(static REQUEST_POOL: &'static MessagePool<RequestHead> = MessagePool::<RequestHead>::create());
-thread_local!(static RESPONSE_POOL: &'static BoxedResponsePool = BoxedResponsePool::create());
+thread_local!(static REQUEST_POOL: MessagePool<RequestHead> = MessagePool::<RequestHead>::create());
+thread_local!(static RESPONSE_POOL: BoxedResponsePool = BoxedResponsePool::create());

 impl<T: Head> MessagePool<T> {
-    fn create() -> &'static MessagePool<T> {
-        let pool = MessagePool(RefCell::new(Vec::with_capacity(128)));
-        Box::leak(Box::new(pool))
+    fn create() -> MessagePool<T> {
+        MessagePool(RefCell::new(Vec::with_capacity(128)))
    }

    /// Get message from the pool
    #[inline]
-    fn get_message(&'static self) -> Message<T> {
+    fn get_message(&self) -> Message<T> {
        if let Some(mut msg) = self.0.borrow_mut().pop() {
            // Message is put in pool only when it's the last copy.
            // which means it's guaranteed to be unique when popped out.
@ -464,14 +459,13 @@ impl<T: Head> MessagePool<T> {
 }

 impl BoxedResponsePool {
-    fn create() -> &'static BoxedResponsePool {
-        let pool = BoxedResponsePool(RefCell::new(Vec::with_capacity(128)));
-        Box::leak(Box::new(pool))
+    fn create() -> BoxedResponsePool {
+        BoxedResponsePool(RefCell::new(Vec::with_capacity(128)))
    }

    /// Get message from the pool
    #[inline]
-    fn get_message(&'static self, status: StatusCode) -> BoxedResponseHead {
+    fn get_message(&self, status: StatusCode) -> BoxedResponseHead {
        if let Some(mut head) = self.0.borrow_mut().pop() {
            head.reason = None;
            head.status = status;
@ -480,17 +474,17 @@ impl BoxedResponsePool {
            BoxedResponseHead { head: Some(head) }
        } else {
            BoxedResponseHead {
-                head: Some(Box::alloc().init(ResponseHead::new(status))),
+                head: Some(Box::new(ResponseHead::new(status))),
            }
        }
    }

    #[inline]
    /// Release request instance
-    fn release(&self, msg: Box<ResponseHead>) {
+    fn release(&self, mut msg: Box<ResponseHead>) {
        let v = &mut self.0.borrow_mut();
        if v.len() < 128 {
-            msg.extensions.borrow_mut().clear();
+            msg.extensions.get_mut().clear();
            v.push(msg);
        }
    }
--- a/actix-http/src/request.rs
+++ b/actix-http/src/request.rs
@ -1,5 +1,9 @@
-use std::cell::{Ref, RefMut};
-use std::{fmt, net};
+//! HTTP requests.
+
+use std::{
+    cell::{Ref, RefMut},
+    fmt, net,
+};

 use http::{header, Method, Uri, Version};

@ -173,13 +177,17 @@ impl<P> fmt::Debug for Request<P> {
            self.method(),
            self.path()
        )?;
+
        if let Some(q) = self.uri().query().as_ref() {
            writeln!(f, "  query: ?{:?}", q)?;
        }
+
        writeln!(f, "  headers:")?;
-        for (key, val) in self.headers() {
+
+        for (key, val) in self.headers().iter() {
            writeln!(f, "    {:?}: {:?}", key, val)?;
        }
+
        Ok(())
    }
 }
--- a/actix-http/src/response.rs
+++ b/actix-http/src/response.rs
@ -1,10 +1,15 @@
-//! Http response
-use std::cell::{Ref, RefMut};
-use std::convert::TryFrom;
-use std::future::Future;
-use std::pin::Pin;
-use std::task::{Context, Poll};
-use std::{fmt, str};
+//! HTTP responses.
+
+use std::{
+    cell::{Ref, RefMut},
+    convert::TryInto,
+    fmt,
+    future::Future,
+    ops,
+    pin::Pin,
+    str,
+    task::{Context, Poll},
+};

 use bytes::{Bytes, BytesMut};
 use futures_core::Stream;
@ -14,7 +19,7 @@ use crate::body::{Body, BodyStream, MessageBody, ResponseBody};
 use crate::cookie::{Cookie, CookieJar};
 use crate::error::Error;
 use crate::extensions::Extensions;
-use crate::header::{Header, IntoHeaderValue};
+use crate::header::{IntoHeaderPair, IntoHeaderValue};
 use crate::http::header::{self, HeaderName, HeaderValue};
 use crate::http::{Error as HttpError, HeaderMap, StatusCode};
 use crate::message::{BoxedResponseHead, ConnectionType, ResponseHead};
@ -341,93 +346,98 @@ impl ResponseBuilder {
        self
    }

-    /// Set a header.
+    /// Insert a header, replacing any that were set with an equivalent field name.
    ///
    /// ```rust
-    /// use actix_http::{http, Request, Response, Result};
+    /// # use actix_http::Response;
+    /// use actix_http::http::header::ContentType;
    ///
-    /// fn index(req: Request) -> Result<Response> {
-    ///     Ok(Response::Ok()
-    ///         .set(http::header::IfModifiedSince(
-    ///             "Sun, 07 Nov 1994 08:48:37 GMT".parse()?,
-    ///         ))
-    ///         .finish())
-    /// }
-    /// ```
-    #[doc(hidden)]
-    pub fn set<H: Header>(&mut self, hdr: H) -> &mut Self {
-        if let Some(parts) = parts(&mut self.head, &self.err) {
-            match hdr.try_into() {
-                Ok(value) => {
-                    parts.headers.append(H::name(), value);
-                }
-                Err(e) => self.err = Some(e.into()),
-            }
-        }
-        self
-    }
-
-    /// Append a header to existing headers.
-    ///
-    /// ```rust
-    /// use actix_http::{http, Request, Response};
-    ///
-    /// fn index(req: Request) -> Response {
    /// Response::Ok()
-    ///         .header("X-TEST", "value")
-    ///         .header(http::header::CONTENT_TYPE, "application/json")
-    ///         .finish()
-    /// }
+    ///     .insert_header(ContentType(mime::APPLICATION_JSON))
+    ///     .insert_header(("X-TEST", "value"))
+    ///     .finish();
    /// ```
-    pub fn header<K, V>(&mut self, key: K, value: V) -> &mut Self
+    pub fn insert_header<H>(&mut self, header: H) -> &mut Self
    where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
+        H: IntoHeaderPair,
    {
        if let Some(parts) = parts(&mut self.head, &self.err) {
-            match HeaderName::try_from(key) {
-                Ok(key) => match value.try_into() {
-                    Ok(value) => {
-                        parts.headers.append(key, value);
-                    }
-                    Err(e) => self.err = Some(e.into()),
-                },
-                Err(e) => self.err = Some(e.into()),
-            };
-        }
-        self
-    }
-
-    /// Set a header.
-    ///
-    /// ```rust
-    /// use actix_http::{http, Request, Response};
-    ///
-    /// fn index(req: Request) -> Response {
-    ///     Response::Ok()
-    ///         .set_header("X-TEST", "value")
-    ///         .set_header(http::header::CONTENT_TYPE, "application/json")
-    ///         .finish()
-    /// }
-    /// ```
-    pub fn set_header<K, V>(&mut self, key: K, value: V) -> &mut Self
-    where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
-    {
-        if let Some(parts) = parts(&mut self.head, &self.err) {
-            match HeaderName::try_from(key) {
-                Ok(key) => match value.try_into() {
-                    Ok(value) => {
+            match header.try_into_header_pair() {
+                Ok((key, value)) => {
                    parts.headers.insert(key, value);
                }
                Err(e) => self.err = Some(e.into()),
-                },
+            };
+        }
+
+        self
+    }
+
+    /// Append a header, keeping any that were set with an equivalent field name.
+    ///
+    /// ```rust
+    /// # use actix_http::Response;
+    /// use actix_http::http::header::ContentType;
+    ///
+    /// Response::Ok()
+    ///     .append_header(ContentType(mime::APPLICATION_JSON))
+    ///     .append_header(("X-TEST", "value1"))
+    ///     .append_header(("X-TEST", "value2"))
+    ///     .finish();
+    /// ```
+    pub fn append_header<H>(&mut self, header: H) -> &mut Self
+    where
+        H: IntoHeaderPair,
+    {
+        if let Some(parts) = parts(&mut self.head, &self.err) {
+            match header.try_into_header_pair() {
+                Ok((key, value)) => parts.headers.append(key, value),
                Err(e) => self.err = Some(e.into()),
            };
        }
+
+        self
+    }
+
+    /// Replaced with [`Self::insert_header()`].
+    #[deprecated = "Replaced with `insert_header((key, value))`."]
+    pub fn set_header<K, V>(&mut self, key: K, value: V) -> &mut Self
+    where
+        K: TryInto<HeaderName>,
+        K::Error: Into<HttpError>,
+        V: IntoHeaderValue,
+    {
+        if self.err.is_some() {
+            return self;
+        }
+
+        match (key.try_into(), value.try_into_value()) {
+            (Ok(name), Ok(value)) => return self.insert_header((name, value)),
+            (Err(err), _) => self.err = Some(err.into()),
+            (_, Err(err)) => self.err = Some(err.into()),
+        }
+
+        self
+    }
+
+    /// Replaced with [`Self::append_header()`].
+    #[deprecated = "Replaced with `append_header((key, value))`."]
+    pub fn header<K, V>(&mut self, key: K, value: V) -> &mut Self
+    where
+        K: TryInto<HeaderName>,
+        K::Error: Into<HttpError>,
+        V: IntoHeaderValue,
+    {
+        if self.err.is_some() {
+            return self;
+        }
+
+        match (key.try_into(), value.try_into_value()) {
+            (Ok(name), Ok(value)) => return self.append_header((name, value)),
+            (Err(err), _) => self.err = Some(err.into()),
+            (_, Err(err)) => self.err = Some(err.into()),
+        }
+
        self
    }

@ -458,7 +468,12 @@ impl ResponseBuilder {
        if let Some(parts) = parts(&mut self.head, &self.err) {
            parts.set_connection_type(ConnectionType::Upgrade);
        }
-        self.set_header(header::UPGRADE, value)
+
+        if let Ok(value) = value.try_into_value() {
+            self.insert_header((header::UPGRADE, value));
+        }
+
+        self
    }

    /// Force close connection, even if it is marked as keep-alive
@ -473,7 +488,7 @@ impl ResponseBuilder {
    /// Disable chunked transfer encoding for HTTP/1.1 streaming responses.
    #[inline]
    pub fn no_chunking(&mut self, len: u64) -> &mut Self {
-        self.header(header::CONTENT_LENGTH, len);
+        self.insert_header((header::CONTENT_LENGTH, len));

        if let Some(parts) = parts(&mut self.head, &self.err) {
            parts.no_chunking(true);
@ -481,15 +496,14 @@ impl ResponseBuilder {
        self
    }

-    /// Set response content type
+    /// Set response content type.
    #[inline]
    pub fn content_type<V>(&mut self, value: V) -> &mut Self
    where
-        HeaderValue: TryFrom<V>,
-        <HeaderValue as TryFrom<V>>::Error: Into<HttpError>,
+        V: IntoHeaderValue,
    {
        if let Some(parts) = parts(&mut self.head, &self.err) {
-            match HeaderValue::try_from(value) {
+            match value.try_into_value() {
                Ok(value) => {
                    parts.headers.insert(header::CONTENT_TYPE, value);
                }
@ -640,27 +654,24 @@ impl ResponseBuilder {
        self.body(Body::from_message(BodyStream::new(stream)))
    }

-    #[inline]
    /// Set a json body and generate `Response`
    ///
    /// `ResponseBuilder` can not be used after this call.
-    pub fn json<T: Serialize>(&mut self, value: T) -> Response {
-        self.json2(&value)
-    }
-
-    /// Set a json body and generate `Response`
-    ///
-    /// `ResponseBuilder` can not be used after this call.
-    pub fn json2<T: Serialize>(&mut self, value: &T) -> Response {
-        match serde_json::to_string(value) {
+    pub fn json<T>(&mut self, value: T) -> Response
+    where
+        T: ops::Deref,
+        T::Target: Serialize,
+    {
+        match serde_json::to_string(&*value) {
            Ok(body) => {
                let contains = if let Some(parts) = parts(&mut self.head, &self.err) {
                    parts.headers.contains_key(header::CONTENT_TYPE)
                } else {
                    true
                };
+
                if !contains {
-                    self.header(header::CONTENT_TYPE, "application/json");
+                    self.insert_header(header::ContentType(mime::APPLICATION_JSON));
                }

                self.body(Body::from(body))
@ -743,9 +754,11 @@ impl<'a> From<&'a ResponseHead> for ResponseBuilder {
        let mut msg = BoxedResponseHead::new(head.status);
        msg.version = head.version;
        msg.reason = head.reason;
-        for (k, v) in &head.headers {
+
+        for (k, v) in head.headers.iter() {
            msg.headers.append(k.clone(), v.clone());
        }
+
        msg.no_chunking(!head.chunked());

        ResponseBuilder {
@ -802,7 +815,7 @@ impl From<ResponseBuilder> for Response {
 impl From<&'static str> for Response {
    fn from(val: &'static str) -> Self {
        Response::Ok()
-            .content_type("text/plain; charset=utf-8")
+            .content_type(mime::TEXT_PLAIN_UTF_8)
            .body(val)
    }
 }
@ -810,7 +823,7 @@ impl From<&'static str> for Response {
 impl From<&'static [u8]> for Response {
    fn from(val: &'static [u8]) -> Self {
        Response::Ok()
-            .content_type("application/octet-stream")
+            .content_type(mime::APPLICATION_OCTET_STREAM)
            .body(val)
    }
 }
@ -818,7 +831,7 @@ impl From<&'static [u8]> for Response {
 impl From<String> for Response {
    fn from(val: String) -> Self {
        Response::Ok()
-            .content_type("text/plain; charset=utf-8")
+            .content_type(mime::TEXT_PLAIN_UTF_8)
            .body(val)
    }
 }
@ -826,7 +839,7 @@ impl From<String> for Response {
 impl<'a> From<&'a String> for Response {
    fn from(val: &'a String) -> Self {
        Response::Ok()
-            .content_type("text/plain; charset=utf-8")
+            .content_type(mime::TEXT_PLAIN_UTF_8)
            .body(val)
    }
 }
@ -834,7 +847,7 @@ impl<'a> From<&'a String> for Response {
 impl From<Bytes> for Response {
    fn from(val: Bytes) -> Self {
        Response::Ok()
-            .content_type("application/octet-stream")
+            .content_type(mime::APPLICATION_OCTET_STREAM)
            .body(val)
    }
 }
@ -842,13 +855,15 @@ impl From<Bytes> for Response {
 impl From<BytesMut> for Response {
    fn from(val: BytesMut) -> Self {
        Response::Ok()
-            .content_type("application/octet-stream")
+            .content_type(mime::APPLICATION_OCTET_STREAM)
            .body(val)
    }
 }

 #[cfg(test)]
 mod tests {
+    use serde_json::json;
+
    use super::*;
    use crate::body::Body;
    use crate::http::header::{HeaderValue, CONTENT_TYPE, COOKIE, SET_COOKIE};
@ -856,8 +871,8 @@ mod tests {
    #[test]
    fn test_debug() {
        let resp = Response::Ok()
-            .header(COOKIE, HeaderValue::from_static("cookie1=value1; "))
-            .header(COOKIE, HeaderValue::from_static("cookie2=value2; "))
+            .append_header((COOKIE, HeaderValue::from_static("cookie1=value1; ")))
+            .append_header((COOKIE, HeaderValue::from_static("cookie2=value2; ")))
            .finish();
        let dbg = format!("{:?}", resp);
        assert!(dbg.contains("Response"));
@ -868,8 +883,8 @@ mod tests {
        use crate::httpmessage::HttpMessage;

        let req = crate::test::TestRequest::default()
-            .header(COOKIE, "cookie1=value1")
-            .header(COOKIE, "cookie2=value2")
+            .append_header((COOKIE, "cookie1=value1"))
+            .append_header((COOKIE, "cookie2=value2"))
            .finish();
        let cookies = req.cookies().unwrap();

@ -882,16 +897,20 @@ mod tests {
                    .max_age(time::Duration::days(1))
                    .finish(),
            )
-            .del_cookie(&cookies[1])
+            .del_cookie(&cookies[0])
            .finish();

-        let mut val: Vec<_> = resp
+        let mut val = resp
            .headers()
            .get_all(SET_COOKIE)
            .map(|v| v.to_str().unwrap().to_owned())
-            .collect();
+            .collect::<Vec<_>>();
        val.sort();
+
+        // the .del_cookie call
        assert!(val[0].starts_with("cookie1=; Max-Age=0;"));
+
+        // the .cookie call
        assert_eq!(
            val[1],
            "name=value; HttpOnly; Path=/test; Domain=www.rust-lang.org; Max-Age=86400"
@ -916,14 +935,14 @@ mod tests {

        let mut iter = r.cookies();
        let v = iter.next().unwrap();
-        assert_eq!((v.name(), v.value()), ("cookie3", "val300"));
-        let v = iter.next().unwrap();
        assert_eq!((v.name(), v.value()), ("original", "val100"));
+        let v = iter.next().unwrap();
+        assert_eq!((v.name(), v.value()), ("cookie3", "val300"));
    }

    #[test]
    fn test_basic_builder() {
-        let resp = Response::Ok().header("X-TEST", "value").finish();
+        let resp = Response::Ok().insert_header(("X-TEST", "value")).finish();
        assert_eq!(resp.status(), StatusCode::OK);
    }

@ -964,26 +983,8 @@ mod tests {
    #[test]
    fn test_json_ct() {
        let resp = Response::build(StatusCode::OK)
-            .header(CONTENT_TYPE, "text/json")
-            .json(vec!["v1", "v2", "v3"]);
-        let ct = resp.headers().get(CONTENT_TYPE).unwrap();
-        assert_eq!(ct, HeaderValue::from_static("text/json"));
-        assert_eq!(resp.body().get_ref(), b"[\"v1\",\"v2\",\"v3\"]");
-    }
-
-    #[test]
-    fn test_json2() {
-        let resp = Response::build(StatusCode::OK).json2(&vec!["v1", "v2", "v3"]);
-        let ct = resp.headers().get(CONTENT_TYPE).unwrap();
-        assert_eq!(ct, HeaderValue::from_static("application/json"));
-        assert_eq!(resp.body().get_ref(), b"[\"v1\",\"v2\",\"v3\"]");
-    }
-
-    #[test]
-    fn test_json2_ct() {
-        let resp = Response::build(StatusCode::OK)
-            .header(CONTENT_TYPE, "text/json")
-            .json2(&vec!["v1", "v2", "v3"]);
+            .insert_header((CONTENT_TYPE, "text/json"))
+            .json(&vec!["v1", "v2", "v3"]);
        let ct = resp.headers().get(CONTENT_TYPE).unwrap();
        assert_eq!(ct, HeaderValue::from_static("text/json"));
        assert_eq!(resp.body().get_ref(), b"[\"v1\",\"v2\",\"v3\"]");
@ -1082,4 +1083,54 @@ mod tests {
        let cookie = resp.cookies().next().unwrap();
        assert_eq!((cookie.name(), cookie.value()), ("cookie1", "val100"));
    }
+
+    #[test]
+    fn response_builder_header_insert_kv() {
+        let mut res = Response::Ok();
+        res.insert_header(("Content-Type", "application/octet-stream"));
+        let res = res.finish();
+
+        assert_eq!(
+            res.headers().get("Content-Type"),
+            Some(&HeaderValue::from_static("application/octet-stream"))
+        );
+    }
+
+    #[test]
+    fn response_builder_header_insert_typed() {
+        let mut res = Response::Ok();
+        res.insert_header(header::ContentType(mime::APPLICATION_OCTET_STREAM));
+        let res = res.finish();
+
+        assert_eq!(
+            res.headers().get("Content-Type"),
+            Some(&HeaderValue::from_static("application/octet-stream"))
+        );
+    }
+
+    #[test]
+    fn response_builder_header_append_kv() {
+        let mut res = Response::Ok();
+        res.append_header(("Content-Type", "application/octet-stream"));
+        res.append_header(("Content-Type", "application/json"));
+        let res = res.finish();
+
+        let headers: Vec<_> = res.headers().get_all("Content-Type").cloned().collect();
+        assert_eq!(headers.len(), 2);
+        assert!(headers.contains(&HeaderValue::from_static("application/octet-stream")));
+        assert!(headers.contains(&HeaderValue::from_static("application/json")));
+    }
+
+    #[test]
+    fn response_builder_header_append_typed() {
+        let mut res = Response::Ok();
+        res.append_header(header::ContentType(mime::APPLICATION_OCTET_STREAM));
+        res.append_header(header::ContentType(mime::APPLICATION_JSON));
+        let res = res.finish();
+
+        let headers: Vec<_> = res.headers().get_all("Content-Type").cloned().collect();
+        assert_eq!(headers.len(), 2);
+        assert!(headers.contains(&HeaderValue::from_static("application/octet-stream")));
+        assert!(headers.contains(&HeaderValue::from_static("application/json")));
+    }
 }
--- a/actix-http/src/service.rs
+++ b/actix-http/src/service.rs
@ -1,4 +1,3 @@
-use std::cell::RefCell;
 use std::marker::PhantomData;
 use std::pin::Pin;
 use std::task::{Context, Poll};
@ -440,7 +439,7 @@ where
    X: Service<Request>,
    U: Service<(Request, Framed<T, h1::Codec>)>,
 {
-    flow: Rc<RefCell<HttpFlow<S, X, U>>>,
+    flow: Rc<HttpFlow<S, X, U>>,
    cfg: ServiceConfig,
    on_connect_ext: Option<Rc<ConnectCallback<T>>>,
    _phantom: PhantomData<B>,
@ -454,12 +453,12 @@ pub(super) struct HttpFlow<S, X, U> {
 }

 impl<S, X, U> HttpFlow<S, X, U> {
-    pub(super) fn new(service: S, expect: X, upgrade: Option<U>) -> Rc<RefCell<Self>> {
-        Rc::new(RefCell::new(Self {
+    pub(super) fn new(service: S, expect: X, upgrade: Option<U>) -> Rc<Self> {
+        Rc::new(Self {
            service,
            expect,
            upgrade,
-        }))
+        })
    }
 }

@ -509,9 +508,9 @@ where
    type Error = DispatchError;
    type Future = HttpServiceHandlerResponse<T, S, B, X, U>;

-    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        let mut flow = self.flow.borrow_mut();
-        let ready = flow
+    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        let ready = self
+            .flow
            .expect
            .poll_ready(cx)
            .map_err(|e| {
@ -521,7 +520,8 @@ where
            })?
            .is_ready();

-        let ready = flow
+        let ready = self
+            .flow
            .service
            .poll_ready(cx)
            .map_err(|e| {
@ -532,7 +532,7 @@ where
            .is_ready()
            && ready;

-        let ready = if let Some(ref mut upg) = flow.upgrade {
+        let ready = if let Some(ref upg) = self.flow.upgrade {
            upg.poll_ready(cx)
                .map_err(|e| {
                    let e = e.into();
@ -553,7 +553,7 @@ where
    }

    fn call(
-        &mut self,
+        &self,
        (io, proto, peer_addr): (T, Protocol, Option<net::SocketAddr>),
    ) -> Self::Future {
        let on_connect_data =
@ -604,7 +604,7 @@ where
        Option<(
            Handshake<T, Bytes>,
            ServiceConfig,
-            Rc<RefCell<HttpFlow<S, X, U>>>,
+            Rc<HttpFlow<S, X, U>>,
            OnConnectData,
            Option<net::SocketAddr>,
        )>,
--- a/actix-http/src/test.rs
+++ b/actix-http/src/test.rs
@ -2,7 +2,6 @@

 use std::{
    cell::{Ref, RefCell},
-    convert::TryFrom,
    io::{self, Read, Write},
    pin::Pin,
    rc::Rc,
@ -12,14 +11,17 @@ use std::{

 use actix_codec::{AsyncRead, AsyncWrite, ReadBuf};
 use bytes::{Bytes, BytesMut};
-use http::header::{self, HeaderName, HeaderValue};
-use http::{Error as HttpError, Method, Uri, Version};
+use http::{
+    header::{self, HeaderValue},
+    Method, Uri, Version,
+};

-use crate::cookie::{Cookie, CookieJar};
-use crate::header::HeaderMap;
-use crate::header::{Header, IntoHeaderValue};
-use crate::payload::Payload;
-use crate::Request;
+use crate::{
+    cookie::{Cookie, CookieJar},
+    header::{HeaderMap, IntoHeaderPair},
+    payload::Payload,
+    Request,
+};

 /// Test `Request` builder
 ///
@ -36,7 +38,7 @@ use crate::Request;
 ///     }
 /// }
 ///
-/// let resp = TestRequest::with_header("content-type", "text/plain")
+/// let resp = TestRequest::default().insert_header("content-type", "text/plain")
 ///     .run(&index)
 ///     .unwrap();
 /// assert_eq!(resp.status(), StatusCode::OK);
@ -69,76 +71,73 @@ impl Default for TestRequest {
 }

 impl TestRequest {
-    /// Create TestRequest and set request uri
+    /// Create a default TestRequest and then set its URI.
    pub fn with_uri(path: &str) -> TestRequest {
        TestRequest::default().uri(path).take()
    }

-    /// Create TestRequest and set header
-    pub fn with_hdr<H: Header>(hdr: H) -> TestRequest {
-        TestRequest::default().set(hdr).take()
-    }
-
-    /// Create TestRequest and set header
-    pub fn with_header<K, V>(key: K, value: V) -> TestRequest
-    where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
-    {
-        TestRequest::default().header(key, value).take()
-    }
-
-    /// Set HTTP version of this request
+    /// Set HTTP version of this request.
    pub fn version(&mut self, ver: Version) -> &mut Self {
        parts(&mut self.0).version = ver;
        self
    }

-    /// Set HTTP method of this request
+    /// Set HTTP method of this request.
    pub fn method(&mut self, meth: Method) -> &mut Self {
        parts(&mut self.0).method = meth;
        self
    }

-    /// Set HTTP Uri of this request
+    /// Set URI of this request.
+    ///
+    /// # Panics
+    /// If provided URI is invalid.
    pub fn uri(&mut self, path: &str) -> &mut Self {
        parts(&mut self.0).uri = Uri::from_str(path).unwrap();
        self
    }

-    /// Set a header
-    pub fn set<H: Header>(&mut self, hdr: H) -> &mut Self {
-        if let Ok(value) = hdr.try_into() {
-            parts(&mut self.0).headers.append(H::name(), value);
-            return self;
-        }
-        panic!("Can not set header");
-    }
-
-    /// Set a header
-    pub fn header<K, V>(&mut self, key: K, value: V) -> &mut Self
+    /// Insert a header, replacing any that were set with an equivalent field name.
+    pub fn insert_header<H>(&mut self, header: H) -> &mut Self
    where
-        HeaderName: TryFrom<K>,
-        <HeaderName as TryFrom<K>>::Error: Into<HttpError>,
-        V: IntoHeaderValue,
+        H: IntoHeaderPair,
    {
-        if let Ok(key) = HeaderName::try_from(key) {
-            if let Ok(value) = value.try_into() {
-                parts(&mut self.0).headers.append(key, value);
-                return self;
+        match header.try_into_header_pair() {
+            Ok((key, value)) => {
+                parts(&mut self.0).headers.insert(key, value);
            }
+            Err(err) => {
+                panic!("Error inserting test header: {}.", err.into());
            }
-        panic!("Can not create header");
        }

-    /// Set cookie for this request
+        self
+    }
+
+    /// Append a header, keeping any that were set with an equivalent field name.
+    pub fn append_header<H>(&mut self, header: H) -> &mut Self
+    where
+        H: IntoHeaderPair,
+    {
+        match header.try_into_header_pair() {
+            Ok((key, value)) => {
+                parts(&mut self.0).headers.append(key, value);
+            }
+            Err(err) => {
+                panic!("Error inserting test header: {}.", err.into());
+            }
+        }
+
+        self
+    }
+
+    /// Set cookie for this request.
    pub fn cookie<'a>(&mut self, cookie: Cookie<'a>) -> &mut Self {
        parts(&mut self.0).cookies.add(cookie.into_owned());
        self
    }

-    /// Set request payload
+    /// Set request payload.
    pub fn set_payload<B: Into<Bytes>>(&mut self, data: B) -> &mut Self {
        let mut payload = crate::h1::Payload::empty();
        payload.unread_data(data.into());
@ -150,7 +149,7 @@ impl TestRequest {
        TestRequest(self.0.take())
    }

-    /// Complete request creation and generate `Request` instance
+    /// Complete request creation and generate `Request` instance.
    pub fn finish(&mut self) -> Request {
        let inner = self.0.take().expect("cannot reuse test request builder");

--- a/actix-http/src/ws/codec.rs
+++ b/actix-http/src/ws/codec.rs
@ -89,7 +89,7 @@ impl Codec {

    /// Set max frame size.
    ///
-    /// By default max size is set to 64kb.
+    /// By default max size is set to 64kB.
    pub fn max_size(mut self, size: usize) -> Self {
        self.max_size = size;
        self
--- a/actix-http/src/ws/mask.rs
+++ b/actix-http/src/ws/mask.rs
@ -3,7 +3,7 @@
 use std::ptr::copy_nonoverlapping;
 use std::slice;

-// Holds a slice guaranteed to be shorter than 8 bytes
+/// Holds a slice guaranteed to be shorter than 8 bytes.
 struct ShortSlice<'a> {
    inner: &'a mut [u8],
 }
@ -80,8 +80,10 @@ unsafe fn cast_slice(buf: &mut [u8]) -> &mut [u64] {
    slice::from_raw_parts_mut(buf.as_mut_ptr() as *mut u64, buf.len() >> 3)
 }

-// Splits a slice into three parts: an unaligned short head and tail, plus an aligned
-// u64 mid section.
+/// Splits a slice into three parts:
+/// - an unaligned short head
+/// - an aligned `u64` slice mid section
+/// - an unaligned short tail
 #[inline]
 fn align_buf(buf: &mut [u8]) -> (ShortSlice<'_>, &mut [u64], ShortSlice<'_>) {
    let start_ptr = buf.as_ptr() as usize;
--- a/actix-http/src/ws/mod.rs
+++ b/actix-http/src/ws/mod.rs
@ -101,7 +101,7 @@ impl ResponseError for HandshakeError {
    fn error_response(&self) -> Response {
        match self {
            HandshakeError::GetMethodRequired => Response::MethodNotAllowed()
-                .header(header::ALLOW, "GET")
+                .insert_header((header::ALLOW, "GET"))
                .finish(),

            HandshakeError::NoWebsocketUpgrade => Response::BadRequest()
@ -128,18 +128,12 @@ impl ResponseError for HandshakeError {
 }

 /// Verify `WebSocket` handshake request and create handshake response.
-// /// `protocols` is a sequence of known protocols. On successful handshake,
-// /// the returned response headers contain the first protocol in this list
-// /// which the server also knows.
 pub fn handshake(req: &RequestHead) -> Result<ResponseBuilder, HandshakeError> {
    verify_handshake(req)?;
    Ok(handshake_response(req))
 }

 /// Verify `WebSocket` handshake request.
-// /// `protocols` is a sequence of known protocols. On successful handshake,
-// /// the returned response headers contain the first protocol in this list
-// /// which the server also knows.
 pub fn verify_handshake(req: &RequestHead) -> Result<(), HandshakeError> {
    // WebSocket accepts only GET
    if req.method != Method::GET {
@ -198,8 +192,8 @@ pub fn handshake_response(req: &RequestHead) -> ResponseBuilder {

    Response::build(StatusCode::SWITCHING_PROTOCOLS)
        .upgrade("websocket")
-        .header(header::TRANSFER_ENCODING, "chunked")
-        .header(header::SEC_WEBSOCKET_ACCEPT, key.as_str())
+        .insert_header((header::TRANSFER_ENCODING, "chunked"))
+        .insert_header((header::SEC_WEBSOCKET_ACCEPT, key))
        .take()
 }

@ -224,7 +218,7 @@ mod tests {
        );

        let req = TestRequest::default()
-            .header(header::UPGRADE, header::HeaderValue::from_static("test"))
+            .insert_header((header::UPGRADE, header::HeaderValue::from_static("test")))
            .finish();
        assert_eq!(
            HandshakeError::NoWebsocketUpgrade,
@ -232,10 +226,10 @@ mod tests {
        );

        let req = TestRequest::default()
-            .header(
+            .insert_header((
                header::UPGRADE,
                header::HeaderValue::from_static("websocket"),
-            )
+            ))
            .finish();
        assert_eq!(
            HandshakeError::NoConnectionUpgrade,
@ -243,14 +237,14 @@ mod tests {
        );

        let req = TestRequest::default()
-            .header(
+            .insert_header((
                header::UPGRADE,
                header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                header::CONNECTION,
                header::HeaderValue::from_static("upgrade"),
-            )
+            ))
            .finish();
        assert_eq!(
            HandshakeError::NoVersionHeader,
@ -258,18 +252,18 @@ mod tests {
        );

        let req = TestRequest::default()
-            .header(
+            .insert_header((
                header::UPGRADE,
                header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                header::CONNECTION,
                header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                header::SEC_WEBSOCKET_VERSION,
                header::HeaderValue::from_static("5"),
-            )
+            ))
            .finish();
        assert_eq!(
            HandshakeError::UnsupportedVersion,
@ -277,18 +271,18 @@ mod tests {
        );

        let req = TestRequest::default()
-            .header(
+            .insert_header((
                header::UPGRADE,
                header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                header::CONNECTION,
                header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                header::SEC_WEBSOCKET_VERSION,
                header::HeaderValue::from_static("13"),
-            )
+            ))
            .finish();
        assert_eq!(
            HandshakeError::BadWebsocketKey,
@ -296,22 +290,22 @@ mod tests {
        );

        let req = TestRequest::default()
-            .header(
+            .insert_header((
                header::UPGRADE,
                header::HeaderValue::from_static("websocket"),
-            )
-            .header(
+            ))
+            .insert_header((
                header::CONNECTION,
                header::HeaderValue::from_static("upgrade"),
-            )
-            .header(
+            ))
+            .insert_header((
                header::SEC_WEBSOCKET_VERSION,
                header::HeaderValue::from_static("13"),
-            )
-            .header(
+            ))
+            .insert_header((
                header::SEC_WEBSOCKET_KEY,
                header::HeaderValue::from_static("13"),
-            )
+            ))
            .finish();
        assert_eq!(
            StatusCode::SWITCHING_PROTOCOLS,
--- a/actix-http/tests/test_client.rs
+++ b/actix-http/tests/test_client.rs
@ -38,7 +38,7 @@ async fn test_h1_v2() {
    let response = srv.get("/").send().await.unwrap();
    assert!(response.status().is_success());

-    let request = srv.get("/").header("x-test", "111").send();
+    let request = srv.get("/").insert_header(("x-test", "111")).send();
    let mut response = request.await.unwrap();
    assert!(response.status().is_success());

--- a/actix-http/tests/test_openssl.rs
+++ b/actix-http/tests/test_openssl.rs
@ -1,4 +1,7 @@
 #![cfg(feature = "openssl")]
+
+extern crate tls_openssl as openssl;
+
 use std::io;

 use actix_http::error::{ErrorBadRequest, PayloadError};
@ -11,7 +14,7 @@ use actix_service::{fn_service, ServiceFactoryExt};
 use bytes::{Bytes, BytesMut};
 use futures_util::future::{err, ok, ready};
 use futures_util::stream::{once, Stream, StreamExt};
-use open_ssl::ssl::{AlpnError, SslAcceptor, SslFiletype, SslMethod};
+use openssl::ssl::{AlpnError, SslAcceptor, SslFiletype, SslMethod};

 async fn load_body<S>(stream: S) -> Result<BytesMut, PayloadError>
 where
@ -173,8 +176,8 @@ async fn test_h2_headers() {
        HttpService::build().h2(move |_| {
            let mut builder = Response::Ok();
            for idx in 0..90 {
-                builder.header(
-                    format!("X-TEST-{}", idx).as_str(),
+                builder.insert_header(
+                    (format!("X-TEST-{}", idx).as_str(),
                    "TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
@ -188,7 +191,7 @@ async fn test_h2_headers() {
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST ",
-                );
+                ));
            }
            ok::<_, ()>(builder.body(data.clone()))
        })
@ -341,7 +344,7 @@ async fn test_h2_body_chunked_explicit() {
                let body = once(ok::<_, Error>(Bytes::from_static(STR.as_ref())));
                ok::<_, ()>(
                    Response::Ok()
-                        .header(header::TRANSFER_ENCODING, "chunked")
+                        .insert_header((header::TRANSFER_ENCODING, "chunked"))
                        .streaming(body),
                )
            })
@ -369,7 +372,7 @@ async fn test_h2_response_http_error_handling() {
                let broken_header = Bytes::from_static(b"\0\0\0");
                ok::<_, ()>(
                    Response::Ok()
-                        .header(header::CONTENT_TYPE, broken_header)
+                        .insert_header((header::CONTENT_TYPE, broken_header))
                        .body(STR),
                )
            }))
@ -408,7 +411,9 @@ async fn test_h2_service_error() {
 async fn test_h2_on_connect() {
    let srv = test_server(move || {
        HttpService::build()
-            .on_connect_ext(|_, data| data.insert(20isize))
+            .on_connect_ext(|_, data| {
+                data.insert(20isize);
+            })
            .h2(|req: Request| {
                assert!(req.extensions().contains::<isize>());
                ok::<_, ()>(Response::Ok().finish())
--- a/actix-http/tests/test_rustls.rs
+++ b/actix-http/tests/test_rustls.rs
@ -1,4 +1,7 @@
 #![cfg(feature = "rustls")]
+
+extern crate tls_rustls as rustls;
+
 use actix_http::error::PayloadError;
 use actix_http::http::header::{self, HeaderName, HeaderValue};
 use actix_http::http::{Method, StatusCode, Version};
@ -9,7 +12,7 @@ use actix_service::{fn_factory_with_config, fn_service};
 use bytes::{Bytes, BytesMut};
 use futures_util::future::{self, err, ok};
 use futures_util::stream::{once, Stream, StreamExt};
-use rust_tls::{
+use rustls::{
    internal::pemfile::{certs, pkcs8_private_keys},
    NoClientAuth, ServerConfig as RustlsServerConfig,
 };
@ -181,7 +184,7 @@ async fn test_h2_headers() {
        HttpService::build().h2(move |_| {
            let mut config = Response::Ok();
            for idx in 0..90 {
-                config.header(
+                config.insert_header((
                    format!("X-TEST-{}", idx).as_str(),
                    "TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
@ -196,7 +199,7 @@ async fn test_h2_headers() {
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST ",
-                );
+                ));
            }
            future::ok::<_, ()>(config.body(data.clone()))
        })
@ -352,7 +355,7 @@ async fn test_h2_body_chunked_explicit() {
                let body = once(ok::<_, Error>(Bytes::from_static(STR.as_ref())));
                ok::<_, ()>(
                    Response::Ok()
-                        .header(header::TRANSFER_ENCODING, "chunked")
+                        .insert_header((header::TRANSFER_ENCODING, "chunked"))
                        .streaming(body),
                )
            })
@ -380,7 +383,7 @@ async fn test_h2_response_http_error_handling() {
                    let broken_header = Bytes::from_static(b"\0\0\0");
                    ok::<_, ()>(
                        Response::Ok()
-                            .header(http::header::CONTENT_TYPE, broken_header)
+                            .insert_header((http::header::CONTENT_TYPE, broken_header))
                            .body(STR),
                    )
                }))
--- a/actix-http/tests/test_server.rs
+++ b/actix-http/tests/test_server.rs
@ -392,7 +392,7 @@ async fn test_h1_headers() {
        HttpService::build().h1(move |_| {
            let mut builder = Response::Ok();
            for idx in 0..90 {
-                builder.header(
+                builder.insert_header((
                    format!("X-TEST-{}", idx).as_str(),
                    "TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
@ -407,7 +407,7 @@ async fn test_h1_headers() {
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST \
                        TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST ",
-                );
+                ));
            }
            future::ok::<_, ()>(builder.body(data.clone()))
        }).tcp()
@ -561,7 +561,7 @@ async fn test_h1_body_chunked_explicit() {
                let body = once(ok::<_, Error>(Bytes::from_static(STR.as_ref())));
                ok::<_, ()>(
                    Response::Ok()
-                        .header(header::TRANSFER_ENCODING, "chunked")
+                        .insert_header((header::TRANSFER_ENCODING, "chunked"))
                        .streaming(body),
                )
            })
@ -625,7 +625,7 @@ async fn test_h1_response_http_error_handling() {
                let broken_header = Bytes::from_static(b"\0\0\0");
                ok::<_, ()>(
                    Response::Ok()
-                        .header(http::header::CONTENT_TYPE, broken_header)
+                        .insert_header((http::header::CONTENT_TYPE, broken_header))
                        .body(STR),
                )
            }))
@ -662,7 +662,9 @@ async fn test_h1_service_error() {
 async fn test_h1_on_connect() {
    let srv = test_server(|| {
        HttpService::build()
-            .on_connect_ext(|_, data| data.insert(20isize))
+            .on_connect_ext(|_, data| {
+                data.insert(20isize);
+            })
            .h1(|req: Request| {
                assert!(req.extensions().contains::<isize>());
                future::ok::<_, ()>(Response::Ok().finish())
--- a/actix-http/tests/test_ws.rs
+++ b/actix-http/tests/test_ws.rs
@ -21,7 +21,7 @@ impl<T> WsService<T> {
        WsService(Arc::new(Mutex::new((PhantomData, Cell::new(false)))))
    }

-    fn set_polled(&mut self) {
+    fn set_polled(&self) {
        *self.0.lock().unwrap().1.get_mut() = true;
    }

@ -44,15 +44,12 @@ where
    type Error = Error;
    type Future = Pin<Box<dyn Future<Output = Result<(), Error>>>>;

-    fn poll_ready(&mut self, _ctx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    fn poll_ready(&self, _ctx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        self.set_polled();
        Poll::Ready(Ok(()))
    }

-    fn call(
-        &mut self,
-        (req, mut framed): (Request, Framed<T, h1::Codec>),
-    ) -> Self::Future {
+    fn call(&self, (req, mut framed): (Request, Framed<T, h1::Codec>)) -> Self::Future {
        let fut = async move {
            let res = ws::handshake(req.head()).unwrap().message_body(());

--- a/actix-multipart/CHANGES.md
+++ b/actix-multipart/CHANGES.md
@ -3,6 +3,10 @@
 ## Unreleased - 2021-xx-xx


+## 0.4.0-beta.2 - 2021-02-10
+* No notable changes.
+
+
 ## 0.4.0-beta.1 - 2021-01-07
 * Fix multipart consuming payload before header checks. [#1513]
 * Update `bytes` to `1.0`. [#1813]
--- a/actix-multipart/Cargo.toml
+++ b/actix-multipart/Cargo.toml
@ -1,8 +1,8 @@
 [package]
 name = "actix-multipart"
-version = "0.4.0-beta.1"
+version = "0.4.0-beta.2"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
-description = "Multipart support for actix web framework."
+description = "Multipart form support for Actix Web"
 readme = "README.md"
 keywords = ["http", "web", "framework", "async", "futures"]
 homepage = "https://actix.rs"
@ -16,8 +16,8 @@ name = "actix_multipart"
 path = "src/lib.rs"

 [dependencies]
-actix-web = { version = "4.0.0-beta.1", default-features = false }
-actix-utils = "3.0.0-beta.1"
+actix-web = { version = "4.0.0-beta.2", default-features = false }
+actix-utils = "3.0.0-beta.2"

 bytes = "1"
 derive_more = "0.99.5"
@ -28,5 +28,5 @@ mime = "0.3"
 twoway = "0.2"

 [dev-dependencies]
-actix-rt = "2.0.0-beta.1"
-actix-http = "3.0.0-beta.1"
+actix-rt = "2"
+actix-http = "3.0.0-beta.2"
--- a/actix-multipart/README.md
+++ b/actix-multipart/README.md
@ -1,8 +1,18 @@
-# Multipart support for actix web framework [![Build Status](https://travis-ci.org/actix/actix-web.svg?branch=master)](https://travis-ci.org/actix/actix-web) [![codecov](https://codecov.io/gh/actix/actix-web/branch/master/graph/badge.svg)](https://codecov.io/gh/actix/actix-web) [![crates.io](https://meritbadge.herokuapp.com/actix-multipart)](https://crates.io/crates/actix-multipart) [![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+# actix-multipart

-## Documentation & community resources
+> Multipart form support for Actix Web.

-* [API Documentation](https://docs.rs/actix-multipart/)
-* [Chat on gitter](https://gitter.im/actix/actix)
-* Cargo package: [actix-multipart](https://crates.io/crates/actix-multipart)
-* Minimum supported Rust version: 1.40 or later
+[![crates.io](https://img.shields.io/crates/v/actix-multipart?label=latest)](https://crates.io/crates/actix-multipart)
+[![Documentation](https://docs.rs/actix-multipart/badge.svg?version=0.4.0-beta.2)](https://docs.rs/actix-multipart/0.4.0-beta.2)
+[![Version](https://img.shields.io/badge/rustc-1.46+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.46.html)
+![MIT or Apache 2.0 licensed](https://img.shields.io/crates/l/actix-multipart.svg)
+<br />
+[![dependency status](https://deps.rs/crate/actix-multipart/0.4.0-beta.2/status.svg)](https://deps.rs/crate/actix-multipart/0.4.0-beta.2)
+[![Download](https://img.shields.io/crates/d/actix-multipart.svg)](https://crates.io/crates/actix-multipart)
+[![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
+## Documentation & Resources
+
+- [API Documentation](https://docs.rs/actix-multipart)
+- [Chat on Gitter](https://gitter.im/actix/actix-web)
+- Minimum Supported Rust Version (MSRV): 1.46.0
--- a/actix-multipart/src/lib.rs
+++ b/actix-multipart/src/lib.rs
@ -1,4 +1,4 @@
-//! Multipart form support for Actix web.
+//! Multipart form support for Actix Web.

 #![deny(rust_2018_idioms)]
 #![allow(clippy::borrow_interior_mutable_const)]
--- a/actix-web-actors/CHANGES.md
+++ b/actix-web-actors/CHANGES.md
@ -3,6 +3,10 @@
 ## Unreleased - 2021-xx-xx


+## 4.0.0-beta.2 - 2021-02-10
+* No notable changes.
+
+
 ## 4.0.0-beta.1 - 2021-01-07
 * Update `pin-project` to `1.0`.
 * Update `bytes` to `1.0`. [#1813]
--- a/actix-web-actors/Cargo.toml
+++ b/actix-web-actors/Cargo.toml
@ -1,8 +1,8 @@
 [package]
 name = "actix-web-actors"
-version = "4.0.0-beta.1"
+version = "4.0.0-beta.2"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
-description = "Actix actors support for actix web framework."
+description = "Actix actors support for Actix Web"
 readme = "README.md"
 keywords = ["actix", "http", "web", "framework", "async"]
 homepage = "https://actix.rs"
@ -16,10 +16,10 @@ name = "actix_web_actors"
 path = "src/lib.rs"

 [dependencies]
-actix = "0.11.0-beta.1"
+actix = { version = "0.11.0-beta.2", default-features = false }
 actix-codec = "0.4.0-beta.1"
-actix-http = "3.0.0-beta.1"
-actix-web = { version = "4.0.0-beta.1", default-features = false }
+actix-http = "3.0.0-beta.2"
+actix-web = { version = "4.0.0-beta.2", default-features = false }

 bytes = "1"
 bytestring = "1"
@ -28,6 +28,6 @@ pin-project = "1.0.0"
 tokio = { version = "1", features = ["sync"] }

 [dev-dependencies]
-actix-rt = "2.0.0-beta.1"
-env_logger = "0.7"
+actix-rt = "2"
+env_logger = "0.8"
 futures-util = { version = "0.3.7", default-features = false }
--- a/actix-web-actors/README.md
+++ b/actix-web-actors/README.md
@ -1,8 +1,18 @@
-Actix actors support for actix web framework [![Build Status](https://travis-ci.org/actix/actix-web.svg?branch=master)](https://travis-ci.org/actix/actix-web) [![codecov](https://codecov.io/gh/actix/actix-web/branch/master/graph/badge.svg)](https://codecov.io/gh/actix/actix-web) [![crates.io](https://meritbadge.herokuapp.com/actix-web-actors)](https://crates.io/crates/actix-web-actors) [![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+# actix-web-actors

-## Documentation & community resources
+> Actix actors support for Actix Web.

-* [API Documentation](https://docs.rs/actix-web-actors/)
-* [Chat on gitter](https://gitter.im/actix/actix)
-* Cargo package: [actix-web-actors](https://crates.io/crates/actix-web-actors)
-* Minimum supported Rust version: 1.40 or later
+[![crates.io](https://img.shields.io/crates/v/actix-web-actors?label=latest)](https://crates.io/crates/actix-web-actors)
+[![Documentation](https://docs.rs/actix-web-actors/badge.svg?version=0.5.0)](https://docs.rs/actix-web-actors/0.5.0)
+[![Version](https://img.shields.io/badge/rustc-1.46+-ab6000.svg)](https://blog.rust-lang.org/2020/03/12/Rust-1.46.html)
+![License](https://img.shields.io/crates/l/actix-web-actors.svg)
+<br />
+[![dependency status](https://deps.rs/crate/actix-web-actors/0.5.0/status.svg)](https://deps.rs/crate/actix-web-actors/0.5.0)
+[![Download](https://img.shields.io/crates/d/actix-web-actors.svg)](https://crates.io/crates/actix-web-actors)
+[![Join the chat at https://gitter.im/actix/actix](https://badges.gitter.im/actix/actix.svg)](https://gitter.im/actix/actix?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
+## Documentation & Resources
+
+- [API Documentation](https://docs.rs/actix-web-actors)
+- [Chat on Gitter](https://gitter.im/actix/actix-web)
+- Minimum supported Rust version: 1.46 or later
--- a/actix-web-actors/src/context.rs
+++ b/actix-web-actors/src/context.rs
@ -233,14 +233,13 @@ mod tests {

    #[actix_rt::test]
    async fn test_default_resource() {
-        let mut srv =
-            init_service(App::new().service(web::resource("/test").to(|| {
+        let srv = init_service(App::new().service(web::resource("/test").to(|| {
            HttpResponse::Ok().streaming(HttpContext::create(MyActor { count: 0 }))
        })))
        .await;

        let req = TestRequest::with_uri("/test").to_request();
-        let resp = call_service(&mut srv, req).await;
+        let resp = call_service(&srv, req).await;
        assert_eq!(resp.status(), StatusCode::OK);

        let body = read_body(resp).await;
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Rob Ede	991363a104	consistent case s/web/Web	2021-02-10 12:12:03 +00:00
Rob Ede	a290e58982	prepare beta 2 release set (#1975 )	2021-02-10 12:10:03 +00:00
fakeshadow	dcad9724bc	ensure poll_flush on h1 connection disconnect (#1974 )	2021-02-10 10:11:53 +00:00
Rob Ede	949d14ae2b	clean up header map (#1964 )	2021-02-09 22:59:17 +00:00
fakeshadow	a6ed4aee84	add poll_flush after a non blocked write to h1 dispatcher (#1971 )	2021-02-09 22:32:46 +00:00
fakeshadow	519d7f2b8a	add trust-dns optional feature for actix-http and awc (#1969 )	2021-02-09 10:41:20 +00:00
fakeshadow	dddb623a11	add services register for tuple and vec of services (#1933 )	2021-02-07 23:47:51 +00:00
fakeshadow	266cf0622c	reduce branch.remove deadcode for h1 dispatcher (#1962 )	2021-02-07 22:48:27 +00:00
Rob Ede	9604e249c9	use stable clippy (#1963 )	2021-02-07 20:33:53 +00:00
fakeshadow	dbc47c9122	optimize actix-http messages (#1914 )	2021-02-07 20:19:10 +00:00
fakeshadow	4c243cbf89	simplify methods of awc::connect::Connect trait (#1941 )	2021-02-07 18:56:39 +00:00
Alexander Jackson	deafb7c8b8	Improve `impl ResponseError` documentation (#1939 ) Co-authored-by: Rob Ede <robjtede@icloud.com>	2021-02-07 04:54:41 +00:00
Jens Reidel	50309aa295	Use askama-escape for html escaping (#1953 )	2021-02-07 04:50:23 +00:00
Rob Ede	9eaea6a2fd	tweak feature flags	2021-02-07 03:54:58 +00:00
fakeshadow	830fb2cdb2	properly drop h2 connection (#1926 )	2021-02-07 03:51:36 +00:00
fakeshadow	7cfed73be8	fix memory usage for h1 and read bug on buffer size. (#1929 )	2021-02-07 03:20:35 +00:00
fakeshadow	41bc04b1c4	Use immutable reference of service state. Update awc dns resolver. (#1905 )	2021-02-07 01:00:40 +00:00
fakeshadow	20cf0094e5	fix master branch build. change web::block output type. (#1957 )	2021-02-06 16:23:59 +00:00
fakeshadow	83fb4978ad	fix awc test_client test (#1960 )	2021-02-06 16:05:33 +00:00
fakeshadow	51e54dac8b	fix limit not working on HttpMessageBody::limit (#1938 )	2021-01-27 10:49:57 +00:00
Jonas Platte	c201c15f8c	Improve documentation for PayloadConfig (#1923 )	2021-01-24 00:32:10 +00:00
Logan Magee	0c8196f8b0	Remove HttpResponseBuilder::json2() (#1903 ) It's not necessary to keep both json() and json2() around since the former reduces the ownership of its parameter to a borrow only to pass the reference to the latter. Users can instead borrow themselves when passing an owned value: there doesn't need to be two separate functions. This change also makes HttpResponseBuilder::json() take T: Deref so it can accept both references and web extractors like web::Json.	2021-01-18 12:14:29 +00:00
Rob Ede	ee10148444	revive commented out tests (#1912 )	2021-01-17 05:19:32 +00:00
fakeshadow	1c95fc2654	Refactor poll_keepalive for readability (#1901 )	2021-01-16 00:15:06 +00:00
Rob Ede	da69bb4d12	implement `App::data` as `App::app_data(Data::new(T)))` (#1906 )	2021-01-15 23:37:33 +00:00
Rob Ede	0a506bf2e9	cleanup top level doc comments	2021-01-15 05:38:50 +00:00
Rob Ede	b2a9ba2ee4	Update PULL_REQUEST_TEMPLATE.md	2021-01-15 04:54:23 +00:00
Rob Ede	f976150b67	return option item from Extensions::insert (#1904 )	2021-01-15 04:22:42 +00:00
Rob Ede	b1dd8d28bc	response header rework (#1869 )	2021-01-15 02:11:10 +00:00
fakeshadow	4edeb5ce47	optimize ErrorHandler middleware (#1902 )	2021-01-14 01:43:44 +00:00
fakeshadow	d34a8689e5	Refactor h1 encoder (#1900 )	2021-01-12 14:38:53 +00:00
Robin Schoonover	a919d2de56	actix-files: Fix If-(Un)Modified to not consider sub-seconds (#1887 )	2021-01-11 18:18:23 +00:00
fakeshadow	46a8f28b74	fix actix-files doc about thread pool (#1898 )	2021-01-11 17:27:33 +00:00
fakeshadow	57398c6df1	Refactor/service request (#1893 )	2021-01-11 01:29:16 +00:00
fakeshadow	7affc6878e	simplify h1 dispatcher (#1899 ) Co-authored-by: Rob Ede <robjtede@icloud.com>	2021-01-11 00:13:56 +00:00
fakeshadow	46b2f7eaaf	use a non leak pool for HttpRequestInner (#1889 ) Co-authored-by: Rob Ede <robjtede@icloud.com>	2021-01-10 22:59:44 +00:00
fakeshadow	9e401b6ef7	refactor Scope (#1895 )	2021-01-09 18:06:49 +00:00
fakeshadow	fe392abeb4	remove actix-threadpool.use actix_rt::task::spawn_blocking (#1878 )	2021-01-09 16:04:19 +00:00
fakeshadow	f6cc829758	remove leaked box in REQUEST_POOL and RESPONSE_POOL (#1896 )	2021-01-09 15:40:20 +00:00
Rob Ede	6575ee93f2	big clean up and docs improvmenet of types mod (#1894 )	2021-01-09 13:17:19 +00:00
fakeshadow	530d03791d	refactor Resource (#1883 )	2021-01-09 03:36:58 +00:00
fakeshadow	d40ae8c8ca	use sync method on Responder trait (#1891 )	2021-01-08 22:17:19 +00:00
Rob Ede	2204614134	don't run awc doctests that rely on external public endpoints (#1888 )	2021-01-08 12:00:58 +00:00
fakeshadow	188ee44f81	remove copyless dependency (#1884 )	2021-01-07 21:55:00 +00:00
fakeshadow	a4c9aaf337	fix extra branch in h1 dispatcher timer (#1882 )	2021-01-07 20:42:09 +00:00