Drop dependency on futures-channel

Tokio already provides mpsc and oneshot, and it is an unconditional
dependency. Use those implementations and drop a superfluous dependency.

Author: WhyNotHugo

Cargo.toml

@@ -28,7 +28,6 @@ tokio = { version = "1", features = ["sync"] }
 # Optional
 
 atomic-waker = { version = "1.1.2", optional = true }
-futures-channel = { version = "0.3", optional = true }
 futures-core = { version = "0.3.31", optional = true }
 futures-util = { version = "0.3", default-features = false, features = ["alloc"], optional = true }
 h2 = { version = "0.4.2", optional = true }
@@ -44,7 +43,6 @@ want = { version = "0.3", optional = true }
 
 [dev-dependencies]
 form_urlencoded = "1"
-futures-channel = { version = "0.3", features = ["sink"] }
 futures-util = { version = "0.3", default-features = false, features = ["alloc", "sink"] }
 http-body-util = "0.1"
 pretty_env_logger = "0.5"
@@ -80,8 +78,8 @@ full = [
 ]
 
 # HTTP versions
-http1 = ["dep:atomic-waker", "dep:futures-channel", "dep:futures-core", "dep:httparse", "dep:itoa", "dep:pin-utils"]
-http2 = ["dep:futures-channel", "dep:futures-core", "dep:h2"]
+http1 = ["dep:atomic-waker", "dep:futures-core", "dep:httparse", "dep:itoa", "dep:pin-utils"]
+http2 = ["dep:futures-core", "dep:h2"]
 
 # Client/Server
 client = ["dep:want", "dep:pin-project-lite", "dep:smallvec"]

benches/end_to_end.rs

@@ -341,7 +341,7 @@ impl Opts {
         let make_request = || {
             let chunk_cnt = self.request_chunks;
             let body = if chunk_cnt > 0 {
-                let (mut tx, rx) = futures_channel::mpsc::channel(0);
+                let (mut tx, rx) = tokio::sync::mpsc::channel(0);
 
                 let chunk = self
                     .request_body

src/body/incoming.rs

@@ -5,18 +5,16 @@ use std::pin::Pin;
 use std::task::{Context, Poll};
 
 use bytes::Bytes;
-#[cfg(all(feature = "http1", any(feature = "client", feature = "server")))]
-use futures_channel::{mpsc, oneshot};
 #[cfg(all(
     any(feature = "http1", feature = "http2"),
     any(feature = "client", feature = "server")
 ))]
 use futures_core::ready;
 #[cfg(all(feature = "http1", any(feature = "client", feature = "server")))]
-use futures_core::{stream::FusedStream, Stream}; // for mpsc::Receiver
-#[cfg(all(feature = "http1", any(feature = "client", feature = "server")))]
 use http::HeaderMap;
 use http_body::{Body, Frame, SizeHint};
+#[cfg(all(feature = "http1", any(feature = "client", feature = "server")))]
+use tokio::sync::{mpsc, oneshot};
 
 #[cfg(all(
     any(feature = "http1", feature = "http2"),
@@ -219,8 +217,8 @@ impl Body for Incoming {
             } => {
                 want_tx.send(WANT_READY);
 
-                if !data_rx.is_terminated() {
-                    if let Some(chunk) = ready!(Pin::new(data_rx).poll_next(cx)?) {
+                if !data_rx.is_closed() {
+                    if let Some(chunk) = ready!(Pin::new(data_rx).poll_recv(cx)?) {
                         len.sub_if(chunk.len() as u64);
                         return Poll::Ready(Some(Ok(Frame::data(chunk))));
                     }
@@ -353,9 +351,11 @@ impl Sender {
     pub(crate) fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<crate::Result<()>> {
         // Check if the receiver end has tried polling for the body yet
         ready!(self.poll_want(cx)?);
-        self.data_tx
-            .poll_ready(cx)
-            .map_err(|_| crate::Error::new_closed())
+        if self.data_tx.capacity() > 0 {
+            Poll::Ready(Ok(()))
+        } else {
+            Poll::Pending
+        }
     }
 
     fn poll_want(&mut self, cx: &mut Context<'_>) -> Poll<crate::Result<()>> {

src/proto/h2/client.rs

@@ -9,13 +9,13 @@ use std::{
 
 use crate::rt::{Read, Write};
 use bytes::Bytes;
-use futures_channel::mpsc::{Receiver, Sender};
-use futures_channel::{mpsc, oneshot};
-use futures_core::{ready, FusedFuture, FusedStream, Stream};
+use futures_core::{ready, FusedFuture};
 use h2::client::{Builder, Connection, SendRequest};
 use h2::SendStream;
 use http::{Method, StatusCode};
 use pin_project_lite::pin_project;
+use tokio::sync::mpsc::{Receiver, Sender};
+use tokio::sync::{mpsc, oneshot};
 
 use super::ping::{Ponger, Recorder};
 use super::{ping, H2Upgraded, PipeToSendStream, SendBuf};
@@ -343,7 +343,7 @@ where
             return Poll::Ready(());
         }
 
-        if !this.drop_rx.is_terminated() && Pin::new(&mut this.drop_rx).poll_next(cx).is_ready() {
+        if !this.drop_rx.is_closed() && Pin::new(&mut this.drop_rx).poll_recv(cx).is_ready() {
             // mpsc has been dropped, hopefully polling
             // the connection some more should start shutdown
             // and then close.

tests/client.rs

@@ -17,10 +17,10 @@ use hyper::header::{HeaderMap, HeaderName, HeaderValue};
 use hyper::{Method, Request, StatusCode, Uri, Version};
 
 use bytes::Bytes;
-use futures_channel::oneshot;
 use futures_util::future::{self, FutureExt, TryFuture, TryFutureExt};
 use support::TokioIo;
 use tokio::net::TcpStream;
+use tokio::sync::oneshot;
 mod support;
 
 fn s(buf: &[u8]) -> &str {
@@ -1494,12 +1494,12 @@ mod conn {
     use std::time::Duration;
 
     use bytes::{Buf, Bytes};
-    use futures_channel::{mpsc, oneshot};
     use futures_util::future::{self, poll_fn, FutureExt, TryFutureExt};
     use http_body_util::{BodyExt, Empty, Full, StreamBody};
     use hyper::rt::Timer;
     use tokio::io::{AsyncReadExt as _, AsyncWriteExt as _, DuplexStream};
     use tokio::net::{TcpListener as TkTcpListener, TcpStream};
+    use tokio::sync::{mpsc, oneshot};
 
     use hyper::body::{Body, Frame};
     use hyper::client::conn;

tests/server.rs

@@ -14,7 +14,6 @@ use std::thread;
 use std::time::Duration;
 
 use bytes::Bytes;
-use futures_channel::oneshot;
 use futures_util::future::{self, Either, FutureExt};
 use h2::client::SendRequest;
 use h2::{RecvStream, SendStream};
@@ -25,6 +24,7 @@ use hyper::rt::{Read as AsyncRead, Write as AsyncWrite};
 use support::{TokioExecutor, TokioIo, TokioTimer};
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::{TcpListener as TkTcpListener, TcpListener, TcpStream as TkTcpStream};
+use tokio::sync::oneshot;
 
 use hyper::body::{Body, Incoming as IncomingBody};
 use hyper::server::conn::{http1, http2};