Move stream items into tokio-stream (#3277)

This change removes all references to `Stream` from
within the `tokio` crate and moves them into a new
`tokio-stream` crate. Most types have had their
`impl Stream` removed as well in-favor of their
inherent methods.

Closes #2870

tokio-util/src/codec/decoder.rs

@@ -153,7 +153,7 @@ pub trait Decoder {
     /// calling `split` on the [`Framed`] returned by this method, which will
     /// break them into separate objects, allowing them to interact more easily.
     ///
-    /// [`Stream`]: tokio::stream::Stream
+    /// [`Stream`]: tokio_stream::Stream
     /// [`Sink`]: futures_sink::Sink
     /// [`Framed`]: crate::codec::Framed
     fn framed<T: AsyncRead + AsyncWrite + Sized>(self, io: T) -> Framed<T, Self>

tokio-util/src/codec/framed.rs

@@ -2,10 +2,8 @@ use crate::codec::decoder::Decoder;
 use crate::codec::encoder::Encoder;
 use crate::codec::framed_impl::{FramedImpl, RWFrames, ReadFrame, WriteFrame};
 
-use tokio::{
-    io::{AsyncRead, AsyncWrite},
-    stream::Stream,
-};
+use tokio::io::{AsyncRead, AsyncWrite};
+use tokio_stream::Stream;
 
 use bytes::BytesMut;
 use futures_sink::Sink;
@@ -22,7 +20,7 @@ pin_project! {
     /// You can create a `Framed` instance by using the [`Decoder::framed`] adapter, or
     /// by using the `new` function seen below.
     ///
-    /// [`Stream`]: tokio::stream::Stream
+    /// [`Stream`]: tokio_stream::Stream
     /// [`Sink`]: futures_sink::Sink
     /// [`AsyncRead`]: tokio::io::AsyncRead
     /// [`Decoder::framed`]: crate::codec::Decoder::framed()
@@ -54,7 +52,7 @@ where
     /// calling [`split`] on the `Framed` returned by this method, which will
     /// break them into separate objects, allowing them to interact more easily.
     ///
-    /// [`Stream`]: tokio::stream::Stream
+    /// [`Stream`]: tokio_stream::Stream
     /// [`Sink`]: futures_sink::Sink
     /// [`Decode`]: crate::codec::Decoder
     /// [`Encoder`]: crate::codec::Encoder
@@ -88,7 +86,7 @@ where
     /// calling [`split`] on the `Framed` returned by this method, which will
     /// break them into separate objects, allowing them to interact more easily.
     ///
-    /// [`Stream`]: tokio::stream::Stream
+    /// [`Stream`]: tokio_stream::Stream
     /// [`Sink`]: futures_sink::Sink
     /// [`Decode`]: crate::codec::Decoder
     /// [`Encoder`]: crate::codec::Encoder
@@ -133,7 +131,7 @@ impl<T, U> Framed<T, U> {
     /// calling [`split`] on the `Framed` returned by this method, which will
     /// break them into separate objects, allowing them to interact more easily.
     ///
-    /// [`Stream`]: tokio::stream::Stream
+    /// [`Stream`]: tokio_stream::Stream
     /// [`Sink`]: futures_sink::Sink
     /// [`Decoder`]: crate::codec::Decoder
     /// [`Encoder`]: crate::codec::Encoder

tokio-util/src/codec/framed_impl.rs

@@ -1,10 +1,8 @@
 use crate::codec::decoder::Decoder;
 use crate::codec::encoder::Encoder;
 
-use tokio::{
-    io::{AsyncRead, AsyncWrite},
-    stream::Stream,
-};
+use tokio::io::{AsyncRead, AsyncWrite};
+use tokio_stream::Stream;
 
 use bytes::BytesMut;
 use futures_core::ready;

tokio-util/src/codec/framed_read.rs

@@ -1,7 +1,8 @@
 use crate::codec::framed_impl::{FramedImpl, ReadFrame};
 use crate::codec::Decoder;
 
-use tokio::{io::AsyncRead, stream::Stream};
+use tokio::io::AsyncRead;
+use tokio_stream::Stream;
 
 use bytes::BytesMut;
 use futures_sink::Sink;
@@ -13,7 +14,7 @@ use std::task::{Context, Poll};
 pin_project! {
     /// A [`Stream`] of messages decoded from an [`AsyncRead`].
     ///
-    /// [`Stream`]: tokio::stream::Stream
+    /// [`Stream`]: tokio_stream::Stream
     /// [`AsyncRead`]: tokio::io::AsyncRead
     pub struct FramedRead<T, D> {
         #[pin]

tokio-util/src/codec/framed_write.rs

@@ -1,7 +1,8 @@
 use crate::codec::encoder::Encoder;
 use crate::codec::framed_impl::{FramedImpl, WriteFrame};
 
-use tokio::{io::AsyncWrite, stream::Stream};
+use tokio::io::AsyncWrite;
+use tokio_stream::Stream;
 
 use futures_sink::Sink;
 use pin_project_lite::pin_project;

tokio-util/src/codec/mod.rs

@@ -11,7 +11,7 @@
 //!
 //! [`AsyncRead`]: tokio::io::AsyncRead
 //! [`AsyncWrite`]: tokio::io::AsyncWrite
-//! [`Stream`]: tokio::stream::Stream
+//! [`Stream`]: tokio_stream::Stream
 //! [`Sink`]: futures_sink::Sink
 
 mod bytes_codec;