From 63325e5d756b382fbc7abb979455f00d859d7e76 Mon Sep 17 00:00:00 2001
From: tottoto <tottotodev@gmail.com>
Date: Fri, 22 Sep 2023 20:46:54 +0900
Subject: [PATCH] chore(codec): Replace tonic::codec::encode::fuse with
 tokio-stream

---
 tonic/src/codec/encode.rs | 65 ++++-----------------------------------
 1 file changed, 6 insertions(+), 59 deletions(-)

diff --git a/tonic/src/codec/encode.rs b/tonic/src/codec/encode.rs
index bd48ee47b..d5d82e3c5 100644
--- a/tonic/src/codec/encode.rs
+++ b/tonic/src/codec/encode.rs
@@ -11,8 +11,6 @@ use std::{
 };
 use tokio_stream::{Stream, StreamExt};
 
-use fuse::Fuse;
-
 pub(super) const BUFFER_SIZE: usize = 8 * 1024;
 const YIELD_THRESHOLD: usize = 32 * 1024;
 
@@ -71,7 +69,7 @@ where
     U: Stream<Item = Result<T::Item, Status>>,
 {
     #[pin]
-    source: Fuse<U>,
+    source: U,
     encoder: T,
     compression_encoding: Option<CompressionEncoding>,
     max_message_size: Option<usize>,
@@ -107,7 +105,7 @@ where
         };
 
         return EncodedBytes {
-            source: Fuse::new(source),
+            source,
             encoder,
             compression_encoding,
             max_message_size,
@@ -126,7 +124,7 @@ where
 
     fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         let EncodedBytesProj {
-            mut source,
+            source,
             encoder,
             compression_encoding,
             max_message_size,
@@ -134,6 +132,9 @@ where
             uncompression_buf,
         } = self.project();
 
+        let source = source.fuse();
+        tokio::pin!(source);
+
         loop {
             match source.as_mut().poll_next(cx) {
                 Poll::Pending if buf.is_empty() => {
@@ -345,57 +346,3 @@ where
         Poll::Ready(self.project().state.trailers())
     }
 }
-
-mod fuse {
-    use std::{
-        pin::Pin,
-        task::{ready, Context, Poll},
-    };
-
-    use tokio_stream::Stream;
-
-    /// Stream for the [`fuse`](super::StreamExt::fuse) method.
-    #[derive(Debug)]
-    #[pin_project::pin_project]
-    #[must_use = "streams do nothing unless polled"]
-    pub(crate) struct Fuse<St> {
-        #[pin]
-        stream: St,
-        done: bool,
-    }
-
-    impl<St> Fuse<St> {
-        pub(crate) fn new(stream: St) -> Self {
-            Self {
-                stream,
-                done: false,
-            }
-        }
-    }
-
-    impl<S: Stream> Stream for Fuse<S> {
-        type Item = S::Item;
-
-        fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<S::Item>> {
-            let this = self.project();
-
-            if *this.done {
-                return Poll::Ready(None);
-            }
-
-            let item = ready!(this.stream.poll_next(cx));
-            if item.is_none() {
-                *this.done = true;
-            }
-            Poll::Ready(item)
-        }
-
-        fn size_hint(&self) -> (usize, Option<usize>) {
-            if self.done {
-                (0, Some(0))
-            } else {
-                self.stream.size_hint()
-            }
-        }
-    }
-}