refactor client body (#1462)

* add kind field to debug impl for body

Signed-off-by: tottoto <tottotodev@gmail.com>

* simplify body implementation

Signed-off-by: tottoto <tottotodev@gmail.com>

* simplify Body::into_data_stream method signature

Signed-off-by: tottoto <tottotodev@gmail.com>

* enhance client body document

Signed-off-by: tottoto <tottotodev@gmail.com>

---------

Signed-off-by: tottoto <tottotodev@gmail.com>

kube-client/src/client/body.rs

@@ -17,7 +17,12 @@ pub struct Body {
 
 impl fmt::Debug for Body {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Body").finish()
+        let mut builder = f.debug_struct("Body");
+        match self.kind {
+            Kind::Once(_) => builder.field("kind", &"Once"),
+            Kind::Wrap(_) => builder.field("kind", &"Wrap"),
+        };
+        builder.finish()
     }
 }
 
@@ -36,6 +41,7 @@ impl Body {
         Self::new(Kind::Once(None))
     }
 
+    // Create a body from an existing body
     pub(crate) fn wrap_body<B>(body: B) -> Self
     where
         B: HttpBody<Data = Bytes> + Send + 'static,
@@ -44,14 +50,13 @@ impl Body {
         Body::new(Kind::Wrap(body.map_err(Into::into).boxed_unsync()))
     }
 
-    /// Collect all the data frames and trailers of the request body
+    /// Collect all the data frames and trailers of this request body and return the data frame
     pub async fn collect_bytes(self) -> Result<Bytes, crate::Error> {
         Ok(self.collect().await?.to_bytes())
     }
 
-    pub(crate) fn into_data_stream(
-        self,
-    ) -> impl Stream<Item = Result<<Self as HttpBody>::Data, <Self as HttpBody>::Error>> {
+    // Convert this body into `Stream` which iterates only data frame skipping the other kind of frame
+    pub(crate) fn into_data_stream(self) -> impl Stream<Item = Result<Bytes, crate::Error>> {
         Box::pin(BodyStream::new(self).try_filter_map(|frame| async { Ok(frame.into_data().ok()) }))
     }
 }
@@ -79,17 +84,11 @@ impl HttpBody for Body {
     fn poll_frame(
         mut self: Pin<&mut Self>,
         cx: &mut Context<'_>,
-    ) -> Poll<Option<Result<http_body::Frame<Self::Data>, Self::Error>>> {
-        match self.kind {
-            Kind::Once(ref mut val) => {
-                if let Some(data) = val.take() {
-                    Poll::Ready(Some(Ok(Frame::data(data))))
-                } else {
-                    Poll::Ready(None)
-                }
-            }
-            Kind::Wrap(ref mut stream) => Poll::Ready(
-                ready!(Pin::new(stream).poll_frame(cx))
+    ) -> Poll<Option<Result<Frame<Self::Data>, Self::Error>>> {
+        match &mut self.kind {
+            Kind::Once(val) => Poll::Ready(val.take().map(|bytes| Ok(Frame::data(bytes)))),
+            Kind::Wrap(body) => Poll::Ready(
+                ready!(Pin::new(body).poll_frame(cx))
                     .map(|opt_chunk| opt_chunk.map_err(crate::Error::Service)),
             ),
         }