1 files changed, 34 insertions, 23 deletions
diff --git a/tokio/src/io/util/read_buf.rs b/tokio/src/io/util/read_buf.rs
index 696deefd..7df429d7 100644
--- a/tokio/src/io/util/read_buf.rs
+++ b/tokio/src/io/util/read_buf.rs
@@ -40,33 +40,44 @@ where
     type Output = io::Result<usize>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<usize>> {
-        use crate::io::ReadBuf;
-        use std::mem::MaybeUninit;
-
-        let me = self.project();
+        let mut me = self.project();
+        poll_read_buf(&mut me.reader, &mut me.buf, cx)
+    }
+}
 
-        if !me.buf.has_remaining_mut() {
-            return Poll::Ready(Ok(0));
-        }
+pub(crate) fn poll_read_buf<'a, R, B>(
+    reader: &'a mut R,
+    buf: &'a mut B,
+    cx: &mut Context<'_>,
+) -> Poll<io::Result<usize>>
+where
+    R: AsyncRead + Unpin,
+    B: BufMut,
+{
+    use crate::io::ReadBuf;
+    use std::mem::MaybeUninit;
 
-        let n = {
-            let dst = me.buf.bytes_mut();
-            let dst = unsafe { &mut *(dst as *mut _ as *mut [MaybeUninit<u8>]) };
-            let mut buf = ReadBuf::uninit(dst);
-            let ptr = buf.filled().as_ptr();
-            ready!(Pin::new(me.reader).poll_read(cx, &mut buf)?);
+    if !buf.has_remaining_mut() {
+        return Poll::Ready(Ok(0));
+    }
 
-            // Ensure the pointer does not change from under us
-            assert_eq!(ptr, buf.filled().as_ptr());
-            buf.filled().len()
-        };
+    let n = {
+        let dst = buf.bytes_mut();
+        let dst = unsafe { &mut *(dst as *mut _ as *mut [MaybeUninit<u8>]) };
+        let mut buf = ReadBuf::uninit(dst);
+        let ptr = buf.filled().as_ptr();
+        ready!(Pin::new(reader).poll_read(cx, &mut buf)?);
 
-        // Safety: This is guaranteed to be the number of initialized (and read)
-        // bytes due to the invariants provided by `ReadBuf::filled`.
-        unsafe {
-            me.buf.advance_mut(n);
-        }
+        // Ensure the pointer does not change from under us
+        assert_eq!(ptr, buf.filled().as_ptr());
+        buf.filled().len()
+    };
 
-        Poll::Ready(Ok(n))
+    // Safety: This is guaranteed to be the number of initialized (and read)
+    // bytes due to the invariants provided by `ReadBuf::filled`.
+    unsafe {
+        buf.advance_mut(n);
     }
+
+    Poll::Ready(Ok(n))
 }