Add AsyncBufRead implementation for ProgressBarIter

src/iter.rs

@@ -1,4 +1,6 @@
 use crate::progress_bar::ProgressBar;
+#[cfg(feature = "tokio")]
+use std::borrow::BorrowMut;
 use std::convert::TryFrom;
 use std::io::{self, IoSliceMut};
 use std::iter::FusedIterator;
@@ -199,6 +201,26 @@ impl<W: tokio::io::AsyncSeek + Unpin> tokio::io::AsyncSeek for ProgressBarIter<W
         Pin::new(&mut self.it).poll_complete(cx)
     }
 }
+#[cfg(feature = "tokio")]
+impl<W: tokio::io::AsyncBufRead + Unpin + tokio::io::AsyncRead> tokio::io::AsyncBufRead
+    for ProgressBarIter<W>
+{
+    fn poll_fill_buf(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<&[u8]>> {
+        let pb = self.progress.clone();
+        Pin::new(self.get_mut().it.borrow_mut())
+            .poll_fill_buf(cx)
+            .map(|x| {
+                x.map(|buf| {
+                    pb.inc(buf.len() as u64);
+                    buf
+                })
+            })
+    }
+
+    fn consume(mut self: Pin<&mut Self>, amt: usize) {
+        Pin::new(&mut self.it).consume(amt);
+    }
+}
 
 impl<W: io::Write> io::Write for ProgressBarIter<W> {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {