feat(proto): add generic proto reader

proto/src/reader/utils.rs

@@ -0,0 +1,24 @@
+use async_trait::async_trait;
+use tokio::io::{AsyncBufRead, AsyncBufReadExt};
+
+#[async_trait]
+pub trait AsyncPeek {
+    async fn peek(&mut self, buf: &mut [u8]) -> std::io::Result<usize>;
+}
+
+#[async_trait]
+impl<T> AsyncPeek for T
+where
+    T: AsyncBufRead + Unpin + Send,
+{
+    async fn peek(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
+        let filled = self.fill_buf().await?;
+        if filled.len() >= buf.len() {
+            buf.copy_from_slice(&filled[..buf.len()]);
+            Ok(buf.len())
+        } else {
+            buf[..filled.len()].copy_from_slice(filled);
+            Ok(filled.len())
+        }
+    }
+}