refactor: read the expected number of bytes form recv stream

- When reading from a stream, we first read the header which gives us
information about the exact number of bytes to read the reamining content,
thus when calling RecvStream::read_to_end we can use that number as a limit.

src/wire_msg.rs

@@ -40,40 +40,38 @@ impl WireMsg {
 
         let msg_header = MsgHeader::from_bytes(header_bytes);
 
+        // https://github.com/rust-lang/rust/issues/70460 for work on a cleaner alternative:
+        #[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))]
+        {
+            compile_error!("You need an architecture capable of addressing 32-bit pointers");
+        }
+        // we know we can convert without loss thanks to our assertions above
+        let header_length = msg_header.user_header_len() as usize;
+        let dst_length = msg_header.user_dst_len() as usize;
+        let payload_length = msg_header.user_payload_len() as usize;
+        let total_length = header_length + dst_length + payload_length;
+
         let start = Instant::now();
-        let all_bytes = recv.read_to_end(1024 * 1024 * 100).await?;
+        let all_bytes = recv.read_to_end(total_length).await?;
 
         let duration = start.elapsed();
         trace!(
-            "Incoming new msg. Reading {:?} bytes took: {:?}",
+            "Incoming new msg. Reading {:?} bytes took: {duration:?}",
             all_bytes.len(),
-            duration
         );
 
         if all_bytes.is_empty() {
             return Err(RecvError::EmptyMsgPayload);
         }
 
-        let mut bytes = Bytes::from(all_bytes);
-
-        // https://github.com/rust-lang/rust/issues/70460 for work on a cleaner alternative:
-        #[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))]
-        {
-            compile_error!("You need an architecture capable of addressing 32-bit pointers");
-        }
-        // we know we can convert without loss thanks to our assertions above
-        let header_length = msg_header.user_header_len() as usize;
-        let dst_length = msg_header.user_dst_len() as usize;
-        let payload_length = msg_header.user_payload_len() as usize;
-
         // Check we have all the data and we weren't cut short, otherwise
         // the following would panic...
-        if bytes.len() != (header_length + dst_length + payload_length) {
+        if all_bytes.len() != total_length {
             return Err(RecvError::NotEnoughBytes);
         }
 
+        let mut bytes = Bytes::from(all_bytes);
         let header_data = bytes.split_to(header_length);
-
         let dst_data = bytes.split_to(dst_length);
         let payload_data = bytes;