Silence noisy debug message on reading nothing

src/serial.rs

@@ -69,6 +69,7 @@ pub fn find_packet(buffer: &[u8]) -> Result<PacketBounds> {
 pub struct SerialInterface {
     interface: Box<dyn tokio_serial::SerialPort>,
     buffer: Vec<u8>,
+    mute_available_bytes_debug_message: bool,
 }
 
 impl SerialInterface {
@@ -79,6 +80,7 @@ impl SerialInterface {
         return Ok(Self {
             interface: interface,
             buffer: Vec::new(),
+            mute_available_bytes_debug_message: false,
         });
     }
 
@@ -108,13 +110,23 @@ impl SerialInterface {
             .context("Failed to figure out how many bytes are available to read")?
             .try_into()?;
 
-        debug!("Available bytes to read: {}", available_bytes);
-        let mut buffer: Vec<u8> = vec![0; available_bytes];
 
-        if buffer.len() <= 0 {
-            debug!("No bytes available to read");
+        if available_bytes <= 0 && self.mute_available_bytes_debug_message {
             return Ok(());
         }
+        else {
+            self.mute_available_bytes_debug_message = false;
+        }
+
+        debug!("Available bytes to read: {}", available_bytes);
+
+        if available_bytes <= 0 {
+            debug!("Trying to read more bytes...");
+            self.mute_available_bytes_debug_message = true;
+            return Ok(());
+        }
+
+        let mut buffer: Vec<u8> = vec![0; available_bytes];
 
         self.interface.read(&mut buffer)
             .context("Failed to read bytes from serial device")?;