Buffer read but unhandled data from serial device

src/serial.rs

@@ -42,6 +42,7 @@ pub fn find_begin_of_improv_packet(buffer: &Vec<u8>) -> Result<usize> {
 
 pub struct SerialInterface {
     interface: Box<dyn tokio_serial::SerialPort>,
+    buffer: Vec<u8>,
 }
 
 impl SerialInterface {
@@ -51,6 +52,7 @@ impl SerialInterface {
 
         return Ok(Self {
             interface: interface,
+            buffer: Vec::new(),
         });
     }
 
@@ -76,20 +78,42 @@ impl SerialInterface {
     }
 
     pub fn recv_bytes(&mut self) -> Result<Vec<u8>> {
-        let available_bytes = self.interface.bytes_to_read()?.try_into()?;
+        let available_bytes = self.interface.bytes_to_read()
+            .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];
-        self.interface.read(&mut buffer)?;
+
+        if buffer.len() > 0 {
+            self.interface.read(&mut buffer)
+                .context("Failed to read bytes from serial device")?;
+        }
 
         if log_enabled!(Level::Debug) {
             debug!("Received bytes: \n{}\n{}", hex::encode(&buffer), to_ascii_debug(&buffer));
         }
 
+        self.buffer.append(&mut buffer);
+
+        buffer = self.buffer.clone();
+
+        if log_enabled!(Level::Debug) {
+            debug!("Buffer: \n{}\n{}", hex::encode(&buffer), to_ascii_debug(&buffer));
+        }
+
         let improv_packet_offset = find_begin_of_improv_packet(&buffer).context("Failed to find improv header in received bytes from serial device")?;
 
         let improv_packet_end = improv_packet_offset + 10 + <u8 as Into<usize>>::into(buffer[improv_packet_offset+8]);
 
+        if buffer.len() <= improv_packet_end {
+            bail!("Incomplete packet, packet longer than available in buffer");
+        }
+
         let packet_bytes = buffer[improv_packet_offset..improv_packet_end].to_vec();
 
+        self.buffer = buffer[improv_packet_end..].to_vec();
+
         if log_enabled!(Level::Debug) {
             debug!("Received packet: \n{}\n{}", hex::encode(&packet_bytes), to_ascii_debug(&packet_bytes));
         }