Move codecs into own module

src/codecs.rs

@@ -0,0 +1,62 @@
+use bytes::{Bytes, BytesMut};
+use rsip::message::SipMessage;
+use rtp::packet::Packet as RtpPacket;
+use tokio_util::codec::{Decoder, Encoder};
+use tracing::{event, instrument, Level};
+use webrtc_util::marshal::Unmarshal;
+
+pub struct SipCodec {}
+
+impl Decoder for SipCodec {
+    type Item = SipMessage;
+    type Error = std::io::Error;
+
+    fn decode(&mut self, src: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
+        if src.is_empty() {
+            Ok(None)
+        } else {
+            // We're assuming we get an entire sip message at once here.
+            match SipMessage::try_from(src.as_ref()) {
+                Ok(msg) => {
+                    src.clear();
+                    Ok(Some(msg))
+                }
+                Err(e) => {
+                    src.clear(); // Still clear the buf to be ready for the next packet
+                    event!(Level::ERROR, error = %e, "Error decoding SIP message.");
+                    Ok(None)
+                }
+            }
+        }
+    }
+}
+
+impl Encoder<SipMessage> for SipCodec {
+    type Error = std::io::Error;
+
+    #[instrument(level = "debug", skip(self, item, dst))]
+    fn encode(&mut self, item: SipMessage, dst: &mut BytesMut) -> Result<(), Self::Error> {
+        let stuff: Bytes = item.into();
+        dst.reserve(stuff.len());
+        dst.extend_from_slice(&stuff);
+        Ok(())
+    }
+}
+
+pub struct RtpCodec {}
+
+impl Decoder for RtpCodec {
+    type Item = RtpPacket;
+    type Error = std::io::Error;
+
+    fn decode(&mut self, src: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
+        if src.is_empty() {
+            Ok(None)
+        } else {
+            match RtpPacket::unmarshal(src) {
+                Ok(p) => Ok(Some(p)),
+                Err(e) => Err(Self::Error::new(std::io::ErrorKind::Other, e.to_string())),
+            }
+        }
+    }
+}