Events: Add SsrcKnown event

Knowing your own SSRC is useful for handling RTCP packets, which may detail information about *ourselves* rather than another host. In theory, at least: this confirms that Discord just sends ReceiverReports containing your own packet stats.

This would have been better to fit into Driver(Re)Connect, but that would be a breaking change: when this change is made, `SsrcKnown` shall be deprecated.

src/driver/connection/mod.rs

@@ -7,6 +7,7 @@ use super::{
 };
 use crate::{
     constants::*,
+    events::CoreContext,
     model::{
         payload::{Identify, Resume, SelectProtocol},
         Event as GatewayEvent,
@@ -195,6 +196,10 @@ impl Connection {
             .mixer
             .send(MixerMessage::SetConn(mix_conn, ready.ssrc))?;
 
+        let _ = interconnect
+            .events
+            .send(EventMessage::FireCoreEvent(CoreContext::SsrcKnown(ssrc)));
+
         spawn(ws_task::runner(
             interconnect.clone(),
             ws_msg_rx,

src/events/context.rs

@@ -69,16 +69,25 @@ pub enum EventContext<'a> {
     ClientConnect(ClientConnect),
     /// Fired whenever a client disconnects.
     ClientDisconnect(ClientDisconnect),
-    /// Fires when this driver successully connects to a voice channel.
+    /// Fires when this driver successfully connects to a voice channel.
     DriverConnect,
-    /// Fires when this driver successful reconnects after a network error.
+    /// Fires when this driver successfully reconnects after a network error.
     DriverReconnect,
     /// Fires when this driver fails to connect to a voice channel.
     DriverConnectFailed,
     /// Fires when this driver fails to reconnect to a voice channel after a network error.
     ///
     /// Users will need to manually reconnect on receipt of this error.
     DriverReconnectFailed,
+    /// Fires whenever the driver is assigned a new [RTP SSRC] by the voice server.
+    ///
+    /// This typically fires alongside a [DriverConnect], or a full [DriverReconnect].
+    ///
+    /// [RTP SSRC]: https://tools.ietf.org/html/rfc3550#section-3
+    /// [DriverConnect]: Self::DriverConnect
+    /// [DriverReconnect]: Self::DriverReconnect
+    // TODO: move assigned SSRC into payload of Driver(Re)Connect as part of next breaking, and deprecate this.
+    SsrcKnown(u32),
 }
 
 #[derive(Clone, Debug)]
@@ -105,6 +114,7 @@ pub enum CoreContext {
     DriverReconnect,
     DriverConnectFailed,
     DriverReconnectFailed,
+    SsrcKnown(u32),
 }
 
 impl<'a> CoreContext {
@@ -143,6 +153,7 @@ impl<'a> CoreContext {
             DriverReconnect => EventContext::DriverReconnect,
             DriverConnectFailed => EventContext::DriverConnectFailed,
             DriverReconnectFailed => EventContext::DriverReconnectFailed,
+            SsrcKnown(s) => EventContext::SsrcKnown(*s),
         }
     }
 }
@@ -164,6 +175,7 @@ impl EventContext<'_> {
             DriverReconnect => Some(CoreEvent::DriverReconnect),
             DriverConnectFailed => Some(CoreEvent::DriverConnectFailed),
             DriverReconnectFailed => Some(CoreEvent::DriverReconnectFailed),
+            SsrcKnown(_) => Some(CoreEvent::SsrcKnown),
             _ => None,
         }
     }

src/events/core.rs

@@ -29,14 +29,23 @@ pub enum CoreEvent {
     ClientConnect,
     /// Fires whenever a user disconnects from the same stream as the bot.
     ClientDisconnect,
-    /// Fires when this driver successully connects to a voice channel.
+    /// Fires when this driver successfully connects to a voice channel.
     DriverConnect,
-    /// Fires when this driver successful reconnects after a network error.
+    /// Fires when this driver successfully reconnects after a network error.
     DriverReconnect,
     /// Fires when this driver fails to connect to a voice channel.
     DriverConnectFailed,
     /// Fires when this driver fails to reconnect to a voice channel after a network error.
     ///
     /// Users will need to manually reconnect on receipt of this error.
     DriverReconnectFailed,
+    /// Fires whenever the driver is assigned a new [RTP SSRC] by the voice server.
+    ///
+    /// This typically fires alongside a [DriverConnect], or a full [DriverReconnect].
+    ///
+    /// [RTP SSRC]: https://tools.ietf.org/html/rfc3550#section-3
+    /// [DriverConnect]: Self::DriverConnect
+    /// [DriverReconnect]: Self::DriverReconnect
+    // TODO: deprecate in next breaking after fusing with Driver(Re)Connect.
+    SsrcKnown,
 }