internal/pipewire: respond to Core::Ping

There is currently no known message that will get the PipeWire server to emit this event. It should be handled regardless.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pipewire/pipewire.go

@@ -218,6 +218,14 @@ func (ctx *Context) writeMessage(Id Int, v Message) (err error) {
 	return
 }
 
+// mustWriteMessage calls writeMessage and panics if a non-nil error is returned.
+// This must only be called from eventProxy.consume.
+func (ctx *Context) mustWriteMessage(Id Int, v Message) {
+	if err := ctx.writeMessage(Id, v); err != nil {
+		panic(err)
+	}
+}
+
 // newProxyId returns a newly allocated proxy Id for the specified type.
 func (ctx *Context) newProxyId(proxy eventProxy, ack bool) Int {
 	newId := ctx.nextId
@@ -620,6 +628,10 @@ func (ctx *Context) roundtrip() (err error) {
 	}
 }
 
+// currentRemoteSeq returns the current remote sequence number.
+// This must only be called from eventProxy.consume.
+func (ctx *Context) currentRemoteSeq() Int { return ctx.remoteSequence - 1 }
+
 // consume receives messages from the server and processes events.
 func (ctx *Context) consume(receiveRemaining []byte) (remaining []byte, err error) {
 	defer func() {