feat: add capacity and max_capacity to the subscription API

core/src/server/helpers.rs

@@ -142,6 +142,16 @@ impl MethodSink {
 		self.tx.send_timeout(msg, timeout).await.map_err(Into::into)
 	}
 
+	/// Get the capacity of the channel.
+	pub fn capacity(&self) -> usize {
+		self.tx.capacity()
+	}
+
+	/// Get the max capacity of the channel.
+	pub fn max_capacity(&self) -> usize {
+		self.tx.max_capacity()
+	}
+
 	/// Waits for there to be space on the return channel.
 	pub async fn has_capacity(&self) -> Result<(), DisconnectError> {
 		match self.tx.reserve().await {

core/src/server/subscription.rs

@@ -306,6 +306,16 @@ impl PendingSubscriptionSink {
 		self.uniq_sub.conn_id
 	}
 
+	/// Get the capacity of the channel.
+	pub fn capacity(&self) -> usize {
+		self.inner.capacity()
+	}
+
+	/// Get the max capacity of the channel.
+	pub fn max_capacity(&self) -> usize {
+		self.inner.max_capacity()
+	}
+
 	/// Get the method name.
 	pub fn method_name(&self) -> &str {
 		self.method
@@ -406,6 +416,16 @@ impl SubscriptionSink {
 		}
 	}
 
+	/// Get the capacity of the subscription sink.
+	pub fn capacity(&self) -> usize {
+		self.inner.capacity()
+	}
+
+	/// Get the max capacity of the subscription.
+	pub fn max_capacity(&self) -> usize {
+		self.inner.max_capacity()
+	}
+
 	fn is_active_subscription(&self) -> bool {
 		!self.unsubscribe.is_unsubscribed()
 	}