Fix potential memory issue with websocket write buffers.

client_server/websocket_client.cc

@@ -182,7 +182,8 @@ void websocket_client::do_write()
                 [this](boost::beast::error_code ec, std::size_t bytes_transferred) {
 					 on_write(ec, bytes_transferred);
                 });
-		} else {
+		}
+	else {
 		ws_stream_->async_write(
 			msg.buffer->data(),
 			[this](boost::beast::error_code ec, std::size_t bytes_transferred) {

client_server/websocket_server.cc

@@ -124,8 +124,12 @@ void websocket_server::connection::send(const std::string& message)
 	{
 	if (!is_websocket_) return;
 
-	message_queue_.push(message);
-
+	queued_message msg;
+	msg.data   = message;
+	msg.buffer = std::make_shared<boost::beast::flat_buffer>();
+	boost::beast::ostream(*msg.buffer) << msg.data;
+
+	message_queue_.push(msg);
 	if (!writing_) {
 		do_write();
 		}
@@ -140,10 +144,9 @@ void websocket_server::connection::do_write()
 
 	writing_ = true;
 	auto msg = message_queue_.front();
-	message_queue_.pop();
 
 	ws_stream_->async_write(
-		boost::asio::buffer(msg),
+		msg.buffer->data(),
 		[self = shared_from_this()](
 			boost::beast::error_code ec, std::size_t bytes_transferred) {
 		self->on_write(ec, bytes_transferred);
@@ -167,7 +170,8 @@ void websocket_server::connection::close()
 
 void websocket_server::connection::on_write(boost::beast::error_code ec, std::size_t)
 	{
-	if (ec) {
+	message_queue_.pop();
+	if(ec) {
 		server_.remove_connection(id_);
 		return;
 		}

client_server/websocket_server.hh

@@ -76,7 +76,11 @@ class websocket_server {
 				websocket_server&              server_;
 
 				id_type id_;
-				std::queue<std::string> message_queue_;
+				struct queued_message {
+						std::string data;
+						std::shared_ptr<boost::beast::flat_buffer> buffer;
+				};
+				std::queue<queued_message> message_queue_;
 				bool writing_{false};
 				bool is_websocket_{false};
 		};