Refactor EventsHandler to stream responses via chunked encoding

Author: jschmidt-icinga

lib/remote/eventshandler.cpp

@@ -102,33 +102,27 @@ bool EventsHandler::HandleRequest(
 
 	EventsSubscriber subscriber (std::move(eventTypes), HttpUtility::GetLastParameter(params, "filter"), l_ApiQuery);
 
-	server.StartDetectClientSideShutdown();
+	IoBoundWorkSlot dontLockTheIoThread (yc);
 
 	response.result(http::status::ok);
 	response.set(http::field::content_type, "application/json");
+	response.StartStreaming(true);
+	// Send response headers before waiting for the first event.
+	response.Flush(yc);
 
-	IoBoundWorkSlot dontLockTheIoThread (yc);
-
-	http::async_write(stream, response, yc);
-	stream.async_flush(yc);
-
-	asio::const_buffer newLine ("\n", 1);
+	auto encoder = response.GetJsonEncoder();
 
 	for (;;) {
 		auto event (subscriber.GetInbox()->Shift(yc));
 
-		if (event) {
-			String body = JsonEncode(event);
-
-			boost::algorithm::replace_all(body, "\n", "");
-
-			asio::const_buffer payload (body.CStr(), body.GetLength());
-
-			asio::async_write(stream, payload, yc);
-			asio::async_write(stream, newLine, yc);
-			stream.async_flush(yc);
-		} else if (server.Disconnected()) {
+		if (response.IsClientDisconnected()) {
 			return true;
 		}
+
+		if (event) {
+			encoder.Encode(event);
+			response.body() << '\n';
+			response.Flush(yc);
+		}
 	}
 }