io.reactivex.netty.examples.http.perf.PerfHelloWorldServer Maven / Gradle / Ivy
/*
* Copyright 2015 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package io.reactivex.netty.examples.http.perf;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.reactivex.netty.examples.ExamplesEnvironment;
import io.reactivex.netty.examples.http.helloworld.HelloWorldServer;
import io.reactivex.netty.protocol.http.server.HttpServer;
import io.reactivex.netty.protocol.http.server.HttpServerResponse;
import rx.Observable;
import static io.netty.handler.codec.http.HttpHeaderNames.*;
import static rx.Observable.*;
/**
* This is an HTTP server example used to do "Hello World" benchmarks. A "Hello World" benchmark is a good benchmark to
* analyze library overheads as the application code does not do much.
*
* This server is not representative of the otherwise normal {@link HelloWorldServer} which is much simpler. This
* example instead does micro-optimizations like using {@link HttpServerResponse#flushOnlyOnReadComplete()}, setting
* the content-length header and storing the response content stream, etc. These optimizations reduce the overheads that
* are usually not significant for applications that do any "real work".
*/
public final class PerfHelloWorldServer {
private static final ByteBuf WELCOME_MSG_BUFFER = Unpooled.buffer().writeBytes("Welcome!!".getBytes());
/*Store the response content Observable to reduce object allocation overheads*/
private static final Observable RESPONSE_CONTENT = just(WELCOME_MSG_BUFFER)
/*Since, we are using the same buffer for all writes, retain it once before every write, so the buffer does
* not get recycled. Every write will release the buffer once.*/
.doOnSubscribe(WELCOME_MSG_BUFFER::retain);
// Does not use int as this omits conversion to string for every response.
private static final String CONTENT_LENGTH_HEADER_VAL = String.valueOf(WELCOME_MSG_BUFFER.readableBytes());
public static void main(final String[] args) {
ExamplesEnvironment env = ExamplesEnvironment.newEnvironment(PerfHelloWorldServer.class);
/*Reduce overhead of event publishing*/
//RxNetty.disableEventPublishing(); // Uncomment when running load test
HttpServer server;
server = HttpServer.newServer()
.start((req, resp) ->
resp.setHeader(CONTENT_LENGTH, CONTENT_LENGTH_HEADER_VAL)
.flushOnlyOnReadComplete()
.write(RESPONSE_CONTENT)
);
/*Wait for shutdown if not called from the client (passed an arg)*/
if (env.shouldWaitForShutdown(args)) {
/*When testing the args are set, to avoid blocking till shutdown*/
server.awaitShutdown();
}
/*If not waiting for shutdown, assign the ephemeral port used to a field so that it can be read and used by
the caller, if any.*/
env.registerServerAddress(server.getServerAddress());
}
}