/*
* Copyright (c) 2011-2014 The original author or authors
* ------------------------------------------------------
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Apache License v2.0 which accompanies this distribution.
*
* The Eclipse Public License is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* The Apache License v2.0 is available at
* http://www.opensource.org/licenses/apache2.0.php
*
* You may elect to redistribute this code under either of these licenses.
*/
package io.vertx.core.eventbus;
import io.vertx.codegen.annotations.Fluent;
import io.vertx.codegen.annotations.GenIgnore;
import io.vertx.codegen.annotations.VertxGen;
import io.vertx.core.AsyncResult;
import io.vertx.core.Handler;
import io.vertx.core.metrics.Measured;
/**
* A Vert.x event-bus is a light-weight distributed messaging system which allows different parts of your application,
* or different applications and services to communicate with each in a loosely coupled way.
* <p>
* An event-bus supports publish-subscribe messaging, point-to-point messaging and request-response messaging.
* <p>
* Message delivery is best-effort and messages can be lost if failure of all or part of the event bus occurs.
* <p>
* Please refer to the documentation for more information on the event bus.
*
* @author <a href="http://tfox.org">Tim Fox</a>
*/
@VertxGen
public interface EventBus extends Measured {
/**
* Sends a message.
* <p>
* The message will be delivered to at most one of the handlers registered to the address.
*
* @param address the address to send it to
* @param message the message, may be {@code null}
* @return a reference to this, so the API can be used fluently
*/
@Fluent
EventBus send(String address, Object message);
/**
* Like {@link #send(String, Object)} but specifying a {@code replyHandler} that will be called if the recipient
* subsequently replies to the message.
*
* @param address the address to send it to
* @param message the message, may be {@code null}
* @param replyHandler reply handler will be called when any reply from the recipient is received, may be {@code null}
* @return a reference to this, so the API can be used fluently
*/
@Fluent
<T> EventBus send(String address, Object message, Handler<AsyncResult<Message<T>>> replyHandler);
/**
* Like {@link #send(String, Object)} but specifying {@code options} that can be used to configure the delivery.
*
* @param address the address to send it to
* @param message the message, may be {@code null}
* @param options delivery options
* @return a reference to this, so the API can be used fluently
*/
@Fluent
EventBus send(String address, Object message, DeliveryOptions options);
/**
* Like {@link #send(String, Object, DeliveryOptions)} but specifying a {@code replyHandler} that will be called if the recipient
* subsequently replies to the message.
*
* @param address the address to send it to
* @param message the message, may be {@code null}
* @param options delivery options
* @param replyHandler reply handler will be called when any reply from the recipient is received, may be {@code null}
* @return a reference to this, so the API can be used fluently
*/
@Fluent
<T> EventBus send(String address, Object message, DeliveryOptions options, Handler<AsyncResult<Message<T>>> replyHandler);
/**
* Publish a message.<p>
* The message will be delivered to all handlers registered to the address.
*
* @param address the address to publish it to
* @param message the message, may be {@code null}
* @return a reference to this, so the API can be used fluently
*
*/
@Fluent
EventBus publish(String address, Object message);
/**
* Like {@link #publish(String, Object)} but specifying {@code options} that can be used to configure the delivery.
*
* @param address the address to publish it to
* @param message the message, may be {@code null}
* @param options the delivery options
* @return a reference to this, so the API can be used fluently
*/
@Fluent
EventBus publish(String address, Object message, DeliveryOptions options);
/**
* Create a message consumer against the specified address.
* <p>
* The returned consumer is not yet registered
* at the address, registration will be effective when {@link MessageConsumer#handler(io.vertx.core.Handler)}
* is called.
*
* @param address the address that it will register it at
* @return the event bus message consumer
*/
<T> MessageConsumer<T> consumer(String address);
/**
* Create a consumer and register it against the specified address.
*
* @param address the address that will register it at
* @param handler the handler that will process the received messages
*
* @return the event bus message consumer
*/
<T> MessageConsumer<T> consumer(String address, Handler<Message<T>> handler);
/**
* Like {@link #consumer(String)} but the address won't be propagated across the cluster.
*
* @param address the address to register it at
* @return the event bus message consumer
*/
<T> MessageConsumer<T> localConsumer(String address);
/**
* Like {@link #consumer(String, Handler)} but the address won't be propagated across the cluster.
*
* @param address the address that will register it at
* @param handler the handler that will process the received messages
* @return the event bus message consumer
*/
<T> MessageConsumer<T> localConsumer(String address, Handler<Message<T>> handler);
/**
* Create a message sender against the specified address.
* <p>
* The returned sender will invoke the {@link #send(String, Object)}
* method when the stream {@link io.vertx.core.streams.WriteStream#write(Object)} method is called with the sender
* address and the provided data.
*
* @param address the address to send it to
* @return The sender
*/
<T> MessageProducer<T> sender(String address);
/**
* Like {@link #sender(String)} but specifying delivery options that will be used for configuring the delivery of
* the message.
*
* @param address the address to send it to
* @param options the delivery options
* @return The sender
*/
<T> MessageProducer<T> sender(String address, DeliveryOptions options);
/**
* Create a message publisher against the specified address.
* <p>
* The returned publisher will invoke the {@link #publish(String, Object)}
* method when the stream {@link io.vertx.core.streams.WriteStream#write(Object)} method is called with the publisher
* address and the provided data.
*
* @param address The address to publish it to
* @return The publisher
*/
<T> MessageProducer<T> publisher(String address);
/**
* Like {@link #publisher(String)} but specifying delivery options that will be used for configuring the delivery of
* the message.
*
* @param address the address to publish it to
* @param options the delivery options
* @return The publisher
*/
<T> MessageProducer<T> publisher(String address, DeliveryOptions options);
/**
* Register a message codec.
* <p>
* You can register a message codec if you want to send any non standard message across the event bus.
* E.g. you might want to send POJOs directly across the event bus.
* <p>
* To use a message codec for a send, you should specify it in the delivery options.
*
* @param codec the message codec to register
* @return a reference to this, so the API can be used fluently
*/
@GenIgnore
EventBus registerCodec(MessageCodec codec);
/**
* Unregister a message codec.
* <p>
* @param name the name of the codec
* @return a reference to this, so the API can be used fluently
*/
@GenIgnore
EventBus unregisterCodec(String name);
/**
* Register a default message codec.
* <p>
* You can register a message codec if you want to send any non standard message across the event bus.
* E.g. you might want to send POJOs directly across the event bus.
* <p>
* Default message codecs will be used to serialise any messages of the specified type on the event bus without
* the codec having to be specified in the delivery options.
*
* @param clazz the class for which to use this codec
* @param codec the message codec to register
* @return a reference to this, so the API can be used fluently
*/
@GenIgnore
<T> EventBus registerDefaultCodec(Class<T> clazz, MessageCodec<T, ?> codec);
/**
* Unregister a default message codec.
* <p>
* @param clazz the class for which the codec was registered
* @return a reference to this, so the API can be used fluently
*/
@GenIgnore
EventBus unregisterDefaultCodec(Class clazz);
/**
* Start the event bus. This would not normally be called in user code
*
* @param completionHandler handler will be called when event bus is started
*/
@GenIgnore
void start(Handler<AsyncResult<Void>> completionHandler);
/**
* Close the event bus and release any resources held. This would not normally be called in user code
*
* @param completionHandler may be {@code null}
*/
@GenIgnore
void close(Handler<AsyncResult<Void>> completionHandler);
/**
* Add an interceptor that will be called whenever a message is sent from Vert.x
*
* @param interceptor the interceptor
* @return a reference to this, so the API can be used fluently
*/
EventBus addInterceptor(Handler<SendContext> interceptor);
/**
* Remove an interceptor
*
* @param interceptor the interceptor
* @return a reference to this, so the API can be used fluently
*/
EventBus removeInterceptor(Handler<SendContext> interceptor);
}