com.yahoo.jdisc.service.ServerProvider Maven / Gradle / Ivy
// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.jdisc.service;
import com.yahoo.jdisc.Container;
import com.yahoo.jdisc.Request;
import com.yahoo.jdisc.SharedResource;
import com.yahoo.jdisc.application.Application;
import com.yahoo.jdisc.application.ContainerActivator;
import com.yahoo.jdisc.application.ContainerBuilder;
import com.yahoo.jdisc.application.ServerRepository;
import java.net.URI;
/**
* This interface defines a component that is capable of acting as a server for an external client. To activate a
* ServerProvider it must be {@link ServerRepository#install(ServerProvider) installed} in a {@link ContainerBuilder},
* and that builder must be {@link ContainerActivator#activateContainer(ContainerBuilder) activated}.
*
* If a ServerProvider is to expire due to {@link Application} reconfiguration, it is necessary to close() that
* ServerProvider before deactivating the owning {@link Container}. Typically:
*
*
* myExpiredServers.close();
* reconfiguredContainerBuilder.servers().install(myRetainedServers);
* containerActivator.activateContainer(reconfiguredContainerBuilder);
*
*
* All implementations of this interface will need to have a {@link CurrentContainer} injected into its constructor
* so that it is able to create and dispatch new {@link Request}s.
*
* @author Simon Thoresen Hult
*/
public interface ServerProvider extends SharedResource {
/**
* This is a synchronous method to configure this ServerProvider and bind the listen port (or equivalent). The
* {@link Container} does not call this method, instead it is a required step in the {@link Application}
* initialization code.
*/
void start();
/**
* This is a synchronous method to close the listen port (or equivalent) of this ServerProvider and flush any
* input buffers that will cause calls to {@link CurrentContainer#newReference(URI)}. This method must not
* return until the implementation can guarantee that there will be no further calls to CurrentContainer. All
* previously dispatched {@link Request}s are processed as before.
*
* The {@link Container} does not call this method, instead it is a required step in the {@link
* Application} shutdown code.
*/
void close();
/**
* Whether multiple instances of this can coexist, by means of a multiplexer on top of any exclusive resource.
* If this is true, new instances to replace old ones, during a graph generation switch, will be started before
* the obsolete ones are stopped; otherwise, the old will be stopped, and then the new ones started.
*/
default boolean isMultiplexed() { return false; }
}