net.kuujo.copycat.state.StateMachine Maven / Gradle / Ivy
/*
* Copyright 2014 the original author or authors.
*
* 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 net.kuujo.copycat.state;
import java.util.function.BiConsumer;
import net.kuujo.copycat.cluster.ClusterConfig;
import net.kuujo.copycat.cluster.internal.coordinator.ClusterCoordinator;
import net.kuujo.copycat.cluster.internal.coordinator.CoordinatorConfig;
import net.kuujo.copycat.cluster.internal.coordinator.DefaultClusterCoordinator;
import net.kuujo.copycat.resource.Resource;
import net.kuujo.copycat.util.function.TriConsumer;
/**
* State machine.
*
* @author Jordan Halterman
*/
public interface StateMachine extends Resource> {
/**
* Creates a new state machine with the default cluster and state machine configurations.
*
* The state machine will be constructed with the default cluster configuration. The default cluster configuration
* searches for two resources on the classpath - {@code cluster} and {cluster-defaults} - in that order. Configuration
* options specified in {@code cluster.conf} will override those in {cluster-defaults.conf}.
*
* Additionally, the state machine will be constructed with an state machine configuration that searches the classpath for
* three configuration files - {@code {name}}, {@code state-machine}, {@code state-machine-defaults}, {@code resource}, and
* {@code resource-defaults} - in that order. The first resource is a configuration resource with the same name
* as the state machine resource. If the resource is namespaced - e.g. `state-machines.my-machine.conf` - then resource
* configurations will be loaded according to namespaces as well; for example, `state-machines.conf`.
*
* @param name The state machine resource name.
* @param stateType The state machine state type.
* @param initialState The state machine state.
* @return The state machine.
*/
static StateMachine create(String name, Class stateType, Class initialState) {
return create(name, new ClusterConfig(), new StateMachineConfig().withStateType(stateType).withInitialState(initialState));
}
/**
* Creates a new state machine with the default state machine configuration.
*
* The state machine will be constructed with an state machine configuration that searches the classpath for three
* configuration files - {@code {name}}, {@code state-machine}, {@code state-machine-defaults}, {@code resource}, and
* {@code resource-defaults} - in that order. The first resource is a configuration resource with the same name
* as the state machine resource. If the resource is namespaced - e.g. `state-machines.my-machine.conf` - then resource
* configurations will be loaded according to namespaces as well; for example, `state-machines.conf`.
*
* @param name The state machine resource name.
* @param stateType The state machine state type.
* @param initialState The state machine state.
* @param cluster The state machine cluster configuration.
* @return The state machine.
*/
static StateMachine create(String name, Class stateType, Class initialState, ClusterConfig cluster) {
return create(name, cluster, new StateMachineConfig().withStateType(stateType).withInitialState(initialState));
}
/**
* Creates a new state machine.
*
* @param name The state machine resource name.
* @param cluster The state machine cluster configuration.
* @param config The state machine configuration.
* @return The state machine.
*/
static StateMachine create(String name, ClusterConfig cluster, StateMachineConfig config) {
ClusterCoordinator coordinator = new DefaultClusterCoordinator(new CoordinatorConfig().withName(name).withClusterConfig(cluster));
return coordinator.>getResource(name, config.resolve(cluster))
.addStartupTask(() -> coordinator.open().thenApply(v -> null))
.addShutdownTask(coordinator::close);
}
/**
* Creates a state machine proxy.
*
* @param type The proxy interface.
* @param The proxy type.
* @return The proxy object.
*/
U createProxy(Class type);
/**
* Creates a state machine proxy.
*
* @param type The proxy interface.
* @param classLoader The class loader to define the proxy class.
* @param The proxy type.
* @return The proxy object.
*/
U createProxy(Class type, ClassLoader classLoader);
/**
* Register a watcher to be notified when state machine is mutated.
*/
void registerWatcher(TriConsumer watcher);
/**
* Unregisters a watcher.
*/
void unregisterWatcher(TriConsumer watcher);
}