/*
* Copyright 2016 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 org.springframework.statemachine.persist;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import org.springframework.statemachine.ExtendedState;
import org.springframework.statemachine.StateMachine;
import org.springframework.statemachine.StateMachineContext;
import org.springframework.statemachine.StateMachinePersist;
import org.springframework.statemachine.access.StateMachineAccess;
import org.springframework.statemachine.access.StateMachineFunction;
import org.springframework.statemachine.region.Region;
import org.springframework.statemachine.state.AbstractState;
import org.springframework.statemachine.state.HistoryPseudoState;
import org.springframework.statemachine.state.PseudoState;
import org.springframework.statemachine.state.State;
import org.springframework.statemachine.support.AbstractStateMachine;
import org.springframework.statemachine.support.DefaultExtendedState;
import org.springframework.statemachine.support.DefaultStateMachineContext;
import org.springframework.util.Assert;
/**
* Base implementation of a {@link StateMachinePersister} easing persist
* and restore operations with a {@link StateMachinePersist}.
*
* @author Janne Valkealahti
*
* @param <S> the type of state
* @param <E> the type of event
* @param <T> the type of context object
*/
public abstract class AbstractStateMachinePersister<S, E, T> implements StateMachinePersister<S, E, T> {
private final StateMachinePersist<S, E, T> stateMachinePersist;
/**
* Instantiates a new abstract state machine persister.
*
* @param stateMachinePersist the state machine persist
*/
public AbstractStateMachinePersister(StateMachinePersist<S, E, T> stateMachinePersist) {
Assert.notNull(stateMachinePersist, "StateMachinePersist must be set");
this.stateMachinePersist = stateMachinePersist;
}
@Override
public final void persist(StateMachine<S, E> stateMachine, T contextObj) throws Exception {
stateMachinePersist.write(buildStateMachineContext(stateMachine), contextObj);
}
@Override
public final StateMachine<S, E> restore(StateMachine<S, E> stateMachine, T contextObj) throws Exception {
final StateMachineContext<S, E> context = stateMachinePersist.read(contextObj);
stateMachine.stop();
stateMachine.getStateMachineAccessor().doWithAllRegions(new StateMachineFunction<StateMachineAccess<S, E>>() {
@Override
public void apply(StateMachineAccess<S, E> function) {
function.resetStateMachine(context);
}
});
stateMachine.start();
return stateMachine;
}
/**
* Builds the state machine context which is used for persist operation.
*
* @param stateMachine the state machine
* @return the state machine context
*/
protected StateMachineContext<S, E> buildStateMachineContext(StateMachine<S, E> stateMachine) {
// TODO: need to make this fully recursive
ExtendedState extendedState = new DefaultExtendedState();
extendedState.getVariables().putAll(stateMachine.getExtendedState().getVariables());
ArrayList<StateMachineContext<S, E>> childs = new ArrayList<StateMachineContext<S, E>>();
S id = null;
State<S, E> state = stateMachine.getState();
if (state.isSubmachineState()) {
Collection<S> ids1 = state.getIds();
@SuppressWarnings("unchecked")
S[] ids2 = (S[]) ids1.toArray();
// TODO: can this be empty as then we'd get error?
id = ids2[ids2.length-1];
} else if (state.isOrthogonal()) {
Collection<Region<S, E>> regions = ((AbstractState<S, E>)state).getRegions();
for (Region<S, E> r : regions) {
S s = r.getState().getId();
childs.add(new DefaultStateMachineContext<S, E>(s, null, null, null));
}
id = state.getId();
} else {
id = state.getId();
}
// building history state mappings
Map<S, S> historyStates = new HashMap<S, S>();
PseudoState<S, E> historyState = ((AbstractStateMachine<S, E>) stateMachine).getHistoryState();
if (historyState != null) {
historyStates.put(null, ((HistoryPseudoState<S, E>)historyState).getState().getId());
}
Collection<State<S, E>> states = stateMachine.getStates();
for (State<S, E> ss : states) {
if (ss.isSubmachineState()) {
StateMachine<S, E> submachine = ((AbstractState<S, E>) ss).getSubmachine();
PseudoState<S, E> ps = ((AbstractStateMachine<S, E>) submachine).getHistoryState();
if (ps != null) {
State<S, E> pss = ((HistoryPseudoState<S, E>)ps).getState();
if (pss != null) {
historyStates.put(ss.getId(), pss.getId());
}
}
}
}
return new DefaultStateMachineContext<S, E>(childs, id, null, null, extendedState, historyStates, stateMachine.getId());
}
}