/*
* Copyright 2003-2017 JetBrains s.r.o.
*
* 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 jetbrains.mps.generator.impl.plan;
import jetbrains.mps.generator.ModelGenerationPlan.Checkpoint;
import jetbrains.mps.generator.plan.CheckpointIdentity;
import jetbrains.mps.smodel.ModelImports;
import jetbrains.mps.util.CollectionUtil;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.mps.openapi.model.SModelReference;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;
/**
* All checkpoint models known for (associated with) the given original model.
* @author Artem Tikhomirov
* @since 3.3
*/
public class ModelCheckpoints {
// modifiable list (set, iterate+remove operations)
private final List<CheckpointState> myStates;
/**
* @param state not null
*/
/*package*/ ModelCheckpoints(CheckpointState state) {
myStates = new ArrayList<>(2);
myStates.add(state);
}
/**
* @param states not null
*/
/*package*/ ModelCheckpoints(Collection<CheckpointState> states) {
// XXX shall I assert all states are for the same original model?
// FIXME shall I assert no duplicated states (model for same cp)?
myStates = new ArrayList<>(states); // copy
}
/**
* Retrieve state that corresponds to transition between specified checkpoints.
* Starting checkpoint is optional, original input model is assumed to be 'checkpoint' in this case.
* FIXME perhaps, shall have a distinct Checkpoint to indicate initial model (don't want to keep the model in transients, though
* and OTOH don't want to tell whether there's a model for Checkpoint based on special Checkpoint instance.
* @return <code>null</code> if no saved state for the point found
*/
@Nullable
public CheckpointState find(@NotNull Checkpoint targetPoint) {
return find(targetPoint.getIdentity());
}
@Nullable
public CheckpointState find(@NotNull CheckpointIdentity tp) {
for (CheckpointState cps : myStates) {
if (cps.getCheckpoint().equals(tp)) {
return cps;
}
}
return null;
}
/*package*/ List<CheckpointIdentity> getKnownCheckpoints() {
return StreamSupport.stream(myStates.spliterator(), false).map(CheckpointState::getCheckpoint).collect(Collectors.toList());
}
/**
* we've got new state for some checkpoint
* @param state not null
* @return stale checkpoint (the one that has been discarded), if any.
*/
/*package*/ CheckpointState updateAndDiscardOutdated(CheckpointState state) {
for (int i = 0; i < myStates.size(); i++) {
CheckpointState cps = myStates.get(i);
if (!cps.getCheckpoint().equals(state.getCheckpoint())) {
continue;
}
myStates.set(i, state);
return cps;
}
// there's no matching state, record a new one
myStates.add(state);
return null;
}
/**
* Once there's a discarded checkpoint state, we need to update (discard) states that used to reference it.
* @param outdatedModels models that are no longer valid
* @param discarded collection with stale states to update
*/
/*package*/ void discardOutdated(Collection<SModelReference> outdatedModels, Collection<CheckpointState> discarded) {
for (Iterator<CheckpointState> it = myStates.iterator(); it.hasNext(); ) {
CheckpointState next = it.next();
if (CollectionUtil.intersects(new ModelImports(next.getCheckpointModel()).getImportedModels(), outdatedModels)) {
discarded.add(next);
it.remove();
}
}
}
}