org.apache.cayenne.commitlog.model.MutableChangeMap Maven / Gradle / Ivy
/*****************************************************************
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.cayenne.commitlog.model;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import org.apache.cayenne.ObjectId;
/**
* A mutable implementation of {@link ChangeMap}.
*
* @since 4.0
*/
public class MutableChangeMap implements ChangeMap {
private Map changes;
public MutableObjectChange getOrCreate(ObjectId id, ObjectChangeType type) {
MutableObjectChange changeSet = getOrCreate(id);
changeSet.setType(type);
return changeSet;
}
private MutableObjectChange getOrCreate(ObjectId id) {
MutableObjectChange objectChange = changes != null ? changes.get(id) : null;
if (objectChange == null) {
if (changes == null) {
changes = new HashMap<>();
}
objectChange = new MutableObjectChange(id);
changes.put(id, objectChange);
}
return objectChange;
}
public MutableObjectChange aliasId(ObjectId preCommitId, ObjectId postCommitId) {
MutableObjectChange changeSet = getOrCreate(preCommitId);
changeSet.setPostCommitId(postCommitId);
changes.put(postCommitId, changeSet);
return changeSet;
}
@Override
public Collection getUniqueChanges() {
// ensure distinct change set
return changes == null ? Collections. emptySet() : new HashSet<>(changes.values());
}
@Override
public Map getChanges() {
return changes == null ? Collections. emptyMap() : changes;
}
}