org.apache.cayenne.commitlog.model.MutableChangeMap Maven / Gradle / Ivy
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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;
}
}