/*
* Copyright 2013 Red Hat, Inc. and/or its affiliates.
*
* 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.optaplanner.core.impl.domain.valuerange.buildin.composite;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Random;
import com.google.common.collect.Iterators;
import org.optaplanner.core.api.domain.valuerange.CountableValueRange;
import org.optaplanner.core.api.domain.valuerange.ValueRange;
import org.optaplanner.core.impl.domain.valuerange.AbstractCountableValueRange;
import org.optaplanner.core.impl.domain.valuerange.util.ValueRangeIterator;
import org.optaplanner.core.impl.solver.random.RandomUtils;
public class CompositeCountableValueRange<T> extends AbstractCountableValueRange<T> {
private final List<? extends CountableValueRange<T>> childValueRangeList;
private final long size;
public CompositeCountableValueRange(List<? extends CountableValueRange<T>> childValueRangeList) {
this.childValueRangeList = childValueRangeList;
long size = 0L;
for (CountableValueRange<T> childValueRange : childValueRangeList) {
size += childValueRange.getSize();
}
this.size = size;
}
public List<? extends ValueRange<T>> getChildValueRangeList() {
return childValueRangeList;
}
@Override
public long getSize() {
return size;
}
@Override
public T get(long index) {
long remainingIndex = index;
for (CountableValueRange<T> childValueRange : childValueRangeList) {
long childSize = childValueRange.getSize();
if (remainingIndex < childSize) {
return childValueRange.get(remainingIndex);
}
remainingIndex -= childSize;
}
throw new IndexOutOfBoundsException("The index (" + index + ") must be less than the size (" + size + ").");
}
@Override
public boolean contains(T value) {
for (CountableValueRange<T> childValueRange : childValueRangeList) {
if (childValueRange.contains(value)) {
return true;
}
}
return false;
}
@Override
public Iterator<T> createOriginalIterator() {
List<Iterator<T>> iteratorList = new ArrayList<>(childValueRangeList.size());
for (CountableValueRange<T> childValueRange : childValueRangeList) {
iteratorList.add(childValueRange.createOriginalIterator());
}
return Iterators.concat(iteratorList.iterator());
}
@Override
public Iterator<T> createRandomIterator(Random workingRandom) {
return new RandomCompositeValueRangeIterator(workingRandom);
}
private class RandomCompositeValueRangeIterator extends ValueRangeIterator<T> {
private final Random workingRandom;
public RandomCompositeValueRangeIterator(Random workingRandom) {
this.workingRandom = workingRandom;
}
@Override
public boolean hasNext() {
return true;
}
@Override
public T next() {
long index = RandomUtils.nextLong(workingRandom, size);
long remainingIndex = index;
for (CountableValueRange<T> childValueRange : childValueRangeList) {
long childSize = childValueRange.getSize();
if (remainingIndex < childSize) {
return childValueRange.get(remainingIndex);
}
remainingIndex -= childSize;
}
throw new IllegalStateException("Impossible state because index (" + index
+ ") is always less than the size (" + size + ").");
}
}
}