/**
* 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.mahout.fpm.pfpgrowth;
import java.util.Iterator;
import java.util.List;
import com.google.common.collect.AbstractIterator;
import org.apache.mahout.common.Pair;
/**
* Iterates over multiple transaction trees to produce a single iterator of transactions
*/
public final class MultiTransactionTreeIterator extends AbstractIterator<List<Integer>> {
private final Iterator<Pair<List<Integer>,Long>> pIterator;
private List<Integer> current;
private long currentMaxCount;
private long currentCount;
public MultiTransactionTreeIterator(Iterator<Pair<List<Integer>,Long>> iterator) {
this.pIterator = iterator;
}
@Override
protected List<Integer> computeNext() {
if (currentCount >= currentMaxCount) {
if (pIterator.hasNext()) {
Pair<List<Integer>,Long> nextValue = pIterator.next();
current = nextValue.getFirst();
currentMaxCount = nextValue.getSecond();
currentCount = 0;
} else {
return endOfData();
}
}
currentCount++;
return current;
}
}